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Biomedical subjects

H Garcia

Publications and source records attributed to H Garcia.

At least 19 recordsLinked to original sources
PubMed1999

Change from conventional haemodiafiltration to on-line haemodiafiltration.

BACKGROUND: On-line haemodiafiltration (HDF) is a technique which combines diffusion with elevated convection and uses pyrogen-free dialysate as a replacement fluid. The purpose of this study was to evaluate the difference between conventional HDF (1-3 l/h) and on-line HDF (6-12 l/h). METHODS: The study included 37 patients, 25 males and 12 females. The mean age was 56.5 +/- 13 years and duration of dialysis was 62.7 +/- 49 months. Three patients dropped out for transplantation, three patients died and three failed to complete the study period. Initially all patients were on conventional HDF with high-flux membranes over the preceding 34 +/- 32 months. Treatment was performed with blood flow (QB) 402 +/- 41 ml/min, dialysis time (Td) 187 min, dialysate flow (QD) 654 +/- 126 ml/min and replacement fluid (Qi) 4.0 +/- 2 l/session. Patients were changed to on-line HDF with the same filtre and dialysis time, QD 679 +/- 38 ml/min (NS), QB 434 +/- 68 ml/min (P < 0.05) and post-dilutional replacement fluid 22.5 +/- 4.3 l/session (P < 0.001). We compared conventional HDF with on-line HDF over a period of 1 year. Dialysis adequacy was monitored according to standard clinical and biochemical criteria. Kinetic analysis of urea and beta2-micro-globulin (beta2m) was performed monthly. RESULTS: Tolerance was excellent and no pyrogenic reactions were observed. Pre-dialysis sodium increased 2 mEq/l during on-line HDF. Plasma potassium, pre- and post-dialysis bicarbonate, uric acid, phosphate, calcium, iPTH, albumin, total proteins, cholesterol and triglycerides remained stable. The mean plasma beta2m reduction ratio increased from 56.1 +/- 8.7% in conventional HDF to 71.1 +/- 9.1% in on-line HDF (P < 0.001). The pre-dialysis plasma beta2m decreased from 27.4 +/- 8.1 to 24.2 +/- 6.5 mg/l (P < 0.01). Mean Kt/V (Daugirdas 2nd generation) was 1.35 +/- 0.21 in conventional HDF compared with 1.56 +/- 0.29 in on-line HDF (P < 0.01), Kt/Vr (Kt/V taking into consideration post-dialysis urea rebound) 1.12 +/- 0.17 vs 1.26 +/- 0.20 (P < 0.01), BUN time average concentration (TAC) 44.4 +/- 9 vs 40.6 +/- 10 mg/dl (P < 0.05) and protein catabolic rate (PCR) 1.13 +/- 0.22 vs 1.13 +/- 0.24 g/kg (NS). There was a significant increase in haemoglobin (10.66 +/- 1.1 vs 11.4 +/- 1.5) and haematocrit (32.2 +/- 2.9 vs 34.0 +/- 4.4%), P < 0.05, during the on-line HDF period, which allowed a decrease in the erythropoietin doses (3861 +/- 2446 vs 3232 +/- 2492 UI/week), (P < 0.05). Better blood pressure control (MAP 103.8 +/- 15 vs 97.8 +/- 11 mmHg, P < 0.01) and a lower percentage of patients requiring antihypertensive drugs were also observed. CONCLUSION: The change from conventional HDF to on-line HDF results in increased convective removal and fluid replacement (18 l/session). During on-line HDF treatment, dialysis dose was increased for both small and large molecules with a decrease in uraemic toxicity level (TAC). On-line HDF provided a better correction of anaemia with lower dosages of erythropoietin. Finally, blood pressure was easily controlled.

Adult↗
PubMed1999

Pulmonary artery fibrous bands: report of a case with extensive lung infarction and superinfection with Coccidioides immitis, Pseudomonas, and acid-fast bacilli.

A 46-year-old woman presented with shortness of breath and frequent lower respiratory tract infections. A ventilation-perfusion scan showed markedly reduced perfusion of the right lung, and pulmonary arteriogram showed stenosis of the right pulmonary artery. A right pneumonectomy revealed dense white fibrous bands partially occluding the pulmonary artery branches and two large abscess cavities filled with pus in the upper and lower lobes. Microscopic examination revealed extensive necrosis of lung parenchyma, suppurative granulomatous inflammation with Coccidioides immitis organisms and rare acid-fast bacilli. Pulmonary artery fibrous bands were originally believed to be congenital; however, they are now known to be sequelae of thromboembolic phenomena.

