Severe depression of gut absorptive capacity in patients following trauma or sepsis

Although clinical studies suggest enteral, as opposed to parenteral, feeding lowers morbidity and mortality rates following severe trauma and after sepsis, it is unknown whether gut absorptive capacity (GAC) is indeed maintained under such conditions. To study this, GAC was determined in patients with blunt trauma (n = 8) and with sepsis (n = 11) by the 1-hour D-xylose absorption test. Excluded were patients with ileus, nasogastric output of more than 600 mL/24 hours, or residual gastric content of more than 25 mL after the D-xylose test. Trauma patients (ISS 8-14) and patients with intra-abdominal sepsis had an initial D-xylose test within 24 to 48 hours of admission, at 72 to 96 hours, and then weekly until D-xylose absorption had returned to normal. D-xylose (25 g in 200 mL water) was given via nasogastric tube to patients and orally to healthy volunteers (controls: n = 8). Results show that GAC was depressed at 24 to 96 hours in both groups but returned to normal by 1 to 3 weeks after trauma or resolution of sepsis. Thus (1) gut absorptive capacity was severely depressed early after trauma and after the onset of sepsis; and (2) the 1-hour D-xylose absorption test provided a simple, quantitative assessment of GAC in critically ill patients. Hence, therapeutic agents that restore gut absorptive capacity may be useful for further reducing morbidity and mortality rates following trauma or the onset of sepsis.     

Adjuvant radiotherapy and chemotherapy in node-positive premenopausal women with breast cancer

BACKGROUND: Radiotherapy after mastectomy to treat early breast cancer has been known since the 1940s to reduce rates of local relapse. However, the routine use of postoperative radiotherapy began to decline in the 1980s because it failed to improve overall survival. We prospectively tested the efficacy of combining radiotherapy with chemotherapy. METHODS: From 1978 through 1986, 318 premenopausal women with node-positive breast cancer were randomly assigned, after modified radical mastectomy, to receive chemotherapy plus radiotherapy or chemotherapy alone. Radiotherapy was given to the chest wall and locoregional lymph nodes between the fourth and fifth cycles of cyclophosphamide, methotrexate, and fluorouracil. RESULTS: After 15 years of follow-up, the women assigned to chemotherapy plus radiotherapy had a 33 percent reduction in the rate of recurrence (relative risk, 0.67; 95 percent confidence interval, 0.50 to 0.90) and a 29 percent reduction in mortality from breast cancer (relative risk, 0.71; 95 percent confidence interval, 0.51 to 0.99), as compared with the women treated with chemotherapy alone. CONCLUSIONS: Radiotherapy combined with chemotherapy after modified radical mastectomy decreases rates of locoregional and systemic relapse and reduces mortality from breast cancer.     

Peptide polymerisation facilitates incorporation into ISCOMs and increases antigen-specific IgG2a production

Synthetic peptides can be tailor-made to include any B or T epitopes desired from a single or multiple antigens or organisms. However, peptides in general are not very immunogenic and have not proven easy to incorporate into immunogenic vaccines. ISCOMs is an adjuvant system that has the capability not only to enhance the humoral immunogenicity of a protein but has also been shown to induce cell-mediated immune responses in animals. Synthetic peptide ISCOM vaccines are few because of the difficulty in incorporation of these peptides into ISCOMs. We have shown in this study that non-immunogenic peptides could be made immunogenic by polymerisation, and these polymers could be incorporated into ISCOMs to give highly immunogenic vaccines. Synthetic 20mer peptides containing known B and T-helper epitopes from the E7 protein of the cervical cancer associated human papillomavirus type 16 (HPV16 E7) have been used here as model immunogens. We have compared the humoral immunity induced by these peptides as polymers or as copolymers with a lipid binding 20mer peptide (LAP 20), with or without incorporation into ISCOMs. Unpolymerised peptide elicited no measurable antibody. When polymerised peptide was administered with CFA, or in phosphate-buffered saline (PBS) without adjuvant, or incorporated into ISCOMs, antibodies recognising both the immunising peptide and HPV16 E7 protein were produced. For equal quantities of administered peptide (5 micrograms), ISCOMs gave higher titres of antibody than CFA or PBS. Polymerised peptides induced high antigen-specific IgG2a:IgG1 ratios, which increased with multiple immunisations. These data indicate that polymerised peptides could be incorporated into ISCOMs to form efficient immunogens which may elicit a Th1 type response.     

