Primate renal transplants using immunotoxin

BACKGROUND

T-lymphocyte depletion 7 days before transplantation with immunotoxin FN 18-CRM9 has resulted in tolerance to subsequent renal allografts. We tested the effect of giving immunotoxin on the day of the transplantation and evaluated its effect on rhesus monkey and allograft survival, on antibody production, and on T-cell recovery.

METHODS

Major histocompatibility complex mismatched renal allografts were performed in rhesus monkeys. Immunotoxin was given starting on the day of transplantation, with and without prednisone and mycophenolate mofetil for 3 days. T-cell subsets and alloantibody levels were measured by flow cytometry. The ability of treated monkeys to develop antibody to tetanus, diphtheria, and xenoantibody was measured. Histology of renal transplants was read in a blinded manner.

RESULTS

Immunotoxin started on the day of transplantation resulted in prolonged allograft survival in all treatment groups. Graft loss between days 50 and 135 was most often due to interstitial nephritis. Later graft loss was due to chronic rejection. Monkeys had intact antibody responses to alloantigen, tetanus, diphtheria, and xenoantibody. Their CD4 cells recovered gradually over 6 months.

CONCLUSIONS

Immunotoxin reliably prolongs renal allograft survival when started on the day of transplantation, but interstitial nephritis and chronic rejection limit the development of long-term tolerance. T-cell-dependent B-cell responses remain intact after treatment.

Analysis of primate renal allografts after T-cell depletion with anti-CD3-CRM9

BACKGROUND

FN18-CRM9 is a CD3-specific immunotoxin that is capable of depleting CD3+ T cells. Pretreatment of rhesus monkeys with this agent before transplantation can induce donor-specific tolerance and "split tolerance" to renal allografts.

METHODS

Heterotopic renal transplants were performed on monkeys that received posttransplant FN18-CRM9. Histological and immunohistological staining, as well as analysis of the intragraft cytokine profile by reverse transcriptase polymerase chain reaction, was performed on percutaneous allograft biopsies.

RESULTS

Experimental monkeys had significant prolongation of allograft survival. Although an interstitial, mononuclear cell infiltrate was seen in all of the renal transplants, there was minimal evidence of acute cellular rejection. Histological evidence of alloantibody-mediated damage was detected 3 to 5 months after transplantation in the monkeys treated with FN18-CRM9. Immunohistology demonstrated the reappearance of CD3+ and CD4+ T cells, as well as CD20+ B cells, in the grafts. Cytokine analysis demonstrated expression of interferon-gamma. An intact anti-donor IgG response was seen.

CONCLUSION

Treatment of monkeys with FN18-CRM9 immediately after transplantation significantly prolongs renal allograft survival. Allograft biopsies demonstrate a lack of acute cellular rejection; however, alloantibody-mediated graft damage and rejection occur, with an intact anti-donor IgG response. The intragraft expression of the interferon-gamma may reflect this ongoing humoral rejection. These data suggest that even a brief period of T-cell allosensitization may lead to humorally mediated allograft damage. Efforts to achieve tolerance with posttransplant FN18-CRM9 will require modification of the protocol to deplete T cells before allosensitization exposure or to supplement the posttransplant immunomodification strategy.

Choosing reconstruction after mastectomy: a qualitative analysis

PURPOSE/OBJECTIVES

To describe women's perspectives on factors that influenced their decision to have reconstructive surgery after a breast cancer diagnosis.

DESIGN

Exploratory, descriptive, qualitative study.

SETTING

A comprehensive cancer center in an urban setting.

SAMPLE

Eleven women who underwent mastectomy and reconstruction. Six participants had autologous transverse rectus abdominis musculocutaneous-flap reconstruction, four had saline implants, and one had a silicone implant. All but one reconstruction was performed at the time of mastectomy.

METHODS

Open-ended, face-to-face interviews using an interview guide were conducted within one month of reconstruction. One to two follow-up interviews were conducted approximately six months later.

MAIN RESEARCH VARIABLES

Decision making about reconstruction, perceptions of information needs and sources, sources of support, and factors important to decision making.

FINDINGS

The main theme identified was Getting My Life Back. The participants described this in terms of the themes of Information Seeking, Talking It Over, and Seeking Normality. The interactive skills of the healthcare provider played an important role in the women's decision making.

