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Biomedical subjects

C Cruz

Publications and source records attributed to C Cruz.

At least 73 records · Page 4Linked to original sources
PubMed1998

Induction of clusterin in tubules of nephrotic rats.

Clusterin is a glycoprotein induced after renal tubular cell injury. The purpose of this study was to examine the expression of clusterin in a disease model characterized early in its course by predominant glomerular injury. Male Wistar rats (weighing 251 +/- 16 g) were treated with puromycin aminonucleoside (PAN: 15 mg/100 g body wt, subcutaneously; n = 7) or vehicle (control; n = 8). The kidneys were harvested 6 d after treatment, when rats were nephrotic. Clusterin mRNA was markedly induced in the kidneys of nephrotic rats (8.5-fold versus control). Immunohistochemistry studies demonstrated clusterin primarily in tubules in the cortex and medulla. Many of the tubules staining for clusterin were dilated but had no other differentiating morphologic features. Increased numbers of proliferating tubular cells were seen at 6 d, but there was no correlation between these cells and clusterin staining. In contrast to the extent and pattern of clusterin staining, vimentin was seen in only sporadic, dilated tubules, in addition to its expected glomerular localization. An increase in clusterin mRNA was not seen 1, 2, or 4 d after PAN injection. In conclusion, tubular epithelial cell induction of clusterin occurs in the kidneys of nephrotic rats. The appearance of clusterin precedes the development of tubulointerstitial disease and may be a response to the proteinuria.

Animals↗
PubMed1998

[Prenatal cardiology. Suspicion to confirmation].

The mortality rate is high and prognosis is worse among new-borns with prenatal diagnosis of heart malformation, mainly due to factors such as its association with other malformations, and a range of more severe diseases probably resulting from the predominance of the obstetric use of the four chamber view. In this study we retrospectively assessed the range of cardiopathies diagnosed by foetal echocardiography and their evolution, compared with previous years. From January 1994 to December 1995, 1173 foetal echocardiograms were performed at a gestation age of 24 weeks. Sixty-one foetuses (5.2%) had cardiac anomalies, structural in 56 and arrhythmia in 5. The risks and indications were maternal in 37%, foetal in 31%, familial in 17% and environmental in 15%. Three were false negatives (VSD:2; truncus arteriosus: 1). Five died in utero, and 18 were assessed after birth with a mean gestational age of 37 weeks and birth weight of 3 Kg, a caesarean section was performed in 9. All but one were born in central hospitals. Six children were operated on. Two children died, one after surgery. Compared with the four previous years of activity, indication due to foetal risk rose from 6 to 31%, the number of cases diagnosed with heart disease increased from 14 to 30 per year, and the mortality decreased from 59 to 11%. Despite this, we still observe that the vast majority of new-borns who are hospitalised due to a severe heart disease had no prenatal diagnosis, indicating the need to continue our educational policy in this field.

Female↗
PubMed1997

Increased prevalence of the seven-repeat variant of the dopamine D4 receptor gene in patients with obsessive-compulsive disorder with tics.

The polymorphism characterized by a varying number of 48 bp repeats (VNTR) in the dopamine D4 receptor (DRD4) gene was examined in 61 obsessive-compulsive disorder (OCD) probands with and without tics. Most of the OCD patients with tics showed at least one copy of the 7-fold variant compared to those affected subjects without tics (91 vs. 48%, respectively, Yates corrected chi2 = 5.54, P = 0.018). Similarly, a higher number of copies of this common variant were detected in the group of probands displaying tics compared to those OCD's without tics (Yates corrected chi2 = 4.66, P = 0.03). Our study suggests that the seven-repeat allele of the DRD4 gene could be a factor in the phenotypic variance of tics among OCD individuals.

Alleles↗
PubMed1997

Ultrastructural study of brain microvessels in patients with traumatic cerebral contusions.

Brain tissue from 11 patients with traumatic cerebral contusions submitted to surgery was studied. Control biopsy specimens were obtained from 5 patients undergoing ventriculo-peritoneal shunts for "communicating" hydrocephalus. After collection, the small fragments were fixed by immersion in glutaraldehyde-osmium and embedded in Epon. Semi-thin sections stained with toluidine blue were observed with the light microscope. Thin sections stained with lead citrate and uranyl acetate were observed using a Jeol electron microscope. In tissues from patients with head trauma a clear space most probably corresponding to fluid accumulation was systematically observed around microvessels. Ultrastructurally endothelial cells from these specimens exhibited signs of marked intracellular oedema, tight junctions being intact. Pinocytotic activity was increased, mainly at the abluminal surface. Swelling of astrocytic perivascular processes and the appearance of macrophagic cells with voluminous lysosomes were also observed. The authors conclude that the oedema of endothelial cells probably represent a central fact in the pathophysiology of traumatic brain oedema and speculate on the putative involvement of stretch-activated receptors in this condition.

