Screening travelers for hepatitis A antibodies: an observational cost-comparison study of vaccine use

OBJECTIVES

To measure the seroprevalence of antibodies to hepatitis A virus (anti-HAV) in a health plan population of travelers and to determine whether prevaccination screening for anti-HAV can reduce unnecessary vaccination and thus promote the most effective, economic use of hepatitis A vaccine.

DESIGN

Observational, cost-comparison study.

SETTING

Central injection clinic of a health maintenance organization medical center.

SUBJECTS

Five hundred twenty-seven adults who denied having previous hepatitis A or vaccination. MAIN OUTCOME MEASURES Subgroups with the greatest prevalence of anti-HAV seen between June 1995 and April 1996 for immunizations before traveling to nonindustrialized countries. Relative costs of their screening and immunization.

RESULTS

The presence of anti-HAV precluded the need for vaccination in 148 subjects (28.1%). The highest prevalence of anti-HAV (82.7%) was found in subjects born in nonindustrialized countries (62/75), in subjects who had previously traveled to areas of endemic hepatitis A (32.1% [135/420]), and in subjects born before 1945 (29.2% [92/315]). Costs of screening and vaccinating travelers were cheapest if prevaccination antibody sera testing was limited to subjects born in nonindustrialized countries and those born before 1945.

CONCLUSIONS

Prevaccination screening of travelers for hepatitis A can be done selectively on the basis of age and country of origin. This strategy could lead to a more economic use of the vaccine and clinic resources.

Blastocyst viability and generation of transgenic cattle following freezing of in vitro produced, DNA-injected embryos

This study examined whether the viability, determined in vitro, of DNA-injected bovine embryos produced in vitro was affected by freezing, and if the frozen embryos developed to term following transfer to recipients. In vitro fertilized zygotes were injected with the pBL1 gene and then co-cultured with mouse embryonic fibroblasts (MEF) in CR1aa medium. Embryos were prepared for cryopreservation by exposure to a 10% (v/v) glycerol solution, loaded into 0.25 ml straws and then frozen by conventional slow freezing. Thawing was by rapid warming in water (37 degrees C) and embryos were rehydrated in PBS diluents of 6%, 3% and 0% (v/v) glycerol supplemented with 0.25 M sucrose and 0.5% (w/v) BSA. In Experiment 1, blastocysts that developed from DNA-injected embryos were individually classified into three morphological groups and three stages of development prior to freezing. DNA-injected blastocysts of excellent quality at freezing showed a higher survival rate (78.8+/-10.6%) after thawing than those of good (60. 9+/-16.4%) or fair (12.5+/-5.9%) quality (P<0.05). Post-thaw survival rate, judged in vitro, increased with more advanced stage of blastocyst development at freezing (early 48.8+/-15.9%, mid 52. 1+/-12.6% and expanded 71.2+/-1.1; P<0.05). In Experiment 2, the frozen/thawed embryos were transferred to recipients to examine in vivo viability. Following transfer of one or two embryos per recipient, pregnancy rates at 60 days of gestation were 13.6% (13/96) for frozen embryos and 26.5% (43/162) for fresh embryos (P<0. 05). Of the 12 live calves born from the frozen/thawed embryos, two males (18.3%) were transgenic. None of the live-born calves derived from fresh embryos exhibited the transgene. One of transgenic bulls did not produce transgenic sperm. Three out of 23 calves (13.0%) produced from cows inseminated with semen of the other bull were transgenic, suggesting that this animal was a germ-line mosaic. These studies indicated that the viability of in vitro produced, DNA-injected bovine blastocysts was affected by freezing and by both the quality and stage of development of the embryo prior to freezing. The generation of transgenic cattle demonstrates that it is feasible to freeze DNA-injected, in vitro produced embryos.

In vitro development of reconstructed porcine oocytes after somatic cell nuclear transfer

