Prospective randomized trial of low- versus high-dose radiation therapy in adults with supratentorial low-grade glioma: initial report of a North Central Cancer Treatment Group/Radiation Therapy Oncology Group/Eastern Cooperative Oncology Group study

PURPOSE

To compare survival and toxicity in adult patients treated with low-dose (50.4 Gy/28 fractions) versus high-dose (64.8 Gy/36 fractions) localized radiation therapy (RT) for supratentorial low-grade astrocytoma, oligodendroglioma, and mixed oligoastrocytoma.

PATIENTS AND METHODS

From 1986 to 1994, 203 eligible/analyzable patients were randomized: 101 to low-dose RT, 102 to high-dose RT. Almost half were younger than 40 years, and 95% had grade 2 tumors. Histologic subtype was astrocytoma (or mixed oligo-astrocytoma with astrocytoma dominant) in 32% of patients and oligodendroglioma (or oligoastrocytoma with oligodendroglioma dominant) in 68%. Tumor diameter was less than 5 cm in 35% of patients, and 41% of tumors showed some degree of contrast enhancement. Extent of resection was gross total in 14% of patients, subtotal in 35%, and biopsy only in 51%.

RESULTS

At the time of the present analysis, 83 patients (41%) are dead, and median follow-up is 6.43 years in the 120 who are still alive. Survival at 2 and 5 years is nonsignificantly better with low-dose RT; survival at 2 and 5 years was 94% and 72%, respectively, with low-dose RT and 85% and 64%, respectively, with high-dose RT (log rank P =.48). Multivariate analysis identified histologic subtype, tumor size, and age as the most significant prognostic factors. Survival is significantly better in patients who are younger than 40 years and in patients who have oligodendroglioma or oligo-dominant histology. Grade 3 to 5 radiation neurotoxicity (necrosis) was observed in seven patients, with one fatality in each treatment arm. The 2-year actuarial incidence of grade 3 to 5 radiation necrosis was 2.5% with low-dose RT and 5% with high-dose RT.

CONCLUSION

This phase III prospective randomized trial of low- versus high-dose radiation therapy for adults with supratentorial low-grade astrocytoma, oligodendroglioma, and oligoastrocytoma found somewhat lower survival and slightly higher incidence of radiation necrosis in the high-dose RT arm. The most important prognostic factors for survival are histologic subtype, tumor size, and age. The study design of the ongoing intergroup trial in this population will be discussed.

Mapping quantitative trait loci controlling early growth in a (longleaf pine x slash pine) x slash pine BC(1) family

Random amplified polymorphic DNA (RAPD) markers were employed to map the genome and quantitative trait loci controlling the early growth of a pine hybrid F(1) tree ( Pinus palustris Mill. x P. elliottii Engl.) and a recurrent slash pine tree ( P. elliottii Engl.) in a (longleaf pine x slash pine) x slash pine BC(1) family consisting of 258 progeny. Of the 150 hybrid F(1) parent-specific RAPD markers, 133 were mapped into 17 linkage groups covering a genetic distance of 1,338.2 cM. Of the 116 slash pine parent-specific RAPD markers, 83 were mapped into 19 linkage groups covering a genetic distance of 994.6 cM. A total of 11 different marker intervals were found to be significantly associated with 13 of the 20 traits on height and diameter growth using MAPMAKER/QTL. Nine of the eleven marker intervals were unique to the hybrid parent 488 genome, and two were unique to the recurrent parent 18-27 genome. The amount of phenotypic variance explained by the putative QTLs ranged from 3.6% to 11.0%. Different QTLs were detected at different ages. Two marker intervals from the hybrid parent 488 were found to have QTL by environment interactions.

Extracellular arginine aminopeptidase from Streptococcus gordonii FSS2

Streptococcus gordonii is a primary etiological agent in the development of subacute bacterial endocarditis (SBE), producing thrombus formation and tissue damage on the surfaces of heart valves. This is ironic, considering its normal role as a benign inhabitant of the oral microflora. However, strain FSS2 of S. gordonii has been found to produce several extracellular aminopeptidase- and fibrinogen-degrading activities during growth in a pH-controlled batch culture. In this report, we describe the purification, characterization, and partial cloning of a predicted serine class arginine aminopeptidase (RAP) with some cysteine class characteristics. Isolation of this enzyme by anion-exchange, gel filtration, and isoelectric focusing chromatography yielded a protein monomer of approximately 70 kDa, as shown by matrix-assisted laser desorption ionization, gel filtration, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis under denaturing conditions. Nested-PCR cloning enabled the isolation of a 324-bp-long DNA fragment encoding the 108-amino-acid N terminus of RAP. Culture activity profiles and N-terminal sequence analysis indicated the export of this protein from the cell surface. Homology was found with a putative dipeptidase from Streptococcus pyogenes and nonspecific dipeptidases from Lactobacillus helveticus and Lactococcus lactis. We believe that RAP may serve as a critical factor for arginine acquisition during nutrient stress in vivo and also in the proteolysis of host proteins and peptides during SBE pathology.

Rapid killing of Streptococcus pneumoniae with a bacteriophage cell wall hydrolase

Nasopharyngeal carriage is the major reservoir for Streptococcus pneumoniae in the community. Although eliminating this reservoir would greatly reduce disease occurrence, no suitable intervention has been available for this purpose. We show here that seconds after contact, a purified pneumococcal bacteriophage lytic enzyme (Pal) is able to kill 15 common serotypes of pneumococci, including highly penicillin-resistant strains. In vivo, previously colonized mice revealed undetectable pneumococcal titers 5 hours after a single enzyme treatment. Pal enzyme had little or no effect on microorganisms normally found in the human oropharynx, and Pal-resistant pneumococci could not be detected after extensive exposure to the enzyme.

Tumor necrosis factor-alpha induces Bax-Bak interaction and apoptosis, which is inhibited by adenovirus E1B 19K

Tumor necrosis factor (TNF)-alpha-mediated death signaling induces oligomerization of proapoptotic Bcl-2 family member Bax into a high molecular mass protein complex in mitochondrial membranes. Bax complex formation is associated with the release of cytochrome c, which propagates death signaling by acting as a cofactor for caspase-9 activation. The adenovirus Bcl-2 homologue E1B 19K blocks TNF-alpha-mediated apoptosis by preventing cytochrome c release, caspase-9 activation, and apoptosis of virus-infected cells. TNF-alpha induces E1B 19K-Bax interaction and inhibits Bax oligomerization. Oligomerized Bax may form a pore to release mitochondrial proteins, analogous to the homologous pore-forming domains of bacterial toxins. E1B 19K can also bind to proapoptotic Bak, but the functional significance is not known. TNF-alpha signaling induced Bak-Bax interaction and both Bak and Bax oligomerization. E1B 19K was constitutively in a complex with Bak, and blocked the Bak-Bax interaction and oligomerization of both. The TNF-alpha-mediated cytochrome c and Smac/DIABLO release from mitochondria was inhibited by E1B 19K expression in adenovirus-infected cells. Since either Bax or Bak is essential for death signaling by TNF-alpha, the interaction between E1B 19K and both Bak and Bax may be required to inhibit their cooperative or independent oligomerization to release proteins from mitochondria which promote caspase activation and cell death.

