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Biomedical subjects

G Abraham

Publications and source records attributed to G Abraham.

At least 37 records · Page 2Linked to original sources
PubMed2003

Blastocystis hominis--an emerging cause of diarrhoea in renal transplant recipients.

Blastocystis hominis is an intestinal protozoan that is emerging as an important cause of diarrhea in the immunosuppressed population. We report two cases of diarrhea caused by this organism in renal transplant recipients. The infection was diagnosed promptly by careful stool examination and treated successfully with metronidazole. These case report highlights the fact that unusual parasites like Blastocystis hominis should be looked for and treated in cases of diarrhea occurring in renal transplant recipients. This reduces the rate of post-transplant morbidity and mortality.

Adult↗
PubMed2002

Regulation of equine lymphocyte beta-adrenoceptors under the influence of clenbuterol and dexamethasone.

In 12 healthy horses, the effects of the beta2-agonist clenbuterol and the glucocorticoid dexamethasone on the lymphocyte beta2-adrenoceptor density and affinity (determined by (-)-[125I]-iodocyanopindolol binding) as well as its responsiveness (assessed by lymphocyte cyclic AMP [cAMP] responses to 10 micromol/l (-)-isoprenaline) were studied. Clenbuterol treatment, 2 x 0.8 microg/kg/day i.v. for 12 days, decreased significantly ICYP binding sites by approximately 30-40%; concomitantly, lymphocyte cAMP response to (-)-isoprenaline was reduced. After withdrawal of clenbuterol, beta2-adrenoceptor density and responsiveness gradually increased, reaching predrug levels after 4 days. The effects of dexamethasone on clenbuterol-induced desensitisation were further investigated. Administration of dexamethasone (1 x 0.1 mg/kg/day, i.v. for 5 days) immediately after clenbuterol withdrawal accelerated beta2-adrenoceptor recovery: only 24 h after administration dexamethasone restored the number of binding sites and cAMP response to (-)-isoprenaline to levels statistically indistinguishable from values before clenbuterol treatment. Three days after dexamethasone administration, lymphocyte beta2-adrenoceptors were further increased about 2-fold the pretreatment values, and this increase declined gradually after dexamethasone withdrawal, reaching baseline values after 4 days. Furthermore, in groups exposed simultaneously to both drugs, dexamethasone completely prevented clenbuterol-induced decrease in lymphocyte beta2-adrenergic receptor density and responsiveness. No significant change was observed in the dissociation constant for ICYP in any of the situations. We conclude that dexamethasone (glucocorticoids) can reverse and prevent Clenbuterol-induced desensitisation (down-regulation) of the lymphocyte beta2-adrenoceptors and therefore, a combined therapy with clenbuterol and dexamethasone may be potentially beneficial in horses suffering from chronic obstructive pulmonary disease (COPD).

Adrenergic beta-Agonists↗
PubMed2001

Effects of carbodiimide crosslinking conditions on the physical properties of laminated intestinal submucosa.

Functional tissue engineering of load-bearing repair tissues requires the design and production of biomaterials that provide a remodelable scaffold for host infiltration and tissue regeneration while maintaining the repair function throughout the remodeling process. Layered constructs have been fabricated from chemically and mechanically cleaned porcine intestinal collagen using ethyl-3(3-dimethylamino) propyl carbodiimide (EDC) and an acetone solvent. By varying the concentration of the crosslinker from 1 to 10 mM and the solvent from 0 to 90% acetone, the strength, stiffness, maximum strain, thermal stability, lamination strength, and suture retention strength can be adjusted. These parameters have either functional importance or the potential to modify the remodeling kinetics, or they have both. This study investigates the interdependence of these parameters, the specific effects that variations in concentration can achieve, and how the two crosslinking variables interact. The results demonstrate that there is substantial latitude in the design of these constructs by these straightforward crosslinking modifications. These data provide the basis for studying the in vivo response to crosslinking conditions that will supply the requisite strength while still allowing host cell infiltration and remodeling.

Acetone↗
PubMed2001

Anticholinergicity and cognitive processing in chronic schizophrenia.

