Anal polyp caused by Schistosoma mansoni

We describe a schistosomal polyp in the anus of a 24-year-old patient, born in Viçosa, State of Minas Gerais, and living in Belo Horizonte, State of Minas Gerais. From 8 to 13 years of age, he swam in the rivers that bathe Viçosa. The histopathological examination has shown a lesion, lined by a keratinized squamous epithelium, ulcerated, with granulomas, centered or not by Schistosoma mansoni egg, laid, in loco, by the female present in the vascular lumen of a vein of the hemorrhoidal plexus. There was also a diffuse, nonspecific inflammation in the dermis. The patient was treated with praziquantel. Four months after the treatment, sigmoidoscopy showed a normal rectal mucosa, and negative oogram and stool tests. Ultrasound of abdomen was normal.

Testicular schistosomiasis as differential diagnosis for testicular nodules: a case report

AbstractDespite its infrequent occurrence, testicular schistosomiasis forming pseudo-tumors can be considered in the differential diagnosis of testicular tumors, especially in areas where the parasitic disease is endemic. In this report, we present a case of testicular schistosomiasis caused by Schistosoma mansoni and mimicking a testicular neoplasm. We describe the patterns of a testicular nodule on ultrasonography and magnetic resonance images in a 46-year-old man. The nodule was removed after a pre-operative diagnosis of a non-malignant lesion. Histology demonstrated granulomas with epithelioid macrophages and eosinophils around S. mansoni eggs within a fibrous tissue that formed a nodular structure.

Fatal pulmonary thromboembolism in gastrectomy intraoperative procedures by gastric adenocarcinoma: case report

The case of a patient with gastric adenocarcinoma with indication for gastrectomy is reported. The surgery took place without complications. A palliative, subtotal gastrectomy was performed after para-aortic lymph nodes compromised by neoplasm were found, which was confirmed by pathological exam of frozen sections carried out during the intervention. At the end of the gastroenteroanastomosis procedure, the patient began to show intense bradycardia: 38 beats per minute (bpm), arterial hypotension, changes in the electrocardiogram's waveform (upper unlevelling of segment ST), and cardiac arrest. Resuscitation maneuvers were performed with temporary success. Subsequently, the patient had another circulatory breakdown and again was recovered. Finally, the third cardiac arrest proved to be irreversible, and the intra-operative death occurred. Necropsy showed massive pulmonary embolism. The medical literature has recommended heparinization of patients, in an attempt to avoid pulmonary thromboembolism following major surgical interventions. However, in the present case, heparinization would have been insufficient to prevent death. This case indicates that it is necessary to develop preoperative propedeutics for diagnosing the presence of venous thrombi with potential to migrate, causing pulmonary thromboembolism (PTE). If such thrombi could be detected, preventative measures, such as filter installation in the Cava vein could be undertaken.

Mortalidade por neoplasias malignas na população residente próximo de minas de urânio em Portugal : Epidemiologia

