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Biomedical subjects

H Rico

Publications and source records attributed to H Rico.

At least 127 records · Page 7Linked to original sources
PubMed1991

Candida albicans mycelial wall structure: supramolecular complexes released by zymolyase, chitinase and beta-mercaptoethanol.

Different techniques released from the wall of Candida albicans mycelial cells high molecular weight mannoprotein materials with different levels of complexity. SDS solubilized among others one protein of 180 kDa which reacted with a monoclonal antibody (MAb) specific of a O-glycosylated protein secreted by regenerating mycelial protoplasts [Elorza et al. (1989) Biochem Biophys Res Commun 162:1118-1125]. Zymolyase, chitinase and beta-mercaptoethanol, released different types of high molecular highly polydisperse mannoprotein materials (greater than 180 kDa) that also reacted with the same MAb. These materials had N-glycosidically linked sugar chains, in addition to the O-glycosidically bonded sugars, as their molecular masses were significantly reduced by Endo H digestion. Besides, the specific materials released by either zymolyase or chitinase seemed to be the same throughout the process of germ tube formation. Transmission electron microscopy of thin sections of cells and walls showed that mannoproteins and chitin are evenly distributed throughout the entire cell wall structure.

Blotting, Western↗
PubMed1991

An electron microscopy study of wall expansion during Candida albicans yeast and mycelial growth using concanavalin A-ferritin labelling of mannoproteins.

Depending upon growth temperature, Candida albicans can exhibit two different morphologies, a budding yeast or a mycelium. By studying the distribution of concanavalin A-ferritin particles on the cell wall surface during bud and germ tube formation, we have elucidated the way cell wall extension occurs. Both processes initially require the localized lysis of the wall in order to allow the incorporation of the newly synthesized material. Later on, the cell wall behaves as an elastic structure, allowing extension by an intussusception process and, as a consequence, cell growth.

Candida albicans↗
PubMed1991

Total and regional bone mineral content in normal premenopausal women.

In the present, cross-section study, a total of 185 normal premenopausal females--aged 15 through 19 years (n = 40), 20 to 29 years (n = 60), 30 through 39 years (n = 40) and 40 to 49 years (n = 45)--were assessed in order to observe and evaluate the total body bone mineral content and the regional body mineral content of different anatomical regions (head, trunk, arms and legs), when the bone mass peak is established in women and its course during premenopause. All subjects underwent bone densitometry with dual energy X-ray absorptiometry with a Norland XR-26 bone densitometer. No differences between groups were found in total body bone mineral and regional bone mineral content values. Total body bone mineral values (mean +/- SD) were 2546 +/- 461 g and 2691 +/- 499 g in the 15-19 year-old group and 40-49 year-old group respectively. The regional bone mineral content values for the same age group were 495 +/- 75 g and 499 +/- 89 g for the head, 1007 +/- 254 g and 1043 +/- 212 g for the trunk, 327 +/- 74 g and 336 +/- 81 for the arms, and 860 +/- 167 g and 811 +/- 146 g for the legs. The results of this study indicate that the peak bone mass is reached at the age of 20 years and that it remains stable in the premenopausal eugonadal females.

Absorptiometry, Photon↗
PubMed1991

Reversion of the steroid-induced decrease of serum osteocalcin with sodium fluoride.

Osteopenia observed in corticotherapy is due, among other causes, to a decrease in bone formation as can be shown by a steroid-induced osteocalcin decrease. Although various treatments have been proposed there is no agreement as to which one is the best. Two such treatments, sodium fluoride and vitamin D administration increase osteocalcin levels. We treated a group of 12 patients under corticoid therapy (mean dose 16 mg per day) with 50 mg/day p.o. sodium fluoride, and determined osteocalcin levels before and two weeks after sodium fluoride treatment. Similarly, another group of 9 patients with a similar mean steroid dose was treated with 0.5 micrograms/day of 1 alpha (OH)2D3 in order to assess the effect of this vitamin on osteocalcin and to determine which was the best treatment. Both groups were compared with respective control groups. A significant osteocalcin increase was observed in the control groups (p less than 0.001); similar significance was observed in the sodium fluoride group, whereas a lower significance (p less than 0.01) was observed in the vitamin D group. These results suggest that sodium fluoride could be more effective than vitamin D in the treatment of steroid-induced osteopenia.

