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Biomedical subjects

J Haas

Publications and source records attributed to J Haas.

At least 181 records · Page 10Linked to original sources
PubMed1991

The use of recombinant antigens in ELISA procedures for the quantification of intrathecally produced HIV-1-specific antibodies.

An ELISA procedure is described for the quantification of intrathecally synthesized immunoglobulin G antibodies to human immunodeficiency virus (HIV) antigens. Recombinant p17, p24, endonuclease (END), reverse transcriptase (RT), a peptide from the transmembrane region of gp41 (ENV80) and a fusion protein containing HIV-1 and HIV-2 epitopes were compared with a commercially available ELISA. Using a reference serum, antibodies in serum and cerebrospinal fluid (CSF) to all of the antigens could be measured quantitatively in a reliable and reproducible fashion. Despite the fact that the titer varied up to 10(5)-fold between CSF and serum, interassay variability ranged from 3.87% for p17 to 8.41% for RT and intra-assay variability varied from 3.9% +/- 1.2% for p17 to 14.3% +/- 3.9% for the commercial ELISA. Antibody specificity indices (ASI) obtained by relating CSF/serum titers with reference to the corresponding IgG concentrations can be used to detect intrathecal synthesis of virus specific antibodies.

Enzyme-Linked Immunosorbent Assay↗
PubMed1991

Quisqualate-induced excitotoxic death of glial cells: transient vulnerability of cultured astrocytes.

The cytotoxic effect of quisqualate, a potent excitatory amino acid (EAA), was examined in purified astrocyte cultures obtained from neonatal rat cerebral cortex and grown in a serum-free, defined medium (G5). Excitotoxicity was evaluated by phase contrast microscopy and quantified by the measurement of lactic dehydrogenase (LDH) activity released from the damaged cells into the culture medium. Quisqualate evoked not only osmotic swelling, but also cytotoxic cell death of cultured astrocytes. The vulnerability of cells was restricted to a period between day 4 and 8 in subculture, with a maximal sensitivity on day 7. The present findings indicate that not only neurons, but also glial cells may exhibit excitotoxic vulnerability. The vulnerability to quisqualate appears to be a transient phenomenon, at least in cultured astrocytes.

Animals↗
PubMed1991

The surgical management of children with incompletely resected hepatic cancer is facilitated by intensive chemotherapy.

This prospective study was undertaken to evaluate the efficacy of continuous-infusion doxorubicin and cisplatin (CI-DOX/CPPD) for the treatment of children with incompletely resected hepatic cancer. Of the 46 evaluable patients, 32 had hepatoblastoma (70%) and 14 had hepatocellular carcinoma. Ten children had stage II tumors (microscopic residual), 25 were defined as stage III (gross residual), and 11 had distant metastasis (stage IV). Twelve patients underwent initial incomplete resection of their hepatic lesions and in the 34 others tumor biopsy specimens were obtained. Chemotherapy was administered and the majority of the children (70%) had an excellent clinical response with a decrease in both alpha-fetoprotein levels and measured tumor dimensions. The combination of CI-DOX/CPDD clearly facilitated surgical management, allowing for delayed hepatic resections in 20 of the 34 patients (59%) whose tumors were initially biopsied and considered to be unresectable. Overall survival in this study demonstrates a significant improvement in comparison to the historical controls. Twenty-one patients (46%) remain in complete clinical remission an average of 30 months following diagnosis (range, 17 to 40 months). The outcome of the children with hepatoblastoma was much better than those with hepatocellular carcinoma (63% v 17% survival). Survival of the 20 children who underwent delayed hepatic resections was not statistically different from the 12 patients whose hepatic tumors were removed at the initial laparotomy (41% v 58% survival). Although no obvious survival advantage was observed in those patients who underwent initial hepatic resections, there did appear to be an increased risk of postoperative complications in children whose tumors were resected following chemotherapy (8% v 25%).

Adolescent↗
PubMed1991

Serum antibodies to GM1 and GM3-gangliosides in systemic lupus erythematosus with chronic inflammatory demyelinating polyradiculoneuropathy.

Acute symmetric demyelinating polyneuropathy of the Guillain-Barré type is known in systemic lupus erythematosus (SLE). Chronic idiopathic demyelinating polyneuropathy (CIDP) has been reported rarely with SLE. A case is reported of CIDP accompanying SLE with autoantibodies against GM1- and GM3-gangliosides. There was no historical evidence to suggest SLE, and CIDP was the first manifestation of SLE. The 38-year-old patient had elevated CSF-protein, slow nerve conduction velocities, sural nerve biopsy revealed mixed axon loss with demyelination and CIDP white matter lesions were observed in magnetic resonance imaging, the GM1- and GM3-autoantibodies may play a role in the pathogenesis of CIDP in SLE.

