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Biomedical subjects

R Cohen

Publications and source records attributed to R Cohen.

At least 73 records · Page 4Linked to original sources
PubMed2001

Socioeconomic status and breast cancer incidence in California for different race/ethnic groups.

OBJECTIVE: The majority of research on breast cancer risk and socioeconomic status (SES) has been conducted for blacks and whites. This study evaluates the relationship between SES and breast cancer incidence in California for four race/ethnic groups. METHODS: Principal component analysis was used to create an SES index using 1990 Census data. Untracted cases were randomly allocated to census block groups within their county of residence. A total of 97,227 female breast cancer cases diagnosed in California between 1988 and 1992 were evaluated. Incidence rates and rate ratios (RRs) were estimated and a chi2 test for trend across SES levels was performed. RESULTS: SES was positively related to breast cancer incidence, and this effect was stronger for Hispanics and Asian/others than for whites and blacks. Adjusting by SES did not eliminate the differences in breast cancer rates among race/ethnic groups. RR differences between the race/ethnic groups were greatest in the lowest SES category and attenuated with increasing SES. An increasing trend over SES was statistically significant for all race/ethnic groups. Including randomly allocated cases affected RR estimates for white women only. CONCLUSIONS: Our results are consistent with similar findings for the Los Angeles area but differ from previous results for the San Francisco Bay area.

Adolescent↗
PubMed2001

Increased semantic and repetition priming in schizophrenic patients.

Positive and negative priming (PP and NP) in schizophrenia were studied with a lexical-decision task. Probe words, presented 800 ms after the response to the prime (containing a word and a nonword), were either identical to, semantically related to, or unrelated to the prime target word (PP) or to the prime distractor word (NP). Schizophrenic patients displayed stronger semantic and repetition PP than controls after controlling for their slower responses. Significant NP was observed in both groups for word repetition only. The PP findings contrast with results from studies with similar prime-probe intervals but without prime responses. It is proposed that schizophrenic patients, because of impaired (controlled) processes of response selection, strongly benefit from (or rely on) the automatic retrieval of processing episodes containing response information. Related findings indicating automatic response facilitation in schizophrenia are discussed.

Adult↗
PubMed2001

Complete surgical lymph node resection does not prevent authentic recurrences of medullary thyroid carcinoma.

BACKGROUND: Medullary thyroid carcinoma is a rare tumour derived from the thyroid parafollicular calcitonin-secreting cells. Calcitonin is a very specific marker of this cancer that allows preoperative diagnosis. Serum calcitonin assay is particularly useful to define the postoperative state of patients (cured, apparently cured, not cured) and, because of its great sensitivity, it has a major place in the postoperative follow-up. OBJECTIVE: To identify, among patients thyroidectomized for medullary thyroid carcinoma (MTC), the characteristics of authentic recurrent MTC [re-elevation of stimulated serum calcitonin (CT) level measured by a sensitive immunoradiometric assay, after postoperative normalization]. PATIENTS AND METHODS: We first collected, through the national registry of the French Calcitonin Tumour Study Group (GETC), patients who had undergone a total thyroidectomy with or without lymph node surgery and who were not cured at the last follow-up visit. Among 453 such patients included in the database, 15 patients met the criteria for authentic recurrence as defined in previous studies: they had been first considered as cured during the 6 months following the initial surgical procedure (basal and pentagastrin-stimulated serum calcitonin level <or= 10 ng/l) but had a secondary rerise of their pentagastrin-stimulated calcitonin level, over 10 ng/l. Eight of them even had an undetectable (< 2 ng/l) immediate postoperative CT, confirming the initial postoperative cure. The characteristics (age, nature of disease, stage at surgery and type of node dissection) of these 15 patients were studied. RESULTS: According to the Tumour Node Metastasis classification, nine patients were T1 and, among them, five patients had had complete lymph node surgery without any evidence of nodal metastases (N0). The recurrence was 3.2 +/- 2.2 years (range: 0.7-7.5) after the initial surgery. CONCLUSIONS: 3.3% of patients not cured at the last visit had a recurrent MTC. This recurrence occurred whatever the stage, and even if the primary surgery for MTC was a priori complete. These results emphasize the need for a regular biochemical follow-up because recurrence may appear many years after the initial surgery.

Adolescent↗
PubMed2001

Transcript and activity levels of different Pleurotus ostreatus peroxidases are differentially affected by Mn2+.

