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Biomedical subjects

M Marshall

Publications and source records attributed to M Marshall.

At least 145 records · Page 8Linked to original sources
PubMed1990

[Iloprost in the treatment of ischemic tissue lesions in diabetics. Results of a placebo-controlled multicenter study with a stable prostacyclin derivative].

The efficacy of iloprost, a stable prostacyclin analog, was investigated in a placebo-controlled trial in 109 diabetics with ischemic lesions. 56 patients were randomly allocated to iloprost and 53 patients to placebo. Iloprost was intravenously applied for 6 hours daily on 28 consecutive days at an individually tolerated dose up to 2 ng/kg/min. The control group received identical solvent volumes. In addition all patients had an intensive basic, mainly local, therapy. At the end of the treatment in the iloprost group 31 of 50 patients (62%) showed partial (greater than 30%) or total healing of the lesion(s). In the placebo group this was the case in 12 of 51 patients (22.5%). The difference of 38.5% was statistically significant (p less than 0.05, chi 2-test, alpha = 0.05, beta = 0.1). The percentage of patients who were free of pain increased from 23% to 42% (+19%) in the iloprost group and from 38% to 48% (+10%) in the placebo group. After dose-titration iloprost was well tolerated. Flush, headache and abdominal complaints were the most frequent side effects. Heart rate and blood pressure were not influenced and the control of diabetes was not altered.

Adult↗
PubMed1990

"Problem deflation" and the ethnographic record: interpretation and introspection in anthropological studies of alcohol.

A controversy that has continued over the past 5 years concerning whether ethnographic studies of alcohol systematically "deflate" alcohol-related problems is discussed and critiqued. This debate harbors some fundamentally significant matters that have important implications for the future of alcohol and culture studies. These matters concern the epistemological basis of ethnography, and the reliability of ethnographic research methods. Drawing upon data from Truk, Federated States of Micronesia, these issues are explored in detail. It is suggested that the presence or absence of "alcohol problems" in ethnographic accounts is largely a result of particular interpretations made at specific historical moments in the changing, open-ended systems that anthropologists study. It is concluded that by alerting us to likely biases in the ethnographic record, Room has performed a signal service to the anthropology of alcohol.

Alcohol Drinking↗
PubMed1990

[Terminology of ultrasonic vascular diagnosis].

There is at present no accepted nomenclature regarding diagnostic vascular ultrasound. At two scientific meetings, the Study Group for Vascular Diagnosis of the German Society of Ultrasound in Medicine (DEGUM) developed a terminology for Doppler and duplex sonography of the arteries and veins supplying the brain and of peripheral vessels. The most important of these sonographic terms and their synonyms are presented. Recommendations as to which of the presently employed terms should be avoided, are given.

Brain↗
PubMed1990

Studies of aerosol distributions in a small laboratory containing a heated phantom.

In order to provide information to assist in the design and planning of workplace air-sampling facilities, we have studied the variations in time and space of aerosol concentrations in a small room containing a glove-box and a heated phantom. Aerosol concentrations are reduced by factors of 10(2)-10(3) between the source and the phantom and walls of the room. Time-series plots of concentration show large departures from mean concentrations and fluctuations measured at the mouth and chest of the phantom are frequently uncorrelated. Both the average concentration around the phantom and the fluctuations in concentration tend to increase when the phantom is heated.

Aerosols↗
PubMed1990

Combining insights from epidemiological and ethnographic data to investigate substance use in Truk, Federated States of Micronesia.

There has been a recent concern in medical anthropology to combine quantitative epidemiological survey methods with qualitative ethnographic fieldwork methods as a means for drawing on the strengths of both approaches. This article shows the advantages of doing this by examining data on substance use and abuse from Truk, Federated States of Micronesia. Ethnographic research in 1976 based solely on qualitative methods is compared with a second study by the same investigator on the same island 9 years later that combined ethnographic fieldwork with an epidemiological general population survey of substance use by 1000 adults. The survey data were found to support many of the ethnographic conclusions, provide some new information not revealed by use of the qualitative methods and call into question a few interpretations of Trukese drinking based on qualitative data alone. This buttresses the argument that these methods are complementary, provide a cross-check on one another and yield more information when used together than either does by itself.

