Age, growth and demography of the silky shark Carcharhinus falciformis from the southwestern Atlantic

The silky shark Carcharhinus falciformis is considered one of the least productive pelagic shark species. The estimation of growth and demographic parameters presented here is fundamental to a sound knowledge of population status of the species in the Atlantic Ocean. Data was collected through an onboard observer program of the Brazilian chartered pelagic longline fishing fleet that operates in the Equatorial Southwestern Atlantic. Vertebral analysis produced the von Bertalanffy growth parameters for pooled sexes L∞ = 283.05 cm; k = 0.0987 yr-1 and t0 = -3.47 yr. Males reached sexual maturity at 8.6 yr and females at 9.9 yr. Longevity was estimated at 27.2 yr. Age structure analysis indicated that 80.5% of the catch was composed of juveniles, with recruitment to the fishery from the first year of life (age 1+). These biological parameters are responsible for the species’ low resistance to fishing pressure, and our demographic analysis (Leslie Matrix) shows an annual population decline of 12.7% yr-1 under the current fishing scenario for the period analyzed. Therefore, conservation measures must be enacted to reestablish the population of silky sharks to safe levels for the maintenance of this species in the South Atlantic.

Chlamydia trachomatis Infections in a Tertiary Care Portuguese Hospital: An 11-Year Retrospective Study

BACKGROUND

Chlamydia trachomatis infections remain a burden worldwide. The goals of this study were to determine the number of C. trachomatis infections per year, characterize the demographic traits of the infected population and identify the associated sexually transmitted infections (STI), over the last 11 years, in Lisbon main Hospital Centre.

MATERIALS AND METHODS

Laboratorial confirmed C. trachomatis infections diagnosed between January 1st, 2009 and December 31st, 2019 were evaluated.

RESULTS

A total of 6404 samples were collected, with 602 being positive for C. trachomatis, corresponding to 550 patients. 60% of diagnoses were made by dermatovenereologists and most cases occurred in males (n = 371; 67.5%), with a median age of 26.1 years (standard deviation 7.98), ranging from 13 to 68 years. More than half the cases (51.3%) occurred below the age of 25 years. In 87 patients (15.8%) there was previous history of STI, in 198 patients (36%) a concomitant STI was present and 43 patients (7.8%) developed a posterior STI. Concerning follow-up, 196 patients (corresponding to 35.6% of total patients) did not show for a re-evaluation after the diagnosis was made.

CONCLUSION

Confirmed cases of C. trachomatis infection have risen along the years, affecting mainly people younger than 25 years. C. trachomatis infection is especially associated with Neisseria gonorrhoeae infection, but other STI are also very prevalent. Considering the potential complications of C. trachomatis infection, screening and treatment are necessary. The high percentage of diagnoses made by dermatovenereologists support the pivotal role of dermatovenereology in diagnosing C. trachomatis infections.

Chlamydia trachomatis Infections in a Tertiary Care Portuguese Hospital: An 11-Year Retrospective Study

BACKGROUND

Chlamydia trachomatis infections remain a burden worldwide. The goals of this study were to determine the number of C.trachomatis infections per year, characterize the demographic traits of the infected population and identify the associated sexually transmitted infections (STI), over the last 11years, in Lisbon main Hospital Centre.

MATERIALS AND METHODS

Laboratorial confirmed C.trachomatis infections diagnosed between January 1st, 2009 and December 31st, 2019 were evaluated.

RESULTS

A total of 6404 samples were collected, with 602 being positive for C.trachomatis, corresponding to 550 patients. 60% of diagnoses were made by dermatovenereologists and most cases occurred in males (n=371; 67.5%), with a median age of 26.1years (standard deviation 7.98), ranging from 13 to 68years. More than half the cases (51.3%) occurred below the age of 25years. In 87 patients (15.8%) there was previous history of STI, in 198 patients (36%) a concomitant STI was present and 43 patients (7.8%) developed a posterior STI. Concerning follow-up, 196 patients (corresponding to 35.6% of total patients) did not show for a re-evaluation after the diagnosis was made.

