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Biomedical subjects

J Garcia

Publications and source records attributed to J Garcia.

At least 127 records · Page 7Linked to original sources
PubMed1998

Isolation and characterization of desulfovibrio senezii sp. nov., A halotolerant sulfate reducer from a solar saltern and phylogenetic confirmation of desulfovibrio fructosovorans as a new species

A new halotolerant Desulfovibrio, strain CVLT (T = type strain), was isolated from a solar saltern in California. The curved, gram-negative, nonsporeforming cells (0.3 x 1.0-1.3 &mgr;m) occurred singly, in pairs, or in chains, were motile by a single polar flagellum and tolerated up to 12.5% NaCl. Strain CVLT had a generation time of 60 min when grown in lactate-yeast extract medium under optimal conditions (37 degreesC, pH 7.6, 2.5% NaCl). It used lactate, pyruvate, cysteine, or H2/CO2 + acetate as electron donors, and sulfate, sulfite, thiosulfate, or fumarate as electron acceptors. Elemental sulfur, nitrate, or oxygen were not used. Sulfite and thiosulfate were disproportionated to sulfate and sulfide. The G+C content of the DNA was 62 mol%. Phylogenetic analysis revealed that Desulfovibrio fructosovorans was the nearest relative. Strain CVLT is clearly different from other Desulfovibrio species, and is designated Desulfovibrio senezii sp. nov. (DSM 8436).

Journal Article↗
PubMed1998

Rebound bilirubin levels in infants receiving phototherapy.

A retrospective medical record review was completed for 264 consecutive newborns receiving phototherapy for hyperbilirubinemia to determine whether a "rebound" increase in total serum bilirubin (TSB) level occurs after termination of phototherapy. The difference between mean TSB levels at discontinuation of phototherapy and at rebound was calculated by paired t test. TSB levels at rebound were significantly lower than at discontinuation of phototherapy for infants weighing > 1800 g (positive and negative Coombs' test results). There were no statistically significant differences among infants in the smaller weight categories, regardless of Coombs' test results. Infants completing phototherapy for hyperbilirubinemia who are otherwise healthy do not require follow-up solely to identify a rebound bilirubin level.

Bilirubin↗
PubMed1998

Pharmacokinetics and pharmacodynamics of milrinone lactate in pediatric patients with septic shock.

OBJECTIVES: The objectives of this study were to determine the pharmacokinetics of milrinone lactate in pediatric patients with septic shock and to determine whether a relationship exists between steady-state plasma milrinone concentrations and changes in hemodynamic variables. STUDY DESIGN: This was a randomized, double-blind, placebo-controlled, interventional study. In study phase 1 patients were randomized and underwent loading and infusion with milrinone lactate (50 microg/kg, then 0.5 microg/kg/min), and invasive hemodynamic values were determined. Steady-state was determined by obtaining plasma samples at 30, 15, and 0 minutes before the end of the milrinone infusion. Study phase 2 started when milrinone was discontinued by the patient care team. Steady-state was reaffirmed and plasma samples were obtained at 0.5, 1, 2, 4, 6, and 8 hours after the end of the infusion. RESULTS: The average plasma concentration at steady-state (Css avg) and total body clearance for phase 1 were 81.3+/-38.6 ng/ml (mean +/- SD) and 0.0106+/-0.0053 L/kg/min, respectively (n = 9). All but two patients underwent reloading with milrinone. In phase 2 Css avg and total body clearance were 65.8+/-42.1 ng/ml and 0.0110+/-0.0096 L/kg/min, respectively (n = 11). The average time of infusion was 51+/-21 hours. Eight patients were evaluated for phase 2 elimination. The mean elimination rate constant was 0.0091+/-0.0061 min(-1) (n = 8). The median half-life was 1.47 hours (range, 0.62 to 10.85 hours). All patients had creatinine clearances greater than 61 ml/min/1.73 m2. The volume of distribution at steady-state was 1.47+/-1.03 L/kg. No correlation existed between age and the elimination rate constant or the volume of distribution at steady-state. All patients achieved at least a 20% change in cardiac index and systemic vascular resistance index while maintaining a Css avg of 35 to 160 ng/ml. No adverse effects were noted. All patients achieved primary hemodynamic end points (cardiac index and systemic vascular resistance index) during the milrinone infusion. CONCLUSIONS: Loading doses of 75 microg/kg milrinone lactate and starting infusion rates of 0.75 to 1.0 microg/kg/min for patients with normal renal function should be used; the infusion rate should then be titrated to effect. We recommend that for every increase of 0.25 microg/kg/min, a 25 microg/kg bolus dose be given. Because the median half-life is 1.47 hours, immediate hemodynamic effects may not be seen unless appropriate loading doses and infusion adjustments are made.

