Carbohydroxamido-oxazolidines: antibacterial agents that target lipid A biosynthesis

A series of carbohydroxamido-oxazolidine inhibitors of UDP-3-O-[R-3-hydroxymyristoyl]-GlcNAc deacetylase, the enzyme responsible for the second step in lipid A biosynthesis, was identified. The most potent analog L-161,240 showed an IC50 = 30 nM in the DEACET assay and displayed an MIC of 1-3 microg/mL against wild-type E. coli.

Pretreatment nomogram for prostate-specific antigen recurrence after radical prostatectomy or external-beam radiation therapy for clinically localized prostate cancer

PURPOSE

To present nomograms providing estimates of prostate-specific antigen (PSA) failure-free survival after radical prostatectomy (RP) or external-beam radiation therapy (RT) for men diagnosed during the PSA era with clinically localized disease.

PATIENTS AND METHODS

A Cox regression multivariable analysis was used to determine the prognostic significance of the pretreatment PSA level, 1992 American Joint Committee on Cancer (AJCC) clinical stage, and biopsy Gleason score in predicting the time to posttherapy PSA failure in 1,654 men with T1c,2 prostate cancer managed with either RP or RT.

RESULTS

Pretherapy PSA, AJCC clinical stage, and biopsy Gleason score were independent predictors (P < .0001) of time to posttherapy PSA failure in patients managed with either RP or RT. Two-year PSA failure rates derived from the Cox regression model and bootstrap estimates of the 95% confidence intervals are presented in the format of a nomogram stratified by the pretreatment PSA, AJCC clinical stage, biopsy Gleason score, and local treatment modality.

CONCLUSION

Men at high risk (> 50%) for early (< or = 2 years) PSA failure could be identified on the basis of the type of local therapy received and the clinical information obtained as part of the routine work-up for localized prostate cancer. Selection of these men for trials evaluating adjuvant systemic and improved local therapies may be justified.

Heritability estimates from human twin data by incorporating historical prior information

Bayesian methods are commonly used in some analyses of human genetic data, such as segregation and linkage analyses, but they are not typically used for analyses of human twin data. In this paper we develop a scheme for a Bayesian analysis of human twin data. We develop prior elicitation schemes to incorporate historical information. We consider three prior schemes: fully informative, semi-informative and noninformative. We use Markov chain Monte Carlo sampling algorithms to facilitate Bayesian computation and provide detailed implementation schemes. We also develop model diagnostics for assessing the goodness of fit of twin models. Using a simulation study, we show that if the purpose of the study is to estimate the intraclass correlations or heritability in twin studies, then the semi-informative prior is as informative as the fully informative prior. Finally, a real data example is used to illustrate the proposed methodologies.

The combination of preoperative prostate specific antigen and postoperative pathological findings to predict prostate specific antigen outcome in clinically localized prostate cancer

PURPOSE

The independent clinical and pathological predictors of time to postoperative prostate specific antigen (PSA) failure were used to identify prostate cancer patients at high risk for this end point.

MATERIALS AND METHODS

A Cox regression multivariate analysis was used to determine the prognostic significance of preoperative PSA, pathological stage, prostatectomy Gleason score and margin status in predicting the time to postoperative PSA failure in 862 men with palpable (T2) or PSA detected (T1c) prostate cancer. The 2-year PSA failure rates with 95% confidence intervals were calculated using the results of Cox regression analysis and a bootstrap procedure with 2,000 replications, respectively, and are presented in nomogram format stratified by preoperative PSA, pathological stage, prostatectomy Gleason score and margin status.

RESULTS

Preoperative PSA (p = 0.0001), pathological stage (p< or =0.002), margin status (p = 0.0001) and prostatectomy Gleason score (p = 0.034) were independent predictors of time to postoperative PSA failure.

CONCLUSIONS

Patients at high risk for early PSA failure could be identified postoperatively on the basis of preoperative PSA and prostatectomy pathology. Adjuvant therapy trials in these select patients may be justified.

