Isotoshi Yamamoto

Determination of glyphosate, glyphosate metabolites, and glufosinate in human serum by gas chromatography-mass spectrometry.

This paper describes an assay for the determination of glyphosate (GLYP), glyphosate metabolites [(aminomethyl) phosphonic acid] (AMPA), and glufosinate (GLUF) in human serum. After protein precipitation using acetonitrile and solid-phase extraction, serum samples were derivatized and analyzed by gas chromatography-mass spectrometry (GC-MS). The assay was linear over a concentration range of 3-100.0 microg/ml for GLYP, AMPA, and GLUF. The overall recoveries for the three compounds were >73%. The intra- and inter-day variations were <15%. Precision and accuracy were 6.4-10.6% and 88.2-103.7%, respectively. The validated method was applied to quantify the GLYP and AMPA content in the serum of a GLYP-poisoned patient. In conclusion, the method was successfully applied for the determination of GLYP and its metabolite AMPA in serum obtained from patient of GLYP-poisoning.

Determination of metaldehyde in human serum by headspace solid-phase microextraction and gas chromatography-mass spectrometry

A rapid headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) method has been developed for the determination of metaldehyde in human serum samples. Metaldehyde is extensively used as a molluscicide for the control of slugs and snails, and cases of metaldehyde poisoning have been reported. Metaldehyde was headspace-extracted on a polydimethylsiloxane (PDMS) fiber at 70 degrees C for 25 min, desorbed, and analyzed rapidly by GC-MS. The method was validated for limit of detection (LOD), linearity, precision, and recovery. Although the recovery of the sample was very low, the method itself was rapid with a low detection limit of 0.25 microg/ml, R.S.D. value 12.6%, and linearity range 0.5-25.0 microg/ml (r(2)=0.999). The results demonstrated that the SPME-GC-MS method for the analysis of metaldehyde is simple, rapid, solvent-free, and does not require any pre-analysis conversions.

Lactate as a prognostic factor in carbon monoxide poisoning: a case report

Carbon monoxide (CO) poisoning results in various neuropsychological impairments, including delayed encephalopathy (DE) and death. However, factors related to these outcomes are unknown. A group suicide was attempted by 3 young people--a 31-year-old man (patient 1), a 21-year-old woman (patient 2), and a 20-year-old man (patient 3)--by burning charcoal in a closed car. At the emergency department, hypotension and hyperthermia were severe in patient 1, moderate in patient 2, and absent in patient 3, although all the patients were comatose. The initial serum lactate levels were 75.1 mg/dL in patient 1, 41.9 mg/dL in patient 2, and 26.3 mg/dL in patient 3, although the carboxyhemoglobin levels were approximately equal in all the patients. Hyperbaric oxygen therapy (HBOT) was immediately initiated and continued for 10 days in all the cases; however, the outcomes of these patients varied considerably. Patient 1 remained comatose and died on day 31 because of central diabetes insipidus after shock. Patient 2 recovered from coma and was discharged; however, she was rehospitalized for DE on day 45 and recovered completely after another 10-day HBOT. Patient 3 gained consciousness and recovered completely with no sequelae during the 1-year follow-up. From these cases, we can consider that the initial blood lactate may correlate with the patient outcomes and prove to be a useful prognostic factor. Thus, we should particularly consider elevated lactate levels in CO poisoning.

RISK FACTORS FOR RHABDOMYOLYSIS IN SELF-INDUCED WATER INTOXICATION (SIWI) PATIENTS

Self-induced water intoxication (SIWI) patients present with various neurological and non-neurological symptoms. However, it is reported that non-neurological manifestations such as rhabdomyolysis are comparatively rare. The mechanism underlying rhabdomyolysis remains controversial. To investigate this further, we evaluated 22 SIWI patients for rhabdomyolysis. We reviewed the records of 22 patients with SIWI and evaluated their clinical characteristics. These patients were divided into the following two groups: Group A with rhabdomyolysis and Group B without it. We compared these groups to study the risk factors underlying the occurrence of rhabdomyolysis. Furthermore, we compared the complications and the duration of hospitalization between the two groups. The maximum serum sodium correction speed per hour, the increase in the serum sodium level in the initial 24 h, and the duration of hospitalization for group A were faster, higher, and longer, respectively, when compared with those in group B. Only group A patients showed complications. The rapid correction of hyponatremia may possibly trigger rhabdomyolysis in SIWI patients.

