Periodicity exhibited by Dirofilaria immitis microfilariae identified in dogs of Korea

Microfilarial periodicity of Dirofilaria immitis (the dog heartworm) was determined at two hr intervals for 72 consecutive hrs in 10 naturally infected war dogs, 3-9 years old, in Korea to facilitate harvest of the microfilariae for possible use in laboratory works and to elucidate further the periodicity of the microfilaria depending on geographic location. Although the periodicity had been observed as being low-grade nocturnal, maximal microfilarial counts were found at 21:00 hr and minimal at 11:00 hr, giving rise to an evident peak in fluctuation of the larval counts. This is the first record of the periodicity of the microfilariae identified as D. immitis in Korea.

An Escherichia coli expression assay and screen for human immunodeficiency virus protease variants with decreased susceptibility to indinavir

We have developed a recombinant Escherichia coli screening system for the rapid detection and identification of amino acid substitutions in the human immunodeficiency virus (HIV) protease associated with decreased susceptibility to the protease inhibitor indinavir (MK-639; Merck & Co.). The assay depends upon the correct processing of a segment of the HIV-1 HXB2 gag-pol polyprotein followed by detection of HIV reverse transcriptase activity by a highly sensitive, colorimetric enzyme-linked immunosorbent assay. The highly sensitive system detects the contributions of single substitutions such as I84V, L90M, and L63P. The combination of single substitutions further decreases the sensitivity to indinavir. We constructed a library of HIV protease variant genes containing dispersed mutations and, using the E. coli recombinant system, screened for mutants with decreased indinavir sensitivity. The discovered HIV protease variants contain amino acid substitutions commonly associated with indinavir resistance in clinical isolates, including the substitutions L90M, L63P, I64V, V82A, L24I, and I54T. One substitution, W6R, is also frequently found by the screen and has not been reported elsewhere. Of a total of 12,000 isolates that were screened, 12 protease variants with decreased sensitivity to indinavir were found. The L63P substitution, which is also associated with indinavir resistance, increases the stability of the isolated protease relative to that of the native HXB2 protease. The rapidity, sensitivity, and accuracy of this screen also make it useful for screening for novel inhibitors. We have found the approach described here to be useful for the detection of amino acid substitutions in HIV protease that have been associated with drug resistance as well as for the screening of novel compounds for inhibitory activity.

Electrogastrographic study of the effect of transcatheter arterial chemoembolization on gastric myoelectric activity

BACKGROUND

Transcatheter arterial chemoembolization (TACE) of the hepatic artery is frequently used in the treatment of inoperable hepatocellular carcinoma (HCC). TACE causes not only effective tumor tissue necrosis in patients with hepatoma but also adverse effects on extrahepatic abdominal organs. There are no published reports on the effect of TACE on the gastric myoelectric activity. In this study, using cutaneous electrogastrography (EGG), we evaluated the effect of TACE on gastric myoelectric activity in patients with HCC.

METHODS

A total of 27 patients (24 men and 3 women, aged 22 to 78 years) with hepatoma, admitted for TACE, were included in this study. Furthermore, 28 patients (24 men and 4 women, aged 26 to 75 years), admitted for diagnostic angiography of the liver, served as the control group. Cutaneous EGG was performed before and after TACE or angiography.

RESULTS

In the TACE group there were significant changes in dominant frequency (DF) and percentages of DF in the defined normal range, bradygastric range, and tachygastric range on post-meal EGG. On fasting EGG, only the dominant frequency and percentages of DF in the bradygastric range changed significantly. However, there was no correlation between the occurrence of nausea/vomiting and the degree of change in the EGG variables, during both fasting and postprandial states. In the control group there were no significant differences in EGG variables before and after angiography.

CONCLUSIONS

TACE can affect gastric myoelectric activity in HCC patients. Nevertheless, the relationship between changes in myoelectric activity and the occurrence of gastrointestinal symptoms needs further investigation.

