Total occlusion of left main coronary artery by dilated main pulmonary artery in a patient with severe pulmonary hypertension

A 34-year-old woman was admitted to the hospital because of recently aggravated right heart failure without angina for 5 months. When she was 25 years old, patch repair with Polytetrafluoroethylene (PTFE) was performed for the secondum type of atrial septal defect (ASD) with moderate pulmonary hypertension. The chest PA, echocardiography and cardiac catheterization at current admission revealed Eisenmenger syndrome without intracardiac shunt. Chest CT scan with contrast revealed markedly dilated pulmonary trunk, both pulmonary arteries and concave disfigurement of the left side of the ascending aorta suggesting extrinsic compression, as well as total occlusion of the ostium of the left main coronary artery that was retrogradly filled with collateral circulation from the right coronary artery. The coronary angiography showed normal right coronary artery and the collaterals that come out from the conus branch to the mid-left anterior descending artery (LAD) and that from distal right coronary artery to the left circumflex artery (LCX) and to the distal LAD, respectively. On aortography, the left main coronary artery was not visualized with no stump, suggestive of total occlusion of the ostium of the left main coronary artery. From our experience, it is possible to say that the occlusion of the ostium of the left main coronary can be induced by the dilated pulmonary artery trunk due to ASD with pulmonary hypertension and that, if the ASD closure was too late, the narrowing or obstruction of the left coronary artery could not be resolved even after operation owing to irreversible pulmonary hypertension.

Analysis of vivax malaria cases in Gangwon-do (province), Korea in the year 2000

A total of 827 malaria cases were reported in the Gangwon-do in the year 2000. There were 18.2 cases per 100,000 inhabitants. There were 283 cases among civilians and 544 cases among the military. 90.6% of cases were reported in Cheorwon--(531), Hwacheon--(152), and Goseong--(66) gun (county), which bordered the demilitarized zone (DMZ). A distinct feature pertaining to the malaria cases in Gangwon-do is that the number of cases has increased about two times over the last year. The mean time from the beginning of symptoms to malaria diagnosis was five days. Control systems for malaria by public health organizations and military organizations are well maintained, but were not able to reduce the malaria prevalence rate. The cause for the increase in pattern of the malaria cases in Gangwon-do may be caused by the spreading of prevalent areas of malaria to the east. Continuous endeavor such as early detection of cases, early treatment, education on clinical symptoms and prevention of mosquito bites with repellent and mosquito nets will help to reduce the infection rate of malaria in Gangwon-do.

Enterobius vermicularis egg positive rates in primary school children in Gangwon-do (province), Korea

A survey of the infection rate of Enterobius vermicularis among students in 4 primary schools located in Gangwon-do (Province) was done from May to June 2001. Among the 398 examinees, 39 (9.8%) were infected with E. vermicularis demonstrated by the adhesive cellotape anal swab method. The infection rates ranged from 8.3% to 11.8% among the four schools. The infection rate of males and females was 10.7% and 7.7% respectively. The first grade students showed the highest infection rate, 28.7%. The confirmed cases were treated with albendazole three times at an interval of 15 days. We were able to confirm that E. vermicularis infection is still prevalent among students in Gangwon-do, Korea.

Primary tubercolous osteomyelitis of the sternum

We present an 82-year-old woman with anterior sternal pain diagnosed as primary mycobacterial osteomyelitis of the sternum. She was treated with simultaneous wide resection and reconstruction of the chest wall. On admission, computed tomographic scan showed a sclerotic sternal mass with soft tissue reaction. Mycobacterium tuberculosis was grown in initial culture. First-line antituberculous medication and local debridement failed. The successful result was achieved by extensive sternal and chondral resection followed by simultaneous bilateral pectoralis major muscle flap positioning.

