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Biomedical subjects

L Meyer

Publications and source records attributed to L Meyer.

At least 163 records · Page 9Linked to original sources
PubMed1994

Surveillance of sexually transmitted diseases in France: recent trends and incidence.

OBJECTIVE: To present recent trends in sexually transmitted diseases (STDs) in France and to estimate the gonorrhoea incidence in 1990. METHODS: Trends were analysed from data of three surveillance systems: (1) STD clinics: number of diagnoses, (2) a sentinel voluntary General Practitioner (GP) network: mean number of acute male urethritis/week/GP, characteristics of the notified urethritis (age, presence of discharge, sexual orientation), (3) a sentinel voluntary laboratory network: mean number of gonorrhoea isolates/month/laboratory, characteristics of patients with positive isolates (sex, age, site of sampling) and of strains (PPNG and TRNG rates). To estimate the gonorrhoea incidence in France in 1990, results of a study held among a national sample of laboratories were used, combined with data from surveillance systems and specific studies. RESULTS: Decreasing trends in gonorrhoea in STD clinics and in the laboratory network as well as in acute male urethritis in the GP network have been observed since implementation of the networks in 1985. The rate of PPNG strains has regularly increased in the laboratory network to reach 14% in 1991. Data suggest that the incidence in some acute non recurrent STDs could have increased among homo/bisexual men since 1988. Chlamydia trachomatis is now the most frequent diagnosis in STD clinics. Estimation of male gonorrhoea incidence rate in France in 1990 of 74/100,000 inhabitants (15-59 years) is consistent with figures observed in England and Wales, where the age distribution is very similar. On the other hand, the estimated female gonorrhoea incidence rate of 14/100,000, which concerns only microbiologically ascertained cases, is one third in France than that observed in England and Wales. CONCLUSION: The consistency of the decreasing trends in gonorrhoea and acute male urethritis observed from the different networks reduces the possibility of a bias due to any change in notification or in prescription. Trends in Chlamydia trachomatis will be better appraised in the near future with the recent implementation of new systems. The French STD surveillance appears quite satisfactory for male infections and has been able to show a marked decrease in the incidence of some STDs in the last years. Surveillance of female STDs is to be improved, in terms of monitored diagnoses and selected health care facilities. Differences between the female gonorrhoea incidence rate observed in England and Wales and the one computed for France could be attributed to differences in contact tracing policies between the two countries or to differences in sexual lifestyles.

Adolescent↗
PubMed1994

Outbreak of pyrogenic reactions and gram-negative bacteremia in a hemodialysis center.

Six episodes of gram-negative bacteremia and seven pyrogenic reactions occurred in 11 patients in one hemodialysis center. Gram-negative bacteremias and/or pyrogenic reactions were not related to reuse and were more likely to occur if dialysis was performed in one unit of the center (8/13 unit 5 vs. 221/1,151 in other units, p < 0.001) and with one type of dialysis machine (10/13 vs. 581/1,151 with other machines, p = 0.05), which was preferentially used in unit 5 (p < 0.01). Bacterial and endotoxin concentrations of water used to prepare dialysate and reprocess hemodialyzers, and of dialysate, exceeded allowable concentrations recommended by the Association for the Advancement of Medical Instrumentation (AAMI). The implicated dialysis machines were disinfected with chemicals daily, but not heat-disinfected daily as suggested by the manufacturer. Results suggest that the outbreak was caused by the use of water that did not meet AAMI standards and inadequate disinfection of one type of dialysis machine.

Adult↗
PubMed1994

[Radiotherapy of ocular melanoma: physical and radiobiological bases, current techniques and future prospects].

Primitive ocular melanoma is a rare tumor in adults. Although this tumor is radio-resistant and located in a very radiosensitive organ, a conservative approach using radiotherapy is feasible for small or medium size melanomas. The physical and radiobiological basis of the techniques presently used, brachytherapy and protontherapy, are presented together with the complications inherent to each treatment. Future prospects discussed concern the association of hyperthermia with conventional irradiation and Boron Neutron Capture Therapy (BNCT). The relevance of each technique with reference to the size and location of the tumor is discussed.

Eye Neoplasms↗
PubMed1993

The psychological morbidity of breast cancer-related arm swelling. Psychological morbidity of lymphoedema.