Adolescent↗
PubMed1989

Collected and neglected: are Oxford hostels for the homeless filling up with disabled psychiatric patients?

OBJECTIVE: To assess the severity of psychiatric symptoms among residents of hostels for homeless people. DESIGN: Survey of residents in two hostels in Oxford, comprising three weeks of background fieldwork, a demographic questionnaire, and rating behaviour over two weeks with a behavioural rating scale (REHAB) and mental state with the brief psychiatric rating scale. SETTING: Two hostels for homeless people in Oxford. SUBJECTS: 146 Medium to long term residents, of whom 48 were selected by hostel workers by the following criteria: continuous residence for at least two months, signs of persistent severe mental disability, and difficulty in coping independently in the community. Two subjects died during the study; three (previously long term psychiatric inpatients) declined to be assessed on the psychiatric scale. MAIN OUTCOME MEASURE: Behavioural disturbance and mental state. RESULTS: Only a third of the total sample had been born in Oxfordshire. Subjects had been accepted into the hostel either by arrangement with the local psychiatric service (22) or straight off the streets (26); 43 had had a previous (non-drug related) psychiatric admission. Subjects were significantly more likely than other residents to have spent longer (greater than 80 weeks) in a hostel in the past three years (p less than 0.02). With reference to norms for deviant behaviour, the 46 subjects assessed showed considerable deviant behaviour (average weekly scores: 0 (11 subjects), 1 (14), 2-3 (16), and greater than or equal to 4 (5] not significantly different from that expected in moderately to severely handicapped psychiatric inpatients (chi 2 = 1.3, df = 3, p greater than 0.7); 22 had scores equivalent to those in most severely handicapped inpatients. Of the 43 subjects assessed with the psychiatric rating scale, 16 had symptoms of neurosis, 29 of florid psychosis, and 32 of a deficit state. Symptoms of deficit state were positively correlated with ratings of low social activity on the behavioural scale (Spearman's rank correlation coefficient 0.30, p = 0.03). CONCLUSIONS: Hostels are having to care for long term severely affected psychiatric patients discharged into the community. The suitability of the services offered to such subjects should be assessed.

Deinstitutionalization↗
PubMed1989

[Phlebologic indications for duplex sonography].

Duplex ultrasonography has all the features required considerably to enrich the angiological-phlebological diagnostic work-up in the doctor's office. It is a harmless, noninvasive, functional and morphological examination technique that is available at any time. Major application possibilities are to be seen in the diagnosis of deep vein thrombosis, in the differentiated evaluation of insufficiency of the major vein, in the direct representation of insufficient perforating veins, and, in particular, for providing highly informative monitoring of the success of therapeutic measures. At the present time, however, points that militate against its use in the doctor's office are the high price of the equipment, and the requirements for further training, which are difficult to meet in the case of practising physicians.

Blood Flow Velocity↗
PubMed1989

[Iloprost, a stable prostacyclin derivative, in stage 4 arterial occlusive disease. A placebo-controlled multicenter study].

The effectiveness of iloprost, a prostacyclin derivative, was assessed in a placebo-controlled multicentre trial on 101 patients with chronic arterial disease, stage IV. All patients were on a basic local treatment, 53 randomly being assigned to the iloprost group, 48 to the placebo one. Both groups received identical saline infusions, one with the other without iloprost. Infusions were given on 28 consecutive days, iloprost being added at a dose of up to 2 ng/kg.min over six hours. At the end of the treatment period, 32 of 52 patients (61.5%) of the iloprost group and eight of the 47 in the placebo group (17%) had partial or complete healing of ulcers (P less than 0.05), the treatment effect persisting in both groups for a mean duration of at least one year. Iloprost was well tolerated, once individual dosages had been appropriately adjusted. Facial flushes, headache and nausea were the most common side effects. Heart rate and blood-pressure variations did not differ between the two groups.

