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Biomedical subjects

C Gennari

Publications and source records attributed to C Gennari.

At least 307 records · Page 17Linked to original sources

Seasonal variation in urinary excretion of cyclic AMP in healthy people.

In a group of healthy young men and women the daily urinary excretion of cyclic adenosine 3', 5'-monophosphate (cAMP), calcium, hydroxyproline and the renal threshold phosphate concentration were evaluated at monthly intervals during 1 yr. A significant seasonal variation in cAMP urinary excretion was demonstrated, with a maximum occurring in spring and a minimum in winter. A clear annual rhythm was also observed when the other above parameters were considered. These findings are of importance in the interpretation of urinary cAMP values in clinical situations, and in the study of bone metabolism.

Adult↗

Relevance of hydration state of the fat free mass in estimating fat mass by body impedance analysis.

Body impedance analysis (BIA) is widely used to assess body composition, however, accurate estimates of fat mass (FM) are sometimes rendered impossible due to over- or dehydration states. In fact, BIA is accurate in total body water (TBW) estimates, and TBW can be converted into fat free mass (FFM) assuming 73% hydration; but, if there is an alteration in the hydration state, such a fixed value does not fit with the real content of fluids in the FFM compartment, thus causing wrong estimates of FFM and in turn of FM. For this reason, phase-sensitive bioelectric analyzers operating at a single frequency or at multiple frequencies have recently been under investigation in order to produce an equation that is also able to estimate the volume of extracellular water (ECW). Some authors, rather than trying to find the best equation or the best instrument approach, have tested the direct use of resistance, reactance and phase angle values derived from 50 kHz impedance measurements, assuming that normal bioelectrical values are associated with normal hydration states. Using a large series of data we have found strong correlations between BIA-derived FM and BMI, and our data show that screening the subjects with normal hydration states using the direct bioelectrical parameters (BIAGRAM) improves the predictivity of standard equations, since it avoids trying to estimate FM in overhydrated subjects.

Adipose Tissue↗

Comparison of effects of guanfacine and clonidine on blood pressure, heart rate, urinary catecholamines, and cyclic nucleotides during and after administration to patients with mild to moderate hypertension.

In a random trial, the effects of treatment and withdrawal of guanfacine were compared with those of clonidine in 20 uncomplicated hypertensive patients. Elevated blood pressure returned to normal or responded well in all the patients given either guanfacine once daily or clonidine thrice daily. The pulse rate was reduced comparably by both treatments after 12 weeks, but the effect of guanfacine developed more gradually. Both guanfacine and clonidine significantly inhibited urinary noradrenaline, dopamine, and cyclic nucleotide excretion, while urinary adrenaline levels were unaffected. Side effects occurred earlier during treatment with clonidine. After sudden withdrawal, all the parameters tended to increase gradually in the guanfacine group, reaching base line by days 4-6. In the clonidine group the increase was more rapid, with pretreatment values reached within the 2nd day, and sometimes these values were surpassed. After withdrawal of clonidine all the patients had one or more side effects, most of them occurring within 48 h, while only 60% of the patients in the guanfacine group reported the appearance of unwanted symptoms, on days 3-6. It is concluded that there are close similarities between the effects of guanfacine and clonidine on the parameters evaluated, except for dopamine excretion, which was significantly less affected by guanfacine. Marked differences were found after abrupt withdrawal, with guanfacine less likely to produce the "discontinuation syndrome," probably due to its long half-life.

Adult↗

Circulating levels of immunoreactive peptides and steroid hormones in bronchogenic carcinoma.

Plasma levels of immunoreactive parathormone (iPTH), immunoreactive calcitonin (iCT) and prostaglandins (PGE2) were measured by RIA in 115 patients with bronchogenic carcinoma. In 37 of these cases the following hormones were also assayed: adrenocorticotropic hormone (ACTH), cortisol, plasma renin activity (PRA), aldosterone, prolactin, human growth hormone (HGH), thyroid stimulating hormone (TSH), luteinizing hormone (LH), follicle stimulating hormone (FSH) human chorionic gonadotropin (HCG), progesterone (P), androstenedione (A), testosterone (T), estradiol (E2) and dehydroepiandrosterone sulphate (DHAS). High serum levels of many hormone-like substances and hormones were found and the levels of certain hormones varied in some cases according to the clinical evolution of the disease and the response to therapy.

