Small bowel transplantation promotes bacterial overgrowth and translocation

Alterations in the symbiotic relationship between immunocompromised hosts and their resident gut microflora may lead to serious complications following small bowel transplantation (SBT). This study examined the effects of SBT and cyclosporine (CsA) immunosuppression on gut bacterial populations and translocation to the mesenteric lymph nodes. Sixty adult male meat-fed Lewis rats were divided into six groups: normal controls, CsA alone (24 mg/kg im qod), CsA carrier vehicle alone, isografts, isografts given CsA, and allografts given CsA. Rats were killed after 3 weeks and segments of small bowel and colon were harvested for quantitative tissue culture. Mesenteric lymph nodes and blood were cultured to identify translocation. Transplantation alone led to an increase in gram-negative aerobes from 2.6 to 4.6 colony forming units/100 mg tissue (P less than 0.05) in the distal ileum (transplanted segment). Eighty-four percent of transplanted animals receiving CsA had bacteria recovered from their mesenteric lymph nodes compared to none in controls (P less than 0.001) and 20% in isografts not receiving CsA (P less than 0.02). Intestinal transplantation alone appears to promote gram-negative overgrowth while the addition of CsA therapy facilitates translocation to the mesenteric lymph nodes and may predispose to gut-associated sepsis following SBT.

Synthesis, calcium-channel-blocking activity, and antihypertensive activity of 4-(diarylmethyl)-1-[3-(aryloxy)propyl]piperidines and structurally related compounds

A series of 4-(diarylmethyl)-1-[3-(aryloxy)propyl]piperidines and structurally related compounds were synthesized as calcium-channel blockers and antihypertensive agents. Compounds were evaluated for calcium-channel-blocking activity by determining their ability to antagonize calcium-induced contractions of isolated rabbit aortic strips. The most potent compounds were those with fluoro substituents in the 3- and/or 4-positions of both rings of the diphenylmethyl group. Bis(4-fluorophenyl)acetonitrile analogue 79 was similar in potency to bis(4-fluorophenyl)methyl compound 1. The methylene analogue of 1 (78) and derivatives of 1 that contained a hydroxyl (76), carbamoyl (80), amino (81), or acetamido (82) substituent on the methyl group were less potent. In most cases, substituents on the phenoxy ring, changes in the distance between the aryloxy group and the piperidine nitrogen, and the substitution of S, N(CH3), or CH2 for the oxygen atom of the aryloxy group had only a small to moderate effect on the potency. The best compounds in this series were more potent than verapamil, diltiazem, flunarizine, and lidoflazine, but were less potent than nifedipine. Compounds were evaluated for antihypertensive activity in spontaneously hypertensive rats (SHR) at an oral dose of 30 mg/kg. Of the 55 compounds tested, only nine produced a statistically significant (p less than 0.05) reduction in blood pressure greater than 20%; all of these compounds had fluoro substituents in both rings of the diphenylmethyl group. One of the most active compounds in the SHR at 30 mg/kg was 1-[4-[3-[4-[bis(3,4-difluorophenyl)methyl]-1- piperidinyl]propoxy]-3-methoxyphenyl]ethanone (63), which produced a 35% reduction in blood pressure and was similar in activity to nifedipine. At lower doses, however, 4-[bis(4-fluorophenyl)methyl]-1-[3-(4-chlorophenoxy)propyl]piperidine (93) was one of the most effective antihypertensive agents, producing reductions in blood pressure of 17 and 11% at oral doses of 10 and 3 mg/kg, respectively; 63 was inactive at 10 mg/kg.

Evaluation of renal transplant dysfunction using color Doppler sonography

Color Doppler sonography (CDS) detects changes in renal blood flow that may be useful in evaluating renal transplant dysfunction (RTD). To assess the performance of CDS as a clinical test, we reviewed results from 223 CDS measurements in 130 renal transplant recipients during a 26 month period. Spectral wave forms were characterized by pulsatility index (PI) (maximum frequency shift minus minimum frequency shift divided by mean frequency shift). In 27 individuals with stable renal function, mean PI was 1.80 +/- 0.23 (S.D.). Abnormal PI were subsequently defined as greater than two S.D. more than the mean (PI greater than or equal to 2.3). CDS performed during the early post-transplant period (n = 91) could not differentiate acute tubular necrosis (ATN), obstruction and rejection. Abnormal studies were seen in 35 of 46 instances of ATN and in three of obstruction. In 132 studies done after the postoperative period, CDS became abnormal during rejection episodes in only 45 of 71 instances (sensitivity rate of 63 per cent). When abnormal, CDS was highly suggestive of rejection, however (45 of 49, 92 per cent specificity). Cyclosporine toxicity was not associated with abnormal pulsatility (zero of seven). In 68 instances, CDS and conventional 99mTc DTPA renogram flow studies were performed together within 24 hours. CDS was more sensitive in detecting rejection but the difference did not reach statistical significance (25 of 36 versus 17 of 36). The major advantage of CDS over conventional radionuclide imaging relates to its shorter examination time, lower cost and portable capabilities. CDS will probably become the roentgenologic imaging modality of choice in renal transplantation.

