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Biomedical subjects

C Rodriguez

Publications and source records attributed to C Rodriguez.

At least 109 records · Page 6Linked to original sources
PubMed1997

Analysis of prognostic factors and patterns of failure in dogs with periodontal tumors treated with megavoltage irradiation.

OBJECTIVE: To determine quality and duration of progression-free survival (PFS) time in dogs with periodontal tumors after definitive megavoltage irradiation and to analyze prognostic factors for PFS time and patterns of treatment failure. DESIGN: Prospective clinical trial. ANIMALS: 47 dogs with acanthomatous, fibromatous, or ossifying epulis. PROCEDURE: Dogs were treated with 48 Gy over 4 weeks on an alternate-day schedule of 4 Gy/fraction. Multivariate analysis was done by use of Cox's proportional hazards regression model to determine prognostic factors for PFS time. RESULTS: The only independent prognostic factor for PFS time was tumor T stage. Pattern of local tumor recurrence (marginal vs infield regrowth) was independent of clinical stage, tumor location, and site. In 4% of the dogs, severe acute radiation reactions in the final week of treatment resulted in treatment discontinuation. In 6.4% of the dogs, chronic radiation reactions included bone necrosis. CLINICAL IMPLICATIONS: Irradiation was a safe and effective treatment of small (T1 and T2 stage) periodontal tumors. The usefulness of the radiation protocol in this study is limited in dogs with large (T3) tumors, particularly those located in the caudal half of the oral cavity, because of poor results and high risk of acute radiation toxicoses.

Animals↗
PubMed1997

Smoking and fatal prostate cancer in a large cohort of adult men.

The authors examined the relation between smoking and the risk of fatal prostate cancer in a large prospective mortality study of 450,279 men who were cancer free at enrollment in 1982. During 9 years of follow-up, 1,748 deaths occurred from prostate cancer. Cox proportional hazards modeling was used to adjust for other risk factors. Current cigarette smoking was associated with fatal prostate cancer (rate ratio = 1.34, 95% confidence interval (CI) 1.16-1.56). The rate ratio was greater at younger ages, decreasing from 1.83 (95% CI 1.04-3.24) among men below the age of 60 years to 1.11 (95% CI 0.79-1.58) among men aged 80 years and above (p for trend = 0.16). No trend in risk was observed with the number of cigarettes per day or with the duration of smoking among current smokers at baseline, and no increased risk was found among former smokers. Race did not significantly modify the association between cigarette smoking and fatal prostate cancer. These data, together with those of three other large prospective studies that find higher death rates from prostate cancer in current cigarette smokers, and inconsistent findings in incidence studies suggest that smoking may adversely affect survival in prostate cancer patients.

Adult↗
PubMed1997

Tubal ligation and fatal ovarian cancer in a large prospective cohort study.

Several studies suggest that tubal sterilization may decrease the risk of ovarian cancer. Data from the Cancer Prevention Study II were analyzed to examine the relation between tubal ligation and ovarian cancer mortality in a large prospective study. A total of 396,114 women who had not had hysterectomies and who had no prior history of cancer (except nonmelanoma skin cancer) were followed prospectively for approximately 9 years from 1982 to 1991. During this time, 799 ovarian cancer deaths were observed. Tubal ligation was significantly associated with a decreased risk of ovarian cancer mortality in an age- and race-adjusted Cox proportional hazards model (hazard ratio (HR) = 0.64, 95% confidence interval (CI) 0.42-0.96), and the results were essentially unchanged when controlling for potential ovarian cancer risk factors (HR = 0.68, 95% CI 0.45-1.03). The protective effect appeared to be greater in the first 20 years after the procedure (HR = 0.49, 95% CI 0.24-0.99) than later (HR = 0.80, 95% CI 0.48-1.34). No interactions between ever having had a tubal ligation and other covariates were observed. These data suggest that tubal ligation reduces the risk of fatal ovarian cancer.

Adult↗
PubMed1997

Autoantibodies against mitochondrial glycerophosphate dehydrogenase in patients with IDDM.

The mitochondrial enzyme FAD-linked glycerophosphate dehydrogenase (mGDH) plays a key role in the recognition of D-glucose as a stimulus for insulin release from the pancreatic islet B-cell. This study reveals that autoantibodies against this enzyme are not uncommonly found in patients with insulin-dependent diabetes mellitus (IDDM) examined at the onset of the disease. Antibodies reacting with a recombinant mGDH fragment product were observed in the serum of four out of 15 type-1 diabetics, but in none of 15 control subjects. The serum of patients positive for the recombinant mGDH fragment also recognized native mGDH in a rat testis extract, provided that the enzymatic protein was first exposed to an anti-mGDH rabbit serum. Antibodies against mGDH were also found in four out 12 patients with autoimmune thyroiditis. These findings reveal that a mitochondrial enzyme, that represents an essential component of the islet B-cell glucose-sensing device, may act as an antigenic determinant in patients with IDDM or other autoimmune diseases.

