Renal Transplantation in Children Treated with Continuous Ambulatory Peritoneal Dialysis

Over the last three years 23 children, who were managed by CAPD at the Hospital for Sick Children, Toronto received a renal transplant. Their actuarial graft survival was similar to those of children on hemodialysis and to patients not dialyzed before transplantation. In addition, we analyzed the actuarial graft survival of 130 children treated before transplantation with peritoneal dialysis (IPD and CAPD), hemodialysis or no dialysis to determine the long-term effects of peritoneal dialysis. Again, we found no significant differences among the various groups. Posttransplantation complications in the CAPD patients included fungal peritonitis in one and ascites in seven.

Observation of edge instability limiting the pedestal growth in tokamak plasmas

With fusion device performance hinging on the edge pedestal pressure, it is imperative to experimentally understand the physical mechanism dictating the pedestal characteristics and to validate and improve pedestal predictive models. This Letter reports direct evidence of density and magnetic fluctuations showing the stiff onset of an edge instability leading to the saturation of the pedestal on the Alcator C-Mod tokamak. Edge stability analyses indicate that the pedestal is unstable to both ballooning mode and kinetic ballooning mode in agreement with observations.

Blackawton bees

BACKGROUND

Real science has the potential to not only amaze, but also transform the way one thinks of the world and oneself. This is because the process of science is little different from the deeply resonant, natural processes of play. Play enables humans (and other mammals) to discover (and create) relationships and patterns. When one adds rules to play, a game is created.

THIS IS SCIENCE

the process of playing with rules that enables one to reveal previously unseen patterns of relationships that extend our collective understanding of nature and human nature. When thought of in this way, science education becomes a more enlightened and intuitive process of asking questions and devising games to address those questions. But, because the outcome of all game-playing is unpredictable, supporting this 'messyness', which is the engine of science, is critical to good science education (and indeed creative education generally). Indeed, we have learned that doing 'real' science in public spaces can stimulate tremendous interest in children and adults in understanding the processes by which we make sense of the world. The present study (on the vision of bumble-bees) goes even further, since it was not only performed outside my laboratory (in a Norman church in the southwest of England), but the 'games' were themselves devised in collaboration with 25 8- to 10-year-old children. They asked the questions, hypothesized the answers, designed the games (in other words, the experiments) to test these hypotheses and analysed the data. They also drew the figures (in coloured pencil) and wrote the paper. Their headteacher (Dave Strudwick) and I devised the educational programme (we call 'i,scientist'), and I trained the bees and transcribed the childrens' words into text (which was done with smaller groups of children at the school's local village pub). So what follows is a novel study (scientifically and conceptually) in 'kids speak' without references to past literature, which is a challenge. Although the historical context of any study is of course important, including references in this instance would be disingenuous for two reasons. First, given the way scientific data are naturally reported, the relevant information is simply inaccessible to the literate ability of 8- to 10-year-old children, and second, the true motivation for any scientific study (at least one of integrity) is one's own curiousity, which for the children was not inspired by the scientific literature, but their own observations of the world. This lack of historical, scientific context does not diminish the resulting data, scientific methodology or merit of the discovery for the scientific and 'non-scientific' audience. On the contrary, it reveals science in its truest (most naive) form, and in this way makes explicit the commonality between science, art and indeed all creative activities.

PRINCIPAL FINDING

'We discovered that bumble-bees can use a combination of colour and spatial relationships in deciding which colour of flower to forage from. We also discovered that science is cool and fun because you get to do stuff that no one has ever done before. (Children from Blackawton)'.

