PubMed Health⌕ Search

Biomedical subjects

P B English

Publications and source records attributed to P B English.

At least 19 recordsLinked to original sources
PubMed1998

Childhood asthma along the United States/Mexico border: hospitalizations and air quality in two California counties.

Since the passage of the North American Free Trade Agreement in 1993, there has been an increasing need to monitor environmental health trends that may be related to the rapid industrialization of the United States/Mexico border. We studied two counties on the California/Baja California border to obtain baseline data on trends in childhood asthma hospitalizations and two pollutants that aggravate asthma, ozone and particulate matter (less than 10 microns in diameter), from 1983 to 1994. Hospital discharge records of children 14 years and younger were analyzed, and rates by county, race, and sex were age-adjusted to the 1990 California population. Data on five ozone and particulate matter indices obtained from the California Environmental Protection Agency were used. Imperial County had the highest childhood asthma hospitalization rates in California for non-Hispanic whites and African-Americans, and the second highest for Hispanics. San Diego County had rates below the state average. Over the time period examined, rates in Imperial County increased 59%, while those in San Diego County decreased 9%. Maximum ozone levels increased 64% in Imperial County but decreased 46% in San Diego County. Particulate matter levels were four times higher in Imperial than in San Diego County. High rates of childhood asthma hospitalizations in Imperial County may be partially related to high levels of poverty and worsening air quality conditions produced by increased burdens on the local airshed. Asthma prevalence surveys and binational time-series analyses examining asthma-pollutant relationships are needed.

Adolescent↗
PubMed1998

Misclassification rates for current smokers misclassified as nonsmokers.

OBJECTIVES: This paper provides misclassification rates for current cigarette smokers who report themselves as nonsmokers. Such rates are important in determining smoker misclassification bias in the estimation of relative risks in passive smoking studies. METHODS: True smoking status, either occasional or regular, was determined for individual current smokers in 3 existing studies of nonsmokers by inspecting the cotinine levels of body fluids. The new data, combined with an approximately equal amount in the 1992 Environmental Protection Agency (EPA) report on passive smoking and lung cancer, yielded misclassification rates that not only had lower standard errors but also were stratified by sex and US minority majority status. RESULTS: The misclassification rates for the important category of female smokers misclassified as never smokers were, respectively, 0.8%, 6.0%, 2.8%, and 15.3% for majority regular, majority occasional, US minority regular, and US minority occasional smokers. Misclassification rates for males were mostly somewhat higher. CONCLUSIONS: The new information supports EPA's conclusion that smoker misclassification bias is small. Also, investigators are advised to pay attention to minority/majority status of cohorts when correcting for smoker misclassification bias.

Bias↗
PubMed1997

Pregnancy outcomes and risk factors in Mexican Americans: the effect of language use and mother's birthplace.

Effects of acculturation have been thought to contribute adversely to poor reproductive health in Mexican immigrants, and a traditional Mexican orientation has been hypothesized to be protective against poor birth outcomes. A population-based cross-sectional study of 4404 births of Mexico-born and U.S.-born Mexican-American women was conducted in California in 1992 to examine the effect of language use (as a proxy measure of acculturation) on reproductive outcomes. Utilizing birth certificates, supplemental questionnaires, and 1990 U.S. Census data, the study analyzed differences in the proportions of pregnancy risk factors, low birth weight infants, and preterm deliveries in six nativity/language subgroups. Compared to U.S.-born English-speakers, U.S.-born Spanish-speakers had a higher risk profile and Mexico-born English-speakers had a lower risk profile for adverse pregnancy outcomes. After controlling for covariates, U.S.-born Spanish-speakers had the highest odds for low birth weight (OR = 1.98, 95% C.I. = 1.00, 3.93) and Mexico-born English-speakers had the lowest odds for preterm delivery (OR = 0.70, 95% C.I. = 0.35, 1.40) compared to U.S.-born English-speakers. These nativity/language differences in risk profiles and pregnancy outcomes suggest that Mexican Americans do not experience a simple negative mode of adaptation to U.S. society, but rather a complex process of positive and negative acculturation, which may be dependent on socio-economic conditions or selection factors related to immigration.

Acculturation↗
PubMed1995

Effect of United States residence on birth outcomes among Mexican immigrants: an exploratory study.

