Biomedical subjects
Publications and source records attributed to B Feldman.
Traumatic perforation of the esophagus follows oropharyngeal suctioning or endotracheal intubation. The diagnosis frequently is made from a routine chest roentgenogram that shows a nasogastric tube in the right pleural space with or without a pneumothorax. The lesion is seen most often in infants of low birth weight.
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The myopathy associated with vitamin D deficiency has not been well characterized, and it is not known if weakness is a result of a specific effect of vitamin D deficiency on skeletal muscle. Chicks were raised from hatching on a vitamin D-deficient diet, and by 3 wk of age were hypocalcemic and appeared weak. Tension generated by triceps surae during repetitive stimulation of posterior tibial nerve was significantly less than that developed by chicks given vitamin D(3) supplements (309 g tension/g wet weight of triceps surae, SD 60, for vitamin D-deficient chicks; 470, SD 77, for vitamin D(3)-treated chicks, P < 0.01). Histochemical and electron microscopic examination of skeletal muscles of these chicks showed no abnormalities, and there were no electrophysiologic evidences of motor nerve or neuromuscular junction dysfunction. The concentration of ATP in skeletal muscle of the vitamin D-deficient chicks (5.75 mumol/g wet weight, SD 0.17) was not significantly different from that in vitamin D-treated chicks (5.60, SD 0.50). There was no correlation between strength and serum calcium, serum inorganic phosphate, or skeletal muscle inorganic phosphate. Relaxation of tension after tetanic stimulation was slowed in the vitamin D-deficient chicks (20.6 ms, SD 1.7, vs. 15.4, SD 1.3, in vitamin D-treated chicks and 15.3, SD 1.0, in normal control chicks), and in vitro (45)Ca(++) transport by sarcoplasmic reticulum from the vitamin D-deficient chicks was reduced. Calcium content of mitochondria prepared from leg muscles of vitamin D-deficient chicks (24 nmol/mg mitochondrial protein, SD 6) was considerably lower than that of mitochondria from normal control chicks (45, SD 8) or from chicks treated with vitamin D for 2 wk or more (66-100, depending upon level and duration of therapy). Treatment of the vitamin D-deficient chicks from hatching with sufficient dietary calcium to produce hypercalcemia did not significantly raise skeletal muscle mitochondrial calcium content (31 nmol/mg mitochondrial protein, SD 7) and did not prevent weakness. These studies demonstrate objective weakness as a result of myopathy in vitamin D-deficient chicks, and provide evidence that vitamin D deficiency has effects on skeletal muscle calcium metabolism not secondary to altered plasma concentrations of calcium and phosphate.
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We have examined, by protein binding assays, thermal denaturation, and circular dichroism, the possible effects of histones on nonhistone chromosomal protein (NHCP) interactions with DNA. For these studies, we have fractionated mouse Krebs II chromosomal proteins into three discrete fractions: Mo, 5 M urea-soluble NHCP; M1, 5 M urea-1 M NaCl-soluble NHCP from 5 M urea-extracted chromatin; and M3, 5 M urea-3 M NaCl-soluble chromosomal proteins from 5 M urea-1 M NaCl-extracted chromatin. These fractions contain heterogeneous populations of NHCP, and were found to differentially affect histone binding to DNA by methods of reconstitution, or by direct binding of M0, M1, or M3 to urea-salt reconstituted DNA with histones. M0 was found to exert a unique effect on the thermal denaturation and circular dichroic spectra of DNA-histone complexes. M0 from Krebs II chromatin was also found to complete for DNA sites in the presence of M0 from mouse liver chromatin. In addition, in 5 M urea, pH 8.0, histone binding to DNA reached saturation at 1.85 mg/mg of DNA, higher than the in vivo ratio of 1.00 mg/mg of DNA. Saturation of histone binding to DNA occurred only in the presence of 5 M urea, resulting in a reduction of nonspecific histone-histone interactions on DNA.
This has been a brief summary of the problems emerging as more community hospitals develop neonatal intensive care, analyzing their possible origins and significance. A description of one solution to the problem has been given, exemplified by an outreach program from the University of California, San Diego, and University Hospital, San Diego, with the community of Las Vegas, Nevada. We feel strongly that the responsibilities of medical schools toward community hospitals and toward regionalization in isolated communities should be unique and are not covered by usual regulations or traditional concepts of regionalization.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Tritiated [(16 alpha-ethyl-21-hydroxy-19-nor-pregn-4-ene-3,20-dione)-6,7-3H] (ORG-2058) and 17,21-dimethyl-19-nor-pregna-4,9-diene-3,20-dione (R5020) were compared as ligands in the assay of progesterone receptor in human and rat breast tumors. We found that ORG-2058 is a better ligand because of its low nonspecific binding. Most of the nonspecific binding of the other ligand R5020, is to proteins which bind corticosteroids. In cancerous tissue ORG-2058 binds to progesterone receptor linearly in a range of protein concentrations which are normally used in the receptor assay. On the other hand, R5020 exhibits binding linearity over a narrower protein concentration in many tumor biopsies, which may cause severe limitation in the assay procedure or frequent underestimation of receptor content.
