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Biomedical subjects

C Guerra

Publications and source records attributed to C Guerra.

At least 19 recordsLinked to original sources
PubMed2005

Medical ethnobotany of the Teribes of Bocas del Toro, Panama.

Ethnomedical uses of 108 medicinal plant species, belonging to 52 families, 89 genera, used by the Teribe Amerindians of Bocas del Toro Province in Panama, along with their socio-cultural practices are reported here. The methods of administration of the herbal remedies, the plant parts used, their families and local names are also documented. The recorded medicinal plants were used mainly for fever, various type of pain and inflammation. The potential value of 26 plants and their traditional uses was elucidated through literature search.

Ethnobotany↗
PubMed2005

Decay of sperm obtained from epididymes of wild ruminants depending on postmortem time.

We have carried out a study on the effect of postmortem time (PT) in some characteristics of epididymal sperm salvaged from hunted Iberian red deer and roe deer. Testis were collected, identified, refrigerated down to 5 degrees C, and sent to our laboratory by the wardens of the hunting reserves. This way, samples were delivered at different times postmortem. Sperm were extracted from the cauda epididymis by means of cuts. Analyzed parameters were: osmolality, pH, motility-both subjectively and with CASA, HOS test reactivity, acrosomal status and viability (assessed with propidium iodide). Osmolality and pH rose with prolonged postmortem time, possibly due to tissue decomposition. Most sperm quality parameters negatively correlated with PT. Besides, when comparing PT classes (groups of 24 h for red deer and 30 h for roe deer), we could appreciate that motility was more affected by PT than other quality variables. Progressive motility was especially impaired. We also classified the samples in high, medium and low quality for each PT group (considering progressive motility, intact acrosomes and reactivity to the HOS test), and it was clear that after 2 days the number of high quality samples was testimonial, and after several days, we almost found only low quality samples. In conclusion, epididymal sperm from Iberian red deer and roe deer undergo a decrease of quality with PT, but it could stay acceptable within many hours postmortem. There are implications for wildlife conservation programs, as epididymal sperm is a good source of germplasm. If valuable animals die and it is not possible to process their sperm immediately, it may still be possible to obtain viable spermatozoa many hours later.

Acrosome↗
PubMed2002

Are dyspepsia management guidelines coherent with primary care practice?

BACKGROUND: Spontaneous physician behaviour can affect guideline applicability, implementation strategies and application costs, particularly in relation to widespread pathologies chiefly managed by general practitioners (GPs). Of the array of dyspepsia management guidelines, the closest to general practice, partly owing to proposing committee composition, are the European Society for Primary Care Gastroenterology (ESPCG) guidelines. METHODS: To evaluate variability in dyspepsia management among GPs in Padua and divergence in spontaneous prescriptive behaviour from the ESPCG dyspepsia guideline, we prospectively studied the behaviour of 39 GPs over a 3-month period of outpatient activity, through questionnaires on each consultation. Test-group representativeness was preliminarily defined in terms of antisecretory drug expenditure. RESULTS: 1790 forms on dyspepsia-related consultations were studied in a population of 51,193 registered patients; 1264 patients with a history of dyspeptic pathology consulted their GP (19% duodenal ulcer (DU), 9% gastric ulcer (GU), 54% gastro-oesophageal reflux disease (GERD), 32% non-ulcer dyspepsia (NUD), 1% cholelithiasis), while 526 patients presented with symptoms of dyspepsia with no previous gastroscopy (EGDS) (42% were aged <45 years), of whom 42% had twice consulted their GP. Empirical management by prescription of symptomatic drugs was the most common procedure in DU (33%), GU (73%) and NUD (74%) relapses. Helicobacter pylori eradication therapy was prescribed in only 2% of patients with a history of organic or functional dyspepsia. 145 patients with uninvestigated dyspepsia were referred for second-level endoscopy and 43 for H. pylori testing. Forty-four percent of endoscopies prescribed for uninvestigated patients did not comply with the ESPCG guideline; full compliance would have determined a 105% rise in endoscopies. Prescriptive variability between GPs was high (based on the Goodman-Kruskal (0.41, P < 0.001) and Cramer tests (V = 0.51, P < 0.005)) and agreement between observed and expected prescriptions according to ESPCG criteria was as low as V = 0.11. On the basis of the most frequently observed behaviours, we developed three options of the ESPCG guideline and compared them to spontaneous prescriptions. CONCLUSIONS: Highest compliance emerged where the clinical approach for all patients with uninvestigated dyspepsia was symptomatic therapy at first presentation followed by a different attitude at second presentation, setting a higher cut-off age than in the guideline (which in our case proved, on mathematical calculation, to be 55 years).

