Management of dairy heifers and its relationships with the incidence of clinical mastitis.

AIM: To describe aspects of management of dairy heifers before calving and determine risk factors for clinical mastitis postpartum in heifers, at the herd level, under pasture-based management systems in the Waikato and Taranaki regions of New Zealand. METHODS: Dairy herdowners (n=578) provided information via a prospective survey about their practices for rearing heifers and management of mastitis. A proportion of herdowners (n=250) subsequently provided data on the cases of clinical mastitis in their herds, including the date, cow identification, age and quarter affected from cases occurring in the 4 months after the planned start of calving (PSC) in the subsequent lactation. The relationship between management factors and the proportion of heifers diagnosed with clinical mastitis within a herd was examined using bivariate and multivariate analyses. RESULTS: The herd average percentage of heifers with clinical mastitis was 13.6 (95% confidence interval (CI)=12.3-14.9)%, and multiparous cows with clinical mastitis was 9.0 (95% CI=8.2-9.8)% in the first 4 months of lactation. There were positive relationships between the proportion of heifers with clinical mastitis and average milk production per cow (kg milksolids/ lactation; p<0.001), number of cows milked per labour unit (p=0.003), stocking rate (<> 3.30 cows/ha; p=0.002), and incidence of clinical mastitis in multiparous cows (%/120 days; p<0.04), in the final multivariate model. The proportion of heifers with clinical mastitis per herd was lower in herds that milked their lactating cows in multiple groups (p=0.02). CONCLUSIONS: The risk of clinical mastitis in heifers was significantly associated with management practices. It may be possible to reduce the incidence of clinical mastitis in heifers by modification of management practices at the herd level, and further studies are required to investigate this.

Is total pelvic exenteration reasonable primary treatment for rectal carcinoma?

Total pelvic exeneration (TPE) is reasonable primary surgical therapy in select patients with large bulky locally invasive rectal cancers that can be removed en bloc. Many do not have either nodal or distant metastasis. Furthermore, TPE can be curative and often is palliative for similar lesions that are recurrent or nonresponsive to radiation therapy. Operative mortality rates should be under 10% and can be under 5% for primary cases. Although improvement in preoperative management and operative technique, especially with urinary conduits and postoperative care is clear, both early and late complications are significant. Unfortunately, preoperative identification of those patients requiring TPE rather than abdominoperineal or low anterior resection remains poor. Furthermore, recent improvements in techniques for pelvic slings to prevent small bowel entrapment and protection from irradiation or myocutaneous flaps to obliterate the massive dead space are not yet clearly established as preventors of either early or later complications.

The safety of the hepatitis B vaccine. Inactivation of the AIDS virus during routine vaccine manufacture.

In the United States, one hepatitis B vaccine (Heptavax-B) has been licensed for the prevention of hepatitis B virus infections. Even though this vaccine has been shown to be highly effective and well tolerated in controlled trials and has been recommended for use in those at risk for acquiring infection by hepatitis B virus, many individuals have been reluctant to be immunized for fear of contracting acquired immunodeficiency syndrome (AIDS). In this study, we demonstrate that each of the three inactivation steps used in the manufacture of Heptavax-B independently will inactivate the infectivity of high-titered preparations of the AIDS virus; recipients of the hepatitis B vaccine do not develop antibodies to the AIDS virus; the hepatitis B vaccine does not contain detectable levels of nucleic acids related to the AIDS virus. These observations clearly demonstrate that vaccination with the currently available hepatitis B vaccine poses no demonstrable risk for acquiring AIDS.

Deficiency of the autologous mixed lymphocyte reaction in patients with classic hemophilia treated with commercial factor VIII concentrate. Correlation with T cell subset distribution, antibodies to lymphadenopathy-associated or human T lymphotropic virus, and analysis of the cellular basis of the deficiency.

