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Biomedical subjects

R Joshi

Publications and source records attributed to R Joshi.

At least 73 records · Page 4Linked to original sources
PubMed1990

Anaesthesia for renal transplantation in sickle cell disease.

Sickle cell disease (SCD) is associated with many pathological and functional abnormalities affecting all organ systems. Renal manifestations of SCD may result in end-stage renal disease (ESRD), which can be treated by chronic haemodialysis or renal transplantation. Renal transplantation was successfully performed in a 25-yr-old male with sickle cell beta-thalassaemia and nephrotic syndrome. We present a case report of this patient, a discussion of the renal complications associated with SCD and the perioperative management of a patient with SCD undergoing renal transplantation.

Adult↗
PubMed1989

Hypoxanthine-guanine phosphoribosyltransferase deficiency in three brothers with gout: characterization of a variant, HPRTEdinburgh, having altered isoelectric point, increased thermal lability and normal levels of messenger RNA.

Three brothers who developed acute gouty arthritis at ages 16, 20 and 26 years were found to have increased plasma urate. Erythrocyte hypoxanthine phosphoribosyltransferase (HPRT) activity was less than 1% of normal and adenine phosphoribosyltransferase (APRT) activity was increased 2-3-fold. This variant, HPRTEdinburgh, was further studied using lymphoblast lines established from these patients and the following observations are consistent with a mutation involving a single amino acid substitution. Lymphoblasts from these patients had 0.9-1.6% of control HPRT activity which was 8-fold more labile than control activity at 75 degrees C. Isoelectric focusing of the variant protein in polyacrylamide gels indicated a pI of 6.5-6.7 which is more basic than normal HPRT, pI 6.0-6.3. The Michaelis constants were increased: 10-fold for hypoxanthine from 1.3 to 13 mumol/L, and 5-fold for PP-ribose-P from 6 to 30 mumol/L, for control and variant respectively. The Ki for product inhibition by GMP was marginally increased in the variant. Northern blot analysis of variant lymphoblast RNA indicated normal amounts of the expected 1.6 kilobase messenger RNA.

Adolescent↗
PubMed1989

Molecular probes for general testicular and specific spermatogenic function.

Northern analysis of human testis poly(A+) RNA with a mixture of oligonucleotide primer extended cDNA probes revealed several similar RNAs. These RNAs were subsequently cloned into a VPCS (vector-primer-cloner-sequencer) plasmid. One of these clones, NDHu1, was represented within the library a number of times and hybridized strongly to a poly(A+) RNA of congruent to 1.2 kb. Sequence analysis identified this clone as the URF 1 subunit of the mitochondrial NADH dehydrogenase (NDHu1). Comparison of the relative levels of the NDHu1 and human protamine 1 (HP1) transcripts revealed that HP1 was less abundant than NDHu1. This was unexpected, since it is known that within differentiating mammalian spermatid cells, protamine (HP1) is an abundant transcript. This suggested that the ratio of the relative levels of these two very different mRNAs was indicative of the relationship between specific spermatogenic function (germ cell transcription, determined by the level of the HP1 transcript) and general testicular cell function (determined by the level of the mitochondrial mRNAs, i.e. NDHu1). This correlation was maintained when several individuals expressing various degrees of testicular dysfunction were examined. This study suggests that these probes may be useful markers for general testicular and specific spermatogenic function.

Base Sequence↗
PubMed1989

Eosinophilic granuloma of stomach.

A case of eosinophilic granuloma presenting as a large benign gastric ulcer is reported. On operation table, the lesion was interpreted as malignant.

Adult↗
PubMed1988

Electrical excitability of artificial enzyme membranes. IV. Theoretical approach of the membrane potential of synthetic proteinic films.

This paper deals with the theoretical approach of the membrane potential of artificial proteinic film. Programming techniques using finite difference simulations for the steady state and transient solutions of the Nernst-Planck and Poisson equations were used and solved by the collocation and corrector methods. This approach allows one to calculate the membrane potential without any discontinuity between the Donnan and the diffusion potentials, the thickness of the boundary layers being automatically determined by the intrinsic properties of the solution and of the membrane. The theoretical results are compared with experimental potentials measured on proteinic artificial films.

Enzymes↗
PubMed1988

Mitomycin, ifosfamide and cis-platin in non-small cell lung cancer: treatment good enough to compare.