Adult↗
PubMed2001

A regulatory light chain of ciliary outer arm dynein in Tetrahymena thermophila.

Ciliary beat frequency is primarily regulated by outer arm dyneins (22 S dynein). Chilcote and Johnson (Chilcote, T. J., and Johnson, K. A. (1990) J. Biol. Chem. 256, 17257-17266) previously studied isolated Tetrahymena 22 S dynein, identifying a protein p34, which showed cAMP-dependent phosphorylation. Here, we characterize the molecular biochemistry of p34 further, demonstrating that it is the functional ortholog of the 22 S dynein regulatory light chain, p29, in Paramecium. p34, thiophosphorylated in isolated axonemes in the presence of cAMP, co-purified with 22 S dynein and not with inner arm dynein (14 S dynein). Isolated 22 S dynein containing phosphorylated p34 showed approximately 70% increase in in vitro microtubule translocation velocity compared with its unphosphorylated counterpart. Extracted p34 rebound to isolated 22 S dynein from either Tetrahymena or Paramecium but not to 14 S dynein from either ciliate. Binding of radiolabeled p34 to 22 S dynein was competitive with p29. Phosphorylated p34 was not present in axonemes isolated from a mutant lacking outer arms. Two-dimensional gel electrophoresis followed by phosphorimaging revealed at least five phosphorylated p34-related spots, consistent with multiple phosphorylation sites in p34 or perhaps multiple isoforms of p34. These new features suggest that a class of outer arm dynein light chains including p34 regulates microtubule sliding velocity and consequently ciliary beat frequency through phosphorylation.

Animals↗
PubMed2001

Effects of local bupivacaine instillation on pain after laparoscopy.

STUDY OBJECTIVE: To evaluate the effect of preincisional and intraperitoneal bupivacaine administration on immediate and late pain after operative laparoscopy. DESIGN: Randomized study (Canadian Task Force classification I). SETTING: University teaching hospital. PATIENTS: One hundred fifty women undergoing laparoscopy for various gynecologic indications. INTERVENTION: A dose of 0.5% bupivacaine 10 ml (50 mg) was injected into cannula sites before incisions and another 10 ml diluted with 100 ml saline into the peritoneal cavity at completion of the procedure. Equal amount of physiologic saline was used in controls. MEASUREMENTS AND MAIN RESULTS: Modified McGill pain intensity scores and amount of analgesic required in the recovery room and within 24 hours postoperatively were evaluated. Of 150 women, 142 completed the study (71 bupivacaine group, 71 controls). Groups did not differ significantly in body mass index, duration of surgery, return to consciousness, and analgesic requirement during 3-hour observation in the recovery room and 24 hours after discharge. Pain scores were highest 30 minutes after the procedure in both groups. At that time the pain score in the bupivacaine group was lower than that in the control group (1.8 +/- 0.2 vs 2.3 +/- 0.2, p <0.05). Beyond that time, the groups did not differ in pain scores and analgesic requirements. CONCLUSION: Postoperative pain is the highest within 30 minutes after laparoscopy. Local instillation of bupivacaine before incision and intraperitoneally was effective in reducing pain immediately after operative laparoscopy, but the effect was not seen beyond 30 minutes.

Anesthetics, Local↗
PubMed2001

Brown adipose tissue-specific insulin receptor knockout shows diabetic phenotype without insulin resistance.

