Progestin alone as primary treatment of endometrial carcinoma in premenopausal women. Report of seven cases and review of the literature

BACKGROUND

The standard treatment for endometrial carcinoma is staging laparotomy with total abdominal hysterectomy and bilateral salpingo-oophorectomy. In an attempt to preserve childbearing potential, selected patients with endometrial carcinoma were treated with progestin alone as primary therapy.

METHODS

Patients were identified through searches of tumor registries and solicitation of consulting gynecologic oncologists at the affiliated institutions of the University of California-Los Angeles Center for the Health Sciences. Only those patients with a diagnosis of endometrial carcinoma treated with progestin alone as primary therapy were included in the study. Independent pathologic review was performed by a recognized expert gynecologic pathologist to exclude cases of endometrial hyperplasia. A MEDLINE search was conducted to identify reports of similarly treated patients.

RESULTS

Seven patients were treated with progestin alone for endometrial carcinoma at the study institution. Fourteen additional patients were identified through the literature search. Combining the data for all patients, 13 of 21 patients (62%) had an initial response to progestins. Three initial responders later developed recurrent disease, one of whom was found to have extrauterine disease at laparotomy. Eight of 21 patients (38%) did not respond to progestins and underwent more definitive treatment. None of these patients later developed recurrent disease. Six viable infants were delivered of three patients after therapy. Nineteen of 21 patients were alive without evidence of disease at last follow-up.

CONCLUSIONS

The results of this study show that premenopausal women with endometrial carcinoma may be treated successfully with progestin therapy alone as primary therapy to preserve childbearing potential.

Troger's base molecular scaffolds in dicarboxylic acid recognition

Artificial receptors (1-5) have been designed and synthesized from simple precursors. The chain length selectivity studies of dicarboxylic acids within the cavities of new fluorescent Troger's base molecular frameworks (1-3) have been carried out with a critical examination of their role of rigidity as well as flexibility in selective binding in comparison to receptor 5. The chiral resolution of the racemic Troger's base receptors (1 and 2) by chiral recognition with (+)- camphoric acid using hydrogen-bonding interactions has been studied.

Effects of sequence of thioated oligonucleotides on cultured human mammary epithelial cells

We have compared the effects of a number of different oligonucleotides on the growth and morphology of normal finite life span and immortally transformed human mammary epithelial cells. The oligonucleotide sequences chosen initially for study were based on that of the NB-1 gene, which encodes a calmodulin-like protein of unknown function. We found that certain thioated oligonucleotides 15-20 residues in length altered the morphology and decreased the growth rate of the normal cells in a concentration-dependent manner. These effects were rapid, occurring within 24-48 h of oligonucleotide addition. The effects, which occurred without an accompanying detectable decrease in the levels of NB-1 mRNA or protein, were most pronounced in the normal epithelial cells, less apparent in the immortalized epithelial cells, and unobserved in normal breast fibroblasts. Identical sequences having mixed phosphodiester and phosphorothioate backbones, or phosphodiester backbones alone, had little or no effect on normal epithelial cell morphology or growth. Two out of seven additional thioated oligonucleotides which were not complementary to NB-1 mRNA, also affected normal epithelial cell morphology and growth when used at similar concentrations (10 microM). Taken together, the observed effects on normal epithelial cells indicate that certain thioated oligonucleotides may have pharmacological consequences that do not depend on strict complementarity of their sequences to known mRNAs.

Obstetrical outcomes among women with extrapulmonary tuberculosis

BACKGROUND

The prevalence of tuberculosis, especially extrapulmonary tuberculosis, is increasing worldwide. Because information on the outcome of pregnancy among women with extrapulmonary tuberculosis is limited, we studied the course of pregnancy and labor and the perinatal outcome in these women and their infants.

METHODS

From 1983 to 1993, we followed 33 pregnant women who had extrapulmonary tuberculosis (12 with tuberculous lymphadenitis and 9 with intestinal, 7 with skeletal, 2 with renal, 2 with meningeal, and 1 with endometrial tuberculosis) through their deliveries. Of the 33, 29 received antituberculosis treatment during pregnancy. The antenatal complications, intrapartum events, and perinatal outcomes were compared with those among 132 healthy pregnant women without tuberculosis who were matched for age, parity, and socioeconomic status.

