Intratumoral dendritic cell-CD4+ T helper cell niches enable CD8+ T cell differentiation following PD-1 blockade in hepatocellular carcinoma

Despite no apparent defects in T cell priming and recruitment to tumors, a large subset of T cell rich tumors fail to respond to immune checkpoint blockade (ICB). We leveraged a neoadjuvant anti-PD-1 trial in patients with hepatocellular carcinoma (HCC), as well as additional samples collected from patients treated off-label, to explore correlates of response to ICB within T cell-rich tumors. We show that ICB response correlated with the clonal expansion of intratumoral CXCL13+CH25H+IL-21+PD-1+CD4+ T helper cells ("CXCL13+ TH") and Granzyme K+ PD-1+ effector-like CD8+ T cells, whereas terminally exhausted CD39hiTOXhiPD-1hiCD8+ T cells dominated in nonresponders. CD4+ and CD8+ T cell clones that expanded post-treatment were found in pretreatment biopsies. Notably, PD-1+TCF-1+ (Progenitor-exhausted) CD8+ T cells shared clones mainly with effector-like cells in responders or terminally exhausted cells in nonresponders, suggesting that local CD8+ T cell differentiation occurs upon ICB. We found that these Progenitor CD8+ T cells interact with CXCL13+ TH within cellular triads around dendritic cells enriched in maturation and regulatory molecules, or "mregDC". These results suggest that discrete intratumoral niches that include mregDC and CXCL13+ TH control the differentiation of tumor-specific Progenitor exhasuted CD8+ T cells following ICB.

Toward indicators of the performance of US Infrastructures under climate change risks

Built infrastructures are increasingly disrupted by climate-related extreme events. Being able to monitor what climate change implies for US infrastructures is of considerable importance to all levels of decision-makers. A capacity to develop cross-cutting, widely applicable indicators for more than a dozen different kinds of infrastructure, however, is severely limited at present. The development of such indicators must be considered an ongoing activity that will require expansion and refinement. A number of recent consensus reports suggest four priorities for indicators that portray the impacts of climate change, climate-related extreme events, and other driving forces on infrastructure. These are changes in the reliability of infrastructure services and the implications for costs; changes in the resilience of infrastructures to climate and other stresses; impacts due to the interdependencies of infrastructures; and ongoing adaptation in infrastructures.

Liquid Chromatographic Determination of Major Organic Acids in Apple Juice and Cranberry Juice Cocktail: Collaborative Study

Twelve laboratories collaboratively studied a liquid chromatographic method for determination of quinic, malic, and citric acids in cranberry juice cocktail and apple juice. Samples are passed through a disposable silica cartridge, filtered, and directly injected into the chromatograph. The mobile phase is 0.2M KH2PO4 (pH 2.4). Two reverse phase columns are used, with UV detection at 214 nm. Six samples of cranberry juice cocktail and 6 samples of apple juice were sent to each collaborator. Repeatability and reproducibility coefficients of variation ranged from 1.2 to 7.6% and from 2.9 to 14.7%, respectively, for quinic, malic, and citric acid levels above 0.10%. The precision of the method is satisfactory. The method has been adopted official first action.

Twitter as a Potential Data Source for Cardiovascular Disease Research

Importance

As society is increasingly becoming more networked, researchers are beginning to explore how social media can be used to study person-to-person communication about health and health care use. Twitter is an online messaging platform used by more than 300 million people who have generated several billion Tweets, yet little work has focused on the potential applications of these data for studying public attitudes and behaviors associated with cardiovascular health.

Objective

To describe the volume and content of Tweets associated with cardiovascular disease as well as the characteristics of Twitter users.

Design, Setting, and Participants

We used Twitter to access a random sample of approximately 10 billion English-language Tweets originating from US counties from July 23, 2009, to February 5, 2015, associated with cardiovascular disease. We characterized each Tweet relative to estimated user demographics. A random subset of 2500 Tweets was hand-coded for content and modifiers.

Main Outcomes and Measures

The volume of Tweets about cardiovascular disease and the content of these Tweets.

Results

Of 550 338 Tweets associated with cardiovascular disease, the terms diabetes (n = 239 989) and myocardial infarction (n = 269 907) were used more frequently than heart failure (n = 9414). Users who Tweeted about cardiovascular disease were more likely to be older than the general population of Twitter users (mean age, 28.7 vs 25.4 years; P < .01) and less likely to be male (59 082 of 124 896 [47.3%] vs 8433 of 17 270 [48.8%]; P < .01). Most Tweets (2338 of 2500 [93.5%]) were associated with a health topic; common themes of Tweets included risk factors (1048 of 2500 [41.9%]), awareness (585 of 2500 [23.4%]), and management (541 of 2500 [21.6%]) of cardiovascular disease.

Conclusions and Relevance

Twitter offers promise for studying public communication about cardiovascular disease.

A Coordinated Effort to Manage Soybean Rust in North America: A Success Story in Soybean Disease Monitoring

Existing crop monitoring programs determine the incidence and distribution of plant diseases and pathogens and assess the damage caused within a crop production region. These programs have traditionally used observed or predicted disease and pathogen data and environmental information to prescribe management practices that minimize crop loss. Monitoring programs are especially important for crops with broad geographic distribution or for diseases that can cause rapid and great economic losses. Successful monitoring programs have been developed for several plant diseases, including downy mildew of cucurbits, Fusarium head blight of wheat, potato late blight, and rusts of cereal crops. A recent example of a successful disease-monitoring program for an economically important crop is the soybean rust (SBR) monitoring effort within North America. SBR, caused by the fungus Phakopsora pachyrhizi, was first identified in the continental United States in November 2004. SBR causes moderate to severe yield losses globally. The fungus produces foliar lesions on soybean (Glycine max) and other legume hosts. P. pachyrhizi diverts nutrients from the host to its own growth and reproduction. The lesions also reduce photosynthetic area. Uredinia rupture the host epidermis and diminish stomatal regulation of transpiration to cause tissue desiccation and premature defoliation. Severe soybean yield losses can occur if plants defoliate during the mid-reproductive growth stages. The rapid response to the threat of SBR in North America resulted in an unprecedented amount of information dissemination and the development of a real-time, publicly available monitoring and prediction system known as the Soybean Rust-Pest Information Platform for Extension and Education (SBR-PIPE). The objectives of this article are (i) to highlight the successful response effort to SBR in North America, and (ii) to introduce researchers to the quantity and type of data generated by SBR-PIPE. Data from this system may now be used to answer questions about the biology, ecology, and epidemiology of an important pathogen and disease of soybean.