Adult↗
PubMed1989

[Social medicine significance, costs, course, therapy and prognosis of venous diseases].

In particular chronic venous diseases are of considerable sociomedical and socioeconomic significance, and often start early in the age of professional activity. In Germany the number of early retirement is about 2.500 per year. Nevertheless they lack the well-deserved acceptance in the medicopolitical and sociomedical sector, what in addition makes the care for persons suffering from venous diseases at their place of work more difficult, as well as the problematic assessment of chronic venous diseases anyhow and the suitable rehabilitation. Even if there is no occupational disease which manifests itself in the venous system in a particular way, the venous diseases would have essential importance for the occupational medicine. Thus standing pursuit of profession means an essential strain of the peripheral venous system, at least in men it is a risk factor for the appearance of varices, and in women it increasingly leads to pain in the legs. Apart from traumatic lesions in the venous system the "thrombose par effort" may be caused in an almost typical way by hard professional work. The interactions, too, between the therapy of venous diseases and pursuit of profession are manifold, for example a compression treatment at sitting activity. The works medical officer, after all, and if need be, even the expert's opinion has particular chances concerning venous diseases: information and vocational guidance; non-invasive, functional orientated diagnostics; primary and secondary prevention; equipment of working place and process and support of treatment and rehabilitation with simple but effective measures. The therapeutic possibilities in venous diseases are differentiated and practicable.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Insulin-like growth factor-II (IGF-II): a potential autocrine/paracrine growth factor for human breast cancer acting via the IGF-I receptor.

Insulin-like growth factor-II (IGF-II) is a potent mitogen for several types of cultured cells and tissues. We have studied the interaction of IGF-II with a panel of cultured human breast cancer cell lines, examining the possibility that these cells synthesize and secrete IGF-II activity which could have autocrine/paracrine functions. Synthetic IGF-II was mitogenic in five of seven cell lines tested, including the estrogen receptor-positive lines MCF-7L, ZR75-1, and T47D and the estrogen receptor (ER)-negative lines Hs578T and MDA-231. IGF-II was slightly less potent than IGF-I in stimulating DNA synthesis in MCF-71 cells, an effect that paralleled its ability to compete for [125I]IGF-I binding in these cells. Affinity labeling studies revealed that IGF-II could also compete for binding to the 130,000 mol wt alpha-subunit of the IGF-I receptor. A monoclonal antibody to the IGF-I receptor inhibited the mitogenic effects of IGF-II in MCF-7L and MDA-231 cells, suggesting that this receptor mediates the growth effects of IGF-II in these breast cancer cells. Using a RIA and a RRA, IGF-II-like activity was detected in conditioned medium extracts processed to remove IGF-binding proteins from several breast cancer cell lines, with the highest levels found in conditioned medium from MCF-7L and T47D cell lines. IGF-II mRNA transcripts in MCF-7L and T47D cells were identified by Northern blot analysis and were confirmed by RNase protection assay. IGF-II mRNA was increased by estrogen in MCF-7L cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding, Competitive↗
PubMed1988

Determination of transforming growth factor activity in effusions from cancer patients.

Transforming growth factors (TGF) are polypeptides that stimulate anchorage-independent growth of various nontransformed cells in vitro. Transforming growth factors have been found in tumor extracts and in the urine of cancer patients. The specific questions of our study were whether TGF activity can be detected in malignant effusions, how different assays for TGF correlate with each other, and how assays for TGF correlate with soft agar tumor colony formation as measured by the human tumor cloning assay (HTCA). The TGF activity was measured by a normal rat kidney transformation assay (NRKA), a 125I-EGF radioreceptor assay (RRA), and a radioimmunoassay (RIA) for TGF-alpha. Cells from effusions were cytologically examined and plated in the HTCA. A total of 104 effusions from cancer patients and 17 effusions from non-cancer patients was tested. Transforming growth factor activity was detected in some specimens. Only the TGF-alpha RIA and the HTCA showed significant differences between cancer and noncancer patients. Immunoreactive TGF-alpha was measurable in some cases by RIA even when cytologic testing failed to detect malignant cells. Spearman correlations between assays indicated that RIA results correlate significantly with all other assays. It is concluded that TGF-alpha activity might be important for in vitro colony formation of human tumor cells.

