Características histoquímicas e estruturais do testículo do morcego hematófago (Desmodus rotundus rotundus, Geoffrey, 1810).

The testicular stroma of the vampire bat including the testicular capsula and the lamina propria of the seminiferous tubuli, was strongly PAS-positive. This observation was a possible indication of great amounts of structural glycogen and other glycoconjugates at the level of smooth muscle cells; elongated contractile cells and/or collagen frameworks of the tunica albuginea and tubular lamina propria. In the last the basement membranes of the seminiferous tubules were particularly strongly PAS positive, as an indication of their neutral mucosubstances structural composition, previously described (Malmi et al., 1987). The epithelium lining from the cavitary and surface rete testis complex showed low reactivities to mucosubstances; total proteins and lipids and oxidative enzymes studied. Although the apical granulation at the rete testis epithelium showed an intense PAS reactivity with hypothesis of glycoprotein secretion, through the rete. The PAS, Sudan Black B, NADH, MDH and LDH reactions of the testicular interstitium seem correlate to steroid metabolism (biosynthesis and secretion), at the Leydig cells level. The seminiferous epithelium generally had low reactions to all the histochemical studies realized. Particularly in the adbasal compartment the histochemical localizations of NADH diaphorase and LDH were possible related to glycolytic activities and general carbohydrates metabolism, both enzymes, and hydrogen transport, the NADH. The strong PAS, diastase and PAS, and alcian blue pH 2.5 and PAS reactions observed in the adluminal seminiferous epithelium compartment were directly related to the spermatids acrosomal glycoconjugates structuration. Also the SDH localization at this level seems to be related to the mitochondrial activities at the middle piece level in the late spermatids.

Fever response induced by intravenous and intracerebrovascular injection of pyrogen in thyroidectomised and protein-calorie malnourished rabbits

The development of a fever in response to intravenous (IV, 1.5 μg/kg body mass) and intracerebroventricular (ICV, 1.5 μg/animal) injections of Escherichia coli lipopolysaccharide (LPS) was studied in control, thyroidectomised and protein-calorie malnourished rabbits (New Zealand Whites, n = 55). ICV injection of LPS is control rabbits produced a fever response, the characteristics of which differed from those obtained after IV pyrogen injection. Thyroid deficiency caused an attenuated fever response, irrespective of whether LPS had been administered by IV or ICV injection. Protein-calorie malnourished rabbits showed a smaller fever response after IV or ICV pyrogen injections. Malnourished rabbits, refed over a period of 15 days, showed a typical biphasic fever response, but with lower magnitude than controls. The results of these experiments suggest that ICV injection of LPS is not an appropriate model for the study of fever mechanisms in disease states, and that the attenuated fever response observed in protein-calorie malnourished rabbits may be related, at least in part, to a decreased ability to produce the endogenous pyrogen interleukin-1.

Fine structure of the boundary tissue of the seminiferous tubuli of the vampire bat (Desmodus rotundus, G.; Microchiroptera).

Structurally the boundary tissue of the vampire bat seminiferous tubuli showed 2 to 5 layers of connective tissue in which elongated contractile cells and lamellar and/or fibrillar collagen were noticed. This boundary tissue forms the seminiferous tubular lamina propria. Its structure was more complex around the seminiferous tubuli near the Capsula testicularis than between the adjacent and contiguous tubuli into the testicular lobuli. The whole ultrastructural organization of the seminiferous lamina propria was described here.

Fine structure of the ductuli efferentes of the hamster (Mesocricetus auratus).

Structurally the ductuli efferentes of the hamster showed 2 distinct segments, a testicular and an epididymal. Both of these segments were lined by a pseudostratified epithelium, which showed basically non-ciliated and ciliated cells. In the testicular segment a 3rd type of oval dark cells was observed. The ultrastructural characteristics of these cells were presented and discussed in this report.

Características ultra-estruturais das células de Sertoli do morecego hematófago (Desmodus rotundus rotundus, Geoffrey, 1810).

This paper deals with the ultrastructural study of mature vampire bat Sertoli cells and their relationships with the different stages of testicular germ cells. In vampire bat seminiferous epithelium there are different types of junctional specializations among Sertoli cells and among Sertoli cells and different germ cells, with special emphasis to tight junctions and to junctions like as desmosomes. Ectoplasmic junctions through the Sertoli cells, including the smooth ER, are observed. These cellular interactions and their cytophysiological roles are discussed. Also are related some ultrastructural peculiarities of the Sertoli cell nucleus, nucleolus, cytoplasmic organelles and lipidic inclusions.

