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Biomedical subjects

R Gonzalez

Publications and source records attributed to R Gonzalez.

At least 37 records · Page 2Linked to original sources
PubMed2003

Doxorubicin in combination with fluorouracil and cyclophosphamide (i.v. FAC regimen, day 1, 21) versus methotrexate in combination with fluorouracil and cyclophosphamide (i.v. CMF regimen, day 1, 21) as adjuvant chemotherapy for operable breast cancer: a study by the GEICAM group.

BACKGROUND: The purpose of this study was to determine the relative efficacy of doxorubicin versus methotrexate in combination with intravenous cyclophosphamide and 5-fluorouracil (FAC versus CMF) as adjuvant chemotherapy for operable breast cancer. PATIENTS AND METHODS: Over a 4-year period, 985 women undergoing curative surgery for breast cancer (T1-3 N0-2 M0, stage I-IIIA, UICC) from nine hospitals were stratified with respect to axillary node involvement (node positive versus node negative) and randomized to receive either FAC (500/50/500/m(2)) every 3 weeks for six cycles or CMF (600/60/600/m(2)) every 3 weeks for six cycles. RESULTS: The relative dose intensities of FAC and CMF were 87% and 85% of planned doses, respectively. Unadjusted data indicated a non-significant trend towards better results with FAC. In the prospectively formed subset of node-negative patients, disease-free survival and overall survival were statistically superior in the FAC treatment arm (P = 0.041 and 0.034, respectively), but this advantage was not seen in the subset of node-positive patients, probably because of a difference in the percentage of patients with four or more positive nodes. Adjusting data for size of treatment effect and potential interactions (number of positive nodes, tumor size, treatment center), the overall relative risk (RR) of disease recurrence and death were significantly lower with FAC treatment (RR 1.2, P = 0.03, and RR 1.3, P = 0.05, respectively). This result was mainly due to the difference observed in the node-negative patient population. Toxicity was mild: FAC induced more alopecia, emesis, mucositis and cardiotoxicity; this last was of clinical concern, but was infrequent and manageable. CMF induced more conjunctivitis and weight gain. There were no toxic deaths. CONCLUSIONS: Doxorubicin in combination with day 1 i.v. cyclophosphamide and 5-fluorouracil is superior to methotrexate in combination with day 1 i.v. cyclophosphamide and 5-fluorouracil as adjuvant chemotherapy for operable breast cancer. A treatment effect is particularly evident in the node-negative patients. Although the clinical toxicity of FAC is greater than that of CMF, the levels were manageable and clinically acceptable.

Adolescent↗
PubMed2002

Botulinum toxin-induced paralysis of frontotemporal muscles improves seizure focus localization.

BACKGROUND: Scalp EEG localization of epileptic foci may be obscured by electromyographic (EMG) artifact produced by ictal contraction of cranial muscles. Injection of botulinum toxin type A (BTX-A) into frontotemporal scalp muscles reduces EMG activity. Initial scalp video-EEG monitoring in three patients suggested partial seizures, but definitive lateralization or localization was precluded by EMG artifact. METHODS: EMG-guided BTX-A injection to bilateral frontotemporal muscles was performed. When artifact persisted, BTX-A administration was selectively repeated. Patients subsequently underwent scalp video-EEG monitoring 1 week later. RESULTS: All patients had reduction of EMG artifact during subsequent scalp video-EEG monitoring. No patient had adverse effects after BTX-A administration. All three patients had localization to either frontal or temporal lobes and definitive lateralization. Two of the three patients were able to proceed to invasive placement of frontotemporal subdural grid electrodes based on the BTX-A scalp video-EEG localization, and the third patient was determined to have a multifocal seizure disorder. CONCLUSIONS: Paralysis of frontotemporal scalp muscle after BTX-A administration reduces EMG artifact and may improve localization and lateralization of a seizure focus, providing a noninvasive technique for advancement toward epilepsy surgery.

Botulinum Toxins, Type A↗
PubMed2002

Application of low intensity ultrasonics to cheese manufacturing processes.

