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J Lopez

Publications and source records attributed to J Lopez.

At least 37 records · Page 2Linked to original sources
PubMed2000

Comparative genotyping of Candida albicans bloodstream and nonbloodstream isolates at a polymorphic microsatellite locus.

Molecular typing studies have shown that the predominant form of reproduction of Candida albicans is clonal and that, in a majority of situations, persistent or recurrent infections are due to a unique strain. Characterization of distinct subpopulations and correlation with clinical features may thus be important to understanding the pathogenesis of candidiasis. In a clonal model, a unique polymorphic marker may identify populations with different biological properties. We therefore compared 48 bloodstream isolates and 48 nonbloodstream matched strains of C. albicans at the elongation factor 3-encoding gene (CEF3) polymorphic microsatellite locus of C. albicans. Sizing of the alleles was performed by automated capillary electrophoresis. A new, 137-bp allele was characterized, and seven nondescribed combinations were observed, resulting in 15 and 11 distinct CEF3 profiles in bloodstream and control strains, respectively. Genotypes 126-135, 130-136, and 131-131 accounted for 60.4% of both bloodstream and control strains. Four bloodstream isolates but no control strains displayed the 135-135 combination. None of the other genotypes was present at an increased frequency in bloodstream isolates. Bloodstream and nonbloodstream strains of C. albicans thus have a heterogeneous structure at the CEF3 locus, with three major and multiple minor allelic combinations.

Alleles↗
PubMed1999

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Journal Article↗
PubMed1999

Immunodetection of the microvillous cytoskeleton molecules villin and ezrin in the parasitophorous vacuole wall of Cryptosporidium parvum (Protozoa: Apicomplexa).

Microvilli - actin - villin - ezrin - Cryptosporidium parvum The sporozoites and merozoites of the Apicomplexan protozoan Cryptosporidium parvum (C. parvum) invade the apical side of enterocytes and induce the formation of a parasitophorous vacuole which stays in the brush border area and disturbs the distribution of microvilli. The vacuole is separated from the apical cytoplasm of the cell by an electron-dense layer of undetermined composition. In order to characterize the enterocyte cytoskeleton changes that occur during C. parvum invasion and development, we used both confocal immunofluorescence and immunoelectron microscopy to examine at the C.parvum-enterocyte interface the distribution of three components of the microvillous skeleton, actin, villin and ezrin. In infected cells, rhodamine-phalloidin and anti-villin and anti-ezrin antibodies recognized ring-like structures surrounding the developing parasites. By immunoelectron microscopy, both villin and ezrin were detected in the parasitophorous vacuole wall surrounding the luminal and lateral sides of the intracellular parasite. In contrast, anti-beta and anti-gamma actin antibodies showed no significant labelling of the vacuolar wall. These observations indicate that the parasitophorous vacuole wall contains at least two microvillus-derived components, villin and ezrin, as well as a low amount of F-actin. These data suggest that C.parvum infection induces a rearrangement of cytoskeleton molecules at the apical pole of the host cell that are used to build the parasitophorous vacuole.

Actins↗
PubMed1999

Prospective analysis of complications 30 days after outpatient colonoscopy.

BACKGROUND: Our objective was to (1) determine whether more complications are reported by patients 30 days after outpatient colonoscopy than are discussed at our monthly morbidity and mortality conferences, (2) identify complications resulting in visits to the emergency department or physician's office or leading to hospitalization, and (3) assess which factors put patients at highest risk. A secondary goal was to determine the rate of work lost after outpatient colonoscopy. METHODS: Trained interviewers performed standardized telephone interviews of consecutive outpatients undergoing colonoscopy at Georgetown University Hospital over a 1-year period. RESULTS: One thousand one hundred ninety-six patients were contacted 30 days after outpatient colonoscopy and participated in our study. Twenty patients had complications that required a visit to an emergency department or physician. Ninety percent of these cases (18) were detected at 30 days, but 15% (3) were discussed at morbidity and mortality conferences. All seven complications that necessitated hospitalization were identified at 30 days, but only two were discussed at our morbidity and mortality conference. The most common complications reported by patients were abdominal discomfort (5.4%) and rectal bleeding (2.1%). CONCLUSION: More complications are detected by means of contacting patients 30 days after outpatient colonoscopy than are discussed at our morbidity and mortality conferences.

Abdominal Pain↗
PubMed1999

Synchronous laparoscopic vasectomy and hernia repair.

