Cerebral effects of nitrous oxide during isoflurane-induced hypotension in the pig

We have studied the effects of nitrous oxide on cerebral blood flow (CBF), cerebral blood flow velocity (CBFV) and intracranial pressure (ICP) during isoflurane-induced hypotension in 10 pigs. CBF was measured using laser Doppler flowmetry, CBFV in the right middle cerebral artery was calculated using Doppler ultrasound and ICP was measured using an extradural ICP monitor. Each animal was studied under four conditions, examined sequentially: (i) mean intra-arterial pressure (MAP) 85 mm Hg, maintained with isoflurane, (ii) MAP 50-55 mm Hg, induced by isoflurane only, (iii) MAP 85 mm Hg, maintained with isoflurane and 50% nitrous oxide, and (iv) MAP 50-55 mm Hg, induced by isoflurane and 50% nitrous oxide. No significant differences were noted between conditions with respect to ICP. There was a significant difference in CBF during condition (ii) compared with (i) (mean 75(SD 21) vs 100(0)%) and during condition (iv) compared with (iii) (90(26) vs 109(13)%). Animals under condition (iv) exhibited a 20% reduction in CBFV compared with those under condition (iii) (57 vs 69 cm s-1). For animals under normotensive conditions, addition of nitrous oxide to isoflurane resulted in a 16% increase in CBFV (69 vs 60 cm s-1). Comparing isoflurane-induced hypotension ((ii) vs (iv)), there was no statistical difference in either CBF or CBFV on addition of 50% nitrous oxide. The correlation between changes in CBF and CBFV was not significant. We conclude that the use of nitrous oxide during isoflurane-induced hypotension has no significant effect on CBF, CBFV or ICP compared with the use of isoflurane alone.

Cardiotoxin II from Taiwan cobra venom, Naja naja atra. Structure in solution and comparison among homologous cardiotoxins

The three-dimensional structure in solution of cardiotoxin II, a membrane toxin from the venom of Taiwan cobra, Naja naja atra, was determined using 1H nuclear magnetic resonance spectroscopy and molecular modeling based on the hybrid distance geometry/dynamic simulated annealing technique. A complete sequence-specific proton assignment was obtained, and the secondary structures of the protein were determined from information on nuclear Overhauser effect connectivities, coupling constants, and hydrogen exchange were confirmed using the main-chain-directed strategy. Twelve simulated annealing structures found to be within a single family were selected based on the condition of distance constraint violation less than 0.02 nm and the dihedral angle violation less than 4 degrees. The average atomic root mean square deviation between the selected structures and their geometric average are 0.079 nm for the backbone atoms and 0.137 nm for all heavy atoms; they are 0.044 nm and 0.117 nm, respectively, when considering the secondary structural residues only. The molecule adopts a compact structure consisting of three major loops emerging from a globular head. These loops contain five strands to form double- and a triple-stranded antiparallel beta sheets. Comparisons are made between this structure and those of its homologous cardiotoxins in order to derive further information on their structural variations.

Hyponatremia and syndrome of inappropriate antidiuretic hormone secretion in adult spinal surgery

STUDY DESIGN

Patients undergoing spinal surgery were monitored for sodium balance, fluid type, and volume input and output during surgery and for the first 3 postoperative days.

OBJECTIVE

To prospectively document the true incidence of the syndrome of inappropriate antidiuretic hormone secretion and hyponatremia, and identify risk and protective factors for the development of the syndrome of inappropriate antidiuretic hormone secretion after spinal surgery.

METHODS

Data on medical history, surgical procedure, estimated blood loss, and volumes and types of intraoperative and postoperative fluids were collected on 116 consecutive spinal surgery patients during March to July 1992.

RESULTS

One hundred one spinal operations in 96 patients were evaluated. There were 48 males and 48 females, with a mean age of 52 years (range, 16 to 90 years). Hyponatremia developed in 45 (44.6%) patients. The etiology of hyponatremia was the syndrome of inappropriate antidiuretic hormone secretion in seven patients (6.9%), hypovolemia in 19 patients (18%), and other causes in six patients.

CONCLUSIONS

Spine patients are at risk for hyponatremia and the syndrome of inappropriate antidiuretic hormone secretion. The incidence of the syndrome of inappropriate antidiuretic hormone secretion was 6.9%. Serum sodium should be monitored postoperatively. Patients who undergo a revision operation have an approximately two to four times greater risk of being affected by the syndrome of inappropriate antidiuretic hormone secretion than those who have primary surgery.

Solution conformation of enopeptin A, a depsipeptide antibiotic, using 2D NMR and restrained molecular dynamics studies

Studies on the solution conformation of the cyclic depsipeptide antibiotic enopeptin A have been carried out using 2D NMR and molecular modelling techniques. The proton resonances of the antibiotic in DMSO-d6 have been assigned by the use of TOCSY and ROESY experiments. The interproton distance information obtained from the ROESY experiments have been used as the basis for elucidating the probable structures in solution. The restrained molecular dynamics technique was applied to calculate the structures in solution, and six resultant structures with fewer distance constraint violations were obtained that satisfy the experimental restraints very well. The conformation of the cyclic moiety of the molecules is well defined whereas the aliphatic chain segment is disordered.

