Effects of diet and weight gain on circulating tumour necrosis factor-α concentrations in Thoroughbred geldings.

Low-grade inflammation precedes the development of obesity-related metabolic disorders in humans, but whether the same is true in the horse is not known. The objective of this study was to examine the effects of weight gain and diet on the inflammatory state of horses as determined by serum concentrations of tumour necrosis factor-α (TNF), an inflammatory cytokine. Fifteen mature Thoroughbred geldings with an initial body weight (BW) of 519±12 kg and body condition score (BCS) of 4.3±0.1 were fed a diet of hay plus a concentrate that was either high in non-structural carbohydrates (NSC) (i.e. starch and sugar), similar to those commercially available (CON) or one that had the energy source replaced with fat and fibre (FAT) for 32 weeks. Weight gain was achieved by feeding an additional 20 Mcal/day in excess of digestible energy maintenance requirements and resulted in a final BW of 608±12 kg and BCS of 6.9±0.1. Horses were exercised twice daily at a walk during the weight gain period. Horses were assessed bi-weekly for BW and BCS. Serum TNF was analysed from blood samples collected at 4-week intervals. Although treatment groups began the study with similar mean serum TNF concentrations, 12 weeks of FAT feeding promoted a decrease in circulating TNF that was maintained throughout the study with the exception of weeks 20 and 32. For either diet, there were no linear correlations between serum TNF concentration and BCS when horses increased in BCS from four to seven. The higher level of TNF observed in horses fed the CON diet indicates an increase in some level of systemic inflammation that was independent of their weight gain from a moderately thin to fleshy condition. The influence of diet on serum TNF concentrations should be investigated in horses fed to maintain body condition.

Milk leptin in sows and blood leptin and growth of their offspring.

Twenty-one mixed-parity (average 2.4 +/- 0.49) crossbred sows and their offspring were used to determine whether sow milk leptin at farrowing was related to neonatal serum leptin and pig growth to weaning. During farrowing, pigs were randomly allotted to suckling (n = 99) or delayed suckling (n = 89) groups, with delayed suckling pigs placed in a group pen apart from the dam before suckling. Both groups had access to heat lamps. Colostrum samples were collected no more than 2 h after farrowing the first pig. Blood samples were collected from all pigs approximately 2 h after farrowing was complete; pigs were then ear notched and returned to their dams. Pig BW was recorded at 1.2 +/- 0.04 d of age and again at weaning. Milk and blood serum were collected after centrifugation; leptin concentrations were estimated using RIA. Leptin was detected in colostral milk, as expected, and averaged 46.0 +/- 1.1 ng/mL. Pig serum leptin (P < 0.02) was greater in suckling pigs than in delayed suckling pigs, averaging 0.69 +/- 0.08 and 0.54 +/- 0.07 ng/mL, respectively. Although male pigs were heavier (P < 0.01) at birth than female pigs (1,507 +/- 52 vs. 1,381 +/- 43 g), ADG to weaning and weaning weights were similar for both sexes, averaging 229 +/- 14 g and 5,829 +/- 323 g, respectively, for all pigs; serum leptin concentrations were not affected by sex of the pig. Milk serum leptin was not associated with litter size, parity, pig birth weight, ADG to weaning, or weaning weight. Suckling status did not influence ADG to weaning or weaning weight of pigs; neonatal pig serum leptin was not related to birth weight, weaning weight, or ADG to weaning. These results indicate that leptin is not directly related to early neonatal growth in the pig; however, more in-depth studies are needed to determine possible indirect or long-term effects of early leptin exposure.

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.

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.

Did scarlet fever and rheumatic fever exist in Hippocrates' time?

Case histories recorded by Hippocrates around 400 B.C. describe the clinical manifestations of scarlet fever and rheumatic fever, although the entities are not identified by name. Although the descriptions are not as detailed or complete as they would be today, they strongly suggest the existence of scarlet fever and rheumatic fever at that time. Hippocrates' references to these illnesses were presumably the first to be documented and/or discovered, as a thorough search of the worldwide medical literature revealed no prior descriptions.