Over the last few years, general surgery has seen the use of more and more laparoscopic techniques in the management of common surgical problems. This expanded use is attributable not only to the excellent results seen with laparoscopic procedures but also to patient demand. A 48-year-old man requested a laparoscopic hernia repair with synchronous vasectomy. The technique of synchronous laparoscopic hernia repair and vasectomy is discussed, and a literature review is provided. Certain disadvantages along with the difficulty in reanastomosis after a laparoscopic vasectomy will prevent the replacement of traditional vasectomy with the laparoscopic technique.

Hernia, Inguinal↗
PubMed1999

Prospective analysis of complications 30 days after outpatient upper endoscopy.

OBJECTIVE: The aim of this study was to compare complication rates reported by patients 30 days after outpatient upper endoscopy with those discussed at our monthly morbidity and mortality conference. We also intended to establish which complications were reported most frequently 30 days after upper endoscopy, and which patients or procedures involved the highest risk. METHODS: Trained interviewers performed standardized telephone interviews on consecutive outpatients undergoing upper endoscopy over a 1-yr period. Patients were queried regarding potential events related to their upper endoscopy in the 30 days subsequent, including symptoms, emergency room (ER) and/or physician visits, and hospitalizations. The indications, findings, and therapies were reviewed from endoscopic reports. RESULTS: A total of 473 patients were contacted 30 days after outpatient upper endoscopy and agreed to participate in our study. The most common complications reported by patients at 30 days were sore throat (9.5%) and abdominal discomfort (5.3%). Twelve patients (2.5%) required an ER/physician visit and five patients (1.1%) required hospitalization. The minority of both ER/physician visits (16.7%) and hospitalizations (40%) were discussed at our monthly morbidity and mortality conferences. CONCLUSIONS: More complications were reported by patients 30 days after outpatient upper endoscopy than were discussed at our monthly morbidity and mortality conferences. The most frequent complications reported by patients were sore throat and abdominal pain. The minority of ER/physician visits and hospitalizations were discussed at our morbidity and mortality conferences.

Abdominal Pain↗
PubMed1999

The impact of delaying gastric emptying by either meal substrate or drug on the [13C]-urea breath test.

OBJECTIVE: Optimal [13C]-urea breath test (UBT) conditions for diagnosis of Helicobacter pylori infection are still being fine-tuned. In the present study we investigated the impact of delaying gastric emptying by different meal substrates or L-DOPA, a drug known to induce gastric stasis, on the performance of the [13C]-UBT. METHODS: A total of 115 patients participated in the study. On two consecutive days, participants ingested [13C]-urea (100 mg) 10 min after either 270 ml of a mixed formula meal (1 Kcal/ml) or an equivalent amount of tap water. In 11 participants two additional tests were performed with or without oral 500 mg L-DOPA given 30 min before [13C]-urea load. The 13C/12C ratio in a basal breath sample was compared with ratios in samples collected 30 and 60 min after [13C]-urea. Histological assessment of H. pylori presence in antral biopsy served as reference standard. RESULTS: Formula UBT showed excellent specificity (100% at 30 and 60 min) and good sensitivity (97% at both time intervals), whereas water UBT had the same specificity but slightly lower sensitivity (94% at 30 min and 73% at 60 min). In formula UBT, 13C/12C ratios were higher at 60 min than at 30 min (21.7+/-2 vs 17.7+/-1.8 per thousand respectively, p < 0.01, whereas in water UBT 13C/12C ratios were higher at 30 min than at 60 min (13.9+/-1.5 vs 8.4+/-0.09 per thousand respectively, p < 0.01). Pretreatment with L-DOPA did not modify either the sensitivity or the specificity of the UBT. CONCLUSIONS: The performance of the [13C]-urea with a formula meal may not be improved by pharmacologically delaying gastric emptying. A short, water-based test may be a sensible approach to worldwide standardization of the [13C]-UBT for H. pylori infection.

Adult↗
PubMed1999

Safety and efficacy of metformin in a restricted formulary.