Nucleolar organizer regions in benign and malignant prostatic disease

A modified silver stain technique for visualizing nucleolar organizer regions (AgNOR counting) was applied to 24 benign and 23 malignant prostatic biopsies. Marked inter-observer variation was found, particularly in sections with high AgNOR counts. After averaging the AgNOR counts of both observers, there was no significant difference in counts between the benign and the malignant biopsies. The AgNOR count appeared to be increased in tumours up to Gleason histological grade 6, but not in tumours of Gleason histological grade 7 or more.

Small bowel transplantation in the rat with immediate restoration of intestinal continuity

Compared with other rat transplant models, small bowel transplantation (SBT) is associated with higher peritransplant morbidity and mortality. We describe a two-stage technique of SBT in the rat that minimizes perioperative complications and also allows immediate restoration of intestinal continuity. Inbred Lewis strain rats were used as donors and recipients. A one-stage technique was originally adopted whereby the distal 50% of the jejunoileum was transplanted followed by near-total resection of the native small intestine and restoration of intestinal continuity. Among 20 rats transplanted with this technique, only one survived longer than 30 days. With the two-stage technique, transplantation of the donor jejunoileum in continuity was performed, followed by native enterectomy 7 days later. With the two-stage technique 17 of 20 rats survived indefinitely (greater than 50 days). Other important technical modifications are described. In the hands of a skilled microvascular surgeon, the two-stage SBT technique results in consistently improved survival and minimal morbidity.

Effect of elimination of OX-19+ and OX-8+ T-cell subsets upon pancreatic allograft survival

Depletion of T cell subsets with monoclonal antibody (mAb) permits analysis of cellular events mediating allograft destruction. Mab OX-19 and mAb OX-8 were used singly and in combination together with a short pretransplant course of cyclosporine A (CsA) to deplete OX-19+ cells (all T cells) and OX-8+ cells (cytotoxic/suppressor and NK cells), respectively, in diabetic Lewis (Lew) recipients of a Wistar Furth (WF) pancreatic allograft. Depletion of lymph node T cell subsets was assessed at rejection (blood sugar greater than 250 mg/dl) by flow cytometry. Untreated Lew recipients (Group 1) rapidly rejected their allograft (11.5 +/- 2.5 days). MAb OX-19 administration on the day prior to surgery (Day -1), on the day of surgery (Day 0), and alternate days thereafter until rejection (Group 2) prolonged graft survival (15.0 +/- 1.6 days, P less than 0.05). MAb OX-19 administration on alternate days beginning 14 days prior to transplantation (Day -14) until rejection (Group 3) further prolonged graft survival (22.6 +/- 3.4 days, P less than 0.01). At rejection large numbers of OX-19+ cells were present in both groups. Administration of mAb OX-8 alone (Group 4) failed to prolong graft survival despite marked depletion of OX-8+ cells at rejection. Administration of mAb OX-19 from Day -14 together with CsA (15 mg/kg) from Days -14 to -8 inclusive (Group 5) resulted in a marked and sustained depletion of OX-19+ cells at rejection but only a modest prolongation of graft survival (27.6 +/- 6.0 days, P = 0.11). CsA alone from Days -14 to -8 failed to prolong graft survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Sibs with growth deficiency, delayed bone age, congenital hip dislocation, and iridocorneal abnormalities with glaucoma

We report on a brother and sister with short stature, delayed bone age, developmental delay, congenital hip dislocation, and iridocorneal abnormalities with onset of glaucoma at or soon after birth. Results of endocrine evaluation were normal. To our knowledge, no similar pattern of defects has been reported previously.

