PubMed Health⌕ Search

Biomedical subjects

P S Amenta

Publications and source records attributed to P S Amenta.

At least 19 recordsLinked to original sources
PubMed1992

Implications for the pathogenesis of aneurysm formation: metastatic choriocarcinoma with spontaneous splenic rupture. Case report and a review.

We report a case of ruptured intracranial aneurysm from metastatic choriocarcinoma in a patient presenting with intracerebral hemorrhage. Operative evacuation of the hematoma with clipping of a distal right middle cerebral artery aneurysm was performed. Postoperatively, the patient developed hypovolemic shock from spontaneous splenic rupture. Histopathologic examination of the cerebral aneurysm showed choriocarcinoma invading the vessel wall. Metastatic choriocarcinoma should be considered in the differential diagnosis of intracerebral or subarachnoid hemorrhage in women of child-bearing age.

Adult↗
PubMed1992

Ontogenesis of the murine hepatic extracellular matrix: an immunohistochemical study.

To define the role of the extracellular matrix (ECM) in hepatogenesis, we examined the temporal and spatial deposition of fibronectin, laminin and collagen types I and IV in 12.5-21.5 day fetal and 1, 7 and 14 day postnatal rat livers. In early fetal liver, discontinuous deposits of the four ECM components studied were present in the perisinusoidal space, with laminin being the most prevalent. All basement membrane zones contained collagen type IV and laminin, including those of the capsule (mesothelial), portal vein radicles and bile ductules. Fibronectin had a distribution similar to that of collagen type IV early in gestation. However, at later gestational dates, fibronectin distribution in the portal triads approached that of collagen type I, being present in the interstitial connective tissues; whereas, collagen type IV and laminin were restricted to vascular and biliary basement membrane zones in those regions. The cytoplasm of some sinusoidal lining cells and hepatocytes reacted with antibodies to extracellular matrix components. By electron microscopy the immunoreactive material was localized in the endoplasmic reticulum, indicating the ability of these cells to synthesize these ECM proteins. Biliary ductular cells had prominent intracytoplasmic staining for laminin and collagen type IV from day 19.5 gestation until 7 days of postnatal life, but lacked demonstrable fibronectin or collagen type I. These results demonstrate that by 12.5 days of gestation the rat liver anlage has deposited a complex extracellular matrix in the perisinusoidal space. The prevalence of laminin in the developing hepatic lobules suggests a possible role for this glycoprotein in hepatic morphogenesis. In view of the intimate association of the hepatic lobular extracellular matrix with the developing vasculature, we hypothesize that laminin provides a scaffold of the developing liver, but once the ontogenesis is complete, intrahepatic perisinusoidal laminin expression is suppressed.

Animals↗
PubMed1992

Choriocarcinoma of the kidney.

Choriocarcinoma is a malignant germ cell tumor that usually arises from a previous gestation, but may also arise from germ cells anywhere along their known migratory pathway during fetal development. Gestational choriocarcinoma is highly sensitive to chemotherapy. This malignancy is known to undergo spontaneous regression of the primary tumor, which, in the face of metastases, may obscure the primary tumor site. The authors report the case of a patient with choriocarcinoma who was seen with pulmonary metastases and a single large lesion in the kidney 5 years posthysterectomy. The problems in resolving the primary site and the importance of a tissue diagnosis before nephrectomy are discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

The substitution of arginine for glycine 85 of the alpha 1(I) procollagen chain results in mild osteogenesis imperfecta. The mutation provides direct evidence for three discrete domains of cooperative melting of intact type I collagen.

We report a case of mild osteogenesis imperfecta in a 56-year-old male undergoing aortic valve replacement surgery. The primary defect in this patient was the substitution of arginine for glycine 85 in one of the two chains of alpha 1(I) procollagen. The thermal stability of the type I collagen synthesized by the patient's cultured skin fibroblasts was examined by enzymatic digestion. Digestion of the mutant type I collagen with trypsin and chymotrypsin at increasing temperatures sequentially generated three discrete collagenous fragments, approximately 90, 170, and 230 amino acids shorter than normal type I collagen. This incremental thermal denaturation is indicative of cooperative melting blocks within the type I collagen. This is the first demonstration of such cooperative blocks of melting in intact, essentially normal post-translationally modified type I collagen. This direct evidence for cooperative melting domains of uncut type I collagen suggests that discrete blocks of amino acids function as core sites stabilizing the collagen helix. The location of mutations of the alpha chains of type I collagen relative to these discrete blocks of amino acids may influence the severity of the disease phenotype.