Aged↗

[Evaluation of early biomarkers of cartilage degeneration in the diagnosis and clinico-therapeutic monitoring of primary osteoarthrosis].

It is known that in the course of osteoarthritis (OA), articular cartilage develops biochemical and structural changes. In the last years, serum and urinary markers of both the synthesis and destruction of cartilage have been dosed, above all in order to carry out an early diagnosis of OA. Among them, the urinary excretion of pyridinoline seems to correlate with the entity of the degradation of cartilage. The aim of the present study is to evaluate the above mentioned markers in OA patients compared to control subjects. Moreover, the possible influence on cartilage of two different non steroidal antiinflammatory drugs (NSAIDs), in particular Nabumetone and Piroxicam, has been verified. The study shows that the urinary excretion of pyridinoline is able to express the severity of OA. At last, the study shows that the tested drugs do not interfere with the metabolism of cartilage.

Aged↗

Hyperuricemia and gout in thyroid endocrine disorders.

OBJECTIVE: A significant correlation between thyroid function and purine nucleotide metabolism has been established in hypothyroidism. On the contrary, the relationship between hyperthyroidism and purine metabolism is more controversial. The present study evaluates the prevalence of hyperuricemia and gout in patients affected by primary hypothyroidism and hyperthyroidism. METHODS: We studied 28 patients with primary hypothyroidism and 18 patients with primary hyperthyroidism, all hospitalized because of endocrine dysfunction. All underwent a series of clinical, biochemical and instrumental evaluations; in particular, thyroid-stimulatin hormone (TSH), free thyroxine (fT4), blood urea, serum creatinine, creatinine clearance, serum and urinary uric acid levels were measured. RESULTS: In comparison to the prevalence reported in the general population, a significant increase of both hyperuricemia and gout was found in the hypothyroid patients, and of hyperuricemia in the hyperthyroid patients. In hyperthyroidism the hyperuricemia is due to the increased urate production, while in hypothyroidism the hyperuricemia is secondary to a decreased renal plasma flow and impaired glomerular filtration. CONCLUSIONS: Ourfindings confirm the data in the literature concerning the high prevalence of hyperuricemia and gout in hypothyroidism. It shows that hyperthyroidism can cause a significant increase in serum uric acid, as well, although lower than the hyperuricemia due to thyroid hormone deficiency.

Adult↗

[Ultrasonography techniques in the evaluation of the osteoporotic patient].

Previous studies have shown a significant but weak correlation between speed of sound (SOS) and broadband ultrasound attenuation (BUA) in bone, and densitometric bone measurements. These findings indicate that these techniques reflect different properties of bone. We measured SOS and BUA in the os calcis (Achilles, Lunar Corp.) and bone mineral density of the lumbar spine (BMS-LS; by DEXA) and of the ultradistal radius (BMD-UDR; by DPA) in 60 postmenopausal women (age range 50-65): 30 were osteoporotic women (OP) and 30 were age-matched normal postmenopausal women (N). Mean values of SOS and BUA resulted significantly lower in OP group (p < 0.001). SOS and BUA measurements significantly correlated with DEXA of the lumbar spine (r = 0.52 p < 0.001, r = 0.56 p < 0.001, respectively) and DPA of ultradistal radius (r = 0.60 p < 0.001 and r = 0.62 p < 0.001, respectively). In conclusion, these techniques show good correlations with absorptiometric techniques. The best correlation has been found between BUA and DPA of ultradistal radius. Furthermore, US techniques are able to separate a normal from an osteoporotic population. Therefore, US techniques seem to be a useful tool for screening of osteoporotic disease.

Absorptiometry, Photon↗

Dietary L-lysine and calcium metabolism in humans.