This study was designed to examine the developmental ability of porcine embryos after somatic cell nuclear transfer. Porcine fibroblasts were isolated from fetuses at Day 40 of gestation. In vitro-matured porcine oocytes were enucleated and electrically fused with somatic cells. The reconstructed eggs were activated using electrical stimulus and cultured in vitro for 6 days. Nuclear-transferred (NT) embryos activated at a field strength of 120 V/mm (11.6 +/- 1.6%) showed a higher developmental rate as compared to the 150-V/mm group (6.5 +/- 2.3%) (P: < 0.05), but the mean cell numbers of blastocysts were similar between the two groups. Rates of blastocyst development from NT embryos electrically pulsed at different times (2, 4, and 6 h) after electrofusion were 11.6 +/- 2.9, 6.6 +/- 2.3, and 8.1 +/- 3.3%, respectively. The mean cell numbers of blastocysts developed from NT embryos were gradually decreased (30.4 +/- 10.4 > 24.6 +/- 10.1 > 16.5 +/- 7.4 per blastocyst) as exposure time (2, 4, and 6 h) of nuclei to oocyte cytoplast before activation was prolonged. There was a significant difference in the cell number between the 2- and 6-h groups (P: < 0. 05). Nuclear-transferred embryos (9.4 +/- 0.9%) had a lower developmental rate than in vitro fertilization (IVF)-derived (21.4 +/- 1.9%) or parthenogenetic embryos (22.4 +/- 7.2%) (P: < 0.01). The mean cell number (28.9 +/- 11.4) of NT-derived blastocysts was smaller than that (38.6 +/- 10.4) of IVF-derived blastocysts (P: < 0. 05) and was similar to that (29.9 +/- 12.1) of parthenogenetic embryos. Our results suggest that porcine NT eggs using somatic cells after electrical activation have developmental potential to the blastocyst stage, although with smaller cell numbers compared to IVF embryos.

The binding of Proteus mirabilis nonagglutinating fimbriae to ganglio-series asialoglycolipids and lactosyl ceramide

Proteus mirabilis is a common opportunistic Gram-negative uropathogen that infects the upper urinary tract. We have examined the role of the nonagglutinating fimbriae (NAF) of P. mirabilis in mediating bacterial adhesion to cell surface receptors. Purified NAF of P. mirabilis were demonstrated to bind to a number of glycolipids, including asialo-GM1, asialo-GM2, and lactosyl ceramide (LacCer) in solid-phase binding assays and in thin layer chromatography (TLC) overlay assays. Furthermore, preincubation of the biotinylated NAF (Bt-NAF) with anti-NAF monoclonal antibodies resulted in inhibition of NAF binding to immobilized asialo-GM1, asialo-GM2, and LacCer. In adherence assays, P. mirabilis binding to Madin-Darby canine kidney (MDCK) cells was inhibited by murine anti-asialo-GM1 monoclonal antibodies H2G10 to about 50% of the binding level in the absence of the antibody, specific for the terminal beta-galactopyranosyl residue of asialo-GM1 (Harrison et al. 1998). The results of this study suggest that NAF of P. mirabilis recognize a GalNAc beta 1-4Gal moiety present in the ganglio-series of asialoglycolipids, and that the terminal beta-galactopyranosyl-containing glycoconjugates play a role in NAF-mediated adherence of P. mirabilis to MDCK cells. Similarly to other bacteria, P. mirabilis NAF was also shown to express the LacCer specificity.

All optical quasi-steady-state photorefractive spatial solitons

We have created a one- (rather than two-) dimensional quasi-steady-state photorefractive spatial soliton induced by a laser beam instead of an applied electric field. The formation of this type of spatial soliton depends on the intensity of the self-trapped beam, which is different from quasi-steady-state spatial solitons reported in the literature. The optically induced spatial soliton can be exploited in all optical switching applications.

Neurotransmitters, neuropeptides and calcium binding proteins in developing human cerebellum: a review

Many endogenous neurochemicals that are known to have important functions in the mature central nervous system have also been found in the developing human cerebellum. Cholinergic neurons, as revealed by immunoreactivities towards choline acetyltransferase or acetylcholinesterase, appear early at 23 weeks of gestation in the cerebellar cortex and deep nuclei. Immunoreactivities gradually increase until the first postnatal month. Enkephalin is localized in the developing cerebellum, initially in the fibers of the cortex and deep nuclei at 16-20 weeks and then also in the Purkinje cells, granule cells, basket cells and Golgi cells at 23 weeks onward. Another neuropeptide, substance P, is localized mainly in the fibers of the dentate nucleus from 9 to 24 weeks but substance P immunoreactivity declines thereafter. GABA, an inhibitory neurotransmitter of the central nervous system, starts to appear at 16 weeks in the Purkinje cells, stellate cells, basket cells, mossy fibers and neurons of deep nuclei. GABA expression is gradually upregulated toward term forming networks of GABA-positive fibers and neurons. Catecholaminergic fibers and neurons are also detected in the cortex and deep nuclei at as early as 16 weeks. Calcium binding proteins, calbindin D28K and parvalbumin, make their first appearance in the cortex and deep nuclei at 14 weeks and then their expression decreases toward term, while calretinin appears later at 21 weeks but its expression increases with fetal age. The above findings suggest that many neurotransmitters, neuropeptides and calcium binding proteins (1) appear early during development of the cerebellum; (2) have specific temporal and spatial expression patterns; (3) may have functions other than those found in the mature neural systems; and (4) may be able to interact with each other during early development.