RESULTS

Tuberculous lymphadenitis did not affect the course of pregnancy or labor or the perinatal outcome. However, as compared with the control women, the 21 women with tubercular involvement of other extrapulmonary sites had higher rates of antenatal hospitalization (24 percent vs. 2 percent, P< 0.001), infants with low Apgar scores (< or =6) soon after birth (19 percent vs. 3 percent, P=0.01), and low-birth-weight (<2500 g) infants (33 percent vs. 11 percent, P=0.01).

CONCLUSIONS

Extrapulmonary tuberculosis that is confined to the lymph nodes has no effect on obstetrical outcomes, but tuberculosis at other extrapulmonary sites does adversely affect the outcome of pregnancy.

Hereditary thrombophilia as a cause of Budd-Chiari syndrome: a study from Western India

The inherited deficiencies of protein C, protein S, antithrombin III, factor V Leiden mutation, prothrombin gene polymorphism, and antiphospholipids were studied in 53 Budd-Chiari syndrome (BCS) and 33 portal vein thrombosis (PVT) cases and compared with 223 age- and sex-matched controls. Protein C deficiency was detected in 7 (13.2%), protein S in 3 (5.7%), and antithrombin III in 2 (3.8%) of the BCS cases. Factor V Leiden was the most common risk factor, i.e., 14 of 53 (26.4%) in BCS cases followed by protein C, as compared with PVT cases, i.e., 2 of 33 (6.06%) and controls, i.e., 5 of 223 (2.3%). In PVT cases, protein C deficiency was present in 3 (9.09%), protein S deficiency in 1 (3.03%), and factor V Leiden mutation in 2 (6.06%) of the cases. The prothrombin gene polymorphism was not found in either the controls or the patients. The antiphospholipids were seen in 11 (20.75%) of the BCS cases and 6 (18.18%) of the PVT cases. Other acquired risk factors like pregnancy, surgery, and oral contraceptives were present in 8 (15.09%) of BCS and 3 (9.09%) of PVT cases. Thus overall, 59% of the BCS and 30% of the PVT cases could be explained by at least one of the etiologic factors studied.

A randomized trial comparing the dorzolamide-timolol combination given twice daily to monotherapy with timolol and dorzolamide. Dorzolamide-Timolol Study Group

OBJECTIVE

To compare the efficacy and safety of a fixed combination of 2.0% dorzolamide and 0.5% timolol administered twice daily with each of the individual components administered in their usual monotherapy dose regimens in patients who had washed out all ocular hypotensive medications.

DESIGN

A 3-month, parallel, randomized, double-masked, active-controlled, multicenter clinical trial.

PARTICIPANTS

A total of 335 patients with bilateral ocular hypertension or open-angle glaucoma participated.

INTERVENTION

After completing a washout of ocular hypotensive medications, patients were randomized to receive either the dorzolamide-timolol combination twice daily plus placebo once daily, 0.5% timolol twice daily plus placebo once daily, or 2.0% dorzolamide three times daily.

MAIN OUTCOME MEASURES

Intraocular pressure (IOP) was measured at morning trough (hour 0) and peak (2 hours postdose) on day 1, week 2, and months 1, 2, and 3. Ocular and systemic safety were evaluated at each study visit.

RESULTS

Intraocular pressure reduction was greater on average in the combination group than in the dorzolamide and timolol groups. At morning trough (month 3, hour 0), the mean reduction in IOP from baseline was 27.4% (-7.7 mmHg) for the combination, 15.5% (-4.6 mmHg) for dorzolamide, and 22.2% (-6.4 mmHg) for timolol. At morning peak (month 3, hour 2), the mean IOP reduction from baseline was 32.7% (-9.0 mmHg), 19.8% (-5.4 mmHg), and 22.6% (-6.3 mmHg) for the combination, dorzolamide, and timolol, respectively. Overall, the incidence of clinical adverse experiences was comparable between the combination and each of its components. The proportion of patients who discontinued from the study because of clinical adverse experiences was also comparable between the combination and dorzolamide, although it was significantly greater in the combination group than in the timolol group (7% vs. 1%, P = 0.035). Similarly, comparable numbers of patients in the combination and dorzolamide groups reported ocular symptoms; however, when compared to the timolol group, more patients receiving the combination reported blurred vision, burning eye, stinging eye, and tearing eye.

