Effects of nitric oxide on magnocellular neurons of the supraoptic nucleus involve multiple mechanisms

Physiological evidence indicates that the supraoptic nucleus (SON) is an important region for integrating information related to homeostasis of body fluids. Located bilaterally to the optic chiasm, this nucleus is composed of magnocellular neurosecretory cells (MNCs) responsible for the synthesis and release of vasopressin and oxytocin to the neurohypophysis. At the cellular level, the control of vasopressin and oxytocin release is directly linked to the firing frequency of MNCs. In general, we can say that the excitability of these cells can be controlled via two distinct mechanisms: 1) the intrinsic membrane properties of the MNCs themselves and 2) synaptic input from circumventricular organs that contain osmosensitive neurons. It has also been demonstrated that MNCs are sensitive to osmotic stimuli in the physiological range. Therefore, the study of their intrinsic membrane properties became imperative to explain the osmosensitivity of MNCs. In addition to this, the discovery that several neurotransmitters and neuropeptides can modulate their electrical activity greatly increased our knowledge about the role played by the MNCs in fluid homeostasis. In particular, nitric oxide (NO) may be an important player in fluid balance homeostasis, because it has been demonstrated that the enzyme responsible for its production has an increased activity following a hypertonic stimulation of the system. At the cellular level, NO has been shown to change the electrical excitability of MNCs. Therefore, in this review, we focus on some important points concerning nitrergic modulation of the neuroendocrine system, particularly the effects of NO on the SON.

Effect of microRNA-21 on the proliferation of human degenerated nucleus pulposus by targeting programmed cell death 4

This study aims to explore the effect of microRNA-21 (miR-21) on the proliferation of human degenerated nucleus pulposus (NP) by targeting programmed cell death 4 (PDCD4) tumor suppressor. NP tissues were collected from 20 intervertebral disc degeneration (IDD) patients, and from 5 patients with traumatic spine fracture. MiR-21 expressions were tested. NP cells from IDD patients were collected and divided into blank control group, negative control group (transfected with miR-21 negative sequences), miR-21 inhibitor group (transfected with miR-21 inhibitors), miR-21 mimics group (transfected with miR-21 mimics) and PDCD4 siRNA group (transfected with PDCD4 siRNAs). Cell growth was estimated by Cell Counting Kit-8; PDCD4, MMP-2,MMP-9 mRNA expressions were evaluated by qRT-PCR; PDCD4, c-Jun and p-c-Jun expressions were tested using western blot. In IDD patients, the expressions of miR-21 and PDCD4 mRNA were respectively elevated and decreased (both P<0.05). The miR-21 expressions were positively correlated with Pfirrmann grades, but negatively correlated with PDCD4 mRNA (both P<0.001). In miR-21 inhibitor group, cell growth, MMP-2 and MMP-9 mRNA expressions, and p-c-Jun protein expressions were significantly lower, while PDCD4 mRNA and protein expressions were higher than the other groups (all P<0.05). These expressions in the PDCD4 siRNA and miR-21 mimics groups was inverted compared to that in the miR-21 inhibitor group (all P<0.05). MiR-21 could promote the proliferation of human degenerated NP cells by targeting PDCD4, increasing phosphorylation of c-Jun protein, and activating AP-1-dependent transcription of MMPs, indicating that miR-21 may be a crucial biomarker in the pathogenesis of IDD.

