MERS-CoV in a healthcare worker in Jeddah, Saudi Arabia: an index case investigation

In September 2015, a confirmed case of Middle East respiratory syndrome (MERS) was diagnosed in a healthcare worker in Jeddah, Saudi Arabia. Given the absence of confirmed MERS cases in Jeddah at the time, an epidemiological index case investigation took place. The investigation identified a probable source of an index case who had been in hospital in Jordan in August 2015 while there was an ongoing MERS outbreak and who then subsequently sought medical care in Jeddah.

The Effect of Protease Inhibitors on Digestive Proteolytic Activity in the Raspberry Weevil, Aegorhinus superciliosus (Guérin) (Coleoptera: Curculionidae)

The raspberry weevil, Aegorhinus superciliosus (Guérin) (Coleoptera: Curculionidae), is an economically important pest of blueberry in southern Chile. The digestive protease activity of adult insects was investigated using general and specific substrates and inhibitors. Enzymatic assays demonstrated the presence of trypsin- and chymotrypsin-like serine proteinases. Furthermore, in vitro assays using phenylmethylsulfonyl fluoride (PMSF) and soybean trypsin inhibitor (SBTI) at 0.01 and 0.1 mM showed percentages of enzymatic inhibition between 0 and 16% for PMSF and 67 to 76% for SBTI, whereas in vivo assays indicated that SBTI caused between 50 and 90% mortality in males and between 80 and 100% in females. Our data indicate the presence of serine proteases and suggest that digestive proteases could be a target for the design and development of strategies to control the raspberry weevil.

Morphology and Distribution of Sensilla on the Antennae of Hylamorpha elegans Burmeister (Coleoptera: Scarabaeidae)

Considering that sensilla constitute important functional elements of sensory systems in insects, the aim of this study was to determine the type and distribution of sensilla in the antennae of Hylamorpha elegans Burmeister examined by scanning electron microscopy. Hylamorpha elegans antennae are lamellate and consist of the scape, pedicel, and flagellum. The antennal club of this beetle consists of three terminal plates: proximal, middle, and distal lamellae. Four types of sensilla were observed in the lamellae from both sexes: sensilla trichoidea, chaetica, coeloconica, and placodea. Antennal length was larger in males than in females, and significant sexual variation in the number of sensilla placodea and sensilla coeloconica was observed.

Molecular Characterization and In Silico Analysis of the Pheromone-Binding Protein of the European Grapevine Moth Lobesia botrana (Denis & Schiffermüller) (Lepidoptera, Tortricidae)

The European grapevine moth Lobesia botrana (Denis & Schiffermüller) is an economically important insect in Europe. The species invaded vineyards in Chile, Argentina, and California during 2008-2010 causing severe problems. A major component of the sex pheromone, (E,Z)-7,9-dodecadienyl acetate (E7,Z9-12:Ac), is used in a mating disruption technique when grapevine moth populations are low or to monitor pest numbers. It is thought that these sexual pheromones are blends of volatiles that typically are specific to a species and are transported in the insect antenna by pheromone-binding proteins (PBPs) across the sensillar lymph to the olfactory receptors. Currently, an increasing number of Lepidopteran PBPs are being identified and cloned. However, there are no studies of the olfactory system and of proteins involved in the olfactory perception of L. botrana at the molecular level. In the present study, we report, for the first time, the sequence of a PBP from L. botrana (LbotPBP), which was determined using reverse transcription technology. Homology modeling was used to generate the three-dimensional protein structure. The model suggests that PBP consists of six α-helices as follows: Lys2-Met23 (α1), Thr28-Phe36 (α2), Arg46-Leu59 (α3), His70-Asn80 (α4), Glu84-Asn100 (α5), and Cys108-Lys125 (α6), held together by three disulfide bridges, Cys19-Cys54, Cys50-Cys108, and Cys97-Cys117. Docking simulations based on this model suggested that Trp114 is a key residue in the recognition of acetate pheromones, such as E7,Z9-12:Ac. In silico results in this study are consistent with previous findings in which E7,Z9-12:Ac acts as the most active compound in behavioral and electroantennographic assays.