C. elegans nuclear envelope proteins emerin, MAN1, lamin, and nucleoporins reveal unique timing of nuclear envelope breakdown during mitosis

Emerin, MAN1, and LAP2 are integral membrane proteins of the vertebrate nuclear envelope. They share a 43-residue N-terminal motif termed the LEM domain. We found three putative LEM domain genes in Caenorhabditis elegans, designated emr-1, lem-2, and lem-3. We analyzed emr-l, which encodes Ce-emerin, and lem-2, which encodes Ce-MAN1. Ce-emerin and Ce-MAN1 migrate on SDS-PAGE as 17- and 52-kDa proteins, respectively. Based on their biochemical extraction properties and immunolocalization, both Ce-emerin and Ce-MAN1 are integral membrane proteins localized at the nuclear envelope. We used antibodies against Ce-MAN1, Ce-emerin, nucleoporins, and Ce-lamin to determine the timing of nuclear envelope breakdown during mitosis in C. elegans. The C. elegans nuclear envelope disassembles very late compared with vertebrates and Drosophila. The nuclear membranes remained intact everywhere except near spindle poles during metaphase and early anaphase, fully disassembling only during mid-late anaphase. Disassembly of pore complexes, and to a lesser extent the lamina, depended on embryo age: pore complexes were absent during metaphase in >30-cell embryos but existed until anaphase in 2- to 24-cell embryos. Intranuclear mRNA splicing factors disassembled after prophase. The timing of nuclear disassembly in C. elegans is novel and may reflect its evolutionary position between unicellular and more complex eukaryotes.

Potent and stage-specific action of glutathione on the development of goat early embryos in vitro

The effect of glutathione (GSH) addition on the development of 1- or 2-cell goat early embryos in vitro was examined. Embryos were collected from superovulated Korean black goat (Capra hircus aegagrus) and cultured for 6 days in synthetic oviduct fluid medium supplemented with either bovine serum albumin (BSA) or serum. Without GSH addition, almost all embryos could not develop beyond 8- to 16-cell block. However, GSH addition greatly improved in vitro development of early embryos to blastocyst stage, and its action was highly dependent on the presence and source of proteins supplemented into the culture medium. Among the protein-supplemented cultures, GSH effect was most prominent in 10% FBS-supplemented culture, in which the proportion (91%) of blastocysts developed from early embryos was much higher than that of BSA- (42-64% depending on its content) or goat serum (GS)-supplemented cultures (21%), or even than that of somatic cell-supported co-culture (60%). As well as in terms of the morphological development, mean cell number of blastocysts (185 +/- 12) developed from FBS condition was significantly higher than that of blastocysts developed from any other culture conditions and moreover comparable to that of blastocysts developed in vivo (190 +/- 9). The viability of these blastocysts was finally confirmed by their term development (6/12) from embryo transfer. To delineate action time of GSH during embryo development, GSH was treated at 1-day intervals through 6-days culture periods excepting the last day. In the GSH-treated embryos at day 3 of culture, which corresponds to the time of in vitro 8- to 16-cell block stage, the proportion of blastocyst was markedly increased up to 77% of cultured embryos and conversely that of the arrested embryos was decreased to 7%. In the embryos treated later, however, their developmental potency decreased abruptly. Therefore, these results clearly demonstrated that GSH could greatly improve the in vitro development of goat early embryos by specifically acting on the 8- to 16-cell block stage during in vitro development, suggesting that GSH may be one of the important regulators on the development of goat embryos in vivo.

Effect of intravenous omeprazole on recurrent bleeding after endoscopic treatment of bleeding peptic ulcers

BACKGROUND

After endoscopic treatment of bleeding peptic ulcers, bleeding recurs in 15 to 20 percent of patients.