Sequence of electron carriers in the process of methanol oxidation by a new obligate methylotrophic bacterium

From pink soluble fractions prepared from cells cultured in a copper-free medium, active methanol dehydrogenase (MDH) and two soluble c-type cytochromes (c-I and c-II) were purified homogeneously. The green fractions from cells grown on a medium containing 1.0 mg/l of copper had inactive MDH, cytochrome c-II, and blue copper protein. The amount of copper retained in the blue copper protein increased with cultivation time. The oxidized blue copper protein was similar to the classical type I blue copper proteins since it had the novel absorption peak at 625 nm. However, when the blue protein was reduced with MDH or dithionite, it showed the same spectrum as ferrocytochrome c-I. The isoelectric points of cytochrome c-I, blue copper protein and cytochrome c-II were 9.08, 9.08 and 6.52, respectively. These results suggest that the identity of the purified blue copper protein is cytochrome c-I, and copper ions bind to the cytochrome as methanol is depleted in the culture medium. In addition, MDH activity was not detected at all in the methanol-depleted condition. The data suggest that blue copper protein acts as a negative regulator for MDH. The electrons were transferred as follows: MDH-->cytochrome c-II-->cytochrome c-I (blue copper protein). It was also revealed that the initial 'docking' of MDH and cytochrome c-II is accompanied by electrostatic interactions between lysine or arginine residues on the alpha-subunit of MDH and carboxyl groups on the cytochrome c-II.

Microbiologically induced corrosion of aluminum alloys in fuel-oil/aqueous system

To investigate the microbiologically induced corrosion of aluminum alloys in fuel-oil/aqueous system, aluminum alloys A356, AA 5052, AA 5083 and AA 6061 were chosen as the test alloys and Cladosporium and several fuel-oil contaminated microbes isolated in Taiwan were used as test organisms. Aluminum alloy AA 5083 in fuel-oil/aqueous system was the most susceptible material for microbial corrosion, then followed by aluminum alloys AA 5052 and A356, and AA 6061 was more resistant to microbial aggression. Mixed culture had high capability of corrosion, then followed by Penicillium sp. AM-F5, Fusarium sp. AM-F1, Pseudomonas aeruginosa AM-B5, Ps. fluorescens AM-B9, C. resinae ATCC 22712, Penicillium sp. AM-F2, Candida sp. AM-Y1 and Ps. aeruginosa AM-B11. From energy dispersive spectrometer analysis, aluminum and magnesium contents decreased in the corrosion area, while chlorine and sulfur contents increased. The major organic acid produced in fuel-oil/aqueous system was acetic acid, and the total organic acids content had a positive correlation with the degree of microbial corrosion.

First metacarpal subsidence during pinch after ligament reconstruction and tendon interposition basal joint arthroplasty of the thumb

Trapeziectomy, ligament reconstruction and tendon interposition arthroplasty is one of the most commonly performed procedures to address pain and instability due to osteoarthritis at the basal joint of the thumb. To determine the effect of stress on first metacarpal subsidence, 15 ligament reconstruction and tendon interposition basal joint arthroplasties were evaluated after a mean follow-up of 32 months. Radiographs were obtained of the arthroplasty at rest and then with maximal effort key pinch stress, which is known to subject the first carpometacarpal joint to considerable axial compression stress. Compared with the preoperative x-rays, the first metacarpal had subsided 21% of the arthroplasty space at rest. Under stress, the first metacarpal was found to subside another 10.5% in height. No subluxation of the metacarpal base could be detected. Key pinch strength improved 17% from the preoperative strength. Tip-to-tip pinch strength improved 17% from the preoperative measurement. Grip strength improved 17% from the preoperative measurement. Grip strength was 9% greater than the preoperative grip strength. There was no statistical association between the amount of first metacarpal subsidence and follow-up key pinch, tip pinch, or grip strength. With axial compressive loading of the arthroplasty, such as in lateral pinch, there is some further proximal migration of the first metacarpal, but this is minimal and does not correlate with functional outcome.