Avaliação da percepção da fala com ruído competitivo em adultos com implante coclear

OBJETIVOS: Avaliar os efeitos das diferentes relações sinal/ruído no reconhecimento da fala com o implante coclear (IC); comparar o reconhecimento da fala no ruído com diferentes tipos de implantes cocleares (ICs) multicanais e avaliar o grau de dificuldade dos usuários de IC em situações com ruído competitivo no dia-a-dia. FORAMA DE ESTUDO: coorte transversal. MATERIAL E MÉTODO: Quarenta adultos com deficiência auditiva pós-lingual, com os IC Nucleus 22, Nucleus 24, Combi 40, Combi 40+ e Clarion. Foi avaliado o reconhecimento das sentenças CPA no silêncio e nas relações S/R de +15 dB, +10 dB, +5 dB e aplicado o questionário Social Hearing Handicap Index (SHHI) para a auto-avaliação do desempenho com o IC. RESULTADOS E CONCLUSÕES: Os usuários de todos os tipos de IC apresentaram redução significativa dos índices de reconhecimento de sentenças CPA em função da diminuição da relação S/R, a curva das medianas de reconhecimento das sentenças CPA alcançou 50% na relação S/R de +10 dB. Não houve diferença estatisticamente significante nos índices de reconhecimento das sentenças CPA e escores de dificuldade do SHHI, obtidos com os diferentes tipos de ICs. As dificuldades dos usuários de IC foram raras nas situações de silêncio e ocasionais nas situações com ruído competitivo no questionário SHHI.

Telemetria de resposta neural intra-operatória em usuários de implante coclear

A possibilidade de realizar o implante coclear em crianças pequenas torna necessário o uso de medidas objetivas para auxiliar a programação do processador de fala. Telemetria é a propriedade que permite, no Nucleus 24®, a obtenção do potencial de ação composto evocado do VIII par (EAP) utilizando o implante como instrumento de estimulação e gravação para o estudo das propriedades neurais remanescentes. OBJETIVO: Descrever a utilização do sistema de telemetria para a gravação do EAP, caracterizando as respostas obtidas e a sua prevalência na condição intraoperatória. FORMA DE ESTUDO: clínico com coorte transversal. MATERIAL E MÉTODO: Medidas das impedâncias dos eletrodos e do EAP em um grupo de 17 indivíduos usuários do implante Nucleus 24® durante a cirurgia. Análise das respostas de acordo com a etiologia, o tempo de duração da surdez e a posição dos eletrodos dentro da cóclea. RESULTADOS: Maior prevalência nos eletrodos apicais e limiares mais elevados nos casos de meningite e otosclerose. CONCLUSÃO: A telemetria é eficiente para a verificação da integridade dos eletrodos na condição intraoperatória e para a gravação do EAP, apresentando alta prevalência na população estudada.

Efeitos do potencial de ação neural sobre a percepção de fala em usuários de implante coclear

O Potencial de Ação Composto Evocado Eletricamente reflete a atividade do nervo auditivo, podendo ser registrado através dos eletrodos do implante coclear. A determinação dos elementos neurais estimuláveis pode contribuir para explicar a variabilidade de desempenho entre indivíduos implantados. OBJETIVO: Comparar o desempenho nos testes de percepção da fala entre pacientes que apresentaram e que não apresentaram potencial de ação composto evocado eletricamente no momento intra-operatório. MATERIAL E MÉTODO: Estudo prospectivo no qual 100 indivíduos usuários do implante coclear Nucleus 24 foram divididos em dois grupos de acordo com a presença ou ausência do potencial de ação intra-operatório. Após 6 meses de uso do dispositivo, os resultados dos testes de percepção de fala foram comparados entre os grupos. RESULTADOS: O potencial foi observado em 72% dos pacientes. A percepção no teste de frases em formato aberto foi melhor nos indivíduos com presença de potencial (média 82,8% contra 41,0%, p = 0,005). Houve associação entre ausência do potencial e etiologia da surdez por meningite. CONCLUSÃO: Ausência de potencial neural intraoperatório esteve associada ao pior desempenho na percepção da fala e à etiologia da surdez por meningite. Por outro lado, a presença do potencial de ação intraoperatório sugere ótimo prognóstico.