Ultrasound has been used to non-destructively assess the quality of many foods such as meat, fish, vegetables and dairy products. This paper addresses the applications of low intensity ultrasonics in the cheese manufacturing processes and highlights the areas where ultrasonics could be successfully implemented in the future. The decrease of ultrasonic attenuation during the renneting process can be used to determine the optimum cut time for cheese making. The ultrasonic velocity increases during maturation for those types of cheese that become harder during this manufacturing stage, thus being an indicator of the maturity degree. Moreover, ultrasonic measurements could be linked to sensory parameters. From the ultrasonic velocity measurements at two different temperatures, it is possible to assess cheese composition, thus allowing an improvement in the quality and uniformity of cheese commercialization. In addition, in pulse-echo mode it is possible to detect cracked pieces due to abnormal fermentations and also to assess the distance of the crack from the surface.

Journal Article↗
PubMed2002

Case Reports. Infection due to Scedosporium apiospermum in renal transplant recipients: a report of two cases and literature review of central nervous system and cutaneous infections by Pseudallescheria boydii/Sc. apiospermum.

Two cases of infections due to Scedosporium apiospermum in renal transplant recipients, one localized in the central nervous system, the other in the skin, are presented, and a literature review of 21 cases of central nervous system and cutaneous infections due to Pseudallescheria boydii/Sc. apiospermum is given.

Biopsy↗
PubMed2002

Pre-emptive oral ganciclovir can reduce the risk of cytomegalovirus disease in liver transplant recipients.

A cohort of 65 liver transplant recipients was prospectively monitored with qualitative polymerase chain reaction (PCR) in plasma. The first 25 patients did not receive prophylaxis. From a consecutive group of 40 recipients, 11 high-risk patients donor CMV-seropositive/receptor CMV-seronegative (D+/R-), persistent CMV replication) received pre-emptive oral ganciclovir (1000 mg three times daily), when a marker of risk was identified, until day 90. The overall incidence of cytomegalovirus (CMV) disease at six months was 20% (five of 25 patients) in the non-prophylaxis group and 2.5% (one of 40 patients) in the group treated with pre-emptive oral ganciclovir (relative risk, 0.11; 95% confidence interval; 0.01-0.96; P = 0.04). The PCR sensitivity for detecting CMV disease was 80%, the specificity was 90%, and the positive and negative predictive values were 66% and 95%, respectively. Adverse events, graft rejection and survival were similar between groups. We conclude that pre-emptive oral ganciclovir in high-risk patients can reduce the risk of CMV disease.

Antiviral Agents↗
PubMed2002

Development and evaluation of the Kids Count Farm Safety Lesson.

The Kids Count Farm Safety Lesson was delivered to nearly 2,000 fifth-grade students in 15 rural schools in Hillsborough County, Florida. The lesson covered animal, machinery, water, and general safety topics applicable to farming in Florida. A staggered pretest-posttest study design was followed whereby five schools received a multiple-choice pretest and posttest and the remainder of the schools (N = 10) received the posttest only. Results of the study showed a significant increase in the mean number of correct answers on the posttests compared to the pretests. There was no significant difference in the mean number of correct answers of those students who received the pretest and those students who had not, eliminating a "pretest" effect. This study fills an important gap in the literature by evaluating a farm safety curriculum offered in the elementary school setting. It also included migrant schoolchildren in the study population. It is strongly recommended that agricultural safety information be included into the health education curriculum of these elementary schools.

Accidents, Occupational↗
PubMed2002

Natural history of acute HCV infection in hemodialysis patients.