CONCLUSIONS

After a washout of ocular hypotensive therapy, the IOP-lowering effect of the dorzolamide-timolol combination was greater than that of either of its components administered as monotherapy. The combination is generally well-tolerated and provides a convenient alternative to concomitant therapy with its individual components.

Perinatal outcome in pregnancies complicated by pulmonary tuberculosis

OBJECTIVES

To assess the perinatal outcome of pregnancies complicated by active pulmonary tuberculosis.

METHODS

The perinatal outcome of 79 gravidas with pulmonary tuberculosis was compared with that of 316 normal gravidas of similar age, parity and socioeconomic status.

RESULTS

The mean birthweight of infants (2649 g) born to tuberculous mothers was 215 g less than that of control group (P < 0.001). Pulmonary tuberculosis was associated with an approximate 2-fold increase in prematurity (22.8% vs. 11.1%, P < 0.01), small for gestational age (20.2% vs. 7.9%, P < 0.005) and low birthweight neonates (34.2% vs. 16.5%, P < 0.001), and 6-fold increase in perinatal deaths (10.1% vs. 1.6%, P < 0.001). The adverse perinatal outcome was pronounced in cases with late diagnosis, incomplete and irregular treatment, and advanced pulmonary lesions.

CONCLUSIONS

Maternal tuberculosis is a high-risk perinatal condition. The study emphasizes the need for early diagnosis and treatment of tuberculosis, preferably before pregnancy, regular medical supervision and good perinatal care for tuberculous mothers.

A double-masked, randomized, 1-year study comparing the corneal effects of dorzolamide, timolol, and betaxolol. Dorzolamide Corneal Effects Study Group

OBJECTIVE

To compare the long-term effects of dorzolamide hydrochloride (Trusopt, Merck and Co Inc, White-house Station, NJ), timolol maleate, and betaxolol hydrochloride on corneal endothelial cell density and corneal thickness.

METHODS

This 1-year multicenter study was conducted in 298 patients with ocular hypertension or open-angle glaucoma who had a baseline central corneal endothelial cell density greater than 1500 cells/mm2 and central corneal thickness less than 0.68 mm in each eye. Patients were randomized to 0.5% betaxolol twice daily, 0.5% timolol twice daily, or 2.0% dorzolamide 3 times daily. Specular microscopy and ultrasonic pachymetry of the central cornea was performed at baseline and 6 and 12 months following institution of therapy. Endothelial cell densities were determined by a single masked observer.

RESULTS

The mean percent changes from baseline for both outcome measures were similar in all 3 treatment groups at both 6 and 12 months. After 1 year of treatment, the mean percent loss in endothelial cell density from baseline was 3.6%, 4.5%, and 4.2% for the dorzolamide, timolol, and betaxolol groups, respectively. The mean percent change from baseline for corneal thickness was 0.47%, -0.25%, and 0.39% for the dorzolamide, timolol, and betaxolol groups, respectively.

CONCLUSIONS

Dorzolamide is equivalent to timolol and betaxolol in terms of the change in central endothelial cell density and thickness after 1 year of therapy. All 3 treatments exhibit good long-term corneal tolerability in patients with normal corneas at baseline.

Deferoxamine improves spatial memory performance following experimental brain injury in rats

Traumatic brain injury (TBI) causes impairments of both motor and spatial memory performances. Research is only beginning to reveal the biochemical mechanism(s) underlying these deficits. It has been postulated that reactive oxygen species such as the superoxide and hydroxyl radicals, as well as the peroxynitrite anion, are generated by injury and may play a critical role in the observed memory deficits. The highly reactive hydroxyl radical, which is thought to contribute to neuronal toxicity, can be generated by an iron-catalyzed reaction. The source of this iron (or iron-bound proteins) could be a compromise of the blood-brain barrier, which can occur following TBI. In this report, we investigate the ability of deferoxamine, a scavenger of free iron, the hydroxyl radical and the peroxynitrite anion, to facilitate behavioral recovery following a controlled cortical impact of rats. Intraperitoneal administration of this drug prior to the injury did not affect the rate of recovery from motor deficits in comparison to vehicle (saline)-injected animals. However, deferoxamine-treated animals showed significant improvement in spatial memory performance in a Morris water maze task. Volumetric analysis of cortical tissue loss showed no significant differences between vehicle- and drug-injected animals. Similarly, histological examination of the hippocampus did not reveal any gross differences between the two groups. These results indicate that deferoxamine improves spatial memory performance, possibly through protection from neuronal dysfunction.

