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Biomedical subjects

G Nuki

Publications and source records attributed to G Nuki.

At least 109 records · Page 6Linked to original sources

A study of amyloid arthropathy in multiple myeloma.

Forty-three patients with classical multiple myeloma were studied to assess the prevalence and characteristics of amyloid arthropathy using clinical, radiological, and histological methods. Two patients were found to have amyloid arthropathy, and a third case is described in detail. Complement and cryoprecipitate analysis of the synovial fluid, and electronmicroscopy of the synovium, synovial debris and cartilage were undertaken in an attempt to shed further light onto the pathogenesis of what has hitherto been regarded as a rare complication of multiple myeloma. Complement components were not depressed and no evidence of specific light chain containing immune complexes was found in synovial fluid cryoprecipitates. Histochemical and electron microscopic localization of amyloid in perichondrocytic lacunae as well as in synovial fluid debris, synovium and the articular cartilage surface suggest the possibility that chondrocytes and synovial macrophages may share a role in processing immunoglobulin components as a prelude to the formation of amyloid fibrils. Amyloid arthropathy occurs in about 5 per cent of patients with multiple myeloma. The clinical picture can resemble rheumatoid arthritis with median nerve compression in the carpal tunnel and symmetrical arthritis of the wrists and small joints of the hands. Diagnosis can be established by examination of Congo red stained synovial fluid sediments under polarized light even in the absence of other clinical features of amyloidosis and when rectal biopsy is negative.

Aged↗

Clinical and enzymological studies in a child with type I glycogen storage disease associated with partial deficiency of hepatic glucose-6-phosphatase.

1. GSD-I is described in a child with partial deficiency of hepatic glucose-6-phosphatase. 2. Growth retardation and hepatosplenomegaly were major clinical features. 3. Hyperlipidaemia, lactic acidaemia, hyperuricaemia and reduced uric acid clearance were major biochemical findings. 4. Although the glucose response to glucagon and galactose was impaired, there was a striking absence of hypoglycaemia which may be attributable to residual catalytic activity of the enzyme. 5. Preliminary studies of the crude liver enzyme showed it to have a normal pH inactivation profile and apparent Km with a reduced Vmax. 6. No evidence of increased PP-ribose-P availability in fresh liver tissue was detected. 7. Continuous glucose feeding resulted in accelerated growth without complete correction of lactic acidosis or hyperuricaemia. 8. GSD-I with partial deficiency of hepatic glucose-6-phosphatase should be considered in patients with gout or hyperuricaemia associated with hypertriglyceridaemia and lactic acidaemia even in the absence of hypoglycaemia.

Blood Glucose↗

Radiology of the pelvis and hips in adults with Down's syndrome.

In a radiological study of the pelvis in 66 adult subjects with Down's syndrome, 25 (38%) were found to have the classical pelvic sharpe associated with Down's syndrome in infancy and childhood. The appearance of the pelvis and hip joints was very variable and matched the variety of appearances seen in normal subjects, except that generally the pelvis was smaller than normal. The discriminating value of the iliac index (which is abnormal in up to 80% of affected infants) was lost in this group of affected adults. Subluxation and osteoarthrosis of the hips were very uncommon features. In addition to the primary morphological abnormalities in the pelvis in Down's syndrome that are described in the literature, posture probably plays a part in producing the variable radiological appearances of the pelvis.

Adult↗

Pyoderma gangrenosum: clinical and laboratory findings in 15 patients with special reference to polyarthritis.

Fifteen consecutive patients with PG have been studied during the period 1971-78. Systemic disease was found in 13 of the patients and preceded the skin disease in 10 patients by 1-25 years. Only two patients had ulcerative colitis. One patient had paroxysmal nocturnal hemoglobinuria and three patients had an IgA myeloma. Eight patients had polyarthritis; this was classical seropositive rheumatoid arthritis in two patients, and a seronegative inflammatory polyarthritis in six patients. Four patients had an unusual progressive erosive seronegative polyarthritis without evidence of granulomatous bowel disease, psoriasis, genital, urinary tract or eye disease. In three of these four patients the arthritis preceded the PG. Synovial fluid analysis showed depressed complement levels and in one patient deposits of immunoglobulins and complement were demonstrated in the synovial membrane. The course of the arthritis was progressive with development of disabling joint deformities and erosive destruction of joints, despite treatment with penicillamine, corticosteroids and nonsteroidal anti-inflammatory drugs. One other patient had severe degenerative joint disease and chondrocalcinosis in association with a seronegative inflammatory polyarthritis, and another patient had ulcerative proctitis and severe degenerative joint disease secondary to chronic seronegative inflammatory polyarthritis. None of the patients had colitic arthritis, but in view of the association between PG and ulcerative colitis, some patients previously reported with PG and joint disease may have been suffering from the arthritis of ulcerative colitis. PG developed at the site of skin trauma in six patients. The natural history of the skin disease ran one of two courses: an acute, progressive course in which the ulcers rapidly enlarged until arrested by treatment; and a chronic course in which the lesions extended slowly and which after a period of weeks began to show signs of spontaneous healing. In only the patients with ulcerative colitis was there any correlation between the activity of the associated disease and the onset and progression of the skin disease. Serum complement levels were normal and no circulating cryoprecipitable immune complexes were found. Skin histology showed no evidence of vasculitis and direct immunofluorescence examination of involved skin was negative for IgG, IgM, IgA and C3. No consistent abnormality of cell-mediated immunity or neutrophil function was found and no significantly increased prevalence of any HLA antigen type was noted. Twelve patients have been treated with systemic corticosteroids. Six of these patients developed serious steroid complications and four patients have died, all from complications of steroid therapy.