De novo unbalanced translocation resulting in monosomy for proximal 14q and distal 4p in a fetus with intrauterine growth retardation, Wolf-Hirschhorn syndrome, hypertrophic cardiomyopathy, and partial hemihypoplasia

We present the perinatal findings of a fetus with a de novo unbalanced chromosome translocation that resulted in monosomy for proximal 14q and monosomy for distal 4p. Prenatal sonographic examination at 27 weeks of gestation showed intrauterine growth retardation, microcephaly, cardiomegaly with arrhythmia, and asymmetry of the upper limbs. Genetic amniocentesis showed an abnormal karyotype of 45,XX,der(4)t(4;14)(p16.3;q12),-14. Linkage analysis of the family confirmed the maternal origin of the deletions. Molecular refinement of the deletion breakpoints indicated that the breakpoints at 4p16.3 and 14q12 were located between loci D4S403 (present) and D4S394 (absent), and between loci D14S252 (present) and D14S64 (absent), respectively. Necropsy showed dysmorphic features compatible with Wolf-Hirschhorn syndrome, hypertrophic cardiomyopathy, partial hemihypoplasia, and a normal brain without evidence of holoprosencephaly. Our case adds to the list of clinical phenotypes associated with the proximal regions of 14q.

Analyzing outcome-based staging for clinically localized adenocarcinoma of the prostate

BACKGROUND

A clinical staging system based on the prostate-specific antigen (PSA) and the calculated prostate carcinoma volume (cVCa) construct previously has been proposed. This study was performed to assess whether this proposed clinical staging system was valid in an independent surgical and radiation data set in patients with clinically localized disease.

METHODS

Cox regression multivariable analyses were used to assess the significance of staging systems (1992 American Joint Commission on Cancer Staging [AJCC] clinical and pathologic stage, versus cVCa-PSA clinical stage) to predict time to posttherapy PSA failure in 441 and 465 patients managed by surgery and radiation, respectively. Significant staging systems identified using Cox regression were tested further using established comparative measures to define the most clinically useful system.

RESULTS

Both the 1992 AJCC pathologic stage and the cVCa-PSA clinical stage were significant predictors of time to postoperative PSA failure (P = 0.0001), whereas only the cVCa-PSA clinical stage was a significant predictor of time to postradiation PSA failure (P = 0.0001) using a Cox regression multivariable analysis. Further analyses using a pairwise comparison of the 1992 AJCC pathologic stage and cVCa-PSA clinical stage found the cVCa-PSA staging system provided a more clinically useful prediction of time to postoperative PSA failure. Specifically, the cVCa-PSA staging system was able to identify surgically managed patients with pathologic AJCC T2 disease who did poorly (3-year bNED = 22%) while also selecting patients with clinical AJCC T2b,c disease that was managed by radiation who did well (3-year bNED = 100%).

CONCLUSIONS

A clinical staging system based on parameters obtained during the routine evaluation for AJCC clinical T1,2 prostate carcinoma provided a clinically useful stratification of both postoperative and postradiation PSA failure free survival.

Hepatitis C virus variants circumventing cytotoxic T lymphocyte activity as a mechanism of chronicity

BACKGROUND & AIMS

High rate of chronicity after acute hepatitis C virus (HCV) infection cannot be explained in the presence of a multispecific cytotoxic T lymphocyte (CTL) response. The aim of this study was to investigate the effect of virus variants on CTL activity in patients in whom chronicity developed.

METHODS

CTL clones specific to a decapeptide epitope derived from hypervariable region 1 were generated from 5 HLA-A2-positive patients with acute hepatitis C by in vitro stimulation with synthetic peptides. The sequential change of this CTL epitope and its influence on the CTL recognition were examined.

RESULTS

Virus variants did not appear in 3 patients with recovery, whereas variants with altered peptide ligands capable of antagonizing CTL activity emerged rapidly in the remaining 2 patients in whom chronicity developed. Importantly, these HLA-A2-restricted, hypervariable region 1-specific CTL clones shared the use of T-cell receptor (TCR) genes AV6 and BV17.

