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Biomedical subjects

J Gerard

Publications and source records attributed to J Gerard.

At least 19 recordsLinked to original sources

[Porphyrias, a rare cause of acute abdominal pain].

The porphyrias are uncommon disorders caused by deficiencies of some enzymes of the heme biosynthetic pathway. Only four hepatic porphyrias are able to cause acute abdominal syndrome. In any case, the diagnosis requires the demonstration of increased urinary or stool excretion of accumulated metabolites of heme synthesis. Treatment is now possible and is able to reduce the burden of these metabolic diseases. The management implies also the identification of trigger exogenous factors such as oral contraceptives.

Abdominal Pain↗

Isolation and characterization of a new peroxiredoxin from poplar sieve tubes that uses either glutaredoxin or thioredoxin as a proton donor.

A sequence coding for a peroxiredoxin (Prx) was isolated from a xylem/phloem cDNA library from Populus trichocarpa and subsequently inserted into an expression plasmid yielding the construction pET-Prx. The recombinant protein was produced in Escherichia coli cells and purified to homogeneity with a high yield. The poplar Prx is composed of 162 residues, a property that makes it the shortest plant Prx sequence isolated so far. It was shown that the protein is monomeric and possesses two conserved cysteines (Cys). The Prx degrades hydrogen peroxide and alkyl hydroperoxides in the presence of an exogenous proton donor that can be either thioredoxin or glutaredoxin (Grx). Based on this finding, we propose that the poplar protein represents a new type of Prx that differs from the so-called 2-Cys and 1-Cys Prx, a suggestion supported by the existence of natural fusion sequences constituted of a Prx motif coupled to a Grx motif. The protein was shown to be highly expressed in sieve tubes where thioredoxin h and Grx are also major proteins.

Amino Acid Sequence↗

Massetolides A-H, antimycobacterial cyclic depsipeptides produced by two pseudomonads isolated from marine habitats.

Massetolides A-H (1-8), novel cyclic depsipeptides, and the known compound viscosin (9) have been isolated from cultures of two Pseudomonas sp. isolated from a marine alga and a marine tube worm, respectively. Massetolide A (1) and viscosin (9) exhibit in vitro antimicrobial activity against Mycobacterium tuberculosis and Mycobacterium avium-intracellulare. Precursor-directed biosynthesis has been used to generate unnatural massetolides 11-13 incorporating nonprotein amino acids.

Anti-Bacterial Agents↗

Differential categorization of words by learning disabled, gifted, and nonexceptional students.

This research was done to answer whether learning disabled students attend to different word features than nonexceptional and gifted students and whether there is a difference by grade. Word sorts of meaningful and nonsense words were used to estimate differences between 145 first- and fifth-grade learning disabled, nonexceptional, and gifted groups. Analyses indicated that 54 learning disabled students were more likely to provide no response or to give simpler responses than 61 nonexceptional or 30 gifted peers. Older children (n = 78) attended to more and varied word features, were more likely to focus on recognizable meaning, and were more able to use syllables as a tool for sorting than were 67 younger children. Significant differences were noted between grade and exceptionality groups. Implications for practical application and further research are discussed.

Attention↗

Presentation of Yersinia enterocolitica enteritis in children.

Yersinia enterocolitica enteritis is a potentially treatable infection. To understand its seasonal incidence and clinical presentation in children, we reviewed case records of children seen in Cardinal Glennon Children's Hospital in St. Louis, MO. We found the incidence of Yersinia enteritis to be as frequent as enteritis caused by Campylobacter. It occurred more frequently during the winter months (P < 0.002) than during the rest of the year. Fever was common in infants with Yersinia enteritis. Abdominal pain and distention were infrequent. Seventeen (35%) patients were 3 months of age or younger; 4 of 17 (28%) developed Yersinia sepsis as a complication of the enteritis. Physicians should perform stool cultures for Y. enterocolitica in young infants who present with high fever and diarrhea in winter months, especially when there is blood in stools or the patient appears septic.

Age Factors↗

Verification of endotracheal tube placement with colorimetric end-tidal CO2 detection.

