Features of pediatric head injury in Hong Kong

Head injury in children causes special concern in most communities. From 1989 to 1994, 2,785 children younger than 16 years old were admitted to our neurosurgical service because of head injury. Fall from a height was the major cause of head injury leading to admission in infants and children in preschool age groups, whereas traffic-related or bicycle-related accidents were more likely to be the cause of head injury for those aged 11–15 years. In all age groups there was a male preponderance. The overall mortality was 0.6%. Traffic-ralated accidents caused more severe injury and accounted for 67% of all fatalities. For patients under 6 years old, about 40% of head injuries occurred at home. Preventive measures for pediatric head injury in Hong Kong are suggested.     

Role for interleukin-1 (IL-1) in benzene-induced hematotoxicity: inhibition of conversion of pre-IL-1 alpha to mature cytokine in murine macrophages by hydroquinone and prevention of benzene-induced hematotoxicity in mice by IL-1 alpha

Chronic exposure of humans to benzene (BZ), a myelotoxin, causes aplastic anemia and acute leukemia. The stromal macrophage that produces interleukin-1 (IL-1), a cytokine essential for hematopoiesis, is a target of BZ's toxicity. Monocyte dysfunction and decreased IL-1 production have been shown to be involved in aplastic anemia in humans. Hydroquinone (HQ), a toxic bone marrow (BM) metabolite of BZ, causes time- and concentration-dependent inhibition of processing of the 34-Kd pre-interleukin-1 alpha (IL-1 alpha) to the 17-Kd mature cytokine in murine P388D1 macrophages and BM stromal macrophages, as measured by Western immunoblots of cell lysate proteins using a polyclonal rabbit antimurine IL-1 alpha antibody. HQ over a 10-fold concentration range had no effect on the lipopolysaccharide (LPS)-induced production of pre- IL-1 alpha precursor or on cell viability or DNA and protein synthesis. Stromal macrophages obtained from the femoral BM of C57Bl/6 mice exposed to BZ (600 or 800 mg/kg body weight) for 2 days were incapable of processing the 34-Kd pre-IL-1 alpha to the mature 17-Kd cytokine when stimulated in culture with LPS. Stromal macrophages from mice coadministered BZ and indomethacin, a prostaglandin H synthase (PHS) inhibitor that has been shown to prevent BZ-induced myelotoxic and genotoxic effects in mice when coadministered with benzene were able to convert the pre-IL-1 alpha to mature cytokine. Administration of recombinant murine IL-1 alpha (rMuIL-1 alpha) to mice before a dose of BZ that causes severe depression of BM cellularity completely prevents BM depression, most probably by bypassing the inability of the stromal macrophage in BZ-treated animals to process pre-IL-1 alpha to the mature cytokine.     

Angioedema due to angiotensin-converting enzyme inhibitor use: Radiographic findings in 3 patients

Angioedema of the oropharynx and hypopharynx due to oral angiotensin-converting enzyme (ACE) inhibitors is a potentially life-threatening event and has not been well described in the radiology literature. A retrospective review of the clinical and radiologic findings in three patients with angioedema due to ACE inhibitor use was performed.Our subgroup of patients treated with ACE inhibitors presented with varying degrees of dysphagia, dyspnea, and facial swelling. Plain radiographic findings included enlargement of the epiglottis, aryepiglottic folds, and prevertebral and submental soft tissue. Computed tomography confirmed extensive retropharyngeal and subcutaneous edema. Clinical symptoms resolved in each case in 24–48 hours with cessation of the ACE inhibitor and concomitant steriod therapy.Our cases demonstrate the typical clinical and radiographic presentation of neck angioedema in the setting of ACE inhibitor use. As ACE inhibitors are increasingly being used as first-line agents in the treatment of hypertension, we caution that neck angioedema may be encountered with increased frequency in adults. Early recognition and immediate intervention result in rapid resolution of this potentially life-threatening event.     

Proximal gastric vagotomy. The preferred operation for perforations in acute duodenal ulcer.

Simple closure, the conventional operation for perforated acute duodenal ulcers, is associated with symptomatic relapse in a large proportion of patients. In order to assess the role of immediate definitive surgery, 78 fit patients with perforated acute ulcers were prospectively randomized to undergo either closure alone or proximal gastric vagotomy with closure (PGV). Patients taking potentially ulcerogenic drugs or who had severe stress were excluded from the study. Both groups were comparable with respect to age, sex, general medical health, duration of perforation, length of ulcer history, and presence of duodenal scarring. There was no hospital mortality. Minor complications occurred in 7.3% after closure and 10.8% after PGV. At 3 years follow-up, the cumulative recurrence rates were 36.6% and 10.6% after closure and PGV, respectively (p = 0.001). Eighty-five per cent of recurrences after closure were symptomatic, and half of them required reoperation. Duodenal scarring itself did not appear to influence the outcome after closure. PGV was not associated with dumping, diarrhea or other unwanted side effects. Although less than that in chronic ulcers, there is a substantial risk of symptomatic relapse after closure of perforated acute duodenal ulcers. With judicious patient selection, PGV effectively reduces this risk without incurring disabling side effects associated with other ulcer operations.     

