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Biomedical subjects

H Cohen

Publications and source records attributed to H Cohen.

At least 109 records · Page 6Linked to original sources
PubMed2000

Responses and concerns of healthcare providers to medication errors.

This descriptive, correlational study examined the responses and concerns of healthcare professionals about making medication errors and estimated patient harm from such errors. A systematic random sample of nurses, pharmacists, and physicians (N = 402) completed a self-report survey about a medication error they judged to be serious. Respondents were guilty, nervous, and worried about the error. They feared for the safety of the patient, disciplinary action, and punishment. A few subjects indicated that they never reported the errors. The most frequent symptoms associated with errors were neurologically based. The injury suffered by patients was not severe overall according to the harm scales. Weak correlations were found for the harm scales and responses and concerns. The authors suggest a supportive environment for the provider following an error and continuous quality improvement efforts to eliminate system-based errors.

Attitude of Health Personnel↗
PubMed2000

Be a watchdog.

Review the advances in computerized prescriber order entry and automated storage and administration devices, which effectively reduce medication errors.

Clinical Pharmacy Information Systems↗
PubMed2000

Heterogeneity of gastric histology and function in food cobalamin malabsorption: absence of atrophic gastritis and achlorhydria in some patients with severe malabsorption.

BACKGROUND: The common but incompletely understood entity of malabsorption of food bound cobalamin is generally presumed to arise from gastritis and/or achlorhydria. AIM: To conduct a systematic comparative examination of gastric histology and function. SUBJECTS: Nineteen volunteers, either healthy or with low cobalamin levels, were prospectively studied without prior knowledge of their absorption or gastric status. METHODS: All subjects underwent prospective assessment of food cobalamin absorption by the egg yolk cobalamin absorption test, endoscopy, histological grading of biopsies from six gastric sites, measurement of gastric secretory function, assay for serum gastrin and antiparietal cell antibodies, and direct tests for Helicobacter pylori infection. RESULTS: The six subjects with severe malabsorption (group I) had worse histological scores overall and lower acid and pepsin secretion than the eight subjects with normal absorption (group III) or the five subjects with mild malabsorption (group II). However, histological findings, and acid and pepsin secretion overlapped considerably between individual subjects in group I and group III. Two distinct subgroups of three subjects each emerged within group I. One subgroup (IA) had severe gastric atrophy and achlorhydria. The other subgroup (IB) had little atrophy and only mild hypochlorhydria; the gastric findings were indistinguishable from those in many subjects with normal absorption. Absorption improved in the two subjects in subgroup IB and in one subject in group II who received antibiotics, along with evidence of clearing of H pylori. None of the subjects in group IA responded to antibiotics. CONCLUSIONS: Food cobalamin malabsorption arises in at least two different gastric settings, one of which involves neither gastric atrophy nor achlorhydria. Malabsorption can respond to antibiotics, but only in some patients. Food cobalamin malabsorption is not always synonymous with atrophic gastritis and achlorhydria, and hypochlorhydria does not always guarantee food cobalamin malabsorption.

Achlorhydria↗
PubMed2000

Increased 5alpha-reductase and normal 11beta-hydroxysteroid dehydrogenase metabolism of C19 and C21 steroids in a young population with polycystic ovarian syndrome.

OBJECTIVE: To test the hypothesis that 5alpha-reductase (5alphaR) and 11beta-hydroxysteroid dehydrogenase (11beta-HSD) activity are increased in adolescent and young-adult women with PCOS and that an altered regulation of the hypothalamic-pituitary-adrenal (HPA) axis occurred in these subjects. DESIGN: Prospective non-randomized study in an academic research environment. PATIENTS: Eleven women, aged 14 to 25 years, were studied who were at least one year post-menarche and who had a diagnosis of PCOS based on a history of oligomenorrhea and elevated total and or free serum testosterone. INTERVENTION: 24-Hour urinary metabolites were assessed in nine subjects and five underwent stimulation with ovine corticotropin releasing factor (oCRF). OUTCOME MEASURES: C19 and C21 steroid urinary metabolite 5-alpha/5-beta pairs, 11-oxo/11-hydroxy products and the ratio of the total 5-alpha/5-beta reduced and 11-oxo/11-hydroxy products were compared to values in control women. Urinary cortisol (F) (sum of conjugated and free, and free F) and total F metabolites (the sum of THE, THF, 5alpha-THF, cortolones, and cortols) were determined. A 1 microg/kg oCRF stimulation test was performed with timed samples determined for plasma ACTH and serum F levels. RESULT: The 24-hour total and free urinary F were not different from control. However, the total F metabolites were markedly elevated (7922+/-2666 vs 5418+/-1549 microg/24 h, p<0.01). A marked increase in the total 5-alpha reduced C19 and C21 metabolites was observed in the PCOS population vs control (5084+/-1977 vs 2681+/-1188 microg/24 h, p<0.01). The total urinary 11-oxo/11-hydroxy metabolite ratio was not different, p=0.23. The basal values and response of both ACTH and F to oCRF stimulation were not different from those of controls. CONCLUSION: There is a marked increase in 5alphaR metabolism of both C19 and C21 steroids in younger women with PCOS.