AIMS: Chronic liver disease develops in the majority of non-uremic patients with hepatitis C virus (HCV) infection. The aim of this study was to analyze the evolution towards chronic hepatopathy in 19 cases of acute hepatitis C observed in hemodialysis patients from 1990 to 2001. METHODS: A prospective follow-up study on HCV infection was conducted in 3 HD units from April 1990 to June 2001 to study clinical outcomes after acute hepatitis C. A total of 781 patients were tested monthly for alanine aminotransferase and anti-HCV in serum. In this period, 19 patients suffered from acute hepatitis C. Evolution to chronic liver disease in the follow-up was evaluated by means of biochemical (increased ALT) and virological criteria (HCV-RNA+). The transmission mechanism, the apparition of anti-HCV, clinical manifestations and mortality were also investigated. RESULTS: In 15 (78.9%) of the 19 patients, the viremia remained positive (chronic viremia) and 11 patients (57.8%) evolved to chronic liver disease (chronic viremia and high transaminase levels) with a median follow-up of 3 years (range 1 - 6). Five of them who underwent liver biopsies had histologic signs of chronic active hepatitis. One of them (5.2%) evolved to liver cirrhosis in the follow-up. In 4 out of 19 patients (21%) the HCV infection resolved. Although 7 (36.8%) of them died in the follow-up, acute hepatitis C infection was not a short-term independent risk factor of death. CONCLUSIONS: Three years after acute hepatitis C, 87.5% of the hemodialysis patients remained HCV-RNA positive and 56.2% evolved to chronic liver disease. It is important to stress that HCV infection spontaneously cleared in 4 out of 19 patients (21%).

Acute Disease↗
PubMed2001

A simplified method to quantitate atherosclerosis in the rabbit aorta.

A simple method to quantitatively evaluate atherosclerosis in the rabbit aorta by measuring macroscopic lesion areas (%) was attempted in the present study. Ten female New Zealand white rabbits were fed on a cholesterol-rich diet (5/1000 g of food) during 4 months. Five of them were oophorectomized at the beginning and all were sacrificed at the end. Total levels of cholesterol increased from 50.7+/-14.7 mg/dl to 782.8+/-296.0. No significant differences were observed between oophorectomized and intact rabbits. At 4 months, the cholesterol-rich diet caused in both, intact and oophorectomized rabbits, atherosclerotic lesions affecting 17 and 46% of the aortic surface, respectively. This method may be more practical, easy and useful for quantitative evaluation of aortic atherosclerosis in a large number of rabbits, than histological observations of serial sections of rabbit's aortas.

Animals↗
PubMed2001

Management of primary cutaneous melanoma of the head and neck: The University of Colorado experience and a review of the literature.

BACKGROUND: While elective lymph node dissection (ELND), adjuvant radiation therapy and sentinel lymph node biopsy have all been advocated in the routine management of primary cutaneous melanoma arising in the head and neck, the optimal management has not been defined. METHODS: We have reviewed our experience of 273 patients with primary melanoma of the head and neck entered into a prospective database at the University of Colorado Health Sciences Center (UCHSC) from 1978 through 1998 and contrasted this with other reports in the literature. RESULTS: A total of 168 patients were identified that received their initial management at UCHSC and had no clinical evidence of distant disease. Only nine patients (5%) underwent ELND, and no patients received adjuvant radiation therapy. The local recurrence rate and 5-year melanoma specific survival, according to Breslow thickness, were similar to centers where adjuvant radiation therapy or ELND are routinely performed. Our preliminary experience and a review of the literature suggests that the technique of sentinel lymph node biopsy is an accurate and low risk procedure that provides valuable prognostic information useful in the further management of these patients. CONCLUSIONS: There is no clear indication that either ELND or adjuvant radiation therapy impacts on the outcome of patients with primary melanoma of the head and neck. Sentinel lymph node biopsy, in appropriate cases, is becoming the standard of care.

Adolescent↗
PubMed2001

Influence of iron on growth, production of siderophore compounds, membrane proteins, and lipase activity in Acinetobacter calcoaceticus BD 413.

Acinetobacter calcoaceticus BD413 was examined for production of siderophores and iron-repressible outer membrane proteins following growth in iron-restricted media. The iron-scavenging phenotype was associated with the secretion of iron-repressible catechol and the induction of a group of six outer membrane proteins with molecular weights ranging from 34 to 85 kDa. The amount of catechol produced was dependent on medium composition and iron stringency. The relation between iron limitation and lipase production was studied at the level of lipA transcription and extracellular lipase activity. In minimal medium, iron limitation slightly affected lipA expression but decreased exo-lipase activity significantly. However, if iron limitation and rich nitrogen sources were simultaneously present in the culture media, the production of lipase was increased approximately 4 times.

