Association between bovine leukemia virus, production, and population age in Michigan dairy herds.

The objective of this study was to determine the herd-level effect of bovine leukemia virus (BLV) infection on dairy production, culling, and cow longevity. During routine herd testing, Dairy Herd Improvement Association technicians collected milk samples from about 40 cows from each of 104 randomly selected Michigan dairy herds averaging ≥120 milking cows and 11,686 kg of milk/yr. Milk samples were analyzed for the presence of anti-BLV antibodies by ELISA, and herd- and lactation-specific estimates of BLV prevalence were computed to determine which were the most predictive of herd milk production, culling rate, and cow longevity (proportion of cows in their third or greater lactation). On this basis, the herd BLV index (an unweighted mean BLV prevalence rate for lactation number 1, 2, 3, and ≥4) was selected as the measure of BLV prevalence that was the most highly associated with BLV economic impact. Step-down multivariate analysis was used to determine the extent to which any of 19 herd-level management variables may have confounded the association of BLV index and measures of herd economic impact (milk production and cow longevity). The BLV index was not associated with the 12-mo culling rate, but was negatively associated in the final multivariable model with the proportion of cows that were ≥third lactation, and was negatively associated with herd milk production. In summary, increased prevalence of BLV within Michigan dairy herds was found to be associated with decreased herd milk production and decreased cow longevity. Our results provide evidence that BLV infection is associated with herd-level economic impacts in high-performing dairy herds.

Review and clinical perspectives for the use of infliximab in ulcerative colitis.

Infliximab is a chimeric, monoclonal anti-tumour necrosis factor-alpha antibody. It has been previously demonstrated to be an effective treatment for patients with Crohn's disease who do not achieve the desired response with conventional treatments. Although the etiology of ulcerative colitis (UC) differs from that of Crohn's disease, randomized controlled trials have demonstrated that infliximab is also beneficial for the treatment of moderate to severe UC in patients who are either intolerant of or refractory to immunosuppressant agents or steroids, or those who are steroid-dependent. A review of the literature is followed by practical recommendations regarding infliximab that address the needs of clinicians and UC patients. Where there is a lack of evidence-based information, the expert panel provides its combined opinion derived from the members' clinical experiences.

Facial hirsutism treated with the normal-mode ruby laser: results of a 12-month follow-up study.

Fifty-one patients of skin type I to IV with facial hirsutism received treatment with the normal-mode ruby laser (950-micros pulse; 4-mm spot; mean fluence, 49 J/cm(2); maximum fluence, 66 J/cm(2)). For each patient, one site was treated once only, and a second site was treated 4 times at 4-week intervals. After 48 weeks, 46 patients were available for assessment. After a single treatment, hair counts were reduced to a mean of 45% at 4 weeks (pretreatment median of 63 hairs down to 26), increased to 80% (median, 51 hairs) at 12 weeks, were 65% (median, 41 hairs) at 24 weeks, and were 59% (median, 35 hairs) at 48 weeks. Four weeks after 3 treatments, the hair counts had reduced to a mean of 30% (pretreatment median of 68 hairs down to 15). Twelve weeks after 4 treatments, the hair counts had increased to 45% (median, 24 hairs) and were 39% after 36 weeks (median, 22.5 hairs). No anesthesia was needed. Treatment tolerance improved with consecutive visits, allowing higher fluences to be used. Hyperpigmentation developed in 9 patients, which had faded completely in 8 patients at the end of the study. One patient showed hypopigmentation. Depressions in the skin below the jaw line developed in 5 patients, which resolved completely within 4 to 32 weeks. We conclude that normal-mode ruby laser treatment is well tolerated and leads to significant improvement of facial hirsutism, which is maintained for at least 48 weeks. Repeated treatments result in greater clinical effects.

Ruby laser treatment for hirsutism: clinical response and patient tolerance.

We report the results of a study of the ruby laser in normal mode for treatment of hirsutism in 43 patients with skin types I-IV. A pulse width of 950 microseconds, a 4 mm spot and a fluence sufficient to produce minimal whitening of the epidermis were used (mean 48 J/cm2). In each patient, one site was treated once only, and a second site received four treatments at monthly intervals. After a single treatment, hair counts had reduced to a mean of 46% (median 67, reduced to 26) of the pretreatment values at 1 month, but increased to 80% (median 42) at 3 months and were 66% (median 37) at 6 months. One month after three treatments, hair counts had reduced to a mean of 29% (median 60, reduced to 15) of pretreatment values, and 3 months after four treatments at the same site, counts had increased to 44% (median 21). Patient tolerance of the treatment was good and higher fluences tended to be tolerated at consecutive visits. The first treatment was followed by mild, short-lived erythema and swelling in 60% (25 of 42) patients. Fourteen per cent (six of 42) experienced mild blistering and 33% (14 of 42) crusting. More severe reactions were seen infrequently. These results indicate that normal mode ruby laser treatment is well tolerated. Sustained reduction in hair counts can be achieved for at least 6 months, and multiple treatments produce greater clinical effects.

