Human C4orf14 interacts with the mitochondrial nucleoid and is involved in the biogenesis of the small mitochondrial ribosomal subunit.

The bacterial homologue of C4orf14, YqeH, has been linked to assembly of the small ribosomal subunit. Here, recombinant C4orf14 isolated from human cells, co-purified with the small, 28S subunit of the mitochondrial ribosome and the endogenous protein co-fractionated with the 28S subunit in sucrose gradients. Gene silencing of C4orf14 specifically affected components of the small subunit, leading to decreased protein synthesis in the organelle. The GTPase of C4orf14 was critical to its interaction with the 28S subunit, as was GTP. Therefore, we propose that C4orf14, with bound GTP, binds to components of the 28S subunit facilitating its assembly, and GTP hydrolysis acts as the release mechanism. C4orf14 was also found to be associated with human mitochondrial nucleoids, and C4orf14 gene silencing caused mitochondrial DNA depletion. In vitro C4orf14 is capable of binding to DNA. The association of C4orf14 with mitochondrial translation factors and the mitochondrial nucleoid suggests that the 28S subunit is assembled at the mitochondrial nucleoid, enabling the direct transfer of messenger RNA from the nucleoid to the ribosome in the organelle.

Actin and myosin contribute to mammalian mitochondrial DNA maintenance.

Mitochondrial DNA maintenance and segregation are dependent on the actin cytoskeleton in budding yeast. We found two cytoskeletal proteins among six proteins tightly associated with rat liver mitochondrial DNA: non-muscle myosin heavy chain IIA and ß-actin. In human cells, transient gene silencing of MYH9 (encoding non-muscle myosin heavy chain IIA), or the closely related MYH10 gene (encoding non-muscle myosin heavy chain IIB), altered the topology and increased the copy number of mitochondrial DNA; and the latter effect was enhanced when both genes were targeted simultaneously. In contrast, genetic ablation of non-muscle myosin IIB was associated with a 60% decrease in mitochondrial DNA copy number in mouse embryonic fibroblasts, compared to control cells. Gene silencing of ß-actin also affected mitochondrial DNA copy number and organization. Protease-protection experiments and iodixanol gradient analysis suggest some ß-actin and non-muscle myosin heavy chain IIA reside within human mitochondria and confirm that they are associated with mitochondrial DNA. Collectively, these results strongly implicate the actomyosin cytoskeleton in mammalian mitochondrial DNA maintenance.

Effects of CSN1S2 Genotypes on Economic Traits in Chinese Dairy Goats.

The aim of this study was to investigate allele frequencies at the CSN1S2 locus in two Chinese dairy goat breeds and the effects of its variation on dairy goat economic traits. Seven hundred and eight goats from Xinong Saanen (XS, n = 268) and Guanzhong (GZ, N = 440) breeds were selected. The milk samples of 268 XS goats were collected during the middle of lactation, body size parameters (708 goats) and daily milk yield (202 goats) were registered. The RFLP (restriction fragment length polymorphism) and SSCP (single strand conformation polymorphism) were used to detect the polymorphisms in CSN1S2. The Hardy-Weinberg (HW) equilibrium and the associations between body size, milk yield and composition and the genotypes were calculated. The results revealed that only A and F CSN1S2 alleles were found in the two Chinese dairy goat breeds. Allelic frequencies of A and F were 0.795, 0.205 and 0.739, 0.261 in Xinong Saanen and Guanzhong population respectively. Xinong Saanen breed was in Hardy-Weinberg equilibrium, while Guanzhong breed deviated from Hardy-Weinberg equilibrium (p<0.05). The association of polymorphism with economic traits indicated that the goats with FF genotype have higher milk fat and total solid concentration than those with AA and AF genotypes (p<0.05).

Characterization of cytochrome b diversity in Chinese domestic horses.

Previous mitochondrial DNA (mtDNA) D-loop and microsatellite studies have shown that Chinese horses have multiple maternal origins and high genetic diversity. To better characterize maternal genetic origins and diversity of Chinese domestic horses, we conducted a comprehensive analysis of 407 complete 1140 bp sequences of the horse mitochondrially encoded cytochrome b (CYTB) gene, including 323 horses from 13 Chinese indigenous breeds and 84 reference sequences from GenBank. A total of 114 haplotypes were identified, of which 73 appeared among the 13 Chinese horse breeds. The high mitochondrially encoded cytochrome b haplotypic diversity suggests multiple maternal origins in Chinese horses.

The turnover rate of gamma-aminobutyric acid in the nuclei of telencephalon: implications in the pharmacology of antipsychotics and of a minor tranquilizer.