Mutational analysis of the HIV-1 LTR as a promoter of negative sense transcription

The HIV-1 gene promoter is a bi-directional promoter of transcription. We report the characterization of the negative sense promoter (NSP) by analysis of the effect on negative sense transcription of a series of LTR U3 region substitution mutants. Mutations in the region nt -58 to -183 (positive sense transcription initiation nt +1) reduced transcription to <15% of wild type NSP activity. This region, essential for NSP activity, was designated the core basal promoter. Over expression of NF-kappaB RelA(p65) and LEF-1 increased negative sense expression, as did over expression of H-ras oncogene, consistent with the presence of cognate sequence motifs for NF-kappaB, LEF-1 and RBF. We were also able to confirm that the NSP is a TATA-less promoter inhibited by HIV-1 Tat. Based on our findings, we propose a model for the interaction between the NSP and PSP, and the role of Tat in regulating the interaction.

Inhibition of intestinal tumors by curcumin is associated with changes in the intestinal immune cell profile

BACKGROUND

The C57BL/6J-Min/+ (Min/+) mouse bears a germline mutation in Apc and is therefore a model for familial adenomatous polyposis and sporadic colorectal cancer. Min/+ intestinal mucosa exhibits a marked tendency for spontaneous adenoma formation. Curcumin is a phenolic antioxidant known for its antitumor and immune modulatory functions in vitro. Curcumin prevents adenoma formation in Min/+ mice, through a mechanism that may be related to its immunomodulatory properties.

MATERIALS AND METHODS

To study the relationship between intestinal immunity and curcumin-induced antitumor response, we used immunohistochemistry to characterize the effect of curcumin treatment on resident intestinal immune effector cells in Min/+ mice.

RESULTS/CONCLUSION

These results show that mucosal CD4(+) T cells and B cells increase in animals treated with curcumin, suggesting that curcumin modulates lymphocyte-mediated immune functions.

The effects of housing enrichment on cardiovascular parameters in spontaneously hypertensive rats

By using radiotelemetry, we measured blood pressure, heart rate, and locomotor activity in adult male spontaneously hypertensive (SHR) rats during three consecutive periods in which they received various social and non-social cage enrichments. The objective was to determine whether these enriching experiences would affect cardiovascular parameters. During the first period, the readings from four individually housed males, each with a telemetry transmitter in the abdominal cavity and connected to a femoral artery catheter, were compared to those from five similarly instrumented rats that were each housed with another rat. Systolic blood pressure and activity but not diastolic blood pressure or heart rate were higher in rats housed with another rat compared to those housed alone. During the second period, each cage of animals was enriched by including a large piece of plastic drainpipe and several golf balls. In addition, the nine animals were placed together daily for two hours at the beginning of the dark phase of the photoperiod in a large, three-tiered enclosure containing a running wheel, several lengths of plastic drainpipe, and multiple golf balls. Systolic and diastolic blood pressures but not heart rate or activity were higher in the double-housed rats than those housed alone. During the last period, the rats previously housed with another rat were switched to single housing, and those previously housed alone were placed with another rat. The daily activity and cage enrichments were otherwise continued. Removal of a cage mate increased systolic blood pressure, diastolic blood pressure, and heart rate but not activity compared parameters in animals that were changed from single to double housing. During the entire experiment, activity and all cardiovascular parameters were increased during the dark phase compared to the light phase of the daily photoperiod. However, there was no statistically significant correlation between these circadian changes and the housing conditions. In summary, providing social enrichment in the form of another rat or non-social cage enrichment combined with a daily period of group housing and physical activity increased diastolic and/or systolic blood pressure of SHR rats. In addition, the loss of continuous social enrichment increased blood pressure and heart rate even when the other enrichments were continued. These changes were not always related to increased activity in the cage.

Treatment of early seropositive rheumatoid arthritis with minocycline: four-year followup of a double-blind, placebo-controlled trial

OBJECTIVE

Rheumatoid arthritis (RA) causes substantial morbidity and mortality, and current treatments are suboptimal. Recent studies have demonstrated the short-term efficacy of minocycline in the treatment of patients with early RA. This study was undertaken to compare patients treated with conventional therapy in the early phase of their RA and those treated with minocycline, after 4 years of followup.