Development, validation and application of an LC-MS/MS based method for the determination of deoxynivalenol and its conjugates in different types of beer

After water and tea, beer is the third most popular beverage worldwide. Brewed from malted cereal grains, beer is known to be potentially contaminated with mycotoxins. Some studies have shown that not only the Fusarium mycotoxins deoxynivalenol (DON) and 3-acetyl-DON (3-ADON), but also the conjugated mycotoxin deoxynivalenol-3-glucoside (D3G) can be found in beer on a regular basis, albeit usually at low concentrations. The aim of this work was to develop the first triple quadrupole LC-MS/MS based method for the determination of DON, D3G and 3-ADON in beer and to perform an in-house validation. The simple sample preparation includes degassing, precipitation of matrix compounds and reconstitution of the dried-down sample in solvent. Since different kinds of beer exist and method performance parameters will likely differ, we categorised the samples into pale, wheat, dark, bock and non-alcoholic beers, as well as shandies, and validated all six matrices. Although three individual beers for each category were spiked at eight levels prior to sample preparation, the repeatability of the overall method was still excellent with relative standard deviations from 4-16% for all analytes and types of beer. Limits of detection were in the sub- or low-μg/kg range. Apparent recoveries of 60-90% for DON, 39-69% for D3G and 96-124% for 3-ADON were obtained for the different types of beer, with dark and bock beers being the most difficult matrices. To prove the applicability of the method, ten beers of each category were analysed. While average concentrations of 6.6 μg/l for DON and D3G were found, no 3-ADON was detected in any of the samples.

Oral pantoprazole in the form of granules or tablets are pharmacodynamically equivalent in suppressing acid output in patients with gastro-oesophageal reflux disease and a history of erosive oesophagitis

AIM

To demonstrate the pharmacodynamic comparability between oral 40 mg pantoprazole delayed-release granules and tablets.

METHODS

This was a multicentre, randomized, open-label, 2-period, 2-sequence, 9-week crossover study in patients aged 18-65 years with gastro-oesophageal reflux disease and documented erosive oesophagitis. The primary endpoint was a comparison of the inhibition of pentagastrin-stimulated maximum acid output (MAO) at steady state after once daily dosing for 1 week and 23 h after the last dose of pantoprazole granules and tablets. Basal acid output was measured prior to MAO. Standard safety evaluations were performed. The one-sided t-test was used to test the null hypothesis that granules - 1.2 x tablet >/= 0 against the alternative hypothesis that this difference was <0 for both MAO and basal acid output values.

RESULTS

Sixty patients completed the study. The mean MAO values were 7.11 +/- 4.98 and 7.29 +/- 4.77 mmol/h, while the mean basal acid output values were 0.74 +/- 0.91 and 0.58 +/- 0.63 mmol/h for the granules and tablets, respectively. The two formulations were shown statistically to be pharmacodynamically equivalent in suppressing MAO (P = 0.006), safe and well tolerated.

CONCLUSION

Patients with gastro-oesophageal reflux disease who are unable to swallow the tablet may safely be prescribed the pantoprazole sodium granules.

Clinical observation: Beau's lines on fingernails after deep saturation dives

Transverse furrows, or Beau's lines, were noted in the fingernails of all 6 divers following a deep saturation dive to apressure equal to 1100 feet (335 meters) ofsea water (3,370 kPa), and in 2 of6 divers following a similar dive to 1000 feet (305 meters) of sea water (3,164 kPa). Both dives took place at the Ocean Simulation Facility of the Navy Experimental Diving Unit in Panama City, Florida. The divers breathed a partial pressure of 0.40 - 0.44 atm abs (40.5 - 44.6 kPa) oxygen, with the balance helium, during most of the time under pressure. All divers performed hard work on bicycle ergometers during the dives. Four of the divers on the first dive were treated during the dive for pain-only decompression sickness. Beau's lines have been reported in numerous medical conditions such as typhus, rheumatic fever, malaria, myocardial infarction, and other severe metabolic stresses. To the author's knowledge this is the first report of Beau's lines associated with saturation diving.

Seven-day therapy for Helicobacter pylori in the United States

BACKGROUND

The ideal duration of Helicobacter pylori treatment in the United States and whether eradication therapy is as successful in nonulcer dyspepsia as in peptic ulcer disease are controversial topics.

AIM

This study compared the efficacy of 3-, 7- and 10-day triple therapies with rabeprazole to a 10-day omeprazole control triple therapy for the eradication of Helicobacter pylori in patients with and without peptic ulcer disease in the United States.

METHODS

This was a multicentre, double-blind, randomized, parallel-group trial. A total of 803 patients with H. pylori infection (determined by [13C]urea breath test and rapid urease test or culture) received either rabeprazole 20 mg b.d., amoxicillin 1000 mg b.d., and clarithromycin 500 mg b.d. for 3, 7, or 10 days, or 10 days of omeprazole 20 mg b.d. with the same antibiotic regimen (control). H. pylori status was assessed by [13C]urea breath test > or =6 weeks after completing treatment.

RESULTS

In intent-to-treat patients, the eradication percentages achieved for the rabeprazole-based treatments were: 3-day, 27% (95% confidence interval: 21%-34%); 7-day, 77% (95% confidence interval: 71%-83%); and 10-day, 78% (95% confidence interval: 72%-84%). The eradication percentage with the 10-day omeprazole-based treatment was 73% (95% confidence interval: 67%-79%). There was no statistically significant difference between the 7-day rabeprazole-based regimen and the 10-day rabeprazole- and omeprazole-based regimens.

CONCLUSIONS

Seven-day therapy with rabeprazole, clarithromycin, and amoxicillin is similar in efficacy to 10-day therapies and had similar efficacy in patients with and without ulcer disease.

An acute clinical trial evaluating the cardiovascular effects of an herbal ephedra-caffeine weight loss product in healthy overweight adults

OBJECTIVE

This study was undertaken to determine the acute effects of a commercial weight loss supplement containing herbal ephedrine and caffeine on cardiovascular function in healthy overweight adults.

DESIGN

Randomized double blind clinical trial evaluating the cardiovascular effects of an ephedra-caffeine (Xenadrine(TM); XEN) based herbal product vs placebo (PLA).

SUBJECTS

Twenty-seven healthy overweight adults (age 21-60 y; body mass index > or = 25 kg/m(2)).

MEASUREMENTS

Systolic and diastolic blood pressure, heart rate, serial electrocardiograms (EKG) and Doppler echocardiograms.

