PubMed Health⌕ Search

Biomedical subjects

R B Read

Publications and source records attributed to R B Read.

At least 19 recordsLinked to original sources
PubMed1986

Analysis of factors responsible for continuing mortality after paracetamol overdose.

To determine reasons for the continuing mortality in patients taking a paracetamol overdose, the presentation, drug ingestion history, patient background, use of antidote (N-acetylcysteine and methionine), clinical course and outcome were determined in 247 patients treated at King's College Hospital in 1982 and 1983. Patients (147) were referred from other centres because of severe liver damage and 100 were local patients seen in the accident and emergency department. Survival in the local patients was 100% and, for those with severe liver damage, 49 and 63% (1982 and 1983 values). Delay in initial presentation to hospital was a major factor in determination of an adverse outcome, with a median delay of 30 h in the referred patients and 8 h in the local cases. Such a delay precluded administration of antidote to the majority of patients in the referred group, but in 11 cases where antidote could have been given a full course was not provided and all 11 patients died. Included among these were four patients in whom the serum paracetamol concentration was in the 'non-toxic' range. One patient with a chronic alcohol-drinking history (greater than 200 g/day) received N-acetylcysteine at 12 h but died from liver failure. However, in the complete series prior alcohol consumption was not associated with a significantly worse prognosis and simultaneous ingestion of alcohol with paracetamol had no effect on outcome. The concomitant ingestion of dextropropoxyphene caused an early and marked impairment of consciousness unrelated to any hepatotoxicity but, in three cases where dextropropoxyphene combinations were used, death occurred subsequently from liver failure.

Acetaminophen↗
PubMed1986

Effects of ethanol ingestion on the metabolism of a hepatotoxic dose of paracetamol in mice.

After administration to mice of a hepatotoxic dose of paracetamol (400 mg/kg body wt, p.o.) peak plasma concentrations of the drug and its glucuronide were approximately 900 microM around one hour. Corresponding levels of the sulphate, mercapturate and cysteine conjugates were approximately 100, 35 and 20 microM, respectively. Urinary excretion accounted for 55% of the administered drug 31 h after dosing. Of this total, 64.7% was paracetamol glucuronide, 17.9% paracetamol cysteine, 10.4% paracetamol sulphate, 0.5% paracetamol mercapturate and 6.5% unchanged drug. One hour after acute ethanol administration (3 g/kg, p.o., concomitantly with paracetamol) plasma levels of the glucuronide, cysteine and mercapturate conjugates were decreased by approximately 50%. There were reductions in the urinary excretion of the glucuronide (-13%) and cysteine conjugates (-24%), but increases in the amounts of mercapturate (+52%), sulphate +11%) and unchanged drug (+81%). Chronic ethanol ingestion (15 g/kg per d for 28 d) caused a transient initial increase in plasma paracetamol cysteine (+32%) and mercapturate (+41%) concentrations, but the only substantial change in urinary excretion was a 29% increase in the amount of paracetamol glucuronide. After chronic ethanol consumption, acute ethanol administration had a transient inhibitory effect on paracetamol mono-oxygenation, but glucuronidation was unaffected (as judged by plasma concentrations). Only paracetamol mercapturate excretion was substantially affected (+64%).

Acetaminophen↗
PubMed1985

Effects of ethanol ingestion on the hepatotoxicity and metabolism of paracetamol in mice.

The influence of ethanol on paracetamol-induced liver damage was studied in mice and related to changes in microsomal monooxygenases and plasma paracetamol metabolites in the same group of animals. Paracetamol (400 mg/kg body wt, p.o.) was administered alone or simultaneously with ethanol (3 g/kg, p.o.) to mice fed either a chow diet or pretreated for 4 weeks with a liquid diet containing ethanol (20% of energy). Acute ethanol administration protected against paracetamol hepatotoxicity, but this protection was complete only in mice not fed ethanol previously. Acute ethanol administration also appeared to reduce paracetamol monooxygenation in vivo, but ethanol (50 mM) added to microsomal incubations in vitro had no significant effect on paracetamol activation and covalent binding. The chronic ingestion of ethanol in the diet increased paracetamol-related liver damage, but there appeared to be no induction of paracetamol monooxygenation in these animals. We are unable to confirm current concepts that the potentiation of paracetamol hepatotoxicity by chronic ethanol ingestion and its reduction by acute ethanol administration result solely from contrasting effects of ethanol on cytochrome P-450, and alternative explanations are proposed.