METHODS

Forty-six patients with seropositive RA of <1 year's duration had been enrolled in a double-blind study of minocycline (100 mg twice daily) versus placebo. After the blinded portion of the study (3-6 months, depending upon response), all patients were treated with conventional therapy. This report compares those patients randomized to receive placebo for 3 months and then conventional therapy for the duration of 4 years versus those originally randomized to receive minocycline.

RESULTS

Twenty of the 23 original minocycline-treated patients and 18 of the 23 original placebo-treated patients were available for followup (mean 4 years). At followup, RA was in remission (American College of Rheumatology criteria) without disease-modifying antirheumatic drug (DMARD) or steroid therapy in 8 of the patients originally treated with minocycline compared with 1 patient in the placebo group (P = 0.02). Ten patients in the minocycline group versus 16 in the original placebo group currently require DMARD therapy (P = 0.02).

CONCLUSION

Among patients with seropositive RA, remissions are more frequent and the need for DMARD therapy is less in those treated early in the disease course with minocycline compared with those treated with conventional therapy delayed by an average of only 3 months. Minocycline appears to be an effective therapy for early RA; further investigation into its mechanism of action is needed.

Using a Therapy Dog to Alleviate the Agitation and Desocialization of People With Alzheimer's Disease

1. Short-term exposure to a therapy dog can reduce the number of agitation behaviors in institutionalized persons with Alzheimer's disease (AD), particularly during the period of agitation known as sundown syndrome. 2. The presence of a therapy dog can increase socialization behaviors among a group of persons with AD. 3. A therapy dog can be used as an adjunct to other calming interventions for persons with AD.

Administration of an unconjugated bile acid increases duodenal tumors in a murine model of familial adenomatous polyposis

Intestinal carcinogenesis involves the successive accumulation of multiple genetic defects until cellular transformation to an invasive phenotype occurs. This process is modulated by many epigenetic factors. Unconjugated bile acids are tumor promoters whose presence in intestinal tissues is regulated by dietary factors. We studied the role of the unconjugated bile acid, chenodeoxycholate, in an animal model of familial adenomatous polyposis. Mice susceptible to intestinal tumors as a result of a germline mutation in Apc (Min/+ mice) were given a 10 week dietary treatment with 0.5% chenodeoxycholate. Following this, the mice were examined to determine tumor number, enterocyte proliferation, apoptosis and beta-catenin expression. Intestinal tissue prostaglandin E2 (PGE2) levels were also assessed. Administration of chenodeoxycholate in the diet increased duodenal tumor number in Min/+ mice. Promotion of duodenal tumor formation was accompanied by increased beta-catenin expression in duodenal cells, as well as increased PGE2 in duodenal tissue. These data suggest that unconjugated bile acids contribute to periampullary tumor formation in the setting of an Apc mutation.

Isolated subluxation of the extensor pollicis longus tendon. A cause of 'boutonnière' deformity of the thumb

Isolated ulnar subluxation of the extensor pollicis longus (EPL) tendon occurs when there is damage to the radial side of the extensor hood on the dorsum of the metacarpophalangeal joint of the thumb. The thumb collapses into a pseudoboutonnière deformity because the EPL tendon subluxes and comes to lie palmar to the centre of rotation of the metacarpophalangeal joint to act as a flexor instead of an extensor. The extensor pollicis brevis tendon which lies in a deeper plane to the EPL is unaffected. We describe four cases and propose conservative treatment as being effective in recent injuries.

Treatment of early rheumatoid arthritis with minocycline or placebo: results of a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To determine if minocycline is an effective therapy for seropositive rheumatoid arthritis (RA) when used within the first year of disease.

METHODS

The Rheumatoid Arthritis Investigational Network enrolled 46 patients with RA of <1 year duration into a 6-month study of minocycline (100 mg twice daily) versus placebo. All patients were rheumatoid factor positive. The primary end point of the study was successful completion of 6 months of treatment with no drug toxicity while maintaining 50% improvement in composite symptoms of arthritis.