Xpert® MTB/RIF in pleural fluid for the diagnosis of tuberculosis

An automated nucleic acid amplification assay that simultaneously identifies Mycobacterium tuberculosis and rifampicin resistance, the Xpert® MTB/RIF test, has undergone extensive evaluation in sputum samples. Our aim was to define its diagnostic accuracy when performed on pleural fluid specimens. In 67 patients with pleural effusions, of whom half had tuberculous pleuritis, Xpert yielded 15% sensitivity and 100% specificity in the detection of tuberculosis (TB). Positive Xpert results tended to be more common in patients with microbiologically confirmed TB. Due to its low sensitivity, Xpert testing of pleural fluids has a limited role in the work-up of pleural effusions.

Olfactory response of Haematobia irritans (Diptera: Muscidae) to cattle-derived volatile compounds

In Chile, the horn fly, Hematobia irritans (L., 1758), is a major pest of grazing cattle and affects livestock production during the summer. Previous studies in Europe and the United States have shown that cattle flies, including H. irritans, are differentially attracted to individual cattle within herds and that volatile semiochemicals are responsible for this phenomenon. This study provides evidence that similar differential attractiveness occurs for the interaction between Chilean Holstein-Friesian cattle herds and local H. irritans populations. Thus, Holstein-Friesian dairy cattle, Bos taurus, which were of similar age and physiological condition, were shown to possess an uneven distribution of H. irritans. Heifers h6904 and h8104 were defined as low-carrier heifers and h5804, h2304 and h1404 as high-carrier heifers. Gas chromatography (GC) and coupled GC-mass spectrometric (GC-MS) analysis of samples collected from heifers revealed the presence of compounds previously reported as semiochemicals for cattle flies, including meta- and para-cresol, methylketones (C8-C11), and 6-methyl-5-hepten-2-one. Other compounds identified included carboxylic acids (butanoic, 3-methylbutanoic, pentanoic, and hexanoic acids), 1-hexanol, and 3-octanone. In Y-tube olfactometer studies, both m- and p-cresol attracted H. irritans at the highest doses tested (10(-6) g), as did the positive control 1-octen-3-ol. Of the other compounds tested, only 2-decanone and 2-undecanone produced a behavioral response, with significantly more flies being recorded in the control arm when the former compound was tested (at 10(-6) and 10(-8) g), and more flies being recorded in the treated arm for the latter compound (at 10(-7) g). This demonstration of behavioral activity with the identified compounds represents a first step for research into the application of semiochemicals in monitoring and control of cattle flies in Chile.

Isotopic compositions of cometary matter returned by Stardust

Hydrogen, carbon, nitrogen, and oxygen isotopic compositions are heterogeneous among comet 81P/Wild 2 particle fragments; however, extreme isotopic anomalies are rare, indicating that the comet is not a pristine aggregate of presolar materials. Nonterrestrial nitrogen and neon isotope ratios suggest that indigenous organic matter and highly volatile materials were successfully collected. Except for a single (17)O-enriched circumstellar stardust grain, silicate and oxide minerals have oxygen isotopic compositions consistent with solar system origin. One refractory grain is (16)O-enriched, like refractory inclusions in meteorites, suggesting that Wild 2 contains material formed at high temperature in the inner solar system and transported to the Kuiper belt before comet accretion.

Comet 81P/Wild 2 Under a Microscope

The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these samples shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixing on the grandest scales.

Hemobilia in hereditary hemorrhagic telangiectasia: an unusual complication of endoscopic retrograde cholangiopancreatography

Hepatobiliary manifestations of hereditary hemorrhagic telangiectasia (HHT) are rare, but often involve cholestasis. We report here a case of HHT associated with cholestasis due to common bile duct stenosis. Attempted balloon dilation of the stenosis during endoscopic retrograde cholangiopancreatography (ERCP) resulted in hemobilia. Hemostasis was achieved by adjusting the nasobiliary drain. The aim of this report is to highlight the biliary manifestations of HHT and draw attention to an unusual complication of ERCP in this setting.

