A combined immunohistochemical and electron microscopic study of the second cell type in the developing sheep pineal gland

Ultrastructural and immunohistochemical techniques were used to study the second cell type in sheep embryo pineal glands. Thirty-two embryos were studied from day 54 of development through birth. Specimens were arranged in four age groups, defined in terms of the most relevant histological features: Group 1 (54-67 days of prenatal development), Group 2 (71-92 days), Group 3 (98-113 days), and Group 4 (118-150 days). At 98 days, a second cell type was observed which differed from pinealoblasts and showed uniform ultrastructural characteristics similar to those of astrocytes in the central nervous system. Ultrastructural homogeneity was not matched by the results of histochemical and immunohistochemical analysis: while all Type II cells stained positive to phosphotungstic acid hematoxylin, only 50% expressed glial fibrillary acidic protein. In the course of ovine intrauterine development, the vascular affinity of this second cell population, composed of glial-like or astrocytic cells at varying stages of maturity, leads to the formation of a limiting pineal barrier. This barrier may constitute the morphological expression of a hypothetical functional involvement in the exchange of substances between blood and pineal parenchyma.

[Comparative ontogenic analysis of the epithelium of the non-glandular stomach compartments of merino sheep]

A total of 74 embryos and fetuses were used in a comparative analysis of the epithelium of the non-glandular stomach compartments of merino sheep during development. The mechanical protection showed by the tegumentary epithelium in the superficial layers of the rumen, reticulum and omasum is supported by a buffer system of neutral mucopolysaccharides secreted by the deeper strata. Neutral mucopolysaccharides first appeared in epithelial cells at 46 days of fetal life. Acid mucopolysaccharides, mucins, and mucoid compounds were not detected. Growth curves and formulas were constructed for the epithelial layers.

Prenatal development of the sheep pineal gland: an ultrastructural study

The ultrastructure of the pineal gland of 32 sheep embryos was studied from day 54 of development through birth. Embryos were arranged in four age-groups, defined in terms of the most relevant histological features: group 1 (54 to 67 days of prenatal development), group 2 (71 to 92 days), group 3 (98 to 113 days), and group 4 (118 to 150 days). A primary cell type, designated the pinealoblast, was observed from 54 days until birth; ultrastructurally, this cell was found to contain all the organelles required for hormone synthesis. A second cell population, classified as interstitial cells by virtue of their location among pinealoblasts, appeared at 78 days gestation and persisted until birth. Interstitial cells were scarce and exhibited tropism for the perivascular space. From 118 days gestation until birth, a third cell type, termed the pigmented cell, was visible. Pigmented cells, whose ultrastructural characteristics differed from those of pinealoblasts, contained a large number of pigment granules of varying size and shape. The pineal gland of developing sheep embryos showed considerable innervation and abundant vascularization; this, together with certain ultrastructural characteristics, suggests that the gland has a secretory function in uterine life.

Central venous catheter infections in AIDS patients receiving daily home therapy for cytomegalovirus disease

We studied the infection rate of long-term intravenous access used for daily home treatment of cytomegalovirus (CMV) disease in 61 AIDS patients who had 75 central venous catheters implanted for antiviral maintenance therapy between February 1989 and December 1994. In 39 patients (64%) the risk factor for AIDS was intravenous drug abuse. Sixty-three catheters were Hickman type and 12 were totally implanted ports. The cumulative follow-up time was 19000 catheter-days (52 patient-years), with median duration of placement of 249 days. The infection rate was 0.22 infections per 100 catheter days. The probability of remaining free of catheter-related sepsis was 58% at 6 months. In 25 cases (61%) antimicrobial therapy without catheter removal was successful. Three patients died because of a catheter-related infection (mortality rate 7.3%). Infection-free survival time was not related to the risk factor for AIDS (p = 0.44) or type of device (p = 0.41). The total infection rate in these patients receiving daily home maintenance therapy for CMV disease through a long-term catheter was similar to that in other AIDS patients receiving weekly treatment in hospital facilities.

