Antibody desensitization therapy in highly sensitized lung transplant candidates.

As HLAs antibody detection technology has evolved, there is now detailed HLA antibody information available on prospective transplant recipients. Determining single antigen antibody specificity allows for a calculated panel reactive antibodies (cPRA) value, providing an estimate of the effective donor pool. For broadly sensitized lung transplant candidates (cPRA ≥ 80%), our center adopted a pretransplant multi-modal desensitization protocol in an effort to decrease the cPRA and expand the donor pool. This desensitization protocol included plasmapheresis, solumedrol, bortezomib and rituximab given in combination over 19 days followed by intravenous immunoglobulin. Eight of 18 candidates completed therapy with the primary reasons for early discontinuation being transplant (by avoiding unacceptable antigens) or thrombocytopenia. In a mixed-model analysis, there were no significant changes in PRA or cPRA changes over time with the protocol. A sub-analysis of the median fluorescence intensity (MFI) change indicated a small decline that was significant in antibodies with MFI 5000-10,000. Nine of 18 candidates subsequently had a transplant. Posttransplant survival in these nine recipients was comparable to other pretransplant-sensitized recipients who did not receive therapy. In summary, an aggressive multi-modal desensitization protocol does not significantly reduce pretransplant HLA antibodies in a broadly sensitized lung transplant candidate cohort.

Elevated plasma long pentraxin-3 levels and primary graft dysfunction after lung transplantation for idiopathic pulmonary fibrosis.

Primary graft dysfunction (PGD) after lung transplantation may result from ischemia reperfusion injury (IRI). The innate immune response to IRI may be mediated by Toll-like receptor and IL-1-induced long pentraxin-3 (PTX3) release. We hypothesized that elevated PTX3 levels were associated with PGD. We performed a nested case control study of lung transplant recipients with idiopathic pulmonary fibrosis (IPF) or chronic obstructive pulmonary disease (COPD) from the Lung Transplant Outcomes Group cohort. PTX3 levels were measured pretransplant, and 6 and 24 h postreperfusion. Cases were subjects with grade 3 PGD within 72 h of transplantation and controls were those without grade 3 PGD. Generalized estimating equations and multivariable logistic regression were used for analysis. We selected 40 PGD cases and 79 non-PGD controls. Plasma PTX3 level was associated with PGD in IPF but not COPD recipients (p for interaction < 0.03). Among patients with IPF, PTX3 levels at 6 and 24 h were associated with PGD (OR = 1.6, p = 0.02 at 6 h; OR = 1.4, p = 0.008 at 24 h). Elevated PTX3 levels were associated with the development of PGD after lung transplantation in IPF patients. Future studies evaluating the role of innate immune activation in IPF and PGD are warranted.

Glucoregulatory effects and prolonged duration of action of davalintide: a novel amylinomimetic peptide.

AIMS: Davalintide is a second-generation amylinomimetic peptide possessing enhanced pharmacological properties over rat amylin to reduce food intake in preclinical models. The current experiments in rats describe additional glucoregulatory actions of davalintide consistent with amylin agonism, and explore the duration of action of these effects. METHODS: Subcutaneous (SC) injection of davalintide slowed gastric emptying with equal potency to amylin (ED50's = 2.3 and 4.1 µg/kg). This effect was maintained for 8 h with davalintide, but not amylin. Intraperitoneal injection of davalintide also reduced food intake with a potency similar to amylin (ED50's = 5.0 and 11.3 µg/kg). Consistent with amylin agonism, davalintide (10 µg/kg, SC) suppressed the plasma glucagon response over 90 min following an intravenous arginine bolus in anaesthetized rats. The elimination t(½) of davalintide (200 µg/kg, SC) was 26 min, similar to the t(½) of amylin, suggesting that pharmacokinetic-independent mechanisms contribute to davalintide's enhanced duration of action. Binding kinetic studies using ¹²5I davalintide revealed no appreciable dissociation from the amylin nucleus accumbens receptor after 7 h while ¹²5I rat amylin did dissociate from this receptor (K(off) = 0.013/min). Sustained SC infusion of davalintide (275 µg/kg/day) or amylin (300) decreased plasma glucose after an oral glucose challenge at 2 weeks (by 27 and 31%) and suppressed gastric emptying at 3 weeks (by 29 and 47%), demonstrating durable glucoregulatory actions of both peptides. CONCLUSIONS: These data show glucoregulatory properties of davalintide consistent with amylin agonism and suggest that slowed receptor dissociation plays a role in davalintide's prolonged pharmacodynamic actions.

