Gastric exocrine “failure” in critically ill patients: incidence and associated features

Following the observation that many critically ill patients cannot maintain their gastric juice pH below 4 without treatment a study was performed to measure the gastric juice pH in such patients and relate it to other clinical data. The case notes of 64 patients who had been admitted to the intensive care unit and taken part in two trials of ranitidine treatment were reviewed. During those trials gastric juice was aspirated hourly and the pH and volume measured. In this study the values recorded during a six hour untreated control phase were used. Data on age, diagnosis, treatment, outcome, episodes of hypoxia, episodes of hypotension, and use of inotropic drugs were also reviewed. Full data were available for 61 patients: 27 had a mean baseline pH of >5 during the control phase and 34 a mean baseline pH of <5. Significantly more of those with a high pH suffered hypotension (21/27 v 13/34) and received inotropic drugs (16/27 v 8/34).These findings suggest that hypotension in critically ill patients adversely affects gastric exocrine function; prophylaxis with drugs that can improve gastric mucosal blood flow may be more effective than with antacids.     

Differential processing and regulation of thyroid-stimulating hormone subunit carbohydrate chains in thyrotropic tumors and in normal and hypothyroid pituitaries

Thyroid-stimulating hormone (TSH) alpha- and beta-subunit glycosylation was investigated in mouse thyrotropic tumor and in normal and hypothyroid pituitary cells for various periods of time in the presence of [3H]mannose or [3H]galactose. After sequential precipitation with anti-alpha and anti-beta sera, subunits were treated with Pronase followed by endo-beta-N-acetylglucosaminidase H (Endo H) and analyzed by paper chromatography. In primary cultures of thyrotropic tumor cells incubated for 60 min with [3H]mannose, primarily Man9GlcNAc and Man8GlcNAc were found on TSH + alpha subunits, whereas Glc1Man9GlcNAc and Man9GlcNAc were prominent on free beta subunits. After preincubation of cells for 16 h in the presence or absence of glucose followed by a 60-min pulse of [3H]mannose, there was an 8-fold increase in labeled TSH + alpha but only a minimal change in free beta or total proteins. In the absence of glucose, there was a selective accumulation of Man8GlcNAc on TSH + alpha but not on free beta or total proteins; however, there was no detectable accumulation of Endo H resistant forms during glucose starvation on TSH subunits or total proteins. Normal mouse and rat pituitary minces incubated for 60 min with either [3H]mannose or [3H]galactose showed no glucose-containing species on TSH subunits, but equal amounts of Man9GlcNAc and Man8GlcNAc on TSH + alpha, and mostly Man9GlcNAc on free beta subunits. In contrast, hypothyroid mouse and rat pituitaries exhibited an increase in Glc1Man9NAc and Glc1Man8GlcNAc on free beta but not on TSH + alpha or total proteins.(ABSTRACT TRUNCATED AT 250 WORDS)     

The rapid estimation of microbial contamination of raw meat by measurement of adenosine triphosphate (ATP)

Bacteria were separated from raw meat homogenate by a simple three-stage process. Centrifugation (10 s at 2000 g) removed coarse particles; stirring with the cation exchange resin Bio-Rex 70 removed smaller particles and filtration through 0.22 micron membranes removed soluble materials. By this process 70-80% of the microbial populations of meat homogenates were consistently isolated on the filters. A linear relationship was found between log10 microbial ATP and log10 colony count of meat over the range 10(5)-10(9) cfu/g. The value of ATP/cfu for meat samples was within the range previously reported for pure cultures. These data indicated that ATP extracted from the filters originated from bacteria in the meat samples. Several samples can be analysed simultaneously in an elapsed time of 20-25 min. The variability associated with estimates of both colony counts and ATP levels has been determined.     

An Ustilago maydis Mutant Partially Blocked in P45014DM Activity Is Hypersensitive to Azole Fungicides

An Ustilago maydis ergosterol biosynthesis mutant (A14) which is partially blocked in sterol 14alpha-demethylase (P45014DM) activity is described. This mutant accumulated the abnormal 14alpha-methyl sterols, eburicol, 14alpha-methylfecosterol, and obtusifoliol, along with significant amounts of ergosterol. Although the A14 mutant grew nearly as well as the wild type, it was impaired in cell extension growth, which indicated a dysfunction in apical cell wall synthesis. The mutant was also found to be hypersensitive to the azole fungicides penconazole and tebuconazole.     

Hexazonium pararosaniline as a fixative for animal tissues

Hexazonium pararosaniline is a valuable reagent that has been used in enzyme activity histochemistry for 50 years. It is an aqueous solution containing the tris-diazonium ion derived from pararosaniline, an aminotriarylmethane dye, and it contains an excess of nitrous acid that was not consumed in the diazotization reaction. Other investigators have found that immersion for 2 min in an acidic (pH 3.5) 0.0015 M hexazonium pararosaniline solution can protect cryostat sections of unfixed animal tissues from the deleterious effects of aqueous reagents such as buffered solutions used in immunohistochemistry, while preserving specific affinities for antibodies. In the present investigation hexazonium pararosaniline protected lymphoid tissue and striated muscle against the damaging effects of water or saline. The same protection was conferred on unfixed sections treated with dilute nitrous or hydrochloric acid in concentrations similar to those in hexazonium pararosaniline solutions. Model tissues (solutions, gels or films containing gelatin and/or bovine albumin) responded predictably to well known cross-linking (formaldehyde) or coagulant (mercuric chloride) fixatives. Hexazonium pararosaniline solutions prevented the dissolution of protein gels in water only after 9 or more days of contact, during which time considerable swelling occurred. It is concluded that there is no evidence for a “fixative” action of hexazonium pararosaniline. The protective effect on frozen sections of unfixed tissue is attributable probably to the low pH of the solution.     

Economic evaluation of water loss saving due to the biological control of water hyacinth at New Year’s Dam,Eastern Cape province,South Africa

Water hyacinth Eichhornia crassipes is considered the most damaging aquatic weed in the world. However, few studies have quantified the impact of this weed economically and ecologically, and even fewer studies have quantified the benefits of its control. This paper focuses on water loss saving as the benefit derived from biological control of this plant between 1990 and 2013 at New Year’s Dam, Alicedale, Eastern Cape, South Africa. Estimates of water loss due to evapotranspiration from water hyacinth vary significantly; therefore, the study used three different rates, high, medium and low. A conservative raw agriculture value of R 0.26 per m³ was used to calculate the benefits derived by the water saved. The present benefit and cost values were determined using 10% and 5% discount rates. The benefit/cost ratio at the low evapotranspiration rate was less than one, implying that biological control was not economically viable but, at the higher evapotranspiration rates, the return justified the costs of biological control. However, at the marginal value product of water, the inclusion of the costs of damage to infrastructure, or the adverse effects of water hyacinth on biodiversity, would justify the use of biological control, even at the low transpiration rate.