Pathological study of experimentally induced bovine respiratory syncytial viral infection in lambs

An experimental model was designed to characterize lesions in the lung of lambs inoculated with bovine respiratory syncytial virus (BRSV). Twenty-five Merino lambs of both sexes, with a live weight of 17 +/- 3 kg, received an intratracheal inoculation of 20 ml saline solution containing 1.26 x 10(6) TCID50 BRSV (strain NMK-7) per ml. Lambs were slaughtered 1, 3, 7, 11 and 15 days postinoculation (DPI), and samples were taken for analysis using light-microscopic and immunohistochemical techniques. The results reflected the effect of the virus on airway epithelia. The presence of BRSV in ciliated bronchial and bronchiolar epithelial cells gave rise to cytopathological changes, including loss of cilia and cell necrosis; these changes might be expected to decrease the efficiency of mucociliary clearance, favouring the development of secondary bacterial bronchopneumonia. These results suggest a reduction in BRSV tropism for alveolar epithelia compared to bronchial and bronchiolar epithelia. Light-microscopic analysis revealed a narrowing of alveolar and airway lumina and a considerable interstitial inflammatory reaction.

Lesions in lambs experimentally infected with bovine respiratory syncytial virus

An experimental model was designed to characterize lesions in the lung of lambs inoculated with bovine respiratory syncytial virus (BRSV). 25 Merino lambs of both sexes, with a live weight of 17 +/- 3 Kg, received an intratracheal inoculation of 20 ml saline solution containing 1.26 x 10(6) TCID50 BRSV (strain NMK-7) per ml. Lambs were slaughtered 1, 3, 7, 11 and 15 postinoculation days (PID), and histopathological, immunohistochemical and electron microscopic studies were performed. Results reflected a series of lesions, the most noteworthy of which were bronchiolitis obliterants with destruction of the mucociliary apparatus, the presence of syncytial cells in alveoli and a progressive interstitial reaction. BRSV antigen was detected in lung samples. These changes might be expected to decrease the efficiency of respiratory tract defence mechanisms, rendering the lung parenchyma susceptible to opportunist bacterial infection.

Spontaneous bovine respiratory syncytial virus infection in goats: pathological findings

This paper presents the results of a study of eight cases of natural bovine respiratory syncytial virus (BRSV) infection in a herd of 50 Murciana kids from a intensive goat-farm in Spain. Clinical and pathological analysis confirmed the existence of natural BRSV infection in eight kids. In two of the eight animals there was also evidence of concurrent infection with P. haemolytica A.

The immunologic response to experimental infection with bovine respiratory syncytial virus in lambs

An experimental model was designed to study the humoral immune response in lambs experimentally infected with bovine respiratory syncytial virus (BRSV), 25 Merino lambs of both sexes, with a live weight of 17 +/- 3 kg, received an intratracheal inoculation of 20 ml. saline solution containing 1.26 x 10(6) TCID50 BRSV (strain NMK-7) per ml. Blood samples for serological analysis were collected from the jugular vein of the animals on days 0, 1, 3, 5, 7, 9, 11 and 15 post inoculation. Serum proteins were determined by electrophoresis, and a qualitative and quantitative analysis of immunoglobulins (Ig) was carried out using immunoelectrophoresis (IE) and light nephelometry, respectively. Serum anti-BRSV antibody levels were tested by enzyme-linked immunoabsorbent assay (ELISA). Lambs were necropsied 1, 3, 7, 11 and 15 postinoculation days (p.i.d.), and samples were taken for immunohistochemical analysis. IgA, IgG and IgM were labelled on paraffin-embedded lung sections using an avidin-biotin-peroxidase complex. Results reflected an increase in gamma fractions in experimental animals with respect to controls. IE analysis of these sera revealed a polyclonal increase in immunoglobulins. Nephelometric examination showed an increase in serum IgA, IgG an IgM levels up to 7 p.i.d., coinciding closely with high titres for humoral virus antibodies. After 9 p.i.d., titres and immunoglobulin levels both fell. Immunoglobulin labelling in formol-fixed and paraffin-embedded lung tissue samples detected IgG and IgA, mainly in bronchial, bronchiolar and alveolar epithelia. IgM, however, was not detected in the lungs of infected animals.

A new technique for accessing the cerebral ventricles of the horse

A technique is described for catheterisation of the ventricular recess within the olfactory bulb of the horse. Twelve adult horses were used. The olfactory recess is in the frontal region, 42 +/- 3 mm below the skin, on the line joining the supraorbital foramina, and approximately 18 +/- 2 mm from the midline. The approach is relatively easy under normal experimental conditions.

