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Biomedical subjects

M Carrozzo

Publications and source records attributed to M Carrozzo.

At least 73 records · Page 4Linked to original sources

[Oral candidiasis as the first manifestation of HIV (human immunodeficiency virus) infection. An analysis of 2 cases].

The authors report two cases in which unexplained oral candidiasis led to the diagnosis of HIV infection with clinical form of AIDS-related complex (ARC). It is highlighted that the dentist showed investigate the causes of every unexplained oral candidiasis in adult because this opportunist infection may be the first sign of immunosuppression associated with AIDS and AIDS-related syndromes.

AIDS Serodiagnosis↗

Effect of calcitonin or the anabolic steroid Decadurabolin on serum beta 2 microglobulin in osteoporotic postmenopausal women.

beta 2-Microglobulin (beta 2m) is a small polypeptide of 99 amino acids with a molecular weight of 11.800. It is found in serum, on the surface of almost all mammalian cells and is part of the surface antigen of the cell membrane of human lymphocytes. Moreover, the heavy chain of major histocompatibility complex class I molecules normally associates in the membrane with beta 2m. According to Canalis, et al this polypeptide is a bone derived growth factor. In our study, serum beta 2m, osteocalcin bone Gla-protein (BGP) and calcium phosphorous metabolism were evaluated in a group of 18 osteoporotic women. Nine were treated with an anabolic steroid, DecaDurabolin and 9 with salmon calcitonin (sCT) for 3 months. The same variables were evaluated in a control group (6 osteoporotic women) treated with oral Ca (1,500 mg/day for 3 months). A significant increase in serum beta 2m and BGP (p < 0.001) was observed after anabolic steroid while a significant decrease in serum beta 2m and BGP (p < 0.01) was observed after sCT. No significant variation for serum beta 2m and BGP was observed in the control group. No significant variation of calcium-phosphorous metabolism was observed in either the control group or the treated group. BGP variations suggest that anabolic steroid stimulates bone formation while a decrease in BGP observed after sCT suggests that this hormone depresses bone turnover via a block in osteoclast activity. Moreover it could be suggested that anabolic steroid and sCT affect beta 2m producing cells.

Aged↗

Internal models of limb geometry in the control of hand compliance.

The aim of this article is to describe the role of some neural mechanisms in the adaptive control of limb compliance during preplanned mechanical interaction with objects. We studied the EMG responses and the kinematic responses evoked by pseudorandom perturbations continuously applied by means of a torque motor before and during a catching task. The temporal changes of these responses were studied by means of an identification technique for time-varying systems. We found a transient reversal of EMG stretch reflex responses centered on the time of ball impact on the hand; this reversal results in a transient coactivation of antagonist muscles at both the elbow and the wrist. The kinematic responses describe the relation between torque input and position output. Thus, they provide a global measure of limb compliance. The changes in limb compliance during catching were quantified by computing error criteria either in the Cartesian coordinates of the hand or in the angular coordinates of the elbow and wrist joints. We found that only the hand compliance in Cartesian coordinates is consistently minimized around impact, in coincidence with the transient reversal of the stretch reflex responses. By contrast, the error criteria expressed in the angular coordinates of the joints have a variable time course and are not minimized around impact. It is known that hand compliance depends on both the pattern of muscle activities and the geometrical configuration of the limb. Therefore, the lack of consistent correlation between the changes in hand compliance and the changes in the geometrical configuration of the limb during catching indicates that the gating of the stretch reflex responses around impact time is based on an internal model of limb geometry.

Brain↗

Post biliopancreatic bypass arthritis. Dermatitis syndrome.

A case of arthritis dermatitis syndrome observed after a biliopancreatic bypass for morbid obesity is described. The syndrome had begun 10 days after surgery and involved the knees, ankles, elbows and wrists and erythema nodosum on the legs. After 15 days treatment with sulfasalazine and steroid the symptoms disappeared. The immunologic aetiology of the disease was postulated and the observation of the syndrome, for the first time, after a biliopancreatic bypass suggested that the manifestation of the disease is independent of the kind of the surgical procedures used for the treatment of the morbid obesity.

Arthritis↗

The importance of vitamin C for hydroxylation of vitamin D3 to 1,25(OH)2D3 in man.