Coccidioides↗
PubMed1998

Evaluation of peri- and post-natal toxicity of Policosanol in rats.

The effects of Policosanol, a newly developmented hypocholesterolemic drug administered during the perinatal and postnatal periods, were studied in Sprague-Dawley rats. This compound was administered orally to female rats at dose levels of 0 (control), 5, 50, and 500 mg/kg/day, from day 15 of pregnancy to day 21 after parturition. The animals were allowed to deliver and their offspring were examined for postnatal growth and development. No signs of toxic effects related to the test material were observed in the dams F0 during pregnancy and lactation. No adverse effects were observed on the postnatal growth, behaviours, or reproductive ability of pups F1. The physical and sensorial development of pups F2 was also normal. These results confirm that Policosanol does not affect the reproductive performance or fetal/neonatal development.

Animals↗
PubMed1998

Urea reduction ratio considering urea rebound.

An American National Study shows that survival benefits from higher dialysis doses appear to be present up to a Kt/V level of 1.3 or a urea reduction ratio (URR) of 70%. The effect of increasing dialysis efficiency magnified urea rebound and the error in URR determinations. Several formulas have been developed to calculate URR considering the urea rebound (URRr). Smye and coworkers have proposed a method whereby the equilibrated blood urea nitrogen is predicted by additional intradialytic urea sample. Maduell and colleagues, based on analysis of postdialysis urea rebound, have proposed a method whereby the urea rebound is predicted. To compare measured URRr to estimated by Smye and Maduell formulas, 384 patients were studied, 211 males and 173 females, who received a dialysis session with their habitual parameters. Measurements of plasma urea concentration were obtained at the beginning, 90-100 min following the start of dialysis, at the end, and 45 min after dialysis. The postdialysis urea rebound was 22.4+/-9.7%. The urea kinetic model Kt/V was 1.365+/-0.26, and Kt/Vr was 1.14+/-0.23. URR was 68.7+/-6.6%, and when it was calculated with urea rebound, it decreased to 61.9+/-7.4%. The URRr correlated with calculations by Smye and Maduell formulas: 60.7+/-8.4 (r = 0.722, p < 0.001) and 61.8+/-6.6 (r = 0.933, p < 0.001), respectively. The precision of estimated limits of agreement and percentage of error by Bland and Altman analysis show that URRr estimated Maduell formula could be used in place of the URRr. Otherwise, the degree of agreement of the Smye method was not clinically acceptable. In conclusion, our results led us to suggest that in actual dialysis, the use of URR is not adequate for delivered hemodialysis dose, and URRr should be used. URRr estimated by Maduell formula could be a simple and accurate method for use in clinical practice. The recommended dialysis dose by the American National Study of URR of 70% could correspond, considering urea rebound, to Kt/Vr 1.18 or URRr of 64%.

Adult↗
PubMed1997

Searching for hidden information with Gabor Transform in generalized tonic-clonic seizures.

The analysis of generalized tonic clonic seizures is usually difficult with scalp EEG due to muscle artifact. We applied Gabor Transform to evaluate 20 seizures from 8 consecutive patients admitted for video-EEG monitoring. We studied the relative intensity ratios of alpha, theta and delta bands over time. In 14/20 events we found a significant decremental activity in the delta band at the onset of the seizure indicating that this is dominated by theta and alpha bands. We conclude that GT is a useful auxiliary tool in the analysis of ictal activity that sheds light on the underlying pathophysiological mechanisms.

Adult↗
PubMed1997

Validation of different methods to calculate Kt/V considering postdialysis rebound.