RESULTS

Eighteen of the 46 patients who were enrolled met 50% improvement criteria at 3 months, and maintained at least a 50% improvement for 6 months with no significant drug toxicity. Among them were 15 of the 23 patients (65%) treated with minocycline and 3 of 23 patients (13%) treated with placebo (P < 0.001).

CONCLUSION

In patients with early seropositive RA, therapy with minocycline is superior to placebo.

Regulation of thymus PCNA expression is altered in radiation-sensitive wasted mice

Mice bearing the autosomal recessive mutation 'wasted' (wst/wst) express a disease syndrome characterized by neurologic dysfunction, immunodeficiency, and increased sensitivity to the killing effects of ionizing radiation relative to normal littermates (wst/-) and to parental control mice (BCF1, BALB/c, and C57BL/6). Many of these abnormalities, evident as early as 21 days of age, have been localized to thymic tissues and T-lymphocyte populations. Comparison of two-dimensional gel electrophoresis patterns of proteins from wst/wst and control mouse thymus revealed that an acidic protein with a molecular mass of approximately 30 kDa was consistently expressed at lower levels in wasted mice than in controls. Microsequencing of this protein revealed a sequence of 19 N-terminal amino acids identical to the sequence of murine proliferating cell nuclear antigen (PCNA). Northern blot analyses of PCNA expression in thymus and spleen demonstrated lower accumulation of PCNA-specific transcripts in wasted mice compared with that in controls. Because PCNA expression is associated with cell cycle progression, the percentages of thymic and splenic cells in each stage of the cell cycle were examined; there were no differences in the cell stage distribution of lymphocytes freshly isolated from wasted mice compared with littermate or parental controls. After activation with concanavalin A, however, splenocytes from wst/wst mice showed a lower percentage of cells in S phase compared with that in controls. Southern blots with PCNA probes showed that the PCNA loci from the wasted mice and their normal littermates have the same restriction maps. While differences in polymerase chain reaction (PCR) priming were obtained, these could be attributed to strain-specific differences in mouse PCNA pseudogenes. These results suggest the presence of an alteration in the pathway leading to PCNA expression in radiation-sensitive tissues of wasted mice.

Matrix metalloproteinases and processing of pro-TNF-alpha

Tumor necrosis factor-alpha (TNF-alpha) is released from a cell membrane-anchored precursor by proteolytic cleavage. We have shown that broad spectrum synthetic inhibitors of matrix metalloproteinases (MMPs) prevent the processing of the TNF precursor but do not inhibit the release of other cytokines. Purified MMPs, stromelysin, matrilysin, collagenase, and the gelatinases can all cleave a recombinant pro-TNF substrate to yield mature TNF. MMP inhibitors prevent the rise in blood levels of TNF after endotoxin administration in rats and are effective in animal models of inflammatory disease such as adjuvant arthritis. Drugs that inhibit MMP action and TNF release show great promise for the treatment of autoimmune inflammatory diseases.

Processing of tumour necrosis factor-alpha precursor by metalloproteinases

Tumour necrosis factor-alpha (TNF-alpha) is a potent pro-inflammatory and immunomodulatory cytokine implicated in inflammatory conditions such as rheumatoid arthritis, Crohn's disease, multiple sclerosis and the cachexia associated with cancer or human immunodeficiency virus infection. TNF-alpha is initially expressed as a 233-amino-acid membrane-anchored precursor which is proteolytically processed to yield the mature, 157-amino-acid cytokine. The processing enzyme(s) which cleave TNF-alpha are unknown. Here we show that the release of mature TNF-alpha from leukocytes cultured in vitro is specifically prevented by synthetic hydroxamic acid-based metalloproteinase inhibitors, which also prevent the release of TNF-alpha into the circulation of endotoxin challenged rats. A recombinant, truncated TNF-alpha precursor is cleaved to biologically active, mature TNF-alpha by several matrix metalloproteinase enzymes. These results indicate that processing of the TNF-alpha precursor is dependent on at least one matrix metalloproteinase-like enzyme, inhibition of which represents a novel therapeutic mechanism for interfering with TNF-alpha production.