Acetaminophen↗
PubMed1982

Microbiological quality of dry-milk mixes and milk substitute infant formulas.

The microbiological quality of dry-milk mixes and milk substitute infant formulas at the retail level was determined by a national survey of 1,574 analytical units. The geometric mean values for aerobic plate counts of milk-containing and milk substitute infant formulas were 25 and 52/g, respectively. The mean value for Staphylococcus aureus and for coliform organisms was less than 3/g. Each unit had an Escherichia coli most-probable-number value of less than 3/g.

Animals↗
PubMed1982

Microbiological quality of frozen cauliflower, corn, and peas obtained at retail markets.

The microbiological quality of blanched frozen cauliflower, cut corn, and peas at the retail level was determined. At 35 degrees C, mean aerobic plate count (APC) values for cauliflower, corn, and peas, respectively, were 30,000, 6,100, and 4,700 per g; at 30 degrees C, the mean APC values were 45,000, 8,500, and 6,800 per g, respectively. Geometric means for coliform, Escherichia coli, and Staphylococcus aureus counts for all three vegetables were less than 10 per g.

Bacteria↗
PubMed1982

Microbiological quality of macaroni and noodle products obtained at retail markets.

The microbiological quality of macaroni and noodle products was determined by a statistically based national survey at the retail level. Geometric means of aerobic plate counts for macaroni and noodle products were 520 and 1,400 per g, respectively. Means for yeast and mold counts were 72 per g for macaroni and 100 per g for noodles. Means for counts of coliforms and Staphylococcus aureus were less than 3 per g for both products. Escherichia coli was not found in macaroni but was present in 0.5% of the noodle samples and ranged from 3 to 93 per g.

Bacteria↗
PubMed1982

Microbiological quality of some spices and herbs in retail markets.

The microbiological quality of 10 spices or herbs was determined by a national survey at the retail level. Aerobic plate count values for the 10 products ranged from less than 100 to 3.1 X 10(8) per g; mean values of the individual spices or herbs ranged from 1,400 to 820,000 per g. Coliform counts ranged from less than 3 to 1.1 X 10(6) per g; however, mean values were less than 20 per g for all products. Escherichia coli counts ranged from less than 3 to 2,300 per g. Except for celery seed, which had a mean value of 7 per g, all mean values were less than 3 per g. Yeast and mold counts were made for 5 of the 10 products. Mean values were generally low; the highest mean (290 per g) was obtained for cinnamon.

Bacteria↗
PubMed1982

Microbiological quality of five potato products obtained at retail markets.

The microbiological quality of frozen hash brown potatoes, dried hash brown potatoes with onions, frozen french fried potatoes, dried instant mashed potatoes, and potato salad was determined by a national sampling at the retail level. A wide range of results was obtained, with most sampling units of each products having excellent microbiological quality. Geometric mean aerobic plate counts were as follows: dried hash brown potatoes, 270/g; frozen hash brown potatoes with onions, 580/g; frozen french fried potatoes 78/g; dried instant mashed potatoes, 1.1 x 10(3)/g; and potato salad, 3.6 x 10(3)/g. Mean values of coliforms, Escherichia coli, and Staphylococcus aureus were less than 10/g.

Bacteria↗
PubMed1982

Infant food problems and analytical aspects of providing safe and wholesome infant foods.

The technology of milk and infant food production, storage, and handling has advanced to the point that infant foods have had an excellent record of being free of recognized health hazards. The Infant Formula Council has published methods specifically for these foods. Methods are included from Standard Methods for the Examination of Dairy Products, Official Methods of Analysis, Bacteriological Analytical Manual, the Manual of Clinical Microbiology, and the U.S. Pharmacopeia. Criteria for microbiological quality have been issued by the Codex Alimentarius Commission, the International Commission for Microbiological Specifications for Foods, and the Public Health Service. Surveys in the United States and Canada have shown that sanitary standards are met with ease.