Adolescent↗
PubMed1998

Efficacy of augmented immunosuppressive therapy for early vasculopathy in heart transplantation.

OBJECTIVES: The present study was undertaken to prospectively and comparatively evaluate the role of serial myocardial perfusion imaging and coronary angiography for the detection of early vasculopathy in a large patient population and also to determine the short- and long-term efficacy of augmented immunosuppressive therapy in the potential reversal of the early vasculopathy. BACKGROUND: Allograft vasculopathy is the commonest cause of death after the first year of heart transplantation. Anecdotal studies have reported the efficacy of augmented immunosuppressive therapy after early detection of vascular involvement. However, no prospective study has evaluated the feasibility of early detection and treatment of allograft vasculopathy. METHODS: In 76 cardiac allograft recipients, 230 coronary angiographic and 376 scintigraphic studies were performed in a follow-up period of 8 years. Angiography was performed at 1 month and every year after transplantation, and thallium-201 scintigraphy at 1, 3, 6 and 12 months after transplantation and twice a year thereafter. Prospective follow-up of 76 patients showed that 18 developed either angiographic or scintigraphic evidence of coronary vasculopathy. All episodes were treated with 3-day methylprednisolone pulse and antithymocyte globulin. RESULTS: Twenty-two episodes of vasculopathy were diagnosed and treated in these 18 patients. Of these 22 episodes, two were detected only by angiography, seven by both angiography and scintigraphy, four by scintigraphy and histologic evidence of vasculitis and nine episodes only by thallium-201 scintigraphy studies. Angiographic and/or scintigraphic resolution was observed in 15 of the 22 episodes (68%) with augmented immunosuppression. The likelihood of regression was higher when treatment was instituted within the first year of transplantation (92%) than after the first year (40%) (p = 0.033). Eighty percent of patients who responded to follow-up. CONCLUSIONS: The present study suggests that early detection of allograft coronary vasculopathy is feasible with surveillance myocardial perfusion or coronary angiographic studies. When identified early after transplantation, immunosuppressive treatment may result in regression of coronary disease.

Adult↗
PubMed1998

Metallic fragment deposits during phacoemulsification.

PURPOSE: To describe the nature and origin of foreign metallic intraocular bodies appearing after phacoemulsification. SETTING: Department of Ophthalmology, University Hospital of San Juan, Alicante, Spain. METHODS: Two metallic particles, 1 extracted during surgery and the other from a patient in whom surgery had been performed, were studied by scanning electronic microscopy and X-ray dispersive energy spectroscopy. Also evaluated were all metallic elements used in phacoemulsification including phaco tips, Sinskey hooks, and handpieces. A morphologic analysis at various magnifications was performed and the composition of the elements studied. RESULTS: Scanning electronic microscopy showed irregularities of the phaco tip and Sinskey hook after their use. Spectrographic analysis found that the phaco tip was mainly aluminum and titanium; the Sinskey hook, iron, chromium, cobalt, and nickel; the handpiece, iron, chromium, and nickel; and the 2 metallic particles, iron, chromium, and nickel, the same as the handpiece. CONCLUSION: The metallic particles extracted corresponded to those of the phaco handpiece. Vibration during prolonged use of the phacoemulsifier probably caused these particles to chip off the handpiece.

Alloys↗
PubMed1998

The first randomized trial of human polymerized hemoglobin as a blood substitute in acute trauma and emergent surgery.

BACKGROUND: Human polymerized hemoglobin (PolyHeme) is a universally compatible, disease-free, oxygen-carrying resuscitative fluid. This is the first prospective, randomized trial to compare directly the therapeutic benefit of PolyHeme with that of allogeneic red blood cells (RBCs) in the treatment of acute blood loss. STUDY DESIGN: Forty-four trauma patients (33 male, 11 female) aged 19-75 years with an average Injury Severity Score (ISS) score of 21+/-10 were randomized to receive red cells (n = 23) or up to 6 U (300 g) of PolyHeme (n = 21) as their initial blood replacement after trauma and during emergent operations. RESULTS: There were no serious or unexpected adverse events related to PolyHeme. The PolyHeme infusion of 4.4+/-2.0 units (mean +/- SD) resulted in a plasma [Hb] of 3.9+/-1.3 g/dL, which accounted for 40% of the total circulating [Hb]. There was no difference in total [Hb] between the groups before infusion (10.4+/-2.3 g/dL control vs. 9.4+/-1.9 g/dL experimental). At end-infusion the experimental RBC [Hb] fell to 5.8+/-2.8 g/dL vs. 10.6+/-1.8 g/dL (p < 0.05) in the control, although the total [Hb] was not different between the groups or from pre-infusion. The total number of allogeneic red cell transfusions for the control and experimental groups was 10.4+/-4.2 units vs. 6.8+/-3.9 units (p < 0.05) through day 1, and 11.3+/-4.1 units vs. 7.8 +/-4.2 units (p = 0.06) through day 3. CONCLUSIONS: PolyHeme is safe in acute blood loss, maintains total [Hb] in lieu of red cells despite the marked fall in RBC [Hb], and reduces the use of allogeneic blood. PolyHeme appears to be a clinically useful blood substitute.

