Search PubMed⌕ Search

Biomedical subjects

K Martin

Publications and source records attributed to K Martin.

At least 19 recordsLinked to original sources
PubMed1992

Fenfluramine stimulation of prolactin in obsessive-compulsive disorder.

The success of serotonergic reuptake inhibitors in the treatment of obsessive-compulsive disorder (OCD) has suggested that serotonergic neurotransmission may play a role in the pathogenisis of this disorder. Prolactin responses to a 60-mg oral dose of fenfluramine in 26 medication-free patients with a DSM-III-R diagnosis of OCD were compared with those of 20 controls subjects. Fenfluramine produced a significant elevation of prolactin levels in both OCD patients and controls. Prolactin responses were significantly blunted in OCD patients compared with responses in control subjects. Female subjects in both groups showed greater prolactin responses to fenfluramine than did their male counterparts. There was a significant interaction between sex and the presence of OCD such that female patients had lower prolactin responses than their controls, while the difference between male patients and controls was not significant. Prolactin responses were not correlated with age, weight, drug level, depression, anxiety, or degree of OCD symptoms. The results are consistent with a relative reduction in serotonergic efficacy in the setting of OCD.

Adult↗
PubMed1992

Assessment of the renal circulation during pregnancy with color Doppler ultrasonography.

OBJECTIVES: A non-invasive method of assessing the renal vasculature during pregnancy would be useful in the management of patients with renal dysfunction resulting from preeclampsia or chronic renal disease. The objectives of this study were to determine (1) whether color ultrasonography during pregnancy facilitates Doppler interrogation of renal and intrarenal arteries, allowing (2) the assessment of differences between waveforms from nonpregnant and pregnant women and (3) the analysis of waveform variability throughout the kidney and between the right and left kidneys. STUDY DESIGN: In a cross-sectional study renal and intrarenal artery flow waveforms were obtained from women in early (12 to 19 weeks; n = 8), mid (20 to 29 weeks; n = 11), and late (30 to 37 weeks; n = 14) pregnancy with eight age-matched, nonpregnant women acting as controls. Waveforms were analyzed for pulsatility index, resistive index, and systolic/diastolic ratio. RESULTS: Left or right renal and upper- and lower-pole interlobar artery waveforms were obtained from all women. The mean pulsatility index values for the nonpregnant women were not significantly different from those women in early, mid, or late pregnancy. In the nonpregnant women, the left renal artery pulsatility index (1.13 +/- 0.13) was greater than the left lower interlobular artery pulsatility index (0.91 +/- 0.08; p < 0.05). During pregnancy renal and interlobar artery pulsatility index values were greater than those for the corresponding interlobular arteries, but the differences were not significant. Mean renal and intrarenal artery pulsatility index values were greater on the right, but the difference was significant only for the lower interlobular artery in midpregnancy. CONCLUSIONS: Pregnancy does not significantly affect renal and intrarenal artery flow waveforms, nor are there significant differences between waveforms from the renal and interlobar arteries.

Adult↗
PubMed1992

The assessment of carotid and vertebral arteries: a comparison of CFM duplex ultrasound with intravenous digital subtraction angiography.

The use of duplex ultrasound with colour flow mapping is compared with that of intravenous digital subtraction angiography (IVDSA) in the investigation of carotid and vertebral artery disease. Ninety-nine carotid and vertebral arteries were examined independently by IVDSA and ultrasound for location and degree of disease in 30 men (mean age 58) and 20 women (mean age 53). For purposes of comparison the carotid tree was divided into six segments. In 46% of cases no disease was detected by either modality. In 36% of cases where disease was found, ultrasound found mild disease in arteries reported as normal by IVDSA. Both modalities detected the six cases of total occlusion found in the study. IVDSA underestimated five cases of major disease found by ultrasound at the bifurcation or in the bulb. Overall agreement in grading vessel segments was good, with 74.5% in complete agreement and 90.3% grading stenoses to within +/- 25% of the other modality. There was good qualitative agreement in the findings for vertebral arteries. In four patients conventional arteriography was also available for comparison.

Adult↗
PubMed1992

The Omaha System. A research-based model for decision making.

This article describes the value, diversity, and potential benefits of the Omaha System in generalizing and manipulating client, clinical, and financial data. The authors provide examples of its utility for day-to-day and long-range clinical and financial decision making in home and public health agencies, colleges of nursing, and ambulatory care centers throughout the United States and Canada.

Aged↗
PubMed1991

Nuclear transport of influenza virus ribonucleoproteins: the viral matrix protein (M1) promotes export and inhibits import.