The non-operative management of radial head fractures: a randomized trial of three treatments

Ninety-eight consecutive patients with Mason type 1 and 2 radial head fractures were randomized into three treatment groups to compare early mobilization with immobilization in flexion and extension. Eighty-one patients were reviewed on average 25 months following fracture and assessed for pain, disability and range of movement. Loss of full extension was the most frequent restriction of movement and was found in 17 patients. Two patients had restricted flexion without limited extension. Patients immobilized in a flexion cast had a significantly reduced range of movement compared with patients immobilized in extension (P = 0.02). Nineteen patients had residual pain and again the flexion group fared worse than the extension group (P = 0.06). Results from early mobilization in a sling were not significantly different from the other two groups. Treatment of radial head fractures in flexion casts should be avoided.

SPECT Imaging in the Diagnosis of Meniscal Tears

Sixty patients scheduled for arthroscopy of a knee because of suspected meniscal tears had preoperative planar and single photon emission computed tomography (SPECT) radionuclide scans. A crescentic pattern of uptake on the SPECT transaxial view was used as a criterion for diagnosing a tear of a meniscus. The sensitivity of the investigation was 77%, specificity 74%, negative predictive value (NPV) 65%, positive predictive value (PPV) 83%, and accuracy 76%. Tears of the posterior horn of the cartilage were also associated with intense focal uptake on the transaxial view as well as increased equilibrium activity in the adjacent femoral condyle. When these appearances were included as additional criteria the sensitivity rose to 90%, NPV 81%, and accuracy 84%. This study confirms the usefulness of SPECT imaging in identifying meniscal tears.

Role of endothelium-derived nitric oxide in hemodynamic adaptations after graded renal mass reduction

The mediator(s) of the adaptive increases in renal blood flow (RBF) and glomerular filtration rate (GFR) after renal mass reduction have not been identified. The present studies were designed to investigate the role of endothelium-derived nitric oxide (EDNO) in the hemodynamic adaptations after graded renal mass reduction. The experiments were performed in rats that had undergone a sham reduction in renal mass, uninephrectomy (UNX), or 5/6 NX (UNX plus excision of both poles of the contralateral kidney) 3-4 wk before. Measurements of RBF, GFR, renal vascular resistance (RVR), mean arterial pressure (MAP), and plasma renin concentration (PRC) were obtained before and after administration of the EDNO synthesis inhibitor NG-monomethyl-L-arginine (L-NMMA). L-NMMA (50 mg/kg bolus plus 500 micrograms.kg-1.min-1 infusion) led to significant (P < 0.01) and comparable increases in MAP (mmHg) (P < 0.01) in sham rats (117 +/- 6 to 154 +/- 6), UNX rats (112 +/- 5 to 139 +/- 7), and 5/6 NX rats (116 +/- 5 to 149 +/- 7). RVR increased significantly in all three groups (P < 0.01). The resultant decrease in RBF (ml.min-1.kg-1) was similar in sham rats (34.9 +/- 2.6 to 23.8 +/- 1.6), UNX rats (43.9 +/- 3.6 to 27.3 +/- 2.8), and 5/6 NX rats (34.6 +/- 2 to 22.3 +/- 1.6) (P < 0.01 for all groups).(ABSTRACT TRUNCATED AT 250 WORDS)

Reversible compensatory hypertrophy in rat kidneys: morphometric characterization