11-beta-Hydroxysteroid Dehydrogenase Type 1↗
PubMed2000

Perimeter trapping strategy to reduce Mediterranean fruit fly (Diptera: Tephritidae) damage on different host species in Israel.

To evaluate the perimeter trapping strategy as a control method, field tests were conducted in three different host species of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), in Israel. Dry traps baited with a three component food-based synthetic attractant that were hung in the peripheral rows of a plum, a pear, and a persimmon orchard, caught female C. capitata (up to 20.1, 1.4, and 4.1 female C. capitata per trap per day, respectively). Fruit damage, estimated at harvest, indicated a negligible percentage for the plum orchard (< 1%), 3% for the persimmon orchard (compared with 9% at an untreated neighboring plot), and no damaged fruit in the pear orchard. Finally, dissections of female C. capitata caught in dry traps on different host plant species indicate that a high percentage (range, 84-100%) contained mature eggs. The attraction of mature females to the dry traps might explain the successful results. Future research, to determine precisely how many traps should be placed and how frequently they should be serviced, is necessary before applying this strategy on a commercial basis.

Animals↗
PubMed2000

Experience with the insertion of vena caval filters in acutely burned patients.

The use of inferior vena caval filters in patients at high risk of pulmonary emboli is a standard practice in many types of patients. The usefulness of such filters in acutely burned patients has yet to be established. Twenty inferior vena caval filters were inserted in burn patients. Five were inserted because of preexisting thromboembolic disease. Fifteen were placed prophylactically because of high-risk states, including prolonged immobilization, old age, bleeding problems, and obesity. There were no complications due to filter insertion. No postinsertion emboli were recognized. There were no cases of postinsertion thrombophlebitis. In this small series, the procedure appears to be effective and safe.

Acute Disease↗
PubMed2000

Normalization of heart rate variability in post-traumatic stress disorder patients following fluoxetine treatment: preliminary results.

BACKGROUND: Spectral analysis of heart rate variability has been shown to be a reliable non-invasive test for quantitative assessment of cardiovascular autonomic regulatory responses, providing a window reflecting the interaction of sympathetic and parasympathetic tone. Alterations in autonomic function are associated with a variety of physiologic and pathophysiologic processes and may contribute substantially to morbidity and mortality. Our previous study shows that patients with post-traumatic stress disorder have significantly lower HRV compared to controls, reflecting a basal autonomic state characterized by increased sympathetic and decreased parasympathetic tone. OBJECTIVES: To apply this tool to PTSD patients treated with selective serotonin re-uptake inhibitors in order to assess the impact of such treatment on the autonomic dysregulation characterizing these patients. METHODS: Standardized heart rate analysis was carried out in nine PTSD patients treated with SSRI agents and compared to that in a matched control group of nine healthy volunteers and in nine untreated PTSD patients, based on a 15 minute resting electrocardiogram. RESULTS: Our preliminary results show that the HRV parameters indicating autonomic dysregulation, which characterize PTSD patients at rest, are normalized in responding patients by use of SSRIs. Neither the clinical implications of these findings nor their physiological mechanisms are clear at present, although we presume that they reflect a central effect, since the peripheral autonomic effects of SSRIs are relatively negligible.

Adult↗
PubMed2000

[The immunological basis of the administration of DTP-polio vaccine].

