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Biomedical subjects

M Weiss

Publications and source records attributed to M Weiss.

At least 181 records · Page 10Linked to original sources

The effects of syringe plunger design on drug delivery during vertical displacement of syringe pumps.

Fluid delivery from four types of commercially available 50-ml syringes was measured using an electronic balance at an infusion rate of 1 ml.h(-1). Retrograde aspiration volume and zero-drug delivery time were recorded after lowering the syringe pump by 50 cm. Syringe compliance was calculated from the volume of bolus released after occlusion at 100 mmHg. Zero-drug delivery times differed significantly between syringes, ranging from [mean (SD)] 3.26 (0.40) min to 6.38 (0.56) min (F = 55.5, d.f. = 3/20, p < 0.0001). Syringe compliance correlated well with aspiration volume (Pearson r(2) = 0.92, p < 0.001) and zero-drug delivery time (r(2) = 0.90, p < 0.001). Syringe design affected the internal syringe compliance. All syringes were associated with potentially relevant zero-drug delivery times after moderate vertical displacement. To minimise this risk, vertical displacement of syringe pumps delivering highly vasoactive drugs should be avoided.

Compliance↗

Health seeking and perceived causes of tuberculosis among patients in Manila, Philippines.

Inefficient case finding is an important stumbling block to successful control of tuberculosis (TB). Multiple health seeking may account for delayed case finding. Health-seeking behaviour, health seeking delay, perceived causes, and perceived quality of care related to TB were studied in interviews with 319 sputum smear-positive TB patients. The patients were treated in 22 governmental health centres of Malabon, a municipality of Metro Manila, Philippines. Only 29% of the respondents had gone first to a health centre after onset of TB-related symptoms, and more than half (53%) had initially consulted a private doctor. A chest X-ray was obtained for nearly everyone (97%). Two thirds of the patients (66%) had received a prescription for drugs, and 29% had purchased and taken anti-TB drugs for at least three weeks before they came to a governmental health centre. Concerning community interactions, 36% said they knew at least one person who had been treated for TB without success. The health seeking delay after symptom onset was relatively short - 64% of the respondents said they went to a health facility within 1 month. Case studies illustrate the rationale for health seeking and explain delayed initiation of appropriate treatment for many patients. Findings underscore the need for and indicate approaches to health communication for improved control of TB. Our findings from interview narratives also suggest that improved interpersonal skills of health centre staff and co-ordination between the private doctors and the health centres may substantially improve services for TB patients.

Adult↗

Human Müllerian-inhibiting substance promoter contains a functional TFII-I-binding initiator.

Müllerian-inhibiting substance (MIS) plays an essential role in mammalian male sexual development; thus, it is important to determine how the tightly regulated expression of the MIS gene is transcriptionally controlled. Transcription of eukaryotic genes is dependent on regulatory elements in the enhancer and one or both distinct elements in the core promoter: the TATA box, and the initiator (Inr) element. Because the human MIS gene does not contain a consensus TATA and has not been reported to contain an Inr element, we hypothesized that the initiator region of the core promoter was essential for promoter activity. Transient transfection assays were conducted using an immortalized Embryonic Day 14.5 male rat urogenital ridge cell line (CH34) that expresses low levels of MIS. These studies revealed that promoter activity is dependent on the region around the start site (-6 to +10) but not on the nonconsensus TATA region. Electrophoretic mobility shift assays demonstrated that the human MIS initiator sequence forms a specific DNA-protein complex with CH34 cell nuclear extract, HeLa cell nuclear extract, and purified TFII-I. This complex could be blocked or supershifted by the addition of antibodies directed against TFII-I. These data suggest that the human MIS gene contains a functional initiator that is specifically recognized by TFII-I.

Animals↗

ADHD in parents.

Explore the source record for details and available documents.

Adult↗

Impact of infusion line compliance on syringe pump performance.

