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Biomedical subjects

F Garcia

Publications and source records attributed to F Garcia.

At least 109 records · Page 6Linked to original sources
PubMed1995

Evaluation of enzyme immunoassay for hepatitis B virus DNA based on anti-double-stranded DNA.

We have evaluated a new enzyme immunoassay technology to detect the products of PCR-based amplification that may be applicable to routine testing of hepatitis B virus (HBV) DNA. Two hundred eight serum samples were studied: 73 were basal samples and 135 were sequential serum samples from patients with chronic hepatitis, some of whom were being treated with alpha interferon. We compared the new detection method (PCR-DNA enzyme immunoassay [DEIA]) with dot blot hybridization performed without prior PCR amplification and with two other methods for detection of PCR products: agarose gel electrophoresis with ethidium bromide staining (PCR-EB) and dot blot (PCR-dot blot). For hepatitis B-antigen-positive basal samples, HBV DNA was detected in 70.4% by dot blot, 74.1% by PCR-EB, and 100% by PCR-DEIA and PCR-dot blot; for anti-hepatitis B e-antigen basal samples, HBV DNA was found in 10.5% by dot blot and PCR-EB and in 42.1% by PCR-DEIA and PCR-dot blot. Chi-square tests showed a strong association between dot blot and PCR-EB and between PCR-DEIA and PCR dot blot. Using PCR-dot blot as the reference, dot blot shows a 56.9% sensitivity and a 100% specificity, PCR-EB shows a 55.0% sensitivity and a 100% specificity, and PCR-DEIA shows a 95.4% sensitivity and a 97% specificity. We conclude that the technical advantages of the DEIA method and its high sensitivity and specificity may facilitate the use of PCR in routine testing for HBV DNA in clinical microbiology laboratories.

Base Sequence↗
PubMed1995

The National Drug Control Strategy: the first-line approach to decreasing violence in our communities.

The National Drug Control Strategy is designed to address all aspects of drug abuse: drug use, drug trafficking, and drug-related crimes. The nine-pronged program encompasses efforts at the federal, state, and local levels, forming a partnership between government and the private and public sectors. The strategy includes prevention initiatives that reduce the demand for drugs; individualized treatment programs for high-risk groups; greater community policing efforts to reduce violent crimes by drug users and pushers; and education aimed at children and adults. It is a national strategy that strives to find solutions at the local level.

Adolescent↗
PubMed1994

Selection for transport competence of C-terminal polypeptides derived from Escherichia coli hemolysin: the shortest peptide capable of autonomous HlyB/HlyD-dependent secretion comprises the C-terminal 62 amino acids of HlyA.

Escherichia coli hemolysin (HlyA) is secreted by a specific export machinery which recognizes a topogenic secretion signal located at the C-terminal end of HlyA. This signal sequence has been variously defined as comprising from 27 to about 300 amino acids at the C-terminus of HlyA. We have used here a combined genetic and immunological approach to select for C-terminal HlyA peptides that are still secretion-component. A deletion library of HlyA mutant proteins was generated in vitro by successive degradation of hylA from the 5' end with exonuclease III. Secretion competence was tested by immunoblotting of the supernatant of each clone with an antiserum raised against a C-terminal portion of hemolysin. It was found that the hemolysin secretion system has no apparent size limitation for HlyA proteins over a range from 1024 to 62 amino acids. The smallest autonomously secretable peptide isolated in this selection procedure consists of the C-terminal 62 amino acids of HlyA. This sequence is shared by all secretion-competent, truncated HlyA proteins, which suggests that secretion of the E. coli hemolysin is strictly post-translational. The capacity of the hemolysin secretion machinery was found to be unsaturated by the steady-state level of its natural HlyA substrate and large amounts of truncated HlyA derivatives could still be secreted in addition to full-length HlyA.

Antibodies, Bacterial↗
PubMed1994

Epidemiology of hepatitis C virus infection in patients with renal disease.

