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Biomedical subjects

A G Weinberg

Publications and source records attributed to A G Weinberg.

At least 19 recordsLinked to original sources
PubMed1996

A quantitative evaluation of mucosal eosinophils in the pediatric gastrointestinal tract.

Evaluation of the mucosal eosinophil content is important in the interpretation of endoscopic biopsies, as high eosinophil densities might reflect allergic gastrointestinal disease. Reference ranges gleaned from the literature have an upper limit of normal varying from 6 to 20 eosinophils per 400 x high power field. Preliminary data suggest a geographic variation with higher eosinophil counts in the southern United States. We examined intestinal tract mucosa from 44 infants and children who died suddenly and unexpectedly in northeastern Texas. Subjects ranged in age from 3 wks to 17 yrs and were without known gastrointestinal disease. Using formalin-fixed, hematoxylin and eosin-stained 4-microns sections, intramucosal eosinophils were counted in ten consecutive high power fields and the mean eosinophil count determined. Twenty-three subjects (52%) had counts of > 20 eosinophils/high power field from at least one site. There was no correlation with age, sex, season, or cause of death. In a subset of 11 subjects, more extensive sampling showed the cecum and appendix to have the highest concentration of eosinophils and relatively low counts in the stomach and distal large intestine. These observations correlate with our impression that increased numbers of eosinophils, particularly in the proximal colon, are a common feature of otherwise unremarkable pediatric endoscopic biopsies. Efforts to distinguish the proportion of activated eosinophils in B5-fixed mucosal biopsies using the EG2 monoclonal antibody were unsuccessful, as this antibody does not appear specific for activation in B5-fixed tissue. Mucosal eosinophil counts should be interpreted with caution in geographic areas where a high background count is endemic.

Abdominal Pain↗
PubMed1995

Fetal hypokinesia syndrome in the monochorionic pair of a triplet pregnancy secondary to severe disruptive cerebral injury.

We report a set of triplets, two of whom were monochorionic diamnionic and demonstrated cerebellar hypoplasia and progressive arthrogryposis on an antenatal sonogram. At delivery the infants exhibited a Pena-Shokier phenotype. At autopsy, the twins were concordant for severe disruptive lesions of the cerebrum. The mechanism resulting in the devastating symmetric lesions may have been a transient cerebral vascular compromise associated with placenta vascular anastomoses characteristic of monochorionic twinning. This report accentuates the vulnerability of the monochorionic twin for ischemic cerebral injury.

Abnormalities, Multiple↗
PubMed1993

Renal angiomyolipomas and HMB-45 reactivity.

BACKGROUND: Renal angiomyolipomas (RAML) are mesenchymal hamartomas composed of varying amounts of blood vessels, smooth muscle, adipose tissue, and supporting connective tissue. Although most of these tumors are easy to recognize, some show unusual histologic features and may pose a diagnostic dilemma. Recent reports indicate that RAML are immunoreactive for HMB-45 antibody, which is directed against a premelanomasome-associated glycoprotein and is thought to be specific for melanocytic differentiation. METHODS: To determine whether HMB-45 reactivity would differentiate RAML from other renal tumors, the authors immunostained 72 primary renal tumors, including 19 angiomyolipomas and 2 retroperitoneal liposarcomas extending into the kidney, with HMB-45 monoclonal antibody. Also, the immunohistochemical profile of 19 renal angiomyolipomas was investigated using a broad panel of immunostains, including cytokeratin (AE1/AE3), epithelial membrane antigen, vimentin, smooth muscle actin (SMA), desmin, muscle-specific actin (MSA), S-100 protein, and neuron-specific enolase (NSE). RESULTS: All tumors except RAML were negative for HMB-45 antibody. HMB-45 immunoreactivity was present in 17 of 19 RAML. Seventeen of 19 were positive for SMA and MSA (HHF 35), 8 for desmin, 17 for vimentin, and 9 for NSE. CONCLUSIONS: Based on this study, it was concluded that, along with SMA and MSA, HMB-45 reactivity is a useful tool to distinguish RAML, especially those with unusual morphological features, from other primary renal neoplasms, including liposarcomas that extend into the kidney.

Antibodies, Monoclonal↗
PubMed1992

Cellular localization of the folate receptor: potential role in drug toxicity and folate homeostasis.

In the past year, gp38, a glycosyl-phosphatidylinositol linked membrane protein that is overexpressed in some malignant tissues, has been shown to be the folate receptor. Using immunohistochemical techniques with the monoclonal antibody MOv19 against gp38, we evaluated the cellular localization of folate receptors in normal human tissues, which are potential target sites for drugs that utilize this uptake mechanism. The choroid plexus was intensely positive with staining limited to the epithelium, which in some foci had a distinct bilaminar pattern limited to the luminal and basal surfaces. The epithelium of the fallopian tube, uterus, and epididymis was highly immunoreactive. The acinar cells of the breast, submandibular salivary, and bronchial glands also showed intense staining as did the trophoblastic cells of the placenta. In the kidney reactivity was localized to the proximal tubules. Lung alveolar lining including type I and II pneumocytes stained intensely. Limited but focal reactivity was noted in the vas deferens, ovary, thyroid, and pancreas. This study in conjunction with previous work showing marked overexpression of folate receptor in some malignant cells suggests that the folate receptor may be an important target for diagnostic or therapeutic exploitation and indicates sites of potential drug toxicity.