Histological alterations in liver and testis of Astyanax aff. bimaculatus caused by acute exposition to zinc

This study investigated the effect of acute exposition to zinc (Zn) on histology of the liver and testes of yellow tail lambari (Astyanax aff. bimaculatus). The exposure consisted of six concentrations of Zn (0, 3, 5, 10, 15, and 20 mg/L) for 96 hours of exposure. Fragments of liver and testis were routinely processed and embedded in plastic resin based on glycol methacrylate. Fragments of bones, muscles, liver and testis were dehydrated and digested to quantify the absorption levels of Zn in the tissue. Acute exposure to concentrations above 10mg/L has produced structural changes in the liver and gonads. The changes found in the liver were vascular congestion; decrease of cellular volume; displacement of the hepatocyte nucleus; necrosis; disarrangement of cordon structure; leukocyte infiltrate and vacuolization. The changes found in the gonads were ruptured cyst, delayed development of germ cells, pyknotic nucleus, cell cluster, displacement of cyst wall and vacuolization. The histological changes observed were compatible with the increasing concentration of zinc in environment, compromising liver and reproductive functions, because there was an increase in relative frequency of hepatocytes and reduced sperm production

Trypanosoma (Herpetosoma) rangeli Tejera, 1920: intracellular amastigote stages of reproduction in white mice

The method, site, and stage of multiplication of Trypanosoma (Herpetosoma) rangeli Tejera, 1920 has not hitherto been known. "We have now observed many intracellular nests or pseudocysts, containing amastigotes and trypomastigotes of this parasite in the heart, liver, and spleen of suckling (5.0 g) male white mice (NMRI strain) inoculated i.p. with 9 x 10(4) metatrypomastigotes/g body weight from a 12-day-old culture of the "Dog-82" strain of T. rangeli. At the peak of parasitemia (1.9 x 10(6) trypomastigotes/ml blood, 3 days post-inoculation) various tissues were taken for sectioning and staining. The heart was most intensely parasitized. The amastigotes were rounded or ellipsoidal, with a rounded nucleus and the kinetoplast in the form of a straight or curved bar; the average maximum diameter of 50 measured amastigotes was 4.2 p. Binary fission was seen in the nucleus and kinetoplast of some amastigotes; no blood trypomastigotes were seen in division. The above characteristics, as well as the location of the pseudocysts in the tissues, are similar to T. cruzi. Comparison of these results with those reported for other Herpetosoma suggest study of the taxonomic position of T. rangeli.

Distribution of phlebotomine sandflies (Diptera: Psychodidae) of medical importance in Mato Grosso State, Brazil

Intense environmental impacts, causing alterations of the natural habitats of fauna, including those of sandfly disease vectors are observed in Mato Grosso State, Central Brazil. Entomologic survey of phlebotomines was based on light trap and was carried out by entomological nucleus of the FUNASA and SES in the period between 1996 and 2001. Eighty eight species were identified, including the following sandflies with medical importance to leishmaniasis: Lutzomyia amazonensis, L. anduzei, L. antunesi, L. ayrozai, L. carrerai carrerai, L. complexa, L. cruzi, L. flaviscutellata, L. intermedia, L. longipalpis, L. migonei, L. paraensis, L. ubiquitalis, L. whitmani and L. yuilli yuilli. Most sandflies of medical importance occurred in the Amazon forest and savannah. L. longipalpis and L. cruzi had high densities in the savannah region. L. flaviscutellata is predominating in both the Amazon forest and the savannah region. L. whitmani and L. antunesi were sampled in the Amazon forest, savannah and marsh land.