Adrenal Cortex Hormones↗
PubMed1991

The value of bone scintigraphy in the follow-up of vertebral osteoporosis.

In an open study, we have assessed the bone/soft tissue uptake index in recent osteoporotic vertebral collapse using scintigraphy. The evolution of these cases was followed-up at 6 months in 22 patients treated with 100 IU of salmon calcitonin plus 500 mg of elemental calcium/10 days per month and in 18 patients treated with 500 mg of elemental calcium only on a daily basis. There were no index differences between groups prior to treatment. At six months, the group treated with calcitonin plus calcium showed a significant decrease from 10.2 +/- 6.4 to 3.2 +/- 1.1 (p less than 0.001), while the calcium only group did not show any significant changes (12.1 +/- 6.6 vs 9.2 +/- 4.6), considering that there were significant differences between groups (p less than 0.001). On a mid-term basis, these results have shown the values of the bone/soft tissue index in the follow-up of osteoporotic vertebral collapse.

Aged↗
PubMed1991

The measurement of osteoporosis in clinical practice.

It has been reported that metacarpal morphometry does not correlate with iliac crest histomorphometry in patients with hip fractures. Such disagreement led us to study the correlation between both types of measurements on 35 patients who had suffered hip fracture. We observed a significant correlation between metacarpal morphometry and iliac crest cortical width (p less than 0.001), and to a lesser degree with the trabecular bone volume (p less than 0.01). The same was also true if we assessed separately the patients with cervical or trochanteric hip fractures.

Aged↗
PubMed1991

Total body bone mineral and pelvis bone mineral content as parameters of bone mass in men. A dual-energy X-ray absorptiometry study.

Total body bone mineral content (TBBM) is a highly discriminating determinant of bone mass. We correlated TBBM with pelvis bone mineral content (PBMC) and pelvis bone mineral density (PBMD) in 179 normal men, in order to observe whether the pelvis is an adequate region of bone mass evaluation. There was a good correlation between PBMC and TBBM (r = 927, p less than 0.001), and significant correlations between PBMD and TBBM (r = 818, p less than 0.001) and between PBMC and PBMD (r = 0.902, p less than 0.001). As the pelvis does not undergo the densitometric changes so often observed in the spine, we believe that the pelvis is appropriate as anatomic region for bone mass evaluation studies.

Absorptiometry, Photon↗
PubMed1991

Behavior of calciotropic hormones in psoriasis.

This report was motivated by the finding that calciotropic hormones, except parathormone (PTH), do not show any response to 1a(OH)D3 therapy in psoriatic patients. These showed high basal whole PTH levels (127 +/- 38 pg/ml) which declined to 45 +/- 15 pg/ml after treatment (p less than 0.001) but did not correlate to calcemia values. Basal calcemia and calciuria were normal and rose with treatment (p less than 0.001 for both). Basal calcitonin and 25(OH)D3 were normal and did not change with treatment nor correlate to changes in calcemia. Due to the effect of 1-hydroxyvitamin D and calcemia on calcitonin and 25(OH)D, the lack of changes in the latter suggests a calciotropic hormone imbalance in psoriasis, which may be an etiologic factor in this entity.

Adult↗
PubMed1991

Age- and weight-related changes in total body bone mineral in men.

Since the incidence of osteoporotic fractures in men increase with age, bone mass, as total body bone mineral content (TBBM) measured by dual energy X-ray absorptiometry (DEXA), and other variables were determined in men in order to observe whether changes in these parameters justify the increased incidence of bone fractures in men with age. Measurements were conducted in 190 men aged 20-85 years. By correlation tests, no changes were observed in body weight and age. There was a significant correlation (r = 0.67981, r2 = 0.46214, p less than 0.001) between TBBM and body weight, and an inverse significant correlation between TBBM with age (r = 0.34729, r2 = 0.12061, p less than 0.001); this decrease is linear with age and represents a 0.3% annual bone loss. These results suggest that lower weight and/or worse psychomotor response and its effects minimizing trauma, may be responsible for the high fracture rate observed in older males.