The white-rot fungus Pleurotus ostreatus produces both manganese-dependent peroxidase (MnP) and versatile peroxidase (VP) in non-manganese-amended peptone medium (PM). We studied the effect of Mn2+ supplementation on MnPs and VPs in P. ostreatus by analysing the enzymatic and transcript abundance profiles of the peroxidases, as well as the lignin mineralization rate. The fungus was grown in PM under solid-state conditions using perlite as an inert solid support. Mn2+ amendment resulted in a 1.7-fold increase in [14C]-lignin mineralization relative to unamended medium. Anion-exchange chromatography was used to resolve the fungal peroxidase's enzymatic activity profile. Five peaks (P1-P5) of VP and one peak (P6) of MnP activity were detected in unamended medium. In Mn2+-amended medium, a reduction in the activity of the VPs was observed. On the other hand, a sharp increase in the MnP activity level of peak P6 was detected. The P6 isoenzyme was purified and showed manganese-dependent peroxidation of phenolic substrates. Internal sequence analysis of the purified enzyme revealed 100% identity with the deduced amino acid sequence of P. ostreatus MnP3 (GenBank AB016519). The effect of Mn2+ on the relative abundance of gene transcripts of three VPs and one MnP from P. ostreatus was monitored using reverse transcription-polymerase chain reaction (RT-PCR) with oligonucleotide primer sets synthesized on the basis of non-conserved sequences of the different peroxidases. The reduction in VP gene transcript abundance and the increase in mnp3 transcript level were collinear with the changes observed in the enzyme activity profiles. These results indicate that the activity of peroxidases is regulated at the transcriptional level. We suggest that the expression of MnP and VP may be differentially regulated by the presence of Mn2+.

Agaricales↗
PubMed2001

A screening process predicts success rates in residency re-training among new immigrant physicians in Israel.

OBJECTIVES: To evaluate predictors of success in training programs for Israeli international medical graduates (IMGs) from the former USSR. SUBJECTS: IMGs up to the age of 45 who passed a national licensing examination and a Hebrew knowledge exam were eligible for participation. INTERVENTION: Each IMG participated in one of three programs that offered similar academic activities. In two programs there was a preliminary selection process and one program had supplementary teaching hours. MAIN OUTCOME MEASURES: Resident's self-evaluation of skills compared with evaluation by department heads. The evaluation included eight clinical skills, a general evaluation, and the passing rate for Phase I of the National Certification Exam. FINDINGS: A total of 176 IMGs, all graduates from medical schools in USSR who immigrated to Israel from 1990 to 1996, and 20 heads of the participating departments completed the questionnaires. The response rate was 64% among the residents and 71% among the department heads. All residents had a similar level of self-esteem regarding clinical skills and considered themselves equal to or better than Israeli-trained residents. The department heads did not concur with this assessment, particularly for residents who participated in the program with no preliminary selection. Participants in the programs with preliminary selection received better evaluations from department heads than those in the program without and had significantly greater success in the written part of the board certification examination (p < 0.05). DISCUSSION AND CONCLUSIONS: Re-training programs for IMGs should include a preliminary process for participant selection. The training program should be implemented in academic departments, in which case supplementary teaching hours are not required.

Journal Article↗
PubMed2001

Current approaches to otitis media.

Acute otitis media is the most commonly diagnosed illness in children, and is one of the most common reasons for antibiotic prescription. In many countries, antibiotic resistance is increasing among the bacteria that are implicated in acute otitis media, particularly Streptococcus pneumoniae. This evolution should stimulate changes in the management of acute otitis media, particularly the following: improvement in diagnostic accuracy; reduction in antibiotic use; selection of the most appropriate drugs at the appropriate dosage; reduction in duration of treatment, when possible; and implementation of new vaccines.

Acute Disease↗
PubMed2001

Crohn's disease arthritis treated with infliximab: an open trial in four patients.

Four patients with Crohn's disease arthritis, who were unresponsive to conventional treatment, improved very rapidly and safely with the use of infliximab, the chimeric antibody directed against tumor necrosis factor alpha. The patients were able to stop or significantly decrease other antirheumatic medications after the infliximab infusions. It is likely that tumor necrosis factor plays a major role in the arthritis as well as the bowel involvement that is seen in Crohn's disease. Suppression of this cytokine may effectively ameliorate Crohn's disease arthritis in some patients.

Journal Article↗
PubMed2001

Impairments of attention and effort among patients with major affective disorders.

