Mycoplasma pneumoniae infection and neurological disease

The cases are reported of 13 children seen over a 22 month period who presented with a variety of acute neurological illnesses associated with Mycoplasma pneumoniae infection. Although presentation with a decreased level of consciousness or seizures was common, psychosis, hemiparesis, cranial nerve palsies, and Guillain-Barré syndrome were also seen. In contrast with published reports, only one child had an associated chest infection. Although some children have been left with residual disability, most have made a complete recovery. In this recent experience, M pneumoniae is a not rare cause of neurological illness in childhood and may present in unusual ways.     

Nitric oxide treatment for fulminant pulmonary hypertension

A 3 year old child with known pulmonary haemosiderosis suffered acute circulatory collapse secondary to raised pulmonary vascular resistance. Nitric oxide inhalation produced a profound improvement in circulatory parameters and gaseous exchange. Nitric oxide may have a therapeutic role in acute pulmonary hypertensive crisis.     

The effect of temperature reduction on respiratory rate in febrile illnesses

A raised respiratory rate is a useful sign in the diagnosis of pneumonia in children. It was observed that children with malaria and other febrile illnesses may also present with a raised respiratory rate. To determine the extent to which increased body temperature contributes to the raised respiratory rate observed in these children the effect of change in body temperature on respiratory rate was measured in 186 sick Gambian children with a raised respiratory rate, including those with pneumonia or malaria. A temperature dependent effect on respiratory rate of 3.7 breaths per minute per degree centigrade was demonstrated for the whole study cohort, with no significant difference between children with pneumonia or malaria. Twenty three per cent of children with pneumonia whose temperature fell had a final respiratory rate below that currently recommended by the World Health Organisation for the diagnosis of pneumonia. It is concluded that respiratory rate is to some extent dependent on body temperature in children with febrile illnesses such as pneumonia and malaria, but that this does not alone account for the raised respiratory rate seen in these children. The effect of reduction in body temperature on respiratory rate does not help to distinguish children with pneumonia from those with malaria. A history of recent use of an antipyretic or other measures to control fever is important when evaluating children for possible pneumonia.     

Obstructive sleep apnea and hypertension: are peripheral chemoreceptors involved?

The mechanism of pathogenesis of hypertension in patients with obstructive sleep apnea (OSA) is unknown. Many investigators point to the high sympathetic nervous system activity (SNS) observed in OSA patients. However, there is no clear explanation as to the mechanism for the development of SNS hyperactivity in these patients. A common feature of patients with OSA is repetitive bouts of transient hypoxemia during sleep. Repetitive transient hypoxemia in rats has resulted in hypertension. In OSA patients, resolution of nocturnal hypoxemia with CPAP has corrected nocturnal and diurnal hypertension. Also, exposure to hyperoxia reduces blood pressure and sympathetic activity in OSA patients, but not in normals. These data suggest a significant role of peripheral chemoreceptors in the regulation of vascular tone. We hypothesize that peripheral chemoreceptors significantly contribute to the pathogenesis of hypertension in patients with OSA and that this is associated with chemoreceptor hyperactivity. This implies that correcting the intermittent nocturnal hypoxemia alone may prevent the cardiovascular morbidity associated with obstructive sleep apnea.     

Unrelated donor or autologous marrow transplantation for treatment of acute leukemia

High-dose chemoradiotherapy followed by marrow transplantation from an HLA-matched sibling donor is curative for patients with acute leukemia. Autologous marrow transplantation has been used with success for some patients without such a sibling. Alternatively, the option of performing a transplant from an HLA-matched unrelated donor has been made possible by the recent development of large registries of HLA- typed volunteers. The purpose of this study was to compare the outcomes for patients with advanced leukemia treated by unrelated or autologous marrow transplantation. Forty-three patients with acute myeloid or lymphoid leukemia were transplanted from a closely HLA-matched unrelated donor. Results were compared with those of a disease-, disease-stage-, and age-matched cohort of 77 patients treated with autologous marrow transplantation at the same institution during the same period. Myeloid reconstitution with peripheral granulocyte counts greater than 10(9)/L was achieved in 93% of unrelated recipients and 70% of autologous recipients at a median of 24 and 36 days after transplantation, respectively (P = .0001). The cumulative proportions of patients discharged alive (79% v 77%) and times from transplant to first hospital discharge (35 v 34 days) were not different between unrelated and autologous recipients (P = .65). For patients transplanted in complete remission, relapse occurred after transplantation in 27% of the unrelated and in 55% of the autologous recipients (P = .08). For patients transplanted in relapse, the corresponding posttransplant relapse rates were 48% and 63%, respectively (P = .72). Forty percent of unrelated recipients and 28% of autologous recipients died in remission. Leukemia-free survivals were 33% for unrelated and 25% for autologous recipients transplanted in remission (P = .45), and 12% for unrelated and 5% for autologous recipients transplanted in relapse (P = .75). Unrelated donor transplants appear no less effective than autologous transplants to achieve long-term survival and may be more effective in eradicating leukemia in patients who have failed conventional chemotherapy. Further studies are warranted to assess the relative effectiveness of unrelated and autologous transplantation performed earlier in the course of the disease.     