Adult↗
PubMed1991

Total body bone mineral and tartrate-resistant acid phosphatase levels in type I and III osteogenesis imperfecta.

Serum tartrate-resistant acid phosphatase (TRAP) and total body bone mineral content (TBBM) were determined in a group of 16 children with osteogenesis imperfecta (OI) aged 5-14 years, 9 of whom suffered from type I and 7 from type III OI. TRAP and TBBM were also determined in a group of 26 normal children of a similar age range. TRAP levels were reduced in the type I and III OI groups (p less than 0.001). TBBM levels were lower in type I OI than in type III (p less than 0.005), and both OI groups showed reduced levels compared to the controls (p less than 0.001). The control group subjects showed a significant correlation between TRAP and TBBM (r = -0.62; p less than 0.001) which was not observed in the OI groups. Since TRAP is a biological marker of bone turnover, the results suggest that bone turnover is reduced in OI.

Absorptiometry, Photon↗
PubMed1991

[Bone mass peak, evaluation using bone densitometry of the whole body in a normal female population in our environment].

Considerable debate exists about when the maximal bone mass, or "bone mass peak" is physiological acquired. In the present study, 140 normal females aged 15 through 19 years (n = 18), 20 through 29 years (n = 58) and 30 through 39 years (n = 64), were assessed in order to determine their total body bone mineral (TBBM) content, as bone mass parameter, by bone densitometry with dual energy X rays. We did not observe significant differences in TBBM values between the different groups. A positive and significant correlation existed between age and TBBM (r = 0.486, p less than 0.05) in female aged 15 to 19 years but not in the rest of the groups. These data suggest that female acquired their maximal bone mass, or bone mass peak, up to the age of 20 years and that it remains stable until, at lest, the age of 39 years. We point up the importance of achieving an adequate skeletal development in females during their first 20 years of life that could perhaps protect them from suffering subsequently from osteoporosis.

Absorptiometry, Photon↗
PubMed1990

Osteopenia in rheumatoid arthritis: a biochemical, hormonal and histomorphometric study.

To determine whether the osteopenia of rheumatoid arthritis (RA) is due to reduction of trabecular bone mass (TBV) and/or cortical width (CW), we evaluated these parameters by bone histomorphometry; we also measured the calciotropic hormones parathormone(PTH) and calcitonin (CT), vitamin D [25(OH)D] and the biological markers of bone remodeling in a group of patients with RA. Study subjects were divided into Group C - premenopausal patients, and Group A - menopausal patients and men of the same ages. These groups were compared to two age-matched control groups, B and D. In both A vs. B and C vs. D, TBV and CW were significantly lower in patients. There were no differences in PTH or CT, but 25(OH)D was significantly reduced, and BGP, OHP/Cr and AP were raised in patients. Patients also exhibited TBV loss in more than 55% and CW loss in more than 98%. These changes suggest that the decline in bone mass, mainly cortical, but also trabecular, is due to increased bone turnover and enhanced resorption and seem to reflect intrinsic alterations of RA.

Adult↗
PubMed1990

Treatment of multiple myeloma with nasal spray calcitonin: a histomorphometric and biochemical study.

To evaluate the effect of calcitonin on the bone lesions of multiple myeloma, we studied 11 patients treated for 3 months with salmon calcitonin in nasal spray (200 IU) and 500 mg of elemental calcium/day. Pre- and post-treatment biochemical and histomorphometric parameters were compared to those of 12 patients treated for the same time with 500 mg elemental calcium alone. Both groups received the same hematological treatment. In the group treated with calcitonin there was a significant increase (P less than 0.01) in trabecular bone volume, cortical thickness, osteoid volume and osteoid seam thickness index and the osteoclast resorption surface fell significantly (P less than 0.01). There was also a decline (P less than 0.001) in corrected serum calcium and OHP/Cr, which accounts for the diminished bone resorption. The group not treated with calcitonin showed only significant changes in OHP/Cr which increase (P less than 0.05). Calcitonin was perfectly tolerated by all patients and our results show it to be useful in the treatment of bone lesions of multiple myeloma.

Administration, Intranasal↗
PubMed1990

Effect of calcium pidolate on biochemical and hormonal parameters in involutional osteoporosis.