RESUMO - Introdução: O encerramento das minas de urânio em Portugal tem suscitado preocupação no que respeita aos eventuais efeitos que as radiações emitidas e os agentes químicos presentes terão na saúde das populações. Para esclarecer a existência de tal efeito foi delineado um programa de investigação em que o presente estudo se enquadra. Sendo conhecido que as populações expostas a minas de urânio, nomeadamente os mineiros, têm risco acrescido de sofrer de neoplasias, especialmente de «neoplasias da traqueia, dos brônquios e do pulmão», foi este o grupo de neoplasias seleccionado para constituir a hipótese principal do estudo. Assim, o estudo pretendeu verificar se existe associação entre exposição a minas de urânio e suas escombreiras (especialmente à mina da Urgeiriça, no concelho de Nelas) e a mortalidade por alguns grupos de neoplasias malignas, nomeadamente as «neoplasias malignas da traqueia, dos brônquios e do pulmão». Material e métodos: Trata-se de um estudo «ecológico» em que se consideraram «expostos» os residentes no concelho de Nelas, bem como no conjunto de concelhos com minas de urânio, e «não expostos» os residentes nos restantes concelhos das NUTS Dão-Lafões e Beira Interior Norte e Serra da Estrela. A análise centrou-se no cálculo, para cada concelho ou grupo de concelhos, das razões padronizadas de mortalidade (RPM) por «neoplasias malignas da traqueia, dos brônquios e do pulmão», por «neoplasia maligna do estômago» e por «todas as neoplasias malignas » no período de vinte anos compreendido entre 1980 e 1999. Resultados: Tomando os dois sexos em conjunto, o concelho de Nelas teve a RPM mais elevada para as «neoplasias malignas da traqueia, dos brônquios e do pulmão» (RPM = 133; p = 0,003). Teve também o valor mais elevado no sexo masculino (RPM = 126, não significativo) e o segundo mais elevado no sexo feminino (RPM = 142, não significativo). A razão das RPM concelho de Nelas/concelhos limítrofes de Nelas foi 1,46, p = 0,002 (homens: 1,50 p = 0,003; mulheres: 1,27, não significativo). As razões das RPM concelho de Nelas/concelhos com minas (1,94, p = 0,001) e concelho de Nelas/concelhos sem minas (1,57, p = 0,001) foram claramente superiores a 1. Pelo contrário, as RPM por «neoplasia maligna do estômago » foram sobretudo elevadas nos concelhos da NUTS Beira Interior Norte, que inclui grande parte do distrito da Guarda, (Trancoso: 154, p = 0,000; Sabugal: 146, p = 0,000), embora se tenham observado valores elevados em alguns concelhos da NUTS Dão-Lafões (Vila Nova de Paiva: 154, p = 0,001). Saliente-se que os dois valores mais baixos ocorreram nos concelhos de Tábua (RPM = 57; p = 0,000) e de Nelas (RPM = 60; p = 0,000). Para o conjunto de «todas as neoplasias malignas» as RPM dos vários concelhos variaram entre 62 e 100 sem que a distribuição desses valores sugerisse qualquer associação positiva relevante. Discussão: Os resultados mostraram que a população do concelho de Nelas teve, no período estudado, um risco acrescido de morrer por «neoplasias malignas da traqueia, dos brônquios e do pulmão» quando comparado com a dos concelhos limítrofes e restantes concelhos das NUTS estudadas. A existência da mina da Urgeiriça e da sua escombreira é uma possível causa desse excesso de mortalidade. Ele poderá ter sido gerado, por um lado, através da existência de uma percentagem elevada de ex-mineiros, bem como, por outro lado, através de uma exposição ambiental geral, facto este que é sustentado pela ocorrência de excesso de mortalidade tanto em homens como em mulheres. O excesso de mortalidade por aquele grupo de neoplasias pode ainda ter origem noutras exposições cujo potencial papel é discutido.

Meningeal carcinomatosis as the initial manifestation of a gallbladder adenocarcinoma associated with a Krukenberg tumor

A case of malignant neoplasm is described in which the initial manifestations were mental dysfunction and meningeal irritation, mimicking chronic or subacute meningitis. Physical examination showed cranial nerve involvement and a pelvic tumor. There was progressive deterioration, and death occurred in 2 weeks. The autopsy revealed a gallbladder adenocarcinoma, meningeal carcinomatosis, and ovarian metastasis presenting as a Krukenberg tumor. The authors emphasize the importance of including meningeal carcinomatosis as a possibility in the differential diagnosis of non-characteristic clinical pictures, as well as the importance of the cerebrospinal fluid cytologic examination, repeated as needed, in order to confirm this diagnosis.

Conservative therapies for hemorrhagic radiation proctitis: a review

Chronic radiation proctitis represents a challenging condition seen with increased frequency due to the common use of radiation for treatment of pelvic cancer. Hemorrhagic radiation proctitis represents the most feared complication of chronic radiation proctitis. There is no consensus for the management of this condition despite the great number of clinical approaches and techniques that have been employed. Rectal resection represents an available option although associated with high morbidity and risk of permanent colostomy. The effectiveness of nonoperative approaches remains far from desirable, and hemorrhagic recurrence represents a major drawback that leads to a need for consecutive therapeutic sessions and combination of techniques. We conducted a critical review of published reports regarding conservative management of hemorrhagic chronic radiation proctitis. Although prospective randomized trials about hemorrhagic radiation proctitis are still lacking, there is enough evidence to conclude that topical formalin therapy and an endoscopic approach delivering an argon plasma coagulation represent available options associated with elevated effectiveness for interruption of rectal bleeding in patients with chronic radiation proctitis.