METHODS

We assessed whether the use of a high dose of a proton-pump inhibitor would reduce the frequency of recurrent bleeding after endoscopic treatment of bleeding peptic ulcers. Patients with actively bleeding ulcers or ulcers with nonbleeding visible vessels were treated with an epinephrine injection followed by thermocoagulation. After hemostasis had been achieved, they were randomly assigned in a double-blind fashion to receive omeprazole (given as a bolus intravenous injection of 80 mg followed by an infusion of 8 mg per hour for 72 hours) or placebo. After the infusion, all patients were given 20 mg of omeprazole orally per day for eight weeks. The primary end point was recurrent bleeding within 30 days after endoscopy.

RESULTS

We enrolled 240 patients, 120 in each group. Bleeding recurred within 30 days in 8 patients (6.7 percent) in the omeprazole group, as compared with 27 (22.5 percent) in the placebo group (hazard ratio, 3.9; 95 percent confidence interval, 1.7 to 9.0). Most episodes of recurrent bleeding occurred during the first three days, which made up the infusion period (5 in the omeprazole group and 24 in the placebo group, P<0.001). Three patients in the omeprazole group and nine in the placebo group underwent surgery (P=0.14). Five patients (4.2 percent) in the omeprazole group and 12 (10 percent) in the placebo group died within 30 days after endoscopy (P=0.13).

CONCLUSIONS

After endoscopic treatment of bleeding peptic ulcers, a high-dose infusion of omeprazole substantially reduces the risk of recurrent bleeding.

A comparative evaluation of polytetrafluoroethylene, umbilical vein, and saphenous vein bypass grafts for femoral-popliteal above-knee revascularization: a prospective randomized Department of Veterans Affairs cooperative study

PURPOSE

Currently, the choice of a vascular prosthesis for a femoral-popliteal above-knee arterial bypass graft is left to the surgeon's preference, because the available information on comparative evaluations is inconclusive. The Department of Veterans Affairs (VA) Cooperative Study 141 was established to identify whether improved patency exists with different bypass graft materials for patients with femoral-popliteal above-knee bypass grafts.

METHODS

Between June 1983 and June 1988, 752 patients at 20 VA medical centers were randomized to receive either an externally supported polytetrafluoroethylene (PTFE; N = 265), human umbilical vein (HUV; N = 261), or saphenous vein (SV; N = 226) for an above-knee femoral-popliteal bypass graft. The indication for the bypass grafting operation was limb salvage in 67.5% of the patients. Patients were observed every 3 months for the first year and every 6 months thereafter. All patients were instructed to take aspirin (650 mg) daily for the duration of the study.Doppler-derived ankle-brachial indices (ABIs) were determined preoperatively and serially postoperatively. A bypass graft was considered to be patent when the Doppler-derived postoperative ABI remained significantly improved (more than 0.15 units higher than their preoperative value) and additional objective information, such as angiograms or operations, did not contradict these observations. Patency failure also included bypass grafts that were removed because of an infection or aneurysmal degeneration. Patency rates were compared by using the Kaplan-Meier life table analysis.

RESULTS

The cumulative assisted primary patency rates were statistically similar among the different conduit types at 2 years (SV, 81%; HUV, 70%; PTFE, 69%). After 5 years, above-knee SV bypass grafts had a significantly (P </=.01) better patency rate (73%) than HUV bypass grafts (53%), which had a significantly (P </=.01) better patency rate than PTFE bypass grafts (39%). Limb salvage was slightly worse with PTFE conduits. The number of bypass graft thromboses and major amputations within the first 30 days was highest in the HUV group.

CONCLUSION

The overall results of this prospective randomized study suggest that the SV should be considered as the bypass graft of choice for femoral-popliteal above-knee reconstruction and that, when a prosthetic bypass graft is used, an HUV should also be considered as an alternative choice to PTFE.

Effect of short interspersed element sequences on the integration and expression of a reporter gene in the preimplantation-stage mouse embryos

Based on the assumption that foreign DNA sequences may have increased chance of integration into the host genome if they are flanked by high copy-numbered genomic sequences such as SINEs (short interspersed elements), we investigated the integration frequency of Lac Z reporter gene flanked by a fused B1/B2 in an in vivo system using pronuclear microinjection technique in the mouse. The SINE-flanked DNA showed a 4-fold increased integration frequency of the reporter gene than the control DNA (63% vs. 16%). Moreover, the level of beta-galactosidase expression, estimated from the X-Gal staining intensity in transgenic embryos, was greatly higher in SINE-carrying DNA. These results suggest that the SINE sequences can serve a very useful tool in improving the efficiency of current transgenic animal technology.