Comprehensive review of morbidity and mortality trends for rheumatic fever, streptococcal disease, and scarlet fever: the decline of rheumatic fever.

This review of the medical literature reveals that the incidence of rheumatic fever has been declining for at least 150 years, preceding by many decades the use of penicillin as a preventive measure. Simultaneously, the prevalence of rheumatic heart disease has diminished. Streptococcal upper respiratory tract infections remain common but with reduced severity and fewer subsequent cases of rheumatic fever. Scarlet fever has become relatively benign, with low mortality. Whether recent sporadic outbreaks of rheumatic fever due to known rheumatogenic strains of group A streptococci will have a significant effect on morbidity and mortality trends remains to be seen. Relatively high rates of rheumatic fever and rheumatic heart disease in developing countries are difficult to evaluate because of irregularities in reporting and investigative procedures.

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.

Acquisition of group A streptococcal M protein antibodies.

Seventy-five children who acquired positive throat cultures for Group A streptococci among 250 cultured weekly were studied during the school years 1972-1973 and 1973-1974 in order to investigate streptococcal M protein antibodies. Eleven (14.7%) of the children had strain-specific serum M protein antibodies at the time a positive throat culture was first detected or 6 weeks previously. Eight of 64 (12.5%) children acquired strain specific serum M protein antibodies within 6 weeks and another 6 of 46 (13%) did so within 1 year of infection. The presence of strain-specific serum M protein antibodies did not appear to be protective. One-third of the 75 children who acquired positive throat cultures had a significant rise in anti-streptolysin O or anti-hyaluronidase antibody titers. Among those who acquired Group A streptococci, 25 children had positive cultures on 7 or more culture dates.

Contraceptive practices of women attending the Sexually Transmitted Disease Clinic in Nashville, Tennessee.

The decision to be sexually active involves two health risks for women: unwanted pregnancy and sexually transmitted diseases. Use of contraception affects both these risks. Data from the Metropolitan Health Department in Nashville, Tennessee, were examined to determine the effects of particular contraceptive methods on gonococcal infection in women. The results suggest that not only barrier methods but also other types of contraception were associated with protection against gonorrhea in females. The use of contraception was unusually high (87%) among the study population of 1,303 women. Five hundred eighteen (40%) of these clinic attendees were infected with Neisseria gonorrhoea. Infected women tended to be younger than those not infected and were significantly more likely to be black than white and somewhat more likely to be single. Contraceptors tended to be younger and were more likely to be black than were noncontraceptors.

PIP: The effects of particular contraceptive methods on gonococcal infection were examined in 1303 women attending a public venereal disease clinic during 1979. 1132 (87%) of clinic attenders were using some method of fertility control. The major methods in this series were oral contraceptives, 47%; surgical methods, 18%, and IUDs, 12%. Barrier methods accounted for 5% of contraceptive usage. Of all the women who came to the clinic, 518 (40%) were actually infected with N gonorrhoeae. Those infected with N gonorrhoeae were likely to be younger than those not infected and were more often black and single. Significantly more noncontraceptors than contraceptors were black and young (under 20 years of age). Women not using contraceptives were over 3 times more likely to be infected than contraceptive users (94% infection rate versus 30%). All methods of contraception provided some degree of protection against gonococcal infection. Barrier methods appeared to have the strongest protective effect; only 9.4% of barrier method users were infected (relative risk 0.11). In some cases, the relationship observed in this study between use of specific contraceptive methods and lower rates of gonorrhea may be biological. The explanation in other cases may be behavioral: women who use birth control may be less risk taking in their sexual behavior. It is concluded that motivating women to use contraception, especially barrier methods, could help reduce the incidence of sexually transmitted diseases. Extrapolation of the findings of this study suggests that nearly 200,000 of the 250,000 cases of gonorrhea reported in the US in 1983 could have been averted by use of barrier methods of contraception on the part of noncontraceptors and those using nonbarrier methods.