Histomorphometric analysis of the omasum of sheep during development

Histomorphometric and scanning electron microscopic analyses were performed on 74 embryos and fetuses and 20 sheep (early postnatal to adult age). Histologic differentiation of the omasum took place at 33 days of fetal life, with the appearance of first-order laminae. Second-, third-, and fourth-order laminae appeared at 39, 50, and 59 days, respectively. Neutral mucopolysaccharides first appeared in epithelial cells at 46 days of fetal life, decreasing quantitatively until birth, before subsequently stabilizing in postnatal life. Acid mucopolysaccharides, mucins, and mucoid compounds were not detected. Growth curves and formulas were constructed for each tissue layer. Initial tests involved multiplicative (y = axb), exponential (y = EXP [a + bx]), linear (y = a + bx), and polynomial models (y = a + bx + cx2 + dx3).

Histomorphometric analysis of the reticulum of the sheep during development

Histomorphometric and scanning electron microscopic analysis were performed on 74 embryos and foetuses and on 20 sheep (early post-natal to adult age). Histodifferentiation of the reticulum took place at 33 days of foetal life. Reticular ribs were observed as evaginations of the epithelial stratum germinativum at 64 days. Neutral mucopolysaccharides first appeared in epithelial cells at 46 foetal days, thereafter to decrease gradually in number, subsequently stabilising in postnatal life. Acid mucopolysaccharides, mucins and mucoid compounds were not detected. Growth curves and formulae were constructed for each tissue layer. Initial test involved multiplicative (y = axb), linear (y = a+bx) and polynomial model (y = a+b+cx2+dx3).

Histomorphometric analysis of the abomasum of the sheep during development

Histomorphometric analyses were carried out on 64 embryos and fetuses and on 20 sheep (early postnatal to adult age). Histodifferentiation of the abomasum took place at 33 days of fetal life, with the appearance of abomasal villi at 53 days. By 64 fetal days, the epithelium had changed from pseudostratified to simple mucous cylindrical. Acidic glycoproteins appeared at 46 fetal days. Neutral glycoproteins did not appear until later stages of development, near birth. We believe that the configuration of a simple epithelium with acidic secretion is enhanced at birth by the secretion of neutral glycoproteins which act as a buffer against acidic substances, and particularly against the abomasal acidity during lactation. Growth curves and formulae were set out for each tissue layer.

[Thyroid lymphoma in a 51-year-old woman]

Thyroid gland is an uncommon site for involvement by lymphoma. Because of the lack of specific histopathologic criteria for diagnosis, thyroid lymphomas are not usually diagnosed until a thyroidectomy is done, even when a fine-needle aspiration biopsy is performed before surgery. We report the case of a woman with a non-Hodgkin lymphoma presenting as thyroid enlargement with systemic manifestations of the disease. The preoperative histologic diagnosis was poorly differentiated thyroid carcinoma. If the lymphoma was primarily thyroid or the involvement of thyroid was a part of the generalized dissemination of a nodal non-Hodgkin lymphoma is difficult to establish. She was treated with a combination of surgery and chemotherapy with excellent outcome. We comment the problems in the diagnosis of this disease.

Changes in the coxofemoral articular cartilage in Wistar rats after systemic administration of corticoids

A structural, ultrastructural and morphometric study of the coxofemoral articular cartilage of 48 Wistar rats was carried out after daily intramuscular injections of 2.5 mg prednisolone. The animals were divided into four groups, members of which were killed 15, 30, 60 and 90 days respectively after the start of the experiment. A degenerative process developed in the experimental animals, which led progressively to the death of chondrocytes in the middle zone of the articular cartilage after 90 days. Structural, ultrastructural and morphometric alterations were observed, both in cells and in the cartilage matrix. These gave rise to superficial changes in the femoral head.

Experimental reproduction of acute pneumonic pasteurellosis in rabbits

A histomorphometric and physiopathological study was made of the lung parenchyma of Belgian White SPF rabbits infected experimentally with Pasteurella multocida type A. Symptoms observed were characteristic of the acute respiratory syndrome. Mean serum cortisol concentration and rectal temperature increased in all experimental groups. Histopathological changes included alveolitis and leukocytic bronchitis. Changes in alveolar and bronchial cytoarchitecture were attributed to the degeneration and necrosis of constituent epithelial cells.

