Biomedical subjects

D Gonzalez

Publications and source records attributed to D Gonzalez.

At least 37 records · Page 2Linked to original sources

PubMed1997

Overcoming the learning curve in microvascular head and neck reconstruction.

BACKGROUND: It is widely accepted that most microvascular reconstructive surgeons experience a learning curve. A compilation of 6 series of microvascular surgery reported in the literature revealed that the average rate of successful free flap transfer rose from 79% to 96% as the surgeons gained clinical experience. OBJECTIVE: To review the collective experience of 3 otolaryngologist-head and neck surgeons performing free flaps during their first year of clinical practice after completion of postgraduate training. DESIGN: A multi-institutional retrospective case series. SETTING: Three academic tertiary care otolaryngology-head and neck surgery programs. PATIENTS: Eighty-one microvascular free flaps were performed in patients undergoing surgical reconstruction of head and neck defects during a 1-year period. INTERVENTIONS: Free flap selection was based on specific defect characteristics. Radial forearm, fibula, and rectus abdominis flaps together accounted for 90% of the donor sites selected. MAIN OUTCOME MEASURE: Reported incidence of partial or complete free flap necrosis. RESULTS: There were 2 perioperative deaths. Among the surviving patients, there were 2 cases of complete flap failure, for an overall success rate of 97.5%. There were 2 additional cases of partial flap necrosis (2.5%) that were related to errors in flap insetting. CONCLUSION: The availability of high-quality postgraduate training combined with the judicious selection of free flaps that offer long vascular pedicles and large diameter vessels can allow junior microvascular head and neck surgeons to achieve free flap survival rates that are comparable with those reported by experienced microvascular surgeons.

Clinical Competence↗

PubMed1997

Sequence analysis of the structural tbpA gene: protein topology and variable regions within neisserial receptors for transferrin iron acquisition.

The gene coding for the 98-kDa meningococcal outer membrane transferrin binding protein 1 (TbpA) from strain B385 was cloned and sequenced. Sequence comparison among its deduced aminoacid sequence and those from TbpA and the closely related LbpA (lactoferrin binding protein) gene from three different meningococcal strains, and four isolates from two other bacterial pathogens, showed that TbpA variability is confined to five specific segments, designated VR1 (199-287), VR2 (306-381), VR3 (480-546), VR4 (618-651) and VR5 (681-708). The third VR was the most variable among strains both at the nucleotide and amino acid levels. Six additional tbpA genes from different meningococcal strains were cloned and its VR3 sequence determined. On the basis of this data we were able to cluster tbpA genes in two groups: D (bearing a deletion in VR3) and N (nondeleted); all N and D strains belonging to the groups of high or low molecular weight transferrin receptor isotype, respectively. However, by phenogram analysis, the prototypical strain M982 (Group II) was clustered with M990 (B16B6 isotype, Group I). These results point to the existence of important exposed regions as well as to the possibility of horizontal gene exchange involving this locus. A topology model with 14 exposed loops and 28 membrane spanning segments was postulated. According to this tentative analysis, TbpA as well as LbpA proteins should form a gated channel in the neisserial outer membrane. The variable regions were located in the fifth, sixth, eighth, 10th and 11th loops respectively. Among TbpAs VR1, VR2, and VR3 resulted the most relevant regions.

Amino Acid Sequence↗

PubMed1997

Long-term effect of gluten restriction on bone mineral density of patients with coeliac disease.

AIM: To assess the long-term effect of a gluten-free diet on bone mineral density of adults with untreated coeliac disease. METHODS: Bone mineral density was assessed at baseline and after a mean duration of 37 months of treatment in 25 unselected newly diagnosed coeliac patients. RESULTS: At baseline, osteopenia (> -1 s.d. below normal) was evident in the lumbar spine and total skeleton in 18 (72%) and 21 (84%) patients, respectively. At the end of the study, bone density had increased (mean bone mass Z-score increase: Z-score +1.0 for the lumbar spine and +1.1 for total skeleton) in 22 and 23 patients, respectively. Patients who adhered to strict gluten restriction (n = 15) demonstrated a similar bone remineralization in the spine than those patients with partial compliance (n = 10) (mean Z-score increase: +1.0, in both areas). A greater mean annual change in Z-score in the total skeleton was noted in patients who followed strict gluten restriction (0.4 +/- 0.1) respect to those with partial compliance (0.3 +/- 0.1); however, this difference was not statistically significant. Pre-menopausal women had significantly greater remineralization that post-menopausals (P > 0.05). Remineralization showed an inverse correlation with the degree of basal osteopenia (r = -0.525; P < 0.002). CONCLUSIONS: Long-term treatment with gluten-free diet produces a significant improvement in bone density in coeliac patients. Remineralization was more pronounced in patients who better comply with gluten-free diet, in pre-menopausal women and in patients with the lowest baseline bone mineral density.

