Expression of ornithine decarboxylase in pancreatic development

We examined the relationship between ornithine decarboxylase (ODC) and growth and differentiation in the developing rat exocrine pancreas. The ODC activity profile showed 2 distinct stages of increases with the first occurred at 14-16 days of age, and a second at 21-23 days of age. Growth parameters evaluated as gains in tissue mass, protein and DNA content in the pancreas indicated a low growth rate soon after birth with a transition to a much more rapid growth rate around the age of 20-21 days, a time corresponded to the second rise in ODC activity. Differentiation parameters evaluated as the accumulation of trypsinogen, amylase and lipase showed different temporal changes. While the rate of accumulation of all three enzymes was relatively low following birth, a rapid rate of accumulation of trypsinogen and amylase started around 15-16 days, a time corresponding to the first rise in ODC activity. Lipase, however, did not show an increase in its accumulation until around age 20 days. These results indicate that a rise in ODC activity is closely associated with growth and differentiation in the developing rat pancreas. To further examine this issue, the steady state levels of ODC mRNA in developing rats were evaluated by Northern blots probed with an ODC cDNA. The developmental profile of ODC mRNA showed a broad peak with a pronounced shoulder occurring at 10 days of age. A higher peak was reached around 20 days of age, then dropped precipitously to a very low level at the age of 24 days. This temporal changes in the level of ODC mRNA show good relationship to the changes in ODC activity suggesting that the control of ODC expression occurs at least in part at the pre-translational level.

Prognostic significance of ferritin expression in colorectal adenocarcinoma

In recent years, there has been considerable interest in ferritin as an oncofetal protein. However, the clinical significance of ferritin expression in cancer tissues remains unknown. We performed an immunohistochemical study to examine the expression of ferritin in colorectal adenocarcinoma (n = 104). A total of 95 out of 104 (91.3%) colon cancers were positive for ferritin expression. The degree of immunoreactivity has no significant correlation with tumor grade (p = 0.964), size (p = 0.659), serosal invasion (p = 0.331), nodal metastasis (p = 0.955), distant metastasis (p = 0.354) and DNA ploidy status (p = 0.126), but there was a strong association between ferritin expression of tumor cells and stromal mononuclear cell infiltration (p = 0.004). In terms of prognostic significance, multivariate analysis showed that nodal metastasis (p = 0.0123) and distant metastasis (p = 0.0237) were independent poor prognostic factors. However, there was no significant difference in survival between patients with weak and strong ferritin expression in cancer tissues (p = 0.3766). The results indicate that the majority of colorectal adenocarcinomas exhibit ferritin expression. The grade of ferritin expression is strongly associated with stromal mononuclear cell infiltration, but has no significant correlation with any staging parameters or the survival of cancer patients.

Normalization of pancreatic exocrine enzymes by islet transplantation in diabetic rats

In an effort to evaluate the effectiveness of islet transplantation in correcting exocrine dysfunction, young male Lewis rats were made diabetic by i.v. streptozotocin injection. Diabetes status was confirmed by decrease in insulin and increase in blood glucose and glycosylated hemoglobin levels. Pancreatic islets were isolated from age-matched control syngeneic rats by collagenase digestion followed by purification through a Ficoll gradient. Islets (approximately 1200) were grafted to the liver by intraportal injection to animals at 8 weeks after diabetes was established. Transplanted rats were sacrificed 4 weeks after correction of hyperglycemia. Diabetes resulted in decrease in body weight. Transplantation reversed the body weight loss and led to a body weight gain. Diabetes resulted in a decrease in pancreatic amylase (1.4 +/- 0.4 U/mg protein compared with a control value of 121.9 +/- 3.2 U/mg protein) and a slight increase in lipase (87.3 +/- 5.5 U/mg protein compared with a control value of 69 +/- 4.7 U/mg protein). Transplantation completely normalized amylase (132.2 +/- 25.0 U/mg protein) and lipase (56.3 +/- 3.9 U/mg protein) in spite of an imperfect correction of blood insulin, glucose, and glycosylated haemoglobin levels in these rats. These data demonstrated that islet transplantation is very effective in correcting the exocrine enzyme changes resulting from diabetes. Evaluation of steady-state levels of amylase mRNA in these groups of animals by Northern blots showed a decrease in the amylase mRNA level in diabetes and a return to that of control in transplanted rats, indicating that the control of amylase expression is most likely at the pretranslational level.