CONCLUSION

Confirmed cases of C.trachomatis infection have risen along the years, affecting mainly people younger than 25 years. C.trachomatis infection is especially associated with Neisseriagonorrhoeae infection, but other STI are also very prevalent. Considering the potential complications of C.trachomatis infection, screening and treatment are necessary. The high percentage of diagnoses made by dermatovenereologists support the pivotal role of dermatovenereology in diagnosing C.trachomatis infections.

Nonlinear fluctuating hydrodynamics with many conserved fields: The case of a three-dimensional anharmonic chain

We propose a model for a chain vibrating in three dimensions, with first neighbors anharmonic interatomic potential, which depends on their distance, and subjected to an external tension. In the framework of the nonlinear fluctuating hydrodynamic theory, which was successfully applied to one-dimensional chains, we obtain a heat mode, two longitudinal, and four transverse sound modes. We compute their spatiotemporal correlations comparing the theoretical results with molecular dynamics simulations, finding a good agreement for high temperatures. We find that the transverse sound modes behave diffusively, meanwhile the heat and longitudinal sound modes behave superdiffusively, exploring their possible scaling functions and characteristic exponents.

Mutation in the Sodium Channel Gene Corresponds With Phenotypic Resistance of Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) to Pyrethroids

The brown dog tick, Rhipicephalus sanguineus sensu lato (Latreille), is a cosmopolitan ectoparasite and vector of pathogens that kill humans and animals. Pyrethroids represent a class of synthetic acaricides that have been used intensely to try to control the brown dog tick and mitigate the risk of tick-borne disease transmission. However, acaricide resistance is an emerging problem in the management of the brown dog tick. Understanding the mechanism of resistance to acaricides, including pyrethroids, is important to adapt brown dog tick control strategies. The main objective of this study was to determine if target-site mutations associated with pyrethroid resistance in other pests could be associated with phenotypic resistance detected in a brown dog tick population from Florida. We amplified segment 6 of the domain III of the voltage-sensitive sodium channel protein, using cDNAs synthesized from pyrethroid-susceptible and pyrethroid-resistant tick strains. A single nucleotide point mutation (SNP) identified in a highly conserved region of domain III S6 in the resistant ticks resulted in an amino acid change from phenylalanine to leucine. This mutation is characteristic of resistance phenotypes in other tick species, and is the first report of this mutation in R. sanguineus. Molecular assays based on this knowledge could be developed to diagnose the risk for pyrethroid resistance, and to inform decisions on integrated brown dog tick management practices.

Neutrophil gelatinase-associated lipocalin is a biomarker of acute-on-chronic liver failure and prognosis in cirrhosis

BACKGROUND & AIMS

Acute-on-chronic liver failure (ACLF) is a syndrome that occurs in cirrhosis characterized by organ failure(s) and high mortality rate. There are no biomarkers of ACLF. The LCN2 gene and its product, neutrophil gelatinase-associated lipocalin (NGAL), are upregulated in experimental models of liver injury and cultured hepatocytes as a result of injury by toxins or proinflammatory cytokines, particularly Interleukin-6. The aim of this study was to investigate whether NGAL could be a biomarker of ACLF and whether LCN2 gene may be upregulated in the liver in ACLF.

METHODS

We analyzed urine and plasma NGAL levels in 716 patients hospitalized for complications of cirrhosis, 148 with ACLF. LCN2 expression was assessed in liver biopsies from 29 additional patients with decompensated cirrhosis with and without ACLF.

RESULTS

Urine NGAL was markedly increased in ACLF vs. no ACLF patients (108(35-400) vs. 29(12-73)μg/g creatinine; p<0.001) and was an independent predictive factor of ACLF; the independent association persisted after adjustment for kidney function or exclusion of variables present in ACLF definition. Urine NGAL was also an independent predictive factor of 28day transplant-free mortality together with MELD score and leukocyte count (AUROC 0.88(0.83-0.92)). Urine NGAL improved significantly the accuracy of MELD in predicting prognosis. The LCN2 gene was markedly upregulated in the liver of patients with ACLF. Gene expression correlated directly with serum bilirubin and INR (r=0.79; p<0.001 and r=0.67; p<0.001), MELD (r=0.68; p<0.001) and Interleukin-6 (r=0.65; p<0.001).