14 patients with hemophilia were studied for the distribution of T cell subsets, the presence of antibody to lymphadenopathy-associated or human T lymphotropic virus type III (LAV/HTLV-III), and their responsiveness in autologous mixed lymphocyte reactions. In addition, mitogen and alloantigen responsiveness and Interleukin-2 production were investigated. Seven patients were found to have low Leu 3a/Leu 2a (T4/T8) ratios; eight patients had antibody to LAV/HTLV-III; and an additional patient had acquired immunodeficiency syndrome. Responsiveness to mitogens and alloantigens as well as Interleukin-2 production were comparable with those of healthy individuals. However, patients with low ratio, many of whom had antibodies to LAV/HTLV-III, had a highly deficient autologous mixed lymphocyte reaction. This reduced response of T cells to autologous non-T cells could not be corrected by elimination of Leu 2a/T8 cells, which indicated that there was a preferential loss of the Leu 3a cell subset(s) which responded to autologous non-T cells. Thus, these patients have a deficiency of intercellular communication within their immune system.

Isolation and characterization of a human T cell leukemia virus type II from a hemophilia-A patient with pancytopenia.

Human T cell leukemia virus (HTLV) type I has been isolated from the cultured T cells of several patients with adult T cell leukemia (ATL) and has been etiologically linked to ATL. However, HTLV-type II has been isolated only once, from the T cells of a patient with a T cell variant of hairy-cell leukemia. We report here the isolation of HTLV-II-related virus from the cultured T cells of a hemophilia-A patient with pancytopenia. The T cell line (CM) grows in the absence of T cell growth factor. Cord blood T cells were rapidly transformed when co-cultivated with irradiated CM cells. Heterologous competition radioimmunoassays using purified HTLV-I p24 showed the expression of HTLV-IIMO-related protein in these cells. Electron microscopy of the CM cells showed the presence of intracellular and extracellular type C viral particles. Comparison of the proviral genome in the CM cell line and the prototype HTLV-IIMO-containing cell line (MO) by molecular hybridization with probes specific for HTLV-IIMO indicated that restriction cleavage sites were identical. The fresh peripheral blood leukocytes of the patient contained two complete copies of the proviral genome, despite the lack of HTLV-II p24 expression. The virus from the cell line CM is designated as HTLV-IICM to distinguish it from the original HTLV-IIMO isolate.

Effect of capsaicin upon fluoride sensitive acid phosphatases in selected ganglia and spinal cord and upon neuronal size and number in dorsal root ganglion.

A quantitative method for the analytical separation of the fluoride sensitive acid phosphatases of rat spinal cord and peripheral nervous tissues into tartrate-sensitive and tartrate-resistant forms (TSAP and TRAP, respectively) is described. Evidence supporting the use of L-(+)-tartrate rather than fluoride as an inhibitor is presented. The method is used for the quantitative description of the consequences of neonatal capsaicin treatment, and the results appear to justify the attribution of the TRAP activity to the capsaicin sensitive neurons. In the first experiment, rats were killed at weekly intervals after neonatal capsaicin treatment. In controls, both TRAP and TSAP activities in dorsal root ganglia (DRG) increased during the second postnatal week and remained constant thereafter. At all ages (1-4 weeks) TRAP activity was reduced 50-60% in capsaicin-treated DRG. Reduction of TSAP activity was much less. In a second experiment, rats were treated neonatally with capsaicin or vehicle (control) and allowed to grow to adulthood (4 months). TRAP activity was found to be decreased 38% in the dorsal half of the lumbar spinal cord (L3-L5), decreased 33% in nodose ganglion, and unchanged in superior cervical ganglion of the capsaicin treated animals. TSAP activity was unchanged in dorsal spinal cord and superior cervical ganglion and decreased 33% in nodose ganglion. The number of neurons in C8 DRG was found to be reduced 28% in capsaicin treated animals. The loss appeared to be among the small neurons. The number of large neurons was actually increased in ganglia from capsaicin-treated animals.(ABSTRACT TRUNCATED AT 250 WORDS)