RESULTS

A comparison of means between the groups indicated no statistically significant differences at the start of the study for the variables above. There were no serious adverse events. When examining the effects of XEN vs PLA on cardiovascular health/function, there were no significant effects observed in heart rate, systolic blood pressure, diastolic blood pressure, left ventricular ejection fraction, heart valve function or in cardiovascular physiology within the parameters measured.

CONCLUSION

These findings indicate that, over a 14-day period, ingestion of the commercial weight loss supplement in a healthy overweight population did not produce any noticeable cardiovascular side effects.

Double-blind placebo-controlled multicentre studies of rebamipide, a gastroprotective drug, in the treatment of functional dyspepsia with or without Helicobacter pylori infection

BACKGROUND

Functional dyspepsia is a problem that is difficult to treat in clinical practice.

AIM

To evaluate the efficacy and safety of rebamipide (a cytoprotective drug) in functional dyspepsia.

METHODS

Patients with functional dyspepsia (n=557) were divided a priori into two studies by Helicobacter pylori status, and enrolled in a 2-week baseline evaluation period. Ninety-nine patients with Helicobacter pylori and 173 patients without Helicobacter pylori, continuing to have at least moderate upper abdominal pain or discomfort, were randomly assigned to rebamipide 100 mg, rebamipide 200 mg or placebo, three times a day, in a double-blind design for 8 weeks.

RESULTS

There was significant improvement of individual symptom scores from baseline in all the treatment arms. No significant improvement of individual symptom scores was observed in either rebamipide group at the end of the studies compared to placebo, although the belching score was significantly reduced in the rebamipide 100 mg and 200 mg groups at week 2 (P=0.017 and P=0.012, respectively) in the Helicobacter pylori-positive patients. The ratio of patients who requested usage of the study medication again was greater in the rebamipide 100 mg (85%) and 200 mg (96%, P=0.020) groups compared with the placebo group (72%) among Helicobacter pylori-positive patients. There were no serious study medication related adverse events.

CONCLUSIONS

Rebamipide was not superior to placebo in terms of individual symptoms at the end of treatment.

[Analysis of a programme of direct referral between primary and specialist care in potential surgery patients]

OBJECTIVE

To describe the results of a programme of direct referral of potential surgery patients between primary and specialist care, designed to lessen waiting-times.Design. Prospective, longitudinal and descriptive study.

SETTING

Health Area N. masculine 19 (Valencian Health Service): Surgery Service of Elche Hospital and 6 Health Centres.

PARTICIPANTS

Patients with pathologies that do not need special techniques for diagnosis except examination and who have a clear irrefutable indication of surgery without risk factors (ASA I-II).Intervention. The referral protocol consists of: a) diagnosis of pathology and pre-operative study in primary care (PC); b) appointment made by phone for the surgery clinic at the hospital, where diagnosis and pre-operative study are confirmed; c) referral and operation in the unit of non-hospital major surgery (UCMA); d) monitoring post-operation by the home hospitalisation unit (HHU) or preferably by the health centre, and e) check-up at the surgery clinic. Main measurements. The degree of agreement between PC and the specialist, assessment of the pre-operative study, and waiting time.

RESULTS

86 patients were referred (average age, 35; 76% male) by 28 doctors. The most common pathologies were hernia (36%), pilonidal sinus (23.2%) and miscellaneous (32.5%). There was general agreement in diagnosis in 90.7% of cases. 89.5% of patients brought the proper pre-operative study. Mean waiting time between the primary care consultation in the different procedures and the first hospital consultation was 19 days; with 44 more days elapsing till the surgical operation.

CONCLUSIONS

This new programme is effective and economic, in that there is <<adequate referral>> of patients, waiting time is reduced by over 7 months for pilonidal sinus and by over 2 years for hernia pathology, and the procedure can be used for a large number of patients, as the pathologies involved are very common.

An endoscopic comparison of the effects of alendronate and risedronate on upper gastrointestinal mucosae

OBJECTIVES

The nitrogen-containing bisphosphonates alendronate and risedronate have been reported to have upper gastrointestinal (GI) safety and tolerability profiles comparable to those of placebo. Nevertheless, both agents have demonstrated similar potential for irritation of gastric mucosa at high doses in preclinical studies. The present study compared the potential for alendronate and risedronate to produce endoscopic upper GI mucosal irritation using the highest approved dosage regimens for the two agents.

METHODS

This was a multicenter, randomized, parallel-group, double-blind, placebo-controlled trial in which a total of 235 patients (men or postmenopausal women, aged 45-80 yr) with normal upper GI endoscopy at baseline received 28-day treatments with the following: alendronate 40 mg/day (N = 90), risedronate 30 mg/day (N = 89), placebo (N = 36), or placebo with aspirin 650 mg q.i.d. for the last 7 days (N = 20). Endoscopy was repeated on day 29 using standardized scoring scales.

RESULTS

After 28 days of treatment, the alendronate and risedronate groups had comparable mean gastric and duodenal erosion scores that were significantly lower than those of the aspirin group. Esophageal scores were comparable in all groups. Gastric ulcers and/or large numbers of gastric erosions occurred in approximately 3% of alendronate and risedronate patients versus 60% with aspirin. Both bisphosphonates were clinically well tolerated.

CONCLUSIONS

The potential for gastroduodenal irritation is similar for alendronate and risedronate and is markedly less than for aspirin. The findings of this study, together with the large placebo-controlled clinical trial experience with both agents and extensive epidemiological data for alendronate, suggest that the risk for clinically important gastric irritation with these bisphosphonates is very low, even at the highest available doses.

Identification of bovine IgG as a major cross-reactive vertebrate meat allergen

BACKGROUND

Although beef is a main source of protein in Western diets, very little has been published on allergic reactions to beef or the main allergens implicated in these reactions. The aim was to evaluate the IgE antibody response to beef in suspected meat-allergic subjects and assess cross-reactivity of beef with other vertebrate meats.

METHODS

Fifty-seven sera from suspected meat-allergic subjects were tested by grid blot for specific IgE antibodies to vertebrate meats (beef, lamb, pork, venison, and chicken), and the patterns of recognition of meat proteins were assessed by immunoblot studies.

RESULTS

A 160-kDa band, identified as bovine IgG, was detected in raw beef in 83% (10/12) of beef-allergic subjects but in only 24% of the beef-tolerant subjects. IgE reactivity to a band of similar mol. mass was detected also in lamb and venison, but rarely in pork or chicken. Complete inhibition of the IgE reactivity to the bovine IgG was obtained with lamb, venison, and milk. IgE reactivity to this band also completely disappeared when beef or lamb extracts were separated under reducing conditions, indicating conformational epitopes.