Although insulin regulates metabolism in both brown and white adipocytes, the role of these tissues in energy storage and utilization is quite different. Recombination technology using the Cre-loxP approach allows inactivation of the insulin receptor in a tissue-specific manner. Mice lacking insulin receptors in brown adipocytes show an age-dependent loss of interscapular brown fat but increased expression of uncoupling protein-1 and -2. In parallel, these mice develop an insulin-secretion defect resulting in a progressive glucose intolerance, without insulin resistance. This model provides direct evidence for not only a role for the insulin receptors in brown fat adipogenesis, the data also suggest a novel role of brown adipose tissue in the regulation of insulin secretion and glucose homeostasis.

Adipose Tissue, Brown↗
PubMed2000

Synergistic gene interactions control the induction of the mitochondrial uncoupling protein (Ucp1) gene in white fat tissue.

Among a selected group of mouse strains susceptible to dietary obesity, those with an enhanced capacity for Ucp1 and brown adipocyte induction in white fat preferentially lost body weight following adrenergic stimulation. Based on the generality of this mechanism for reducing obesity, a genetic analysis was initiated to identify genes that control brown adipocyte induction in white fat depots in mice. Quantitative trait locus (QTL) analysis was performed using the variations of retroperitoneal fat Ucp1 mRNA expression in progeny of genetic crosses between the A/J and C57BL/6J parental strains and selected AXB recombinant inbred strains. Three A/J-derived loci on chromosomes 2, 3, and 8 and one C57BL/6J locus on chromosome 19 were linked to Ucp1 induction in retroperitoneal fat. Although A/J-derived alleles seemed to contribute to elevated Ucp1 expression, the C57BL/6J allele on chromosome 19 increased Ucp1 mRNA to levels higher than parental values. Thus, novel patterns of C57BL/6J and A/J recombinant genotypes among the four mapped loci resulted in a transgressive variation of Ucp1 phenotypes. Although the extent of the interchromosomal interactions have not been fully explored, strong synergistic interactions occur between a C57BL/6J allele on chromosome 19 and an A/J allele on chromosome 8. In addition to selective synergistic interactions between loci, variations in recessive and dominant effects also contribute to the final levels of Ucp1 expression.

Adipose Tissue↗
PubMed2000

The midvastus surgical approach in total knee arthroplasty.

We report a study of 2 surgical approaches to the knee in 42 consecutive patients undergoing a total arthroplasty. They were divided into 2 groups. In Group 1 (n=17) the knee was exposed through classic medial parapatellar arthrotomy and in Group 2 (n=25) the knee was approached through the fibers of the medial vastus. Preoperative assessment did not reveal any statistical differences between the groups, and blood loss, operation time, biochemistry values and radiographic evaluation were also similar. However, a higher number of lateral releases, a loss of knee extension and a reduced range of motion were significantly associated with classical parapatellar arthrotomy. As the number of operative or postoperative complications was not increased, we recommend the mid-vastus approach for total knee arthroplasty.

Aged↗
PubMed1999

A Sec7-related protein in Paramecium.

We have cloned and sequenced a SEC7-related gene in Paramecium tetraurelia that contains an open reading frame for 1135 amino acids encoding a 133 kDa protein, PSec7. Sec7, first identified in vesicular trafficking mutants in yeast, and its phylogenetic homologues function as guanine-nucleotide exchange factors for small G-proteins such as ARF (ADP-ribosylation factor). The deduced amino acid sequence in PSec7 for the motifs that form the ARF binding site are more than 70% identical to yeast Sec7 and similarly identical to ARNO, the human ARF exchange factor, with correct positioning of the critical glutamic acid residue within the motif region. Overall, the identity of PSec7 to yeast Sec7 is 32%. The deduced amino acid sequence also has five sequences that resemble IQ motifs, EF hand binding domains found in all myosins, and two pleckstrin homology domains. Similar sequences are present in yeast Sec7 and other Sec7-related molecules. A protein kinase A phosphorylation site may also be present. Southern blots suggest that a single gene encodes PSec7. Northern blots show that the message encoding PSec7 is induced on deciliation, followed by ciliogenesis, which suggests a role for PSec7 in cilia such as transport or targeting of ciliary membrane components.

Amino Acid Sequence↗
PubMed1998

Abnormal nonshivering thermogenesis in mice with inherited defects of fatty acid oxidation.