Anorectal leiomyomas: report of two cases with different anatomical patterns and literature review

Gastrointestinal mesenchymal tumors comprise a rare group of gastrointestinal tract wall tumors that have long been a source of confusion and controversy, especially in terms of pathological classification, preoperative diagnosis, management strategies, and prognosis. This report describes the clinical manifestations and management of 2 rectal leiomyomas and reviews the pertinent literature. Case 1: A 44-year-old woman was admitted reporting a nodule in the right para-anal region for the previous 2 years. At proctological examination, a 4-cm diameter fibrous mass situated in the para-anal region that produced an arch under the smooth muscle on the right rectal wall just above the anorectal ring was noted. Computed tomography and magnetic resonance imaging of the abdomen and pelvis showed the lesion and detected no other abnormalities. Surgical treatment consisted of wide local resection of the tumor through a para-anal incision, with no attempts to perform lymphadenectomy. Case 2: A 40-year-old male patient was admitted reporting constant anal pain for 4 months. He presented a 3-cm submucosal nodule at the anterior rectal wall just above the dentate line. After 2 inconclusive preoperative biopsies, transanal resection of the tumor was performed. Histological analysis of the specimen showed a benign leiomyoma. A review of the literature is presented, emphasizing some clinical and therapeutic aspects of this unusual rectal tumor.

Retrospective evaluation of bone pain palliation after samarium-153-EDTMP therapy

PURPOSE: The aim of this study was to evaluate the degree of metastatic bone pain palliation and medullar toxicity associated with samarium-153-EDTMP treatment. METHODS: Seventy-three patients with metastatic bone pain having previously undergone therapy with samarium-153-EDTMP (1 mCi/kg) were retrospectively evaluated. Routine follow-up included pain evaluation and blood counts for 2 months after treatment. Pain was evaluated using a subjective scale (from 0 to 10) before and for 8 weeks after the treatment. Blood counts were obtained before treatment and once a week for 2 months during follow-up. Dosimetry, based upon the urinary excretion of the isotope, was estimated in 41 individuals, and the resulting radiation absorbed doses were correlated with hematological data. RESULTS: Reduction in pain scores of 75% to 100% was obtained in 36 patients (49%), with a decrease of 50% to 75%, 25% to 50%, and 0% to 25% in, respectively, 20 (27%), 10 (14%), and 7 (10%) patients. There was no significant relationship between the pain response and location of the primary tumor (breast or prostate cancer). Mild to moderate myelosuppression was noted in 75.3% of patients, usually with hematological recovery at 8 weeks. The mean bone marrow dose was 347 ± 65 cGy, and only a weak correlation was found between absorbed dose and myelosuppression (Pearson coefficient = .4). CONCLUSIONS: Samarium-153-EDTMP is a valuable method for metastatic bone pain palliation. A mild to moderate and transitory myelosuppression is the main toxicity observed after samarium therapy, showing a weak correlation with dosimetric measures.

Otimização de esquemas terapêuticos do carcinoma da próstata envolvendo braquiterapia de baixa taxa de dose e radioterapia externa : abordagens física e radiobiológica

