Search PubMed⌕ Search

Biomedical subjects

G Abraham

Publications and source records attributed to G Abraham.

At least 55 records · Page 3Linked to original sources

Does akathisia influence psychopathology in psychotic patients treated with clozapine?

BACKGROUND: Akathisia has been reported to predict more severe symptoms and poorer treatment response to typical neuroleptics among patients with schizophrenia. Akathisia has also been associated with symptom exacerbation. This study addressed four questions: 1) Does akathisia predict greater severity in global psychopathology? 2) Is this effect global or specific? 3) Does clozapine treatment alter this relationship? 4) Does severity of psychopathology covary with the level of akathisia? METHODS: Akathisia and clinical symptoms were examined in 33 "treatment refractory" schizophrenic patients treated with clozapine across 16 weeks. Weekly ratings were Barnes Akathisia Rating Scale, Abbreviated Dyskinesia Rating Scale, and Brief Psychiatric Rating Scale (BPRS). Patients were classified as "with" (n = 15) or "without" (n = 18) akathisia. Data analyses involved independent t-test comparisons of selected variables, between-group multivariate analyses of variance across time for BPRS Total scores and Guy's five factors, and partial correlations to assess covariation between BPRS scores and level of akathisia. RESULTS: Akathisia predicted more severe global psychopathology, specific to the Activation (AC) and Thought Disturbance (TH) factors. These relationships did not change with clozapine treatment even when akathisia declined. Interestingly, level of akathisia did not covary with severity of psychopathology. CONCLUSIONS: In this sample, akathisia predicted more severe psychopathology, specific to AC and TH BPRS factor scores. Clozapine treatment did not alter this relationship. Although the presence of akathisia predicted more severe symptoms, the level of akathisia did not covary across time with severity of psychopathology, suggesting an "uncoupling" of these symptom domains.

Adult↗

Remodeling of an acellular collagen graft into a physiologically responsive neovessel.

Surgical treatment of vascular disease has become common, creating the need for a readily available, small-diameter vascular graft. However, the use of synthetic materials is limited to grafts larger than 5-6 mm because of the frequency of occlusion observed with smaller-diameter prosthetics. An alternative to synthetic materials would be a biomaterial that could be used in the design of a tissue-engineered graft. We demonstrate that a small-diameter (4 mm) graft constructed from a collagen biomaterial derived from the submucosa of the small intestine and type I bovine collagen has the potential to integrate into the host tissue and provide a scaffold for remodeling into a functional blood vessel. The results obtained using a rabbit arterial bypass model have shown excellent hemostasis and patency. Furthermore, within three months after implantation, the collagen grafts were remodeled into cellularized vessels that exhibited physiological activity in response to vasoactive agents.

Animals↗

The ex vivo antimicrobial activity and colonization rate of two antimicrobial-bonded central venous catheters.

OBJECTIVE: Catheter-related sepsis is an important complication associated with the use of central venous catheters. Recent studies have suggested that antimicrobial-bonded catheters may reduce catheter colonization and catheter-related sepsis. The aim of this study was to determine the relationship between the antimicrobial activity and the colonization rate of two commercially available antimicrobial-bonded central venous catheters. DESIGN: Prospective, randomized, controlled, nonblinded study. SETTING: Medical intensive care unit of a university-affiliated teaching hospital. PATIENTS: One hundred twenty consecutive medical intensive care unit patients requiring new central venous catheters (fresh stick). INTERVENTIONS: Patients were randomized to receive a) a Standard Arrow; b) an ARROWgard; or c) a Cook Bio-Guard Spectrum central venous catheter. Central venous catheters were removed when they were no longer required or when catheter-related sepsis was suspected. Under aseptic conditions, the distal 12 cm of the removed catheters were cut into six 2-cm segments. Semiquantitative culture was performed (by roll technique) on the distal segment. Colonization was defined as >15 colony-forming units. Using a modified Kirby-Bauer technique, the zone of inhibition of the remaining five segments was determined against the following organisms: methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Enterococcus faecalis, Acinetobacter baumannii, and Candida albicans Catheters that were removed within 24 hrs of insertion were excluded from the analysis. MEASUREMENTS AND MAIN RESULTS: Seven patients were not assessable. The baseline clinical and demographic characteristics were similar among the three groups of patients. Eleven Standard Arrow (28%), seven ARROWgard (19%), and four Bio-Guard (11%) catheters were colonized (p = .05 for Bio-Guard vs. control). Staphylococci were the most common colonizing organisms. Two patients with Standard Arrow catheters (5%) and one patient with an ARROWgard catheter (3%) developed catheter-related sepsis. Antibiotic-coated catheters significantly inhibited the growth of all test organisms except C. albicans (p < or = .05). Zones of inhibition were significantly larger for the Bio-Guard compared with the ARROWgard catheter when tested against MRSA, S. epidermidis, and E. faecalis (p < or = .002). CONCLUSION: The Bio-Guard central venous catheter had greater ex vivo antimicrobial activity against MRSA, S. epidermidis, and E. faecalis compared with the ARROWgard catheter, and this was associated with a significantly lower rate of catheter colonization.