Ascitic Fluid↗
PubMed1988

Proteolysis as a probe of ligand-associated conformational changes in rat carbamyl phosphate synthetase I.

Elastase, V8 protease, subtilisin, trypsin, and chymotrypsin all cleaved the 1462-residue polypeptide of rat carbamyl phosphate synthetase I in segment C 160-180 residues from the COOH-end. Its activator N-acetylglutamate (AcGlu) increased the rate of cleavage approximately ninefold, presumably by binding preferentially to the conformation in which C is exposed. ATP/Mg2+ prevented proteolysis both +/- AcGlu. Kd,app for AcGlu (66 microM) and ATP (4.2 microM with AcGlu and 5 mM Mg2+) was estimated from the pseudo-first-order rate constants for inactivation caused by cleavage with elastase at C. Chymotrypsin and trypsin also hydrolyzed the enzyme, independent of AcGlu, at site D within less than 20 residues of the COOH-end. D was protected by ATP only in the presence of AcGlu and K+, and enzyme hydrolyzed exclusively at D had greater than 30-fold higher Km's for AcGlu and ATP. Digestion by trypsin at a third site (B) approximately 530 residues upstream from C appeared to occur subsequent to hydrolysis at C. Slow cleavage by elastase at an additional site (A) to give 360- and 1100-residue peptides was unaffected by AcGlu and ATP, and caused only modest loss of activity. These peptides were isolated by chromatography on DEAE-cellulose. Assignment of the smaller one to the NH2-end on the basis of its cysteine content places site A in the junction between the segments homologous to the small glutaminase and large synthetase subunits of Escherichia coli carbamyl phosphate synthetase II. Neither peptide alone was active; maximal regain of activity (approximately 25%) occurred on combining them in equimolar proportions. The sizes of the peptides produced by further digestion of the site A digest gave the approximate locations of the other sites. Sites A (Ala-417) and B (Arg-787) have recently been identified by NH2-terminal sequencing (S. G. Powers-Lee and K. Corina (1986) J. Biol. Chem. 261, 15349-15352). Reasons for the low value of KAcGlu,app are examined, and protection by ATP is discussed in relation to previous models for the conformational equilibria of the enzyme.

Adenosine↗
PubMed1988

Sources of resistance to an intern support group.

When senior house officers were observed to be resistant to an intern support group, they were surveyed in order to identify the sources of their resistance. Sixty-nine percent of house officers in postgraduate year two (PGY-2) and PGY-3 responded to an anonymous seven-item survey. Although their attitudes toward supportive programs were generally favorable, a minority of the house officers felt that residents expressing the need for support were less competent than other residents or needed to change to a less rigorous specialty. A majority felt that it was unfair to require senior house officers to provide coverage for interns attending a support group. They felt that support should be made available to all house officers rather than interns only and that stress would be reduced by eliminating the sources of stress as well as by providing supportive programs. Training program directors need to be aware of and anticipate these attitudes before designing supportive programs.

Attitude of Health Personnel↗
PubMed1988

Blood rheology in patients with transient ischemic attacks.

A complete ischemic stroke is associated with a significant hemorheologic disturbance leading to a rise of the viscous component of the peripheral resistance. This abnormality represents a consequence of the acute event. Nonetheless, it could be causally related to ischemia. In an attempt to clarify this question, 26 patients suffering from transient ischemic attacks were compared with controls in terms of blood and plasma viscosity, hematocrit, blood cell filterability, and erythrocyte aggregation. In patients there was a significant impairment of blood fluidity comprising plasma viscosity, blood cell filterability, and erythrocyte aggregation, suggesting that the flow properties of blood are jeopardized even before an acute stroke. Most likely this is due to the underlying arteriosclerotic process. Our results open the way to speculating that hemorheologic mechanisms might predispose to the development of a stroke by decreasing cerebral blood flow. If this hypothesis were true, it would have important therapeutic implications.