The reproducibility of the iliac crest as a marker of lumbar spine level.

The postero-anterior lumbar spine X rays of 163 patients undergoing investigation for back pain were reviewed and the spinal level marking the intersection of a line joining the iliac crests was determined. This point coincided with the L4 spinous process or the L4-5 interspace in 78.6% of patients but was as high as the L3-4 interspace in 3.7% of cases. Reliance on this landmark might lead to more cranial placement of epidural or spinal needles than was intended and this may increase the risk of spinal cord damage.

Validation of a telemetry system for long-term measurement of blood pressure.

We have used an implanted telemetry system to continuously monitor blood pressure (BP) in three dogs for durations ranging from 28 to 75 wk after implantation. Measurements of BP obtained by telemetry were compared every 3-12 wk, with measurements of BP recorded with a manometer-tipped catheter that was inserted into a femoral artery. Over a wide range of both physiological and pharmacologically manipulated pressures (40-200 mmHg), the values of BP obtained by the two methods were highly correlated (all r > 0.966; all P < or = 0.0001). However, the mean differences between the values obtained by the two systems were different from zero (range +29.6 to -1.5 mmHg; P < or = 0.0001), indicating an offset in the BP values recorded from the implanted system. Furthermore, this offset was dependent on the absolute level of the BP. The findings indicate that, for a period of at least 28 wk and up to 75 wk after implantation, the telemetry system accurately measures acute changes in BP and can reliably measure absolute BP provided that the system is properly validated.

Forum. An evaluation of the levering laryngoscope.

This study was undertaken to evaluate the effect of the levering laryngoscope on the view obtained at laryngoscopy. Two hundred and ten consecutive patients who required tracheal intubation were studied. The view at laryngoscopy with the levering laryngoscope blade in the neutral and elevated positions was recorded. In patients in whom there was a Cormack and Lehane grade 3 view of the larynx with the blade in the neutral position, elevation of the levered tip of the blade significantly improved the visualisation of the larynx. In patients where the view of the larynx was grade 1 or 2 with the blade in the neutral position, elevation of the levered tip often (23%) resulted in the view being impaired. This was not a clinical problem as the blade could simply be returned to the neutral position. The levering laryngoscope is a useful additional aid to laryngeal visualisation.

Neural expression of the pituitary GH gene.

It is well established that GH-like proteins and mRNA are present in extrapituitary tissues, but it is not known whether this reflects ectopic transcription of the pituitary GH gene or the expression of a closely related gene. This possibility was, therefore, further investigated. Immunoreactive (IR) GH-like proteins were readily measured by RIA and immunoblotting in hypothalamic and extrahypothalamic brain tissues of the domestic fowl, in which GH-IR was similar in size and antigenicity to pituitary GH. RT-PCR of mRNA from these brain tissues, with oligonucleotide primers spanning the coding region of pituitary GH cDNA, also generated cDNA fragments identical in size (689 bp) to pituitary GH cDNA. The amplified brain cDNA sequences contained BamH1 and Rsa1 cleavage sites similar to those located in pituitary GH cDNA. These cDNA sequences also hybridized with a cDNA probe for chicken GH cDNA, producing moieties of expected size that were identical to the hybridizing moieties in pituitary tissue. The nucleotide sequences of the PCR products generated from hypothalamic and extrahypothalamic brain tissues, determined by a modified cycle dideoxy chain termination method, were also identical to pituitary GH cDNA. This homology extended over 594 bp of the hypothalamic cDNA fragment (spanning nucleotides 65 to 659 of the pituitary GH cDNA and its coding region for amino acids 4 to 201) and 550 bp of the extrahypothalamic cDNA fragment (spanning nucleotides 76 to 626 of pituitary GH cDNA and its coding region for amino acids 8 to 190). These results clearly establish that pituitary GH mRNA sequences are transcribed in hypothalamic and extrahypothalamic tissues of the chicken brain, in which GH-IR proteins are abundantly located. However, as GH mRNA could not be detected in the chicken brain by Northern blotting, its turnover may be more rapid than in pituitary tissue. The local production of GH within the brain nevertheless suggests that it has paracrine roles in modulating neural or neuroendocrine function.

Expression of the growth hormone gene in immune tissues.

