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Biomedical subjects

D Friedman

Publications and source records attributed to D Friedman.

At least 181 records · Page 10Linked to original sources

Subdural electrodes in the evaluation for epilepsy surgery in children and adults.

To evaluate the utility and safety of chronic extraoperative subdural EEG and functional localization studies in children compared to adults, we studied 61 patients each of whom had similar evaluations for epilepsy surgery, regardless of age. The 23 children and adolescents (3 to 18 years old) and the 38 adults (20 to 41 years old) each had several days and nights of extraoperative EEG from scalp and chronically-implanted subdural electrodes, and the same percentage of children and adults also had functional localization studies including cortical electrical stimulation. The methods and results of these studies and of the subsequent resections did not differ between the two groups, and they both had similar rate of complications and similar incidence of good outcome. The subdural technique was as effective and well-tolerated in children and adolescents as in adults. Other invasive EEG techniques have not yet been systematically compared between children and adults, but the subdural technique, at least, appears to be suitable for patients over a wide age range.

Adolescent↗

Accumulation of RNA homologous to human papillomavirus type 16 open reading frames in genital precancers.

The accumulation of human papillomavirus type 16 (HPV-16)-specific RNAs in tissue sections from biopsies of patients with genital precancers was studied by in situ hybridization with single-stranded 35S-labeled RNA. These analyses revealed that the most abundant early-region RNAs were derived from the E4 and E5 open reading frames (ORFs). RNAs homologous to the E6/E7 ORFs were also detected, whereas RNAs homologous to the intervening E1 ORF were not. This suggests that the E4 and E5 mRNAs are derived by splicing to the upstream E6/E7 ORFs, consistent with studies of HPV-11 in condylomata (L. T. Chow et al., Cancer Cells (Cold Spring Harbor) 5:55-72, 1987). Abundant RNAs homologous to the 5' portion of L1 were also detected. These RNAs were localized to the apical strata of the epithelium. HPV-16 RNAs accumulated in discrete regions of these lesions, and when present were most abundant in the upper cell layers of the precancerous epithelium. RNAs homologous to early ORFs were also detected in some germinal cells within the basal layer of the epithelium.

Epithelium↗

A comparison of biotin and isotope-labeled ribonucleic acid probes for in situ detection of HPV-16 ribonucleic acid in genital precancers.

Genital precancers were analyzed by in situ hybridization for the presence of HPV RNA using single-stranded RNA probes. To compare the sensitivity of biotin- and 35S-labeled probes, serial sections from three biopsies containing variable amounts of HPV 16 RNA were analyzed with probes containing each label. The probe template was a cloned fragment of the HPV 16 genome spanning portions of the E2, E5 and L2 orf's. When a focus contained a strong hybridization signal with 35S-labeled probes (i.e., target/background ratio greater than 40) serial sections of the same area usually demonstrated a strongly positive signal with biotin-labeled probes. When the signal with 35S in a given focus was weak (target/background ratio less than 20), serial sections contained either a very weak or no detectable signal with the biotinylated probe. From this study it appears than 35S-labeled RNA probes exceed the sensitivity of biotin-labeled probes by nearly an order of magnitude with short exposures (4 days), and with longer exposures (1 to 2 weeks), approach the sensitivity of that reported for tritiated probes and exposures of 1 month or longer.

Biotin↗

Detection of papillomavirus nucleic acids in genital precancers with the in situ hybridization technique.

Recent advances in in situ hybridization technology have made it possible to analyze the distribution of human papillomavirus (HPV) type 16 nucleic acid sequences in genital neoplasms. This review addresses the methodology of in situ hybridization as it relates to the detection of HPV sequences in precancerous lesions and explores the potential value of this technique for both detecting HPV sequences in tissue sections and analyzing HPV gene functions that may be important in the genesis of squamous neoplasia.

DNA, Viral↗

Body composition after 'very-little-stomach' biliopancreatic bypass.

The nutritional status prior to and 3 months and 1 year after biliopancreatic bypass surgery was evaluated. The common nutritional indexes (serum albumin and transferin concentrations, daily urinary creatinine excretion and delayed hypersensitivity) were determined. The body compartments were derived from total body water (TBW) and total body sodium (TBNa), measured by dilutional technique, and total body potassium (TBK), calculated from TBW, TBNa, and the ratio of the sodium plus potassium content divided by the water content in a sample of whole blood. Before surgery, obese patients showed a dilatation of both fat an lean compartments with a normal lean body mass (LBM) qualitative composition, as indicated by TBNa/TBW, and TBNa/TBK ratios not greater than those measured in controls. Three months following very-little-stomach biliopancreatic bypass (VLS BPB), a consistent reduction of body weight and body fat were observed. The body cell mass value fell and reached a level closely similar to that found in lean control subjects. LBM showed only a slight decrease. A sharp increase of TBNa/TBW and TBNa/TBK ratios demonstrated a dilatation of the extracellular space. This malnutritional status was not detected by the usual nutritional parameters. One year after VLS BPB surgery, the patients' body composition became very similar to that of lean subjects, though a TBNa greater than that of controls suggested that a slightly expanded extracellular space was still present.

Adult↗