Laparoscopic radical nephrectomy in 100 patients: a single center experience from the United States

BACKGROUND

The objective of the current study was to report a single-surgeon, single-center experience with 100 consecutive laparoscopic radical nephrectomies with intact specimen extraction, with the aim of evaluating the oncologic adequacy of the laparoscopic dissection from a technical standpoint and various parameters including the learning curve.

METHODS

Of the 140 laparoscopic radical nephrectomies performed at the study institution since August 1997, the initial 100 are evaluated herein. To evaluate the technical oncologic adequacy, comparison was made with 40 contemporary open radical nephrectomy specimens with regard to detailed radiologic (computed tomography scan) and pathologic data.

RESULTS

In the 100 patients studied (with a mean tumor size of 5.1 cm), the mean surgical time was 2.8 hours, the blood loss was 212 mL, the specimen weight was 554.3 g, and the hospital stay was 1.6 days. Complications occurred in 14 patients (14%) and were major in 3 (3%) and minor in 11 (11%). Two patients (2%) were converted to open surgery. There was no perioperative mortality. Over a mean follow-up of 16.1 months, there was no local or port site recurrence reported; 2 patients developed metastatic disease with 1 death occurring at 11 months. When evaluating the learning curve in the initial 50 versus the second 50 patients, a shorter surgical time (P = 0.02) appeared to be the only significant variable. On multivariate analyses, the only variables found to impact on surgical time were specimen weight (P < 0.001) and chronologic time period of surgery (P = 0.05). All laparoscopic specimens were extracted intact; surgical margins were negative for tumor in all 100 patients. All detailed radiologic and histopathologic parameters evaluated were nearly identical between the laparoscopic and open surgery groups.

CONCLUSIONS

Laparoscopic radical nephrectomy with intact specimen extraction currently is a routine, effective, and efficacious treatment option for patients with T1-T3aN0M0 renal tumors. Although no long-term data were available as of last follow-up, the negative surgical margins achieved routinely in the current series provide encouraging surrogate evidence of the technical efficacy of laparoscopy from an oncologic standpoint. As such, at the study institution, laparoscopic radical nephrectomy with intact specimen extraction currently is the standard-of-care for patients with T1-3aN0M0 renal tumors measuring < or = 10-12 cm in size.

Vasoresponsiveness of sarcoidosis-associated pulmonary hypertension

OBJECTIVE

To assess short-term and long-term responses to treatment with pulmonary vasodilators in patients with sarcoidosis-related pulmonary hypertension.

METHODS

A prospective, observational study was performed on eight patients with moderate-to-severe sarcoidosis-related pulmonary hypertension. Patients underwent a short-term vasodilator trial, using inhaled nitric oxide (iNO), IV epoprostenol, and/or oral calcium-channel blockers. A favorable short-term response was considered a > or = 20% decrease in pulmonary vascular resistance (PVR). Five patients received long-term treatment with iNO (with one patient receiving epoprostenol in addition) and underwent follow-up hemodynamic and/or 6-min walk testing. Two patients received long-term treatment with calcium-channel blockers.

RESULTS

Baseline (+/- SE) mean pulmonary artery pressure (mPAP) was 55 +/- 4 mm Hg and PVR was 896 +/- 200 dyne.s.cm(-5). A favorable short-term response was seen in seven of eight patients receiving iNO, four of six patients receiving epoprostenol, and two of five patients receiving calcium-channel blockers. With iNO, PVR decreased 31 +/- 5% (p = 0.006) and mPAP decreased 18 +/- 4% (p = 0.003); with epoprostenol, PVR decreased 25 +/- 6% (p = 0.016) and mPAP decreased 6 +/- 2% (p = not significant). Decreased systemic vascular resistance was the only significant response to treatment with calcium-channel blockers. Follow-up 6-min walk test results improved in all five patients receiving long-term treatment with iNO. Follow-up hemodynamic responses in three patients showed preserved vasoresponsiveness. These three patients subsequently died, as did the two patients receiving calcium-channel blockers. The two remaining patients continue to receive iNO.

CONCLUSION

In the short term, pulmonary hypertension in patients with sarcoidosis is responsive to treatment with pulmonary vasodilators; these patients may benefit from long-term iNO therapy.

Prevalence of evaluation for latex allergy and association with practice characteristics in United States dermatologists: results of a cross-sectional survey

BACKGROUND

Natural rubber latex allergy is a potentially life-threatening, immunoglobin E (IgE) mediated reaction. Despite great strides in identification of high-risk groups, methods for diagnosis remain limited in the United States and most evaluations are performed by allergists.

OBJECTIVE

The objective of this study was to estimate the prevalence of evaluation for latex allergy and association with practice characteristics in United States dermatologists.

METHODS

A cross-sectional survey of one third of United States Fellows of the American Academy of Dermatology.

RESULTS

The survey response rate was 43%. Of responding dermatologists, 17% stated that they evaluate patients for latex allergy, most commonly with a radioallergosorbent (RAST) or use test. Only 3.6% stated that they perform prick or scratch tests for latex allergy in their office, and most of these dermatologists (86%) prepare their own latex prick test solutions. Evaluation for latex allergy was significantly associated with patch testing, photopatch testing, an interest in contact dermatitis, and number of contact dermatitis books owned, but not with number of years in practice.

CONCLUSIONS

Most United States dermatologists do not evaluate patients for latex allergy, most likely because of lack of available antigens and because methods for diagnosing latex allergy are not familiar to most dermatologists.

The immune anti-tumor effects of GM-CSF and B7-1 gene transfection are enhanced by surgical debulking of tumor

Malignant mesothelioma (MM) is a solid tumor largely unresponsive to conventional therapies. Immunological gene therapy shows promise in murine models and human clinical trials; however, the role of surgery in combination with gene therapy has not been widely studied. The aim of this study was to determine if debulking surgery improved the effectiveness of gene therapy in a murine MM model. Mice were subcutaneously inoculated with the MM cell line, AC29, at two different sites, 4 days apart, to allow a surgical and distal site tumor to develop. Once tumors were established, the surgical site tumor was debulked and vaccination of syngeneic tumor transfectants encoding genes for IL-4, IL-2, GM-CSF, B7-1 or allogeneic MHC molecules commenced at a site away from both tumors, and tumor growth was measured. Neither debulking surgery nor gene therapy alone delayed tumor growth. However, there was a clear delay of tumor growth when debulking surgery was combined with vaccination of tumor transfectants expressing B7-1 or high levels of GM-CSF. Combinations of these two transfectants did not lead to a synergistic effect. This study demonstrates that debulking surgery can augment the immunostimulatory effects of immunological gene therapy and can delay tumor growth. This has implications for the future design of human gene therapy trials for solid tumors such as MM.