Pathological changes in kidneys of dogs with natural Leishmania infection

A study was made of the nephropathy in canine leishmaniasis produced in ten adult dogs naturally infected with Leishmania infantum. Renal function analyses were performed (uraemia, creatinaemia, plasma proteins, biochemistry and urinary sediment), the humoral immune response (fluorescent antibodies and levels of serum IgG, IgM and IgA) was assessed and histopathological studies were carried out. Correlation of the results showed acute renal insufficiency which was reversible in two animals (endotheliomesangial glomerulonephritis) and irreversible in four cases corresponding to glomerulonephritis in its Type I and Type II proliferative forms; extensive increase in the glomerular basal membrane, proliferation of mesangial cells and growth of the mesangial matrix were observed, as was a widespread incidence of immune complex deposits. Two animals showed chronic renal insufficiency. Lack of renal changes (minimal-changes glomerulonephritis) in two dogs was accounted for in one animal by an almost complete absence of symptoms and in the other by chronic viscerocutaneous symptoms; neither showed more than a slight immunoglobulin response.

Adenocarcinoma of the ethmoid olfactory mucosa: a histopathological and ultrastructural study with evidence of virus-like particles

A histopathological, morphometric and ultrastructural study was made of enzootic nasal neoplasia in a group of 25 Verata goats. A nasal adenocarcinoma was diagnosed. The neoplasm contained two clearly defined zones, one cystic and the other compact. The tumour stroma was composed of abundant loose connective tissue, in which mononuclear infiltrate was clearly identifiable. The observed viral particles were morphologically similar to Visna-Maedi. These particles had an eccentrically located electrodense core. The diameter of the virus was about 90 nm and it showed envelope numerous spikes on the surface. The virus is assumed to be the causative primary agent of the tumour.

Linear unilateral basaloid follicular hamartoma

A 36-year-old woman with a linear and unilateral cutaneous hamartoma is described. The lesions consisted of hypopigmented macules that coalesced into a linear plaque that involved only the left side of her body. Within this plaque were several pearly papules and an ulcerated area that clinically resembled basal cell carcinomas. Histologic features of the hypopigmented linear plaque included multiple and multifocal basaloid proliferations in the papillary and mid dermis. The isolated pearly papules showed the typical findings of basal cell carcinoma.

Histomorphometric analysis of the rumen of sheep during development

Histomorphometric and scanning electron microscopic analyses were carried out on 74 embryos and fetuses and 20 sheep (early postnatal to adult age). Histodifferentiation of the rumen took place at 33 days of fetal life. Ruminal pillars were observed at 42 days, and at 61 days, ruminal papillae appeared as evaginations of the epithelial stratum basale. Neutral mucopolysaccharides first appeared in epithelial cells at 46 days of fetal life; thereafter, numbers decreased gradually and subsequently stabilized in postnatal life. Acid mucopolysaccharides, mucins, and mucoid compounds were not detected. Age and diet were recognized as factors that determine the structure of the ruminal mucosa. Growth curves and formulas were set out for each tissue layer.

[Primary neuroendocrine carcinoma of the pavilion of the ear]

We present a case of primary neuroendocrine carcinoma (Merkel cell carcinoma) of the external ear and its treatment. This paper also deals with histogenesis, pathology, clinical findings, diagnosis and treatment of this tumor.

[Warthin's tumor: clinical aspects and a cytological study using fine-needle puncture-aspiration in 16 cases]

The clinical and fine-needle cytologic findings of 16 Warthin's tumors (papillary cystadenoma lymphomatosum) are presented. They were studied during a period of 38 months, between February 1987 and April 1990. A preoperative diagnosis of "Warthin's tumor" was made in 13 cases (80%); 3 cases were diagnosed as non neoplastic benign lesions (2 retention cysts and 1 chronic sialoadenitis). 10 cases were surgically excised and preoperative diagnosis was histologically confirmed. We compare the cytologic findings of our cases with the literature ones.