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.

Epidemiology of group A streptococcal infections--their changing frequency and severity.

The frequency and severity of streptococcal infections and their sequelae have declined dramatically in the past century, yet the prevalence of streptococcal infections is still high. The reasons for this decline must be intimately related to host resistance, virulence of the agent, and environmental factors, especially crowding. Close examination of these fundamental influences does not reveal any evidence that humans have become less resistant to streptococcal infections, but they react less violently. There is some evidence that the agent may have lost a degree of its virulence. The decline in morbidity and mortality due to streptococcal infections began long before antibiotics, especially penicillin, were available. However, penicillin has proved to be an important factor in prevention of streptococcal infections, especially in rheumatic fever prophylaxis. There are certain indications that repeated streptococcal infections due to similar M types, occurring in young children over the past several decades, have resulted in some degree of immunity as well as the possible evolution of less virulent, but not less infectious, strains of group A streptococci. Also, a decrease in crowding would be expected to result in fewer streptococcal infections. Although there are more people in the world than at any other time in the history of man, urban population density in the western world, at least, is less than in the late 1800s and early 1900s.

A survey of 251 patients with acute syphilis treated in the collaborative penicillin study of 1943-1950.

The dramatic and apparently curative effect of penicillin for the treatment of acute syphilis led to follow-up studies for only comparatively brief periods, and the acceptance of the long-term benefit of penicillin has rested on uncontrolled clinical impressions. More certainty about the efficacy of penicillin was sought by a follow-up review of 251 patients treated between March 1944 and December 1950 under the Penicillin Study of the Office of Scientific Research and Development (OSRD) and continued under U. S. Public Health Service after World War II. Eighty-eight patients were interviewed and examined. Telephone conversation or correspondence was had with 43 subjects; an additional nine are known to be living but did not respond to letters. Thirty-two patients died greater than or equal to 20 years after treatment, and 21 patients died within less than 20 years of treatment. Fifty-eight patients could not be found. Treatment failures were documented. Syphilis was not shown to be the cause of disability or death, except for a patient with meningovascular syphilis who died soon after initial treatment. Disabilities recorded and deaths documented revealed only diseases common to any middle-aged population. The outcomes of 17 pregnancies of women treated for acute syphilis were documented. Blood samples obtained from the 88 subjects examined were tested at the Center for Disease Control (Atlanta, Ga.); the results are recorded and discussed. Methods for locating the patients are described, and the psychosocial findings for the 88 patients interviewed are presented. The study has confirmed the clinical impressions of the therapeutic effectiveness of penicillin, which have been accepted for greater than 30 years.

Serologic groups of Neisseria gonorrhoeae recovered from patients in Nashville, Tennessee, 1971--1976.

The objective of this study was to develop and apply a serologic method for identification of different strains of Neisseria gonorrhoeae. Several procedures for preparation of cell-free extracts were tried; the most satisfactory was that with phosphate-buffered saline solution. Both capillary tube and immunodiffusion precipitin techniques were evaluated, and the latter proved preferable. Serologic grouping was attempted for 704 strains of N. gonorrhoeae isolated during 1971--1976. Groupable strains shifted from a predominance of group A to a predominance of group B strains. The percentages of isolates of groups C and D increased, and group E appeared occasionally. Nongroupable strains were much more common after 1973. Four of six strains that were etiologic for recrudescent gonococcal urethritis belonged to the same serogroup that had caused the initial infection; two of six were different. The partners in nine male and female sexual pairs were infected by the same serogroups, four pairs by nongroupable strains, and the partners of five pairs harbored differed serogroups. The immunodiffusion technique described should be useful in clinical and epidemiologic studies of gonorrhea. The antigenic material was shown to be a high-molecular-weight polysaccharide.

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.

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.

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.

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.

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.