Mutational spectrum in the p53 gene in bladder tumors from the endemic area of black foot disease in Taiwan

An elevated risk of bladder cancer has been reported in the endemic region of 'black foot disease' on the southwest coast of Taiwan and may be related to high arsenic levels in artesian well water. Thirteen urothelial tumors from this endemic region were examined for mutations in exons 5-8 of the p53 gene to identify the effects of possible exogenous factors at the DNA level. DNA was extracted from archival tissue after microdissection of tumors and analyzed by PCR-SSCP (polymerase chain reaction-based single strand conformation polymorphism), followed by direct sequencing. Eight cases (62%) showed mutations and 9 of the 10 point mutations observed were transitions. The type and position of the mutations were not significantly different when compared with the spectra of p53 mutations previously reported for transitional cell carcinomas (TCCs). However, two of the mutations were CGC-->CAC base changes at codon 175, a mutational hotspot for many tumor types but previously unreported in TCCs except in cases associated with inflammatory agents. Three of the tumors examined were found to contain double mutations, a relatively rare mutagenic event in human cancers. Our results suggest that the agents responsible for the high risk of bladder cancer in the black foot disease region may operate through an inflammation-based mechanism which increases the amount of DNA damage per mutagenic event.

Propofol does not reduce infarct volume in rats undergoing permanent middle cerebral artery occlusion

As propofol has been reported to have effects similar to those of thiopentone on cerebral blood flow, intracranial pressure and cerebral metabolic rate, we postulated that it might also have a protective effect on focal cerebral ischemia. This experiment was designed to test whether or not propofol can alter infarct volume resulting from permanent focal cerebral ischemia in rats. Forty-five rats were randomly assigned to three groups, all of which received xylaxine (5 mg kg-1 im) and ketamine (100 mg kg-1 ip) anesthesia. Rectal temperatures were controlled at 36-37 degrees C. A right temporal craniotomy was performed and the middle cerebral artery (MCA) was ligated with a 10-O suture. Both common carotid arteries (CCAs) were then occluded for 60 minutes using aneurysm clips. In Group 1 rats (n = 15), normal saline (1 ml kg-1 i.v.) was given right after MCA and CCAs ligation. In Group 2 rats (N = 15), propofol (10 mg kg-1 i.v. bolus) was given right after MCA and CCAs ligation. In Group 3 rats (n = 15), continuous intravenous infusion of propofol (16 mg kg-1 hr-1) was given for four hours following MCA and CCAs ligation, during which time mean arterial pressure was maintained approximately 90 mmHg. Twenty-four hours after ischemia, the brains were removed, frozen, sectioned and stained with 2% 2,3,5-triphenyltetrazolium chloride. The cross-sectional area of infarction on each brain slice was measured using computer imaging analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of focal ischemic brain injury on tail-flick latency in the rat

Tail-flick latency (TFL), a measure of response threshold to pain, was investigated in rats with focal ischemic brain injury resulting from middle cerebral artery occlusion (MCAO) as compared to sham and non-operative (non-op) groups on the 1st, 7th, 14th, 21st and 28th days following surgery or anesthesia. No significant differences were observed between MCAO and sham groups postoperatively, indicating focal ischemic insult induced by this model had no significant influence on TFL. Increased sensitivity to TFL in early postoperative period was shown when compared sham or MCAO with non-op group. The correlation between TFL and the time from surgery was statistically significant on the 1st and 7th days in sham group and the 1st, 7th and 14th days in MCAO group. We conclude that the focal ischemic injury resulting from middle cerebral artery occlusion that has no obvious neurologic effects does not alter pain threshold; however, surgical procedure increases postoperative sensitivity to pain stimulation.

Idiopathic autoimmune hemolytic anemia during pregnancy

A case of idiopathic autoimmune hemolytic anemia occurring during the third trimester of pregnancy is presented. The hemolytic process was quite severe in the mother but responded to steroid therapy. A healthy baby without evidence of hemolysis was delivered uneventfully through the vagina. We postulate the mechanism of the discuss the clinical picture, management of the disease and the possible effect on the fetus.

Two molecular pathways to transitional cell carcinoma of the bladder

Noninvasive transitional cell carcinomas of the bladder can have two distinct morphologies suggesting they contain different genetic alterations. Papillary transitional cell carcinomas (T(a) tumors) are often multifocal and only occasionally progress, whereas flat tumors (carcinomas in situ, CIS), frequently progress to invasive disease. We examined 216 bladder tumors of various stages and histopathologies for two genetic alterations previously described to be of importance in bladder tumorigenesis. Loss of heterozygosity of chromosome 9 was observed in 24 of 70 (34%) T(a) tumors but was present in only 3 of 24 (12%) CIS and dysplasia lesions (P = 0.04). In contrast, only 1 of 36 (3%) T(a) tumors contained a p53 gene mutation compared to 15 of 23 (65%) CIS and dysplasias (P < 0.001), a frequency comparable to that observed in muscle invasive tumors (25 of 49; 51%). The presence of p53 mutations in CIS and dysplasia could explain their propensities to progress since these mutations are known to destabilize the genome. Analysis of several tumor pairs involving a CIS and an invasive cancer provided evidence that the chromosome 9 alteration may in some cases be involved in the progression of CIS to more invasive tumors, in addition to its role in the initiation of T(a) tumors. However, the CIS and secondary tumor were found to contain different genetic alterations in some patients suggesting divergent progression pathways. Bladder carcinogenesis may therefore proceed through two distinct genetic alteration pathways responsible for generating superficial tumors with differing morphologies and pathologies.