Simultaneous bilateral lung and pancreas transplantation in recipient with cystic fibrosis.

INTRODUCTION: Cystic fibrosis (CF) is an inherited disorder that presents in childhood as a multisystem disease. Pulmonary failure and pancreatic insufficiency, including CF-related diabetes (CFRD) and exocrine insufficiency, are significant causes of morbidity and mortality in these patients. In this report we have reviewed our experience with a simultaneous lung and pancreas transplantation in a patient with CF. METHODS: The recipient was a 25-year-old man with CF complicated by bronchiectasis with recurrent episodes of pneumonia, pancreatic exocrine insufficiency, and CFRD. He had normal hepatic and renal function. SURGICAL TECHNIQUE: The lung and pancreas allografts were procured from a single cadaveric donor. The double lung transplantation was performed through separate thoracic incisions. The pancreas transplantation was performed through a midline incision with systemic venous drainage and proximal enteric exocrine drainage. RESULTS: The recipient recovered well from his transplantation with early extubation. The pancreas allograft functioned well with normal blood glucose independent of insulin. As a result of the enteric drainage of the pancreas allograft, the patient no longer required supplemental pancreatic enzymes. His postoperative course was complicated by distal intestinal obstruction, a complex wound infection, and reversible leukoencephalopathy. At 1-year posttransplantation he remains free of supplemental oxygen, insulin, and pancreatic enzyme replacement. CONCLUSION: Simultaneous lung and pancreas transplantation in a patient with CF was performed safely, providing the advantages of normalization of glucose and improved nutrition for a patient requiring lung transplantation.

The blood contribution to early myocardial reperfusion injury is amplified in diabetes.

Cardiovascular disease is excessive in diabetes, and blood cell function is altered. It is not clear, however, if alterations in the blood contribute to the excessive cardiovascular complications of this disease. In this study, we compared the contribution of nondiabetic and diabetic blood to myocardial reperfusion injury. The recovery of cardiac contractile function following no-flow ischemia was studied in isolated diabetic and nondiabetic rat hearts perfused with diabetic or nondiabetic diluted whole blood. Hearts were isolated from 10- to 12-week-old diabetic (streptozotocin, 65 mg/kg, i.v.) and nondiabetic rats and perfused with a Krebs-albumin-red cell solution (K2RBC, Hct 20%). After a 30-min pre-ischemic control period, during which cardiac pump function was evaluated, diabetic and nondiabetic hearts were perfused for 5 min with diluted whole blood (DWB; Hct 20%) collected from either diabetic or nondiabetic donor animals. Coronary flow was then stopped and the hearts subjected to 30 min of no-flow ischemia. Following ischemia, the hearts were reperfused with the K2RBC perfusate. Cardiac contractile function was evaluated throughout the 60-min reperfusion period. Six groups were studied: diabetic and nondiabetic hearts perfused before ischemia with either K2RBC, nondiabetic DWB (NDDWB), or diabetic DWB (DDWB). Perfusion with DWB prior to ischemia impaired the recovery of contractile function in all cases. The impairment to recovery was greater with DDWB than with NDDWB. Although diabetic hearts perfused with K2RBC throughout recovered quite well, the effect of DDWB perfusion in the diabetic hearts was dramatic. In an effort to determine why diabetic blood impaired functional recovery, measures of blood filterability and the generation of reactive oxygen species (ROS) were made. We found that diabetic blood was less filterable than nondiabetic blood; that is, the diabetic blood cells tended to plug the 5-microm filter pores more readily than the nondiabetic blood cells. Also, we found that the diabetic blood was capable of generating significantly greater ROS (oxygen free radicals) than nondiabetic blood (P < 0.05). These findings suggest that the blood contribution to myocardial reperfusion injury is amplified in diabetes. A tendency for diabetic blood cells to plug capillary-sized pores and show enhanced oxygen free radical production may account for the excessive contribution of diabetic blood to reperfusion injury in the heart.