Adult↗
PubMed1997

Transient alteration of the reproductive function in nephrotic rats.

The reproductive function of male and female rats with induced nephrotic syndrome was examined by assessing hormonal levels, the estrous cycle pattern and fertility. Measurements were carried out on day 10 (nephrotic stage) and on day 30 (remission stage) after treatment (a single s.c. dose of puromycin aminonucleoside 15 mg/100 g body wt.). Serum concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and progesterone (P4) from both sexes as well as 17beta-estradiol (E2) in females and total testosterone (tT) in males were assayed at both phases of the illness by specific radioimmunoassays; free and urine testosterone (fT, uT) was also determined in male rats on day 10. The estrous cycle was followed alongside the study through vaginal smears, while fertility was estimated by the rate of pregnancies (females) or pregnancy induction (males), and by the litter size. The results showed that most serum hormone levels, except FSH in females, were significantly reduced at the nephrotic stage of the illness, returning to their normal values after 30 days. Besides, on day 10, fT was found reduced in nephrotic males, while uT concentrations remained unmodified. The ovulatory cycle of nephrotic rats was disrupted on day 3 and not restored until day 23; nevertheless, the reproductive function, measured as a fertility index, was fully reinstalled at the remission stage. Interestingly, the capacity of fertilization of the nephrotic males was not entirely abolished during the acute phase, since 37% of the animals were fertile. Moreover, on day 30 the reproductive function in nephrotic males was totally recovered. The data from this study show the existence of reversible endocrine disorders in rats bearing nephrotic syndrome; such changes are manifested during the acute phase of the illness as a temporary cessation of the reproductive processes.

Animals↗
PubMed1997

Reduced kidney branched chain aminotransferase expression in puromycin aminonucleoside-induced nephrotic syndrome.

Injection of puromycin aminonucleoside to rats induces nephrotic syndrome characterized by hypoalbuminemia, proteinuria and hypercholesterolemia. In these rats, a low protein diet (6% casein diet) increased serum albumin by 26.3%, decreased proteinuria by 39% and reduced total cholesterol by 32%. Branched chain aminotransferase activity in kidney mitochondria of nephrotic rats fed 20 or 6% casein diet decreased by 30 and 24% with respect to their pair-fed groups and it was not modified by the protein content of the diet. Mitochondrial branched chain aminotransferase mRNA expression decreased by 67.3 and 72.5% in nephrotic rats fed 20 and 6% casein diet in comparison to their pair-fed groups. Total serum branched chain amino acids concentration (leucine, isoleucine, valine) in nephrotic rats was 30% higher than their pair-fed groups and it was associated with a decrease in the branched chain aminotransferase activity and mRNA expression suggesting that the catabolism of branched chain amino acid is reduced to conserve body nitrogen.

Animals↗
PubMed1997

Long-term efficacy and safety of Jessner's solution and 35% trichloroacetic acid vs 5% fluorouracil in the treatment of widespread facial actinic keratoses.

BACKGROUND: Few studies have examined the long-term efficacy of fluorouracil (FU) or chemical peels for the treatment of actinic keratoses (AK). Our earlier work examined the efficacy and safety of a medium-depth chemical peel compared with the standard regimen of topical FU in the treatment of widespread facial AK through 12 months. OBJECTIVES: To determine long-term efficacy of both treatments by extending our observations through 32 months. METHODS: Fifteen patients with severe facial actinic damage were treated on the left side with a single application of Jessner's solution and 35% trichloroacetic acid and on the right side with twice daily applications of 5% FU cream for 3 weeks. Parameters evaluated at 1, 6, 12, and 32 months included counts of visible AK, random skin biopsies from both treatment areas, development of intercurrent neoplasms, and surveys assessing sun exposure. RESULTS: Eight patients were available for reevaluation at 32 months. Both treatment sides showed a reduction in mean number of AK at 12 months followed by an increase in mean AK number between 12 and 32 months. Improvements in biopsies of clinically actinically damaged skin were seen in keratinocytic atypia, hyperkeratosis, parakeratosis, and inflammation at all treatment times during the study with both treatments. Three squamous cell carcinomas developed in the patients after initial treatment; one developed on the side treated with the peel, and two developed on the side treated with fluorouracil. Surveys failed to demonstrate an association between sun exposure and clinical response. CONCLUSION: Based on these findings, patient with widespread actinic keratoses treated with medium-depth chemical peel or with 5% FU should be reevaluated yearly or every 1.5 years for reappearance of AK and retreatment.

