Cow-level association between serum 25-hydroxyvitamin D concentration and Mycobacterium avium subspecies paratuberculosis antibody seropositivity: a pilot study.

Vitamin D deficiency has been associated with various human diseases. Therefore, the objective of this study was to evaluate the cow-level association between serum 25-hydroxyvitamin D [25(OH)D] concentration and Mycobacterium avium ssp. paratuberculosis (MAP) seropositivity of dairy cows, adjusting for diet, breed, hair coat color, stage of lactation, reproductive status, and cow age. The sera of 80 MAP antibody ELISA-positive and 80 test-negative herd mates from 5 Minnesota dairy herds were analyzed for 25(OH)D and 1,25-dihydroxyvitamin D [1,25(OH)(2)D]. The cows' age, production records, and hair coat color were recorded. Additionally, feed samples were obtained and analyzed for vitamin D(2) and vitamin D(3) content. A linear mixed model was used to identify potential predictors for serum 25(OH)D concentration, accounting for herd of origin. The majority of rations analyzed had over 22,000 IU of vitamin D/day (maximum: 52,000 I U/d) and the study cows' average serum 25(OH)D concentration was 62.5 ± 13.8 ng/mL. Serum ELISA-positive cows had, on average, 5.3 ng/mL lower 25(OH)D serum levels than test-negative herd mates. The reproductive status of cows was also associated with the 25(OH)D levels, with fresh cows having the lowest serum concentration. In this cross-sectional study, a temporal or causal association between MAP antibody ELISA status and serum 25(OH)D concentration could not be evaluated. In addition, the high levels of vitamin D in the rations of participating farms and the average 25(OH)D serum concentration suggest that additional supplementation with vitamin D in the ration is likely to be ineffective.

AIDS-related MR hyperintensity of the basal ganglia.

PURPOSE: Our goal was to describe the MR imaging appearance and clinical pathologic correlates of bilateral basal ganglia hyperintensity in acquired immunodeficiency syndrome (AIDS). METHODS: Medical records and laboratory data were reviewed retrospectively in nine cases of bilateral basal ganglia hyperintensity on long-repetition-time MR images. Opportunistic infections of the central nervous system were excluded by clinical and laboratory data. Postmortem neuropathologic examination was obtained in two cases. RESULTS: All patients presented acutely with new seizures or changes in mental status. A history of drug abuse was elicited in seven of the nine remaining patients. Renal failure was present in six cases. Symmetric bilateral caudate and putamen hyperintensity on T2-weighted images was found in all cases with variable extension to the surrounding white matter, thalamus, and brain stem. Postmortem neuropathologic examination in two cases revealed numerous microinfarcts in a distribution similar to the MR signal abnormalities. CONCLUSION: The MR appearance of basal ganglia hyperintensity in this series of AIDS patients represents ischemic tissue injury. We propose that this clinicopathologic entity is precipitated by the combined effects of human immunodeficiency virus infection and drug use, particularly cocaine and/or associated toxic contaminants.

Infarctlike lesions in the brain: prevalence and anatomic characteristics at MR imaging of the elderly--data from the Cardiovascular Health Study.

PURPOSE: To determine the prevalence and anatomic characteristics of infarctlike lesions seen on cranial magnetic resonance (MR) images. MATERIALS AND METHODS: The study cohort consisted of 5,888 community-living individuals aged 65 years and older enrolled in a longitudinal, population-based study of cardiovascular disease. MR images were obtained from 3,658 participants and evaluated by trained readers. Lesion size, anatomic location, and signal intensity were recorded. Infarctlike lesion was defined as a nonmass, hyperintense region on spin-density- and T2-weighted images and, in cerebral white matter and brain stem, a hypointense region on T1-weighted images. RESULTS: Infarctlike lesions were depicted on MR images of 1,323 (36%) participants. Eighty-five percent (1,128 participants) had lesions 3 mm or larger in maximum dimension, although 70.9% (1,320 of 1,861) of these lesions were 10 mm or less. Lesion prevalence increased with age, especially with lesions 3 mm or larger, which increased from 22.1% (86 of 389) in the 65-69-year age group to 42.9% (88 of 205) in the over-85-year age group (P < .0001). Lesion prevalence was slightly greater in men (497 of 1,527 [32.5%]) than in women (631 of 2,131 [29.6%]), but did not differ between blacks and non-blacks. The deep nuclei were the most commonly affected anatomic sites, with 78.2% (1,451 of 1,856) of lesions. Lesions that involved the cerebrum and posterior fossa accounted for 11.7% (218 of 1,856) and 10.1% (187 of 1,856) of lesions, respectively. CONCLUSION: If the lesions reported in this study indicate cerebrovascular disease, subclinical disease may be more prevalent than clinical disease, and the prevalence of disease may rise with age. Also, infarctlike lesions have a distinctive anatomic profile.

Efficacy of fetal part elevation to visualise internal cervical os.

The diagnosis or exclusion of placenta previa is best achieved by direct visualisation of the relationship of the lower edge of the placenta to the internal cervical os. In later pregnancy, the presenting fetal part frequently obscures this area. Elevation of the presenting part was attempted in 56 consecutive pregnancies of greater than 30 weeks gestation, with a success rate of 71%. This confirms that in a minority of pregnancies, other manoeuvres or ultrasound techniques are necessary to visualise the lower placental margin directly.

Placental compressibility: implications for indirect diagnosis of posterior placenta previa.

A number of problems beset the indirect diagnosis of posterior placenta previa using transabdominal ultrasound. We add a new potential complicating factor. In 128 pregnancies at or beyond 30 weeks' gestation, measurements were taken from the fetal skull to the maternal sacrum before and after compression. Up to 69% compressibility of the placenta was found in vivo and in vitro. Modified fetal skull to maternal sacrum measurement criteria were devised from the results. Placenta previa is highly unlikely if the measurement from the fetal skull to maternal sacrum is less than 10 mm before compression or less than 7 mm after compression. Placenta previa is probable if the measurement is greater than 20 mm before compression or greater than 15 mm after compression. In 40% of the cases, posterior placenta previa could not be excluded. We conclude that placental compressibility is an additional confounding problem for indirect ultrasound assessment of posterior placenta previa and that indirect assessment should be attempted only if maneuvers to image the lower uterine segment directly are unsuccessful.

Infra-hyoid metastases in supra-hyoid squamous cell carcinoma.

The CT scans of 71 patients with primary squamous cell tumours of head and neck sites were reviewed and compared with clinical examination in the assessment of lymph nodes above and below the hyoid. Above the hyoid, CT and clinical examination disagreed on the presence or absence of metastases in 13/42 cases (31%); below the hyoid where palpation is presumably easier, there was disagreement in 1 of 10 cases (10%). Abandoning infra-hyoid scans to save scanner time would save only seven slices on average per case and it is possible that further, clinically silent lesions would be missed. We conclude that staging scans in head and neck cancer should continue to include the infra-hyoid region. The inadequacies of existing knowledge based on clinical staging are discussed.