BACKGROUND: The psychological morbidity, functional impairment, and disturbance in psychosocial adjustment to illness was evaluated in relation to breast cancer-related arm swelling. METHODS: Fifty women with breast cancer-related arm swelling were matched with 50 control subjects for age, duration since treatment, and type of treatment received. All study participants were free from active disease and had been treated more than 1 year ago. RESULTS: Patients with arm swelling showed greater psychological morbidity at formal psychiatric interview, impaired adjustment to illness as evaluated by the Psychosocial Adjustment to Illness Scale, and greater impairment of physical functioning. CONCLUSIONS: Patients with arm swelling in relation to breast cancer experienced functional impairment, psychosocial maladjustment, and increased psychological morbidity. These findings have implications for management of breast cancer.

Activities of Daily Living↗
PubMed1993

Experimental thrombosis on a collagen coated arterioarterial shunt in rats: a pharmacological model to study antithrombotic agents inhibiting thrombin formation and platelet deposition.

A rat thrombosis model was developed to assess the efficacity of antithrombotic drugs. It had the following characteristics: controlled hemodynamic and rheological conditions corresponding to arterial flow, a collagen coated surface as a relevant thrombogenic stimulus, a method of measurement allowing dynamic monitoring of thrombus formation and the possibility to assess the thrombus structure. A shunt composed of polyethylene and silicone catheters, including in the middle of the shunt a collagen coated glass capillary, was inserted between the two primitive carotids of the rat. The duration of patency of the shunt was recorded using a thermic probe fixed on its central part. In this model, the patency of the shunt was 539 +/- 55 s. Platelet and fibrinogen-fibrin accumulation in successive one centimeter segments along the shunt were measured using 111In labeled platelets and 125I labeled fibrinogen. Platelet accumulation occurred on the collagen coated surface and at the junctions between the different components of the shunt, where flow was disturbed. The effects of four antithrombotic agents were measured: aspirin, clopidogrel, heparin and r-hirudin. Clopidogrel, heparin and hirudin significantly prolonged patency duration of the shunt, whereas aspirin was inactive. Aspirin did not reduce platelet or fibrinogen-fibrin accumulation on the collagen coated surface. Platelet accumulation on the collagen surface was significantly lower in the clopidogrel group (50 mg/kg) than in the group treated with heparin (500 U/kg), demonstrating the direct antiplatelet effect of clopidogrel. Hirudin at doses giving similar values of APTT as heparin (500 U/kg) prolonged the occlusion time to over 2 h while the heparin occlusion time was only 20 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

GM-CSF triggers a rapid, glucose dependent extracellular acidification by TF-1 cells: evidence for sodium/proton antiporter and PKC mediated activation of acid production.

The extracellular acidification rate of the human bone marrow cell line, TF-1, increases rapidly in response to a bolus of recombinant granulocyte-macrophage colony stimulating factor (GM-CSF). Extracellular acidification rates were measured using a silicon microphysiometer. This instrument contains micro-flow chambers equipped with potentiometric sensors to monitor pH. The cells are immobilized in a fibrin clot sandwiched between two porous polycarbonate membranes. The membranes are part of a disposable plastic "cell capsule" that fits into the microphysiometer flow chamber. The GM-CSF activated acidification burst is dose dependent and can be neutralized by pretreating the cytokine with anti-GM-CSF antibody. The acidification burst can be resolved kinetically into at least two components. A rapid component of the burst is due to activation of the sodium/proton antiporter as evidenced by its elimination in sodium-free medium and in the presence of amiloride. A slower component of the GM-CSF response is a consequence of increased glycolytic metabolism as demonstrated by its dependence on D-glucose as a medium nutrient. Okadaic acid (a phospho-serine/threonine phosphatase inhibitor), phorbol 12-myristate 13-acetate (PMA, a protein kinase C (PKC) activator), and ionomycin (a calcium ionophore) all produce metabolic bursts in TF-1 cells similar to the GM-CSF response. Pretreatment of TF-1 cells with PMA for 18 h resulted in loss of the GM-CSF acidification response. Although this treatment is reported to destroy protein kinase activity, we demonstrate here that it also down-regulates expression of high-affinity GM-CSF receptors on the surface of TF-1 cells. In addition, GM-CSF driven TF-1 cell proliferation was decreased after the 18 h PMA treatment. Short-term treatment with PMA (1-2 h) again resulted in loss of the GM-CSF acidification response, but without a decrease in expression of high-affinity GM-CSF receptors. Evidence for involvement of PKC in GM-CSF signal transduction was obtained using calphostin C, a specific inhibitor of PKC, which inhibited the GM-CSF metabolic burst at a subtoxic concentration. Genistein and herbimycin A, tyrosine kinase inhibitors, both inhibited the GM-CSF response of TF-1 cells, but only at levels high enough to also inhibit stimulation by PMA. These results indicate that GM-CSF activated extracellular acidification of TF-1 cells is caused by increases in sodium/proton antiporter activity and glycolysis, through protein kinase signalling pathways which can be both activated and down-regulated by PMA.

