[Amylase production of Streptomyces rimosus TM-55 and their 2-deoxyglucose resistant mutants]

Streptomyces rimosus TM-55 was treated with 3% ethyl melthylsulfonate for 60 minutes to generate mutants producing high amount of amylase, and 1,283 mutants were isolated from yeast extract starch (YS) medium containing 0.1% 2-deoxyglucose. Amylase activity was primarily screened by clear zone formation on YS medium after spraying with iodine solution. Two mutants designed as D-35 and D-62 had higher amylase activity than that of the parent strain. Amylase activity of the mutants in the YS broth was 2.97- and 3.45-fold of the parent strain, respectively. With the addition of 0.1% lactose, and 2-deoxyglucose, amylase activity of the mutants D-35 and D-62 was 27-73% and 4-7% higher than that of the parent strain. With the addition of 0.1% sucrose, amylase activity of the mutant D-35 was 18.37% lower than that of the parent strain. Moreover, with the supplement of 0.1% glucose, amylase activity of both the mutants D-35 and D-62 was 3.67 and 3.40 fold of the parent strain.

Histopathology of fetal diastrophic dysplasia

We report on three cases of diastrophic dysplasia in second trimester fetuses and discuss the differential diagnosis and clinical, radiologic, and histopathologic findings. Manifestations of typical diastrophic dysplasia in infants and older patients include abnormal pinnae, scoliosis, and joint contractures; these were absent in the fetuses, in keeping with the tendency for the clinical and radiologic aspects of this disease to become more severe with age. The histopathologic characteristics of the cartilage appear to be similar in the fetus and older patient, and therefore may be useful in differentiating diastrophic dysplasia from other osteochondrodysplasias in the second trimester.

Morphogenesis, biomass and oxytetracycline production of Streptomyces rimosus in submerged cultivation

The minimal concentration of adenosine triphosphate (ATP) which could be detected with spectrophotometry, HPLC and luciferin-luciferase methods was 1.0 microM, 3.3 microM and 100 nM, respectively. In submerged cultivation, most Streptomyces rimosus TM-55 was in hyphae fragment form at 65 h, became short-rod mycelia at 166 h, and lysed at 504 h incubation. The ATP content had maximal value at 24 h, then gradually decreased during cultivation. The oxytetracycline potency increased as incubation occurred, had maximal potency 178.9 micrograms/ml at 166 h, and then gradually decreased. Morphogenesis was very important in oxytetracycline production in submerged cultivation of Streptomyces; short-rod mycelia had high oxytetracycline production.

Portal blood flow in acute hepatitis with and without ascites: a non-invasive measurement using an ultrasonic Doppler

To evaluate the role of portal blood flow in severe acute hepatitis leading to the formation of ascites, we studied the portal blood flow of 30 patients with severe acute hepatitis (20 without ascites and 10 with ascites), 20 patients with mild acute hepatitis and 20 healthy normal volunteers using duplex sonography. The portal blood flow of patients with severe acute hepatitis and ascites (421 +/- 94 mL/min) was lower than that of the volunteers (725 +/- 131 mL/min), the mild acute hepatitis (658 +/- 148 mL/min), and the severe acute hepatitis (633 +/- 108mL/min) without ascites (P < 0.001). The congestion index of severe acute hepatitis and ascites (0.16 +/- 0.04 cm.s) was higher than that of the volunteers (0.09 +/- 0.03 cm.s, P < 0.001), the mild acute hepatitis (0.09 +/- 0.02 cm.s, P < 0.001), and the severe acute hepatitis (0.12 +/- 0.04 cm.s, P < 0.02) without ascites. Portal blood flow was negatively correlated with prolonged prothrombin time (P < 0.001) and serum total bilirubin level (P = 0.002) and congestion index was positively correlated with heart rate (P = 0.006), prolonged prothrombin time (P < 0.001) and serum total bilirubin level (P = 0.001). Our study shows that in severe acute hepatitis, portal blood flow was reduced in patients with ascites. The non-invasive ultrasonic Doppler is a safe and helpful method in the clinical evaluation of portal hypertension in severe acute hepatitis.

