Characterization of hard metal dusts from sintering and detonation coating processes and comparative hydroxyl radical production

Dust samples from sintering and detonation coating hard-metal processes were characterized, compared, and contrasted for morphology, composition, and generation of hydroxyl radicals. Inhalation of respirable hard-metal (sintered carbide) dusts from hard-metal processes is known to cause fibrotic and asthmatic lung disease. Scanning electron microscopy/energy-dispersive X-ray analysis was used for morphology, composition, and elemental distribution. An electron spin resonance (ESR) spin trapping technique was used to detect hydroxyl radical generation. Samples were incubated with air-saturated buffer solutions containing a spin trap and analyzed by ESR for the presence of *OH in solution. Postdetonation coating samples often had surface contamination of Co on the WC particles, as shown by elemental mapping of individual particles; this was not evident in predetonation samples or unsintered materials in this study. ESR measurements show that both detonation-gun materials were capable of generating *OH , while the WC, cobalt, and presintered mixture did not produce detectable amounts of *OH radicals. The DMPO/*OH adduct formation was apparently facilitated by Fe-mediated reactions for predetonation dusts, and by Fe-mediated site-specific reactions for postdetonation dusts. The overspray materials from the detonation-gun process produced 9-fold more *OH radicals than the predetonation coating mixture. Overall, this study indicates there are substantial differences between postdetonation materials and both predetonation and unsintered hard-metal process materials with respect to morphology, elemental distribution, and *OH radical generation reactions and that these differences may be important in the toxic potential of those materials.     

Mucor mycosis infection presenting as a non-healing ulcer in an immunocompromised patient

Mucor mycosis is an uncommon saprophytic opportunistic fungus causing localized cutaneous infection associated with high morbidity and, on dissemination, high mortality. We report the case of an immunocompromised patient with an aggressively progressing, painful non-traumatic ulceration, unresponsive to standard treatment. Deep biopsies for haematoxylin and eosin staining and fungal culture revealed the characteristic broad non-septate irregular hyphae of mucor allowing introduction of the appropriate treatment. Infection with mucor mycosis must be considered in today's medical environment as the number of immunocompromised patients increases.     

Comment on ‘Predicting recurrence in axillary node negative breast cancer patients’, by Rosner and Lane

on behalf of the Nottingham Breast Unit     

Prevalence of behaviour disorders in low birthweight infants

OBJECTIVE--To determine the prevalence of behaviour disorders in low birthweight infants. DESIGN--Children of birth weight < or = 2000 g born to mothers resident in Merseyside in 1980-1 assessed using the Rutter parent and teacher behaviour questionnaires and the Conner modification of the Rutter teacher questionnaire. Children attending normal schools were assessed with controls matched for age, sex, and class in school. Children attending special schools were assessed unmatched. SUBJECTS--233 matched case-control pairs attending normal primary schools and 46 unmatched children attending special schools. SETTING--Primary and special schools. MAIN OUTCOME MEASURES--Emotional, conduct, and undifferentiated behaviour disorders and hyperactivity. RESULTS--On the parental questionnaire screen, 36% of the cases and 22% of the controls had a behaviour disorder and on the teacher questionnaire the proportions were 27% and 12% respectively. Hyperactivity was significantly more common among male cases than their controls (21% v 5.0%) but differed little among female cases and controls (9% v 7%). CONCLUSIONS--Improving neonatal survival of low birthweight infants is accompanied by a higher prevalence of behaviour disorders. The long term implications for psychiatric morbidity and other adult disease must be monitored.     

Isolated brain-stem third nerve palsy

Midbrain hemorrhage from a presumed vascular anomaly caused a severe third nerve palsy without other ocular motor or neurologic signs or symptoms.     

BENIGN GASTROCOLIC FISTULA ASSOCIATED WITH PERITONITIS

SUMMARY Gastrocolic fistula is most often related to malignancy or previous gastric surgery. It is an uncommon complication of benign gastric ulceration in patients who have not had a previous operation. Benign gastrocolic fistula associated with peritonitis is extremely rare — this case is only the fourth ever reported. The patient presented with an acute abdomen, and subsequent investigations demonstrated a gastrocolic fistula of benign aetiology.