Prediction of mesiodistal diameter of unerupted lower canines and premolars using 45 degrees cephalometric radiography

The reliability of using the oblique cephalometric radiograph for early prediction of the mesiodistal widths of unerupted lower canines and premolars was investigated. Mandibular models and oblique cephalometric radiographs were obtained for 40 Brazilian children (20 boys and 20 girls), in the mixed dentition phase. Further models were obtained for the same sample when all permanent teeth had erupted. A Student t test showed statistically significant differences of tooth size between the sexes but not between right and left sides. Measurements of the unerupted canines and premolars taken from the 45 degrees cephalometric radiograph were statistically greater than the actual values, although a high correlation was observed between them. Linear regression equations and correction tables were established to compensate for this magnification. The actual values for these teeth were compared with the corrected predicted values from the 45 degrees radiograph and with the predicted values obtained from the methods of Ballard and Wylie, Carey, Moyers, and Tanaka and Johnston. A high correlation was observed only between the actual values and the corrected predicted values from the radiograph. The results indicate that, correcting the magnification, the 45 degrees cephalometric radiographic may be used in predicting unerupted lower canine and premolar widths in Brazilian children.

Growth and threshold weaning weights among captive rhesus macaques

Interspecific analyses of infant growth and the time to maternal reconception (or weaning) demonstrate a consistent threshold for weaning weight at close to four times neonate weight, irrespective of the duration of lactation (Lee et al., [1991] J. Zool. Lond. 225:99-114). Intraspecific variation in the attainment of a threshold weaning weight was determined in a sample of 31 captive infant rhesus macaques, where growth between birth and subsequent parturition was measured along with information on maternal size, weight, and social characteristics. A threshold weaning weight was found, with infants attaining approximately 1,335 g at the time of reconception. Birth weights of the infants were influenced by maternal physical and social variables in that larger mothers, and alpha ranking mothers, produced larger neonates. Postnatal growth rate, which determined the attainment of the threshold weight, was independent of maternal size or condition, but was influenced by offspring sex and the probability of reconception. Future reproductive status of mothers was specifically related to differences in patterns of growth among the infants. Mothers who conceived again at 30 weeks had infants who grew more slowly after the first 12 weeks of life, especially if these infants were sons. Mothers in this colony appeared to make decisions about the need to sustain their infants' growth in relation to their ability to invest in current offspring, which may compromise their subsequent reproduction.

Platelet activating factor inhibition reduces lung injury after cardiopulmonary bypass

Because cardiopulmonary bypass (CPB) produces a diffuse inflammatory reaction that may injure multiple organs and complicate cardiac surgical procedures, we examined the use of a competitive inhibitor of platelet activating factor (SDZ HUL-412) in a porcine model of CPB as a means to ameliorate pulmonary injury after CPB. Thirteen pigs (35 to 40 kg) underwent CPB at 28 degrees C for 2 hours, followed by 2 hours of observation. Group I (n = 6) received SDZ HUL-412 (a quinolinium compound) intravenously (3 mg/kg loading dose and 2 mg.kg-1.h-1 continuous infusion) starting before sternotomy. Group II (n = 7) received a saline vehicle. Peak airway pressure, pulmonary arterial pressure, left atrial pressure, and arterial blood gases were measured and flow cytometry evaluated surface expression of adhesion molecule subunit CD18 on circulating neutrophils. Pulmonary function was significantly improved in group I. Fifteen minutes after CPB, dynamic lung compliance in group I was 91% +/- 12% of baseline versus 49% +/- 5.2% in group II (p = 0.06 by analysis of variance). After CPB, the arterial oxygen pressure was also significantly better in group I than in group II (425 +/- 61 versus 234 +/- 76 mm Hg) (p < 0.05). The rise in pulmonary vascular resistance after CPB was less in group I (p < 0.05) (323 +/- 55 to 553 +/- 106 dynes.s.cm-5) than in group II (531 +/- 177 to 884 +/- 419 dynes.s.cm-5) at the end of the observation period. CD18 up-regulation increased similarly in the two groups during CPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Neutrophil modulation results in improved pulmonary function after 12 and 24 hours of preservation

