Biomedical subjects

R Gonzalez

Publications and source records attributed to R Gonzalez.

At least 19 recordsLinked to original sources

PubMed2006

Isolation and characterization of a thermally extracted yeast cell wall fraction potentially useful for improving the foaming properties of sparkling wines.

Two different yeast cell wall extracts were obtained using enzymatic digestion and thermal treatment. The effects of the extracts obtained on the foaming properties of a model wine and two sparkling wines were studied. The model wine and sparkling wines, supplemented with the thermal extract, presented better foaming properties than did the samples supplemented with the enzymatic extract. The fractioning (Con A chromatography) and characterization (SDS-PAGE, SEC, GC, and RP-HPLC) of both extracts showed that the fraction responsible for the foaming properties is constituted by mannoproteins with a relative molecular weight between 10 and 30 kDa, presenting an equilibrated composition of the hydrophobic and hydrophilic protein domains. This thermal extract did not modify the protein stability in both the model wine and the sparkling wines. These results demonstrate that the enrichment of a sparkling wine with mannoproteins extracted by mild heat procedures will contribute to improving its foaming properties.

Carbonated Beverages↗

PubMed2006

Does experience preclude leaks in laparoscopic gastric bypass?

BACKGROUND: Improved outcomes of laparoscopic Roux-en-Y gastric bypass (LRYGB) have been demonstrated once pratice has moved beyond the learning curve. However, there is no evidence that experience has a favorable impact on the incidence of leaks. This study evaluated the incidence of staple-line leaks as experience accrued in a university-based bariatric surgery program. METHODS: Prospectively collected data on our first 200 patients undergoing LRYGB since July 1998 were analyzed. Linear staplers were used to divide the stomach and to create a side-to-side jejunojejunostomy. A side-to-side cardiojejunostomy was created using a 21-mm circular stapler. Patient characteristics, operative data, and outcomes were evaluated chronologically with comparison of outcomes between quartiles. RESULTS: Staple-line leaks developed in 9 (4.5%) of the first 200 patients undergoing LRYGB. Among the 200 patients were 190 women (95%). The median age of the patients was 48 years (ranges, 24-62 years), and their body mass index was 43 kg/m(2) (ranges, 32-59 kg/m(2)). As surgeons' experience increased over time, there was a significant increase in the weight of patients and the percentage of patients with previous abdominal operations. There also was a significant decrease in conversion rates and operative times. Leaks occurred in six patients at the cardiojejunostomy (3%), in two patients jejunojejunostomy (1%), and in one patient at the excluded stomach (0.5%). Of the 50 leaks that occurred in each quartile, there were in the 3 in the 1st quartile, 1 in the 2nd quartile, 2 in the 3rd quartile, 3 in the 4th quartile. The differences were not significant. There was no correlation between the number of LRYGBs, and the occurrence of a leak (p = 0.59 confidence interval -0.13-0.22). CONCLUSIONS: The incidence of staple-line leaks appears to be independent of the number of LRYGBs performed. These data suggest that surgeons' experience may not eliminate anastomotic complications experienced by patients undergoing LRYGB.

Adult↗

PubMed2006

Does establishing a bariatric surgery fellowship training program influence operative outcomes?

BACKGROUND: Roux-en-Y gastric bypass (RYGB) has a long learning curve that may be reflected in operative outcomes. This study sought to assess whether training a fellow has an impact on the operative outcomes of the training program. METHODS: Prospectively collected data on 150 consecutive patients were compared before (group 1) and after (group 2) establishment of a fellowship-training program. RESULTS: A greater number of patients underwent laparoscopic RYGB (LRYGB) in group 2 than in group 1 (63% vs 46%; p = 0.01). The group 2 patients were similar to the group 1 patients in terms of age, gender, length of stay, and complication rate. However, they had a higher body mass index (BMI) (median 50 kg/m2; range, 39-64 kg/m2 vs median, 46 kg/m2; range, 38-56 kg/m2; p = 0.01) and a higher incidence of prior abdominal procedures (21% vs 7%; p = 0.006). In addition, operative time was significantly shorter for the patients who underwent open RYGB (ORYGB) (median, 150 min; range, 65-280 min vs median, 110 min; range, 50-210 min; p < 0.001) and LRYGB (median, 202 min; range, 105-450 min vs median, 134 min; range, 50-191 min; p < 0.001) in group 2 than for the patients in group 1. The patients who underwent ORYGB in groups 1 and 2 had similar characteristics and outcomes. Increasing experience with both ORYGB and LRYGB correlated with a decrease in operative times for group 2 (p < 0.001), but not for group 1. CONCLUSION: Establishment of a fellowship program shortens the operative times for both open and laparoscopic RYGB and expands the scope of bariatric practice by compounding the experience of the operating team without increasing complications.

