Acute zolpidem overdose--report of two cases.

This report describes two cases of acute zolpidem overdose. The decedent in the first case was a 36-year-old female found dead in bed in her secured home. She had a history of psychiatric illness, including paranoid disorder, depression with panic episodes, and post-traumatic stress disorder. She was treated with risperidone and sertraline. Nine months prior to her death, the decedent was also prescribed zolpidem (Ambien). The postmortem examination revealed white foam within the larynx and upper trachea, which is indicative of pulmonary edema. Toxicological analyses of the urine showed the presence of caffeine, risperidone, and zolpidem. Subsequent quantitation of postmortem iliac serum revealed 5.6 microg/L of 9-hydroxyrisperidone and the following zolpidem concentrations: blood (subclavian), 4.5 mg/L; blood (iliac), 7.7 mg/L; vitreous humor, 1.6 mg/L; bile, 8.9 mg/L; urine, 1.2 mg/L; liver, 22.6 mg/kg; and gastric contents, 42 mg. The second case involved a 58-year old female, also found dead in bed, with white foam around her mouth. The decedent had a 25-year history of hypertension and mental illness--manic depression and schizophrenia. She was medicated with carbamazepine, naproxen, risperidone, and zolpidem. The postmortem examination revealed cardiomegaly, pulmonary edema, hepatomegaly, mild coronary atherosclerosis, and no signs of trauma. Toxicological analyses of the urine showed the presence of zolpidem and carbamazepine and metabolite. Zolpidem concentrations were as follows: blood (iliac), 1.6 mg/L; vitreous humor, 0.52 mg/L; bile, 2.6 mg/L; liver, 12 mg/kg; and gastric contents, 0.9 mg. The zolpidem blood concentrations of these cases are consistent with those of the previously published fatalities. The blood/vitreous humor ratios of zolpidem were 2.81 (subclavian) and 4.81 (iliac) in the first case and 3.08 (iliac) in the second case. These ratios, along with the sampling times of blood and vitreous humor for both cases, are not conclusive to indicate a definitive presence or absence of postmortem drug redistribution of zolpidem. The cause of death for both cases was determined to be acute zolpidem overdose, and manner of death was suicide.

Nucleotide sequence of the mitochondrial genome of Paramecium.

The nucleotide sequence for 40,469 bp of the linear Paramecium aurelia mitochondrial (mt) genome is presented with the locations of the known genes, presumed ORFs, and their transcripts. Many of the genes commonly encoded in mt DNA of other organisms have been identified in the Paramecium mt genome but several unusual genes have been found. Ribosomal protein genes rps14, rps12, and rpl2 are clustered in a region that also contains two other genes usually found in chloroplasts, but rpl14 is over 16 kbp away. The ATP synthase gene, atp9, is encoded in this mt genome, but the atp6, atp8, and COIII genes have not been identified. All of the identified genes are transcribed. Many mono- and poly- cistronic transcripts have been detected which cover most of the genome, including large regions where genes have yet to be identified. Based on sequence comparisons with known tRNAs, only those for phe, trp, and tyr are encoded in Paramecium mt DNA.

Analysis of NADH dehydrogenase proteins, ATPase subunit 9, cytochrome b, and ribosomal protein L14 encoded in the mitochondrial DNA of Paramecium.

The mitochondrial (mt) encoded ndh1, ndh3, ndh4, ndh5, rpl14, cyt b and atp9 gene products were identified by sequence comparisons with known proteins. Amino acid sequence comparisons between predicted Paramecium mt gene products and proteins in current databases were quantitated approximately by the means of similarity scores for pairs of aligned sequences. The comparisons show that the Paramecium gene products are very divergent from all others with the exception of those from a closely related ciliate, Tetrahymena. The similarity scores of comparisons between a Paramecium mt DNA encoded protein, cytochrome b for example, and the homologous protein from a group of organisms as diverse as other protozoans, vertebrates, fungi, plants, and prokaryotes were all about the same. The Paramecium gene products appear to be equally divergent from proteins representing a number of different kingdoms and organelles.

Mature rat testis contains a high molecular weight species of phosphatidylinositol transfer protein.

Immunoblot analysis of a rat testis cytosol fraction revealed two proteins which reacted with a polyclonal rabbit antibody to bovine phosphatidylinositol transfer protein. These two proteins were separated by anion exchange and molecular sieve column chromatographic procedures and shown to catalyze the transfer of phosphatidylinositol and phosphatidylcholine between populations of small unilamellar vesicles. One protein was identified as the phosphatidylinositol transfer protein detectable in 16 other rat tissues and many eukaryotic species; the other phosphatidylinositol transfer protein was unique to testis. The molecular masses of the proteins, determined under denaturing electrophoretic conditions, were 35 and 41 kDa, respectively. When testis was examined in animals from birth to six weeks of age, the 35-kDa protein was present throughout, while the 41-kDa protein first appeared during week 4 and increased to adult levels by week 6; a small yet significant increase in tissue phosphatidylinositol transfer activity accompanied this expression of the testis-specific protein. Selective destruction of Leydig cells by ethylene dimethanesulfonate did not cause any detectable loss of the 41-kDa phosphatidylinositol transfer protein. The structural and catalytic relationships between the two testicular phosphatidylinositol transfer protein species remain to be elucidated.