Patients with chronic schizophrenia suffer from alterations in cholinergic functioning due to several factors, including the disease diathesis and pharmacologic treatments. Acetylcholine-cognition relationships are well explored in normals but are unclear in schizophrenia. Prior work indicated serum anticholinergicity does not cause global cognitive impairment in this group (Tracy et al., 1998a), raising the possibility that anticholinergicity normalizes an abnormal hyperactive cholinergic state. Serum anticholinergic levels were determined in 38 chronic schizophrenia patients using an established radioreceptor assay method. Six cognitive functions associated with cholinergic tone in normals were tested. The potential role of autonomic arousal and cigarette smoking were also assessed as both have been linked to cholinergic functioning. Regression analyses showed measures of inhibitory executive control and effortful memory accounted for a greater proportion of the variance in the anticholinergicity measure compared to the other variables. The data demonstrate a relationship between high anticholinergicity and worse performance on two types of attention-resource demanding cognitive processes and do not support the notion that reduced cholinergic tone normalizes a hyperactive cortical acetylcholine substrate. Relevant neuroanatomic structures and implications for models of cognitive deficits in schizophrenia are discussed.

Acetylcholine↗
PubMed2001

The use of antigen-capture enzyme-linked immunosorbent assay (ELISA) for the diagnosis of rinderpest and peste des petits ruminants in ethiopia.

Rinderpest had been reported in most parts of Ethiopia when the Pan African Rinderpest Campaign (PARC) was launched. As a result of intensive disease investigation and strategic vaccination, most parts of the country are now considered provisionally free, and widespread vaccination has been replaced by clinical and serological surveillance. Details of any episodes of disease are recorded and followed up after laboratory confirmation of suspected cass using antigen-capture ELISA. This paper is based on observations on the performance of the antigen detection ELISA compared to the agar gel immunodiffusion (AGID) test, which also differentiates rinderpest from peste des petits ruminants (PPR). The stability of the specific viral antigen was monitored for 4 days, and rinderpest and PPR antigens were still detected, depending on the type of specimen. Antigen capture ELISA is more rapid, sensitive and virus specific than the AGID. Even if the cold chain of the specimen is compromised for a day or two during sample collection and submission, the specimen may still be suitable for testing by ELISA.

Animals↗
PubMed2001

Recurrent peritoneal mesothelioma with long-delayed recurrence.

Peritoneal mesothelioma is a rare malignancy with a poor prognosis. Etiology is unclear and presentation of this disease is often atypical. There are very few cases of long-term survival in patients with peritoneal mesothelioma. We report the case of a patient with peritoneal mesothelioma of 19 years' duration. To the best of our knowledge, there have been no reports of recurrent peritoneal mesothelioma with such long-delayed recurrence and survival. Recurrent peritoneal mesothelioma in the current patient was confirmed by comparing the biopsies of omentum taken in 1979 with that taken in 1997. An extensive literature search was undertaken to look for previous reports of recurrent peritoneal mesothelioma. Aggressive and intensive chemotherapy appeared to provide a longer survival time. Our patient had paraneoplastic manifestations that included paraneoplastic hepatopathy and a wasting syndrome. Peritoneal mesothelioma is a rare malignancy with one to two cases per million in the United States. It is known to exhibit unusual paraneoplastic manifestations, including paraneoplastic hepatopathy. Treatment is often unsuccessful, with a median survival time of approximately 18 months from diagnosis. A better understanding and aggressive management of this disease appear to help prolong survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Influence of the dopamine D2 receptor (DRD2) exon 8 genotype on efficacy of tiapride and clinical outcome of alcohol withdrawal.

We tested the hypothesis that allelic variants of the human dopamine D2 receptor E8 genotype are associated with (i) dopamine D2 antagonist tiapride dose in treatment of alcohol withdrawal (n = 50) and (ii) with anxiety and depression in patients during alcoholism detoxification therapy (admission n = 87; discharge n = 50). DRD2 E8 A/A genotype was associated with increased dose of tiapride during a 9-day detoxification therapy and with increased anxiety and depression scores on admission and 2 weeks later. The findings suggest a pharmacogenetic influence of DRD2 E8 genotype on tiapride efficacy in alcohol withdrawal. In an earlier report, DRD2 E8 A/A genotype was associated with reduced responsiveness to the dopamine D2 agonist apomorphine; however, it is not clear whether both findings share the same biological basis. Earlier findings concerning association of DRD2 E8 A/A with increased anxiety and depression are replicated for the first time.

Adult↗
PubMed2001

Identification and characterisation of beta-adrenoceptors on intact equine peripheral blood lymphocytes with the radioligand (-)-[125I]-iodocyanopindolol.