Occurrence of a diploid type and a new first intermediate host of a human lung fluke, Paragonimus westermani, in Korea

The biology, chromosome number, and karyotype of a lung fluke, Paragonimus westermani (Kerbert, 1878) collected in Haenam, Haenam-gun Chollanam-do, Korea were analyzed. We compared the size of metacercariae from Haenam with those taken from a crayfish collected at Youngam, Youngam-gun, Chollanam-do, Korea. The mean length of P. westermani metacercariae from Haenam was 300.3 microm and that from Youngam was 362.0 microm. Adult worms were recovered from the lungs of experimentally infected dogs. The mean egg sizes obtained from adult flukes were 72.1 x 46.8 microm from Haenam and 93.5 x 54.2 microm from Youngam. Semisulcospira tegulata collected in the Youngam area were found to be infected with cercariae of P. westermani, one of the snail-borne human lung fluke trematodes in Korea. Of 4218 snails studied, 5 (0.12%) harbored P. westrermani larvae. This is the first report of S. tegulata serving as the initial intermediate host of P. westermani. The chromosome numbers of P. westermani from Haenam and Youngam were 2n = 22 and 3n = 33. The diploid type of P. westermani has not been previously reported in Korea.

Rac1 regulates heat shock responses by reorganization of vimentin filaments: identification using MALDI-TOF MS

Rac1 has been implicated in a wide variety of biological processes, including actin remodeling and various signaling cascades. Here we have examined whether Rac1 might be involved in heat shock-induced cell signaling. We found that Rat2 stable cells expressing a dominant negative Rac1 mutant, RacN17 (Rat2-RacN17), were significantly more tolerant to heat shock than control Rat2 cells, and simultaneously inhibited the activation of SAPK/JNK by heat shock compared to control Rat2 cells. However, no discernible effect was observed in typical heat shock responses including total protein synthesis and heat shock protein synthesis. To identify the proteins involved in this difference, we separated the proteins of both Rat2 and Rat2-RacN17 cell lines after heat shock using two-dimensional gel electrophoresis and identified the differentially expressed proteins by matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) after in-gel trypsin digestion. Differentially expressed proteins between two cell lines were identified as vimentin. Rat2-RacN17 cells showed significant changes in vimentin as well as marked changes in vimentin reorganization by heat shock. The vimentin changes were identified as N-terminal head domain cleavage. These results suggest that Rac1 plays a pivotal role in the heat shock-induced signaling cascade by modifying intermediate vimentin filaments.

Crystal structure and kinetic analysis of beta-lactamase inhibitor protein-II in complex with TEM-1 beta-lactamase

The structure of the 28 kDa beta-lactamase inhibitor protein-II (BLIP-II) in complex with the TEM-1 beta-lactamase has been determined to 2.3 A resolution. BLIP-II is a secreted protein produced by the soil bacterium Streptomyces exfoliatus SMF19 and is able to bind and inhibit TEM-1 with subnanomolar affinity. BLIP-II is a seven-bladed beta-propeller with a unique blade motif consisting of only three antiparallel beta-strands. The overall fold is highly similar to the core structure of the human regulator of chromosome condensation (RCC1). Although BLIP-II does not share the same fold with BLIP, the first beta-lactamase inhibitor protein for which structural data was available, a comparison of the two complexes reveals a number of similarities and provides further insights into key components of the TEM-1-BLIP and TEM-1-BLIP-II interfaces. Our preliminary results from gene knock-out studies and scanning electron microscopy also reveal a critical role of BLIP-II in sporulation.

Molt-inhibiting hormone immunoreactive neurons in the eyestalk neuroendocrine system of the blue crab, Callinectes sapidus

The production of ecdysteroid molting hormones by crustacean Y-organs is negatively regulated by a neuropeptide, molt-inhibiting hormone. It is generally agreed that molt-inhibiting hormone is produced and released by the eyestalk neuroendocrine system. In the present study, immunocytochemical methods were used to detect molt-inhibiting hormone immunoreactive neurons in eyestalk ganglia of the blue crab, Callinectes sapidus. The primary antiserum used was generated against molt-inhibiting hormone of the green shore crab, Carcinus maenas. A preliminary Western blot analysis indicated the antiserum binds molt-inhibiting hormone of Callinectes sapidus. Using confocal and conventional immunofluorescence microscopy, molt-inhibiting hormone immunoreactivity was visualized in whole mounts and thin sections of Callinectes sapidus eyestalk ganglia. Immunoreactivity was detected in 15-25 neurosecretory cell bodies in the medulla terminalis X-organ, their associated axons and collateral branches, and their axon terminals in the neurohemal sinus gland. The cellular organization of molt-inhibiting hormone immunoreactive neurons in blue crabs is generally similar to that reported for other crab species. The combined results suggest the cellular structure of the molt-inhibiting hormone neuroendocrine system is highly conserved among brachyurans.