Because influenza virus replicates in the nucleus and buds from the plasma membrane, its ribonucleoproteins (RNPs) must undergo bidirectional transport across the nuclear membrane. Export from the nucleus to the cytoplasm was found to depend on the viral matrix protein (M1). M1 associated with newly assembled viral RNPs (vRNPs) in the nucleus and escorted them to the cytoplasm through the nuclear pores. In contrast, during entry of the virus into a new host cell, M1 protein dissociated from the RNPs, allowing them to enter the nucleus. Amantadine, an antiviral agent that induces an early block in influenza A infection, was found to block the dissociation event and thereby to prevent import of incoming RNPs into the nucleus. Together, these results showed that M1 modulates the directionality of vRNP transport into and out of the nucleus.

Amantadine↗
PubMed1991

Single-dose i.v. dexamethasone--an effective anti-emetic in cancer chemotherapy.

We conducted a randomised, single-blind, placebo-controlled crossover study to assess the efficacy of a single i.v. dose of 20 mg dexamethasone as an anti-emetic in 31 patients receiving cancer chemotherapy. Patients receiving dexamethasone experienced significantly less nausea and vomiting (P less than 0.001 and P less than 0.01, respectively), and appetite and activity were normal in a majority of the treated group. Side effects were insignificant. We conclude that single-dose dexamethasone given i.v. at a dose of 20 mg is a safe and effective anti-emetic for patients receiving cancer chemotherapy excluding cisplatin.

Adult↗
PubMed1991

Trends in diagnostic ultrasound exposure.

Trends in exposure for diagnostic ultrasonic equipment and a contemporary survey of exposure values are presented. It is demonstrated that both time-averaged intensities and peak pressures have increased steadily over the last two decades. Currently available diagnostic equipment generates pulses for which the average worst-case rarefaction pressure, p-, is about 2 MPa in water, irrespective of the mode of operation. Overall the highest values of p- are found in short-focus beams. Average spatial-peak time-averaged intensities, I(SPTA), are greatest for pulsed Doppler operation at a little over 1 W cm-2. M-mode and colour Doppler operation have average values of I(SPTA) of about 100 mW cm-2 and imaging operates at about an order of magnitude lower again. Vaginal transducers differ little in operational exposure from other transducers. Exposure measurement on colour Doppler systems demands a knowledge of the effect of scanner controls on the field, and some details are given.

Humans↗
PubMed1991

Transport of incoming influenza virus nucleocapsids into the nucleus.

Upon penetration of the influenza virus nucleocapsid into the host cell cytoplasm, the viral RNA and associated proteins are transported to the nucleus, where viral transcription and replication occur. By using quantitative confocal microscopy, we have found that over half of cell-associated nucleoprotein (NP) entered the nucleus with a half time of 10 min after penetration into CHO cells. Microinjection and immunoelectron microscopy experiments indicated that the NP entered the nucleus through the nuclear pore as part of an intact ribonucleoprotein (RNP) structure and that its transport was an active process. Transport of the incoming RNPs into the nucleus was not dependent on an intact microfilament, microtubule, or intermediate filament network. Subsequent to penetration, the matrix (M1) protein appeared to dissociate from the RNP structure and to enter the nucleus independently of the RNP. We found that 50% of penetrated M1 entered the nucleus with a half time of 25 min after penetration into CHO cells. Nuclear transport of M1 appeared to occur by passive diffusion. Entry of incoming M1 into the nucleus was not a prerequisite for infection.

Animals↗
PubMed1990

[Characteristics of the occurrence of hematotoxic side effects of cytostatic drugs--results of a retrospective 10 year study of a district hospital].

From 1978 to 1988 in 77 patients of a district hospital, 58 females and 19 males, with malignant tumours or haemoblastoses a therapy with cytostatic agents was finished. A retrospective study analyses characteristics of haematotoxic side effects of cytostatic agents, which despite usual dosage according to the valid guide-lines have appeared in this patient population. According to this the granulocytopoiesis is injured most frequently and most severely. In one third of all patients under influence of cytostatic agents the number of the segment-nuclear granulocytes in the peripheral blood decreased deeper than 0.5 Gpt/l (severe neutropenia). In toxic influences on the thrombopoiesis slight and medium degrees of severity are dominating. Lesions of the erythropoiesis are apparently more infrequent, though they are more difficult to be proved. Further characteristics in the occurrence of severe neutropenias (date, dependence on age, pharmacological aspects) are demonstrated and discussed.

Aged↗
PubMed1990

Host response to mycobacterial infection in the alcoholic rat.