Production of biologically active human granulocyte colony stimulating factor in the milk of transgenic goat

We have developed a transgenic female goat harboring goat beta-casein promoter/human granulocyte colony stimulating factor (G-CSF) fusion gene by microinjection into fertilized one-cell goat zygotes. Human G-CSF was produced at levels of up to 50 microg/ml in transgenic goat milk. Its biological activity was equivalent to recombinant human G-CSF expressed from Chinese hamster ovary (CHO) cell when assayed using in vitro HL-60 cell proliferation. Human G-CSF from transgenic goat milk increased the total number of white blood cells in C57BL/6N mice with leucopenia induced by cyclophosphamide (CPA). The secreted human G-CSF was glycosylated although the degree of O-glycosylation was lower compared to CHO cell-derived human G-CSF.

Outcome and quality of life of patients with acute pancreatitis requiring intensive care

BACKGROUND

Patients with severe acute pancreatitis often require intensive care unit (ICU) admission, have multiple complications, spend weeks to months in the hospital, and consume a large amount of resources. The aim of this study was to evaluate the ICU course, costs, mortality, and quality of life of patients who require ICU admission for acute pancreatitis.

METHODS

Patients with acute pancreatitis requiring ICU admission were identified retrospectively. Data regarding in-hospital morbidity, mortality, and hospital costs were obtained. Long-term quality of life was assessed using the Short Form-36 Health Survey (SF-36).

RESULTS

Fifty-two patients were identified. There were 31 men and 21 women: the mean age was 53 years (range, 22-89). The most common causes of acute pancreatitis were gallstones (44%) and alcoholism (17%). Pulmonary failure (52% required mechanical ventilation) and renal failure (21% required dialysis) were common. There were 39 (75%) hospital survivors and 13 (25%) nonsurvivors. In the first 24 h, the mean Acute Physiology and Chronic Health Evaluation (APACHE) II scores were 10 +/- 6 in survivors and 16 +/- 4 in the nonsurvivors (<0.01). Mean length of ICU (15 +/- 18 and 28 +/- 31 days) and hospital (40 +/- 34 and 38 +/- 34 days) stays were similar in survivors and nonsurvivors, respectively (NS). The mean hospital cost for survivors was $83,611 +/- 88,434 and that for nonsurvivors was $136,730 +/- 95,045 (P = 0. 09). The estimated cost to obtain one hospital survivor was $129,188. Of the 39 hospital survivors, 5 died later, 21 completed the SF-36, and 13 were lost to follow-up. Long-term quality of life (SF-36) was similar to that of an age-matched population. Twenty of twenty-one felt their general health was at least as good as it had been 1 year previously.

CONCLUSIONS

Patients with severe acute pancreatitis need prolonged ICU and hospital stays. APACHE II may be a good predictor of outcome; further, prospective evaluation is needed. Although resource utilization is high, most patients survive and have good long-term quality of life.

The Drosophila melanogaster sex determination gene sisA is required in yolk nuclei for midgut formation

During sex determination, the sisterlessA (sisA) gene functions as one of four X:A numerator elements that set the alternative male or female regulatory states of the switch gene Sex-lethal. In somatic cells, sisA functions specifically in sex determination, but its expression pattern also hints at a role in the yolk cell, a syncytial structure believed to provide energy and nutrients to the developing embryo. Previous studies of sisA have been limited by the lack of a null allele, leaving open the possibility that sisA has additional functions. Here we report the isolation and molecular characterization of four new sisA alleles including two null mutations. Our findings highlight key aspects of sisA structure-function and reveal important qualitative differences between the effects of sisA and the other strong X:A numerator element, sisterlessB, on Sex-lethal expression. We use genetic, expression, clonal, and phenotypic analyses to demonstrate that sisA has an essential function in the yolk nuclei of both sexes. In the absence of sisA, endoderm migration and midgut formation are blocked, suggesting that the yolk cell may have a direct role in larval gut development. To our knowledge, this is the first report of a requirement for the yolk nuclei in Drosophila development.

