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Biomedical subjects

D Platt

Publications and source records attributed to D Platt.

306 records · Page 17Linked to original sources
PubMedDate not supplied

Herpes simplex virus type 1 replication in a gingival cell line.

Propagation of herpes simplex virus type 1 (HSV-1) in gingival cells is advantageous since these cells are more definitive than HeLa cells in demonstrating viral-induced cytopathic effects and are easily and economically maintained in the laboratory. They also provide a potential medium for studying oral tissue reactions to HSV-1 infection. HSV-1-induced cytopathic effects are clearly characterized following inoculation with virus from standard laboratory cultures and human infections.

Cell Line↗
PubMedDate not supplied

Installing PACS--lessons learned.

In 1997, Carson-Tahoe Hospital in Carson City, Nev., looked into the possibility of installing its own PACS system. Increased productivity was the main business goal the hospital hoped a PACS system would meet. Only two of three chosen vendors seriously considered the request to bid because of the small number of films produced by the hospital. After installation, the hospital identified the referring physicians who used the most film and then directed its marketing efforts to them. Lessons learned include the tremendous need for training of staff, referring physicians and radiologists. Expect everyone to be slow the first week the new system is running. Map out all processes to prepare for contingencies. Make plans for archiving and be flexible in assigning tasks--next week things may change. Consider bringing in an outside consultant to measure people's expectations and fears. After nearly a year, neither the technologists nor physicians express any regrets about the installation of PACS at Carson-Tahoe.

Capital Expenditures↗
PubMedDate not supplied

[Fe59 studies on the question of rabbit erythrocyte life-span].

The present paper demonstrates a method to separate red cells of different age. The erythrocytes were separated by ultracentrifugation. The validity of this method was examined with radioactive iron (59Fe). During seventy days kinetic studies were performed in liver and spleen. A body scan was used to distinguish liver and spleen by radioactive iron.

Animals↗
PubMedDate not supplied

[Aging--from the molecule to the organism].

Age-related changes at the molecular, cellular and organ level, as well as at the organism level are heterogeneous with respect to their timing and intensity. Theories on aging are numerous, but for none is there yet any strong, convincing evidence, particularly in regard to whether or not age-changes are programmed or are due to accumulations of random changes in constituent cells. Recent studies indicate, however, that DNA damage and repair may be central to cellular senescence, e.g., there is a direct relationship between the repair capacity and the maximum life span of a given species. The limited division potential of normal human diploid fibroblast cells in vitro is well documented and has been established as a model for cellular aging. Thus, fibroblasts taken from young individuals have a greater total doubling capacity as compared to fibroblasts derived from older individuals. Aging of the brain, heart, liver, and locomotory system are discussed. Within the context of organism aging the multimorbidity, chronic diseases, as well as some peculiarities of pharmacokinetics are also discussed.

Adaptation, Physiological↗
PubMedDate not supplied

[Effect of age on the activity of Mg-Na-K-ATPase, as well as on the K and Na concentration in human erythrocytes].

42 persons of two age groups (14--28 years and 70--87 years) free of liver and hematological diseases without treatment with cardiac glycosides were investigated in this study. The activities of Mg++-ATPase and Na+-K+-ATPase were measured in red cell membranes. Furthermore the intracellular concentration of sodium and potassium was measured in erythrocytes of 10 persons. These results display a significant age dependent decrease of enzyme activities. Contrary to this, measurements of intracellular sodium and potassium concentrations disclosed no age dependent changes. There was no positive or negative correlation between the enzyme activities and the intracellular concentrations of sodium and potassium. The influence of 8 different drugs on Mg++-ATPase activities was proofed. The results displayed changes dependent on age and drug concentrations. The results were discussed with those of the literature.

Adult↗
PubMedDate not supplied

[Rehabilitative treatment of cerebral apoplectic insults in advanced age and evaluating its effectiveness--results of a model project].

This report is of a two year study of stroke rehabilitation. Given certain conditions with specialized personnel and equipment the rehabilitation of elderly stroke patients can be managed co-operatively in hospitals and old age care centres. The rehabilitation of stroke affected is based on the support of multidisciplinary diagnosis and interdisciplinary teamwork between physicians, physiotherapists, occupational therapists, speech therapists, psychologists and social workers. Each patient requires an individual treatment program. In this study were 72 patients ranging in age from 42-87 years, average age 73 years. They had been judged as progressively degenerative and helpless following their stroke and consequently regarded as patients for a nursing home. Following special rehabilitation treatment 75% (54 patients) had improved enough that it was possible for them to return to their homes. Only 12.5% (9 patients) had to remain in a nursing home. 6.6% (4 patients) transferred to an old people's home. 6.9% (9 patients) were readmitted to hospital because of additional serious complications. The average duration of rehabilitative treatment was 72.3 days. The degree of hemiplegia and the patients ability to lead their own active daily independent life was reviewed before and after rehabilitation and used as control. 76.6% showed an improvement in their motor function. 61.1% returned to their own independent daily life as measured by ADL-Indices. (a. Barthel Index, b. ADL-Index-Katz-, c. Patient Classification for Long Term Care-Jones-, d. Crichton Royal Behavioural Rating Scale-Robinson-.).(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMedDate not supplied

[Pharmacokinetics of naftidrofuryl in multimorbidity in geriatric patients].