This study was carried out to determine the prevalence of hepatitis C virus (HCV) antibodies and the epidemiologic factors associated with HCV infection in patients with chronic renal failure before the onset of ESRD. Sex, age, type of renal disease, level of renal function, and history of blood transfusions and invasive procedures were analyzed in 226 patients with renal disease, compared with a population of 1,244 normal subjects and 124 patients with impaired immunity (patients having autoimmune diseases and receiving chemotherapy treatment). Eighteen seropositive patients with renal disease (prevalence, 7.9%) were found, which was significantly higher than the prevalence in the normal population (1.03% in blood donors, 0.98% in pregnant women; P < 0.001, chi 2). There was no significant association of sex, number of blood transfusions, or history of invasive procedures with the presence of HCV antibodies. The prevalence of HCV antibodies was higher (16.6%) in patients with glomerulonephritis compared with patients diagnosed with interstitial nephritis, pyelonephritis, nephrosclerosis, diabetes mellitus, polycystic kidney, and miscellaneous renal diseases (P < 0.01, chi 2). There was a higher prevalence of HCV antibodies in patients with creatinine clearance lower than 30 mL/min (13%) compared with patients with creatinine clearance higher than 30 mL/min (2.7%) (P < 0.01, chi 2). These data suggest that HCV infection may be associated with the pathogenesis of glomerulonephritis. Alternatively, glomerulonephritis or severe renal insufficiency may increase the likelihood of HCV infection.

Adult↗
PubMed1994

Critical evaluation of the present experience on microsurgical sperm aspiration.

Microsurgical epididymal sperm aspiration (MESA) and IVF techniques are indicated in those cases of bilateral congenital absence of the vas deferens (BCAVD) and in cases of epididymal obstruction (EO) of other aetiologies were vasoepididymostomy is not possible or has failed. Microsurgical deferential sperm aspiration (MDSA) is indicated in those cases where spermatogenesis and epididymal permeability are conserved but spermatozoa, for different causes, cannot reach the ejaculate and other therapies have failed. We have performed this procedure in 70 patients by two different human reproduction teams. Both teams achieved very similar results regarding fertilization rate: 5.5 and 7.2% in cases of BCAVD, 6.5 and 8.8% in cases of EO and 33.3 and 26.7% in cases of non-epididymal pathology (NEP). However, the fertilization rate per patient presents differences between both teams: 27 and 44.4% in BCAVD, 31 and 11% in EO and 80 and 100% in NEP. In spite of a better fertilization rate per patient in team two, it was in the other where pregnancies were achieved (7% in BCAVD, 15% in EO and 20% in NEP). One pregnancy in EO group was achieved by intracytoplasmatic sperm injection. The pregnancy rates per transfer were 25% in BCAVD, 50% in EO and 25% in NEP.

Epididymis↗
PubMed1994

Radiopharmacological evaluation in dogs of a new renal function agent.

The hydrophilic penta-anionic complex [Technetium (Carboxymethylisocyanide)6]-5, [Tc(CNCH2COO-)6]-5 (Tc-CAMI) was synthesized to evaluate its potential as a renal function imaging agent. The compound contains six distally arranged carboxyl groups that can act as substrates for the organic acid receptor of the renal cell to effect tubular secretion of this agent. Dynamic gamma-camera imaging of 99mTc-CAMI was performed in normal dogs to compare its bio-distribution and pharmacokinetics with those of proven tubular secretion (99mTc-MAG3) and globular filtration (99mTc-DTPA) agents. The relative difference between the observed mean renal transit times (MRTT) of 99mTc-CAMI and 99mTc-MAG3 was 0.15 compared with 1.24 for 99mTc-CAMI and 99mTc-DTPA. Pathological models of obstructive uropathy, renal arterial stenosis and renal denervation were produced in the same animals to demonstrate the diagnostic potential of the agent. These experiments and data showing that probenecid competes with 99mTc-CAMI for renal transport indicate that this compound functions as a tubular secretion agent and may be useful for monitoring renal function in various disease states.

Animals↗
PubMed1993

Endoscopic ligation compared with sclerotherapy for the treatment of bleeding esophageal varices.