Administration, Topical↗
PubMed1997

Commerce in health services in North America within the context of the North American Free Trade Agreement.

This article discusses the future of commercial trade in personal health services in North America within the context of the North American Free Trade Agreement (NAFTA) and the latter's potential influence on health care for the Mexican people. It begins by defining concepts related to international trade of services, particularly health services, and then proceeds to analyze elements of NAFTA that affect the delivery, regulation, and financing of such services, as well as their future trade within the NAFTA area. It concludes with some recommendations directed at helping Mexico's national health care system confront the risks posed while taking advantage of the opportunities offered by the Mexican economy's entry into a broader market.

Commerce↗
PubMed1997

Biochemical bone markers, bone mineral content, and bone mineral density in rats with experimental nephrotic syndrome.

The human nephrotic syndrome (NS) is accompanied by important alterations of mineral and bone metabolism. The purpose of the present study was to examine bone metabolism in rats with experimental NS and normal creatinine clearance, and to evaluate the reversibility of this alteration. NS was induced by three injections of puromycin aminonucleoside (PAN) on days 0, 21, and 35 (10, 5, and 5 mg/100 g body weight, respectively). The biochemical markers of bone formation (osteocalcin and alkaline phosphatase) and bone resorption (hydroxyproline and pyridinoline), bone mineral content (BMC), and bone mineral density (BMD), determined by dual-energy x-ray absorptiometry (DEXA), were studied on days 0, 7, 14, 28, 42, 56, 84, and 112. Proteinuria was present throughout the study. Hypoproteinemia was seen on days 7, 28, 42, and 56, returning to control values on days 84 and 112. In serum, osteocalcin (OC) concentration increased (p < 0.001), and alkaline phosphatase (ALP) decreased (p = 0.002). In urine, hydroxyproline increased (p < 0.001), but urinary pyridinoline was not different from the control group throughout the study. Increased serum parathyroid hormone concentration and decreased levels of 25-hydroxy and 1,25-dihydroxyvitamin D were found from day 7. During the intense proteinuria, bone resorption predominates and decreased BMC and BMD ensues in PAN-nephrotic rats. PAN-nephrotic rats showed low BMC and BMD compared to control group (p < 0.001). At the end of the study, when proteinuria persisted but total serum protein returned to control values, the biochemical bone markers, BMC, and BMD returned to normal. In conclusion, PAN-nephrotic rats had reversible bone alterations that were related to the magnitude of proteinuria and the concentration of total serum protein.

Alkaline Phosphatase↗
PubMed1997

In vitro culture of Taenia crassiceps larval cells and cyst regeneration after injection into mice.

Taenia crassiceps cysticerci were disrupted through trypsinization to isolate cells which can be maintained in culture for up to 15 days. When injected intraperitoneally into susceptible BALB/cAnN mice, complete cysticerci were recovered in a number that is proportional to the quantity of injected cells. Thus, cysticerci contain cells which can reconstitute complete cysts, suggesting that individual cells play a role, independent to budding, during asexual multiplication of T. crassiceps cysticerci in the peritoneal cavity of mice. In contrast, injection of the cells into resistant C57BL/6J mice does not result in the recovery of complete cysts. These findings provide a new experimental model to identify resistance factors in the hosts, for the in vitro screening of anti-cysticerci drugs and for the genetic manipulation of cysticerci through recombinant DNA techniques.

Animals↗
PubMed1996

Dimethyl disulfide derivatization of ethyl (9Z,12Z)-9, 12-octadecadienoate and ethyl (9E,12E)-9,12-octadecadienoate.