CONCLUSIONS

Bovine IgG appears to be a major cross-reacting meat allergen that could predict beef allergy. Further studies with oral IgG challenges should be performed to document the conclusion that in vitro reactivity correlates with clinical hypersensitivity. The role of bovine IgG in other bovine products such as milk, dander, or hair must also be studied, and the hypothesis that it is a cross-reacting allergen with other mammalian products validated.

A randomized trial comparing the effect of rofecoxib, a cyclooxygenase 2-specific inhibitor, with that of ibuprofen on the gastroduodenal mucosa of patients with osteoarthritis. Rofecoxib Osteoarthritis Endoscopy Study Group

BACKGROUND & AIMS

Prostaglandin production in the normal gastrointestinal tract, believed to be critical for mucosal integrity, is mediated by cyclooxygenase (COX)-1, whereas prostaglandin production at inflammatory sites seems to occur via induction of COX-2. We hypothesized that COX-2-specific inhibition with rofecoxib (25 mg once daily) in the treatment of patients with osteoarthritis would cause fewer gastroduodenal ulcers than an equally effective dose of ibuprofen (800 mg 3 times a day), a nonspecific COX inhibitor.

METHODS

A total of 742 osteoarthritis patients without ulcers on baseline endoscopy were randomly assigned to receive rofecoxib (25 or 50 mg once daily), ibuprofen (800 mg 3 times daily), or placebo. Endoscopy was repeated at 6, 12, and 24 weeks. At 16 weeks, by study design, 95% of the placebo group and 5% of the other groups were discontinued.

RESULTS

The cumulative incidence of gastroduodenal ulcers >/=3 mm with rofecoxib (25 or 50 mg once daily) was significantly (P < 0.001) lower than with ibuprofen and was statistically equivalent to placebo at week 12 (placebo, 9.9%; 25 mg rofecoxib, 4.1%; 50 mg rofecoxib, 7.3%; and ibuprofen, 27.7%). At 24 weeks, ulcer rates were 25 mg rofecoxib, 9. 6%; 50 mg rofecoxib, 14.7%; and ibuprofen, 45.8% (P < 0.001, ibuprofen vs. 25 and 50 mg rofecoxib).

CONCLUSIONS

Rofecoxib, at doses 2-4 times the dose demonstrated to relieve symptoms of osteoarthritis, caused significantly less gastroduodenal ulceration than ibuprofen, with ulcer rates comparable to placebo.

The effect of anti-diuretic hormone on the endolymphatic sac of the inner ear

The anti-diuretic hormone vasopressin (AVP) regulates water excretion from the kidney by increasing the water permeability of the collecting duct. AVP binds to V2-receptors and induces the translocation of aquaporin-2 water channels (AQP-2) into the apical plasma membrane of principal cells. By this mechanism AVP controls water reabsorption in the kidney. The effects of AVP on the endolymphatic sac (ES) of the inner ear, which is thought to mediate reabsorption of endolymph, were investigated. Both the V2-receptor and the AQP-2 water channel were found to be expressed in the ES epithelium. In the ES AVP binds to receptors most probably of the V2-subtype. Application of AVP to organotypically cultured ES inhibits membrane turnover in ribosomal-rich cells of the ES epithelia, which is thought to mediate translocation of AQP-2 into the surface membrane. This suggests that AVP has contrasting effects in the inner ear and kidney, which may be physiologically useful for maintaining endolymphatic pressure during severe hypovolemia. Animal experiments show that AVP causes endolymphatic hydrops after systemic application to guinea-pigs, which suggests a causal role for the increased AVP levels found in humans suffering from Ménière's disease.

Comparison of chromosome telomere integrity in multiple tissues from subjects at different ages

Telomere DNA, at the ends of each chromosome, is conserved in nature and required for chromosome replication and stability. Reduction in telomere length has been observed in several malignancies as well as in leukocytes from healthy persons with advancing age. There is a paucity of data regarding telomere length and the effects of in vivo aging in different tissues. These data could be helpful in interpreting telomere length and understanding the role of telomere integrity and telomerase activity in malignant cells. We report telomeric DNA integrity studies of blood and skin collected from eight Caucasians of both sexes representing each decade of life from the fetus to 72 years of age without exposure to chemotherapy or radiation. In addition, telomeric data from 15 other tissues from the fetus and 8 other tissues from the 72-year-old male were examined. No significant differences were found in the shortest telomere size, the average telomere size, or telomere size variation between blood and skin from subjects at different ages. The average telomere size was 11.7 +/- 2.2 kb for blood and 12.8 +/- 3.7 for skin in all subjects studied. The shortest telomere length was 5.4 +/- 1.9 kb for blood and 4.3 +/- 0.9 kb for skin. Significant differences (P < 0.001) were found in the overall length of the DNA hybridization signal representing the shortest telomere size and the length of the DNA peak migration hybridization signal representing variation in telomere size between the 20-week fetus and the 72-year-old male. The 72-year-old male showed the shortest telomeres and the most variation (heterogeneity) in telomere size for all tissues studied, but the greatest differences were observed in blood compared with other tissues (e.g., average telomere length was 12.2 kb in the fetus and 7.2 kb in the 72-year-old male). The size of the telomere was negatively correlated with age for all tissues studied.

Intranasal budesonide aqueous pump spray (Rhinocort Aqua) for the treatment of seasonal allergic rhinitis. Rhinocort Aqua Study Group

To determine the relative efficacy, compare the incidence of adverse events, and ascertain the systemic glucocorticoid effect of the nasal application of several doses of budesonide, 406 patients with seasonal ragweed-induced allergic rhinitis were randomized in a double-blind, parallel group design to receive intranasal budesonide aqueous pump spray (Rhinocort Aqua) 32 micrograms, 64 micrograms, 128 micrograms, 256 micrograms, or placebo once daily for 4 weeks. A total of 231 adults and 175 children participated in the study conducted at 14 centers in two geographic regions, the Midwest and the Northeast United States, during the 1994 ragweed season. Pollen counts were collected at each site by the Rotorod method. The primary efficacy parameter was the change from baseline nasal index score (NIS) for the overall study population--defined as the sum of scores for nasal congestion, runny nose, and sneezing. The study was powered only to evaluate the overall study population for statistical significance. Significant differences in NIS were observed in each active treatment group compared with placebo (p < or = 0.003). Compared with placebo, budesonide aqueous spray significantly reduced individual symptoms of runny nose and sneezing at all doses (p < or = 0.008), and nasal congestion and nasal itching at all doses except 64 micrograms (p < or = 0.022). In the Midwest pollen belt where the 1994 ragweed season was representative of a typical pollen season, it was possible to establish a dose-response relationship for comparison of budesonide aqueous spray 256 micrograms versus 32 micrograms (p = 0.017). The incidence of adverse events was similar between budesonide aqueous-treated and placebo-treated patients. Importantly, there was no effect of budesonide aqueous spray on basal or ACTH-stimulated plasma cortisol levels in either adults or children at the end of 4 weeks of treatment. Intranasal budesonide aqueous pump spray, administered once daily, was efficacious and was generally well tolerated in both adults and children with seasonal allergic rhinitis.