When placed in the cold (4 degreesC), BALB/cByJ mice of both genders rapidly lose body temperature as compared with the control strain, C57BL/6J. This sensitivity to cold resembles that previously described for mice with a defect in nonshivering thermogenesis due to the targeted inactivation of the brown adipocyte-specific mitochondrial uncoupling protein gene, Ucp1. Genetic mapping of the trait placed the gene on chromosome 5 near Acads, a gene encoding the short chain acyl CoA dehydrogenase, which is mutated in BALB/cByJ mice. The analysis of candidate genes in the region indicated a defect only in the expression of Acads. Confirmation of the importance of fatty acid oxidation to thermogenesis came from our finding that mice carrying the targeted inactivation of the long chain acyl CoA dehydrogenase gene (Acadl) are also sensitive to the cold. Both of these mutations attenuate the induction of genes normally responsive to adrenergic signaling in brown adipocytes. These results suggest that the action of fatty acids as regulators of gene expression has been perturbed in the mutant mice. From a clinical perspective, it is important to determine whether defects in thermogenesis may be a phenotype in human neonates with inherited deficiencies in fatty acid beta-oxidation.

Acyl-CoA Dehydrogenase↗
PubMed1998

Emergence of brown adipocytes in white fat in mice is under genetic control. Effects on body weight and adiposity.

The mRNA levels for the mitochondrial uncoupling protein (UCP1) in fat tissues of A/J and C57BL/6J inbred strains of mice varied in a regional-specific manner after stimulation of adrenergic signaling by cold exposure or treatment with a beta3-adrenergic agonist. While the differences between strains were minimal in interscapular brown fat, large differences occurred in white fat tissues, particularly in retroperitoneal fat. Among the AXB recombinant inbred strains, the Ucp1 mRNA levels varied up to 130-fold. This large induction at the mRNA level was accompanied by a corresponding increase in brown adipocytes as revealed by immunohistology with anti-UCP1 antibodies. A high capacity to induce brown fat in areas of traditional white fat had no impact on the ability to gain weight in response to high fat and sucrose diets, but did correlate with the loss of weight in response to treatment with a beta3-adrenergic agonist (CL 316,243). This genetic variation in mice provides an experimental approach to identify genes controlling the induction of brown adipocytes in white fat tissues.

Adipocytes↗
PubMed1997

Regional and temporal differences in real-time dopamine efflux in the nucleus accumbens during free-choice novelty.

To assess dopamine efflux during novelty-seeking behavior in rats, fast-scan cyclic voltammetry in the nucleus accumbens was combined with free-choice entry into a novel environment. Cyclic voltammograms, confirmed by in vitro testing, revealed that entry into novel, but not familiar, surroundings increased dopamine efflux in a regionally and temporally distinct pattern. Whereas dopamine failed to change in the core region of the accumbens and overlying neostriatum, an abrupt increase occurred in accumbal shell, a limbic-related area implicated in goal-directed behavior. Although the dopamine response was confined to the brief period of entry into novelty (approximately 8 s duration), a less rapid and more persistent dopamine change (> 20 s duration) occurred in the shell-core transition zone, the so-called shore. These results suggest that novelty mimics other positively reinforcing stimuli in enhancing dopamine transmission in the nucleus accumbens, but the regional and temporal heterogeneity of this effect may represent different aspects of accumbal dopamine function.

Animals↗
PubMed1997

Mice lacking mitochondrial uncoupling protein are cold-sensitive but not obese.

The mitochondrial uncoupling protein (UCP) in the mitochondrial inner membrane of mammalian brown adipose tissue generates heat by uncoupling oxidative phosphorylation. This process protects against cold and regulates energy balance. Manipulation of thermogenesis could be an effective strategy against obesity. Here we determine the role of UCP in the regulation of body mass by targeted inactivation of the gene encoding it. We find that UCP-deficient mice consume less oxygen after treatment with a beta3-adrenergic-receptor agonist and that they are sensitive to cold, indicating that their thermoregulation is defective. However, this deficiency caused neither hyperphagia nor obesity in mice fed on either a standard or a high-fat diet. We propose that the loss of UCP may be compensated by UCP2, a newly discovered homologue of UCP; this gene is ubiquitously expressed and is induced in the brown fat of UCP-deficient mice.