Antibodies, Monoclonal↗
PubMed1992

Acute megakaryoblastic leukemia simulating carcinoma.

Acute megakaryoblastic leukemia has emerged as an important subset of early childhood leukemia. It often presents a diagnostic dilemma because of its many morphologic manifestations and propensity to mimic metastatic carcinoma. An abdominal mass was identified by sonographic and computed tomographic scans in a 10-month-old girl, who had anemia and thrombocytopenia. An open biopsy of the 3-cm, peripancreatic mass showed cohesive nests and sheets of tumor cells with focal spindling and desmoplasia. Although the diagnosis of acute megakaryoblastic leukemia was established from a bone marrow aspirate using immunocytochemical techniques and karyotype analysis, a coexistent abdominal epithelial malignant neoplasm could not be excluded entirely by light microscopic examination alone. The megakaryoblastic nature of the abdominal tumor was established by immunocytochemical stains for glycoprotein IIIa on paraffin-embedded tissue.

Abdominal Neoplasms↗
PubMed1991

Keratitis, hepatitis, ichthyosis, and deafness: report and review of KID syndrome.

A 14-year-old girl with ichthyosis and severe liver disease is compared to 35 reported cases of KID or Senter syndrome. Common manifestations such as ichthyosis (35/35 patients), sensorineural deafness (33/34), "ectodermal dysplasia" (25/28), corneal abnormality (26/31) were present in the proposita, while less common manifestations such as chronic infections (15/20) and neuromuscular disease (12/35) were absent. Two families with vertical transmission and 28 sporadic cases are compatible with an autosomal dominant form of KID syndrome, while one inbred sibship with liver disease suggests the existence of an autosomal recessive form. The proposita was similar to the latter patients in having progressive cirrhosis necessitating liver transplantation; she also had short stature (10/35 patients) and mental retardation (3/35). Hepatic findings included micronodular cirrhosis, cholestasis, hyperplastic Kupffer cells, abundant Mallory's hyaline, copper accumulation without steatosis, and normal peroxisomes.

Adolescent↗
PubMed1991

Urine screen for bacteriuria in symptomatic pediatric outpatients.

A retrospective review of 1019 symptomatic pediatric outpatients compared urine dipstick including leukocyte esterase and nitrite to semiquantitative Gram-stained smear of uncentrifuged urine for the identification of specimens that contained greater than or equal to 10(5) organisms/ml as determined by semiquantitative urine cultures. The Gram-stained smear was slightly more sensitive than the dipstick; 97.6% (any microorganisms seen or greater than or equal to 2 organisms/oil immersion field) vs. 90.2% (either leukocyte esterase- or nitrite-positive). The negative predictive value of both screening methods was excellent (99.9 and 99.6%, respectively). The predictive value of a positive screen was low for both methods although the predictive value of a positive screen of the Gram-stained smear did reach 63% when there were greater than or equal to 5 organisms/oil immersion field. Neither method of urine screen should substitute for a urine culture in the symptomatic outpatient. However, the urine dipstick test is a reasonable alternative to a Gram-stained smear for initial patient assessment.

Bacterial Typing Techniques↗
PubMed1989

Allergic aspergillosis: a newly recognized form of sinusitis in the pediatric population.

In 1983, Katzenstein, et al. first described a form of noninvasive sinusitis in adults, which was histologically identical to allergic bronchopulmonary aspergillosis, with mucin-containing eosinophils, Charcot-Leyden crystals, and fungal elements resembling Aspergillus species. The authors have treated six pediatric patients ages 8 to 16 who had findings typical of allergic Aspergillus sinusitis. All patients presented with nasal polyposis and progressive facial deformity. All patients had computed tomography findings of diffuse expansile sinus disease and four patients had evidence of bony erosion, raising the suspicion of malignancy. At surgery, all were found to have multiple sinuses densely packed with greenish-black inspissated mucin. Therapy consisted of wide surgical drainage with careful follow-up and nasal steroids.

Adolescent↗
PubMed1988

Isolated infundibuloarterial inversion (S,D,I): a newly recognized form of congenital heart disease.