Functional renal compensatory hypertrophy (RCH) in the uninephrectomized rat is completely reversible by transplantation in Brown Norway (BN) rats, while anatomic RCH is not. To determine the nephron element(s) responsible for persistent anatomic RCH, we performed morphometric analysis on perfusion fixed rat kidneys following renal function studies. In this model the function of renal transplants is not different from contralateral and unmanipulated control kidneys, and there is no histological evidence of rejection. Rats uninephrectomized for three or six weeks had larger glomeruli than controls, and after transplantation of a previously hypertrophied kidney into a rat with a normal or a solitary hypertrophied kidney, glomerular size returned to control levels. Increased glomerular capillary volume (CVCP) in kidneys with RCH was due to increased capillary length (LCP; 13.1 +/- 1.0 mm cf. 10.3 +/- 0.9, P < 0.01) without increase in capillary radius (RCP; 3.26 +/- 0.33 microM cf. 3.28 +/- 0.24). In contrast, return of CVCP to control levels in kidneys undergoing regression was associated with persistently elevated LCP (13.0 +2- 2.9 mm; native previously hypertrophied kidney; 12.2 +/- 0.9; transplanted previously hypertrophied kidney vs. 10.3 +/- 0.9, P < 0.01) and decreased RCP (2.79 +/- 0.10 microM and 2.73 +/- 0.09, cf 3.28 +/- 0.24, P < 0.01). RCH was associated with proportional increases in glomerular, tubular, and vascular-interstitial volumes while only elevated tubular volume persisted during regression. Altered glomerular capillary dimensions and increased tubular volumes acquired during renal RCH induced by unilateral nephrectomy persisted during complete functional regression.(ABSTRACT TRUNCATED AT 250 WORDS)

Streptozotocin-induced renal hemodynamic changes in isogenic Lewis rats: a kidney transplant study

Streptozotocin (STZ)-induced diabetes mellitus is associated with decreased renal clearances of inulin and p-aminohippurate (PAH). The present experiments were designed to determine whether STZ-induced renal hemodynamic changes are due to the drug per se, rather than to the diabetic state that it induces. Isogenic Lewis rats with native right and transplanted left kidneys were studied. In one group, kidney donors received 50 mg STZ/kg body wt on day 1 and transplantation was performed on day 4 (untreated recipients). On day 29, the inulin and PAH clearances of these nondiabetic recipients were, respectively, 0.94 +/- 0.04 and 2.58 +/- 0.11 ml.min-1 x g-1 for the transplanted left kidney (previously exposed to STZ) and 0.95 +/- 0.07 and 2.54 +/- 0.14 ml.min-1 x g-1 for the native right kidney (never exposed to STZ). In another group, recipients received STZ on day 1 and transplantation was performed on day 4 (untreated donors). On day 29, the inulin and PAH clearances of these diabetic recipients were, respectively, 0.62 +/- 0.04 and 1.46 +/- 0.11 ml.min-1 x g-1 for the transplanted left kidney (never exposed to STZ) and 0.61 +/- 0.05 and 1.42 +/- 0.08 ml.min-1 x g-1 for the native right kidney (previously exposed to STZ). We conclude that the diabetic state, rather than STZ, is responsible for the decreased renal clearances of inulin and PAH in this experimental model.

Reversible compensatory hypertrophy in transplanted brown Norway rat kidneys

Recently we described methods for optimizing the function of transplanted rat kidneys. In unilaterally nephrectomized recipients, one week after surgery, the left transplanted kidney was identical to the right native kidney with respect to wet weight and the clearances of inulin and para-aminohippuric acid (PAH). The goals of the present experiments were first, to extend the post-surgery period to three weeks (sufficient to allow hypertrophic changes), and second, to study function of transplanted hypertrophied kidneys. Genetically identical Brown Norway rats were used as donor and recipients. Three weeks after transplanting a normal kidney into a unilaterally-nephrectomized recipient, the transplanted kidney had a normal plasma flow and was identical to the contralateral native kidney with respect to wet weight and the clearances of inulin and PAH. Three weeks after transplanting a normal kidney into a bilaterally-nephrectomized recipient, the wet weight, inulin and PAH clearances, and plasma flow of the transplanted kidney were all higher than control, and not significantly different from those observed in unilaterally-nephrectomized control rats. Thus, transplanted and native kidneys exhibited the same degree of compensatory hypertrophy. Hypertrophied donor kidneys (that is, the donor rat had been unilaterally-nephrectomized three weeks previously) remained hypertrophied in bilaterally-nephrectomized recipients, but in unilaterally-nephrectomized recipients, they regressed towards normal (that is, the values of wet weight, inulin and PAH clearances and plasma flow were significantly less than those in rats with only one kidney) while the contralateral native kidney remained normal (values of wet weight and inulin and PAH clearances were not different from control).(ABSTRACT TRUNCATED AT 250 WORDS)