Fibula osteoseptocutaneous flap for reconstruction of composite mandibular defects

The fibula osteoseptocutaneous flap is a versatile method for reconstruction of composite-tissue defects of the mandible. The vascularized fibula can be osteotomized to permit contouring of any mandibular defect. The skin flap is reliable and can be used to resurface intraoral, extraoral, or both intraoral and extraoral defects. Twenty-seven fibula osteoseptocutaneous flaps were used for composite mandibular reconstructions in 25 patients. All the defects were reconstructed primarily following resection of oral cancers (23), excision of radiation-induced osteonecrotic lesions (2), excision of a chronic osteomyelitic lesion (1), or postinfective mandibular hypoplasia (1). The mandibular defects were between 6 and 14 cm in length. The number of fibular osteotomy sites ranged from one to three. All patients had associated soft-tissue losses. Six of the reconstructions had only oral lining defects, and 1 had only an external facial defect, while 18 had both lining and skin defects. Five patients used the skin portion of the fibula osteoseptocutaneous flaps for both oral lining and external facial reconstruction, while 13 patients required a second simultaneous free skin or musculocutaneous flap because of the size of the defects. Four of these flaps used the distal runoff of the peroneal pedicles as the recipient vessels. There was one total flap failure (96.3 percent success). There were no instances of isolated partial or complete skin necrosis. All osteotomy sites healed primarily. The contour of the mandibles was good to excellent.

Purification and characterization of L-aminoacylase from Alcaligenes denitrificans DA181

The L-aminoacylase produced intracellularly by Alcaligenes denitrificans DA181 was purified to homogeneity. This enzyme had an apparent molecular weight of 80,000, and was composed of two subunits of identical molecular weight. Its isoelectric point was pH 5.1. The optimal reaction temperature and pH were 65 degrees C and 8.0, respectively. This enzyme showed specificity toward N-acetyl-derivative of hydrophobic L-amino acids with N-acetyl-L-valine as the favored substrate, followed by N-acetyl-L-alanine.

Continuous succinylcholine infusion and phase II block in short surgical procedures

The study was designed to observe continuous succinylcholine infusion and phase II block in short surgical procedures (duration < 90 min). The characteristics of neuromuscular blockade produced by continuous succinylcholine infusion were observed in 15 adult patients anesthetized with nitrous-oxide-isoflurane (0.7% end tidal concentration) and fentanyl, and were compared with the single-dose technique (n = 13) in recovery time. Ulnar nerve was stimulated supramaximally with repeated train-of-four (interval = 10 sec, frequency = 2 Hz) via surface electrodes at the wrist using an electromyographic monitor (Datex, Relaxograph, Finland). The infusion rate was adjusted to maintain the height of the first twitch (T1) in each train of four at 5-10% of control twitch height. The mean duration of infusion was 50.74 +/- 18.06 minutes. The steady state infusion rate required to maintain 90% to 95% twitch depression was 83.5 +/- 21.4 micrograms/kg/min. Five patients developed phase II block (T4/T1 < 0.5) designated as IB. The other ten did not develop phase II block as IA. Recovery times (T1 = 10.50%, 10-100%) between IA and IB were not statistically significantly different. The recovery time of train-of-four fade (T1 = 10% to T1 = 100% and train of four > 75%) was 5.73 +/- 0.43 minutes. However, recovery times between continuous infusion group and single dose group were significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Microsatellite instability in bladder cancer

Somatic instability at microsatellite repeats was detected in 6 of 200 transitional cell carcinomas of the bladder. Instabilities were apparent as changes in (GT)n repeat lengths on human chromosome 9 for four tumors and as alterations in a (CAG)n repeat in the androgen receptor gene on the X chromosome for three tumors. Single locus alterations were detected in three tumors, while three other tumors revealed changes in two or more loci. In one tumor we found microsatellite instability in all five loci analyzed on chromosome 9. The alterations detected were either minor 2-base pair changes or larger (> 2 base pairs) alterations in repeat length. All six tumors were low stage (Ta-T1), suggesting that these alterations can occur early in bladder tumorigenesis.

Prolonged fasting in pediatric outpatients does not cause hypoglycemia

Two hundred and thirty healthy children scheduled for receiving elective minor surgery were assigned into 4 different groups. Group I (small infant group) included 27 infants of age from 1 to 3 months (2.0 +/- 0.6 months), Group II (infant group) included 42 infants age from 3 to 12 months (7.4 +/- 2.8 months), Group III (pre-school children group) included 122 patients of age from 1 to 6 years (3.1 +/- 1.4 years). The remained 39 cases of age older than 6-years-old (8.0 +/- 1.5 years) were collected in group IV (old children group). All studied children were starved for at least 4, 6, or 8 hours in infants, pre-school children, and old children group, respectively, pre-operatively. The fasting time and fasting blood glucose levels of the 4 groups were 6.7 +/- 1.4 hours and 109.0 +/- 22.9 mg% in group I, 7.7 +/- 2.3 hours and 98.6 +/- 18.0 mg% in group II, 10.4 +/- 2.9 hours and 96.9 +/- 24.7 mg% in group III, and 12.6 +/- 2.6 hours and 95.7 +/- 20.5 mg% in group IV, respectively. No one in the 230 children had blood glucose less than 40 mg% even in 5 infants who were starved for 12 hours or more. Therefore, we concluded that preoperative starvation is well tolerated than the originally expected in the infants and children. The fasting time before anesthesia can be executed safely even though the operation schedule may not be right on time.