Amino Acid Sequence↗
PubMed1991

Successful treatment of lupus nephritis in MRL-lpr/lpr mice by inhibiting ornithine decarboxylase.

Ornithine decarboxylase (ODC) is a key enzyme in the biosynthesis of cellular polyamines, putrescine, spermidine and spermine. Difluoromethylornithine (DFMO) is an irreversible inhibitor of ODC and thereby depletes putrescine and spermidine levels in vivo and in vitro. Previous studies in lupus-prone MRL-lpr/lpr mice treated with 1% DFMO in drinking water have been associated with improved lifespan, and reduced anti-DNA antibody production, lymphadenopathy, and splenic polyamine levels. Since glomerulonephritis is a major cause of morbidity and mortality in lupus, we studied the effect of DFMO on renal histology of MRL-lpr/lpr mice. Female BALB/c and MRL-(+)/+ mice were used as controls. Dose response studies revealed that 1.5% DFMO in drinking water had maximum therapeutic efficacy and produced a significant 79% increase in the median lifespan of a group of 20 mice compared to an equal number of controls (P less than 0.001). Renal histologic studies were performed on kidney sections from four to five mice each from DFMO-treated and untreated groups at 12, 16, 20, 24 and 29 weeks of age. Sections were read blinded to duration and treatment and scored by four major histologic criteria (glomerulonephritis, interstitial inflammation, perivascular inflammation, and vasculitis) and showed significant reduction in all these parameters in DFMO-treated mice when compared to age- and sex-matched untreated mice of the same strain. DFMO treatment had no significant effect on pulmonary histologic findings on these mice. DFMO treatment reduced ODC activity and polyamine concentrations in treated mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

The radiologic diagnosis of Barrett esophagus: importance of mucosal surface abnormalities on air-contrast barium studies.

Patients with Barrett esophagus are predisposed to the development of esophageal adenocarcinoma. Identification of these patients before this complication develops is essential. We prospectively made the diagnosis of Barrett esophagus on routine biphasic upper gastrointestinal series in nine patients in whom a mucosal surface pattern alteration was the only radiologic abnormality on the esophagogram. The diagnosis was confirmed by biopsy in eight patients and during surgery in one patient. Only a third of the patients had symptoms related to the esophagus. Two types of surface changes were noted. A reticular pattern was present in six cases and a villous pattern in five cases. Both patterns were noted in two patients. This series was obtained in a 5-year interval during which there were 15 additional patients with Barrett esophagus and corresponding esophagograms. None of these patients had normal results on esophagograms. Recognition of these subtle surface patterns, particularly in the absence of other reflux-induced abnormalities, may improve detection of Barrett esophagus and aid in the selection of patients for subsequent surveillance.

Barium Sulfate↗
PubMed1991

The extracellular matrix in hepatic regeneration. Localization of collagen types I, III, IV, laminin, and fibronectin.

After partial hepatectomy, the liver is capable of complete regeneration, restoring normal hepatic size, architecture, and function. To study the role of the extracellular matrix in regeneration, the temporal and spatial sequence of deposition of several of its components, including collagen types I, III, and IV, laminin, and fibronectin, in rat liver, after an 80% hepatectomy, was characterized by light microscopy immunohistochemistry. A minimum of five animals were studied for each date. In agreement with previous reports, subsequent to 80% hepatectomy, there was a brisk mitosis of hepatocytes. The mitotic activity was maximal at 48 hours, primarily in the periportal and centrilobular zones, and resulted in the formation of hepatocyte clusters and widening of the hepatic plates. Of the extracellular matrix components studied, laminin was the one demonstrating the most dramatic changes. By 24 hours, laminin appeared in the hepatic sinusoids reaching a maximum staining intensity at 48 hours. Intracellular laminin was prominent in numerous non-parenchymal cells, with many having the morphology, location, and desmin content characteristic of Ito cells. Laminin staining decreased in the sinusoids at 4 days; however, some intracellular staining of Ito cells was present even at 8 days after hepatectomy. At the completion of regeneration, there was no evidence of any substantial change in the ratio: extracellular matrix/cell mass. The results indicate that: (a) hepatocytes can divide without prior removal of the subsinusoidal extracellular matrix; (b) during regeneration, hepatocyte division precedes sinusoidal formation; (c) during hepatic regeneration, and in spite of the presence of laminin in Ito cells, no basement membranes are formed; (d) the prominent expression of laminin and its proposed functions in morphogenesis suggest a critical role for this matrix component in the formation and reorganization of the regenerating liver.