CONCLUSIONS

Reconstruction minimized the negative consequences of breast cancer and its treatment for the women in the study. The decision-making process was aimed at getting the person's life back as close to what it was before the diagnosis as possible or improving it. The three themes of decision making are interactive in nature, with participants returning to information Seeking and Talking It Over as necessary to increasing their understanding and clarifying their "normality goals."

IMPLICATIONS FOR NURSING PRACTICE

Healthcare professionals should determine how a woman wants to participate in decision making as well as the kind, amount, and sources of information the individual with breast cancer wants to have to make her decisions. Healthcare providers are key sources of information about treatment options, and they are critical to patient satisfaction with the decision-making process and with the final results of the surgical procedure. Family members, friends, and other women with breast cancer play a crucial role in talking it over.

Computed tomographic angiography with three-dimensional reconstruction in patients with complex diverticular disease and portal hypertension: report of a case

We report a case of a patient with portal hypertension secondary to alcoholic cirrhosis (Child's Class C) who initially presented with a colovaginal fistula secondary to acute sigmoid diverticulitis. The patient had a prior history of hepatic cirrhosis with ascites, coagulopathy, and portal hypertension. Computed tomography of the abdomen and pelvis demonstrated a large diverticular phlegmon and ascites. Computed tomographic angiography demonstrated a large left anterior abdominal wall varix in the region of the anticipated sigmoid resection. Three-dimensional reconstruction of the computed tomographic angiography further delineated the path of this large varix, confirming the increased risk from surgical intervention. Following initial conservative treatment with intravenous antibiotics, parenteral nutrition, and percutaneous abscess drainage, a transjugular intrahepatic portosystemic shunt procedure was performed to decompress the portal system varices. A repeat computed tomographic scan with three-dimensional reconstruction confirmed decompression of the varix. A successful sigmoid resection was subsequently performed. Preoperative computed tomographic angiography with three-dimensional reconstruction is a useful adjunct in planning the operative strategy in patients with complex intraabdominal pathology and collateral portovenous flow secondary to portal hypertension.

Peak oxygen uptake and maturation in 12-yr olds

The influences of gender and sexual maturation on the peak VO2 of 12-yr olds were examined. Subjects were 106 boys and 106 girls, ages 12.2 +/- 0.4 yr. The sexual maturity of 93 boys and 83 girls was classified according to Tanner's indices of pubic hair. No significant gender differences (P > 0.05) were detected in age, stature, or hemoglobin concentration. Peak VO2 was determined on a treadmill and boys' peak VO2 was significantly higher (P < 0.01) than girls' whether expressed in L x min(-1) (2.10 +/- 0.34 vs 1.92 +/- 0.28) or mL x kg(-1) x min(-1) (52 +/- 6 vs 44 +/- 5). With body mass controlled for using log-linear ANCOVA, the gender difference decreased from 18.2 to 17.1% but remained significant (P < 0.01). For peak VO2 (L x min[-1]) ANOVA revealed no significant interaction (P > 0.05) but significant (P < 0.01) main effects for both gender and maturation. For peak VO2 in ratio with body mass (mL x kg(-1) x min[-1]), ANOVA detected no significant interaction (P > 0.05) or significant main effect (P > 0.05) for maturation although the main effect for gender was significant (P < 0.01). Analysis of peak VO2 with body mass controlled for using log-linear ANCOVA revealed no significant interaction (P > 0.05) but main effects (P < 0.01) for both gender and maturation. Thus, gender differences, which are not simply explained by differences in body size or hemoglobin concentration, have been demonstrated in the peak VO2 of 12-yr olds. A log-linear scaling model has identified in both boys and girls a significant influence of maturation on peak VO2 independent of body mass. This effect may have been masked in previous studies by the inappropriate use of peak VO2 in ratio with body mass.

Prepubescents' ventilatory responses to exercise with reference to sex and body size

STUDY OBJECTIVES

To examine the ventilatory responses of prepubescent children to submaximal and peak exercise using appropriate allometric modeling to control for differences in body size.

DESIGN

Cross-sectional study of a representative sample of children.