Polar [4+2(+)] diels-alder cycloaddition to nitrilium and immonium ions in the gas phase: Applications of multiple stage mass spectrometry in a pentaquadrupole instrument

Multiple stage MS(2) and MS(3) mass spectrometric experiments, performed using a pentaquadrupole instrument, are employed to explore the gas-phase ion-molecule chemistry of several nitrilium [R-C≡N(+)-H (1), R-C≡N(+)-CH3 (2), and H-C≡N(+)-C2H5 (3)] as well as immonium ions RR(1)C=N(+)R(2)R(3) (4) with the neutral diene isoprene. Polar [4+2(+)] Diels-Alder cycloaddition is observed for nitrilium ions when the energy gap between the lowest unoccupied molecular orbital (LUMO) of the ion and the highest occupied molecular orbital (HOMO) of the isoprene is small and the competing proton transfer reaction is endothermic. Thus, C-protonated methyl isonitrile H-C≡N(+)-CH3 (2a) and its higher homolog H-C≡N(+)-C2H5 (3a) form abundant [4+2(+)] cycloadducts with isoprene, but several protonated nitriles 1 do not; instead they show exothermic proton transfer as the main ion-molecule reaction. Replacement of the methyne hydrogen in 2a by a methyl, ethyl, or phenyl group (2b-d) raises the LUMO-HOMO gap, which greatly decreases the total yield of ion-molecule products and precludes cycloaddition. On the other hand, the electron-withdrawing acetyl and bromine substituents in 2e and 2f substantially lower the LUMO energy of the ions and cycloaddition reaction occurs readily. The simplest member of the immonium ion series, CH2=NH 2 (+) (4a), reacts readily by cycloaddition, whereas alkyl substitution on either the carbon or nitrogen (4b-f) dramatically lowers the overall reactivity, which substantially decreases or even precludes cycloaddition. In strong contrast, the N-phenyl (4g) and N-acetyl (4h) ions and the N-vinyl-substituted immonium ion, N-protonated 2-aza-butadiene (4i), react extensively with isoprene, mainly by [4+2(+)] cycloaddition. However, the isomeric C-vinyl-substituted ion (4j) displays only modest reactivity in both the proton-transfer and the cycloaddition channels.Collision-induced dissociation (CID) of the cycloadducts performed by on-line MS(3) experiments demonstrates that they are covalently bound and supports their assignments as cycloaddition products. Retro Diels-Alder fragmentation is a major process for cycloadducts of both the immonium and the nitrilium ions, but other fragmentation processes also are observed. The cycloadduct of 4a with butadiene displays CID fragmentation identical to that of the authentic ion produced by protonation of 1,2,3,6-tetrahydropyridine, which thus strengthens the [4+2(+)] cycloaddition proposal. AM1 calculations also support the formation of the [4+2(+)] cycloadducts, which are shown in several cases to be much more stable than the products of simple addition, that is, the ring-open isomers.

Doppler echocardiography in normal functioning valve prostheses

Even though there has been some criticism regarding the Doppler evaluation in prosthetic valves because of inter-observer and intra-observer variability, among other factors, and Doppler study has a tendency to have falsely high gradients compared to invasive studies, especially mechanical aortic prostheses, Doppler evaluation can provide reliable hemodynamic information about valve function. This test may be particularly useful if used serially, when baseline values are known. Doppler measurement of gradient and valve area has an expected normal range that is specific for the prosthetic type, size, anatomical position, and chronological age. Clearly, a database involving these aspects is needed to provide a more accurate normal range. This study is intended to provide guidance for echocardiographers.

Prenatal screening for cardiac anomalies: the value of routine addition of the aortic root to the four-chamber view

OBJECTIVE

To determine whether the addition of the aortic-root view would detect more congenital cardiac anomalies than a standard four-chamber view alone.

METHODS

The study included fetuses of 14 weeks' gestation or more who were scanned in our unit during a 28-month period. Outcome information was obtained from postnatal echocardiograms and autopsies. Abnormal hearts were classified as to whether the four-chamber or aortic-root view was abnormal.