The effect of estrogens and antiestrogens in a rat model for hot flush

The present studies evaluated the effect of estrogens and the selective estrogen receptor modulator (SERM) tamoxifen and raloxifene in a rat model for hot flush. In this model, ovariectomized rats were treated for 8 or 9 days either sc or po. Rats were dependent to morphine by implanting a morphine pellet (75 mg each) sc on days 3 and 5 of treatment. On the last day of treatment, a thermistor, connected to a data acquisition system, was placed on the tail of each animal and morphine addiction was withdrawn by naloxone injection (1.0 mg/kg, sc). Temperature measurements were taken for 1 h under ketamine (80 mg/kg, im) anesthesia. In general, vehicle treated rats showed a 5-6 degrees C elevation of their tail skin temperature with the peak occurring about 15 min after naloxone injection. 17 alpha-Ethinyl estradiol (EE) was evaluated both sc and po using a broad range of doses. The IC50 for inhibition of tail skin temperature rise was approximately 0.1 mg/kg, sc and 0.2 mg/kg, po. 17 beta-Estradiol and 17 alpha-estradiol were also active in this model whereas non-estrogenic steroids were inactive. Raloxifene and tamoxifen were tested for estrogen agonist and antagonist activity administered sc and po. Raloxifene did not demonstrate reproducible estrogen agonist activity at doses up to 10 mg/kg, whereas it demonstrated significant antagonistic activity at the 10 mg/kg dose regardless of the route of administration. Tamoxifen exhibited significant estrogen agonist activity at all doses tested (0.1-10.0 mg/kg) and was a significant antagonist of EE at the 1.0 mg/kg dose. Our results demonstrate the potential utility of this model to evaluate and discriminate among classes of compounds with varying degrees of estrogen agonist and antagonist activity.

Reproducible methodology for the isolation of mesenchymal stem cells from human umbilical cord and its potential for cardiomyocyte generation

Mesenchymal stem cells (MSCs) are considered to be a source of stem cells in tissue regeneration and therapeutics, due to their ability to undergo proliferation and differentiation. Complications associated with bone marrow-derived MSCs has prompted researchers to explore alternative sources of MSCs. The human umbilical cord is one such source; it is easily available and its collection is non-invasive. The sources of MSCs are non-controversial and thus they are not subjected to ethical constraints, as in the case of embryonic stem cells. MSCs are multipotent stem cells and has the ability to differentiate into various cell types of the mesodermal lineage. The aim of this study was to establish a reproducible method for the isolation of MSCs from human umbilical cord, as the few methods published till date gave inconsistent results and had a mixed population of contaminating endothelial cells. In our isolation strategy, we isolated a pure population of MSCs from Wharton's jelly of the human umbilical cord, which is very rich in collagen, and we used a high concentration of collagenase enzyme in the isolation of MSCs. Extensive phenotypic characterization analysis of these cells, using flow cytometry and antibody staining methods, have shown that we were able to isolate a pure population of the mesenchymal lineage cells that is devoid of haematopoietic and endothelial cell contaminants. When these MSCs were subjected to cardiomyocyte differentiation, we observed a change in the morphological characteristics, which was accompanied by the formation of myotube structures and spontaneous beating after 21 days.

