Multidrug overdose-induced myoclonus complicated by rhabdomyolysis: possible role and mechanism of muscle toxicity of risperidone.

WHAT IS KNOWN AND OBJECTIVE: Atypical antipsychotics are considered safe for treating schizophrenia and are rarely reported to induce rhabdomyolysis. CASE SUMMARY: Here is a case of a woman with schizophrenia who developed rhabdomyolysis following overdose of risperidone, trihexyphenidyl and benzodiazepines. There was no recurrence of rhabdomyolysis when above medication was resumed with therapeutic dose. WHAT IS NEW AND CONCLUSION: Multidrug overdose are common but are rarely reported to induce rhabdomyolysis. Overdose risperidone may increase the risk of rhabdomyolysis and need to be kept in mind.

Diphenhydramine dependence through deep intramuscular injection resulting in myonecrosis and prolonged QT interval.

WHAT IS KNOWN AND OBJECTIVE: Diphenhydramine (DPH) is a first-generation antihistamine, which is useful in treating allergic reaction, and is usually considered innocuous. We describe a retired nurse with history of depression, who began to develop drug-seeking behaviour after her first receiving of an intramuscular (IM) DPH injection due to urticaria. CASE SUMMARY: The 49-year-old patient had developed IM DPH dependence within 4 months. She needed to receive psychiatric inpatient treatment because of depressive mood, serious myonecrosis over injected sites, and prolongation of QT interval. WHAT IS NEW AND CONCLUSION: This is the first reported case of DPH dependence through the IM route. Second-generation antihistamines might be better choices for patients with psychiatric illness by reason of their lower effects on central nervous system and lower risk of abuse.

Association study of catechol-O-methyltransferase gene polymorphisms with schizophrenia and psychopathological symptoms in Han Chinese.

Although dysfunction of catechol-O-methyltransferase (COMT)-mediated dopamine transmission is implicated in the etiology of schizophrenia, the human COMT gene has not been associated consistently with schizophrenia. The purpose of this study was to investigate whether the COMT gene is associated with the development of schizophrenia and whether the polymorphisms of this gene influence the psychopathological symptoms in patients with schizophrenia. Fourteen polymorphisms of the COMT gene were analyzed in a case-control study of 876 Han Chinese individuals (434 patients and 442 controls). All participants were screened using a Chinese version of the modified Schedule for Affective Disorders and Schizophrenia-Lifetime Version (SADS-L) and all patients met the criteria for schizophrenia. Furthermore, pretreatment of psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS) in a subset of 224 hospitalized schizophrenia patients, who were drug-naÏve or drug-free, to examine the association between clinical symptomatology and COMT polymorphisms. No significant differences in allele or genotype frequencies were observed between schizophrenia patients and controls, for all variants investigated. Haplotype analysis showed that three haplotype blocks of the COMT gene were not associated with the development of schizophrenia. Moreover, these COMT polymorphisms did not influence the PANSS scores of schizophrenia patients. This study suggests that the COMT gene may not contribute to the risk of schizophrenia and to the psychopathological symptoms of schizophrenia among Han Chinese.

Neither single-marker nor haplotype analyses support an association between the dopamine transporter gene and heroin dependence in Han Chinese.

Much evidence suggests that dysfunction of dopamine transporter-mediated dopamine transmission may be involved in the pathophysiology of substance abuse and dependence. The aim of this study was to examine whether the dopamine transporter gene (DAT1; SLC6A3) is associated with the development of heroin dependence (HD) and whether DAT1 influences personality traits in patients with HD. Polymorphisms of DAT1 were analyzed in a case-control study of 1046 Han Chinese (615 patients and 431 controls). All participants were screened using a Chinese version of the modified Schedule of Affective Disorder and Schizophrenia-Lifetime and all patients met the criteria for HD. Furthermore, a Chinese version of the Tridimensional Personality Questionnaire (TPQ) was used to assess personality traits in the patient group and examine the association between their personality traits and DAT1 polymorphisms. Of the patient group, 271 completed the TPQ. No statistically significant differences in allele or genotype frequencies of all investigated variants between HD patients and controls were observed. In haplotype analyses, four haplotype blocks of DAT1 were not associated with the development of HD. These DAT1 polymorphisms did not influence novelty seeking and harm avoidance scores in HD patients. This study suggests that the DAT1 gene may not contribute to the risk of HD and specific personality traits in HD among the Han Chinese population.

