Assessment of Photoinduced Frontal Polymerization Processes for a Stable 1K System

Frontal polymerization (FP) has attracted increasing interest in recent years in various applications. This polymerization method can be very promising for the polymerization of thick materials with high fillers content in the range of 50–80% (weight) by local application of a reasonable amount of energy. In this work, recent advances in controllable and predictive behavior for photoinduced frontal photopolymerization are reported. Here, tert-butyl peroxybenzoate (Luperox-P) is selected to initiate thermal polymerization at depth because its high polymerization ability and its decomposition temperature is in a promising range, i.e., neither extremely high (monomer decomposition) nor very low (storage stability issues). Thermal imaging experiments are used to follow the temperatures in the samples in real time. The number of cured layers and the depth of cure are also determined. This paper investigates various factors such as the contents of both photo and thermal initiators, the light intensity, the fiber contents, the irradiation time, etc., resulting in a statistical design of experiments with the factors: 1) content of Luperox P and 2) the irradiation time used to investigate the influence on photoinduced frontal polymerization. Markedly, FP appears to be fully controllable for a storage-stable, tunable 1K system.     

High dietary folate supplementation affects gestational development and dietary protein utilization in rats.

There is new evidence that good folate status may play a critical role in the prevention of neural tube defects and in the maintenance of adequate homocysteine levels, an amino acid recently identified as a risk factor for cardiovascular disease. This has led to different folate recommendations, all of them much higher than the present dietary recommendations. Folic acid is a water-soluble vitamin with a low potential toxicity. However, the possible consequences of long-term, high folate intakes are unknown. Therefore, the present study was undertaken to determine the effects of long-term, high dietary folate supplementation on gestational and nutritional markers in pregnant and virgin rats. Four groups of Wistar rats were classified on the basis of physiological status (virgin or pregnant) and the experimental diets administered (folic acid supplemented, 40 mg/kg diet; or control diet, 2 mg folic acid/kg diet). Rats were fed their respective diets for 3 wk. Two critical periods were used for metabolic balance studies (experimental d 1-5 and 17-21), which involved the determination of fat and protein digestibilities as well as metabolic protein utilization (MPU) and net protein utilization (NPU). Gestational development (number of live fetuses) was adequate in both diet groups regardless of folate supplementation. However, body weight and vertex-coccyx length in fetuses from supplemented dams were less than (P < 0.0001) in fetuses of control dams. Fat and nitrogen digestibilities were not affected by supplementation, but MPU and NPU coefficients were significantly lower (P < 0.05) in the folic acid-supplemented groups, irrespective of physiological status, compared to control rats. These new findings of macro-micronutrient interactions caused by high folate supplementation are discussed on the basis that the vitamin may act as a xenobiotic more than as a nutrient.     

Broad band spectral EEG parameters correlated with different IQ measurements

The relationship of IQ (measured by WAIS and all its subscales) and EEG broad band spectral parameters were studied in 40 right-handed, male volunteers ranging in age from 20 to 25 years old. EEGs were recorded in 20 derivations during rest with eyes opened. The results obtained reveal positive and negative correlations with abundant frontal participation in all bands. Mean frequency data show a frequency shift in a very narrow range suggesting that more relations in narrow band could be achieved. These results highlight the need of psychological tests that measure more homogeneous abilities and finer measurement technique to reveal clearly explainable correlations and demonstrate that EEG recordings do reflect intellectual abilities.     

Short-term chemotherapy of leprosy using the combination rifampicin + cotrimoxazole + isoniazid

With the fixed combination RMP + SXT + INH an objective and subjective improvement was obtained within two months, even in severe LL-cases. Treatment resulted in final and relapse-free cure. In the majority of patients the typical erythematous infiltrative oedematous skin processes disappeared within the two months of treatment, in some of them (three of 21) within the six-month follow-up period. Lepromas (15 cases) disappeared in two patients within the two months of treatment. In the sixth month of the follow-up period nine patients were free from lepromas. In another six cases they subsided in the course of the following months. Reactions occurred in 13 patients, in part during treatment, in part during the follow-up period. Three of them were reversal reactions. Chemotherapy was not interrupted. When required, corticosteroids or thalidomide were given in addition. Erythema nodosum leprosum (17 cases) quickly subsided under treatment. Tolerance and compliance were excellent. The subjective minor "side effects" were not specific and cannot clearly be attributed to the medication. The major advantage of the combination RMP + INH + SXT described in this paper lies in the considerably reduced treatment duration (two to four months instead of two years), the rapid disappearance of the symptoms typical of leprosy, the high tolerance, the ease of application as fixed combination and the absence of relapses. So far the patients have been followed up for two years. Through the short treatment duration the cost of treatment is considerably reduced. The new combination allows outpatient treatment and is universally applicable. The patient can maintain his social and professional habits.     