BACKGROUND: The effect of increasing dialysis efficiency magnifies rebound urea and the error in Kt/V determinations from single pool urea kinetics. Several formulae have been developed to calculate Kt/V taking into account the rebound urea (Kt/Vr). Smye et al. proposed a method whereby the equilibrated BUN is predicted by an additional intradialytic urea sample (Kt/VrSmye). Daugirdas et al. proposed a method where a single pool Kt/V is modified according to the speed of dialysis to obtain a double pool Kt/V (Kt/VrDaug). Maduell et al. developed a method based on analysis of post-dialysis urea rebound whereby the Kt/Vr is predicted according to the single pool Kt/V and K/V (Kt/VrMad). DESIGN OF THE STUDY: We compared Kt/Vr estimated by these three formulae (Smye, Daugirdas, and Maduell) in 384 patients consisting of 211 males and 173 females, who received dialysis according to their regular protocols. Plasma urea was measured at the beginning, 90-100 min following the start of dialysis, the end, and 45 min post-dialysis. RESULTS: Post-dialysis rebound urea was 22.4 +/- 9.7%. Kt/V and Kt/Vr obtained with rea kinetic model Kt/V 1.184 +/- 0.22 and 0.984 +/- 0.20, respectively. These was a good correlation between Kt/Vr and the Smye formula (Kt/VrSmye = 0.956 +/- 0.21, r = 0.729, P < 0.001), and a better one for Daugirdas (Kt/VrDaug = 0.984 +/- 0.18, r = 0.931, P < 0.001), and Maduell formulae (Kt/VrMad = 0.980 +/- 0.18, r = 0.946, P < 0.001). Limits of agreement and percentage of error estimated according to Bland and Altman show that Kt/Vr estimated by Daugirdas and Maduell formulae could be used in place of the Kt/Vr. The degree of agreement with the Smye method is not clinically acceptable. CONCLUSION: Our results suggest that the use of a single pool Kt/V is not adequate to estimate the haemodialysis dose delivered and Kt/V taking rebound urea in consideration. Kt/Vr estimated by Daugirdas or Maduell formulae are a simple and accurate method for use in clinical practice.

Adult↗
PubMed1997

Involuntary movements during thermolesion predict a better outcome after microelectrode guided posteroventral pallidotomy.

Eight of the first 15 patients with advanced Parkinson's disease who underwent microelectrode guided posteroventral pallidotomy developed transient abnormal involuntary movements during thermolesion, four of whom also did so during high frequency macrostimulation. Abnormal involuntary movements found before thermolesion were choreic, ballistic, or choreoathetoid in nature, usually persisted less than 60 minutes, and were contralateral to the site of thermolesion in six and bilateral in two of them. The appearance of abnormal involuntary movements during macrostimulation or thermolesion of the internal globus pallidus correlated with better surgical outcome as measured by UPDRS motor items and CAPIT timed test, so that they seem to be of prognostic value.

Aged↗
PubMed1996

Comparison study of the immunogenicity and safety of 5- and 10-microgram dosages of a recombinant hepatitis B vaccine in healthy infants.

BACKGROUND: It has been suggested that lower dosages of hepatitis B vaccine may be adequate for vaccinating infants and would be less costly. OBJECTIVES: To compare the immunogenicity and safety of 5 and 10 micrograms of Engerix-B recombinant hepatitis B vaccine given to healthy infants. METHODS: A prospective randomized comparison of 5- and 10-micrograms doses of Engerix-B recombinant hepatitis B vaccine given to infants at 2, 4 and 6 months of age. Seroconversion (antihepatitis B surface antigen (anti-HBs) > or = 1 mIU/ ml) and seroprotection (anti-HBs > or = 10 mIU/ml) rates as well as geometric mean antibody titers were compared at 4, 6 and 8 months. RESULTS: A total of 190 healthy infants were screened and received the first dose of vaccine. Of these infants 153 were eligible to continue in the study. Both dosages proved to be highly immunogenic, producing high seroconversion and seroprotection rates and geometric mean anti-HBs concentrations after 3 doses. Although 10 micrograms induced significantly greater geometric mean concentrations (1641 mIU/ml compared 880 mIU/ml at 8 months of age), the seroprotection rates were identical (98.5%). CONCLUSIONS: Both dosages were well-tolerated and no serious adverse experiences were reported. However, the 5 micrograms of Engerix-B administered at 2, 4 and 6 months of age did not induce as great an anti-Hbs concentration as did 10 micrograms. Long term studies are required to determine whether using the lower dosage would sacrifice long term efficacy.

Dose-Response Relationship, Immunologic↗
PubMed1995

Liver transplantation in patients with Budd-Chiari syndrome.

Patients with Budd-Chiari syndrome (obstruction of the hepatic veins) and associated hepatic insufficiency may be candidates for orthotopic liver transplantation (OLT). In our series of 405 OLT patients, 3 were transplanted due to Budd-Chiari syndrome (0.7%). The indication for liver transplantation in these patients was severe hepatic insufficiency (chronic in two and acute in the third one). Morphologic study of the obstructions revealed apparently different causes, including thrombi, membranous webs in hepatic veins, and hydatid cyst compression. The surgical technique employed in these transplantations was similar to that for other etiologies. Due to its implications for the future course of OLT, it is important to determine the exact etiology of Budd-Chiari syndrome in the pretransplant period and to treat the patients with early and long-term anticoagulant therapy to avoid syndrome recurrence.

Adolescent↗
PubMed1995

Growth hormone (GH) responses to GH-releasing peptide and to GH-releasing hormone in GH-deficient children.

