Head and neck injuries in fatal motorcycle collisions as determined by detailed autopsy.

Detailed layer-by-layer autopsy of the head and neck was performed on a series of seventy-three fatally injured motorcyclists in order to identify occult soft tissue injuries such as subluxation of the cervical spine or hemorrhage of vertebral or internal carotid arteries. The fatal cases were gathered as part of a larger study of 1082 on-scene in-depth motorcycle crash investigations in Thailand. Injuries were coded using the 1990 Abbreviated Injury Scale (AIS 90) and an Injury Severity Score (ISS) was determined for each case. Twenty-eight motorcyclists had been wearing a helmet at the start of the collision sequence, but only nine helmets remained in place through the entire collision event. Both helmeted and unhelmeted motorcyclists showed a high frequency of neck injuries such as hemorrhages in the carotid sheath compressing the vagus nerve, hemorrhages surrounding the phrenic nerves or the brachial plexus, or hemorrhages surrounding the vertebral arteries. The most significant finding of this study was the identification of serious internal neck injuries even when there was no external physical evidence of trauma to the neck. Virtually all riders with significant head injuries showed some of these soft tissue neck injuries. This may be important for trauma physicians, who are presented with critically injured motorcyclists with complex multiple trauma, which may include occult soft tissue neck injuries.

Exchange transfusion in severe falciparum malaria: a simple method modified from hemodialysis circuit.

We set up a simple extracorporeal circuit, modified from the extracorporeal method generally used in conventional hemodialysis, for exchange transfusion. Temporary vascular access was used in exchange transfusion for both draining the infected blood and infusion of the freshly non-infected blood. This method of exchange transfusion was performed in 3 severe complicated falciparum malaria patients who had a percentage of parasitemia of 80, 40, and 35. The magnitude of parasitemia decreased immediately to less than one per cent and this value persisted twenty-four hours after the procedure. No complications of exchange transfusion were detected in all patients. Erythrocyte morphology determined by scanning electron microscopy was unaltered by exchange transfusion. Because of the simplicity, the effectiveness, and the safety of the procedure, this extracorporeal circuit modified from hemodialysis circuit would be a more beneficial exchange transfusion method in the treatment of severe complicated falciparum malaria than the manually-performed one.

Effect of serotonin depletion on nitric oxide induced cerebrovascular nociceptive response.

The study was conducted to investigate the effect of serotonin depletion on nitric oxide-induced meningeal vascular response and cerebrovascular nociception. Nitroglycerin was infused i.v. to control and serotonin-depleted rats. Pial circulation was monitored by intravital fluorescent videomicroscopy and Fos immunoreactivity trigeminal nucleus caudalis neurons was used as an indicator for the cerebrovascular nociception. The results showed that the degree of nitric oxide-induced pial microvascular dilatation was significantly greater in the serotonin-depleted group than the control. The number of nitric oxide-evoked Fos-immunoreactive cells between the two groups remained comparable. The results suggest that though depletion of serotonin can facilitate the vascular response to nitric oxide it does not alter the nitric oxide-induced craniovascular nociceptive response.

Modification of the acetylcholinesterase (AchE) staining method in Hirschsprung's disease.

Demonstration of the increasing activity of acetylcholinesterase (AChE) in a segment of the colon has proved to be the most accurate diagnostic tool to diagnose Hirschsprung's disease. Two methods of histochemical assessment were tried to establish the most appropriate and effective method for this study within the limitation of available equipment. Lake's method was chosen and was modified as the standard histochemical examination.

Comparative effects of garlic and aspirin on diabetic cardiovascular complications.

