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Biomedical subjects

R W Quinn

Publications and source records attributed to R W Quinn.

At least 19 recordsLinked to original sources

Voluntary intake and digestibility of reed canarygrass and timothy hay fed to horses.

Thousands of hectares of timothy (Phleum pretense L.) grown in the Mid-Atlantic region are infected by cereal rust mite (Abacarus hysterix) that causes discoloration and curling of leaves, decreased nutritional quality, and substantial decreases in yield. A decline in production of timothy hay can lower income for hay producers and cause horse owners to search for alternative hays. Low alkaloid reed canarygrass (Phalaris arundinacea L.) hay has potential as an alternative to timothy hay because it grows well in the Mid-Atlantic region, is believed to have a similar nutrient quality to timothy, and is not as susceptible to cereal rust mite. Eleven mature, stalled Thoroughbred geldings (549 +/- 12.1 kg) that were exercised daily were used to compare voluntary DMI and apparent nutrient DM digestibility of timothy and low-alkaloid Chiefton variety reed canarygrass hay. Horses were paired by age and BW and randomly assigned to timothy or reed canarygrass hay during a 14-d period to measure voluntary DMI followed by a 4-d period to measure apparent DM digestibility. Both hays met the minimum requirements for DE, CP, Ca, P, K, Fe, and Mn, but they did not meet the minimum requirements for Cu, Zn, and Na for horses at maintenance and averaging 550 kg of BW. Timothy hay seemed to have a lower CP concentration (14.4%) compared with reed canarygrass hay (17.1%) and a more desirable Ca:P ratio at 1.6:1 compared with 0.8:1 for reed canarygrass hay. Horses fed timothy consumed more hay (P <0.001) during the voluntary DMI period compared with horses fed reed canarygrass. Greater voluntary DMI of timothy occurred on d 1, 3, and 5 (P <0.05), but DMI was similar for other days. Apparent DM digestibility was greater in horses fed timothy hay by 9.6% compared with horses fed reed canarygrass hay (P <0.05). Horses fed timothy had greater DM digestibility of ADF (P = 0.001), NDF (P = 0.001), sugar (P = 0.05), and Ca (P = 0.001) but lower apparent DM digestibility of CP (P = 0.012) and crude fat (P = 0.004). Timothy hay was superior in voluntary DMI and apparent DM digestibility compared with low-alkaloid reed canarygrass hay fed to horses.

Animal Feed↗

Increased incidence of syphilis in Tennessee during the 1980s: challenges for a new decade.

Although recent increases in the incidence of syphilis are well known to public health officials, the general medical community is less well informed regarding the dramatic rise in cases. We present trend data from Nashville and Tennessee over the past decade. These statistics emphasize specific factors, such as drug abuse, that contribute to new difficulties in controlling this sexually transmitted disease.

Contact Tracing↗

Gonococcal infections in women attending the Venereal Disease Clinic of the Nashville Davidson County Metropolitan Health Department, 1984.

During the first six months of 1984, slightly more than a third (34.1%) of the 1,549 women who attended the Venereal Disease Clinic of the Nashville Davidson County Health Department in this study were found to be infected with Neisseria gonorrhoeae. Infection prevalence was 36.7% for black women and 27.1% for white. The frequency of sexual intercourse and the number of sexual partners during the previous 30 days were similar for black and white patients. Fewer women were using contraceptives (67.8%) than in 1979 (87%). Exceptionally high rates of infection were found in women whose sexual partners had gonorrhea. Even with similar levels of sexual activity, black women faced greater risk of infection than white women, possibly because they were much more likely to be exposed to an infected man.

Adult↗

Epidemiology of a thermonuclear bomb-burst over Nashville, Tennessee: a theoretic study.

A thermonuclear bomb explosion over any city in the world would have a devastating effect on the population and environment. For those who survive, with or without injuries, life would become primitive with little or no uncontaminated food or water, and with inadequate housing, fuel, and medical care, resulting in a breakdown of family and interpersonal relationships. This theoretic study of the potential outcome of a thermonuclear bomb-burst over Nashville, Tennessee, discusses epidemiologically the wide range of medical and psychologic effects from the direct trauma of blast and fire, widespread epidemics of otherwise controlled disease, long-term chronic illness, genetic damage, and catastrophic environmental havoc.

Adolescent↗

Hemolytic streptococci in Nashville school children.