CONCLUSIONS

NGAL is a biomarker of ACLF and prognosis and correlates with liver failure and systemic inflammation. There is remarkable overexpression of LCN2 gene in the liver in ACLF syndrome.

LAY SUMMARY

Urine NGAL is a biomarker of acute-on-chronic liver failure (ACLF). NGAL is a protein that may be expressed in several tissues in response to injury. The protein is filtered by the kidneys due to its small size and can be measured in the urine. Ariza, Graupera and colleagues found in a series of 716 patients with cirrhosis that urine NGAL was markedly increased in patients with ACLF and correlated with prognosis. Moreover, gene coding NGAL was markedly overexpressed in the liver tissue in ACLF.

Experimental radiotherapy-induced enteritis: a probiotic interventional study

OBJECTIVE

Acute radiation of the small intestine causes an immediate and potentially reversible effect on the sensitive regenerative epithelium of the intestinal mucosa while markedly altering the overall intestinal ecosystem. The aim of the present study was test a novel probiotic mixture formulation (Microflorana-F) in an experimental model of acute radiation enteritis with particular interest in endotoxinemia and bacterial translocation.

MATERIALS AND METHODS

Male Wistar rats allocated to three groups were fed for 7 days with: (A) a standard balanced diet; (B) a standard diet with the addition of 1 mL t.i.d. of Microflorana-F and (C) the same probiotic but after heat inactivation. Under ketamine anesthesia, abdominal irradiation was performed at a single dose rate of 20 Gy. Sham-radiated healthy rats served as a control (D). Standard food and active/inactive probiotic supplementation schedule was maintained throughout the study period. When they were killed 14 days later a midline laparotomy and a medium sternotomy was carried out. The mesenteric lymph nodes, whole spleen and liver samples as well as blood, the portal vein and bile samples were cultured. Endotoxinemia was also measured.

RESULTS

Early deaths (1 week) occurred mostly in rats fed standard food or inactivated probiotic. The endotoxin level significantly increased in irradiated rats fed standard food and inactivated probiotic while supplementation with the active form of the probiotic mixture significantly improved such parameters (P < 0.05). After radiation injury, mesenteric lymph nodes and portal blood were the samples most frequently yielding bacterial growth. Treatment with only the active form of probiotic significantly reduced the incidence of bacterial contamination in all samples.

CONCLUSIONS

These data suggest that the manipulation of gut ecosystem by biologically effective probiotic preparations might be a worthwhile therapeutic and preventive tool in radiation-induced enteritis.

Preventive strategy for Candida gut translocation during ischemia-reperfusion injury supervening on protein-calorie malnutrition

OBJECTIVE

The aim of the present study was to test the hypothesis that protein-calorie malnutrition aggravates the gut translocation of Candida albicans triggered by mesenteric ischemia-reperfusion (IR) injury in an experimental model while testing a natural product containing the antifungal anethole/polygodial mixture (Kolorex).

METHODS

MFI strain white mice (n = 90) were randomly allocated to a 4-week dietary regimen: (1) standard pellet diet containing 25% casein; (2) low-protein (2.5%) casein diet; (3) as group 2 plus oral supplementation with 20 microL of a 5% solution of Kolorex during the last 4 days. Twenty rats from each of these groups (termed 1a, 2a and 3a) were orally inoculated with Candida suspension 6 h prior to mesenteric IR injury. Animals of each group but without Candida inoculation (termed 1b, 2b and 3b) served as control. A colon permeability study was carried out as well. Rats were killed prior to the IR injury and 3 h afterwards. Control rats were killed at the same time.

RESULTS

Over 60% of the mesenteric lymph nodes and 30% of kidney samples were positive for C. albicans in the low-protein-fed rats after IR injury. Kolorex significantly decreased that rate of positivity and also significantly reduced the concentration of C. albicans per gram of each positive tissue sample examined. Protein-calorie malnourished animals showed a statistically significant increase in colon permeability and this phenomenon further increased after IR injury. The groups of rats treated with Kolorex compound showed a partial, although significant, improvement of this parameter.