Persistent hyperdynamic cardiovascular state at rest and during exercise in children after successful repair of coarctation of the aorta.

OBJECTIVES: The purposes of this study were to evaluate left ventricular performance and contractility at rest and during exercise to determine mechanisms and correlates for alterations in performance and blood pressure in pediatric patients after successful repair of coarctation of the aorta. BACKGROUND: Blood pressure and left ventricular function are elevated in children despite successful repair. The mechanisms for these changes are not understood. METHODS: Thirty asymptomatic pediatric patients with successful coarctation repair (mean age [+/- SD] 12.5 +/- 4 years) underwent echocardiographic determination of left ventricular mass, performance (shortening fraction), preload (indexed diastolic dimension), afterload (end-systolic wall stress), contractility (velocity of circumferential fiber shortening/wall stress relation) and Doppler gradient at rest and during exercise. Data were compared with those of 24 control subjects (mean age 21.0 +- 4 years). Because of the age discrepancy between groups, age-dependent echocardiographic data were indexed by body surface area. RESULTS: The mean age at operation was 5 +/- 4 years, and the average follow-up period was 7.5 +/- 3 years. The average blood pressure gradient between upper and lower limbs was 4 mm Hg. Left ventricular mass was higher in the postoperative group than in the control group (1.58 vs. 1.31 g/ht2.7, p = 0.04), as were values at rest for performance (44% vs. 31%, p = 0.0001), preload (3.9 vs. 3.7 cm/body surface area0.5), indexes systolic blood pressure (1.05 vs. 0.91, p = 0.0001) and contractility (0.23 vs. -0.05 circumferences/s, p= 0.001). Afterload was lower at rest (36 vs. 52 g/cm2, p = 0.0004). These differences between groups persisted during and after exercise. Contractility underwent an exaggerated increase after exercise in the postoperative group. CONCLUSIONS: Left ventricular performance in children after coarctation repair is higher at rest and during exercise than in control subjects as a result of higher preload and contractility and lower afterload. These changes may be due to associated hypertrophy. Persistent postoperative hypertension may be due to a hyperdynamic, hypercontractile state caused by residual gradients manifested only during exertion.

Brief perfusion with diluted whole blood after global myocardial ischaemia increases reperfusion injury.

OBJECTIVES: In vivo studies indicate that blood components, especially leucocytes, contribute to reperfusion injury after myocardial ischaemia. This study was designed to: (1) develop a small animal heart model of ischaemia-reperfusion that demonstrates the contribution of blood to reperfusion injury; (2) determine when the presence of blood in the heart--that is, during ischaemia or during early reperfusion--caused greater dysfunction; and (3) attempt to limit the blood contribution to reperfusion injury by leucocyte depletion. METHODS: Adult rat hearts were perfused in situ with a Krebs-albumin red cell solution (K2RBC), then isolated. Cardiac pump function was assessed with an intraventricular balloon as left ventricular developed pressure and contractility (dP/dt). Group I served as a non-ischaemic control group. Group II was subjected to global, no flow ischaemia for 30 min followed by 45 min reperfusion. In group III, diluted whole blood replaced the K2RBC for five min immediately before ischaemia. In group IV, diluted whole blood was perfused during the first five min reperfusion. In group V, the hearts were reperfused with leucocyte poor diluted whole blood. RESULTS: Pre-ischaemic pump function values were similar to other blood perfused, isolated heart models. Group I showed no increase in coronary resistance or decrease in pump function with time or in response to diluted whole blood. After 35 min reperfusion, the recovery (% control) of dP/dt in group II was 56(12), in group III it was 39(15) and in group IV it was only 19(6) (p < 0.05). Large increases in coronary vascular resistance, oedema, and contracture during reperfusion were also seen in group IV. When leucocytes were depleted from the diluted whole blood (group V), the recoveries were similar to reperfusion without diluted whole blood (group II). CONCLUSIONS: Thirty min of global, normothermic ischaemia caused significant cardiac dysfunction early during reperfusion. Perfusion with unstimulated blood for a limited period further impaired the recovery of function and enhanced myocardial oedema. Dysfunction was particularly evident when diluted whole blood was perfused during the first minutes of reperfusion. The leucocyte depletion studies suggest that leucocytes are necessary, but may not be sufficient, to demonstrate the blood contribution to reperfusion injury.