CONCLUSIONS

These data suggest that there is only a narrow T-cell repertoire responding to a single viral peptide/HLA ligand. The emergence of HCV variants with altered peptide ligands as TCR antagonists accompanied by a limited TCR repertoire may provide a mechanism for HCV chronicity.

Hypertrophic remodeling: gender differences in the early response to left ventricular pressure overload

OBJECTIVES

To identify gender differences in left ventricular remodeling, hypertrophy, and function in response to pressure overload due to ascending aortic banding in rats.

BACKGROUND

Gender may influence the adaptation to pressure overload, as women with aortic stenosis have greater degrees of left ventricular hypertrophy and better left ventricular function than men.

METHODS

Fifty-two weanling rats underwent ascending aortic banding (16 males, 18 females), or sham surgery (9 males, 9 females). At 6 and 20 weeks, rats underwent transthoracic echo Doppler studies, and closed-chest left ventricular pressures with direct left ventricular puncture. Perfusion-fixed tissues from eight rats were examined morphometrically for myocyte cross-sectional area and percent collagen volume.

RESULTS

At 6 weeks after aortic banding, left ventricular remodeling, extent of hypertrophy, and function appeared similar in male and female rats. At 20 weeks, male but not female rats showed an early transition to heart failure, with onset of cavity dilatation (left ventricular diameter=155% vs. 121% of same-sex sham), loss of concentric remodeling (relative wall thickness=102% vs. 139% of sham), elevated wall stress (systolic stress=266% vs. 154% of sham), and diastolic dysfunction (deceleration of rapid filling=251% vs. 190% of sham). Left ventricular systolic pressures were higher in female compared with male rats (186+/-20 vs. 139+/-13 mm Hg), while diastolic pressures tended to be lower (14+/-4 vs. 17+/-4 mm Hg).

CONCLUSIONS

Gender significantly influences the evolution of the early response to pressure overload, including the transition to heart failure in rats with aortic stenosis.

Effectiveness of slow-release lanreotide, a long-acting somatostatin analogue, in the treatment of acromegaly

We evaluated the effectiveness of slow-release lanreotide, a long-acting somatostatin analogue, in the treatment of acromegaly. Eleven patients with acromegaly were recruited, six of whom had received long-term treatment with octreotide. Lanreotide 30 mg was administered by intramuscular injection every other week for 24 weeks. The frequency of injection was adjusted as clinically needed after 2 weeks. Clinical effects were evaluated, and symptoms were recorded and scored. Finger circumferences and hand volumes were measured. Serum growth hormone (GH) and insulin-like growth factor-1 (IGF-1) concentrations were determined, and an oral glucose test was done at baseline and after treatment. Symptom scores, circumferences of the fingers, hand volumes, and serum GH and IGF-1 concentrations significantly decreased during treatment. Serum GH concentrations returned to normal in five (46%) of the 11 patients, while serum IGF-1 concentrations returned to normal in three (27%). Glucose intolerance was not significantly improved at the end of treatment. Although the mean serum GH concentration was significantly decreased after treatment, it was still not suppressed by glucose. In conclusion, slow-release lanreotide, given either twice or three times a month, is effective in controlling acromegalic symptoms as well as GH and IGF-1 hypersecretion. The treatment is well tolerated and convenient for patients.

Changes in reproductive hormones and sex hormone-binding globulin in a group of postmenopausal women measured over 10 years

OBJECTIVE

As part of a study on hormones and bone density in older women, we measured a number of steroid and polypeptide hormones at 4- to 6-month intervals in 32 women over a 10-year period.

DESIGN

All women were postmenopausal during this time and all measurements from 12 months after the menopause to the end were used in the analysis. To determine whether there was a significant trend in steroid or polypeptide hormones over the years, the data were analyzed by random coefficient linear regression against number of months since menopause.

RESULTS

There was no significant trend in the concentrations of estrone, estrone sulfate, dehydroepiandrosterone, and follicle stimulating hormone. There was a significant decline in the concentrations of estradiol, dihydrotestosterone, dehydroepiandrosterone sulfate, and luteinizing hormone. There was a rise in the levels of androstenedione and testosterone.