Benzoquinones↗
PubMed1993

Comparison of patient telephone survey with traditional surveillance and monthly physician questionnaires in monitoring surgical wound infections.

OBJECTIVE: To evaluate the utility of patient telephone surveys in further improving the detection of surgical wound infections (SWIs) postdischarge in the setting of ongoing traditional surveillance system and monthly physician surveys. DESIGN: Prospective surveillance study of randomly selected patients undergoing surgery in inpatient or outpatient settings. SETTING: Tertiary care suburban hospital. RESULTS: Five hundred one patients were randomly selected for telephone contact, of whom 189 (38%) were successfully contacted after three attempts. Eighteen (9.5%) patients reported one or more signs or symptoms of possible SWI. However, none of these patients required antibiotic therapy, was hospitalized with an SWI, or reported by his or her physician (based on the monthly questionnaire) to have had an SWI. Total time spent contacting patients was 47 hours and 48 minutes, or 15 minutes per each successful telephone contact. CONCLUSIONS: Patient telephone surveys as conducted in this study were inefficient and failed to substantially improve the rate of detection of SWIs over traditional surveillance system and monthly physician questionnaires.

Evaluation Studies as Topic↗
PubMed1993

Puncture injuries due to needles removed from intravenous lines: should the source patient routinely be tested for bloodborne infections?

OBJECTIVE: To better assess the risk of exposure to bloodborne pathogens following puncture injuries due to needles removed from intravenous (IV) lines. SETTING: Tertiary care community medical center. PATIENTS: A convenience sample of hospitalized patients requiring IV piggy-back medications. METHODS: Examination of 501 IV ports of peripheral lines, heparin-locks, and central venous lines for visible blood and testing the residual fluid in the needles removed from these ports for the presence of occult blood by using guaiac-impregnated paper. RESULTS: The proximal ports of central venous lines and heparin-locks were statistically more likely to contain visible blood than proximal and distal ports of peripheral lines (17% and 20% versus 1% and 3% respectively, P < 0.05). Similarly, needles removed from proximal ports of central venous lines and heparin-locks were statistically more likely to contain occult blood than those from peripheral lines (11% and 14% versus 2%, respectively, P < 0.05). Only two needles removed from IV lines without visible blood contained occult blood: one from the proximal port of a central line and another from a heparin-lock. None of the needles from peripheral lines without visible blood contained occult blood. Estimation of the risk of transmission of hepatitis B and C and human immunodeficiency virus (HIV) following injury by needles from various IV lines revealed that injury due to needles removed from peripheral IV lines and distal ports of central lines without visible blood was associated with "near zero" risk of transmission of these bloodborne infections at our medical center. CONCLUSIONS: Routine serological testing of source patients involving injury due to needles removed from peripheral IV lines and distal ports of central lines without visible blood is not necessary at our medical center. Conversely, due to the relatively high rate of occult blood in the needles removed from proximal ports of central venous lines and heparin-locks, puncture injuries due to these needles are considered significant and managed accordingly.

Catheterization↗
PubMed1993

Evidence for an interaction of halothane with the L-type Ca2+ channel in human myocardium.

BACKGROUND: The present study was aimed at investigating the underlying mechanisms for the cardiac depressant effect of halothane. To test the hypothesis, whether there is an interaction of halothane with the L-type Ca2+ channels in human myocardium and whether this interaction has functional consequences for force generation in the human myocardium, effects of halothane were studied in human myocardial membranes and isolated cardiac preparations. METHODS: The experiments were performed on isolated, electrically driven ventricular preparations (1 Hz, 37 degrees C) and cardiac membranes with radioligand binding experiments using 3H-PN 200-110. Myocardium from human failing and non-failing hearts was obtained at cardiac surgery. RESULTS: Halothane produced a negative inotropic effect, which was similar in nonfailing and failing myocardium. Halothane shifted the concentration-response curve for the positive inotropic effect of the L-type Ca2+ channel agonist BayK 8644 to the right. The density of dihydropyridine receptors as judged from 3H-PN 200-110 radioligand binding experiments was similar in nonfailing and failing myocardium, whereas the density of beta-adrenoceptors was reduced. Halothane concentration dependently reduced the binding of 3H-PN 200-110, an antagonist at the 1,4 dihydropyridine receptor site of the Ca2+ channel, to myocardial membranes. Furthermore, halothane produced a rightward shift of the competition curve of BayK 8644 for binding of 3H-PN 200-110 to cardiac membranes. CONCLUSIONS: In human ventricular myocardium, halothane exhibits an interaction with the L-type Ca2+ channel by interfering with its dihydropyridine binding sites. This may explain, at least in part, the observed negative inotropic effect of this agent and could hypothetically play a general role in its anesthetic effects.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1993

Deaths from volatile substance abuse in those under 18 years: results from a national epidemiological study.

