The effects of amount of whole barley, barley bulk density, and form of roughage on feedlot lamb performance, carcass characteristics, and digesta kinetics

We conducted two feedlot trials and one metabolism trial to evaluate the effect of barley level, barley bulk density, and physical form of roughage on lamb growth performance and digesta kinetics. Level of whole barley (50, 70, 90%) and type of roughage (chopped or pelleted alfalfa) were evaluated in Trial 1 (50 d period). Trial 2 (50 d) evaluated barley bulk density (heavy = 671 and light = 607 kg/m3), form of roughage (pelleted or chopped alfalfa), and level of barley (80 or 40%). The influence of treatments used in Trial 2 on digesta kinetics was evaluated in Trial 3. Gain:feed increased and DMI decreased (P < .10) linearly with increasing level of barley, and ADG and DMI were greater (P < . 10) for lambs fed pelleted vs chopped alfalfa in Trial 1. The 70% barley diet produced the highest yield grade and kidney-pelvic fat and the lowest leg score among barley levels (P < .10). Lambs fed pelleted alfalfa had heavier carcasses and a thicker body wall than lambs fed chopped alfalfa (P < .02). In Trial 2, DMI was less and gain:feed greater (P < .01) for lambs fed the heavy barley than for lambs fed the light barley and for the 80% barley diet compared to the 40% barley diet. Lambs fed pelleted alfalfa had greater dressing percentages than lambs fed chopped alfalfa. Backfat and body wall thickness were greater (P < .10) for lambs fed the 80% barley diet than for those fed the 40% barley diet. In Trial 3, retention time of barley was greater (P < .10) for lambs fed light rather than heavy barley, and retention time of alfalfa was greater (P < .10) for lambs fed chopped compared with pelleted alfalfa. Acetate:propionate ratio was greater (P < .10) for lambs fed light vs heavy barley and lambs fed the 40 vs 80% barley diets. Ruminal pH was lower (P = .05) and in situ barley digestion greater (P = .03) over time in lambs fed the 80% barley diet than in lambs fed the 40% barley diet. Feedlot lamb ADG was not always greatest with high levels of barley; however, gain:feed improved at the higher barley levels. The higher barley levels seemed to result in fatter lambs.     

High affinity presentation of an autoantigenic peptide in type I diabetes by an HLA class II protein encoded in a haplotype protecting from disease

Tissue composition and the distribution of body mass are described for four genera of East African Bovidae (Madoqua, Gazella, Damaliscus, Hippotragus) with supporting data from four others (Neotragus, Oryx, Tragelaphus, Connochaetes). These species are high in muscle mass, an adaptation convergent with other high-speed terrestrial cursors, bounders, and saltators. The segments below the elbow/cubitus and knee/stifle/genu joints in small bovids are both lighter in percent of total body mass (8.6% TBM) and less heavily muscled (10-15% of total limb musculature) than those segments in macaques (13.6% TBM, 20-25% of the limb musculature). Bovid species differ from one another in the regional distribution of muscle mass. Madoqua kirkii (4-5 kg) concentrates muscle in the lumbar extensors and hindlimbs; large species such as Damaliscus doreas (50-60 kg) and Hippotragus niger (160-220 kg) distribute it more evenly between the lumbar and cervical regions and between the hindlimbs and forelimbs. Gazella dorcas (10-20 kg) is quantitatively intermediate in those characteristics. The redistribution of muscle mass with increasing size correlates with the loss of axial bending of the vertebral column: in small, hindlimb dominant, 'dorsomobile' species such as Madoqua sagittal mobility increases stride length through 'extended' suspension; in large 'dorsostable' species such as Damaliscus and Hippotragus the vertebral column resists bending, consequently abbreviating or omitting this non-contact phase of the gait cycle. Locomotor adaptation as it is reflected in size, shape, and musculoskeletal structure is the key to habitat choice, dietary specialization, social structure, and male agonistic behavior and, therefore, central to the fabric of behavioral ecology.     

Influence of absorbable dusting powders on wound infection

OBJECTIVE: To investigate the lymphocyte subpopulations (T4, T8 and macrophages) and major histocompatibility (MHC) II antigens in patients with superficial bladder cancer before and after intravesical instillations of recombinant interferon-gamma (IFN-gamma). PATIENTS AND METHODS: Four intravesical weekly instillations of either 1.3 mg (20 patients, group A) or 0.7 mg (11 patients, group B) IFN-gamma were administered in 31 evaluable patients (28 men and three women, mean age 68.5 years). The CD4+, CD8+, CD68+ and HLA-DR antigens were detected immunohistochemically in tumours and a marker tumour before and after intravesical instillations. RESULTS: The median number of T4 lymphocytes increased from 15 per high-power field (HPF) to 27.5 in group A (P = 0.0029) and to 45 in group B (P = 0.0117). Macrophages increased from 6 cells/HPF to 15 cells/HPF in group A (P = 0.0029) and from 2 to 8.75 cells/HPF in group B (P = 0.0117). The T8 lymphocyte subpopulation decreased from 4 to 3 cells/HPF (P = 0.0231) in group A and from 5 to 2 cells/HPF (P = 0.0759) in group B. The median percentage of HLA-DR antigens increased from 1.5% to 18% in general, (P < 0.001), from 2.5% to 15% in group A (P = 0.0064) and from 0% to 20% in group B (P = 0.0077). The induction of HLA-DR antigens was statistically significant in those receiving the lower dose (from 0% before instillation to 20% afterward, P = 0.0277), while it was not with the higher dose (from 0% to 5%, P = 0.068). Irrespective of the dose of IFN used. T4 lymphocytes and macrophages increased significantly after treatment in patients in whom the tumour HLA-DR antigens were either up-regulated or remained stable. The median net increase in T4 cells was 17.5 and 30 cells/HPF for groups A and B, respectively (P = 0.0429). CONCLUSION: T4 lymphocytes, macrophages and HLA-DR antigens increased after intravesical IFN-gamma in patients with superficial bladder cancer, but T8 lymphocytes decreased. Irrespective of the drug dose used, patients with either upregulated or stable HLA-DR antigens after treatment showed the same pattern of changes in the lymphocyte subpopulations. The two doses generally had the same effect on the immunological variables assessed but the lower dose was more effective in inducing HLA-DR antigens and in increasing the number of T4 lymphocytes in the tumours.     