Delirium affects length of hospital stay after lung transplantation.

BACKGROUND: Delirium is relatively common after lung transplantation, although its prevalence and prognostic significance have not been systematically studied. The purpose of the present study was to examine pretransplant predictors of delirium and the short-term impact of delirium on clinical outcomes among lung transplant recipients. METHODS: Participants underwent pretransplant cognitive testing using the Repeatable Battery for the Assessment of Neuropsychological Status and the Trail Making Test. After transplant, delirium was assessed using the Confusion Assessment Method until discharge. RESULTS: Sixty-three patients were transplanted between March and November 2013, of which 23 (37%) developed delirium. Among transplanted patients, 48 patients completed pretransplant cognitive testing. Better pretransplant cognitive function was associated with lower risk of delirium (odds ratio, 0.69 [95% confidence interval 0.48, 0.99], P = .043); and demographic and clinical features including native disease (P = .236), the Charlson comorbidity index (P = .581), and the lung allocation score (P = .871) were unrelated to risk of delirium, although there was a trend for women to experience delirium less frequently (P = .071). The presence (P = .006) and duration (P = .027) of delirium were both associated with longer hospital stays. CONCLUSION: Delirium occurs in more than one-third of patients after lung transplantation. Delirium was associated with poorer pretransplant cognitive functioning and longer hospital stays, after accounting for other medical and demographic factors.

Disposition of fluorescein-labelled dextran (150 kD) in isolated perfused livers from control and diabetic rats.

Isolated perfused livers were used to study the hepatic disposition of fluorescein-labelled dextran with a MW of 150 kD (FD-150), in control and streptozotocin-induced diabetic rats. A 100-microliter volume of FD-150 solution (10%, w/v) was injected as a rapid bolus dose into the inlet catheter of the isolated livers, and samples were collected from the outlet catheter in 2-sec intervals for 80 sec. Statistical moment theory was used to calculate the distribution and elimination parameters of the tracer based on the concentrations of FD-150 in the outflow. The values (mean +/- SD) of mean transit time, volume of distribution, and extraction ratio of FD-150 in the isolated livers from control rats were 16.3 +/- 2.00 sec, 0.298 +/- 0.054 ml/g liver, and 0.24, respectively. Similar values were obtained in diabetic livers, suggesting that streptozotocin-induced diabetes does not affect the hepatic disposition of FD-150.

Psychiatric adjustment in end-stage renal disease: a follow up study of former paediatric patients.

Life-time psychiatric adjustment was studied in forty-five young adult survivors of a paediatric dialysis and transplantation programme and in a comparison group matched for age and sex. Renal patients reported more psychological problems in childhood and had lower self-esteem in adulthood, but adult lifetime psychiatric morbidity was comparable in both groups. There were differences in the pattern of psychiatric disorder with a trend for more depressive states in the renal group. Lower self-esteem was linked to early onset renal disease and to educational and social dysfunction. Results indicate relatively favourable adult adjustment of juvenile renal patients.

Dose dependency of the kinetics of dextrans in rats: effects of molecular weight.

