Biomedical subjects
Publications and source records attributed to R Fernandez.
External ear manifestations of sarcoidosis are rare. We review six cases in the literature and also report a case. The otolaryngologist plays an important role in making the diagnosis because of the ease of biopsy in all cases of sarcoidosis of the external ear.
A female patient with a structurally abnormal idic(Y) (p11.32) chromosome was studied using fluorescence in situ hybridization and PCR to define the precise position of the breakpoint. The patient had a complex mosaic karyotype with eight cell lines and at least two morphologically distinct derivatives from the Y chromosome. The rearrangement was a result of a meiosis I exchange between sister chromatids at the pseudoautosomal region, followed by centromere misdivision at meiosis II. Due to instability of the dicentric Y chromosome, new cell lines later arose because of mitotic errors occurring during embryonic development. Physical examination revealed a normal female phenotype without genital ambiguity, a normal uterus and rudimentary gonads which were surgically removed.
Ataxia telangiectasia is a rare, multiorgan neurodegenerative disorder with enhanced vulnerability to cancer and infection. Median survival in two large cohorts of patients with this disease, one prospective and one retrospective, is 25 and 19 years, with a wide range. Life expectancy does not correlate well with severity of neurological impairment.
We evaluated mosquitoes collected in the Amazon Basin, near Iquitos, Peru, for their susceptibility to a subtype IIIC strain of the Venezuelan equine encephalomyelitis complex. This virus had been previously isolated from a pool of mixed Culex vomerifer and Cx. gnomatos captured near Iquitos, Peru, in 1997. After feeding on hamsters with viremias of about 10(8) plaque-forming units of virus per ml, Cx. gnomatos was the most efficient vector. Other species, such as Ochlerotatus fulvus and Psorophora cingulata, although highly susceptible to infection, were not efficient laboratory vectors of this virus due to a significant salivary gland barrier. The Cx. (Culex) species, consisting mostly of Cx. (Cux.) coronator, were nearly refractory to subtype IIIC virus and exhibited both midgut infection as well as salivary gland barriers. Additional studies on biting behavior, mosquito population densities, and vertebrate reservoir hosts of subtype IIIC virus are needed to determine the role that these species play in the maintenance and spread of this virus in the Amazon Basin region.
BACKGROUND: Approximately 15% to 25% of all hospitalised patients have indwelling urethral catheters, mainly to assist clinicians to accurately monitor urine output during acute illness or following surgery, to treat urinary retention, and for investigative purposes. OBJECTIVES: The objective of this review was to determine the best strategies for the removal of catheters from patients with a short-term indwelling urethral catheter. SEARCH STRATEGY: We searched the Cochrane Incontinence Group specialised register (searched 16 December 2002), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2004), MEDLINE (January 1966 to 12 October 2004), EMBASE (January 1980 to 12 October 2004), CINAHL (January 1982 to 12 October 2004), Nursing Collection (January 1995 to January 2002) and reference lists of relevant articles and conference proceedings were searched. We also contacted manufacturers and researchers in the field. No language or other restrictions were applied. SELECTION CRITERIA: All randomised and quasi-randomised controlled trials (RCTs) that compared the effects of alternative strategies for removal of short-term indwelling urethral catheters on patient outcomes were considered for inclusion in the review. DATA COLLECTION AND ANALYSIS: Eligibility of the trials for inclusion in the review, details of eligible trials and the methodological quality of the trials were assessed independently by two reviewers. Relative risks (RR) for dichotomous data and a weighted mean difference (WMD) for continuous data were calculated with 95% confidence intervals (CI). Where synthesis was inappropriate, trials were considered separately. MAIN RESULTS: Eighteen trials involving a total of 1964 participants were included in the review. One trial included three treatment groups. In eight RCTs amongst 1020 people, removal at midnight was associated with large volumes of urine at first void, longer times to first void, and shorter lengths of hospitalisation. There was no significant difference in need for recatheterisation, although recatheterisation after removal at night was more likely to be during working hours. In eight trials amongst 822 participants early rather than delayed catheter removal was associated with shorter hospitalisation, but the estimates of other differences were all imprecise. In three trials involving 234 participants the data were too few to assess differential effects of catheter clamping compared with free drainage prior to withdrawal. No eligible trials compared flexible with fixed duration of catheterisation, or assessed prophylactic alpha sympathetic blocker drugs prior to catheter removal. AUTHORS' CONCLUSIONS: There is suggestive but inconclusive evidence of a benefit from midnight removal of the indwelling urethral catheter. There are resource implications but the magnitude of these is not clear from the trials. The evidence also suggests shorter hospital stay after early rather than delayed catheter removal but the effects on other outcomes are unclear. There is little evidence on which to judge other aspects of management, such as catheter clamping.