Incidence and prevalence of hemolytic and group A streptococci were determined for 3,479 school children in Nashville, Tennessee from 1953-1954 through 1973-1974 inclusive. Of 53,827 throat cultures, 17.98% were positive for hemolytic streptococci and 12.87% for group A; 26.19% group A strains were typable. Types 6, 1, 12, 4, 5, and 3 were the most frequently isolated. Percentages of children with at least one positive culture for both hemolytic (H) and group A streptococci (A) were highest in 1953-1954 (H--79.3%, A--71.0%); 1963-1964 (H--83.5%, A--74.6%); 1969-1970 (H--74.6%, A--65.0%); and 1973-1974 (H--83.1%, A--71.1%) and highest by month in February, declining erratically until the summer. Some children acquired type-specific antibodies in the absence of streptococcal disease. There was a significant increase in positivity rates for hemolytic and group A streptococci from ages 5 to 7 through age groups 6 to 8 and 7 to 9 and a slow decline in the older age groups. Race did not appear to be an important factor in determining positivity rates; rates were significantly higher among children from low socioeconomic areas regardless of whether they were black or white.

Adolescent↗

Significance of hemolytic streptococci for Nashville school children: clinical and serologic observations.

The results of this study (1969-1971 confirm previous findings that incidence rates for hemolytic and group A streptococci in Nashville school children fluctuate sporadically. During these two years, there was a significant decrease in streptococcal incidence and in typability of group A streptococci. A positive throat culture was not associated significantly more often with symptoms of an infection of the upper respiratory tract than when symptoms were absent. The larger the number of group A streptococci present in the throat culture, the more likely was a streptococcal antibody increase to occur. Nevertheless, some children with small numbers of group A streptococci had an antibody increase, and the degree of positivity of the throat culture was not a very accurate indication of whether an antibody response would occur. Epidemiologic factors such as age, sex, race, or crowding in the home did not seem to play a highly significant role in rates. Seasonal influences were marked in 1969-1970 but not in 1970-1971. Regarding socioeconomic background, the rates were consistently lower in Clemons school, which serves a predominantly black neighborhood of higher socioeconomic level, than in the other two schools. Our findings confirm that the incidence of acquisition of the hemolytic streptococcus is a continually changing, dynamic process among school children.

Antibodies, Bacterial↗

Recurrences and sequelae of rheumatic fever in Nashville. A follow-up study.

A follow-up study of 311 patients who acquired rheumatic fever in Nashville, Tenn, during the period from 1963 to 1969 showed that 53% took penicillin prophylaxis regularly, 36% did not take it as recommended, and 11% did not take it at all. There were no recurrences among those who received prophylaxis by injection regularly, six recurrences among those who took oral prophylaxis regularly, and no recurrences among 45 subjects who did not take prophylaxis. Among these 45, however, were 29 for whom prophylaxis was not recommended by their physicians. The original study indicated that the incidence of acute rheumatic fever among blacks was twice as high as among whites. In the present study, incidence of rheumatic heart disease and recurrences was substantially higher among blacks than among whites.

Administration, Oral↗

Further studies of some "nontypable" group A streptococci.

Thirty-two strains of group A hemolytic streptococci which could not be M typed with the available typing sera in Nashville, Tenn., were reinvestigated at the Streptococcus Reference Laboratory in Colindale, England, in order to estimate the efficacy of other antisera not available in Nashville and newer techniques (the opacity factor inhibition test) of typing strains not isolated in England. Fifty percent were eventually typed and all but four contained enough M protein to suggest that they would have been typed had the appropriate typing sera been available. The results indicate that group A streptococci truly lacking M protein were seldom isolated from the Nashville children from whom the streptococci were cultured. Several factors responsible for nontypability were considered, including the nonavailability of the necessary type-specific antisera and loss of M protein due to a change from Matt to glossy colonial types in the laboratory.

Animals↗

Streptococcal L forms and phage. A clinical-epidemiologic study.

This study showed that streptococcal L forms could not be isolated from children who were either carriers of group A streptococci or had disease due to this pathogen. It was possible to induce L colony formation in 15 strains of group A. Streptococcal bacteriophages were demonstrated in 20% of group A streptococci isolated from school children who were carriers, but did not have clinical evidence of streptococcal disease, and from 44.9% of children whose physicians considered they had acute streptococcal upper respiratory infections. Lysogeny (bacteriophage) was demonstrated more frequently during 1969-70 when carrier rates were high and from children who had manifest streptococcal disease, suggesting a possible positive relationship between lysogeny, high carrier rates, and infection in the children studied. Lysogeny and erythrogenic toxin production by group A streptococci occurred simultaneously in approximately half of the strains of group A streptococci tested, suggesting that lysogeny is not a sine qua non for erythrogenic toxin production.

Bacteriophages↗

Significance of hemolytic colonies in throat cultures.

These studies indicate that a single strain of hemolytic streptococci almost exclusively predominates the bacterial flora in patients with streptococcal infections and in the carrier state. One can proceed with confidence that, in isolating streptococci from throat swabs cultured on blood-agar plates, only a single hemolytic colony need be picked for serological grouping and typing.

Carrier State↗