Impairments of attention are common among people with major affective disorders, yet the influence of effortful task demands on attentional performance in unipolar and bipolar illness has been little studied. The authors compared psychiatric inpatients with primary diagnoses of unipolar or bipolar affective disorder (n=27) and age-matched normal control subjects (n=20) on a battery of eight neuropsychological tasks designed to measure different attentional functions. There were low-effort and high-effort versions of each task. Significant group differences were consistently observed on tasks demanding sustained and focused attention, but not on tasks requiring visual selective attention. Although affective disorder patients showed impairments on most tasks regardless of level of task effort, group differences were greatest on high-effort conditions. Results indicate that patients with major affective disorders show significant attentional impairments on most measures of effortful attention, and the magnitude of these impairments increases as the effortful demands of the task increase.

Adult↗
PubMed2001

Dementia severity and pattern of cognitive performance in vascular dementia.

We evaluated the influence of dementia severity on cognitive performance in two groups of individuals with vascular dementia (VaD). Performance on the Mini-Mental State Exam (MMSE) was used to determine dementia severity. Tests of executive function, psychomotor speed, memory, language, and visuospatial function were administered. As expected, individuals with severe VaD (MMSE < 18) performed significantly more poorly than individuals with mild VaD (MMSE > or = 18) on most tests. More important, deficits were evident for both groups in each cognitive domain when compared to normative data. These results indicate that multiple cognitive domains are affected even in mild cases of VaD. Clinicians should be aware that although the presence of "patchy" cognitive deficits may indicate stroke, general cognitive dysfunction may occur in mild cases of VaD.

Aged↗
PubMed2001

[Reversible hypokinetic cardiomyopathy revealing severe hypocalcemia].

Dilated cardiomyopathy may be primary or secondary. Although some causes are well known, such as toxic substances (alcohol, chemotherapy...) or viral infections, biochemical abnormalities are much less common. The authors report the case of a 58 year old woman with no previous history admitted to hospital for an inaugural episode of cardiac failure. The ECG showed sinus tachycardia with a long QT interval (560 mm) and a dilated hypokinetic cardiomyopathy with a left ventricular ejection fraction of 20%. The aetiological investigation showed severe hypocalcaemia (0.66 mmol/L) related to primary hypoparathyroidism. This is an important cause to remember because its treatment leads to correction of the cardiac disease, usually within weeks.

Calcifediol↗
PubMed2001

Phase I trial of a melanoma vaccine with gp100(280-288) peptide and tetanus helper peptide in adjuvant: immunologic and clinical outcomes.

A melanoma vaccine composed of HLA-A2-restricted peptide YLEPGPVTA (gp100(280)), with or without a modified T-helper epitope from tetanus toxoid AQYIKANSKFIGITEL, has been evaluated in a Phase I trial to assess safety and immunological response. The vaccines were administered s.c. in either of two adjuvants, Montanide ISA-51 or QS-21, to 22 patients with high-risk resected melanoma (stage IIB-IV). Local and systemic toxicities were mild and transient. We detected CTL responses to the gp100(280) peptide in peripheral blood in 14% of patients. Helper T-cell responses to the tetanus helper peptide were detected in 79% of patients and had a Th1 cytokine profile. One patient with a CTL response to gp100 had a recurrence in a lymph node 2 years later; her nodes contained CD8+ cells reactive to gp100(280) (0.24%), which proliferated in response to peptide. The overall survival of patients is 75% (95% confidence interval, 57-94%) at 4.7 years follow-up, which compares favorably with expected survival. Four of 14 patients who completed at least six vaccines subsequently developed metastases, all of which were solitary and surgically resectable. They remain alive and clinically free of disease at last follow-up. Data from this trial demonstrate immunogenicity of the gp100(280) peptide and suggest that immune responses may persist long-term in some patients. The frequency and magnitude of the CTL response may be improved with more aggressive vaccination regimens. Although this Phase I study was not intended to evaluate clinical benefit, the excellent survival of patients on this protocol suggests the possibility of a benefit that should be assessed in future studies.

Adjuvants, Immunologic↗
PubMed2001

Primary care work-up of acute and chronic symptoms.

Low back pain may present as acute pain or as an acute exacerbation of a chronic pain problem. Acute low back pain is self-limited, with 90% of affected individuals recovering within 3 weeks to 3 months. Pain duration of more than 4 weeks warrants a more complete work-up, including ruling out malignancy. Pain duration of more than 6 months defines chronic pain, which is frequently associated with affective and behavioral components. When taking the history, determine pain intensity, location, pattern of radiation, onset, and duration. A gentle physical exam may help locate the source of pain through palpation and maneuvers, such as the straight leg raise test. Imaging is recommended for patients with a clinical finding that raises suspicion of spinal malignancy.

Acute Disease↗