Search for Dark Photon Dark Matter in the Mass Range 74-110 µeV with a Cryogenic Millimeter-Wave Receiver.

We search for the dark photon dark matter (DPDM) using a cryogenic millimeter-wave receiver. DPDM has a kinetic coupling with electromagnetic fields with a coupling constant of χ and is converted into ordinary photons at the surface of a metal plate. We search for signal of this conversion in the frequency range 18-26.5 GHz, which corresponds to the mass range 74-110 µeV/c^{2}. We observed no significant signal excess, allowing us to set an upper bound of χ<(0.3-2.0)×10^{-10} at 95% confidence level. This is the most stringent constraint to date and tighter than cosmological constraints. Improvements from previous studies are obtained by employing a cryogenic optical path and a fast spectrometer.

Structure of the gene encoding human alpha 2-HS glycoprotein (AHSG).

Alpha 2-HS glycoprotein (AHSG) is a human plasma glycoprotein and fetuin is the homologue in the calf. In this report, we present the structure and organization of the AHSG gene. Introns and the 5' and 3'-flanking regions were obtained by polymerase chain reaction (PCR) and the inverted PCR, respectively, from genomic DNA using AHSG cDNA-specific oligonucleotide primers. The sequence of the PCR products shows that the coding region spans approximately 8.2 kb and is composed of seven exons interrupted by six introns. The exon-intron splice junctions agree with the consensus sequence, and the positions interrupted by introns are precisely identical to those of the rat insulin receptor tyrosine kinase inhibitor (fetuin) gene. The 5'-promoter region contains several characteristic sequences such as an A + T-rich sequence of TAAATAA, C/EBP-binding site, and hepatocyte nuclear factor-5 (HNF-5) and serum response factor (SRF) sites.

Association of plasma triglyceride-rich lipoprotein remnants with coronary atherosclerosis in cases of sudden cardiac death.

Among the risk factors for coronary atherosclerosis, elevated LDL-C level is best known. The action of lipoprotein lipase on triglyceride-rich lipoproteins produces remnant lipoprotein particles enriched in cholesterol and apolipoprotein E (apo E). Apo E serves as the ligand for uptake of remnant lipoproteins via the LDL-receptor or the remnant receptor. In this study, postmortem plasma total cholesterol, triglycerides (TG), VLDL-C, HDL-C, lipoprotein (a) [Lp(a)] and remnant-like lipoprotein particles (RLP)-cholesterol, RLP-TG, apolipoproteins B, C III and E were measured, together with LDL-C to assess their potential contribution to the severity of coronary and aortic atherosclerosis of the 197 cases of sudden death (132 cardiac death and 65 non-cardiac death). In all cases, the severity of coronary atherosclerosis was determined at postmortem pathological examination. RLP-cholesterol (RLP-C) and LDL-C concentrations were significantly higher in cases with advanced coronary atherosclerosis compared with those without coronary atherosclerosis; respective median values were 13.5 vs 8.4 mg/dl (P < 0.001) and 140 vs 115 mg/dl (P < 0.05). RLP-C levels were more strongly correlated with the severity score of coronary atherosclerosis than LDL-C.

Acute toluene poisoning during painting.

Autopsy findings on a man who fell from a height due to acute toluene poisoning while painting are described. Gas chromatographic examination revealed that the toluene concentrations of his blood, lung, liver and brain were 48, 35, 65 and 80 micrograms/g, respectively. These toluene levels were not enough to be definitely lethal, but were high enough to anesthetize the central nervous system.

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.

Increased complex formation of Gc globulin with actin in plasma from human cadavers.

Gc globulin binds actin at an equimolar ratio with a high affinity. It has been revealed that complexes of Gc with actin are present in the plasma of human cadavers. In the present study, an immunoassay which we developed using a specific anti-Gc monoclonal antibody was applied to evaluate the complexed Gc in cadaver plasma. The percentage of Gc in the complexed form was found to be 38.3 +/- 19.8% (n = 45), and a significantly higher percentage was observed in the plasma of cadavers from burn death. However, the plot of the complex percentage against the time since death showed a relatively low correlation, with a coefficient (r) of 0.51. This was supposed to be due to different environmental conditions after death. Since the complex formation represents the release of cytoplasmic actin into plasma from collapsed cells, the phenomenon should be noted in forensic postmortem chemistry.

A case of homicidal poisoning involving several drugs.