HIPERTERMIA EM RATOS INDUZIDA PELA LESAO ELETROLITICA DO MESENCEFALO: PARTICIPACAO DAS PROSTAGLANDINAS

The present studies were conducted to determine the role of prostaglandins in the etiology of a rise of body temperature observed in rats after electrolytic lesion made on the dorsal mesencephalic areas. This hyperthermia was abolished by intraperitoneal administration of indomethacin, an inhibitor of prostaglandins synthesis. These results strengthen the suggestion of a similar mechanism for both neurogenic hyperthermia and the fevers produced by pyrogens. However, until further experiments are carried out, the possibility of lesion in producing hyperthermia by different mechanisms cannot be ruled out.

Body temperature and thermoregulatory behaviour of the lizard Ameiva ameiva in Central Amazonian forests

Body temperatures and thermoregulatory behaviour of the teiid lizard Ameiva ameiva inhabiting the edge and the understory were studied in Central Amazonian forests Despite of differences in the thermal profile of the habitates. the mean body temperature was the some for active lizards observed at the edge or inside the forest. where only slight peculiarities in thermoregulatory behaviour were observed. A. ameiva is capable of maintaining body temperature significantly above microhabitat temperature.

Um Modelo para a Determinação do Equilíbrio Térmico de Bovinos em Ambientes Tropicais

An equation based on heat transfer theory was presented to estimate the rate of heat loss from cattle exposed to a tropical environment, specified by the air temperature, humidity, solar radiation, and wind speed. The animals' variables (sweating rate, rectal temperature, respiratory rate, surface temperature, haircoat color, and body weight) were considered together with environmental variables (air temperature and humidity, solar radiation, wind speed, and globe temperature). The equation allows the prediction of (a) the metabolic heat production level necessary to balance heat losses under specified environmental conditions; (b) the combination of environmental factors that provide a determined heat flux between a given animal and its environment.

Laparoscopic evaluation and treatment of the impalpable testis

Objectives: To evaluate the laparoscopic technique as a diagnostic and therapeutic tool in the management of patients with impalpable testis. Material and Methods: Fifty-nine patients with mean age of 6.3 years underwent laparoscopy to evaluate 85 impalpable testes that were classified as absent, canalicular and intra-abdominal. In the case of testicular absence, the procedure was terminated. In the case of canalicular testis, open inguinal exploration was performed. In intra-abdominal testis, either laparoscopic orchiopexy or orchiectomy was performed. According to the length of the vascular pedicle, orchipexy was performed either with or without vascular ligature. Post-operatively, the treated testes were evaluated according to size and location in the scrotum. Results: Seventeen (20%) of the 85 impalpable testes were diagnosed as absent, 21 (24.7%) as canalicular and 47 (55.3%) as intra-abdominal. Of the canalicular testes, 20 were explored by inguinotomy and one by laparoscopy. All the intra-abdominal testes were treated initially by laparoscopy, four being removed due to atrophy, 31 submitted to vascular ligature and 12 to primary orchipexy. Of those submitted to vascular ligature, 22 underwent a second stage orchipexy, of which 18 laparoscopically and 4 by inguinotomy. Of the 18 testes brought to the scrotum by staged laparoscopic orchipexy, 15 (83.3%) presented normal characteristics in the late follow-up, while of the 12 submitted to primary laparoscopic orchipexy, 8 (66.6%) were normal. There were no perioperative or late complications. Conclusions: Laparoscopy is a minimally invasive procedure with low morbidity that enables precise diagnosis of the impalpable testes. When intra-abdominal testes are found, either immediate laparoscopic orchiectomy, or primary and staged orchipexy are possible, with results equivalent to open procedures, with the advantage of smaller surgical incisions and shorter postoperative recovery.

The comparative efficacy of yohimbine and atipamezole to treat amitraz intoxication in dogs

This study compared the efficacy of yohimbine with atipamezole, a new α2-adrenergic antagonist, to treat canine amitraz intoxication. Thirty dogs were divided equally into 3 groups (A, AY, and AA). Group A received 2.5% amitraz iv at 1 mg/kg; Group AY received the same dose of amitraz followed 30 min later by 0.1 mg/kg (2 mg/mL) yohimbine iv; and Group AA received the same dose of amitraz followed 30 min later by 0.2 mg/kg (5 mg/mL) atipamezole iv. Temperature, heart rate, respiratory frequency, mean arterial pressure, degree of sedation, mean time of tranquilization and diameter of pupils were monitored for 360 min. Sedation, logs of reflexes, hypothermia bradycardia, hypotension, bradypnea and mydriasis were observed in Group A, with 3rd eyelid prolapse, increased diuresis and vomiting in some animals. Yohimbine reversed all alterations induced by amitraz, but induced significant cardiorespiratory effects such as tachycardia and tachypnea. Atipamezole was a useful antagonist for amitraz, with less cardiorespiratory effects, suggesting its potential role as an alternative treatment of amitraz intoxication in dogs.