Adult↗

PubMed2006

Concurrent comparison of three water contact measurement tools in four endemic villages of the Philippines. The schistosomiasis transmission ecology in the Philippines project (STEP).

BACKGROUND: Schistosomiasis japonica is a chronic helminthic infection contracted through contact with water infested with Schistosoma japonicum. The infection is associated with severe disease and is an important public health concern in Philippines. OBJECT: To estimate the agreement in the frequency of water contact between bimonthly interviews, self-administered diaries and observations. METHODS: A total of 286 individuals were followed over either a 4 or a 6 months period. Agreement between direct observation and both the bimonthly and diary methods were estimated. RESULTS: The agreement between the observation and the bimonthly interview was 71.8% when days without any water contacts were considered, but decreased to 23.3% when only days with at least some water contact were considered. The agreement between the observation and the diary was 78.7% when days without any water contacts were considered and 40.8% when only days with some water contacts were considered. CONCLUSIONS: Agreement about the degree of water contact is poor between the different measurement tools. This has important implications for future research, since a high degree of measurement error can severely bias any results from studies involving water contact.

Adult↗

PubMed2005

Development of swimming in the medicinal leech, the gradual acquisition of a behavior.

Observing the development of behavior provides an assay for the developmental state of an embryo's nervous system. We have previously described the development of behaviors that were largely confined to one or a few segments. We now extend the work to a kinematic analysis of the development of swimming, a behavior that requires coordination of the entire body. When leech embryos first begin to swim they make little forward progress, but within several days they swim as effectively as adults. This increase in efficacy depends on changes in body shape and on improved intersegmental coordination of the swim central pattern generator. These kinematic details suggest how the swim central pattern generating circuit is assembled during embryogenesis.

Age Factors↗

PubMed2005

Synchronous balneophototherapy is effective for the different clinical types of psoriasis.

BACKGROUND: The efficacy of synchronous balneophototherapy in clearing psoriasis is based on the multiple-targeted effects of UVB light and Dead Sea salt. Their synchronous application produces a synergic effect. OBJECTIVE: The purpose of this retrospective study is: 1) to evaluate the efficacy of synchronous balneophototherapy for treating different clinical types of psoriasis; 2) to determine whether there is any difference between response to treatment, and 3) to gain more data in order to predict the effect of treatment in different clinical types, and thus to support the selection of patients for treatment. METHODS: Patients received a basic course of synchronous balneophototherapy according to the Regensburg scheme, consisting of 35 treatment sessions, followed by a maintenance course of a further 25 treatments. The patients' skin status was monitored by weekly assessment using the PASI score throughout the course. The efficacy of the treatment was evaluated through the results of 373 patients treated according to protocol during the basic course, and the results of 78 of these patients during the maintenance course. One hundred and eighty-six patients were enrolled into the study comparing the efficacy of the basic course for the different clinical types of psoriasis: data of patients with large plaques, small plaques, guttate and confluating type of skin signs were summarized and compared. RESULTS: During the basic course of treatment 70.7% improvement of the average PASI index was observed; the average PASI index decreased from 16.14 to 4.73. A further improvement from 4.58 to 4.27 of the average PASI was found during the maintenance therapy. Small plaque-type skin signs showed the best response with a PASI decrease of 76.1%; Guttate type had a PASI decrease of 73.7%, large plaque type, 67.1% and confluating type, 62%. Comparing data with the average PASI decrease, a statistically significant lower decrease was found in confluating type cases. CONCLUSIONS: These results confirm that synchronous balneophototherapy is an effective treatment modality for different clinical types of psoriasis. Patients with small plaques have the greatest chance of the most marked clinical clearing; guttate and large plaque types of psoriasis also respond well to the treatment.