Evolving strategies and improving outcomes of the modified norwood procedure: a 10-year single-institution experience

BACKGROUND

This study reviews our 10-year experience with the modified Norwood procedure to determine its early and midterm outcomes. The focus is on the impact of evolving management strategies and accumulated institutional experience.

METHODS

A modified Norwood operation was performed in 171 infants over a 10-year period. Sixty-eight percent of the infants were male, the median age at operation was 6 days (range 1 to 175 days), and the median weight was 3.3 kg (range 1.7 to 4.8 kg). The 10-year period was divided into three eras: era I; 1990 through 1993; era II; 1994 through 1997; and era III; 1998 into 2000. Outcomes and risk factors for mortality were sought.

RESULTS

Hypoplastic left heart syndrome or a variant was the primary diagnosis in 118 infants (69%). The overall 5-year survival rate was 43%. Multivariate analysis revealed that only need of preoperative ventilatory support, earlier date of operation, and lower weight at operation were significant independent predictors of increased time-related mortality. Morphologic features such as a diagnosis other than hypoplastic left heart syndrome, ascending aortic size, and noncardiac anomalies were not significantly associated with an increased risk of death. The hospital survival rate for stage-one palliation in era III was 82%, significantly better than that in the preceding eras (p < 0.001). Attrition between stages one and two accounted for a 15% mortality rate among hospital survivors.

CONCLUSIONS

With increasing experience and improvements in perioperative care and surgical technique, good outcomes can be expected for the first-stage modified Norwood procedure. Greater monitoring of patients in the interstage period may reduce interval mortality and improve overall survival.

Self-expanding coil stent with a long delivery system for palliation of unresectable malignant gastric outlet obstruction: a prospective study

BACKGROUND AND STUDY AIMS

Peroral intubation of a self-expanding metal stent is usually difficult in patients with unresectable malignant gastric outlet obstruction, because the delivery systems currently available are not long enough and cannot easily pass the angulated gastroduodenal structure. We carried out a prospective study to assess the efficacy of a coil stent with a newly developed long delivery system, for palliation of unresectable malignant gastric outlet obstruction.

PATIENTS AND METHODS

In 29 patients with unresectable malignant gastric outlet obstruction, caused by gastric cancer (26 patients), pancreatic head cancer (two patients), or duodenal cancer (one patient), peroral intubation of a self-expanding nickel-titanium coil stent was attempted, using a lengthened delivery system of 150 cm, under endoscopic and fluoroscopic guidance.

RESULTS

Management was successful in 26 of 29 patients (89.7 %) without immediate major complications. In one patient in whom peroral intubation failed, percutaneous intubation of the coil stent via percutaneous endoscopic gastrostomy was done. After insertion of the coil stent, food ingestion with symptomatic improvement with regard to vomiting was achieved in 26 of 27 patients (96.3 %), including the patient with percutaneous stent insertion. During the follow-up period, dysphagia and Karnofsky scores improved significantly. Stent migration occurred in two patients, and tumor ingrowth in another two; re-intervention was done successfully performed in two instances. The mean survival time was 124 days (range 34 - 310 days) in the 22 patients who had no need for re-intervention during follow-up; among these was a patient who experienced stent occlusion by food material, which was easily corrected with endoscopic flushing.

CONCLUSIONS

Peroral intubation of a self-expanding coil stent using a long delivery system is a safe and effective palliative technique for unresectable malignant gastric outlet obstruction, and significantly improves the quality of life of patients.

The role of Tyr248 probed by mutant bovine carboxypeptidase A: insight into the catalytic mechanism of carboxypeptidase A