By using streptozotocin-induced diabetic rats as a studied model, our previous experimental results have indicated that daily oral feeding of garlic extract (100 mg/kg BW) could increase the cardiovascular functions in streptozotocin (STZ) rats; the abnormality of lipid profile was prevented; and garlic extract could increase fibrinolitic activities with the decrease of platelet aggregation. Moreover, the plasma insulin level was increased concomitantly with the decrease of plasma glucose level. However, due to the high incidence of atherosclerosis in diabetes, the present study has been continued for further investigation of the effect of garlic extract on the coronary vascular ultrastructural changes. In addition, to identify the possible mechanism(s) of garlic's therapeutic effects, the cyclooxygenase inhibitor, aspirin, has been included in this present study. By using transmission electron microscopic studies, 16 weeks of daily oral feeding of garlic extract (100 mg/kg BW) caused as an antiatherosclerotic agent at the coronary arteriolar (15-30 microns) wall in STZ-rats. Interestingly, the thickening of coronary capillary (5-10 microns) basement membrane also was significantly attenuated within the group of STZ-rats treated with garlic extract. However, the possible direct action of garlic through the cyclooxygenase pathway has not been confirmed by the results of aspirin: The daily oral feeding of aspirin (10 mg/kg BW) in 16-week STZ-rats has not showed reduced arteriolar vascular wall abnormalities. The irregular patterns of fiber matrix, arranging the basement membrane at the arteriolar walls, were still recognized in the same manner as in STZ-rats. Interestingly, the thickening of the capillary basement membrane occurred in 16-week STZ-rats seems to be attenuated by the aspirin received. At present, garlic extract may open the new era in the medicinal use of garlic to prevent diabetic cardiovascular complications.

Hyposerotonin-induced nitric oxide supersensitivity in the cerebral microcirculation.

OBJECTIVE: To investigate the relationship between hyposerotonin and cranial microvascular responses to nitric oxide (NO). BACKGROUND: Although the mechanism underlying NO supersensitivity in migraine is still unclear, an alteration of the serotonin system is a possible explanation. METHODS: Wistar rats were divided into control and hyposerotonin groups. Serotonin was depleted by intraperitoneal injection with 300 mg/kg of para-chlorophenylalanine (PCPA), a tryptophan hydroxylase inhibitor. Three days after PCPA pretreatment, the animals were prepared for assessment of their NO-induced vasomotor response using glyceryl trinitrate (GTN: 8 to 10 mg/kg, intravenously) as an NO donor. Pial circulation was visualized by the intravital fluorescein videomicroscopic technique. Images of vessels at 0, 5, 15, 30, and 60 minutes post GTN infusion were digitized and measured. At the end of monitoring, the rat brains were removed for ultrastructural study of the brain microvessels. RESULTS: Infusion of GTN produced dose-dependent pial arteriolar dilatation. This vasodilator effect was significantly increased in the PCPA-treated groups, especially at 30 and 60 minutes. The percentage change from baseline diameter at 30 minutes after the 8-mg/kg GTN infusion was 42.6 +/- 3.1 for the hyposerotonin group and 16.8 +/- 2.9 for the control group (P<.001). Electron microscopic study revealed that exposure to the NO donor produced considerable changes in cerebral microvessels, characterized by focal ballooning of endothelial cells, increased microvillous formation, and increased endothelial pinocytosis. These anatomical changes were significantly more prominent in the hyposerotonin group. CONCLUSIONS: A hyposerotoninergic condition can facilitate the NO-induced physiological and pathological responses in meningeal and cerebral microvessels and, therefore, is a possible explanation for the supersensitivity to NO observed in patients with migraine.

Genetic heterogeneity and progression in different areas within high-grade diffuse astrocytoma.

The primary objective of this study was to determine loss of heterozygosity (LOH) in various portions of 9 high-grade diffuse astrocytomas, 8 glioblastomas and 1 anaplastic astrocytoma. LOH was observed on chromosomes 9, 10, 17 and 19 in 8, 3, 4 and 2 cases, respectively. Genetic heterogeneity and a multistep process were identified in 4 glioblastomas explaining the diverse morphological characteristics, a common feature of diffuse astrocytomas. In 2, 2, 3 and 1 cases, the allele losses were found within part of grade IV astrocytomas but not grades II or II/III, on chromosomes 9, 10, 17 and 19, respectively. In one of these, while genetic heterogeneity was observed on chromosome 17 between the area of grade II and grade IV, 9pLOH was found within both areas and occurred on the same allele. The other 5 cases did not demonstrate genetic heterogeneity and the LOH was on the same allele, irrespective of grade, suggesting clonal origin. In conclusion, at the molecular level, the diverse morphological features of astrocytoma develops by a multistep mechanism of genetic alterations from one cell via low-grade and more malignant tumors towards glioblastoma.

Homicide: a report of 4,122 cases from Bangkok and provinces.