The effects of dose on the serum and tissue kinetics of high and low molecular weight (M(r)) dextrans were studied in rats. Single intravenous (iv) doses of 1, 25, or 100 mg of fluorescein-labeled dextrans with average M(r) of approximately 4 kD (FD-4) or 150 kD (FD-150) per kilogram of body weight were administered to rats, and serum, urine, and various tissues were collected over time. The samples were analyzed by a sensitive and specific chromatographic method. For FD-150, the area under the serum concentration-time curves (AUCs) increased disproportionately when the dose was increased from 1 to 100 mg/kg; the dose-corrected AUCs were 50.1 +/- 1.9, 85.9 +/- 2.4, and 122 +/- 3 micrograms.h/mL for the doses of 1, 25, and 100 mg/kg, respectively (p < 0.05). This increase in the dose-corrected AUCs was associated with a high and nonlinear accumulation of FD-150 in the liver; that is, the percent dose recovered in the liver decreased from 68.5 +/- 2.4% to 41.5 +/- 3.4% when the dose was increased from 1 to 100 mg/kg (p < 0.05). On the other hand, the serum kinetics of FD-4 exhibited dose independence [the dose-corrected AUCs were 2.38 +/- 0.04, 2.19 +/- 0.07, and 2.30 +/- 0.07 microgram.h/mL for the doses of 1, 25, and 100 mg/kg, respectively (p > 0.05)]. This dose independence was attributed to a high and linear excretion of FD-4 into urine as indicated by the percent doses of FD-4 excreted into urine [i.e., 82.0 +/- 1.8, 78.7 +/- 4.4, and 82.2 +/- 7.2 for the doses of 1, 25, and 100 mg/kg, respectively (p > 0.05)].(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular weight dependent tissue accumulation of dextrans: in vivo studies in rats.

The effects of molecular weight (M(r)) on the serum and urine pharmacokinetics and tissue distribution of dextrans, potential macromolecular carriers for drug delivery, were studied in rats. A single 5 mg/kg dose of fluorescein-labeled dextrans (FDs) with a M(r) of 4000 (FD-4), 20,000 (FD-20), 70,000 (FD-70), or 150,000 (FD-150) was administered into the tail vein of separate groups of rats. At different times after the administration of each FD, animals were sacrificed, and blood, urine, and various tissues were obtained. The concentrations of FDs in the samples were subsequently determined by using a sensitive and specific high performance size exclusions chromatographic method. Among the tissues studied, high accumulation of dextrans was found only in the liver (liver:serum AUC ratios < or = 29) and spleen (spleen:serum AUC ratios < or = 10), with high concentrations in these tissues persisting even at the last sampling time (96 h). In contrast, the serum concentrations of the studied FDs were not measurable beyond 12 h. The serum and urine kinetics and the liver, spleen, and kidney accumulation of FDs demonstrated a significant degree of M(r) dependency. The total and renal clearance of FDs consistently decreased with an increase in M(r). However, the effects of M(r) on the tissue accumulation of dextrans was tissue dependent. For the liver, the tissue:serum AUC ratios increased from 0.346 for FD-4 to 15.2 for FD-20 and 28.8 for FD-70, while a further increase in M(r) to 150 kDa (FD-150) resulted in lowering the ratio to 8.59 in this tissue. For the spleen, the ratios increased from 0.095 for FD-4 to 9.56 for FD-150.(ABSTRACT TRUNCATED AT 250 WORDS)

The concentration of sodium, potassium and chloride in rabbit submandibular saliva during postnatal development.

Saliva was collected from the cannulated ducts of submandibular glands of rabbits at various ages from birth to adulthood and analysed for sodium, potassium and chloride. Saliva was obtained at all ages by electrical stimulation of the parasympathetic innervation to the gland. On the day of birth (day 1), salivary sodium was 108.5 +/- 3.4 mM (n = 8) and chloride was 89.9 +/- 3.6 mM (n = 9) falling to adult-like concentrations of 5.7 +/- 0.6 mM (n = 13) and 16.5 +/- 1.2 mM (n = 9) respectively by day 10. On Day 1, salivary potassium was 23.9 +/- 1.8 mM (n = 7) and rose progressively to 76.8 +/- 2.5 mM (n = 8) on day 17. Adult potassium concentration was 30-40 mM. A wide range of flows was obtained at all ages and at each age sodium and chloride concentrations were approximately constant at all flows. Therefore the changes in electrolyte concentration cannot be explained by differences in flow. The results suggest a maturation of ductal transport of sodium, potassium and chloride ions concurrent with the structural maturation of striated duct cells.