It is well established that growth hormone (GH)-like proteins and mRNA are present in immune tissues, but it is not known whether this reflects ectopic transcription of the GH gene or the expression of a closely related gene. This possibility was, therefore, investigated. Immunoreactive (IR) GH-like proteins were readily measured by radioimmunoassay and immunoblotting in the spleen, bursa of Fabricius and thymus of immature White Leghorn chickens, in which IR-GH was similar in size and antigenicity to the major GH moieties present in the pituitary gland. RT-PCR of mRNA from these immune tissues, with oligonucleotide primers spanning the coding region of pituitary GH cDNA, also generated cDNA fragments identical in size (689 bp) to pituitary GH cDNA.BamHI andRsaI cleavage sites were located in these cDNA sequences in the same position as those in pituitary GH cDNA. These amplified cDNA sequences also contained sequences that hybridized, by Southern blotting, with a chicken pituitary GH cDNA probe, thus suggesting a high degree of homology between pituitary and immune GH transcripts. The nucleotide sequence of the PCR products generated from these immune tissues, determined by a modified cycle dideoxy chain termination method, were also identical to pituitary GH cDNA. This homology extended over 593 bp of the spleen cDNA (spanning nucleotides 70-663 of the pituitary GH cDNA and its coding region for amino acids 5-201), 613 bp of the bursa cDNA fragment (spanning nucleotides 63-676 of the pituitary GH cDNA and its coding region for amino acids 3-207) and 607 bp of the thymic cDNA fragment (spanning nucleotides 61-665 of pituitary GH cDNA and its coding region for amino acids 4-203). These results clearly establish that the GH mRNA is present in immune tissues, in which GH-IR proteins are present. The local production of GH within the immune system of the domestic fowl, therefore, suggests it has paracrine or autocrine roles in modulating immune function.

Secretagogue-evoked time-course changes on pancreatic juice secretion in the anaesthetized rat.

1. In the present time-course study, we have examined the interactions between the phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and the synthetic gut hormones, cholecystokinin-octapeptide (CCK-8) and secretin on pancreatic juice secretion in anaesthetized rat. 2. Administration of either TPA (10(-8) mol kg-1 hr-1), secretin (100 pmol kg-1 hr-1) or CCK-8 (150 pmol kg-1 hr-1) in the anaesthetized rat resulted in marked time-course increases in pancreatic juice flow, amylase secretion and total protein output compared to saline controls. The effect of secretin on juice flow was more pronounced and sustained compared to the smaller responses obtained with either CCK-8 or TPA. Similarly, CCK-8 evoked increases in protein output and amylase secretion compared to the responses obtained with either secretin or TPA. 3. Simultaneous infusion of TPA with either CCK-8 or secretin resulted in a marked reduction in pancreatic juice flow, total protein output and amylase secretion compared to the responses obtained with either CCK-8 or secretin alone. 4. Administration of polymyxin B (10(-8) mol kg-1 hr-1), a protein kinase C inhibitor with either TPA and CCK-8 or TPA and secretin caused a partial reduction of the inhibitory effect of TPA on CCK-8 and secretin-evoked secretory responses. 5. The present study further implicates the involvement of protein kinase C in the modulation of CCK-8 and secretin-induced pancreatic juice secretion in the anaesthetized rat.

Interaction between secretin and cholecystokinin-octapeptide in the exocrine rat pancreas in vivo and in vitro.

This study investigates the interaction between physiological doses of the synthetic gut hormones, cholecystokinin-octapeptide (CCK8) and secretin on pancreatic juice secretion in the anaesthetized rat and on amylase secretion and Ca2+ and Mg2+ mobilization in isolated pancreatic segments and acinar cells. CCK8 (150 pmol kg-1 h-1) and secretin (100 pmol kg-1 h-1) evoked marked time course increases in pancreatic juice flow, total protein output and amylase secretion in the anaesthetized rat when administered separately compared to saline controls. Simultaneous intravenous infusion of CCK8 and secretin did not yield either an additive response or a potentiation but instead it caused a decrease in secretory responses. Administration of either polymyxin B (10(-8) mol kg-1 h-1) or staurosporine (10(-8) mol kg-1 h-1), two protein kinase C inhibitors, simultaneously with both CCK8 and secretin caused a further decrease in all secretory parameters. Superfusing pancreatic segments with either CCK8 (10(-11) M) or secretin (10(-11) M) elevated amylase output compared to the smaller response with a combination of CCK8 and secretin. Combining staurosporine (10(-6) M) with CCK8 and secretin resulted in a further decrease in amylase output. CCK8 (10(-11) M) evoked a large increase in radiolabelled Ca2+ influx into pancreatic segments and elevated cytosolic free Ca2+ concentration ([Ca2+]i) in acinar cells loaded with the fluorescent dye, Fura-2. Secretin (10(-11) M) alone had no significant effect on Ca2+ mobilization but it markedly attenuated the increases in radiolabelled Ca2+ influx and [Ca2+]i elicited by CCK8. In superfused pancreatic segments CCK8 (10(-11) M) evoked a net efflux of Mg2+ whereas secretin (10(-11) M) induced a net uptake of Mg2+. Combining secretin with CCK8 also resulted in a net uptake of Mg2+. The results indicate that both Ca2+ and Mg2+ mobilization may be associated with the interaction between CCK8 and secretin in the rat pancreas.