Screening and monitoring for bladder cancer: refining the use of NMP22

PURPOSE

While detecting bladder cancer, bladder tumor markers demonstrate improved sensitivity compared with urinary cytology but the current limitation is the low specificity and positive predictive value, that is high false-positive rate. We examined the clinical categories of the false-positive results, established relative exclusion criteria, and recalculated the specificity and positive predictive value of this assay with these criteria.

MATERIALS AND METHODS

A total of 608 patients considered at risk for bladder cancer presented to a urology clinic and submitted a single urine sample. Of the 608 patients 529 (87%) presented with de novo hematuria or chronic voiding symptoms without a diagnosis of bladder cancer. There were 79 (13.0%) patients being monitored with a known history of bladder cancer. Each urine sample was examined via cytology, urinalysis, culture and NMP22 protein assay. All patients underwent office cystoscopy, and transurethral resection and/or biopsy if a bladder tumor was suspected.

RESULTS

Of the 608 patients 226 (37.2%) presented with microscopic hematuria, 143 (23.5%) with gross hematuria and 239 (39.3%) had chronic symptoms of urinary frequency or dysuria. There were 52 (8.6%) patients who had histologically confirmed bladder cancer. Of these 52 cancers NMP22 detected 46 (88.5%), whereas cytology identified only 16 (30.8%). When atypical cytology was considered positive, cytology detected 32 (61.5%) cases. In the 135 patients with increased NMP22 values the 46 identified tumors were accompanied by 89 false-positive values yielding a specificity of 83.9% and a positive predictive value of 34.1%. These false-positive results were divided into 6 clinical categories. Exclusion of these categories improved the specificity and positive predictive value of NMP22 to 99.2% and 92.0%, respectively, yielding results similar to urinary cytology (99.8% and 94.1%).

CONCLUSIONS

Awareness and exclusion of the categories of false-positive results can increase the specificity and positive predictive value of NMP22, enhancing the clinical use of this urinary tumor marker.

Use of the pediatric symptom checklist in strategies to improve preventive behavioral health care

OBJECTIVE

The purpose of this study was to examine the utility of the Pediatric Symptom Checklist (PSC) in identifying youth at risk of behavioral health problems and to develop strategies to meet their mental health needs.

METHODS

The PSC was completed by the parents of 570 children aged two to 18 years at three urban health centers in Massachusetts. Follow-up interviews were conducted with the parents of 95 of the children. Multidisciplinary teams held case conferences to review the cases of 43 of the 95 children who were interviewed and who were determined to have moderate to severe behavioral health problems.

RESULTS

Of the 570 children in the screening sample, 144 (25 percent) had moderate to severe behavioral health problems, as indicated by a positive score on the PSC, and 2 percent had a serious emotional disturbance. Of the 297 pre-school-aged children (younger than six years), 67 (23 percent) received a positive score. Of the 283 school-aged children (age six and older) from both English- and Spanish-speaking families, 77 (27 percent) received a positive score. About one-third of the severely emotionally disturbed youth were receiving some mental health treatment, but only 20 percent were rated by the multidisciplinary team as receiving adequate treatment.

CONCLUSIONS

The study provided further support for the validity and reliability of the PSC and confirmed the results of earlier studies that found a high level of unmet needs for mental health services among this population. Use of the PSC in this study promoted an increase in referrals for children in need.

Slow-binding inhibition of gamma-glutamyl transpeptidase by gamma-boroGlu

gamma-Glutamyl transpeptidase (gammaGTase) catalyzes the transfer of the gamma-glutamyl moiety of gamma-glutamyl-derived peptides, such as glutathione (gammaGlu-Cys-Gly), and anilides, such as gamma-glutamyl-7-amido-4-methylcoumarin (gammaGlu-AMC), to acceptor molecules, including water and various dipeptides. These acyl-transfer reactions all occur through a common acyl-enzyme intermediate formed from attack of an active site hydroxyl on the gamma-carbonyl carbon of gammaGlu-X with displacement of X. In this paper, we report that gammaGTase is potently inhibited by the gamma-boronic acid analogue of L-glutamic acid, 3-amino-3-carboxypropaneboronic acid (gamma-boroGlu). We propose that gamma-boroGlu adds to the active site hydroxyl of gammaGTase to form a covalent, tetrahedral adduct that resembles tetrahedral transition states and intermediates that occur along the reaction pathway for gammaGTase-catalyzed reactions. Our studies demonstrate that gamma-boroGlu is a competitive inhibitor of the gammaGTase-catalyzed hydrolysis of gammaGlu-AMC with a K(i) value of 35 nM. Kinetics of inhibition studies allow us to estimate the following values: k(on) = 400 mM(-1) s(-1) and k(off) = 0.02 s(-1). We also found that gamma-boroGlu is an uncompetitive inhibitor of Gly-Gly-promoted transamidation of gammaGlu-AMC. This observation is consistent with the kinetic mechanism we determined for gammaGTase-catalyzed transamidation of gammaGlu-AMC by Gly-Gly to form gammaGlu-Gly-Gly. To probe rate-limiting transition states for gammaGTase catalysis and inhibition, we determined solvent deuterium isotope effects. Solvent isotope effects on k(c)/K(m) for hydrolysis of gammaGlu-AMC and k(on) for inhibition by gamma-boroGlu are identical and equal unity, suggesting that the processes governed by these rate constants are both rate-limited by a step that is insensitive to solvent deuterium such as a conformational fluctuation of the initially formed E-S or E-I complex. In contrast, the solvent isotope effect on k(c) is 2.4. k(c) is rate-limited by hydrolysis of the acyl-enzyme intermediate that is formed during reaction of gammaGTase with gammaGlu-AMC. Thus, the magnitude of this isotope effect suggests the formation of a catalytically important protonic bridge in the rate-limiting transition state for deacylation.

Educating men about prostate cancer screening. A randomized trial of a mailed pamphlet

CONTEXT

Although evidence-based guidelines recommend that physicians inform men about prostate cancer screening, the most efficient way to do this is not known.

OBJECTIVE

To evaluate whether a mailed educational pamphlet affected men's knowledge about early detection of prostate cancer.

DESIGN

Randomized, controlled trial.

SETTING

Primary care clinic of the Minneapolis VA Medical Center.

PATIENTS

342 men at least 50 years of age who responded to a mailed survey (overall response rate, 68%) and did not report a history of prostate cancer.

INTERVENTION

"Early Prostate Cancer" pamphlet mailed to patients in the intervention group 1 week before their scheduled clinic appointments.

OUTCOME MEASURES

Patients' responses to a survey mailed 1 week after their clinic appointments; prostate-specific antigen (PSA) testing determined from electronic medical records.

