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Biomedical subjects

D Goldstein

Publications and source records attributed to D Goldstein.

At least 235 records · Page 13Linked to original sources
PubMed1975

Letter: Avanti G. P.

Explore the source record for details and available documents.

General Practice, Dental↗
PubMed1975

Severe hypertension in chronic renal failure treated successfully with Minoxidil.

In fifteen patients with severe hypertension, eight of whom had end-stage kidney disease, blood pressure could not be adequately controlled with conventional oral antihypertensive drugs. Minoxidil, an orally administered drug which lowers blood pressure by reducing total peripheral resistance, produced a substantial reduction in blood pressure in all patients who were treated, including patients who prior to its availiability would have been considered for bilateral nephrectomy.

Adult↗
PubMed1972

Model for branch initiation in Aspergillus nidulans based on measurements of growth parameters.

The rate of hyphal elongation and the number of branches per hypha were measured on short sporelings of Aspergillus nidulans growing at different rates. The rate of elongation was proportional to total length in unbranched and branched hyphae. At each growth rate, the number of branches per hypha increased with increasing length and gave approximately straight-line graphs when plotted against length. The average number of branches per unit of hyphal length was quite different for the various growth rates and increased in direct proportion to the growth rate. The results are interpreted to mean that (i) growing tips have a maximum rate at which they can elongate and which is reached at hyphal lengths characteristic of the particular growth rate and (ii) a new branch is formed when the capacity of the hypha to elongate exceeds that of the existing tips.

Acetates↗
PubMed1970

A study on the transcription of the polyoma viral genome.

The transcription of polyoma (Py) viral RNA was studied in primary mouse kidney cell cultures (a) during normal, asynchronous infection, (b) under conditions where Py-induced DNA synthesis was inhibited with 5-fluorodeoxyuridine, and (c) after the synchronized onset of Py-induced DNA synthesis. The results obtained suggest that the bulk of Py RNA transcribed after the (asynchronous or synchronized) onset of Py-induced DNA synthesis, designated as "late" Py RNA, corresponds to the polycistronic transcript of most or all of the genetic information contained in a strand of circular Py DNA. The rate at which late Py RNA is transcribed is related to the amount of free Py DNA present in the cultures. Py-infected cultures contain a second, minor component of Py RNA (of one or possibly more species), designated as "early" Py RNA. At least some of this RNA continues to be transcribed if Py-induced DNA synthesis is inhibited with 5-fluorodeoxyuridine and, possibly, also late during normal infection.

Centrifugation, Density Gradient↗
PubMed1966

A computer analysis of serial interactions in spaced responding.

Serial dependencies in interresponse times were studied by means of a digital computer. In monkeys exposed to a DRL 20-sec schedule of reinforcement, serial interactions appeared at all stages of training. Early in training the serial effects consisted of trains of relatively long interresponse times interspersed among trains of relatively short ones. Later on, the serial effects appeared to be characterized by a tendency to drift up and down in long wavelength periods around the minimum interval required for reinforcement. After training to a point at which most interresponse times produced reinforcement, serial effects of a still more subtle nature appeared. These effects were made apparent by autocorrelation and power spectrum methods and consisted of both long-term and extremely short-term fluctuations in interresponse times.

Animals↗
PubMedDate not supplied

Model for short-term intracranial pressure changes following traumatic injury.

Results from primate studies show a transient increase in intracranial pressure (ICP) after a nonimpact inertial loading condition. The measured ICP increase varies linearly with the peak tangential load of these experiments. These experiments point to possible alterations in cerebral blood flow. This paper investigates the possible etiology of this particular phenomenon, and presents a simple analytical model that could explain the changes in intracranial pressure. The model combines the effects of cerebral venous constriction, arterial dilatation, and raised mean blood pressure to yield the characteristic immediate rise and exponential decay of ICP. The main contributor to the increase in intracranial pressure is believed to be vasodilation of cerebral arteries following venous constriction. Passive release of cerebrospinal fluid (CSF) is believed to mediate the long-term decay of intracranial pressure and possibly contribute to local hyperemia.

Animals↗
PubMedDate not supplied

Bufo toads and bufotenine: fact and fiction surrounding an alleged psychedelic.

This paper investigates the supposedly psychedelic Bufo toad and the allegedly psychedelic drug bufotenine, which is contained in the skin and glands of this toad. The bufo toad has held a place in human mythologies and medicines worldwide since archaic times. Used by ancient peoples for a variety of purposes, its most spectacular effects, according to lore, involve magical and shamanic or occult uses for casting spells and for divination. In the Middle Ages, the Bufo toad was celebrated as a panacea and persecuted as a powerful poison. More recently, in the 1960s the Bufo toad was resurrected as a countercultural icon, with people purportedly licking or smoking the secretions to get high. Bufotenine has been at the center of a scientific debate since its discovery in 1893. This paper examines the extensive literature surrounding the Bufo toad and bufotenine, and untangles many of the myths and the misinformation that continue to vex both science and popular reporting. Finally, to promote further investigation, a comprehensive bibliography is provided that charts the history of the Bufo toad and bufotenine.

Animals↗
PubMedDate not supplied

Smooth muscle cells influence monocyte response to LDL as well as their adhesion and transmigration in a coculture model of the arterial wall.

