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Biomedical subjects

M D Young

Publications and source records attributed to M D Young.

At least 19 recordsLinked to original sources

A multi-center controlled study of rapid hepatitis B vaccination using a novel triple antigen recombinant vaccine.

Hepatitis B vaccines have been available for 20 years, however, the disease still remains a global problem. Clearly, the protection of at-risk groups could be improved if a more potent vaccine with a shorter vaccination regimen were available. Hepacare is new recombinant vaccine, which contains three of the surface antigens of the HB virus and has higher immunogenicity than present single antigen (HBsAg only) vaccines. This study evaluates the potential for developing seroprotection rapidly and the viability of a 1 month/two dose regimen. A total of 400 adult subjects were vaccinated using either the present accelerated 2 month/three dose regimen of Engerix-B or a 1 month/two dose regimen of a novel triple antigen vaccine (Hepacare). Both vaccines were well tolerated. Four weeks after a single dose, the seroprotective rates for Engerix-B and the triple antigen vaccine were 5 and 17%, respectively. By month 2, 4 weeks after two doses of vaccine, it was 38 and 61%. Finally by month 3, 4 weeks after a third dose of Engerix-B or placebo, respectively, the seroprotection rates were 71 and 82%. The geometric mean titres (GMTs), of these responders was then 119 and 120 IU/l, respectively. Both vaccines were well tolerated. At all points up to and including 3 months after beginning vaccination, the novel 1 month/two dose regimen of Hepacare was significantly more effective in producing seroporotective titres than the 2 month/three dose regimen of Engerix-B (P = 0.001).

Adolescent↗

Comparison of a triple antigen and a single antigen recombinant vaccine for adult hepatitis B vaccination.

Hepatitis B and its sequelae are a major public health problem. Vaccines have been available for almost 20 years; however the disease still remains a global problem. Many factors contribute to the failure to control hepatitis B, including the limited nature of the vaccination programs implemented initially. Only relatively recently has mass childhood vaccination begun to be implemented and vaccination of high-risk groups, other than healthcare workers, is still not general policy. Additional factors contributing to continued persistence of hepatitis B in the developed world are that the present vaccines are not fully used by those recommended to be vaccinated and even when vaccination is carried out appropriately, there remain some who fail to achieve adequate protection. Clearly, the protection of at-risk groups who have inadequate response to current vaccines, and those who are unwilling or unable to comply with protracted multi-dose vaccine regimens, could be improved if there were a more potent vaccine and/or a shorter vaccination regimen available. Adults who had never been vaccinated against hepatitis B were randomised to receive a vaccination course of either a present single antigen (S) vaccine (Recombivax-HB) or a novel triple antigen (S, pre-S1, and pre-S2) recombinant vaccine (Hepacare Medeva Pharma plc). Doses were given at baseline and 1 month and 6 months later. Hepatitis B surface antibody (anti-HBs) levels were measured at 2, 4, 6, and 7 months after beginning vaccination. The primary efficacy parameter was the degree of protection, measured as the percentage of subjects with anti-HBs titres > or = 10 IU/L, 6 or 7 months (26 +/- 2 weeks) after beginning vaccination. A total of 303 adult subjects entered the study and were vaccinated. Of these, 11 failed to complete the study (4 on Hepacare and 7 on Recombivax-HB); however all but 2 (1 to receive the triple antigen vaccine and 1 to receive Recombivax-HB) were included in the intent-to-treat population for efficacy evaluation. Treatment randomisation was stratified at entry based on age (above and below 40 years old) and gender. The standard three-dose/6-month vaccination regimen of the single antigen vaccine protected 83% of subjects by 7 months after starting vaccination whereas the triple antigen vaccine as a two-dose/1-month regimen protected 88% within 6 months and as a three-dose/6-month regimen protected 97% by 7 months after starting vaccination. Thus the protection rate provided by the shortened (0, 1) regimen of the novel vaccine was "essentially equivalent" (i.e., not statistically inferior) to that provided by the full (0, 1, and 6) regimen of today's vaccine (88% vs. 81%, P < 0.001), and the protection rate provided by a three-dose/6-month (0, 1, and 6) regimen of the new vaccine was significantly superior to that provided by present vaccines (97% vs. 83% P < 0.001). The percentage of subjects protected increases with time after beginning vaccination and at all time points up to and including 6 months was significantly greater with the two-dose regimen of the triple antigen vaccine than with the single antigen vaccine regimen. In adults at risk for a reduced response to hepatitis B vaccination [i.e., older adults (>/=40), the obese, males, and smokers], the triple antigen vaccine produced a significantly greater percentage of protected subjects (P < 0.001) and higher geometric mean titre (P < 0.001). Indeed as a three-dose/6 month regimen, the triple antigen vaccine raised the level of protection in these vulnerable subgroups to that seen when a single antigen vaccine is used in the optimal younger adult group. Both vaccines were well tolerated and had similar safety profiles. The most frequently (> or = 10%) reported adverse events with the use of either vaccine were pain at the site of injection (38% vs. 41% vs. 20% for the two-dose Hepacare regimen, the three-dose Hepacare regimen, and the three-dose Recombivax-HB regimen, respectively), infections at the site of injection (1% vs. 14% vs. 9%), headache (9% vs. 13% vs. 11%), and nausea (7% vs. 11% vs. 3%). It is concluded that in healthy normal adults, a triple antigen hepatitis B vaccine that contained S and pre-S antigens produced an enhanced immunological response. This was exemplified by the novel vaccine's ability to overcome factors such as advancing age (> or = 40 years), obesity, and smoking, each of which is known to reduce the potential for protection with present recombinant S only vaccines. A two-dose/1-month (0 and 1) regimen of this triple antigen vaccine was as effective as the standard three-dose/6 month (0, 1, and 6) regimen of present single antigen vaccines. (c) 2001 Wiley-Liss, Inc.

