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Biomedical subjects

J Punt

Publications and source records attributed to J Punt.

46 records · Page 3Linked to original sources

Primary thalamic haemorrhage in the newborn: a new clinical entity.

4 healthy full-term babies presented between 11 and 14 days of age with neurological abnormalities. Eye signs in 3 suggested involvement of tracts closely related to the thalamus. Spontaneous intrathalamic haemorrhage was confirmed with computed tomography and real-time ultrasound scans. Ventricular dilatation occurred in 3 babies and 2 of these needed ventriculoperitoneal shunts. The short-term neurodevelopmental outcome was fairly good.

Cerebral Hemorrhage↗

Importance of immunoglobulin isotype in human antibody-dependent, cell-mediated cytotoxicity directed by murine monoclonal antibodies.

Using the fluorescence activated cell sorter to select rare IgG2a- and IgG2b-producing variants, we developed switch variant families of hybridomas from IgG1-producing hybridomas, ME1 and MA2.1. The IgG2a and IgG2b antibodies produced by such switch variants have the same binding activities for HLA as the IgG1 antibodies produced by the parent hybridomas. Using these antibodies, we directly compared the IgG1, IgG2a, and IgG2b murine Ig isotypes for their capacities to direct human peripheral blood lymphocytes (PBL) in antibody-dependent cell-mediated cytotoxicity (ADCC) against a B lymphoblastoid cell line. We demonstrate that, for antibodies of identical binding affinity and specificity, the murine IgG2a isotype is the most effective in directing ADCC by human effector cells. The murine IgG2b directs intermediate levels of ADCC activity while IgG1 is inactive. We identified the effector cells in human PBL that mediate IgG2a or IgG2b ADCC as nonadherent killer (K) cells. These cells express the C3bi receptor and have cytolytic activity which is specifically blocked by a monoclonal antibody (anti-Leu-11a) that binds the Fc receptor (FcR) of such cells. Finally, FcR-bearing K cells bind to target cell-bound, rather than free, IgG2a or IgG2b molecules.

Animals↗

Local cerebral glucose utilisation in experimental chronic hydrocephalus in the rat.

Many of the clinical features of normal pressure hydrocephalus have been ascribed to stretching of the periventricular nerve fibres. However, many patients may be asymptomatic despite considerable ventriculomegaly. To define the periventricular changes in cerebral energy metabolism we have measured local cerebral glucose utilisation in hydrocephalic and control Sprague-Dawley rats. Experimental hydrocephalus was induced by injection of kaolin into the cisterna magna of 3-week-old rats. After 3 months, the animals fed and walked normally. LCGU was measured using the 14C-deoxyglucose method of Sokoloff. Autoradiographs were prepared and isotope concentration determined by densitometry. Glucose utilisation was measured in 39 anatomically defined areas, widely distributed throughout the brain, and comparisons between hydrocephalic animals and controls (given intracisternal saline) were made by analysis of variance. It was found that there was no significant difference in glucose utilisation between the two groups of rats in any of the areas measured. Hence ventriculomegaly in the young rat does not impair LCGU in surviving periventricular tissue.

Animals↗

Multiple cerebral gummata. Case report.

The case of a patient with multiple small cerebral gummata presenting with severely raised intracranial pressure is reported. The diagnosis, which was quite unexpected, was based on positive serological tests for syphilis. Computerized tomography (CT) showed small enhancing lesions with intense cerebral edema. The patient was treated successfully with penicillin, and resolution of the lesions was observed on CT scanning over a 1-year period. The importance of "routine" serological testing is noted.

Adult↗

Neuroblastoma: a review of 21 cases presenting with spinal cord compression.

