Determination of the effect of polyamines on an oil-degrading strain of Yarrowia lipolytica using an odc minus mutant.

Yarrowia lipolytica is an ascomycetous dimorphic yeast with immense potential for industrial applications, including bioremediation of crude oil-contaminated environments. It has been shown that a dimorphic marine isolate of Y. lipolytica (var. indica) has significant capacity to degrade fatty acids and alkanes, when in its yeast morphology. It has also been demonstrated that polyamines play an important role in the yeast-to-mycelium transition of different strains of Y. lipolytica that are unable to utilize those carbon sources. To determine the role of polyamines on their capacity to utilize oils and hydrocarbons, on the dimorphic transition, and also on other characteristics of the var. indica strain of Y. lipolytica, we proceeded to obtain ornithine decarboxylase minus (odc-) mutants. These mutants behaved as yeasts independently of the concentrations of putrescine added. Further, they conserved the oil-degrading capacity of the parent strain. The odc- mutant can thus be used in fatty acid degradation, and oil spill remediation with distinct advantages.

Can fungi compete with marine sources for chitosan production?

Chitosan, a ß-1,4-linked glucosamine polymer is formed by deacetylation of chitin. It has a wide range of applications from agriculture to human health care products. Chitosan is commercially produced from shellfish, shrimp waste, crab and lobster processing using strong alkalis at high temperatures for long time periods. The production of chitin and chitosan from fungal sources has gained increased attention in recent years due to potential advantages in terms of homogenous polymer length, high degree of deacetylation and solubility over the current marine source. Zygomycetous fungi such as Absidia coerulea, Benjaminiella poitrasii, Cunninghamella elegans, Gongrenella butleri, Mucor rouxii, Mucor racemosus and Rhizopus oryzae have been studied extensively. Isolation of chitosan are reported from few edible basidiomycetous fungi like Agaricus bisporus, Lentinula edodes and Pleurotus sajor-caju. Other organisms from mycotech industries explored for chitosan production are Aspergillus niger, Penicillium chrysogenum, Saccharomyces cerevisiae and other wine yeasts. Number of aspects such as value addition to the existing applications of fungi, utilization of waste from agriculture sector, and issues and challenges for the production of fungal chitosan to compete with existing sources, metabolic engineering and novel applications have been discussed to adjudge the potential of fungal sources for commercial chitosan production.

Anti-tumour necrosis factor treatment increases circulating T helper type 17 cells similarly in different types of inflammatory arthritis.

We investigated changes in circulating T helper type 17 (Th17) cells following anti-tumour necrosis factor (TNF) in rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) patients. Peripheral blood mononuclear cells (PBMC) were isolated from 25 RA, 15 AS and eight PsA patients at baseline 4 and 12 weeks after treatment, and Th17 cell frequencies were analysed using interleukin (IL)-17 enzyme-linked immunospot (ELISPOT) and flow cytometry. A significant increase in IL-17-producing cells was observed by ELISPOT in RA and AS patients at 12 weeks. Flow cytometry confirmed significant increases in CD4(+) IL-17(+) cells at 12 weeks in RA and AS and 4 weeks in PsA patients. Anti-TNF treatment increases circulating Th17 cells in three different diseases.

A biochemical correlate of dimorphism in a zygomycete Benjaminiella poitrasii: characterization of purified NAD-dependent glutamate dehydrogenase, a target for antifungal agents.

The fungal organisms, especially pathogens, change their vegetative (Y, unicellular yeast and H, hypha) morphology reversibly for survival and proliferation in the host environment. NAD-dependent glutamate dehydrogenase (NAD-GDH, EC 1.4.1.2) from a non-pathogenic dimorphic zygomycete Benjaminiella poitrasii was previously reported to be an important biochemical correlate of the transition process. The enzyme was purified to homogeneity and characterized. It is a 371 kDa native molecular weight protein made up of four identical subunits. Kinetic studies showed that unlike other NAD-GDHs, it may act as an anabolic enzyme and has more affinity towards 2-oxoglutarate than L-glutamate. Chemical modifications revealed the involvement of single histidine and lysine residues in the catalytic activity of the enzyme. The phosphorylation and dephosphorylation study showed that the NAD-GDH is present in active phosphorylated form in hyphal cells of B. poitrasii. Two of the 1,2,3 triazole linked ß-lactam-bile acid conjugates synthesized in the laboratory (B18, B20) were found to be potent inhibitors of purified NAD-GDH which also significantly affected Y-H transition in B. poitrasii. Furthermore, the compound B20 inhibited germ tube formation during Y-H transition in Candida albicans strains and Yarrowia lipolytica. The possible use of NAD-GDH as a target for antifungal agents is discussed.