Role of chromosome 9 in human bladder cancer

The tumors of 20 patients with multifocal primary transitional cell carcinoma of the bladder or lymph node metastases were examined for molecular genetic defects which we have previously found to be present in > 50% of invasive tumors. These included loss of heterozygosity (LOH) of chromosome 9, which occurs in superficial as well as invasive bladder tumors, and LOH of chromosome 17p and p53 mutations, which are commonly found only in invasive tumors. Analysis of multiple or recurrent primary tumors in 7 patients for these markers was generally consistent with recently published data that the tumors are monoclonal in origin and that p53 mutations occur as a late event in the generation of invasive bladder cancers. Comparison of the primary tumors and metastases to regional lymph nodes in 14 patients demonstrated a complete concordance between the molecular genetic defects present, showing that LOH of chromosomes 9 and 17p and p53 mutations occurred in the primary tumors before metastasis. Because of the importance of chromosome 9 in bladder cancer, we mapped the location of a putative tumor suppressor gene by restriction fragment length polymorphism analysis of 123 cases obtained in this and earlier studies. Most of the tumors showed LOH for more than one marker on chromosome 9. Results of mapping of 4 tumors with partial deletion of chromosome 9 suggests that the tumor suppressor gene is located between 9p12 and 9q34.1.

Deoxyribonuclease of Syncephalastrum racemosum--enzymatic properties and molecular structure

Among the isolated fungal species of soil, one filamentous fungus, Syncephalastrum racemosum, produces a relatively large amount of DNase. This enzyme has been purified to apparent homogeneity by column chromatography on DEAE-cellulose, hydroxylapatite, phenyl-Sepharose CL-4B, and Sephadex G-100. The active enzyme requires divalent metal ions and has an optimum pH of 7.0 with Mg2+ and 7.2 with Mn2+. This enzyme is an acidic glycoprotein with a pI 5.0 and is relatively unstable at low concentrations. The M(r) of the enzyme is 56,000 during gel filtration under nondenaturing conditions but is 28,000 during polyacrylamide gel electrophoresis in sodium dodecyl sulfate. These results suggest a structure consisting of two subunits. The subunits of the holoenzyme can be cross-linked with glutaraldehyde. The yield of N-terminal phenylthiohydantoin-alanine from the holoenzyme is 140% and that of one peptide (D-Y-V-S-S-G-Y-D-R), obtained from the tryptic digest is 160%, indicating that the native enzyme is composed of two identical subunits and probably has two active domains. Fungal DNase can be inactivated by Cu(2+)-iodoacetate under conditions that inactivate bovine pancreatic DNase. The specific activity (units/mg of protein) of fungal DNase is 6.5 times that of bovine DNase. The amino acid content of fungal DNase, relative to bovine DNase, is higher in Gly and lower in Ser and Val. The fungal N-terminal 40-residue sequence shows a high degree of homology with a consensus sequence derived from DNase of three mammalian species.

Comparison of the effect of EMLA cream, subcutaneous ring anaesthesia and a double cuff technique in the prevention of tourniquet pain

We have examined the effect of EMLA on tourniquet pain and compared it with those of subcutaneous ring anaesthesia (SRA), a double cuff technique and a single cuff (control) during i.v. regional anaesthesia. The durations of analgesia (mean 57.3 (SD 16.6) min) and tolerance (72.3 (13.9) min) to tourniquet inflation in the EMLA group were comparable to those in the SRA group (54.1 (16.2) min and 68.3 (19.0) min), but significantly (P < 0.05) greater than those in the control group (30.0 (10.7) min and 45.6 (14.0) min). The double cuff technique was the most effective method, with 91.5 (14.9) min duration of analgesia. We conclude that EMLA provided a significant analgesic effect on tourniquet pain compared with the control group, but a relatively limited analgesic effect compared with a double cuff technique.

Distinct pattern of p53 mutations in bladder cancer: relationship to tobacco usage

A distinct mutational spectrum for the p53 tumor suppressor gene in bladder carcinomas was established in patients with known exposures to cigarette smoke. Single-strand conformational polymorphism analysis of exons 5 through 8 of the p53 gene showed inactivating mutations in 16 of 40 (40%) bladder tumors from smokers and 13 of 40 (33%) tumors from lifetime nonsmokers. Overall, 13 of the 50 (26%) total point mutations discovered in this and previous work were G:C-->C:G transversions, a relatively rare mutational type in human tumors. In six tumors, identical AGA (Arg)-->ACA (Thr) point mutations at codon 280 were observed, suggesting a mutational hotspot in these tumors. Comparison of the mutational spectra from smokers and nonsmokers revealed no obvious differences in the types or positions of inactivating mutations; however, 5 of 15 tumors containing point mutations from cigarette smokers had double mutations, four of which were tandem mutations on the same allele. No double mutations were found in tumors from nonsmoking patients. None of the mutations in smokers were G:C-->T:A transversions, which would be anticipated for exposure to the suspected cigarette smoke carcinogen 4-aminobiphenyl. The results suggest that, although cigarette smoke exposure may not significantly alter the kinds of mutations sustained in the p53 gene, it may act to increase the extent of DNA damage per mutagenic event.