Mitomycin, ifosfamide and cis-platin are three of the most active single agents in the chemotherapy of non-small cell lung cancer. We have combined them for a phase 2 study in patients with inoperable non-small cell lung cancer. The regimen ('MIC') comprised: mitomycin 6 mg m-2, ifosfamide 3 g m-2 and cis-platin 50 mg m-2, with routine use of lorazepam, dexamethasone and high dose metoclopramide for anti-emesis. Seventy-four ambulatory patients with untreated, limited (LD) or extensive (ED) disease have entered this study, and 66 are evaluable for response. Thirty patients (45%) have achieved partial remission and 7 (11%) complete remission, as assessed radiologically. The overall response rate is thus 56% (95% confidence interval 44%-68%). There have been 29/43 responses in LD (67%, 95% CI 53%-81%) and 8/23 in ED (35%, 95% CI 15%-55%). The median response duration, measured from the start of treatment is 8.75 months. The median survival for the whole group is 9.2 months. The principal toxicity was nausea and vomiting which was severe or prolonged (greater than 48 h) for one or more courses, in 9% of patients. Performance status (PS) and weight were assessed before, and 3 weeks after the last course of chemotherapy. Fifteen (of 31 evaluable) responders improved their PS and only 1 responder deteriorated. Twenty-one of the 28 evaluable non-responders had no change in PS. The difference in PS change between responders and non-responders is highly significant (P = 0.002). Thirty evaluable responders experienced a mean increase in weight of 2.9% with treatment, whereas 24 evaluable non-responders had a mean weight loss of 3.8%. This change is also highly significant (P = 0.0013). MIC is clearly a well tolerated regime and among the most active combinations in non-small cell lung cancer. It will now be tested in a randomized trial against no chemotherapy.

Adult↗
PubMed1987

[Peroral long-term treatment of psoriasis using fumaric acid derivatives].

Oral treatment of psoriasis on an outpatient basis, using a preparation containing fumaric acid derivatives, was evaluated as initial monotherapy (3 months) and as long-term basic therapy (12-14 months) in 13 and 11 patients, respectively. The course of the disease was analysed in each individual case. After completion of both parts of the trial, half of the patients that had only responded poorly to conventional antipsoriatic therapy showed a significant improvement which occurred after several weeks of treatment. In 4 patients the medication had to be stopped because of abdominal pain. No severe side effects, particularly of a renal, hepatic or haematological nature, could be established. Studies in mice and rats disclosed only a low acute toxicity of the fumaric acid derivatives used. In additional analyses, hypotheses were dealt with concerning the mechanism of action of fumaric acid in psoriasis. To establish fumaric acid derivatives in the treatment of psoriasis, studies on chronic toxicity and pharmacokinetics will have to be conducted. Further clinical trials should evaluate a single fumaric acid derivative instead of mixtures.

Animals↗
PubMed1986

Prediction and prevention of relapse of acute lymphoblastic leukaemia after bone marrow transplantation.

Results of bone marrow transplantation (BMT) in 63 adults and children with ALL transplanted in the 5-year period 1979-83 were analysed. Twenty-one patients (33%) relapsed, 25% of the group died in relapse and 19% died from complications of BMT. The actuarial disease-free survival at 6 years was 38%. Relapse after BMT could be predicted by standard prognostic diagnostic features such as age, sex, cell type and presenting blast cell count. Patients transplanted in first remission selected for their poor prognosis had a lower relapse risk than a similar group of poor prognosis patients transplanted in second or subsequent remission (P less than 0.05). Relapse following second and subsequent remission BMT was predicted by a score based on standard prognostic features or by the pace of the disease: patients with an interval of less than 2 years between diagnosis and first relapse having a 15% actuarial disease-free survival, compared with 81% for patients with an interval greater than 2 years (P less than 0.001). These results emphasize that ALL is a heterogeneous disease and establishes the importance of determining relapse risk when selecting BMT and other treatment schedules for ALL patients.

Acute Disease↗
PubMed1985

How should acute lymphoblastic leukaemia relapsing after bone-marrow transplantation be treated?

21 of 63 patients given bone-marrow transplantation (BMT) for acute lymphoblastic leukaemia (ALL) relapsed between day 75 and day 1126 after BMT. 19 patients were given leukaemic induction treatment with standard combination chemotherapy. 7 patients achieved a sustained remission, of whom 5 are alive in remission 88-1240 days after relapse; the 2 others died during a second BMT. 2 of the remaining 14 obtained partial remission but all 14 ultimately died with relapsed leukaemia. A favourable outcome for ALL relapsing after BMT was predicted by the pace of the disease: the 5 survivors had an interval between diagnosis and first relapse of more than 2 years and a disease-free period after BMT of 500 days or more. These results indicate that further conventional chemotherapy should be used rather than a second marrow transplant to prolong disease-free survival in patients with ALL relapsing after BMT.