To determine the impact of infusion line compliance on the time to occlusion alarm (occlusion time) and the size of the subsequent occlusion release bolus, we studied three different infusion lines in combination with a 50-ml and 10-ml syringe. The mean occlusion time of the 50-ml syringe amounted to 20.3 +/- 0.28 min and increased to 26.2 +/- 0.19 min with the infusion with the infusion line yeielding the largest compliance (P<0.0001). The mean occlusion time of the 10-ml syringe was 2.5 +/- 0.75 min and showed a 2.7-fold variation with the three infusion lines (2.6+/-0.08, 5.6 +/- 0.28 and 6.9 +/- 0.35 min, respectively; P<0.0001). Occlusion times correlated strongly to be calculated estimated compliance of the syringe-infusion line assembly (Pearson's r=0.998, P<0.0001). Infusion line compliance has an important impact on time to occlusion, particularly when using small, low compliant infusion pump syringes.

Compliance↗

Three methods for investigating, assessing and supporting the normal and pathological gait and manipulation activity.

Three methods to describe biped locomotion as well as manipulation activity are presented. Methods using so-called couple oscillators as rhythm generators are described. Based on a mathematical model, results of computer simulation of biped locomotion are presented. An indices method of assessing human gait for both normal and pathological cases was proposed and tested. The results showed that it is relatively easy to distinguish different gaits by using this method. This method was tested in clinical conditions. The third method deals with the problem of supporting the lost function of prehension movements. Implanted stimulators on the nerves combined with external orthoses were used. The clinical results show that these methods have practical advantages.

Computer Simulation↗

Second generation to Holocaust survivors: enhanced differentiation of trauma transmission.

"Second generation to Holocaust Survivors" is a description of a segment of society, as well as an attempt at characterizing these individuals. It is common to speak of mechanisms of transmission of trauma as characterizing the dynamics of the second generation. This paper intends to advance differentiation between two kinds of transmission of trauma: direct transmission (also called transposition) and indirect transmission. There seems to be some confusion in this realm, since there is some discrepancy between clinical and the experimental publications: Whereas the first usually presents evidence of direct transmission of trauma in the second generation, the second mostly demonstrates indirect transmission. We shall present a clinical account of group therapy demonstrating indirect transmission, proposing a distinction between second-generation individuals owing to the relative dominance of each of the mechanisms in their mental structuring. This distinction has significant clinical consequences.

Adult↗

Do antisiphon valves reduce flow irregularities during vertical displacement of infusion pump systems?

Vertical displacement of syringe pumps may cause irregular drug delivery due to hydrostatic pressure changes in the infusion line. The extent of flow fluctuations depends on the internal compliance of infusion lines, syringes and syringe pumps. We evaluated whether pressure regulation by antisiphon valves (ASV) reduces the flow variation during vertical displacement of 50 ml standard syringes and infusion pumps. An infusion assembly comprising a standard 50 ml BD Plastipak or a 50 ml Fresenius syringe, with syringe pump and 2 m low compliance infusion line was used for in vitro measurement of fluid delivery. The assembly was tested without ASV, and with two ASVs of differing operating pressure (ASV:75: valve opening pressure = 75 mmHg; ASV:155, 155 mmHg). Retrograde aspiration volume, zero-drug delivery time and valve opening bolus were determined after lowering the syringe pump by 50 cm. After elevating the syringe pump to its initial position the ensuing infusion bolus was recorded. Without an antisiphon valve the observed zero-drug delivery times after lowering the syringe pump were (mean +/- SD) 2.4 +/- 0.2 min using the BD Plastipak syringe and 4.09 +/- 0.55 min using the Fresenius syringe. Introduction of the antisiphon valve prolonged the zero drug delivery time 58% (ASV:75) and 88% (ASV:155) in the BD Plastipak syringe assembly and 43% (ASV:75) and 81% (ASV:155) in the Fresenius syringe assembly (P < 0.001). Antisiphon valves worsen flow irregularities caused by vertical displacement of syringe pumps and when used with delivery of concentrated inotropic drugs at low infusion rates, they may aggravate haemodynamic consequences of inconstant drug delivery.

Infusion Pumps↗

Clinical suggestions for management of stimulant treatment in adolescents.