Determination of chronic methamphetamine abuse by hair analysis

A 30-year-old male truck driver, known to be asthmatic, was found dead at the roadside lying near his car. A nebulizer bottle of Berotec (fenoterol hydrobromide) was found near his hand. The anatomic cause of death was suspected to be asthma. Toxicological screening of urine using Triage demonstrated the presence of methamphetamine. The blood concentration of methamphetamine was 0.4 microg/ml, and fenoterol was not detected. Hair analysis clearly indicated chronic methamphetamine abuse and medium dependency during the 2 months before death. We conclude that death might have been induced by the interaction of fenoterol and methamphetamine.

Painless acute aortic dissection with a left hemiparesis.

BackgroundPatients who present with only neurological symptoms and no pain challenge the recognition of acute aortic dissection.ResultsWe report three patients with completely painless acute aortic dissection who presented with left hemiparesis. All patients presented with a left-sided weakness of sudden onset. We suspected an ischemic stroke but diagnosed acute aortic dissection (DeBakey Type II, Stanford Type A). We suspect that the innominate artery is occluded when the blood flow of the false lumen is dominant. In our cases, surgical and autopsy findings showed dissection of the innominate artery.ConclusionsHighly unusual presentations of aortic dissection with acute ischemic stroke exist. A wide mediastinum on plain chest X-ray was present in all cases.

Correlating the severity of paraquat poisoning with specific hemodynamic and oxygen metabolism variables

Objective To investigate the hemodynamics and oxygen metabolism of patients with varying degrees of severity of paraquat poisoning. Design Prospective, observational, clinical study. Setting Intensive care unit in a university hospital. Patients Forty-three consecutive patients with paraquat and/or diquat poisoning were classified into three groups by the severity index of paraquat poisoning (SIPP; hr/mg/L). Interventions Standard treatments included specific respiratory management, fluid resuscitation, and aggressive circulatory support. Measurements and Main Results Serum paraquat and diquat levels were measured at arrival, and SIPP was calculated. The cardiac index (CI), left ventricular stroke work index (LVSWI), systemic vascular resistance index (SVRI), oxygen delivery index (˙Do2I), oxygen consumption index (&OV0312;o2I), and oxygen extraction ratio (O2ER) were measured at 6, 12, 24, 36, 48, 72, and 96 hrs postadmission. A significant inverse correlation between SIPP and survival time was found in 31 fatal cases (r2 = .85;p < .001). In the SIPP 10–50 group, CI, ˙Do2I, &OV0312;o2I, and O2ER were maintained at higher levels than in the SIPP group of <10 (p < .05), whereas SVRI decreased significantly (p < .05). In the SIPP group of >50, CI, LVSWI, SVRI, ˙Do2I, and &OV0312;o2I decreased, whereas O2ER had a tendency to increase progressively. There was a significant correlation between SVRI and SIPP, O2ER and SIPP, and O2ER and SVRI 24 hrs after admission, respectively (p < .001). Conclusions Paraquat poisoning is characterized by high oxygen consumption with high oxygen extraction, with the degree of derangement based on the severity index. The development of a marked imbalance between increased oxygen demand and decreased oxygen supply because of myocardial depression might be a possible cause of death in circulatory failure.

