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Biomedical subjects

C C Mao

Publications and source records attributed to C C Mao.

At least 19 recordsLinked to original sources

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.

Adult↗

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.

Administration, Oral↗

Exon/intron organization, chromosome localization, alternative splicing, and transcription units of the human apolipoprotein E receptor 2 gene.

Apolipoprotein E receptor 2 is a recently identified receptor that resembles low and very low density lipoprotein receptors. Isolation and characterization of genomic clones encoding human apolipoprotein E receptor 2 revealed that the gene spans approximately 60 kilobases and contains 19 exons. The positions of the exon/intron boundaries of the gene are almost identical to those of low and very low density lipoprotein receptors. Fluorescent in situ hybridization of human chromosomes revealed that the gene is located on chromosome 1p34. Isolation of a cDNA encoding a variant receptor and reverse transcription-polymerase chain reaction indicate the presence of multiple variants with different numbers of cysteine-rich repeats in the binding domain of the receptor. We also found a variant receptor lacking a 59-amino acid insertion in the cytoplasmic domain. The transcription start site was mapped to the position 236 base pairs upstream of the AUG translation initiator codon by primer extension analysis. Sequence inspection of the 5'-flanking region revealed potential DNA elements: AP-2, GC factor, PEA3, and Sp1. The minimal promoter region and a region required for nerve growth factor inducibility in PC12 cells were also determined.

Alternative Splicing↗

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.

Anesthetics, Intravenous↗

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.

Adult↗

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.

Abdomen↗

Adenosquamous cell carcinoma of the cervix--a clinical analysis of 23 cases.

From January 1976 through December 1985, 895 patients with cervical carcinoma were treated with radical hysterectomy and pelvic lymphadenectomy. The surgical specimens of 23 cases were proved to be adenosquamous cell carcinoma, the incidence being 2.6%. Among them, 15 were at stage IB, 7 were at stage IIA and one was at stage IIB. The overall 5-year survival rate was 55.0% and there was no difference between patients at stage IB and IIA. During the same period the 5-year survival rate of squamous cell carcinoma was 87.5% for patients at stage IB and 75.0% for patients at stage IIA. Pelvic lymph node metastasis and parametrial involvement are considered to be poor prognostic factors. When metastasis or invasion happens, the metastatic or invasive lesions can be found in the form of pure squamous carcinoma or adenocarcinoma. Postoperative adjuvant radiotherapy (external irradiation plus brachytherapy) seems to be effective in preventing recurrence. Chemotherapy (PVB regimen) needs more clinical evaluation. In this study, when metastasis or recurrence developed, the response to radiotherapy and/or chemotherapy were poor and 75% of patients died within one year.

Adenocarcinoma↗

Vaginal intraepithelial neoplasia: diagnosis and management.

A review of 42 patients with vaginal intraepithelial neoplasia (VAIN) seen in Gynecologic Department of Veterans General Hospital-Taipei between 1971 and 1987 was made. The patients were from 36 to 79 years of age with a mean 58 of years. Fifteen patients (36%) had synchronous cervical neoplasia, 26 cases (62%) had antecedent cervical neoplasia and one had undergone operation for uterine myoma. Twenty-four of 27 patients with VAIN alone presented an abnormal Papanicolou smear. The upper one third of the vagina was the most common site of the lesion. Multifocal lesions were demonstrated in 58% cases while unifocal disease accounted for 42% cases who had VAIN subsequent to cervical neoplasia. Colposcopically directed biopsies were used for diagnosis in 13 patients. White epithelium and punctation were the most common findings of VAIN. While the results of different treatments were reviewed, surgical excision was found to be the most frequently employed method and radiotherapy was the second. Both were effective and 5 patients died of vaginal disease. On account of the relatively benign nature of VAIN than that of invasive vaginal cancer and the need for preservation of a functional vagina, more conservative approaches, for example, topical 5-Fluorouracil application and carbon dioxide laser vaporization, are discussed.

Adult↗

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.