OBJECTIVE: To assess the efficacy and safety of metformin (MET) in the Veterans' Administration Northern California Health Care System during the period from June 1995 through April 1996 when its use required approval by Endocrinology. STUDY DESIGN: A retrospective review of patient charts and computerized pharmacy and laboratory records. Patients served as their own historical controls. PATIENTS AND METHODS: Patients receiving MET (n = 251) were identified from the pharmacy database. On-line laboratory data, including the intermediate outcome variable HbA1c, were retrieved by computer for the interval 4 months prior to the initial prescription to May 1996. Clinical data including weight and blood pressure were obtained from chart review. RESULTS: Of 228 patients whose charts were available for review, 29 reported side effects, and 12 discontinued use due to these side effects. No patients were identified with lactic acidosis. Both baseline and treatment data on HbA1c were available on 164 patients. Mean HbA1c (%) data (unpaired), expressed as mean +/- SE, were as follows: between 4 months pretreatment and 1 month pretreatment, 9.41 +/- 0.19 (n = 103 tests); between 1 month pretreatment and baseline, 9.41 +/- 0.19 (n = 110 tests); 3 months of treatment, 8.79 +/- 0.16 (n = 157 tests, P < 0.05); 6 months of treatment, 8.30 +/- 0.17 (n = 79 tests, P < 0.0001); 9 months of treatment, 8.72 +/- 0.24 (n = 70 tests, P < 0.05), compared to pretreatment values. Similar analysis of unpaired weight and blood pressure data in 152 patients did not reveal any reduction in these clinical parameters over this treatment period. Serum lipids were unchanged on treatment (by paired analysis), but the number of tests was limited. CONCLUSION: In this setting, MET provided sustained beneficial effects on glycemic control and was well tolerated. Any effects on weight, blood pressure, and serum lipids were not demonstrable in this analysis. We conclude that MET can substantially improve outcome of diabetes care.

Blood Pressure↗
PubMed1999

The superior colliculus, a neuronal network resistant to the Gaba withdrawal syndrome.

Chronic intracortical perfusion of GABA (Gamma Amino Butyric Acid) and its subsequent withdrawal generates the GABA withdrawal syndrome (GWS). This particular epileptic model has been observed in the motor cortex of monkeys and rats. Our purpose was to study the GWS in the motor cortex (MC), dorsal hippocampus (DH), and superior colliculus (SC). Thirty chronically-implanted adult Wistar rats were separated into 3 groups of 10 (8 experimental and 2 controls). The first group received GABA in MC, the second in the DH and the third in the SC. GABA was released in doses of 10 to 60 micrograms/microliter/h for 6 days employing osmotic mini-pumps. Two control rats per group received saline solution in the above-mentioned structures. Rats perfused in the MC showed GWS after interruption of the GABA flow. The group perfused in the DH showed paroxysmal discharges and epileptic seizures during perfusion. They also later showed GWS. No epileptic effects were observed in the SC-perfused group during either the GABA perfusion or during withdrawal. None of the six control animals showed epileptic effects. Our results show that the SC offers a strong resistance to GWS. This could be explained by the particular neuronal network structure of rat SC.

Animals↗
PubMed1998

Directional coronary atherectomy for the treatment of Palmaz-Schatz in-stent restenosis.

Management of in-stent restenosis has become a significant challenge in interventional cardiology. The results of balloon angioplasty have been disappointing due to the high recurrence of restenosis at follow-up. Debulking of the restenotic tissue within the stents using directional coronary atherectomy (DCA) may offer a therapeutic advantage. We report the immediate clinical and angiographic outcomes and long-term clinical follow-up results of 45 patients (46 lesions), mean age 63+/-12 years, 73% men, with a mean reference diameter of 2.9+/-0.6 mm, treated with DCA for symptomatic Palmaz-Schatz in-stent restenosis. DCA was performed successfully in all 46 lesions and resulted in a postprocedural minimal luminal diameter of 2.7+/-0.7 mm and a residual diameter stenosis of 17+/-10%. There were no in-hospital deaths, Q-wave myocardial infarctions, or emergency coronary artery bypass surgeries. Four patients (9%) suffered a non-Q-wave myocardial infarction. Target lesion revascularization was 28.3% at a mean follow-up of 10+/-4.6 months. Kaplan-Meier event-free survival (freedom from death, myocardial infarction, and repeat target lesion revascularization) was 71.2% and 64.7% at 6 and 12 months after DCA, respectively. Thus, DCA is safe and efficacious for the treatment of Palmaz-Schatz in-stent restenosis. It results in a large postprocedural minimal luminal diameter and a low rate of both target lesion revascularization and combined major clinical events at follow-up.

Angioplasty, Balloon↗
PubMed1998

Migration, ethnicity and environment: HIV risk factors for women on the sugar cane plantations of the Dominican Republic.