STUDY OBJECTIVE: To determine the ability of a disposable colorimetric CO2 detector to accurately confirm or refute endotracheal tube placement. DESIGN: Two hundred fifty prospective emergency intubations. SETTING: Emergency intubations performed in the emergency department, helicopter, and prehospital ground environment. TYPE OF PARTICIPANTS: Intubations were performed by emergency medicine residents, paramedics, and flight nurses. INTERVENTIONS: The FEF CO2 detector was applied after 250 emergency intubations. Notation of color change indicating intratracheal placement was recorded in each case. Confirmation of refutation of the detector's results was determined subsequently through traditional methods. RESULTS: The sensitivity for confirmation of endotracheal intubation in the 137 patients with a palpable pulse was 100%. However, only 76 of 103 patients (sensitivity, 72%) in cardiac arrest had endotracheal intubation confirmed by color change. The device was uniformly specific for tracheal intubation in 73 arrested patients in whom a color change was noted (100%). There was one instance (of a total of seven misintubations) in which a positive color change was noted, but the tube was not intratracheal (specificity, 86%). Overall sensitivity for tracheal intubation was 88% (95% confidence limits; range, 0.83 to 0.92), and specificity for tracheal intubation was 92% (95% confidence limits; range, 0.62 to 0.99). CONCLUSION: The FEF colorimetric detector reliably detects intratracheal placement in the nonarrested patient. Its use in prolonged cardiac arrest merits further study.

Breath Tests↗

Assessment of the clinical efficacy and tolerance of two new alpha-glucosidase inhibitors in insulin-treated diabetics.

The present study aimed at investigating the metabolic effects and tolerance of two desoxynojirimycin derivatives with alpha-glucosidase inhibitory properties (BAY m 1099 and BAY o 1248). The study was performed in a double-blind cross-over manner on 7 insulin-treated outpatient diabetics (6 males, 1 female; mean age 43 +/- 14 years; mean duration of diabetes 5.8 +/- 4.2 years; all within +/- 10% of their ideal body weight). The usual diet containing 24.5 +/- 8 g dietary fibers and 52 +/- 22 g simple sugars was maintained throughout the study. After a 7-day run-in period, 4 consecutive periods of 7 days were considered for each patient. The patients were randomly allocated for 1 week to BAY o 1248 (20 mg with breakfast) or Bay m 1099 (50 mg with breakfast and dinner). After a 7-day wash-out period the patients underwent the alternate treatment. At the end of each period, the patients were admitted to the Metabolic Ward for detailed metabolic and hormonal investigations. No significant changes were observed in the daily insulin requirements (45 +/- 15 U/day). HbA1c did not change significantly. Residual insulin secretion was low (plasma C-peptide: 0.077 +/- 0.09 and 0.154 +/- 0.15 pmol/ml during fasting and 2 hours post-breakfast, respectively); it was not modified by the treatments. Increments in blood glucose were significantly lower after breakfast with both drugs. No differences were observed in plasma free insulin. A marked increase in breath hydrogen was observed after lunch with BAY o 1248 only. Clinical and biological tolerance was excellent for both compounds.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Deoxynojirimycin↗

Utilization of oral sucrose load during exercise in humans. Effect of the alpha-glucosidase inhibitor acarbose.