Adult↗

PubMed1997

Longitudinal study on the effect of treatment on body composition and anthropometry of celiac disease patients.

OBJECTIVES: This prospective study was designed to assess the nutritional changes associated with the long-term treatment of celiac disease. In addition, we analyzed whether these changes were related to the degree of compliance with a gluten-free diet. METHODS: We studied nutritional parameters and body composition in 25 newly diagnosed celiac patients after a mean period of 37 months (range 25-49 months) on a gluten-free diet. Body composition parameters (fat, lean tissue, and bone masses) were measured by dual energy x-ray absorptiometry. Anthropometry was measured according to conventional formulas. RESULTS: At diagnosis, fat (-49%), lean tissue (-12%), and bone (-24%) compartments were reduced, compared with that of sex- and age-matched controls. After treatment, we noted a significant increase in body weight (p < 0.0001), fat mass (p < 0.0005), bone mass (p < 0.002), and body mass index (p < 0.005). In contrast, we did not observe a significant increase in lean-tissue mass or muscle mass. Patients who adhered strictly to a gluten-free diet experienced a greater, though nonsignificant improvement in fat mass, body weight, and body mass index than patients whose compliance had been partial. Mean caloric intake at the end of the study was significantly lower among those patients who had adhered strictly to a gluten-free diet, compared with those who had complied only partially with the diet (p < 0.05). CONCLUSIONS: This study shows that the institution of a gluten-free diet in celiac disease patients results in a significant improvement in nutritional parameters, as measured by anthropometry and/or body composition. This effect was more pronounced in patients who followed strict gluten restriction and was related mainly to changes in fat and bone compartments.

Adult↗

PubMed1996

Positive role of non-N-methyl-D-aspartate receptors in the control of growth hormone secretion in male rats.

The role of kainic acid (KA) (an agonist of non-NMDA receptors) in the control of GH secretion and the modulation of KA action by gonadal secretion were analysed in male rats. In the first experiment 4, 8, 12, 16, 20 and 30-day old males were sacrificed 15 min after injecting with vehicle or KA (2.5 mg/kg BW). In the second experiment, the effects of KA, 6,7-dinitroquinoxaline-2,3-dione (DNQX) and MK-801 were analysed in monolayer cultures of dispersed adenohypophyseal cells. In the third experiment, adult males were sham-operated or orchiectomized and decapitated seven days later, 15 min after injecting with vehicle or KA (2.5 or 15 mg/kg BW). In the fourth experiment, males neonatally injected with estradiol benzoate or vehicle were sacrificed on days 45, 60 or 90, 15 min after administration of vehicle or KA (2.5 or 15 mg/kg BW). We found that: (i) KA is a powerful secretagogue for GH in neonatal and postpubertal males but its releasing effectiveness decreases in adulthood; (ii) GH secretion by cultured pituitary cells remains unaffected in the presence of KA (1,10 or 100 mumol/l); (iii) the KA-stimulated GH secretion is increased after orchiectomy and abolished in males neonatally estrogenized. These results indicate that in male rats activation of non-NMDA receptors, probably those located in hypothalamus, increases GH secretion. The releasing properties of KA increases in orchiectomized males and completely disappears in males neonatally estrogenized.

Animals↗

PubMed1996

Clinical amnionitis and endometritis in patients with premature rupture of membranes: endocervical prostaglandin E2 gel versus oxytocin for induction of labor.