Sugar profiles of the pods of cultivated and wild types of carob bean (Ceratonia siliqua L.) in Turkey

The aim of the study was to determine the main sugar profiles of the pods, without the seeds, of cultivated and wild types of the carob bean grown in the Mediterranean and Aegean basin of Turkey. The most abundant sugar in the pods was sucrose with smaller amounts of glucose and fructose. The pods of cultivated varieties had a higher (p < 0.05) total sugar concentration of 531 ± 93 g/kg dry weight than the wild type selections which had 437 ± 77 g/kg. However, this difference was due to the greater concentration of sucrose in the cultivated varieties which did not differ from the wild types in their concentrations of fructose or glucose. The ratios of individual sugars to total sugars in the pods were similar in both varieties. There is a need to identify extreme wild types, including high seeds and low pod, and cultivated types, containing low seeds and high pod, rich in sugar for an exhaustive picture of the sugar profiles of the varieties.     

Non-Hodgkin's lymphoma of the thyroid: a retrospective review of all patients diagnosed in Nottinghamshire from 1973 to 1992

The pathological and clinical features were reviewed of all primary non-Hodgkin's lymphomas (NHL) of the thyroid gland diagnosed between 1973 and 1992 in the population (1.1 million) served by the Nottingham and North Nottinghamshire Health Authorities. Of the 43 patients with histologically proven NHL, three had low grade mucosa associated lymphoid tissue (MALT) lymphomas (Stage IEA, 2; Stage IIEA, 1), 35 had intermediate or high grade lymphomas, Stage IEA or IIEA (intermediate MALT, 2; high grade MALT, 14; B-cell diffuse centroblastic, 17; anaplastic large cell (Ki-1) of null cell type, 1; high grade unclassifiable, 1), and one had unclassifiable NHL Stage IIEA. One patient had Stage IIIEA disease (high grade MALT) and three had stage IVA disease (high grade MALT, 2; B-cell diffuse centroblastic, 1). The median age was 68 years (range 45-86) with a female: male ratio of 6:1. For the 35 patients with intermediate or high grade thyroid NHL (Stages IEA and IIEA) the 5- and 10-year cause specific survival was 60%. The 21 patients treated between 1985 and 1992 initially with chemotherapy (except stage IEA (< 5 cm diameter) had a 5-year cause specific survival of 69% (95% CI 48-90) compared with 46% (95% CI 19-73) for the 14 patients treated between 1973 and 1984 with initial radiotherapy (Chi 2 = 1.62). The survival of those patients with intermediate or high grade MALT lymphomas was not significantly greater than of those patients with B-cell diffuse centroblastic NHL.     

Regulation of capillary perfusion by small arterioles is spatially organized

To explore a mechanism for spatial recruitment of capillaries, this study determined whether the arterioles controlling capillary perfusion, which typically arise as sequential branches along a transverse arteriole, could respond differently from each other in situ in a spatially ordered way. Diameter changes were measured for these arterioles at a known location in the intact microvasculature in the cremaster muscle of anesthetized Golden hamsters (N = 67); each arteriole controls separate capillary groups. These arterioles all had the same concentration dependence to locally (by micropipette) applied norepinephrine (NE, 10(-9) to 10(-3) mol/L), and 10(-9) mol/L NE did not induce diameter changes when applied locally to individual vessels. However, 10(-9) mol/L NE added to the tissue superfusate, or 5% added superfusate oxygen (also locally subthreshold), each induced significant diameter changes (both constrictions and dilations), in different branches, that were presumably due to summation of individually subthreshold events that changed the prevailing conditions at the point of observation. These significant diameter changes were related to the maximal diameter or to initial tone of the branches, but these changes occurred in different ways for NE versus oxygen. With NE, the branch arterioles that constricted (versus dilated) were significantly larger (maximal diameter, 22.3 +/- 2.6 versus 15.9 +/- 2.1 microns) and had higher tone (fractional constriction, 0.53 +/- 0.05 versus 0.63 +/- 0.05); with oxygen, those that constricted were the same size as those that dilated (maximal diameter, 28.6 +/- 1.1 versus 30.5 +/- 2.7 microns), but constrictors had lower tone (fractional constriction, 0.49 +/- 0.04 versus 0.39 +/- 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)     