RESUMO: Este trabalho teve como objetivo a determinação de esquemas de tratamento alternativos para o carcinoma da próstata com radioterapia externa (EBRT) e braquiterapia de baixa taxa de dose (LDRBT) com implantes permanentes de Iodo-125, biologicamente equivalentes aos convencionalmente usados na prática clínica, com recurso a modelos teóricos e a métodos de Monte Carlo (MC). Os conceitos de dose biológica efetiva (BED) e de dose uniforme equivalente (EUD) foram utilizados, com o modelo linear-quadrático (LQ), para a determinação de regimes de tratamento equivalentes. Numa primeira abordagem, utilizou-se a BED para determinar: 1) esquemas hipofracionados de EBRT mantendo as complicações retais tardias de regimes convencionais com doses totais de 75,6 Gy, 77,4 Gy, 79,2 Gy e 81,0 Gy; e 2) a relação entre as doses totais de EBRT e LDRBT de modo a manter a BED do regime convencional de 45 Gy de EBRT e 110 Gy de LDRBT. Numa segunda abordagem, recorreu-se ao código de MC MCNPX para a simulação de distribuições de dose de EBRT e LDRBT em dois fantomas de voxel segmentados a partir das imagens de tomografia computorizada de pacientes com carcinoma da próstata. Os resultados das simulações de EBRT e LDRBT foram somados e determinada uma EUD total de forma a obterem-se: 1) esquemas equivalentes ao tratamento convencional de 25 frações de 1,8 Gy de EBRT em combinação com 110 Gy de LDRBT; e 2) esquemas equivalentes a EUD na próstata de 67 Gy, 72 Gy, 80 Gy, 90 Gy, 100 Gy e 110 Gy. Em todos os resultados nota-se um ganho terapêutico teórico na utilização de esquemas hipofracionados de EBRT. Para uma BED no reto equivalente ao esquema convencional, tem-se um aumento de 2% na BED da próstata com menos 5 frações. Este incremento dá-se de forma cada vez mais visível à medida que se reduz o número de frações, sendo da ordem dos 10-11% com menos 20 frações e dos 35-45% com menos 40 frações. Considerando os resultados das simulações de EBRT, obteve-se uma EUD média de 107 Gy para a próstata e de 42 Gy para o reto, com o esquema convencional de 110 Gy de LDRBT, seguidos de 25 frações de 1,8 Gy de EBRT. Em termos de probabilidade de controlo tumoral (igual EUD), é equivalente a este tratamento a administração de EBRT em 66 frações de 1,8 Gy, 56 de 2 Gy, 40 de 2,5 Gy, 31 de 3 Gy, 20 de 4 Gy ou 13 de 5 Gy. Relativamente à administração de 66 frações de 1,8 Gy, a EUD generalizada no reto reduz em 6% com o recurso a frações de 2,5 Gy e em 10% com frações de 4 Gy. Determinou-se uma BED total de 162 Gy para a administração de 25 frações de 1,8 Gy de EBRT em combinação com 110 Gy de LDRBT. Variando-se a dose total de LDRBT (TDLDRBT) em função da dose total de EBRT (TDEBRT), de modo a garantir uma BED de 162 Gy, obteve-se a seguinte relação:.......... Os resultados das simulações mostram que a EUD no reto diminui com o aumento da dose total de LDRBT para dose por fração de EBRT (dEBRT) inferiores a 2, Gy e aumenta para dEBRT a partir dos 3 Gy. Para quantidades de TDLDRBT mais baixas (<50 Gy), o reto beneficia de frações maiores de EBRT. À medida que se aumenta a TDLDRBT, a EUD generalizada no reto torna-se menos dependente da dEBRT. Este trabalho mostra que é possível a utilização de diferentes regimes de tratamento para o carcinoma da próstata com radioterapia que possibilitem um ganho terapêutico, quer seja administrando uma maior dose biológica com efeitos tardios constantes, quer mantendo a dose no tumor e diminuindo a toxicidade retal. A utilização com precaução de esquemas hipofracionados de EBRT, para além do benefício terapêutico, pode trazer vantagens ao nível da conveniência para o paciente e economia de custos. Os resultados das simulações deste estudo e conversão para doses de efeito biológico para o tratamento do carcinoma da próstata apresentam linhas de orientação teórica de interesse para novos ensaios clínicos. --------------------------------------------------ABSTRACT: The purpose of this work was to determine alternative radiotherapy regimens for the treatment of prostate cancer using external beam radiotherapy (EBRT) and low dose-rate brachytherapy (LDRBT) with Iodine-125 permanent implants which are biologically equivalent to conventional clinical treatments, by the use of theoretical models and Monte Carlo techniques. The concepts of biological effective dose (BED) and equivalent uniform dose (EUD), together with the linear-quadratic model (LQ), were used for determining equivalent treatment regimens. In a first approach, the BED concept was used to determine: 1) hypofractionated schemes of EBRT maintaining late rectal complications as with the conventional regimens with total doses of 75.6 Gy, 77.4 Gy, 79.2 Gy and 81.0 Gy; and 2) the relationship between total doses of EBRT and LDRBT in order to keep the BED of the conventional treatment of 45 Gy of EBRT and 110 Gy of LDRBT. In a second approach, the MC code MCNPX was used for simulating dose distributions of EBRT and LDRBT in two voxel phantoms segmented from the computed tomography of patients with prostate cancer. The results of the simulations of EBRT and LDRBT were added up and given an overall EUD in order to obtain: 1) equivalent to conventional treatment regimens of 25 fraction of 1.8 Gy of EBRT in combination with 110Gy of LDRBT; and 2) equivalent schemes of EUD of 67 Gy, 72 Gy, 80 Gy, 90 Gy, 100 Gy, and 110Gy to the prostate. In all the results it is noted a therapeutic gain using hypofractionated EBRT schemes. For a rectal BED equivalent to the conventional regimen, an increment of 2% in the prostate BED was achieved with less 5 fractions. This increase is visibly higher as the number of fractions decrease, amounting 10-11% with less 20 fractions and 35-45% with less 20 fractions. Considering the results of the EBRT simulations an average EUD of 107 Gy was achieved for the prostate and of 42 Gy for the rectum with the conventional scheme of 110 Gy of LDRBT followed by 25 fractions of 1.8 Gy of EBRT. In terms of tumor control probability (same EUD) it is equivalent to this treatment, for example, delivering the EBRT in 66 fractions of 1.8 Gy, 56 fractions of 2 Gy, 40 fractions of 2.5 Gy, 31 fractions of 3 Gy, 20 fractions of 4 Gy or 13 fractions of 5 Gy. Regarding the use of 66 fractions of 1.8 Gy, the rectum EUD is reduced to 6% with 2.5 Gy per fraction and to 10% with 4 Gy. A total BED of 162 Gy was achieved for the delivery of 25 fractions of 1.8 Gy of EBRT in combination with 110 Gy of LDRBT. By varying the total dose of LDRBT (TDLDRBT) with the total dose of EBRT (TDEBRT) so as to ensure a BED of 162 Gy, the following relationship was obtained: ....... The simulation results show that the rectum EUD decreases with the increase of the TDLDRBT, for EBRT dose per fracion (dEBRT) less than 2.5 Gy and increases for dEBRT above 3 Gy. For lower amounts of TDLDRBT (< 50Gy), the rectum benefits of larger EBRT fractions. As the TDLDRBT increases, the rectum gEUD becomes less dependent on the dEBRT. The use of different regimens which enable a therapeutic gain, whether deivering a higher dose with the same late biological effects or maintaining the dose to the tumor and reducing rectal toxicity is possible. The use with precaution of hypofractionated regimens, in addition to the therapeutic benefit, can bring advantages in terms of convenience for the patient and cost savings. The simulation results of this study together with the biological dose conversion for the treatment of prostate cancer serve as guidelines of interest for new clinical trials.