The effects of vitamin C on 1,25(OH)2D3 synthesis in humans were evaluated; the study included 20 females. They were divided into 2 groups. The first of the 10 subjects (age range 55-71) received ascorbic acid at a dose of 150 mg/die i.v. for 10 days; the second 10 subjects (age range 55-69) received a placebo i.v. for 10 days. In a later study (after a 30-day washout) the same two groups were tested for the second time with ascorbic acid at a dose of 1,000 mg/die i.v. for 10 days and placebo i.v. for 10 days. Serum calcium and phosphorus, serum Ca++, serum proteins, blood and urinary pH, serum 25(OH)D3 and 1,25(OH)2D3, serum PTH, urinary hydroxyprolin were tested before and after the treatments. In the first study a significant increase in serum 1,25(OH)2D3 was observed after ascorbic acid while no significant variation was observed for the other parameters. In the second study, a significant increase in serum Ca++ and a significant decrease in serum 1,25(OH)2D3 were observed after ascorbic acid while no significant variation was observed for the other parameters. The authors conclude that ascorbic acid promotes 1,25(OH)2D3 synthesis at a paraphysiologic dose (150 mg/die) in humans but this synthesis is inhibited at higher doses (1,000 mg/die). The latter effect by Ca++ or by an effect of ascorbate on 1 alpha-hydroxylase enzyme could be mediated.

Adult↗

Mixed sclerosing bone dystrophy with features resembling osteopoikilosis and osteopathia striata.

A 64-year old man, presenting pain in his back and left sciatalgia, was found to have a mixed sclerosing bone dystrophy with features resembling osteopoikilosis and osteopathia striata. Oval and round densities were found in the humeral heads, elbows, wrists, hands, pelvis, knees, feet. Striata densities were in the diaphyses of metacarpal and metatarsal bones. Bone scan was negative. Standard biochemical examinations of the blood and urine were negative. According to our investigations no evidence of osteopoikilosis other sclerosing bone dystrophies were found in the family of our patient. These data were discussed.

Aged↗

Mononuclear cells are not involved in BGP synthesis and secretion.

Osteocalcin or bone GLA protein (BGP) is found at high levels in only two tissues, the extracellular matrix of bone and dentine. Tissue culture experiments have demonstrated that BGP is synthesized by two osteoblastic osteosarcoma cell lines (ROS 2/3 and 17/2) and by normal osteoblastic cells in primary culture. BGP was not found in rat cartilage nor in liver, kidney, lung, spleen, brain, heart, thymus, skeletal muscle. In this study secretion of BGP was assayed by RIA in the supernatants of 48-hour cultures of peripheral blood lymphocytes or monocytes. Lymphocyte cultures were carried out using RPMI-1640 supplemented with L-glutamine and antibiotics at the concentration of 1 x 10(6) cells/ml and activated by PHA (10 ng/ml). Peripheral blood monocytes were purified by adherence to plastic Petri dishes and treated with cold PBS supplemented with EDTA. Monocytes were cultured as previously described and stimulated with LPS (50 micrograms/ml). Cell-free supernatants were obtained by centrifugation and stored at -20 degrees C, until the BGP assay was performed. The authors did not observe secretion of detectable amounts of BGP in the supernatants of short-term lymphocyte or monocyte cultures. These data indicate that circulating mononuclear cells are not involved in BGP synthesis and secretion.

Cells, Cultured↗

Transient reversal of the stretch reflex in human arm muscles.