In this study, beta-adrenoceptors of intact equine lymphocytes were identified and subclassified by (-)-[125I]-iodocyanopindolol (ICYP) binding. ICYP binding to intact equine lymphocytes was rapid, saturable (maximal number of binding sites 320 +/- 20 ICYP binding sites/cell, n = 12) and of high affinity (KD value for ICYP 14.4 +/- 1.7 pmol/l, n = 12). Binding was stereospecific as shown by the 10 times greater potency of (-)-propranolol to inhibit binding than its (+)-isomer. Beta-adrenoceptor agonists inhibited ICYP binding with an order of potency: (-)-isoprenaline >(-)-adrenaline >(-)-noradrenaline; the same order of potency was obtained for agonist-induced stimulation of lymphocyte cyclic AMP content. The selective beta2-adrenoceptor antagonist ICI 118,551 was about 1000 times more potent in inhibiting ICYP binding than was the beta1-selective adrenoceptor antagonist CGP 20712A. It is, therefore, concluded that in intact equine lymphocytes, ICYP labels a class of functional beta-adrenoceptors that belong predominantly (>90%) to the beta2-adrenoceptor subtype; a small (<10%) beta1-adrenoceptor component, however, cannot be ruled out completely. ICYP binding to equine lymphocytes might be a suitable model to study function and regulation of the beta-adrenoceptor system in the horse in vivo. The aim of this study was to characterise the beta-adrenoreceptor subtypes present on equine lymphocytes.

Adrenergic beta-Antagonists↗
PubMed2001

Diagnostic dilemma in coinfection.

A Fifteen years girl belonging to a low socioeconomic status was admitted with peritonsillar abscess caused by methicillin resistant Staphylococcus aureus (MRSA), high fever, diarrhoea and septicaemic shock. Initial blood cultures and widal test, stool cultures and routine stool examination were non-contributory to the diagnosis. A bone marrow culture in the second week confirmed the diagnosis of Salmonella typhi infection. Examination of a fresh stool sample showed cysts of Entamoeba histolytica. She was treated with ciprofloxacin, metronidazole, augmentin and ceftriaxone. She had no clinical evidence of immunosuppression prior to this episode and her HIV test was negative. This case report highlights the presence of community acquired MRSA infection causing perititonsillar abscess, and the diagnostic dilemma of fever and diarrhoea due to coinfection with Salmonella typhi and Entamobea histolytica.

Adolescent↗
PubMed2001

Tuberculous peritonitis in a cohort of continuous ambulatory peritoneal dialysis patients.

Among 155 patients who were initiated on continuous ambulatory peritoneal dialysis (CAPD), 4 patients (2 men, 2 women) developed tuberculous peritonitis. They had been on PD for between 2 months and 84 months when they developed the peritonitis. The Mantoux test was negative in all of them. The diagnosis was made by a variety of means in the various cases: demonstration of Mycobacterium tuberculosis in the peritoneal cavity; presence of caseating granuloma in a peritoneal biopsy; Mycobacterium tuberculosis in a cold abscess adjacent to the peritoneal cavity; and demonstration of IS6110 and MPB64 genes of Mycobacterium tuberculosis by polymerase chain reaction (PCR) technique. Two of the patients developed ultrafiltration failure. Among 3 patients who were switched to hemodialysis, 2 died and 1 continues on maintenance dialysis. The last patient, whose catheter was removed, was reimplanted with a new catheter and continues on PD without ultrafiltration failure. Any patient with peritonitis unresponsive to conventional therapy should be investigated for tuberculous peritonitis. Institution of chemotherapy without delay will preserve peritoneal membrane integrity.

Adolescent↗
PubMed2000

Thyroid function and response to 48-hour sleep deprivation in treatment-resistant depressed patients.

BACKGROUND: Clinical depression is associated with abnormalities of the hypothalamic-pituitary-thyroid axis. Changes in thyroid function during sleep deprivation may be related to its antidepressant effects. METHODS: Levels of thyroid-stimulating hormone, tri-iodothyronine, tri-iodothyronine uptake, thyroxine, and free thyroxine were measured before, during, and after a 48-hour sleep deprivation in nine treatment-resistant depressed patients. Clinical state was assessed every 4 hours. A retrospective study of 26 similar patients was added for cross-validation. RESULTS: Significant increases in thyroid-stimulating hormone and tri-iodothyronine during sleep deprivation were not correlated with clinical improvement. Sleep deprivation responders had lower tri-iodothyronine uptake levels than nonresponders in both the prospective (p <.02) and the retrospective (p <.03) samples. CONCLUSIONS: The lower tri-iodothyronine uptake values in responders may identify a subgroup of depressed patients who respond to sleep deprivation by virtue of some abnormality of the hypothalamic-pituitary-thyroid axis that is temporarily corrected by sleep deprivation.

Adult↗