The main subject of this essay is the analysis of the immunizing properties and possible side effects of DTP (whole cell)-polio vaccine, which since 1964 is the backbone of the immunization programme in the Netherlands. The concept, that the basis of the immunity conferred by diphtheria and tetanus toxoid and inactivated poliovirus is humoral, is now generally accepted. Assessment of the potency of these three components is based on their binding properties to specific immunoglobulines in standard-antisera. An example is the testing of neutralising antibodies against the three types of poliovirus in sera obtained from different groups of infants injected with increasing doses of this vaccine. Side-effects after injecting diphtheria- and tetanus toxoids and three types inactivated poliovaccine are negligible. For the pertussis component of the vaccine, this is not the case. The standardization of the potency of cellular pertussis vaccine is still based on the analysis of the protective capacity of a number of plain vaccine lots in the intercerebral mouse-protection test relative to the protection they confer in children. An international standard vaccine is available for this purpose, and the potency of individual lots can be expressed in International Units. At present acellular pertussis vaccines are also available for immunization against this disease. The components of such vaccines are at least for a number of components, arbitrarily chosen. Recently in a trial in Sweden, a five-component pertussis vaccine has given a similar protection of infants as a cellular vaccine of British origin. In addition this acellular vaccine induced less febrile reactions. However, acellular vaccines do not protect mice against intracerebral infection. because producers have decided to omit the "Outer Membrane Complex (OMC) as a component of the vaccine. In addition it has recently been shown that the presence of the cellular pertussis component in DPT vaccine will almost completely suppress tetanus antitoxins in the IgE fraction of the serum. This observation could indicate that this suppression is the result of a cellular immunity reaction by components in the bacteria.

Animals↗
PubMed1999

Homicidal behavior in schizophrenia associated with a genetic polymorphism determining low catechol O-methyltransferase (COMT) activity.

Although aggressive, violent, and dangerous behavior in man has multifactorial causes, genetic factors are estimated by twin and adoption studies to substantially contribute to the development of such conduct. Recently, homozygosity of a low enzyme activity variant of the catechol O-methyltransferase (COMT) gene was reported to be associated with aggressive behavior in a group of schizophrenic patients. We observe a similar tendency in a group of 30 schizophrenic patients who were confined to a maximum-security psychiatric facility for homicide. Significant excess (46.7% versus 21.0%) homozygosity of the low activity COMTmet/met genotype was observed in 30 mostly male (28 of 30) homicidal schizophrenic patients compared with 415 control subjects (Pearson chi(2) = 10.53, P = 0.005, df = 2). No difference in COMT genotype was found between 62 nonviolent schizophrenic patients and the 415 control subjects (chi(2) = 0.963, P > 0.1, df = 2). A trend for excess (46.7% versus 25.8%) homozygosity of the low activity COMTmet/met genotype was also observed when the homicidal schizophrenic subjects were compared directly with the nonviolent schizophrenic patients (chi(2) = 4.03, P = 0.1, df = 2). Similarly, an excess of the low activity COMTmet allele was observed in homicidal versus nonviolent schizophrenic patients (chi(2) = 2.92, P = 0.087, df = 2). Similar results were obtained if only male subjects were examined. No significant difference was found between control (257 Ashkenazi and 152 non-Ashkenazi Jews) COMT genotypes in the two principal ethnic groups examined (chi(2) = 3.79, P > 0.1, df = 2). Finally, no association was observed between homicidal behavior in schizophrenic patients and the dopamine D4 exon III repeat length polymorphism (D4DR) and the serotonin transporter promoter-region polymorphism (5-HTTLPR). Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:628-633, 1999.

Adult↗
PubMed1999

Tapasin enhances assembly of transporters associated with antigen processing-dependent and -independent peptides with HLA-A2 and HLA-B27 expressed in insect cells.