APACHE↗

Effect of compressed carbon dioxide on microbial cell viability.

In order to study the influence of compressed carbon dioxide, over a range of pressures (1.5 to 5.5 MPa) and exposure times (up to 7 h), on the survival of Escherichia coli, Saccharomyces cerevisiae, and Enterococcus faecalis, a new pressurizable reactor system was conceived. Microbial cells were inoculated onto a solid hydrophilic medium and treated at room temperature; their sensitivities to inactivation varied greatly. The CO2 treatment had an enhanced efficiency in cell destruction when the pressure and the duration of exposure were increased. The effects of these parameters on the loss of viability was also studied by response-surface methodology. This study showed that a linear correlation exists between microbial inactivation and CO2 pressure and exposure time, and in it models were proposed which were adequate to predict the experimental values. The end point acidity was measured for all the samples in order to understand the mechanism of microbial inactivation. The pHs of the treated samples did not vary, regardless of the experimental conditions. Other parameters, such as water content and pressure release time, were also investigated.

Carbon Dioxide↗

Double-blind study of clozapine dose response in chronic schizophrenia.

OBJECTIVE: This study explored the relative efficacy of three different doses of clozapine. METHOD: Fifty patients who met Kane et al.'s criteria for treatment-refractory schizophrenia or schizoaffective disorder were studied. All subjects were randomly assigned to 100, 300, or 600 mg/day of clozapine for 16 weeks of double-blind treatment. Forty-eight patients completed this first 16 weeks. Of the 50 patients, 36 went on to second and third 16-week trials of double-blind treatment at the remaining doses. RESULTS: Four subjects (8%) responded to the first 16-week condition, and one subject (2%) responded to the next 16-week crossover condition. A chi-square comparison of the response rates from the three dose groups failed to show a significant effect. An analysis of variance (ANOVA) comparison of Brief Psychiatric Rating Scale-Anchored (BPRS-A) total change scores from baseline to last observation carried forward showed a significant dose effect (600>300>100 mg/day) at 16 weeks of treatment. A crossover ANOVA of the BPRS-A total scores from the 48-week study also showed that the main effect for dose was highly significant; the 100-mg/day dose gave the higher (poorer) values, and the 300- and 600-mg/ day doses gave equal (better) values. Gender played a role in clinical response to treatment at 100 mg/day. CONCLUSIONS: Clozapine treatment at 100 mg/day was less effective than at 300 or 600 mg/day. At 100 mg/day, women responded better than did men. The 600 mg/day group had the best results, but an occasional patient required up to 900 mg/day. Overall response rates were lower than expected.

Antipsychotic Agents↗

Postmenopausal dehydroepiandrosterone administration increases free insulin-like growth factor-I and decreases high-density lipoprotein: a six-month trial.