Transanal total mesorectal excision: a pure NOTES approach for selected patients.

Transanal total mesorectal excision: a pure NOTES approach for selected patients.

Síntese de derivados de adenina e guanina

Tese de Doutoramento em Ciências (Especialidade em Química)

Estimation of statistical cure from cancer using population-based data

Dissertação de mestrado em Estatística

Endometritis clínica y subclínica en vacas lecheras: validez de su diagnóstico y costo-eficacia del tratamiento con prostaglandina y un inmunomodulador

La endometritis posparto es una afección que influye negativamente sobre la eficiencia reproductiva de los rodeos lecheros. A pesar de que existen varios métodos de diagnostico disponibles, no hay consenso entre los investigadores y técnicos sobre cuál es el más indicado y el criterio para determinar la presencia o ausencia de la enfermedad. Dado que el diagnóstico es controversial, la eficacia de los tratamientos evaluados hasta la fecha es también muy controvertida, lo que se ve reflejado en la gran disparidad de resultados reportados. El propósito fundamental de este proyecto es determinar la validez de distintos métodos de diagnostico de endometritis clínica y subclínica en rodeos lecheros de la Provincia de Cordoba y estimar el costo-eficacia del tratamiento de endometritis mediante el uso combinado de prostaglandinas y un inmunomodulador, sobre la eficiencia reproductiva. La Etapa I se realizará en 10 tambos de la zona de Villa María, con aproximadamente 350 vacas en ordeño cada uno y manejo tradicional de base pastoril. Se incluirán vacas multíparas y de primer parto, las que serán sometidas a un examen ginecológico entre los 20 y 35 días posparto (tacto rectal, vaginoscopía y cytobrush). Los animales estudiados serán monitoreados desde el momento del diagnóstico hasta los 200 días posparto para evaluar el efecto de la endometritis clínica y subclínica sobre la fertilidad. En la Etapa II, vacas con endometritis serán asignadas al azar a tres grupos: Control (sin tratamiento), tratadas con prostaglandina al cabo del diagnostico y las tratadas con prostaglandina más un inmunomodulador (MCC). Todas las vacas serán liberadas para la Inseminación Artificial a los 45 días posparto, siguiendo el manejo reproductivo usual de cada tambo. Se espera que el método de cytobrush permita detectar una proporción importante de vacas con endometritis no diagnosticadas por el método tradicional y obtener precisiones sobre el valor umbral de infiltración de polimorfonucleares (como indicativo de inflamación del endometrio) para el diagnostico de la endometritis en nuestras condiciones de producción. Además, esta identificación permitirá ver si esas vacas con endometritis clínica y subclínica experimentan una mayor proporción de fallas reproductivas. Por último, se espera que la tasa de curación para aquellas vacas con endometritis y tratadas con prostaglandina y MCC, sea mayor que los controles y el beneficio compense los costos del tratamiento, dada la mayor tasa de preñez a observar en el grupo tratado.