Accidental or suicidal poisonings due to benzodiazepines have been previously reported. A case of fatal, homicidal poisoning with benzodiazepines, antipyretic analgesics (anti-inflammatory drugs), and beer is described here. In this homicidal poisoning, the drugs and beer were given to the decedent by his wife. Autopsy findings showed no clinically significant macroscopic findings except for slight postmortem change. Capillary gas chromatography coupled to mass spectrometry was employed to quantitate the drugs in biological fluids and stomach contents. Six drugs (brotizolam, triazolam, ibuprofen, dihydrocodeine, phenylpropanolamine, and chlorpheniramine) were identified and quantitated in blood, urine, and stomach contents. Although each drug was present in a very small quantity, the cause of death was determined to be the combination of these drugs and alcohol poisoning.

Plasma triglyceride-rich lipoprotein remnants as a risk factor of 'Pokkuri disease'.

In our recent report, it remained unclear whether or not triglyceride-rich lipoprotein remnants (RLP) were associated with the risk of sudden coronary death in younger cases without coronary atherosclerosis that were detected in about 10% of all sudden coronary death cases in Japan. These cases were categorized as 'origin unknown, but suspected to be due to coronary spasm', the so called 'pokkuri disease' in Japan. The present study population consisted of 108 sudden death cases without coronary atherosclerosis [(pokkuri disease n=57) and non-cardiac sudden death (control n=51)] aged 20-69 years from Kanagawa prefecture in Japan. All individuals had died suddenly and unexpectedly, most had no significant history of medical conditions including cardiac symptoms and had not taken medications prior to death according to their medical records. All the autopsies were performed within 12 h after death. Plasma total cholesterol (TC), triglycerides (TG), phospholipids, RLP-C and RLP-TG, VLDL-C, LDL-C, HDL-C, apolipoproteins A-I, A-II, B, C-II, C-III, E, Lp (a) and homocysteine were measured in postmortem plasma samples. The TG-rich lipoprotein remnants measured as RLP-C and RLP-TG were significantly higher in pokkuri disease compared with controls both in fasting and postprandial states (P<0.05 and P<0.001), indicating that RLP-C and RLP-TG were the most significant risk factor in pokkuri disease among the parameters tested in this study. In conclusion the TG level in RLP (RLP-TG) appeared to be strongly associated with the risk of sudden death in the absence of coronary atherosclerosis (pokkuri disease).

Effects of muscle relaxants on EEG, ABR and EMG in rabbits.

The effects of baclofen and pancuronium bromide on evoked electromyogram (EMG), cortical electroencephalogram (EEG) and auditory brainstem responses (ABR) were studied in pentobarbital anesthetized normal rabbits. Evoked EMG was measured in the gastrocnemius muscle by electrical stimulation of the sciatic nerve. Intravenous injection of baclofen decreased EEG and arterial blood pressure and light reflex, however, it had no significant influence on EMG or ABR at doses of 10 and 20 mg/kg/h. Pancuronium bromide immediately inhibited respiration, decreased EEG and EMG, however, it had no significant influence on arterial blood pressure, ABR, or light reflex, at doses of 0.4 and 1.0 mg/kg/h in anesthetized rabbits. ABR waves were observed until just before cardiac arrest with both of the muscle relaxants. It is suggested that ABR are not influenced by central or peripheral muscle relaxants, or by pentobarbital.

Detection of hydroquinone in a poisoning case.

A fatality due to the ingestion of photographic developer solution containing hydroquinone is described. Hydroquinone was extracted from autopsy materials and identified using gas chromatography-mass spectrometry (GC-MS). The concentration of hydroquinone in the urine, liver, and kidney were 3.4 micrograms/mL, 0.5 and 0.2 microgram/g, respectively.

Fatal methemoglobinemia caused by liniment solutions containing sodium nitrite.

We describe a case of fatal methemoglobinemia (MetHb-emia) resulting from application of liniment solution containing large quantities of sodium nitrite. As a remedial treatment of atopic dermatitis, the liniment solution was applied all over the boy's body. Autopsy findings showed no significant macroscopic or microscopic findings except blood tinted chocolate brown color and chronic atopic dermatitis over the whole surface of the body. Quantitation of the methemoglobin (MetHb) in the blood was performed using spectrophotometer; MetHb concentration of the blood was 76%. Ion chromatographic determination revealed a nitrite concentration of 1 mg/L in the serum. Such a liniment solution is not authorized by the Ministry of Public Welfare.

Comparison of postmortem autolysis in cardiac and skeletal muscle.