Adolescent↗
PubMed1997

Effect of high ionic strength and inhibitors of H,K-ATPase on the ouabain-sensitive K-p-nitrophenylphosphatase activity in the sea anemone Stichodactyla helianthus.

The ouabain-sensitive, K-stimulated p-nitrophenyl phosphatase (K-pNPPase) activity, an associated activity of the Na,K-ATPase, was assayed in tentacles of the sea anemone Stichodactyla helianthus to investigate the possibility that the sea anemone Na,K-ATPase activity is an associated activity of an H,K-ATPase. Activity was maximal at pH 6.5-7.0, decreasing only slightly in acidic medium but falling abruptly in alkaline medium to 60% of maximum at pH 7.4. The pH of maximum activity was not remarkably altered in high ionic strength medium (560 mM choline chloride), but ouabain-sensitive K-pNPPase activity of both rat and sea anemone was strongly inhibited. Inhibitors of the gastric H,K-ATPase, 100 microM omeprazole and 10 microM SCH 28080, did not inhibit the ouabain-sensitive K-pNPPase activity. Activity of the sea anemone enzyme was inhibited by 10 microM ammonium vanadate, an inhibitor of P-type ATPase, and not by 2.5 mM sodium azide, an inhibitor of both F-type and V-type ATPase. Because the sea anemone K-pNPPase activity was previously found to be more sensitive to ouabain than the Na,K-ATPase activity, K(+)-ouabain antagonism was investigated and found to be relatively muted, whereas K(+)-Na+ competition was stronger than in the rat kidney.

4-Nitrophenylphosphatase↗
PubMed1997

Characterization of pharmaceutical solvates by combined thermogravimetric and infrared analysis.

The combined physical analytical technique of thermogravimetric and infrared analysis (TG/IR) is described for the investigation of pharmaceutical solids. TG/IR provides an unequivocal identification of the volatile content of a pharmaceutical solid. In the case of pharmaceutical solvates, TG/IR provides identification of the evolved gas from the crystalline solid. Variable temperature X-ray diffraction and differential scanning calorimetry techniques provide the required information to ascertain whether the evolved gas was due to a solvent incorporated into the crystal lattice or physically adsorbed onto the solid. This work illustrates three examples of TG/IR as utilized in a multidisciplinary approach to the physical characterization of pharmaceutical solids.

Calorimetry, Differential Scanning↗
PubMed1997

Assessment of cardiovascular changes during laparoscopic hernia repair using oesophageal Doppler.

We have used an oesophageal Doppler to measure aortic blood flow velocity before, during and after induction of carbon dioxide pneumoperitoneum in 10 consecutive patients, mean age 58 yr, undergoing laparoscopic hernia repair. Derived values for stroke distance, minute distance and systemic vascular resistance showed considerable interpatient variation indicating unpredictable haemodynamic responses. Five minutes after insufflation of the abdomen there was a significant increase in mean arterial pressure from 82.5 to 103.6 mm Hg (P < 0.05) but both stroke distance and minute distance decreased significantly (mean 12.0 (SEM 1.4) cm to 9.0 (0.7) cm, P < 0.05; and 747.5 (82) cm min-1 to 596 (49) cm min-1, P < 0.05; respectively) indicating a significant decrease in cardiac output. There was a corresponding increase in the index of systemic vascular resistance from 1092 (747) to 2079 (400) (P < 0.05) which persisted after deflation of the abdomen. Oesophageal Doppler can provide continuous online haemodynamic data with a rapid response to acute changes and may have a role in non-invasive haemodynamic monitoring during laparoscopic procedures in older patients with cardiovascular disease.

Adult↗
PubMed1997

Simultaneous mandibular and maxillary distraction in hemifacial microsomia in adults: avoiding occlusal disasters.