OBJECTIVE: To determine risk factors for HIV infection among women living in the sugar cane plantation communities (bateyes) of a large private sugar cane company in the Dominican Republic. DESIGN: Cross-sectional study of sexually active female volunteers living in the bateyes. METHODS: Of 98 bateyes, 23 were randomly selected and visited by a mobile medical unit, to interview, examine and test volunteers for seroreactivity to HIV and syphilis. RESULTS: The 490 subjects ranged in age from 16 to 72 years (median, 37 years); 53% were born in Haiti, 36% in Dominican Republic bateyes, and 12% elsewhere in the Dominican Republic; 58% had no formal education; and 87% had no income. HIV seropositivity was found in 28 women (5.7%), including 8.8% of those aged < 35 years. By logistic regression analysis, HIV infection was independently associated with age < 35 years [odds ratio (OR), 4.5; P < 0.01), being single with children (OR, 4.3; P < 0.01), more than one lifetime sex partners (OR, 3.4; P = 0.06), engaging in sex during menses (OR, 3.2; P = 0.02), and self-description as a prostitute (OR, 4.4; P = 0.05)1. For Haitian women, those coming to the Dominican Republic alone were more likely to have HIV infection than those coming with a male partner. Less than 4% of women reported condom use at last intercourse. CONCLUSIONS: Women in the bateyes have a much higher rate of HIV infection than that estimated for women in the general population of Dominican Republic and a rate comparable to that of female sex workers in the Dominican Republic. AIDS prevention in the bateyes should address condom education and distribution as well as employment opportunities and education for women.

Adolescent↗
PubMed1998

Retroviral transfer and long-term expression of the adrenoleukodystrophy gene in human CD34+ cells.

Adrenoleukodystrophy (ALD) is a demyelinating disease of the central nervous system that results from a genetic deficiency of ALDP, an ABC protein involved in the transport of very long-chain fatty acids (VLCFAs). The cloning of the ALD gene and the positive effects of allogeneic bone marrow transplantation support the feasibility of a gene therapy approach. We report the retroviral transfer of the ALD cDNA to peripheral blood and bone marrow CD34+ cells from control donors and ALD patients. Prestimulation of these cells with cytokines, followed by infection with the M48-ALD retroviral vector, resulted in 20% transduction efficiency (4-40%) and expression of the vector-encoded ALDP in 20% of CD34+ cells (7.3-50%). Long-term culture (LTC) of transduced CD34+ cells from two ALD patients showed efficient transduction (24-28%) and stable expression (25-32%) of ALDP in derived clonogenic progenitors at 3 weeks of culture. The expression of ALDP in CFU cells derived from 5 and 6 weeks of LTC confirmed the effective transduction of LTC-initiating cells. Expression of ALDP was observed in CD68+ CFU-derived cells, suggesting that monocyte-macrophages, the target bone marrow cells in ALD, were produced from transduced progenitor cells. VL-CFA content was corrected in LTC and CFU-derived cells in proportion to the percentage of transduced cells, indicating that the vector-encoded ALDP was functional. Although not efficient yet to allow a clinical perspective, these results demonstrate the feasibility of ALD gene transfer into CD34+ cells of ALD patients.

3T3 Cells↗
PubMed1998

Comparison of primary coronary stenting to primary balloon angioplasty with stent bailout for the treatment of patients with acute myocardial infarction.

This study compares the immediate and long-term outcomes of a primary coronary stenting strategy with primary balloon angioplasty with stent bailout in the treatment of patients with acute myocardial infarction (AMI). One hundred forty-seven consecutive patients who underwent primary balloon angioplasty with stent bailout (n = 94) or primary stenting (n = 53) for AMI were clinically followed for 8.1 +/- 5.7 and 8.5 +/- 4.5 months, respectively. Immediate results, as well as in-hospital and long-term ischemic events (death, reinfarction, and repeat revascularization) were compared between both groups. Angiographic success was 91.5% in the balloon angioplasty group and 94% in the stent group. In-hospital and late follow-up combined ischemic events were 22 of 94 (23%) versus 0 of 53 (0%); p < 0.001 and 33 of 78 (42%) versus 13 of 53 (25%), p = 0.04 for the balloon angioplasty and stent groups, respectively. At 6 months, the cumulative probability of repeat target lesion revascularization was higher in the balloon angioplasty group (47% vs 18%, p = 0.0006) as was the probability of late target revascularization (36% vs 18%, p = 0.046); the cumulative event-free survival after 6 months was significantly lower in the balloon angioplasty group (44% vs 80%, p = 0.0001). This study demonstrates that a primary stent placement strategy in patients with AMI is safe, feasible, and superior to primary balloon angioplasty with stent bailout. Primary stenting results in a larger postprocedural minimal luminal diameter, a lower early and late recurrent ischemic event rate, and a lower incidence of target lesion revascularization at follow-up.

