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Biomedical subjects

A Feldman

Publications and source records attributed to A Feldman.

At least 19 recordsLinked to original sources
PubMed1992

The legal aspects of treating and being treated by an individual infected with human immunodeficiency virus.

Since the first AIDS case was reported in 1981, the AIDS epidemic is spreading dramatically in the United States. In dealing with the prevention of HIV transmission, we need to carefully balance the protection of civil rights that may be devastated by the disclosure of HIV-infection and the protection of public health against HIV infection in the health care setting. Recognizing the need of guidances in this regard, the CDC has issued recommendations regarding the prevention of HIV transmission in the health care setting on the basis of scientific data. In order to assure the acceptance of CDC guidelines in the health care setting, Congress recently passed a law that requires every state to institute CDC guidelines or its equivalent within 1 year. It is hoped that this requirement will ensure that HIV infection control measures are uniform throughout the nations and help HCWs and patients know their legal rights and obligations. Most importantly, the law regulating HIV-infection control will from now on rely on scientific data rather than on the irrational fear of the general public.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Clustering a large number of compounds. 3. The limits of classification.

Clustering is normally used to group items that are similar. In this application of obtaining a diverse sample from the 230,000 compounds in the National Cancer Institute Repository, we cluster to select compounds that are different from the rest, to optimize screening for new leads. With these constraints, our approach yielded many singleton clusters. We can interpret these results as evidence for a limit to classification, contrary to the customary view of chemistry as a study of classes of compounds.

Antineoplastic Agents↗
PubMed1988

Broad-spectrum antiviral activity of the acyclic guanosine phosphonate (R,S)-HPMPG.

(R,S)-9-(3-hydroxy-2-phosphonomethoxypropyl)guanine [(R,S)-HPMPG] exhibits broad spectrum antiviral activity with an ED50 of less than 1 microM against herpes simplex virus (HSV) types 1 and 2, varicella zoster virus, human cytomegalovirus (HCMV) and vaccinia in plaque reduction assays. Wild type HSV-2 and its thymidine kinase deficient variant are equally sensitive to (R,S)-HPMPG. (R,S)-HPMPG is 100-fold more potent than acyclovir (ED50 = 0.45 microM vs. 44 microM, respectively) against HCMV in cell culture, and 10-fold more active than acyclovir in extending survival time in mice intraperitoneally infected with 70 LD50 HSV-1. However, (R,S)-HPMPG is toxic when administered repeatedly at 44 mg/kg/day in uninfected adult mice. The diphosphoryl derivative of HPMPG was enzymatically synthesized and is a competitive inhibitor of HSV-1 DNA polymerase relative to dGTP (K1 = 0.03 microM). HPMPG-PP is 70-fold less active at inhibiting HeLa DNA polymerase alpha than HSV-1 DNA polymerase. At concentrations between 0.3 and 1.5 microM (R,S)-HPMPG inhibited HSV-1 DNA replication greater than or equal to 50% in infected cells as measured by nucleic acid hybridization. Consistent with inhibition of viral DNA synthesis, 6 to 30 microM (R,S)-HPMPG reduces late viral polypeptide synthesis in HSV-1 infected cells. These data indicate that (R,S)-HPMPG is a thymidine kinase independent broad spectrum antiviral drug which is capable of inhibiting viral DNA polymerase.

Acyclovir↗
PubMed1988

Evaluation of diagnostic criteria for borderline personality disorder.

A comparison of 17 narrowly defined borderline patients with 20 nonpatient control subjects indicated that certain individual and combinations of criteria may be more highly correlated with the disorder than others. Requiring any four or certain specific combinations of two or three of the five most discriminating criteria provided the optimal balance of sensitivity, specificity, predictive power, and diagnostic efficiency considerations. Fewer than five DSM-III-R criteria adequately identified the patients.

Adolescent↗
PubMed1986

Hypophysiotropic hormone testing in a patient with hypothalamic hypopituitarism.