Mandibular elongation by gradual distraction in patients with hemifacial microsomia is a simple and effective procedure to correct facial asymmetry. The two-pin system joined by a softer distracting screw achieves elongation in vertical and sagittal directions as well as medial rotation. The changes in mandibular shape result in changes in dental occlusion. These are minimal in children because of the rapid growth of the maxilla and can be corrected easily with minor orthodontic work. Mandibular distraction in adults with hemifacial microsomia, who usually have stable dental occlusion, produces good aesthetic results but also severe alterations in the occlusion requiring complex orthodontic treatment over a long period. To avoid this problem, an incomplete Le Fort I osteotomy is done simultaneously with the mandibular corticotomy. Intermaxillary fixation is done on the fifth postoperative day, and distraction is initiated. In a series of seven patients, the maxilla was distracted simultaneously with the mandible, preserving the preexisting stable occlusion. Preoperative deviation of the occlusal plane from the horizontal varied from 12 to 18 degrees. The plane became horizontal in four patients, and deviation of 2 degrees persisted in three. The distance from the inferior orbital rim to the occlusal plane on the affected side was increased in all patients, achieving 100 percent correction (compared with the normal side) in four patients and 95, 96, and 97 percent in the other three.

Adult↗
PubMed1997

Identification and retting efficiencies of fungi isolated from dew-retted flax in the United States and europe.

Seven strains of filamentous fungi and one yeast were isolated from flax that was dew retted in the United States. These filamentous fungi were subcultured to purity and identified, and six appear not to have been reported earlier as isolates from dew-retted flax. Five of the purified U.S. strains, two fungi isolated from flax that was dew retted in Europe, and a laboratory culture of Aspergillus sojae were tested for their ability to ret flax stems. The monocultures were evaluated for the degree of retting, fiber strength, dry weight loss, and tactile response (i.e., feel of softness) as reflected in the retted fiber. Structural modifications of representative samples of the retted flax were assessed by scanning electron microscopy. All of the filamentous fungi were able to carry out some retting, whereas the isolated yeast could not. All organisms produced pectinases when they were cultivated in shake flasks on ball-milled flax as the sole carbon source. Some fungi also produced cellulases, mannanases, and xylanases. Rhizomucor pusillus and Fusarium lateritium were noteworthy as retting organisms by their high level of pectinase activity, ability to attack noncellulosic cell types without attacking cellulose, capacity to penetrate the cuticular surface of the stem, and efficient fiber release from the core. The results indicated that these organisms deserve further study as potential organisms for retting of bast fibers in industrial applications.

Journal Article↗
PubMed1997

Stable behaviors associated with adults' 10-year change in body mass index and likelihood of gain at the waist.

OBJECTIVES: The purpose of this study was to identify behaviors associated with change in body mass index or with weight gain at the waist. METHODS: A cohort of 79236 White, non-Hispanic, healthy adults was questioned in 1982 and 1992 about diet and 10 physical activities. Estimates were made of the mean effects of stable behaviors on 10-year change in body mass index and on odds ratios for gain at the waist. RESULTS: Ten-year changes in body mass index was associated positively with meat consumption and smoking cessation and inversely with vegetable consumption, vitamin E supplementation, continued smoking, and some vigorous activities (e.g., jogging/running). Women's body mass index decreased with walking 4 or more hours per week and with regular alcohol intake, but these behaviors had a smaller effect on men's body mass index. weight gain was inversely associated with high vegetable consumption, walking 4 or more hours per week, and jogging/running 1 to 3 hours per week but not with less demanding physical activities. CONCLUSIONS: Simple derivation of behaviors associated with weight loss or reduced abdominal obesity may enhance programs designed to prevent obesity and chronic diseases.

Adult↗
PubMed1997

Use of intrarenal needle manometry in acute renal dysfunction following renal transplantation.

Intrarenal manometry (IRM) using the Salaman fine-needle technique was routinely performed in 28 renal transplant patients in order to make the differential diagnosis of acute tubular necrosis, cyclosporin nephrotoxocity, and acute rejection. A total of 246 IRM determinations with simultaneous percutaneous renal biopsies were obtained in cases of acute renal failure following a renal transplant. Normal IRM values were 21.4 +/- 1.3 mm Hg. After collecting the clinical data, cyclosporin levels, ultrasound information, response to therapy, and renal biopsy results, we retrospectively obtained 49 IRM measurements in acute rejection, 9 in cyclosporin nephrotoxicity, and 26 in acute tubular necrosis. The values in acute rejection (41.3 +/- 9.5 mm Hg) were significantly different from the normally functioning kidneys, cyclosporin nephrotoxicity, or acute tubular necrosis. The values in cyclosporin nephrotoxicity were slightly elevated when compared to the normal or acute tubular necrosis determinations (p < 0.04) but were still significantly lower than the acute rejection. Our results suggest that IRM represents a useful technique in the approach to the acute renal dysfunction in renal transplant recipients.