SETTING

Middle schools (8 to 11 years) in Exeter, UK.

PARTICIPANTS

We studied 101 boys and 76 girls aged 11.1 (0.4) years and classified Tanner stage 1 for pubic hair (no true pubic hair).

MEASUREMENTS

At rest: stature, mass, sum of skinfolds, hemoglobin concentration, FVC, and FEV1. During treadmill exercise at 7, 8, 9, and 10 km/h, and at peak exercise: oxygen uptake (VO2), minute ventilation (VE), tidal volume (VT), and respiratory frequency (Rf).

RESULTS

At peak exercise, boys' VO2, VE, and VT were significantly (p<0.01) higher than girls' values and remained so even when the influence of body size was controlled using allometric principles. There were no significant (p>0.05) sex differences in Rf or the ratios VT/FVC or VE/VO2. When data were compared at the same relative exercise intensity (ie, 70 to 75% or 80 to 85% peak VO2), no significant (p>0.05) sex differences in Rf, VT/FVC, or VE/VO2 were detected. Boys' higher (p<0.001) VO2 values were reflected by their higher VE which remained higher than values for girls at both submaximal levels even when the influence of body size was covaried out.

CONCLUSIONS

Prepubescent boys demonstrate higher peak VO2 than girls and this is supported by a higher VE and VT, even when the influence of body size is accounted for using allometry. Other ventilatory responses to both peak exercise and exercise at the same relative intensity are remarkably similar in both boys and girls.

Expression of naked plasmid DNA injected into the afferent and efferent vessels of rodent and dog livers

A variety of reporter genes within plasmid constructs were injected into the afferent and efferent vessels of the liver in mice, rats, and dogs. Efficient plasmid expression was obtained following delivery via the portal vein, the hepatic vein, and the bile duct. The use of hyperosmotic injection solutions and occlusion of the blood outflow from the liver substantially increased the expression levels. Combining these surgical approaches with improved plasmid vectors enabled uncommonly high levels of foreign gene expression in which over 15 microg of luciferase protein/liver was produced in mice and over 50 microg in rats. Equally high levels of beta-galactosidase (beta-Gal) expression were obtained, in that over 5% of the hepatocytes had intense blue staining. Expression of luciferase or beta-Gal was evenly distributed in hepatocytes throughout the entire liver when either of the three routes were injected. Peri-acinar hepatocytes were preferentially transfected when the portal vein was injected in rats. These levels of foreign gene expression are among the highest levels obtained with nonviral vectors. Repetitive plasmid administration through the bile duct led to successive events of foreign gene expression. The integration of these findings into laboratory and clinical protocols is discussed.

Responses of young girls to two modes of aerobic training

OBJECTIVES

To investigate the physiological effects of two different three times a week, eight week training programmes on the aerobic fitness of nine to ten year old girls.

METHODS

Treadmill determined peak VO2, submaximal heart rates, and submaximal blood lactate were the criterion measures. Seventeen girls completed a programme of "aerobics" training where sessions lasted 20-25 minutes. Eighteen girls followed a cycle ergometer training programme which involved pedalling continuously for 20 minutes with the heart rate maintained between 160 and 170 beats/minute. A control group of 16 girls completed the criterion tests but did not train. In the cycle ergometer group and eight control subjects plasma total cholesterol and high density lipoprotein cholesterol were determined before and after training.

RESULTS

Peak VO2 did not change significantly with training in either training group, neither were there any significant changes in submaximal heart rates. Blood lactate declined significantly at the two lowest submaximal exercise intensities in the cycle ergometer training group (from 2.3 (1.1) to 1.4 (0.06) mmol/l at stage 1 and from 2.1 (1.2) to 1.6 (0.06) mmol/l at stage 2; means (SD); P < 0.01). Total cholesterol and high density lipoprotein cholesterol remained unchanged with training.

CONCLUSIONS

These findings suggest that an eight week structured exercise programme produces minimal changes in either the aerobic fitness or blood lipids of young girls. It may be more beneficial for long term health to promote enjoyment in activity and positive attitudes to exercise rather than attempting to enhance aerobic fitness through strenuous exercise programmes.