We investigated the possible interference of smooth muscle cells with monocyte response to LDL as well as with their adhesion and transmigration in a coculture of porcine endothelial and smooth muscle cells. Lysophosphatidylcholine (LPC), a component of oxidized LDL (oxLDL), stimulated the adhesion of THP-1 cells to endothelial cells both in mono- and in coculture with smooth muscle cells. When THP-1 cells were incubated with endothelial cells in the presence of copper oxLDL, their adhesion was increased, but only in coculture. The addition of sodium nitroprusside (SNP) together with oxLDL markedly increased the adhesion of THP-1 cells in coculture. Close proximity between endothelial and smooth muscle cells was necessary to observe that effect. Furthermore, this increase in adhesion of THP-1 cells can, at least in part, be attributed to the augmented production of monocyte chemoattractant protein-1 (MCP-1) observed in coculture under the influence of oxLDL and SNP. The passage of THP-1 cells through the coculture was stimulated by MCP-1 and LPC. These results show that physical contacts or close proximity between endothelial and smooth muscle cells play a key role in the adhesion of monocytes and their infiltration into the intima in response to oxLDL.

Animals↗
PubMedDate not supplied

Effects of prolonged irrigation with treated municipal effluent on runoff rate.

The use of domestic effluents for the irrigation of crops has been widespread in Israel for the past 30 years. The sodium adsorption ratio (SAR) of the standardized domestic effluents ranges between 4 and 6. According to the literature, when soils with SAR levels of 4 to 6 are exposed to direct raindrop impact they are subjected to enhanced aggregate disintegration, leading to sealing processes of the soil surface and subsequent increased runoff and soil erosion. However, these phenomena were not observed in the laboratory and field experiments of this study. On the other hand, a rapid decrease of the soil SAR to its initial values was observed, in laboratory and fieldwork, once the soil was subjected to a simulated rainstorm of distilled water (laboratory) or natural rainstorms (field plots). We can conclude that the process of SAR increase during irrigation with standardized effluent water is reversible. Further investigation in this direction can lead to recommendations regarding the necessary levels of domestic sewage water purification in correlation with soil types, climatic conditions, and hazards to tap water aquifers.

Adsorption↗
PubMedDate not supplied

The relationship between psychological factors and blood glucose regulation in insulin-dependent diabetic adolescents.

Fifty-two insulin-dependent diabetic, white, rural, middle-class adolescent subjects who had diabetes 5 or more years participated in a project comparing psychological and personality variables to the degree of altered blood glucose regulation as measured by hemoglobin A1c (HbA1c) levels. An HbA1c level of 9.5% was arbitrarily chosen as a cutoff score to divide subjects into two groups: those having "adequate" (N = 25) and those having "inadequate" (N = 27) blood glucose regulation. There were no significant differences between high and low HbA1c groups for all psychological variables tested, i.e., anxiety, locus of control, self-concept, and various personality traits measured by the High School Personality Questionnaire (HSPQ). Female subjects scored significantly higher on the anxiety scale and had significantly higher HbA1c values and weight percentiles compared with male subjects. Six self-report diabetes questionnaires dealing with various aspects of diabetes care and adjustment were completed by mothers and five similar questionnaires were completed by the adolescents. There were no significant differences in the mean scores of the 11 diabetes questionnaires between the high and low HbA1c groups. Girls scored significantly higher than boys in "self-care" and on individual items pertaining to dysphoric feelings about diabetes. Our findings may have resulted from the homogeneity of the sample, but underlying metabolic and genetic factors need to be considered in differentiating subjects according to the level of blood glucose regulation.

Adolescent↗
PubMedDate not supplied

The role of interferon in cancer therapy: a current perspective.

Recombinant interferon alpha has now been established as having a distinct if narrow role when used as a single agent in cancer therapy. The responses to single-agent therapy can be grouped as shown in Table 7. Interferon is likely to be the treatment of choice for hairy cell leukemia and possibly also for symptomatic nodular lymphoma. Interferon is very useful in treating papillomas and condylomas, and its role as a local agent will probably expand. The list of responding cancers for alpha interferon or other subtypes as a single agent is unlikely to expand greatly over the next few years. Nevertheless, in both melanoma and renal carcinoma, meaningful responses do occur. It is important to be aware of the possibility of both delayed and increasing extent of response with duration of treatment; adequate trials of interferon may therefore require longer periods of treatment than does conventional chemotherapy. Furthermore, because prior failure to respond to chemotherapy does not predict response to interferon, its use as a second-line agent should also be considered. The future of such biological agents, however, clearly lies in combination with other agents as the "fourth arm" of cancer therapy. The challenge is to define what the role of that fourth arm will be. There seems to be a clear choice with the interferons. They can be used at pharmacological doses, in which case their antiproliferative effect is likely to be due to induction of certain enzymes that result in a cytostatic effect in susceptible cancers, of which there are a limited but therapeutically important number. Alternatively, the interferons can be used at physiological doses, which are more likely to cause immunological and cell membrane effects such as NK-cell stimulation, as well as Fc-receptor and tumor-antigen expression. Thus, combination with cytotoxic agents may well require high doses, whereas combination with other biological agents, such as monoclonal antibodies or LAK cells, may be most effective at much lower doses. Over the next few years it will be important to establish the optimal biological doses of the interferons, so that we can maximize their usefulness in therapy and avoid the trap of thinking of them as purely cytotoxic agents.

Humans↗
PubMedDate not supplied

Lasso the power of the Internet.

News about the Internet is everywhere. The reality, however, is that the Internet is neither a passing fad nor a false alarm. It is a dynamic new way for healthcare organizations to disseminate and retrieve information, conduct market research, communicate with broad provider networks, educate consumers and sell products and services.

Community Participation↗