Somatosensory evoked potentials in subclinical portosystemic encephalopathy: a comparison with psychometric tests

We prospectively studied the role of somatosensory evoked potentials (SEPs) and psychometric tests in the assessment of subclinical portosystemic encephalopathy (PSE) in 61 cirrhotic patients with grade 0 PSE and 20 controls. Six additional uneducated controls underwent only psychometric tests. Median nerve-evoked cortical responses were recorded for N20-N65 interpeak latencies (IPLs). Psychometric tests were conducted within 4 hours of SEP testing. Seven (26.9%) controls and 30 (49.2%) cirrhotic patients had abnormal psychometric test results (writing sample tests, 20; five-point star tests, 17; number-connection tests, 19; and following-a-track tests, 18); seven controls and 25 cirrhotic patients had 6 or fewer years of education; 7 controls and 28 cirrhotics were older than 50 years of age. Cirrhotic patients (47.6 +/- 8.3 milliseconds) had higher N20-N65 IPLs than controls (40.2 +/- 3.0 milliseconds; P < .001). Twenty-nine (47.5%) cirrhotic patients had abnormal N20-N65 IPLs. Of the 26 cirrhotic patients with more than 6 years of education, 15 (57.7%) had abnormal N20-N65 IPLs and 5 (19.2%) had abnormal psychometric test results (P = .005). Our data show that N20-N65 IPLs of SEPs are helpful in the assessment of subclinical PSE; 47.5% of cirrhotic patients had subclinical PSE. Poorly educated and older subjects tended to have abnormal psychometric test results. SEPs were not affected by education and age and were more sensitive than psychometric tests in the assessment of subclinical PSE in better-educated cirrhotic patients.

Regulation of Sos activity by intramolecular interactions

The guanine nucleotide exchange factor Sos mediates the coupling of receptor tyrosine kinases to Ras activation. To investigate the mechanisms that control Sos activity, we have analyzed the contribution of various domains to its catalytic activity. Using human Sos1 (hSos1) truncation mutants, we show that Sos proteins lacking either the amino or the carboxyl terminus domain, or both, display a guanine nucleotide exchange activity that is significantly higher compared with that of the full-length protein. These results demonstrate that both the amino and the carboxyl terminus domains of Sos are involved in the negative regulation of its catalytic activity. Furthermore, in vitro Ras binding experiments suggest that the amino and carboxyl terminus domains exert negative allosteric control on the interaction of the Sos catalytic domain with Ras. The guanine nucleotide exchange activity of hSos1 was not augmented by growth factor stimulation, indicating that Sos activity is constitutively maintained in a downregulated state. Deletion of both the amino and the carboxyl terminus domains was sufficient to activate the transforming potential of Sos. These findings suggest a novel negative regulatory role for the amino terminus domain of Sos and indicate a cooperation between the amino and the carboxyl terminus domains in the regulation of Sos activity.

Aluminum utensils contribute to aluminum accumulation in patients with renal disease

Presently, aluminum utensils are widely used in the world, especially in the developing countries. However, whether aluminum leaching from such utensils contributes to aluminum accumulation or causes any damage in patients with renal disease remains unknown. We designed a prospective study to evaluate this problem. After excluding patients who were not examined at follow-up or who poorly complied during the study period, the opened randomized study consisted of 42 patients with chronic renal insufficiency (creatinine clearance <60 mL/min and >10 mL/min). All patients had not taken any aluminum-containing agents for 3 months, but used aluminum kitchen utensils for more than 1 year. Twelve patients comprised the control group; the other 30 patients comprised the study group. The aluminum kitchen utensils used by the study group patients were replaced with stainless steel utensils for 3 months, but those used by the control group were not. After 3 months, the decrements of serum aluminum (5.5 +/- 4.6 microg/L v 2.1 +/- 3.5 microg/L; P = 0.012) and daily urine aluminum excretion (14.3 +/- 15.2 microg/d v 2.1 +/- 5.6 microg/d; P = 0.005) in the study group patients were greater than those in the control group patients. The increments of transferrin saturation of the study group patients (1.8% +/- 9.5% v -3.7% +/- 9.5%; P = 0.052) were greater than those of the control group patients. In addition, the increments of iron (r = 0.368, P = 0.035) and transferrin saturation (r = 0.345, P = 0.049) positively correlated with the decrements of daily aluminum excretion in all patients. The study group patients with greater decrements of serum aluminum (>5.5 microg/L) had greater serum iron levels (90.2 +/- 27.7 microg/dL v 71.9 +/- 27.8 microg/dL; P = 0.047) and transferrin saturation (30.5% +/- 11.0% v 23.0% +/- 9.5%; P = 0.046) than those with less decrements of serum aluminum (<5.5 microg/L) after the study. Our study demonstrates that aluminum kitchen utensils may be the important aluminum exposure source for patients with chronic renal insufficiency who are not taking aluminum-containing agents, and hints that the long-term exposure of aluminum leaching from aluminum utensils probably affects iron levels in patients with chronic renal insufficiency. Further studies are clearly needed to confirm this observation.