A 59-year-old woman with metastatic breast carcinoma presented with weight loss, vomiting, and polyuria. Basal endocrine testing revealed low levels of thyroxine, cortisol, and gonadotropins, and the presence of diabetes insipidus. Direct stimulation of the pituitary with hypophysiotropic hormones indicated intact pituitary reserve. Insulin-induced hypoglycemia, however, failed to increase plasma cortisol or growth hormone levels significantly. On computed tomographic scanning, a lesion was found in the area of the hypothalamus. Thus, a functional abnormality of the hypothalamic-pituitary axis causing clinically significant hypothalamic hypopituitarism was not clearly apparent following administration of hypothalamic releasing factors but was demonstrable with indirect stimulation via insulin-induced hypoglycemia. Insulin-induced hypoglycemia remains an important diagnostic test in the evaluation of hypopituitarism.

Female↗
PubMed1986

Heat-sensitivity and the immune response of a methylcholanthrene-induced tumor.

Our results indicate that this methylcholanthrene (MCA)-induced tumor is immunogenic and that its heat-sensitivity is linked to the immune response of the host. Stimulation or reduction of the latter caused a corresponding change in the former. A therapeutic heat-dose failed to protect a majority of the treated mice against a second tumor challenge.

Animals↗
PubMed1979

The effect of active versus passive exploration on memory for spatial location in children.

The effect of active exploration upon memory for spatial location of an event was assessed for children at 2 age levels. Each child took a walk through the same unfamiliar hallway in search of a hidden object which he was later asked to relocate. Half the children were accompanied by an adult holding their hand (passive condition), while the other half proceeded on their own with an adult following behind (active condition). An age x condition interaction revealed that active exploration significantly improved performance of the 3- and 4-year-old group while not affecting the performance of the 9- and 10-year-olds. The 3- and 4-year-olds in the active condition, however, were still significantly less accurate than the older children, despite their experience of self-directed exploration. The results are interpreted as supporting the hypothesis that self-directed activity serves to increase attention of preoperational children to relevant topological cues in the environment, whereas concrete operational children, due to their knowledge of projective and Euclidean space, demonstrate increased capacity to efficiently encode spatial information regardless of the mode of exploration.

Child↗
PubMed1978

The family practitioner as psychiatrist.

The author describes attitudes held by nonpsychiatric physicians that are responsible for poor psychological handling of patients, including low interest in psychosocial aspects of illness, judgment of and disinterest in hypochondriasis or conversion reaction, avoidance of psychotic or terminally ill patients, and anger toward patients with unpleasant characteristics. He discusses reasons for these attitudes and suggests that medical schools increase psychological education and psychiatry departments increase the relevance of their teaching.

Attitude of Health Personnel↗
PubMed1977

[Moschowitz's disease: efficacy of anti-platelet aggregation agents].

In November 1976, a 52 year old woman presented with a Moschowitz syndrome with clinical manifestations of continuous fever at 39 degrees and a transient Wernicke type aphasia. Laboratory findings included schizocytosis, a peripheral thrombocytopaenia and functional renal insufficiency. The ethanol tests was positive but there was no frank defibrination syndrome. After corticosteroid therapy failed, the patient was treated with Dipyridamole 400 mg/24 hours IV and acetylsalicylic acid 4 g/24 hours IV. Fever disappeared on the same day and the thrombocytopaenia was corrected in 48 hours. The patient was considered to be cured 15 days later. No precise aetiology to explain the Moschowitz syndrome was discovered apart from the recent ingestion of oestrogens. The authors emphasise the considerable progress which this use of a combination of Dipyridamole and aspirin represents, resulting in the cure of Moschowitz syndrome, a condition considered to be fatal up until a few years ago.

Adrenocorticotropic Hormone↗
PubMed1977

SI prefixes.

Explore the source record for details and available documents.

Documentation↗
PubMed1976

Effect of prolactin on maintenance of prelactating human mammary gland in vitro.