Animals↗
PubMed1990

Giant hyperplastic polyps of the gastric remnant simulating carcinoma.

Large hyperplastic polyps of the gastric remnant were detected in 2 male patients who had undergone Billroth II gastrojejunostomy for peptic ulcer disease 13 and 18 years earlier. Both patients presented with iron deficiency anemia due to chronic occult gastrointestinal bleeding. The clinical and radiographic findings were initially suggestive of gastric stump malignancy, and one of the resected hyperplastic polyps contained foci of carcinoma in situ. We illustrate the radiographic and pathologic features of these lesions together with a review of the pertinent literature.

Aged↗
PubMed1990

Vulvar epithelioid sarcoma metastatic to the scalp. A case report and review of the literature.

We report a case of vulvar epithelioid sarcoma with metastases to the scalp, an inguinal lymph node, lungs, liver, and kidneys. Epithelioid sarcoma typically involves the extremities of young men and may be confused histologically with various benign and malignant processes. Only five cases of primary vulvar epithelioid sarcoma have been previously reported. The present case represents the first report of cutaneous metastases from this primary site. We also review the literature pertaining to the clinical, pathologic, and immunohistochemical features of this rare tumor.

Female↗
PubMed1990

An unusual extramedullary relapse of acute nonlymphocytic leukemia after allogeneic bone marrow transplantation.

Recurrent leukemia following allogeneic bone marrow transplantation (BMT) for acute nonlymphocytic leukemia (ANLL) continues to be a cause of morbidity and mortality. Most relapses occur within the first 6-12 months, although disease-free survival curves do not begin to plateau until 24 months posttransplant. The majority of relapses occur in the bone marrow. Extramedullary relapses usually occur in "sequestered sites," i.e., the testis and central nervous system. Although the true incidence of extramedullary relapse in "nonsequestered" sites after allogeneic BMT for ANLL is unknown, it appears that this type of relapse is distinctly unusual. The authors present a case of an unusual extramedullary relapse of ANLL in the breast at day +613 after allogeneic BMT for ANLL. In addition, we briefly review the English BMT literature and discuss the differential diagnosis of breast masses in women who survive allogeneic BMT for ANLL.

Adult↗
PubMed1989

Cerebral Pseudallescheria boydii infection: unique occurrence of fungus ball formation in the brain.

Pseudallescheria (Petriellidium) boydii is the most frequent etiologic agent of mycetoma in temperate regions of the world. In addition, it may also occur as a systemic infection in immunocompromised patients. Infection of the central nervous system is rare, and only eleven cases of Pseudallescheria brain abscess have been documented. We report a leukemic patient in whom disseminated pseudallescheriasis was diagnosed only after death. This case is unique in that a white matter cavitation was present containing a fungoma of Pseudallescheria, the first report of a cerebral fungus ball caused by this organism. The previous cases of Pseudallescheria brain abscess are reviewed, and the histopathologic features of Pseudallescheria which permit its differentiation from Aspergillus and other fungi are discussed.

Adult↗
PubMed1989

Concurrent focal segmental glomerulosclerosis and membranous nephropathy.

Focal segmental glomerulosclerosis and membranous glomerulonephropathy are two entities that may result in the nephrotic syndrome. Two young women exhibited concurrent focal segmental glomerulosclerosis and focal segmental membranous nephropathy on renal biopsy. Although the lesions were severe, both patients had asymptomatic proteinuria, normal renal function, and a benign clinical course. The concurrence of these glomerulopathies may portend a more benign clinical course than expected for a patient presenting with either lesion alone.

Adult↗
PubMed1988

Comparative ultrastructural localization of collagen types III, IV, VI and laminin in rat uterus and kidney.

Antibodies against collagen types III and VI have been localized by electron immunohistochemistry with two different techniques in normal rat uterus and kidney. Antibodies directed against two components of the extracellular matrix with known localization, laminin and type IV collagen, were used as controls for the specificity of the localization. The results demonstrate that types III and VI are found in the interstitium as fine (10- to 15-nm), beaded fibrils and filaments (6- to 10-nm), respectively. Both are often found associated with thick, crossbanded type I collagen fibers (30- to 35-nm) and occasionally associated with some basement membranes adjacent to the interstitium. Further, the findings suggest that collagens III and VI may connect the various components of the extracellular matrix, such as type I fibers with basement membranes and other structures, thus forming an integrated functional unit.