SOUTH AMERICAN COLLABORATION IN SCIENTIFIC PUBLICATIONS ON LEISHMANIASIS: BIBLIOMETRIC ANALYSIS IN SCOPUS (2000-2011)

Objectives: Evaluate the production and the research collaborative network on Leishmaniasis in South America. Methods: A bibliometric research was carried out using SCOPUS database. The analysis unit was original research articles published from 2000 to 2011, that dealt with leishmaniasis and that included at least one South American author. The following items were obtained for each article: journal name, language, year of publication, number of authors, institutions, countries, and others variables. Results: 3,174 articles were published, 2,272 of them were original articles. 1,160 different institutional signatures, 58 different countries and 398 scientific journals were identified. Brazil was the country with more articles (60.7%) and Oswaldo Cruz Foundation (FIOCRUZ) had 18% of Brazilian production, which is the South American nucleus of the major scientific network in Leishmaniasis. Conclusions: South American scientific production on Leishmaniasis published in journals indexed in SCOPUS is focused on Brazilian research activity. It is necessary to strengthen the collaboration networks. The first step is to identify the institutions with higher production, in order to perform collaborative research according to the priorities of each country.

Soap bubble appearance in brain magnetic resonance imaging: cryptococcal meningoencephalitis

Although cryptococcal infections begin in the lungs, meningoencephalitis is the most frequently encountered manifestation of cryptococcosis among individuals with advanced immunosuppression. As the infection progresses along the Virchow-Robin spaces, these structures may become dilated with mucoid material produced by the capsule of the organism. We report a case of a 24-year-old man with cryptococcal meningoencephalitis in which magnetic resonance imaging showed clusters of gelatinous pseudocysts in the periventricular white matter, basal ganglia, mammillary bodies, midbrain peduncles and nucleus dentatus with a soap bubble appearance.

Effects of bariatric surgery on the central nervous system and eating behavior in humans: a systematic review on the neuroimaging studies

INTRODUCTION: Neuroimaging studies suggest that obese people might show hyperactivity of brain areas regarding reward processing, and hypoactivity of brain areas concerning cognitive control, when exposed to food cues. Although the effects of bariatric surgery on the central nervous system and eating behavior are well known, few studies have used neuroimage techniques with the aim of investigating the central effects of bariatric surgery in humans. OBJECTIVES: This paper systematically and critically reviews studies using functional neuroimaging to investigate changes on the patterns of activation of central areas related to the regulation of eating behavior after bariatric surgery. METHOD: A search on the databases Medline, Web of Science, Lilacs and Science Direct on Line, was conducted in February 2013, using the keywords "Neuroimaging", "Positron-Emission Tomography", "Magnetic Resonance Imaging", "Gastric Bypass", "Gastroplasty", "Jejunoileal Bypass", "Bariatric Surgery". RESULTS: Seven manuscripts were included; the great majority studied the central effects of Roux en Y gastric bypass, using positron emission tomography or functional magnetic resonance. CONCLUSIONS: Bariatric surgery might normalize the activity of central areas concerned with reward and incentive salience processing, as the nucleus accumbens and mesencephalic tegmental ventral area, as well as circuitries processing behavioral inhibition, as the dorsolateral prefrontal cortex.

Antidepressant induced excessive yawning and indifference

Introduction Antidepressant induced excessive yawning has been described as a possible side effect of pharmacotherapy. A syndrome of indifference has also been described as another possible side effect. The frequency of those phenomena and their physiopathology are unknown. They are both considered benign and reversible after antidepressant discontinuation but severe cases with complications as temporomandibular lesions, have been described. Methods We report two unprecedented cases in which excessive yawning and indifference occurred simultaneously as side effects of antidepressant therapy, discussing possible physiopathological mechanisms for this co-occurrence. Case 1: A male patient presented excessive yawning (approximately 80/day) and apathy after venlafaxine XR treatment. Symptoms reduced after a switch to escitalopram, with a reduction to 50 yawns/day. Case 2: A female patient presented excessive yawning (approximately 25/day) and inability to react to environmental stressors with desvenlafaxine. Conclusion Induction of indifference and excessive yawning may be modulated by serotonergic and noradrenergic mechanisms. One proposal to unify these side effects would be enhancement of serotonin in midbrain, especially paraventricular and raphe nucleus.