The purpose of this study was to determine the value of calcium pidolate in the treatment of involutional osteoporosis. This compound has been reported to be better absorbed than other calcium salts, to lower the levels of parathyroid hormone (PTH) and to raise those of growth hormone (GH). We accordingly treated one group of 10 women suffering from involutional osteoporosis with the equivalent of 1 g elemental calcium and administered a placebo to a second group of 10 osteoporotic women whose mean age and body surface area were comparable. Basal sequential multiple analysis (SMA-12) was performed in all subjects to determine calcium, phosphorus, alkaline phosphatase (ALP) and total protein levels, the same blood samples being used for the evaluation of mean PTH, GH and osteocalcin (BGP). Urinary 24-h calcium excretion was determined and the calcium/creatinine (Ca/Cr) and hydroxyproline/Cr (HP/Cr) ratios were measured in 12-h fasting urine samples, the results being corrected for glomerular filtrate. The same parameters were measured again following a month of uninterrupted treatment. After 30 days, we observed no differences in either group as regards calcaemia, phosphataemia, ALP, total proteins, PTH, GH, BGP or 24-hour calciuria. The only noteworthy changes seen were significant decreases (P less than 0.001) in the Ca/Cr and HP/Cr ratios in the group treated with calcium pidolate. These results show that calcium pidolate at the dose administered inhibits bone resorption but does not affect the levels of PTH, GH, BGP or ALP in the medium term. Our findings indicate that it has no influence on bone formation.

Aged↗
PubMed1990

Hyperparathyroidism in metastases of prostatic carcinoma: a biochemical, hormonal and histomorphometric study.

Secondary hyperparathyroidism can develop as a result of bone metastases from prostatic cancer, but this has not been studied from the multiple aspects of biochemistry, hormonal status and histomorphometry. In 20 patients with stage-D prostatic cancer, a transiliac bone biopsy was performed for histomorphometric study. In all of them, molecular parathormone (PTH-M) and osteocalcin were determined by radioimmunoassay together with other parameters considered to be biological markers of bone remodelling. Of these 20 patients, only 2 (10%) had elevated PTH-M (240 +/- 20.6 pmol/l), differing significantly from the other 18 (58.6 +/- 11.7 pmol/l) and from controls (60.4 +/- 7.2 pmol/l). In the high PTH-M patients, corrected calcium was low (7.8 +/- 0.4 mg/dl) as compared to normal PTH-M patients (9.2 +/- 0.5 mg/dl, p less than 0.001), and this was also the case for serum phosphorus (2.2 +/- 0.6 vs. 3.2 +/- 0.3 and 3.4 +/- 0.4 mg/dl, respectively p less than 0.001). Alkaline phosphatase was raised in the patient groups as compared to controls (p less than 0.001) and was higher in the high PTH-M group (362 +/- 58 vs. 224 +/- 62 U/l, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Neoplasms↗
PubMed1990

[Biological profile of tartrate-resistant acid phosphatase as a marker of bone resorption].

Tartrate-resistant serum acid phosphatase was measured in 123 subjects, 80 of which were normal and the rest pathologic, in order to define the profile and value of this parameter as a biological marker of osteoclastic activity. Normal subjects were divided into age groups based on the period where skeletal growth ends (under 20 years), at the age of menopause in women (50 years, between 20 and 50 years) and those over 50 years. There was an increase in tartrate-resistant serum acid phosphatase coinciding with puberty and no sex differences were observed after the 50 year mark, when women showed higher values than men (p less than 0.001). Such tartrate-resistant serum acid phosphatase increase, is reflected as higher values in the 50 year group than in the 20 to 50 year group (p less than 0.001), the only age limit where a negative significant correlation between tartrate-resistant serum acid phosphatase values and age could be observed (p less than 0.05). Values were higher up to the age of 20 years (p less than 0.001) than in any other older age group. Levels increased significantly (p less than 0.001 for both groups) in post-menopausal osteoporosis (n = 20) and in Paget's disease of bone (n = 15), and decreased significantly (p less than 0.05) in imperfect osteogenesis (n = 8), thus revealing its value as a biological marker of osteoclastic activity.

Acid Phosphatase↗