OBJECTIVE: This study compared the incidence of acute or chronic rejection and adverse events in lung transplant patients receiving induction basiliximab versus controls not receiving treatment. MATERIALS AND METHODS: Basiliximab was administered to 15 patients with impaired renal function, advanced age, or high surgical risk, (group I). The mean age was 48.9 years; nine were double-lung and six single-lung grafts. They were compared to 13 lung transplants performed in 2001 (mean age 43.6 years, 11 double lung and two single lung [group II]). RESULTS: The incidence of acute rejection was 13.3% in group I versus 38.5% in group II (P = .19, OR 4.06), with chronic rejection in 20% and 38.5% of cases, respectively (P = .4, OR 2.5). No significant differences were observed in the incidence of infections or malignancies. Nor were there any direct adverse events due to the administration of the drug. The estimated 2-year survival was 80% for group I and 54% for group II (P = .14). CONCLUSIONS: Basiliximab has a trend to reduce the rate of acute and chronic rejection in lung transplant recipients, with no increased incidence of infections or malignancies. The 2-year survival for patients treated with basiliximab was better than the control group, despite including high risk transplant patients.
As part of a comprehensive study on the ecology of arthropod-borne viruses in the Amazon Basin region of Peru, we assayed 539,694 mosquitoes captured in Loreto Department, Peru, for arboviruses. Mosquitoes were captured either by dry ice-baited miniature light traps or with aspirators while mosquitoes were landing on human collectors, identified to species, and later tested on Vero cells for virus. In total, 164 virus isolations were made and included members of the Alphavirus (eastern equine encephalomyelitis, Trocara, Una, Venezuelan equine encephalomyelitis, and western equine encephalomyelitis viruses), Flavivirus (Ilheus and St. Louis encephalitis), and Orthobunyavirus (Caraparu, Itaqui, Mirim, Murutucu, and Wyeomyia viruses) genera. In addition, several viruses distinct from the above-mentioned genera were identified to the serogroup level. Eastern equine encephalomyelitis virus was associated primarily with Culex pedroi Sirivanakarn & Belkin, whereas Venezuelan equine encephalomyelitis virus was associated primarily with Culex gnomatos Sallum, Huchings & Ferreira. Most isolations of Ilheus virus were made from Psorophora ferox (Von Humboldt). Although species of the Culex subgenus Melanoconion accounted for only 45% of the mosquitoes collected, 85% of the virus isolations were made from this subgenus. Knowledge of the viruses that are being transmitted in the Amazon Basin region of Peru will enable the development of more effective diagnostic assays, more efficient and rapid diagnoses of clinical illnesses caused by these pathogens, risk analysis for military/civilian operations, and development of potential disease control measures.
In the present study we determined the effect of chronic diet supplementation with n-3 PUFA on renal function of healthy and cachectic subjects by providing fish oil (1 g/kg body weight) to female rats throughout pregnancy and lactation and then to their offspring post-weaning and examined its effect on renal function parameters during their adulthood. The animals were divided into four groups of 5-10 rats in each group: control, control supplemented with fish oil (P), cachectic Walker 256 tumor-bearing (W), and W supplemented with fish oil (WP). Food intake was significantly lower in the W group compared to control (12.66 +/- 4.24 vs 25.30 +/- 1.07 g/day). Treatment with fish oil significantly reversed this reduction (22.70 +/- 2.94 g/day). Tumor growth rate was markedly reduced in the P group (16.41 +/- 2.09 for WP vs 24.06 +/- 2.64 g for W). WP group showed a significant increase in mean glomerular filtration rate compared to P and control (1.520 +/- 0.214 ml min-1 kg body weight-1; P < 0.05). Tumor-bearing groups had low urine osmolality compared to control rats. The fractional sodium excretion decreased in the W group compared to control (0.43 +/- 0.16 vs 2.99 +/- 0.87%; P < 0.05), and partially recovered in the WP group (0.90 +/- 0.20%). In summary, the chronic supplementation with fish oil used in this study increased the amount of fat in the diet by only 0.1%, but caused remarkable changes in tumor growth rate and cachexia, also showing a renoprotective function.