OBJECTIVE: To compare the rates of clinical amnionitis and endometritis in patients with premature rupture of membranes (PROM), using endocervical prostaglandin E2 (PGE2) gel for induction of labor versus immediate oxytocin induction of labor. METHODS: We randomized 118 patients to receive either endocervical 0.5 mg of PGE2 gel (study group) or immediate oxytocin induction of labor (control group). If labor was not established in the group receiving PGE2 gel in 24 hours, intravenous oxytocin was given in incremental doses. The rates of clinical amnionitis and endometritis in the two groups were analyzed. Also compared were hours of labor, duration of rupture of membranes and number of vaginal examinations. Student t test, chi 2, or Wilcoxon rank-sum test were used for statistical analysis, as appropriate. P < .05 was considered significant. RESULTS: The rates of clinical amnionitis were 5.3% in the PGE2 group and 8% in the control group. Endometritis developed in 1.7% of PGE2 patients and 3.2% of controls. These differences in maternal infection rates were not statistically significant. The two groups were comparable with respect to age, parity, and antepartum group B streptococcal colonization. No significant differences in hours of labor, duration of ruptured membranes, or vaginal examinations were observed. Neonatal outcome data (mean birth weight, Apgar scores at 1 and 5 minutes, Apgar score less than 7 at 5 minutes) were not statistically significant. CONCLUSION: Endocervical placement of 0.5 mg of PGE2 gel does not increase the incidence of clinical amnionitis and endometritis in patients with PROM at term when compared with immediate induction of labor with oxytocin.

Administration, Topical↗

PubMed1996

Neural and glial-mediated effects of growth factors acting via tyrosine kinase receptors on luteinizing hormone-releasing hormone neurons.

It is becoming increasingly evident that the secretory activity of LHRH neurons is regulated not only by transsynaptic inputs but also by trophic molecules of glial and neuronal origin. The present experiments were undertaken to gain insights into the potential cell-cell mechanisms by which basic fibroblast growth factor (bFGF) and transforming growth factor-alpha (TGF alpha), two growth factors produced in the hypothalamus, may affect LHRH neuronal function. Northern blot analysis showed that the LHRH-producing cell line GT1-7 contains the messenger RNA (mRNA) encoding the type 1 fibroblast growth factor receptor (FGFR-1) but not that encoding the epidermal growth factor (EGF) receptors, which mediates the biological actions of both TGF alpha and EGF. Ligand-induced receptor phosphorylation experiments demonstrated that GT1-7 cells possess biologically active FGFR-1s but not EGF receptors. Exposure of the cells to bFGF resulted not only in FGFR-1 tyrosine phosphorylation, but also in tyrosine phosphorylation of phospholipase C gamma, one of the initial enzymes in the intracellular signaling cascade initiated by FGFR activation. GT1-7 cells proliferated in response to this activation. Despite the presence of biologically active receptors, bFGF did not significantly stimulate release of the mature LHRH decapeptide. Instead, bFGF increased the steady-state levels of the mRNA encoding the LHRH precursor processing endoprotease PC2, with a time course comparable to that of phorbol esters, suggesting that, as shown in the companion paper, the actions of the growth factor on LHRH neurons involve facilitation of the initial step in LHRH prohormone processing. The increase in PC2 gene expression was not accompanied by changes in LHRH mRNA levels. Unlike these direct actions of bFGF on GT-1 cells, TGF alpha appears to act indirectly via astroglial intermediacy. Exposure of GT1-7 cells to TGF alpha or EGF failed to affect several parameters of cellular activity including LHRH release, LHRH and PC2 mRNA levels, and cell proliferation. In contrast, astrocyte culture medium conditioned by treatment with TGF alpha led to sustained stimulation of LHRH release with no changes in LHRH gene expression and a transient increase in PC2 mRNA levels. Although no definitive evidence for the presence of FGFR-1 in normal LHRH neurons could be obtained by either double immunohistochemistry or double in situ hybridization procedures, fetal LHRH neurons in primary culture responded to bFGF with neurite outgrowth. Thus, normal LHRH neurons may have an FGFR-1 content too low for detection by regular histochemical procedures, and/or detectable expression of the receptor may be confined to a much earlier developmental stage. The mitogenic effect of bFGF on GT1-7 cells supports this possibility and suggests a role for FGF in the cell proliferation events that precede acquisition of the LHRH neuronal phenotype. It appears that once this phenotype is established, bFGF may promote the differentiation of LHRH neurons. The results also suggest that the secretory capacity of LHRH neurons develops under a dual trophic influence, one on peptide processing exerted directly by bFGF on early neurons, and another on LHRH release, exerted by TGF alpha via the intermediacy of astroglial cells.