We have investigated the function of Tyr248 using bovine wild-type CPA and its Y248F and Y248A mutants to find that the K(M) values were increased by 4.5-11-fold and the k(cat) values were reduced by 4.5-10.7-fold by the replacement of Tyr248 with Phe for the hydrolysis of hippuryl-L-Phe (HPA) and N-[3-(2-furyl)acryloyl]-Phe-Phe (FAPP), respectively. In the case of O-(trans-p-chlorocinnamoyl)-L-beta-phenyllactate (ClCPL), an ester substrate, the K(M) value was increased by 2.5-fold, and the k(cat) was reduced by 20-fold. The replacement of Tyr248 with Ala decreased the k(cat) values by about 18- and 237-fold for HPA and ClCPL, respectively, demonstrating that the aromatic ring of Tyr248 plays a critical role in the enzymic reaction. The increases of the K(M) values were only 6- and 5-fold for HPA and ClCPL, respectively. Thus, the present study indicates clearly that Tyr248 plays an important role not only in the binding of substrate but also in the enzymic hydrolysis. The kinetic results may be rationalized by the proposition that the phenolic hydroxyl of Tyr248 forms a hydrogen bond with the zinc-bound water molecule, causing further activation of the water molecule by reducing its pK(a) value. The pH dependency study of k(cat) values and the solvent isotope effects also support the proposition. A unified catalytic mechanism is proposed that can account for the different kinetic behavior observed in the CPA-catalyzed hydrolysis of peptide and ester substrates.

Resetting wave forms in dictyostelium territories

The mechanism by which spiral wave patterns appear in populations of Dictyostelium was probed experimentally by external chemical perturbation. Spiral waves, which often arise from the breakup of circular waves driven by pacemakers, typically entrain those pacemakers. We studied these processes by resetting the waves with a spatially uniform pulse of extrinsic cyclic AMP. A pattern of spirals reappeared if resetting was early in the signaling stage, but only targets emerged following late resetting, in a manner analogous to cardiac defibrillation. This supports recent hypotheses that wave pattern selection naturally occurs by slow temporal variation of the excitability of the cells.

Fatal pulmonary-renal syndrome manifested with immune complex crescentic glomerulonephritis in a patient with MPO-ANCA seropositivity

Recent reports have indicated that a significant number of immune complex glomerulonephritis (GN) cases are associated with antineutrophilic cytoplasmic antibody (ANCA). However, most of the reported cases were associated with underlying primary glomerular diseases. When primary glomerular diseases were not found, immune deposits tended to be non-specific and the level of ANCA is usually borderline. We report here upon a case of life-threatening pulmonary-renal syndrome manifested simultaneously with immune complex GN and myeloperoxidase (MPO)-ANCA seropositivity. A 29- year-old man was admitted with pulmonary hemorrhage and rapidly progressing renal dysfunction. On admission, ANCA revealed perinuclear staining with a titer of 1:160. The MPO-ANCA level was 59 IU by ELISA. Other serologic markers including ANA, anti-DS-DNA and anti-GBM Ab were negative. Renal biopsy showed cellular crescents in eight of 18 glomeruli. Immunofluorescence staining showed strong granular deposits of C3, C1q, IgG and IgM in the capillary loop and the mesangium. Electron microscopy showed multifocal electron dense deposits scattered in the mesangium, paramesangium, and the subendothelial and subepithelial areas. The patient initially responded to steroid and cyclophosphamide. MPO-ANCA decreased to less than 10 IU. Twenty three days after hospital discharge, the patient was re-admitted urgently with fever, generalized papulonodular skin lesions, and a recurrence of massive pulmonary hemorrhage and renal dysfunction. He died from uncontrolled pulmonary hemorrhage and respiratory insufficiency. P-ANCA titer and MPO-ANCA level at the second admission were 1:320 and 82 U/ml respectively. Interestingly, relapse was shown to be triggered by varicella zoster infection.

A study on the distribution of chlorination by-products (CBPs) in treated water in Korea

Fifteen chlorination by-products were analyzed in 416 water samples collected from 35 water treatment plants in Korea from 1996 to 1998. These samples were divided into five groups according to water sources (Han-river, Nakdong-river, Youngsan-river, Kum-river and Cheju) and detected CBPs were classified into six classes (trihalomethanes; THMs, haloacetic acids; HAAs, haloacetonitriles: HANs haloketones; HKs, chloralhydrate; CH, chloropicrin; CP) and then, it was observed the detection tendency and frequency of CBPs in each water source. The total concentration of CBPs in treated water from Nakdong-river or Han-river was higher than those from the other rivers. And the distribution pattern of each class of CBPs was similar in all water sources. THMs were the highest portion in the range of 40-50%, and HAAs and HANs were 28-35 and 9-15%, respectively. And there was a strong correlation between HANs and HKs (r=0.813). Each and total concentrations of CBPs showed to be more affected by the water source in two-way analysis of variance (two-way ANOVA) among the concentration of CBPs, the source of water and season.