The present work describes an experiment to obtain a local reference dose value in lateral skull teleradiography for dental applications. The reference value was based on patient measurements in seven dental X-ray units, using thermoluminescent chips, and measurements on a rubber globe filled with water at another 78 installations. Dosemeters were located initially in the head and neck of a human phantom to select the most suitable locations, and on the cephalostat of the X-ray unit at two appropriate locations, which did not interfere with the patient or with the usual imaging routine. The skin projection of the Porion point was considered the best position. 523 patients were monitored in the seven units; then patient doses and dose values from measurements on rubber balloons were compared to normalize and combine the data. The provisional reference value proposed is 400 microGy.
Cancer cachexia is characterized by anorexia and intense peripheral catabolism. We examine the potential benefits of combination of different anabolic agents such as insulin and clenbuterol associated to prostaglandin synthesis inhibitor (naproxen) on tumor growth, cachexia and renal function in Walker 256 tumor-bearing rats (WK). Groups were separated into WK, and WK with naproxen (WK N) or naproxen plus clenbuterol (WK NCb) or naproxen plus clenbuterol plus insulin (WK NCbI). Treatment begins at the 4th day after tumor inoculation, at the 14th day they were killed, glycemia, lacticidemia, glycogen content from liver, soleus and gastrocnemius muscles, tumor mass, body weight and kidney function were determined. Glycemia and glycogen content were reduced and lacticidemia increased in WK (p<0.05) as compared to control rats. The glycogen content recovered in all treated groups. Tumor weight was significantly reduced by the different treatments. At the 14th weight change (carcass-initial body weight) in the control increased by 38% and in the WK -2%. Naproxen treatment (WK N) induced an increased by 14%. The inclusion of clenbuterol (WK NCb) and insulin (WK NCbI) by 38 and 41%, respectively. Mean glomerular filtration rate (GFR) increased in the WK (p<0.05) as compared to control, but in the WK NCb the GFR was similar to control. Our results suggest that naproxen is able to reduce tumor growth and its association with insulin and clenbuterol induce mass weight gain and recovery energy fuel.
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OBJECTIVES: To study hydration status in referees (main) and assistant referees (linesmen) during official football matches. METHODS: Twelve male football referees were evaluated; all were volunteers. Before and after each match, the referee and one of the assistants were weighed without clothes and a blood sample was taken. Total water loss was determined for each subject from the change in body weight. The main haematological variables were analysed in the blood samples. Total plasma protein concentration and osmolarity were also determined. Variation in plasma volume was determined from changes in packed cell volume and a combination of changes in packed cell volume and haemoglobin concentrations. RESULTS: During a match, total body water loss was 1.60 (0.13) litres, equivalent to 2.05 (0.18)% of body weight. Body weight was reduced by 1.55 (0.12)%, showing that water ingestion during the interval replaces only 24.4% of the body fluids lost during the match. The assistants lost 0.79 (0.19) litre of water, equivalent to 1.05 (0.25)% of body weight. The referees showed a significant decrease in plasma volume of 4.99 (1.33)%. The assistants showed a non-significant increase in plasma volume. The reduction in plasma volume observed in the referees correlated significantly with total body water loss (r = 0.9623). From these data, it is possible to predict that a dehydration of 1% reflects a reduction in plasma volume of nearly 2.5%. CONCLUSIONS: Referees are moderately dehydrated after a football match (2%), whereas assistants show a non-significant dehydration of 1% of their body weight.