Consumer Product Safety↗
PubMed1980

Microbiological quality of frozen shrimp and lobster tail in the retail market.

The microbiological quality of three frozen shrimp products and frozen lobster tail at the retail level was determined. The number of retail units of the four products examined and the geometric means for aerobic plate counts at 30 and 35 degrees C, respectively, were: 1,464 units of cooked, peeled shrimp--13,000 and 7,200 per g; 1,468 units of raw, peeled shrimp--860,000 and 300,000 per g; 1,300 units of raw, in-shell shrimp--800,000 and 300,000 per g; 1,315 units of lobster tail--140,000 and 42,000 per g. Geometric means for coliform, Escherichia coli, and Staphylococcus aureus counts for all products were < 10 per g.

Decapoda↗
PubMed1976

Microbiological quality of frozen breaded fish and shellfish products.

A survey was made of the microbiological quality of seven frozen, breaded, precooked fish and shellfish products and of frozen, breaded, uncooked shrimp at the retail level. Geometric mean aerobic plate counts per gram (and number of units examined) were as follows: fish sticks, 8,300 (1,539); fish cakes, 5,600 (1,378); crab cakes, 4,900 (1,226); scallops, 1,700 (1,392); clams, 450 (1,384); haddock, 15,000 (1,306); fish in fish and chips dinner, 7,200 (1,485); and uncooked shrimp, 220,000 (1,462). Geometric mean coliform, Escherichia coli, and Staphylococcus aureus counts for all eight products ranged from 1 to 10/g.

Cell Count↗
PubMed1975

Microbiological methods. Methodology for enteropathogenic Escherichia coli.

Pathogenic biotypes of Escherichia coli grow poorly at temperatures greatly different from that of the host. Percentages quantitatively recovered at 42.0, 44.0, 44.5, and 45.5 degrees C in lauryl tryptose broth were 100, 76, 76, and 42, respectively. Corresponding values for 175 strains of varied origin were 98, 89, 82, and 65%. Maximal growth temperature is dependent upon medium. Lauryl tryptose and elevated coliform broths were equivalent in the recovery of small inocula (100 cells/ml) at 41.5-44.5 degrees. MacConkey, enteric enrichment, and Gram-negative broths were inhibitory at corresponding values. Growth at elevated temperature in nutrient broth is enhanced by carbohydrate. Standard lactose enrichment media fail to recover slow lactose fermenters. An acidified glutamic acid medium was unsuitable for recovery of E. coli. The data suggest modification of standard temperatures for the recovery of pathogenic biotypes. Previously recommended analytical methods have been simplified and supplemented. The enhancement of motility in indole-nitrite broth at 35 degrees C is recommended. A 4-tube semiquantitative test is offered for tentative identification of somatic and capsular antigens. Inclusion of Alkalescens-Dispar strains is warranted by their pathogenic behavior. Examination in Shigella and Alkalescens-Dispar sera is required to cover the dysentery-like biotypes. Pathogenic potential cannot be inferred from serotype.

Bacteriological Techniques↗
PubMed1971

Detection of sulfa drugs and antibiotics in milk.

A disc assay method for testing sulfa drugs and antibiotics in milk was developed wherein Bacillus megaterium ATCC 9855 was used as the test organism and Mueller-Hinton agar was used as the test substrate. Incubation was at 37 C for 4 to 5 hr. The test procedure is an improvement over the Bacillus subtilis-Antibiotic Medium No. 1 method, as described in Standard Methods for the Examination of Dairy Products, in that it is sensitive to eight sulfa drugs and to bacitracin without a significant change in sensitivity to eight other antibiotics commonly used for mastitis therapy.

Journal Article↗
PubMed1971

Inactivation of thirty viruses by gamma radiation.

Decimal reduction values (D value) for 30 viruses were determined. The weighted D values of the viruses suspended in Eagle's minimum essential medium ranged from 0.39 to 0.53 Mrads. It was necessary to increase the radiation dose by a factor of >3 to inactivate virus suspended in Eagle's minimum essential medium as compared to the same virus suspended in distilled water. The destruction rate curves were of a first-order reaction.

Amino Acids↗