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Biomedical subjects

G Rocha

Publications and source records attributed to G Rocha.

At least 19 recordsLinked to original sources
PubMed2005

Constraints on changes in fundamental constants from a cosmologically distant OH absorber or emitter.

We have detected the four 18 cm OH lines from the z approximaetely 0.765 gravitational lens toward PMN J0134-0931. The 1612 and 1720 MHz lines are in conjugate absorption and emission, providing a laboratory to test the evolution of fundamental constants over a large lookback time. We compare the HI and OH main line absorption redshifts of the different components in the z approximately 0.765 absorber and the z approximately 0.685 lens toward B0218 + 357 to place stringent constraints on changes in F triple-bond g(p)[alpha(2)/mu](1.57). We obtain [DeltaF/F] = (0.44 +/- 0.36(stat) +/- 1.0(sys)t) x 10(-5), consistent with no evolution over the redshift range 0 < z < or = 0.7. The measurements have a 2sigma sensitivity of [Deltaalpha/alpha] < 6.7 x 10(-6) or [Deltamu/mu] < 1.4 x 10(-5) to fractional changes in alpha and mu over a period of approximately 6.5 G yr, half the age of the Universe. These are among the most sensitive constraints on changes in mu.

Journal Article↗
PubMed2004

Seroprevalence of hepatitis B and C in the Western Brazilian Amazon region (Rio Branco, Acre): a pilot study carried out during a hepatitis B vaccination program.

In 1999, on the occasion of the application of the first vaccine dose during the state vaccination campaign against hepatitis B virus (HBV), 390 individuals from the town of Rio Branco, Acre, aged two or more years were selected for the determination of the seroprevalence of HBV and HCV. HBV markers (HBsAg, anti-HBs, and anti-HBc IgG) were determined on this occasion and anti-HBs antibodies were also assessed 30 days after the third vaccine dose. At the time of vaccination, 39% of the individuals were still susceptible to HBV, while 61% presented serologic evidence of previous HBV contact or previous vaccination. The individuals with previous HBV contact were significantly older (p<0.001) than those without HBV markers. Of the 192 individuals who returned for reexamination, 30 days after the third dose, 158 (82.3%) had received three vaccine doses, and only 60 (31.2%) belonged to the group without HBV markers. In these individuals, the seroconversion rate after the third dose was 92% (55/60). In conclusion, we found considerable HBV in this population, indicating the need for pursuing the immunization programs. We also found high rates of vaccination coverage in the Western Brazilian Amazon region.

Adolescent↗
PubMed2004

New findings in partial trisomy 16q: clinical report.

UNLABELLED: Partial trisomy 16q is a rare disorder associated with significant dysmorphism, psychomotor retardation and limited postnatal survival. A female infant with a partial trisomy 16q from a de novo translocation 11;16 is described. Clinical findings were consistent with previous reports, with the exceptions of megalocornea, partial callosal agenesis and mild bilateral occipital lobe hypoplasia. CONCLUSION: Based on this clinical report, megalocornea, partial callosal agenesis and mild bilateral occipital lobe hypoplasia should perhaps be included in the list of anomalies associated with partial trisomy 16q.

Chromosome Aberrations↗
PubMed2003

The CHARM programme.

Explore the source record for details and available documents.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2002

Lupus nephritis: a retrospective review of 78 cases from a single center.

