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Biomedical subjects

M Rana

Publications and source records attributed to M Rana.

16 recordsLinked to original sources

Selective recruitment of CCR6-expressing cells by increased production of MIP-3 alpha in rheumatoid arthritis.

Infiltration of various types of leucocytes has been shown to play a crucial role in the pathogenesis of rheumatoid arthritis (RA). Macrophage inflammatory protein-3 alpha (MIP-3 alpha) is a recently identified chemokine which is a selective chemoattractant for leucocytes such as memory T cells, naïve B cells and immature dendritic cells. In this study, we investigated the expression of MIP-3 alpha and its specific receptor CCR6 in the inflamed joints of patients with RA. Increased amounts of MIP-3 alpha were found by ELISA in synovial fluids (SF) of patients with RA. MIP-3 alpha was apparently detected in all synovial tissue specimens of RA patients (n = 6), but it could not be detected in that of osteoarthritis (OA) patients (n = 4). Expression of MIP-3 alpha was detected especially in the sublining layer, and infiltrating mononuclear cells in RA synovial tissue. Gene expression of MIP-3 alpha was also found in six out of 11 RA-synovial fluid cells by RT-PCR. Cultured synovial fibroblasts derived from either RA or OA patients were capable of producing MIP-3 alpha in response to IL-1 beta and TNFalpha in vitro. Furthermore, expression of CCR6 was found in infiltrating mononuclear cells in the cellular clusters and around the vessels of RA synovial tissue. These findings indicate that increased production of MIP-3 alpha may contribute to the selective recruitment of CCR6-expressing cells in RA.

Arthritis, Rheumatoid↗

[A case of primary antiphospholipid syndrome complicated with pulmonary hypertension].

We describe the case of 55-year old male with antiphospholipid syndrome (APS) who developed pulmonary hypertension without any thromboembolic episode. Multiple pulmonary perfusion defects suggestive of in situ thrombosis were observed. Hematological findings revealed microangiopathic hemolytic anemia and thrombocytopenia. These findings were improved by anticoagulant therapy. We monitored mean pressure of pulmonary artery (mPAP) and total pulmonary vascular resistance (TPR) before and after using vasodilator agents by Swan-Ganz catheter. mPAP and TPR showed improvement on treatment with oxygen supplementation therapy and Isosorbide administration. Previously 11 cases with APS complicated with pulmonary hypertension were reported. Majority of these patients have had recurrent venous thrombosis, particularly deep vein thrombosis often accompanied by pulmonary thromboembolism (8/11 cases, 72%). However in this case pulmonary hypertension with APS may be induced by in situ thrombosis in pulmonary micro vessels.

Anemia, Hemolytic↗

Single-fiber PCR in MELAS(3243) patients: correlations between intratissue distribution and phenotypic expression of the mtDNA(A3243G) genotype.

We performed morphological, biochemical, and genetic studies, including single-fiber PCR (sf PCR), on muscle biopsies obtained from a mother and daughter with MELAS syndrome due to the A3243G transition of mitochondrial DNA (mtDNA). The severity of muscle involvement appeared quite distinct, in spite of the fact that both patients segregated similar mutant mtDNA levels on total muscle DNA. The daughter did not show any clinical muscle involvement: muscle biopsy revealed many ragged red fibers (RRFs) mostly positive for cytochrome-c oxidase (COX) activity. In contrast, her mother had developed a generalized myopathy without progressive external ophthalmoplegia (PEO), morphologically characterized by many COX-negative RRFs. Single-muscle fiber PCR demonstrated in both patients significantly higher percentages of wild-type mtDNA in normal fibers (daughter: 23.25 +/- 15.22; mother: 43.13 +/- 26.11) than in COX-positive RRFs (daughter: 11.25 +/- 5.22, P < 0.005; mother: 9.12 +/- 5.9, P < 0.001) and in COX-negative RRFs (daughter: 8.9 +/- 4.2, P < 0.001 mother: 4.8 +/- 2.8, P < 0.001). Wild-type mtDNA levels resulted higher also in COX-positive vs. COX-negative RRFs (daughter: P < 0.05; mother: P < 0.001). Our data confirm a direct correlation between A3243G levels and impairment of COX function at the single-muscle fiber level. Moreover, the evidence of a clinical myopathy in the patient with higher amounts of COX-negative RRFs bolsters the concept that a differential distribution of mutant mtDNAs at the cellular level may have effects on the clinical involvement of individual tissues. However, the occurrence of a similar morphological and biochemical muscle phenotype also in PEO(3243) patients suggests that other genetic factors involved in the interaction between mitochondrial and nuclear DNA, rather than the stochastic distribution of mtDNA genomes during embryogenesis, are primarily implicated in determining the various clinical expressions of the A3243G of mtDNA.