Children with attention-deficit hyperactivity disorder (ADHD) do not typically outgrow this condition in adolescence, which is a challenging period of development. Management of ADHD in adolescence requires specific accommodations. These include providing adolescents with as much control over treatment as possible, so that they perceive treatment to be widening their autonomy rather than limiting it. Wherever possible, medication needs to be long-acting to facilitate compliance and to minimize problems with rebound misbehaviour and moodiness. Comorbid psychiatric symptoms and syndromes need to be evaluated carefully both pre- and posttreatment. Ongoing psychoeducation and support can help to restructure the demands that an adolescent with ADHD faces at home and school so that they are more manageable. With active treatment it may be possible to prevent the serious morbidity associated with ADHD during this period and to lay a foundation for adulthood.

Adolescent↗

Bone mineral density and turnover in children with attention-deficit hyperactivity disorder receiving methylphenidate.

Attention-deficit hyperactivity disorder (ADHD) is the most common behavior disorder among children; methylphenidate is a drug frequently prescribed for the control of its symptoms. One of the potential side effects of methylphenidate that concerns parents is its impact on the growth of children, since the mechanism by which methylphenidate might influence growth is not known. As linear growth is associated with an increase in bone mineral density and turnover, this study was undertaken to evaluate bone mineral density by dual photon absorptiometry and bone turnover by measuring serum bone-specific alkaline phosphatase and the urinary deoxypyridinoline excretion rate in children treated with methylphenidate for 1 to 2 years as compared to a control group. There were no significant differences in bone mineral density at either the lumbar spine or femoral neck in the study group (0.662 +/- 0.04 and 0.735 +/- 0.07 g/cm2, respectively) as compared to the controls (0.675 +/- 0.05 g/cm2 and 0.734 +/- 0.07 g/cm2, respectively). Furthermore, there were no significant differences in serum bone-specific alkaline phosphatase in the study group (58 +/- 22 U/L) as compared to the control children (71 +/- 34 U/L) or in urinary deoxypyridinoline in the study group (34 +/- 38 nM/mM), as compared to the control group (27 +/- 12 nM/mM). In conclusion, our data do not support a significant effect of methylphenidate on bone mineral density turnover in children when used for 1 to 2 years.

Attention Deficit Disorder with Hyperactivity↗

Diagnosis of polycystic ovary disease in obese women with a 24-hour hormone profile after buserelin stimulation.

OBJECTIVE: To evaluate the 24-hour hormone response to GnRH agonist stimulation in the diagnosis of polycystic ovary disease (PCOD) in obese women. STUDY DESIGN: Forty-three obese PCOD patients and 23 controls were randomized to 1 mg buserelin (BSRL) stimulation (PCOD group P-1, n = 31; control group C-1, n = 12) or 0.1 mg (PCOD group P-0.1, n = 12; control group C-0.1, n = 11). RESULTS: Whereas following 1 mg BSRL administration, serum levels of 17 hydroxyprogesterone (17OHP), delta 4 androstenedione, estradiol (E2) and luteinizing hormone increment (delta LH) as well as the delta LH/delta follicle stimulating hormone ratio were all higher in group P-1 than in group C-1 (P < .001, < .01, < .01, = .08 and < .001, respectively), only 17OHP and E2 serum levels were higher in group P-0.1 than in group C-0.1 (P < .001, and = .01, respectively). Whereas 24-hour LH inversely correlated with body mass index (r = .37, P = .04), 24-hour hormone profile, and basal or glucose-stimulated serum insulin levels did not correlate in group P-1. CONCLUSION: The 1-mg BSRL stimulation test is a convenient diagnostic means in obesity-associated PCOD. The hormone response to BSRL administration is related to obesity, not to insulin resistance.

Adolescent↗

[Metastases in malignant melanoma despite histologically negative sentinel lymph node: should the concept be changed?].

AIM: The Sentinel Lymph Node (SLN) is of considerable prognostic relevance, because extended lymph node dissection may not be performed in patients presenting with histologically negative SLN. The aim of the present study was to prove the prognostic value of the SLN-concept in these patients. METHODS: So far the clinical follow-up of 162 patients with histologically proven malignant melanoma and metastatically uninvolved (negative) SLN was investigated. Histological examination included standard methods (HE-Test) and special histochemical techniques (S-100, HMB-45). All patients underwent clinical examination, ultrasonic diagnosis of the regional lymph nodes, and x-ray of the chest every 3 months. RESULTS: Despite of negative SLN-findings in 8/162 patients metastases of the malignant melanoma were found after a time period of 5-27 months. Three patients presented with recurrence in the previously mapped (negative) SLN-basin. In another case the scintigraphically visualized SLN could not be identified intraoperatively by means of the hand-held gamma probe. One patient showed intransit-metastases or skin-metastases, respectively; another patient recurred in the scar area. One patient showed hematogenic dissemination (liver) which is not detectable by lymphoscintigraphy; in another patient metastases were found outside the primary lymphatic basin (cervical). CONCLUSION: In our patient group 4.9% presented with metastases despite negative SLN while published data report up to 11% (observation period 35 months), among them only 3 patients (1.9%) being real concept failures. Our results underline that there is no evidence to change this concept in patients with clinically early stage.