1. Load perturbation responses can violate the law of reciprocal innervation between antagonist muscles under particular conditions. Thus flexor and extensor muscles of wrist and elbow joints are reflexly coactivated by the impact of a ball on the hand during a catching task. The aim of this study was to determine whether reflex coactivation can be preset within the central nervous system (CNS) or whether it is entirely due to the peripheral stimulus. To this end, we studied the behavior of stretch reflex responses of arm muscles evoked by torque motor perturbations applied before and during the catching task. 2. Subjects were instructed to catch a ball dropped from 1.6 m. A torque motor delivered perturbations to the elbow joint, resulting in angular motion at both elbow and wrist joints because of their dynamic mechanical coupling. Two series of experiments were performed that differed in the perturbation waveform. In the first series, a single torque pulse could be randomly applied at different times during the task. The corresponding responses were recovered by subtracting the average of the unperturbed trials from the averages of perturbed trials. In the second series of experiments, a train of pseudorandom pulses was applied continuously during each trial. The time-varying impulse responses were computed at 20-ms intervals by cross-correlation methods. 3. The pattern of the short-latency electromyographic responses evoked by either single pulses or pseudorandom perturbations obeyed the law of reciprocal innervation of antagonist muscles under basal conditions. However, the pattern of the responses evoked by the same perturbations around the time of ball impact on the hand consisted of a substantial coactivation of both stretched and shortening muscles. Reflex coactivation resulted from response patterns that differed at different joints. At the elbow, reflex coactivation resulted from a transient reversal of the direction of the short-latency responses of flexor muscles, with little changes of the responses of extensor muscles. At the wrist, instead, reflex coactivation resulted from simultaneous changes in the response waveform of both flexor and extensor muscles. 4. The peripheral conditions associated with the applied perturbations were constant before the time of ball impact. Thus, because the changes of the stretch reflex responses began before that time, they must have been generated within the CNS. It is here hypothesized that the reversal of the reflex responses is centrally gated by switching from the pathways of reciprocal inhibition to those of coactivation of antagonist alpha-motoneurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Arm↗

Normal serum concentrations of 1,25 dihydroxyvitamin D in osteoporosis.

With the aim of evaluating the role of 1,25 dihydroxyvitamin D in the pathogenesis of osteoporosis, this hormone was studied in 90 subjects. They were divided into three groups: the first group consisted of 30 normal female subjects (aged 30 to 45); the second group comprised 30 elderly female subjects (aged 67 to 90) the third group consisted of female patients (aged 65 to 87) with clinical and radiological evidence of osteoporosis. Variations of serum 1,25 dihydroxyvitamin D, after stimulation with oral P04 (1,000 mg/day for 10 days) and stimulation with oral Ca (1,000 mg/day for 10 days), were studied in 16 osteoporotic females (10 of them received P04) and six Ca (Controls). This second study was performed to evaluate the renal 1-alpha-hydroxylation. No significant variation between serum 1,25 dihydroxyvitamin D of elderly and osteoporotic females was observed when compared with normal young healthy subjects. Moreover, a significant increase in serum 1,25(OH)2D after oral P04 was found in accordance with a significant increase in serum parathormone. These data demonstrate that changes in serum 1,25(OH)2D levels did not seem to play a significant part in the pathogenesis of osteoporosis in our population neither could a deficit of renal 1-alpha-hydroxylation be demonstrated.

Adult↗

[Linear bone densitometry by monochromatic photon absorptiometry. A study of a normal population in Apulia].

An epidemiological survey was conducted on a group of Apulian residents in order to compare the densitometric data obtained with those produced by other European and North American authors. The results confirm the need for personal data on our own population given the often significant differences in order to avoid errors in monitoring patients who may require even long-term treatment.

Absorptiometry, Photon↗

[Tetracycline in the evaluation of bone turnover].

A new and easy technique for the fluorimetric evaluation of rolitetracycline calcium complex was studied. The study was carried out in 3 different groups of rats; an increase in power of fluorescence in the rats on a low calcium diet (LC) and on a low calcium diet plus vitamin D (LC + D) versus the group of rats on a normal calcium diet (NC) was found. Moreover, the amount of spongy bone showed a significant decrease in bone mass in the first two groups (LC and LC + D) versus control. These data indicated that the bone tie of tetracycline was only related to the high turnover of bone and there was no relationship with bone mass. This new technique, in comparison with the others, (double marking and evaluation of space between the two fluorescent bands) enables to evaluate the kind and the evolution of bone rarefaction by biopsy.

Animals↗

Evaluation of mineral metabolism and bone turnover in osteoporotic females treated with phosphorus and salmon calcitonin.

