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Biomedical subjects

R Tandon

Publications and source records attributed to R Tandon.

At least 325 records · Page 18Linked to original sources
PubMedDate not supplied

Severity of rheumatic mitral regurgitation.

Thirty patients below the age of 15 years (range 8-1/2 to 15 years, mean 11.8 years) have been studied for the severity of rheumatic mitral regurgitation. Moderately severe to severe pulmonary venous hypertension was found in 76.6% and pulmonary arterial hypertension in 60%. Left ventricular volumes could be calculated in 13 patients. The end-diastolic volume was elevated in 11 and the endsystolic volume in 12 cases. The regurgitant fraction, calculated in nine patients was 0.6 or more in seven cases. The clinical and hemodynamic severity of mitral regurgitation in children was identical to that seen in adults in the absence of active rheumatic carditis. Children with dominant rheumatic mitral regurgitation can develop congestive failure on the basis of valvar damage per se.

Adolescent↗
PubMedDate not supplied

Patterns of substance abuse in schizophrenia: nature and significance.

Recent literature suggests that the increasingly prevalent problem of substance abuse may have important implications for the symptoms and course of schizophrenia. To further examine the impact of substance abuse on this disorder, the clinical and research charts of 67 schizophrenic patients admitted to the Schizophrenia Program of the University of Michigan between 1987 and 1990 were reviewed and data on symptomatology, history of substance use, age at onset and first hospitalization, and family psychiatric history were gleaned. This information was analyzed with respect to clinical, demographic, and outcome variables with the following findings: (i) female subjects abused substances at a much lower rate (20%) than male subjects (48%); (ii) substance-abusing patients with schizophrenia had lower pre- and post-treatment Hamilton Rating Scale of Depression scores, poorer post-discharge treatment compliance, and were younger at first hospitalization than were non-abusing patients; (iii) the most often abused substance was cannabis (28%) followed closely by alcohol (21%), with cocaine, hallucinogens, and stimulants all abused by significantly fewer patients; (iv) rates of family history of schizophrenia were similar in substance-abusing and non-substance-abusing schizophrenic patients. These data suggest that substance abuse may not be etiologically related to schizophrenia but influences the onset, course, and symptomatology of schizophrenia.

Adolescent↗
PubMedDate not supplied

Facilitation and interference of selective attention in schizophrenia.

Theories of attentional impairment in schizophrenia predict excessive interference in selective attention tasks, such as the Stroop task, where subjects must name the color of words which spell colors different than the to-be-named-color. However, a recent study actually found greater facilitation, i.e. improved color-naming time when the color-word agrees with the to-be-named color, and near-normal interference in schizophrenic patients when compared to normal controls. To evaluate these findings, we studied 12 schizophrenic patients (10 on neuroleptics), and 12 age- and gender-matched, healthy subjects in a trial-by-trial Stroop task. The patients exhibited significantly greater facilitation on the Stroop task compared to the normal controls (81 and 12 ms, respectively). Interference effects were not significantly greater for the schizophrenic patients. These findings suggest a need for more work to investigate why schizophrenic patients appear to benefit from the facilitation condition more than normal controls do.

Adult↗
PubMedDate not supplied

Muscarinic cholinergic hyperactivity in schizophrenia. Relationship to positive and negative symptoms.

Based on the implication of increased muscarinic ACh activity in the production of negative symptoms, the association of decreasing cholinergic activity with positive symptoms, and the covariance of positive and negative symptoms in the psychotic phase of schizophrenia, a model of (DA) dopaminergic/(ACh) cholinergic interactions in schizophrenia was recently formulated. It suggests that DA/ACh balance is of central importance in schizophrenic pathophysiology and that muscarinic ACh activity increases in an attempt to maintain this balance in the face of increasing DA activity that occurs in the psychotic phase of the illness. The model further suggests that the muscarinic system exerts a damping influence on the emergence of positive symptoms associated with DA hyperactivity, but that this compensatory increase in muscarinic activity is accompanied by an intensification of negative symptoms. In the present study, we tested two important postulates of this model. We tested the prediction that muscarinic activity is increased in schizophrenia by comparing the effect of biperiden, an antimuscarinic M-1 agent, on REM latency in 12 drug-free schizophrenic inpatients and matched normal controls. We found that biperiden caused a smaller increase in REM latency in schizophrenic patients, suggesting that muscarinic activity is increased in schizophrenia. We tested the prediction that an anticholinergic agent would increase positive symptoms and decrease negative symptoms by studying the effect of 8 mg of biperiden/day for 2 days on positive and negative symptoms (assessed by the BPRS) in 30 medication-free schizophrenic inpatients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Symptom correlates of global measures of severity in schizophrenia.

There is an increasing need for practical instruments that can rapidly and accurately assess the effectiveness of treatments for mental illness in clinical settings. Symptom rating scales used in clinical research are too complex and time-consuming to be useful in these settings. In contrast, single-item global measures of severity such as the Clinical Global Impression-severity scale (CGI) and the Global Assessment of Function scale (GAF) are brief and easy to complete, but little is known about their relationship with the specific symptoms of severe mental illnesses. In this study, we examine the extent to which CGI and GAF scores reflect the severity and the change in severity of positive, negative, depressive, and agitation symptoms in a sample of 102 schizophrenia inpatients at the University of Michigan Medical Center. At admission, positive symptoms were the strongest correlates of both CGI and GAF scores, followed by negative symptoms, and agitation. Depressive symptoms did not correlate significantly with either global measure. The three symptom scores together explained 58% of the variation in CGI and 39% of the variation in GAF. A similar pattern of association was found for the scores measured at discharge and for the relationships between the change in global measures and change in specific symptom clusters. Thus, by demonstrating that single-item global measures, particularly the CGI, can be reasonably good indicators of psychopathology, this study suggests that these measures may be practical tools for routine monitoring of the effectiveness of treatments for severe mental illness in community settings.