Calcium deficiency contributes to age-related bone loss; consequently, any preventive approach to osteoporosis should include dietary Ca adjustment or supplementation. The ideal Ca supplement would yield the greatest bioavailability. Studies in animals have shown that dietary supplements with certain amino acids, particularly L-lysine, can increase Ca absorption. Therefore, we examined the potential effect of this essential amino acid on Ca metabolism in humans. In one study, the acute effects of an oral Ca load (3 g as CaCl2) administered with or without 400 mg of L-lysine were compared in 15 healthy and 15 osteoporotic women. In all cases, the oral Ca load determined a progressive increase in serum total Ca and Ca2+ and a concomitant decrease in neophrogenous cAMP. As expected, a progressive increase in urinary Ca excretion was also observed, except in the L-lysine-treated healthy subjects, who exhibited a blunted calciuric response to the Ca load. In a second study, the effects of a short-term dietary supplementation with either L-lysine, L-valine, or L-tryptophan (800 mg/day) on 47Ca fraction absorption were compared in 45 osteoporotic patients. L-Lysine but not L-valine or L-tryptophan significantly increased the intestinal absorption of the mineral. Our results suggest that L-lysine can both enhance intestinal Ca absorption and improve the renal conservation of the absorbed Ca. The combined effects may contribute to a positive Ca balance, thus suggesting a potential usefulness of L-lysine supplements for both preventive and therapeutic interventions in osteoporosis.

Adult↗

[Ultrasound transmission velocity in the patella of normal subjects and in patients with postmenopausal osteoporosis].

Recently, ultrasound transmission velocity (UTV) has been used to assess skeletal status. The basic principle of UTV measurement of bone is that the speed at which ultrasounds propagate in bone is determined by the mass density and by the index of elasticity, which is intimately correlated with bone strength. Theoretically UTV should provide more information about bone fragility than the absorptiometric techniques of measurement of bone mass. To test this hypothesis, UTV was measured using the SIGNET(TM) (Osteo Technology, Framingham, MA, USA) in the patella of 79 postmenopausal nonobese women. The subjects were divided into 2 groups: 29 postmenopausal normal women (NPM) and 50 patients with at least one vertebral crush fracture due to postmenopausal osteoporosis (PMO). Besides UTV measurements in all subjects lumbar spine bone mineral density (BMD) was measured by dual energy Rx (Hologic QDR 1000). UTV in NPM (mean age 57.9 +/- 8 SD years) averaged 1867 +/- 62 m/sec, and in PMO (mean age 63.5 +/- 7.8 SD years) averaged 1771 +/- 74 m/sec. It follows that the difference between the two groups was about 96 m/sec. UTV correlated significantly with BMD measured in the lumbar spine (r = 0.51; p less than 0.001), giving a discrimination power virtually identical to that obtained by using spine BMD values. This preliminary data are promising for the use of this new technique which offers a simple, noninvasive measure of bone quality without the limitation of radiation exposure.

Aged↗

Acute antihypertensive, diuretic and metabolic effects of etozolin and chlorthalidone.

Etozolin, a new diuretic agent, has shown a dose-dependent diuretic and saluretic effect in both experimental and clinical studies. Etoxolin, when compared to furosemide or thiazides, exerts a similar effect on urinary excretion of water and Na+, but induces a lower urinary K+ and Cl- excretion and a smaller activation of the renin-angiotensin-aldosterone system. Furthermore, the E series of the prostaglandin system seems to play a role in the mechanism of action of the drug. Seven uncomplicated hypertensive patients were included in this double blind, placebo controlled study, according to a latin square design. Each patient received three single oral doses of etozolin (200 mg, 400 mg, 600 mg), of chlorthalidone (25 mg, 50 mg, 75 mg) and one dose of placebo. Etozolin and chlorthalidone caused a similar, dose-dependent antihypertensive and diuretic effect. However, several haemodynamic and metabolic differences were observed between the two drugs. Etozolin, unlike chlorthalidone, caused no increase of heart rate, no decrease of serum K+ levels and a marked rise plasma PGE2. Moreover, etozolin caused a significantly smaller decrease of serum Na levels compared to chlorthalidone, and a significantly lower increase of supine and standing PRA, of plasma aldosterone and of the urinary excretion of Na and K. These results confirm that the acute antihypertensive and diuretic activity of etozolin occur with little involvement of the RAA system and with a significant but still unclear activation of the prostaglandin system.

Antihypertensive Agents↗

[Physiopathology and therapy of localized osteopenia].