Production of novel oligosaccharide oxidase by wheat bran solid-state fermentation

A search for oxidases that catalyze the oxidation of oligosaccharides has resulted in the isolation of several soil-derived fungus strains which produced novel oligosaccharide oxidases with different substrate specificity on wheat bran solid culture. One of these oxidases produced by Acremonium strictum T1 strain has been characterized. This enzyme showed high reactivity toward maltose, lactose, cellobiose and maltooligosaccharides composed of up to seven glucose units, and was named as glucooligosaccharide oxidase based on its substrate specificity. Strain T1 was subjected to a strain improvement program, and an enzyme hyper-producing mutant strain T1-38 was selected. This mutant strain produced glucooligosaccharide oxidase 75 times higher than the wild type strain T1. When cultivated in a solid medium comprised of 1 part of wheat bran and 1 part of water (w/w), enzyme activity reached a maximum level of 6 units per g of culture medium after 4 days cultivation. Characteristics of the enzyme including the substrate specificity were compared with two other novel oligosaccharide oxidases isolated in this laboratory. Batch type conversion of lactose to lactobionic acid using crude enzyme was also discussed.

Absence of p53 gene mutations in primary nasopharyngeal carcinomas

Alterations in the p53 tumor suppressor gene and Epstein-Barr virus status were investigated in 15 nasopharyngeal carcinoma (NPC) biopsies, 4 xenografts, and 2 cell lines from the Cantonese region of southern China. One other established NPC cell line obtained from a northern Chinese patient was also studied. Restriction fragment length polymorphism analysis revealed a loss of heterozygosity for chromosome 17p, where the p53 gene resides, in only one of 15 NPC biopsies. Polymerase chain reaction-single-stranded conformational polymorphism analysis and direct sequencing failed to detect sequence alterations in exons 5 through 8 of the p53 gene in the 15 tumors and in the 4 NPC xenografts, all of which tested positive for Epstein-Barr virus. In contrast, the 3 NPC cell lines were all negative for Epstein-Barr virus and contained G----C transversions in the p53 gene, with cell lines CNE-1 and CNE-2 harboring identical AGA (arginine) to ACA (threonine) changes at codon 280. These results suggest that p53 inactivation is not a necessary component of nasopharyngeal carcinogenesis in Cantonese but may be important in the establishment of cell lines derived from these tumors.

Unusual short rib-polydactyly syndrome

We present a case of lethal short rib-polydactyly syndrome (SRPS) that cannot be categorized into the existing classification. A nosologic discussion is presented. To our knowledge, situs inversus totalis, as in our case, has not been described before in any SRPS.

Effect of premedication on the changes of neuropeptide Y (NPY) in anesthesia

Premedication is one of the popular techniques in anesthesia, not only for the decrease of side effects but also for the increase of actions. Clinically, we found that plasma neuropeptide Y-like immunoreactivity (NPY-IR) was lowered in patients who had received premedication. In rats, plasma NPY-IR was not modified by the intravenous injection of diazepam. Pethidine reduced the plasma NPY-IR level which could be reversed by naloxone. Direct inhibition of plasma NPY-IR through an activation of opioid receptors can thus be considered. To the cold-stress stimulation, plasma NPY-IR was markedly raised. Diazepam reduced this stimulation-induced increase of plasma NPY-IR in a dose-dependent manner. Similar derivative of benzodiazepine produced an inhibition in a way following the potency as that to produce anxiolytic action. Also, this inhibition was reversed by PK11195, an antagonist of peripheral benzodiazepine receptors. Moreover, pain-stimulated increase of plasma NPY-IR in rats was also reduced by pethidine. This action was totally reversed in the presence of naloxone, indicating the participation of opioid receptors in the process. The obtained results suggest that premedication of diazepam and/or pethidine has the ability to decrease plasma NPY-IR in animals.

Production and immobilization of D-aminoacylase of Alcaligenes faecalis DA1 for optical resolution of N-acyl-DL-amino acids

The production of D-aminoacylase by Alcaligenes faecalis DA1 was induced 5- to 50-fold by N-acetyl-D-amino acids. This strain produced about 443 units of D-aminoacylase and 52 units of L-aminoacylase per gram of cells (wet weight) when cultivated in a medium containing 1% N-acetyl-DL-leucine as the carbon source. The D-aminoacylase was partially purified by Fractogel DEAE 650 column chromatography and then immobilized on another Fractogel DEAE 650 column. The catalytic activity of the immobilized D-aminoacylase was 2,650 units per milliliter of gel. The Km values for the free and the immobilized enzymes were found to be 1.00 and 0.22 mM, respectively, using N-acetyl-D-methionine as a substrate. The optimal reaction pH and temperature for both soluble and immobilized enzyme were around 8.0 and 45 degrees C, respectively. The free enzyme was stable in the pH range from 5.0 to 11.0, whereas the immobilized enzyme tended to detach from the gel at pH values higher than 9.0. Both forms of enzyme were stable up to 40 degrees C. When used for the optical resolution of N-acetyl-DL-methionine, the immobilized enzyme maintained 90% initial activity after 17 days of continuous operation at 45 degrees C. The process of purification and immobilization of D-aminoacylase described in this report is very effective and easy to scale up.

Methylation, mutation and cancer

The fifth base in human DNA, 5-methylcytosine, is inherently mutagenic. This has led to marked changes in the distribution of the CpG methyl acceptor site and an 80% depletion in its frequency of occurrence in vertebrate DNA. The coding regions of many genes contain CpGs which are methylated in sperm and serve as hot spots for mutation in human genetic diseases. Fully 30-40% of all human germline point mutations are thought to be methylation induced even though the CpG dinucleotide is under-represented and efficient cellular repair systems exist. Importantly, tumor suppressor genes such as p53 also contain methylated CpGs and these serve as hot spots for mutations in some, but not all, human cancers. Comparison of the spectrum of mutations present in this gene in different human cancers allows for predictions to be made on the molecular mechanisms of tumorigenesis.