Animals↗

PubMed1996

Mechanisms of inhibitory action of kainic acid on prolactin secretion in male rats.

Activation of excitatory N-methyl-D-aspartate and kainate receptors evokes multiple and diverse neuroendocrine changes. We have previously shown that kainic acid (KA), an agonist of kainate receptors, inhibits prolactin (PRL) secretion in male rats when given systemically. In the present studies we have characterized this inhibitory action. KA inhibited in vivo PRL secretion in neonatal, prepubertal and adult male rats. This inhibition was independent of gonadal secretion and was evident in male rats whether intact, orchidectomized, or orchidectomized and treated with testosterone. In addition, KA inhibited PRL secretion in male rats rendered hyperprolactinaemic by neonatal administration of oestradiol benzoate. The decrease in serum PRL levels after KA administration was accompanied by an increase in pituitary concentrations of dopamine, and the KA effect on PRL disappeared in males pretreated with domperidone, an antagonist of dopaminergic receptors. These findings strongly suggest that an increase in dopamine release was involved in the effects of KA. Also, KA inhibited in vitro PRL secretion by adenohypophysial dispersed cells and this effect was blocked by 6,7-dinitroquinoxaline, a kainate receptor antagonist, which indicates that the pituitary is also a possible site of action of KA. Nw-nitro-L-arginine-methyl ester, a blocker of nitric oxide synthase, reduced the effects of KA in vivo and slightly stimulated PRL release in vitro. We conclude that the inhibitory action of KA is independent of the age of the animal, the gonadal status and the prevailing PRL levels. The action of KA is probably mediated by an increase in dopamine secretion and by a direct effect at the pituitary level. Finally, the effect of KA on PRL secretion is partially dependent on endogenous nitric oxide.

Animals↗

PubMed1996

Early changes of body composition in asymptomatic celiac disease patients.

BACKGROUND/AIM: This is a study of patients with asymptomatic celiac disease. The aims of this study were: 1) To evaluate the nutritional status of asymptomatic patients with newly diagnosed celiac disease, and 2) to compare these findings with those of untreated/symptomatic and treated patients. MATERIAL: We examined 41 patients with celiac disease divided into three groups: a) 8 asymptomatic (diagnosed in a study of first-degree relatives of probands), b) 20 untreated/symptomatic patients, and c) 13 treated patients. Nutrition of patients from groups A and B was assessed at the time of diagnosis. METHODS: Nutritional status was evaluated by: 1) body composition (fat and lean mass) by dual energy x-ray absorptiometry (DEXA), and 2) anthropometric measurements. RESULTS: Compared with sex and age matched controls (n = 153), asymptomatic patients presented a moderate but significant reduction of the fat compartment (-29%; p < 0.001), but not of the lean-tissue mass (p = NS). Untreated/symptomatic patients showed a more severe depletion of fat (-46%; p < 0.001) and lean mass (-9.0%; p < 0.05) compared with healthy controls. Although fat mass of treated patients was significantly reduced with respect to controls (-24%; p < 0.003), lean mass was not affected. The anthropometric measurements of fat showed a significant correlation with the evaluation by DEXA (multiple regression analysis r = 0.918). CONCLUSION: Asymptomatic patients in our study with an unequivocal diagnosis of celiac disease established by mucosal biopsy exhibited a modified body composition.

Absorptiometry, Photon↗

PubMed1996

Body composition in normal and osteoporotic women.

