Microsporidiosis in the graft of a renal transplant recipient.

Microsporidia are intracellular protozoa that are emerging as significant opportunistic infections in AIDS patients. Although there are numerous published reports of intestinal and disseminated infections in patients with AIDS, there have been only two previous reports in transplantation medicine, both on intestinal microsporidiosis. We report here the first documented case of extra-intestinal microsporidiosis in a transplant recipient. A 39-year-old renal transplant recipient presented with a pyrexia and deteriorating graft function. Light microscopic examination of a renal allograft biopsy revealed numerous microsporidian spores within the renal tubular epithelium. Transmission electron microscopy confirmed the presence of an Encephalitozoon infection and was highly suggestive of Encephalitozoon intestinalis. Therapy with albendazole was extremely effective and resulted in recovery of renal function. Although a rare cause of renal allograft dysfunction, microsporidiosis is curable. It may be underdiagnosed, and should be considered in the differential diagnosis of transplant recipients presenting with opportunistic infections.

Postpartum microneuromas of the uterine cervix.

The cervices of 300 hysterectomy specimens have been examined for the presence of abnormal nerves morphologically resembling traumatic neuromas. These were present in 165 uteri (55%) overall but in only two of the 48 nulliparous patients (4%), indicating a probable causation by parturition. The microneuromas could be graded. The larger, more complex lesions were associated with more extensive involvement of the cervix but not with increased parity.

Cerebellopontine angle tumours in black South Africans--how rare are acoustic schwannomas?

Previous reports of intracranial neoplasms from Africa have all shown a very low incidence of acoustic schwannomas (neuromas). In this series a group of 11 cerebellopontine angle solid tumours from black Africans were studied. On conventional histological examination only 3 had the features of a schwannoma. However, by using immunohistochemistry, a further 3 examples were identified. As controls, the same antisera were also applied to known schwannomas and meningiomas. During the period of the study, 163 patients with primary intracranial neoplasms were seen and thus acoustic schwannomas accounted for 3.7%. Although this figure is low by world standards, it still represents a far higher figure than has previously been reported from Africa. This study therefore emphasises the value of immunohistochemistry in the diagnosis of brain tumours and, furthermore, shows that acoustic schwannoma must be considered in the appropriate clinical setting, even in a group previously regarded as low-risk.

Demyelinisation in the spinal cord of vitamin B12 deficient fruit bats.

1. Vitamin B12 deficiency induced in the fruit bat by a combination of dietary deprivation and exposure to nitrous oxide (N2O) is accompanied by profound neurological impairment, thus providing an experimental model for the study of vitamin B12 neuropathy. 2. Electron microscopy of the spinal cord of vitamin B12 deficient bats shows marked changes in the myelin of the posterior columns in the form of distension, separation and vacuolation of myelin lamellae similar to the changes described in the dietary induced B12 deficient monkey model. 3. No equivalent change occurred in bats exposed to N2O and supplemented with vitamin B12.