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Biomedical subjects

L Cohen

Publications and source records attributed to L Cohen.

At least 181 records · Page 10Linked to original sources
PubMed1995

Off the prescription pad and over the counter: the trend toward drug deregulation grows.

In the future, regulatory agencies may authorize the switch of more drugs from prescription-only to over-the-counter status. This could have the double effect of reducing the number of doctor visits and cutting drug costs. Although some physicians worry about the escape of reasonably potent drugs from medical surveillance, pharmacists are assuming a more significant counselling and medication-tracking role. This article looks at the negative and positive sides of drug deregulation from the perspectives of the physician, pharmacist and patient.

Canada↗
PubMed1995

Cytochalasin J affects chromosome congression and spindle microtubule organization in PtK1 cells.

PtK1 cells were treated with 10 micrograms/ml cytochalasin J (CJ) for 15 min at various stages of mitosis. When applied at nuclear envelope breakdown (NEB) chromosome congression was blocked or substantially slowed, and chromosomes failed to show organization patterns typical of prometaphase. Spindle microtubule (MT) numbers appeared unaffected as judged by the pattern of birefringent retardation. However, ultrastructural analysis showed MTs to be reorganized within the spindle domain with some exhibiting fragmentation and others failing to interact with poorly defined kinetochore laminae. The spindle domain took on a curved, almost banana-like shape, as related to the position of the centrosomes and lack of orientation of chromosomes. Serial section analysis of kinetochore regions showed reduced contour length and maturation of the kinetochore plate with few MTs associated with this structure. Cells similarly treated with 10 micrograms/ml CJ at NEB for 15 min and then released into conditioned medium for 15 min showed the most chromosomes resumed congression to the metaphase plate. Ultrastructural analysis revealed a more normal organization of spindle MTs, but kinetochore structure remained affected. CJ treatment of cells in prometaphase slightly affected chromosomes congression with most chromosomes aligning at the metaphase plate after 10-15 min of treatment. Ultrastructural analysis showed that astral MTs were disrupted and spindle MTs were fragmented; few MTs coursed from kinetochore to pole. Kinetochore structure was also affected with only small numbers of short MTs seen associated with kinetochores. Application of CJ at anaphase onset had little effect on anaphase A and B, but cytokinesis failed to occur. Anti-tubulin staining of a monolayer of cells treated with 10 micrograms/ml CJ for 15 min showed that over 60% of mitotic figures exhibited changes in MT organization. Cells showing the greatest effect of treatment had several foci of bundles of MTs, as if the spindle were multipolar. Chromosomes were arranged near the periphery of the spindle which could be a result of abnormalities of kinetochore structure. Improper association of spindle MTs with kinetochores and, thus, changes in kinetochore position could account for these changes in spindle architecture.

Actins↗
PubMed1995

Parental hostility and its sources in psychologically abusive mothers: a test of the three-factor theory.

A revised version of the three-factor theory of child abuse (Lesnik-Oberstein, Cohen, & Koers, 1982) is presented. Further, we report on a research designed to test three main hypotheses derived from Factor I (1) (a high level of hostility in abusive parents) and its sources. The three main hypotheses are: (1) that psychologically abusive mothers have a high level of hostile feelings (Factor I); (2) that the high level of hostile feelings in abusive mothers is associated with low marital coping skills (resulting in affectionless, violent marriages), a negative childhood upbringing (punitive, uncaring, over controlling), a high level of stress (objective stress), and a high level of strain (low self-esteem, depression, neurotic symptoms, social anxiety, feelings of being wronged); and (3) that maternal psychological child abuse is associated with low marital coping skills, a negative childhood upbringing, a high level of stress and a high level of strain. Forty-four psychologically abusing mothers were compared with 128 nonabusing mothers on a variety of measures and were matched for age and educational level. All the mothers had children who were hospitalized for medical symptoms. The three hypotheses were supported, with the exception of the component of hypothesis 2 concerning the association between objective stress and maternal hostility. The positive results are consistent with the three-factor theory.

Adaptation, Psychological↗
PubMed1995

The role of the output phonological buffer in the control of speech timing: a single case study.

A patient with a selective impairment of speech output, associating phonemic paraphasias and pervasive preverbal pauses, it is described. Experimental data are discussed in relation to current models of speech production. On clinical evaluation, the pattern of paraphasias was strongly suggestive of a functional lesion affecting the output phonological buffer. This hypothesis received substantial support from a study of word and non-word repetition, as well as from a study of picture naming latencies, with various imposed delays between stimulus presentation and vocal response. In order to determine the origin of the preverbal pauses, the patient was also submitted to other timed motor tasks implicity probing higher levels of word production (gender decision and phonemic matching). We suggest that the pauses probably resulted from the conjunction of several mechanisms, including a general slowing apparent in all timed motor tasks, as well as a more specific time lag in speech initiation originating from the output buffer or from the articulator itself.

Anomia↗
PubMed1995

A selective impairment of hand posture for object utilization in apraxia.