Experience with eosin-5'-maleimide as a diagnostic tool for red cell membrane cytoskeleton disorders

The diagnosis of hereditary spherocytosis (HS) is based on red cell morphology and other conventional tests such as osmotic fragility, autohemolysis and acidified glycerol lysis. However, milder cases are at times difficult to diagnose. Confirmation by red blood cell (RBC) membrane protein analysis is not possible in most laboratories. Recently, a flow cytometric method has been described for quantitating the fluorescence intensity of intact red cells after incubation with the dye eosin-5'-maleimide (EMA), which binds specifically to the anion transport protein (band-3) at lysine-430. This has been shown to be an effective screening test for red cell membrane disorders. We evaluated the usefulness of this approach for screening membrane protein disorders such as HS and hereditary elliptocytosis (HE) and its value in discriminating this group from other hemolytic anemias, such as glucose-6-phosphate dehydrogenase (G6PD) deficiency, beta-thalassemia trait, sickle cell anemia and autoimmune hemolytic anemia. Fluorescence intensity, expressed in mean channel fluorescence (MCF) units, was determined using a Becton Dickinson FACS Caliber flow cytometer. Membrane protein analysis was carried out by sodium dodecyl sulfate-polyacrylamide gel eletrophoresis (SDS-PAGE). RBCs from patients with HS and HE gave significantly lower MCF values (P < 0.001) than the normal control group and other patient groups. The diagnosis of HS in four cases was confirmed by RBC membrane protein electrophoresis and all showed a deficiency of spectrin. The advantage of the EMA dye method are its specificity for membrane disorders, as well as being a simple, user-friendly and rapid method which is inexpensive, provided a flow cytometer is available.

Venous thromboembolism in young patients from western India: a study

The goal of this article is to study the association of known markers of thrombophilia with venous thrombosis in young patients (< 45 years) from the Western part of India. A prospective study of 432 patients (252 males and 180 females, age 1-45 years) was conducted between 1994 and 2000 (6 years). The diagnosis was confirmed in all the patients by ultrasound with Doppler or by a computed tomograph (CT) scan of the brain with or without contrast depending on the case. Detailed clinical examination, and family history was taken to establish recurrent thrombosis and familial occurrence of thrombosis. The markers studied were protein C, protein S, antithrombin (AT) III, factor V Leiden mutation, prothrombin gene G20210A polymorphism, and the thermolabile MTHFR variant C677T polymorphism, using appropriate techniques. Lupus inhibitor was tested in the first 72 patients using Dilute Russel Viper Venom Time (DRVVT) test, and anticardiolipin antibodies were tested by enzyme-linked immunosorbent assay. Protein C, protein S, and AT III deficiency was detected in 9.5%, 6.5%, and 2.6%, respectively, among the patients. Anticardiolipin antibody was present in 9.9% of the patients, whereas lupus anticoagulant was present in 8.3% of patients; factor V Leiden mutation was detected in 3% of patients; thermolabile variant of MTHFR C677T polymorphism was present in 14.9% of patients with 1.2% homozygotes. Prothrombin G20210A polymorphism was not detected in any sample in this population. One hundred and four patients of 432 (24.9%) had recurrent attacks of thrombosis without any proximate precipitating cause, whereas 7.5 % of the patients had another close member of the family with a history of deep venous thrombosis. Eighty-six members from 28 families (out of 32 families giving family history of thrombosis) were investigated and found to have protein C and protein S deficiency in seven each; factor V Leiden was present in 6, and MTHFR C677T polymorphism was present in 5 cases. Hence, 25 of 86 members (28%) from the family of patients with familial history deep venous thrombosis had positive markers for thrombophilia. Thus, we could show that in young patients presenting with thrombosis, at least 34% of them had a demonstrable cause for thrombophilia. Prothrombin gene polymorphism G20210A seems to be nonexistent in our population and AT III deficiency also appears to be low compared to other markers of thrombophilia. There is a high prevalence of variant MTHFR C677T in our series, but the incidence of MTHFR C677T in our general population is also high. Hence, the significance of this finding in our cases of deep venous thrombosis remains to be seen, but we did not see any homozygotes when we tested 70 randomly selected asymptomatic persons, whereas in the present series, 1.8% of the patients had homozygosity for the MTHFR C677T polymorphism.