Evoked potentials in liver diseases

Evoked potentials are objective and quantitative methods capable of evaluating functions of both peripheral and central nervous systems (PNS and CNS). During the past 8 years, we have been using somatosensory, brainstem auditory, and pattern-reversal visual evoked potentials (SEP, BAEP, VEP) to study hepatic encephalopathy (HE) as well as functional status of the PNS and CNS in various liver diseases including viral hepatitis B, alcoholic liver disease and Wilson's disease (WD). In HE irrespective of its etiologies, there is a sequential prolongation and eventual disappearance of cortical components of the median nerve evoked SEP while there is no change in BAEP, suggesting that HE is primarily due to a disturbance in cerebral cortical function and that median SEP may be used for early detection of HE and for monitoring its clinical course. In addition, absence of the N20-P25 component, or presence of only the N20 component of the wave complex in fulminant hepatic failure is associated with high mortality, whereas presence of late cortical components in HE is usually associated with reversibility of clinical course. Central conduction time (CCT) of the BAEP is prolonged in patients with WD, alcoholic liver disease and liver cirrhosis due to hepatitis B. Furthermore, BAEP abnormality is most severe in WD, followed by alcoholic liver disease, and finally hepatitis B. Peripheral nerve conduction as determined by the N9 latency of SEP is slowed in alcoholic liver disease and liver cirrhosis of chronic hepatitis B, but normal in WD. Our studies, therefore, suggest that evoked potentials may be useful in the evaluation of both CNS and PNS functions in various liver diseases and also in the diagnosis and monitoring of HE.

Highly potent oxathiin carboxanilide derivatives with efficacy against nonnucleoside reverse transcriptase inhibitor-resistant human immunodeficiency virus isolates

The structure-activity relationships of a series of compounds related to the nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) oxathiin carboxanilide have been described (R. W. Buckheit, Jr., T. L. Kinjerski, V. Fliakas-Boltz, J. D. Russell, T. L. Stup, L. A. Pallansch, W. G. Brouwer, D. C. Dao, W. A. Harrison, R. J. Schultz, J. P. Bader, and S. S. Yang, Antimicrob. Agents Chemother. 39:2718-2727, 1996). From these studies, the furanyl-containing analog UC10 was identified as the most potent inhibitor of human immunodeficiency virus type 1 (HIV-1) replication and a promising candidate for further development. Three new UC analogs (UC040, UC82, and UC781) have been determined to inhibit laboratory-derived and low-passage-number, primary virus isolates at low nanomolar concentrations in both established and fresh human cells. Each of the compounds synergistically interacted with the nucleoside analogs zidovudine, dideoxyinosine, dideoxycytosine, and lamivudine to inhibit HIV-1 replication. As a group, the UC compounds were found to be less active against viruses with the L100I, K103N, and Y181C amino acid changes in the RT and, upon in vitro selection, yielded resistant virus with the Y181C mutation in the RT. The most potent of the three new compounds, UC781, contains a furanyl side chain, similar to UC10, but differs in having an extended ether side chain instead of an oxime chain. The broad therapeutic index of UC781 (>62,000) resulted in effective inhibition of NNRTI-resistant virus isolates at high nanomolar concentrations. Furthermore, UC781 and the NNRTI costatolide were able to synergistically inhibit HIV-1 replication when used in combination, suggesting that UC781 may interact with the RT differently than the other UC analogs. The favorable anti-HIV properties of the UC compounds suggest they should be considered for further clinical development.