The GH-releasing peptides (GHRPs) are a family of hexa- and heptapeptides that specifically stimulate GH secretion in normal adults and children. They would be an attractive potential form of therapy for GH deficiency (GHD) if they are also active in these patients. Their action, however, appears to result at least in part through hypothalamic responses, which may be impaired in GHD, and their ability to evoke a GH response in these patients must therefore be directly examined. We studied GH responses to the heptapeptide GHRP-1 in 22 prepubertal children with previously documented GHD and growth failure and compared them to responses to GHRH and the two peptides administered together. Patients received 1 microgram/kg GHRH-(1-44)NH2, 1 microgram/kg GHRP-1, or both, in random order. Tests were separated by at least 1 week. GHRP-1 evoked a significant GH response in 60% of the patients, comparable to the 68% who responded to GHRH. The magnitudes of the peak responses were similar (7.5 +/- 8.0 micrograms/L to GHRP-1 and 11.2 +/- 12.1 to GHRH), although the duration of the GH rise was briefer after GHRP-1. Both responses were lower than those previously observed in normal subjects. There was a marked synergy in responses when the two were given together; the GH peak (34.2 +/- 44.8 micrograms/L) significantly exceeded the sum of the individual responses, and the proportion of patients who responded (86%) was also higher. Thus, despite the absence of endogenous GHRH reflexes in most patients with GHD, these children can respond to GHRP-1 similarly to GHRH, and GHRP-1 can markedly enhance the response to GHRH. These results suggest that GHRPs or their analogs could form the basis for therapy of GHD.

Adolescent↗
PubMed1994

Etiopathogenesis and prognosis of centrilobular necrosis in hepatic grafts.

The incidence, contributing etiopathogenetic factors, and prognostic significance of centrilobular necrosis were investigated in 270 hepatic transplants to 215 immunosuppressed patients in whom 837 biopsies were performed. Twenty-six (9.6%) grafts demonstrated centrilobular necrosis in one or more biopsy specimens. The immunological, clinical, histopathological, and evolutionary features of this patient group (group A) were compared with a control group of patients who had undergone 92 consecutive transplants with no necrosis (group B). Group A was younger (p < 0.01), had a higher average of warm and cold-ischemia time (p < 0.05), a higher incidence (p < 0.001) and earlier appearance of acute rejection episodes (p < 0.01), and a closer association with evolution to chronic rejection (A: 53.8% vs B: 13.1%, p < 0.001). Survival rates for grafts and patients with necrosis at 12 and 30 months were significantly lower (p < 0.001). The 26 grafts were distributed into three chronological subgroups according to when necrosis appeared: (1) First week--All these grafts were lost (four through primary graft nonfunction and one due to protal recurrent thrombosis); (2) Second week--seven grafts with associated acute rejection, with three evolving to chronic rejection; (3) After the second week (116 +/- 82 days)--five with isolated necrosis, two with associated acute rejection, four with associated ductopenia, and three with associated acute rejection and ductopenia. In 11 grafts the necrosis persisted and evolved to chronic rejection. In conclusion, these findings indicate that centrilobular necrosis is a histopathological sign associated with poor prognosis in most hepatic grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Comparative study of the immunogenicity and safety of two dosing schedules of Engerix-B hepatitis B vaccine in neonates.

A randomized multicenter study compared the routine hepatitis B vaccine schedule of 0, 1, 6 months with an accelerated schedule of 0, 1, 2 months in newborns. Two hundred ninety-nine infants whose mothers were seronegative for hepatitis B were enrolled in the study and randomized to either the routine or accelerated schedule. All infants had blood drawn for antibody titers to hepatitis B at 2, 3, 6 and 7 months of age. For 222 infants data were evaluable, at least for safety; 193 of these 22 had antibody titers that were evaluable. The infants vaccinated on the accelerated schedule developed seroprotective concentrations of antibody more quickly than the infants vaccinated on the routine schedule; 92.6% vs. 66.1% had seroprotective concentrations (> or = 10 mIU/ml) at 3 months of age (P < 0.001). However, infants in the accelerated schedule had lower geometric mean antibody titers at 7 months, 420.0 vs. 3141.8. We conclude that the accelerated vaccination schedule resulted in the more rapid development of seroprotective concentrations of antibody, but levels of antibodies were not as high as in the routinely vaccinated infants at 7 months. These data suggest that an accelerated vaccine schedule can be used in the newborn period. The effectiveness of the accelerated schedule in preventing perinatal infections compared to the standard schedule and the necessity for booster doses of vaccine remain to be studied.