Purification and characterization of a novel glucooligosaccharide oxidase from Acremonium strictum T1

A novel glucooligosaccharide oxidase was purified 495-fold from wheat bran culture of a soil-isolated Acremonium strictum strain T1 with an overall yield of 21%. This enzyme was composed of a single polypeptide chain with a molecular mass of 61 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis and size-exclusion high-performance liquid chromatography. Its isoelectric point was pH 4.3-4.5. This enzyme contained 1 mol of FAD per mol of enzyme and showed absorption maxima at 274, 379 and 444 nm. This enzyme was stable in the pH range of 5.0 to 11.0 with an optimal reaction pH of 10.0. The optimal reaction temperature was 50 degrees C. It was stable up to 50 degrees C for 1 h at pH 7.8. This enzyme oxidized those oligosaccharides with glucose residue on the reducing end and each sugar residue jointed by alpha or beta-1,4 glucosidic bond. The relative activity of this enzyme toward maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose, lactose, cellobiose and glucose was 100:94:74:46:66:56:64:47:59. To our knowledge, this is the first report on the discovery of an glucooligosaccharide oxidase as judged from enzyme substrate specificity.

High-yield extraction and purification of glutathione reductase from baker's yeast

Glutathione reductase was extracted from toluene-treated baker's yeast cells by a two-stage buffer autolysis method. The yeast cells were treated with toluene for 1 h at 40 degrees C. After removal of the toluene, the cells were then allowed to autolysis in buffer for 72 h at 4 degrees C. The cells were collected and resuspended in buffer. A second stage autolysis was carried out for another 96 h at 4 degrees C. The enzyme was purified to 786-fold from the second stage cell autolysate by using two steps of affinity chromatography with triazine dyes (Yellow H-E4G and Yellow H-E6G) coupled to Sepharose CL-4B. By using this simplified method, 1.44 mg (165 units/mg) of glutathione reductase was obtained from 65 g (wet weight) of yeast cells, equivalent to 80% enzyme recovery.

Identification of p53 gene mutations in bladder cancers and urine samples

Although bladder cancers are very common, little is known about their molecular pathogenesis. In this study, invasive bladder cancers were evaluated for the presence of gene mutations in the p53 suppressor gene. Of 18 tumors evaluated, 11 (61 percent) were found to have genetic alterations of p53. The alterations included ten point mutations resulting in single amino acid substitutions, and one 24-base pair deletion. In all but one case, the mutations were associated with chromosome 17p allelic deletions, leaving the cells with only mutant forms of the p53 gene products. Through the use of the polymerase chain reaction and oligomer-specific hybridization, p53 mutations were identified in 1 to 7 percent of the cells within the urine sediment of each of three patients tested. The p53 mutations are the first genetic alterations demonstrated to occur in a high proportion of primary invasive bladder cancers. Detection of such mutations ex vivo has clinical implications for monitoring individuals whose tumor cells are shed extracorporeally.

Purification and Characterization of d -Aminoacylase from Alcaligenes faecalis DA1

A d -aminoacylase from Alcaligenes faecalis DA1 has been purified to homogeneity by a simple purification procedure with two columns, Fractogel DEAE-650 and HW-50. The specific activity of the purified enzyme was found to be 580 U/mg of protein with N -acetyl- dl -methionine as the reaction substrate. The apparent molecular weight and isoelectric point of this enzyme were determined to be 55,000 and 5.4, respectively.

[The effect of succinylcholine on the recovery of atracurium-induced neuromuscular blockade]

At the end of abdominal surgery, a brief but profound neuromuscular blockade may be needed to facilitate closure of abdominal wall. Succinylcholine (Sch) was the agent used in this regard before. This study was undertaken to observe the effect after administration of Sch (1 mg/kg) at various levels of recovery from atracurium. 40 ASA I or II patients undergoing elective surgery were randomly assigned to one of four groups with 10 in each. Anesthesia was induced with thiopental 5 mg/kg and Sch 1.5 mg/kg i.v., and maintained with 0.7% isoflurane (end-tidal concentration) and 50% N2O in O2 The electromyographic response of the hypothenar muscle was recorded in response to supramaximal train-of-four stimuli delivered to the ulnar nerve at 20 s intervals using a relaxograph (Datex). Control records were obtained after induction of anesthesia. When the first twitch (T1) had recovered above 50% from the intubating dose of Sch, atracurium 0.5 mg/kg was administered. Spontaneous recovery of T1 was observed. Patients in group I received 1 mg/kg of Sch, when T1 returned to 20% and those in groups II, III, and IV received the same dose of Sch when T1 returned to 40%, 60% or 80% of control respectively. The response was observed at 20s intervals for at least 5 min after the administration of Sch. It was regarded as effective response if the T1 returned to less than 5% of control.(ABSTRACT TRUNCATED AT 250 WORDS)

Eyebrow revascularization

A 41-year-old man suffered from an incompletely avulsed right eyebrow and forehead after a windshield injury in a traffic accident. Microsurgical techniques were used to revascularize the avulsed tissue of the right eyebrow and forehead with anastomosis of one branch of the frontal branch of the right superficial temporal artery. The revascularized eyebrow and forehead remained viable and provided a good cosmetic result. An aggressive microsurgical approach, either by direct arterial anastomosis or bypass with vein graft, should be encouraged in all incompletely avulsed tissue with inadequate blood supply in the face, hand, and foot.