An unusual region of Paramecium mitochondrial DNA containing chloroplast-like genes.

Based on DNA and amino acid comparisons with known genes and their products, a region of the Paramecium aurelia mitochondrial (mt) genome has been found to encode the following gene products: (1) photosystem II protein G (psbG); (2) a large open reading frame (ORF400) which is also found encoded in the chloroplast (cp) DNA of tobacco (as ORF393) and liverwort (as ORF392), and in the kinetoplast maxicircle DNA of Leishmania tarentolae (as ORFs 3 and 4); (3) ribosomal protein L2 (rpl2); (4) ribosomal protein S12 (rps12); (5) ribosomal protein S14 (rps14); and (6) NADH dehydrogenase subunit 2 (ndh2). All of these genes have been found in cp DNA, but the psbG gene has never been identified in a mt genome, and ribosomal protein genes have never been located in an animal or protozoan mitochondrion. The ndh2 gene has been found in both mitochondria and plastids. The Paramecium genes are among the most divergent of those sequenced to date. Two of the genes are encoded on the strand of DNA complementary to that encoding all other known Paramecium mt genes. No gene contains an identifiable intron. The rps12 and psbG genes are probably overlapping. It is not yet known whether these genes are transcribed or have functional gene products. The presence of these genes in the mt genome raises interesting questions concerning their evolutionary origin.

Tissue distribution, purification and characterization of rat phosphatidylinositol transfer protein.

Phosphatidylinositol transfer activity is measured in cytosol fractions prepared from 13 rat tissues; specific activity is highest in brain and lowest in adipose and skeletal muscle. Based upon electrophoretic analysis phosphatidylinositol transfer protein is purified to homogeneity from whole rat brain. The protein has a molecular weight of 36,000 and exists as a mixture of species having isoelectric points of 4.9 and 5.3. In a vesicle-vesicle assay system, the intermembrane transfer rate is greatest for phosphatidylinositol and less by a factor of 2 for phosphatidylcholine; transfer of phosphatidylethanolamine, phosphatidylserine or sphingomyelin is not observed. Using a polyclonal rabbit antibody against bovine phosphatidylinositol transfer protein, immunologic cross-reactivity is noted between the rat protein and other mammalian phosphatidylinositol transfer proteins. A strong correlation is established between a tissue's capacity for phosphatidylinositol transfer and the amount of immunoreactive transfer protein seen in that tissue. Purified phosphatidylinositol transfer protein is capable of transporting newly synthesized phosphatidylinositol molecules from rat brain microsomes to small unilamellar phospholipid vesicles. The results are discussed within the context of cellular phosphoinositide metabolism and the maintenance of the metabolically responsive pool of phosphatidylinositol in the plasma membrane.

Regional distribution in rat brain of phosphatidylinositol and phosphatidylcholine synthetic and intermembrane transfer activities.

Rat brains were dissected into major anatomical regions, including caudate nucleus, cerebellum, inferior and superior colliculi, cortex, hippocampus, olfactory bulb, pituitary gland, pons-medulla, spinal cord and thalamus. Tissue fractionation yielded microsomes and cytosol which were assayed for several phospholipid synthetic enzyme activities; using a vesicle-vesicle system the cytosol fractions were also examined for intermembrane phospholipid transfer activities. For the metabolism of phosphatidylinositol, specific activities were determined for CTP: phosphatidate cytidylyltransferase and CDP-diacylglycerol: inositol phosphatidyltransferase. Regions with high phosphatidylinositol synthetic activity were pituitary gland, pons-medulla, caudate and thalamus. For the metabolism of phosphatidylcholine the measured enzymes were CTP: phosphocholine cytidylyltransferase and CDP-choline: diacylglycerol cholinephosphotransferase. These enzymes showed the highest activity in the colliculi, olfactory bulb, pituitary gland and pons-medulla. The pons-medulla cytosol fraction contained the highest level of phosphatidylinositol transfer activity, while the colliculi and pons-medulla had the highest level of phosphatidylcholine transfer activity. In contrast, the pituitary gland displayed the lowest levels of both phosphatidylinositol and phosphatidylcholine transfer activity. The relationships between synthetic and transfer activities are discussed in terms of regional phospholipid metabolism.