A retrospective review of 4,122 homicides was carried out between 1991 and 1995. About 47 per cent of cases occurred in the Bangkok Metropolitan area (BKK) and 53 per cent in the nearby provinces. A steady increase in the murder rate was noted in the latter. BKK was the place where most killings occurred, but was probably related to the high number of extrajudicial executions. Of the victims, 86 per cent were men and 14 per cent were women. The incidence peaked in the 3rd decade of life but there was also a rising trend among teenagers. Three major causes of death were firearms, sharp-force, and blunt-force in combination accounting for 92 per cent of the deaths. Firearms alone were used in about half of all murder cases. An analysis of organ injuries in relation to the types of weapons used was also presented. The data indicate the necessity to limit access to firearms.

Epithelial-myoepithelial carcinoma of parotid gland: a case report with immunohistochemical and ultrastructural studies.

A 66-year-old man presented with a painless mass of the parotid gland. Light and electron microscopic studies verified the basic nature of the tumor as epithelial-myoepithelial carcinoma, a low-grade malignant neoplasm of the salivary gland. Pathologically, there were two types of cells; the inner eosinophilic epithelial cells lining the ducts and the outer clear cells. The former cells displayed immunoreactivity for cytokeratin and ultrastructural features of apical microvilli and desmosome. The latter cells were positive for actin, S-100 protein, vimentin and the cytoplasm contained actin microfilaments. Such pathological findings were characteristic features of this rare tumor. To our knowledge, this is the first reported case of EMC in Thailand.

Effects of Russell's viper venom on human erythrocytes in vitro.

The effects of Russell's viper venom (RVV) on human erythrocytes were studied in vitro with respect to packed cell volume (hematocrit), the erythrocyte morphology, and the effect of antivenom. Venom at various dosages ranging from 50 ng to 120 micrograms increased hematocrit significantly. The maximal effect was detected at 800 ng of venom. The biconcave erythrocytes shown by scanning electron microscopy became sphero-echinocytes. Such altered morphology was observed immediately at 1 minute and reached maximum at 30 minutes. The mild degree of erythrocyte deformation was observed at 60 and 120 min with 100 ng of RVV. There were no morphologic changes when ethylenediaminetetracetate (EDTA) was used as an anticoagulant or when plasma was substituted by isotonic saline, acetar, albumin added acetar solution. Phospholipase A2 at equivalent dose as compared to the venom could also produce the sphero-echinocytosis. The phospholipase A2 inhibitor, p-bromophenacyl bromide markedly reduced the degree of RVV induced sphero-echinocytosis. Verapamil, a phenylalkylamine calcium channel blocker, could not prevent the RVV induced sphero-echinocytosis. Although antivenom could not reverse the RVV induced sphero-echinocytosis, it minimized these effects. The RVV induced sphero-echinocytosis is likely caused by phospholipase A2. Calcium and some plasma factors are required for this process. Early treatment with antivenom plays some role in prevention of RVV induced sphero-echinocytosis which may reduce hypoxic cell injury.

Derangement of serotonin system in migrainous patients with analgesic abuse headache: clues from platelets.

Accumulating evidence indicates that serotonin (5-HT) may be involved in the process of analgesic-induced headache transformation. In order to clarify this hypothesis, we investigated the 5-HT system in migraine patients with analgesic abuse headache by using platelets as a neuronal model. Our results revealed a significant decrease in platelet 5-HT content in these patients compared to migraine patients and nonheadache controls (179.24 +/- 10.18, 451.22 +/- 14.35, and 480.22 +/- 13.98 ng/10(9) platelets, respectively; P < 0.001). This biochemical result was well correlated with a significant decrease (P < 0.001) in platelet dense body number observed in these patients (5.9 +/- 0.4 and 9.2 +/- 0.6 granules/10 platelets. For migraine patients with and without analgesic abuse headache, respectively). Beside the 5-HT depletion, the presence of numerous large intracytoplasmic vacuoles formed from the surface-connecting canaliculi system was found in this condition. Such a finding has not been previously described. The total area occupied by these vacuoles was significantly greater (P < 0.01) in migraine patients with analgesic overuse than in migraine patients and nonheadache controls (249.2 +/- 19.5, 164.1 +/- 19.5, and 183.1 +/- 20.3 nm2/cells, respectively). As this canaliculi system plays a significant role in the platelet secretory response, such dilatation may imply an excessive release of substances from this system. Based on this platelet model, we suggest that excessive use of analgesics alters the central 5-HT system by depleting 5-HT from its storage sites and results in the hyposerotonergic state. This analgesic-induced 5-HT alteration may be a possible mechanism of headache transformation observed in this condition.

Clinicopathological features predicting recurrence of intracranial meningiomas.