Effect of training on the aerobic power and anaerobic performance of prepubertal girls

The purpose of this study was to investigate the effects of two, three times a week, 8-week training programmes on the aerobic power and anaerobic performance of 30 prepubescent girls, with a mean age of 9.6 y. Peak oxygen uptake assessed by an incremental discontinuous treadmill test, and peak power in 5 s and mean power over 30 s estimated from a Wingate anaerobic test were used as the criterion measures. Twelve girls trained using a continuous cycle ergometer programme, 11 girls followed a sprint running programme and the control group consisted of 7 girls. Both training groups significantly (p < 0.05) increased their peak oxygen uptake and peak power in 5 s. However, the increase reported here are lower than those generally observed in adolescents following training. The control group demonstrated no significant (p > 0.05) change in either variable. No significant (p > 0.05) changes in mean power over 30 s were observed in any group.

Short-range cell-cell signals control ectodermal patterning in the oral region of the sea urchin embryo

The ectoderm of the sea urchin embryo has been a useful system for understanding how regions of a simple epithelium are specified during early development, as well as how pattern formation leads to the correct localization of mesenchyme cells during morphogenesis. This study examines cell-cell signals that regulate precise patterning of ectoderm within the oral region of embryos of the sea urchin, Lytechinus variegatus. The oral ectoderm contains at least two types of patterned tissues: (1) the ectoderm that forms the stomodeum and (2) ectoderm expressing pattern information required for formation of parallel oral skeletal rods by primary mesenchyme cells (PMCs). Using microsurgical isolations and cell transplantation, we show (1) that cell-cell signaling is capable of producing new oral ectodermal structures until immediately prior to the gastrula stage, (2) that the presumptive oral ectoderm is not committed to produce oral structures until the early gastrula stage, (3) that oral ectodermal patterning cues for PMCs are highly local in character, and (4) that interactions between the tip of the archenteron and the presumptive oral ectoderm are not required for the differentiation of cells within either tissue. These studies suggest that short-range cell-cell signals within the ectoderm are involved in specifying regionalized oral ectodermal tissues immediately prior to gastrulation, and that this patterned ectoderm then influences the localization of skeletogenic mesenchyme cells in the oral region.

Exercise performance and magnetic resonance imaging-determined thigh muscle volume in children

This study examined the relationships between thigh muscle volume (TMV) and aerobic and anaerobic performance in children. A total of 32 children, 16 boys and 16 girls, aged 9.9 (0.3) years completed a treadmill running test to exhaustion for the determination of peak oxygen uptake (peak VO2) and a Wingate Anaerobic Test (WAnT) for the determination of peak power (PP) and mean power (MP). The volume of the right thigh muscle was determined using magnetic resonance imaging. TMV was not significantly different in boys and girls [2.39 (0.29) l vs 2.18 (0.38) l, P > 0.05]. Peak VO2 and MP were significantly higher in boys than girls (P < 0.01) whether expressed in absolute, mass-related or allometrically scaled terms. Absolute PP was not significantly different in boys and girls but mass-related and allometrically scaled values were higher in boys (P < 0.01). TMV was correlated with absolute peak VO2, PP and MP in both sexes (r = 0.52-0.89, P < 0.01). In boys, mass-related PP was correlated with TMV (r = 0.53, P < 0.01), and in girls mass-related peak VO2 was correlated with TMV (r = -0.61, P < 0.01). However, in neither sex were allometrically scaled peak VO2, PP or MP correlated with TMV (P > 0.05). There were no significant differences between boys and girls in terms of peak VO2, PP or MP when expressed in a ratio to TMV or allometrically scaled TMV. In conclusion, this study has demonstrated that, when body size is appropriately accounted for using allometric scaling, TMV is unrelated to indices of aerobic and anaerobic power in 10-year-old children. Furthermore, there appear to be no qualitative differences in the muscle function of boys and girls in respect of aerobic and anaerobic function.

Is peak VO2 a maximal index of children's aerobic fitness?