The turnover rate of GABA is measured in substantia nigra, globus pallidus, N. accumbens, and striatum of rats injected with muscimol, a potent GABA agonist, and diazepam. The similarity of action of the two drugs on GABA turnover further supports the theory that diazepam acts as a GABA-mimetic drug. Haloperidol and clozapine affect GABA turnover differently in different nuclei. Haloperidol decreases GABA turnover in caudate but does not affect that in substantia nigra, whereas clozapine increases GABA turnover in both areas. However, both drugs accelerate GABA turnover in globus pallidus and N. accumbens. It is suggested that an increase of GABA turnover and perhaps of GABA release in striatum and substantia nigra may account for the lack of tardive dyskinesia and extrapyramidal side effects of clozapine.

Anterior operculum syndrome.

The anterior operculum syndrome (AOS) is a well-defined clinical entity that has received little attention in the English literature. We report the clinical and CT findings in 3 cases of AOS; 2 were caused by bilateral cerebral infarctions secondary to bilateral internal carotid occlusion and 1 by the residual effects of viral encephalitis. Although there was variability in the range of deficits found in our cases, each of these patients presented with characteristic facio-pharyngo-glosso-masticatory diplegia with a dramatic automatic-voluntary movement dissociation. This syndrome deserves attention for its characteristic anatomic and prognostic implications.

Evidence for an involvement of GABA in the mediation of the cerebellar cGMP decrease and the anticonvulsant action diazepam.

Subcutaneous injections of isoniazid or picrotoxin increase the cerebellar content of 3',5'-cyclic guanosine monophosphate (cGMP) without changing the 3',5'-cyclic adenosine monophosphate cAMP. This increase was dose dependent and the threshold for the cGMP increase was lower than that for convulsions. In cerebellum the increase of cGMP content elicited by isoniazid but not that caused by picrotoxin was paralleled by a decrease of GABA content. Diazepam doses starting from 1.74 mumol/kg intraperitoneally produced a dose dependent decrease of cerebellar cGMP concentration without changing cAMP or GABA content. Smaller doses of diazepam (0.5 mumol/kg i.p.)failed to decrease the basal cerebellar content of cGMP. However, this dose of diazepam antagonized the increase of cGMP produced by isoniazid but not that produced by picrotoxin. Higher doses of diazepam were necessary to block the increase of cerebellar cGMP elicited by picrotoxin. Low doses of diazepam (0.14 mumol/kg) antagonized the convulsions in 50% of the rats injected with 3.3 mmol/kg of isoniazid. The doses of diazepam required to block picrotoxin, pentylenetetrazol or strychnine convulsions were 7, 25 and 40 times higher than those required to block isoniazid convulsions, respectively. Desmethyldiazepam, chloridiazepoxide, oxazepam were also several times more potent in antagonizing isoniazid than picrotoxin, pentylenetetrazol, or strychnine convulsions. In contrast, barbiturates were equipotent against all the convulsants studied. These experiments suggest that diazepam may act in the CNS either by altering the disposition of endogenous GABA or by mimicking the action of GABA at specific synaptic receptors.

EMLA cream and lidocaine local injection in the treatment of extravenous thiopental injection--a case report.

Thiopental extravasation which would cause tissue edema and necrosis in rapid progression by chemical reaction and vascular spasm is a potentially serious complication in anesthesia. Early diagnosis and treatment may bear a favorable outcome. A patient who sustained thiopental extravasation and received local injection of lidocaine and local application of EMLA (Eutectic Mixture of Local Anesthetics) for treatment with excellent results is presented hereunder.

Anesthetic management in a parturient with progressive systemic sclerosis during cesarean section--a case report.

This case report concerns a successful Cesarean section (C/S) delivery in an expectant woman affected with progressive systemic sclerosis (PSS) with clinical manifestations of severe pulmonary hypertension (PH), cor pulmonale, severely restrictive ventilatory impairment, pregnancy-induced hypertension (PIH), and esophageal dysfunction under general anesthesia (GA). This is an extremely rare condition in obstetrics and the victim is usually in a great peril of conception, delivery, surgery and anesthesia because of poor pulmonary and cardiac reserves. We herewith reported our experience in two GAs given uniquely to the same patient who was affected with the disorder and discuss the problem.

Failure of prevention against postoperative vomiting by ondansetron or prochlorperazine in patients undergoing gynecological laparoscopy.