Entry of US medical school graduates into family practice residencies: 1997-1998 and 3-year summary

This is the 17th report prepared by the American Academy of Family Physicians (AAFP) on the percentage of each US medical school's graduates entering family practice residency programs. Approximately 16.6% of the 15,894 graduates of US medical schools between July 1996 and June 1997 were first-year family practice residents in October 1997, compared with 15.9% in 1996 and 14.6% in 1995. This is the highest percentage since this series of studies began in 1980-1981 (12.8%). Medical school graduates from publicly funded medical schools were almost twice as likely to be first-year family practice residents in October 1997 than were residents from privately funded schools, 19.8% compared with 11.8%. The Mountain region reported the highest percentage of medical school graduates who were first-year residents in family practice programs in October 1997 at 25.8%; the Middle Atlantic and New England regions reported the lowest percentages at 11.7% and 10.7%, respectively. Nearly half of the medical school graduates (48.1%) entering a family practice residency program as first-year residents in October 1997 entered a program in the same state where they graduated from medical school. The percentages for each medical school have varied substantially from year to year since the AAFP began reporting this information. This article reports the average percentage for each medical school for the last 3 years. Also reported are the number and percentage of graduates of colleges of osteopathic medicine who entered Accreditation Council for Graduate Medical Education-accredited family practice residency programs, based on estimates provided by the American Association of Colleges of Osteopathic Medicine.     

Increased stem cell somatic mutation in the non-neoplastic colorectal mucosa of patients with familial adenomatous polyposis

Colorectal tumorigenesis in familial adenomatous polyposis (FAP) results from somatic mutation of either the normal APC allele or another growth control gene in epithelial cells bearing a germline APC defect. The rate at which tumors develop is therefore dependent on the somatic mutation frequency; it is not known whether this is normal or elevated in FAP. We aimed to quantify stem cell somatic mutation in FAP, comparing it with hereditary nonpolyposis colorectal cancer (HNPCC) and Crohn's disease (CD). Stem cell somatic mutation frequency was studied in 47 FAP patients, 5 HNPCC patients, and 13 CD patients, all younger than 49 years, by quantifying crypt-restricted loss of O-acetyltransferase activity in sections of morphologically normal colonic mucosa from individuals heterozygous for this monogenically inherited polymorphism. Median stem cell somatic mutation frequency was significantly higher in FAP than HNPCC (4.2 x 10(-4) v 1.4 x 10(-4), Mann-Whitney U, P < .02). The level in CD (4.0 x 10(-4)) was similar to FAP. Mutated crypts occurred in groups more frequently in FAP (22%) than HNPCC (12%) or CD (10%), suggesting an increase in stem cell division associated with crypt fission in FAP. We conclude that stem cell somatic mutation frequency is raised in non-neoplastic colorectal mucosa in FAP. This is probably related to increased stem cell proliferation and contributes to the high rate of tumor formation in this condition.     

Kinetic and spectroscopic properties of the YZ* radical in Ca2+- and Cl--depleted photosystem II preparations

Depletion of Ca2+ and/or Cl- ions from PSII membranes blocks the electron-transfer reactions that precede O2 evolution on the oxidizing side of the enzyme. Illumination of these inhibited preparations at 273 K generates a paramagnetic species that is detectable by low-temperature (T < 20 K) EPR as a signal in the g = 2 region, 90-230 G wide, depending on the treatment that PSII has undergone. This signal has recently been assigned to YZ* in magnetic interaction with the manganese cluster in its S2 state [Gilchrist et al. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 9545-9549]. This view, however, is not universal, owing, in part, to the fact that its spectroscopic properties depend on the preparation and the experimental conditions used for its study and, in part, to uncertainties as to the room temperature behavior of YZ* in inhibited preparations. Here, we report time-resolved and conventional EPR data showing that, at room temperature and at 273 K, YZ* can be accumulated in its 20 G form in high yields in both Ca2+-depleted and acetate-inhibited preparations, and that the kinetics of its decay match the decay kinetics of the low-temperature signal generated in corresponding samples. The properties of the YZ* signal, however, are shown to depend on the polypeptide content, the temperature, and the electron donors and acceptors present in the sample under examination. Our results support assignment of the EPR signal in inhibited preparations to S2 YZ* and demonstrate a protective role of the 17 and 23 kDa extrinsic polypeptides for the manganese cluster against externally added reductants.