Body composition and bone mineral density using dual-energy X-ray absorptiometry (DEXA) was determined in a large group of normal women and osteoporotic patients with atraumatic vertebral fractures. Between the third and seventh decades, there was an increase of 9.5 kg of body weight and 7.5 kg of fat mass in the normal women. The percentage of fat augmented from 33% to 42%. However, the lean mass showed no modifications over these decades. Fat mass in the osteoporotic women was significantly less than that in the age and sex matched controls (22.4 +/- 1.0 vs 26.6 +/- 1.0 kg; p < 0.006). However, lean tissue mass was similar in the two groups. The decrease in fat mass explain 74% of the difference of body weight between osteoporotics and controls. The fat mass of 13 osteoporotic patients (30%) was lower than the lowest value found in the controls and 20(45%) were lower than minus one standard deviation of the values for controls. The osteoporotic patients had less fat mass in the three subregions evaluated, but the difference was more significant in the trunk (-18%) and legs (-17%) than in the arms (-11%). Fat mass may have an important protective effect on the skeleton. The mechanism has yet to be elucidated.

Absorptiometry, Photon↗

PubMed1996

Clinical Significance of a cervical cytologic diagnosis of atypical squamous cells of undetermined significance. Favoring a reactive process or low grade squamous intraepithelial lesion.

OBJECTIVE: To define the clinical significance of qualifying the cytologic diagnosis of atypical squamous cells of undetermined significance (ASCUS) as favoring either a reactive process or a low grade squamous intraepithelial lesion (LSIL) in an effort to provide management guidelines. STUDY DESIGN: A total of 118 consecutive nonpregnant women with a cytological diagnosis of ASCUS favoring either a reactive process or LSIL were evaluated in our colposcopy clinic by repeat cervical cytologic smear, colposcopy and colposcopically directed biopsies and/or endocervical curettage, as indicated. RESULTS: Of the 58 patients evaluated for a smear of ASCUS, favoring a reactive process, 5 (8.6%) had cervical intraepithelial neoplasia (CIN) CIN 1 documented by biopsy. None had a high grade lesion. Twenty-six (45%) of the 58 patients who had a cytologic diagnosis of ASCUS favoring a reactive process had a repeat smear that was normal. None was found to have CIN. Of the 60 patients who had a cervical diagnosis of ASCUS favoring LSIL, 9 (15%) had CIN 1 or CIN 2. Nineteen (32%) of the 60 patients who had a cytologic diagnosis of ASCUS favoring LSIL had a repeat smear that was normal. One of these patients had CIN 1 on biopsy. The sensitivity of a repeat smear, in this limited series, after an initial smear of ASCUS favoring a reactive process is 100%, while it was 66% after an initial smear of ASCUS favoring LSIL. CONCLUSION: This study showed that in our laboratory a cytologic diagnosis of ASCUS favoring either a reactive process or LSIL is associated with a very low risk that the patient is haboring CIN. In the patient whose initial smear shows ASCUS favoring a reactive process, a repeat smear that is normal is reassuring. The patient whose smear shows ASCUS favoring LSIL probably requires further evaluation even in the presence of a normal repeat smear.

Adolescent↗

PubMed1995

Remodeling of mouse milk glycoconjugates by transgenic expression of a human glycosyltransferase.

The mammary gland is a unique biosynthetic tissue that produces a variety of species-specific glycoconjugates, but the factors regulating the production of specific glycoconjugates are not well understood. To explore the underlying regulation, a fusion gene containing a cDNA encoding the human alpha 1,2-fucosyltransferase (alpha 1,2FT), which generates the H-blood group antigen, flanked by the murine whey acidic protein promoter and a polyadenylation signal, was introduced into mice. Milk samples from transgenic animals contained soluble forms of the alpha 1,2FT, as revealed by Western blots of milk samples using an anti-alpha 1,2FT antiserum and by the demonstration of alpha 1,2FT enzyme activity. Milk from transgenic animals also contained large quantities of 2'-fucosyllactose (Fuc alpha 1-2Gal beta 1-4Glc) and modified glycoproteins containing the H-antigen, whereas milk from control animals lacked these glycoconjugates. Expression levels of 2'-fucosyllactose were high in most animals and represented 1/3 to nearly 1/2 of the total milk oligosaccharides. These results demonstrate that heterologous transgenic expression of a glycosyltransferase can result in the expression of both the transgene and its secondary gene products and that the structures of milk oligosaccharides can be remodeled depending on expression of the appropriate enzyme. Furthermore, these results suggest that the lactating mammary gland may be a unique biosynthetic reactor for the production of biologically active oligosaccharides and glycoconjugates.