Adolescent↗

Gold and penicillamine: a proposed mode of action in rheumatoid arthritis, based on synovial fluid analysis.

Although in common use, there is still controversy as to the way in which gold and penicillamine act in rheumatoid arthritis (RA). In this study, synovial fluids from 4 groups of patients have been compared: (1) RA patients on gold/penicillamine, (2) RA patients on non-steriodal anti-inflammatory drugs (NSAID) only, (3) osteoarthritis patients, and (4) patients with sero-negative arthropathies. The parameters measured were differential agglutination titre (DAT), total haemolytic complement (CH50), total protein, total white cell count, and immunoglobulins. RA patients on gold/penicillamine have lower synovial DAT levels and higher CH50 levels than RA patients on NSAID only, and total and cryoprecipitable IgM levels very close to those found in the sero-negative joint fluids. The non-specific inflammatory parameters, ie, white cell count and total protein are unchanged after good/penicillamine therapy. In a second study, the serum DATs of patients in total remission after gold/penicillamine were compared with similar patients on NSAID only. The DAT falls significantly in the former group (P less than 0.001), but not in the latter suggesting that fall in DAT is a consequence of therapy rather than remission. The parameters altered by gold/penicillamine in the synovial fluid are those that distinguish RA from non-rheumatoid arthropathies suggesting the drug's primary effect is to render the disease sero-negative. The results support the hypothesis that both drugs have a common mode of action based on their active thiol groups, and that the fall in DAT is due to the reduction of the antigenicity of the IgG complexes.

Anti-Inflammatory Agents, Non-Steroidal↗

Dermatitis herpetiformis--a skin manifestation of a generalized disturbance in immunity.

Detailed investigations on 42 patients with dermatitis herpetiformis (DH) are presented, emphasis being placed on the presence of other disorders having a prominent immunopathogenic basis. These patients and 42 age and sex matched controls were submitted to an extensive clinical and investigative search for the presence of disorders with an immunological basis including the atopic disorders. The findings provided further evidence supporting the association of dermatitis herpetiformis with thyroid disease and pernicious anaemia. A statistically increased incidence of Raynaud's phenomenon and atopy was found in the patients with dermatitis herpetiformis compared to the control group. In addition, of the patients with dermatitis herpetiformis, two had rheumatoid arthritis, two had ulcerative colitis, one had systemic lupus erythematosus and four had splenomegaly. The possible basis for these associations is discussed and it is suggested that dermatitis herpetiformis may be part of a wider spectrum of disease. Genetic linkage and the formation of immune complexes following exposure to a dietary antigen may both be responsible for the disorders associated with DH.

Adult↗

Purine and pyrimidine nucleotides in some mutant human lymphoblasts.

To study the role of purine ribonucleotides as possible regulators of the rate of de novo purine biosynthesis in living human cells, we measured intracellular ribonucleotide concentrations by high-pressure liquid chromatography in a series of cloned human lymphoblast mutants selected by resistance to 8-azaguanine, in which the severity of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) deficiency could be correlated with increases in the rate of de novo purine biosynthesis and increases in intracellular concentrations of phosphoribosyl pyrophosphate (PP-ribose-P). Compared with appropriate normal controls, intracellular purine ribonucleotide concentrations were not reduced in HGPRT-deficient lymphoblasts but there were striking increases in intracellular concentrations of some pyrimidine nucleotides and nucleotide sugars which appeared to be related to the degree of the deficiency. Similar changes were found in lymphoblasts from a Lesch-Nyhan boy. These data support the hypothesis that the accelerated rate of purine biosynthesis in HGPRT-deficient cells result from increases in intracellular PP-ribose-P concentration and not from changes in intracellular purine ribonucleotide concentrations. The possibility that the abnormality of pyrimidine nucleotide metabolism results from coordinate regulation of purine and pyrimidine biosynthesis by PP-ribose-P was not substantiated by measurement of rates of pyrimidine synthesis and experimental elevation of intracellular concentrations of PP-ribose-P after incubation of cells with inorganic phosphate.

Adenine Nucleotides↗

Purine and pyrimidine nucleotide concentrations in cells with decreased hypoxanthine-guanine-phosphoribosyltransferase (HGPRT) activity.