RESULTS

Respondents were predominantly elderly white men (mean age, 71 years; 90% white) with chronic illnesses (48% described their health as "fair" or "poor"). Men who received the educational pamphlet were better informed than men in the usual care group, as measured by correct responses to the following three questions about prostate cancer screening: the natural history of prostate cancer (32% vs. 24%; P = 0.10), whether treatment lengthens lives of men with early prostate cancer (56% vs. 44%; P = 0.04), and accuracy of PSA testing (46% vs. 27%; P < 0.008). The overall proportion of correctly answered questions was greater in the intervention group (45% vs. 32%; P < 0.001). Testing for PSA in the year after the index clinic appointments did not differ significantly between the intervention group and the usual care group (31% vs. 37%; P > 0.2).

CONCLUSIONS

Male veterans are poorly informed about the potential benefits and risks of prostate cancer screening. Although our mailed educational pamphlet enhanced knowledge only modestly, it was an inexpensive and easily implemented intervention.

Detection of widespread fluids in the Tibetan crust by magnetotelluric studies

Magnetotelluric exploration has shown that the middle and lower crust is anomalously conductive across most of the north-to-south width of the Tibetan plateau. The integrated conductivity (conductance) of the Tibetan crust ranges from 3000 to greater than 20,000 siemens. In contrast, stable continental regions typically exhibit conductances from 20 to 1000 siemens, averaging 100 siemens. Such pervasively high conductance suggests that partial melt and/or aqueous fluids are widespread within the Tibetan crust. In southern Tibet, the high-conductivity layer is at a depth of 15 to 20 kilometers and is probably due to partial melt and aqueous fluids in the crust. In northern Tibet, the conductive layer is at 30 to 40 kilometers and is due to partial melting. Zones of fluid may represent weaker areas that could accommodate deformation and lower crustal flow.

Use of consumer ratings for quality improvement in behavioral health insurance plans

BACKGROUND

The Consumer Assessment of Behavioral Healthcare Services (CABHS) survey collects consumers' reports about their health care plans and treatment. The use of the CABHS to identify opportunities for improvement, with specific attention to how organizations have used the survey information for quality improvement, is described.

METHODS

In 1998 and 1999, data were collected from five groups of adult patients in commercial health plans and five groups of adult patients in public assistance health plans with services received through four organizations (one of three managed behavioral health care organizations or a health system). Patients who received behavioral health care services during the previous year were mailed the CABHS survey. Non-respondents were contacted by telephone to complete the survey.

RESULTS

Response rates ranged from 49% to 65% for commercial patient groups and from 36% to 51% for public assistance patients. Promptly getting treatment from clinicians and aspects of care most influenced by health plan policies and operations, such as access to treatment and plan administrative services, received the least positive responses, whereas questions about communication received the most positive responses. In addition, questions about access- and plan-related aspects of quality showed the most interplan variability. Three of the organizations in this study focused quality improvement efforts on access to treatment.

DISCUSSION

Surveys such as the CABHS can identify aspects of the plan and treatment that are improvement priorities. Use of these data is likely to extend beyond the behavioral health plan to consumers, purchasers, regulators, and policymakers, particularly because the National Committee for Quality Assurance is encouraging behavioral health plans to use a similar survey for accreditation purposes.

Triple-bonded unsaturated fatty acids are redox active compounds

Unsaturated fatty acids with triple bonds are used as inhibitors of unsaturated fatty acid metabolism or cytochrome P450 reactions because they are believed to be chemically inert. In this paper we use in vitro cytochrome C reduction to show that two commonly used triple-bonded unsaturated fatty acids are in fact potent electron transfer agents and could affect the multiple cellular systems that are redox-modulated.

Prevention and elimination of upper respiratory colonization of mice by group A streptococci by using a bacteriophage lytic enzyme

Bacteriophage lytic enzymes quickly destroy the cell wall of the host bacterium to release progeny phage. Because such lytic enzymes specifically kill the species in which they were produced, they may represent an effective way to control pathogenic bacteria without disturbing normal microflora. In this report, we studied a murein hydrolase from the streptococcal bacteriophage C(1) termed lysin. This enzyme is specific for groups A, C, and E streptococci, with little or no activity toward several oral streptococci or other commensal organisms tested. Using purified lysin in vitro, we show that 1,000 units (10 ng) of enzyme is sufficient to sterilize a culture of approximately 10(7) group A streptococci within 5 seconds. When a single dose of lysin (250 units) is first added to the oral cavity of mice, followed by 10(7) live group A streptococci, it provides protection from colonization (28.5% infected, n = 21) compared with controls without lysin (70.5% infected, n = 17) (P < 0.03). Furthermore, when lysin (500 units) was given orally to 9 heavily colonized mice, no detectable streptococci were observed 2 h after lysin treatment. In all, these studies show that lysin represents a unique murein hydrolase that has a rapid lethal effect both in vitro and in vivo on group A streptococci, without affecting other indigenous microorganisms analyzed. This general approach may be used to either eliminate or reduce streptococci from the upper respiratory mucosal epithelium of either carriers or infected individuals, thus reducing associated disease.

Measurement of CP-violating asymmetries in B0 decays to CP eigenstates

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst).

Intravenous cocaine increases plasma epinephrine and norepinephrine in humans

Cocaine has been shown to activate the sympathoadrenal system in both animal and human studies. Controlled human studies have found inconclusive results regarding whether acute cocaine treatment elevates plasma epinephrine and norepinephrine concentrations. The purpose of this study was to investigate whether commonly abused doses of cocaine increase plasma epinephrine and norepinephrine concentrations in humans, in a double-blind, placebo-controlled study. Five male cocaine users were given an intravenous injection of 0.46 mg/kg dose of cocaine or placebo, on two consecutive days. Plasma epinephrine and norepinephrine concentrations were significantly increased in response to cocaine injection compared to placebo. Peak plasma epinephrine and norepinephrine concentrations were reached 3 and 12 min after cocaine injection, respectively. While changes in epinephrine levels following cocaine were correlated with systolic blood pressure and heart rate changes, changes in plasma norepinephrine were correlated with diastolic blood pressure and heart rate changes following cocaine administration. These results suggest that plasma epinephrine and norepinephrine can be used as a measure for cocaine induced sympathoadrenal system activation.

Risk factors for cerebral edema in children with diabetic ketoacidosis. The Pediatric Emergency Medicine Collaborative Research Committee of the American Academy of Pediatrics

BACKGROUND

Cerebral edema is an uncommon but devastating complication of diabetic ketoacidosis in children. Risk factors for this complication have not been clearly defined.

METHODS

In this multicenter study, we identified 61 children who had been hospitalized for diabetic ketoacidosis within a 15-year period and in whom cerebral edema had developed. Two additional groups of children with diabetic ketoacidosis but without cerebral edema were also identified: 181 randomly selected children and 174 children matched to those in the cerebral-edema group with respect to age at presentation, onset of diabetes (established vs. newly diagnosed disease), initial serum glucose concentration, and initial venous pH. Using logistic regression we compared the three groups with respect to demographic characteristics and biochemical variables at presentation and compared the matched groups with respect to therapeutic interventions and changes in biochemical values during treatment.