RESULTS

There were 5967 fetuses in whom a four-chamber view could be obtained. In 5111 of these, an aortic-root view could also be obtained. The four-chamber view detected 24 (47%) of the 51 fetuses with abnormal hearts. Adding the aortic-root view increased the sensitivity to 78%.

CONCLUSIONS

Visualization of the aortic root is a quick and easy means of evaluating the aortic outflow tract during routine scanning. Adding the aortic-root view to the standard four-chamber view will result in the detection of most cardiac anomalies prenatally.

Impact of screening blood donors for hepatitis C antibody on posttransfusion hepatitis: a prospective study with a second-generation anti-hepatitis C virus assay

BACKGROUND

Hepatitis C is the major cause of posttransfusion hepatitis. Blood components that are positive for antibody to hepatitis C virus (anti-HCV) can transmit posttransfusion hepatitis.

STUDY DESIGN AND METHODS

To investigate the effect on posttransfusion hepatitis of screening blood donors with a second-generation test for anti-HCV, 249 transfusion recipients who underwent cardiovascular surgery were prospectively followed. Six recipients who were positive for anti-HCV before transfusion and 51 subjects with incomplete follow-up were excluded from this study.

RESULTS

Eleven (13.8%) of 80 subjects who received unscreened blood had two successive serum alanine aminotransferase levels > 90 U per L. Seven (8.8% of total) developed anti-HCV and HCV RNA and two (2.5% of total) developed IgM antibody to cytomegalovirus (IgM anti-CMV). By contrast, 3 (2.7%) of the 112 subjects who received anti-HCV-screened blood had two successive serum alanine aminotransferase levels > 90 U per L. None of these three developed anti-HCV and HCV RNA, but two (1.8% of total) showed the development of IgM anti-CMV. The study shows that screening for anti-HCV in blood donors with a second-generation test almost abrogated posttransfusion viral hepatitis C.

CONCLUSION

After anti-HCV screening, other body fluid-transmitted viruses such as CMV may become important in posttransfusion hepatitis.

Determination of aldicarb, aldicarb sulfoxide and aldicarb sulfone in tobacco using high-performance liquid chromatography with dual post-column reaction and fluorescence detection

A screening method for the determination of aldicarb (AS) and its sulfoxide (ASX) and sulfone (ASN) metabolites in tobacco at low ppm levels is described. Tobacco samples are extracted using methanol with the aid of sonication at ambient conditions. The extract is filtered and then injected into a high-performance liquid chromatograph equipped with a dual post-column reaction system and a fluorescence detector. Chromatographic separation is performed on a C18 column with a mixture of methanol-acetonitrile-water containing 0.1% of triethanolamine as the mobile phase. Triethanolamine is added to improve peak shape of AS residues and to reduce the undesired interaction between residual silanols and interferences, mainly amino acids and other amines. The average recoveries for AS residues spiked in tobacco are higher than 95% for AS, 91% for ASN and 85% for ASX at levels of 0.5-10 ppm (w/w). The detection limit is 0.5 ppm for each of the target compounds.

Chronic elemental mercury intoxication: clinical and field studies in lampsocket manufacturers

Four workers chronically exposed to elemental mental mercury in a lampsocket manufacturing factory were studied. The clinical manifestations were severe in one, mild in another, and suspicious in the remaining two. Correlation between severity of clinical features and increased urinary mercury concentrations was found. The time weighted average mercury concentrations were 0.945 mg/m3 and 0.709 mg/m3 for two workers in one room and 0.225 mg/m3 in the other. After stopping exposure, the workers recovered spontaneously or with D-penicillamine treatment within six months. It is concluded that recovery from chronic elemental mercury intoxication may be complete when patients are removed early from the exposure environment. The hazard of mercury intoxication in recycling of waste substances is emphasised.

Cystic enlargement of the iliopsoas bursa causing venous obstruction as a complication of total hip arthroplasty. A case report

The authors report an unusual complication of total hip arthroplasty. A patient developed significant swelling and discomfort in the left lower extremity 4 1/2 years following a left total hip arthroplasty. Magnetic resonance imaging and venography demonstrated a large intrapelvic mass compressing the external iliac vein. An arthrogram revealed a cystic cavity consistent with an iliopsoas bursa in communication with the hip pseudocapsule. Two aspirations of the bursa led to resolution of the cystic enlargement and symptoms. An enlarged iliopsoas bursa should be considered in the differential diagnosis of hip pain or extremity swelling after total hip arthroplasty.