Acute femoral artery thrombosis associated with functional protein C deficiency as the presenting manifestation of acute monocytic leukemia

Acute leukemia may be linked to disturbances of the coagulation system, which are usually due to hyperviscosity because of disseminated intravascular coagulation or a high white cell count. We report a unique case of femoral artery thrombosis as the beginning symptom of acute monocytic leukemia (M5) associated with a low level of functional protein C. The patient had multiple recurrent episodes of thrombosis with low levels of functional protein C associated with the relapse of the leukemia. A review of the literature shows that this is an extremely rare phenomenon.

Mutation detection by a two-hybrid assay

Yeast-based assays have been developed to detect inactivating mutations in human genes, but these assays generally rely on the human protein having a biological function in yeast. We describe a simple method to detect mutations by virtue of their ability to abolish a protein-protein interaction in the yeast two-hybrid assay. By the use of direct recombinational cloning in yeast of a reverse transcription-PCR product followed by a simple growth selection this method distinguished both homozygous and heterozygous mutations in the p53 tumor suppressor gene. This approach should be applicable to many human genes whose encoded proteins have suitable partners in the two-hybrid assay.

Triple versus dual therapy for eradicating Helicobacter pylori and preventing ulcer recurrence: a randomized, double-blind, multicenter study of lansoprazole, clarithromycin, and/or amoxicillin in different dosing regimens

OBJECTIVE

The efficacy and safety of dual and triple therapies with a proton pump inhibitor and antibiotic(s) for therapy of Helicobacter pylori-associated duodenal ulcer disease have been compared using results from independent studies using different methods and regimens, making interpretation difficult. In a large, double-blind, multicenter study conducted in the United States, we compared a triple therapy regimen with four dual therapy and one monotherapy regimens in the eradication of H. pylori and the prevention of ulcer recurrence.

METHODS

Patients with active duodenal ulcer disease or history of duodenal ulcer disease within the past year and H. pylori infection were randomized to receive one of six 14-day treatment regimens: lansoprazole 30 mg, clarithromycin 500 mg, and amoxicillin 1 gm b.i.d.; lansoprazole 30 mg b.id. and either clarithromycin 500 mg b.i.d. or t.i.d.; lansoprazole 30 mg b.i.d. or t.i.d. with amoxicillin 1 gm t.i.d.; or lansoprazole 30 mg t.i.d. alone. No additional acid suppression therapy followed eradication therapy. Primary efficacy endpoints were eradication of H. pylori and ulcer recurrence.

RESULTS

Of 396 patients enrolled in the study, 352 met the entry criteria for duodenal ulcer status and H. pylori positivity. At 4-6 wk after the end of therapy, H. pylori was eradicated from 94% (44 of 47) of patients receiving lansoprazole, clarithromycin, and amoxicillin triple therapy, 77% (39 of 51) of those receiving lansoprazole t.i.d./amoxicillin t.i.d., 75% (36 of 48) of those receiving lansoprazole b.i.d./clarithromycin t.i.d., 57% (28 of 49) of those receiving lansoprazole b.i.d./clarithromycin b.i.d., 53% (26 of 49) of those receiving lansoprazole b.i.d./amoxicillin t.i.d., and 2% (1 of 53) of those receiving lansoprazole monotherapy (p < or = 0.05, triple therapy vs each dual therapy and each dual therapy vs monotherapy). Of those patients who were documented as free of ulcer at 4-6 wk after treatment, ulcers recurred within 6 months in 7% of patients receiving triple therapy, as compared with 13-23% of patients receiving dual therapy, and 69% of patients receiving lansoprazole monotherapy. Patients who were H. pylori negative at 4-6 wk after treatment were less likely to have an ulcer recurrence than were patients who were H. pylori positive (11% [10 of 95] vs 47% [20 of 43], respectively, across treatment groups). For triple therapy and dual therapy, a similar proportion of patients reported a drug-related adverse event (23% vs 17-33%, respectively).

CONCLUSIONS

In patients with active or a recent history of duodenal ulcer, a 14-day course of lansoprazole-based triple therapy without additional acid suppression therapy is highly effective in the eradication of H. pylori and in preventing ulcer recurrence. Among the dual therapies, higher eradication rates occurred when lansoprazole (with amoxicillin) or clarithromycin (with lansoprazole) was administered t.i.d. vs b.i.d., but the rates were still significantly lower than with lansoprazole triple therapy with all three drugs administered b.i.d.

The ChemTrak Hp Chek fingerstick whole blood serology test for the detection of Helicobacter pylori infection

OBJECTIVE

To evaluate a new whole blood serology test (Hp Chek; ChemTrak) that detects IgG antibodies to Helicobacter pylori.

METHODS

The study was conducted at 10 sites within the United States. Patients undergoing upper endoscopy for dyspepsia were recruited for enrollment. Those treated for H. pylori infection within a year of endoscopy and those who had regularly used proton pump inhibitors, bismuth compounds, or antibiotics within a month of endoscopy were not eligible. During endoscopy, specimens were obtained from the corpus and antrum for histological examination, which was performed by a single experienced pathologist. The Hp Chek was tested using whole blood and serum. Serum was also tested with a reference enzyme-linked immunosorbent assay (ELISA) at a centralized location. Test characteristics for the Hp Chek and ELISA were calculated using histology as the "gold standard."

RESULTS

Two hundred eighty-seven patients (140 women and 147 men; mean age 53 +/- 6 yr) were enrolled. The Hp Chek was easy to perform and yielded results 9 min after inoculation of the test cassette with whole blood or serum. When the Hp Chek used with whole blood was compared with histology as the gold standard, the sensitivity was 88%, specificity 85%, positive predictive value 83%, negative predictive value 90%, and percent agreement 86%. There were no statistically significant differences among the results obtained with the Hp Chek using whole blood, the Hp Chek using serum, or reference ELISA.