Computational and experimental studies of the catalytic mechanism of Thermobifida fusca cellulase Cel6A (E2)

Mutagenesis experiments suggest that Asp79 in cellulase Cel6A (E2) from Thermobifida fusca has a catalytic role, in spite of the fact that this residue is more than 13 A from the scissile bond in models of the enzyme-substrate complex built upon the crystal structure of the protein. This suggests that there is a substantial conformational shift in the protein upon substrate binding. Molecular mechanics simulations were used to investigate possible alternate conformations of the protein bound to a tetrasaccharide substrate, primarily involving shifts of the loop containing Asp79, and to model the role of water in the active site complex for both the native conformation and alternative low-energy conformations. Several alternative conformations of reasonable energy have been identified, including one in which the overall energy of the enzyme-substrate complex in solution is lower than that of the conformation in the crystal structure. This conformation was found to be stable in molecular dynamics simulations with a cellotetraose substrate and water. In simulations of the substrate complexed with the native protein conformation, the sugar ring in the -1 binding site was observed to make a spontaneous transition from the (4)C(1) conformation to a twist-boat conformer, consistent with generally accepted glycosidase mechanisms. Also, from these simulations Tyr73 and Arg78 were found to have important roles in the active site. Based on the results of these various MD simulations, a new catalytic mechanism is proposed. Using this mechanism, predictions about the effects of changes in Arg78 were made which were confirmed by site-directed mutagenesis.

Computational studies on mutant protein stability: The correlation between surface thermal expansion and protein stability

Thermal stability of mutant proteins has been investigated using temperature dependent molecular dynamics (MD) simulations in vacuo. The numerical modeling was aimed at mimicking protein expansion upon heating. After the conditions for an expanding protein accessible surface area were established for T4 lysozyme and barnase wild-type proteins, MD simulations were carried out under the same conditions using the crystal structures of several mutant proteins. The computed thermal expansion of the accessible surface area of mutant proteins was found to be strongly correlated with their experimentally measured stabilities. A similar, albeit weaker, correlation was observed for model mutant proteins. This opens the possibility of obtaining stability information directly from protein structure.

[Nutritional risk factors for gallstones. Epidemiological analysis]

This article reviews the role of nutrition in the incidence of gallstones. The epidemiological situation of gallbladder disease has wide worldwide geographical variations, being Pima Indians and the Chileans the most affected populations. The main nutritional risk factor is obesity. Other risk are serum cholesterol and triglyceride levels, unbalanced and excessive caloric intake, fasting periods of more than eight hours, hypocaloric diets of less than 700 Kcal/day, specially in obese subjects and parenteral nutrition lasting more than two weeks. The main conclusion of this revision is that nutritional behaviors of the population must be improved through public health programs, to reduce the incidence of obesity and related nutritional imbalances.

Pseudoaneurysm causing partial obliteration of the left atrium: case report and review

We describe a case of left ventricular pseudoaneurysm with subepicardial dissection onto the left atrial wall, mimicking a smooth left atrial mass, causing partial obliteration of the left atrial cavity. This patient presented with a transient ischemic attack, most likely resulting from a thromboembolic episode to the brain. Emergent surgery was successfully performed and the patient is doing well at 1-year follow-up, with no signs of left atrial compression by transthoracic echocardiography.

Esophageal motility disorders in patients with Sjögren's syndrome

Esophageal motility was studied in 21 patients with Sjögren's syndrome, and in 25 normal volunteers, in order to record the prevalence and type of esophageal motor abnormalities. Esophageal motor abnormalities were detected in seven of the 21 patients (33.3%). These esophageal abnormalities did not correlate with the presence of dysphagia, the extraglandular involvement, or the presence of autoantibodies.