OBJECTIVE: Comparison of the safety and efficacy of endoscopic sclerotherapy and ligation for the treatment of bleeding esophageal varices. DESIGN: Randomized, controlled trial. SETTING: An urban county hospital. PATIENTS: Patients with clinically severe bleeding from esophageal varices. INTERVENTION: A total of 77 patients were randomly assigned to receive sclerotherapy or ligation at the initial endoscopic examination. Treatment was repeated weekly until variceal obliteration was achieved. After eradication, patients had endoscopic examinations every 3 months or for any episode of rebleeding. Recurrent varices were treated with the originally assigned form of endoscopic therapy. MEASUREMENTS: Patients were assessed for further bleeding, for transfusion requirements, for time in hospital, for variceal eradication, for number of treatment sessions required, for complications, for treatment failure, and for risk of death. RESULTS: Rebleeding tended to be less frequent with ligation than with sclerotherapy: 10 of 38 (26%) compared with 17 of 39 (44%) (difference, 17% [95 CI, -4% to 38%]), but results in the two groups were comparable for blood transfusions, for length of hospital stay, and for risk of death. Comparison of Kaplan-Meier estimates of time to rebleeding and death showed no statistical differences between treatments. Complications were less common in the ligation group: fewer patients in the ligation group had esophageal strictures (0 of 38 compared with 13 of 39 [33%]; P < 0.001) and had complicated esophageal ulcers (1 of 38 [2.6%] compared with 6 of 39 [15%]; P = 0.11). In addition, fewer ligation treatments were required to achieve variceal eradication (4.1 +/- 0.3 compared with 6.2 +/- 0.4; P < 0.001). CONCLUSION: Endoscopic ligation causes statistically fewer local complications than sclerotherapy and achieves variceal eradication more rapidly. Ligation is a viable alternative to sclerotherapy and may have some advantages as a treatment for bleeding esophageal varices.

Adult↗
PubMed1993

Biomarker and cytologic abnormalities in women at high and low risk for breast cancer.

Fine needle aspirates (FNA) from 106 high-risk women and 25 low-risk women were evaluated for overexpression of estrogen receptor (ER), epidermal growth factor receptor (EGFR), mutant p53, and HER-2/neu by immunocytochemistry, and for aneuploidy by image analysis. Aspirates were also classified cytologically as normal, apocrine metaplasia, epithelial hyperplasia (EH), or dysplasia. High-risk women were those with a first-degree relative with breast cancer (76%), precancerous breast disease (26%), prior cancer of the contralateral breast (9%), or multiple abnormalities (11%). Low-risk women had none of the above risk factors, nor a prior breast biopsy or clinical evidence of fibrocystic disease. The median 10-year Gail risk for the high-risk group was 4%, compared to 0.7% for the low-risk group. There were significant differences (p < 0.01) between high- and low-risk women in the prevalences of hyperplasia (55% versus 12%), dysplasia (19% versus 0%), aneuploidy (32% versus 0%), overexpressed EGFR (32% versus 4%), and overexpressed p53 (29% versus 4%). The prevalence of multiple biomarker abnormalities was also greater in high-risk than in low-risk women (28% versus 0%; p < 0.01). Four percent (4%) of FNAs from high-risk women with normal cytology, 29% of aspirates with hyperplastic cytology, and 60% of those with dysplasia were associated with two or more biomarker abnormalities. The differences in the prevalence of multiple biomarker abnormalities among various cytologic categories were statistically significant (p = 0.02, normal versus EH; p = 0.02, EH versus dysplasia; p < 0.01, normal versus dysplasia).(ABSTRACT TRUNCATED AT 250 WORDS)

Biomarkers, Tumor↗
PubMed1993

Mutant p53 expression in prostate carcinoma.

The expression of the mutant p53 tumor suppressor gene was evaluated in 33 human prostate carcinomas. Using an immunohistochemical method with monoclonal antibodies PAb 1801 and PAb 240, 26 (79%) tumors demonstrated positive immunostaining for mutant p53. Only areas of glandular tumor were positive, with adjacent stromal elements and areas of glandular hyperplasia being negative. The predominant staining pattern was cytoplasmic. This pattern may be related to p53 binding to certain heat shock proteins (HSP 72/73), as a monoclonal antibody to these proteins demonstrated a cytoplasmic location as well. These results demonstrate that abnormal p53 expression is a frequent event in prostate cancer.

Adenocarcinoma↗
PubMed1993

A butterfly vertebra or a wedge fracture?

Two patients, who had injuries to the dorsal spine with vertebral wedging, are described. In both a compression wedge fracture was diagnosed, but a careful study of the anteroposterior radiographs showed that the presumed injury was a butterfly vertebra. This rare congenital anomaly, which is usually without clinical significance, may be mistaken for a wedge fracture unless the anteroposterior view is correctly assessed.

Diagnosis, Differential↗
PubMed1993

Metabolic and structural changes in newly synthesized proteoglycans induced by implantation of a polyethylene sheet in the rabbit knee joint.