Allelic loss of chromosome 17p distinguishes high grade from low grade transitional cell carcinomas of the bladder

Forty-three transitional cell carcinomas of the bladder of differing grades and stages were examined for reduction to homozygosity for chromosomes 9q, 11p, and 17p. Allelic loss of chromosome 9q was seen in 24 of 38 informative grades II, III, and IV tumors providing further evidence for a bladder tumor suppressor gene on this chromosome. In contrast to the grade-independent involvement of chromosome 9q, allelic losses of chromosomes 11p and 17p were seen only in grade III and IV tumors. The results with chromosome 17p were particularly striking and showed that 0 of 10 grade II versus 20 of 31 grade III and IV tumors had allelic losses for this chromosome harboring the p53 tumor suppressor gene often mutated in other human cancers. The data suggest that cumulative genetic damage is sustained in transitional cell carcinomas and that one of the underlying molecular mechanisms distinguishing low grade from high grade tumors involves chromosome 17p.

Emergency free flaps to the type IIIC tibial fracture

Type IIIC tibial fractures are complex injuries involving extensive bone and soft-tissue devascularization that result in a high percentage of complications and ultimate amputation. An emergency free flap transfer not only may salvage the limb but also may improve the aesthetic and functional results of reconstruction by placing the injured structures in a well-vascularized bed. Two cases of type IIIC tibial fracture were treated in this manner, and we present our experience with a 30-month follow-up of one patient and a 6-month follow-up of another patient.

[Speech outcome after early or delayed hard palate closure]

Delayed hard palate closure (after age 6-7) was widely used for palatal repair in cleft palate children from 1976 to 1982. Since 1982, the approach has been revised into early complete closure of the soft and hard palate (before age 2). The articulation skills of 60 children with cleft lip and palate (age 3-5:11) who underwent early complete palate closure were compared with 47 children of similar age with soft palate closure only. The results indicated that the early complete closure group had more children with adequate articulation skills than the delayed hard palate closure group. Detailed analysis of the articulation patterns in each group revealed that the articulation substitution patterns made by the early complete closure group followed the trends of developmental articulation patterns, i.e. unaspirated, stopping and fronting phonological features. On the contrary, the articulation substitution patterns made by the delayed hard palate closure group were more related to structural deficits, i.e. compensatory articulation. Age 3-5 is a critical period for articulation maturation. We advocate that the complete palatal closure should be achieved before age 2 in order to equip cleft palate children with an equally normal oral structures to enhance speech/language development in a normal learning process during this critical period.

Jadassohn's nevus sebaceous of the head and face

The nevus sebaceous is a congenital skin lesion that usually appears in the head and face area. The lesions often cause aesthetic problems for patients and have a high incidence of malignant degeneration. The nevus sebaceous is rarely discussed in plastic surgery literature, however. This article describes 62 cases with a review of the literature.

Study of plasma neuropeptide Y (NPY) and catecholamines levels during spinal anesthesia

Plasma levels of neuropeptide Y (NPY) and catecholamines were investigated during spinal anesthesia. Ten ASA physical status I-II patients were studied after obtaining institutional approval and informed contents. All patients were free from endocrine and metabolic disease underwent elective low risk operation. No premedication was given before operation. Spinal anesthesia was performed on lateral position from L3-4 interspace with 15 mg tetracaine without added epinephrine. The analgesic level was about at T6 dermatone. Blood samples were obtained from radial artery catheter, 15 minutes before spinal anesthesia and 5', 15', 30', 60', 120', during operative period and 30' after operation in postanesthesia recovery room. The results showed that there were significant elevation in plasma level of NPY during spinal anesthesia compared with the level before anesthesia. However, no statistically significant changes of plasma catecholamines were found.

Clinical experience of free forearm flap in head and neck surgery

The radial forearm flap can be safely used in intraoral reconstruction. From 1988 to 1989 ten patients received this kind of operation without a flap loss. The radial forearm flap has the advantage of easy dissection without adding too much operation time and cost to the patient. The thin flap is ideal for the intraoral reconstruction and minimizes the need for bulky myocutaneous flaps which are commonly used now.

Elevated transferrin receptor content in human prostate cancer cell lines assessed in vitro and in vivo

Transferrin receptors (TfR) were measured in benign and malignant prostatic cells by performing Scatchard analysis following the administration of 125I-transferrin. Established human prostate cancer cell lines (PC-3 and DU-145) as well as biologically aggressive variants (PC-3 ASC and PC-3 DES) were shown to possess significant levels of high affinity TfR when assessed in vitro. In contrast, TfR content was negligible in cultured stromal cell fractions derived from human benign prostatic hyperplasia (BPH) specimens. Scatchard analysis was also performed on in vivo derived prostatic tissues: tumors resulting from the subcutaneous xenografting of PC-3 ASC cells into athymic, nude mice and fresh BPH surgical specimens. These tissues were dissociated and their stromal and epithelial components separated. TfR were only detected in the epithelial component of both malignant and benign epithelial cells. PC-3 ASC tumor cells exhibited TfR levels comparable to their in vitro expression and these levels were 10-fold greater than in the BPH cells. These findings suggest that elevated TfRs may serve as another useful marker of the transformed phenotype within human prostate tumor systems.