Improved development of DNA-injected bovine embryos co-cultured with mouse embryonic fibroblast cells

The in vitro development of DNA-injected bovine zygotes, produced in vitro, was compared when cultured with or without mouse embryonic fibroblasts (MEF). The in vivo viability of the embryos produced in these in vitro culture systems was assessed by single or double transfer to recipients taken to term. For these experiments, in vitro fertilized oocytes were not injected (Experiment 1) or were injected with pBL1 gene (Experiment 2) and then cultured for 2 days in CR1aa medium supplemented with 3 mg/ml BSA at 38.5 degrees C in a humidified atmosphere of 5% CO(2) in air. Embryos that developed to the 4- to 8-cell stage at the end of this period were randomly assigned to the two cultured systems and cultured for a further 5 days in groups of 10 to 15 embryos in 0.75 ml medium. These two culture systems were CR1aa medium alone or co-culture with MEF in CR1aa medium supplemented with 10% fetal bovine serum (FBS). Every 48 h, 0.5 ml of the medium was replaced with fresh CR1aa medium and at Day 5 of culture, both media were supplemented by the addition of 5.56 mM glucose and 1x GMS-X supplement solutions. Results were assessed as morphological development of the embryos and data were analyzed by Chi-square test or Student's t-test. The development rate of in vitro fertilization (IVF)-derived embryos co-cultured with MEF (24.4%, 49/201) was significantly higher than those cultured alone (14.4%, 28/194; P<0.05) in Experiment 1. There was a similar difference between the treatments in the proportions of embryos which reached the hatching stage or hatched (10.9%, 22/201 vs. 4.1%, 8/194, respectively; P<0.05). DNA-injected embryos co-cultured with MEF (13.7%, 28/205) showed a higher developmental rate than that of the embryos cultured without MEF (6.7%, 13/193; P<0.05) in Experiment 2. Following the transfer to recipients of one or two DNA-injected blastocysts, the pregnancy rates for two culture systems were similar (MEF co-culture 27.4%, 23/84; CR1aa culture 24. 2%, 16/66). However, the numbers of calves born alive from these pregnancies were higher on the MEF co-culture group (82.6%, 19/23) than the CR1aa culture group (56.2%, 9/16). It was concluded that in vitro embryo development to the blastocyst stage and subsequent in vivo development to term of DNA-injected bovine embryos was improved in comparison to culture in CR1aa alone when the last 5 days of in vitro culture were in a MEF co-culture system.

Molecular cloning and characterization of the mouse peroxiredoxin V gene

We have cloned two cDNA isoforms as well as genomic sequences of the mouse Prx V gene and characterized their molecular genetic features. Two isoforms of the mouse Prx V cDNA were identified from liver and testis. The testis-originated long transcripts had extra 1164-bp 5'-UTR sequences compared to the liver-originated short transcripts. Primer extension and sequence analyses revealed that the two isoforms were presumably transcribed at the same gene locus. The gene was composed of six exons spanning 3.2 kb. The short transcript was abundantly expressed in the kidney, liver, and heart of the adult mouse tissues and in the extra-membrane of the 10.5 dpc embryos. The long transcript of 1985 bp was abundantly detected in testis with trace amounts in other tissues. Interestingly, in testis and fetus, only mRNA expression of the long form was identified. However, the protein expression was not found in testis, implying that the long form could not properly direct the protein expression. The long Prx V cDNA has eight uORFs in the extra 5'-UTR, which proceed the major ORF. The inability of protein expression for the long-form cDNA in testis suggests that the uORFs might inhibit translation of the major ORF and thereby confer the tissue-specific regulation of the mouse Prx V gene.

Myelomatous effusion with poor response to chemotherapy

While pleural effusion in multiple myeloma is relatively infrequent, myelomatous pleural effusion is extremely rare. We experienced a 61-year-old woman with IgD-lambda multiple myeloma and pleural effusion. The diagnosis was made originally by pleural biopsy, pleural fluid cytology and immunoelectropheresis of pleural fluid. Transient improvement of the pleural effusion was observed after administration of combination chemotherapy of vincristine, melphalan, cyclophosphamide, prednisone (VMCP)/vincristine, cyclophosphamide, adriamycin, prednisone (VCAP). Two months later, myelomatous pleural effusion recurred and no response to salvage therapy was observed. We reviewed the clinical feature of this case and literature concerning myelomatous pleural effusion.