ABO Blood-Group System↗

PubMed1995

EORTC guidelines for writing protocols for clinical trials of radiotherapy.

The concept of a Master Protocol for phase III studies was raised at the Steering Committee of the EORTC Radiotherapy Group, in order to make the work of the study coordinators easier, when writing protocols and to give them more homogeneity. The Master Protocol defines and clarifies in a logical order the different steps which must be taken when designing a randomized trial--from the rationale to the references. It pays particular attention to eligibility criteria, volumes of interest defined in agreement with ICRU Report 50 (gross tumor volume, clinical target volume, planning target volume and organs at risk), simulation procedure, treatment technique, normal tissue sparing, dose computation, equipment, dose specification (also in agreement with ICRU Report 50). Last but not least, the different procedures of quality assurance for protocols and patients are also defined (site visits, dummy run procedure, in vivo dosimetry, individual case review) to allow working plans to be made in advance. We are aware that this work is not exhaustive, but hope that the contents will be of help to those who are writing a protocol.

Clinical Trials as Topic↗

PubMed1995

Mechanisms of altered LH secretion in neonatally oestrogenized male rats.

It is well known that the control of LH secretion depends on the steroid milieu during the postnatal period. In this study LH secretion was analysed in adult male rats injected neonatally with 500 micrograms oestradiol benzoate (1) after orchidectomy, (2) after selective elimination of androgens by destruction of Leydig cells with ethylene dimethane sulphonate (EDS), and (3) after removal in orchidectomized animals of Silastic capsules containing testosterone. In addition, (4) in vivo and in vitro LH secretion in response to LHRH agonist and antagonists, (5) the hypothalamic LHRH content, (6) the basal and stimulated in vitro LHRH release, and (7) the LH responses after administration of naloxone (2 mg/kg), alpha-methyl-p-tyrosine (alpha-MPT; 250 mg/kg), N-methyl-D-aspartic acid (NMDA, 15 mg/kg) or kainic acid (KA; 15 mg/kg) were also examined. Our data indicated that (1) the LH response after orchidectomy, after EDS administration and after removal of Silastic capsules containing testosterone was diminished in oestrogenized male rats, (2) the pituitaries from oestrogenized males retained responsiveness to LHRH, (3) hypothalamic LHRH content was reduced in oestrogenized males, but the hypothalamus from oestrogenized males released more LHRH than those of control groups both under basal conditions or after depolarization, (4) alpha-MPT decreased LH secretion only in oestrogenized males, and (5) NMDA and KA stimulated LH only in oestrogenized males. We conclude that in oestrogenized male rates the loss of sensitivity to the negative feedback action of testosterone on LH secretion was not due to decreased pituitary responsiveness to LHRH stimulation or to the inherent damage of LHRH neurones.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Pulmonary arteriovenous fistula ruptured to pleural cavity in pregnancy.

Congenital pulmonary arteriovenous fistula is frequently associated with hereditary haemorrhagic telangiectasia (Rendu-Osler-Weber disease). With the increased blood flow in pregnancy such fistulas enlarge, occasionally giving rise to haemothorax, which generally has a poor prognosis. A familial case is presented in which massive haemothorax required emergency thoracotomy in the 27th week of pregnancy.

Adult↗

PubMed1995

Furosemide renal excretion rate and the effects of the diuretic on different tubular sites are modified by endogenous dopamine in normohydrated rats.