Adverse pregnancy outcomes such as low birth weight are increased among US-born mothers of Mexican descent compared with immigrant mothers born in Mexico. It is unknown whether adverse reproductive outcomes change among Mexican immigrants after only 5 years of US residence. The authors conducted a study of 1,114 Mexican immigrant mothers and their infants in two California counties. The relation between US residence status and birth outcomes was examined, controlling for sociodemographic factors and maternal behaviors. Long-term immigrants who have lived in the United States for more than 5 years were more likely to deliver preterm infants (odds ratio (OR) = 1.9, 95% confidence interval (CI) 1.1-3.3) and low birth weight infants (OR = 1.5, 95% CI 0.8-2.7) than newcomers who have lived in the United States for 5 years or less. Long-term immigrants had higher parity, more pregnancy complications, and fewer planned pregnancies, and were more likely to smoke than newcomers. After controlling for confounders, the effect of residence status on preterm delivery was of borderline significance (adjusted OR = 1.8, 95% CI 1.0-3.2). Pregnancy complications was an intervening variable between residence status and preterm delivery. Length of US residence is associated with an increase in low birth weight via a decrease in gestational age rather than intrauterine growth retardation.

Birth Weight↗
PubMed1994

Black-white differences in serum cotinine levels among pregnant women and subsequent effects on infant birthweight.

OBJECTIVES: Higher levels of serum cotinine (a metabolite of nicotine) have been found in Black smokers than in White smokers even after self-reported cigarette dose was controlled. It is unknown whether higher cotinine levels in Black pregnant smokers may increase the risk of delivering an infant of reduced birthweight. METHODS: We analyzed serum cotinine levels of 374 Black and 829 White women who smoked during pregnancy and who delivered between April 1964 and April 1967. Racial differences in the relationship between cotinine and birthweight were examined. RESULTS: Cotinine levels were 27.4 ng/mL higher in Black smokers after cigarette dose and confounding variables were controlled. Blacks had higher cotinine levels than Whites at each dose. No significant racial differences in the rate of decrease in birthweight per nanogram of cotinine per milliliter were found. CONCLUSIONS: Our results confirm previous research showing higher cotinine levels at each smoking dose in Black smokers than in White smokers. Because there was no difference in the rate of decrease in birthweight due to cotinine, our results suggest that cigarette smoking among Blacks may have a greater effect on birthweight than it does among Whites.

Black or African American↗
PubMed1992

Reinterpreting the effects of maternal smoking on infant birthweight and perinatal mortality: a multivariate approach to birthweight standardization.

Infants of women who smoke during pregnancy have lower birthweights and have been observed to have higher rates of perinatal mortality than infants of non-smokers. It is not clear whether this increased risk of mortality is due to an excess of small births among smokers or to an independent effect of smoking. Although infants of smokers have overall higher mortality rates than non-smokers, low birthweight (< 2500 g) infants of smokers have lower mortality rates than low birthweight infants of non-smokers. However, comparison of birthweight-specific mortality between two groups is problematic when there are differences in the birthweight distributions. Methods that have been developed to standardize for these differences by comparing mortality rates relative to their own mean do not allow for simultaneous control of confounding variables. Using data from over 13,000 births of women who participated in a prepaid health care plan we present a method to standardize for birthweight while adjusting for variables that may confound the relationship between maternal smoking and perinatal mortality. After controlling for race, maternal age, education, parity, and number of cigarettes smoked, we found that 85% of the increased mortality due to smoking was attributable to an excess of small births in the birthweight distribution of offspring of smoking mothers, while 15% was due to higher birthweight-specific mortality at almost all standardized birthweights. Contrary to previous reports, we found that low birthweight infants of smoking mothers are at higher risk of perinatal mortality if a population-specific standard for birthweight is used.

Birth Weight↗
PubMed1992

Use of augmented cultural techniques in the diagnosis of the bacterial cause of clinical bovine mastitis.

Preculture incubation, preculture freezing, and increased plate inoculation volumes were tested in an attempt to increase the recovery rate of pathogens in milk from cases of clinical bovine mastitis. Culture of milk from 291 cases of clinical bovine mastitis was performed using standard milk culture techniques (.01 ml of fresh milk streaked on trypticase soy agar plates with 5% sheep blood and .1% esculin). The sensitivity of this method was compared with that of cultures performed using augmented techniques: 4 and 18 h of preculture incubation; preculture freezing of samples overnight at -20 degrees C; and increasing the plate inoculation volume to .05 and .1 ml for fresh, incubated, and frozen samples. Preculture incubation and larger plate inoculation volumes significantly increased the recovery rate of bacterial pathogens over the standard culture method. The greatest improvement in sensitivity without a concomitant increase in contamination was achieved when samples were incubated for 4 h and plates were inoculated with .1 ml of the sample. Recovery was enhanced significantly by this method for several organisms, including environmental streptococci and coliform bacteria. Freezing milk before culture yielded a significantly higher positive culture rate overall, but freezing did not affect the positive culture rate of any individual bacterial species.

Animals↗
PubMed1991

Hepatotoxic and nephrotoxic principles in Terminalia oblongata.

