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Biomedical subjects

L D Mirkin

Publications and source records attributed to L D Mirkin.

At least 19 recordsLinked to original sources
PubMed2000

Mercaptoethylguanidine attenuates inflammation in bacterial meningitis in rabbits.

Reactive oxygen and nitrogen species participate in the inflammatory process during meningitis. Among them, superoxide, nitric oxide (NO), and their reaction product peroxynitrite exert cytotoxic effects. Mercaptoethylguanidine (MEG) exerts beneficial effects in in vivo inflammatory conditions by scavenging peroxynitrite and inhibiting the inducible NO synthase. This study was designed to investigate whether MEG may attenuate inflammation and brain injury in experimental meningitis. Meningitis increased nitrite/nitrate, and protein content in the cerebrospinal fluid (CSF). In the brain tissue high levels of malondialdehyde and formation of nitrotyrosine indicated lipid peroxidation and nitrosative stress, respectively. Myeloperoxidase activity was increased indicating accumulation of neutrophils into the brain parenchyma. Treatment with MEG decreased nitrite/nitrate levels whereas it did not affect the bacterial clearance from the CSF. Furthermore, treatment with MEG markedly reduced brain tissue levels of myeloperoxidase and malondialdehyde. These data demonstrate that MEG could have a therapeutic role in meningitis.

Animals↗
PubMed1999

Congenital subependymal giant-cell astrocytoma: case report with prenatal ultrasonogram.

BACKGROUND: A prenatal sonogram at 27 weeks of gestation revealed a brain mass along the frontal horn and body of the lateral ventricle near the foramen of Monro in the fetus. MATERIALS AND METHODS: A huge subependymal giant-cell astrocytoma was nearly totally resected at 11 days of age. RESULTS: There was no syndromic family history, but features substantiating the diagnosis of tuberous sclerosis were recognized at 4 years of age. CONCLUSION: The sonographic finding of a tumor in the region of the foramen of Monro should raise the suspicion of a subependymal giant-cell astrocytoma, a tumor characteristically associated with tuberous sclerosis.

Astrocytoma↗
PubMed1993

Intrauterine infarction of a pulmonary segment in a full-term newborn. A case report.

Intrauterine pulmonary infarction is extremely rare. In a series of 775 stillborn and newborn infants, only a few cases of acute pulmonary infarction were reported. The authors present the findings from a full-term infant who died at 9 hours of age of a chronic pulmonary infarction. Several pathogenic mechanisms, including the entry of placental thromboplastin into the fetal circulation, are discussed.

Fatal Outcome↗
PubMed1990

Extrarenal Wilms' tumor with cerebellar metastasis in a four-year-old girl with spina bifida.

This report documents the occurrence of an extrarenal nephroblastoma from which a cerebellar metastasis developed in a four-year-old girl with spina bifida. The second tumor became symptomatic two years after the resection of the primary, suggesting a treatment effect as a factor for the delay in the growing of the metastatic neoplasm. Histologic and ultrastructural features of the metastasis were similar to those described in Wilms' tumors of the kidney. The pathogenesis of this exceptional association, including malformation, malignancy, and unusual site of metastasis, is discussed.

Cerebellar Neoplasms↗
PubMed1990

Hyaline membranes in postmature infants.

Hyaline membranes in 21 of postmature infant autopsies were studied, using 27 term infant autopsies as the control population. The occurrence of hyaline membranes was much higher in postterm (86%) than term infant autopsies (26%). Seventeen of 21 postmature infants had clinical and microscopic evidence of aspiration, contaminated by meconium in 14, suggesting that meconium and/or amniotic aspiration may be an etiologic factor in postmature hyaline membrane formation. Thirteen infants had severe hyaline membrane formation, microscopically distinguishable from hyaline membrane disease of the premature only by the maturity of the underlying lung. Besides the pulmonary findings, little difference in organ histology was observed between the two groups. This study showed that hyaline membrane formation resulted in asphyxia and respiratory failure in the majority of the postmature infants who were already troubled with hypoxia and a combined respiratory and metabolic acidosis secondary to meconium aspiration, and eventually led to death.

Brain↗
PubMed1988

Nager acrofacial dysostosis: evidence for apparent heterogeneity.

Nager acrofacial dysostosis is characterized by malar, mandibular, and maxillary hypoplasia, macrostomia, abnormal ears, and radial defects. The lower limbs are usually normal. Two patients were reported with many of these manifestations, in addition to severe facial clefts and limb deficiency. These more severely affected patients were thought to have a severe form of Nager acrofacial dysostosis or a new syndrome. We report on a patient with limb findings of intermediate severity. This patient also had hydrocephalus, micropolygyria, and tetralogy of Fallot. This may indicate apparent heterogeneity or a single condition with widely variable expression.

Craniofacial Dysostosis↗
PubMed1988

Malignant renal rhabdoid tumour. Immunohistochemical and ultrastructural studies.