Retrospective analysis of 5037 patients with nasopharyngeal carcinoma treated during 1976-1985: overall survival and patterns of failure.

This is a retrospective analysis of 5037 patients with squamous cell carcinoma of the nasopharynx treated during the years 1976-1985. The stage distribution according to Ho's classification was 9% Stage I, 13% II, 50% III, 22% IV, and 6% Stage V. Only 4488 (89%) patients had a full course of megavoltage radiation therapy. The median equivalent dose to the nasopharyngeal region was 65 Gy and cervical region in node-positive patients 53 Gy. Seventy percent (906/1290) of the node-negative patients had no prophylactic neck irradiation. The overall actuarial 10-year survival rate was 43%, and the corresponding failure-free survival 34%. Altogether, 4157 (83%) patients achieved complete remission lasting more than 6 months, but 53% (2205/4157) of them relapsed after a median interval of 1.4 years. The 10-year actuarial local, regional, and distant failure-free rates were 61%, 64%, and 59%, respectively. Thirty-eight percent (338/891) of all patients with local recurrence achieved second local remission. The local complete remission rate with aggressive re-irradiation alone was 47% (333/706). But 37% (124/338) of the responders recurred the second time. The incidence of distant failure correlated significantly with both the N-stage and the T-stage, with the highest (57%) occurring in patients with N3 disease. The incidence of nodal relapse in node-negative patients was 11% (44/384) among those given prophylactic neck irradiation, but 40% (362/906) among those without. Therapeutic irradiation achieved a complete regional remission rate of 90% (306/339). However, despite successful salvage, these patients had a significantly higher distant failure rate than those without nodal relapse, even if they remained local-failure-free (21% vs 6%). Patients treated during 1981-1985 achieved significantly better treatment results than those treated during 1976-1980, especially in terms of the overall survival (57% vs 47% at 5-year), the overall failure-free survival (42% vs 35% at 5-year), and the local failure-free rate (70% vs 63% at 5-year). The possible contributing factors are discussed.     

Contractile actions of thrombin receptor-derived polypeptides in human umbilical and placental vasculature: evidence for distinct receptor systems.

1. We studied the structure-activity profiles of four thrombin receptor-derived polypeptides (TRPs) (P5, SFLLR; P5-NH2, SFLLR-NH2; P7, SFLLRNP; P7-NH2, SFLLRN) in contractile human placental artery (PA), umbilical artery (UA) and umbilical vein (UV) preparations and in a human platelet aggregation assay. 2. The contractile actions of the TRPs in the two arterial preparations were endothelium-independent, whereas in the UV tissue a contractile response was observed only in an endothelium-denuded preparation; no endothelium-mediated relaxation responses were observed in any of the vascular preparations. 3. In the three vascular preparations, the contractile responses required extracellular calcium and were attenuated by the tyrosine kinase inhibitor, genistein. 4. The relative contractile orders of potencies of the TRPs in the three vascular preparations were distinct from each other (PA: P7-NH2 > P7 > P5-NH2 > P5; UA: P7-NH2 > or = P5-NH2 approximately = P7 > > P5; UV: P5-NH2 > > P7-NH2 = P7 > > P5) and these were in turn distinct from the potency order observed in the platelet aggregation assay (P5-NH2 > or = P7-NH2 > P7 > > P5). 5. Despite the markedly dissimilar TRP potency orders in the placental artery and umbilical vein preparations, the cDNA sequences for the thrombin receptor obtained by polymerase chain reaction cloning of cDNA from the two tissue sources were identical. 6. We conclude that the four tissues studied possess functionally distinct thrombin receptor systems that interact in a distinct way with agonist peptides. In view of the identity of the thrombin receptor cDNA in the two tissues displaying the most dissimilar structure-activity profiles, we suggest that in different tissues, differences in post-translational receptor processing or differences in receptor-effector coupling interactions may result in unique thrombin receptor systems that can display distinct structure-activity profiles.     

Third ventricular primary cerebral neuroblastoma. Electron-microscopic and immunohistochemical study

A case of third ventricular primary cerebral neuroblastoma with secondary hydrocephalus is reported. Light microscopy showed a cell pattern that resembled either ependymoma or oligodendroglioma. The tumor was confirmed to be neuroblastoma by electron microscopy and immunohistochemistry. Immunoperoxidase staining was positive for neuron-specific enolase and negative for glial fibrillary acidic protein.