CONCLUSIONS

The changes in the concentration of sex hormone-binding globulin could be fitted to a quadratic equation with an initial rise in the concentration followed by a decline. Thus, the trend in hormone concentrations shows no set pattern with aging in the postmenopausal years.

The significance of locating and filling the canal isthmus in multiple root canal systems. A scanning electron microscopy study of the mesiobuccal root of maxillary first permanent molars

The mesiobuccal (MB) roots of 50 randomly selected maxillary first permanent molars were examined to evaluate the different configurations of canal isthmus and their incidences. Sections of the roots at 3.4, and 5 mm from the apex were prepared, acid etched, washed and dried. The apical side of each section was sputter coated with gold, examined by a Hitachi S-2500 scanning electron microscope and photographed. 36% of the mesiobuccal roots had one canal, whereas 64% had two canals. In the roots with two canals 31.25% contained either a complete isthmus, or accessory canals between the two main canals 31.25% showed partial isthmus formation. The significance of the different configurations is discussed. Our present findings indicate that the mesiobuccal roots of maxillary first permanent molars exhibit complex anatomy. Prudent judgement is essential in the canal isthmus preparation so that operators must provide meticulous skill and care to the patients.

Assessment of outcome prediction models for localized prostate cancer in patients managed with external beam radiation therapy

A comparison of the ability of all published proposed clinical staging systems to predict time to prostate-specific antigen (PSA) failure after external beam radiation therapy for clinically localized prostate cancer was performed using an independent radiation database. Cox regression multivariable analyses were used to assess the significance of the proposed staging systems to predict time to post-radiation PSA failure in 465 radiation managed patients. Significant staging systems identified using Cox regression were further tested using established comparative estimates to define the most predictive system. Both the Risk Score staging system and the staging system based on the calculated volume of prostate cancer (cV(Ca)) and PSA optimized the prediction of time to post-treatment PSA failure. The cV(Ca)-PSA system, however, provided a more clinically useful stratification of outcome. Many clinical staging systems for prostate cancer have been proposed. A single clinical staging system for patients with localized prostate cancer based on parameters obtained during the routine workup provided a statistically and clinically significant stratification of outcome after external beam radiation therapy.

Assessment of outcome prediction models for patients with localized prostate carcinoma managed with radical prostatectomy or external beam radiation therapy

BACKGROUND

A clinical staging system for localized prostate carcinoma that provides reliable information on which management decisions regarding an individual patient can be based is lacking. This study compared the abilities of all published proposed clinical staging systems to predict time to prostate specific antigen (PSA) failure after radical prostatectomy or external beam radiation therapy for clinically localized prostate carcinoma.

METHODS

A total of 1441 clinically localized prostate carcinoma patients who were managed with radical prostatectomy at the University of Pennsylvania in Philadelphia (n = 688) or the Brigham and Women's Hospital in Boston (n = 288) or with external beam radiation therapy at the Joint Center for Radiation Therapy in Boston (n = 465) were entered into this study. Patients who received adjuvant or neoadjuvant hormonal or radiation therapy were excluded. Akaike's Information Criterion (AIC) and Schwartz Bayesian Criterion (SBC) estimates, which are comparative measures, were calculated for each clinical staging system. Pairwise comparisons of the AIC and SBC estimates for the most predictive clinical staging systems were performed using a formal bootstrap technique with 2000 replications.

RESULTS

Both the staging system based on the risk score and the staging system based on the calculated volume of prostate carcinoma and PSA (cVCa-PSA) optimized the prediction of time to posttreatment PSA failure. The cVCa-PSA system, however, provided a more clinically useful stratification of outcome.

CONCLUSIONS

Improved clinical staging for patients with localized prostate carcinoma may be possible with parameters obtained during routine evaluation. Validation by other investigators is underway.