Adult↗
PubMed1998

Pharmacokinetics and electrocardiographic effect of ebastine in young versus elderly healthy subjects.

The objective of this study was to compare the single- and multiple-dose pharmacokinetics and electrocardiographic effect of a 10-mg oral dose of ebastine in elderly (ages, 65-85 years) and young (ages, 18-35 years) healthy volunteers. Thirty-seven subjects completed this randomized, double-blind, multiple-dose, placebo-controlled, parallel group study. The elderly group consisted of 18 subjects, with 13 subjects receiving 10 mg ebastine and 5 receiving matching placebo. The young group consisted of 19 subjects, with 13 subjects receiving 10 mg ebastine and 6 receiving matching placebo. On study days 1 and 3 through 10, each subject received a single 10-mg dose of ebastine or matching placebo in the morning with a standard breakfast. No drug was administered on study day 2 because of pharmacokinetic sampling. Blood samples were collected at selected times postdose on study days 1, 2, and 10. Plasma samples were analyzed for ebastine and its active metabolite, carebastine, using a validated high-performance liquid chromatography method. No plasma ebastine concentrations were detected, suggesting essentially complete metabolic conversion of ebastine to its metabolites. Analysis of variance showed no statistically significant differences between young and elderly single- and multiple-dose carebastine pharmacokinetics with respect to area under the plasma concentration-time curve, maximum concentration (Cmax ), terminal elimination rate constant, apparent oral clearance, or apparent volume of distribution. The mean time of maximum concentration value for young subjects was 1 hour longer than that for elderly subjects after single-dose administration but was comparable after multiple-dose administration. Within-group comparisons of both the young and elderly showed that pharmacokinetics between single dose and steady state were not statistically different. However, the mean steady-state carebastine Cmax values were approximately twofold greater than the mean Cmax values obtained after single-dose administration. A twofold increase in Cmax values between single-dose and steady-state administration is predicted for drugs such as carebastine, because its input interval is approximately equal to its elimination half-life. Twelve-lead electrocardiography was performed before dosing on day 1 and repeated 4 hours postdose on days 1, 5, and 10. Twenty-four hour Holter monitoring was also performed before and at the end of the study. No clinically relevant findings were found by electrocardiography or Holter monitoring between ebastine and placebo in the elderly and young subjects.

Administration, Oral↗
PubMed1998

A randomised controlled trial of care of the perineum during second stage of normal labour.

OBJECTIVE: To compare the effect of two methods of perineal management used during spontaneous vaginal delivery on the prevalence of perineal pain reported at 10 days after birth. DESIGN: Randomised controlled trial. SETTING: Two English maternity care units. SAMPLE: 5471 women who gave birth between December 1994 and December 1996. METHODS: At the end of the second stage of labour women were allocated to either the 'hands on' method, in which the midwife's hands put pressure on the baby's head and support ('guard') the perineum; lateral flexion is then used to facilitate delivery of the shoulders, or the 'hands poised' method, in which the midwife keeps her hands poised, not touching the head or perineum, allowing spontaneous delivery of the shoulders. MAIN OUTCOME MEASURE: Perineal pain in the previous 24 hours reported by women in self-administered questionnaire 10 days after birth. RESULTS: Questionnaires were completed by 97% of women at 10 days after birth. 910 (34.1%) women in the 'hands poised' group reported pain in the previous 24 hours compared with 823 (31.1%) in the 'hands on' group (RR 1.10, 95% CI 1.01 to 1.18: absolute difference 3%, 0.5% to 5%, P = 0.02). The rate of episiotomy was significantly lower in the 'hands poised' group (RR 0.79, 99% CI 0.65 to 0.96, P = 0.008) but the rate of manual removal of placenta was significantly higher (RR 1.69, 99% CI 1.02 to 2.78; P = 0.008). There were no other statistically significant differences detected between the two methods. CONCLUSION: The reduction in pain observed in the 'hands on' group was statistically significant and the difference detected potentially affects a substantial number of women. These results provide evidence to enable individual women and health professionals to decide which perineal management is preferable.