Aspirates of serous ear fluids from 57 children were examined for aerobic and anaerobic bacteria. Bacterial growth was noted in 23 patients (40 per cent). Aerobic organisms only were recovered in 13 aspirates (57 per cent of the culture-positive aspirates); anaerobic bacteria in four (17 per cent); and mixed aerobic and anaerobic bacteria in six (26 per cent). A total of 45 bacterial isolates were recovered, accounting for 2.0 isolates per specimen (1.4 aerobes and 0.6 anaerobe). There were a total of 31 aerobic isolates, including Hemophilus influenzae (eight isolates), Staphylococcus aureus and Streptococcus pneumoniae (five of each), and Staphylococcus epidermidis and alpha-hemolytic streptococcus (four of each). Fourteen anaerobes were recovered, including anaerobic gram-positive cocci and Bacteroides melaninogenicus (five isolates each) and Propionibacterium acnes (three isolates).
OBJECTIVE: The goal of the study was to evaluate the significance of delayed laboratory analysis of maternal serum alpha-fetoprotein, beta-subunit of human chorionic gonadotropin, and unconjugated estriol for prenatal screening. METHODS: Biochemical analysis of 30 consecutive biochemical screening specimens of maternal serum alpha-fetoprotein, beta-subunit of human chorionic gonadotropin, and unconjugated estriol was performed immediately upon arrival to the laboratory, 7 days later, and again 14 days after maternal blood was drawn. Differences among the results of the three sets of biochemical studies were evaluated by one-way analysis of variance for repeated measures. RESULTS: No significant differences were found among the results of immediate assays as compared with those at a 7- or a 14-day delay for all three biochemical markers. CONCLUSIONS: Our data suggest that up to a 14-day delay in the performance of the 2nd-trimester maternal serum biochemical screening assays will not alter the results significantly. The results of maternal serum screening are, thus, clinically valid even if the laboratory assays were performed several days after maternal blood was drawn.
OBJECTIVE: Amnioinfusion plays an important role in the intrauterine evaluation and treatment of fetal obstructive uropathy. However, it may significantly increase the risk for chorioamnionitis, premature rupture of membranes and premature labor. We evaluated the impact of prophylactic antibiotics on postamnioinfusion complications. METHODS: Thirty pregnancies complicated by fetal obstructive uropathy, treated by amnioinfusion and with documentation of pregnancy outcome were identified from our database. Pregnancy outcomes were compared between patients who were treated with prophylactic antibiotics and those with no prophylaxis. RESULTS: Chorioamnionitis was diagnosed in 3 out of 15 (20%) patients who did not receive prophylactic antibiotics as compared to 2 (13%) in the treated group. The overall rate of serious obstetrical complication was significantly higher in the untreated group (66 vs. 20%; p = 0. 021). Patients receiving prophylactic antibiotics delivered at a significantly greater gestational age than those who did not receive antibiotics (34.0 +/- 3.7 vs. 31.3 +/- 1.9 weeks, respectively; p = 0.018). CONCLUSIONS: Our study supports the use of oral prophylactic antibiotics as being effective in reducing the previously observed significant risks associated with amnioinfusion in fetal obstructive uropathy.
OBJECTIVES: Maternal nutritional deficiency is an important predisposing factor to congenital neural tube defects (NTDs). It was hypothesized that obese women may have an increased risk for NTDs. The aim of the present study was to address this question in a large cohort. METHODS: A total of 72,915 consecutive cases of biochemical screening that had documented maternal weights and pregnancy outcomes were identified from the Quest Diagnostic Laboratories database. Patients were divided into five ranges of maternal weights, and the incidence of NTDs was calculated for each group. Based on the different definitions of maternal overweight, the data were also analyzed based on 2 groups only, obese and nonobese, using three cutoff points. RESULTS: Seventy-nine pregnancies were complicated by NTDs (incidence of 1.08 per 1,000 pregnancies). Differences between maternal weights ranges were not found to be statistically significant (chi2 = 5.997, p = 0.19, power = 0.99). Differences between obese and nonobese mothers were not found to be statistically significant for all three analyses as well. CONCLUSIONS: Our present results do not support an association between maternal obesity and NTDs.