Cysts reabsorption in the testis of the bee wax pest Achroia grisella (Lepidoptera, Pyralidae) during spermatogenesis

The present paper reports the occurrence of testicular cysts degeneration during spermatogenesis of Achroia grisella, a Lepidoptera with dimorphic spermatogenesis, through ultrastrucutural studies. Signs of cysts degeneration can be detected in the last larval instar but it increases during pupation and early adulthood. The degeneration affects the eupyrene, as well apyrene cysts but it is not always possible to recognize which cysts are degenerating. Some morphological features of cysts degeneration resemble apoptosis.

Description of the nucleolar activity and karyotype in germinative cell lines of Rhodnius domesticus (Triatominae, Heteroptera)

The purpose of this work was to study the karyotype, spermatogenesis and nucleolar activity at meiosis, in the species Rhodnius domesticus (Heteroptera, Triatominae). The testicular tubules were cytologically prepared by the conventional method of cell crushing and subsequent application of cytogenetic staining techniques with lacto-acetic orcein and silver-ion impregnation. The species under study presented karyotype 2n= 20A+XY, the modal number of the subfamily Triatominae. The chromosomes presented no primary constriction and were therefore characterized as holocentric. It was observed that the sex chromosomes sometimes were located at the periphery, close to the ring formed by autosomes, at first meiotic division. At metaphases II, sex chromosomes were positioned in the center of the autosomal ring, thus evidencing a postreductional behavior. These same chromosomes showed late migration at anaphases and were clearly impregnated with silver-ions, suggesting they bore Nucleolar Organizer Regions. Dispersed nucleolar corpuscles in cytoplasm until telophase II and small dots in spermatids strongly impregnated with silver, could be seen. Thus, it may be inferred that, in triatomines, the nucleolus does not completely disappear but remains in the form of small corpuscles that have a role in cell differentiation.

Diagnosis of 5α-reductase type 2 deficiency: Contribution of anti-Müllerian hormone evaluation

Aim: To evaluate anti-Müllerian hormone (AMH) levels in patients with clinical and molecular diagnosis of 5α-reductase 2 deficiency. Patients and methods: Data from 14 patients whose age ranged from 21 days to 29 years were analyzed according to age and pubertal stage. Sexual ambiguity was rated as Prader III in 11 patients. LH, FSH, testosterone (T), dihydrotestosterone (DHT) and AMH serum levels were measured in all but two patients, who had been previously submitted to gonadectomy; T and DHT were also measured in 20 age-matched controls. Results: Gonadotropin levels were normal in all but one patient who retained gonads (six of whom had reached puberty) and T/DHT ratio was elevated in all patients when compared to controls. All prepubertal patients had AMH levels < -1 SD for age, while most pubertal patients had AMH levels compatible with pubertal stage. Conclusions: Prepubertal patients with 5α-reductase 2 deficiency have AMH values in the lower part of the normal range. These data indicate that T does not need to be converted to DHT to inhibit AMH secretion by Sertoli cells. © Freund Publishing House Ltd., London.

Chromosomal similarities and differences among four Neotropical Elateridae (Conoderini and Pyrophorini) and other related species, with comments on the NOR patterns in Coleoptera

This work deals with the comparative cytogenetic analysis of four Neotropical Elateridae species and reviews the nucleolar organizer region (NOR) patterns on Coleoptera chromosomes, for the first time. The cytogenetic characterization of Conoderus malleatus (Conoderini), Pyrearinus candelarius, Pyrophorus divergens and Pyrophorus punctatissimus (Pyrophorini) was accomplished through the study of mitotic and meiotic cells submitted to standard (Giemsa) and differential staining [silver impregnation and GC-specific chromomycin A 3 (CMA 3) plus AT-specific 4′-6-diamidino-2-phenylindole (DAPI) fluorochromes]. The analysis of spermatogonial cells revealed the diploid numbers: 2n = 17 in C. malleatus and 2n = 15 in P. candelarius, P. divergens and P. punctatissimus. In these species, the X0 type sex-determination system and the acrocentric morphology of almost all chromosomes were observed. The study of meiotic cells of the four species revealed the occurrence of total synapsis between the autosomes, the presence of one terminal or interstitial chiasma in the majority of the bivalents, and the reductional behaviour and regular segregation of all chromosomes. Although the three Pyrophorini species demonstrated many similar karyotypical characteristics, there was one discrepancy, which was noted in the diplotene cells and concerns the number of bivalents with two chiasmata; P. candelarius only presented one bivalent, P. divergens showed two bivalents and P. punctatissimus exhibited up to four bivalents with two chiasmata. Testicular cells impregnated with silver nitrate demonstrated two terminal NORs located on the fourth autosomal pair of the Conoderini species and on the second autosomal pair of the three Pyrophorini representatives. Use of CMA 3/distamycin A (DA)/DAPI staining on the P. candelarius and P. punctatissimus chromosomes revealed that the CMA 3 labelled regions were coincident with the NORs. The main strategies of karyotypical differentiation that have occurred among the four Elateridae species and other related species, and the general trends of the NOR shifts during Coleoptera chromosomal evolution are discussed in this work. © 2007 The Authors.