This study reports the case of an apraxic patient who was impaired in all aspects of gestural behavior following bilateral posterior parietal cortex lesions. The main impairment concerned manual prehension of objects during their utilization. The deficit contrasted with both normal movement trajectories of the arm during execution of such gestures, and with accurate manual prehension in the context of simple reaching movements. Although recognition of gestures and pantomimes made by the examiner was preserved, the patient showed a striking inability to visually discriminate or describe manual prehension associated with object utilization. We thus propose the existence of specialized cortical mechanisms for the representation and activation of the postural schemata of the hand required for complex actions.

Apraxias↗
PubMed1995

Increased types I and III collagen and transforming growth factor-beta 1 mRNA and protein in hypertrophic burn scar.

Hypertrophic scar is the result of abnormal healing that often follows thermal injury. Hypertrophic scar is characterized by excessive dermal fibrosis and scarring. Five cases of human hypertrophic scar were compared with normal skin using in situ hybridization to localize mRNAs for procollagen types I and III and transforming growth factor-beta 1. Expression of type I procollagen and TGF-beta 1 were also examined with immunohistochemistry. The results demonstrated a significant increase in the expression of mRNA for types I and III procollagen and type I procollagen protein by fibroblasts in hypertrophic scar compared with normal skin. In all cases of hypertrophic scar, significant numbers of cells expressed TGF-beta 1 mRNA or peptide. Neither TGF-beta 1 mRNA nor protein was detected in control tissues. These results suggest a profound increase in production and expression of types I and III collagen mRNA by the fibroblasts in hypertrophic scar. This may result from increased TGF-beta 1 production, through paracrine and autocrine pathways, as have been described for this fibrogenic cytokine.

Base Sequence↗
PubMed1995

T cell receptor repertoire in the peripheral blood and intestinal mucosa of coeliac patients.

The alpha beta and gamma delta T cell receptor (TCR) repertoire in the peripheral blood and intestinal mucosa of six coeliac and six age-matched controls was analysed by reverse transcription and polymerase chain reaction (PCR). No TCR alpha and gamma delta restriction was observed in coeliacs and controls. However, V gamma 3 was expressed only in coeliac peripheral and intestinal T cells. V delta 2 was strongly expressed in coeliacs and scarcely transcribed in control cells. The unique expression of these gamma delta TCR in coeliac patients suggests that V gamma 3 and perhaps V delta 2 TCR-bearing lymphocytes may play a role in the pathogenesis of coeliac disease.

Celiac Disease↗
PubMed1995

Compulsive and impulsive symptomatology in trichotillomania.

Although classified as a disorder of impulse control, trichotillomania (hair pulling) may have some phenomenological overlap with obsessive-compulsive disorder (OCD). The question arises as to whether trichotillomania is best conceptualized as a disorder characterized by impulsivity or compulsivity. Impulsive and compulsive symptoms and traits were compared in 43 patients who presented for treatment of trichotillomania, OCD or impulsive personality disorder. Trichotillomania patients had significantly lower scores of obsessive-compulsive symptoms than OCD patients, and significantly higher impulsiveness scores than this group. Measures of aggression did not differ significantly between groups.

Adult↗
PubMed1995

Seasonal rhythm of platelet [3H]imipramine binding in adolescents who attempted suicide.

OBJECTIVE: This study was designed to determine the seasonality of serotonin functions among adolescents who attempt suicide. METHOD: Platelet [3H]imipramine binding was assessed over a period of 18 months in 98 adolescents who attempted suicide and a comparison group of 23 never-suicidal youths with conduct disorder. RESULTS: [3H]Imipramine (Bmax) was uncorrelated with age, but showed considerable seasonal variability over time in those who had attempted suicide. CONCLUSIONS: [3H]Imipramine binding density in adolescents who attempted suicide exhibited significant seasonality, reaching a nadir in late winter/early spring.

Adolescent↗
PubMed1995

Body dysmorphic disorder in the DSM-IV field trial for obsessive-compulsive disorder.

OBJECTIVE: This study investigated the prevalence and phenomenology of body dysmorphic disorder in patients with obsessive-compulsive disorder. METHOD: The authors studied 442 patients who participated in the DSM-IV field trial for obsessive-compulsive disorder. RESULTS: Twelve percent (N = 51) of the patients had a lifetime comorbid diagnosis of body dysmorphic disorder. Patients with and without body dysmorphic disorder did not differ in demographic characteristics of obsessive-compulsive symptoms. Patients with obsessive-compulsive disorder and body dysmorphic disorder had more anxious, impulsive, and schizotypal features than patients with obsessive-compulsive disorder alone. Age at onset was similar for the two disorders, and severity correlated. However, insight was significantly more impaired for body dysmorphic disorder than for obsessive-compulsive disorder. CONCLUSIONS: As previously thought, these findings suggest that the two disorders are strongly related but also have differences that require further investigation.

Adult↗
PubMed1995

Suramin and hydrocortisone: determining drug efficacy in androgen-independent prostate cancer.