Nuevos aportes a la historia natural de la mulita pampeana Dasypus hybridus (Mammalia, Dasypodidae)

En este trabajo se presentan nuevos aportes sobre la historia natural de la mulita pampeana Dasypus hybridus (Desmarest, 1804) (Mammalia, Xenarthra, Dasypodidae). Los estudios de campo fueron llevados a cabo en 100 ha de cuatro establecimientos agropecuarios de la provincia de Buenos Aires, Argentina. Durante tres años se realizó un muestreo estacional de armadillos por captura y liberación. Se obtuvieron datos de hábitos alimentarios, uso del espacio y del tiempo, comportamiento, termorregulación, datos poblacionales y morfológicos. Se realizaron 71 capturas. En la dieta el ítem principal registrado fue material vegetal, seguido por hormigas e insectos coleópteros; no se observó una diferencia estacional en los hábitos alimentarios. La actividad de las mulitas se concentra durante el día, existió una baja en la frecuencia de observación durante las estaciones frías (otoño e invierno). La mulita pampeana prefiere suelos húmicos, terrenos altos y pastizales densos y altos; asimismo seleccionan los montes para refugiarse. Son individuos asociales. La temperatura rectal mostró correlaciones positivas con la temperatura ambiente. La proporción de sexos fue cercana a uno y no se observó dimorfismo sexual. Los resultados obtenidos concuerdan parcialmente con lo observado para otras especies del género, destacando las tendencias observadas en los hábitos alimentarios y en la estrategia termorregulatoria. Este trabajo representa un aporte en varios aspectos de una especie poco estudiada en una zona bajo importantes presiones de uso y modificación de hábitat.

Anatomy and histology of Embolyntha batesi MacLahlan, 1877 (Embiidina)

The Embioptera are rather generalized insects whose internal anatomy is simple and not subject to great modifications. For this reason these insects form an ideal group for elementary anatomical and histological studies (fig. 2). The digestive tract is a long, simple tube without convolutions or diverticulae from the buccal cavity to the rectum. The buccal structures are of the chewing type. The oesophagus and ingluvia are differentiated only by slight dilation of their walls. In nymphs and females the proventriculus is very distinct due to folds which flatten as the structure becomes packed with food. The enteron is the largest in such forms and in both sexes limited caudally by the Malpighian tubules. The proctodeus has six large rectal papillae. The nervous system is complete with only the fifth abdominal segment lacking a ganglion in the metathorax includes the ganglion of the first abdominal segment. The brain exhibits very clear structure in histological sections. The tracheal system includes two pairs of thoracic spiracles and eight abdominal pairs. Only th metathoracic spiracle has an air expiration function; all others serve for inspiration. Various structures in the spiracles protect the atrium. The circulatory system includes a long, simple dorsal vessel which extends forward from the ninth abdominal segment into the cranium. It opens anteriorly near the circumoesophageal connectives. The dorsal vessel has a pair of ostia and valves corresponding to each abdominal and thoracic segment. It lacks the diverticulae or folds commonly found in more highly evolved insects. The excretory system is represented by Malphighian tubules, pericardial cells, and fat-body. The number and disposition of Malpighian tubules is variable within the order. The pericardial cells are localized around the entire dorsal vessel up to the opening of the aorta in the head. The fat-bodies form compact layers in the dorsal and ventral regions of the body. In males they are more developed in the abdominal region. The mandibles, maxillae, and salivary glands are of a simple type with very few cytological modifications. Only the salivary glands which extend into the mesothoracic region show appreciable specialization. The reproductive system is bi-sixual and shows considerable sexual dimorphism. Males have five pair of testes with a metameric disposition, two distinct ducts, two epidymis, and the ejaculatory organs. The accessory glands vary in number and size and open in the anterior portion of the ejaculatory duct. The female reproductive organs are of the panoistic type. The system includes five pairs of ovarioles, two long paired oviducts a small, unpaired oviduct and the spermatheca which opens in the vagina. Reproduction usually involves a union of male and female gametes, and eggs are usually laid in clusters attached to a substrate.