Adult↗

PubMed2004

Laparoscopic palliative surgery for complicated colorectal cancer.

BACKGROUND: The aim of this study was to evaluate the feasibility and outcomes of the laparoscopic approach for the palliation of advanced complicated colorectal cancer (CRC). METHODS: We reviewed 21 laparoscopic palliative procedures for emergent complications of advanced CRC between 1994 and 2002. Intraoperative complications, estimated blood loss, transfusions, operative times, time to first bowel movement, length of hospital stay, and postoperative complications were assessed. RESULTS: Indications for surgery included perforation (n = 10), bleeding (n = 7), and obstruction (n = 4). A proximal diverting procedure was performed in all patients, and a concomitant colon resection was performed in 18 patients (86%). The mean operative time was 181 +/- 22 min. Estimated blood loss was 283 +/- 48 cc, with three patients (14%) requiring transfusions. The average length of hospital stay was 8.6 +/- 2 days, and time to first bowel movement was 61 +/- 9 h. The complication rate and the 30-day mortality rate were 33% and 0%, respectively. CONCLUSION: A laparoscopic approach to address advanced CRC is safe and effective and should be considered part of the surgeon's armamentarium for the palliation of advanced complicated CRC.

Colorectal Neoplasms↗

PubMed2004

A multimodal assessment of driving performance in HIV infection.

OBJECTIVE: To examine if HIV-seropositive (HIV+) individuals are at risk for impaired driving. METHODS: Sixty licensed drivers (40 HIV+, 20 HIV-) completed a neuropsychological (NP) test battery and driving assessments. Eleven HIV+ subjects were NP-impaired. Driving-related skills were assessed using 1) two driving simulations (examining accident avoidance and navigational abilities), 2) the Useful Field of View (UFOV) test, and 3) an on-road evaluation. RESULTS: HIV+ NP-impaired subjects had greater difficulty than cognitively intact subjects on all driving measures, whereas the HIV- and HIV+ NP-normal groups performed similarly. On the UFOV, the HIV+ NP-impaired group had worse performance on Visual Processing and Divided Attention tasks but not in overall risk classification. They also had a higher number of simulator accidents (1.3 vs 2.0; p = 0.03), were less efficient at completing the navigation task (3.2 vs 9.2 blocks; p = 0.001), and were more likely to fail the on-road evaluation (6 vs 36%; p = 0.02). Impairment in Executive Functioning was the strongest NP predictor of failing the on-road drive test. NP performance and both simulations independently contributed to a model predicting 48% of the variance in on-road performance. CONCLUSION: HIV+ NP-impaired individuals are at increased risk for on-road driving impairments, whereas HIV+ individuals with normal cognition are not at a significantly higher risk than HIV- subjects. Executive Functioning is most strongly associated with impaired on-road performance. Cognitive and simulator testing may each provide data in identifying driving-impaired individuals.

AIDS Dementia Complex↗

PubMed2004

Resistance to adhesion formation: a comparative study of treated and untreated mesh products placed in the abdominal cavity.

BACKGROUND: New materials have been devised to prevent postoperative adhesions when placing a prosthesis in contact with abdominal contents. METHODS: Eighty rats underwent laparotomy and denudation of the serosa of the cecum and peritoneal covering of the abdominal wall. Five treated mesh products (Parietex Composite, Parietene Composite, Bard Composix E/X, Sepramesh, and Gore-Tex Dual Mesh) and one untreated mesh product (untreated Parietene) were randomly placed between the cecum and abdominal wall. A group without mesh was used as control. The animals were sacrificed at 21 days following surgery and analyzed for the presence of adhesions. RESULTS: The incidence of adhesion formation, mean adhesion area, maximum adhesion length, and strength of adhesion separation were similar between Parietex Composite, Parietene Composite, and Bard Composix E/X, and they were significantly less than with Sepramesh, untreated Parietene, and the control group. Gore-Tex Dual Mesh resulted in less adhesions, adhesion area, mean strength of separation, and work of separation than the untreated Parietene group and the control group. Sepramesh resulted in less strength and work of separation compared to the control group. CONCLUSIONS: The incidence of adhesions and work and strength of adhesion separation are reduced when using a treated mesh, compared to the untreated mesh and the control group without mesh. Parietex Composite, Parietene Composite, Bard Composix E/X, and Gore-Tex Dual Mesh were superior to Sepramesh, untreated Parietene, and the control group in the prevention of adhesion formation.