Neutrophils are important mediators of reperfusion injury, and suppression of neutrophil function or numbers can reduce reperfusion injury and improve long-term organ preservation in transplantation. NPC 15669, a leumedin, is a novel compound that prevents recruitment of neutrophils at inflammatory foci by inhibiting CD11b/CD18 adhesion molecule expression. NPC 15669 was used to inhibit neutrophil adhesion during reperfusion of isolated rabbit lungs after 12 and 24 hours of cold storage. Lungs (New Zealand White male rabbits, 2 to 3 kg) were flushed with 4 degrees C Euro-Collins (EC) solution, harvested en bloc, stored under various study conditions, and reperfused for 3 hours with fresh whole blood at 37 degrees C in an isolated perfusion system at constant flow and an inspired oxygen fraction of 1. Four groups (n = 6 each) were studied. Group I underwent immediate whole blood reperfusion. Group II were stored for 12 hours in 4 degrees C EC solution before reperfusion. Group III were stored for 12 hours in 4 degrees C EC solution and reperfused with whole blood containing NPC 15669 (10 mg/kg whole body weight). Group IV were stored for 24 hours in 4 degrees C EC solution and reperfused with whole blood containing NPC 15669 (10 mg/kg). Pulmonary artery and peak airway pressures were significantly lower and compliance higher in groups III and IV lungs after 3 hours of reperfusion (p < 0.05) compared with group I. Group I and III lungs had significantly less edema than group II (p < 0.05). The arterial partial pressure of oxygen was similar in all stored groups (II to IV).(ABSTRACT TRUNCATED AT 250 WORDS)

Right ventricular myxoma in a 12-year-old child: a case report

Cardiac myxoma especially of the right ventricle, is rare in children. A 12-year-old boy with right ventricle myxoma is reported. His heart murmur was found incidentally when he visited the Outpatient Department (OPD) because of upper respiratory infection symptoms. There was no exertional dyspnea, no palpitation, no syncope and no skin lesion. The echocardiogram revealed a heart tumor of about 4 x 3 cm in the right ventricle (RV) extending to the right atrium (RA). The tumor grew from the interventricular septum, resulting in an RV outlet and inlet obstruction. Magnetic resonance image (MRI) revealed a well-defined mass in the RV ventricle, with good enhancement after injecting a contrast medium. The patient received right atriotomy and total excision of the tumor with repairing of the interventricular septum base. Pathology revealed myxoma with gelatinous whitish color and central hemorrhage. At post-operative follow-up, the patient's condition was good.

Two decades of coronary artery bypass graft surgery in young adults

Between January 1970 and December 1991, 201 patients < or = 40 years of age underwent coronary artery bypass graft surgery (CABG). Group 1 (1970 to 1980, n = 119) and group 2 (1981 to 1991, n = 82) corresponded to the eras before and after the onset of percutaneous transluminal coronary angioplasty (PTCA), respectively, and were analyzed for trends in patient profile, treatment, and risk factors for coronary artery disease (CAD): smoking, hypertension, hypercholesterolemia, diabetes, and family history. Mean age at operation was similar in the groups (1, 37 +/- 3.4 years; 2, 36 +/- 3.1 years). Women made up 18% of group 1 and 27% of group 2 (P = .048). Risk factor profile differed in the two groups: group 1 had more smokers (80%) than group 2 (68%) (P = .085), fewer patients with hypercholesterolemia (1, 37%; 2, 52%; P = .065), and significantly fewer diabetics (1, 10%; 2, 25%; P < .043). Mean preoperative New York Heart Association (NYHA) class was 3.2 in group 1 and 3.0 in group 2. The distributions of single-, double-, and triple-vessel CAD were similar in the groups. Preoperative myocardial infarction occurred in 55% of group 1 versus 61% in group 2 (P = NS). No group 1 patient received PTCA before CABG, but PTCA was performed in 15 group 2 patients. Left internal mammary artery grafts were used in 4% of group 1 and 57% of group 2 patients. CABG operative mortality was 7.0% in group 1 and 1.2% in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Age and gender effect on the inducibility of steroid metabolizing cytochrome P450 in rat liver