1. In order to investigate the role of purine ribonucleotides in the regulation of de novo purine synthesis in living human cells deficient in HGPRT, intracellular ribonucleotide concentrations have been measured in HGPRT lymphoblasts, fibroblasts and erythrocytes and in appropriate HGPRT controls by high pressure liquid chromatography. 2. Purine Purine ribonucleotide concentrations were not reduced in HGPRT cells, supporting the hypothesis that accelerated purine biosynthesis de novo results from increased availability of PP-ribose-P and not from altered feedback regulation by purine ribonucleotides in HGPRT deficient cells. 3. Striking increases in intracellular concentrations of some pyrimidine nucleotides and nucleotide sugars were detected in HGPRT lymphoblasts and erythrocytes, but not in fibroblasts. 4. The possibiiity that this abnormality of pyrimidine metabolism might result from coordinate regulation of purine and pyrimidine synthesis de novo by PP-ribose-P was not substantiated by measurements of rates of pyrimidine synthesis and experimental elevation of intracellular concentrations of PP-ribose-P following incubation of cells with inorganic phosphate.

Cell Line↗

Stimulation of human purine synthesis de novo by fructose infusion.

In order to clarify the mechanism of hyperuricemia and hyperuricosuria resulting from rapid infusion of fructose in man, the effects of an intravenous infusion of 125-200 g of fructose given over 3-4 hr on the rate of purine synthesis de novo was measured in one individual with osteoarthritis and four patients with gout. The incorporation of 1-minus 14C glycine into urinary uric acid was measured, and the pool size and turnover of urate were assessed by renal excretion of simultaneously administered 15-N urate. Fructose caused an expansion of body urate pool in all subjects, while urate turnover was increased in four. The rate of incorporation of 14-C glycine into urinary uric acid corrected for extrarenal disposal was increased in all cases (21%-430%). In two patients, rates of incorporation of 14-C glycine into urinary creatinine were increased by 10% and 11%, while rates of incorporation into uric acid were increased 84% and 159%, respectively, as a result of fructose infusion. Specific enhancement of the rate of purine synthesis de novo was suggested by these findings. The rate of infusion appeared more important than total dose in determining the magnitude of this effect. Whether the increased rate of purine synthesis was a result of direct stimulation by a fructose metabolite or was secondary to fructose-induced purine nucleotide depletion is uncertain, since the kinetics of glycine incorporation were consistent with either mechanism. Erythrocyte PP-ribose-P concentrations, however, were diminished during infusion rather than increased as might be expected if fructose infusion stimulated purine synthesis by increasing availability of this regulatory substrate.

Adolescent↗

Liver disease in rheumatoid arthritis and Sjøgren's syndrome. Prospective study using biochemical and serological markers of hepatic dysfunction.

Inter-relationships of biochemical and immunological tests of liver function have been studied in a prospective study of 216 patients with rheumatoid arthritis (RA), 32 patients with Sjogren's syndrome, and 27 patients with the sicca syndrome, and these results have been compared with those obtained 289 patients with osteoarthrosis or with a form of seronegative polyarthropathy. In general the prevalence of abnormalities in serum alkaline phosphatase, bromsulphthalein excretion, smooth muscle antibody, and mitochondrial antibody in the former three groups was higher than in patients with osteoarthrosis. Patients with Sjogren's syndrome with RA had a higher prevalence of abnormalities of bromsulphthalein excretion, salivary duct antibody than patients with the sicca syndrome. Patients with RA had a higher pervalence of rheumatoid factor than those with the sicca syndrome. Patients with a positive smooth muscle or mitochondrial antibody were found to have a higher prevalence of hepatomegaly and splenomegaly, of abnormal liver function tests, of other autoantibodies, and of histological abnromalitis of liver than those in whom these tests were negative.

Aged↗

Potassium metabolism in patients with rheumatoid arthritis. Effects of treatment with depot tetracosactrin, spironolactone, and oral supplements of potassium chloride.

(1) Plasma and urine electrolytes and whole body potassium have measured before and after a 2-week administration of depot tetracosactrin 0.5 mg on alternate days to eight patients with rheumatoid arthritis (RA.) The effects of adding supplements of potassium chloride (48 mmol/d) and spironolactone 200 mg daily have been investigated. (2) Acute changes in red blood cell water and potassium content, plasma electrolyte concentration, and plasma 11-hydroxycorticosteroid levels were measured for 48 hours after a single intramuscular injection of 0.5 mg depot tetracosactrin in six patients with RA. (3) The measured total body potassium was significantly less than that predicted from the height, weight, and age formula in patients with RA. (4) Treatment with depot tetracosactrin resulted in an acute fall in plasma and red cell potassium independent of external potassium loss. (5) Two weeks of treatment with depot tetracosactrin resulted in hypokalaemia and a rise in plasma sodium and bicarbonate. There was no associated electrocardiogram changes or a rise in blood pressure. (6) Neither oral potassium supplements nor spironolactone altered total body potassium. (7) The significance of the findings and the physiological mechanisms underlying them are discussed.

Adult↗

Abnormalities in mineral metabolism suggestive of parathyroid over-activity in rheumatoid arthritis.

A three-part study on mineral metabolism in patients with classical rheumatoid arthritis is described. In the first two parts, biochemical abnormalities were revealed suggestive of parathyroid over-activity, and in the third part, observation on calcium absorption provides a hyperparathyroid pattern. The importance of these findings in relation to demineralisation of bone in rheumatoid arthritis is discussed.

Adult↗