Twenty-five patients with radiological and clinical evidence of osteoporosis were studied. Nineteen patients received oral phosphorus at a dose of 1,000 mg/die for 10 days followed by salmon calcitonin (100 U MRC/die) for 20 days. Six patients received only oral calcium at a dose of 1,000 mg/die). In the first group, a significant increase in serum osteocalcin and parathyroid hormone, after administration of phosphorus and persisting after treatment with salmon calcitonin, was found. No variation in the controls was observed. In a later study, a significant increase in serum 1,25 dihydroxyvitamin D (1,25(OH)2D3), after receiving phosphorus and persisting after salmon calcitonin, was demonstrated. In accordance with the authors' results, phosphorus could be considered a useful activator of bone formation and this stimulus by parathyroid hormone was mediated. Finally, the positive effects of phosphorus on circulating 1,25(OH)2D3 must be considered for a good treatment protocol of osteoporosis.

Administration, Oral↗

[Changes in urinary serotonin in subjects treated with calcitonin].

In a first stage, the authors have evaluated the relationship between plasma calcitonin and urinary serotonin in patients presenting a chronic pathology, mostly of respiratory nature. The results have demonstrated that plasma calcitonin and urinary elimination of serotonin were increased (p less than 0.05) in patients presenting a chronic pathology, compared to 16 healthy patients of the same age and sex. In a second stage, the authors have evaluated the variations of urinary serotonin 24 hours after injection of 100 U MRC of calcitonin from salmon, in the same patients. The results showed (p less than 0.001) an increase of urinary serotonin at 24 hours. This increase is not observed after injection of eel or human calcitonin. The effect of the various calcitonin on serotonin metabolism is discussed.

Aged↗

25-Hydroxycholecalciferol in experimental osteoporosis.

UNLABELLED: The authors, using the experimental pattern of bone rarefaction induced by a low calcium diet, tried to determine if 25-hydroxycholecalciferol, administered at doses and according to procedures similar to those used in osteoporosis, might interfere in such a process of rarefaction. The statistical evaluation of the results concerning the size of the amount of spongy bone presented evidence for the sharp decrease in the specific bone volume in rats placed on a low calcium diet as compared to control rats. Such a difference is found even between rats treated with 25-OH-D3. Nonetheless, the authors reported a difference--although not statistically significant--that indicated an increase in the amount of bone in rats on a normal diet but treated with vitamin D as compared to control rats. IN CONCLUSION: 25-OH-D3 by itself, the diet being the same, was not able to ameliorate the amount of bone.

Animals↗

[Evaluation of the effects of anabolic steroids, calcitonin and 25-hydroxycholecalciferol on the spongy bone of rats].

Prevention of the experimental bone rarefaction which occurs in rats put on a low calcium diet was attempted by using salmon calcitonin and 25 hydroxyvitamin D given with a similar regimen to that used in human disease. Results were compared with the previously reported effects of synthetic anabolic steroids. Statistical analysis was carried out on measurements of cancellous bone mass. No statistically significant increase in the femoral trabecular bone volume occurred in rats put on an hypocalcemic diet plus treatment by calcitonin and vitamin D whereas such an increase had been noted when anabolic steroids were used. Measurement of the trabecular bone volume of proximal and distal epiphyses demonstrated a statistically significant difference between rats on a hypocalcemic diet treated by 25-OH-D3 and rats treated by calcitonin or controls on a normal diet. In rats on a normal diet, 25 hydroxyvitamin D led to an increase in bone mass which did not reach statistical significance but is probably explained by improvement in calcium intestinal absorption.

Anabolic Agents↗

[Polymyalgia rheumatica: a systemic vasculitis. Review of the literature and presentation of 2 clinical cases].

A brief historical account of the nosological and pathogenetic classification of rheumatic polymyalgia (RPM) is followed by an indication of the importance of vasculitis during its course. Elective involvement of the temporal artery is not always observed, though there may also, or exclusively, be involvement of other arterial districts, such as those of the subaxillary and subclavicular, that of the thoracic and abdominal aorta, and of the large branches of the lower limbs. Two clinical cases are presented in support of these assertions. It is also shown that arteritis may appear several months after the onset of RPM, and that its progress may be quite separate from that of the latter. Doppler examination is now of assistance in the diagnosis of these forms, since it permits exploration of the various districts and the detection of subclinical lesions. It is also useful in the monitoring of arteritis and its response to treatment.

Aged↗