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Biomedical subjects

H Feldman

Publications and source records attributed to H Feldman.

At least 91 records · Page 5Linked to original sources
PubMed1982

Neuroepithelial bodies (NEB) and solitary endocrine cells in the hamster lung.

Periodic acid-Schiff (PAS)-positive small-granule endocrine cells identified in serial plastic sections through 95% of the infracardiac lobe of a Syrian golden hamster lung were marked on a 70X cardboard reconstruction of the airways and recorded for computerized analysis as described in the preceding paper in this volume [1]. When airways were subdivided into thirds and the resulting small pieces of airway surface were analyzed statistically, endocrine cell loci appeared to be randomly distributed in the epithelial layer. Nevertheless, loci were absent from only 10 of 209 unit airways, far short of the 28 predicted from a random distribution. Solitary endocrine cells accounted for 37% of 980 loci but only 6% of all endocrine cells; 63% of loci consisted of endocrine cell clusters, broadly defined as "neuroepithelial bodies," of from 2 to 107 cells. Although small groups were preponderant, no significant discontinuity occurred in the size distribution between 1 and 56 cells per locus. Neuroepithelial bodies predominated everywhere, but especially in the lobar bronchus and at bronchioloalveolar portals, where cuboidal bronchiolar epithelium gives way to the attenuated epithelium of the respiratory zone; 45% were related to peribronchial smooth muscle and 18% to pulmonary capillaries. Only 3.3% of solitary cells were related to capillaries, 29% to airway muscle; 68% occurred in muscle-free regions of the airway, associated preferentially with ciliated epithelial cells. We conclude that endocrine cells are distributed in such a way that virtually all airways have at least one locus. This nonrandomness suggests that these cells are in fact important to normal lung function. Furthermore, because solitary endocrine cells and "neuroepithelial" cell clusters have different intrapulmonary distributions, they may well have distinct identities and functions.

APUD Cells↗
PubMed1981

Heparin-induced thrombotic thrombocytopenia.

Following subcutaneous therapy with heparin, the patient developed signs and symptoms of vascular occlusion in both legs. This was accompanied by thrombocytopenia and platelet aggregation when the patient's platelets were incubated with heparin. The clinical features and implications of this syndrome are discussed.

Aged↗
PubMed1981

An appreciation of the new St. Jude valvular prosthesis.

Beginning in March, 1978, 88 patients have had cardiac valve replacements with St. Jude prostheses. There were 26 males and 62 females, aged 6 to 80 years (mean 60). Single valve replacement was done in 67. Double valve replacement was done in 21; 12 of them had two St. Jude valves and nine had a different second valve. There were 57 mitral and 43 aortic valves replaced. Thirty-six patients had concomitant aorta-coronary bypass, and six others had additional cardiac procedures. All patients have been followed for a total of 807 patient-months (mean 9 months). Seventy-nine have been receiving sodium warfarin and seven are not receiving anticoagulants. There has been one embolic episode. There are no valve failures to date. Early mortality is 2.3% and late mortality, 5.7%; no death was valve related. Fifty-three survivors have improved by two or more N.Y.H.A. classifications. Fifty-four valves studied postoperatively at rest, during pacing, and during isoproterenol infusion have demonstrated significantly better hemodynamic performance than have mitral porcine xenografts studied in an identical manner (p < 0.05). Phonocardiography, M-mode and two-dimensional echocardiography, and cinefluoroscopy, carried out in 18 patients, have proved to be reliable noninvasive techniques for long-term follow-up. This experience indicates that the St. Jude prosthesis offers an excellent and predictable alternative in the surgeon's decision-making concerning valve choices.

Adolescent↗
PubMed1980

Social anxiety and psychiatric diagnosis.

Difficulties in interpersonal relationships are common complaints of psychiatric patients, and some investigators have contended that a lack of social skills, excessive social anxiety, and interpersonal problems are important causes of psychiatric disorders. To investigate further the relationship between social anxiety and psychiatric disorders, a survey of outpatients (N = 303) and untreated controls (N = 216) was conducted using measures of social anxiety, self-consciousness, general anxiety, and depression. Schizophrenics, secondary depressives, and nonpsychotic patients in individual and group psychotherapy characterized themselves as most shy in the diagnostically mixed patient group. Patients with primary effective disorders and family therapy patients were less socially anxious and resembled the control group in this respect. The single best predictor of status as a patient vs. status as a control was level of depression as determined by a stepwise discriminant function analysis. The relationship between social anxiety and secondary depression deserves additional attention in order to assess the possible causal links between this variables.