To understand the mechanism in postmortem autolysis better, processes in the postmortem degradation of myofibril proteins in the presence of protease inhibitors were studied. Male Wistar rats were given injections of the carboxyl-, thiol-, and serine-protease inhibitors, pepstatin, Ep-475[L-transepoxysuccinyl-leucylamide(3-methyl) butane; E-64-C], and chymostatin, via the femoral vein. Control rats were similarly treated with saline. Then, myofibril proteins were isolated from their cardiac and femoral muscles and from those of control animals at various times after death, and degradation of these myofibril proteins with time was examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In cardiac muscle, alpha-actinin was degraded rapidly, followed by the heavy chain of myosin and light chain of myosin (L2). Actin and the light chain of myosin (L1) were degraded slowly. the degradations of the heavy chain of myosin, alpha-actinin, tropomyosin and L2 after 14 days were not inhibited by pepstatin, but were inhibited by Ep-475 and chymostatin. In skeletal muscle, L1 and L2 were degraded rapidly, followed by the heavy chain of myosin and alpha-actinin. Actin was degraded slowly and was still unchanged 2 weeks after death. The degradations of protein components were inhibited by pepstatin, Ep-475 and chymostatin. These results indicated that after death the components of myofibrils are degraded by various proteases at various rates depending on their properties or structures. This degradation is fundamentally the same in cardiac and skeletal muscles, but inhibitors have somewhat different effects on the postmortem degradation processes after death in the two types of muscle.

Fatal methamphetamine poisoning in police custody.

A fatal case of methamphetamine poisoning whilst in police custody is described. Drug identification and quantification in postmortem blood, urine, brain and gastric contents was achieved using gas chromatography-mass spectrometry. The blood concentration of methamphetamine was 4.92 micromol/100 g, which is in the lethal range. It is necessary for police officers to have a good knowledge of the toxic effects of abused drugs.

[Clinical and laboratory evaluation of pediatric kidney disease].

In infancy, the kidney by itself is immature and the body fluid composition is extremely different from that in adults. Further more, there are various renal diseases in children with characteristics different from those in adults. Thus in childhood, consideration for aging is critical for evaluation of renal function, and diagnosis of the disease. Recently, mass screening for infants or children in kindergarten or school has enabled us to find many children with renal disease, in whom symptoms are not overt. Thus the disease can be treated in an early phase. This may give a better prognosis for such children. To make an early diagnosis of renal disease it is essential to consider what laboratory tests are chosen and how the data accumulated are interpreted. In the present study, individual laboratory tests for the diagnosis of renal diseases and an indication of such tests as well as interpretation of the data are reviewed.

Sudden death of a cocaine abuser.

We report an autopsy case of a 28-year-old male who died after intravenous use of cocaine. Cocaine and ecgonine methyl ester, the major metabolite of cocaine, were detected in the blood with gas chromatography/mass spectrometry. Postmortem examination showed contraction band necrosis together with patchy fibrosis and inflammatory cell infiltration in the heart. The sudden death appeared to be caused by a cardiac disorder associated with arrhythmia or coronary vasoconstriction.

[Long-term follow-up study of children with minimal change nephrotic syndrome].

We conducted a long-term follow-up study of 37 children with biopsy-proved minimal change nephrotic syndrome during a period of over 6 years from onset to adulthood. These patients were classified into 4 groups of 13 infrequent relapsers, 17 frequent relapsers, 3 non-responders and 4 no-relapsers according to the International Study of Kidney Disease in Children (ISKDC). All patients were treated with conventional prednisolone therapy. Two cases of infrequent relapsers, 7 cases of frequent relapsers and 1 case of non responders relapsed in adult life. Two cases of infrequent relapsers and 1 case of frequent relapsers relapsed in adult life after remission for 5 or more years. We concluded that minimal change nephrotic syndromes in childhood should be followed up over a long duration in adult life, evenly in cases with good steroid responsiveness.

[Exercise-induced acute renal failure observed in a boy with idiopathic renal hypouricemia caused by postsecretary reabsorption defect of uric acid].

Acute renal failure without oliguria developed in an 11-year boy after running exercise. With improvement of his renal function, marked hypouricemia became apparent (0.8-0.9 mg/dl). Increased excretion of uric acid into the urine, increased clearance ratio of uric acid against creatinine (CUA/CCr), normal concentration of plasma xanthine and hypoxanthine, and suppression of CUA/CCr ratio by pyrazinamide loading but not by probenecid, were observed in the patient and his two siblings, suggesting that hereditary abnormalities of reabsorption of uric acid after secretion from the renal tubules resulted in the hypouricemia. The mechanism of acute renal failure in this disease remains unknown.

[Searching for a new risk factor of sudden cardiac death].

