Kallikrein gene expression in human pituitary tissues

Somatostatin has been suggested to influence the somatotrophic axis outside the central nervous system, in reducing GH-induced IGF-I mRNA and IGF-I generation. This study aimed to determine whether such effects were mediated via the GH receptor (GHR). GH-deficient dwarf rats aged 45-47 days (n = 8 per group) received twice daily subcutaneous injections of octreotide (1 mg/kg) (group O), saline (group S), octreotide (1 mg/kg) plus bovine GH (0.25 mg/kg) (group OG), or bovine GH (0.25 mg/kg) plus saline (group G) for 10 days. Octreotide-treated animals had less weight gain compared with saline-treated animals, but not when GH cotreated (group OG vs G). Octreotide had an overall effect on decreasing length gain (P < 0.01). Serum IGF-I (ng/ml) was reduced by octreotide (group O 171 +/- 11, group S 239 +/- 20, P < 0.01; group OG 283 +/- 30, group G 362 +/- 10, P < 0.001), as was serum insulin (P < 0.001). A significant decrease in hepatic and muscle IGF-I mRNA expression was found as expected, yet this was not associated with decreased hepatic GHR expression. Rather, an increase in hepatic 125I-bovine GH specific binding was observed (P < 0.001) and, in GH-cotreated animals (OG), hepatic GHR and GH binding protein (GHBP) mRNA expression were also increased by octreotide by approximately 40%. In muscle, octreotide was associated with an approximately 30% decrease in GHBP mRNA and no effect on GHR mRNA. This study suggests that the suppressive effects of octreotide on IGF-I metabolism, at least in liver, are not mediated via down-regulation of GHR expression, but more likely by direct effects on IGF-I expression.     

Actin associates with the nucleocapsid domain of the human immunodeficiency virus Gag polyprotein

Recently, it was shown that actin molecules are present in human immunodeficiency virus type 1 (HIV-1) particles. We have examined the basis for incorporation and the location of actin molecules within HIV-1 and murine retrovirus particles. Our results show that the retroviral Gag polyprotein is sufficient for actin uptake. Immunolabeling studies demonstrate that actin molecules localize to a specific radial position within the immature particle, clearly displaced from the matrix domain underneath the viral membrane but in proximity to the nucleocapsid (NC) domain of the Gag polyprotein. When virus or subviral Gag particles were disrupted with nonionic detergent, actin molecules remained associated with the disrupted particles. Actin molecules remained in a stable complex with the NC cleavage product (or an NC-RNA complex) after treatment of the disrupted HIV-1 particles with recombinant HIV-1 protease. In contrast, matrix and capsid molecules were released. The same result was obtained when mature HIV-1 particles were disrupted with detergent. Taken together, these results indicate that actin molecules are associated with the NC domain of the viral polyprotein.     

INFLUENCE OF DRYING/CONDITIONING SCHEDULES ON STRESS DEVELOPMENT,RELIEF AND PRONG TEST

ABSTRACT

The prong test often displays ambiguous responses as shown in recent research. The objective of this paper was to learn how different drying/conditioning schedules influence the stress development/relief of lumber and therefore the prong response. During each drying/conditioning schedule, residual stress analysis was used to obtain stress levels, moisture content gradients and prong responses. The analysis of the data revealed the following: stress levels are strongly influenced by different schedules; in contrast, prong responses are only slightly influenced by different schedules. Stress levels are more effectively relieved by using a multiple- step increase of the equilibrium moisture content than a single-step increase. It is concluded that the schedule governs the final stress level. Even though differences in stress level are measurable by the slice test, the prong test does not reliably display these differences.     

DETERMINING THE SOURCE OF CHANGING SHRINKAGE RATES DURING KILN DRYING

The conclusions drawn by researchers on the source of changing shrinkage rates are discussed. The objective of this study was to determine the source of changing shrinkage rates early in drying and whether shrinkage would make a useful parameter for an automated kiln control system. In this study, four loads of red oak and one of maple were kiln dried using established schedules Shrinkage of the lumber was continuously recorded, and moisture content and released elastic strain were periodically recorded. The moisture content and strain data showed that the changing shrinkage rates early in drying boards were caused by reduced internal stress levels, not the occurrence of fiber saturation point or temperature as reported by some. Results of this study indicate it may be possible to develop an automated kiln system using shrinkage as the controlling parameter. This would reduce the drying time while avoiding additional drying defects.     

MATERIAL RESPONSE-BASED KILN CONTROL SYSTEM

The origin of material response (changing shrinkage rates) during drying is changing stress levels within the lumber as was determined in a previous paper. The object of this research was to demonstrate that a kiln control system based on material response parameters can reduce the drying time while incurring no additional drying defects. One control run and two pilot runs were performed. The results showed that it is possible to advance the kiln schedule using only material response as the controlling parameter and maintain or improve the quality of the lumber. Accelerating the drying substantially reduced the residual stress levels in the final product.     