Cross-resistance analysis and molecular modeling of nonnucleoside reverse transcriptase inhibitors targeting drug-resistance mutations in the reverse transcriptase of human immunodeficiency virus

Oxathlin carboxanilide analogs (UC) and alpha APA, compounds recognized as nonnucleoside reverse transcriptase (RT) inhibitors (NNRTI), were evaluated for activity against the human immunodeficiency virus (HIV-1) and drug-resistant variants. These NNRTIs are structurally diverse but potent inhibitors of HIV-1 with efficacy in the nanomolar to low micromolar concentrations. They interact at a specific site in the pain domain of the p66 subunit of RT. Treatment of HIV-1 infected cell cultures with UC compounds resulted in the selection of drug-resistant viruses bearing specific amino acid changes at 100, 101, 103, 106, and/or 181. Since Y181C and L1001 are the most commonly observed resistance-engendering mutations, RT enzymatic analysis was correlated with molecular modeling to glean information on the structural interactions between these NNRTIs and RT. Information derived from these studies will facilitate rational drug design and the selection of complementary anti-HIV drugs for combination therapy.

Identification of a mid-anaphase checkpoint in budding yeast

Activation of a facultative, dicentric chromosome provides a unique opportunity to introduce a double strand DNA break into a chromosome at mitosis. Time lapse video enhanced-differential interference contrast analysis of the cellular response upon dicentric activation reveals that the majority of cells initiates anaphase B, characterized by pole-pole separation, and pauses in mid-anaphase for 30-120 min with spindles spanning the neck of the bud before completing spindle elongation and cytokinesis. The length of the spindle at the delay point (3-4 microm) is not dependent on the physical distance between the two centromeres, indicating that the arrest represents surveillance of a dicentric induced aberration. No mid-anaphase delay is observed in the absence of the RAD9 checkpoint gene, which prevents cell cycle progression in the presence of damaged DNA. These observations reveal RAD9-dependent events well past the G2/M boundary and have considerable implications in understanding how chromosome integrity and the position and state of the mitotic spindle are monitored before cytokinesis.

Recent advances in the residue analysis of N-methylcarbamate pesticides

This paper highlights recent advances in the determination of methylcarbamate residues in water, soil and plant tissues. Chromatographic analyses (e.g., HPLC, GC, supercritical fluid chromatography and TLC) with various sample pretreatment procedures and detection methods are reviewed. More generally, some non-chromatographic techniques such as immunoassay, biosensor and spectrophotometry are included.

A rare variant of mirror hand: a case report

Mirror hand is one of the rarest congenital differences of the upper extremity. Typically, there is absence of the radius, duplication of the ulna, and 7 digits in mirrored symmetry about the middle finger. We report a case of a rarer subset of hand duplication in which there is a normal radius and ulna and a hand with 8 digits. The patient underwent surgery to excise the radial 3 digits and to reconstruct the remaining radial digit to function as an opposable, 2 phalanx thumb. Wrist extension was augmented by transferring the digital extensors from the excised fingers to the radial wrist extensors.

Microbial corrosion of aluminum alloy

Several microbes were isolated from the contaminated fuel-oil in Taiwan and the microbial corrosion of aluminum alloy A356-T6 was tested by MIL-STD-810E test method. Penicillium sp. AM-F5 and Cladosporium resinac ATCC 22712 had significant adsorption and pitting on the surface of aluminum alloy, Pseudomonas acruginosa AM-B5 had weak adsorption and some precipitation in the bottom, and Candida sp. AM-Y1 had the less adsorption and few cavities formation on the surface. pH of the aqueous phase decreased 0.3 to 0.7 unit for 4 months of incubation. The corrosion of aluminum alloy was very significant in the cultures of Penicillium sp. AM-F2, Penicillium sp. AM-F5 and C. resinac ATCC 22712. The major metabolites in the aqueous phase with the inoculation of C. resinac were citric acid and oxalic acid, while succinic acid and fumaric acid were the minors.

Evaluation of micellar electrokinetic capillary chromatography for the analysis of selected tobacco alkaloids

Micellar electrokinetic capillary chromatography was evaluated for simultaneous determination of several tobacco alkaloids with similar molecular structure. Satisfactory separation of nicotine, nornicotine, myosmine, anatabine and anabasine extracted from tobacco was achieved by introducing an ionic surfactant, sodium dodecyl sulfate, into the buffer system at a concentration of 100 mM. Sample preparation involved a single extraction with water containing 1% triethanolamine. Separation was performed on a 72 cm long, uncoated fused-silica capillary. Experimental parameters such as applied voltage, pH value, buffer composition and surfactant concentration were optimized. Enhancement of UV absorption of alkaloids in the presence of micelles was also studied.

