Protective effect of RibCys following high-dose irradiation of the rectosigmoid

Ribose-cysteine (RibCys) is a prodrug of L-cysteine that stimulates glutathione biosynthesis. Increased glutathione levels have been shown to have a protective effect against radiation-induced injury and oxidative stress. Surface oximetry has previously been used successfully to predict anastomotic leakage. PURPOSE: The following study was done to evaluate the protective effect of RibCys and the predictive value of PtO2 determinations in a swine model. METHODS: Domestic swine were divided into three groups: Group A served as a nonradiated control; Group B received 6,000 to 6,500 rad to the rectosigmoid; and Group C received RibCys (1 g/kg) prior to receiving 6,000 to 6,500 rad. Radiated animals and controls underwent rectosigmoid resection after a three-week rest period. Intraoperative anastomotic PtO2 was checked with a modified Clark electrode. Anastomoses were evaluated radiographically at three and seven days; animals were sacrificed, and bursting strength was recorded at 10 days. RESULTS: Mean bursting pressures were 243.8 +/- 59.4, 199.5 +/- 37.8, and 209.5 +/- 54.9 mmHg (NS) for Groups A, B, and C, respectively. Anastomotic PtO2 ranged from 19 to 98 mmHg and could not be correlated with anastomotic leaks or bursting pressure. There were 11/15 radiation-related deaths and leaks (eight deaths and three leaks) in the radiated group and 4/12 radiation-related deaths and leaks (three deaths and one leak) in the group receiving radiation and RibCys (P < 0.04). CONCLUSIONS: 1) RibCys protected animals against radiation-related deaths and anastomotic leaks following high doses of pelvic irradiation; 2) anastomotic PtO2 levels did not correlate with anastomotic healing in this model.     

Two forms of type IV zinc-finger motif and their kingdom-specific distribution between the flora, fauna and fungi

Using the direct immunofluorescence method with a Chlamyset of Orion Co. Finland for detection of Chlamydia trachomatis, the authors examined smears from male and female patients with manifestations of non-specific urethritis and cervicitis. In women also specimens from the cervix were examined. The IF examinations of smears from the urethra of 72 men were positive in 25, i.e. 34.7%. IF examinations of 70 women with manifestations of cervicitis and urethritis were positive in 17, i.e. 24.3% from the urethra and in 20 cases, i.e. 28.6% from the cervix. The positive findings of Chlamydia trachomatis indicate the importance of diagnosing urethritis of chlamydial origin and aimed treatment.     

Quantification and identification of particle movement in epidermis after thermal injury

Skin samples from a rabbit hind limb were taken from controls and at 5 min, 2 and 6 hr after a mild thermal injury (60 degrees C for 1 min). Large aggregates of intercellular particles, usually ribosomal in appearance, were seen in 6 hr samples and were accompanied by some peripheral aggregates of particles and by granule-coated vesicles. These structures were present in earlier samples to a lesser extent and were absent from control material. Quantitative assessment showed that intercellular particles apparently increased up to 6 hr whereas peripheral aggregation was maximum at 2 hr. Histochemical analysis confirmed that the particles contained ribonucleoprotein. Other larger particles were seen occasionally and contained carbohydrate. Lymph draining the site showed cellular changes, little change in enzyme activities, and no aggregates of particles.     

Establishing generalized verb-noun instruction-following skills in retarded children

Diazotized (125I)-diiodosulfanilic acid (DD125ISA) binds specifically to the exposed proteins on the surface of the rabbit platelet plasma membrane. This was demonstrated by the following observations with the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of whole platelets and the isolated plasma membrane fraction: (1) the specific activity of isolated membrane protein was sevenfold that of whole platelet protein, (2) no proteins of intact platelets were labeled which were not represented in the isolated plasma membrane, (3) DD125ISA-labeled proteins were altered by trypsin treatment of intact, labeled platelets, and (4) the pattern of labeling produced by reaction of isolated membranes with DD125ISA differed from that produced by the labeling of intact platelets. Reaction of DD125ISA with intact platelets produced labeling of only the three membrane glycoproteins (molecular weights: 180,000, 125,000, and 92,000 daltons) with greatest labeling of the largest glycoprotein and least labeling of the smallest glycoprotein. When rabbit platelets were labeled simultaneously with DD125ISA and 51Cr, the two isotopes were similarly distributed in various density populations of platelets. Some DD125ISA was solubilized from labeled and washed platelets by sonication, but all platelet DD125ISA was recovered in the plasma membrane fraction after 30 minutes' circulation in vivo. In vivo 51Cr recovery and survival were not altered by simultaneous labeling of platelets with DD125ISA. The disappearance of DD125ISA from circulating platelets (T 1/2 = 17 hours) was more rapid than 51Cr (T 1/2 = 30 hours) and appeared exponential in contrast to the linear 51Cr disappearance. On the other hand, DD125ISA did not disappear from platelets faster than 51Cr when doubly labeled platelets were harvested after 3 hours' circulation and incubated in autologous plasma (T 1/2 of DD125ISA elution = 43 hours, 51Cr = 33 hours). SDS-PAGE analysis of DD125ISA-labeled platelets after 14 to 20 hours' circulation in vivo demonstrated the same pattern of DD125ISA distribution on membrane glycoproteins as on the platelets prior to infusion. We interpret this symmetrical loss of the membrane label to indicate symmetrical loss of membrane proteins, suggesting that the platelet may lose pieces of membrane and not specific surface proteins during circulation. This could occur during reversible adhesion encounters during the process of hemostasis and cause the smaller size and decreased effectiveness of older platelets.     

An infrared study of the carbon monoxide complexes of cytochrome P-450 and cytochrome P-420

The infrared stretch vibrations (upsilonCO) of the CO-complexes of cytochrome P-450 and cytochrome P-420 have been determined from infrared difference spectra. The CO-complexes exhibit IR-bands at 1949 cm-1 and 1966 cm-1 with half widths of approximately 17 cm-1 and approximately 20 cm-1 respectively. These results are compared with the CO-stretch frequencies of other haemoproteins and discussed with respect to specific interactions of the CO-ligand with the protein moiety and to the ligand trans to CO of the cytochromes.