Adolescent↗

Gene delivery from the E3 region of replicating human adenovirus: evaluation of the 6.7 K/gp19 K region.

The use of genetically engineered, replication-selective viruses to treat cancer is being realized with viruses such as ONYX-015, a human adenovirus that selectively destroys p53 mutant cancer cells. To enhance further the clinical efficacy of ONYX-015 and viruses like it, we have developed a novel gene delivery system for replicating adenoviruses. This system has two unique features. First, it uses the endogenous adenoviral gene expression machinery (promoter, splicing, polyadenylation) to drive transgene expression. Second, a single region or gene in the multi-gene E3 transcription unit is selectively substituted for by the therapeutic transgene(s). Analyzing various transgene substitutions for the 6.7 K/gp19 K region of E3, we demonstrate the following: (1) transgene expression in this system is predictable and mimics the substituted endogenous gene expression pattern, (2) expression of surrounding E3 genes can be retained, (3) the insertion site choice can effect both the transgene expression level and the viral life cycle, and, (4) expression levels from this system are superior to those generated from a replication-defective virus using the HCMV enhancer-promoter and this is dependent on viral DNA replication. This unique methodology has broad application to the rapidly evolving field of replicating virus-based therapies.

Adenovirus E3 Proteins↗

Adult hepatitis B vaccination using a novel triple antigen recombinant vaccine.

Present hepatitis B vaccines use multidose prolonged regimens, which even healthcare workers at risk do not always complete. Moreover, when vaccination is completed there remain some who fail to achieve adequate protection. The protection of adults at risk could be improved if there were a more potent vaccine and/or a shorter vaccination regimen available. Vaccine-naive adults were randomized to vaccination with either Engerix-B (SmithKline Biologicals, Rixensart, Belgium) or a novel triple antigen (S, pre-S1, and pre-S2) recombinant vaccine (Hepacare; Medeva Pharma Plc, Speke, UK). The primary efficacy parameter was the degree of seroprotection 6 or 7 months (26 +/- 2 weeks) after beginning vaccination. A total of 304 adults entered the study. Of these, 16 failed to complete the study (9 on Hepacare and 7 on Engerix-B). With the Engerix-B standard (0, 1, 6) regimen, 88% of subjects were protected by month 7, whereas with the triple antigen vaccine a 2-dose regimen (0, 1) provided equivalent protection (91%) within 6 months and a 3-dose (0, 1, 6) regimen was significantly superior (98% seroprotected by 7 months after starting vaccination P <.001). With adults at risk for a suboptimal response (i.e., older adults, the obese, men, and smokers) the triple antigen vaccine produced a greater degree of protection. The vaccines had similar safety profiles. Both vaccines were well tolerated. In healthy normal adults, a triple antigen hepatitis B vaccine containing S and pre-S antigens produced an enhanced immunologic response and was as effective as a 2- and 3-dose regimen.