Abdominal Cavity↗

PubMed2004

No significant change of plasma beta-endorphin levels of psoriasis patients after synchronous balneophototherapy.

BACKGROUND/PURPOSE: Previous studies suggested that beta-endorphin has a pathogenic role in psoriasis: its increased plasma concentration may play a role in the neuroimmunological processes in the pathomechanism of the disease, and plasma beta-endorphin levels should reflect the changes in the patients' skin status. The purpose of this study was to investigate the changes of peripheral blood beta-endorphin levels in psoriatic patients in conjunction with changes in their skin symptoms after synchronous balneophototherapy. METHODS: With synchronous balneophototherapy, 12 patients with extended skin symptoms of psoriasis were treated. The therapy followed the Regensburg protocol, consisting of a basic course of 35 sessions. Patients' skin status was characterized by evaluating the Psoriasis Area and Severity Index score before and after the therapy course. Blood samples were taken before treatment, and 1 day after the last session, with symptom-free skin. Plasma beta-endorphin levels were measured by a specific radioimmunoassay developed by the authors. RESULTS: There was no significant change in plasma levels of beta-endorphin after clinical clearance of psoriatic skin symptoms. CONCLUSION: In this non-randomized, uncontrolled study no significant difference could be detected between plasma beta-endorphin levels before and after a basic course of synchronous balneophototherapy in patients with psoriasis. Although beta-endorphin has many neuroimmunological effects, the changes of its plasma level do not consistently reflect the skin status. Inflammation in psoriatic skin lesions is probably not mediated directly by circulating beta-endorphin.

Adult↗

PubMed2004

Detection of human immunodeficiency virus type 1 antiretroviral resistance mutations by high-density DNA probe arrays.

Genotypic resistance testing has become an important tool in the clinical management of patients infected with human immunodeficiency virus type 1 (HIV-1). Standard sequencing methodology and hybridization-based technology are the two principal methods used for HIV-1 genotyping. This report describes an evaluation of a new hybridization-based HIV-1 genotypic test of 99 clinical samples from patients infected mostly with HIV-1 subtype B and receiving treatment. This test combines RNA extraction with magnetic silica particles, amplification by nested reverse transcriptase PCR, and detection with high-density probe arrays designed to detect 204 antiretroviral resistance mutations simultaneously in Gag cleavage sites, protease, reverse transcriptase, integrase, and gp41. The nested reverse transcriptase PCR success rates at viral loads exceeding 1,000 copies/ml were 98% for the 2.1-kb amplicon that covers the Gag cleavage sites and the protease and reverse transcriptase genes, 92% for the gp41 amplicon, and 100% for the integrase amplicon. We analyzed 4,465 relevant codons with the HIV-1 DNA chip genotyping assay and the classic sequence-based method. Key resistance mutations in protease and reverse transcriptase were identified correctly 95 and 92% of the time, respectively. This test should be a valuable alternative to the standard sequence-based system for HIV-1 drug resistance monitoring and a useful diagnostic tool for simultaneous multiple genetic analyses.

Anti-HIV Agents↗

PubMed2003

Laparoscopic vs open resection for the treatment of diverticular disease.

INTRODUCTION: The aim of this study was to evaluate whether laparoscopic colon resection (LCR) offers any advantages over open colon resection (OCR) in the treatment of diverticular disease. METHODS: Between 1992 and 2002, 95 patients underwent LCR and 80 patients underwent OCR for the treatment of diverticular disease. Demographics, details of operative procedure, outcome, and pathology were compared. RESULTS: Patients in both groups were matched for age, sex, body mass index, history of previous abdominal operations, comorbidities, location of the disease, and presence of complications. LCR resulted in significantly less estimated blood loss and postoperative complications, shorter time to first bowel movement, and shorter length of stay than the OCR. There was no difference in operative time, intraoperative complications, mortality rates between groups. CONCLUSIONS: LCR is a safe and effective approach for the treatment of patients with diverticular disease. It results in less estimated blood loss, shorter time to first bowel movement, less postoperative complications, and shorter length of hospital stay.

Aged↗

PubMed2003

Preoperative factors predictive of complicated postoperative management after Roux-en-Y gastric bypass for morbid obesity.