Ankylosing spondylitis and undifferentiated spondyloarthritis in Kuwait: a comparison between Arabs and South Asians.

The objectives of this study were to describe and compare the clinical characteristics of ankylosing spondylitis (AS) and undifferentiated spondyloarthritis (USpA) in Middle East Arab (MEA) and South Asian (SA) patients diagnosed in our unit. Fifty-eight consecutive patients diagnosed with SpA were studied after classifying them into MEA and SA. They were further classified as per disease diagnosis. Excluding three patients with miscellaneous ethnicity, there were 29 MEA and 26 SA patients. Seventy-two percent of MEA patients were males (vs 92% of SA patients). Of the 29 patients with MEA ethnicity, 17 had AS and 9 had USpA. Of the 26 patients with SA ethnicity, 10 had AS and 14 had USpA. Fifty-nine percent of MEA patients had AS (vs 39% of SA patients). Mean age at onset in AS patients was similar in the two ethnic groups. However, in patients with USpA, mean age at onset was somewhat lower at 21.8 years in the MEA group compared with 29.4 years in the SA group. Family history in first-degree relatives was significantly more common in MEA patients. Weight loss, inflammatory spinal pain, gluteal pain, and enthesopathy were equally common in both ethnic groups. Knee, ankle, and metatarsophalangeal joint involvement was less common in MEA patients. There were no significant differences in the occurrence of syndesmophytes, bamboo spine, and sacroiliitis in the two ethnic groups. HLA-B27 positivity rates in MEA patients were 87% for AS and 67% for USpA compared to 75 and 71%, respectively, in SA patients. It is concluded that some significant new findings have arisen from this study: the majority of MEA patients presented with AS, whereas the majority of SA patients had a picture of USpA. Family history was more common in MEA patients. Peripheral arthritis was less common in MEA patients. Worldwide, this is the first study to show that there are significant differences in the clinical expression of the various SpA in MEA patients compared to SA patients.

Myelodysplasia and acute myeloid leukaemia in a case of rheumatoid arthritis with secondary amyloidosis treated with chlorambucil.

Immunosuppressive therapy related secondary haematologic malignancy is well reported. A 52 years lady with established rheumatoid arthritis developed reactive amyloidosis. This was initially treated with colchicine and cyclophosphamide and later with chlorambucil. Ten months after stopping chlorambucil she developed pancytopenia and vitamin B12 deficient megaloblastic anaemia. The pancytopenia was refractory to vitamin B12 supplements and a repeat bone marrow confirmed myelodysplasia (FABI RAEB-T). Within three weeks of this diagnosis she evolved into acute myeloid leukaemia and expired due to refractory thrombocytopenia and uncontrolled bleeding. This case stresses the need for long term follow up of RA patients treated with alkylating agents.

Rheumatoid arthritis and the kidney.

It is clear that kidney is involved in rheumatoid arthritis (RA) with both glomerular and tubular damage. Renal disease in RA however is usually asymptomatic and is detected only on laboratory investigations. It is often difficult to differentiate between damage due to disease activity and that due to drugs used to treat RA. Although there are a number of parameters to study renal function, these cannot be applied to day to day practice and still remain research tools. In such a scenario, it is important to periodically monitor serum creatinine and carry out urine examination so as to pick up the earliest signs of renal dysfunction.

Ultrasonography in the diagnosis and follow-up of idiopathic inflammatory myopathies--a preliminary study.