In several tissues ammonium ions are able to use the transport pathways of other ions, particularly of K+. We investigated this possibility in the C11 clone of MDCK cells, thought to represent intercalated cells, in control and 0 Cl- conditions. Cell pH was measured by ratiometric fluorescence microscopy using the pH indicator BCECF. After preincubating the cells for 10 min in control or 0 Cl- (substituted by gluconate) Ringer, an ammonium pulse was applied to induce cell acidification. The magnitude of the initial alkalinization (DeltapH) was 0.24+/-0.03 ( n=28) pH units in controls, which fell to 0.023+/-0.01 ( n=12) in 0 Cl-, suggesting uptake of NH4+ balancing the alkalinization by NH3. Addition of 10(-3) M bumetanide or furosemide to the 0 Cl- medium, or 10(-4 )M hexamethylene amiloride, did not alter DeltapH. However, with 5 mM Ba+, DeltapH increased to 38% of control. When 2.5x10(-4) M ouabain, an inhibitor of Na+-K+ ATPase, was used, DeltapH increased to 46% of control. Inhibition of H+-K+ ATPase by SCH28080 or by omeprazol caused significant increase in DeltapH. In 0 Cl- solution, these cells underwent a mean volume reduction (-d V) of -10.24+/-1.96% per 10 min as measured by confocal microscopy. To investigate if NH4+ influx was regulated by cell volume or by cell Cl-, volume reduction was avoided by two procedures. When preincubating with NPPB, a Cl- channel blocker, in 0 Cl-, volume reduction was inhibited (d V=-2.12% per 10 min), and DeltapH was 0.24+/-0.04 ( n=5). When the cells were preincubated in hypotonic 0 Cl- (260 mosmol/l), cell volume reduction was abolished (d V=+2.6% per 10 min) and DeltapH was 0.52+/-0.07 ( n=7). Thus, activation of NH4+ influx by several transporters was due to volume reduction rather than to [Cl-] alteration.
BACKGROUND AND OBJECTIVE: Alexander disease is a slowly progressive CNS disorder that most commonly occurs in children. Until recently, the diagnosis could only be established by the histologic finding of Rosenthal fibers in brain specimens. Mutations in the glial fibrillary acidic protein (GFAP) gene have now been shown in a number of biopsy- or autopsy-proven patients with Alexander disease. A prospective study on patients suspected to have Alexander disease was conducted to determine the extent to which clinical and MRI criteria could accurately diagnose affected individuals, using GFAP gene sequencing as the confirmatory assay. METHODS: Patients who showed MRI white matter abnormalities consistent with Alexander disease, unremarkable family history, normal karyotype, and normal metabolic screening were included in this study. Genomic DNA from patients was screened for mutations in the entire coding region, including the exon-intron boundaries, of the GFAP gene. RESULTS: Twelve of 13 patients (approximately 90%) were found to have mutations in GFAP. Seven of those 12 patients presented in infancy with seizures and megalencephaly. Five were juvenile-onset patients with more variable symptoms. Two patients in the latter group were asymptomatic or minimally affected at the time of their initial MRI scan. The mutations were distributed throughout the gene, and all involved sporadic single amino acid heterozygous changes that changed the charge of the mutant protein. Four of the nine changes were novel mutations. CONCLUSIONS: In symptomatic and asymptomatic patients with a predominantly frontal leukoencephalopathy by MRI, GFAP gene mutation analysis should be included in the initial diagnostic evaluation process for Alexander disease.