Fibrinolysis, inhibitors of blood coagulation, and monocyte derived coagulant activity in acute malaria

Different parameters of fibrinolytic systems like t-PA, PAI, D-dimer, and inhibitors of blood coagulation, i.e., protein C (PC), protein S(PS), and antithrombin III (AT-III), have been studied in cases of acute malaria due to Plasmodium falciparum and plasmodium vivax infection, and these patients were followed up. It was observed that the plasma PAI-1 was very high in cases of P. falciparum malaria infection as compared to normal controls and P. vivax infection. The changes in complicated cases of P. falciparum were remarkable as compared to uncomplicated ones. The PC, PS, and AT-III levels were also low in P. falciparum, particularly so in complicated cases, and were normal in P. vivax infection. The factor VIII R:Ag levels were invariably high in acute malaria. On follow-up of some of these cases the values came back to normal after the antiparasite treatment. The monocyte procoagulant activity was found to be significantly higher in P. falciparum infection as compared to that of P. vivax infection. All these findings therefore contribute towards the production of a hypercoagulable state in P. falciparum infection and partly explain the complications of P. falciparum infection like cerebral malaria.

Changes in platelet glycoprotein receptors after smoking--a flow cytometric study

Cigarette smoking is accepted to be one of the major factors which increase the risk of coronary artery disease, peripheral vascular disease and stroke. A number of studies have been carried out on the acute and chronic effects of tobacco smoking on platelet activation. An enhancing effect of high nicotine cigarette smoking on platelet aggregation has been reported. Since platelet receptors are involved in the final stage of platelet aggregation, the intention of this study was to investigate platelet receptors in acute and chronic smokers before and after smoking. Nineteen chronic smokers, 18 acute smokers and 18 healthy non-smoking controls were included in the present study. Platelet aggregation was carried out using ristocetin, adenosine diphosphate (ADP) and collagen both before and after smoking in acute and chronic smokers. Flow cytometric studies of platelets were carried out utilizing fluorescein isothiocyanate (FITC)-labelled anti-human fibrinogen antibody in unstimulated and ADP-stimulated platelets, FITC-labelled anti-GP IIb/IIa antibody, FITC-labelled anti-GP Ib/IX antibody and FITC-labelled P-selectin antibody. The intensity of fluorescence was graded into three groups and expressed in arbitrary units. The interesting data generated in the present work is that in vivo platelet activation occurs immediately after smoking a cigarette which is detected by using FITC-labelled anti-human fibrinogen antibody binding to platelet and by P-selectin expression. It is also quite evident from the present study that a significant number of circulating platelets are in the activated state in chronic smokers. Therefore this study suggests that smoking-induced platelet activation may be an important contributory mechanism for acute coronary events in smokers.

Vaccination with alum-precipitated recombinant Ancylostoma-secreted protein 1 protects mice against challenge infections with infective hookworm (Ancylostoma caninum) larvae

Ancylostoma-secreted protein 1 (ASP-1) is the major protein secreted by infective hookworm larvae (Ancylostoma caninum). The Escherichia coli-expressed recombinant protein was evaluated as a vaccine antigen in a mouse model of ancylostomiasis. A. caninum larvae migrate through mouse lungs, with maximal migration occurring 48-54 h after oral infection. Quantitative larval recovery from the lungs at this time was used as an end point for vaccine evaluation. All mice developed antibodies to recombinant ASP-1 (rASP-1) after immunization and boosting with the alum-precipitated protein. The immunized mice had their worm burden reduced 79% (P < .0001) compared with controls. Immunization with rASP-1 in the presence of Corynebacterium parvum adjuvant also showed a vaccine effect (63% protection; P < .0001). The possibility that this protective effect resulted from delayed larval lung entry was excluded. rASP-1 offers promise as a hookworm vaccine antigen.

Experimental approaches to the development of a recombinant hookworm vaccine

Hookworm infection is a major parasitic cause of morbidity in the developing nations of the tropics. Development of a genetically engineered vaccine would be a useful tool in the control of this infection in highly endemic areas. Recombinant polypeptides belonging to the Ancylostoma secreted protein (ASP)-1 family have shown promise for reducing hookworm burdens after larval challenge infections in mice. Typically, these polypeptides are expressed in Escherichia coli and administered as an alum precipitate. Vaccine protection is antibody dependent. It is anticipated that a cocktail of different recombinant hookworm antigens may be required in order to effectively prevent heavy hookworm infections and disease. The progress of this work has been hampered by the absence of both a convenient laboratory animal with which to study hookworm infections resembling human infection, as well as the lack of easy availability of native hookworm antigens. In addition, useful human serologic correlates of antihookworm immunity are still poorly defined.