High osmolality-low pH flush solutions improve renal transplant function in rats

Although transplanting rat kidneys is an established microsurgical technique, inulin clearance is abnormally low, due to rejection and/or warm ischemia-induced damage. In the present studies, rejection was avoided by using inbred Brown Norway rats as donors and recipients. Donor kidneys were flushed with ice-cold solutions of various composition (saline, saline + 200 or 400 mM mannitol) and pHs (5.7, 6.4, and 7.4), and the kidneys were kept cold during transplantation into unilaterally nephrectomized recipients. Renal function was assessed by clearance techniques 1 week later. In control rats, with both native kidneys intact, the ratio of inulin clearance, left kidney to right kidney, was 0.99 +/- 0.02. In rats with a native right kidney and a transplanted left kidney that had been flushed with saline, the ratio was considerably lower (0.46 +/- 0.09). Adding 200 mM mannitol to the saline flush solution increased the ratio (0.89 +/- 0.09). In comparison, adding 200 mM mannitol and 5 mM phosphate buffer at pH 7.4 resulted in a somewhat lower ratio (0.80 +/- 0.09), whereas adding 200 mM mannitol and 5 mM phosphate buffer at pH 5.7 resulted in a higher ratio, one that was indistinguishable from control (0.97 +/- 0.09). Thus, in this latter group, the inulin clearances of the transplanted kidneys were identical to those of the contralateral native kidneys.

Anterolateral rupture of popliteal cysts in rheumatoid arthritis

Popliteal cysts occur commonly in both normal and arthritic knees. Most cysts are formed by distension of the medially situated semimembranosus bursa. Popliteus bursa distension occurs uncommonly as a lateral popliteal cyst. Two cases of rupture of lateral cysts which produced symptoms related to the anterolateral lower leg are reported. The difficulty of diagnosing the condition because of this unusual site of inflammation and subsequent management problems are discussed.

Kidney transplants in cyclosporine-treated Sprague-Dawley rats

Previous studies by others have shown that transplanted rat kidneys have abnormally low clearances of paraaminohippuric acid, inulin, and creatinine, due to rejection and/or to warm-ischemia-induced injury. In the present studies, randomly bred Sprague-Dawley rats were used as donors and recipients. The left kidneys of recipients were removed, and the right kidneys were left intact. Donor kidneys were flushed with an ice-cold hypertonic solution (150 mM NaCl, 200 mM mannitol, pH 6.4), and the kidneys were kept cold during surgery. Renal function was assessed 1 week later. The left transplanted kidneys in untreated recipients exhibited morphologic evidence of rejection, and the clearances of PAH and inulin were approximately 50% of those of the right native kidneys. CsA-treated rats did not reject the transplants, and the PAH and inulin clearances of the left transplanted kidneys were identical to those of the right native kidneys. Untreated and CsA-treated rats with both native kidneys intact served as controls. The amount of CsA given during the 7-day period produced no measurable change in renal function. This is the first demonstration of virtually normal hemodynamics in transplanted rat kidneys when randomly bred animals are used as donors and recipients. Moreover, the results indicate that if both rejection and warm ischemia are avoided, the presence of a functioning native kidney does not have a detrimental effect on the function of a transplanted kidney.