Recurrence of atrial septal defect in three generations

Beginning with a patient presenting with an atrial septal defect (ASD) of the secundum type, the genealogy was identified in four affected individuals who belonged to three successive generations of the same family. The defects were visually confirmed in all individuals and were found to be anatomically similar. No other congenital malformations were present in these individuals. The genealogy was identified in 1972, when ASD recurred in two generations, and it was concluded that the mechanism of transmission was autosomal recessive. The fifth individual, identified 21 years later, and having an anomaly identical to that of the others, was the child of a couple who had no consaguinity and whose mother was a member of the previously studied genealogy. Considering the absence of phenotype in the parents and the rarity of the ASD gene in the general population, the occurrence of the uniparental disomy for this family nucleus, and the same autosomal recessive mechanism of transmission by this affected individual is possible. This study reports the familial occurrence of ASD by genetic mechanisms of transmission, emphasizing the necessity for genetic-clinical studies in members of the familial nucleus in order to detect new carriers, who usually are asymptomatic, thereby allowing for early and adequate treatment of individuals who may be affected.

Neural Mechanisms and Delayed Gastric Emptying of Liquid Induced Through Acute Myocardial Infarction in Rats

Background: In pathological situations, such as acute myocardial infarction, disorders of motility of the proximal gut can trigger symptoms like nausea and vomiting. Acute myocardial infarction delays gastric emptying (GE) of liquid in rats. Objective: Investigate the involvement of the vagus nerve, α 1-adrenoceptors, central nervous system GABAB receptors and also participation of paraventricular nucleus (PVN) of the hypothalamus in GE and gastric compliance (GC) in infarcted rats. Methods: Wistar rats, N = 8-15 in each group, were divided as INF group and sham (SH) group and subdivided. The infarction was performed through ligation of the left anterior descending coronary artery. GC was estimated with pressure-volume curves. Vagotomy was performed by sectioning the dorsal and ventral branches. To verify the action of GABAB receptors, baclofen was injected via icv (intracerebroventricular). Intravenous prazosin was used to produce chemical sympathectomy. The lesion in the PVN of the hypothalamus was performed using a 1mA/10s electrical current and GE was determined by measuring the percentage of gastric retention (% GR) of a saline meal. Results: No significant differences were observed regarding GC between groups; vagotomy significantly reduced % GR in INF group; icv treatment with baclofen significantly reduced %GR. GABAB receptors were not conclusively involved in delaying GE; intravenous treatment with prazosin significantly reduced GR% in INF group. PVN lesion abolished the effect of myocardial infarction on GE. Conclusion: Gastric emptying of liquids induced through acute myocardial infarction in rats showed the involvement of the vagus nerve, alpha1- adrenergic receptors and PVN.