The epidemiology of deaths from volatile substance abuse (VSA) in those under 18 years that occurred in the UK from 1981-90 is described. The analysis of deaths is based on a national register, which has information obtained from a regular survey of coroners, the Office of Population Censuses and Surveys, and a press clippings agency. Altogether 605 people under 18 died from VSA during this period. Seventy per cent of deaths occurred between the ages of 14 and 16. The largest number of deaths were attributed to butane gas lighter refills. There was a large north-south gradient in age specific mortality ratios (Scotland 180, south east England 87) and nearly four times as many deaths occurred in social class V compared with social class I. Deaths from VSA are an important and preventable cause of deaths in those under 18. Strategies aimed at prevention should include measures to reduce experimentation, intervention to reduce socioeconomic deprivation, and health education campaigns aimed at schools and parents.

Adolescent↗
PubMed1993

Protein catabolic rate in patients with acute renal failure on continuous arteriovenous hemofiltration and total parenteral nutrition.

Continuous arteriovenous hemofiltration (CAVH) has been used to provide nutrition support to critically ill patients in acute renal failure (ARF). Limited information exists regarding protein needs of these patients. Nineteen postoperative patients in ARF and on CAVH and total parenteral nutrition (TPN) were studied (10 men; 9 women; mean age, 65 yr) to determine protein needs (protein catabolic rate; PCR), urea nitrogen appearance (UNA), and total nitrogen appearance (TNA). TPN was adjusted to meet the needs estimated by the Harris-Benedict and Long equations. A total of 38 24-h studies were conducted on the 19 subjects. TNA, UNA, and PCR were determined by direct measurement of body losses and calculation of body pool nitrogen changes. Patients received an average of 93.9 +/- 30.5 g of protein (1.4 g/kg) and 2,600 +/- 534 kcal/day in TPN. Mean PCR was 117.5 +/- 42.8 g/day; UNA was 18.3 +/- 6.9 g/day. TNA and UNA were strongly correlated (r = 0.99; P < 0.001). PCR was less strongly correlated with estimated protein needs (r = 0.35; P = 0.03). A regression equation was developed describing the relationship between TNA and UNA as follows: TNA = 1.895 + 0.9444 (UNA) or UNA = 0.1602 (PCR) - 0.916. On the basis of this study, CAVH permits the provision of adequate nutrition support to critically ill, unstable patients. It appears that the protein needs of patients in ARF on CAVH can be accurately estimated by determining UNA through the measurement of urea losses and urea body pool changes and by regression equations to calculate PCR.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1993

[Cardiovascular autonomic neuropathy and blood pressure variability in insulin-dependent diabetes].

The aim of this study was to analyse the role of cardiac autonomic neuropathy (CAN) in the changes of Blood-Pressure (BP) variability among insulin-dependent diabetics and to determine the relationship between BP variability and diabetic complications. Ambulatory BP monitoring was performed during 24 hours on 93 insulin-dependent diabetics and 77 normal subjects of similar age (Group 1). CAN was assessed by the cardiovascular autonomic function tests described by Ewing and the diabetics were divided in two groups: Group 2 including patients without CAN (n = 46) and Group 3 including patients with CAN (n = 47). The 24 h standard deviation (variability) and the day/night difference for systolic and diastolic BP were calculated for each subjects. Systolic and diastolic BP variability is more elevated in Group 3 than in the other groups during the diurnal period. Furthermore, the day/night difference of systolic and diastolic BP is lower in Group 3 compared to groups 2 and 3. Diabetic complications are also more frequently observed among diabetic patients with CAN (p < 0.001). So CAN seems to have two types of consequences on BP curve among diabetic patients: a decrease of day/night BP difference which can be responsible of relative hypertension during the night and an increase of BP variability. As frequency of diabetic retinopathy and nephropathy is more elevated among diabetic patients with CAN, it is possible that CAN plays a role in the occurrence of these complications. Therefore, a simple juxtaposition of these facts is also possible.

Adult↗