The abnormal prostate: MR imaging at 1.5 T with histopathologic correlation

Thirteen patients with biopsy-proved adenocarcinoma were prospectively examined with magnetic resonance (MR) imaging with use of a 1.5-T superconducting magnet. All patients subsequently underwent radical prostatectomy and careful, axial, histologic mapping of prostatic disease. Histologic findings were recorded on serial, axial diagrams to ensure precise pathologic correlation with the MR images. MR permitted identification of eight of 12 (67%) adenocarcinomas as hypointense foci (relative to the surrounding, higher intensity, peripheral zone); but tumor volume was under-estimated with MR imaging in five of eight cases (63%). Nodules of prostatic hyperplasia were identified correctly in only one of nine patients (11%). These findings suggest that, despite that fact that high field strength MR imaging currently does not depict all pathologic foci within the prostate, it may be of predictive value in the differential diagnosis of prostatic abnormalities when their locations are demonstrable.     

Long-term stable hematopoietic chimerism following marrow transplantation for acute lymphoblastic leukemia: a case report with in vitro marrow culture studies

This article describes the course of a patient who received an allogeneic marrow graft from his HLA-identical sister for acute lymphoblastic leukemia in second remission. In the second month after grafting, marrow aspirates showed the presence of 7%-10% lymphoblasts. In addition, cytogenetic examination indicated the persistence of host cells. Thereafter, the patient had morphologically normal marrow examinations, with no evidence for recurrent leukemia. In addition, stable hematopoietic chimerism in both the lymphoid and myeloid cell lines has persisted for over 5 yr. Between 20% and 50% of phytohemagglutinin-stimulated peripheral blood mononuclear cells were host-derived on repeated studies. A marrow sample 4 yr after transplantation was established in long-term culture and produced 2% host granulocyte-macrophage colonies at its inception, but 24% host colonies by week 4. Despite this persistent chimerism, no in vitro or in vivo abnormalities of hematopoiesis have been detected.     

Reduction of patient exposure by use of heavy elements as radiation filters in diagnostic radiology

The effect on patient exposure of x-ray filters made of heavy elements has been studied in excretory urography and lumbar spine examinations. Several elements with atomic numbers between 62 and 74 were tested in experiments using radiographic phantoms and in patient studies. A holmium filter reduced skin exposure by more than 50% in excretory urography. Similar results were obtained with ytterbium and tungsten in lumbar spine studies.     

Measurement error in computed tomography pelvimetry

Computed tomography pelvimetry is still used in clinical practice. We wished to quantify observer error in order to assess the level of confidence with which pelvic measurements can be described as adequate or inadequate. Anteroposterior inlet, anteroposterior outlet, transverse inlet and interspinous distances were measured from 11 CT pelvimetry examinations by five observers at one institution. Three CT pelvimetries were measured by five observers at a second institution. Intraobserver and interobserver variation was assessed using analysis of variance. Reliability of measurements was assessed using intraclass correlation coefficient. Combined error was calculated to determine 95% confidence limits for published minimum recommended pelvic measurements. The standard error of measurement, combining all sources, for measurement of the bony dimensions of the pelvis were: for anteroposterior inlet, 2.0 mm; anteroposterior outlet, 6.9 mm; transverse inlet, 1.3 mm; and interspinous distance, 2.1 mm. The 95% confidence interval around the recommended anteroposterior outlet of 100 mm was 88.5–111.3 mm. Observer variation in measurement of anteroposterior outlet is so large as to make the measurement of doubtful clinical utility.     

Metachromatic leukodystrophy: consequences of sulphatide accumulation

Metachromatic leukodystrophy is a lysosomal lipid storage disorder. It is caused by mutations in the gene for arylsulphatase A, an enzyme involved in the degradation of the sphingolipid 3'-O-sulphogalactosylceramide (sulphatide). This membrane lipid can be found in various cell types, but in particularly high concentrations in the myelin of the nervous system. Patients suffer from progressive, finally lethal, demyelination due to accumulation of sulphatide. In the nervous system, lipid storage not only affects oligodendrocytes but also neurons and, in addition, leads to astrogliosis and activation of microglia. At the cellular level, lysosomal sulphatide storage also affects the lipid composition of myelin itself and has consequences for the amount and localization of particular myelin membrane-associated proteins. Here we review data, largely based on an arylsulphatase A knock-out mouse model of metachromatic leukodystrophy.
Conclusion : The knock-out mouse model of metachromatic leukodystrophy has provided insights into the histopathological and cellular consequences of sulphatide storage.