HIV seroprevalence among male prison inmates in the Wisconsin Correctional System

OBJECTIVE

To estimate HIV seroprevalence and the acceptance of voluntary HIV testing among male inmates entering the Wisconsin Correctional System during July 1, 1994-June 30, 1995, and compare these estimates with similar data obtained in 1987-1988.

METHODS

A blinded HIV seroprevalence survey concurrent with a review of voluntary HIV antibody testing records.

RESULTS

HIV test results were obtained for 3,681 (89%) male prison entrants during the study period; 26 (0.7%) were HIV-1 seropositive. Based on this estimate and the total number of male prison entrants (4,134), an estimated 29 HIV-1 seropositive male inmates entered the Wisconsin Correctional System during the study period. Eighty-four percent of all inmates were tested voluntarily. Among inmates testing HIV-1 seropositive, 69% were tested voluntarily.

CONCLUSIONS

These data suggest that HIV-1 seroprevalence among male prison inmates in Wisconsin is low, and is unchanged from the late 1980s; however, a large increase in the prison population has resulted in a substantial increase in the absolute number of HIV-1 seropositive inmates entering the correctional system. Although overall acceptance of voluntary HIV testing is high, nearly one third of HIV-1 seropositive inmates declined voluntary HIV testing.

Immunoperoxidase staining in the differential diagnosis of parathyroid from thyroid origin in fine needle aspirates of suspected parathyroid lesions

OBJECTIVE

To determine whether immunoperoxidase staining could be used for differential diagnosis of parathyroid from thyroid origin in fine needle aspirates of suspected parathyroid lesions.

STUDY DESIGN

Immunoperoxidase staining of parathyroid hormone and thyroglobulin was performed on aspirated smears from 10 patients with parathyroid lesions (6 of 10 patients also associated with thyroid lesions) and 10 patients with thyroid lesions. All of them had surgical tissue proof of the diagnosis.

RESULTS

Aspirated smears of six patients with parathyroid lesions had strong to moderate staining for parathyroid hormone and negative staining for thyroglobulin. Another four patients with parathyroid lesions had equivocal staining for parathyroid hormone and negative staining for thyroglobulin. All aspirated smears from the 16 thyroid lesions had negative staining for parathyroid hormone and positive staining for thyroglobulin.

CONCLUSION

Immunoperoxidase staining of parathyroid hormone and thyroglobulin, done for each suspected parathyroid lesion, was helpful in the differential diagnosis of parathyroid vs. thyroid origin.

Prenatal diagnosis of de novo isochromosome 13q associated with microcephaly, alobar holoprosencephaly and cebocephaly in a fetus

We report on the prenatal diagnosis, genetic studies, and pathology of a case with de novo isochromosome 13q. A 31-year-old primigravida was referred for genetic counselling at 26 weeks' gestation due to the sonographic findings of intrauterine growth retardation and microcephaly. Level II ultrasonograms further demonstrated alobar holoprosencephaly, hypotelorism, polydactyly, a ventricular septal defect, and a single nostril. A diagnosis of cebocephaly was made. Genetic amniocentesis and cord blood sampling revealed translocation trisomy 13 with a de novo t(13q13q) rearrangement. Chromosomal analysis using G- and C-banding techniques and fluorescence in situ hybridization (FISH) showed an apparent monocentric isochromosome. Molecular analyses using polymorphic molecular markers showed that the rearrangement was consistent with an isochromosome of maternal chromosome 13q[46,XX,i(13)(q10)]. Necropsy confirmed cebocephaly and the prenatally detected anomalies.