Adolescent↗

An out-of-frame cytochrome b gene deletion from a patient with parkinsonism is associated with impaired complex III assembly and an increase in free radical production.

We have isolated transmitochondrial cybrids containing a mitochondrial DNA cytochrome b 4-base pair deletion previously identified in a patient with parkinsonism. This presentation is in contrast to that of most patients with cytochrome b mutations, who present with exercise intolerance. Clones containing different levels of the cytochrome b 4-base pair deletion showed that high levels of the mutation were associated with a respiratory deficiency and a specific complex III defect. Newly synthesized full-length cytochrome b was undetectable by metabolic labeling of mutant cells, and these cells were unable to grow in media that restricts proliferation of cells with defective oxidative phosphorylation. Steady state levels of some subunits previously found to be in close association with cytochrome b by crystallography and biochemical analysis (ie, Rieske [2Fe-2S] protein and subunit VI) were drastically reduced in clones containing high levels of the mutation, whereas the reduction in the core-1 subunit was milder. The absence of cytochrome b and complex III activity was also associated with increased hydrogen peroxide production. These findings, together with the variable tissue distribution of pathogenic mitochondrial DNA molecules, provide clues to the heterogeneous phenotypes associated with mitochondrial DNA mutations and establish a link between different forms of parkinsonism and oxidative phosphorylation defects.

Cytochrome b Group↗

Cerebral blood flow changes in rhinogenic subdural empyema and the role of hyperaemia in brain swelling.

BACKGROUND: Previous studies have demonstrated that rhinogenic subdural empyema (SDE) generally has a good prognosis. Most patients are admitted with an altered level of consciousness or significant neurological deficit, but eventually have a good outcome. It is well known that intra-operative brain swelling may occur with subdural empyema. OBJECTIVE: To define cerebral blood flow (CBF) dynamics and determine the role of cerebral hyperaemia, if any, in intracranial SDE. METHODS: CBF dynamics were assessed in five patients (mean age 13.2 +/- 2.2 years) with unilateral rhinogenic convexity SDE documented on computer tomography (CT). Regional cortical blood flow (rCBF) was measured using a thermo-coupled sensor placed on the cortex at the time of surgery. Dynamic CT scans were performed to assess cerebral blood volume (CBV) quantitatively, while transcranial Doppler ultrasonography (TCD) was used to measure cerebral blood flow velocities (CBF velocities) both pre- and post-operatively for 21 days. The opposite 'normal' hemisphere served as a control for each patient. RESULTS: Post-operative rCBF and CBF velocities in the pathological hemisphere progressively increased to plateau at 96 hours. Cerebral blood volume was increased bilaterally, but to a greater extent in the pathological hemisphere and more so in grey than white matter. These haemodynamic changes, though clinically significant did not reach statistical significance (p>0.05). CONCLUSION: Our results suggest that the accompanying brain swelling in rhinogenic SDE is a complex event, with reactive cerebral hyperaemia possibly playing neuroprotective role. Furthermore, unilateral convexity empyema causes bilateral cerebral haemodynamic changes. Future studies are necessary to define the aetiology of brain swelling in intracranial SDE.

Adolescent↗

Efficacy of sulfamethoxazole-trimethoprim administration in the prevention of Pneumocystis carinii pneumonia in patients with connective tissue disease.

The efficacy and adverse effects of prophylactic administration of Sulfamethoxazole-Trimethoprim (ST) for Pneumocystis carinii Pneumonia (PCP) were assessed in patients with connective tissue diseases (CTD). Eighty-four patients who were receiving more than 40 mg/day of prednisolone were entried in the present study. Patients with at least one of the two PCP risk factors (interstitial pulmonary fibrosis and lymphopenia), were administered either one (11 patients) or two (26 patients) ST tablets/day. The remaining 47 patients who did not receive ST served as the controls. Although PCP was detected in 4.3% of the patients in the no-ST group, none of the patients who received ST developed PCP. Five of these 26 patients who received two tablets of ST/day, experienced adverse reactions. However, no adverse reactions were detected in the patients who received one tablet of ST/day (p < 0.05). Abnormal laboratory data were obtained for 10 (38.5%) of the patients who received two tablets of ST/day and for 4 (36.4%) of the 11 patients who received one tablet of ST/day. The results of the present study suggest that the prophylactic administration of one tablets of ST in patients with CTD that have at least one of the two PCP risk factors is effective in preventing PCP.

Adult↗

A late-onset mitochondrial myopathy is associated with a novel mitochondrial DNA (mtDNA) point mutation in the tRNA(Trp) gene.