Assembly of HLA class I-peptide complexes is assisted by multiple proteins that associate with HLA molecules in loading complexes. These include the housekeeping chaperones calnexin and calreticulin and two essential proteins, the transporters associated with antigen processing (TAP) for peptide supply, and the protein tapasin which is thought to act as a specialized chaperone. We dissected functional effects of processing cofactors by co-expressing in insect cells various combinations of the human proteins HLA-A2, HLA-B27, beta(2)-microglobulin, TAP, calnexin, calreticulin, and tapasin. Stability at 37 degrees C and surface expression of class I dimers correlated closely in baculovirus-infected Sf9 cells, suggesting that these cells retain empty dimers in the endoplasmic reticulum. Both HLA molecules form substantial quantities of stable complexes with insect cell-produced peptide pools. These pools are TAP-selected cytosolic peptides for HLA-B27 but endoplasmic reticulum-derived, i.e. TAP-independent peptides for HLA-A2. This discrepancy may be due to peptide selection by human TAP which is much better adapted to the HLA-B27 than to the HLA-A2 ligand preferences. HLA class I assembly with peptides from TAP-dependent and -independent pools was enhanced strongly by tapasin. Thus, tapasin acts as a chaperone and/or peptide editor that facilitates assembly of peptides with HLA class I molecules independently of mediating their interaction with TAP and/or retention in the endoplasmic reticulum.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Repression and activation of transcription of phosphoenolpyruvate carboxykinase gene during liver development.

Transcriptional activation of the hepatic phosphoenolpyruvate carboxykinase (PEPCK) gene at birth is critical since PEPCK appearance initiates hepatic gluconeogenesis. A delayed appearance results in hypoglycemia, while a premature appearance results in neonatal diabetes, both are incompatible with sustaining life. Experiments using transgenic mice and transfected hepatoma cells suggest that both repression and activation underlie the correct onset of hepatic PEPCK gene transcription. In transgenic mice, transgenes driven by the proximal PEPCK promoter are prematurely expressed in the fetal liver and over-expressed in the neonatal liver, indicating that sequences upstream of the proximal promoter restrain perinatal expression. In Hepa1c1c7 cells, which mimic the fetal liver, the proximal PEPCK promoter (597 bp) exhibited a 3. 5-10-fold higher activity than longer promoters. Repression of the longer promoter (2000 bp) was diminished upon deletion of the sequence spanning positions(-840) to(- 1116) which contains a PPAR/RXR recognition element. The intact 2000 bp PEPCK promoter could be markedly activated by co-transfecting the transcription factor HNF-1 together with C/EBP. It could be repressed by co-transfection with RXRalpha and adding PPARalpha relieved this inhibition.

Animals↗
PubMed1999

Serious hazards of transfusion (SHOT) initiative: analysis of the first two annual reports.

OBJECTIVE: To receive and collate reports of death or major complications of transfusion of blood or components. DESIGN: Haematologists were invited confidentially to report deaths and major complications after blood transfusion during October 1996 to September 1998. SETTING: Hospitals in United Kingdom and Ireland. SUBJECTS: Patients who died or experienced serious complications, as defined below, associated with transfusion of red cells, platelets, fresh frozen plasma, or cryoprecipitate. MAIN OUTCOME MEASURES: Death, "wrong" blood transfused to patient, acute and delayed transfusion reactions, transfusion related acute lung injury, transfusion associated graft versus host disease, post-transfusion purpura, and infection transmitted by transfusion. Circumstances relating to these cases and relative frequency of complications. RESULTS: Over 24 months, 366 cases were reported, of which 191 (52%) were "wrong blood to patient" episodes. Analysis of these revealed multiple errors of identification, often beginning when blood was collected from the blood bank. There were 22 deaths from all causes, including three from ABO incompatibility. There were 12 infections: four bacterial (one fatal), seven viral, and one fatal case of malaria. During the second 12 months, 164/424 hospitals (39%) submitted a "nil to report" return. CONCLUSIONS: Transfusion is now extremely safe, but vigilance is needed to ensure correct identification of blood and patient. Staff education should include awareness of ABO incompatibility and bacterial contamination as causes of life threatening reactions to blood.

Blood Component Transfusion↗
PubMed1999

Articulatory consequences of Parkinson's disease: perspectives from two modalities.

Language production involves complex yet productively varying motor behavior. Rule-governed combinations yield a finite set of formational units combined in an infinite number of ways. The creativity of language ensures that no particular articulation will be highly automatized. Linguistic articulation is highly complex and varied. As such, it differs from the other more automatized motor behaviors typically studied such as learned movements in apraxia studies or repetitive behavior as occurs in walking or other everyday activities. Language also strives to maintain a balance between ease of articulation and ease of perception, while maintaining linguistically relevant distinctions. We report here a number of studies on the articulatory consequences of Parkinson's disease (PD) in the spoken and signed modalities. Our goal is to highlight the commonalities and distinctions between the two modalities of speech and sign that will allow us to better understand the impingements of PD on language production in general.

Aged↗