A series of 11 recurrent meningiomas was studied. Most lesions occurred in women. The youngest patient was 17 years old and the oldest was 73 years. The mean age was 44 years. Multifactorial risk factors were involved in the tumor regrowth including age of patients, location of tumors, adequacy of initial surgery, certain histopathological features and subtypes of tumors. Tumors in young adults tended to have a rapid interval of regrowth as well as a tendency of multiple recurrences. Brain invasion, extensive bone and muscle involvement, foci of necrosis and hemorrhage, high mitotic index, angioblastic and papillary patterns were common pathological risk factors. Additionally, recurrent tumors may retain their original pathological appearance or become more aggressive by showing marked cellular pleomorphism. Area of liposarcomatous component was encountered in one recurrent lesion.

Moderately differentiated neuroendocrine carcinoma (atypical carcinoid) of the larynx.

A moderately differentiated neuroendocrine carcinoma or atypical carcinoid of the larynx occurred in a 68-year-old woman who developed rapidly progressive dysphagia, hoarseness and a neck mass. Immunohistochemical and electron microscopic studies verified the nature of this tumor. Local invasion and distant metastases are common. It is suggested that cigarette smoking could increase the risk of developing this neoplasm.

Castleman's disease: a clinicopathologic study of 12 cases.

Castleman's disease observed in 12 Thai patients was investigated. The male to female ratio was 1:3. Peak prevalence was in the third and fourth decades. It is suggested that the disease in Orientals tends to have extrathoracic mass more often than in Caucasians. Solitary non-tender slow growing mass was the most common symptom. Generalized lymphadenopathy in association with cutaneous plasmocytoma was noted in one example while asymptmatic pelvic lesion in a patient was discovered incidentally. Histologically, the hyaline-vascular type was found in 8 instances, the remainders were plasma-cell type. Surgery was effective for localized lesions while systemic form could benefit from chemotherapy.

Bullet embolus to the right pulmonary artery after abdominal gunshot wound with "piggyback bullet".

This report describes a 17-year-old man with piggyback bullets to the abdomen followed by bullet embolization to the right pulmonary artery. The first bullet was removed from the abdomen while the second missile in the lung was left intact. We believe this is the first case in Thailand of a bullet embolus resulting from piggyback bullets.

Combined angioma and glioma (angioglioma).

Ten patients in whom tissue proliferation akin to angioglioma occurred within the brain are described; seven of the lesions were supratentorial and three infratentorial. Only 31 accepted instances of such neoplasms have been found in the literature. The combined lesions usually become symptomatic in the second and third decades. In all 10 cases, the angiomatous part of the combined tumors showed characteristic vascular malformation such as severe hyalinization, tortuosity, and some were even calcified. The number of abnormal blood vessels were excessive in all examples. The glial portion consisted of either astrocytoma, oligodendroglioma, or mixtures of these gliomas. Dedifferentiation of the neuroglia combined with neoplastic endothelial proliferation indicates the true neoplastic nature rather than reactive gliosis associated with a vascular anomaly.

Primary ovarian carcinoid: a mixture of insular, trabecular and mucinous components.

A case of primary ovarian carcinoid in a 53-year-old woman is described. The tumor which replaced the left ovary showed a mixture of insular, trabecular and mucinous cell types in the same mass. The nature of the neoplastic cells has been verified by light and electron microscopic studies. The latter investigation demonstrated bundles of tonofilament and apical villi of the trabecular cells in addition to the morphologic difference of neurosecretory granules among these various cells.

Mucin-producing malignant meningioma with papillary and glandular patterns.

An exceedingly rare intracranial malignant meningioma with papillary and glandular patterns in a 45-year-old man is described. Intracellular mucin production was demonstrated. The nature of the neoplastic cells was verified by immunohistochemical and electron microscopic studies.

Effects of law promulgation for compulsory use of protective helmets on death following motorcycle accidents.

This study revealed a significant decrease in mortality from injuries sustained by motorcycle accidents following the decree promulgated in 1992 for compulsory use of safety helmets by motorcyclists and pillion riders. The helmets can help only in protection of head injury but do not affect the number of accidents. This safety device can not protect any serious injuries of the neck, chest or internal organs which could result in death or permanent disability. To gain maximum benefit from the law, the helmets should be of standard specification and worn properly. Education to drivers and pillion riders particularly male adolescents is essential in reducing the incidence of motorcycle accidents.