Cyclosporine↗
PubMed1997

[Ataxia-telangiectasia and cancer: an open question].

Ataxia-telangiectasia is a rare recessive disorder which, among other clinical signs, is characterized by an extreme sensitivity to ionising radiation. Cells isolated from AT patients show radioresistant DNA synthesis and this has lead to the hypothesis that the product of the genetic determinant of AT may play a role in the detection, signalling or repair of double stranded DNA breaks. The gene to AT, called ATM has been recently cloned and characterized. It codes for a large RNA transcript of 13,000 bp of which a 3,500 aa protein is translated. The gene itself covers 150 kb, spread over 64 exons. The amino acid sequence has revealed the existence, at the carboxyterminal end of the protein, of a domain presenting homology to PI-3 kinase. This characteristic has allowed the description of a new family of nuclear protein, in yeast, drosophila an human, functionally involved in DNA damage signalling. It is interesting to note that a vast majority of mutations described in AT patients lead to the truncation of the protein and consequently to the elimination of the PI-3K domain, thus suggesting an important role in the normal function of the protein. An important question linked to AT mutation concerns the cancer risk associated to heterozygous mutations. It is well established that AT patients, homozygous for the mutation, present a 100-200 fold increased risk of cancer. Epidemiological studies have described a 3-5 fold increase risk of cancer (particular breast cancer in women) associated to the heterozygous mutation. Knowing that the incidence of the heterozygotes can be estimated to range 0.5 to 1% in the general population this question is of great importance in terms of public health.

Adult↗
PubMed1997

Phase II study of recombinant interleukin 1alpha and etoposide in patients with relapsed osteosarcoma.

A Phase II trial using interleukin 1alpha (IL-1alpha) and etoposide for patients with relapsed osteosarcoma (OS) was undertaken to assess the feasibility and tolerability of combination therapy with biotherapy and chemotherapy. Nine patients with histologically proven relapsed OS were treated with IL-1alpha immediately followed by etoposide daily for 5 days every 3 weeks. Surgical resection of lung metastasis or peripheral tumor was performed after two or three cycles. We observed three partial responses; disease was stable in another case. One case could not be evaluated. The side effects associated with combination therapy were as predicted from known side effects of the individual agents; however, more profound neutropenia was observed. Four patients exhibited clinical signs of capillary leak syndrome, i.e., hypotension, edema, and weight gain. The etiology of the capillary leak was unclear, because serum IL-1alpha, IL-2, tumor necrosis factor, and nitric oxide levels could not be used to predict which patients would develop capillary leak. Histological analysis of tumor specimens obtained after two or more courses of therapy showed changes consistent with a response to a biological response modifier: peripheral fibrosis surrounded the metastasis with infiltration of chronic and acute inflammatory cells. Because the response of relapsed OS to any type of salvage regimen has been poor, we interpret the clinical response of this therapy as good. However, the significant side effects associated with this therapy must also be taken into consideration before deciding to use this combination therapy. It is unfortunate that the study was stopped early due to halted production of IL-1alpha. If this agent is again manufactured for clinical use, we conclude that additional evaluation in patients with relapsed OS is warranted.

Adolescent↗
PubMed1996

Diethylstilbestrol and risk of fatal breast cancer in a prospective cohort of US women.

The authors examined the association between the use of diethylstilbestrol during pregnancy and the risk of subsequent fatal breast cancer in a large prospective study of US adults. After 9 years of follow-up, 1,574 cases of fatal breast cancer were observed among 501,536 gravid women who reported no prior history of cancer in 1982. Results from Cox proportional hazards models showed a positive association between a history of diethylstilbestrol exposure (reported by 3.9% of all women) and fatal breast cancer (adjusted rate ratio = 1.34, 95% confidence interval 1.06-1.69). This excess risk did not increase over time; women who were exposed more than 35 years ago (rate ratio = 1.35, 95% confidence interval 0.97-1.87) were not at greater risk than women who were exposed within the past 35 years (rate ratio = 1.39, 95% confidence interval 1.01-1.93). The positive association was not observed in women who used diethylstilbestrol before age 25 years but was seen at all other ages. The age of study participants did not modify the association between exposure and breast cancer, and there were no significant interactions between ever use of diethylstilbestrol and any of the other potential risk factors included in the analysis. These findings are consistent with those of several other studies of diethylstilbestrol exposure and breast cancer.

Adult↗
PubMed1996

Regulation of the aminolevulinate synthase gene in the Syrian hamster Harderian gland: changes during development and circadian rhythm and role of some hormones.