On the ultrastructure of softened cartilage: a possible model for structural transformation

The fibrillar architecture in the general matrix of softened cartilage has been compared with that of the normal matrix using both Nomarski light microscopy and transmission electron microscopy with combined stereoscopic reconstruction. A pseudorandom network developed from an overall radial arrangement of collagen fibrils is the most fundamental ultrastructural characteristic of the normal general matrix. This, in turn, provides an efficient entrapment system for the swelling proteoglycans. Conversely, the most distinctive feature of the softened matrix is the presence of parallel and relatively unentwined fibrils, strongly aligned in the radial direction. The presence of an optically resolvable fibrous texture in the softened cartilage matrix indicates the presence of discrete bundles of closely packed and aligned fibrils at the ultrastructural level of organisation. The general absence of such texture in the normal cartilage general matrix is consistent with the much greater degree of interconnectedness and related short-range obliquity in the fibrillar architecture, hence the importance of the term pseudorandom network. A mechanism of structural transformation is proposed based on the important property of lateral interconnectivity in the fibrils which involves both entwinement and nonentwinement based interactions. The previously reported difference in intrinsic mechanical strength between the normal and softened matrices is consistent with the transformation model proposed in this study.

A low rate of reinfection following effective therapy against Helicobacter pylori in a developing nation (China)

BACKGROUND & AIMS

In developed countries, reinfection after successful eradication of Helicobacter pylori appears unusual. High prevalences of H. pylori in developing countries may result in high reinfection rates. The aim of this study was to determine the rate of reinfection and ulcer recurrence in Chinese patients cured of H. pylori and duodenal ulcer disease.

METHODS

One hundred eighty-four patients with duodenal ulcer disease shown by endoscopic examination (1 month) and 14C-urea breath test (3 months) after termination of treatment to have cleared their H. pylori were investigated. Patients were followed up by endoscopy (12 and 24 months) and breath test (6, 9, 12, 18, and 24 months). H. pylori status at endoscopic examination was determined by rapid urease, histology, and culture. In reinfected patients, random amplification of polymorphic DNA fingerprinting was used to compare isolates before and after therapy.

RESULTS

Four patients were reinfected with H. pylori over 24 months (3 within 6 months and 1 at 24 months; average annual recurrence rate, 1.08%). Fingerprinting of isolates from 3 patients showed 1 patient (6 months) to have identical strains and the remainder to have nonidentical strains before and after treatment. Ulcer relapse occurred in 6 patients (4 H. pylori positive).

CONCLUSIONS

Reinfection with H. pylori is rare in developing countries where treatment is effective.

Laparoscopically assisted abdominal aortic aneurysm repair: first 20 cases

PURPOSE

Laparoscopic surgery decreases postoperative pain, shortens hospital stay, and returns patients to full functional status more quickly than open surgery for a variety of surgical procedures. This study was undertaken to evaluate laparoscopic techniques for application to abdominal aortic aneurysm (AAA) repair.

METHODS

Twenty patients who had AAAs that required a tube graft underwent laparoscopically assisted AAA repair. The procedure consisted of transperitoneal laparoscopic dissection of the aneurysm neck and iliac vessels. A standard endoaneurysmorrhaphy was then performed through a minilaparotomy using the port sites for the aortic and iliac clamps. Data included operative times, duration of nasogastric suction, intensive care unit days, and postoperative hospital days. Pulmonary artery catheters and transesophageal echocardiography were used in seven patients. For these patients data included heart rate, pulmonary artery systolic and diastolic pressures, mean arterial pressure, central venous pressure, pulmonary capillary wedge pressure, cardiac index, and end diastolic area. Data were obtained before induction, during and after insufflation, during aortic cross-clamp, and at the end of the procedure.

RESULTS

Laparoscopically assisted AAA repair was completed in 18 of 20 patients. Laparoscopic and total operative times were 1.44 +/- 0.44 and 4.1 +/- 0.92 hours, respectively. Duration of nasogastric suction was 1.3 +/- 0.7 days. Intensive care unit stay was 2.2 +/- 0.9 days. The mean length of hospital stay was 5.8 days excluding three patients who underwent other procedures. There were two minor complications, one major complication (colectomy after colon ischemia), and no deaths. For the eight patients who had intraoperative transesophageal echocardiographic monitoring, no changes were noted in heart rate, pulmonary artery systolic pressure, pulmonary capillary wedge pressure, and cardiac index. Pulmonary artery diastolic pressure and central venous pressure were greatest during insufflation without changes in end-diastolic area. Volume status, as reflected by end-diastolic area and pulmonary capillary wedge pressure, did not change.