Histopathological changes in sheep experimentally infected with Babesia ovis

Histopathological study was made of 12 Merino sheep - five splenectomized and seven intact - experimentally infected with Babesia ovis. Non-purulent encephalitis; initially exudative and subsequently interstitial pneumonia; pericarditis, myocarditis and haemorrhagic endocarditis; centrilobular necrotic hepatitis; hyperplasia of the lymphoreticular system; necrosis and vascular changes in adrenal glands were observed. The kidney was the most severely affected organ, exhibiting acute tubular necrosis typical of kidney shock syndrome. The lesions observed were suggestive of hypovolemic shock culminating in haemorrhagic diathesis owing to consumptive coagulopathy. Additionally, the massive release of catabolites from lysis and necrosis apparently produced endotoxic shock.

[Needle biopsy of pancreatic masses]

We report the results of 66 ultrasound or CT guided needle aspirations in 59 patients with pancreatic masses, from 1983 to 1987. Cytologic and histologic samples were obtained in 45 cases. Histologic samples, formed by minute tissue fragments, were paraffin embedded for standard sections (minibiopsy). Sensitivity, specificity and overall accuracy of the series as a whole were 88, 100 and 89.8%, respectively. We discuss the clinical usefulness of the technique; isolated cytologic and histologic results are compared and the minibiopsy contribution to the cytologic diagnosis is discussed.

Experimental lead nitrate poisoning: microscopic and ultrastructural study of the gills of tench (Tinca tinca, L.)

A microscopic, ultrastructural, and morphometric study was made of the gills of tench (Tinca tinca, L.) subjected to acute experimental lead nitrate poisoning. Twenty-one adult tench were subjected to poisoning and a further 22 were used as controls. Lesions were characterized by the appearance of edema and epithelial hyperplasia and necrosis, both in cells forming part of the filtration barrier and in those in the interlamellar space. These processes developed in the course of the experiment, leading to the death of tench after 12 to 15 days of exposure to 75 ppm lead nitrate, at which point the concentrations of lead in the gills had reached their maximum.

Structural and ultrastructural differentiation of cell types in the gills of the tench (Tinca tinca, L.)

This study used 22 tench of 25-30 cm in length and weighing roughly 200 g. After sacrifice, the gill arch was extracted and fixed in 5% glutaraldehyde for structural, ultrastructural and morphometrical study. Tench gills consist of primary lamellae which are perpendicular to numerous secondary lamellae in which the respiratory barrier is located. A study was made of the structures which make up that barrier and of the multi-layered epithelium situated in the interlamellar space, which is closely linked to maintaining of internal balance in the fish.

[Carcinoma arising in thyroglossal duct cyst: presentation of a new case and review of the literature]

Carcinoma arising in thyroglossal duct remnants is a rare even that appears in about 1% of all surgically treated cases. A survey of the literature reveals more than 100 reported cases. We present a new case of malignant transformation of thyroid remnants in thyroglossal duct cyst wall: a non invasive papillary carcinoma. Local resection by the Sistrunk method, without any other treatment, was considered curative. We also review the available literature regarding this entity.

Glomerular filtration barrier in experimental endotoxin shock: a histopathological and physiopathological study

In the present work a morphopathological study is carried out of the glomerular filtration barrier in 20 Large-White pigs weighing 20 kg, subjected to experimental intravenous inoculations of endotoxin from Salmonella enteritidis. The study is completed with the determination of protein plasmatic levels, through urine test with the determination of pH, density, proteins, glucose, ketone body levels and urinary sediment. The histopathological and physiopathological results reveal alterations at the level of the filtration barrier with quantitative differences between the different experimental groups.

A histopathological and morphometrical study of femur head cartilage in Wistar rats treated with prednisolone

An analysis was made of histopathological developments in femur head cartilage in a group of Wistar rats receiving a daily intra-muscular injection of 2.5 mg prednisolone. This group was divided into four experimental batches, each consisting of 6 rats. Batches were sacrificed at 15, 30, 60 and 90 days after the start of the experiment. Degeneration of the femur head cartilage was observed from the start of the experiment (15 days), and gave rise to chondrocyte necrosis by 90 days. Structural modifications are shown morphologically and morphometrically.