Liver microsomal steroid hydroxylases and 5 alpha reductase activities were evaluated by quantitation of specific metabolites from 4-C14 progesterone after TLC separation. Each enzyme showed a different developmental profile depending on the gender of the rat. Dexamethasone induced both 6 beta and 16 alpha progesterone hydroxylase, being more potent for 6 beta (3 to 4 folds) than 16 alpha (1.2 to 1.6 folds). A comparison of the inducibility of 6 beta and 16 alpha hydroxylase by dexamethasone in rats from different age groups showed that for both enzymes, the degree of increase was higher in the younger than older groups. Thus there is a blunting in the responsiveness to dexamethasone induction of both 6 beta and 16 alpha hydroxylase with age particularly in female animals. This decrease in responsiveness in older females could potentially affect their capacity to metabolize endogenous and exogenous agents.

Interaction of 1-ethynylpyrene and hepatic CYPIA1 from rainbow trout

1-Ethynylpyrene (EP) inhibits microsomal 7-ethoxyresorufin O-deethylase (EROD) activities from the liver of both trout and rat. Trout hepatocytes treated with EP had increased microsomal EROD activity and a concomitant increase in CYPIA1 protein as measured by Western blot analysis. EP at 10(-9)-10(-6) M did not interfere with beta-naphthoflavone (BNF) induction of CYPIA1 in trout hepatocytes. In contrast, treatment with alpha-naphthoflavone (ANF), another inhibitor of CYPIA1, resulted in a significant inhibition of the basal (at 10(-6) M ANF) and BNF induced (at 10(-8) M and higher concentrations of ANF) level of EROD activity. ANF also did not significantly induce CYPIA1 protein but led to attenuation of the induction of CYPIA1 proteins by BNF in trout hepatocyte cultures. Thus, in trout hepatocytes, EP acts differently from ANF in the modulation of CYPIA1.

Congenital coronary artery-cardiac chamber fistulae: a study of fourteen cases

BACKGROUND

Congenital coronary artery fistula is a rare heart defect. Symptoms of the patient and characteristics of the fistula were investigated and the role of surgical treatment was evaluated.

METHODS

Fourteen patients with congenital coronary artery fistulae were diagnosed here between January, 1983, and December, 1991. Only one patient was asymptomatic, but diagnosis was suspected from clinical presentation of a continuous murmur. In the 13 symptomatic patients, angina and exertional dyspnea were the most common symptoms. Congestive heart failure and subacute bacterial endocarditis were rare complications. Cardiac catheterization with selective coronary angiography was performed in all of these patients. The left anterior descending coronary artery was most commonly involved in this series. Findings, different from those in other literature, were the right coronary artery has more usually been reported. Fistulous communication was most often found in the pulmonary artery, right ventricle and right atrium. The mean ratio of pulmonary-to-systemic flow was 1.67 in 10 patients, and the shunt flow of another 4 accidentally diagnosed patients was trivial. Six patients, including all 4 patients, age < 20 years at diagnosis, underwent surgical correction; only 1 patient was not given an aid of cardiopulmonary bypass.

RESULTS

The six patients who received surgical treatment, one died of pneumonia and respiratory failure and the other five patients had no evidence of residual fistula. All five were asymptomatic during a mean follow-up period of five years. The symptoms were slowly progressive, and functional status worsened in two who refused operation and in two high risk patients. In four patients with accidentally diagnosed small fistulae, the symptoms remained unchanged during six years of follow-up.

CONCLUSIONS

The objective of surgical treatment was closure of the fistula tract without compromise of normal flow through the coronary artery. Surgical intervention was recommended for all symptomatic patients and asymptomatic young patients as well, to prevent the development of fistula-related complications.

Patient dosimetry quality assurance program with a commercial diode system

PURPOSE

To evaluate a commercial silicone diode dosimeter for a patient dosimetry quality assurance program.

METHODS AND MATERIALS

The diode dosimeter was calibrated against an ion chamber and percentage depth dose, linearity, anisotropy, virtual source position, and field size factor studies were performed. Correction factors for lack of full scatter medium in the diode entrance and exit dose measurements were acquired. Dosimetry equations were proposed for calculation of dose delivered at isocenter. Diode dose accuracy and reproducibility were tested on phantom and on four patients. A patient dosimetry quality assurance program based on diode measured dose was instituted and patient dose data were collected.