CONCLUSIONS

The Hp Chek whole blood serology test was easy to perform and rapid and yielded performance characteristics comparable to those of a reference ELISA or the Hp Chek used with serum.

Seven-day triple therapy with lansoprazole, clarithromycin, and metronidazole for the cure of Helicobacter pylori infection: a short report

BACKGROUND

To refine our understanding of anti-Helicobacter pylori treatment regimens further, we evaluated the efficacy and safety of lansoprazole given in combination with clarithromycin and metronidazole for 7 days in an open-label, multicenter study.

MATERIALS AND METHODS

H. pylori-positive patients self-administered lansoprazole, 30 mg; clarithromycin, 500 mg; and metronidazole, 500 mg bid for 7 days. Patients were assessed at pretreatment, at which time the presence of H. pylori was documented by rapid urease test or histology and culture, following study drug administration (week 1) for a brief evaluation only, and at least 4 weeks posttreatment (week 5), including endoscopy with collection of biopsy specimens for culture and histology testing.

RESULTS

Of the 60 patients enrolled in the study, 59 had confirmed H. pylori infection, and 51 were included in an intent-to-treat analysis of efficacy. Primary metronidazole and clarithromycin resistance were observed in 84% and 8% of study patients, respectively. One month after the end of therapy, H. pylori infection was cured in 40 of 51 patients (78%); 95% confidence interval, (65%-89%). The triple-therapy regimen was well-tolerated, with only 2 patients (4%) requiring premature withdrawal from the study due to treatment-related adverse events. Taste perversion (15.0%) and diarrhea (11.7%) were the most frequently reported adverse events possibly or probably related to study medication during the treatment period.

CONCLUSION

Despite a high prevalence of metronidazole resistance, a 1-week, triple-drug combination of lansoprazole, clarithromycin, and metronidazole is effective treatment for and well-tolerated by patients with H. pylori infection.

Cadherin-catenin complex: protein interactions and their implications for cadherin function

Cadherins comprise a family of calcium-dependent glycoproteins that function in mediating cell-cell adhesion in virtually all solid tissues of multicellular organisms. In epithelial cells, E-cadherin represents a key molecule in the establishment and stabilization of cellular junctions. On the cellular level, E-cadherin is concentrated at the adherens junction and interacts homophilically with E-cadherin molecules of adjacent cells. Significant progress has been made in understanding the extra- and intracellular interactions of E-cadherin. Recent success in solving the three-dimensional structure of an extracellular cadherin domain provides a structural basis for understanding the homophilic interaction mechanism and the calcium requirement of cadherins. According to the crystal structure, individual cadherin molecules cooperate to form a linear cell adhesion zipper. The intracellular anchorage of cadherins is regulated by the dynamic association with cytoplasmic proteins, termed catenins. The cytoplasmic domain of E-cadherin is complexed with either beta-catenin or plakoglobin (gamma-catenin). Beta-catenin and plakoglobin bind directly to alpha-catenin, giving rise to two distinct cadherin-catenin complexes (CCC). Alpha-catenin is thought to link both CCC's to actin filaments. The anchorage of cadherins to the cytoskeleton appears to be regulated by tyrosine phosphorylation. Phosphorylation-induced junctional disassembly targets the catenins, indicating that catenins are components of signal transduction pathways. The unexpected association of catenins with the product of the tumor suppressor gene APC has led to the discovery of a second, cadherin-independent catenin complex. Two separate catenin complexes are therefore involved in the cross-talk between cell adhesion and signal transduction. In this review we focus on protein interactions regulating the molecular architecture and function of the CCC. In the light of a fundamental role of the CCC during mammalian development and tissue morphogenesis, we also discuss the phenotypes of embryos lacking E-cadherin or beta-catenin.

Cadherin-catenin complex: protein interactions and their implications for cadherin function

Cadherins comprise a family of calcium-dependent glycoproteins that function in mediating cell-cell adhesion in virtually all solid tissues of multicellular organisms. In epithelial cells, E-cadherin represents a key molecule in the establishment and stabilization of cellular junctions. On the cellular level, E-cadherin is concentrated at the adherens junction and interacts homophilically with E-cadherin molecules of adjacent cells. Significant progress has been made in understanding the extra- and intracellular interactions of E-cadherin. Recent success in solving the three-dimensional structure of an extracellular cadherin domain provides a structural basis for understanding the homophilic interaction mechanism and the calcium requirement of cadherins. According to the crystal structure, individual cadherin molecules cooperate to form a linear cell adhesion zipper. The intracellular anchorage of cadherins is regulated by the dynamic association with cytoplasmic proteins, termed catenins. The cytoplasmic domain of E-cadherin is complexed with either beta-catenin or plakoglobin (gamma-catenin). Beta-catenin and plakoglobin bind directly to alpha-catenin, giving rise to two distinct cadherin-catenin complexes (CCC). Alpha-catenin is thought to link both CCC's to actin filaments. The anchorage of cadherins to the cytoskeleton appears to be regulated by tyrosine phosphorylation. Phosphorylation-induced junctional disassembly targets the catenins, indicating that catenins are components of signal transduction pathways. The unexpected association of catenins with the product of the tumor suppressor gene APC has led to the discovery of a second, cadherin-independent catenin complex. Two separate catenin complexes are therefore involved in the cross-talk between cell adhesion and signal transduction. In this review we focus on protein interactions regulating the molecular architecture and function of the CCC. In the light of a fundamental role of the CCC during mammalian development and tissue morphogenesis, we also discuss the phenotypes of embryos lacking E-cadherin or beta-catenin.

Epidemiologic evaluation of encephalitic listeriosis in goats

OBJECTIVE

To evaluate host and environmental factors associated with the development of encephalitic listeriosis in goats.

DESIGN

Retrospective analysis of diagnostic laboratory records and survey of veterinarians and goat producers.

SAMPLE POPULATION

355 goat herds accessible through laboratory records; 38 veterinarians who treated goats and 76 goat producers.

PROCEDURE

Data regarding breed and use for goats affected with encephalitic listeriosis were obtained from surveys and case follow-up information. Listeria monocytogenes isolates from the brains of 7 affected goats were serotyped and subjected to DNA restriction analysis.