INTRODUCTION: This study was undertaken to determine preoperative predictive factors of complicated postoperative management after Roux-en-Y gastric bypass (RYGB) for morbid obesity. METHODS: Between January 1999 and January 2002, 158 patients who underwent a RYGB received a standardized preoperative evaluation and data were collected prospectively. Complicated postoperative management was defined as patients requiring postoperative ICU admission for > or =48 h, or those needing transfer from the floor to the ICU. Patients with complicated management were compared with those in whom ICU admission was not necessary. RESULTS: Twenty-three patients (14.5%) required prolonged ICU admission (mean stay of 6.3 +/- 1.7 days). After multivariate analysis, body mass index (BMI) >50 kg/m2, forced expiratory volume (FEV1) <80% predicted, previous abdominal surgeries, and abnormal EKG were found to be independently associated with an increased likelihood of complicated postoperative care. CONCLUSION: BMI >50 kg/m2, FEV1 <80% predicted, previous abdominal surgeries, and abnormal EKG increase the likelihood of complicated postoperative management after RYGB for morbid obesity.

Adult↗

PubMed2003

Yeast autolytic mutants potentially useful for sparkling wine production.

A selection method, based on a temperature-sensitive autolytic phenotype, has been used to genetically improve a second fermentation Saccharomyces cerevisiae yeast strain by UV mutagenesis. The mutations carried by the resulting strains affected cell morphology, growth kinetics, sporulation and the release of nitrogenous compounds in an accelerated autolysis experimental model. Their fermentation power was not severely impaired.

Fermentation↗

PubMed2003

Can current technology be integrated to facilitate laparoscopic living donor hepatectomy?

BACKGROUND: Living donor hepatectomy (LDH) is a technically demanding procedure that is an alternative for providing livers for transplantation. Unlike liver resections for other pathology, LDH requires preservation of the major vessels and biliary tree. This study was performed to determine if current technology can be integrated to perform laparoscopic LDH. METHODS: Six adult sheep underwent laparoscopic LDH of the left lateral segment under general anesthesia. Instruments utilized included standard dissecting instruments, ultrasound, ultrasonic dissectors, CUSA, the TissueLink Floating Ball, and endoscopic staplers. RESULTS: LDH-harvested liver grafts were 44% of whole liver weight. Estimated blood loss was 300 cc. Warm ischemia time was 5-7 min. Grafts were delivered through 18-cm abdominal wounds. Major vessels and biliary anatomy were positively identified in the grafts. CONCLUSIONS: Laparoscopic LDH can be performed with available technology. Theoretical advantages include reduced liver manipulation and smaller wound size.

Animals↗

PubMed2003

Should patients undergoing a bronchoscopy be sedated?

BACKGROUND: The techniques, drugs and depth of sedation for flexible fiberoptic bronchoscopy is controversial, and several reports consider that the routine use of sedation is not a prerequisite. We evaluate whether the addition of sedation with propofol improves patient tolerance, compared to local anesthesic of the airway only. METHODS: Eighteen patients with pneumonia undergoing flexible fiberoptic bronchoscopy were included in a randomized, single blind, prospective controlled study. The non-sedation group received airway topical anesthesia, whereas the sedation group received topical anesthesia and intravenous sedation with propofol. The degree of pain, cough, sensation of asphyxiation, degree of amnesia, global tolerance and acceptance of another bronchoscopy in the future were noted. Changes in blood pressure, heart rate and saturation of oxygen by pulse oximetry were also evaluated. RESULTS: The patients in sedation group had less cough (P < 0.05), pain (P < 0.01) and sensation of asphyxiation (P < 0.001). Global tolerance to the procedure was significantly better in the group under sedation (P < 0.01). These patients had total amnesia to the procedure (P < 0.0001), thus is more probable that will accept another bronchoscopy in the future (P < 0.01). There was a significant rise in heart rate and blood pressure in the patients without sedation. There were no differences in oxygen saturation (P = 0.75). CONCLUSIONS: Our results show that if we administer propofol for sedation, in addition to local anesthesia of the airway, the tolerance to the procedure is much better. Also it appears that sedation with propofol is safe if we carefully select and monitor the patient.

Adult↗

PubMed2003

Gamma-irradiation enhances transgene expression in leukemic cells.