The use of X‐ray absorption spectroscopy for monitoring the thickness of antiwear films from ZDDP

X‐ray absorption near edge structure (XANES) spectroscopy at the P K‐edge was used to monitor ZDDP antiwear film thickness with rubbing time. Thermal immersion films of varying thickness were generated from the ZDDP and analysed using XANES spectroscopy and the particle induced X‐ray emission (PIXE) technique. P K‐edge XANES edge jumps and (1s → np) peak heights of the spectra were plotted against PIXE mass thickness values in order to establish calibration curves. Antiwear films were analysed using XANES spectroscopy, and average mass thicknesses were extrapolated from the calibration curves. A set of antiwear films formed in the presence of ZDDP and then further rubbed in base oil (no ZDDP) showed no significant decrease in film thickness. A set of antiwear films rubbed in the presence of ZDDP for various lengths of time showed an increase in film thickness, followed by thinning of the film. The decrease in film thickness is believed to be due to wear caused by the ZDDP solution decomposition products acting as an abrasive in the contact region. This revised version was published online in July 2006 with corrections to the Cover Date.     

Accounting for Individual Effort in Cooperative Learning Teams

An “autorating” (peer rating) system designed to account for individual performance in team projects was used in two sophomore‐level chemical engineering courses in which the students did their homework in cooperative learning teams. Team members confidentially rated how well they and each of their teammates fulfilled their responsibilities, the ratings were converted to individual weighting factors, and individual project grades were computed as the product of the team project grade and the weighting factor. Correlations were computed between ratings and grades, self‐ratings and ratings from teammates, and ratings received and given by men and women and by ethnic minorities and non‐minorities. Incidences of “hitchhikers” (students whose performance was considered less than satisfactory by their teammates), “tutors” (students who received top ratings from all of their teammates), dysfunctional teams, and teams agreeing on a common rating were also determined. The results suggest that the autorating system works exceptionally well as a rule, and the benefits it provides more than compensate for the relatively infrequent problems that may occur in its use.     

The effects of data model representation method on task performance

Data models are frequently created with little thought about their layout. Our research examined how data models organized in a columnar fashion compared to equivalent data models which did not, by improving novice designer's performance in error detection, comprehension, and query construction.     

Pharmacokinetics of nicotine carbomer enemas: a new treatment modality for ulcerative colitis

BACKGROUND: Ulcerative colitis is largely a disease of nonsmokers, and transdermal nicotine is of therapeutic value in the active disease. Because side effects are common, we developed a topical enema formulation of nicotine. OBJECTIVE: To study the pharmacokinetics of nicotine complexed with a polyacrylic carbomer and administered by enema to eight healthy volunteers and to eight patients with active ulcerative colitis, verified sigmoidoscopically. PATIENTS AND METHODS: All 16 subjects were nonsmokers. The mean age for normal subjects was 33 years; the mean for patients with ulcerative colitis was 60 years. Median stool frequency for patients with ulcerative colitis was four daily. Patients were taking 5-amino salicylic acid compounds and five were taking oral prednisolone (median dose, 12 mg daily). Nicotine, 6 mg, complexed with carbomer 974P, 400 mg, was administered in a 100 ml enema after an overnight fast, with serial blood measurements taken over 8 hours. Serum nicotine and cotinine were measured by gas liquid chromatography. Area under the concentration-time curves were calculated by the trapezoidal method, and the terminal elimination half-life was derived by extrapolation of the log-linear terminal phase. RESULTS: With the exception of nicotine time to reach peak concentration, which was longer in patients (median of 60 minutes compared with 45 minutes; p < 0.005), other comparisons between normal subjects and patients showed no statistically significant difference, although there was considerable inter-subject variation. Maximum concentration of nicotine, 8.1 +/- 3.5 ng/ml, in the 16 subjects occurred after a median of 60 minutes (range, 30 to 180 minutes); maximum cotinine concentrations of 60.4 +/- 11.5 ng/ml occurred after 4 hours. Side effects in five subjects were mild (four subjects) or moderate (one subject) and included lightheadedness, nausea, and headache; these five subjects were female lifelong nonsmokers of low body weight. CONCLUSION: Because most of the active ingredient of nicotine is converted to continine on the first pass through the liver, substantial concentrations can be achieved at the site of disease with only modest rises in serum nicotine, which are responsible for side effects; cotinine has low pharmacologic activity. Topical administration of nicotine may be useful treatment for distal ulcerative colitis.     

Final design of an air core, compulsator driven, 60 caliber railgunsystem

The manufacturing phase of a laboratory-based small-caliber electromagnetic (EM) launcher and compulsator power supply is discussed. The objective of the 29-month program is to develop a compact, lightweight test bed capable of accelerating 32 g masses to 2 km/s at a rate of 10 Hz. Both the power supply and launcher feature significant component design advances which will allow the system to operate at considerably higher energy and power densities than previously demonstrated. The 750 kg compulsator will generate 2.2 kV and the silicon-controlled rectifier (SCR) switch will commutate 386 kA pulses into the 1.6-m long, 0.60 caliber augmented solid armature railgun. The final design and predicted operating characteristics of the compulsator system are described. Overall system performance parameters are reported, including results from the optimization code used to aid in the design of the compulsator system. A system design overview is presented, with emphasis on new materials and state-of-the-art machine components to be used for the first time in a compulsator