A study was conducted to identify and characterise the toxic principle in Terminalia oblongata, commonly known as yellow-wood. Crude aqueous extracts of yellow-wood leaf were found to produce the same liver lesion in mice as has been reported in ruminants. The hepatotoxic fraction was isolated and identified as a hydrolysable vegetable tannin called punicalagin. When given orally, the dose required to produce toxicity was at least 20 times greater than when given intraperitoneally. Following a given dose of punicalagin, the onset and severity of liver necrosis was found to be related to the time interval after dosing. In addition to punicalagin, an unidentified nephrotoxic substance was found which was capable of producing avascular renal necrosis without liver necrosis.

Administration, Oral↗
PubMed1991

Evaluation of methods for the diagnosis of Streptococcus agalactiae intramammary infections in dairy cattle.

The sensitivity, specificity, and positive and negative predictive values were compared for six methods of collecting or culturing milk samples for the diagnosis of chronic Streptococcus agalactiae intramammary infection. Cows in four dairy herds were cultured three times in 2 wk to determine infection status. At the second sample period, individual quarter and composite milk samples were taken before and immediately after milking, and two volumes of milk from the composite samples were streaked on culture plates. The sensitivity, specificity, and predictive values for these cultures ranged between 95 and 100% for all diagnostic methods, and no significant differences were found between methods. The results indicate that when either quarter or composite samples are collected before or immediately after milking, 95 to 100% of S. agalactiae culture-positive cows will be infected with S. agalactiae in herds with a prevalence of S. agalactiae between 35 and 55%. A similar proportion of culture-negative cows will be uninfected.

Animals↗
PubMed1990

Shedding pattern of Staphylococcus aureus from bovine intramammary infections.

Twenty-one quarters of seven cows were experimentally infected with Staphylococcus aureus (ATCC 29740) to study the shedding pattern in quarter milk samples. Of 991 consecutive quarter milk samples collected from infected quarters during the trial, 745 were positive for S. aureus by bacteriological culture. The sensitivity of a single quarter milk sample to determine infection status of a quarter was 74.5% based on the mean of each gland's recovery pattern. Sensitivity of bacterial culture increased to 94% and 98% by including a second and a third consecutive sample. Because S. aureus is shed in a cyclical manner from mammary glands, consecutive samples would be advisable for accurate diagnosis of infected quarters.

Animals↗
PubMed1990

Effect of milk sample delivery methods and arrival conditions on bacterial contamination rates.

A cross sectional study was performed of factors believed to contribute to the contamination of bovine milk sample cultures submitted to the Ithaca Regional Laboratory of the Quality Milk Promotion Services/New York State Mastitis Control. Of 871 samples entered in the study, 137 (15.7%) were contaminated. There were interactions between the sample source (veterinarian vs dairyman), delivery method, and time between sample collection and arrival at the laboratory. If only those samples collected and hand delivered by the dairyman within 1 day of collection were compared to a like subset of samples collected and hand delivered by veterinarians, no statistically significant differences in milk sample contamination rate (MSCR) were found. Samples were delivered to the laboratory by hand, US Postal Service, United Parcel Service, via the New York State College of Veterinary Medicine Diagnostic Laboratory, or Northeast Dairy Herd Improvement Association Courier. The MSCR was only 7.6% for hand delivered samples, while 26% of Postal Service samples were contaminated. These rates differed significantly from other delivery methods (P less than 0.0001). The USPS samples arrived a longer time after sampling than did samples sent by other routes, and time had a significant effect on MSCR (0 to 1 day, 8.9%; greater than 1 day, 25.9%; P less than 0.01). Samples packaged with ice packs sent by routes other than the Postal Service had a lower MSCR than those not packaged with ice packs, but ice packs did not reduce the MSCR for samples sent by the Postal Service.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Association between neutral-to-earth and cow contact voltage on New York dairy farms.

Cow contact (or "stray") voltage has been associated with various health and management problems in dairy cows. Neutral-to-earth voltage (voltage between the service entrance neutral bus and a reference ground rod) has been equated with cow contact voltage in previous research. To investigate the association between these two voltages, single ("instantaneous") and continuous voltmeter measurements were made at 97 farms in New York. A small positive correlation was found between all single neutral-to-earth and cow contact measurements. Eleven farms with continuous neutral-to-earth readings of .5 V or greater were resurveyed. Eight of the resurveyed farms showed a small or nonexistent correlation between the two voltages. Neutral-to-earth voltage is not recommended as an indicator to predict the presence or magnitude of cow contact voltage.

Animals↗
PubMed1988

External balance of water and electrolytes in the horse.