The majority of immunotherapy-based gene therapy protocols consist of ex vivo gene transfer in tumor cells. To prevent further in vivo growth, modified cells must be irradiated before reinjection into patients. The present study examines the effects of gamma-irradiation on transgene expression in transduced leukemic cells. Human and murine leukemic cells were transfected with retroviral vectors or plasmids carrying beta-galactosidase, GM-CSF or CD80 genes. Fresh leukemic cells from patients with acute myeloid leukemia (AML) were transfected with AdZ.F(pK7) adenoviral vector. gamma-irradiation at various lethal doses enhanced transgene expression in leukemic cell lines and fresh AML cells when the gene of interest was under CMV promoter but not when SV40 promoter was used. Oxidative stress also enhanced transgene expression and both irradiation and oxidative stress effects were inhibited by addition of N-acetyl-L-cysteine, a thiol anti-oxidant, indicating the involvement of reactive oxygen species. Transgene expression was also enhanced in vivo 48 and 120 h after subcutaneous injection of irradiated leukemic cells in syngeneic mice. These results show that a cell vaccine protocol using ex vivo gene transfer of transduced cells might be feasible in acute leukemia even if leukemic cells must be irradiated at lethal doses prior to reinjection to patients.

Acute Disease↗

PubMed2003

Amniotic fluid levels of immunoreactive monocyte chemotactic protein-1 increase during term parturition.

OBJECTIVE: Parturition is characterized by an influx of inflammatory cells into gestational tissues, a phenomenon conducive to increased myometrial contractility, cervical ripening and decidual/membrane activation. Monocyte chemotactic protein-1 (MCP-1), a potent chemoattractant and activator of monocytes/macrophages, is expressed in gestational tissues and, thus, may participate in the final common pathway of labor. This study was undertaken to determine whether the amniotic fluid concentrations of immunoreactive MCP-1 are altered with gestational age or spontaneous labor at term with and without prelabor rupture of the gestational membranes. We also sought to identify intrapartum differences in the concentrations of immunoreactive MCP-1 between the upper and lower amniotic fluid compartments. METHODS: A cross-sectional study was conducted to assess the concentrations of immunoreactive MCP-1 in amniotic fluid. Amniotic fluid samples were obtained from 225 women as follows: (1) women undergoing mid-trimester (14-18 weeks of gestation) amniocentesis for genetic indications, whose pregnancy outcome was normal (n = 84); (2) women in labor (n = 52) and not in labor (n = 31) at term, with intact gestational membranes; (3) women with rupture of the gestational membranes in labor (n = 18) and not in labor (n = 26), at term; and (4) women in labor at term for whom paired amniotic fluid samples were obtained through transvaginal and transabdominal amniocenteses (n = 14). Immunoreactive MCP-1 was assessed with a specific and sensitive immunoassay that had been validated for amniotic fluid. Non-parametric statistics were used for analysis. RESULTS: Immunoreactive MCP-1 was detected in all amniotic fluid samples. Spontaneous human parturition was associated with a significant increase in the amniotic fluid concentrations of immunoreactive MCP-1 (not in labor: median 595 pg/ml, range 183-3579 pg/ml vs. in labor: median 862 pg/ml, range 183-9609 pg/ml; p = 0.01). The median amniotic fluid concentrations of immunoreactive MCP-1 were significantly higher in the lower amniotic fluid compartment than in the upper amniotic fluid compartment (lower compartment: median 2913 pg/ml, range 1360-17080 pg/ml vs. upper compartment: median 1603 pg/ml, range 1070-8062 pg/ml; p = 0.004.). Spontaneous rupture of the gestational membranes at term was not associated with a significant change in the amniotic fluid concentrations of immunoreactive MCP-1. CONCLUSIONS: Immunoreactive MCP-1 is a physiological constituent of the amniotic fluid. The amniotic fluid levels of immunoreactive MCP-1 increase during spontaneous labor at term. A topographic difference in the concentration of immunoreactive MCP-1 was observed in the amniotic cavity, with higher concentrations being noted in the lower amniotic fluid compartment, as compared with the upper amniotic fluid compartment. These findings support the hypothesis that MCP-1 may play a role in the final common pathway of spontaneous labor.

Adolescent↗