[Utility of high-resonance ultrasonography in the diagnosis of acute appendicitis]

The clinical records and the ultrasound findings of 48 patients studied because of a presumptive diagnosis of acute appendicitis in a one-year period were reviewed. Ultrasound examination was performed using graded compression and high resolution probes when acute appendicitis was suspected and the clinical history or physical examination was unclear. The ultrasound findings were correlated with the clinical course or surgical and pathological findings. This procedure was useful in the diagnosis of acute appendicitis, with 84.6% sensibility and 95.5% specificity. Predictive value for positive results was 95.7% and 84% for negative results. These figures agree with results previously communicated in the literature. It is concluded that high resolution ultrasonography is useful in the differential diagnosis of atypical acute appendicitis.

[Post-surgical results of 48 septal perforations]

We have studied the post-surgical results of 48 perforations of the nasal septum, regarding their etiology, location and size, which must be taken into account when deciding which closure technique to use.

[Paracetamol overdose: a new form of suicide in Chile and the value of N-acetylcysteine administration]

Overdose of paracetamol is associated to varying degrees of hepatic necrosis and may lead to severe hepatic failure. In this paper, we report 2 patients with paracetamol overdose for suicidal purposes who were successfully treated using the antidote N-acetyl-cysteine orally. A brief analysis of the literature follows.

Hepatitis B virus infection in hospital staff: epidemiology and persistence of vaccine-induced antibodies

To establish the epidemiology of viral hepatitis B (HBV) infection in hospital staff the sera of 2462 workers and 176 professional nursing students were examined. The prevalences of HBsAg and anti-HBs among the workers were 4.5 and 42.2% and among the students were 2.3 and 15.3%, respectively. The risk of infection showed a correlation with the profession of the hospital workers, the various jobs carried out in different departments, age, and the number of working years. The anti-hepatitis vaccination with HBVax and HEVAC-B vaccines was used on 142 professional students and 996 hospital workers. Five years after the beginning of the vaccine cycle the percentage of responders observed among the students was 75 (HBVax) and 79% (HEVAC-B). Among the hospital staff the response registered was 66 and 71%, respectively. The best recorded response among the youngest subjects suggests that the anti-hepatitis vaccination should be obligatory for hospital workers at the beginning of their working period or professional training.

Jejunal and ileal absorption of oxprenolol in man: influence of nutrients and digestive secretions on jejunal absorption and systemic availability

1 Study I evaluated the absorption of oxprenolol in the ileum, compared to jejunum, in healthy volunteers by an intestinal perfusion technique. Around 80 mg of drug were delivered as a saline solution directly in the small bowel. 2 Samples taken 30 cm distally to the site of perfusion showed that 63% of perfused oxprenolol was absorbed in the jejunum and 48% in the ileum; the differences were significant. 3 The plasma concentration-time profiles were similar for the two perfusions. The AUC and Cmax values of free and conjugated oxprenolol for the jejunal perfusion were significantly lower than those of ileum. They showed large but consistent intersubject variations in the two treatments. 4 Study II investigated, using the same technique, the influence of nutrients and digestive secretions on jejunal absorption and systemic availability of this drug. A saline (in treatments A and B) or a nutrient (in treatment C) solution containing oxprenolol was perfused into the jejunum below a balloon either inflated (A) or deflated (B and C). 5 The disappearance rate of oxprenolol from the jejunum was unaffected by endogenous secretions. The mean amount of drug absorbed along a 30-cm jejunal segment accounted for 52 (A) and 57% (B) of the total amount perfused. The intestinal absorption rate was markedly increased in the presence of nutrients (mean amount absorbed 96% for C). 6 The change in the rate of disappearance from the intestine had no effect on the systemic availability of oxprenolol (mean AUC values 8740, 8250 and 8020 nmol l-1 h for A, B and C, respectively) or its elimination from plasma.(ABSTRACT TRUNCATED AT 250 WORDS)

Gastric and intestinal absorption of oxprenolol in humans

The gastrointestinal absorption of the beta blocker oxprenolol was investigated in four healthy subjects by an intubation technique. Oxprenolol was introduced into the stomach, dissolved in a homogenized meal containing the marker 14C-polyethylene glycol (PEG) 4000. Unlabeled PEG 4000 was perfused during the whole experiment into the duodenum at the ampulla of Vater. Samples of luminal contents were collected at regular intervals over four hours in the stomach, at the angle of Treitz, and 30 cm below this point. Blood was also collected. Oxprenolol was not absorbed in the stomach. About 80% of the drug emptied from the stomach was absorbed in the duodenum, and 80% of that released from the duodenum was absorbed in a 30-cm segment of the jejunum. The amounts absorbed in these two intestinal segments were directly proportional to the amounts delivered. The areas under the plasma concentration-time curves were not related to the amounts absorbed. A single dose of oxprenolol taken with an homogenized meal did not modify the gastric emptying and secretory response.