Adult↗
PubMed1988

Alcohol consumption as a public health problem in Papua New Guinea.

A 2-year alcohol study was undertaken for the Papua New Guinea Institute of Applied Social and Economic Research (IASER). This paper reports project findings bearing on general public health related to alcohol consumption: (1) Much trauma is alcohol related-particularly trauma caused by motor vehicle accidents. (2) Continued ingestion of nonbeverage alcohols--principally methanol--exacts a significant public health toll. (3) Patterns of drinking and national trends in beverage alcohol consumption suggest that alcoholic cirrhosis and cancer of the upper respiratory and upper digestive tracts will contribute to increased mortality among Papua New Guineans.

Alcoholic Intoxication↗
PubMed1988

[Doppler diagnosis in peripheral arterial occlusive disease].

PHYSICAL AND TECHNICAL FUNDAMENTALS OF DOPPLER ULTRASONOGRAPHIC METHODS: In addition to units recording both velocity and direction of blood flow, mostly using two ultrasonic frequencies and phase-out technique, there are small non-directional units available which provide useful diagnostic information from the acoustic Doppler signal derived. Doppler ultrasonic techniques utilize two physical phenomena: a) High-frequency ultrasonic energy penetrates biologic tissue and is partially reflected at borders between tissues of differing density. b) If the border area is in motion, due to the Doppler effect, there is a change in the reflected ultrasonic frequency with respect to the frequency emitted. In blood vessels the ultrasonic beam is primarily reflected from the flowing red blood cells where the change in frequency is a function of the velocity of flow (Doppler effect). From the Doppler transducer, the continuously-emitted ultrasonic beam is also received after being reflected. The frequency of the reflected beam is directly proportional to the velocity of the flowing blood. If flow is directed toward the transducer, the frequency of the reflected beam increases and if the flow is away from the transducer, the converse is true. The best Doppler signals can be received when the angle beta of the transducer to the studied vessel is about 45 degrees. The unprocessed Doppler signal represents a frequency spectrum corresponding to the various velocities of the individual lamina of the blood stream from which the prevailing velocity is integrated and registered. The penetration depth is dependent on the frequency emitted. Doppler units are preferred with working frequencies of 8 to 10 MHz and 3 to 5 MHz. With 8 MHz, the maximal depth of penetration is 3.5 cm, with 4 MHz, 8 cm. The lowest detectable velocity is also dependent on the frequency emitted: with 8 MHz, minimum is 3 cm/s. Since flow toward the transducer results in a positive Doppler shift and flow away in a negative shift, with the Doppler signal, the direction of flow can also be determined. The recorded Doppler curves enable a qualitative and, to some degree, quantitative assessment. Phase-out and frequency analysis systems enable differentiation of forward and backward flow components. From separate forward and backward flow curves, the instantaneous summation curve (integrated instantaneous hemotachygram) as well as a trend curve over 5 to 7 seconds can be constructed and the mean flow velocity displayed.

Arterial Occlusive Diseases↗
PubMed1988

[Rational diagnosis in phlebologic practice].

Venous diseases are of extraordinary sociomedical and socioeconomic relevance. They are a daily problem in general practice and require careful diagnostic clarification and exact definition with regard to differential diagnosis. In the diagnosis of important venous diseases Doppler sonography must always be carried out after the case history has been taken and a physical examination has been performed. It allows a relatively fast, functionally orientated and differentiated assessment of all venous diseases of the lower and upper extremities and does not involve any risk. At present, it cannot be replaced by any other method either in general or in clinical practice, and also serves as an indication for phlebography for example. Duplex sonography can supplement Doppler ultrasonography significantly, but this examination is still very expensive. There are fundamental sources of error in photoplethysmography and this technique has considerable limitations. It never can replace Doppler ultrasonography. Its only well-founded application - besides a general determination of a more pronounced venous transport disturbance - is to test the haemodynamic effect of eliminating important venous insufficiency points as preparation for invasive forms of therapy. The kind of examination shown here offers the best prerequisites for rational diagnosis in phlebological practice.

Humans↗