UNLABELLED: Lupus nephritis (LN) is a frequent and serious manifestation of systemic lupus erythematosus. However, the outcome has progressively improved in the last 3 decades and this was due to more efficient and early treatment of LN and comorbid situations. The aim of our study was to analyze our experience and outcome in LN, to evaluate clinicopathologic and clinicolaboratory correlations and to search for risk factors for renal and patient survival. PATIENTS AND METHODS: We conducted a retrospective study of 78 patients with biopsy-proven LN. RESULTS: Acute renal failure and subnephrotic proteinuria with microhematuria occurred each one in 39.7% of the patients, nephrotic syndrome in 16.7% and nephritic syndrome in 3.8%. The mean serum creatinine at presentation was 1.45 +/- 1.03 mg/dl and the creatinine clearance was 68.2 +/- 40.3 ml/min. Class IV LN existed in 71.8%, Class III in 20.5%, Class V in 6.4% and Class VI in 1.3%. The treatment included steroids and cytotoxic agents in 87.5% of the patients with proliferative LN. Hypertension, serum creatinine and acute renal failure at presentation, as well as significant chronicity on renal biopsy, were significantly correlated with the progression to chronic renal failure in our population. Males were more prone to develop renal flares. 3.8% of the patients died, 9% lost their renal function, 26.9% are in remission, 33.3% still have subnephrotic proteinuria and microhematuria, 7.7% have nephrotic syndrome and 19.2% have chronic renal failure. The mean global follow-up was 102 +/- 74 months and 96.2% of the patients survived. The actuarial renal survival was 96.1% in the first year; 89.9% at 5 years; and 83.7% at 10 and 20 years. CONCLUSION: We can say that hypertension, serum creatinine and acute renal failure at the onset and significant chronicity on renal biopsy, proved to be risk factors for chronic renal failure in our study population. Male gender was a risk factor for renal flares. The achieved global outcome can be considered a good result.

Acute Kidney Injury↗
PubMed2001

Poisoning with calcium channel blockers--a case report and review of the literature.

The incidence of poisoning with calcium channel blockers, accidental or intentional, has increased in recent years, associated with more frequent use. We present a clinical case of bradycardia and shock of unknown cause, which came to be revealed a poisoning by 3240 mg of slow-release diltiazem, managed with temporary transvenous pacing and dopamine in high concentration. We make a review of the cardiovascular manifestations of the three classic calcium channel blockers: verapamil, diltiazem and nifedipine; namely, hypotension, rhythm and conduction disturbances. We point out the late appearance of the beginning of manifestations with the use of slow releasing formulations. The toxicity by calcium channel blockers can lead to a wide variety of manifestations in the central nervous system, gastrointestinal system, endocrine-metabolic, hematologic and respiratory systems. There is a high clinical suspicion when the following factors are present: hypotension with bradycardia, mental state disturbances, lactic acidosis, hyperglycemia, sinus pauses and refractory shock. Treatment is based on general measures of intoxication support, decreasing the drug absorption and improvement of cardiac function. The bradyarrhythmias are corrected with the use of intravenous calcium, glucagon, atropine and pacemaker. If the intoxication causes depression of cardiac contractility, the use of calcium or/and glucagon is indicated. If there is refractoriness with these measures, catecholamines should be employed. There are alternative and adjuvant drugs such as amrinone, insulin-glucose, 4-aminopyridine and calcium entry promoters. Charcoal hemoperfusion can be useful in the overdose of sustained release preparations, but hemodialysis is unworthy of therapeutical interest.

Aged↗
PubMed1999

The BioMask for treatment of corneal surface irregularities with excimer laser phototherapeutic keratectomy.

PURPOSE: To assess the characteristics of BioMask as a potential masking agent for use with the excimer laser. METHOD: We addressed ablation rate, smoothness, ease of use, dioptric shift, treatment of standardized irregular topography, and ability of BioMask to induce dioptric change in vivo. RESULTS: BioMask ablates at a rate of 0.28 microm per pulse. The BioMask conforms to the base curve of a contact lens in the excimer blank, eye bank eye, and rabbit eye with a r2 of 0.9982, 0.9844, 0.9858, respectively. We are readily able to create 20 diopters of flattening or steepening (r2 = 0.9944). Standardized irregular topography generation in the rabbit eye and then removal with BioMask was successful. The central corneal topography of the rabbit cornea showed predictable changes with various contact lens base curves with the BioMask (r2 = 0.875). CONCLUSIONS: BioMask has excellent potential as an ablatable mask material in the treatment of superficial corneal scars.