The records of 21 children with neuroblastoma presenting with spinal cord compression, encountered over 17 years, were reviewed. Thirteen patients (61%) survive, free of neuroblastoma, at intervals ranging from nine months to 192 months (median, 78 months) from the time of diagnosis. The explanation for this relatively high survival rate was sought in an analysis of the cases which took into account age, site, extent of disease, and histology. The most significant features to emerge were the unusually high proportion of children under 12 months of age at presentation (11 of 21) most of whom survive (9 of 11) and the low incidence (3 of 21) of detectable at the time of diagnosis. The absence of a paraspinal mass was an unfavourable prognostic features (1 of 6 survives) whilst if a paraspinal mass was present, its anatomical level did not influence survival. In particular, children with retroperitoneal tumors fared no worse (survival, 6 of 7) than those with primary tumors at other sites (survival, 6 of 8). Morbidity was high (6 of 13), principally in infants with spinal cord compression from birth. Survival was also related to the histologic maturity of the tumor, even in the presence of metastases. Recommendations for management are made.

Catecholamines↗

Some observations on aneurysms of the proximal internal carotid artery.

The author reports on 41 aneurysms of the proximal internal carotid artery (PICA) demonstrated in 36 patients with subarachnoid hemorrhage. The patients included a striking preponderance of women, and there was a high incidence of multiple aneurysms. In cases with multiple aneurysms the PICA aneurysm was usually found incidentally, a more distal aneurysm on the internal carotid artery being the source of hemorrhage. An infundibulum at the origin of a posterior communicating artery was unusually common in these patients. The origin of the ophthalmic artery is proposed as the angiographic landmark of the level at which the internal carotid artery penetrates the dura mater.

Carotid Artery Diseases↗

Clinical overlap between malaria and severe pneumonia in Africa children in hospital.

Data collected from 200 children admitted to a hospital on the Kenyan coast who met a broad definition of severe acute respiratory infection (ARI) indicated that simple clinical signs alone are unable absolutely to distinguish severe ARI and severe malaria. However, laboratory data showed that marked differences exist in the pathophysiology of unequivocal malaria and unequivocal ARI. Children in the former group had a higher mean oxygen saturation (97 vs. 94, P < 0.001), mean blood urea level (5.3 vs. 1.9 mmol/L, P < 0.001) and geometric mean lactate level (4.5 vs. 2.1 mmol/L, P < 0.001), and lower mean haemoglobin level (5.3 vs. 9.0 g/dL, P < 0.001) and base excess (-9.4 vs. -2.6, P < 0.001) than those in the latter group. Using these discriminatory variables it was estimated that up to 45% of children admitted with respiratory signs indicative of severe ARI probably had malaria as the primary diagnosis. Radiological examination supported this conclusion, indicating that pneumonia characterized by consolidation was uncommon in children with respiratory signs and a high malarial parasitaemia (> or = 10,000/microliters). There is no specific radiological sign of severe malaria. In practice, all children with respiratory signs warranting hospital admission in a malaria endemic area should be treated for both malaria and ARI unless blood film examination excludes malaria. In those with malaria and clinical evidence of acidosis, but no crackles, antibodies may be withheld while appropriate treatment for dehydration and anaemia is given. However, if clinical improvement is not rapid, antibiotics should be started.

Child, Preschool↗

The 'unified hypothesis' of Geddes et al. is not supported by the data.

Inflicted head injury to the developing brain frequently results in serious disability. The pathogenesis of the neuraxial and ocular findings in infants believed to have suffered inflicted head injury remains the subject of considerable debate. Recent neuropathology studies of fatal cases of inflicted head injury and of a foetal/perinatal non-traumatic model have led to the proposal that there is a 'unified hypothesis', the essential feature of which is hypoxic brain swelling secondary to cervicomedullary injury. It has been suggested that less than violent forces may be involved and even that some cases may not be due to trauma at all. The purpose of this paper is to provide a critical review of the data upon which these suppositions are based on a background of what is already known. It is submitted that there are serious flaws in the methodology; the conclusions reached cannot logically be drawn from the data; and the 'unified hypothesis' is not supported by the evidence. On the basis of the data presented, it is also difficult to sustain the secondary hypothesis purporting to describe a minority cohort with 'infantile encephalopathy with subdural and retinal bleeding' of non-traumatic causation.

Brain↗