Pontine-to-midbrain ratio indexes ocular-motor function and illness stage in adult Niemann-Pick disease type C.

BACKGROUND AND PURPOSE: Niemann-Pick disease type C (NPC) is a progressive neurovisceral disorder associated with dystonia, ataxia and a characteristic gaze palsy. Neuropathological studies have demonstrated brainstem atrophy associated with neuronal inclusions and loss, and neurofibrillary tangles, although it is not known whether this pathology can be detected in vivo or how these changes relate to illness variables, particularly ocular-motor changes. Our aim was to utilize a method for brainstem atrophy, validated in progressive supranuclear palsy (PSP), in a group of adult patients with NPC, and explore its relationship to illness variables and ocular-motor functioning. METHODS: We calculated the midbrain and pontine area, and pontine-to-midbrain ratio (PMR) from midsagittal images of 10 adult patients with NPC and 27 age- and gender-matched controls. Measures were correlated with illness variables, and measures of horizontal saccadic functioning. RESULTS: Pontine-to-midbrain ratio was 14% higher in the NPC group, but this difference was not significant. However, PMR showed a significant positive correlation with duration of illness and a measure of illness severity. Furthermore, PMR was significantly negatively correlated with saccadic peak velocity and gain, and self-paced saccadic performance. CONCLUSIONS: Pontine-to-midbrain ratio was increased in adult patients with NPC compared to controls, although not to the same degree as previously described in PSP, which also presents with significant gaze palsy. These changes were driven predominantly by progressive midbrain atrophy. The strong correlation with illness and ocular-motor variables suggests that it may be a useful marker for illness progression in NPC.

Isolation of Haemophilus somnus from dairy cattle in kwaZulu-Natal. An emerging cause of 'dirty cow syndrome' and infertility?

Haemophilus somnus was consistently isolated from vaginal discharges of dairy cows submitted from field cases of vaginitis, cervicitis and/or metritis in the KwaZulu-Natal Midlands during the period July 1995 - December 2000 and from the East Griqualand area in November/December 2000. The purulent vaginal discharges, red granular vaginitis and cervicitis, and pain on palpation described in these cases was very similar to that reported in outbreaks of H.somnus endometritis syndrome in Australia, Europe and North America. In all the herds involved in these outbreaks, natural breeding with bulls was employed. Although there was a good cure rate in clinically-affected animals treated with tetracyclines, culling rates for chronic infertility were unacceptably high. Employment of artificial insemination in these herds improved pregnancy rates in cows that had calved previously, but many cows that had formerly been infected failed to conceive.

Zinc and total parenteral nutrition.

Present knowledge of trace element nutritional requirements and the effects of TPN solutions unsupplemented with zinc indicate that zinc supplementation must be considered for any patient receiving prolonged TPN. Zinc sulfate appears to be the supplement of choice, and infusions of freeze-dried plasma appear to be an unsatisfactory method for supplying zinc, even during short-term therapy. As long as accepted dosage regimens are followed, there appears to be little risk of toxicity when TPN solutions are supplemented with zinc.

Procaine HCl (Gerovital H3): a weak, reversible, fully competitive inhibitor of monoamine oxidase.

A specially stabilized form of procaine hydrochloride (Gerovital H3) has been shown to be a more potent inhibitor of monoamine oxidase than procaine HCl itself and a weaker inhibitor of this enzyme than iproniazid. This preparation was studied to determine its mode of interaction with monoamine oxidase using purified rat brain mitochondrial monoamine oxidase as the enzyme source. Reaction velocities were determined spectrophotometrically by quantitating the rate of appearance of 4-hydroxyquinoline from kynuramine. Dilutional studies comparing the mechanism of inhibition of monoamine oxidase produced by Gerovital H3 and by ipronizid demonstrated that Gerovital H3 was a reversible inhibitor of monoamine oxidase. Analysis of studies using Lineweaver-Burk and Dixon plots revealed that Gerovital H3 was a fully competitive inhibitor of monoamine oxidase. That Gerovital H3 is a weak, reversible, competitive inhibitor of monoamine oxidase may explain the absence of adverse reactions associated with the clinical use of Gerovital H3 as compared to the severe adverse reactions that have been associated with the use of irreversible monoamine oxidase inhibitors.