CONCLUSIONS

These results suggest that Kolorex might exert a competitive effect against with C. albicans colonization. The present study represents the first experimental in vivo investigation of the anethole/polygodial-containing compound under the specific conditions of calorie-protein malnutrition and the results have potential clinical interest.

Experimental acute alcohol pancreatitis-related liver damage and endotoxemia: synbiotics but not metronidazole have a protective effect

OBJECTIVE

The aim of this study was to test the effect of gut manipulation by either novel synbiotics or by metronidazole on either endotoxemia or the severity of liver damage in the course of acute pancreatitis from alcohol ingestion.

METHODS

Sprague-Dawley rats were fed for 1 week through an intragastric tube a liquid diet with either: (i) 1 mL t.i.d. of a mixture of synbiotics (Lactobacillus acidophilus, Lactobacillus helveticus and Bifidobacterium in an enriched medium); (ii) 20 mg/kg t.i.d. metronidazole; or (iii) standard diet. Then, acute pancreatitis was induced by caerulein and when the disease was full-blown, rats were fed an alcohol-rich diet. Synbiotic and metronidazole treatment was given for a further 2 weeks. Transaminase and endotoxemia levels were measured before treatment, after 6 h, after 24 h and 2 weeks later, at the time the rats were killed. Liver samples were obtained for histological analysis.

RESULTS

Synbiotics but not metronidazole improved the acute pancreatitis-induced increase in endotoxemia and transaminase levels. The addition of alcohol worsened these variables to a limited extent in the synbiotic-treated group, while metronidazole had a negative effect on liver damage.

CONCLUSIONS

Gut flora pretreatment with synbiotics was able to effectively protect against endotoxin/bacterial translocation, as well as liver damage in the course of acute pancreatitis and concomitant heavy alcohol consumption. The beneficial effect of synbiotics on liver histology seems to be correlated with endotoxemia. Metronidazole did not produce such a beneficial effect; in fact, it further worsened liver damage when alcohol was added to the background of ongoing acute pancreatic inflammation.

Metal-induced oxidative damage in cultured hepatocytes and hepatic lysosomal fraction: beneficial effect of a curcumin/absinthium compound

OBJECTIVE

Metals undergo redox cycling and there is increasing evidence of free radical generation and oxidative injury in the pathogenesis of liver injury and fibrosis in metal storage diseases. The aim of the present study was to test a natural hepatoprotective compound in metal-induced liver injury.

METHODS

Hepatocytes were isolated from Wistar rats by collagenase perfusion method and cultured as such and also with alpha-linolenic acid (LNA)-bovine serum albumin (BSA). Hepatocytes were then cultured with a graded dilution of PN-M001 (100 microg/mL and 200 microg/mL), which is a curcuma/absinthium-containing compound, or sylibin (100 microg/mL) dissolved in dimethyl sulfoxide for 10 min before the addition of metallic salts (iron, copper and vanadium). Lysosomal fractions were prepared for lysosome fragility tests in which beta-galactosidase activity and lactate dehydrogenase (LDH) leakage were measured, as well as oxidative damage tests in the presence of hydrophilic and lipophilic free radical generators. Quenching activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) was also assessed.

RESULTS

Malonildialdehyde accumulation in the medium showed a direct time-course increase with incubation time. Both PN-M001 and sylibin showed a significant protective effect against all challenge metal ions, as expressed by the half inhibition concentration (IC(50)) against lipid peroxidation. However, on a molar ratio, sylibin seemed to be more effective than PN-M001 in Fe-induced peroxidative damage (P < 0.05). Both test compounds, irrespective of the concentration, significantly reduced the LDH and beta-galactosidase concentration in the lysosomal fractions. As compared with untreated lysosomal fractions challenged with the two peroxide radicals generators, either PN-M001 or sylibin exerted significant protection However, PN-M001 was significantly better than sylibin in suppressing acid phosphatase enzyme activity. Both compounds showed comparable and significant DPPH radical-scavenging activity.

CONCLUSION

These data support the potential clinical application of curcumin-containing compounds.