Adult↗

Evaluation of a new hepatitis B triple-antigen vaccine in inadequate responders to current vaccines.

In this double-blind, randomized, controlled study, healthcare professionals with a history of inadequate response to currently available single-antigen hepatitis B vaccines confirmed by measuring hepatitis B surface antibody titer before entry to the study were revaccinated with a 20-microg dose either of a novel triple-antigen (S, pre-S1, and pre-S2) recombinant vaccine or of a present single-antigen (S only) vaccine. Hepatitis B surface antibody titers were measured 8 weeks' post revaccination. A total of 925 individuals were randomized and vaccinated, of whom 915 (98.9%) completed the study and were included in the efficacy analysis. A single dose of the new triple-antigen hepatitis B vaccine (Hepacare) produced a successful response in over three quarters of these subjects who had not mounted an adequate response to current vaccines. The antibody response was statistically significantly superior (P =.002) to that after a single dose of current vaccines. An evaluation of the overall response showed that only the triple-antigen vaccine was able to raise the average antibody response (geometric mean titer [GMT]) to over 100 IU/L. The superior effect of the new vaccine was most pronounced in subjects who were previously complete nonresponders to currently available hepatitis B vaccines. Both vaccines were well tolerated and had similar safety profiles. This study demonstrated that in healthcare workers who had responded inadequately to at least a full course of immunization (median, 5 doses), a single 20-microg dose of a new triple-antigen vaccine induced protective antibody level in more vaccinees (P =.002) and increased the average antibody titer (GMT) in those protected successfully to a greater degree (P <.001) than a further attempt with a current vaccine (Engerix-B).

Adult↗

Molybdate-dependent expression of dimethylsulfoxide reductase in Rhodobacter capsulatus.

Expression of the dimethylsulfoxide respiratory (dor) operon of Rhodobacter is regulated by oxygen, light intensity and availability of substrate. Since dimethylsulfoxide reductase contains a pterin molybdenum cofactor, the role of molybdate in the regulation of dor operon expression was investigated. In this report we show that the molybdate-responsive transcriptional regulator, MopB, and molybdate are essential for maximal dimethylsulfoxide reductase activity and expression of a dorA::lacZ transcriptional fusion in Rhodobacter capsulatus. In contrast, mop genes are not required for the expression of the periplasmic nitrate reductase or xanthine dehydrogenase in R. capsulatus under conditions of molybdenum sufficiency. This is the first report demonstrating a clear functional difference between the ModE homologues MopB and MopA in this bacterium. The results suggest that MopA is primarily involved in the regulation of nitrogen fixation gene expression in response to molybdate while MopB has a role in nitrogen fixation and dimethylsulfoxide respiration.

Bacterial Proteins↗

Pharmacy practice acts: a decade of progress.

OBJECTIVE: This 10-year follow-up study of previously published surveys of pharmacy practice acts examines 50 state and the District of Columbia pharmacy practice acts to assess the range of statutory definitions and determine the direction and magnitude of statutory changes since 1988. DATA SOURCES: State codes for 50 states and the District of Columbia, with attention focused on the pharmacy practice acts; Puerto Rico and the Virgin Islands were excluded. DATA EXTRACTION: The focus on each statute was the statutory definition of the "practice of pharmacy." DATA SYNTHESIS: Comparing 1998 with 1988, codification of interpreting and evaluating prescriptions increased 22% (1998; 39/47, four states contain no definition of the practice of pharmacy), compounding 8% (47/47), consultation 19% (41/47), dispensing 2.5% (47/47), drug administration threefold (24/47), drug product selection twofold (45/47), drug utilization review 70% (35/47), patient assessment 6.5-fold (6/47), pharmacokinetic services threefold (3/47), pharmacist prescribing 4.6-fold (15/47), and participation in drug research 10.5-fold (10/47). CONCLUSIONS: Since 1988, state pharmacy practice acts have increased the codification of pharmaceutical care services as integral pharmacy functions. Although substantial progress has been made over the past decade, a number of states have not incorporated definitions of pharmaceutical care functions into their state statutes. Enactment of the National Association Boards of Pharmacy Model State Pharmacy Act is one way for pharmacists' practice to expand with the evolution of the practice of pharmacy.