Acinetobacter calcoaceticus↗
PubMed2001

Dolastatin-10 in metastatic melanoma: a phase II and pharmokinetic trial of the California Cancer Consortium.

Dolastatin-10 is a novel pentapeptide agent originally isolated from the marine mollusk Dolabella auricularia with a mechanism of antitumor activity that involves the inhibition of microtubule assembly. We performed a Phase II trial of Dolastatin-10, 400 microg/m2 in patients with advanced melanoma who had received no prior chemotherapy. Dolastatin-10 pharmokinetics were evaluated in a subset of patients following courses 1 and 2. Twelve patients were treated with a median of 2 cycles of Dolastatin-10, and no patient experienced an objective response. The only grade >2 toxicities were grade 3 neutropenia uncomplicated by infection, occurring in 4 patients following the first treatment cycle. The total systemic clearance and volume of distribution at steady-state were 2.61 +/- 1.9 L/h/m2 and 28.4 +/- 13 L/m2, respectively. Due to prolonged terminal elimination. Dolastatin-10 plasma concentrations of greater than 1 nM were sustained for 24 h in all patients studied. Dolastatin-10 is unlikely to have substantial activity in the treatment of melanoma.

Adult↗
PubMed2001

Testing parameters in structural equation modeling: every "one" matters.

A problem with standard errors estimated by many structural equation modeling programs is described. In such programs, a parameter's standard error is sensitive to how the model is identified (i.e., how scale is set). Alternative but equivalent ways to identify a model may yield different standard errors, and hence different Z tests for a parameter, even though the identifications produce the same overall model fit. This lack of invariance due to model identification creates the possibility that different analysts may reach different conclusions about a parameter's significance level even though they test equivalent models on the same data. The authors suggest that parameters be tested for statistical significance through the likelihood ratio test, which is invariant to the identification choice.

Humans↗
PubMed2001

Autoantibody profile in progressive systemic sclerosis as markers for esophageal involvement.

We investigated the relationship between the severity and extent of esophageal involvement in patients with progressive systemic sclerosis (PSS) and the autoantibody profile. We studied 37 consecutive patients with PSS and compared their results to 25 healthy volunteers. Patients with PSS were separated into three subgroups: group 1 (antinuclear antibody [ANA] [+/-], anti-Sc170 antibody [Scl70] [-], and anticentromere antibody [ACA] [-]), group 2 (ANA [+], Scl70 [+], and ACA [-]), and group 3 (ANA [+], Scl70 [-], and ACA [+]). The lower esophageal sphincter pressure and the mean proximal esophageal amplitude were significantly lower in group 3 when compared with group 1, group 2, and the healthy controls. Distal esophageal aperistalsis was noted in 85% of group 3, 40% of group 2, and 30% of group 1. An involvement of esophageal motility was found in 100% of the patients with ACA. Our results suggest that esophageal involvement is more pronounced in patients with PSS with ACA as compared with patients with only Sc170 or ANA.

Adult↗
PubMed2001

Engineering a homo-ethanol pathway in Escherichia coli: increased glycolytic flux and levels of expression of glycolytic genes during xylose fermentation.

Replacement of the native fermentation pathway in Escherichia coli B with a homo-ethanol pathway from Zymomonas mobilis (pdc and adhB genes) resulted in a 30 to 50% increase in growth rate and glycolytic flux during the anaerobic fermentation of xylose. Gene array analysis was used as a tool to investigate differences in expression levels for the 30 genes involved in xylose catabolism in the parent (strain B) and the engineered strain (KO11). Of the 4,290 total open reading frames, only 8% were expressed at a significantly higher level in KO11 (P < 0.05). In contrast, over half of the 30 genes involved in the catabolism of xylose to pyruvate were expressed at 1.5-fold- to 8-fold-higher levels in KO11. For 14 of the 30 genes, higher expression was statistically significant at the 95% confidence level (xylAB, xylE, xylFG, xylR, rpiA, rpiB, pfkA, fbaA, tpiA, gapA, pgk, and pykA) during active fermentation (6, 12, and 24 h). Values at single time points for only four of these genes (eno, fbaA, fbaB, and talA) were higher in strain B than in KO11. The relationship between changes in mRNA (cDNA) levels and changes in specific activities was verified for two genes (xylA and xylB) with good agreement. In KO11, expression levels and activities were threefold higher than in strain B for xylose isomerase (xylA) and twofold higher for xylulokinase (xylB). Increased expression of genes involved in xylose catabolism is proposed as the basis for the increase in growth rate and glycolytic flux in ethanologenic KO11.