The aging/precancerous gastric mucosa: a pilot nutraceutical trial

The aim of this study was to test the effect of antioxidant supplementation on enzymatic abnormalities and free radical-modified DNA adducts associated with premalignant changes in the gastric mucosa of elderly patients with HP-negative atrophic gastritis (CAG). Sixty patients with atrophic gastritis and intestinal metaplasia underwent a nutritional interview and a gastroscopy with multiple biopsy samples in the antrum that were processed for histology and for assaying: alpha-tocopherol, MDA, xanthine oxidase (XO), ornithine decarboxylase (ODC), and 8-OHdG. Patients were randomly allocated into three matched groups and supplemented for 6 months with (1) vitamin E, 300 mg/day; (2) multivitamin, two tablets t.i.d.; and (3) Immun-Age 6 g/day nocte (ORI, Gifu, Japan), a certified fermented papaya preparation with basic science-validated antioxidant/immunomodulant properties. Ten dyspeptic patients served as controls. Histology and biochemistry were blindly repeated at 3 and 6 months. CAG patients showed a significantly (P <.05) increased level of mucosal MDA and XO concentration that were reverted to normal by each supplementation (P <.05). All supplements caused a significant decrease of ODC (P <.01), but Immun-Age yielded the most effective (P < 0.05) and was the only one significantly decreasing 8-OhdG (P < 0.05). These data suggest that antioxidant supplementation, and, namely, Immun-Age, might be potential chemopreventive agents in HP-eradicated CAG patients and especially in the elderly population.

Single-blind follow-up study on the effectiveness of a symbiotic preparation in irritable bowel syndrome

OBJECTIVE

Experimental and clinical studies have shown that a novel symbiotic (known as SCM-III) exerts a beneficial effect on gut translocation and local and systemic inflammatory and microbial metabolic parameters. The present investigation was a preliminary trial on the effectiveness of SCM-III for irritable bowel syndrome (IBS).

METHODS

Sixty-eight consecutive adult patients with IBS who were free from lactose malabsorption, abdominal surgery, overt psychiatric disorders and ongoing psychotropic drug therapy or ethanol abuse were studied prospectively and divided into 2 groups that were comparable for age, gender, body size, education and pattern of presenting symptoms. The 2 groups were blindly given for 12 weeks either SCM-III 10 mL t.i.d or the same dosage of heat-inactivated symbiotic.

RESULTS

Treatment with SCM-III was 'effective' or 'very effective' in more than 80% of the patients (P < 0.01 vs baseline values and control). Less than 5% reported 'not effective' as the final evaluation compared with over 40% of patients in the control group. After 6 weeks of treatment, a significant improvement of pain and bloating was reported in the treatment group compared with control and baseline values. There was also a benefit for bowel habits, mostly for patients with constipation or alternating bowel habits. No overt clinical or biochemical adverse side-effects were recorded.

CONCLUSION

Compared with baseline values and the control group, SCM-III resulted in a significant increase in lactobacilla, eubacteria and bifidobacteria, which suggests that some selected IBS patients could benefit substantially from symbiotics, but the treatment may need to be given on a cyclic schedule because of the temporary modification of the fecal flora.

Cyanocobalamin absorption abnormality in alcoholics is improved by oral supplementation with a fermented papaya-derived antioxidant

BACKGROUND/AIMS

Thirty alcoholic patients and 24 teetotaler dyspeptic patients were considered and underwent baseline blood chemical evaluation and the Schilling test.

METHODOLOGY

During gastroscopy, biopsy samples were taken to assay: routine histology, malonyldialdehyde, vitamin E and glutathione concentration and for testing vitamin B12-Intrinsic Factor binding. Examinations were repeated after 1-week supplementation with Bionormalizer.

RESULTS

Plasma malonyldialdehyde level and lipid hydroperoxides concentration as well as either malonyldialdehyde and xanthine oxidase concentration in the gastric mucosa in alcoholics were significantly higher than in controls and despite unchanged alcohol consumption, significantly decreased after Bionormalizer supplementation. Gastric mucosal glutathione was markedly depressed in alcoholics and partly recovered after Bionormalizer supplementation. Although the alcoholics showed a normal intrinsic factor secretion in the gastric juice, they exhibited a markedly depressed intrinsic factor-cobalamin binding on the "ex vivo" study. Moreover, nearly 23% of them had an abnormal Schilling test. Both these impairments reverted to normal after Bio-normalizer supplementation.