A sheet of polyethylene was surgically implanted in a rabbit right patello-femoral joint and changes in the structure and chemical composition of newly synthesized articular cartilage proteoglycans (PGs) were studied 1 month after surgery. The articular cartilage from implanted and sham-operated control knee joints was labeled in vitro with 3H-glycine and 35S-SO4 and then extracted with 4 M guanidinium chloride (GuHCl) solution. Labeled extracts were analyzed by dissociative CsCl gradient centrifugation and by Sepharose CL-2B column chromatography. The labeled glycosaminoglycan side chains were analyzed by Sephadex G-200 column chromatography and specific enzymatic digestions. Compared with sham-operation, the trochlear articular cartilage of operated joints incorporated more 35S-SO4 and 3H-glycine into newly synthesized PGs and proteins. It also synthesized a higher proportion of extractable, hydrodynamically large and high density 35S-PG monomers with increased proportion of molecules, able to interact with exogeneous hyaluronan (HA). The fibro-cartilagenous 'osteo-chondrophytic' spurs, compared with trochlear hyaline articular cartilages, incorporated less 35S-SO4 and 3H-glycine and synthesized less extractable high density 35S-PG monomers able to interact with exogenous HA. Their 35S-GAG side chains were more heterogeneous and segregated into three distinct peaks as shown by Sephadex G-200 column chromatography. The results of the present studies demonstrate that, in response to the implant, there was an increase in the biosynthetic capacity of chondrocytes which synthetized larger PG monomers able to interact wih HA.

Animals↗
PubMed1993

Pigmented villonodular synovitis of the knee in a patient with Paget's disease of the adjacent femoral bone.

A 49-year-old male patient, diagnosed as having Paget's disease involving the lumbar vertebrae and both femora, felt persistent pain and swelling in the left knee after trauma. A synovectomy was performed. Clinical and histological findings led to the diagnosis of pigmented villonodular synovitis of the knee joint. Only one previous case of this association has been reported. A common aetiology for both diseases is discussed, and traumatic factors should be considered in the aetiology of the association.

Femur↗
PubMed1993

Protein-losing enteropathy and hypoalbuminemia in AIDS.

OBJECTIVE: To assess the contribution of protein-losing enteropathy to AIDS-associated hypoalbuminemia. DESIGN: Prospective assessment of patients with AIDS. SETTING: An urban county hospital (Los Angeles & University of Southern California Medical Center. USA). PATIENTS: Four groups of patients with AIDS were studied: (1) patients with normal serum albumin (> or = 3.9 g/dl) and normal bowel habits; (2) patients with normal serum albumin and diarrhea (> or = four loose or watery stools per day for > or = 2 weeks); (3) patients with hypoalbuminemia (< or = 3.0 g/dl) and normal bowel habits; and (4) patients with hypoalbuminemia and diarrhea. MAIN OUTCOME MEASURE: Fecal alpha 1-antitrypsin concentration was used as a measure of protein loss in the gut. RESULTS: Patients with hypoalbuminemia had a significantly higher mean fecal alpha 1-antitrypsin concentration than those with normal albumin (10.8 +/- 3.0 mg/g dry stool versus 2.4 +/- 0.4 mg/g dry stool; P < or = 0.001). Although mean fecal alpha 1-antitrypsin concentrations were similar in patients with and without diarrhea in the normal albumin group, patients with hypoalbuminemia and diarrhea had significantly higher levels of fecal alpha 1-antitrypsin than those with hypoalbuminemia and normal bowel habits (17.3 +/- 5.8 mg/g dry stool versus 4.6 +/- 1.0 mg/g dry stool; P = 0.009). Twelve out of 36 (33%) patients with normal albumin had elevation of fecal alpha 1-antitrypsin compared with 33 (70%) of 47 patients with hypoalbuminemia (P < or = 0.001). Linear regression analysis showed a significant negative correlation between serum albumin and fecal alpha 1-antitrypsin concentration (r = -0.38; P < or = 0.001). Fecal alpha 1-antitrypsin was significantly higher in patients with mucosal disease visualized at upper endoscopy or flexible sigmoidoscopy than in those without gross abnormalities (13.5 +/- 5.8 mg/g dry stool versus 2.4 +/- 0.7 mg/g dry stool; P = 0.005). CONCLUSION: Protein-losing enteropathy is common in patients with AIDS and may contribute to the development of hypoalbuminemia in these patients.