Animals↗
PubMed1988

Characterization of a renal tubular epithelial cell line which secretes the autologous target antigen of autoimmune experimental interstitial nephritis.

Proximal tubular epithelial cells from mice which develop autoimmune interstitial nephritis were found to express the nephritogenic target antigen, 3M-1. Anti-3M-1 mAbs (alpha 3M-1-Ab) were used to positively select for 3M-1-secreting tubular epithelium and, after stabilization in culture, this new cell line (MCT) was examined for the production of several moieties important to either immune interactions or to the development of extracellular matrix. Alkaline phosphatase-staining MCT cells also express epithelial growth factor receptors with a Kd of 0.87 nM and an epithelial growth factor receptor constant (Ro) of 2.1 X 10(4) receptors/cell. MCT culture supernatants contain greater amounts of laminin, and types IV and V procollagens compared to types I and III procollagens, and growing MCT cells on type I collagen matrix causes them to preferentially secrete even more type IV and V procollagen. The 30,000-Mr 3M-1 antigen could be immunoprecipitated from biosynthetically labeled MCT cell supernatants with alpha 3M-1-Ab. An identical-sized moiety was isolated by immunoaffinity chromatography from collagenase-solubilized mouse kidney tubular basement membranes. The 3M-1 antigen can be found on the MCT cell surface by radioimmunoassay, or deposited in a linear array in the extracellular matrix surrounding the MCT cells in culture by immunofluorescence. Mature messenger RNA species for both class I and class II major histocompatibility complex (MHC) molecules were detected by Northern hybridization, and their corresponding cell surface gene products were detected by cytofluorography of MCT cells stained with haplotype-specific antibodies. Both the cell surface 3M-1 and the small amounts of detected class II MHC molecules appear to be biologically functional, as MCT cells can support the proliferation of 3M-1-specific, class II MHC-restricted helper T cells in culture. These findings suggest that MCT cells provide all the necessary biological parameters for interfacing both as the target of a nephritogenic immune response, and as a potential source for new extracellular matrix which develops as a fibrogenic response to interstitial nephritis.

Animals↗
PubMed1988

Connective tissue of rat lung. II: Ultrastructural localization of collagen types III, IV, and VI.

We localized collagen types III, IV, and VI in normal rat lung by light and electron immunohistochemistry. Type IV collagen was present in every basement membrane examined and was absent from all other structures. Although types III and VI had a similar distribution, being present in the interstitium of major airways, blood vessels, and alveolar septa, as in other organs, they had different morphologies. Type III collagen formed beaded fibers, 15-20 nm in diameter, whereas type VI collagen formed fine filaments, 5-10 nm in diameter. Both collagen types were found exclusively in the interstitium, often associated with thick (30-35 nm) cross-banded type I collagen fibers. Occasionally, type III fibers and type VI filaments could be found bridging from the interstitium to the adventitial aspect of some basement membranes. Furthermore, the association of collagen type VI with types I and III and basement membranes suggests that type VI may contribute to integration of the various components of the pulmonary extracellular matrix into a functional unit.

Animals↗
PubMed1987

Properties and purification of a colony-stimulating factor of granulocytes and macrophages produced by mouse spleen cells.

Mouse splenocytes are induced by pokeweed mitogen to secrete a factor that stimulates mouse hemopoetic (spelling per Nomina Histologica in the Nomina Anatomica, 5th edition, 1983, Williams and Wilkins, Baltimore) progenitor cells to undergo proliferation and differentiation into granulocytes and macrophages in a semi-solid culture system. The granulocyte and macrophage colony-stimulating factor (GM-CSF) was purified with a four-step procedure that includes ultrafiltration, chromatography on DEAE-agarose, Sephacryl S-200, and chromatofocusing gel. The isoelectric point (pI) of 4.2 of the GM-CSF was determined by analytical isoelectrofocusing gel electrophoresis. The sensitivity of the biological activity of GM-CSF to digestion by trypsin and neuraminidase suggests that GM-CSF is a glycoprotein with its sugar moieties at the active site. The GM-CSF is also sensitive to heat denaturation at 60 degrees C or higher suggesting that a three-dimensional conformation is required for its biological activity. The molecular weight of GM-CSF is approximately 57,000 Daltons as determined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate.

Animals↗