Angioplasty, Balloon, Coronary↗
PubMed1998

Pharmacologic treatment of hypertension in the Department of Veterans Affairs during 1995 and 1996.

Patterns of antihypertensive drug use, the cost of this care and potential savings with changes of treatment patterns, were studied for all hypertensives treated at US Veterans Affairs (VA) medical facilities for fiscal years 1995 and 1996. Data was aggregated by individual medication as well as by antihypertensive drug class. Cost estimates were based on median cost and number of units for each dosage form of each medication dispensed at all facilities. Potential savings were estimated by substituting beta-blockers or diuretics for calcium antagonists. In a subset of patients the prevalence of hypertension, and among hypertensives the prevalence of coronary artery disease, congestive heart failure, and diabetes mellitus, was determined. For these patients, patterns of treatment by antihypertensive drug class was examined. For all VA facilities, of the 10 most frequently prescribed antihypertensives in 1995, four were calcium antagonists, two angiotensin converting enzyme (ACE) inhibitors, two beta-blockers, and two diuretics. In 1996, this was changed by the addition of an ACE inhibitor and the subtraction of a diuretic combination. Calcium antagonists accounted for 37% of treatment days in 1995 and 35% in 1996, ACE inhibitor use went from 34% to 36%, beta-blockers from 17% to 18%, and diuretic use remained at 12%. In 1996, approximately 86.6 million dollars were spent on calcium antagonists, 51.8 million on ACE inhibitors, 7.9 million on beta-blockers, and 3.6 million on diuretics. The estimated annual cost savings for each 1% conversion of calcium antagonists to beta-blockers would be $713,000 and to diuretics $758,000. In a subset of 7526 hypertensive patients with known comorbid conditions, calcium antagonists and ACE inhibitors were also the most commonly used drug classes for all categories of patients, including those without coronary artery disease, congestive heart failure, and diabetes mellitus. Calcium antagonists and ACE inhibitors were the most commonly dispensed antihypertensives at VA facilities for both 1995 and 1996, with a small decrease in calcium antagonist use from 1995 to 1996. The cost implications of these practice patterns as compared with the primary use of diuretics and beta-blockers are enormous.

Adrenergic beta-Antagonists↗
PubMed1998

Microinvasive laparoscopic cholecystectomy in pediatric patients.

Although cholelithiasis is uncommon in children, its laparoscopic treatment has progressively become more popular among pediatric surgeons. This is due in part to the fact that compared with the open technique, laparoscopic treatment is less invasive as well as more cost-effective. A review of the literature indicates that it has been customary to use at least one 10-mm port to permit application of the 10-mm endoscopic clip applier for ligation of the cystic duct and artery. We report our experience with two patients in whom a laparoscopic cholecystectomy was performed by use of a 5-mm endoscopic clip applier and a 3-mm laparoscope. The application of a 5-mm clip applier obviated the need for a 10-mm port. It also saved an additional step by eliminating the exchange from the laparoscope to the 10-mm endoscopic clip applier through the 10-mm port. Furthermore, the use of a 3-mm telescope through the smallest port (<5 mm) would achieve a better cosmetic outcome.

Child↗
PubMed1998

Syringocystadenoma papilliferum of the male breast.

A 39-year-old man presented with a 2-cm, mildly tender mass in the right breast of many years' duration. Microscopic examination showed a syringocystadenoma papilliferum. Because of its location in the breast, we studied the lesion for immunohistochemical markers for apocrine differentiation. Gross cystic disease fluid protein-15 (GCDFP-15) staining yielded negative results in the cystic luminal epithelial cells, whereas GCDFP-15 and lysozyme staining yielded strongly positive results in the epithelial cells of adjacent tubular apocrine glands. Focal strong lysozyme positivity was seen in the cystic luminal epithelial cells. These findings do not support apocrine differentiation in this case, despite its location in the breast, an organ rich in specialized apocrine (lactiferous) glands. To our knowledge, this represents the first reported case of syringocystadenoma papilliferum of the male breast. We present the clinical and pathologic features of this unusual case and a review of the literature.

Adenoma, Sweat Gland↗