OBJECTIVE: To study the utility of ultrasonography (US) in diagnosis and follow up of patients with idiopathic inflammatory myopathy (IIM). METHODS: High-resolution US of thigh muscles was recorded at baseline and after six months of treatment in eleven patients of early, active, untreated IIM. Parameters studied were muscle power, timed function tests (TFT), muscle enzymes, electromyography, muscle histopathology and US parameters such as echogenicity of muscle and perimysial septa count per 1 cm muscle width. RESULTS: There was a significant increase in muscle echogenicity and septa count of patients as compared to those of controls (p = 0.002 and 0.00003, respectively). These abnormalities resolved on treatment. Muscle echogenicity and perimysial septa count showed mild positive correlation with walking time, 4-step climbing and myopathic pattern on EMG. Perimysial septa count in addition correlated weakly with creatine phosphokinase, lactate dehydrogenase and muscle fibre necrosis. CONCLUSION: US seems to be a useful, non-invasive, cheap modality to monitor the disease course in IIM. Larger studies to confirm these primary findings are warranted.

A longitudinal study of serum creatinine levels in patients of rheumatoid arthritis on long term NSAID therapy.

AIM: Primary: To study the effect of long term NSAID therapy on serum creatinine in patients of rheumatoid arthritis. Secondary: To study the effect of discontinuation, reduction in the dose or continuation of NSAID and of rechallenge. MATERIAL AND METHODS: Case records of RA patients with a minimum two years of follow up were analysed. Age, sex, duration of RA, type, dose and duration of NSAID and DMARD therapy, co-morbid conditions and serial serum creatinine levels were charted. RESULTS: Ninety nine case records were studied. Incidence of abnormal creatinine level (renal insufficiency) defined as rise in creatinine equal to or above the upper limit of normal was 27.7%. This rise was asymptomatic in all patients. No NSAID was particularly associated with an increased risk in renal insufficiency. The rise of serum creatinine was reversible in most patients irrespective of discontinuation or continuation of NSAID but settled at a higher level. Rechallenge resulted in rise of serum creatinine in 50% patients. Hypertension, DM, IHD and diuretics carried a higher but not statistically significant risk of renal insufficiency. CONCLUSION: NSAID-induced asymptomatic rise of creatinine in patients of RA on long term NSAIDs is common. It is mostly reversible. Regular monitoring of serum creatinine is essential.

Treatment of AA amyloidosis in rheumatoid arthritis.

Four patients of rheumatoid arthritis (RA) with biopsy confirmed AA amyloidosis were treated with chlorambucil. All had established but uncontrolled RA with a persistently raised ESR. Moderate (> 1 gm, < 3.5 gm/d) to nephrotic range (> 3.5 gm/d) proteinuria and a relatively well preserved renal function was noted in three patients. One patient had deranged renal function and required dialysis. On chlorambucil, there was complete recovery, partial improvement and no improvement in one patient each. The fourth patient required haemodialysis, did not tolerate chlorambucil and succumbed to the illness. Therapy with chlorambucil can benefit some patients of RA with AA amyloidosis. Leucopenia is the most important dose limiting side effect.

Efficacy of isoniazid prophylaxis in patients with systemic lupus erythematosus receiving long term steroid treatment.

OBJECTIVE: To study the efficacy of isoniazid prophylaxis (INHP) in patients with systemic lupus erythematosus (SLE) receiving long term glucocorticosteroid treatment. PATIENTS AND METHODS: Treatment with INHP (5 mg/kg/day, max 300 mg/day) together with pyridoxine 10 mg/day for one year was started in all patients with SLE seen between January 1994 and December 1999 and followed up thereafter. Clinical examination and chest radiography were carried out in all patients before the start of INHP treatment. A liver profile was obtained only if liver toxicity was suspected owing to nausea, loss of appetite, and icterus. Only the data of those patients who completed the INHP treatment or who were withdrawn owing to toxicity have been analysed. This was compared with the results of an earlier study of the incidence of tuberculosis (TB) in patients with SLE not receiving INHP. RESULTS: Ninety seven patients were included, of whom 95 completed one year's treatment with INHP. Treatment was discontinued in two owing to toxicity: hepatitis in one and peripheral neuropathy in one, at eight and 10 months, respectively. One patient developed TB within one month of starting INHP. Seventy patients were followed up further for at least one year (mean 26.4 months, range 12-60 months) after completion of the INHP treatment. During this period one patient developed TB after one month. No deaths due to TB or hepatitis occurred. In comparison with earlier series the incidence of TB decreased from 11% to 2%, a reduction of 82%. The cost of treatment for each case of TB prevented in the first year was 5800 rupees. CONCLUSION: INHP is safe and effective in SLE.