A newly recognized form of congenital heart disease is presented that is characterized by viscero-atrial situs solitus (S), D-loop ventricles (D), and inverted normally related great arteries (I), the segmental combination being (S,D,I). This anomaly may be called isolated infundibuloarterial inversion because only the subsemilunar infundibulum and the great arteries are inverted, whereas the atrial and the ventricles are not. All three patients had atrioventricular concordance, ventriculoatrial concordance, dextrocardia, superoinferior ventricles, crisscross atrioventricular relations, underdevelopment of the right ventricle, a large ventricular septal defect, and an inverted tetralogy of Fallot type of malformation of the infundibulum and great arteries. The condition known as crisscross atrioventricular relations was found in these three patients to be a major ventricular malposition characterized by marked clockwise rotation of the ventricles, as seen from the front. Two of these three cases were diagnosed accurately and repaired successfully.

Angiocardiography↗
PubMed1988

A comparison of the microerythrocyte sedimentation rate and the macroerythrocyte sedimentation rate methods in pediatric patients.

A comparison of the micro- and macroerythrocyte sedimentation rate methods performed in disposable polystyrene tubes using venous blood from 524 pediatric patients demonstrates an excellent correlation between the methods. The micromethod produces values higher than the macromethod at values above 10 mm/h but this difference is not of sufficient magnitude at the clinical decision level to warrant a change in the traditional reference ranges. The mean difference between the two methods in the 10-25 mm/h range is 1.4 mm/h. The high bias of the micromethod is accentuated in samples with hematocrits less than 30%. The micro- and macromethods do not maintain a constant relationship throughout the range evaluated.

Blood Sedimentation↗
PubMed1987

Renal-hepatic-pancreatic dysplasia: a syndrome reconsidered.

Five infants, three dying neonatally and two later in the first year of life, had renal, hepatic, and pancreatic dysplasia, a combination of abnormalities first described by Ivemark et al [1959]. The renal malformation consisted of cystic dysplasia, with abnormally differentiated ducts, deficient nephron differentiation, and glomerular cysts. The hepatic abnormality consisted of enlarged portal areas containing numerous elongated biliary "profiles," with a tendency to perilobular fibrosis. Serial liver biopsies in one child with cholestasis from birth showed a progression from bile duct paucity at 1 1/2 wk to typical biliary "dysgenesis" at 7 mo. Four of the five children had intrahepatic ductal dilatation, diagnosed ante mortem in the two older children as Caroli disease. The pancreatic abnormality consisted of fibrosis and cysts, with a diminution of parenchymal tissue. The clinical and functional reflection of these abnormalities in the two children surviving the newborn period included renal insufficiency, chronic jaundice, and insulin-dependent diabetes mellitus. Similar renal, hepatic, and pancreatic abnormalities occur in other syndromes, including trisomy 9, Meckel syndrome, Jeune, Saldino-Noonan, and Elejalde types of chondrodysplasia, and glutaric aciduria II. After exclusion of identifiable syndromes, the remaining cases of renal-hepatic-pancreatic dysplasia do not necessarily constitute a homogeneous group.

Abnormalities, Multiple↗
PubMed1986

Juvenile chronic myelogenous leukemia: surface antigen phenotyping by monoclonal antibodies and cytogenetic studies.

Cells from three children with juvenile chronic myelogenous leukemia were studied using culture in semisolid media, cytogenetic analysis, and surface staining with the monocyte-specific monoclonal antibodies 61D3 and 63D3. The percentage of bone marrow mononuclear cells that were 61D3- and 63D3-positive was markedly increased in all three patients. Bone marrow and peripheral blood mononuclear cells exhibited exceptionally bright immunofluorescence with these antibodies. The presence of monocyte-specific antigens on the surface of juvenile chronic myelogenous leukemia cells suggests that they are derived from a precursor with monocytic characteristics. A specific chromosomal abnormality (47,XY+21) was present in fresh bone marrow cells from one patient; in contrast, 50 metaphases from phytohemagglutinin-stimulated peripheral blood contained a normal karyotype. The chromosomal abnormality was also identified in myeloid colonies grown in vitro from this patient. Granulocytic elements were demonstrated in tissue sections and in cultured myeloid colonies from this child. Our data suggest that malignant transformation in juvenile chronic myelogenous leukemia involves a myeloid progenitor population capable of differentiation in vitro to cells with monocytic or granulocytic characteristics.

Animals↗
PubMed1985

Neonatal blood cell count in health and disease. II. Values for lymphocytes, monocytes, and eosinophils.

The distribution of normal cell counts (the reference range) has been determined previously for circulating neutrophils in infants from birth to 28 days of age. We have determined the reference ranges for the absolute peripheral blood lymphocyte, monocyte, and eosinophil counts obtained from 393 infants in this same cohort. Furthermore, white blood cell counts were obtained from three groups of infants with perinatal complications previously shown to be associated with abnormal neutrophil values (ABO incompatibility, n = 82; maternal hypertension, n = 68; neonatal sepsis, n = 140) and compared with the derived reference ranges; significant alterations in the distribution of cell counts were found in each of these groups at different times. Our data provide reference ranges for lymphocyte, monocyte, and eosinophil counts in the neonatal period and evidence of the effect of specific perinatal events on these cell counts.

Blood Group Incompatibility↗