We investigated the hormonal and metabolic response to a 100-g sucrose load given 15 min after adaptation to moderate-intensity (50% VmaxO2) long-duration (4-h) exercise in healthy volunteers. The effect of a 100-mg dose of the alpha-glucosidase inhibitor Acarbose ingested with the sucrose load was also investigated. "Naturally labeled [13C] sucrose" was used to follow the conversion to expired-air CO2 of the sugar ingested by isotope-ratio mass spectrometry. Circulating hormone and metabolite data were obtained in nine subjects, and indirect calorimetry and stable isotope methodology were applied to six of them. Under placebo, 93 +/- 4 g sucrose were entirely oxidized during the 4 h of exercise, total carbohydrate utilization was 235 +/- 14 g, endogenous carbohydrate utilization was 142 +/- 13 g, and total lipid oxidation was 121 +/- 7 g. A single oral dose of 100 mg Acarbose ingested with the sucrose load did not significantly modify total carbohydrate (239 +/- 2 g/4 h) or lipid (122 +/- 6 g/4 h) oxidation. In contrast, sucrose oxidation was reduced to 53 +/- 6 g/4 h and endogenous carbohydrate utilization increased to 186 +/- 7 g/4 h. Reduction of the rises in blood glucose and fructose and of the increases in plasma insulin and C peptide under Acarbose confirmed these effects, whereas lower circulating levels of alanine suggested a higher rate of gluconeogenesis. These data show that a 100-g glucose load ingested soon after initiation of exercise is a perfect available metabolic substrate.(ABSTRACT TRUNCATED AT 250 WORDS)

Acarbose↗

Glibenclamide pharmacokinetics in acarbose-treated type 2 diabetics.

A single dose of glibenclamide 5 mg was administered to six Type 2 diabetics, randomly treated for 7 days either with acarbose (3 X 100 mg daily) or with placebo. The serum concentration of the drug was measured for 10 h. Peak concentrations, times-to-peak concentration, elimination half-lives and the extent of bioavailability of the drug were not significantly modified by acarbose. The combined administration of glibenclamide and acarbose resulted in a modest improvement in the blood glucose profile after breakfast and lunch, together with a significant diminution in plasma insulin. Thus, acarbose appears a useful additional treatment for Type 2 diabetics already receiving sulphonylurea derivatives.

Acarbose↗

A treatment of non-ketotic hyperglycinaemia.

The treatment comprising a special diet (without glycine, serine, and with a reduced amount of threonine), strychnine nitrate and ursodesoxycholic acid (UDCA) led to normoglycinaemia in this form of severe non-ketotic glycine encephalopathy. Diet and treatment were well tolerated but without significant effect upon psychomotor development. This treatment should be more effective if administered before irreversible brain damage occurs, particularly in moderate and chronic forms of NKH.

Acidosis↗

Hypertension in pregnancy: evaluation of two beta blockers atenolol and labetalol.

There is a major controversy over the relative value of anti-hypertensive drugs in hypertension in pregnancy. Our purpose was to study two different beta-adrenolytic drugs, atenolol, a cardioselective beta blocker, and labetalol, an alpha-beta blocker. Fifty-six hypertensive (BP greater than 140/90 mmHg) pregnant women were treated either with atenolol or labetalol. The patients were divided into two subgroups for which there were no statistical differences with regard to age, number of previous pregnancies, initial level of blood pressure and uricemia, proteinuric pre-eclampsia, beginning of therapeutic trial and delivery. The average daily dosage was 144.6 +/- 47.8 mg day-1 with atenolol and 614 +/- 47.8 mg day-1 with labetalol. This study shows: the same anti-hypertensive effect of the two drugs with control of blood pressure in 82% of the cases; a birth-weight significantly higher with labetalol (3280 +/- 555 g) than with atenolol (2750 +/- 630 g) (P less than 0.001); two still-births with atenolol; no adverse effects of the drugs during pregnancy and the neo-natal period; the trans-placental passage of atenolol and labetalol as shown by plasma dosages in the mothers and the new-born. It is concluded that atenolol and labetalol are safe and they are usually effective in the control of the hypertension complicating pregnancy. But labetalol appears to be better able to prevent the appearance of fetal growth retardation.

Adolescent↗

Angioplastic necrolytic migratory erythema. Unique association of necrolytic migratory erythema, extensive angioplasia, and high molecular weight glucagon-like polypeptide.

A diabetic patient developed necrolytic migratory erythema with extensive angioplasia and high molecular weight glucagon-like polypeptide. There was no associated neoplasm such as glucagonoma. Lesions in the skin were studied by standard optical microscopy and by radioautography after incorporation of tritiated thymidine. Alterations in the skin begin as focal necrosis in the epidermis and in epithelial structures of adnexa, followed by marked angioplasia and a superficial and deep perivascular dermatitis.