Bmp-4 requires the presence of the digits to initiate programmed cell death in limb interdigital tissues

The effects of Bmp-4 on interdigital cell death were investigated in the mouse. Affi-Gel beads, loaded with recombinant Bmp-4 protein, were transplanted into the interdigital tissues of day 12.5 hindlimb, ex utero. It was established that Bmp-4 could induce precocious interdigital cell death. Using in situ hybridization, the expression patterns of bmp-4 and alk-6 receptor were established. Both genes were found coexpressed in the interdigital region of 12.5- and 13. 5-day hindlimbs. This suggests that Bmp-4 may act in an autocrine fashion. We have also studied the effects of Bmp-4 on 12.5-day interdigital tissue cultures. In all specimens examined, the interdigital tissues produced cartilage instead of participating in cell death. The addition of exogenous Bmp-4 to the interdigital cultures did not induce apoptosis but instead enhanced chondrogenesis. The discrepancy between the effects of Bmp-4 in vitro and ex utero was attributed to the presence of digits. When a flanking digit was left attached to the interdigital tissues, in vitro, Bmp-4 promoted apoptosis instead of chondrogenesis. In sum, the results suggest that Bmp-4 is a multifunctional protein and its effect on the interdigital tissues is dependent on the modulating influence of the digits.

Purification and partial characterization of a toxic serine protease produced by pathogenic Vibrio alginolyticus

An extracellular lethal toxin produced by Vibrio alginolyticus strain Swy originally isolated from diseased kuruma prawn (Penaeus japonicus) was purified using the AKTA purifier system with hydrophobic interaction chromatography, anion exchange and gel filtration columns. The toxin is an alkaline serine protease, inhibited by phenyl methylsulphonyl fluoride (PMSF), antipain and shows maximal activity at pH 8 to 11, having a pI of 4.3 and a molecular weight of approximately 33 kD. The toxin was completely inhibited by FeCl2 but partially inhibited by 3,4-dichloroisocoumarin (3,4-DCI), ethylenediamine tetraacetic acid (EDTA), ethylene glycol-bis(beta-amino-ethyl ether) N,N,N',N'-tetraacetic acid (EGTA), CuCl2 and ZnCl2. The purified protease was lethal for kuruma prawn at an LD50 of 0.29 microgram protein/g body weight. The haemolymph withdrawn from the moribund prawns injected with the toxic protease was unable to clot. The coagulogen in the kuruma prawn plasma showed an increased migration rate after incubation with this serine protease, and a plasma colour change from blue to pink was recorded. The addition of PMSF completely inhibited the lethal toxicity of the purified protease, indicating that this serine protease was a lethal toxin produced by the bacterium. The 33 kD protease was therefore a toxic protease produced by V. alginolyticus strain Swy.

Lethal attribute of serine protease secreted by Vibrio alginolyticus strains in kuruma prawn Penaeus japonicus

Toxicity of the extracellular products (ECP) and the lethal attribute of serine protease secreted by five pathogenic Vibrio alginolyticus strains from various sources in kuruma prawn Penaeus japonicus were studied. The ECPs of organisms originally isolated from diseased kuruma prawn or small abalone Haliotis diversicolor supertexta were more lethal (LD50 value of 0.48 or 0.41 microg protein/g prawn) than those from diseased tiger prawn P. monodon, yellowfin porgy Acanthopagrus latus or horse mackerel (LD50 value of 0.98-1.17 microg protein/g prawn). All the ECPs manifested strong, weak and no activities against gelatin, sheep erythrocytes and chitin, respectively. In immunodiffusion tests using rabbit antiserum to a purified 33 kDa serine protease of strain Swy against ECP of each tested strain produced one single precipitation band in each treatment. Furthermore, the serine protease was suggested to be the dominant protease secreted by V. alginolyticus strains tested since the majority of enzymatic activity of the respective ECP was inhibited by phenylmethanesulfonyl fluoride (PMSF). A higher inhibition of serine protease activity by PMSF resulted in lower mortality rate of the ECPs injected into the prawns suggesting that the protease is one of the major lethal factor(s) secreted by V. alginolyticus.

Efficient integration of short interspersed element-flanked foreign DNA via homologous recombination

We investigated whether mouse short interspersed elements (SINEs) could influence the recombination frequency of foreign DNA. Vectors harboring a reporter gene in combinations of SINEs B1 and/or B2 or a portion of long interspersed element-1 were prepared and tested in vitro by a colony assay using HC11 murine mammary epithelial cells and in vivo by microinjection into fertilized mouse eggs. In transfected HC11 cells, the number of colonies surviving G418 selection increased by 3.5-fold compared with control when the reporter was flanked by fused B1-B2 sequences. Similar results were obtained from microinjection study; in fetuses 11.5 days post coitum, transgene positives in control and SINE-flanked vectors were 16 and 53%, respectively. Individual B1- and B2-harboring vectors showed equivalent activities with each other, as determined by the colony assay (2.8-fold versus 3.2-fold compared with control). We determined the contribution of homologous recombination to the SINE-mediated increase in integration frequency through a polymerase chain reaction-based strategy; in more than half of embryos transgenes underwent homologous recombinations involving B1 sequences. These results demonstrate that the SINE sequences can increase the integration rate of foreign DNA and that such an increase is most likely due to the enhancement of homologous recombination.

