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Biomedical subjects

G Martini

Publications and source records attributed to G Martini.

At least 145 records · Page 8Linked to original sources

Cytological mapping of the human glucose-6-phosphate dehydrogenase gene distal to the fragile-X site suggests a high rate of meiotic recombination across this site.

The human gene for glucose-6-phosphate dehydrogenase (G6PD) has been subregionally mapped to band Xq28 by segregation analysis in rodent-human somatic cell hybrids [Pai, G. S., Sprinkel, J. A., Do, T. T., Mareni, C. E. & Migeon, B. R. (1980) Proc. Natl. Acad. Sci. USA 77, 2810-2813]. We have previously reported a common type of X-linked mental retardation associated with an inducible fragile site at Xq27-Xq28 segregates in a close linkage relationship with a G6PD variant, but the relative position of G6PD with respect to the fragile site has not yet been established. This fragile-X syndrome has been shown to be closely linked also to a Taq I restriction fragment length polymorphism detected by a cDNA probe for factor IX, and the latter locus has been mapped to the subtelomeric region Xq26-Xq28 [Camerino, G., Mattei, M. G., Mattei, G. F., Jaye, B. & Mandel, J. L. (1983) Nature (London) 306, 701-704]. The in situ hybridization studies reported here provide strong evidence that G6PD is located on the Xq telomeric fragment distal to the fragile site. These observations and the well-established knowledge that the genes for Deutan and Protan colorblindness are closely linked to G6PD, but segregate independently of factor IX deficiency, suggest that the fragile site associated with this type of X-linked mental retardation occurs in a region prone to high frequency of meiotic recombination.

Animals↗

[Renal excretion of methylene-diphosphate-technium-99m. Preliminary observations].

The purpose of this study is to elucidate the mechanism of the renal excretion of 99mTc-MDP in man. We compared the renal clearance of 99mTc-MDP and 51Cr-EDTA (glomerular filtration rate agent). Since the 99mTc-MDP is bound to the plasma protein, the free fraction was calculated by dialysis. The clearances were obtained by single-injection technique. The plasma disappearance of the tracers was resolved into three exponential functions and area was calculated. The clearance was calculated by dividing the amount of the tracers excreted during the first four hours and the plasma area. In this study no difference was found in the clearance of the two agents. These findings suggest that the renal excretion of diphosphonate is related to the glomerular filtration rate.

Aged↗

[Treatment of Sudeck's syndrome with human calcitonin].

Human calcitonin (Cibacalcin), at a dose of 0.5 mg daily for 15 days followed by 0.5 mg every other day for 4-6 months, was administered to 11 patients (eight men and three women, aged 36-74 years) with posttraumatic reflex sympathetic dystrophy of the lower limbs (stage I-II). Within one month there was significant lessening of pain, improved mobility and less oedema. Biochemical tests were within normal limits before and after treatment, while the pre-treatment raised bone retention of 99mTc-methylene-diphosphonate and increased blood flow in the affected area became normal during treatment. In nine patients healing occurred in the course of four to six months on treatment, in two patients after more than six months. There were no serious side-effects requiring interruption of treatment. These results indicate that human calcitonin should be tried in the treatment of this condition.

Adult↗

[Regional blood flow and bone uptake of methylene-diphosphonate-technetium-99m].

Sudeck's atrophy of the foot is an acute, patchy osteoporosis that, on bone scan, shows an increase in both bone blood flow and local bone uptake of bone-seeking radionuclides. The purpose of this study was to evaluate the relationship between bone uptake of 99mTc-MDP and local bone blood flow. In some patients with Sudeck's atrophy of one foot we measured local bone blood flow and bone uptake of 99mTc-MDP. External counting of radioactivity, with a count-rate of 1 second was performed for 60 minutes after i.v. injection of a known dose of 99mTc-MDP in some patients with Sudeck's atrophy of the foot. The regions of interest (ROI) were selected on the basis of a bone scan performed 24 hours earlier. We assumed that the data recorded during the first seconds (7-10) reflect local blood flow and the data at 60 minutes reflect the bone uptake. The ratio between the local blood flow in the involved and healthy foot was higher than the local bone uptake ratio. The ratio between bone uptake and local bone blood flow was higher in the normal foot than in the affected one. These results suggest that the bone avidity for bone-seeking radionuclides is lower in Sudeck's atrophy than in normal bone.

Adult↗

Genetic variation in the host and adaptive phenomena in Plasmodium falciparum infection.

The in vitro culture of Plasmodium falciparum, after synchronization, lends itself well to an analysis of the asexual schizogonic cycle. We have found in this system that DNA synthesis and RNA synthesis are associated mainly with the trophozoite stage, with the latter peaking slightly ahead of the former. Distinctive patterns of protein synthesis are seen at serial times along the cycle, with a number of 'stage-specific' bands identifiable on SDS gels. The fate of the infection can be influenced by the genotype of the host cell. Thus, glucose-6-phosphate dehydrogenase (G6PD)-deficient erythrocytes are invaded normally, but maturation of intracellular parasites is delayed and impaired. However, the parasites that do develop will then have a normal behaviour in their next rounds in G6PD-deficient cells, suggesting that an adaptive change has taken place. These results fit well with the relative protection against P. falciparum in vivo of girls heterozygous for G6PD deficiency but not of hemizygous G6PD-deficient boys.

Animals↗

[Metabolic changes induced with salmon calcitonin in post-menopausal osteoporosis].

10 patients suffering from post-menopausal osteoporosis were subjected to venous infusion of salmon calcitonine at a dose of 100 U.M.R.C. Essential inital biochemical data were hypocalcaemia associated with plasma increase in AMPc and, in the late phase, an increase in urinary excretion of phosphate and AMPc. In addition to conserving its physiological properties in osteoporotic disease also, the hormone is thus able to provoke a secondary secretion of parathormone. The use of CT in the treatment of post-menopausal osteoporosis is therefore recommended not only because of its evident action on bone reabsorption processes, which usually predominate in this dysmetabolic disease of the skeleton, but also in the indirect secretion of parathyroid hormone which is capable of positively affecting synthesis of 1-25 (OH)2 D3 and intestinal calcic absorption.

Aged↗