Characteristics of suicide attempters with depressive disorders

Abstract  Attempted suicide is known to be an important risk factor of committed suicide. Past studies of the relationship of attempted suicide with mental disorders have shown that it is most closely related to depression. The objective of the present study was to clarify characteristics of depression and measures to prevent committed suicide by comparing depression with other mental disorders. The patients with depression were significantly more often aged, males, married, and used methods other than poisoning by solids or liquids compared with patients with other mental disorders. Particularly, the major risk factors of attempted suicide (i.e. a younger age and the female gender), did not apply to our depressed patients. These results suggest that approaches such as intensive psychiatric treatment may lead to the prevention of committed suicide in older male patients with depression who have attempted suicide.

The Comparison of Characteristic and Clinical Features of Self-inflicted Abdominal Stab Wound Patients in Japan: Simple Stab Wounds Versus Hara-kiri Wounds

BACKGROUND The proportion of suicide attempts by infliction of abdominal stab wounds (ASWs) is higher in Japan than in other counties. There are few clinical reports on these wounds, especially hara-kiri wounds, which involve transversely cutting the abdomen. This study aimed to investigate Japanese patients with self-inflicted hara-kiri wounds and determine their characteristics and clinical features. METHODS We investigated 84 patients with self-inflicted ASWs who had been transferred to our hospital between April 1994 and March 2004. We recorded their characteristics and clinical features. They were then divided into two groups depending on their wound type, namely, simple stab wounds (SSWs) and hara-kiri wounds. The characteristics and clinical features of each group were then compared. RESULTS SSWs were frequently observed in the periumbilical and epigastric regions, whereas most hara-kiri wounds were observed in the middle abdomen. The rate of organ injury was 58.7% (44 of 75) for SSWs and 66.7% (6 of 9) for hara-kiri wounds; no significant difference was observed in this regard. SSWs resulted in injury to various organs, whereas hara-kiri wounds typically caused small bowel, mesenterium, omentum, and major vascular injuries. Small bowel and major vascular injuries had a significantly high incidence in hara-kiri wounds. The mortality rate caused by hara-kiri wounds was significantly higher than that caused by SSWs (1.3% vs. 22.2%). CONCLUSION The mortality rate caused by ASWs is relatively low. However, hara-kiri wounds might be a risk factor for death. Further, because hara-kiri wounds transversely cut the abdomen, they might be a risk factor for major vascular injury.

Characteristics of elderly Japanese patients with severe burns.

In this study, we report the clinical characteristics of elderly Japanese patients with severe burns. We studied the clinical features of 76 adult patients with severe burns, 35 of whom (46.1%) were ≥65 years old. We evaluated the characteristics of patients with respect to each type of burn. In addition, we studied the rate of death and survival in the elderly and also between the elderly and non-elderly patients. The following parameters were either assessed or compared between the elderly and non-elderly: gender, average age, vital signs (Glasgow Coma Scale, systolic blood pressure, heart rate and respiratory rate) and PaO(2)/FiO(2) (P/F) ratio at admission, cause of burn and a history of physical or psychiatric disease. Further, we investigated whether the burn was caused by attempting suicide and determined the percent total body surface area (%TBSA), second- and third-degree burn area, burn index (BI), prognostic burn index (PBI), presence of tracheal burns, presence of alcohol intoxication and overdose poisoning, presence of tracheal intubation, outcome and cause of death. The male:female ratio of the elderly patients was 17:18 (average age, 78.1 (8.2) years). Burns were mostly caused by flame (26/35), followed by scalding (8/35). Ten patients had attempted suicide. The %TBSA, second-degree burn area, third-degree burn area, BI and PBI, respectively were 46.6% (26.7%), 15.3% (19.0%), 35.6% (26.0%), 41.1 (25.2) and 119.2 (25.9). Of the 35 patients, 23 died. The notable characteristics of the elderly patients who died were flame as the cause of the burns: high %TBSA, BI and PBI, and a high rate of tracheal intubation. Elderly patients constituted approximately 45% of our study population. Most burns were caused by flames. The incidence of accidental bathtub-related burns was higher and that of suicide attempts was lower in the elderly patients, as compared with the non-elderly patients. Severe burns were fatal for elderly patients. Therefore, elderly Japanese people should be educated on how to prevent non-intentional burns.