RESULTS

Diode measured percentage depth dose and field factors agreed to within 3% with those measured with an ion chamber. The diode exhibited less than 1.7% angular dose anisotropy and less than 0.5% nonlinearity up to 4 Gy. Diode dose measurements in phantom showed that the calculated doses differed from the prescribed dose by less than 1.5%; the diode exhibited a daily dose reproducibility of better than 0.2%. On four selected patients, the measured dose reproducibility was 1.5%; the average calculated doses were all within +/- 7% of the prescribed doses. For 33 of 40 patients treated with a 6 MV beam, measured doses were within +/- 7% of the prescribed doses. For 58 of 63 patients treated with an 18 MV beam, measured doses were within +/- 7% of the prescribed doses. For 11 out of 12 patients, a second repeat measurements yielded doses within +/- 7% of the prescribed doses.

CONCLUSIONS

The proposed diode-based patient dosimetry quality assurance program with dose tolerance at +/- 7% is simple and feasible. It is capable of detecting certain serious treatment errors such as incorrect daily dose greater than 7%, incorrect wedge use, incorrect photon energy and patient setup errors involving some incorrect source-to-surface-distance vs. source-to-axis-distance treatments.

Strand- and sequence-specific attenuation of N-methyl-N'-nitro-N-nitrosoguanidine-induced G.C to A.T transitions by expression of human 6-methylguanine-DNA methyltransferase in Chinese hamster ovary cells

The effect of human O6-methylguanine-DNA methyltransferase (MGMT) on the cytotoxicity, the mutagenicity, and the specific kinds of base substitutions induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were examined in non-MGMT transfected Chinese hamster ovary cells (CHOM cells) and in those cells which had been transfected with human MGMT complementary DNA (AGT cells). AGT cells containing a high level of human MGMT activity were markedly more resistant to the cytotoxic and mutagenic effects of MNNG than CHOM cells which had no detectable MGMT activity. The dosages of MNNG which reduced to 50% of colony forming ability were estimated to be 0.8 microM for CHOM and 10 microM for AGT cells. The induction frequency of 6-thioguanine-resistant cells was significantly declined in AGT cells. At 4 microM MNNG, this frequency was declined from 273 mutants/10(6) viable CHOM cells to 13 mutants/10(6) viable AGT cells. The entire coding region of the hypoxanthine (guanine) phosphoribosyltransferase (hprt) gene in 37 AGT and 22 CHOM mutants was characterized by direct sequencing of the mRNA-polymerase chain reaction-amplified complementary DNA. Base changes at the intron-exon boundaries of the hprt DNA in the splicing mutants were further examined. Those results indicated that G to A transitions were significantly reduced in MNNG-treated AGT cells (chi 2 test, P < 0.001), suggesting that O6-methylguanine was repaired error free by human MGMT. In contrast, no difference arose in the frequencies of T to C transitions induced by MNNG in these two populations. All of the G to A transitions induced in AGT cells were located on the nontranscribed strand, assuming that the causative lesion was O6-methylguanine (P < 0.05). Such a strand specificity was not observed in CHOM mutants. Most of the G to A transitions observed in CHOM mutants were located at the middle guanine of 5'-GGPu sequences. Transitions observed at these sites, particularly 5'-GGG, were significantly reduced in AGT mutants (P < 0.05). Our results have suggested that human MGMT specifically repairs O6-methylguanine with a preference to remove those located on the transcribed strand and middle guanine of 5'-GGG.

Thyroxine control of pancreatic amylase gene expression: modulation of PTF1 binding activity

The role of pancreas specific transcription factor (PTF1) in thyroxine (T4) modulation of amylase gene expression in suckling rats was evaluated. Electrophoretic mobility shift assay (EMSA) was used to determine the PTF1 binding activity by the amount of a synthetic oligonucleotide containing the amylase enhancer sequence bound by nuclear protein extracts. Nuclear protein from rat pancreata showed a developmental increase of PTFI activity correlated with age. To study the action of T4, pups were made hyperthyroid by T4 injection and hypothyroid by feeding propylthiouracil (PTU) to the lactating dams. EMSA of nuclear proteins isolated from these groups showed an increase in PTF1 binding activity in the T4 group and a decrease in the PTU group. Concomitantly, T4 increased, while PTU decreased both amylase enzyme and mRNA concentrations. T4 replacement reversed the effect of PTU on PTF1 binding, amylase enzyme activity and mRNA levels. To examine the age dependence of T4 effects, T4 was injected to pups for 5 days prior to killing at the age of 15, and 25 days. T4 was effective when given at an earlier age (15 days) but not at a later stage (25 days) in increasing amylase activity and amylase mRNA levels. Nuclear proteins isolated from pancreata of these groups showed an increase in PTF1 binding activity in the T4-treated 15-day-olds but not in the 25-day-olds in comparison to their corresponding age matched littermates. These results suggest that PTF1 is an important intermediary in T4 modulation of amylase gene expression during ontogeny of the rat exocrine pancreas.