Allelic losses of chromosomes 9, 11, and 17 in human bladder cancer

Twenty-five human bladder tumors were examined for loss of heterozygosity of markers on chromosomes 6p, 9q, 11p, 14q, and 17p. These studies show that all of the markers were reduced to homozygosity in at least some of the tumors. They also confirmed earlier studies by Fearon et al. [Nature (Lond.), 318: 377-380, 1985] that approximately 40% of bladder tumors were reduced to homozygosity for markers on chromosome 11p. However, the greatest frequency of allelic loss was seen for chromosomes 9q (67% of informative cases) and 17p (63% of informative cases) with both chromosomes being lost concordantly in 10 out of 20 informative tumors. Allelic loss of chromosome 9q has not been previously observed with other human cancers; however, deletions of 17p have been reported in breast, lung, and colorectal carcinomas. The data raise the interesting possibility that allelic losses of specific chromosomes might be a feature of cancer in a particular differentiated cell type whereas loss of other chromosomes harboring more generally acting tumor suppressor genes might be a common feature of human cancers.

Molecular cloning of the structural gene for alkaline elastase YaB, a new subtilisin produced by an alkalophilic Bacillus strain

Alkaline elastase YaB is an extracellular serine protease of the alkalophilic Bacillus strain YaB. We cloned the structural gene, ale, and determined the nucleotide sequence. The mature enzyme (268 amino acids) was preceded by a putative signal sequence and a prosequence (27 and 83 amino acids, respectively). The mature enzyme was 55% homologous to subtilisin BPN'. Almost all the positively charged residues are predicted to be on the surface of the molecule, which would facilitate binding to elastin. The P1 substrate site-related sequences differed between alkaline elastase YaB and subtilisin BPN'.

Clinical comparison of commercially available Biobrane preparations

This prospective clinical comparison of the three commercially available Biobrane preparations indicated that: (1) All three products of Biobrane are excellent skin substitutes. (2) Regular Biobrane has satisfactory wound adherence, however, its non-porous structure allows limited wound drainage. Because of this, it has the highest incidence of haematoma and fluid accumulation (13.3 per cent) and delayed epithelialization (18.8 per cent) of the three products. (3) Thin Porous Biobrane has poor adherence which limits patient activity and provides poor pain relief. The infection rate of 10 per cent was the highest of the three products. (4) Regular Porous Biobrane demonstrated superiority to the other two Biobrane products in this study. It provided good wound adherence while maintaining wound drainage because of its porous structure. The incidence of blood or fluid accumulation (7.1 per cent) was the lowest in the three products. (5) Most of the complications such as infection, delayed epithelialization, pain and activity impairment were related to fluid or blood accumulation. Adherence was found to be more important and reliable than pore structure. Operative haemostasis thus should be emphasized when using porous Biobrane, as with all skin substitutes.

Pediatric burns--2 year survey of cases admitted to the Chang Gung Memorial Hospital

A total of 722 patients were admitted to the Burn Unit of Chang Gung Memorial Hospital over a 2-year period, of these 285 (39.5%) were under 15 years of age. The major cause of pediatric burns was scalding, 236 (82.8%). Most of the patients under age of 15 years had total burn surface under 20% (199 patients, 70%), and were discharged from the hospital within one month (263 patients, 91%). Treatments included debridement done in 98 patients (41.5%) and skin grafting in 81 patients (28%). Oxacillin-Resistant Staphylococcus Aureus infections were the most common complication (5.3%). The mortality rate was 5.3%.

Production and Further Characterization of an Alkaline Elastase Produced by Alkalophilic Bacillus Strain Ya-B

The characteristics of the obligate alkalophilic Bacillus sp. strain Ya-B, which produces alkaline elastase extracellularly, were examined. This strain grew at pH 7.0 only in the presence of 1% or more NaCl. Its fatty acid distribution pattern was similar to that of other Bacillus species in which iso-C 15 and anteiso-C 15 were the most abundant fatty acids. About 120 mg of enzyme was recovered from 1 liter of culture broth in a medium (pH 10.1) containing mainly glucose, soymeal, and glycerol. The antiserum against this enzyme did not recognize microbial proteinases, such as subtilisins, but reacted with proteinase C, which was purified from commercial pronase. Chemical modification studies revealed that certain histidine and tyrosine residues might be involved in the enzyme activity. This enzyme underwent a partial unfolding at pHs higher than 12.0, as indicated by the circular dichroism study.

Basal joint reconstruction in a punch injury of the hand

Severe hand trauma caused by an industrial accident resulted in composite tissue loss in the basal joint area of the right hand. The crushed metacarpal bone was replaced, and ligamentous and capsular reconstruction was performed with flexor carpi radialis tendon and additional tendon graft. We present our experience, with a follow-up of one year and eight months.

Specificity of alkaline elastase Bacillus on the oxidized insulin A- and B-chains

The substrate specificity of alkaline elastase Bacillus from alkalophilic Bacillus sp. Ya-B was investigated using oxidized insulin A- and B-chains. Under time-limited cleavage, the initial cleavage site of the enzyme on the oxidized insulin A-chain and B-chain was at the leucine13-tyrosine14 bond and the leucine15-tyrosine16 bond, respectively. When the cleavage was completed, three major cleavage sites and three minor cleavage sites on the A-chain, and five major cleavage sites and four minor cleavage sites on the B-chain were found. However, most of the peptides produced after complete hydrolysis of the A- or B-chain by the enzyme were composed of four to six amino acid residues. The results suggest that this enzyme cleaves the oxidized insulin A- and B-chains in a block-cutting manner.