Paratesticular metastases from congenital retroperitoneal tumor

A retroperitoneal tumor was removed from a fifteen-day-old infant. Light microscopy revealed a teratoma consisting mainly of immature nervous tissue. Three months later the patient had recurrence and numerous peritoneal metastases showing a histologic pattern similar to that of the primary tumor. Twelve months later there was enlargement of the left testis due to metastases from teratoma infiltrating the tunica vaginalis of the left testis, the epididymis, and the spermatic cord. These metastases consisted of mature neurons and glial cells. The early dissemination of the tumor suggests an intracavitary spread pattern. The tumor maturation in paratesticular structures suggests that mesothelial cells are involved in the differentiation of tumoral germ cells.

Juvenile granulosa cell tumor of the testis

Juvenile granulosa cell tumor occurred in a newborn. The tumor presented with testicular torsion, and no malformations were observed. The karyotype was normal. The occurrence of initial tumoral lesions in the seminiferous tubules located in the vicinity of the tumor suggests that the tumor originated from immature Sertoli's cells. To our knowledge, this is the tenth case reported in a newborn and the second associated with testicular torsion.

Glomerular histopathology of the contralateral kidney in experimental unilateral hydronephrosis

The aim of this study was to examine the structural, ultrastructural and morphometric alterations which take place in the contralateral kidneys of rats with experimental unilateral hydronephrosis. 20 Wistar rats weighing 250 g., affected by a process of unilateral hydronephrosis following the ligature of the ureter, were used; these rats were then killed 40, 50, 60, or 70 days after the ligature. Among the perceived alterations, were immunoglobulin G deposits shown by positive immunoperoxidase reaction and increase in the size of the glomerular and corpuscle from around the fortieth day, and structural alterations that included the pedicles, electrondense deposits in the podocytes and pseudogranular structures in the basal membrane of the capillary.

Tubular embryonal remnants in the human spermatic cord

The spermatic cords (SCs) obtained from: (a) autopsies of 67 adults and 50 children; (b) 3 fetuses; (c) 12 surgical specimens from 9 adults and 3 children with testicular tumors, and (d) 26 surgical specimens (14 adults and 12 children) with diagnosis of SC cysts, were studied by light microscopy. The histological study revealed the occurrence of tubular embryonal remnants (TERs) in 19 autopsied adults, 14 autopsied children, 3 fetuses, 2 surgical specimens (1 adult and 1 child) owing to testicular tumors, and 6 surgical specimens with diagnosis of SC cysts. The TERs were found in the low, middle or high thirds of the SC and consisted of a cuboidal or columnar, often ciliated epithelium surrounded by connective tissue. In the 3 fetuses and in 3 autopsied children renal glomeruli were found in close relation with the TERs. In 2 cases of SCs showing cysts and TERs both structures contained spermatozoa. The histological pattern of the TERs suggest that they are wolffian derivatives which might give rise to SC cysts.

[Anderson's disease. Apropos of a new case]

A new case of Anderson's disease in a 3-month-old black female infant is presented. This diagnosis should be considered in infants with chronic diarrhoea, fatty stools, failure to gain weight which may be present from birth, low serum cholesterol concentration (less than 70 mg/ml), low plasma triglyceride levels, and hypobetalipoproteinaemia. However, suspicion of diagnosis clinically can be certainly verified by intestinal biopsy showing characteristic epithelial cell pattern. Steatorrhoea may be effectively treated by substituting medium for long-chain triglycerides in the diet. This disorder needs to be distinguished from familial hypobetalipoproteinaemia as well as abetalipoproteinaemia, and it prognosis is good, because of absence of acanthocytosis, neurological involvement and ocular lesions.

Cystic intra-abdominal testicular torsion in an infant

We report on a 3-month-old infant with cystic intra-abdominal testicular torsion. He presented with abdominal distension and pain. Physical examination showed a movable, well delineated mass in the right iliac and lumbar fossae. Exploration revealed that the mass was connected to the abdominal aorta by a thin vascular cord that was twisted before reaching the mass. The histological study showed that the mass corresponded to a testis with cystic formations. The testicular parenchyma was necrotized, although isolated seminiferous tubules were found. The cystic cavities were filled by hematic and necrotic material, and exhibited no epithelial lining. A fibrous layer in continuity with interstitial hemorrhage surrounded the cysts. The twisted vascular cord corresponded to a spermatic cord with dilated pampiniform plexus veins. The differential diagnosis and the etiopathogenesis of the lesion are discussed.