Comparison of mutation spectra induced by N-ethyl-N-nitrosourea in the hprt gene of Mer+ and Mer- diploid human fibroblasts

N-Ethyl-N-nitrosourea (ENU) forms several major adducts upon reaction with DNA, of which ethylation at the O6 position of guanine and the O4, O2 and N3 positions of thymine have been implicated to be mutagenic lesions. To investigate what specific kinds of ENU-induced mutations were affected by the repair ability of O6-alkylguanine-DNA alkyltransferase (AGT), we examined the mutations in the hypoxanthine (guanine) phosphoribosyltransferase gene (hprt) in 87 independent mutants derived from ENU-treated AGT proficient (Mer+) or deficient (Mer-) diploid human fibroblasts. Of the characterized mutations, 97% were single base substitutions. The major difference in the mutation spectra was that the frequency of G.C to A.T transitions was significantly higher in Mer- mutants (16/38) than in Mer+ mutants (4/33). The results indicate that AGT removes O6-ethylguanine, thus protecting human cells from parts of the cytotoxic and mutagenic effects of ENU. A high frequency of T.A to A.T transversions induced by ENU was observed in both Mer+ (52%) and Mer- (34%) mutants. This type of mutation was less frequently observed (10%) in N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutants derived from the same Mer+ cells in our previous report (J. Mol. Biol., 221, 421, 1991). Comparison of alkylating lesions formed by MNNG and ENU indicates that O2-ethylthymine and N3-ethylthymine are potent mutational adducts for T to A transversions. The occurrence of ENU-induced T.A base pair transversions showed a strong strand bias; 35/37 were located on the non-transcribed strand, assuming thymine is the mutagenic lesion. The result suggests a difference in repair capacity of ethylthymine on the two strands. In addition, this type of mutation preferentially occurred at 5'-Pu-T sequences.

Neutrophil adhesion and complement inhibition prolongs survival of cardiac xenografts in discordant species

Hyperacute rejection results in rapid destruction of a discordant cardiac xenograft and is characterized by antibody deposition, complement activation, and platelet aggregation. The importance of neutrophils is unclear. Complement inhibition prolongs discordant cardiac xenograft survival. The purpose of this experiment was to determine the relative roles of complement and neutrophils. Selective inhibition of complement and neutrophil adhesion was used in a guinea pig-to-Lewis rat cardiac heterotopic xenotransplant model. NPC 15669 (N-[9H-(2,7-dimethylfluorenyl-9-methoxy)carbonyl]-L-leucine), a member of a new class of antiinflammatory agents termed leumedins, specifically prevents recruitment of neutrophils at inflammatory foci by inhibiting upregulation of the CD11b/CD18 adhesion molecule. Soluble complement receptor type 1 (sCR1, BRL 55730) is a potent inhibitor of the alternative and classical complement pathways. Group I (n = 13) received saline vehicle i.v. Group II (n = 15) was treated with NPC 15669 (10 mg/kg i.v. bolus) prior to reperfusion. Group III (n = 13) was treated with sCR1 (20 mg/kg i.v. bolus) prior to reperfusion. Group IV (n = 13) received both NPC 15669 and sCR1. Two xenografts were harvested at each interval time point (Groups I and II, 1, 2, 4, and 6 min; and Groups III and IV, 6, 15, 30, and 60 min). The remainder were followed to cessation of graft function. Graft survival was significantly increased in group IV and group III-375 +/- 13.4 min (mean +/- SD) and 112 +/- 29.4, respectively (P < .05), compared with 9.9 +/- 6.3 in group II and 8.7 +/- 4.9 in group I. Extreme interstitial hemorrhage and edema and contraction band injury were present in group I-III animals at end-stage, and neutrophil infiltration in group III. In group IV grafts, there was a decrease in these parameters despite the longer survival time, and at end-stage rejection the cellular infiltrate was primarily mononuclear. This study demonstrates that complement is an important mediator in early xenograft HYP injury. Combined treatment with NPC 15669 and sCR1 results in reduced histologic injury at all time points and longer graft survival than with sCR1 alone. These results suggest that neutrophil and complement activation play synergistic roles in the pathogenesis of xenograft hyperacute rejection. Neutrophil inhibition may prove to be an important component of multimodality therapy for hyperacute rejection, particularly in less-discordant transplants.