Humans↗

Decreased expression of murine PPARgamma in adipose tissue during endotoxemia.

Infection-induced hyperlipidemia develops due to a combination of factors, one of which is decreased clearance of lipids from the bloodstream due to depressed synthesis of lipoprotein lipase (LPL). Recently, the peroxisome proliferator activated receptors (PPARs) have been shown to be important in the regulation of LPL, particularly PPARgamma. PPARgamma and its heterodimerization partner, RXR alpha have been shown to be transcriptional activators of LPL in co-transfection analysis. Therefore, we hypothesized that the decrease in LPL expression during endotoxemia may be a result of depressed PPARgamma expression. In these studies, we examined the effect of endotoxin or its proximal mediator, tumor necrosis factor (TNF), on the expression of PPARgamma in white (WAT) and brown adipose tissue (BAT) in CD-1 mice. We report that treatment with endotoxin, but not TNF, transiently decreased PPARgamma mRNA levels 4 hr after treatment. However, endotoxin or TNF treatment decreased PPARgamma protein levels after 18 hr, which was at a time when LPL mRNA levels were also depressed. These data suggest that decreased PPARgamma expression following endotoxin or TNF treatment may contribute to the hyperlipidemia due to decreased expression of LPL, which would impair triglyceride clearance.

Adipose Tissue↗

Does surgical subspecialization in pediatrics provide high-quality, cost-effective patient care?

OBJECTIVE: To determine if pediatric surgical subspecialization provides cost-effective, high-quality pediatric patient care. METHODS: Ureteroneocystostomy inpatients over 4 years were studied. Hospital charges and complications were compared between general urologists and fellowship-trained pediatric urologists. RESULTS: Hospital charges were significantly less ($1095) for patients under the care of a pediatric urologist. Complication rates were also lower. CONCLUSIONS: Pediatric urology subspecialization offers high-quality, cost-effective pediatric patient care.

Adolescent↗

Influence of involution on intramammary phagocytic defense mechanisms.

Mammary secretions (n = 34 cows) and mammary phagocytes (n = 18 cows) were collected throughout the nonlactating (dry) period to determine changes in intramammary phagocytic defense mechanisms. Mammary secretions were evaluated for their ability to support phagocytosis of Staphylococcus aureus by neutrophils from donor cows and mammary phagocytes for phagocytic and chemiluminescence activity. Ability of secretions to support phagocytosis decreased with advancing length of the dry period. This effect was more pronounced when dry cow secretions constituted 50% of the phagocytic mixture. Phagocytic activity of mammary phagocytes decreased with advancing dry period when autologous secretion was used in the incubation mixture. With homologous secretion, the percentage of phagocytosis increased 5 to 6 d after drying off compared with before drying off and then gradually decreased throughout the remainder of the dry period. Chemiluminescence activity (log10 counts per minute) of mammary phagocytes was lower during the dry period and decreased with advancing dry period. Results indicated diminishing ability of secretions to support phagocytosis and diminished phagocytic and bactericidal mechanisms during the dry period.

Animals↗

Globalization of the pharmaceutical industry: the physician's role in optimizing drug use.

In this new era of globalization, the physician must consider cultural differences in choosing methods of disseminating information so that practitioners in diverse settings may optimize drug usage. In addition, increasing competition, stimulated by the imminent unification of the European market in 1992, demands that the industry physician be concerned with developing possible new indications and cost-effective applications. These factors will enhance roles for the medical affairs physician in the pharmaceutical industry.

Drug Industry↗

Cimetidine 800 mg twice daily for healing erosions and ulcers in gastroesophageal reflux disease.