In an effort to establish their possible histogenesis, three cases of renal rhabdoid tumour and their metastases were studied both by a battery of polyclonal and monoclonal antibodies using the avidin-biotin-peroxidase complex technique and by electron microscopy. Vimentin was demonstrated in renal rhabdoid tumour in two cases and in all metastatic deposits. Cytokeratin (39, 43 and 50 kD) was not demonstrable in the three renal rhabdoid tumours, but was strongly positive in all metastatic lesions in one case. Epithelial membrane antigen was present in one renal rhabdoid tumour and in pulmonary metastases in two cases. Ultrastructural study showed epithelial differentiation in all tumours: basal lamina and convergent tight junctions were demonstrated; intracytoplasmic intermediate filaments were present in all primary and metastatic tumours. Rhabdoid tumours thus exhibited heterogeneous immunophenotypic expression suggesting that they are derived from mesenchymal cells which are capable of differentiating into epithelial cells.

Antibodies, Monoclonal↗
PubMed1988

Hepatic hemangioendothelioma of infancy associated with elevated alpha fetoprotein and catecholamine by-products.

Five cases of hepatic hemangioendothelioma (HH) were seen in infants ranging from 2 days to 5 months of age. The cases were studied by clinical chemistry, immunohistochemical staining, and electron microscopic techniques. Serum alpha-fetoprotein (AFP) levels were elevated in each of the four patients in whom levels were obtained. The highest elevation was noted in a 2-day-old infant with a diffuse, unresectable lesion involving the right lobe. Two patients who underwent complete resections of their solitary HH had normalization of their AFP levels. This study suggests that AFP levels in patients with HH are closely related to the patients' age, with the youngest patient having the highest levels of AFP. Catecholamine by-products (VMA and HVA) were elevated in one of four patients in whom levels were obtained, this infant was 3 months old at the time of presentation. She also had an elevated AFP level, a diffuse unresectable lesion involving the entire liver, multiple pulmonary nodules, and cutaneous hemangiomas. Immunohistochemical study failed to demonstrate the source of AFP or the catecholamine by-products in the tumor of this patient, suggesting that the source of catecholamine by-products could be stress-induced catecholamine secretion.

Antigens↗
PubMed1987

Acephalus-acardia in twins with aneuploidy.

Since 1963, 11 cases have been reported in which both the acardiac twin and the "normal" co-twin were studied cytogenetically. Aneuploidy or polyploidy was clearly identified in the acardiac twin in 7 cases and in the co-twin in 1 case. We report on 2 additional twin pairs in which aneuploidy was associated with acephalus-acardia. In both cases the "normal" co-twin had a Klinefelter (47,XXY) karyotype. Chromosome analysis in the 2 acardiac twins documented a 47,XXY constitution in one and 94,XXXXYY anomaly in the other. One of the "normal" co-twins also had the VATER association. Given these data we would recommend chromosome analysis of both members of a twin pair when one has acephalus-acardia.

Abnormalities, Severe Teratoid↗
PubMed1986

Diploid-triploid mosaicism: report of necropsy findings.

This is the first report of necropsy findings associated with diploid-triploid mosaicism. The important pathological findings are presented and compared to those of pure triploidy and those noted in noninvasive studies of diploid-triploid mosaics. The clinical findings in this patient are compared with those of other reported cases.

Adrenal Glands↗
PubMed1986

Angiomatoid malignant fibrous histiocytoma with extensive lymphadenopathy simulating Castleman's disease.

We report the association in a 10-year-old boy of an angiomatoid malignant fibrous histiocytoma (AMFH) of the left thigh with ipsilateral inguinal, pelvic and extensive retroperitoneal lymphadenopathy, and severe systemic manifestations. These include growth retardation, fever, severe anemia, hypergammaglobinemia, and hypoalbuminemia. At ultrastructural level the tumor was characterized by an abundance of myofibroblasts, occasional histiocytes, and small vessels with marked reduplication of the basal lamina. Biopsies of the inguinal and abdominal lymph nodes showed follicular hyperplasia and massive plasmacytosis indistinguishable from Castleman's disease (giant lymph node hyperplasia) of plasma cell type. The radical surgical excision of the primary tumor in the thigh resulted in the disappearance of the abdominal lymphadenopathy and a marked reduction in size of the pelvic lymph nodes with marked decrease of the gammaglobulins, thus proving that the nodal lesions were the expression of a reactive process to the tumor rather than a coincidental independent lymphoproliferative disorder. Retroperitoneal and pelvic node dissection was performed 1 year after the radical excision of the thigh tumor because of persistent pelvic lymphadenopathy and failure of serum immunoglobulins M and A to return to normal level, with a recent peak of IgA to twofolds that of normal value. Metastatic AMFH was found in the three pelvic nodes. One month postoperatively IgA returned to near normal level whereas IgM remained slightly elevated.

Castleman Disease↗
PubMed1986

Juvenile xanthogranuloma. Ultrastructural and immunocytochemical studies.