X-ray reflectometer for optical efficiency and scatter measurements.

An instrument has been developed to determine the reflection efficiency and scatter characteristics of optical samples at x-ray wavelengths from 1.5 to 113 A. The reflectometer operates in an oil-free vacuum chamber and measures the reflection efficiency and scatter characteristics as a function of the angle of incidence. The reflection efficiency is given for lambda=8.34 A incident on a fused silica sample finished to a flatness of lambda/10. The experimental reflection efficiency is compared to the theoretical data. The scatter curves are given for the direct x-ray beam and for the beam reflected from the fused silica sample at theta=50 arc minutes. The full-width-at-half-maximum (FWHM) resolution of the instrument is approximately 13 arc seconds as determined by a least-squares smoothing of the experimental data.

Hyaluronidase and its relationship to contraceptive development.

PIP: Pig testicular hyaluronidase was prepared, separated and purified. An assay technique for hyaluronidase which takes advantage of colorimetric methods for the detection of Nacetyglucosamine, which is released from hyaluronic acid was employed. Male and female guinea pigs were immunized with crude pig testicular hyaluronidase or guinea pig epididymal sperm and sacrificed at various times up to 8 weeks. The serum was assayed for inhibition of hyaluronidase. Complete inhibition of enzyme activity is observed in antiserum from female guinea pigs at serum dilutions of 1:100. The implications for this infertility inducing antibody for human use require further study.^ieng

A Le Fort I osteotomy approach to lateral sphenoid sinus encephalocoeles.

Meningo-encephalocoeles of the skull base may present as spontaneous cerebrospinal fluid rhinorrhoea or acute meningitis. Previous approaches to midline skull base lesions have been either intracranial, via a craniotomy, or by transfacial or endoscopic extracranial approaches. This paper presents an alternative approach to lateral sphenoid sinus encephalocoeles through a Le Fort I osteotomy approach.

Platelets do not modulate leukocyte-mediated coronary microvascular damage during early reperfusion.

Several studies indicate that leukocytes and platelets exacerbate the compromise of myocardial function that occurs after ischemia-reperfusion (I/R). However, it is unclear whether both leukocytes and platelets must be present to mediate coronary microvascular damage early during reperfusion after ischemia. To examine the effects of leukocytes and platelets on microvascular damage after I/R, we measured transcoronary albumin extravasation (O/I), perfused coronary capillary density (Caps), and transcoronary albumin extravasation per perfused capillary [(O/I)/Caps] in isolated rat hearts perfused with a Krebs-albumin-red blood cell solution [K(2)RBC], whole rat blood diluted with Krebs buffer (DWB), leukocyte-free, platelet-rich DWB (LFB), or leukocyte-rich, platelet-free DWB (LRB) before and after a 30-min period of global, no-flow ischemia. We found that in isolated hearts perfused with K(2)RBC before ischemia, O/I values were significantly increased (+68%, P < 0.01) and Caps values were significantly decreased (-25%, P < 0.05) after 25 min of reperfusion. A similar pattern of O/I values (+72%, P < 0.01) and Caps values (-40%, P < 0.05) was observed in hearts perfused with LFB. These effects were exacerbated in hearts perfused with DWB or LRB. O/I values were increased 90% (P < 0.01), and Caps values were decreased 62% (P < 0.01) in the DWB-perfused hearts. Similar increases in O/I values (+82%, P < 0.01) and decreases in Caps values (-65%, P < 0.01) were measured in the LRB-perfused hearts. Additionally, (O/I)/Caps values were significantly increased in the hearts perfused with DWB (+93%, P < 0.01) and LRB (+84%, P < 0.01) compared with the hearts perfused with K(2)RBC or LFB. These results suggest that interactions between leukocytes and platelets are not requisite for the development of coronary microvascular damage early during reperfusion after ischemia.