Adult↗

Malignant neoplasms in long-term survivors of bone marrow transplantation. Late Effects Working Party of the European Cooperative Group for Blood and Marrow Transplantation and the European Late Effect Project Group.

BACKGROUND: Patients who receive bone marrow transplants have increased risk for new malignant conditions because of several risk factors, including conditioning with radiation and chemotherapy, immune stimulation, and malignant primary disease. The occurrence of and risk factors for malignant neoplasm in long-term survivors must be assessed. OBJECTIVE: To determine the risk and define potential risk factors for new malignant conditions in long-term survivors after marrow transplantation. DESIGN: Retrospective multicenter study. SETTING: Study of the Late Effects Working Party with 45 transplantation centers cooperating in the European Cooperative Group for Blood and Marrow Transplantation. PATIENTS: 1036 consecutive patients who underwent transplantation for leukemia, lymphoma, inborn diseases of the hematopoietic and immune systems, or severe aplastic anemia. Transplantation was done before December 1985, and patients had survived more than 5 years. MEASUREMENTS: Reports on malignant neoplasms were evaluated, and the incidence was compared to that in the general population. Patient age and sex, primary disease and status at transplantation, histocompatibility of the donor, conditioning regimen, type of prophylaxis of graft-versus-host disease, development of acute and chronic graft-versus-host disease, and treatment of chronic graft-versus-host disease were evaluated as variables. RESULTS: Median follow-up since transplantation was 10.7 years (range, 5 to 22.1 years). Malignant neoplasms were seen in 53 patients; the actuarial incidence (+/- SE) was 3.5% +/- 0.6% at 10 years and 12.8% +/- 2.6% at 15 years. The rate of new malignant disease was 3.8-fold higher than that in an age-matched control population (P < 0.001). The most frequent malignant diseases were neoplasms of the skin (14 patients), oral cavity (7 patients), uterus (including cervix) (5 patients), thyroid gland (5 patients), breast (4 patients), and glial tissue (3 patients). Median age of patients and their donors was 21 years. Malignant neoplasms were more frequent in older patients and in patients with chronic graft-versus-host disease. Older patient age and treatment of chronic graft-versus-host disease with cyclosporine were significant risk factors for new malignant neoplasms after bone marrow transplantation. CONCLUSIONS: The spectrum of neoplasms and immunosuppressive treatment with cyclosporine for chronic graft-versus-host disease as dominant risk factors indicate that immunosuppression is the major cause of malignant neoplasms in patients receiving marrow transplants.

Adolescent↗

[Infants and young children with fever of unknown origin. Systematic procedure based on a diagnosis-therapy diagram].

Febrile children comprise a substantial proportion of ambulatory pediatric visits. The management of febrile children needs to be structured to minimize the likelihood of unfavorable outcomes as well as the unnecessary use of antibiotics. The guidelines for the management of febrile children in this review are based on recently published data and are aimed to be recommendations until bacterial foci and pathogens are identified.

Algorithms↗

[Measles. A viral illness with risk of permanent damage].

Measles is a highly contagious exanthematous disease. After an incubation period of almost two weeks, catarrhal prodromic, associated with initial attacks of fever appear. Typical manifestations are Koplik's spots. The exanthema appears together with the second rise in temperature. The illness confers lifelong immunity. In individual cases, an encephalitis resulting in permanent neurological deficits must be expected. Every effort should be made to prevent this condition from arising. To this end, immunization with a combination measles, mumps, rubella (MMR) vaccine is recommended.

Adolescent↗