Influence of ovariectomy on ventricular myocyte contraction in simulated diabetes

We studied the effect of ovariectomy (OVX) on cardiac contraction in myocytes maintained under a 'diabetes-simulated high-glucose' environment. Female rats were ovariectomized or sham operated (SHAM) and kept for 6 weeks. Isolated myocytes were maintained in a diabetes-simulated high [glucose] medium (HG; 25.5 mM) for 24 h before mechanical properties were measured. Contractile indices analyzed included peak shortening (PS), time to PS (TPS), time to 90% relengthening (TR90), maximal velocity of shortening and relengthening (+/- dL/dt), intracellular Ca2+ fura-2 fluorescence intensity and decay rate (tau). Nitric oxide synthase (NOS) activity was also evaluated. OVX myocytes displayed a longer TR(90), slower +/- dL/dt, lower fluorescence intensity and higher tau (slower decay rate) when compared to SHAM myocytes. In the SHAM group, HG exerted diabetes-like contractile dysfunctions, including depressed PS, prolonged TR90, reduced fluorescence intensity, higher tau and enhanced NOS activity when compared to myocytes maintained in low [glucose] medium (5.5 mM). Interestingly, the HG- induced mechanical alterations were significantly exaggerated (TPS, TR90 and tau), reversed (PS and NOS) or lost (+/- dL/dt and fluorescence intensity) in the OVX group. These data suggest that ovarian hormones play a role in the regulation of cardiac contractile function, and may have potentially protective effects against diabetes-associated cardiac dysfunction.

Restriction fragment length dimorphism-PCR method for the detection of extended-spectrum beta-lactamases unrelated to TEM- and SHV-types

The diagnostic ability of the restriction fragment length dimorphism-polymerase chain reaction (RFLD-PCR) method was evaluated. Seven primer pairs, newly designed from 44 beta-lactamase genes encoding extended-spectrum beta-lactamases not related to TEM- and SHV-types, were used to differentiate OXA-2, FOX-3, CMY-3, IMP-1, and IMI-1 beta-lactamases. The RFLD-PCR was carried out successfully, and these genes were differentiated by the sizes of their PCR products and by the difference in restriction fragment length when each amplicon was digested with a unique restriction enzyme. This discriminatory detection of the genes was confirmed by sequencing the PCR products.

Clinical Features and Prognosis of Lung Cancer with Brain Metastasis

PURPOSE

Brain metastasis is estimated to occur in 20~40% of solid tumor patients and the most common primary tumor is lung cancer. Even though the prognosis of brain metastasis is grave and the 1-year survival rate is only 15%, symptom palliations are made with whole brain radiation therapy. We retrospectively evaluated the clinical features and prognostic factors of lung cancer with brain metastasis.

MATERIALS AND METHODS

From January 1987 to October 1999, 50 lung cancer patients with brain metastasis underwent whole brain radiation therapy. We reviewed the improvement in neurologic symptoms and survival according to the following parameters; performance status, histological type, presence of brain metastasis at the initial diagnosis of lung cancer, presence of extracranial metastasis, multiplicity of brain lesion, presence of primary lung symptom and treatment modalities.

RESULTS

The most frequent symptom with brain metastasis was a headache (50%). Palliation of the headache and other symptoms was achieved in 81% of the patients. Median overall survival after brain metastasis was 21 weeks and the 1 year survival rate was 15%. Patients without extracranial metastasis had a longer median survival than those with, 38 weeks versus 15 weeks, respectively (p=0.01).

CONCLUSION

In lung cancer with brain metastasis, neurologic symptoms can be palliated with whole brain radiation therapy, and in this study among such patients, absence of extracranial metastasis can be a good prognostic factor.