CONCLUSIONS

Laparoscopically assisted AAA repair is technically challenging but feasible. Potential advantages may be early removal of nasogastric suction, shorter intensive care unit and hospital stays, and prompt return to full functional status. The hemodynamic data obtained from the pulmonary artery catheter and transesophageal echocardiogram during pneumoperitoneum suggest that transesophageal echocardiography may be sufficient for evaluation of volume status along with the added benefit of detection of regional wall motion abnormalities and aortic insufficiency. Further refinement in technique and instrumentation will make total laparoscopic AAA repair a reality.

[Decrease of cAMP and increase of amino acids contents in mouse brain after dihydroetorphine tolerance]

AIM

To study the mechanism of dihydroetorphine (DHE) tolerance.

METHODS

DHE tolerance was produced by repeated s.c. injections in progressively increased doses to mice for 8 d. The concentrations of amino acids and cAMP were detected by RP-HPLC/fluorescence assay and radioimmunoassay, respectively.

RESULTS

The basal contents of glutamic acid (Glu), aspartic acid (Asp), and GABA in whole brain (cerebellum removed) were increased respectively from 14.1 +/- 2.1, 3.0 +/- 0.4, and 1.8 +/- 0.8 mumol/g tissue in control mice to 17.2 +/- 2.2, 4.1 +/- 0.6, and 3.2 +/- 1.0 mumol/g tissue in tolerant mice, and the rates of increase were 22.0% (P < 0.05), 36.7% (P < 0.01), and 77.8% (P < 0.05 vs control), respectively. There was no significant difference in the basal contents of Gln (5.1 +/- 1.0 vs 4.5 +/- 1.7 mumol/g tissue of control). The basal contents of cAMP in hypothalamus and striatum were decreased respectively from 271 +/- 38 and 189 +/- 31 nmol/g tissue in control mice to 96 +/- 15 and 65 +/- 21 nmol/g tissue in tolerant mice (P < 0.01), and the rates of decrease were 64.6% and 65.6%, respectively. There was no significant difference of cAMP in cerebral cortex (72 +/- 20 vs 55 +/- 15 nmol/g tissue of control).

CONCLUSION

The increases of Glu, Asp, and GABA in brain and the decrease of cAMP in hypothalamus and striatum were involved in DHE tolerance.

Demonstration of the distal end of the oesophagus by transabdominal ultrasound

This study aimed to demonstrate the distal end of the oesophagus using a transabdominal ultrasound technique (TUS) and to measure the normal oesophageal wall thickness in adults. 65 patients without oesophageal disease and 38 normal volunteers were examined by TUS. A left subcostal approach was used to demonstrate the oesophagus. The wall thickness and length were measured in both the supine and 45 degrees right side up oblique (RUO) positions. The abdominal oesophagus was visualized in 80% of patients in the supine position and 92% in the RUO position. Satisfactory demonstration was obtained in 67% of patients in the supine and 85% in the RUO position. The oesophageal wall thickness averaged 2.8 mm (range 2.0-4.0 mm, SD 0.7 mm). The visualized length in these subjects averaged 2.3 cm in the supine position and 3.0 cm in the RUO position, which included approximately 1.5 cm of the lowest portion of the thoracic oesophagus in addition to the abdominal oesophagus. TUS can demonstrate the abdominal oesophagus in the majority of patients and has the potential to provide information on disorders of structure and motility.

Impact of respiratory maneuvers on cardiac volume within left-breast radiation portals

BACKGROUND

Late cardiac morbidity and mortality have been reported among left-breast cancer survivors treated with radiation therapy. Radiation-induced cardiotoxicity is affected by the volume of myocardium included in the radiation portals. We hypothesize that simple respiratory maneuvers may alter the position of the heart relative to the portals without altering the radiation dose delivered to the breast.