OBJECTIVE: To determine the effect of administering 6 months of oral postmenopausal DHEA therapy on serum DHEA, DHEAS, and T levels and on physiologic endpoints including lipoproteins and insulin-like growth factor-I (IGF-I). DESIGN: Randomized, double-blind, parallel trial. SETTING: Academic referral practice. PATIENT(S): Thirteen normal-weight or overweight, healthy, nonsmoking, postmenopausal women. INTERVENTION(S): Administration of oral micronized DHEA (25 mg/d). MAIN OUTCOME MEASURE(S): Monthly fasting 23 hours postdose levels of serum DHEA, DHEAS, T, lipoproteins, IGF-I, IGF binding protein-3 (IGFBP-3), and liver function tests. Morphometric indices by dual-energy x-ray absorptiometry scan (percent body fat; lean body mass), immune indices, and insulin sensitivity. RESULT(S): Levels of DHEA, DHEAS, and T all rose into premenopausal ranges, but after 6 months, levels of DHEA and T did not differ from baseline or placebo. At 3 months, the ratio of IGF-I to IGFBP-3 rose by 36.1% +/- 12.7%, but it fell to placebo values by 6 months. High-density lipoprotein and apolipoprotein A1 levels declined. CONCLUSION(S): Patients appeared to tolerate 6 months of DHEA therapy well. Given the small study size, no statistically significant differences in morphometric indices, immune indices, or insulin-sensitizing properties were observed, but significant attenuation of bioavailability occurred. Supplementation with DHEA increased IGF-I/IGFBP-3 levels at 3 months and decreased high-density lipoprotein and apolipoprotein A1 levels at 6 months.

Androgens↗

Renal aspergillosis giving rise to obstructive uropathy and recurrent anuric renal failure.

A sixty-year-old previously healthy male patient presented with anuric renal failure of sudden onset. He was detected to have Aspergillus fumigatus fungal balls in the renal pelvis, ureters and bladder which were removed and his renal function improved. He was treated with itraconazole and sent home. Three weeks later he again presented with anuria and renal failure. He had recurrence of the obstruction with the same fungus. The fungal ball was removed, a double 'J' stenting was performed and he was treated with amphotericin B and itraconazole. Hence we report a previously healthy patient with no evidence of immunosuppression presenting an obstructive anuric renal failure due to isolated renal aspergillosis.

Acute Kidney Injury↗

Absence of changes in antidiuretic hormone, angiotensin II, and atrial natriuretic peptide with clozapine treatment of polydipsia-hyponatremia: 2 case reports.

BACKGROUND: Polydipsia-hyponatremia is a poorly understood disorder that causes considerable mortality and morbidity. Hyponatremia in polydipsia-hyponatremia has been attributed to disturbances in antidiuretic hormone (ADH) function. Improvements in polydipsia-hyponatremia during clozapine treatment offered the chance to see if levels of ADH and other hormones associated with osmoregulation changed with improvement in biochemical and clinical measures of polydipsia-hyponatremia. METHOD: In this preliminary, longitudinal study, we studied 2 male schizophrenic patients (DSM-III-R) who had polydipsia-hyponatremia. Measures were (1) biochemical and clinical: serum sodium and osmolality, urine osmolality and specific gravity, normalized diurnal weight gain, and estimated urine volume and (2) endocrine: ADH, angiotensin II, atrial natriuretic peptide, and prolactin. Measures were collected during 2 months of baseline (typical neuroleptic) and 6 months of clozapine treatment. RESULTS: Single-case statistical procedures showed significant changes in sodium levels (a.m. and p.m.), estimated urine volume, and a.m. urine specific gravity in both patients and significantly decreased diurnal weight gain in 1 patient. Both serum and urine osmolality showed improvement, but values did not reach statistical significance. Low baseline ADH levels persisted through 6 months of clozapine treatment and showed no changes in the context of improvements in serum sodium and osmolality. No significant changes were seen in levels of angiotensin II and atrial natriuretic peptide. CONCLUSION: Given the limitations of this study, there is some evidence to suggest that the improvements in serum sodium and osmolality during clozapine treatment of polydipsia-hyponatremia may not be related to serum levels of ADH, although altered ADH receptor function cannot be ruled out. These data need to be extended in larger samples.

Adult↗

Relation of serum anticholinergicity to cognitive status in schizophrenia patients taking clozapine or risperidone.