Animals↗
PubMed1999

[Case report of tuberous sclerosis and congenital heart disease].

The cardiac manifestation usually associated with Tuberous Sclerosis is rhabdomyoma. The authors present a clinical case of Tuberous Sclerosis with the particular coexistence of congenital heart disease (mitral anomaly and pulmonary stenosis) and a single intracardiac rhabdomyoma that appeared at the age of four years.

Child, Preschool↗
PubMed1998

Meta-analysis on the recurrence rates after bare sclera resection with and without mitomycin C use and conjunctival autograft placement in surgery for primary pterygium.

BACKGROUND/AIMS: Bare sclera resection with and without use of mitomycin C and conjunctival autograft placement are three surgical techniques currently in use for the treatment of primary pterygium. The purpose of this study was to determine through a meta-analysis the risk for postoperative pterygium recurrence comparing the three surgical treatment modalities. METHODS: A search through Medline for randomised controlled clinical trials comparing at least two of the three surgical techniques in the treatment of primary pterygium, along with a hand search of all references in relevant papers, was conducted. All eligible clinical trials were graded for quality utilising the Detsky score; those studies with a score of 0.5 or greater were included. The main outcome measurements were the pooled odds ratios and 95% confidence intervals for the risk of pterygium recurrence. These were calculated utilising the Mantel-Haenszel method. RESULTS: Five eligible studies with an adequate quality score were retrieved, three comparing bare sclera resection with and without mitomycin C use, one comparing bare sclera resection with conjunctival autograft placement, and one comparing both. The pooled odds ratio for pterygium recurrence in patients who had only bare sclera resection was 6.1 (95% confidence intervals, 1.8 to 18.8) compared with the patients who had conjunctival autograft placement and 25.4 (9.0 to 66.7) compared with the patients who received mitomycin C. CONCLUSIONS: The odds for pterygium recurrence following surgical treatment of primary pterygium are close to six and 25 times higher if no conjunctival autograft placement is performed or if no intra/postoperative mitomycin C is used, respectively. Surgeons and clinical triallists should not be encouraged in the use of bare sclera resection as a surgical technique for primary pterygium.

Adult↗
PubMed1998

The immunology of corneal graft rejection.

Corneal transplantation is the most successful of organ transplants due to the fact that the eye is an immunologically privileged site, and the cornea is an immunologically privileged tissue. The factors responsible for this include presence of the blood-aqueous barrier, the avascularity of the cornea, the absence of classic antigen-presenting cells (APCs) in the central cornea, inhibitory factors in the aqueous humor, the phenomenon known as anterior chamber-associated immune deviation (ACAID), and the intraocular expression of Fas ligand. Loss of ocular immune privilege can occur with breaching of the blood-ocular barrier, corneal neovascularization, migration of classic APCs to the center of the cornea, loss of inhibitory factors in aqueous humor, abrogation of ACAID, and loss of Fas ligand expression within the anterior chamber. The purpose of this review is to analyze these events and how they relate to corneal graft rejection. A discussion on future research and therapeutic modalities is provided.

Animals↗
PubMed1998

Orbital pathology associated with diabetes mellitus.

Diabetes mellitus may be associated with or result in diverse orbital and adnexal problems. It may include mild manifestations, such as blepharoptosis, blepharitis, xanthomas, increased tear-film glucose levels, and calcification of the trochlear apparatus. More severe findings involve third, fourth, and sixth cranial neuropathies. Finally, the physician always should be alert for the possibility of orbital infections in the diabetic population, especially the life-threatening rhinocerebral mucormycosis.

Diabetes Complications↗
PubMed1997

Cyclosporine monitoring with levels 6 hours after the morning dose in patients with noninfectious uveitis.