RESULTS

A comparison of the children in the cerebral-edema group with those in the random control group showed that cerebral edema was significantly associated with lower initial partial pressures of arterial carbon dioxide (relative risk of cerebral edema for each decrease of 7.8 mm Hg [representing 1 SD], 3.4; 95 percent confidence interval, 1.9 to 6.3; P<0.001) and higher initial serum urea nitrogen concentrations (relative risk of cerebral edema for each increase of 9 mg per deciliter [3.2 mmol per liter] [representing 1 SD], 1.7; 95 percent confidence interval, 1.2 to 2.5; P=0.003). A comparison of the children with cerebral edema with those in the matched control group also showed that cerebral edema was associated with lower partial pressures of arterial carbon dioxide and higher serum urea nitrogen concentrations. Of the therapeutic variables, only treatment with bicarbonate was associated with cerebral edema, after adjustment for other covariates (relative risk, 4.2; 95 percent confidence interval, 1.5 to 12.1; P=0.008).

CONCLUSIONS

Children with diabetic ketoacidosis who have low partial pressures of arterial carbon dioxide and high serum urea nitrogen concentrations at presentation and who are treated with bicarbonate are at increased risk for cerebral edema.

Increased vascular endothelial growth factor expression in human hearts with microvascular fibrin

We have shown that microvascular changes that promote fibrin deposition in human cardiac allografts adversely affect clinical outcome. However, some allografts exhibit phenotypic changes in capillaries following the deposition of fibrin, which subsequently provide a significant survival advantage. The mechanism(s) involved in these capillary changes is(are) unknown. Similarly, although we have shown a significant temporal relationship between microvascular fibrin deposition and vascular endothelial growth factor (VEGF) immunoreactivity in cardiac allografts, the cellular source and relative changes in VEGF gene expression under these conditions are not known. Using immunocytochemical techniques, biopsies devoid of fibrin deposition lacked detectable VEGF immunoreactivity, whereas biopsies with fibrin deposition showed VEGF immunoreactivity in cardiocytes, interstitium, and some microvessels. By in situ hybridization, biopsies without microvascular fibrin deposition showed faint VEGF hybridization signals confined primarily to cardiocytes. In biopsies with fibrin deposition, strong VEGF hybridization signals were detected in cardiocytes, arteriolar smooth muscle cells were occasionally labeled, and endothelial cells were rarely labeled. By quantitative RT-PCR, biopsies with fibrin deposition (n=5) relatively expressed approximately three-fold more VEGF mRNA than biopsies without fibrin deposition (n=5 P=0.02). Serum VEGF titers also were greater (P=0.01) in recipients with fibrin deposition (372.9+/-66.7 pg/ml n=18) compared to recipients without fibrin deposition (172.1+/-25.0 pg/ml n=16). Collectively, these results support the hypothesis that increased myocyte-derived VEGF production following microvascular fibrin deposition in transplanted human hearts may act in a paracrine manner to promote activational and phenotypic changes in capillaries that provide a survival advantage for the allografts.

Superovulation and intrauterine insemination in cases of treated mild pelvic disease

PURPOSE

Our purpose was to examine the effect of treated mild pelvic disease on the outcome of superovulation with intrauterine insemination (SO/IUI).

METHODS

Three hundred cycles of SO/IUI were retrospectively reviewed for 118 women with laparoscopically treated minimal/mild endometriosis and 67 cycles for 28 women with minimal/mild distal tubal disease/adnexal adhesions and compared with 265 cycles in 111 couples with idiopathic infertility.

RESULTS

The monthly fecundity rate (MFR) of 6.8% and live birth rate (LBR) of 6% in the endometriosis group were significantly lower (P = 0.002) than those in the idiopathic infertility group (MFR = 13.5%, LBR = 12.1%). The 10.9% MFR and 7.5% LBR in the minimal/mild tubal/adnexal disease were not significantly different from those in the other two groups.

CONCLUSIONS

MFR and LBR were higher after SO/IUI in idiopathic infertility compared to those for treated mild/minimal endometriosis or mild/minimal tubal/adnexal adhesions. However, SO/IUI still remains a reasonable option for both these groups prior to IVF-ET.

pH-regulated secretion of a glyceraldehyde-3-phosphate dehydrogenase from Streptococcus gordonii FSS2: purification, characterization, and cloning of the gene encoding this enzyme

Streptococcus gordonii and other viridans streptococci (VS) are primary etiologic agents of infective endocarditis, despite being part of the normal oral microflora. Recently, a surface-bound glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been found on the cells of all tested streptococcal species, where it has been implicated as a virulence factor. In contrast, we observed that a soluble extracellular GAPDH was the major secreted protein from S. gordonii FSS2, an endocarditis strain. The biochemical properties and gene sequence of S. gordonii GAPDH are almost identical to those of other streptococcal GAPDHs. Growth at defined pHs showed that secretion of GAPDH is regulated by environmental pH. GAPDH was primarily surface-associated at growth pH 6.5 and shifted to > 90% secreted at growth pH 7.5. Others have identified S. gordonii promoters that are up-regulated by a pH shift similar to that experienced by organisms entering the blood stream (neutral) from the oral cavity (slightly acid). Analysis of our results suggests that secretion of GAPDH may be a similar adaptation by S. gordonii.

In vivo cross-presentation of a soluble protein antigen: kinetics, distribution, and generation of effector CTL recognizing dominant and subdominant epitopes

Cross-presentation of exogenous Ags via the MHC class I pathway is now recognized for its role in self-tolerance, tumor immunity, and vaccine development. However, little is known about the in vivo distribution and kinetics of cross-presented protein Ags, nor the subsequent development of CTL effector responses to dominant or subdominant epitopes. We examined the location and duration of cross-presented Ag by using 5,6-carboxy-succinimidyl-fluorescein ester-labeled T cells from class I-restricted Ag-specific TCR mice. Comparisons of results from an in vitro (51)Cr release CTL assay with an in vivo CTL assay provided physiologically relevant insights into the functional capacities of CTL specific for epitopes with differing affinities. These data demonstrate that efficient cross-presentation of a dominant class I-restricted Ag is dose related and remains largely localized, but not limited to the draining lymph nodes for up to 3 wk following a single injection of soluble protein. Within this period, dominant peptide-specific CTL are fully functional in vivo throughout the secondary lymphoid system. However, no in vivo responses are seen to a subdominant or cryptic epitope. Prolonging Ag cross-presentation via use of IFA promoted persisting in vivo dominant epitope-specific CTL activity and revealed dose-responsive precursor CTL to the subdominant, but not to a cryptic epitope. Analysis of functional in vivo CTL responses demonstrated that, in the presence of strong ongoing responses to the dominant peptide, lytic activity of CTL directed at weaker epitopes is undetectable.