Measurement and global analysis of the absorbance changes in the photocycle of the photoactive yellow protein from Ectothiorhodospira halophila

The photocycle of the photoactive yellow protein (PYP) from Ectothiorhodospira halophila was examined by time-resolved difference absorption spectroscopy in the wavelength range of 300-600 nm. Both time-gated spectra and single wavelength traces were measured. Global analysis of the data established that in the time domain between 5 ns and 2 s only two intermediates are involved in the room temperature photocycle of PYP, as has been proposed before (Meyer T.E., E. Yakali, M. A. Cusanovich, and G. Tollin. 1987. Biochemistry. 26:418-423; Meyer, T. E., G. Tollin, T. P. Causgrove, P. Cheng, and R. E. Blankenship. 1991. Biophys. J. 59:988-991). The first, red-shifted intermediate decays biexponentially (60% with tau = 0.25 ms and 40% with tau = 1.2 ms) to a blue-shifted intermediate. The last step of the photocycle is the biexponential (93% with tau = 0.15 s and 7% with tau = 2.0 s) recovery to the ground state of the protein. Reconstruction of the absolute spectra of these photointermediates yielded absorbance maxima of about 465 and 355 nm for the red- and blue-shifted intermediate with an epsilon max at about 50% and 40% relative to the epsilon max of the ground state. The quantitative analysis of the photocycle in PYP described here paves the way to a detailed biophysical analysis of the processes occurring in this photoreceptor molecule.     

Inhibition of recombinant human mitochondrial aldehyde dehydrogenase by two intermediate metabolites of disulfiram

Disulfiram is used in aversion therapy for alcoholism. S-Methyl-N,N-diethylthiocarbamate (MeDTC) sulfoxide, a potent inhibitor of the target enzyme mitochondrial aldehyde dehydrogenase (ALDH2), is thought to be the principal active metabolite of disulfiram in vivo. We examined the effects on recombinant human ALDH2 of two intermediate metabolites of disulfiram, S-methyl-N,N-diethyldithiocarbamate (MeDDC) sulfoxide and MeDDC sulfine. MeDDC sulfoxide was a potent inhibitor of ALDH2 with an IC50 of 2.2 +/- 0.5 microM (mean +/- SD, N = 4) after preincubation with enzyme for 30 min. MeDDC sulfine was a relatively weak inhibitor of ALDH2 under the same conditions with an IC50 value of 62 +/- 14 microM. The inhibition of ALDH2 by both compounds was irreversible and did not require the cofactor NAD. The latter finding demonstrates that inactivation of ALDH2 is independent of the dehydrogenase activity of the enzyme. GSH blocked almost completely the inhibition by 20 microM of MeDDC sulfoxide and greatly diminished the inhibition by 200 microM of MeDDC sulfine. Inactivation by MeDDC sulfoxide was time dependent. MeDTC sulfoxide was a more potent inhibitor of recombinant human ALDH2 (IC50 = 1.4 +/- 0.3 microM after preincubation for 15 min) than either of the intermediate metabolites, and its inhibition was unaffected by GSH. Our results suggest that these newer intermediate metabolites of disulfiram, especially the more potent MeDTC sulfoxide, have the potential to inhibit the target enzyme ALDH2 in patients receiving disulfiram. However, until the significance of the interactions of the inhibitors with GSH is more fully understood, the contribution of MeDDC sulfine and MeDDC sulfoxide to the pharmacological effects of disulfiram in vivo is uncertain.