Subcortical somatosensory evoked potentials in patients with hepatic encephalopathy caused by severe acute hepatitis

We studied the median nerve stimulated somatosensory evoked potentials (SEP) of 23 patients with hepatic encephalopathy (HE) resulting from severe acute hepatitis and 22 healthy volunteers. Ten patients who improved and survived more than 60 days were classified as Group 1 and the remaining 13 patients who died shortly after the SEP studies were classified as Group 2. The mean N9-N13 interpeak latencies (IPL) were not different among control and two patient groups. The mean N13-N20 IPL of Group 2 was significantly prolonged when compared with normal controls (P < 0.001) and Group 1 (P < 0.001). Five of the six patients with abnormal N13-N20 IPL died of hepatic failure within 24 h after SEP testing. The occurrence of abnormal subcortical conduction together with cortical dysfunction suggested that brain damage in terminal hepatic encephalopathy was diffuse. The presentation of abnormal prolongation of N13-N20 IPL of SEP during the course of severe acute hepatitis indicated a poor prognosis. Peripheral somatosensory conduction is unaffected even in terminal HE.

Listeriosis of the placenta: clinicopathologic study of seven cases

OBJECTIVE

The purpose of our study was to evaluate the usefulness of placental examination in the diagnosis of prenatal listeriosis.

STUDY DESIGN

Over a 7-year period, 4597 placentas with clinical indications for examination were retrospectively studied for morphologic evidence of listeriosis. The microbiology laboratory file records of positive Listeria monocytogenes cultures were used to confirm the diagnosis. The clinical records were studied for manifestations of the infection both in the neonates and in the mothers.

RESULTS

Seven placentas were identified as having listeriosis. The presence of macroabscesses, as opposed to microabscesses, was the most characteristic finding in this study, and the silver impregnation method was more reliable in identification of the bacilli in the tissue sections than the tissue Gram stains.

CONCLUSIONS

Listeriosis could be diagnosed by placental examination alone, and this examination frequently strengthened the clinical diagnosis. When the infection was not suspected clinically, the examination helped us reach the correct diagnosis.

Prospective study of abdominal ultrasonography before laparoscopic cholecystectomy

To investigate the role of abdominal ultrasonography (US) in predicting possible difficulties during laparoscopic cholecystectomy, we performed preoperative US evaluation prospectively in 82 consecutive patients. We correlated our predictions of "easy" and "difficult" with difficulties experienced at operation in surgery. The binary outcomes were analyzed by taking both easy category of US and surgical operation as positive results and both difficult category as negative results. We obtained satisfactory sensitivity (93.8%), accuracy (81.4%), and positive predictive value (84.7%), but low specificity (35.3%) and negative predictive value (60%). The highly positive results were the result of careful US examination. The low specificity and negative predictive value were attributed to the fact that most surgically difficult cases were due to adhesions around the gallbladder, difficult indeed to detect at US. We conclude that thorough abdominal US examination before laparoscopic cholecystectomy is useful in preoperative evaluation of patients undergoing laparoscopic cholecystectomy, even if it not infrequently fails to predict the surgically difficult cases mainly due to adhesions around the gallbladder.

Strategy and implementation of a system for protein engineering

This paper describes an overall view of an industrial protein engineering project from conception to successful completion. The choice of rational design was determined by the availability of an excellent three-dimensional crystal structure and the availability of information in the literature to define a strategy. The design strategy was refined extensively during the course of the project. The development of methods for mutagenesis, expression, verification, purification, and characterization of mutant enzymes is dictated in part by the enzyme property one chooses to modify and must be rapid yet accurate. Such an approach would be applicable to improve the stability of any other protein or enzyme. Using this approach, we successfully increased the stability of subtilisin BL over 10-fold at 50 degrees C with an overall success rate greater than 60%.