Adult↗
PubMedDate not supplied

New atypical antipsychotic medications.

Conventional antipsychotics were the first treatments effective in controlling psychotic symptomatology and revolutionized management of psychotic disorders when introduced in the 1950's. The use of these agents has, however, been marked by several shortcomings, including limited efficacy in treating the negative and cognitive symptoms of schizophrenia, and by significant extrapyramidal and other side-effects. There appears to be justifiable excitement about the introduction of the newer atypical antipsychotics, which may represent the second pharmacological revolution in the treatment of psychotic disorders. But how are these agents really different from their neuroleptic predecessors? How is their pharmacological profile different? Are there clear differences in efficacy? How do side-effect profiles differ? These issues are reviewed in this manuscript. Atypical agents are pharmacologically distinct from their neuroleptic predecessors. Their primary advantage is their superior side effect profiles, particularly with regard to EPS. The implications of EPS reduction touch virtually every domain of pathology in schizophrenia, including short- and long-term movement disorders, negative symptoms, noncompliance, relapse rate, cognitive dysfunction, and dysphoria. It should be emphasized that while atypical antipsychotics share some clinical attributes, there are substantial clinical differences between them as well. These differences are reviewed in this article as well. The drugs' unique profiles with regard to other side effects may make it possible to tailor treatment more individually to patients. Further refinement of our understanding of the clinical utility of these drugs awaits their widespread use in mainstream clinical settings. Controlled studies comparing them to one another should be of particular interest.

Antipsychotic Agents↗
PubMedDate not supplied

Do atypical antipsychotic medications favorably alter the long-term course of schizophrenia?

Schizophrenia is characterized by the greatest degree of clinical deterioration in the first decade following onset of psychosis; in fact, deterioration begins even prior to the onset of frank psychotic symptomatology. While somewhat controversial, it appears that effective early antipsychotic treatment might limit the extent of such deterioration. The newer, atypical antipsychotics such as clozapine, risperidone, olanzapine and quetiapine appear to have antipsychotic efficacy at least equal to the traditional neuroleptics, but with a much more favorable side effect profile. Clozapine is also effective in treating neuroleptic-refractory schizophrenic patients. Data suggest that in comparison to conventional agents, treatment with atypical antipsychotics may be associated with a more benign course of schizophrenic illness. Whether these atypical antipsychotics are associated with greater efficacy in limiting clinical deterioration in schizophrenic illness than traditional neuroleptics is, however, unclear. The following questions will be addressed in this paper: (i) Do atypical antipsychotics differ from traditional neuroleptics in modifying the natural course of symptomatology in schizophrenic illness? (ii) Do atypical antipsychotics differ from typical neuroleptics in modifying the natural course of neurobiological and cognitive abnormalities in schizophrenic illness? (iii) Do atypical antipsychotics differ from typical neuroleptics in modifying the natural course of psychosocial dysfunction in schizophrenic illness? (iv) Are there differences between typical and atypical antipsychotics with regard to their effects on the cost of care and resource utilization? The implications of the answers to these questions for the long-term treatment of schizophrenia will be discussed.

Antipsychotic Agents↗
PubMedDate not supplied

Depression in patients with schizophrenia during an acute psychotic episode.

There is disagreement about whether depressive symptoms in schizophrenia are part of the basic disease process, or whether they represent adverse effects of treatment with antipsychotic medications. In a sample of initially antipsychotic drug-free acutely hospitalized patients with schizophrenia (N = 104), we measured change in depressive symptoms after 4 weeks of treatment. We also examined the relationship of changes in depressive symptoms to changes in positive and negative schizophrenic symptoms. Depressive symptoms improved after 4 weeks of antipsychotic medication treatment, and their improvement corresponded with improvement in both positive and negative schizophrenic symptoms. These results suggest that depressive symptoms in schizophrenia are related to the disease process itself, at least during acute exacerbations of schizophrenia. Depressive symptoms may be responsive to antipsychotic medications directly or as a secondary response to improvement in positive and negative symptoms.

Acute Disease↗
PubMedDate not supplied

Effectiveness of mitomycin C in reducing reformation of adhesions following surgery for restrictive strabismus.

PURPOSE: To evaluate the efficacy of mitomycin C in reducing reformation of adhesions following surgery for restrictive strabismus. METHODS: Sixteen patients with restrictive strabismus resulting from trauma, retinal detachment surgery, and multiple squint surgeries were randomized to either a mitomycin group (8 patients) or a control group (8 patients). Mitomycin C (0.2 mg/mL) was applied intraoperatively for 5 minutes after release of adhesions. Range of passive ductions was scored for comparison. Postoperative follow-up ranged from 3-18 months. RESULTS: Compared to controls, the mitomycin C group had better range of passive ductions. There were no complications related to the cornea, intraocular pressure, uveitis, or muscle disinsertion in the mitomycin C group. CONCLUSION: Intraoperative application of mitomycin C (0.2 mg/mL for 5 minutes) is a safe and effective adjunct to surgery in the treatment of restrictive strabismus.

Adolescent↗