Osteopenia is a condition of reduced bone mineral content including osteoporosis, characterised by a reduced bone mass but normal mineral composition of bone tissue, and osteomalacia, characterised by unchanged bone mass but a deficient level of calcification of the protein matrix. Both conditions possess multifactorial etiopathogeneses and may affect the skeleton as a generalised or local manner, thus creating syndromes of circumscribed osteomalacia (osteomalacia of the patella, of the jaw). In some cases of local osteopenia, genetic, ethnic, dietary (inadequate intake of calcium, vitamin D), behavioural (abuse of smoking, coffee or alcohol), mechanical (reduced muscular exercise) and jatrogenic factors can play an important pathogenetic role. The definition of the exact nature of osteopenia (osteoporosis or osteomalacia), now possible using instrumental and laboratory tests, and the identification of the pathogenetic factors involved enable a correct therapy to be commenced.

Anabolic Agents↗

[Effects on the bones of nandrolone decanoate therapy in postmenopausal osteoporosis].

In many patients with involutional osteoporosis, anabolic steroids may produce a rapid subjective improvement and pronounced reduction of complaints. In animal experiments it has been demonstrated that anabolic steroids can also have objective effect on bone tissue. Twenty postmenopausal osteoporotic patients have been randomly assigned to two different treatments: 10 patients were treated with 50 mg i.m. of nandrolone decanoate every 3 weeks for 12 months; 10 patients were treated with placebo. Both groups received an oral calcium supplement (1 g/day). Bone mineral content (BMC) was measured by dual photon absorptiometry before and after 1, 3, 6 and 12 months. Plasma alkaline phosphatase (A.Ph.) and urinary hydroxyproline/creatinine ratio (HOP) were measured at the same times. Intestinal calcium absorption was measured by the 47Ca oral test before and after treatment. In 4 patients of both groups a transiliac bone biopsy was performed before and after treatment. After 1 year there was a significant increase in the BMC of the lumbar spine in the group receiving calcium plus nandrolone decanoate. A progressive but not significant increase of A.Ph. was observed in the group treated with nandrolone decanoate. Radiocalcium absorption significantly increased in nandrolone treated patients. The histomorphometric study of bone demonstrated a significant increases in trabecular bone volume and in active osteoid surfaces in patients treated with nandrolone decanoate. Because the plasma A.Ph. tendes to increase with no change in bone resorption (as measured by urinary HOP) and the active osteoid surfaces significantly augment, we conclude that nandrolone therapy increases the bone formation rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Anabolic Agents↗

[Clinical efficacy of treatment with salmon calcitonin, administered intranasally for 1 year, in stabilized postmenopausal osteoporosis].

Several controlled clinical studies have confirmed the rationale of calcitonin therapy in postmenopausal osteoporosis. However, administration by injection and side-effects reduced patient compliance and flexibility of dosage. Recently, evidence has been given that an intranasal spray may provide an effective alternative administration route for calcitonin. Forty women with established postmenopausal osteoporosis (at least on vertebral crush fracture) divided into three groups, entered and completed a one-year controlled study on the effects of treatment with synthetic salmon calcitonin nasal spray on bone mass and mineral metabolism. The first group (n = 20) received a daily treatment with 100 I.U. of salmon calcitonin (sCT) nasal spray; the second group (n = 10) received 100 I.U. of sCT by subcutaneous injection every second day; the control group (n = 10) received an oral calcium supplement, 1 g per day. Bone mineral content (BMC), evaluated by dual photon absorptiometry, was measured at the distal radius before and after 6 and 12 months of treatment. Every three months, throughout the year, an evaluation of some parameters of bone remodeling was made. BMC increased (p less than 0.01) in the treatment groups, whereas at the end of treatment, a decrease (p less than 0.05) was observed in the control group. Biochemical estimates of bone resorption, such as urinary hydroxyproline excretion showed a significant decrease in the calcitonin groups. No changes in markers of bone formation, serum alkaline phosphatase and osteocalcin were observed in all patients. This study demonstrates that one-year treatment with sCT nasal spray is able to increase bone mass in osteoporotic patients without important local side-effects.

Administration, Intranasal↗