METHODS AND RESULTS

Fourteen healthy female adult volunteers underwent cardiac MRI to determine the cardiac volume included in the typical left-breast radiation field during respiratory maneuvers. Cardiac volume within the radiation portals was assessed from a transverse stack of 14 1-cm-thick contiguous slices covering the entire heart, obtained during breath holding at end-tidal volume (baseline), deep inspiration, and forced expiration. Thirteen subjects (92%) had inclusion of a portion of the heart within the radiation portals at end-tidal volume (median, 20.9 cm3; range, 1.3 to 88.4 cm3). In these subjects, inspiration decreased the cardiac volume included within the radiation portals (median change: -10.7 cm3 [-40.2%], P<.001 versus end-tidal volume), whereas expiration increased the cardiac volume included (median change: 4.0 cm3 [21.5%]; P<.001 versus end-tidal volume).

CONCLUSIONS

Inclusion of a portion of the heart in the left-breast radiation field is common. The use of simple inspiratory maneuvers significantly decreases cardiac volume within the radiation portals. Such an approach during delivery of radiation therapy may allow for preservation of radiation dosage to the breast while reducing cardiac involvement and subsequent mortality.

Temperature programming and gradient elution in reversed-phase chromatography with packed capillary columns

The two major anisocratic elution modes were compared in reversed-phase chromatography with 180 microns I.D. fused-silica capillary columns packed with 6 microns Zorbax SB ODS-silica. By evaluating the retention factors of alkylbenzenes at acetonitrile concentrations varying from 60 to 80% (v/v) in the aqueous eluent and in the temperature range of 30-80 degrees C, it was found that a 5 degrees C change in column temperature and a 1% change in acetonitrile concentration have almost the same effect on retention. This is illustrated by the almost identical chromatograms of an alkylbenzene sample obtained by temperature programming and by gradient elution under the same conditions otherwise and by simulation of the trajectories of the eluent peaks moving down the column. The results suggest that in reversed-phase HPLC with packed capillary columns temperature programming offers an alternative to gradient elution in a relatively narrow range of the required elution strength. Thermodynamic data from isocratic chromatographic measurements were used to predict the retention times of alkylbenzenes in reversed-phase chromatography with temperature programming at different heating rates and column inlet pressures. Temperature programming was used to separate beta-lactoglobulins A and B by reversed-phase chromatography. It was also employed concomitantly with gradient elution to enhance the separation of a mixture of four standard proteins. The results indicate that temperature programming could serve as an adjunct to gradient elution by means of fine retention tuning to bring about or increase the resolution of closely related macromolecules.

Antecedent hypertension confers increased risk for adverse outcomes after initial myocardial infarction

Several studies have examined the association of blood pressure (BP) after myocardial infarction (MI) with a risk for adverse outcome; however, few studies have investigated prognosis after MI as a function of BP before MI. Our goal was to examine the relation of antecedent hypertension to risk of adverse outcomes after initial MI. From 1967 to 1990, 404 subjects followed at the Framingham Heart Study developed an initial MI. These subjects were classified on the basis of preinfarction BP into normotensive (BP<140/90 mm Hg and not receiving antihypertensive treatment; n=118), stage I-untreated hypertension (BP 140 to 159/90 to 99 mm Hg; n=89), and stage II to IV or treated hypertension (BP > or =160/100 mm Hg or treated hypertension; n=197). Cox models were used to adjust for age, sex, smoking, glucose intolerance, total cholesterol, and prior cardiovascular disease. Antecedent hypertension was related to risk of adverse outcome after MI. Compared with normotensive individuals, stage II to IV hypertensives were at increased risk for reinfarction (hazard ratio [HR], 2.20; 95% confidence interval [CI], 1.20 to 4.04). A similar but nonsignificant association was seen in stage I hypertensives (HR, 1.91; 95% CI, 0.97 to 3.77). Stage II to IV hypertensives were at increased risk for all-cause mortality compared with normotensive persons (HR, 1.45; 95% CI, 1.07 to 1.98). Thus, even after MI, a history of antecedent hypertension remains predictive of adverse outcome. These findings are consistent with beneficial effects of BP control in primary and secondary prevention settings. Effective BP control may both reduce the risk for an initial MI and improve outcome in the event that an MI occurs.