Human mammary tissue from a female at the end of the second trimester of pregnancy was studied in organ culture in a chemically defined medium. Sampling was carried out at 1, 2 and 3 weeks. Without hormones, there was nearly total lobuloalveolar degeneration in all specimens at all times. Addition of insulin, hydrocortisone and ovine prolactin, in combination at a concentration of 5 mug per ml each, did not affect the extent of degeneration. Raising the concentration of prolactin to 50 mug per ml resulted in greatly improved lobulo-alveolar maintenance in all specimens and continued epithelial cell DNA synthesis for up to 3 weeks in vitro.

Breast↗
PubMed1975

In vivo electron spin resonance in rats.

In vivo ESR studies have been made on Wistar and Sprague-Dawley rats using travelling wave helices implanted in the left lobe of the liver. Tissue regenerates completely around the Teflon-enclosed turns of the coil and histological studies have shown that it is composed of liver cells and connective tissue. Electron spin resonance studies of this tissue in vitro reported by Commoner and Ternberg in 1961 have demonstrated that it exhibits the 'tissue radical' signal. The implanted coils have detected, in vivo, a three-line spectrum due to a strong concentration of 4-hydroxy- 2,2,6,6-tetramethylpiperidine-1-oxyl free radical ('tempol'), a nitroxide spin label, injected either intramuscularly, intraperitoneally or intravenously into the experimental animal immediately prior to the measurement. They have also detected, in vivo, a similar three-line spectrum due to 'spin-labelled chlorpromazine', a tranquillizing drug to which this nitroxide spin label has been attached, injected intramuscularly or intraperitoneally into the animal immediately prior o the measurement. Work is currently in progress to increase the in vivo sensitivity of the implanted helices by menas of improved coupling techniques and the use of a time-averaging computer.

Animals↗
PubMed1975

The role of the middle ear in acoustic trauma from impulses.

Exposure to high intensity impulse noise may produce a wide range of audiometric and histological effects in experimental animals. The objective of this study was to assess the changes in the middle ear mechanism after impulse noise exposure and to relate these changes to the audiometric and histological effects. Nine monaural chinchilla were exposed to either 161 or 166 db peak SPL impulses of 1 msec "A" duration, presented at a rate of 1 per minute for 50 minutes. The conductive mechanism of the chinchilla was assessed using standard clinical measures of static and dynamic impedance before and after the noise exposure. Auditory thresholds were measured before and after noise exposure using the average evoked response (AER) technique. At 30 days post-exposure, the animals were sacrificed for histology. Pre-exposure tympanometry showed that: 1. the total mean impedance of the chinchilla ear is considerably lower than that of man; 2. a method related hysterisis effect is present in both the susceptance and conductance tympanograms; and 3. sedation has a significant effect on the total impedance of the ear and on the shape of the tympanograms. After exposure to high level impulse noise: 1. tympanograms become irregular and double peaked, indicating tympanic membrane stress; 2. for the given exposure, 166 db is the impulse intensity needed to rupture consistently the tympanic membrane; and 3. audiometric and histological data correlate with the tympanometric findings and demonstrate a protective effect of a tympanic membrane rupture on the cochlea.

Animals↗
PubMed1975

[Chronic pulmonary artery thrombosis. Therapeutic modality. Apropos of 6 cases].

Six cases of post-embolic chronic cor pulmonale are presented. All six were treated with thrombolytic agents (4 with streptokinase, 2 with urokinase), and in only one case was improvement maintained at the end of one year. Two patients underwent a disobliterative procedure of the pulmonary artery, together with ligation of the inferior vena cava. One of these operations was unsuccessful, and the other had a successful outcome, as confirmed by objective assessment with angiography, scintigraphy and haemodynamic studies. The literature is reviewed at this stage. It was found that the fibrinolytic agents had some chance of working only if the condition was less than a few months old. One major drawback to surgical disobliteration that cannot be foreseen before operation is the presence of thromboses at the arteriolar level in subjects whose main arteries are already blocked proximally. Nervertheless it is possible to obtain good results by surgery, and the operation is worth attempting in young subjects, given the poor prognosis of the untreated condition.

Adult↗