Influence of bile salts and lipids on intestinal absorption of griseofulvin in man

The influence of bile salts and lipids on the intestinal absorption of griseofulvin has been studied in 11 healthy male volunteers by the intestinal perfusion technique. The drug in a nutrient solution (Realmentyl) was perfused into the second part of duodenum at 5 ml/min. Intestinal samples were taken continuously at 1 ml/min, 20 cm (at the angle of Treitz) and 45 cm distal to the perfusion point. To study the effect of lipids on griseofulvin absorption, the drug was perfused with solutions A and B, of which B contained a total lipid and caloric load three times that of A. The influence of bile salts on griseofulvin absorption was examined by perfusing the drug on Day 1 with bile salts and again on the following day after bile salt depletion. Bile salts and a varying quantity of lipid perfusate had no significant influence on the duodeno-jejunal griseofulvin absorption rate per cm of intestine. Lipids, however, may still play a role in griseofulvin absorption along the entire intestine.

Effect of increased amounts of pectin on a solid-liquid meal digestion in healthy man

The effect of three concentrations of high-methoxy apple pectin (5, 10, and 15 g), on solid-liquid meal digestion was studied in 12 healthy men by the gastrointestinal intubation technique. The gastric emptying of water and carbohydrates is significantly reduced only after 10 and 15 g pectin. The changes in gastric pH are similar for pectin-free and pectin-containing meals. Cumulative lipase and trypsin outputs are not significantly different with and without pectin. When gastric uronic acid concentration is above 6 g/l, the duodenal absorption of carbohydrates is significantly reduced (p less than 0.001). The mean blood glucose levels with 10 and 15 g pectin are significantly higher than the control values at 180 min (p less than 0.05). Pectin does not modify serum concentrations of secretin, cholecystokinin (CCK), vasoactive intestinal polypeptide (VIP), gastric inhibitory polypeptide (GIP), and somatostatin but serum motilin and gastrin levels are below the control values after high fiber meal.

Jejunal secretory effect of intraduodenal food in humans. A comparison of mixed nutrients, proteins, lipids, and carbohydrates

The effect of the presence of food in the intestinal lumen on fluid transport by an intestinal loop isolated from nutrients is debatable and seems to be species dependent. The aim of the present study was to investigate this effect in humans. Fluid and ion transport by a 30-cm-long jejunal loop was measured by the perfusion of a plasmalike electrolyte solution below an occlusive balloon inflated at the angle of Treitz. At the same time, the duodenum was infused at the papilla by saline (control period) or one of the following solutions (test period): protein hydrolysate, starch hydrolysate, lipids, or mixed nutrients. The four solutions (pH 7; 300 mosmol/L; 540 kcal/L) were infused in 6 normal subjects in a randomized order. In 6 further subjects, two other loads of intraduodenal lipids (120 and 1080 kcal/L) were tested according to a similar protocol. Blood samples were taken serially for radioimmunoassays of gastrin, secretin, cholecystokinin, pancreatic polypeptide, gastric inhibitory polypeptide, vasoactive intestinal polypeptide, motilin, and somatostatin. Intraduodenal mixed nutrients, proteins, and lipids significantly reduced water and ion jejunal net absorption or induced a net secretion (without dose-effect relationship for lipids) and stimulated plasma cholecystokinin, pancreatic polypeptide, and gastric inhibitory polypeptide. Intraduodenal lipids also stimulated circulating levels of gastrin and vasoactive intestinal polypeptide. Intraduodenal sugars did not change jejunal fluid and ion transport and significantly increased plasma gastric inhibitory polypeptide. Covariance analysis showed transjejunal fluid movements to be linked with plasma levels of cholecystokinin. We conclude that an intraduodenal mixed meal exerts a secretory effect on a jejunal loop isolated from the nutrients and that this effect is due to the lipid and protein content of the meal; our data are compatible with a mediation of this phenomenon by cholecystokinin.