Identification of the mitogen-activated protein kinase phosphorylation sites on human Sos1 that regulate interaction with Grb2

The Son of sevenless proteins (Sos) are guanine nucleotide exchange factors involved in the activation of Ras by cytoplasmic and receptor tyrosine kinases. Growth factor stimulation rapidly induces the phosphorylation of Sos on multiple serine and threonine sites. Previous studies have demonstrated that growth factor-induced Sos phosphorylation occurs at the C-terminal region of the protein and is mediated, in part, by mitogen-activated protein (MAP) kinase. In this report, we describe the identification of five MAP kinase sites (S-1137, S-1167, S-1178, S-1193, and S-1197) on hSos1. We demonstrate that four of these sites, S-1132, S-1167, S-1178, and S-1193, become phosphorylated following growth factor stimulation. The MAP kinase phosphorylation sites are clustered within a region encompassing three proline-rich SH3-binding sites in the C-terminal domain of hSos1. Replacing the MAP kinase phosphorylation sites with alanine residues results in an increase in the binding affinity of Grb2 to hSos1. Interestingly, hSos2 contains only one MAP kinase phosphorylation site and, as demonstrated previously, has an increased affinity toward Grb2 compared with hSos1. These results suggest a role for MAP kinase in the regulation of Grb2-Sos interactions. Since the binding of Grb2 is important for Sos function, the phosphorylation-dependent modulation of Grb2-Sos association may provide a means of controlling Ras activation.

Multiple carpometacarpal dislocations. A case report and review of treatment

Carpometacarpal dislocations of the ulnar four joints are rare injuries that are usually associated with high-energy trauma. Given the small number of cases reported, there exists some controversy regarding their optimal management. The case of a 27-year-old man who sustained a dorsal dislocation (without associated fractures) of the ulnar four carpometacarpal joints as a result of a fall from a height is presented. The literature regarding these hand injuries is reviewed, and the need for anatomic reduction and stabilization is discussed.

[Gastric emptying in non-insulin dependent diabetic patients]

Disordered gastrointestinal motility is an often overlooked clinical problem. Delayed gastric emptying of solid and/or liquid meal in patients with both type 1 and type 2 diabetes mellitus occurs in approximately 50% of these patients. Gastric emptying time (GET) was studied in seventy four non-insulin dependent (type 2) diabetic out-patients by using radionuclide gamma-photography with Tc-99m phytate solid experimental meal. Thirty nine of them received Tc-99m phytate liquid test meal on the next day. Forty six normal healthy volunteers acted as controls. The results showed that solid GET in patients with type 2 diabetes mellitus was significantly delayed (149.44 +/- 64.0 min) as compared with that in the control group (88.7 +/- 14.2 min) (p < 0.001). Fifty three among these 74 diabetic patients had delayed solid GET, accounting for 71.6%. Only 5 of 39 (12.8%) diabetic patients showed delayed liquid GET (average 38.7 +/- 35.3 min; control 46.2 +/- 11.1 min). There were no differences in sugar control, duration of the disease, and upper gastrointestinal symptoms between patients with delayed GET and those with normal GET. We concluded that delayed gastric emptying is very common in patients with non-insulin dependent diabetes mellitus and which has no direct correlation to blood sugar control, duration of the disease, and upper gastrointestinal symptoms. Radionuclide solid gastric emptying test is a both safe (low radioactivity) and convenient (non-invasive) diagnostic tool in non-insulin dependent diabetic gastroparesis.

Paraganglioma of the interatrial septum

The case of a patient undergoing successful resection of an interatrial septal paraganglioma is presented. The diagnosis of an interatrial mass was established preoperatively by echocardiography, ultrafast cine computed tomographic scan, and cardiac catheterization. The tumor was excised in total, and the interatrial septum and the roof of the left atrium were reconstructed using a bovine pericardial patch.