Renal effects of SK&F 82526 in anesthetized rats

Dopamine affects renal hemodynamics, renal tubular functions, and the secretion of renin. We have studied the renal effects of SK&F 82526 (an agonist which is selective for the DA1 subclass of dopamine receptors) in anesthetized rats. Infused intravenously at 0.005 mumol/min/kg, this drug increased renal plasma flow and the clearances of PAH and insulin, effects which are consistent with decreased renovascular resistance. Concomitantly, urine flow and K excretion increased, and Na excretion tended to increase. All these effects of SK&F 82526 were antagonized by intravenous metoclopramide (1 mumol/min/kg). Despite its diuretic effect and despite its lack of effect on arterial blood pressure, SK&F 82526 increased arterial plasma renin concentration, suggesting a stimulatory effect on renin secretory rate. Taken together, our results demonstrate that the renal effects of SK&F 82526 mimic those of dopamine.

Effects of conditioned stimulus preexposure on human electrodermal conditioning

Two experiments investigated the effects of conditioned stimulus (CS) preexposure on Pavlovian differential conditioning and extinction of the skin conductance response. In both experiments, half the subjects were exposed to 20 presentations each of the CS+ and CS-, and the other half were exposed to control stimuli. CS duration was 8 sec. The unconditioned stimulus in Experiment 1 (N = 48) was a 1000 Hz tone of 80 dB which signalled a reaction time requirement, and in Experiment 2 (N = 48), it was a 1 sec burst of white noise at 105 dB. The results of Experiment 1 indicated that no-preexposure groups displayed more CS+/CS- differentiation than preexposure groups during acquisition and more resistance to extinction, at least for the first interval anticipatory response. In addition, the results of Experiment 2 indicated that no-preexposure groups displayed more differentiation than preexposure groups in terms of the second interval anticipatory response. These data constitute a demonstration of the latent inhibition effect with human subjects, and imply that there is an intrinsic relationship between the orienting response and the conditioning process.

Effects of stimulus change on the electrodermal orienting response

This experiment (N = 48) examined recovery of the skin conductance response, following habituation training, to change in type of visual stimulus. Maher and Furedy (1979) have argued that the majority of such studies have not controlled for time, trial, or stimulus-specific effects. These variables were controlled in the present study by using no-change control groups and by counterbalancing training and test stimuli. Experimental groups received either shapes during training and a letter on the test trial (trial 41) or letters during draining and a shape on the test trial; control groups received either shapes or letters for 41 trials. Test trial response magnitude was larger in experimental than control groups, and the effect was independent of the nature of the test stimulus. In addition, responsiveness increased from the last block of training trials to the test trial for experimental groups, but not for control groups. These results demonstrate recovery of the skin conductance response to change per se.

Occurrence of renal pelvic refluxes during rising urine flow rate in rats and hamsters

Retrograde movements of urine into the renal pelvic space (pelvic refluxes) were studied in anesthetized Munich Wistar rats and hamsters. The urine was made green by a continuous i.v. infusion of lissamine green in saline, and the experimental kidney was either placed on a shallow trough or left in situ. The renal pelvis was exposed and illuminated with a fiber optic light, and urine movements were observed through the transparent but intact pelvic wall. Urine was collected from both kidneys in the rats. In both rats and hamsters, the inner medulla of the kidney was analyzed for solutes at the end of the experiment. The experimental procedures did not interfere with the normal function of the experimental kidney, and the results were the same in rats and hamsters. During constant urine flow, full refluxes did not occur. Urine either moved straight down the ureter after it exited from the ducts of Bellini or it briefly bathed the papillary tip. In rats, full pelvic refluxes started approximately 0.8 min after a bolus injection (0.5 ml of isosmotic saline, i.v.), at a time corresponding to a steep rise in urine flow (2 microliter.min-2.100 g body wt-1). Following increased infusion rate, full refluxes were associated with an increase in urine flow of 0.05 g microliter.min-2.100 g body wt-1. Full refluxes were also seen in the hamsters following a bolus injection or increased infusion rate. Increasing intrapelvic pressure by 1 cm H2O also caused full pelvic refluxes. When full refluxes occurred, urine came into contact with all areas of the renal pelvis. Because full pelvic refluxes occur only during rising urine flow, this mechanism would bring urine with decreasing osmolality into contact with the outer medullary areas facing the pelvic space.