BACKGROUND: Various solutions have been recommended for cleansing wounds, however normal saline is favoured as it is an isotonic solution and does not interfere with the normal healing process. Tap water is commonly used in the community for cleansing wounds because it is easily accessible, efficient and cost effective, however, there is an unresolved debate about its use. OBJECTIVES: The objective of this review was to assess the effects of water compared to other solutions for wound cleansing. SEARCH STRATEGY: Randomised and quasi-randomised controlled trials were identified by electronic searches of Cochrane Wounds Group Specialised Trials Register, MEDLINE, EMBASE, CINAHL, and the Cochrane Controlled Trials Register. Primary authors, company representatives and content experts were contacted to identify eligible studies. Reference lists from included trials were also searched. SELECTION CRITERIA: Randomised and quasi randomised controlled trials that compared the use of water with other solutions for wound cleansing were eligible for inclusion. Additional criteria were outcomes that included objective or subjective measures of wound infection or healing. DATA COLLECTION AND ANALYSIS: Trial selection, data extraction and quality assessment were carried out independently by two reviewers and checked by a third reviewer. Differences in opinion were settled by discussion. Some data were pooled using a random effects model. MAIN RESULTS: Three trials were identified that compared rates of infection and healing in wounds cleansed with water and normal saline, two compared cleansing with no cleansing and one compared procaine spirit with water. There were no standard criteria for the assessment of wound infection across the trials which limited the ability to pool the data. The major comparisons were water vs normal saline, and tap water vs no cleansing. For chronic wounds, the odds of developing an infection when cleansed with tap water compared with normal saline was 0.16, 95 % Confidence Interval (CI) 0.01, 2.96. Use of tap water to cleanse acute wounds was associated with a lower rate of infection than saline (OR 0.52, 95 % CI 0.28, 0.96). No statistically significant differences in infection rates were seen when wounds were cleansed with tap water or not cleansed at all (OR 1.06, 95 % CI 0.06, 17.47). Similarly there was no difference in the infection rate in wounds cleansed with water or procaine spirit and those cleansed with isotonic saline, distilled water and boiled water (OR 0.55, 95 % CI 0.18,1.62). REVIEWER'S CONCLUSIONS: Although the evidence is limited one trial has suggested that the use of tap water to cleanse acute wounds reduces the infection rate and other trials conclude that there is no difference in the infection and healing rates between wounds that were not cleansed and those cleansed with tap water and other solutions. However the quality of the tap water should be considered prior to its use and in the absence of potable tap water, boiled and cooled water as well as distilled water can be used as wound cleansing agents.
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BACKGROUND: Size regulation is fundamental in developing multicellular organisms and occurs through the control of cell number and cell size. Studies in Drosophila have identified an evolutionarily conserved signaling pathway that regulates organismal size and that includes the Drosophila insulin receptor substrate homolog Chico, the lipid kinase PI(3)K (Dp110), DAkt1/dPKB, and dS6K. RESULTS: We demonstrate that varying the activity of the Drosophila insulin receptor homolog (DInr) during development regulates organ size by changing cell size and cell number in a cell-autonomous manner. An amino acid substitution at the corresponding position in the kinase domain of the human and Drosophila insulin receptors causes severe growth retardation. Furthermore, we show that the Drosophila genome contains seven insulin-like genes that are expressed in a highly tissue- and stage-specific pattern. Overexpression of one of these insulin-like genes alters growth control in a DInr-dependent manner. CONCLUSIONS: This study shows that the Drosophila insulin receptor autonomously controls cell and organ size, and that overexpression of a gene encoding an insulin-like peptide is sufficient to increase body size.
Trigeminal ganglion neurons comprise three main cell body-size types. This cell size heterogeneity provides an excellent neuronal model to study the cell size-dependent organization and dynamics of the nucleoli, Cajal (coiled) bodies (CBs), and nuclear speckles of pre-mRNA splicing factors, nuclear structures that play a key role in the normal neuronal physiology. We have analyzed the number of nucleoli and CBs and the structural and molecular organization of CBs and nuclear speckles in the three neuronal types by using immunofluorescence with antibodies that recognize nucleoli (fibrillarin), CBs (coilin), and nuclear speckles (snRNPs), confocal microscopy, and electron microscopy. Whereas the mean number of nucleoli per neuron decreases as a function of cell size, the number of CBs per cell significantly increases in large neurons in comparison with the small ones. In addition, large neurons have a higher proportion of CBs associated with the nucleolus. In all neuronal types, CBs concentrate coilin, fibrillarin, snRNPs, and the survival motor neuron protein (SMN). Immunostaining for snRNPs shows small speckle domains and extensive areas of diffuse nucleoplasmic signal in large neurons, in contrast with the large nuclear speckles found in small neurons. Furthermore, flow cytometric analysis shows that all neurons are in the range of diploid cells. These findings indicate that the fusion behavior of nucleoli, the formation of CBs and their relationships with the nucleolus, as well as the compartmentalization of the pre-mRNA splicing machinery, is related to cell body size in the trigeminal ganglion neurons. Because transcriptional activity is a basic determinant mechanism of cell size in diploid cells, we suggest that our findings reflect a distinct transcription-dependent organization of the nucleolus and splicing machinery in the three cell types of trigeminal ganglion neurons.