Adipose Tissue, Brown↗
PubMed1997

Metals of the bottom muds in Belize City Harbor, Belize.

Seven bottom samples extending from the ocean up through Belize Harbor and City were acid leached (EPA method 200.7) and analyzed using inductively coupled plasma spectrometry to measure the bioavailability of Cd, Cr, Cu, Pb and Zn. Soil and environmental chemists would compare data to world averages of unpolluted soils, these samples were higher than this average by a factor of 10 for Cd, 4 for Cu, 2.7 for Zn and 2.6 for Pb. Geochemists argue that it's hard to find unpolluted soil so their comparison is with world average of ancient (pre-man) shales and the Belize samples were higher than this shale average by a factor of 30 for Cd, 3.7 for Pb, 2.2 for Cu and 1.7 for Zn. Ecologists would argue that the metal effect on the biota is the correct way to analyze the data by using the biological effects toxicity method, and this way the samples were above the lower limit by a factor of 5.1 for Cd, 2.9 for Cu and 1.6 for Pb. By all three lines of reasoning, it can be concluded that Cd, Cu, Pb and Zn, in that order, pose environmental problems. Since this site is located in the middle of Belize Barrier Reef, a highly sensitive environmental area that is also economically important to Belize, it poses a critical problem that needs to be addressed further.

Journal Article↗
PubMed1996

Triiodothyronine induces the transcription of the uncoupling protein gene and stabilizes its mRNA in fetal rat brown adipocyte primary cultures.

Confluent fetal rat brown adipocytes in primary culture showed an almost undetectable level of uncoupling protein (UCP) mRNA and a low mitochondrial content of functional UCP. Treatment of confluent cells with 10 nM triiodothyronine in a serum-free medium, in the absence of noradrenergic stimulation, increased the amount of UCP mRNA in a time-dependent manner. This effect was due to an increased UCP gene transcription rate and UCP mRNA stabilization, resulting in a higher content of immunoreactive mitochondrial UCP and functional UCP (detected by its ability to bind GDP). Thus, triiodothyronine might play a significant physiological role in the UCP expression throughout fetal development, when brown adipose tissue starts to differentiate and UCP is primarily expressed.

Adipose Tissue, Brown↗
PubMed1996

Sternoclavicular septic arthritis in a patient with end-stage liver disease.

Sternoclavicular septic arthritis is an uncommon clinical entity that is often misdiagnosed on initial presentation. It has generally been described in IV heroin users and immunocompromised hosts. We report the case of a 43-year-old woman with endstage liver disease who presented with a fever, a painful sternoclavicular joint, and gastrointestinal bleeding. The clinical presentation, diagnosis, and treatment of sternoclavicular septic arthritis are reviewed.

Adult↗
PubMed1996

Transjugular intrahepatic portosystemic shunt versus sclerotherapy in the elective treatment of variceal hemorrhage.

BACKGROUND & AIMS: Uncontrolled studies suggest that placement of a transjugular intrahepatic portosystemic shunt (TIPS) could be useful in the treatment of variceal bleeding. The aim of this study was to evaluate the efficacy and safety of TIPS in the elective treatment of hemorrhage from esophageal varices in a randomized controlled study that compared the effects of TIPS with those of endoscopic sclerotherapy (ES). METHODS: Sixty-three consecutive cirrhotic patients with hemorrhage from esophageal varices were included. Thirty-two patients were randomly allocated to ES and 31 to TIPS groups. RESULTS: One patient in each group died before the therapeutic procedure could be performed. During a mean follow-up period of 15 months, variceal rebleeding occurred in 51.6% of the patients in the ES group and 23% of those in the TIPS group. Uncontrolled rebleeding occurred in 10 of 31 patients in the ES group, whereas rebleeding did not occur in any patient of the TIPS group. Hepatic encephalopathy was more frequent in TIPS patients (33.3%) than in those treated by ES (13%). However, mortality was similar in both treatment groups. CONCLUSIONS: These preliminary results suggest that TIPS is more effective than ES in the prevention of variceal rebleeding in cirrhotic patients, even though no difference in survival was observed.

Adult↗