Efficacy of use of colonoscopy in dextran sulfate sodium induced ulcerative colitis in rats: the evaluation of the effects of antioxidant by colonoscopy

The goals in developing animal models of inflammatory bowel disease (IBD) are to determine the underlying mechanisms and the action of currently available drugs and to evaluate the value of new therapeutic approaches. Because of the difficulty in determining the severity of colitis in living animals, it has been necessary to kill the experimental animals at varying stages in the studies. If colonoscopic evaluation or endoscopic biopsy is feasible in these experimental animals, continuous observations could be possible, thus avoiding the need to kill them. The aims of the current study were to assess the efficacy of endoscopic examination as a monitoring tool for the severity of colitis in rats and to the efficacy of DA-9601, an extract from Artemisia asiatica which has both antioxidative and cytoprotective actions, on dextran sulfate sodium induced ulcerative colitis in rats endoscopically. Sprague-Dawley rats received 4% DSS in drinking water for 5 consecutive days. Either DA-9601 or sulfasalazine was administered twice a day for 8 days, starting 3 days before DSS administration. After the colonoscopic evaluations on days 2, 4, and 5 after DSS administration the rats were also killed for gross and histopathological evaluations. Simultaneous measurements of malondialdehyde (MDA) and myeloperoxidase (MPO) activities were performed. There was a statistically significant correlation between the scores evaluated by the gross examination and colonoscopic scores, between the colonoscopic scores and the levels of MDA or mucosal MPO activities, and between colonoscopic scores and histopathological activity index. DA-9601 showed excellent improvement in gross lesion scores, decreased MDA amounts and MPO activities compared to sulfasalazine. In conclusion, the introduction of appropriate colonoscopic examination in animal models of IBD could avoid the sacrifice of experimental animals for interim evaluation and provide the valuable information on the course and efficacy of treatment. The potential usefulness of antioxidants in treating IBD is very promising based on the colonoscopic intervention of IBD.

Substance p plays a critical role in photic resetting of the circadian pacemaker in the rat hypothalamus

Glutamate is considered to be the primary neurotransmitter in the retinohypothalamic tract (RHT), which delivers photic information from the retina to the suprachiasmatic nucleus (SCN), the locus of the mammalian circadian pacemaker. However, substance P (SP) also has been suggested to play a role in retinohypothalamic transmission. In this study, we sought evidence that SP from the RHT contributes to photic resetting of the circadian pacemaker and further explored the possible interaction of SP with glutamate in this process. In rat hypothalamic slices cut parasagittally, electrical stimulation of the optic nerve in early and late subjective night produced a phase delay (2.4 +/- 0.5 hr; mean +/- SEM) and advance (2.6 +/- 0.3 hr) of the circadian rhythm of SCN neuronal firing activity, respectively. The SP antagonist L-703,606 (10 microm) applied to the slices during the nerve stimulation completely blocked the phase shifts. Likewise, a cocktail of NMDA (2-amino-5-phosphonopentanoic acid, 50 microm) and non-NMDA (6,7-dinitroquinoxaline-2,3-dione, 10 microm) antagonists completely blocked the shifts. Exogenous application of SP (1 microm) or glutamate (100 microm) to the slices in early subjective night produced a phase delay ( approximately 3 hr) of the circadian firing activity rhythm of SCN neurons. Coapplication of the NMDA and non-NMDA antagonist cocktail (as well as L-703,606) resulted in a complete blockade of the SP-induced phase delay, whereas L-703,606 (10 microm) had no effect on the glutamate-induced delay. These results suggest that SP, as well as glutamate, has a critical role in photic resetting. Furthermore, the results suggest that the two agonists act in series, SP working upstream of glutamate.

An application of artificial neural intelligence for personal dose assessment using a multi-area OSL dosimetry system

Significant advances have been made in recent years to improve measurement technology and performance of phosphor materials in the fields of optically stimulated luminescence (OSL) dosimetry. Pulsed and continuous wave OSL studies recently carried out on alpha-Al2O3:C have shown that the material seems to be the most promising for routine application of OSL for dosimetric purposes. The main objective of the study is to propose a new personal dosimetry system using alpha-Al2O3:C by taking advantage of its optical properties and energy dependencies. In the process of the study, a new dose assessment algorithm was developed using artificial neural networks in hopes of achieving a higher degree of accuracy and precision in personal OSL dosimetry system. The original hypothesis of this work is that the spectral information of X- and gamma-ray fields may be obtained by the analysis of the response of a multi-element system. In this study, a feedforward neural network using the error back-propagation method with Bayesian optimization was applied for the response unfolding procedure. The validation of the proposed algorithm was investigated by unfolding the 10 measured responses of alpha-Al2O3:C for arbitrarily mixed photon fields which range from 20 to 662 keV.