Drug Administration Schedule↗
PubMed1994

Fatal massive hemoptysis secondary to intralobar sequestration.

We report the case of a 29-year-old woman who died of massive hemoptysis due to hemorrhage from an intralobar pulmonary sequestration into the tracheobronchial tree. The sequestration had been diagnosed in childhood but had been managed nonoperatively. This case emphasizes the need for early surgical treatment of pulmonary sequestration.

Acute Disease↗
PubMed1993

Hyperbilirubinemia in the breast-fed newborn: a controlled trial of four interventions.

A controlled clinical trial was conducted to compare the effect of four different interventions on hyperbilirubinemia in 125 full-term breast-fed infants. Of 1685 term infants who met the inclusion criteria, 126 (7.4%) had a serum bilirubin concentration > or = 291 mumol/L (17 mg/dL). When the bilirubin reached this level, babies were assigned at random to one of four interventions: (1) continue breast-feeding and observe; (2) discontinue breast-feeding, substitute formula; (3) discontinue breast-feeding, substitute formula and administer phototherapy; (4) continue breast-feeding, administer phototherapy. The serum bilirubin concentration reached 342 mumol/L (20 mg/dL) in 24% of infants in group 1, 19% in group 2, 3% in group 3, and 14% in group 4. When phototherapy was used, the decline in serum bilirubin was significantly larger and more rapid (compared with no phototherapy). In the majority of breast-fed infants whose serum bilirubin levels reach 291 mumol/L (17 mg/dL) the bilirubin will decline spontaneously and will not reach 342 mumol/L (20 mg/dL). If the infant is significantly jaundiced and a decision is made to intervene, parents can be given a number of options and can make an informed decision regarding which, if any, intervention they prefer.

Analysis of Variance↗
PubMed1992

Persistent interleukin-2 activity and molecular evidence for expression of lymphotoxin in the hapten-immune model for pulmonary interstitial fibrosis.

The hapten-immune model for pulmonary fibrosis shows that a specific T-cell-mediated immune response is essential for the induction of a nonresolving fibrosis. Here, we report results from studies that identify soluble factors released by activated T lymphocytes that might mediate long-lasting fibrosis. Pulmonary fibrosis was induced by priming hamsters for contact hypersensitivity responses with an epicutaneous application of 2,4,6-trinitro-1-chlorobenzene (TNCB) in carrier and challenging intratracheally (IT) 5 days later with a single dose of the soluble form of the immunizing hapten. Bronchoalveolar lavage fluid was harvested at various time points after IT challenge and assayed for tumor necrosis factor (TNF) and interleukin-2 (IL-2) bioactivity. After IT challenge with the sensitizing hapten, only the immune animals contained IL-2 activity in the bronchoalveolar lavage fluid. TNF activity was detected in lungs of both immune and nonimmune animals. Interestingly, the TNF activity was significantly higher (P less than 0.05) in nonimmune challenged than in immune challenged animals on day 5. Molecular hybridization studies showed that a similar amount of TNF-alpha mRNA was expressed in adherent cells from both groups. The nonadherent subpopulation of mononuclear cells harvested from challenged-immune animals expressed TNF-beta (lymphotoxin) mRNA. These data show, for the first time, an association of lymphotoxin with the appearance of pulmonary fibrotic disease in an animal model for pulmonary fibrosis. These observations are consistent with the postulates that lymphotoxin and IL-2 participate in the immunopathogenesis of hapten-immune induced pulmonary fibrosis and that TNF-alpha is associated with the healing of the fibrotic process initiated by toxic lung injury.

Animals↗
PubMed1991

Taenia solium: inhibition of spontaneous evagination of cysticerci by the host inflammatory capsule.

The effect of the host's inflammatory capsule or of physical restraint on the spontaneous evagination capacity of Taenia solium cysticerci was evaluated. Parasites obtained from infected pig muscle, in which the surrounding inflammatory capsule was not eliminated, were unable to evaginate spontaneously after 12 or 60 h of culture. This phenomenon was not abolished when the capsule was eliminated and the parasites were cultured in semi-solid agar or in liquid medium.

Animals↗
PubMed1991

Pleomorphic adenoma of the breast. Case report.

A clinicopathologic study of a pleomorphic adenoma of the breast is presented and attention is drawn to a previously unreported association with a cyst. Malignancy was strongly suspected in the light of radiologic features. Immunohistochemistry stresses the similarity between pleomorphic adenoma of salivary gland and breast. A common histogenesis of the two entities is also suggested. Ontogenetic links of both glands are mentioned.

Adenoma↗