A levelling of oxygen uptake (VO2 plateau) at high exercise intensities is conventionally used as the criterion for establishing VO2max during progressive, incremental exercise testing. Only a minority of children, however, demonstrate a VO2 plateau during exercise to voluntary exhaustion. This study was therefore designed to investigate whether a VO2 plateau is required before peak VO2 can be considered a maximal index of children's aerobic fitness. Eighteen girls and 17 boys (age 9.9 +/- 0.4 yrs) carried out three treadmill tests to exhaustion one week apart. The first test comprised a discontinuous, incremental protocol to voluntary exhaustion. In test two each child warmed up and then ran to exhaustion at the same belt speed but on a gradient 2.5% greater than that which had produced an exhaustive effort on the first test. The third test was conducted similarly but the treadmill gradient was raised to 5% greater than that which had produced an exhaustive effort on the first test. Seven girls and 6 boys demonstrated a VO2 plateau (< or = 2 ml.kg-1.min-7) on the first test but no significant differences in either anthropometrical or peak physiological data were detected between those who demonstrated a plateau and those who did not. Mean peak VO2 values during tests two and three (supramaximal tests) did not increase significantly above that achieved on test one although indicators of an increased anaerobic contribution were significantly higher in both supramaximal tests. These findings indicate that peak VO2 in test one was a maximal value despite the absence of a VO2 plateau. The requirement of a VO2 plateau before peak VO2 can be regarded as a maximal index of young children's aerobic fitness is therefore untenable.

Scaling peak VO2 for differences in body size

This paper examined the influence of different statistical modeling techniques on the interpretation of peak VO2 data in groups of prepubertal, circumpubertal, and adult males (group 1M, N = 29; group 2M, N = 26; group 3M, N = 8) and females (group 1F, N = 33; group 2F, N = 34; group 3F, N = 16). Conventional comparisons of the simple per-body-mass ratio (ml.kg-1.min-1) revealed no significant differences between the three male groups (P < 0.05). In females, a decline in VO2 between group 2F and 3F was observed (P < 0.05). Both linear and log-linear (allometric) models revealed significant increases across all three male groups for peak VO2 adjusted for body mass (P < 0.05). In females these scaling models identified a significantly lower peak VO2 in group 1F versus groups 2F and 3F (P < 0.05). Based upon the common mass exponent identified (b = 0.80, SE = 0.04), power function ratios (y.mass0.80) were generated and the logarithms of these compared. Again, results indicated a progressive increase in peak VO2 across groups 1M to 3M (P < 0.05) and an increase between groups 1F and 2F (P < 0.05). Incorporating stature into the allometric equation reduced the mass exponent to 0.71 (SE = 0.06) with the contribution of the stature exponent shown to be 0.44 (SE = 0.20). These results indicate that conventional ratio standards do not adequately account for body size differences when investigating functional changes in peak VO2.

Peak oxygen uptake of 12-18-year-old boys living in a densely populated urban environment

The purposes of this study were to provide data on the peak VO2 of 12-18-year-old boys from Hong Kong, a densely populated urban environment; to compare these data with those for other similarly aged populations; and to examine the correlations between peak VO2 and various anthropometric parameters of this group. A stratified, random sample of 86 ethnic Chinese boys had their peak VO2 determined using an on-line gas analysis system during incremental, treadmill running. The mean peak VO2 of the boys was 2.7 SD 0.44 l.min-1 or, when expressed in relation to body mass, 52.0 SD 5.8 ml.kg-1.min-1. Peak VO2 (l.min-1) was significantly correlated with body mass (r = 0.72, p < 0.001, age (r = 0.49, p < 0.001) and height (r = 0.71, p = 0.001). Peak VO2 (ml.kg-1.min-1) showed no correlation with age or height. These data suggest that this population group has peak VO2 values very similar to those observed in boys from most other population groups.