Adult↗
PubMed1990

Serum fructosamine and amniotic fluid insulin levels in patients with gestational diabetes and healthy control subjects.

Gestational diabetic pregnancies with fetal hyperinsulinism should be identified because these cases require insulin therapy. To determine the relationship between the serum fructosamine and amniotic fluid insulin concentrations, these substances were measured in 87 pregnant women with impaired glucose tolerance. Fructosamine was also measured in 678 healthy pregnant control subjects, in 113 of whom amniotic fluid insulin levels were available. Fetal hyperinsulinism was rare at serum fructosamine levels of less than 2.6 mmol/L. These results suggest that when both the oral glucose tolerance test and fructosamine level are used, only 30% of women with gestational diabetes need to undergo amniocentesis to assess fetal insulin homeostasis.

Adult↗
PubMed1990

Classification schemes of small-for-gestational age and type of intrauterine growth retardation and its implications to early neonatal mortality.

Classification of small-for-gestational age (SGA) and pattern of intrauterine growth retardation (IUGR) and their relationship to early neonatal mortality (first 3 days) were studied in a population of 9201 full-term infants in a maternal and child center in Mexico City. SGA infants were classified on the basis of two methods: one, using the tenth percentile of a birth weight (BW) by gestational age reference growth distribution, and the other, using a cut-off point of birth weight of 2900 g. Crown-heel length (CHL) and Rohrer's ponderal index (PI = BW/CHL3) were used to classify patterns of proportionate and disproportionate IUGR. Overall, infants classified as SGA and type of IUGR had an increased risk of death in comparison to full-term appropriate-weight infants. IUGR proportionate infants with short CHL had a significantly greater mortality than disproportionate IUGR infants with normal CHL. A slightly but not significantly greater mortality was observed for IUGR disproportionate versus proportionate using PI regardless of the method of SGA used. The combination of misclassification for SGA and for type of IUGR were examined relative to the availability of gestational age and the uses of data for clinical management versus research. It is concluded that hospitals may tolerate misclassification of SGA but should pay close attention in assessing the pattern of IUGR when evaluating the mortality of newborn term infants.

Birth Weight↗
PubMed1990

Maternal and fetal responses to the stresses of lactation concurrent with pregnancy and of short recuperative intervals.

In many regions of the world, women breastfeed one child while pregnant with the next. Among rural Guatemalan women participating in a nutrition-supplementation trial, lactation overlapped with pregnancy in 253 of 504 (50.2%) of the pregnancies. For cases where overlap occurred, 41.4% continued to breast-feed into the second trimester and 3.2%, in the third trimester. The maternal and fetal responses to the energetic stresses of overlap and of the duration of the recuperative (nonpregnant, nonlactating) interval were assessed. Overlap resulted in increased supplement intake. Short recuperative periods (less than 6 mo) resulted in increased supplement intake and reduced maternal fat stores. The energetic stresses of overlap and short recuperative periods did not significantly affect fetal growth. The mother appears to buffer the energetic stress, protecting fetal growth. This research demonstrates that evidence of depletion of maternal nutrient stores caused by a demanding reproductive history is found when reproductive stress is characterized adequately.

Anthropometry↗
PubMed1990

[Adjuvant chemotherapy in radical surgery of cervix cancer].

Invasive cervical cancer can be treated by surgery, radiotherapy, and cytostatic chemotherapy. For decades, surgery alone or in combination with radiotherapy has been the treatment of choice. Radiotherapy only was reserved for patients with advanced disease. Antineoplastic agents, especially combinations including cisplatin, achieved good results in patients with advanced disease of after other therapeutic modalities had been exhausted. This led us to use postoperative chemotherapy for high-risk patients with positive pelvic or parametrial nodes or vascular invasion. Radiotherapy had not improved the survival of such patients. A combination of bleomycin, vincristine, mitomycin-C and cisplatin and later a combination of carboplatin and bleomycin was used. The results were compared to those of patients with radical abdominal surgery only (N = 118) or with surgery and postoperative radiotherapy (N = 108). The 32 patients who underwent surgery and chemotherapy had statistically higher incidence of all risk factors. Nonetheless, after 4-year follow-up they had less recurrences and deaths than the other patients.

Antineoplastic Combined Chemotherapy Protocols↗