Animals, chronically treated with alcohol, were inoculated with mycobacteria (bacillus Calmette-Guérin, 10.2 x 10(6) organisms) into the spleen to produce a granulomatous hepatitis. Before infection, chronic alcohol ingestion was associated with a depressed skin test response to phytohemagglutinin, 71.7% of baseline (P = 0.009). Mycobacterial (bacillus Calmette-Guérin) infection stimulated phytohemagglutinin skin test response to 417% of baseline in controls and 299% in alcoholics (P less than 0.001). The hepatic granuloma response was altered with smaller but more numerous granulomas (mean +/- SEM, 81.2 +/- 1.5 microns2 of area with a frequency of 1.8 granulomas per field in alcoholics vs. 129.8 +/- 5.71 microns2 and 1.2 granulomas per field in controls; P less than 0.001). These changes were associated with a 10-fold increase in colony-forming units per gram of liver (54.5 +/- 18.2 in alcoholics vs. 5.6 +/- 1.83 in controls; P = 0.0006). This model offers precise parameters for host response to infection and indicates that alcohol significantly impairs the clearing capacity for mycobacteria from the liver.

Alcoholism↗
PubMed1990

Anabolic steroid effects on immune function: differences between analogues.

As an untoward effect of chronic anabolic steroid use, immunologic alterations may be induced. To evaluate this possibility five commercially available steroids with various types of structural differences were studied in male Sprague-Dawley rats. Animals were divided into five groups and treated with testosterone (Group 1), testosterone propionate (Group 2), testolactone (Group 3), oxandrolone (Group 4), and stanozolol (Group 5). Androgenic anabolic steroids were administered daily, subcutaneously dissolved in oil, at a dose of 1.1 mg/kg. Immune alterations were assessed by skin-test responses to phytohemagglutinin. After five days of treatment (1.1 mg/kg/day) a significant immuno-suppression was observed with all groups. However, by day 10, groups 3, 4, and 5 showed an immuno-stimulation. Using oxandrolone as the model stimulant, serum testosterone levels were significantly suppressed, while castration abolished the stimulatory effect. These observations indicate that immune alterations do occur with anabolic steroids which are immuno-suppressive when the steroid nucleus is intact and immuno-stimulatory with nuclear alterations. It appears that these changes are associated with altered gonadal testosterone release.

Anabolic Agents↗
PubMed1990

Clinical review 15: Management of ovulatory disorders with pulsatile gonadotropin-releasing hormone.

Pulsatile GnRH therapy has yet to achieve widespread acceptance as an alternative to exogenous gonadotropin therapy in women with hypothalamic amenorrhea and complete GnRH deficiency. However, when a physiologically based replacement regimen of pulsatile GnRH is used, a high rate of ovulation and conception can be anticipated in patients with complete GnRH deficiency and hypothalamic amenorrhea. Women with polycystic ovarian syndrome may also benefit from pulsatile GnRH, although rates of ovulation are lower. Pretreatment with a GnRH agonist may improve these rates considerably, but experience is limited. Whether an iv or sc route of administration is chosen, a simplified clinical monitoring protocol can be created which requires a minimum of patient monitoring while assuring maximum safety. Seventy five nanograms per kg appears to be a reasonable initiating dose, with subsequent increases in those who do not respond. The frequency of GnRH administration is best based on the GnRH pulse frequency in normal women. However, further information is needed to determine whether such a variable frequency is clearly superior to a fixed frequency regimen. When used appropriately, pulsatile GnRH is safe, effective, and offers an excellent alternative to conventional gonadotropin therapy for women with disordered endogenous GnRH secretion. Most importantly, and as opposed to exogenous gonadotropin therapy, pulsatile GnRH can be administered by most physicians in the office setting without the necessity of on-line E2 monitoring. This feature will enable more patients to receive treatment by their local physicians, whereas exogenous gonadotropin therapy should be administered by appropriately equipped referral centers. In the future, further studies will be required to determine which other categories of patients might benefit from pulsatile GnRH.

Adult↗
PubMed1989

Basic extraction studies of benzylpenicillin and its determination by liquid chromatography with pre-column derivatisation.

In order to develop a sensitive and precise chemical bioanalysis of benzylpenicillin in biological fluids, basic studies on benzylpenicillin are presented. These studies include pH dependent stability, extraction in aqueous ethylacetate systems in different pH and buffer compositions. A pre-column derivatisation LC method for the detection of benzylpenicillin also is described. The derivatisation of the sample is performed by the beta-lactam ring specific formation of the mercuric(II)mercaptide of the penicillenic acid in the presence of imidazole. The UV spectral properties of the derivative are utilised for detection. The chromatographic conditions are optimised with reference to the pH, the methanol, the imidazole and the mercury(II)chloride content of the mobile phase as well as the column temperature.

Chromatography, Liquid↗