The present study was designed to explore the involvement of endogenous dopamine in furosemide excretion and in the actions of the diuretic on tubular sodium reabsorption. The dose-response relationship for the diuretic effect of furosemide given as i.v. bolus injections (0.2-7.5 mg.kg-1) was studied by clearance technique in pentobarbital-anesthetized rats treated with vehicle, benserazide (BZ) (25 mg.kg-1 i.v.) or SCH 23390 (50 micrograms.kg-1 + 10 micrograms.kg-1.min-1 i.v.). Furosemide induced the maximal diuresis 15 to 30 min after i.v. administration. The diuretic response was dose-dependent and was reduced in the animals treated with BZ and SCH 23390. Fractional sodium excretion was also increased by furosemide from 1.8 to 7.5% during the same period. This effect was reduced by both BZ or SCH 23390 by 35 to 50%. The effects of furosemide on proximal and distal renal tubules were dissected by measuring the renal lithium clearance (CLi+). Furosemide effective on proximal tubular sites (measured by FENa+ prox = CLi+/Cln) were completely abolished by BZ and SCH 23390, whereas both drugs reduced furosemide effects on distal tubular sites (measured by FENa+ distal = CNa+/CLi+) by 20 to 40%. Furosemide excretion rate during the peak response to the diuretic was measured in the urine. BZ and SCH 23390 diminished furosemide excretion by 45 to 80% as compared with vehicle-treated animals. The furosemide tubular effects and the proximal and distal functions measured by CLi+ determined during the peak response were correlated to the maximal excretion rate of furosemide in the urine.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Periovulatory LHRH, LH and FSH secretion in cyclic rats treated with RU486: effects of exogenous LHRH and LHRH antagonist on LH and FSH secretion at early oestrus.

The antiprogesterone RU486 injected on the morning of pro-oestrus blunts the preovulatory secretion of LH and FSH and abolishes the secondary secretion of FSH during oestrus without affecting ovulation in the rat. To ascertain whether the secretion of LHRH is involved in these effects, we studied the effects of RU486 (4 mg/0.2 ml oil), given s.c. at 0800 h on pro-oestrus, on LHRH secretion into the pituitary stalk blood vessels and on peripheral plasma concentrations of LH and FSH at 1800 h on pro-oestrus and 0200 h on oestrus. Furthermore, we determined the effects of an s.c. injection of 1 mg of an LHRH antagonist (LHRH-A; ORG30276) at 2000 h on pro-oestrus and those of an i.p. injection of 100 ng LHRH (Peninsula 7201) at 0100 h on oestrus on serum concentrations of LH, FSH and oestradiol at 0200 h on oestrus in oil- and RU486-treated rats. RU486 decreased LHRH secretion at 1800 h on pro-oestrus while this was increased at 0200 h on oestrus. While the reduction of preovulatory LHRH secretion in RU486-treated rats coincided with a reduction in both LH and FSH surges during the evening of pro-oestrus, the increased LHRH secretion during the early hours of oestrus was only accompanied by an increased concentration of LH. An injection of LHRH stimulated, while that of LHRH-A inhibited serum concentrations of LH at 0200 h on oestrus in both oil- and RU486-treated rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Bone mineral affection in asymptomatic adult patients with celiac disease.

OBJECTIVES: Osteopenia is a well-known complication of overt celiac disease, but whether such defective bone mineralization is present among asymptomatic or silent patients is not known. Our objectives were: 1) to examine bone mineralization of a group of asymptomatic celiac patients; 2) to compare these results with those of symptomatic patients. METHODS: Bone mineral density of the spine and total skeleton by dual energy x-ray absorptiometry and serum parameters of mineral metabolism of eight recently diagnosed asymptomatic patients with celiac disease were studied. Results were compared with those obtained in 20 untreated symptomatic celiacs, 14 patients treated with gluten-free diet for a mean time of 15 yr, and 153 healthy adult subjects, matched by sex and age. RESULTS: Four and five out of eight asymptomatic patients presented with reduced mineralization of the spine and the total skeleton, respectively (> 1 SD below normal values for sex and age). Two patients presented with severe osteopenia of the spine, and the other three presented with severe osteopenia of the whole skeleton (> 2 SD below mean normal values). Osteopenia at plane bone level (total skeleton) was significantly lower when compared to healthy controls (p < 0.02). Symptomatic untreated patients had significantly more severe deterioration of bone mineralization than did asymptomatics (p < 0.05) and treated patients (p < 0.05). No difference in bone mineral density was observed between treated patients and asymptomatic celiacs. Serum levels of calcium, alkaline phosphatase, 25-OH vitamin D, and parathormone did not show conclusive abnormalities. CONCLUSIONS: Our findings provide direct evidence that reduced bone mineralization occurs in asymptomatic celiac patients before any other symptom becomes evident. Only early diagnosis and treatment of celiac disease can avoid the deterioration of the bone structure observed in all clinical status of celiac disease.

Absorptiometry, Photon↗