PURPOSE: The authors evaluate whether monitoring of cyclosporine blood levels 6 hours after the morning dose (T6), as opposed to trough (T0), could reduce the incidence of side effects. METHODS: Cyclosporine dose adjustments were performed based on blood cyclosporine T6 enzyme-multiplied immunologic technique, irrespective of T0 and serum creatinine (SCr), in eight steroid- or azathioprine-resistant uveitis patients. The cyclosporine dose was adjusted to achieve a cyclosporine T6 level of 150 to 250 ng/ml. RESULTS: All patients improved clinically over 16 +/- 10 months. The mean dose of cyclosporine was 3.9 +/- 1.4 mg/kg/day. In 149 visits (47%), 70 dose adjustments were made. Initial and final SCr, potassium, magnesium, and uric acid serum levels and systolic/diastolic blood pressure measurements were not statistically different. There was no change in the creatinine clearance, glomerular filtration rate, or the effective renal plasma flow performed before starting T6 monitoring and at 13 +/- 8 months of follow-up. CONCLUSIONS: Cyclosporine monitoring according to T6 levels is associated with optimal immunosuppression and stable renal function in patients with noninfectious uveitis.

Adult↗
PubMed1997

The Tampa Trephine technique with cat corneal endothelium.

The Tampa Trephine (Martin Marietta Speciality Components, Largo, FL, U.S.A.) penetrating keratoplasty technique uses a 7.0-mm corneal donor button with six rectangular 1 x 2-mm tabs of Bowman's layer, 75 microns in thickness, which are inserted into the recipient stroma beneath Bowman's layer. We evaluated the safety of the Tampa Trephine tissue-trephination method on the cat corneal endothelium combining vital staining and scanning electron microscopy, comparing it with the standard Weck trephination technique. The Tampa Trephine tissue trephination produces a donor button with a 6.7-mm diameter central area of normal endothelium. Localized peripheral areas of cellular loss, endothelial and Descemet's tears, endothelial detachment, and folding along the border of the trephination were observed with the Tampa Trephine method, all located in an area of < or = 150 microns, adjacent to the edge of the button. Standard trephination induced a localized peripheral area of endothelial damage < 50 microns in extension from the donor edge. A theoretic maximal 8.4% peripheral endothelial cell loss is induced with the Tampa Trephine trephination method, compared with a 2.8% loss with the standard procedure. The peripheral location of the alterations after the Tampa Trephine does not hinder the viability of the corneal endothelium, as it has been clinically observed.

Animals↗
PubMed1997

Nitric oxide and transforming growth factor-beta levels during experimental uveitis in the rabbit.

OBJECTIVE: To determine changes in the levels of nitric oxide metabolites and transforming growth factor-beta (TGF-beta) in the rabbit aqueous humour during ocular inflammation. DESIGN: Active experimental uveitis was induced by injection of porcine lens protein (PLP) in three rabbits and of human serum albumin (HSA) in three rabbits; three control rabbits received an injection of saline. OUTCOME MEASURES: Degree of inflammation, antibody titres (determined with the enzyme-linked immunosorbent assay), and aqueous humour levels of nitric oxide metabolites and TGF-beta. A modified Griess assay for nitrites and nitrates (NO2- and NO3-) was used as a measure of nitric oxide generation, and a modification of the CCL-64 mink lung epithelial cell bioassay was used to quantify TGF-beta levels. RESULTS: Following the primary immunologic challenge both experimental groups initially showed a two- to fourfold increment in aqueous levels of nitric oxide metabolites and TGF-beta compared with baseline values. At the peak of the clinically observed inflammation there was a significant increase in the mean nitric oxide metabolite level compared with the control value (p < or = 0.005) (432 nmol/mL for the PLP group and 112 nmol/mL for the HSA group) and a significant decrease (p < or = 0.03) in the mean TGF-beta level (3.1 ng/mL and 0.3 ng/mL respectively). CONCLUSIONS: Nitric oxide may be used as a marker for intraocular inflammation. The increased production of nitric oxide may reflect the loss of immunologic privilege of the ocular microenvironment that occurs during inflammation.

Animals↗