Faecal enzymes: in vivo human skin irritation

Digestive enzymes in faeces have been reported to possess skin irritation potential. The present study was designed to investigate the in vivo irritant potentials of faecal concentrations of proteolytic and lipolytic digestive enzymes in bile salt mixtures. In a 21-day cumulative irritation assay, clinical evaluation and noninvasive bioengineering techniques were used. 5 days occlusive exposure to phosphate buffer (pH = 8) caused no visual skin damage but reflectance spectroscopy demonstrated significant vasodilation (p < 0.01) and increases in transepidermal water loss (TEWL) and skin pH were also observed (p < 0.01). These increases were still present at days 12 and 19. Occlusive exposure to physiologic concentrations of faecal enzymes resulted in significant visual and objective scores at day 5, 12, and 19, with increased readings as a function of exposure time (p < 0.01). The enzyme mixture containing lipase caused delayed onset of skin erythema and epidermal barrier disruption compared to elastase and chymotrypsin containing solutions. Prolonged occlusive exposure to digestive enzymes in faecal concentrations caused severe skin erythema and epidermal barrier disruption in a human model, suggesting a possible etiologic role of digestive enzymes in perianal, circumstomal or diaper dermatitis.

Beam-hardening effects of wedges on a spoiled 6 MV beam

The beam-hardening effects of the wedges on a 6-MV spoiled beam has been studied. The beam quality of all the wedged beams was found to be the same as the open beam. The dmax also stayed unchanged for all the wedges at all field sizes. The relative wedge factors were found to reflect the beam-hardening effect, which is a function of the wedge angles, depths, and field sizes. For the 15 degrees and 30 degrees wedges, the relative wedge factor at depths less than 15 cm were found to deviate less than +2% for all fields, while those for the 45 degrees and 60 degrees wedges for the same depth range from +3% to +4%. The surface doses were found to decrease with the wedged fields. For 15 degrees, 30 degrees, and 45 degrees wedges, the decreases were found to be from 0 to -2.0%. For 60 degrees wedges, the largest deviation was found to be -2.5% for a field size of 10 cm x 10 cm at a depth of 2 mm. The wedge factors at dmax were found to depend slightly on the field sizes. The use of an averaged wedge factor for each individual wedge was found to produce less than +/- 1.2% of error for all field sizes.

Continuous succinylcholine infusion and phase II block in short surgical procedures

The study was designed to observe continuous succinylcholine infusion and phase II block in short surgical procedures (duration < 90 min). The characteristics of neuromuscular blockade produced by continuous succinylcholine infusion were observed in 15 adult patients anesthetized with nitrous-oxide-isoflurane (0.7% end tidal concentration) and fentanyl, and were compared with the single-dose technique (n = 13) in recovery time. Ulnar nerve was stimulated supramaximally with repeated train-of-four (interval = 10 sec, frequency = 2 Hz) via surface electrodes at the wrist using an electromyographic monitor (Datex, Relaxograph, Finland). The infusion rate was adjusted to maintain the height of the first twitch (T1) in each train of four at 5-10% of control twitch height. The mean duration of infusion was 50.74 +/- 18.06 minutes. The steady state infusion rate required to maintain 90% to 95% twitch depression was 83.5 +/- 21.4 micrograms/kg/min. Five patients developed phase II block (T4/T1 < 0.5) designated as IB. The other ten did not develop phase II block as IA. Recovery times (T1 = 10.50%, 10-100%) between IA and IB were not statistically significantly different. The recovery time of train-of-four fade (T1 = 10% to T1 = 100% and train of four > 75%) was 5.73 +/- 0.43 minutes. However, recovery times between continuous infusion group and single dose group were significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)