PURPOSE: The combination of suramin and hydrocortisone has shown clinical benefit in patients with androgen-independent prostate cancer. Widespread use was limited by the complex dose schedules and the need for pharmacologic monitoring. This study reports three sequential pharmacokinetically derived treatment regimens that simplified the administration of suramin and hydrocortisone with reduced toxicity. PATIENTS AND METHODS: Three cohorts of patients with advanced prostate cancer that progressed despite castrate levels of testosterone received oral hydrocortisone plus suramin administered in the following manners: (1) a loading dose of suramin followed by a continuous infusion using an adaptive control program (cohort A); (2) an intermittent schedule using a simplified adaptive control schedule (cohort B); and (3) an empiric dosing regimen (cohort C). Drug concentrations were monitored along with the toxicities associated with each regimen. Efficacy was assessed using measurable-disease criteria, radionuclide scans, and posttherapy changes in prostate-specific antigen (PSA) levels. RESULTS: Fifty-six patients were treated and plasma suramin concentrations were similar for each regimen. A partial response was observed in 4% (one of 28; 95% confidence interval, 0% to 18.4%) of patients with measurable disease, while 12% (six of 50; 95% confidence interval, 4.5% to 24.3%) had a greater than 80% decline in the baseline PSA level. The median duration of response was 12 months. No responses on radionuclide scans were seen. Anemia and lymphocytopenia were the most common toxicities, while 7% of patients developed a sensory or motor neurotoxicity. In the sequential regimens, the frequency of renal insufficiency (P = .04) and coagulopathy (P < .0001) decreased, while transaminase elevations (P = .05) were more common using intermittent infusions (cohorts B and C) versus continuous infusion schedules (cohort A). CONCLUSION: The administration of suramin was simplified and the drug concentrations were maintained. In this cohort of patients with advanced prostate cancer, the clinical activity of suramin using these dosing schedules was limited. Pharmacodynamic issues, patients selection, and criteria to assess efficacy could have effected the clinical outcome.

Adaptation, Physiological↗
PubMed1995

Toward an anthropology of senility: anger, weakness, and Alzheimer's in Banaras, India.

Dementia has seldom been subject to cross-cultural and cross-class analyses that localize the obviousness and meaningfulness of its pathology. Fieldwork with old persons and their families in four neighborhoods of Banaras, India, stratified by class, is presented to suggest the need for an anthropology of senility. The centrality of "hot brain"--of anger rather than memory as a fundamental index of senile difference--is explored through its differential construction across class and gender in these neighborhoods. The hearing of the angry voice is examined in relation to local knowledge about weakness, madness, and "sixtyishness" and to practices that maintain intergenerational difference through the construction of what is here termed a familial body.

Aged↗
PubMed1995

Preconditions for sensitivity in measuring change: visual analogue scales compared to rating scales in a Likert format.

In a study of preconditions of responsiveness, we examined the variances obtained by two different ways of responding to questionnaire items. Subjects were 168 first-year medical students. They all completed a questionnaire of nine items. The original Likert-like scoring was (partially) replaced by visual analogue scoring in three quarters of the questionnaires. For three items the analogue form had a significantly greater variance than the discrete form, but no discrete item had a significantly greater variance than its analogue counterpart. Assuming that a greater variance was indicative for a greater responsiveness, our findings provide some support for the preferred use of analogue scales over discrete response categories in the measurement of changes over time.

Adult↗
PubMed1994

Transcriptional activation of a ras-like gene (kir) by oncogenic tyrosine kinases.

We report the characterization of a member of the ras gene family that is overexpressed in cells transformed by abl tyrosine kinase oncogenes. The gene, named kir (for kinase-inducible ras-like), is induced at the transcriptional level. kir mRNA has a rapid turnover and encodes a protein of 33 kDa with guanine nucleotide-binding activity but undetectable intrinsic GTPase activity. kir was cloned by differential screening of genes present in fully malignant versus growth factor-independent cell lines expressing wild-type or mutant forms of BCR/ABL. BCR/ABL and v-Abl induce transcription of the kir gene via specific signaling pathway(s), but kir overexpression alone is not sufficient to mediate transformation.

3T3 Cells↗
PubMed1994

Aspergillus discitis with acute disc abscess.

STUDY DESIGN: Aspergillus osteomyelitis of the vertebral body and disc space is rare. This report discusses a case that occurred in an immunosuppressed 29-year-old man and reviews the pertinent medical literature. OBJECTIVES: To review the management and treatment of Aspergillus osteomyelitis of the vertebral body and disc space. SUMMARY OF BACKGROUND DATA: The patient presented with acute neurologic compromise resulting from L5-S1 discitis and a large epidural soft tissue component secondary to the Aspergillus infection. RESULTS: The patient underwent aggressive surgical debridement along with treatment with amphotericin B and had a complete clinical recovery. CONCLUSIONS: The authors recommend a combined medical-surgical approach in most cases of vertebral Aspergillus osteomyelitis. Early surgery with vigorous surgical debridement along with antifungal treatment seems to yield a good outcome.

Abscess↗