Adult↗
PubMed1980

Assessment of glomerular filtration rate in children.

Five different methods of assessment of glomerular filtration rate (GFR) were compared in 500 children older than one year of age. Results of each method were compared with standard inulin clearance values: 1. An evaluation of glomerular function may be inferred from plasma creatinine levels; the validity of this inference is, however, limited because of the wide range of normal values; 2. creatinine clearance values calculated over 3 hours significantly overestimate inulin clearance values; 3. clearance values derived from plasma creatinine concentration ahd height show a poor correlation with traditionally calculated inulin clearances; 4. clearance values calculated as the sum of twice the creatinine clearance and once the urea clearance, divided by three, better predict inulin clearance than either C-creatinine or C-urea alone; 5 inulin clearance values calculated by dividing the quantity of inulin perfused by its plasma concentration, once it has become stable, differ significantly from the values obtained by the standard inulin clearance.--Of all the methods studied, none was found to be an ideal alternative to the traditional inulin clearance when a precise assessment of GFR is warranted. It is concluded that in most clinical conditions derived clearance values do not have significant advantages over the simple determination of plasma creatinine, a valuable but not infallible index of glomerular function.

Adolescent↗
PubMed1979

Acoustic and perceptual comparison of chronic and incipient spastic dysphonia.

Vocal symptoms of patients with chronic and incipient spastic dysphonia were compared on a number of acoustic and perceptual parameters. Patients with incipient spastic dysphonia displayed less severe strain-strangle phonation, effort, rhythm, and stress. Harshness was the only perceptual parameter on which incipient spastic dysphonics were rated higher than chronic spastic dysphonics. Changes in the acoustic measures of laryngealization, harmonic change, mean vowel duration, and duration ratio between stressed and unstressed vowels accompanied changes in listeners' perception of strain-strangle phonation and effort. The variation in acoustic characteristics such as laryngealization and harmonic change as well as normal phonation indicated that both groups were characterized by a variety of phonatory modes.

Acoustics↗
PubMed1977

The development of language-like communication without a language model.

Deaf children who are unable to acquire oral language naturally and who are not exposed to a standard manual language can spontaneously develop a structured sign system that has many of the properties of natural spoken language. This communication system appears to be largely the invention of the child himself rather than of the caretakers.

Child, Preschool↗
PubMed1977

A comparison of transcriptional linkage of tRNA cistrons in yeast and E. coli by the ultraviolet light technique.

The ultraviolet light mapping technique was employed to determine the lengths of tRNA cistrons in yeast. The applicability of the method was first tested in the E. coli system, in which the mapping positions for some tRNA cistrons and the ribosomal 5S RNA genes as well as the existence of multimeric transcription units for tRNAs are known. Rates of the synthesis of the tRNAs and small rRNAs after irradiation with various doses of UV light were determined by pulse labeling and quantitation of the RNA species after twodimensional gel electrophoreses. The small ribosomal RNAs served for internal calibration in the estimtion of the target sizes. Our results suggest that--in contrast to the prokaryotic system--in yeast the majority of the tRNA genes are not linked into transcriptional units.

Dose-Response Relationship, Radiation↗
PubMed1976

Hysterical polydipsia (compulsive water drinking) in children.

Two patients had entirely different clinical presentations of hysterical polydipsia: convulsions and coma in a 5-year-old boy with intrinsic renal disease and a single kidney, and abnormal behavior in a 3-year-old girl with normal kidneys. In neither case was the correct diagnosis made on initial evaluation. Physiological studies demonstrated primary polydipsia to be responsible for both clinical presentations. The differential diagnosis of polydipsia and polyuria is reviewed, and the nonuniform presentation of hysterical polydipsia is emphasized. In children with intrinsic renal disease, hysterical polydipsia may be life-threatening.

Child, Preschool↗
PubMed1976

Arangement of transfer-RNA -genes in yeast.

The redundancy and the arrangement of the genes for specific transfer ribonucleic acids in yeast were studied by the hybridization techniques developed by Birnstiel et al., e.g.[1]. The redundancy was found to be in the order of 10 genes for tRNA1Met, tRNA3Met, tRNA2Ser, and tRNA-Pro. High molecular weight yeast DNA was fractionated by density gradient centrifugation in cesium chloride and the [32p]tRNAs were hybridized to the single fractions. The results together with earlier findings [2] suggest that the cistrons for these tRNAs are arranged in tandem interspersed by 6 to 10 times longer segments of spacer DNA which varies in (G+C) content for the different tRNA species.

DNA↗