Reproductive efficiency and maternal-offspring transfer of gossypol in rainbow trout (Oncorhynchus mykiss) fed diets containing cottonseed meal

In a preceding study, complete substitution of fish meal protein with cottonseed meal (CM) protein did not affect the survival or growth rate of adult rainbow trout over a 6-mo period. Gossypol, a naturally occurring compound in cottonseeds, has an antifertility effect in terrestrial animals, but information regarding salmonid fish is lacking. Female rainbow trout in this experiment were fed diets with either 0, 25, 50, 75, or 100% (diets 1 to 5) of the fish meal protein replaced with CM protein until first maturation and spawning to study long-term effects on growth and reproduction. Feeding diets containing CM over a total period of 10 mo did not result in differences in growth and mortality compared to the control group (P > 0.05). Increased CM incorporation levels resulted in decreased (P < 0.05) blood hemoglobin (10.6 +/- 1.3, 8.4 +/- 1.8, 7.3 +/- 1.1, 6.9 +/- 0.8, and 5.6 +/- 1.4 g/dL) and hematocrit (49.6 +/- 3.9, 38.5 +/- 9.3, 34.4 +/- 3.7, 34.8 +/- 4.9 and 28.0 +/- 6.8%) levels in diets 1 to 5, respectively. The CM incorporation level had no effect (P > 0.05) on the number of eggs produced per female but led to a reduction (P < 0.05) in egg weight. Eyed stage survival of embryos was low in all dietary groups and did not show differences (P > 0.05). However, an increasing CM incorporation level led to a linear increase (P < 0.05) in the number of females that produced no viable embryos (23.1, 37.5, 42.9, 60.0, and 71.4%). Gossypol in the diet was absorbed by the female trout and transferred to the eggs (0, 2.2 +/- 0.5, 6.7 +/- 1.6, 10.6 +/- 4.2, and 20.0 +/- 2.6 micrograms/g in diets 1 to 5, respectively). A high concentration of gossypol remained in the juveniles at the swim-up stage (endogenous yolk-absorbed) (0.6 +/- 0.3, 2.4 +/- 0.3, 3.4 +/- 0.0, and 4.7 +/- 1.0 micrograms/g, diets 2 to 5, respectively). The findings suggest that replacement of the dietary fish meal protein with CM protein has no effect on fish growth and mortality but may lead to a reduction in reproductive performance in female rainbow trout.

Emergence of vaccine-induced escape mutant of hepatitis B virus with multiple surface gene mutations in a Korean child

The S protein of hepatitis B virus is the principal component of virus envelope and the primary target of anti-HBs response. Mutants or variants that escape neutralization by anti-HBs have been selected during immunoprophylaxis of HBV after birth and liver transplantation. We investigated a case of a Korean child who was vaccinated at birth against hepatitis B and also given hepatitis B immunoglobulin, but nevertheless later became infected with the virus. Hepatitis B virus-specific deoxyribonucleic acid covering the region of genome encoding the predominant "a" determinant of hepatitis surface antigen was amplified using polymerase chain reaction, and the nucleotide sequence was determined. We present for the first time in Korea the independent emergence of an escape mutant with substitution of arginine for glycine at amino acid 145 and proline for glutamate at amino acid 120 in "a" determinant after immunization.

Distinct roles for Ku protein in transcriptional reinitiation and DNA repair

Transcriptional reinitiation is a distinct phase of the RNA polymerase II transcription cycle. Prior work has shown that reinitiation is deficient in nuclear extracts from Chinese hamster ovary cells lacking the 80-kDa subunit of Ku, a double-strand break repair protein, and that activity is rescued by expression of the corresponding cDNA. We now show that Ku increases the amount or availability of a soluble factor that is limiting for reinitiation, that the factor increases the number of elongation complexes associated with the template at all times during the reaction, and that the factor itself does not form a tight complex with DNA. The factor may consist of a preformed complex of transcription proteins that is stabilized by Ku. A Ku mutant, lacking residues 687-728 in the 80-kDa subunit, preferentially suppresses transcription in Ku-containing extracts, suggesting that Ku interacts directly with proteins required for reinitiation. The Ku mutant functions normally in a DNA end-joining system, indicating that the functions of Ku in transcription and repair are genetically separable. Based on our results, we present a model in which Ku is capable of undergoing a switch between a transcription factor-associated and a repair-active state.