We detected a novel pathogenic mutation, a G-->A transition at position 5521 of mitochondrial tRNA(Trp) gene, in association with familial late-onset mitochondrial myopathy. The mutation was detected in muscle but not in leukocytes from the family's proband. Morphological and biochemical studies documented a severe defect of muscle cytochrome c oxidase (COX) activity. RFLP analysis of single muscle fibers demonstrated segregation of higher percentages of mutated genomes in COX-negative ragged red fibres compared with normal fibers. A predominant impairment in synthesis of subunits I and III of complex IV due to their highest relative content of tryptophane might explain the greater susceptibility of complex IV to the pathogenic effect of this mutation. A progressive accumulation of mutated genomes in muscle can account for the late onset of symptoms observed in affected members.

Aged↗

A novel mitochondrial DNA point mutation in the tRNA(Ile) gene is associated with progressive external ophtalmoplegia.

We report a new mutation, a T-->C transition at nt.4285 in the mitochondrial tRNA(Ile) gene, in a sporadic case of progressive external ophtalmoplegia (PEO) and ragged-red fibers (RRF). The mutation, involving a highly conserved base-pair in the anticodon stem, was detected in high percentages (91%) in muscle, but not in blood. It has never been reported in literature in normal subjects and it was not found in any of 80 controls studied in our laboratory. The absence of the mutation in leukocytes in this case with pure muscle involvement confirms the importance of performing mtDNA studies in PEO patients preferentially on muscle rather than blood, which could give false negative results. Other mutations in the tRNA(Ile) gene associated with different phenotypes have been previously reported. Thus, tRNA(Ile) gene is confirmed to be another "hot spot" region for mtDNA mutations.

Adolescent↗

Comparative patterns of hepatic drug metabolizing enzymes and their possible correlation with chromosomal aberrations in transplantable murine lymphoma: a time course study.

The differential levels of induction of hepatic microsomal cytochrome P-450 (cyt. P-450), UDP-glucuronyl transferase (UDPGT), cytosolic glutathione-S-transferase (GSHT) activities, and major chromosomal aberrations were evaluated over various periods of time, following tumor transplantation in male Swiss Albino mice. Changes in the above markers were studied (1) to monitor the entire carcinogenic process and (2) to test the suitability of chemopreventive exposures in terms of phase and duration of tumor growth. The microsomal cyt. P-450 content and the UDPGT activity were significantly elevated (p < 0.01-0.001) from the early stages of tumor growth while the cytosolic GSHT activity reached its highest level (p < 0.01-0.001) only 10 days after tumor transplantation. During the later stages of tumor growth all the biotransforming enzyme activities showed a downhill trend, which was significantly lower than that of their normal counterparts (p < 0.01-0.001). The frequency of different chromosomal aberrations, which were of major structural, numerical, and physiological types, increased steadily throughout the entire length of the carcinogenic process (30 +/- 2 days).

Animals↗

Manifesting heterozygotes in McArdle's disease: clinical, morphological and biochemical studies in a family.

We report a family with McArdle's disease with several affected individuals in two generations. This unusual pedigree for an autosomal recessive disease is explained by the existence of manifesting heterozygotes in the maternal line. The presence of symptoms in heterozygotes seems to be due to a decrease in myophosphorylase activity below a critical threshold, ranging between 30% and 45% of normal mean value. The occurrence of several manifesting heterozygotes in the maternal line only can be explained by compound heterozygosity of a defective allele and a pseudodeficient allele for myophosphorylase, or by a genetic factor which regulates the phenotypic expression of the gene.

Adolescent↗

Cardiomyopathy may be the only clinical manifestation in female carriers of Duchenne muscular dystrophy.

Cardiomyopathy was reported in a few Duchenne muscular dystrophy (DMD) carriers with clinical evidence of myopathy. We report two carriers with dilated cardiomyopathy, increased serum CK, and no symptoms of muscle weakness. In heart biopsies of both patients, dystrophin-the protein product of DMD locus--was absent in many fibers. Dilated cardiomyopathy may be the only manifestation of dystrophin gene mutation in carriers.

Adult↗

Health planning in Pakistan: a case study.

Health planning is an essential function of the state. For it to be successful, a number of conditions need to be satisfied. In particular it needs to be flexible, participative and integrated with other decision processes. Despite some strengths, the health planning system in Pakistan has generally failed to provide the framework to allow such an approach. Links between strategic and operational planning have been weak; decision-making has been very centralized; there has been a lack of functional clarity; the respective roles of bureaucrats and politicians have been unclear; and, links between capital and recurrent budgets and between planning and implementation have been weak. As a result, there is a number of imbalances in the allocation of resources. The introduction of a revised health planning system for Pakistan is discussed. The constraints on such a system and an initial assessment of its success are presented.

Budgets↗