Adult↗
PubMed1998

Postpartum uterine-artery velocity waveforms in women with sickle cell disease.

OBJECTIVE: To investigate the changes in uterine Doppler velocimetry during the postpartum period in women with homozygous sickle cell (SS) disease and to correlate these findings with values in the third trimester and with neonatal outcomes. METHODS: We studied the postpartum changes in uterine Doppler velocimetry in 16 women with SS disease in relation to third-trimester systolic/diastolic (S/D) ratios and neonatal outcome. All patients had repeated measures of uterine S/D ratios biweekly in the third trimester from 28 weeks of pregnancy until delivery, and at 24 h, and 3 and 6 weeks postpartum. RESULTS: Overall the mean S/D ratio in the first 24 h for these 16 women was 2.72 +/- 0.72 and increased progressively to a mean S/D ratio of 6.88 +/- 0.96 at 6 weeks postpartum, with the reappearance of a diastolic notch by the 3rd postpartum week. Twelve women who had normal (< or = 2.6) uterine S/D ratios during pregnancy delivered appropriate-for-gestational-age (AGA) infants. The remaining 4 women had abnormal uterine S/D ratios, and in 3 of these pregnancies, small-for-gestational-age (SGA) infants were delivered. The mean S/D ratios for the subgroups with abnormal value at each of the three postpartum periods were significantly higher than for the 12 SS patients with normal third-trimester values. Postpartum S/D ratios for the 3 women with SGA births were also significantly higher at 24 h and 6 weeks postpartum when compared to SS patients with AGA infants. CONCLUSION: We concluded that postpartum S/D ratios are higher in women with SS disease that have abnormal values in the third trimester and that they are associated with SGA births. In SS patients the nonpregnant pattern of uterine artery velocity waveforms which reappears postpartum may reflect an increase in the uteroplacental circulatory impedence due to reversal of the alterations in the spiral arteries induced by trophoblastic invasion during pregnancy or subinvolution of the placental bed. Additional studies are needed to further elucidate these important hemodynamic changes in women with hemoglobinopathies and to identify patterns predictive of neonatal outcomes in these high-risk patients.

Adult↗
PubMed1998

[Bronchial endoscopy under local anesthesia and pain in children. The value of a nitrous oxide-oxygen combination].

To evaluate the efficacy of continuous administration of 50% nitrous oxide in oxygen for reducing pain during flexible fiberoptic bronchoscopy 32 children aged 3-60 months were randomly assigned to an experimental or a control group. Indications for endoscopy included persistent atelectasis (6), wheezing (10) cystic fibrosis (2) pneumonia (11) persistent cough (3). All patients received Midazolam (0.3 mg/kg) atropine (20 mcg/kg) intra rectaly 20 minutes before the procedure. The flexible fiberoptic bronchoscope (Olympus BF3C4) was inserted transnasally through a face mask. Topical anesthesia with 1% lidocaine hydrochloride (3 mg/kg) was applied to the nose, larynx, trachea and bronchial tree over 15 minutes through the suction chanel of the bronchoscope. All patients were monitored with a pulse oximeter and a cardiac monitor. The experimental group (n = 16) received 50% nitrous oxide in oxygen prior (3 minutes) and during flexible fiberoptic bronchoscopy, the control group (n = 16) received only oxygen. We measured pain of the children by a behavioral observation scale (Children's Hospital of Eastern Ontario Pain Scale: CHEOPS) at each phase of topical anesthesia during bronchoscopy in the two groups. At the end of bronchoscopy physician's satisfaction was scored by a visual analogue scale (VAS 0-100) in which 0 corresponded to absence of satisfaction. Nitrous oxide was associated with lesser pain scores than those with oxygen. Physician significantly preferred these procedure compared with oxygen. No complication occurred during procedure. Combined with local anesthesia midazolam and atropin the administration of 50% nitrous oxide in oxygen seems a better choice for flexible fiberoptic bronchoscopy in children and should be used routinely.

Adjuvants, Anesthesia↗
PubMed1998

The placental blood program of the Barcelona Cord Blood Bank.

Cord blood has recently become an alternative to bone marrow transplantation, generating the need for cord blood banks where large numbers of frozen cord blood units can be stored. The Barcelona Cord Blood Bank (bcB) was created in October 1995. Initially, several methods for volume reduction were tested, including Ficoll, Percoll, Gelatin and HES sedimentation. Of these, HES sedimentation (88% +/- 11 CD34+ cells recovery) was the one chosen for routine banking. Up to November 1997, the bank has processed 754 units with a median of 1.05 x 10(9) nucleated cells and 2.5 x 10(6) CD34+ cells stored per unit. Nine of these units have been shipped for transplantation.