Pygeum africanum for the treatment of patients with benign prostatic hyperplasia: a systematic review and quantitative meta-analysis

PURPOSE

To conduct a systematic review and quantitative meta-analysis of the therapeutic efficacy and tolerability of Pygeum africanum in men with symptomatic benign prostatic hyperplasia.

METHODS

Studies were identified through the search of Medline (1966 to 2000), Embase, Phytodok, the Cochrane Library, bibliographies of identified trials and review articles, and contact with relevant authors and drug companies. Randomized trials were included if participants had symptomatic benign prostatic hyperplasia, the intervention was a preparation of P. africanum alone or in combination with other phytotherapeutic agents, a control group received placebo or other pharmacologic therapies for benign prostatic hyperplasia, and treatment duration was at least 30 days. Two investigators independently extracted key data on design features, subject characteristics, and therapy allocation.

RESULTS

A total of 18 randomized controlled trials involving 1,562 men met the inclusion criteria and were analyzed. Many studies did not report results in a method that permitted meta-analysis. Only 1 of the studies reported a method of treatment allocation concealment, although 17 were double-blinded. The mean study duration was 64 days (range 30 to 122). Compared with placebo in 6 studies, P. africanum provided a moderately large improvement in the combined outcome of urologic symptoms and flow measures as assessed by an effect size defined by the difference of the mean change for each outcome divided by the pooled standard deviation for each outcome (-0.8 SD [95% confidence interval (CI): -1.4 to -0.3]). Summary estimates of individual outcomes were also improved by P. africanum. Men were more than twice as likely to report an improvement in overall symptoms (risk ratio = 2.1, 95% CI: 1.40 to 3.1). Nocturia was reduced by 19% and residual urine volume by 24%; peak urine flow was increased by 23%. Adverse effects due to P. africanum were mild and similar to placebo. The overall dropout rate was 12% and was similar for P. africanum (13%), placebo (11%), and other controls (8%; P = 0.4 versus placebo and P = 0.5 versus other controls).

CONCLUSIONS

The literature on P. africanum for the treatment of benign prostatic hyperplasia is limited by the short duration of studies and the variability in study design, the use of phytotherapeutic preparations, and the types of reported outcomes. However, the evidence suggests that P. africanum modestly, but significantly, improves urologic symptoms and flow measures. Further research is needed using standardized preparations of P. africanum to determine its long-term effectiveness and ability to prevent complications associated with benign prostatic hyperplasia.

Chronic orthotopic aortic valve implantation model

BACKGROUND AND AIM OF THE STUDY

The ideal animal model to assess implanted prosthetic aortic valves has yet to be universally accepted. The majority of mechanical valves are used for aortic valve replacement (AVR), yet historically animal models have provided data mainly after mitral valve implantation, due to the poor survival of animals undergoing AVR. Proposed regulations will require data from site-specific models. Thus, we modified previously reported chronic ovine models used for orthotopic implantation of aortic valves, to conduct preclinical aortic valve evaluation and to establish a predictive animal model needed for safety, hemodynamics, pathology and handling.

METHODS

Fourteen sheep underwent AVR with 19 mm mechanical valves. Each animal was placed on cardiopulmonary bypass and the prosthetic valve implanted using a complete transverse ascending aortic transection. Hemodynamic data and aortography were obtained intraoperatively and again after 20 weeks, at which time hemodynamic studies, aortography, and pathological examination were performed.

RESULTS

There were two operative deaths, but no significant complications in the other 12 sheep, 11 of which survived for 20 weeks. One animal died two weeks before sacrifice due to valve thrombosis. Chronic hemodynamic and aortographic data were within normal limits for all 11 sheep, and gross pathology of the implanted valve revealed no abnormalities.

CONCLUSION

This study demonstrated the feasibility of the ovine model for orthotopic AVR, thus allowing greater confidence in the predictive value of in vivo hemodynamic and angiographic data gathered before clinical trials. Compared with other species, this ovine model provided improved rates of morbidity and mortality, reproducibility, ease of postoperative care, availability and acceptable anatomical similarities to humans. Future aortic valve studies at Medtronic will build on this knowledge base, making ovines - with this surgical technique - our animal model of choice.

Bacteremia and skin/bone infections in two patients with X-linked agammaglobulinemia caused by an unusual organism related to Flexispira/Helicobacter species

Two patients with Bruton's X-linked agammaglobulinemia are described with bacteremia and skin/bone infection due to an organism which by 16S rRNA gene sequence analysis was most closely related to "Flexispira" rappini (and thus designated a Flexispira-like organism, FLO) and more distantly related to the Helicobacter species. The organism required microaerobic conditions and, supplemental H(2) gas for growth and was reliably stained with acridine orange. In common with Helicobacter cinaedi infections, the focus of the FLO infection was in one case in the blood vessels or lymphatics of an extremity and in the other case in the skin and adjacent bone of an extremity. In both cases, prolonged IV antibiotic therapy was necessary to clear the infection. The susceptibility of XLA patients to FLO infection appears to be related to the fact that XLA is associated with severe B cell (humoral) immunodeficiency and thus these patients have difficulty with intravascular or intralymphatic infection. These findings elucidate the nature of FLO infections in humans and point the way to their detection and treatment.

16alpha-bromoepiandrosterone, a dehydroepiandrosterone (DHEA) analogue, inhibits Plasmodium falciparum and Plasmodium berghei growth

Dehydroepiandrosterone (DHEA) and its analogue, 16alpha-bromoepiandrosterone (alpha-epi-Br), may have activity against viral and parasitic infections, including human immunodeficiency virus (HIV) and Cryptosporidium parvum. Therefore, we evaluated its antimalarial effects on Plasmodium falciparum and Plasmodium berghei. In vitro, chloroquine (CQ)-sensitive and resistant strains of P. falciparum parasitized red blood cells were incubated with escalating doses of alpha-epi-Br or CQ. In vivo, 62 rats were infected with P. berghei and treated with CQ or alpha-epi-Br. At the highest doses tested against a CQ-sensitive strain, parasitemias decreased from 25.4% in the saline control group to 4.3% and 4.8% in the alpha-epi-Br and CQ groups, respectively (P < 0.05). Against two CQ-resistant strains, parasitemias decreased from 22.3-28.8% and 24.8-30% in the CQ and saline groups, respectively, to 2.5-2.7% in the alpha-epi-Br groups (P = 0.003). In vivo, on Day 4, parasitemias decreased from 23% in the saline group to 9-12% and 12% in the in alpha-epi-Br and CQ groups, respectively (P < 0.05). These data demonstrate that alpha-epi-Br shows activity against CQ-sensitive and resistant strains of P. falciparum in vitro. At the doses tested against P. berghei in vivo in rats, alpha-epi-Br is comparable to CQ.