A randomized trial comparing cyclosporine with antilymphoblast-globulin-azathioprine for renal allograft recipients. Results at 2 1/2-6 years

Between September 1980 and June 1984, 246 splenectomized, transfused renal allograft recipients were stratified according to presence of diabetes and donor source, and randomized to treatment with either cyclosporine (CsA)-prednisone (pred) or antilymphoblast-globulin (ALG--azathioprine (AZA)--prednisone. As of August 1986, mean follow-up is 47 months. Over all, actuarial patient survival is 84% and 83%, respectively at 4 years. Corresponding graft survival is 70% and 63% for CsA-treated and ALG-AZA-treated patients (NS). Within the subgroup of diabetic recipients of cadaver grafts, graft survival is 70% for CsA-treated and 53% for ALG-AZA-treated recipients (P = .035). In the CsA group, 71% required either a significant reduction in CsA dosage with the addition of azathioprine or a complete switch to azathioprine, mainly because of CsA-associated nephrotoxicity. Of those CsA patients switched at a mean time of 21.3 +/- 16.4 months posttransplant with mean serum creatinine of 2.40 +/- .67, current serum creatinine is 1.79 +/- .63. Current mean serum creatinine values are significantly greater for patients randomized to CsA-pred (1.73 +/- .60) vs. ALG-AZA-pred (1.49 +/- .59), P = .014, even though most CsA-treated patients were eventually switched. The causes of graft loss are not different between CsA and ALG-AZA randomized patients. In nondiabetics, rejection is the most common cause of graft loss (17/33), whereas in diabetics loss due to complications from overimmunosuppression or death from cardiovascular events is significantly more common (27/44) than corresponding losses in nondiabetics (6/33, P less than .05). Switching does not seem to influence the incidence or cause of graft loss. Since most patients started on CsA-prednisone are ultimately switched to triple drug therapy, the latter is now the preferred initial treatment modality.

Pretransplant cytotoxic conditioning produces effects consistent with clonal deletion mechanisms

A rat cardiac allograft model (ACl to Lewis) was used to investigate the clonal deletion theory. Twelve groups of Lewis recipients received various combinations of donor-specific blood transfusions (DSTs), immediate post-DST immunosuppression with azathioprine/prednisone, and low-dose cyclosporine (1 mg/kg/day) posttransplant. DSTs and cyclosporine together gave modest prolongation of graft survival (from 6.0 to 17 days). DSTs plus immediate post-DST immunosuppression followed by low-dose cyclosporine prolonged graft survival to an average of 45 days. Third-party transfusions alone and in combination with immunosuppression did not significantly prolong allograft survival. Postoperative cyclosporine was required for the expression of this effect suggesting that clonal depression rather than clonal deletion had occurred. Combining DSTs with brief but intense preoperative immunosuppression may be a more effective method of pretransplant conditioning than DSTs alone.

The effect of donor-specific transfusions on rat heart allograft survival

A rat heart allograft model employing donor-specific transfusions (DSTs) was used to investigate several questions relevant to their clinical usage. The effects of varying blood storage duration (stored vs. fresh), number and timing of DSTs as well as use of concomitant azathioprine and cyclosporine (CsA) were assessed in terms of allograft survival and recipient sensitization. A comparison of stored and fresh-blood DSTs revealed that blood stored for up to 5 weeks was as effective as fresh blood and that a 2-week storage was optimal. Increased storage appeared to be associated with decreased sensitization. Multiple DSTs were more effective than a single DST and the peak effect appeared after six. Transfusions given at the time of transplantation were ineffective. The addition of concomitant (preoperative) azathioprine or CsA resulted in a further decrease in sensitization but also resulted in a dose-dependent diminution of the transfusion effect.

Donor-specific blood transfusions with stored and fresh blood in a rat heart allograft model

Donor-specific transfusions ( DSTs ) using stored and fresh blood were investigated in a rat heart allograft model. Lewis rats were recipients of preoperative DSTs and cardiac allografts from ACI donors. Blood was stored for 0, 1, 2, 3, 4, and 5 weeks prior to transfusion. Allograft survival and recipient sensitization were recorded. In all DST groups, allograft survival was superior to nontransfused controls (P less than 0.05). Stored blood was equal or better than fresh blood, and a 2-week storage was optimal (P less than 0.05). Storage of 2 weeks or greater resulted in decreased sensitization compared to storage for 1 week or less (P less than 0.05). This study supports the use of stored blood to enhance allograft survival and reduce recipient sensitization.

Analysis of five tests commonly used in determining the ability to control single motor units

A correlation regression analysis was used to analyze five individual test and two types of scores in terms of their predictive value in determining overall performance in single motor unit (SMU) control. Fine wire electrodes were inserted into the biceps brachii muscle of twenty-five women subjects. Each subject was tested for electrical silence, motor unit isolation, on-off control, frequency control and rhythm control. A detailed protocol and scoring criteria are described for each test. Ten predictors were analyzed--a time score and an error score for each of the five tests. A correlation regression analysis showed that the On-Off Control, the Rhythm Control and the Motor Unit Isolation tests have greater predictive value than the remaining tests. Furthermore, the error scores obtained from these tests are more reliable than the time scores in predicting overall performance in SMU control. The implications that the present findings may have on future studies are discussed.