The dimethyl disulfide derivatization of ethyl (9Z,12Z)-9,12-octadecadienoate and ethyl (9E,12E)-9,12-octadecadienoate was studied. These methylene-interrupted dienes were reacted with dimethyl disulfide and I2 for 72 h at 50 degrees C and the tetrahydrothiopyran, thietane, and tetrahydrothiophene derivatives thus obtained were analyzed by gas chromatography-mass spectrometry. Each configurational isomer displayed a unique gas chromatography trace for the 4-, 5- and 6-membered ring cyclization products thus obtained. Therefore, the cis-cis and trans-trans double bond stereochemistry of 9,12-octadecadienoates can now be determined by dimethyl disulfide derivatization.

Chromatography, Gas↗
PubMed1996

Identification of the novel 7-methyl-6-octadecenoic acid in Holothuria mexicana.

The phospholipid fatty acid composition of Holothuria mexicana was investigated, and the novel 7-methyl-6-octadecenoic acid was identified. Structural characterization was accomplished by means of pyrrolidide derivatization and total synthesis. Other interesting phospholipid fatty acids in H. mexicana were 7-eicosenoic acid, 13-tricosenoic acid, 7-methyl-6-hexadecenoic acid, and 2-hydroxy-15-tetradecenoic acid.

Animals↗
PubMed1996

Time course analysis of serum and urinary proteins by SDS-PAGE in experimental nephrotic syndrome.

Serum and urinary proteins from rats with nephrotic syndrome (NS) induced by puromycin aminonucleoside (PAN) were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Analysis was made on days 2, 4, 6, 8, 10, 12, 16, 20, and 30 after PAN injection. Data were compared with control rats (C). Rats developed proteinuria on days 4-30 and hypoproteinemia on days 4-16. Total protein concentration in serum and urine was similar on day 6. SDS-PAGE revealed that urinary albumin augmented on days 4-30 and serum albumin decreased markedly on days 4-20. Albumin concentration in serum and urine was similar on days 4-16. In addition, the study examined serum changes of 7 other proteins (designed as A, B, C, D, E, F, and G) which appeared or increased in urine, and whose molecular weights were higher (A, B, and C) or lower (D, E, F, and G) than that of albumin. In serum, protein A remained unchanged; protein B and G increased; proteins C, D, E, and F decreased. The qualitative pattern of urinary proteins remained essentially unchanged on days 4-30. During the intense proteinuria, the serum concentrations of protein B and albumin were similar and the urine concentrations of proteins C and D became comparable to that found in serum. These 7 serum proteins did not show the same behavior although all of them were excreted in urine. These data indicate that in PAN-nephrotic rats: (a) urinary proteins can be of low and high molecular weight, (b) serum proteins can be regulated independently of their urinary excretion and molecular weight, (c) the urine concentration of total protein and some specific proteins can reach values similar to that found in serum during the intense hypoproteinemia, and (d) the qualitative pattern of urinary proteins was unrelated to the magnitude of proteinuria.

Analysis of Variance↗
PubMed1996

Impact of peritoneal dialysis modality on nutritional and biochemical parameters.

Several lines of evidence suggest that continuous ambulatory peritoneal dialysis (CAPD) and continuous cycling peritoneal dialysis (CCPD) may differ in glucose, amino acid, and protein mass transfer. Thus, depending on modality, variances in protein and caloric balance could affect nutritional parameters. We prospectively followed 58 patients on CAPD (n = 36) or CCPD (n = 22) for 21 months (age: 54 +/- 14 years; weight: 76 +/- 16 kg; body mass index: 25.8 +/- 5.1 kg/m2). Twenty-four-hour dialysate effluent (Kpt/V) and normalized protein catabolic rate values were comparable in both CAPD and CCPD patients (0.23 +/- 0.05 vs 0.20 +/- 0.05 and 0.93 +/- 0.23 vs 0.87 +/- 0.21 g/kg/day, respectively). At the last trimester, CAPD patients had greater body weight and body mass index increases than those on CCPD (1.6 +/- 1.1 vs 0.3 +/- 1.1 kg and 0.53 +/- 0.42 vs 0.06 +/- 0.35 kg/m2, respectively), which did not reach statistical significance. No differences were noted in serum protein, albumin, or cholesterol levels (6.5 +/- 0.1 vs 6.5 +/- 0.2 g/dL; 3.5 +/- 0.1 vs 3.7 +/- 0.1 g/dL; and 211 +/- 10 vs 209 +/- 10 mg/dL for CAPD and CCPD, respectively). In summary, this study demonstrates that CAPD and CCPD, when delivered in equal amounts, result in similar weight gains and maintain comparable biochemical nutritional parameters.

Adult↗