RESULTS

Odds ratio for the development of encephalitis listeriosis in Angora (mohair-producing) goats was 22.9 by use of diagnostic laboratory records. Survey also revealed a high prevalence in herds of Angora and other breeds that subsisted on woody browse, although Angora goats feeding predominantly on hay or pasture were not affected. Listeria monocytogenes isolates from 4 Angora goats in 3 herds differed in DNA restriction patterns, although the pattern was identical in 3 other goats from another herd.

CLINICAL IMPLICATIONS

Encephalitic listeriosis can be observed in all goat breeds, but a lifestyle of heavy browse consumption seems important to the development of disease in some herds.

Microbial oxidation of ebastine

The microbial oxidation of ebastine to carebastine was investigated. Among the 15 micro-organisms examined, only the Cunninghamella strains showed the desired biotransformation. Cunninghamella blakesleeana oxidised the substrate within 7 days, via the intermediates alcohol and aldehyde, mainly to carebastine, the corresponding carboxylic acid. Optimisation of the culture conditions increased the yield from initially 10% up to a reproducible 40%. For the synthesis of carebastine a substrate concentration of 200 mg/l, a starting pH of 5.0 and the addition of 1% poly(vinyl alcohol) is favourable. The results achieved in experiments with shaking flasks are transferable to the fermentation scale and yielded 270 mg carebastine in a 3-1 fermentation of 600 mg ebastine. The progress of the reaction was detected by TLC and HPLC, the products were identified by mass spectrometry and NMR.

Single amino acid substitutions in proteins of the armadillo gene family abolish their binding to alpha-catenin

Analysis of the calcium-dependent cell adhesion molecule E-cadherin has led to the identification of catenins, which are necessary for cadherin function. Growing evidence that cadherins and catenins are subjected to genetic alterations in carcinogenesis makes it especially important to understand protein-protein interactions within the cadherin-catenin complex. Here we report the identification and analysis of the alpha-catenin binding site in plakoglobin (gamma-catenin). Using N- and C-terminal truncations of plakoglobin, we identified a domain of 29 amino acids necessary and sufficient for binding alpha-catenin. The alpha-catenin binding site is fully encoded within exon 3 of plakoglobin but only partially represented in Armadillo repeat 1. This suggests that exons rather than individual Arm repeats encode functional domains of plakoglobin. Site-directed mutagenesis identified residues in the alpha-catenin binding site indispensable for binding in vitro. Analogous mutations in beta-catenin and Armadillo had identical effects. Our results indicate that single amino acid mutations in the alpha-catenin binding site of homologs of Armadillo could prevent a stable association with alpha-catenin, thus affecting cadherin-mediated adhesion.

[Time consumption at an orthopedic operating theatre. Physicians' ability to predict their own time consumption]

The aim of the study was to investigate the time spent on different procedures in an orthopaedic operating theatre, and to evaluate the ability of doctors to predict their own time consumption. Time schedules were registered for 146 operations, of these 104 were either knee or hip replacements. Sixty percent of the total time was spent on surgery. The median misjudgment was 15 minutes for surgeons and five minutes for anaesthetists. An improvement in the doctors' ability to predict their own time consumption in the course of the study period could not be demonstrated. Comparing the study period with the similar period the year before it was not possible to demonstrate a change in the number of cancelled operations or the number of days with overtime. Epidural anaesthesia with bupivacaine was the most time consuming anaesthesia, the differences between the other forms of anaesthesia used were insignificant.

Kinetic model of the response of precursor and mature rat hepatic mRNA-S14 to thyroid hormone

We found in preliminary experiments that multiple daily injections of triiodothyronine (T3) resulted in an apparent prolongation in the half time (t1/2) of mRNA-S14 decay. To appropriately interpret these observations, we developed a mathematical model of the fluctuations of mRNA-S14 and its nuclear precursor after a single injection or multiple daily injections of T3. The model parameters include 1) the effect of plasma protein binding and metabolic clearance rates on receptor-bound nuclear T3, 2) the threefold circadian variation in mRNA-S14, 3) a 12-min t1/2 for the nuclear precursor and a 1.5-h t1/2 for the mature mRNA-S14, 4) previously derived relationships between the level of plasma T3 and nuclear occupancy, and 5) direct proportionality between nuclear transcription of the S14 gene and T3 nuclear occupancy. The model faithfully predicted the excursions of the mature mRNA-S14 and its nuclear precursor. Nuclear retention of T3 and the effects of circadian variation on S14 gene transcription explain the apparent prolongation in the t1/2 of decay of mature mRNA. Our findings illustrate the feasibility of incorporating parameters at the molecular level into a comprehensive kinetic analysis of hormone action.

The production of a monoclonal T3-antiidiotypic antibody (T3-MAAB) that mimics the effects of T3 on 2-deoxy-D-glucose uptake in chick embryo heart cells

The Ig fraction of rabbit anti-T3 antibody was injected into the spleens of BALB/c mice. Four days later, the lymphocytes were recovered from their spleens and were fused with cells of the 653 myeloma cell line. Screening of the hybrid colonies was carried out in a T3 RIA system. Positive colonies were those whose supernatant displaced 125I-labeled T3 from its antibody. The positive cultures were recloned and one was injected ip into mice. The crude IgG fraction of the ascites fluid was affinity purified on an affigel-10 column containing a covalently bound rabbit anti-T3-IgG. In order to eliminate possible endogenous T3 contamination during the affinity purification, the column was stripped with a 40% solution of acetonitrile in 0.2 M acetic acid, neutralized, and then the purification proceeded as described. The affinity purified antibody was an IgG2a isotype. This monoclonal antibody (T3-MAAB) displaced labeled T3 from its antibody in an RIA system. It also mimicked T3 in the stimulation of [3H]2-deoxy-D-glucose (2-DOG) uptake in cultured chick embryo heart cells. After 6 h exposure, the dose-response curve of 2-DOG uptake to T3-MAAB was shifted to the left by at least one order of magnitude when compared to the dose-response curve obtained with T3. After 24 h exposure, T3 had the expected additional stimulatory effect that was dependent on neosynthesis of proteins, while T3-MAAB did not. Also at 24 h exposure, T3-MAAB did not stimulate the incorporation of labeled leucine and uridine into the heart cells while T3 at an equivalent concentration did. The MAAB activity could be abolished by boiling, while boiling did not affect the activity of an equivalent concentration of T3, thus excluding a T3 contamination-mediated effect. We conclude, therefore, that (a) a monoclonal hybridoma producing an antibody that mimics T3 was established; (b) this antibody competed with labeled T3 for anti-T3 antibody and, like T3, stimulated sugar uptake into cultured chick embryo heart cells; and (c) this antibody, unlike T3, did not stimulate the neosynthesis of proteins.