Bioactive indole alkaloids from the bark of Uncaria guianensis

Bioassay-guided fractionation of the EtOH extract of the bark of Uncaria guianensis (Aubl.) Gmel (Rubiaceae) using a yeast-based assay for DNA-damaging agents has furnished the two weakly but selectively active indole alkaloids uncarine C (1) and uncarine E (2) as the major bioactive constituents in this assay.

Comparative evaluation of externally supported Dacron and polytetrafluoroethylene prosthetic bypasses for femorofemoral and axillofemoral arterial reconstructions. Veterans Affairs Cooperative Study #141

PURPOSE

Currently, the choice of a vascular prosthesis for an extra-anatomic arterial bypass graft is left to the surgeon's preference because well-designed comparative evaluations have not been performed. The Department of Veterans Affairs Cooperative Study 141 was organized to identify whether there is improved patency with different prosthetic grafts for patients with femorofemoral or axillofemoral bypass grafts.

METHODS

Between June 1983 and June 1988, patients at 20 Veterans Affairs Medical Centers who had aortoiliac occlusive disease but were not considered suitable candidates for aortic bypass surgery were randomized to receive either an externally supported polytetrafluoroethylene or Dacron bypass graft for an extra anatomic bypass. Doppler-derived ankle brachial indices (ABIs) were determined before the operation and serially after the operation. Patients were seen in follow-up every 3 months for the first year and every 6 months thereafter. All patients were instructed to take 650 mg of aspirin each day for the duration of the study. A bypass graft was considered to be patent if the Doppler-derived postoperative ABI remained significantly improved (0.15 units above the preoperative value), and additional clinical information (such as subsequent ABIs, angiograms, or operations) did not contradict these observations.

RESULTS

Three hundred forty patients with femorofemoral bypass grafts and 79 patients with axillofemoral or axillofemorofemoral bypass grafts were randomized. The indication for the bypass operation was limb salvage in 72% of the patients. The assisted primary patency rate for a Dacron bypass grafting was 79% at 1 year, 63% at 3 years, and 50% at 5 years; for polytetrafluoroethylene bypass grafting, the patency was 77% at 1 year, 62% at 3 years, and 47% at 5 years.

CONCLUSION

The overall results of this prospective randomized study suggest that the current choices of prosthetic bypass grafting have similar long-term patency in patients who undergo femorofemoral or axillofemoral vascular reconstruction.

Expression and characterization of bioactive human thrombopoietin in the milk of transgenic mice

Human thrombopoietin (hTPO) is the primary physiological regulator of platelet production and plays a pivotal role in promoting the proliferation and maturation of megakaryocytic progenitor cells and megakaryocytes. In this study, transgenic mice were produced harboring either full-length or the erythropoietin (EPO)-like amino-terminal domain of hTPO cDNA sequences fused to the regulatory elements of the bovine beta-casein gene. The transgene RNA was expressed exclusively in the mammary glands of eight transgenic mice, and a trace amount of the transgene was also found in the lungs of one mouse. The full-length form induced efficient expression of the protein with the highest expression level of 1500 microg/ml; however, the EPO-like domain alone expressed the protein at <0.1 microg/ml. The proteins from the two recombinant cDNAs have apparent molecular weights of about 74 and 17 kDa, due to glycosylation in the case of the full-length cDNA. Cell proliferation assay in vitro indicated that both of the recombinant forms stimulated proliferation of the TPO-dependent BaF3-Mpl cells. A positive correlation appeared between the amount of TPO in the milk of lactating animals and their blood platelet levels. About a twofold increase in platelet numbers in the blood was observed after direct subcutaneous injection of the recombinant hTPO at the level of 30 microg/kg of body weight. On the basis of these results, we anticipate that the recombinant hTPO produced efficiently in milk of transgenic mice will have the same activities as the native hTPO in a few in vivo as well as in vitro biochemical aspects.