Bacterial Proteins↗
PubMed2001

Nevi and melanoma: lessons from Turner's syndrome.

Females with Turner's syndrome (TS) have a markedly increased number of cutaneous nevi. While this is a well-recognized risk factor for cutaneous melanoma (CM), the incidence of this tumor in TS and the implications for our understanding of nevi and melanoma have not previously been considered. Here we report a case of an anorectal melanoma in a woman with TS and a review of the literature. Overall, there appears to be a lower than expected incidence of CM. Possible explanations are discussed and in particular the possible relationship between sex hormones and melanoma development as these girls fail to undergo normal pubertal development. Further study of this syndrome may provide important insights into the genetic factors involved in normal melanocyte and nevus development, the potential influence of sex hormones on melanoma development and the relationship between the presence of nevi and the risk of developing CM.

Adult↗
PubMed2001

Association of lymphangioleiomyomatosis (LAM) with endosalpingiosis in the retroperitoneal lymph nodes: report of two cases.

We report 2 patients in whom pulmonary lymphangioleiomyomatosis (LAM) affected the retroperitoneal lymph nodes and was associated with endosalpingiosis. These lesions were large, encapsulated masses with multiple cysts containing chylous fluid. Both were characterized by proliferating LAM cells that formed fascicles separated by slit-like channels. Some cysts were lined by ciliated epithelium resembling that of Fallopian tubes. Other cysts were lined either by flattened endothelial cells or by a mixture of these cells and epithelial cells. Many LAM cells gave a positive reaction with HMB-45 antibody. Most LAM cells in fascicles were reactive for alpha-smooth muscle actin and desmin. In 1 patient, many of the epithelial cells and some of the subjacent LAM cells were positive for estrogen and progesterone receptors. In conclusion, immunostaining with HMB-45 antibody and markers for smooth muscle cells can be helpful in the evaluation of problems in the differential diagnosis of lesions of extrapulmonary LAM, particularly those involving the genital system.

Adult↗
PubMed2001

Interferon therapy in hemodialysis patients with chronic hepatitis C virus infection induces a high rate of long-term sustained virological and biochemical response.

AIM: The aim of the present study was to analyze the efficacy and tolerance of interferon (IFN) therapy in hemodialysis (HD) patients with chronic hepatitis C virus (HCV) infection. Specifically, we assessed whether the "normalization" of serum ALT levels was associated with the disappearance of the HCV-RNA. METHODS: Thirteen hemodialysis patients with chronic hepatitis C were treated for one year with 3 MU of alpha-IFN. The primary end point was a sustained virological response defined as the absence of HCV-RNA in the last follow-up; the secondary end points were normalization of the serum ALT levels and histological improvement. ALT was considered "normal" below 27 IU/l. RESULTS: Ten patients completed the treatment, which was discontinued in the other 3 (23%). By the end of the treatment a virological response was observed in 8 of the 10 patients (80%) who completed the one-year IFN therapy. Biochemical response was associated with a virological response in 8 of the 9 patients in whom ALT levels became normal. Three patients had a biochemical and virological relapse in the follow-up. Two of them received a further year of IFN therapy, which resulted in a sustained biochemical and virological response. In all patients who underwent a liver biopsy (n = 5), the inflammation score improved. After a median follow-up of 5 years (range 2 - 7), a sustained response was observed in 6 (46%) of the 13 patients enrolled. Two patients with a sustained response received a kidney transplant and after more than 6 years still maintain a biochemical and virological response. Side effects included flu-like syndrome (n = 8), hemoglobin decrease (n = 8), thrombocytopenia (n = 3), depression (n = 1) and seizures (n = 1). CONCLUSION: IFN treatment over a one-year period produces a high rate of long-term virological response in HD patients, associated to a biochemical response in all cases.

Adolescent↗