Estudos citológicos em Hemíoteros da família Coreidae

A more or less detailed study of the spermatogenesis in six species of Hemiptera belonging to the Coreid Family is made in the present paper. The species studied and their respective chromosome numbers were: 1) Diactor bilineatus (Fabr.) : spermatogonia with 20 + X, primary spermatocytes with 10 + X, X dividing equationaliv in the first division and passing undivided to one pole in the second. 2) Lcptoglossus gonagra (Fabr.) : spermatogonia with 20 + X, primary spermatocytes with 10 + X, X dividing equationally in the first division and passing undivided to one pole in the second. 3) Phthia picta (Drury) : spermatogonia with 20 + X, primary spermatocytes with 10 + X, X dividing equationally in the first division and passing undivided to one pole in the second. 4) Anisocelis foliacea Fabr. : spermatogonia with 26 + X fthe highest mumber hitherto known in the Family), primary .spermatocytes with 13 + X, X dividing equationally in the first division an passing undivided to one pole in the second. 5) Pachylis pharaonis (Herbtst) : spermatogonia with 16 + X, primary spermatocytes with 8 + X. Behaviour of the heteroehromosome not referred. 6) Pachylis laticornis (Fabr.) : spermatogonia with 14 + X, primary spermatocytes with 7 + X, X passing undivided to one pole in the first division and therefore secondary spermatocytes with 7 + X and 7 chromosomes. General results and conclusions a) Pairing modus of the chromosomes (Telosynapsis or Farasynapsis ?) - In several species of the Coreld bugs the history of the chromosomes from the diffuse stage till diakinesis cannot be follewed in detail due specially to the fact that lhe bivalents, as soon as they begin to be individually distinct they appear as irregular and extremely lax chromatic areas, which through an obscure process give rise to the diakinesis and then to the metaphase chomosomes. Fortunately I was able to analyse the genesis of the cross-shaped chromosomes, becoming thus convinced that even in the less favorable cases like that of Phthia, in which the crosses develop from four small condensation areas of the diffuse chromosomes, nothing in the process permit to interpret the final results as being due to a previous telosynaptic pairing. In the case of long bivalents formed by two parallel strands intimately united at both endsegments and more or less widely open in the middle (Leptoglossus, Pachylis), I could see that the lateral arms of the crosses originate from condensation centers created by a torsion or bending in the unpaired parts of the chromosomes In the relatively short bivalents the lateral branches of the cross are formed in the middle but in the long ones, whose median opening is sometimes considerable, two asymetrical branches or even two independent crosses may develop in the same pair. These observations put away the idea of an end-to-end pairing of the chromosomes, since if it had occured the lateral arms of the crosses would always be symetrical and median and never more than two. The direct observation of a side- toside pairing of the chromosomal threads at synizesis, is in foil agreement with the complete lack of evidence in favour of telosynapsis. b) Anaphasic bridges and interzonal connections - The chromosomes as they separate from each other in anaphase they remain connected by means of two lateral strands corresponding to the unpaired segmenas observed in the bivalents at the stages preceding metaphase. In the early anaphase the chromosomes again reproduce the form they had in late diafcinesis. The connecting threads which may be thick and intensely coloured are generally curved and sometimes unequal in lenght, one being much longer than the other and forming a loop outwardly. This fact points to a continuous flow of chromosomal substance independently from both chromosomes of the pair rather than to a mechanical stretching of a sticky substance. At the end of anaphase almost all the material which formed the bridges is reduced to two small cones from whose vertices a very fine and pale fibril takes its origin. The interzonal fibres, therefore, may be considered as the remnant of the anaphasic bridges. Abnormal behaviour of the anaphase chromosomes showed to be useful in aiding the interpretation of normal aspects. It has been suggested by Schrader (1944) "that the interzonal is nothing more than a sticky coating of the chromosome which is stretched like mucilage between the daughter chromosomes as they move further and further apart". The paired chromosomes being enclosed in a commom sheath, as they separate they give origin to a tube which becomes more and more stretched. Later the walls of the tube collapse forming in this manner an interzonal element. My observations, however, do not confirm Schrader's tubular theory of interzonal connections. In the aspects seen at anaphase of the primary spermatocytes and described in this paper as chromosomal bridges nothing suggests a tubular structure. There is no doubt that the chromosomes are here connected by two independent strands in the first division of the spermatocytes and by a single one in the second. The manner in which the chromosomes separate supports the idea of transverse divion, leaving little place for another interpretation. c) Ptafanoeomc and chromatoid bodies - The colourabtlity of the plasmosome in Diactor and Anisocelis showed to be highly variable. In the latter