Although H2-receptor antagonists have been the mainstay of therapy for gastroesophageal reflux disease (GERD), none of these agents has been approved by the FDA as effective in healing lesions. Since proton pump inhibitors may be associated with long-term disadvantages, a healing regimen with cimetidine would be useful clinically. This multicenter, randomized, double-blind study was conducted to evaluate the efficacy of cimetidine 800 mg b.i.d. in healing lesions and in providing symptomatic relief in patients with ulcerative or erosive esophagitis. Patients with greater than or equal to 8 heartburn episodes during a 1-week screening period, reflux confirmed by esophageal pH monitoring, and esophageal ulcers or erosions confirmed by endoscopy were randomized to treatment with placebo or cimetidine for 12 weeks. Cimetidine provided significantly greater (p less than 0.01) improvement (74% vs. 51%) and complete healing (67% vs. 36%) of esophageal lesions than did placebo. In these patients with erosive or ulcerative esophagitis, the median time to achieve 24 h without heartburn was 13 days with cimetidine and 30 days with placebo (p = 0.01). The mean heartburn severity score in the cimetidine group decreased rapidly during the first week and was consistently lower than in the placebo group. Cimetidine, 800 mg twice daily, is effective in promoting healing of esophageal ulcers and erosions and in providing heartburn relief in patients with symptomatic erosive/ulcerative GERD.

Adult↗

Total and differential somatic cell counts and N-acetyl-beta-D-glucosaminidase activity in mammary secretions during dry period.

Eighteen Holstein cows free of intramammary infection were sampled during dry period to measure changes in total SCC, differential cell counts, and N-acetyl-beta-D-glucosaminidase activity of milk or dry secretion. The design was to sample prior to and at drying off, two or more times during wk 1 of dry period, at 14 and 21 d of dry period, and after calving; 7 cows were sampled rotationally by quarters at 7, 14, and 21 d to avoid altering normal processes by repeated sampling. Total SCC of secretions declined just after drying off, increased to a peak of 6.593 (log10 scale) at 2 wk, and then declined slightly at 3 wk. Percentage of neutrophils rose from 33.3 at drying off to 83.8 at 1 wk and declined to 59.2 at 3 wk. Lymphocyte percentage declined in wk 1 of dry period but increased during wk 2 and 3. Activity of N-acetyl-beta-D-glucosaminidase in secretion rose throughout the first 3 wk of dry period.

Acetylglucosaminidase↗

Parenteral antisecretory drug therapy in patients with Zollinger-Ellison syndrome.

Forty-six patients with Zollinger-Ellison syndrome were studied prospectively to determine a safe and effective method and criterion for controlling gastric acid hypersecretion during periods when oral antisecretory agents could not be used. In each patient it was possible to reduce acid secretion to less than or equal to 10 mEq/h after an i.v. bolus of 150 or 300 mg of cimetidine and a stepwise titration of cimetidine given by continuous infusion. The mean dose given by i.v. infusion was 2.9 mg/kg body wt.h but there was a wide range (0.5-7.0 mg/kg body wt.h) and the minimal dose had to be determined individually for each patient. The minimal i.v. cimetidine dose did not correlate with basal or maximal acid output or fasting gastrin concentration, but correlated closely with either the previous oral dose of cimetidine (r = 0.96, p less than 0.001) or the previous oral dose of ranitidine or famotidine (r = 0.95, p less than 0.001). To study the efficacy and safety of an i.v. infusion of cimetidine, 34 patients undergoing surgery were maintained on i.v. cimetidine for a mean of 12 days (range 1-83 days). One-half of the patients did not require dose adjustment, whereas the remainder required an average of 2 adjustments, usually in the first 3 postoperative days. No patient developed complications attributable to gastric acid hypersecretion in the postoperative period, and there was no detectable neurologic, hematologic, or hepatic toxicity. This study demonstrates that a continuous i.v. infusion of cimetidine adequately inhibits gastric acid hypersecretion in patients with Zollinger-Ellison syndrome. However, high doses were frequently required, the dose had to be determined in a stepwise fashion individually for each patient, and the i.v. dose correlated with the previous oral dose. Reducing acid secretion to less than or equal to 10 mEq/h was a safe criterion during surgery and continuous i.v. cimetidine was safe and effective in achieving this degree of control for up to 83 days.

Administration, Oral↗