The components of the daily external water and electrolyte balances of five normal Standardbred geldings with a mean body weight of 427 kg, were determined over 14 day periods. The mean value of daily total water intake (a summation of free, combined and metabolic water intake) for the group was 27.6 litres, that is, 64.4 ml/kg body weight, while mean values for ambient temperature and humidity ranged from 16 to 25 degrees C and 55.4 to 75.5 per cent, respectively. The mean daily urine volume of 9.9 litres (23.2 ml/kg) for the group, was found to exceed the mean faecal water output of 7.2 litres (16.9 ml/kg). The mean output of sodium for the five animals, in urine and faeces, was 780 mmol or 79 per cent of the intake. The mean output of potassium, chloride, calcium and magnesium were 3163, 2521, 1824 and 1448 mmol or 95, 84, 74 and 75 per cent, respectively of intake. The sodium and potassium not accounted for in urine and faeces may well have been lost in sweat. Results are discussed and compared with those of a previous external balance study in the horse.

Animals↗
PubMed1987

Experimentally induced lactic acidosis in the goat.

Lactic acidosis was produced experimentally twice in each of 4 adult, female goats, by giving sucrose orally at the rate of 18 g/kg bodyweight. Changes in pH, osmolality, lactic acid concentration, and other constituents in ruminal fluid, plasma and blood were monitored over a period of 48 h. Also changes in urinary pH and sediment were examined. To ameliorate the metabolic disturbance, calcium hydroxide and bicarbonate treatment was employed after the 24 h samples had been collected and their acid-base status determined. A feature of the disturbance in the goats was that a metabolic alkalosis preceded the onset of lactic acidosis.

Acidosis, Lactic↗
PubMed1987

Veterinary education in China.

A brief history of the development of veterinary knowledge and education in China and a short account of present-day veterinary education are presented. In dealing with the latter, information on the number and structure of schools, the undergraduate curriculum, graduate numbers and employment on graduation are considered. Information on the staffing of veterinary teaching departments, academic staff salaries and pensions is also added.

China↗
PubMed1986

Pharmacokinetics of cefotaxime in the dog.

Each of five dogs was given cefotaxime at a dose rate of 50 mg/kg by intravenous, intramuscular and subcutaneous routes, in three separate treatments. Plasma concentration time profiles were characterised by a linear two-compartment model after the intravenous administration. After intravenous, intramuscular and subcutaneous injections the mean biological half-lives were 0.74, 0.83 and 1.71 hours, respectively. The apparent steady state volume of distribution was 0.48 litre/kg and body clearance after intravenous injection was approximately 0.63 litre/hour/kg. After intramuscular and subcutaneous injections peak plasma cefotaxime concentrations were 47 +/- 15 and 29.6 +/- 16 micrograms/ml at 0.5 and 0.8 hours, respectively. The average bioavailability of cefotaxime given by intramuscular injection was 86.5 per cent and for cefotaxime given subcutaneously it was approximately 100 per cent. After two hours, the cefotaxime plasma concentration remained higher after subcutaneous than after intramuscular administration.

Animals↗
PubMed1986

Pharmacokinetic evaluation of a slow-release cefotaxime suspension in the dog and in sheep.

Three Merino ewes were given cefotaxime IM, and 3 were given cefotaxime subcutaneously (50 mg/kg of body weight each); each dose was suspended in 6 ml of oil. Five dogs were also given an oily suspension of cefotaxime subcutaneously (SC) (50 mg/kg of body weight). The plasma concentrations (Cp) and pharmacokinetic data obtained after cefotaxime in the oily suspension was injected IM and SC were compared with data from the same animals after they were given an aqueous solution of cefotaxime by the same routes. Key pharmacokinetic values obtained after cefotaxime was administered IV to sheep and to dogs are discussed. Mean peak Cp (Cpeak) in sheep when given the oily suspension IM was approximately 53 micrograms/ml at 0.18 to 0.40 hour, and that value in sheep given the aqueous preparation was 62 micrograms/ml 0.08 to 0.18 hour. Mean Cpeak values after the oily suspension and the aqueous preparation were injected SC were 11.0 micrograms/ml (between 0.8 and 1 hour) and 51 micrograms/ml (between 0.25 and 1 hour), respectively. Bioavailabilities were approximately 70% after IM injection was done and 90% after SC injection was done. The beta-plasma half-lives were 0.7 hour after IM injection was done and 2.9 hours after SC injection was done. Mean Cpeak in dogs when given the oily suspension SC was 30 micrograms/ml at 1.0 hour, and when dogs were given the aqueous preparation SC, Cpeak was 27 micrograms/ml at 0.6 hour. Absorption was virtually complete after the oily suspension and aqueous preparations were given.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