BACKGROUND: Ondansetron has been approved for the treatment and prevention of postoperative emesis. Since it is presumably considered to possess potent antiemetic effect with fewer side effects, the administration of ondansetron to inhibit emesis in patients following gynecological laparoscopic surgery might be recommendable. Hence, we examined the effects of intravenous ondansetron at dosage of 4 and 8 mg in comparison with intravenous prochlorperazine at 5 mg and placebo. METHODS: A total of 120 patients were allocated randomly into 3 groups. Group 1 patients who served as control were given NaCl 0.9% 4 mL (placebo) intravenously (i.v.); patients in group 2 and group 3 were given ondansetron 4 mg ondansetron 8 mg i.v. respectively; patients in group 4 were given prochlorperazine 5 mg i.v. Premedication was omitted. RESULTS: Logistic regression analysis adjusted for prognostic factors revealed no significant difference between 5 mg prochlorperazine group and 4 mg or 8 mg ondansetron group as compared over the 24 h study period. CONCLUSIONS: The results of this study suggest that i.v. 4 or 8 mg ondansetron and 5 mg prochlorperazine were not effective in prevention of postoperative emesis in patients undergoing gynecological laparoscopy. Since the cost of ondansetron is high, its routine use for prevention against postoperative nausea and vomiting is not be recommended clinically because of its uncertain benefit.

Truncal rigidity as a result of epidural sufentanil--a case report.

It is well known that intravenous opioids may cause truncal rigidity. To the best of our knowledge truncal rigidity induced by epidural opioid has never been reported. Recently, we came across an accident of truncal rigidity following epidural sufentanil. The victim was a 65-year-old female who received cholecystectomy, choledochotomy, and cholangiography. For post-operative pain control, an epidural catheter was inserted cephalad [corrected] at L1-2 interspace with a length of 4 cm of the catheter retained in the epidural space. The epidural catheter was secured and tested for correct placement with 3 ml of 2% lidocaine with 1:200,000 epinephrine prior to induction of general anesthesia. No opioid was ever given in the operative course. When the patient was fully awake and complained of wound pain in the recovery room 50 mg of sufentanil in 10 ml normal saline was given via the epidural catheter after a negative evacuation test. About one minute after the epidural shot, she was found to lose consciousness without any slightest warning sign. Truncal rigidity and locked jaw that followed entailed respiratory arrest and rapid deterioration of oxygenation which evidenced a life-threatening airway emergency. It spite of our efforts we could not manage to ventilate her with ordinary means. It was not until the administration of 80 mg of succinylcholine and oral endotracheal intubation could an adequate ventilation be reestablished. She regained spontaneous breathing 15 min after the episode but for safety's sake she remained intubated for 6 h until the dissipation of analgesia. Another test dose was attempted, which reconfirmed that the epidural catheter was in proper position. She stayed in the recovery room for 24 h and returned to ward in satisfactory condition. The incidence disclosed that epidural sufentanil even with a dose as small as 50 micrograms could cause truncal rigidity. Thus when epidural sufentanil is applied for post-operative pain control constant vigilance is necessary in order to avoid accident.

Pre-anesthetic oral clonidine is effective to prevent post-spinal shivering.

BACKGROUND: Shivering is a common event during spinal anesthesia. Customarily we just treat it rather than prevent it. This study was designed to evaluate the efficacy of oral clonidine as a premedication to prevent post-spinal shivering. METHODS: One hundred males of ASA physical status I-III, aged above 40, scheduled for elective urological surgery under spinal anesthesia, were included in this study. All participants were randomly divided into the clonidine and control groups. They received either oral clonidine 150 micrograms (n = 48) or placebo (n = 52) 90 min before spinal anesthesia in a double-blind fashion. Spinal blockade was induced with heavy bupivacaine to a dermatomal level near T10. The shivering was graded as: none, no perceptible tension of muscles observed; mild, slight muscle tonus (masseter muscle); moderate, real shivering (proximal muscles); and severe, generalized shivering (whole body). The tympanic membrane temperature was recorded 30 min after spinal anesthesia. Data were expressed as mean +/- standard deviation. Chi-square and Student's t-test were used. A p value less than 0.05 was considered statistically significant. RESULTS: The incidence of post-spinal shivering, which was graded as none, mild, moderate, and severe, showed statistically significant differences (p < 0.05) between clonidine 150 micrograms and placebo (83% vs. 42%, 10% vs. 6%, 10% vs. 19%, 0% vs. 33%, respectively) during the 30 min immediately after spinal anesthesia. The respective mean tympanic temperature in oral clonidine and placebo groups showed no difference (clonidine vs. control = 35.9 +/- 0.8 degrees C vs. 35.9 +/- 0.7 degrees C). CONCLUSIONS: Pre-anesthetic medication with oral clonidine 150 micrograms is effective to prevent post-spinal shivering in patients undergoing elective urological surgery.