species, one may find in the same cyst nuclei provided with two intensely coloured bodies, the larger of which being the plasmosome, sided by those in which only the heterochromosome took the colour. In the former one the plasmosome strongly coloured seen in the primary metaphase may easily be taken for a supernumerary chromosome. At anaphase this body stays motionless in the equator of the cell while the chromosomes are moving toward the poles. There, when intensely coloured ,it may be confused with the heterochromosome of the secondary spermatocytes, which frequently occupies identical position in the corresponding phase, thus causing missinterpretation. In its place the plasmosome may divide into two equal parts or pass undivided to one cell in whose cytoplasm it breaks down giving rise to a few corpuscles of unequal sizes. In Pachylis pharaonis, as soon as the nuclear membrane breate down, the plasmosome migrates to a place in the periphery of the cell (primary spermatocyte), forming there a large chromatoid body. This body is never found in the cytoplasm prior to the dissolution of the nuclear membrane. It is certain that chromatoid bodies of different origin do exist. Here, however, we are dealing, undoubtedly, with true plasmosomes. d) Movement of the heterochromosome - The heterochromosome in the metaphase of the secondary spermatocytes may occupy the most different places. At the time the autosomes prient themselves in the equatorial plane it may be found some distance apart in this plane or in any other plane and even in the subpolar and polar regions. It remains in its place during anaphase. Therefore, it may appear at the same level with the components of one of the anaphase plates (synchronism), between both plates (succession) or between one plate and tbe pole (precession), what depends upon the moment the cell was fixed. This does not mean that the heterochromosome sometimes moves as quickly as the autosomes, sometimes more rapidly and sometimes less. It implies, on the contrary, that, being anywhere in the cell, the heterochromosome m he attained and passed by the autosomes. In spite of being almost motionless the heterochromosome finishes by being enclosed in one of the resulting nuclei. Consequently, it does move rapidly toward the group formed by the autosomes a little before anaphase is ended. This may be understood assuming that the heterochromosome, which do not divide, having almost inactive kinetochore cannot orient itself, giving from wherever it stays, only a weak response to the polar influences. When in the equator it probably do not perform any movement in virtue of receiving equal solicitation from both poles. When in any other plane, despite the greater influence of the nearer pole, the influence of the opposite pole would permit only so a slow movement that the autosomes would soon reach it and then leave it behind. It is only when the cell begins to divide that the heterochromosome, passing to one of the daughter cells scapes the influence of the other and thence goes quickly to join the autosomes, being enclosed with them in the nucleus formed there. The exceptions observed by BORING (1907) together with ; the facts described here must represent the normal behavior of the heterocromosome of the Hemiptera, the greater frequency of succession being the consequence of the more frequent localization of the heterochromosome in the equatorial plane or in its near and of the anaphase rapidity. Due to its position in metaphase the heterochromosome in early anaphase may be found in precession. In late anaphase, oh the contrary ,it appears almost always in succession. This is attributed to the fact of the heterochromosome being ordinairily localized outside the spindle area it leaves the way free to the anaphasic plate moving toward the pole. Moreover, the heterochromosome being a round element approximately of the size of the autosomes, which are equally round or a little longer in the direction of the movement, it can be passed by the autosomes even when it stands in the area of the spindle, specially if it is not too far from the equatorial plane. e) The kinetochore - This question has been fully discussed in another paper (PIZA 1943a). The facts treated here point to the conclusion that the chromosomes of the Coreidae, like those of Tityus bahiensis, are provided with a kinetochore at each end, as was already admitted by the present writer with regard to the heterochromosome of Protenor. Indeed, taking ipr granted the facts presented in this paper, other cannot be the interpretation. However, the reasons by which the chromosomes of the species studied here do not orient themselves at metaphase of the first division in the same way as the heterochromosome of Protenor, that is, with the major axis parallelly to the equatorial plane, are claiming for explanation. But, admiting that the proximity of the kinetochores at the ends of chromosomes which do not separate until the second division making them respond to the poles as if they were a single kinetochore ,the explanation follows. (See PIZA 1943a). The median opening of the diplonemas when they are going to the diffuse stage as well as the reappearance of the bivalents always united at the end-segments and open in the middle is in full agreement with the existence of two terminal kinetochores. The same can be said with regard to the bivalents which join their extremities to form a ring.