The present pharmacokinetic study of a drug used in geriatric patients with multiple diseases reveals that the half-life in the elderly was extended for about three times as long as in the corresponding control group. There are significant positive as well as negative correlations between the kinetic data and routine parameters of the metabolism. These statistical correlations should be controlled by experimental studies.

Aged↗
PubMedDate not supplied

[Furosemide--pharmacokinetics in geriatric patients with multimorbidity].

20 geriatric patients with multiple diseases were administered a single intravenous dose of 40 mg furosemide. Furosemide plasma and urine concentrations were measured using a thin-layer chromatography method (25) and were fitted to an open 2-compartment model. Furosemide half-life was prolonged twofold in the elderly patients compared with a control group of younger adults. In the same way renal clearance and total clearance were markedly reduced in the geriatric group. The nonrenal clearance and the volume of distribution (beta) were not significantly altered. There were many significant correlations between clinical and biochemical data and pharmacokinetic parameters, especially between blood pressure and the area under the curve (AUC 0-infinity), total clearance and nonrenal clearance of furosemide. Our data suggest a special function of alpha-2-globulins in binding of furosemide. Renal function (i.e. creatinine clearance) was shown to be an important parameter for estimating the elimination rate of furosemide.

Aged↗
PubMedDate not supplied

[Phagocytic activity of isolated perfused liver of rats of different ages. Biochemical and structural studies following perfusion with Cu-ceruloplasmin].

The phagocytic activity of young and old isolated perfused rat livers was measured referred to a glycoprotein (Cu-coeruloplasmin). It was shown that the phagocytic activity of the old rat liver is significantly higher than that of the young rat liver. There was no age-dependent difference of the parameters of liver function GOT, GPT, Kt and the quotients beta-OH-Butyric acid/Acetoacetate and lactate/butyrate.

3-Hydroxybutyric Acid↗
PubMedDate not supplied

Titration of rat liver with digitonin: a well defined short term damage of cellular metabolism.

Carefully performed pulse titration of the isolated rat live in the course of continuous erythrocyte free perfusion with small amounts of digitonin causes a short term permeability of liver cell plasma membranes with concomitant short lived release of intracellular low or high molecular compounds such as ATP or lactate dehydrogenase. Gluconeogenesis from lactate being completely inhibited during this period restores within about one minute up to a level that depends on the amount of perfused digitonin. The described experimental model is suggested to be useful for the measurement of cytoplasmic metabolites under physiological conditions. It moreover offers the possibility to import foreign substances into liver cells that normally do not penetrate liver cell plasma membranes.

Adenosine Triphosphate↗
PubMedDate not supplied

The response of umbilical vessels, with and without vascular endothelium, to local anesthesia in low PO2 and hypercarbia.

BACKGROUND AND OBJECTIVES: Human umbilical vessels are sensitive to local anesthetic agents as well as to a variety of other exogenous and endogenous substances. Changes in blood gases such as hypoxia and hypercarbia may alter these responses. This study examined the effects of local anesthetic agents under these conditions and how the effects are related to the vascular endothelium. METHODS: Veins and arteries, dissected from umbilical cords of healthy newborns, were cross-sectioned to form rings. The rings were mounted in a muscle chamber containing Krebs-Ringer bicarbonate solution that was gassed to approximate control, low PO2 or hypercarbic conditions. Changes in isometric tension were recorded in response to increasing concentrations of bupivacaine (B), lidocaine (L), or 2-chloroprocaine (2-CP). In half the experiments, intimal rubbing was used to remove the endothelium of rings for the purpose of disclosing the role of endothelial-derived factors. RESULTS: The normal contracting (increasing baseline tone) or relaxing (decreasing baseline tone) responses to local anesthesia were unchanged by hypercarbia, but low PO2 suppressed the relaxing effect of 2-CP on arteries. Removal of endothelium enhanced the relaxing effect of 2-CP on arteries, and unmasked a contracting effect of L on arteries. Rubbed vessels, while exposed to low PO2 or hypercarbia, became less responsive to 2-CP. CONCLUSIONS: Changes in the internal environment are capable of altering the response of umbilical vascular smooth muscle to local anesthesia. Additionally, the vascular endothelium appears to influence the degree of response to anesthesia.

Anesthetics, Local↗