Cell cycle-regulated phosphorylation of p220(NPAT) by cyclin E/Cdk2 in Cajal bodies promotes histone gene transcription

Cyclin E/Cdk2 acts at the G1/S-phase transition to promote the E2F transcriptional program and the initiation of DNA synthesis. To explore further how cyclin E/Cdk2 controls S-phase events, we examined the subcellular localization of the cyclin E/Cdk2 interacting protein p220(NPAT) and its regulation by phosphorylation. p220 is localized to discrete nuclear foci. Diploid fibroblasts in Go and G1 contain two p220 foci, whereas S- and G2-phase cells contain primarily four p220 foci. Cells in metaphase and telophase have no detectable focus. p220 foci contain cyclin E and are coincident with Cajal bodies (CBs), subnuclear organelles that associate with histone gene clusters on chromosomes 1 and 6. Interestingly, p220 foci associate with chromosome 6 throughout the cell cycle and with chromosome 1 during S phase. Five cyclin E/Cdk2 phosphorylation sites in p220 were identified. Phospho-specific antibodies against two of these sites react with p220 within CBs in a cell cycle-specific manner. The timing of p220 phosphorylation correlates with the appearance of cyclin E in CBs at the G1/S boundary, and this phosphorylation is maintained until prophase. Expression of p220 activates transcription of the histone H2B promoter. Importantly, mutation of Cdk2 phosphorylation sites to alanine abrogates the ability of p220 to activate the histone H2B promoter. Collectively, these results strongly suggest that p220(NPAT) links cyclical cyclin E/Cdk2 kinase activity to replication-dependent histone gene transcription.

In vivo analysis of an essential myosin light chain mutation linked to familial hypertrophic cardiomyopathy

Mutations in cardiac motor protein genes are associated with familial hypertrophic cardiomyopathy. Mutations in both the regulatory (Glu22Lys) and essential light chains (Met149Val) result in an unusual pattern of hypertrophy, leading to obstruction of the midventricular cavity. When a human genomic fragment containing the Met149Val essential myosin light chain was used to generate transgenic mice, the phenotype was recapitulated. To unambiguously establish a causal relationship for the regulatory and essential light chain mutations in hypertrophic cardiomyopathy, we generated mice that expressed either the wild-type or mutated forms, using cDNA clones encompassing only the coding regions of the gene loci. Expression of the proteins did not lead to a hypertrophic response, even in senescent animals. Changes did occur at the myofilament and cellular levels, with the myofibrils showing increased Ca(2+) sensitivity and significant deficits in relaxation in a transgene dose-dependent manner. Clearly, mice do not always recapitulate important aspects of human hypertrophy. However, because of the discordance of these data with data obtained in transgenic mice containing the human genomic fragment, we believe that the concept that these point mutations by themselves can cause hypertrophic cardiomyopathy should be revisited.

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Association of ureaplasma urealyticum with abnormal reactive oxygen species levels and absence of leukocytospermia

PURPOSE

Ureaplasma urealyticum is a commensal of the lower genitourinary tract of many sexually active adults. The organism is more common in partners of infertile than fertile marriages. We conducted a prospective study at our tertiary care center to confirm a possible association between U. urealyticum and abnormal sperm function parameters.

MATERIALS AND METHODS

A total of 50 consecutive male patients seeking general urology consultation for lower urinary tract symptoms characteristic of chronic prostatitis were evaluated. Urine and semen localization cultures were performed with additional semen cultures for U. urealyticum, Chlamydia trachomatis and Mycoplasma hominis. Specimens from 21 healthy men were used as controls. Specimens were analyzed by a computer assisted semen analyzer, and verified manually for concentration, percent motility and morphology. Leukocytospermia was measured by the Endtz test. Semen specimens were also analyzed for reactive oxygen species (ROS), acrosome reaction and mannose binding assay.

RESULTS

Of the patients 17 had positive U. urealyticum cultures and the other cultures were negative. Patients with U. urealyticum had significantly higher ROS levels (log [ROS + 1] = 2.52 +/- 0.25) than those without U. urealyticum (1.49 +/- 0.20, p = 0.002) or controls (1.31 +/- 0.19, p = 0.002). Leukocytospermia was detected in only 1 of the 17 (6%) positive specimens and 4 (12%) negative specimens.

CONCLUSIONS

Seminal ROS levels are elevated among patients with U. urealyticum. ROS induces lipid peroxidation, which reduces membrane fluidity and sperm fertilization capability, and may be the mechanism by which U. urealyticum impairs sperm function. Absence of leukocytospermia does not exclude U. urealyticum.

Coronary nitric oxide production in response to exercise and endothelium-dependent agonists

BACKGROUND

Endothelium-derived nitric oxide (NO) contributes to epicardial coronary artery vasodilation during exercise. However, blockade of NO production does not impair the increase in coronary blood flow (CBF) during exercise, suggesting that NO is not obligatory for exercise-induced coronary resistance vessel dilation. In contrast, the increases in CBF produced by endothelium-dependent agonists are decreased after NO blockade. Consequently, this study was performed to determine whether the increase in coronary NO production in response to agonists is greater than that which occurs during exercise.

METHODS AND RESULTS

We measured the oxidation products of NO (nitrate+nitrite=NO(x)) in aortic and coronary sinus plasma using chemiluminescence to assess NO(x) production across the coronary circulation in chronically instrumented dogs during a 3-stage treadmill exercise protocol and in response to intracoronary administration of the endothelium-dependent agonists acetylcholine (37.5 microg/min) and bradykinin (3.0 microg/min). No coronary NO(x) production could be detected at rest or during the first 2 stages of exercise; only at the highest level of exercise was a small increase in coronary NO(x) production measured. In contrast, coronary production of NO(x) was significantly increased in response to endothelium-dependent agonists.

CONCLUSIONS

Coronary NO production in response to endothelium-dependent agonists is greater than in response to the increase in shear stress associated with exercise. These findings support previous studies suggesting that NO is not required for the coronary vasodilation that occurs in the normal heart during exercise.

Trends in fruit and vegetable consumption among adults in 16 US states: Behavioral Risk Factor Surveillance System, 1990-1996

OBJECTIVES

This study examined trends in fruit and vegetable consumption among adults in 16 US states.

METHODS

Data from telephone surveys were used to stratify respondents by sociodemographic and health-related characteristics.

RESULTS

The proportion of adults who consumed fruits and vegetables at least 5 times daily was 19%, 22%, and 23% in 1990, 1994, and 1996, respectively. While the proportion increased among those with active leisure-time physical activities and normal weight, it remained almost the same among inactive people and dropped among the obese.

CONCLUSIONS

Progress in fruit and vegetable intake from 1990 to 1994 was encouraging, but it changed little between 1994 and 1996.

The prevalence of thromboembolic events among women with extended bed rest prescribed as part of the treatment for premature labor or preterm premature rupture of membranes

OBJECTIVE

This study was undertaken to determine the prevalence of thromboembolic events among women with extended bed rest prescribed as part of the treatment of premature labor or preterm premature rupture of membranes.