CONCLUSIONS

It can be postulated that the antioxidative action played by Bionormalizer, possibly due to its availability substrates for glutathione synthesis as well as to its effects on local oxidative burst from neutrophil, is able to recover a normal cobalamin absorption.

Pure pancreatic juice from patients with chronic pancreatitis has an impaired antibacterial activity

CONCLUSION

These data show that pure pancreatic juice of AICP patients has a markedly defective antibacterial activity. This finding might be of potential clinical interest in the understanding of the pathophysiology of the disease.

BACKGROUND

The aim of the present study was to test the antibacterial activity of pure pancreatic juice in patients with chronic pancreatitis.

METHODS

The study group consisted of ten patients with ethanol-induced chronic pancreatitis (AICP) and seven control patients free of pancreatic disease. All subjects had recently undergone a secretin-pancreozymin pancreatic function test. After an overnight fast, through a side-viewing endoscope, selective pancreatic duct cannulation was performed. After secretin stimulation, pure pancreatic juice was obtained. Three fractions of different molecular weights were separated. Samples were incubated with 1-mL suspension of 10(5) Escherichia coli ATCC 25,922, and log10 of colony-forming units were counted. Experiments were repeated by grading pancreatic juice concentration, pH of the medium, and inoculum size.

RESULTS

No significant change of pH of pure pancreatic juice appeared between AICP and controls. Starting from 6-h observation, pure pancreatic juice of AICP patients showed a significant bacterial colonization vs controls (p < 0.01). A direct correlation appeared between bacterial colonization and either pH and dilution of pancreatic juice (p < 0.001). Antibacterial activity was independent of inoculum size, enzymatic activation or inhibition, and heat treatment. The fraction with 1000-10,000 molecular weight was the one endowed with antibacterial activity.

Genetic analysis of the transcriptional arrangement of Azotobacter vinelandii alginate biosynthetic genes: identification of two independent promoters

The study of alginate biosynthesis, the exopolysaccharide produced by Azotobacter vinelandii and Pseudomonas aeruginosa, might lead to different biotechnological applications. Here we report the cloning of A. vinelandii algA, the gene coding for the bifunctional enzyme phosphomannose isomerase-guanosine diphospho-o-mannose pyrophosphorylase (PMI-GMP). This gene was selected by the complementation for xanthan gum production of Xanthomonas campestris pv. campestris xanB-mutants, which lack this enzymatic activity. The complementing cosmid clones selected, besides containing algA, presented a gene coding for an alginate lyase activity (algL), and some of them also contained algD which codes for GDP-mannose dehydrogenase. We present here the characterization of the A. vinelandii chromosomal region comprising algD and its promoter region, algA and algL, showing that, as previously reported for P. aeruginosa, A. vinelandii has a cluster of the biosynthetic alginate genes. We provide evidence for the presence of an algD-independent promoter in this region which transcribes at least algL and algA, and which is regulated in a manner that differs from that of the algD promoter.

Estimating past and present sex ratios of sea turtles in Suriname

Leatherback (Dermochelys coriacea) and green (Chelonia mydas) sea turtles in Suriname lay eggs over several months of the year. During this nesting season, changes in rainfall produce changes in sand temperature, which in turn influence the sexual differentiation of incubating sea turtle embryos. The overall sex ratio of leatherback and green sea turtle hatchlings produced at Matapica beach in Suriname was investigated. Estimates of the sex ratios of these turtles in 1993 (green turtles 63.8% female, leatherbacks 69.4% female) were roughly 10% more female-biased than those from an earlier study in 1982. For both species, a significant negative relationship was found between monthly rainfall and monthly sex ratios. Using this relationship and data on rainfall in the past, it was possible to estimate overall sex ratios for an additional 12 years. These estimates varied considerably among different years, ranging from 20 to 90% female in the case of green turtles. Nevertheless, males tended to be produced primarily in April and May, while some females were produced in all months. Such seasonal patterns of production of turtles of different sexes have implications for sea turtle conservation programs that involve manipulating or harvesting eggs.