BACKGROUND: A potential beneficial outcome of treatment with certain of the atypical neuroleptics is the reduced risk of cognitive impairment, stemming from purported low affinity for cholinergic receptors. In vitro experiments have shown that clozapine is highly anticholinergic and risperidone is minimally so. In vivo tests of the anticholinergic burden imposed by these medications and its potential cognitive consequences are needed. This study examines anticholinergic burden in schizophrenia patients taking clozapine and risperidone and tests whether this burden is associated with cognitive deficits. METHOD: Serum anticholinergic levels were determined in a sample of 22 chronic schizophrenia patients using the radioreceptor assay method of Tune and Coyle (1980). Fifteen patients received clozapine; 7 received risperidone. Mean +/- SD age of the sample, comprising 12 men and 10 women (68% white), was 44.7 +/- 8.4 years. Mean +/- SD age at onset of schizophrenia illness was 23.5 +/- 7.4 years. Two anticholinergic assays based on blood samples collected 1 week apart were available on each patient. RESULTS: Data indicated that clozapine patients had significantly (p < .001) higher anticholinergic levels at both collection points, and levels for both drugs remained stable over time. The clozapine and risperidone patients had essentially equivalent scores on the cognitive measure. CONCLUSION: These data suggest that anticholinergicity distinguishes clozapine and risperidone in vivo but that this effect is not associated with differences in global cognitive functioning. Results suggest that clozapine, despite producing moderately high in vivo serum anticholinergic levels, still holds clinical advantage over standard neuroleptics in terms of cognitive side effects. Reasons for this lowered risk of cognitive impairment are discussed.

Adult↗

The effects of clozapine on symptom clusters in treatment-refractory patients.

Preliminary results of a double-blind clozapine study in a population of chronic psychotic patients at a state psychiatric facility are reported. Thirty "treatment-refractory" schizophrenic patients given a diagnosis according to DSM-III-R criteria (mean age of 44 +/- 9.1 years and a duration of illness of 24.9 +/- 8.8 years) who received 300 mg or 600 mg of clozapine and randomized in a double-blind fashion were analyzed. Subjects were evaluated using the Brief Psychiatric Rating Scale (BPRS) and the Clinical Global Impression (CGI) Scale on a weekly basis for 16 weeks. Based on the changes in their CGI scores at week 16 of clozapine treatment, subjects were retrospectively categorized as "improvers" (N = 12) and "nonimprovers" (N = 18). The two groups were compared for changes in total BPRS and BPRS factor scores. In terms of total BPRS scores, we expected a difference between the two groups because they were categorized based on changes in their CGI scores. However, the total BPRS scores in improvers showed a significant decrease by week 6 of clozapine treatment. On analyzing the four BPRS factors, the improvers showed improvement in the thinking disturbance factor by week 1 that remained steady from week 7. On the hostility-suspiciousness factor, the improvers showed an improvement across time when compared with nonimprovers. The withdrawal-retardation factor showed improvement in both groups across time, whereas the anxiety-depression factor was least influenced by clozapine. These observations suggested that all BPRS symptom factors did not uniformly contribute to improvement in overall psychopathology, which was observed as a decrease in total BPRS scores.

Adult↗

A case report of visceral leishmaniasis in Singapore.

Visceral leishmaniasis (Indian kala-azar) caused by infection due to the protozoan Leishmania donovani is endemic in the Indian subcontinent and adjoining regions. Prolonged fever, hepatosplenomegaly, anaemia and pancytopenia, in the appropriate setting, are important clinical markers towards the diagnosis. Diagnosis is established by blood film or bone marrow examination for Leishman Donovan (LD) bodies and/or culture. Treatment with sodium stibogluconate, pentamidine isethionate or even amphotericin B is usually successful. We report the first case of culture-proven visceral leishmaniasis in Singapore, in a 30-year-old Bangladeshi worker who presented with pyrexia of unknown origin (PUO). He had the classical constellation of symptoms and signs as mentioned above. Diagnosis was confirmed by culture on the Novy, NcNeal and Nicolle (NNN) medium. He was successfully treated with 20 days of pentamidine isethionate daily infusions at a dose of 2 mg/kg/day.

Adult↗