AIDS-Related Opportunistic Infections↗
PubMed1993

Hyporeninemic normoaldosteronism in severe autonomic failure.

Sympathetic mechanisms play an important role in the acute regulation of renin release in humans. On the other hand, the effect of chronic sympathetic deprivation on the renin-aldosterone system has not been fully evaluated. We, therefore, studied 24 patients with severe autonomic failure due to pure autonomic failure (n = 14) or to multiple system atrophy (n = 10). Supine plasma renin activity (PRA) was low (0.09 +/- 0.01 ng/(L*s)) and remained virtually unchanged in the upright posture (0.10 +/- 0.01 ng/(L*s)) despite profound orthostatic hypotension to levels that should activate renal baroreceptors. Isoproterenol, at doses that produced significant tachycardia and hypotension, also failed to stimulate PRA. Furthermore, renin-producing cells were absent in the kidneys of two autopsy cases. Norepinephrine depletion alone could not explain these findings because no correlation was found between plasma norepinephrine and PRA, and because PRA was normal in patients with intact sympathetic innervation but congenital absence of norepinephrine. In contrast, supine and upright plasma aldosterone were normal in autonomic failure patients (220 +/- 20 and 440 +/- 70 pmol/L). We speculate that direct sympathetic innervation is essential for the maintenance of renin, perhaps by providing trophic stimuli.

Aged↗
PubMed1992

Localised alveolar-septal amyloidosis with hypersensitivity pneumonitis.

Localised alveolar-septal amyloidosis has been thought irreversible. A woman exposed to the dust of sea-snail shells during the manufacture of nacre buttons had clinical and immunological features typical of hypersensitivity pneumonitis; however, transbronchial lung biopsy showed alveolar-septal amyloidosis. There was no evidence of other diseases known to be associated with amyloidosis, nor were amyloid deposits found in other organs. After a year without exposure to the antigen there was no trace of either pneumonitis or amyloidosis.

Adult↗
PubMed1992

Prospective evaluation of immediate versus delayed refeeding and prognostic value of endoscopy in patients with upper gastrointestinal hemorrhage.

The effects of immediate vs. delayed refeeding and the prognostic value of endoscopic findings in patients with major upper gastrointestinal hemorrhage were assessed in a prospective randomized study. Entry criteria were clinical evidence of major hemorrhage and endoscopic evidence of a Mallory-Weiss tear or an ulcer with a clean base, flat spot, or clot. Two hundred fifty-eight patients were randomly assigned to groups receiving a regular diet immediately or nothing by mouth for 36 hours, then clear liquids for 12 hours, and a regular diet thereafter. Outcomes in the immediate and delayed refeeding groups were comparable: rebleeding occurred in 4% vs. 5%; urgent intervention, 2% vs. 2%; and deaths, 1% vs. 1%, respectively. Rebleeding occurred in 2 (2%) of 96 patients with cleanbased ulcers, 5 (8%) of 65 with ulcers with spots, 3 (14%) of 21 with ulcers with clots (P = 0.05, 3 x 2 chi2 test), and 1 (2%) of 66 with Mallory-Weiss tears. It is concluded that the time of refeeding does not influence the hospital course of patients with a low risk of recurrent bleeding. Patients with clean-based ulcers or nonbleeding Mallory-Weiss tears may be refed and discharged home immediately after stabilization.

Endoscopy↗
PubMed1992

Adhesion to and invasion of cultured human cells by Bartonella bacilliformis.

Bartonella bacilliformis was tested for its ability to adhere to and invade tissue culture cell monolayers. The parasite was able to efficiently bind and penetrate human dermal fibroblasts, human laryngeal epithelium, and human umbilical vein endothelial cells. Exposure of the organism to immune serum prepared against a crude Bartonella extract containing cell wall and membranous material resulted in decreased ability of the parasite to invade host cells. There was also an overall reduction in the invasiveness of bartonellae and total host cell association when human laryngeal epithelial cells and human umbilical vein endothelial cells were preexposed to cytochalasin D, indicating an active involvement of host cells in the uptake of bartonellae. Transmission electron microscopy revealed the presence of bartonellae inside and outside intracellular vacuoles. These data suggest that a surface-associated factor is involved in the invasion process and that internalization of the parasite by host cells involves a microfilament-dependent process similar to phagocytosis.

Adhesins, Bacterial↗