Novel transmembrane GTPase of non-small cell lung cancer identified by mRNA differential display.

The technique of differential display was used previously to profile the gene expression patterns of non-small cell lung cancer, and several genes differentially expressed were thus identified. In this report, we demonstrate that a DNA fragment of 347-bp length, up-regulated in tumor tissues, showed 100% sequence similarity to human cDNA FLJ20693 for a 370-residue protein. The gene product of cDNA FLJ20693 was postulated to be a shorter isoform of transmembrane GTPase, termed TG370, based upon the results of searching for sequence homology. The nucleotide sequence alignment also indicated that the cDNA FLJ20693 and the cDNA for 741-residue human mitofusin 1 (TG741) possibly resulted from the event of alternative splicing from which a 127-bp region was retained in the latter. Analysis of the genome sequence confirmed the speculation that both cDNAs were mapped to the same chromosomal position composing of 18 exons, of which the 127-bp region of TG741 constituted exon 11. The alternative splicing in all lung cancer cell lines was also observed to occur nearly in all tissue specimens examined. The up-regulated expression of transmembrane GTPase was subsequently found in tumor tissues from at least five of seven non-small cell lung cancer patients. Also, a distinct PCR product was initially detected in cell line H520, and further sequence analysis identified the presence of the 86-bp region mapped to the genome sequence immediately followed by exon 10. To evaluate the retention of 86-bp region, it was found that, besides the predicted 486-bp product, an unexpected 332-bp product was concomitantly observed and identified as the result of exon 8 deletion. The expression and subcellular localization of the full-length TG741 and other shorter isoforms were detected by flow cytometry using three polyclonal antibodies. It was concluded that the full-length TG741 located at plasma membrane with its NH(2)-terminal domain exposed extracellularly and the shorter isoforms retained at cytosol. Finally, the up-regulation of transmembrane GTPase in tumor tissues was further illustrated using immunohistochemical staining.

Respiratory management after self-extubation.

BACKGROUND AND PURPOSE: Self-extubation is a potentially life-threatening event, but may also provide an opportunity to wean patients who should have been extubated earlier. The purpose of this study was to determine the risk factors for re-intubation after self-extubation. METHODS: The medical charts of 69 self-extubated patients treated in Shin Kong Hospital, Taipei, from September 1996 through August 1998 were reviewed. Demographic data, ventilator settings before self-extubation, arterial blood gas values, and the type of respiratory management used after self-extubation were examined to determine their association with re-intubation. RESULTS: Of the 69 self-extubated patients, 38 fared well without further ventilatory support after self-extubation. Four factors were associated with extubation outcome: 1) mean pre-extubation FiO2 (fraction of inspired oxygen), which was significantly higher in the re-intubated group (RI) than in the not re-intubated group (NRI) (0.48 vs 0.33, p = 0.002)--all self-extubated patients receiving an FiO2 of more than 0.40 were re-intubated; 2) PaO2/FiO2 (ratio of arterial oxygen tension to inspired oxygen concentration), which was lower in the RI group than in the NRI group (259.4 vs 346.4, p = 0.005); 3) requirement for assist/control ventilatory mode--patients needing this type of ventilatory support had a greater likelihood of reintubation than those requiring partial ventilatory support (odds ratio [OR], 3.790; confidence interval [CI], 1.055-13.621; p = 0.041); and 4) female sex (OR 0.188; CI 0.048-0.732; p = 0.016). CONCLUSIONS: About half of self-extubated patients may not require re-intubation. Pre-extubation FiO2, PaO2/FiO2, and ventilator mode, as well as gender, may be useful in determining the likelihood that a self-extubated patient will require re-intubation.