Skeletal histopathology in fetuses with chondroectodermal dysplasia (Ellis-van Creveld syndrome)

Chondroectodermal dysplasia (CED) is an uncommon autosomal recessive disorder and one of the short rib polydactyly syndromes (SRPS). It is characterized by acromelic and mesomelic shortness of limbs, postaxial polydactyly, small chest, ectodermal dysplasia, and in many cases, congenital heart defects. Controversy exists over possible changes in the growth plate. With the advent of ultrasonographic examination, increasing numbers of fetuses with osteochondrodysplasias are examined by pathologists. Since histopathologic examination of the skeletal system is useful in defining various osteochondrodysplasias and it has not been described in the fetus with CED, we herein describe 3 cases of fetal CED with emphasis on skeletal histopathology. All 3 pregnancies were terminated at 22-23 weeks because of ultrasonographic demonstration of short limbs and growth retardation. Radiologically, each fetus had acromelic and mesomelic shortness of long bones with smooth round metaphyses, vertically short iliac bones, short ribs and normal vertebrae. These findings are similar to those described in the larger newborn infant with CED. Histopathologically, the cartilage of the long bones showed chondrocytic disorganization in the physeal growth zone. The findings are dissimilar to those of larger infants and older children in whom chondrocytic columnization has been seen in the central physis and disorganization in peripheral physis. Furthermore, a variable degree of chondrocytic disorganization was also seen in the central physeal growth zone of vertebrae in these fetuses. Other findings noted at fetopsy were: polydactyly in all 3 cases, congenital heart defect in 2 and an abnormal frenulum in one case. The foregoing phenotypic and radiographic manifestations and skeletal histopathology help separate CED from other SRPS.

Valve-related events and valve-related mortality in 340 mitral valve repairs. A late phase follow-up study

To assess the early and late valve-related events, 340 consecutive patients undergoing mitral valve repair from 1969 to 1988 were evaluated. Follow-up was complete, with a mean of 7.5% years and range from 2 to 22 years (cumulative 2456 patient-years). There were 221 (65%) female patients. Rheumatic valvular disease was present in 246 (68%) patients. The remaining patients had ischemic or congenital valve disease, floppy valve or infective endocarditis. At surgery, 47% of the patients had pure mitral incompetence, 43% had mixed mitral stenosis and incompetence and 10% had predominant mitral stenosis. Seventy-three percent of the patients were in functional class III or IV. Twelve percent had had prior heart surgery. Concomitant valve procedures including coronary revascularization were performed in 62.3%. There were 23 hospital deaths (6.8%) but only 3 of these (0.8%) were valve-related in patients who died at reoperation for valve repair failure. There were 4 other early repair failures who survived early reoperation. Of the 317 hospital survivors, there were 127 late deaths, and an actuarial survival of 44 +/- 3.7% (70% CL) at 14 years. Of these, 13 were valve-related or 0.5% patient-year. Late events included thromboembolism (TE) 1% patient-year, anticoagulant bleeding 0.4% patient-year, infective endocarditis (IE) 0.2% patient-year and late reoperation for mitral valve repair failure in 63 patients or 2.8% patient-year. At the late follow-up, 88% of the hospital survivors were in functional class I or II.(ABSTRACT TRUNCATED AT 250 WORDS)

Protein enrichment of sweet potato residue with co-culture of amylolytic fungi by solid-state fermentation

Protein enrichment of sweet potato residue with amylolytic moulds by solid-state fermentation was higher than that obtained with amylolytic yeasts. The optimum initial moisture content for protein enrichment was 66% to 75%. Incrementally added nitrogen sources to the culture at zero time and at 24 h considerably improved the final protein content. During the cultivation, the moisture, ash and ATP contents increased, while the pH value decreased. A 1:1 co-culture of amylolytic mycelial fungi yielded a product with 32.4% crude protein after 4 days incubation at 30 degrees C.