The Syrian hamster Harderian gland has been advocated as a model to study the porphyrin biosynthetic pathway, since it shows by far the highest porphyrin concentration known to date. Another particular characteristic is the sexual dimorphism at both the morphological and the biochemical levels. We found a variation in the ALV-S (aminolevulinate synthase) gene expression according to sex, with females exhibiting much higher mRNA levels than do males. After castration, ALV-S mRNA rose considerably in males, this increase being inhibited by darkness or treatment with melatonin. Treatment with hCG or progesterone did not vary the ALV-S mRNA levels in females. Castrated males, however, showed a much larger increase when they were treated with hCG. No variations have been found in the expression of the ALV-S gene in female HG throughout the estrous cycle. During development, males and females showed similar ALV-S mRNA levels until they were 20 days old. Afterwards, they started showing gender-associated differences. In females, ALV-S mRNA levels rose during the first 3 months of life, and thereafter they decreased progressively with aging. A circadian rhythm has been found in the gene expression of ALV-S mRNA in females, showing very low levels in the morning and reaching a peak during the first hours of darkness. It was an endogenous rhythm, probably regulated at the transcriptional level. It is proposed that the light-dark period duration modulates this rhythm through the suprachiasmatic nucleus which in turn acts on the pineal secretion of melatonin that regulates ALV-S gene expression.

5-Aminolevulinate Synthetase↗
PubMed1996

Interleukin-1 beta suppresses apoptosis in CD34 positive bone marrow cells through activation of the type I IL-1 receptor.

Interleukin-1 is a pleiotropic cytokine that has been shown previously to suppress active cell death in T cells. Two cell surface receptors for interleukin-1 have been identified and their genes cloned, type I (IL-RI) and type II (IL-RII) receptors. In the present study, we provide evidence for a role of interleukin-1 beta in the short-term suppression of cell death both in purified CD34+/Lin- bone marrow precursors and in the GM-CSF dependent cell line TF-1. Several lines of evidence suggest that the biologic effects of IL-1 beta are mediated by activation of type I IL-1 receptors (IL-1RI) and induction of GM-CSF production. First, neutralizing antibodies to IL-1RI but not IL-1RII drastically abrogated cell survival induced by IL-1 beta in CD34+/Lin- cells and TF-1 cells. Second, neutralizing antibodies against GM-CSF abrogate cell survival supported by IL-1 both in CD34+/Lin- bone marrow cells and in the cell line TF-1. Furthermore, exposure of TF-1 cells to IL-1 beta results in a transient accumulation of GM-CSF mRNA, with a peak at 3 h, which was dramatically decreased by neutralizing anti-IL-1R1 antibodies. In contrast, neutralizing anti-IL-1RII did not change the IL-1 induced cell survival of bone marrow cells and was followed by a paradoxical increase in viable cell numbers, in c-myc and c-myb mRNA accumulation in IL-1 treated TF-1 cells. Together our results indicate that the increase in cell survival induced IL-1 beta occurs through binding to IL-1RI and the subsequent production of endogenous GM-CSF. IL-1RII does not appear to be involved in signal transduction in primary CD34+/Lin- cells but could negatively regulate the response to IL-1 beta in TF-1 cells.

Antigens, CD34↗
PubMed1996

Shh, HoxD, Bmp-2, and Fgf-4 gene expression during development of the polydactylous talpid2, diplopodia1, and diplopodia4 mutant chick limb buds.

Several polydactylous mutants affect the pattern of asymmetry along the anteroposterior axis of the vertebrate limb. In talpid2, diplopodia1, and diplopodia4 chick limb mutants, there is a preaxial extension that results in broader limb buds. Talpid2 shows reduction of the long bones and 9-10 syndactylous digits, none of which are specifically recognizable as members of the normal digit complement. In diplopodia1 and diplopodia4 extra digits are present preaxially in addition to the normal digits. This phenotype resembles the duplications obtained by grafting a polarizing region to the anterior margin of the limb bud. The abnormal skeletal pattern along the anteroposterior limb axis in both mutants suggests alterations in the signaling pathways that mediate growth and patterning of the limb. In situ hybridization studies reveal that whereas shh transcripts are restricted to the posterior limb margins, HoxD, Bmp-2, and Fgf-4 genes are ectopically expressed in the anterior region of the talpid2, diplopodia1, and diplopodia4 limb buds. The results obtained give insights into the molecular basis of talpid2 and diplopodia mutations and also into the possible roles of shh, Bmp-2, HoxD, and Fgf-4 genes in vertebrate limb morphogenesis.

Animals↗