Bacteremia after intestinal transplantation in children correlates temporally with rejection or gastrointestinal lymphoproliferative disease

BACKGROUND: Bacteremia occurs frequently after intestinal transplantation (ITx) in children. During our initial experience with this procedure, we noted that bacteremic episodes tended to occur simultaneously with the presence of rejection and/or gastrointestinal (GI) posttransplant lymphoproliferative disease (PTLD). AIM: To document the association of bacteremia with rejection and GI PTLD in pediatric ITx recipients. METHODS: Retrospective analysis of all medical records from 62 children who underwent ITx between July 1990 and January 1998 at Children's Hospital of Pittsburgh. A bacteremic episode was defined as two positive blood cultures from different sites at the same time or from the same site at different times. Rejection and PTLD were defined using previously published criteria. RESULTS: A total of 39/62 ITx recipients had 133 blood stream infections (2.1 episodes/patient) including 121 episodes of bacteremia and 12 of fungemia. Enteric organisms were the most frequently recovered pathogens (Gram negative rods, n=76; enterococci, n=36). Enteric organisms were recovered as a single organism (n=57), with another enteric bacteria (n=23), or with coagulase negative staphylococci (CONS) (n=24). CONS were recovered as a single organism on 21 occasions. An obvious source of bacteremia was not found for 115/121 episodes. Endoscopy was performed for 107 of the 115 bacteremia episodes; an abnormal histology was identified in 74 revealing rejection (n=36), GI PTLD (n=21), or both (n=17). When endoscopy showed GI pathology, enteric organisms alone or in combination with CONS were recovered on 63/107 occasions, although CONS were recovered alone only 11 times. CONCLUSIONS: Bacteremia accompanies GI rejection and intestinal PTLD in ITx recipients. Endoscopy should be performed to inspect the allograft when bacteremia occurs without an obvious source in these patients. This is especially true for patients with bacteremia due to enteric organisms.     

Immunomodulation for intestinal transplantation by allograft irradiation, adjunct donor bone marrow infusion, or both

BACKGROUND: The passenger leukocytes in the intestine have a lineage profile that predisposes to graft-versus-host disease (GVHD) in some animal models and have inferior tolerogenic qualities compared with the leukocytes in the liver, other solid organs, and bone marrow. Elimination by ex vivo irradiation of mature lymphoid elements from the bowel allografts is known to eliminate the GVHD risk. We hypothesized that infusion of donor bone marrow cells (BMC) in recipients of irradiated intestine would improve tolerogenesis without increasing the risk of GVHD. METHODS: Orthotopic small intestine transplantation was performed with the GVHD-prone Lewis (LEW)-to-Brown Norway (BN) combination and the reverse GVHD-resistant BN-to-LEW model under a short course of tacrolimus treatment (1 mg/kg/day, days 0-13, 20, 27). Grafts were irradiated ex vivo, using a 137Cs source. In selected experimental groups, donor BMC (2.5 x 10(8)) were infused on the day of small intestine transplantation. RESULTS: The unmodified LEW intestine remained intact, whether transplanted alone or with adjunct donor BMC infusion, but all of the BN recipients died of GVHD after approximately 2 months. Intestinal graft irradiation (10 Gy) effectively prevented the GVHD and prolonged survival to 92.5 days, but all of the BN recipients died with chronic rejection of the LEW grafts, which was prevented by infusion of adjunct donor BMC without causing GVHD. In the GVHD-resistant reverse strain direction (BN-->LEW), all intestinal recipients treated for 27 days with tacrolimus survived > or =150 days without regard for graft irradiation or adjunct BMC, but chronic rejection was severe in the irradiated intestine, moderate in the unaltered graft, and least in the irradiated intestine transplanted with adjunct BMC. Mild arteritis in the 150 day allografts of both strain combinations (i.e., LEW--> BN and BN-->LEW) may have been irradiation associated, but this was prevented when weekly doses of tacrolimus were continued for the duration of the experiment rather than being stopped at 27 days. CONCLUSIONS: Recipients are protected from GVHD by irradiating intestinal allografts, but the resulting leukocyte depletion leads to chronic rejection of the transplanted bowel. The chronic rejection is prevented with adjunct donor BMC without causing GVHD. Although application of the strategy may be limited by the possibility of radiation injury, the results are consistent with the paradigm that we have proposed to explain organ-induced graft acceptance, tolerance, and chronic rejection.     

High-dose folic acid supplementation in rats: effects on gestation and the methionine cycle

There is new evidence that a good folate status may play a critical role in the prevention of neural-tube defects and in lowering elevated homocysteine concentrations. This adequate folate status may be achieved through folic acid dietary supplementation. Folate is a water-soluble vitamin with a low potential toxicity. However, the possible consequences of long-term high-dose folic acid supplementation are unknown, especially those related to the methionine cycle, where folate participates as a substrate. With the aim of evaluating such possible effects, four groups of Wistar rats were classified on the basis of physiological status (virgin v. pregnant) and the experimental diet administered (folic-acid-supplemented, 40 mg/kg diet v. control, 2 mg folic acid/kg diet). Animals were fed on the diets for 3 weeks. Results showed that gestation outcome was adequate in both groups regardless of the dietary supplementation. However, there were reductions (P < 0.001) in body weight and vertex-coccyx length in fetuses from supplemented dams v. control animals. Folic acid administration also induced a higher (P < 0.01) S-adenosylmethionine: S-adenosylhomocysteine value due to increased S-adenosylmethionine synthesis (P < 0.01). However, hepatic DNA methylation and serum methionine concentrations remained unchanged. Serum homocysteine levels were reduced in supplemented dams (P < 0.05). Finally, pregnancy caused lower serum folate, vitamin B6 and vitamin B12 levels (P < 0.05). Folic acid administration prevented the effect of pregnancy and raised folate levels in dams, but did not change levels of vitamins B12 and B6. These new findings are discussed on the basis of potential benefits and risks of dietary folic acid supplementation.