Adolescent↗
PubMed1985

Use of donors sharing one genetic haplotype for bone marrow transplantation.

Matched sibling transplants enjoy over 95% survival of the grafting procedure, but are only available for 1:5 patients. A sibling sharing one genetic haplotype is today our next choice of donor (67% survival) faring better than other relatives (50% survival), providing total body irradiation (of the thymus) has been avoided. The latter, without increasing the attack rate (64%) of GvHD more than doubles the deaths (57% as against 27%) attributable to it. Rejection is avoided by (a) suicide of host responders to donor buffy coat; (b) Cyclosporin-A; (c) displacement induction; (d) a higher dose of marrow. Prevention of GvHD is essential, using either Cyclosporin-A or removing donor T-cells from marrow prior to infusion or, probably better, both. Autoblast immunisation should be further explored. Tolerization seems an active process, easier in the very young, and nonirradiation of the thymus is believed important. An assay to assess tolerization (to guide cessation of immunosuppressive measures) is badly needed. Selection of a donor whose lymphocytes can deal with intracellular infections of the host's fibroblasts is now possible. The required increased immunosuppressive measures appear to increase the risk of leukemic relapse, and perhaps should be first improved in the more cost-effective fields of inborn error transplants.

Bone Marrow Transplantation↗
PubMed1982

Cyclosporin A as prophylaxis against graft-versus-host disease in 36 patients.

Oral cyclosporin A was used as prophylaxis against graft-versus-host disease in (a) 31 patients with acute leukaemia or aplastic anaemia given transplants of HLA-matched bone marrow and (b) five patients with inborn errors of metabolism given transplants of haplotype-identical (parental) bone marrow. Twenty-six patients survived longer than two months after the operation. Despite the cyclosporin A, 31 patients (86%) suffered an acute form of graft-versus-host disease and 22 (61%) a chronic form. Nevertheless, the disease was usually treatable with immunosuppressive agents and caused the death of only one patient. Cyclosporin A caused renal toxicity in all cases; occasionally this was associated with a "capillary leak" syndrome, fatal in two patients. In children hypertension, fits, and fluid retention were common side effects. Blood concentrations of cyclosporin A correlated with blood urea values and blood pressure but did not predict the occurrence of graft-versus-host disease. Four different dose schedules were used to find the optimum way to administer this drug. Oral cyclosporin A is extremely effective at reducing the severity of graft-versus-host disease, but prevention of the disease is limited by toxicity of the drug and variable absorption. Better results might be achieved with parenteral administration or by using the drug in combination with other methods.

Adolescent↗
PubMed1982

Bone marrow transplantation for acute lymphoblastic leukaemia.

Twenty patients have undergone bone marrow transplantation for acute lymphoblastic leukaemia (ALL). Eighteen patients were in complete remission and two had less than 10% leukaemic blasts in the marrow aspirate in the week prior to transplantation. Eighteen patients were grafted from HLA/MLC compatible siblings. One identical twin and one fully compatible parent were also used as donors. Two patients died of graft-versus-host disease and one of radiation-induced pneumonitis. Four have subsequently relapsed. Thirteen patients remain well and in remission from 202 to 1126 d post transplantation. These results show that morbidity and mortality from the bone marrow transplantation procedure is low. However, the major obstacle to permanent success in marrow transplantation of patients with ALL is recurrence of the disease (35% actuarial disease free survival at 1126 d).

Adolescent↗
PubMed1981

Response of graft versus host disease to high doses of methyl prednisolone.

High dose methyl prednisolone (HDMP) was used to treat 25 episodes of graft versus host disease (GVHD) in 13 patients after bone marrow transplantation for aplastic anaemia or acute leukemia. All patients showed rapid improvement of GVHD following HDMP with resolutions of gut and skin manifestations over several days, but liver GVHD was less responsive to treatment. The major complication of treatment was infection and four patients died from infection following HDMP. The mode of action of HDMP may be a nonspecific anti-inflammatory effect but it appears to be rapidly effective in controlling GVH reactions.

Adolescent↗