Morphologic features of three cases of juvenile xanthogranuloma (JXG) were consistent with the current concept of a benign process, although the lesion in one case grew steadily to an extensively infiltrating large mass, which clinically suggested a malignant growth. Ultrastructurally, the lesion consisted of morphologically different developmental stages of histiocytes, probably reflecting different functional levels. An interesting finding was the presence of occasional subplasmalemmal linear densities between these cells. These densities were at times symmetrically opposed, forming desmosomelike junctional complexes. Immunohistochemical study for the presence of lysozyme, alpha 1-antitrypsin, and S100 protein by the avidin-biotin-peroxidase complex was performed in all three cases. All immunostains were negative except the positive lysozyme stain in two cases. The ultrastructural and cytochemical characteristics of histiocytes in JXG were similar to epithelioid cells in the lymph node, suggesting that JXG is a reactive lesion.

Desmosomes↗
PubMed1986

Congenital monoblastic leukemia cutis. A case report with chromosomal abnormality: del (10p).

Congenital monoblastic leukemia cutis is a rare disorder. We report an infant who developed infiltrative skin lesions by 2 weeks of age, which, when biopsied at 4 1/2 months of age revealed a monoblastic infiltrate. Blasts in the peripheral blood were not seen until 1 week before her death at 8 months of age. Chromosomal analyses of her bone marrow showed an abnormal clone of cells with a 46,XX,del(10)(p12) karyotype. Although chromosome 10 is rarely involved in hematologic malignancies, abnormalities of this chromosome within the region 10p11-10p13 have now been shown in four of 10 reported cases of congenital monoblastic leukemia.

Bone Marrow↗
PubMed1985

Transvascular migration of L2C leukemic cells studied in the liver of the guinea pig.

The possible routes of transvascular migration of leukemic cells in the liver were studied in guinea pigs with an L2C lymphoblastic cell-line inoculation leukemia. Invasion of the hepatic parenchyma theoretically can occur in three ways: Through the intact sinusoidal endothelium, utilizing either preexistent gaps (normal in the liver), or newly created pores, whether interendothelial or intraendothelial. We could not convincingly demonstrate this, but could not wholly exclude this either. After destruction or retraction of the endothelium, either on account of the remarkable sinusoidal engorgement and distension by masses of leukemic cells, or by direct assault on the endothelium by the leukemic cells. We can clearly demonstrate the former, and hold it to be the major cause of hepatic infiltration. Evidence for a direct endotheliolytic effect was not uncovered in our studies. Secondary infiltration from the portal triads. Heavy leukemic infiltration of the triads, whether from the portal or hepatic veins, or from the lymphatics, is indeed and early an consistent feature--but the infiltration of the hepatic lobule shows no peripheral, or any other zonal preference. In both portal and hepatic veins, leukemic cells transverse the endothelium through a cytoplasmic "pore", adjacent to cell junctions, without obvious damage to the endothelium.

Animals↗
PubMed1985

Response of osteosarcoma to preoperative intravenous high-dose methotrexate chemotherapy: CT evaluation.

The histologic response of an osteosarcoma to preamputation high-dose methotrexate therapy can be used to determine the optimum maintenance chemotherapy regimen to be administered after amputation. This study evaluates computed tomography (CT) as a method of assessing the response of the tumor to the methotrexate therapy. Nine patients with nonmetastatic osteosarcoma of an extremity had a CT scan of the tumor at initial presentation. This was compared with a second CT scan after four courses of high-dose intravenous methotrexate. Each set of scans was evaluated for changes in bony destruction, soft-tissue mass, pattern of calcification, and extent of tumor involvement of the marrow cavity. These findings were correlated with the histologic response of the tumor as measured by the degree of tumor necrosis. The changes seen on CT correlated well with the degree of the histologic response in seven of the nine patients.

Adolescent↗
PubMed1985

Massive congenital mesenchymal malformation of the lung: a case report with ultrastructural study.

An unusual congenital tumorous malformation of mesenchymal tissue caused severe respiratory distress in a premature infant. The solid mass, which replaced almost the entire left lung, was composed of interlacing fascicles of spindle cells that percolated through otherwise well-developed fetal lung tissue. The normal anatomic arrangement of bronchial components was altered, but bronchial cartilages were present. Ultrastructural study of the lesion showed mesenchymal cells with fibroblastic differentation.

Female↗
PubMed1984

The leptomeningeal vein. A site of re-entry of leukemic cells into the systemic circulation.

The possible routes of transvascular migration of leukemic cells were studied in guinea pigs with an L2C lymphoblastic cell-line inoculation leukemia. The leukemic infiltrates were found mostly in and around the superficial leptomeningeal veins, paralleling findings in human leukemia. Reconstructions, based on thin serial sections (Epon blocks), allowed us to conclude: (1) leukemic cells do proliferate under the vascular endothelium; (2) the endothelium when pushed away from its basement membrane degenerates and ultimately disintegrates; (3) junctions between adjacent endothelial cells tend to be preserved, even when the rest of the endothelial cytoplasm has disintegrated; (4) leukemic cells will eventually re-enter the circulation; (5) leukemic cells, either singly or in groups, cross through endothelial pores in otherwise intact endothelial cells, rather than through opened-up junctions. It is concluded that leukemic cells cross the endothelium either through endothelial pores, which they in some way engender, or through large gaps left by disintegrating endothelium, the latter possibly intravasation.

Animals↗