Microbial metabolism of the beta-adrenoreceptor antagonist bisoprolol

Eighteen filamentous fungi and six actinomycetes species were screened for their ability to metabolize bisoprolol, a beta-blocking drug. All strains of Cunninghamella tested accumulated metabolite M4 = EMD 46193 ([4-(2-hydroxy-3-isopropylaminopropoxy)benzyloxy]ethanol). Among the strains investigated only Gliocladium deliquescens excreted the corresponding carbonic acid M1 = EMD 44025 into the culture medium. Biotransformation of bisoprolol by fungi occurred only during growth in complex medium or with resting cells after cultivation in complex medium. The screened Actinomycetes showed no biotransformation of the drug.

Pathogenesis of lipodermatosclerosis of venous disease: the lesson learned from eosinophilic fasciitis

The histological features of lipodermatosclerosis and eosinophilic fasciitis and its variants were compared in a prospective study of outpatients attending the vascular clinic and inpatients in the Department of Medicine of a regional university hospital. Main outcome measures examined were swelling and induration of the subcutaneous layers with a stocking distribution in the calves. The inflammatory and fibrosing alterations involving the panniculus adiposus, superficial fascia and perimysium were essentially indistinguishable histologically in patients with lipodermatosclerosis or eosinophilic fasciitis and its variants. The intensity of the subcutaneous induration was related to the underlying nosological entity and the duration of the process. Infectious cellulitis was found to aggravate the clinical symptoms of lipodermatosclerosis. Since the stereotypical inflammatory and fibrosing processes in lipodermatosclerosis and eosinophilic fasciitis and its variants are similar irrespective of the initiating factors, it is suggested that there is a common final pathway in the pathogenesis of both disorders.

Reading in pure alexia. The effect of strategy

A number of investigators have demonstrated that patients with pure alexia comprehend briefly presented words which they are unable to explicitly identify. We suggested previously that these patients may read by means of two distinct procedures: a laborious letter-by-letter method and a 'whole-word' procedure which, at least initially, does not support explicit word identification. We report a test of this proposal in a patient with pure alexia. We reasoned that if the patient had access to two distinct and incompatible procedures, he might be induced to switch from one to the other by changing task demands. We found that when instructed to name words, the patient employed a letter-by-letter strategy; in contrast, when instructed to make lexical decision or semantic judgements about rapidly presented words, he appeared to use a 'whole-word' strategy. These data support the hypothesis that two distinct procedures are available to this patient. We argue, further, that is necessary to suppress use of the letter-by-letter strategy to demonstrate whole word reading capability in pure alexics, and that failure to do so may account for negative findings in other cases reported in the literature.

Studies on the enzymatic reduction of N-Boc-4S-amino-3-oxo-5-phenylpentanoic acid methylester

The enzymatic reduction of N-Boc-4S-amino-3-oxo-5-phenylpentanoic acid methylester, the key intermediate in the stereoselective synthesis of a statinanalogue, was studied with Hansenula anomala and Hansenula silvicola. Using whole cells of H. anomala gives complete conversion and a diastereomeric excess of 88% of the desired 3S, 4S statinanalogue. The strain contains two NADPH-dependent oxidoreductases, that can be separated by ion exchange chromatography or gelfiltration, yielding the 3S, 4S or 3R, 4S stereoisomers, respectively, with > 99% diastereomeric excess (DE). In the crude extract the 3S, 4S oxidoreductase is very unstable and could be purified with << 1% yield only. In contrast, H. silvicola, which gave poor conversions using whole cells, exhibited about 80-fold higher specific activity in the crude extract than H. anomala. The NADPH-dependent oxidoreductase was purified 317-fold in 12% yield. A single enzyme of 54 kDa reduces the substrate with 97.4% DE. Besides the statinanalogue a wide range of other compounds could be reduced, most notably diones and chinones such as isatin or campherchinone. It was demonstrated that the enzymes often discussed for the reduction of beta-ketoesters with yeast e.g. L-3-hydroxyacyl CoA dehydrogenase (EC 1.1.1.35), the beta-ketoreductase of the fatty acid synthase complex and also the 3-hydroxy-3-methyl glutaryl-CoA dehydrogenase (EC 1.1.1.34) are separated during the purification steps from the oxidoreductase acting on N-Boc-4S-amino-3-oxo-5-phenylpentanoic acid methylester. The physiological role of the new enzyme is still unknown.

Serum prolactin in patients with Laron-type dwarfism: effect of insulin-like growth factor I

Prolactin (PRL) secretion was studied in Laron-type dwarfism (LTD) patients (8 children and 9 adults) in basal condition, after acute insulin-like growth factor (IGF-I) or TRH injections and during 2 months of daily IGF-I treatment. Basal PRL was repeatedly higher (12.6 +/- 1.6 micrograms/l) than that in control subjects (7.6 +/- 1.2 micrograms/l, p < 0.05). Acute IGF-I injection caused an immediate slight decrease in serum PRL and growth hormone (GH), followed by a progressive rise to mean peak levels of 33.3 +/- 4.5 micrograms/l again parallel to serum hGH which rose to 86 +/- 20 micrograms/l--a response to the IGF-I-induced hypoglycemia. Intravenous TRH in LTD children induced a marked response in serum PRL, similar to that registered in estrogenized adult females. Serum PRL did not show consistent changes during chronic IGF-I treatment. It is suggested that the higher-than-normal PRL levels and release in LTD patients are due to a drift phenomenon of the mammosomatotropes which produce large amounts of hGH.

The promastigote surface protease (gp63) of Leishmania is expressed but differentially processed and localized in the amastigote stage

The expression, processing and localization of the promastigote surface glycoprotein, gp63, in the amastigote form of Leishmania mexicana was examined. Metabolically labeled protein was immunoprecipitated from promastigotes and amastigotes. The isolated proteins were subjected to deglycosylation and partial peptide mapping. The cleavage products generated migrated similarly in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that the proteins were closely related. The majority of gp63 in amastigotes was inaccessible to surface-labeling procedures, and lacked the phosphatidylinositol membrane anchor. Immunolocalization of this subpopulation of gp63 revealed it to be present within the parasite's flagellar pocket. Despite the relative paucity of 'membrane-form' gp63, isolation and analysis of surface proteins from lesion amastigotes indicated that gp63 was the most abundant protein on the amastigote surface.