STUDY DESIGN

A retrospective chart review was undertaken of all women who had bed rest of >/=3 days' duration prescribed as part of the treatment of premature labor or preterm premature rupture of membranes in the Akron General Medical Center Perinatal Unit during the period January 1, 1997-December 31, 1998. The prevalence of thromboembolic events in this population was determined. The charts of all additional gravid women with antepartum or postpartum deep vein thrombosis or pulmonary embolism diagnosed during the study period were also reviewed. The prevalence of these disorders among the pregnant population for whom extended bed rest was not prescribed as part of the treatment of premature labor or preterm premature rupture of membranes was also calculated. Statistical comparison of the prevalences in the 2 populations was undertaken by means of the chi(2) analysis with the Fisher exact test.

RESULTS

There were 192 patients admitted during the study period who had extended bed rest prescribed as part of the treatment of premature labor or preterm premature rupture of membranes. Three of these women had thromboembolic events, for a prevalence of 15.6 cases per 1000 women. Five additional gravid women were admitted for the treatment of deep vein thrombosis or pulmonary embolism. There were 6164 deliveries among women not treated with extended bed rest for premature labor or preterm premature rupture of membranes during this period. Thus the prevalence of these phenomena among the remaining pregnant women was 0.8 cases per 1000 women. The prevalences of these disorders in the 2 populations were highly significantly different.

CONCLUSION

The prevalence of thromboembolic events among women for whom extended bed rest is prescribed as part of the treatment of premature labor or preterm premature rupture of membranes is significantly increased with respect to that among gravid women who do not receive this therapy and is substantially higher than previously reported. If this finding is confirmed in other populations, it may be prudent to undertake further studies to determine whether this prevalence can be reduced.

Newer technologies for endoscope disinfection: electrolyzed acid water and disposable-component endoscope systems

Novel technologies have been designed to improve or replace more conventional methods of endoscope disinfection. Electrolyzed acid water has the potential to decrease the time, toxicity, and cost of endoscope disinfection. Disposable-component endoscope systems have the potential to improve the ease of cleaning and disinfection, or eliminate the need altogether.

Emerging family of proline-specific peptidases of Porphyromonas gingivalis: purification and characterization of serine dipeptidyl peptidase, a structural and functional homologue of mammalian prolyl dipeptidyl peptidase IV

Porphyromonas gingivalis is an asaccharolytic and anaerobic bacterium that possesses a complex proteolytic system which is essential for its growth and evasion of host defense mechanisms. In this report, we show the purification and characterization of prolyl dipeptidyl peptidase IV (DPPIV) produced by this organism. The enzyme was purified to homogeneity, and its enzymatic activity and biochemical properties were investigated. P. gingivalis DPPIV, like its human counterpart, is able to cleave the N terminus of synthetic oligopeptides with sequences analogous to those of interleukins 1beta and 2. Additionally, this protease hydrolyzes biologically active peptides including substance P, fibrin inhibitory peptide, and beta-casomorphin. Southern blot analysis of genomic DNA isolated from several P. gingivalis strains reveal that a single copy of the DPPIV gene was present in all strains tested.

Predictors of cardiovascular response to smoked cocaine in humans

The purpose of this study was to examine the predictors of heart rate and blood pressure changes following cocaine administration. Sixty-two smoked cocaine users received a single 0.4 mg/kg dose of smoked cocaine. Male sex, African American race, higher body weight and current marijuana use predicted a greater cardiovascular response to cocaine. In contrast, higher baseline blood pressure, heart rate, amount and frequency of current cocaine use and presence of current cocaine snorting predicted a diminished cardiovascular response to cocaine. Whether these predictors of the cardiovascular response to smoked cocaine in the laboratory also predict cardiovascular complications from long-term cocaine use needs to be studied further.

Sex and menstrual cycle differences in the subjective effects from smoked cocaine in humans

To investigate sex and menstrual cycle effects in response to cocaine administration, data from existing studies were analyzed. First, responses to a single delivery of 0.4 mg/kg smoked cocaine were investigated. Women reported lower ratings for measures of paranoid/suspicious and heart racing/pounding than did men. In addition, women in the luteal phase reported diminished ratings for a measure of feel high than did both women in the follicular phase of the menstrual cycle and men. Second, responses to up to 6 deliveries of 0.4 mg/kg smoked cocaine were investigated. Women, compared with men, had lower ratings on feel high, heart racing/pounding, and feel stimulated. Results suggest that there are significant sex and menstrual phase differences in the subjective effects of cocaine.

Comparative cleavage sites within the reactive-site loop of native and oxidized alpha1-proteinase inhibitor by selected bacterial proteinases

Human alpha1-proteinase inhibitor (alpha1-PI) is responsible for the tight control of neutrophil elastase activity which, if down regulated, may cause local excessive tissue degradation. Many bacterial proteinases can inactivate alpha1-PI by hydrolytic cleavage within its reactive site, resulting in the down regulation of elastase, and this mechanism is likely to contribute to the connective tissue damage often associated with bacterial infections. Another pathway of the inactivation of alpha1-PI is reversible and involves oxidation of a critical active-site methionine residue that may influence inhibitor susceptibility to proteolytic inactivation. Hence, the aim of this work was to determine whether this oxidation event might affectthe rate and pattern of the cleavage of the alpha1-PI reactive-site loop by selected bacterial proteinases, including thermolysin, aureolysin, serralysin, pseudolysin, Staphylococcus aureus serine proteinase, streptopain, and periodontain. A shift of cleavage specificity was observed after alpha1-PI oxidation, with a preference for the Glu354-Ala355 bond by most of the proteinases tested. Only aureolysin and serralysin cleave the oxidized form of alpha1-PI faster than the native inhibitor, suggesting that bacteria which secrete these metalloproteinases may specifically take advantage of the host defense oxidative mechanism to accelerate elimination of alpha1-PI and, consequently, tissue degradation by neutrophil elastase.

Wiskott-Aldrich syndrome protein regulates podosomes in primary human macrophages

Wiskott-Aldrich syndrome protein (WASp) is a hematopoietic-specific, multidomain protein whose mutation is responsible for the immunodeficiency disorder Wiskott-Aldrich syndrome. WASp contains a binding motif for the Rho GTPase CDC42Hs as well as verprolin/cofilin-like actin-regulatory domains, but no specific actin structure regulated by CDC42Hs-WASp has been identified. We found that WASp colocalizes with CDC42Hs and actin in the core of podosomes, a highly dynamic adhesion structure of human blood-derived macrophages. Microinjection of constitutively active V12CDC42Hs or a constitutively active WASp fragment consisting of the verprolin/cofilin-like domains led to the disassemly of podosomes. Conversely, macrophages from patients expressing truncated forms of WASp completely lacked podosomes. These findings indicate that WASp controls podosome assembly and, in cooperation with CDC42Hs, podosome disassembly in primary human macrophages.