Pseudotyping of glycoprotein D-deficient herpes simplex virus type 1 with vesicular stomatitis virus glycoprotein G enables mutant virus attachment and entry

The use of herpes simplex virus (HSV) vectors for in vivo gene therapy will require the targeting of vector infection to specific cell types in certain in vivo applications. Because HSV glycoprotein D (gD) imparts a broad host range for viral infection through recognition of ubiquitous host cell receptors, vector targeting will require the manipulation of gD to provide new cell recognition specificities in a manner designed to preserve gD's essential role in virus entry. In this study, we have determined whether an entry-incompetent HSV mutant with deletions of all Us glycoproteins, including gD, can be complemented by a foreign attachment/entry protein with a different receptor-binding specificity, the vesicular stomatitis virus glycoprotein G (VSV-G). The results showed that transiently expressed VSV-G was incorporated into gD-deficient HSV envelopes and that the resulting pseudotyped virus formed plaques on gD-expressing VD60 cells, albeit at a 50-fold-reduced level compared to that of wild-type gD. This reduction may be related to differences in the entry pathways used by VSV and HSV or to the observed lower rate of incorporation of VSV-G into virus envelopes than that of gD. The rate of VSV-G incorporation was greatly improved by using recombinant molecules in which the transmembrane domain of HSV glycoprotein B or D was substituted for that of VSV-G, but these recombinant molecules failed to promote virus entry. These results show that foreign glycoproteins can be incorporated into the HSV envelope during replication and that gD can be dispensed with on the condition that a suitable attachment/entry function is provided.

Iatrogenic duodenal perforations caused by endoscopic biliary stenting and stent migration: an update

Endoscopic biliary stenting is the preferred method of decompression in obstructive jaundice. Duodenal perforations caused during stenting and stent migration are rare but life-threatening complications, and require judicious management. With the increasing use of therapeutic endoscopy, an awareness of these complications is becoming important in our surgical practice. Advances in interventional radiology, endoscopy, and laparoscopy have enhanced the scope and reduced the morbidity of both conservative and surgical treatments of these perforations. This article presents an update on the current state of our knowledge on the science and the management of this complication.

A comparison of gag, pol and rev antisense oligodeoxynucleotides as inhibitors of HIV-1

Sequences from the gag, pol and rev regions of the RF strain of HIV-1 (HIV-1RF) were chosen as targets for antisense phosphorothioate oligodeoxynucleotides (S-oligos). These sequences were the p18/p24 junction in gag, the active site of HIV protease in pol; a sequence from the first exon of the rev gene and S-oligodeoxycytidylic acid controls. Compounds were tested against HIV-1 in both acutely and chronically infected cells. The results show that these phosphorothioate analogues tested in acutely infected cells were active in the 0.1-2 microM range, were dependent on chain length but had no sequence specificity. To study the mechanism of action, the time of addition of S-oligos to acutely infected cells was delayed for up to 48 h post-infection. It was found that antiviral activity was lost when compounds were added to the cultures later than 10 h post-infection. With chronically infected cells only the antisense rev sequence showed activity at 30 microM and neither of the gag or pol antisense sequences has a significant effect on HIV replication at 50 microM. These results are consistent with previous in vitro studies which demonstrate that antisense S-oligodeoxynucleotides have several modes of action.

Conduction Mechanisms in CVD-Grown Monolayer MoS2 Transistors: From Variable-Range Hopping to Velocity Saturation

We fabricate transistors from chemical vapor deposition-grown monolayer MoS2 crystals and demonstrate excellent current saturation at large drain voltages (Vd). The low-field characteristics of these devices indicate that the electron mobility is likely limited by scattering from charged impurities. The current-voltage characteristics exhibit variable range hopping at low Vd and evidence of velocity saturation at higher Vd. This work confirms the excellent potential of MoS2 as a possible channel-replacement material and highlights the role of multiple transport phenomena in governing its transistor action.