Sudden death of cardiovascular origin has been recognized as a major cause of sudden natural death. Advanced coronary atherosclerosis often co-existent, despite this, little or no coronary atherosclerosis was seen in approximately half of the sudden coronary death cases. Some components in the blood seem to induce not only the coronary atherosclerosis but also coronary spasm and/or thrombogenesis under certain conditions, which does not necessarily relate to the severity of atherosclerosis. Postmortem plasma lipids and lipoprotein levels, especially triglyceride-rich lipoprotein remnants (abbreviated as remnants) were measured as remnant-like particles-cholesterol (RLP-C) and triglyceride (RLP-TG) in two groups of Japanese subjects who died suddenly and unexpectedly due to coronary or non-coronary causes. Our study on the postmortem plasma analysis of lipids and lipoproteins indicated that RLP-C was most strongly correlated with the severity of the coronary atherosclerosis and to be the best predictor among various parameters. Furthermore, RLP-TG appeared to be highly associated with the risk of sudden coronary event or death, especially in cases without advanced coronary atherosclerosis, which might be associated with clinical events as coronary spasm or thrombosis. Biological activities of RLP from postmortem plasmas of sudden coronary death cases showed strong effects on platelet aggregation and impaired vasorelaxation in vitro. RLP determined as RLP-TG might affect on the process of spasm or on the formation of thrombus in the coronary artery at the time of sudden coronary death, independent of the severity of coronary atherosclerosis. These data might be clinically important to predict or to prevent sudden coronary death. The studies were conducted as followed: 1) Separation, purification and quantitative analysis of remnants from postmortem plasma. 2) Isolation and characterization of remnants from postmortem plasma. 2-1) Assessment of the methods of TG measurement. 2-2) Characterization of remnants by HPLC methods. 2-3) Characterization of remnants by electrophoresis. 2-4) Electron microscopical observation of remnants. 3) Lipid and lipoprotein analysis of sudden coronary death and control cases. 3-1) Lipid and lipoprotein levels of sudden coronary death and control cases. 3-2) Plasma remnant levels in the postprandial state. 3-3) Severity of coronary atherosclerosis and plasma lipid and lipoprotein levels, especially remnant levels. 3-4) Sudden coronary death cases without advanced coronary atherosclerosis and their plasma lipid, lipoprotein levels, especially remnant levels. 4) Biological activities of the remnants. 4-1) Endothelium-dependent vasodilator function in the coronary artery. 4-2) Aggregation of human blood platelets by remnants. 5) Fatty acids analysis of remnants from sudden coronary death cases. 6) Immuno-histochemical examination of various apo-lipoproteins on the coronary artery. 7) Gene analysis of plasma lipid metabolites.

An autopsy case of traumatic sinus thrombosis.

A 38-year-old male slipped accidentally and fell from a height of 4.6 m, and was admitted to a hospital. A radiograph indicated a linear fracture of the parietal bone across the sagittal sutura, and a computed tomography scan of the head showed severe subdural hematoma on both parietal sides, so an operation was performed to remove the hematoma. Five hours after the operation, brain death due to a cerebral herniation occurred, and he died six days later. Autopsy revealed a linear fracture of the parietal bones, which crossed obliquely the sagittal sutura. A slightly lacerated wound of the dura mater was seen on the sagittal sutura, from where the latter half of that point to the left and right transverse sinuses were occluded completely with thrombosis. The brain was markedly swollen. From these findings, the victim was considered to have died from acute cerebral swelling due to traumatic thrombosis of the superior sagittal sinus.

Electroencephalographical analysis of acute paraquat poisoning.

The disturbances in the central nervous system of rabbits induced by gramoxon poisoning were studied by examination of subcortical electroencephalograms (EEGs) and power spectral analysis of EEGs. The following results were obtained. Administration of the fatal gramoxon (2.0 ml/kg i.p.) resulted in increases of slow frequency discharges from the reticular formation (RF), and from the hippocampus (Hpc) and sensorimotor cortex (Cm) after about 5 minutes and 20 minutes, respectively, detected by power-spectrum array. After about 30 to 40 minutes, the discharges from the Cm changed to rapid frequency discharges. The discharges from the Hpc and Cm decreased after about 50 to 60 minutes, and increased again in the agonal stage, and then seizure discharges developed. Soon after administration of gramoxon solution, the heart rate and respiratory rate increased and the PCO2, base excess (BE) and [HCO3-] decreased transiently. These findings indicate a shift to acute respiratory alkalosis and thereafter a shift to metabolic acidosis. Subsequently, the blood pressure, heart rate, respiratory rate, pH, BE and [HCO3-] decreased and the PCO2 increased. These findings indicate a shift to respiratory and metabolic acidosis. After about 70 minutes, the EEGs from all leads became almost flat, respiration ceased, and the blood pressure decreased to zero. After administration of gramoxon solution, the paraquat concentration in the blood increased rapidly. These results suggest that rapid increase in the paraquat concentration in the blood after gramoxon administration affects the central nervous system from an early stage.