Adult↗
PubMed1998

Controlled-rate versus uncontrolled-rate cryopreservation of peripheral blood progenitor cells: a prospective multicenter study. Group for Cryobiology and Biology of Bone Marrow Transplantation (CBTMO), Spain.

BACKGROUND AND OBJECTIVE: Cryopreservation of hemopoietic progenitors for transplantation has been traditionally performed by the use of a controlled-rate freezer. Several groups have reported successful cryopreservation of progenitor cells at -80 degrees C without a controlled-rate freezer. In an attempt to elucidate whether both methods are equally efficient, we compared controlled-rate versus uncontrolled cryopreservation of peripheral blood progenitor cells (PBPC) in a prospective, multicenter study. DESIGN AND METHODS: Apheresis products from patients undergoing PBPC mobilization were split into two aliquots, and cryopreserved simultaneously by both methods, in autologous plasma plus 10% dimethylsulfoxide. Controlled-rate samples were placed into a programmable freezer with a cooling rate of 1-2 degrees C/min. Uncontrolled-rate samples were directly introduced into a -80 degrees C mechanical freezer. After thawing, cell counts, assays for viability, clonogenic cultures and CD34+ cell enumeration were performed. RESULTS: A total of 105 cases were included. No significant differences were found in viability (mean 88.8 +/- 13% in the controlled-rate group vs. 89.7 +/- 12% in the uncontrolled-rate group), nucleated cell loss (23.5 +/- 23% vs. 23 +/- 22%), mononuclear cell loss (19 +/- 23% vs. 19.1 +/- 22%), and loss of CD34+ cells (34.3 +/- 33% vs. 28.6 +/- 34%). On the other hand, recovery of granulomonocytic colony-forming units (CFU-GM), was significantly better with the controlled-rate technique, than with the non-controlled-rate method (104.3 +/- 95 vs. 86.5 +/- 80, respectively; p = 0.048). INTERPRETATION AND CONCLUSIONS: Our results indicate that both techniques are suitable for cryopreservation of PBPC, although a better recovery of committed progenitors is achieved by the controlled-rate method. Therefore, the use of controlled-rate freezer should probably be recommended.

Blood Preservation↗
PubMed1997

Scoliosis induced by asymmetric lordosis and rotation: an experimental study.

STUDY DESIGN: An experimental study of the influence of intrinsic muscle imbalance on the spinal column of a growing rabbit. OBJECTIVES: To create an in vivo experimental model of scoliosis for comparison with human scoliosis. SUMMARY OF BACKGROUND DATA: There is evidence that asymmetric lordosis may produce scoliosis and that there is muscle imbalance in scoliotic patients. METHODS: Surgical tethering of the spinous apophysis and transverse apophysis of rabbits was performed at three upper levels on the same side of the spine to simulate dominance of one side of the paravertebral musculature over the other. RESULTS: All animals exhibited scoliosis that was convex toward the side opposite that receiving surgery. Radiography showed the curve to increase with time. Postmortem examination of vertebrae revealed structural alterations similar to those produced in human scoliosis. CONCLUSIONS: Intrinsic muscle imbalance in the spinal column of the experimental growing animal may produce scoliosis with characteristics similar to those of human idiopathic scoliosis.

Animals↗
PubMed1997

Requirements for CD1d recognition by human invariant Valpha24+ CD4-CD8- T cells.

A subset of human CD4-CD8- T cells that expresses an invariant Valpha24-JalphaQ T cell receptor (TCR)-alpha chain, paired predominantly with Vbeta11, has been identified. A series of these Valpha24 Vbeta11 clones were shown to have TCR-beta CDR3 diversity and express the natural killer (NK) locus-encoded C-type lectins NKR-P1A, CD94, and CD69. However, in contrast to NK cells, they did not express killer inhibitory receptors, CD16, CD56, or CD57. All invariant Valpha24(+) clones recognized the MHC class I-like CD16 molecule and discriminated between CD1d and other closely related human CD1 proteins, indicating that recognition was TCR-mediated. Recognition was not dependent upon an endosomal targeting motif in the cytoplasmic tail of CD1d. Upon activation by anti-CD3 or CD1d, the clones produced both Th1 and Th2 cytokines. These results demonstrate that human invariant Valpha24+ CD4-CD8- T cells, and presumably the homologous murine NK1+ T cell population, are CD1d reactive and functionally distinct from NK cells. The conservation of this cell population and of the CD1d ligand across species indicates an important immunological function.

Animals↗