Maximal capacity for fluid absorption in human bowel

The intestinal handling of fluid has been studied in ten healthy volunteers while an isotonic saline solution (NaCl 140 mM, KC1 5 mM) was perfused into the stomach at rates of 5, 10, 15, and 20 ml/min. Polyethylene glycol 4000 (PEG-4000), as a nonabsorbable marker, was infused into the second portion of duodenum, and the intestinal contents were sampled continuously at a steady rate at 25, 50, 155, and 180 cm distally. Radiological assessment showed that the proximal sampling point was located at the angle of Treitz when the distal site was usually in the terminal ileum. Stools were collected for the following 12 hr. Volumes sampled from each site were used as a correction for volumes calculated at each distal site. The absorption rates of water (0.035 ml), sodium (4.72 muEq), and potassium ((0.18 183 muEq) per minute and per centimeter of bowel were constant along the small intestine and were independent of the perfusion rate. Stools only appeared when terminal ileal input to the colon was above 6 ml/min. When this occurred, the net absorption of water by the colon was 2.7 +/- 0.3 ml/min whatever the rate fluid entered the colon. A significant positive correlation was observed between ileal outputs and volume of stools.

[Effect of colonic distension on exocrine pancreatic secretion of the conscious rat]

In the conscious rat the increasing distension of the colon (from 2 to 6 ml) induced a slight decrease of exocrine pancreatic secretion which was more important for protein output than for volume. Nevertheless this inhibitory effect was never significant even with the important distension of 6 ml which induced a visible uneasiness in the animal.

[Endotoxin content of samples of pasteurized milk: preliminary findings]

By Limulus lysate assay, endotoxin was found in pasteurized milk samples from commercial source. The range was 32 to 128 microgram per ml, without any change when the samples were refrigerated. By contrast, the endotoxin content rose 512 to 2048 microgram per ml when milk was maintained at room temperature for 24 hours and 1024 to 6400 microgram per ml when samples were examined after 72 hours. These findings suggest a possible clinical implication, and support the concept that Limulus assay appears to be a rapid, reliable, and sensitive test for a quality control in commercial milk samples.

Secretion of biliary lipids in young Chilean women with cholesterol gallstones

The early appearance of cholesterol gallstones is very common in Chile. To elucidate the mechanisms involved in this phenomenon, the size of the bile acid pool and the secretion of biliary lipids were studied in two groups of young women with normal weights and radiologically functioning gallbladders: nine with cholesterol gallstones and 14 healthy volunteers. The bile acid pool was similar in control and gallstone patients. The secretory rates of bile acids and phospholipids were comparable and significantly correlated in both groups. On the other hand, cholesterol output was higher in gallstone patients. In controls there was a significant correlation between the output of bile acids and cholesterol, but no correlation was found in the gallstone group. This study suggests that cholesterol hypersecretion into the bile is a major factor in the pathogenesis of cholesterol gallstone disease in young Chilean women with normal weights.

[Endotoxic contamination of biological products (ribosomal vaccines, viral vaccines and interferon)]

The A.A. have examined by the Limulus assay the possible endotoxin contamination in some biological products (ribosomal vaccines, viral vaccines, interferon). While the preparations of influenza vaccines and a partially purified fraction of ribosomal vaccine from Pseudomonas aeruginosa exhibit a gelation of lysate with high levels of endotoxin, rubeola vaccines, interferon and a purified fraction of ribosomal vaccine, presented a negligible amount of endotoxin. The results are discussed with the aim to examine the possible role of contaminating endotoxin in the mediation of some adverse effects and of the unsuspected extrinsic adjuvant activities developed in clinical and experimental use of these preparations.