Adult↗

Movement disorders in multiple sclerosis.

Movement disorders other than cerebellar tremor are rare clinical manifestations of multiple sclerosis (MS). Two cases of parkinsonism and a case of chorea associated with MS are reported, and the literature is reviewed.

Adult↗

Synaptic connections from large muscle afferents to the motoneurons of various leg muscles in man.

Cross-correlations between stimuli delivered to peripheral nerves and the discharges of single, voluntarily activated, motor units can provide information about facilitatory and inhibitory projections to single spinal motoneurons in man. The projection frequency, under the given circumstances, of a facilitatory or inhibitory pathway can be obtained from the proportion of the sampled motor units of a given muscle showing the facilitatory or inhibitory effect. Deductions about the shape and relative amplitude of the underlying post-synaptic potentials can be made from the profile of the changes in firing probability. This technique has been used to explore the projections of low threshold muscle afferents to motoneurons of various leg muscles in man. Homonymous facilitation was demonstrated to all the sampled motor units of soleus (SOL), medial gastrocnemius (MG), tibialis anterior (TA) and vastus medialis (VM) and is presumed to represent the effects of the composite muscle spindle group Ia EPSP. Heteronymous facilitation was demonstrated between certain synergists. The projection frequency was less and the magnitude of the change in firing probability was smaller than for homonymous facilitation. SOL motoneurons, however, were not facilitated from low threshold afferents in the medial gastrocnemius nerve. Reciprocal inhibition was demonstrated between certain antagonists. The majority of the sampled motor units of SOL, however, were facilitated from low threshold afferents in the common peroneal nerve. The threshold for this facilitation was higher than for the homonymous facilitation elicited from this nerve and thus a different class of afferents and/or intercalated interneurons may be involved. There are projections across the knee joint in man. Motor units in vastus medialis (VM) were facilitated from low threshold afferents in the common peroneal nerve. It is likely that these reflex connections, which differ from those in other species, reflect the functional relationships between various lower limb muscles in man.

Adult↗

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.

Aminobutyrates↗

Application of principles of steady-state kinetics to the estimation of gamma-aminobutyric acid turnover rate in nuclei of rat brain.

13C-labeled glucose (50 mumol/kg/min) was infused into the rat tail vein for 10 minutes. The animals were killed by a microwave beam focused to the skull at various times after the infusion. In brain nuclei the concentrations of glutamate and gamma-aminobutyric acid (GABA) and their enrichment in 13C were measured by mass fragmentography. The results showed that in the five brain areas studied, substantia nigra contained the highest GABA concentration, followed by globus pallidus, N. accumbens, deep cerebellar nuclei, N. caudatus and cerebellar cortex. The concentrations of glutamate and GABA were comparable in some nuclei (substantia nigra and globus pallidus), but not in others. The glutamate content was 3 to 6 times greater than GABA content in cerebellum (cortex and nuclei) N. accumbens and N. caudatus. The turnover rates of GABA in substantia nigra, globus pallidus, N. caudatus and N. accumbens were calculated by applying principles of steady-state kinetics to the changes with time in the 13C enrichment of glutamic acid and GABA. In substantia nigra, N. accumbens and N. caudatus, the percentage of 13C incorporation into glutamic acid and GABA reached its maximum 10 to 15 minutes after the infusion. In N. caudatus and N. accumbens, the percentage of 13C incorporation into GABA was higher than that in substantia nigra and globus pallidus. The turnover rates of GABA were very similar in N. caudatus, N. accumbens, substantia nigra and globus pallidus (385-562 nmol/mg of protein per hr), but the turnover times were much faster in N. caudatus and N. accumbens. It must be kept in mind that in N. caudatus and N. accumbens the glutamate pool was several-fold greater than that of GABA. Since the data obtained indicate that the compartmentation is more complicated than in the model assumed for turnover estimations, this method should be used only for comparative purposes in drug studies. The validity of this method to obtain absolute measurements of GABA turnover remains to be documented.

Aminobutyrates↗