Disappearance of N20 and P25 components of somatosensory evoked potential: an ominous sign in severe acute hepatitis

The scalp-recorded somatosensory evoked potentials (SSEPs) of 14 patients who died of hepatic encephalopathy (HE) caused by severe acute hepatitis and 22 normal volunteers were studied. The present data showed that progressive deterioration of HE resulted in sequential prolongation and eventual disappearance of SSEP components beginning from the late P90 component towards the early P25 and N20 components. Four patients with systemic hypotension, supposedly due to brain edema and increased intracranial pressure, showed disappearance of the N20 and P25 components and died within 24 hours. The N20 and P25 components were preserved in the other 10 patients without systemic hypotension. The disappearance of the N20 and P25 components as well as later components suggests an almost total loss of cortical function. The present study suggests that the disappearance of the N20 and P25 components during the course of HE is an ominous sign in severe acute hepatitis.

The crystal structure of the Bacillus lentus alkaline protease, subtilisin BL, at 1.4 A resolution

The crystal structure of subtilisin BL, an alkaline protease from Bacillus lentus with activity at pH 11, has been determined to 1.4 A resolution. The structure was solved by molecular replacement starting with the 2.1 A structure of subtilisin BPN' followed by molecular dynamics refinement using X-PLOR. A final crystallographic R-factor of 19% overall was obtained. The enzyme possesses stability at high pH, which is a result of the high pI of the protein. Almost all of the acidic side-chains are involved in some type of electrostatic interaction (ion pairs, calcium binding, etc.). Furthermore, three of seven tyrosine residues have potential partners for forming salt bridges. All of the potential partners are arginine with a pK around 12. Lysine would not function well in a salt bridge with tyrosine as it deprotonates at around the same pH as tyrosine ionizes. Stability at high pH is acquired in part from the pI of the protein, but also from the formation of salt bridges (which would affect the pI). The overall structure of the enzyme is very similar to other subtilisins and shows that the subtilisin fold is more highly conserved than would be expected from the differences in amino acid sequence. The amino acid side-chains in the hydrophobic core are not conserved, though the inter-residue interactions are. Finally, one third of the serine side-chains in the protein have multiple conformations. This presents an opportunity to correlate computer simulations with observed occupancies in the crystal structure.

Effect of moisture content on the microbial activity in JP-5 fuel oil

The water solubility of JP-5 fuel oil was found to be proportional to the reciprocal of absolute temperature from 0 degree C to 60 degrees C. Water in the fuel oil would become condensed once the temperature was shifted from a high temperature to low temperature. During the storage, condensed water was precipitated in the bottom of the tank. Both the static and the dynamic dehumidification processes with molecular sieve could reduce the moisture content of fuel oil to less than 5 ppm. However, pre-dried fuel oil had a mildly hydroscopic phenomenon at relatively high humidity condition. The spores of contaminated microbes could survive in the fuel oil with 5 to 80 ppm of moisture content. High moisture content of fuel oil was not favorable to the spore survival. Penicillium sp. could survive in the fuel oil longer than Cladosporium resinae.

Order and Low Dimensionality in the Organic Superconductor (BEDT-TTF)2Cu(NCS)2 Revealed by STM

Single-crystal samples of [(BEDT-TTF)(2)]+[Cu(NCS)(2)]-were synthesized and studied with a scanning tunneling microscope (STM). Real-space images of the anion and cation surfaces with molecular resolution were obtained. The images show no evidence of structural disorder or stacking faults previously suggested. The presence of an additional modulation commensurate with the lattice provides evidence of a lattice distortion. The cause of this modulation is unknown. The presence of a charge density wave in the material would have implications on the dimensionality of the material that may explain the peculiar temperature dependence of the electrical conductivity. This interpretation is consistent with the calculated Fermi surface, which allows nesting of the wave vector.

Baclofen intoxication: report of four cases and review of the literature

Four cases of baclofen intoxication are reported, with a review of 33 cases from the literature. Analysis of these 37 cases suggests that there are two types of baclofen intoxication syndrome. Patients with acute intoxication present with four major clinical manifestations: encephalopathy (disturbance of consciousness and/or seizure), respiratory depression, muscular hypotonia, and generalized hyporeflexia. Patients with chronic intoxication present with hallucinosis, impaired memory, catatonia, or acute mania. The acute intoxication syndrome has a faster onset, shorter duration, more severe clinical manifestations, and higher incidence of seizures than the chronic intoxication syndrome. Baclofen intoxication, although it may cause grave encephalopathic manifestations and electroencephalographic findings, has a benign outcome if actively managed.