Adult↗

Correlation of variations in intraluminal pressure and potential differences in the perfused colen.

To investigate the nature of variations in the large intestine potential differences, a continuous perfusion of isotonic saline was carried out in the colon of 14 rats. Intraluminal pressure and potential differences between the lumen and the peritoneal cavity were continuously and simultaneously recorded, while impedance of the system and respiration were also constantly monitored. To obtain a quantitative evaluation of the data, Fast Fouier Transform was performed on the signals and their derivatives which were auto- and cross-correlated. While there was no obvious relation between pressure and potential in the unperfused colon, there was clear visual qualirative evidence that, during steady state conditions of perfusion, an increase in intraluminal pressure was accompanied by a decrease in potential differences, while impedance of the recording system remained unchanged. Computer analysis disclosed four narrow ranges of stable frequencies for both pressure and potential. They were centred around 0-3, 1-75, 10-7, and 75 cycles per minute, the latter being synchronous with respiration. It is concluded that the variations of potential differences recorded during perfusion, a well-know phenomenon, are not electrical artefacts: the fast rhythm is probably induced by respiration, which increases intracolonic pressure and that, in turn, reduces the absolute value of potential differences, which remain negative mucosa versus serosa. The slower rhythms are synchronous for pressure and potential. Mechanisms responsible for the decrease in potential related to the increase in pressure remain unknown.

Animals↗

The genesis of bowel sounds: influence of viscus and gastrointestinal content.

This study was undertaken to try to solve the controversy about the influence of gastrointestinal contents on the genesis of bowel sounds, and to probe the respective importance of the various abdominal viscera. Eleven healthy volunteers were intubated by mouth with a multiple-lumen tube. Bowel sounds were recorded for 10 min when the tube was in the stomach, the upper jejunum, and the cecum, while it was left intact in situ, or perfused with isotonic saline (15 ml per min), or with an equal (7.5 ml per min of each) mixture of isotonic saline and air. Using a previously developed method, a computer analysis was made of the recording without any human intervention during the treatment of data. An analysis of variance demonstrated that the effect of perfusion varied according to site, with 46% of counted sounds while the tube was in the stomach, 32% in the jejunum, and 22% in the colon (P less than 0.05). There were two types of sounds: some exceeded in amplitude a preset threshold, and thus were picked up by the computer, but their average absolute value for 20 msec remained inferior to another preset threshold. Their number was kept in memory (NS--sounds having an amplitude exceeding a threshold S1, expressed in number per 10 min). A second type of sounds also exceeded the present threshold but their average absolute value for 20 msec also exceeded another preset threshold. Their number (NE--sounds having an amplitude exceeding the thershold S1 but having also a 20-msec average amplitude above another threshold S2, expressed in number per 10 min) was also memorized. The latter group was composed of two types of sounds: some had a limited spectrum of low frequency (100 Hz) and were of high amplitude and short (congruent to 5 msec) duration (NE1); some others had a higher and more dispersed frequency centered around 300 Hz (NE2). Fifty per cent of high energy (NE) sounds appeared while the tube was in the stomach, 30% in the colon, and 20% in the jejunum (P less than 0.005). Short and high amplitude sounds (NE1) were counted more often (43%) when it was in the colon than in the stomach (38%) and the jejunum (19%) (P less than 0.025), and this was confirmed (P less than 0.005) by a study of the ratio of NE1/NE. On the contrary, higher frequency sounds (NE2) were present more often when the tube was in the stomach (59%) than in the jejunum (24%) and in the colon (17%) (P less than 0.005). There was no influence of the presence of the unperfused tube on the genesis of bowel sounds in different sites (P greater than 0.05). In the stomach and the colon perfusion of the air/saline mixture increased the number of sounds (P less than 0.025) and all types of sounds in the stomach (P less than 0.025), whereas in the jejunum it was the perfusion of saline which increased them (P less than 0.025). It is concluded that the stomach is the most active site of production of bowel sounds, followed by the colon and then the small bowel, that sounds differ in different sites, and that all this is influenced by viscus content.

Cecum↗