Aerobic fitness of prepubescent children

This study was designed to enhance understanding of the assessment and interpretation of the aerobic fitness of prepubertal children. Written informed consent to participate was obtained from 70% of the children in year six of the 15 state schools in the city of Exeter. Twenty-five per cent of the eligible children in each school were randomly selected from those who volunteered. The data reported here are those obtained from the 111 boys (11.1 SD 0.4 years) and 53 girls (10.9 SD 0.3 years) classified as Tanner stage 1 in both pubic hair rating and either genitalia rating (boys) or breast rating (girls). Peak oxygen uptake (peak VO2) was determined using a discontinuous, incremental protocol on a treadmill. Only a minority of children demonstrated a levelling-off or plateau in VO2 despite an increase in exercise intensity. There was no evidence to suggest that the children who demonstrated a VO2 plateau had significantly (p < 0.05) higher peak VO2, peak heart rate, peak respiratory exchange ratio or peak blood lactate than those children who did not demonstrate a plateau in VO2. These findings indicate that a VO2 plateau should not be used as a requirement for defining a maximal exercise test with prepubertal children. Boys had a significantly (p < 0.01) higher peak VO2 than girls, whether expressed in 1.min-1 (1.78 vs 1.46) or in relation to body mass (51 vs 45 ml.kg-1.min-1). The results compare favourably with those of similarly aged children from other countries, but why prepubescent boys have significantly higher (13.3%) mass-related peak VO2 than prepubescent girls is not readily apparent. Although conventional, the expression of peak VO2 as per body mass ratio may not adequately partition out body-size differences. The influence of body mass was therefore removed using a linear adjustment scaling model and a log-linear model, but the boys' peak VO2 remained significantly (p < 0.01) higher than the girls' peak VO2 with the difference now being 16.0% and 16.2%, respectively.

Child-adult differences in whole blood lactate responses to incremental treadmill exercise

The aim of this study was to evaluate whether fixed blood lactate reference values of 2.5 and 4.0 mmol.1(-1) corresponded to the equivalent intensity of exercise in prepubertal and teenage boys, and men. Twenty six prepubertal boys (mean(sd) age) 11.1(0.4) years), 26 teenage boys (mean(sd) age 14.1(0.3) years), and 23 men (mean(sd) age 22.4(2.7) years) gave informed consent to participate in the study. Oxygen consumption (VO2) and heart rates (HR) corresponding to the 2.5 and 4.0 mmol.1(-1) fixed blood lactate reference values were used as the criterion measures during incremental treadmill exercise. At the 2.5 mmol.1(-1) level there were no significant differences (P > 0.05) in % peak VO2 between groups. For both prepubertal and teenage boys the 4.0 mmol.1(-1) lactate level represented a higher mean % peak. VO2 than for the mean (P < 0.05). The prepubertal and teenage values were again not significantly different (P > 0.05). Factors other than maturation during puberty influence blood lactate responses to exercise.

High and low exercisers among 14- and 15-year-old children

To investigate ways in which young people's attitudes about, and motivation for, exercise vary with the levels of exercise they take, a self-completed questionnaire was given to 382 children aged 14-15 in two secondary schools in Devon. It was found that the high exercisers (defined by those in the highest quartile) had attitudes to exercise which were more favourable, received more encouragement to exercise and encouraged others to exercise more. The majority of low exercisers had positive beliefs about the value of exercise although approximately half in boys and one-third in girls were satisfied with the amount and kind of exercise they undertook. Low-exercising boys and girls at all exercise levels preferred their exercise to be noncompetitive. The majority of both sexes accepted that their future health depended on their current behaviour and, in girls, strength of this belief was directly related to exercise level. It may be concluded that advice to young people and physical education programmes in schools should take account of the attitudes and beliefs about exercise held by pupils of all physical abilities.

Children's task and ego goal profiles in sport

The purpose of this study was to examine the combined effects of task and ego goal orientations on children's sport motivation. Participants were 115 boys and 116 girls (mean age = 11.12 yrs). Unlike previous research, where the correlates of the two orientations have been examined separately, this study examined the motivational consequences of different task and ego combinations. Four groups were created based on mean splits on the task and ego scales of the Task and Ego Orientation in Sport Questionnaire. These were low task/low ego, low task/high ego, high task/low ego, and high task/high ego. The hi/hi group emerged as the most motivated and the lo/lo group least motivated in measures of sport enjoyment and perceived sport competence. The lo/lo group, made up primarily of girls, appear to be at high risk for non-participation in sport. Children dominated by a task orientation were more motivated than those dominated by an ego orientation. A similar pattern emerged whether children were in the lower or upper third of the perceived sport competence distribution. A high task orientation appears to provide the vital element for sport motivation. The addition of ego involvement to task involvement may enhance sport enjoyment and does not appear to be motivationally detrimental. Task and ego profile analysis seems to offer important insight into the achievement motivation of children of this age.