Fewer butterflies seen by community scientists across the warming and drying landscapes of the American West

Uncertainty remains regarding the role of anthropogenic climate change in declining insect populations, partly because our understanding of biotic response to climate is often complicated by habitat loss and degradation among other compounding stressors. We addressed this challenge by integrating expert and community scientist datasets that include decades of monitoring across more than 70 locations spanning the western United States. We found a 1.6% annual reduction in the number of individual butterflies observed over the past four decades, associated in particular with warming during fall months. The pervasive declines that we report advance our understanding of climate change impacts and suggest that a new approach is needed for butterfly conservation in the region, focused on suites of species with shared habitat or host associations.

High Yield of Rodent Islets with Intraductal Collagenase and Stationary Digestion—A Comparison with Standard Technique

Intraductal distention of the pancreas with collagenase followed by stationary warm incubation improves the recovery of islets of Langerhans in the rat, but controlled studies are needed for valid comparison with standard isolation methods. We have modified Gotoh's technique of stationary digestion for high-yield isolation in the rat (Stationary). The method is subjected herein to rigorous blinded comparison with the standard chopped tissue (Chopped) technique, based on Lacy et al., as performed in our laboratory for over 10 yr. Islet recovery was determined by a single observer ‘blinded’ to the method of isolation used, and only intact islets of diameter ≥ 100 μm were included. Stationary gave 719 ± 114 islets per pancreas (mean ± SD, n = 21 isolations) vs. 487.5 ± 69 for Chopped (n = 36 isolations), a 47.5% increment in yield (p < 0.0001). In vitro islet perifusion showed no statistical difference in stimulation index (SI) or stimulated area under the curve (SAUC) between the two methods, but Stationary showed a trend towards improved phase II insulin release. In vivo function was assessed by isogeneic transplantation of 2,000 islets beneath the renal capsule of streptozotocin diabetic recipients (65 mg/kg Sigma); Stationary recipients (n = 7) became normoglycemic (≤ 8 mmol/L) by 3.3 ± 4.8 days vs. 1.6 ± 1.5 days for Chopped recipients (p = 0.4 ns, mean ± SEM). IVGTT performed at 1 mo posttransplant gave K-values for Stationary of 2.64 ± 0.8 vs. 2.62 ± 0.8 for Chopped (mean ± SD, p = 0.9 ns, n = 6, unpaired t-test), which were not distinguishable from normal control rats (2.59 ± 0.8) (p = 0.9 ns, n = 10). Graft function remained stable until graft bearing nephrectomy induced hyperglycemia uniformly within 1 day. Graft histology showed a healthy well-preserved structure on light microscopy, with well-granulated beta cells on EM. Economic costs of rat, collagenase, and Ficoll were 26% ($50.82) lower per recipient for Stationary. We conclude that modified stationary digestion significantly improves islet recovery with excellent in vitro and in vivo function, and is cost effective.

Human islet viability and function is maintained during high-density shipment in silicone rubber membrane vessels

BACKGROUND

The shipment of human islets (IE) from processing centers to distant laboratories is beneficial for both research and clinical applications. The maintenance of islet viability and function in transit is critically important. Gas-permeable silicone rubber membrane (SRM) vessels reduce the risk of hypoxia-induced death or dysfunction during high-density islet culture or shipment. SRM vessels may offer additional advantages: they are cost-effective (fewer flasks, less labor needed), safer (lower contamination risk), and simpler (culture vessel can also be used for shipment).

METHOD

IE were isolated from two manufacturing centers and shipped in 10-cm(2) surface area SRM vessels in temperature- and pressure-controlled containers to a distant center after at least 2 days of culture (n = 6). Three conditions were examined: low density (LD), high density (HD), and a microcentrifuge tube negative control (NC). LD was designed to mimic the standard culture density for IE preparations (200 IE/cm(2)), while HD was designed to have a 20-fold higher tissue density, which would enable the culture of an entire human isolation in 1-3 vessels. Upon receipt, islets were assessed for viability (measured by oxygen consumption rate normalized to DNA content [OCR/DNA)]), quantity (measured by DNA), and, when possible, potency and function (measured by dynamic glucose-stimulated insulin secretion measurements and transplants in immunodeficient B6 Rag(+/-) mice). Postshipment OCR/DNA was not reduced in HD vs LD and was substantially reduced in the NC condition. HD islets exhibited normal function postshipment. Based on the data, we conclude that entire islet isolations (up to 400,000 IE) may be shipped using a single, larger SRM vessel with no negative effect on viability and ex vivo and in vivo function.

1,25-Dihydroxyvitamin D inhibits lipopolysaccharide-induced immune activation in human endothelial cells

In addition to its well-known role in mineral and skeletal homeostasis, 1,25-dihydroxyvitamin D3 [1,25-(OH)2, D3] regulates the differentiation, growth and function of a broad range of immune system cells, including monocytes, dendritic cells, T and B lymphocytes. Vascular endothelial cells play a major role in the innate immune activation during infections, sepsis and transplant rejection; however, currently there are no data on the effect of 1,25-(OH)2 D3 on microbial antigen-induced endothelial cell activation. Here we show that 1,25-(OH)2 D3 pretreatment of human microvessel endothelial cells (HMEC) inhibited the enteric gram-negative bacterial lipopolysaccharide (LPS) activation of transcription factor NF-kappaB and interleukin (IL)-6, IL-8 and regulated upon activation normal T cell exposed and secreted (RANTES) release. The effect of 1,25-(OH)2 D3 was not due to increased cell death or inhibition of endothelial cell proliferation. 1,25-(OH)2 D3 pretreatment of HMEC did not block MyD88-independent LPS-induced interferon (IFN)-beta promoter activation. 1,25-(OH)2 D3 pretreatment of HMEC did not modulate Toll-like receptor 4 (TLR4) or MD-2 expression. These data suggest that 1,25-(OH)2 D3 may play a role in LPS-induced immune activation of endothelial cells during gram-negative bacterial infections, and a suggest a potential role for 1,25-(OH)2 D3 and its analogues as an adjuvant in the treatment of gram-negative sepsis.

Geological barriers and restricted gene flow in the holarctic skipper Hesperia comma (Hesperiidae)

Patterns of genetic variation within a species may be a consequence of historical factors, such as past fragmentation, as well as current barriers to gene flow. Using sequence data from the mitochondrial cytochrome oxidase subunit II region (COII) and the nuclear gene wingless, we conducted a phylogeographical study of the holarctic skipper Hesperia comma to elucidate patterns of genetic diversity and to infer historical and contemporary processes maintaining genetic variation. One hundred and fifty-one individuals were sampled from throughout North America and Eurasia, focusing on California and adjacent regions in the western United States where morphological diversity is highest compared to the rest of the range. Analyses of sequence data obtained from both genes revealed a well-supported division between the Old and New World. Within western North America, wingless shows little geographical structure, while a hierarchical analysis of genetic diversity of COII sequences indicates three major clades: a western clade in Oregon and Northern California, an eastern clade including the Great Basin, Rocky Mountains and British Columbia, and a third clade in southern California. The Sierra Nevada and the Transverse Ranges appear to be the major barriers to gene flow for H. comma in the western United States. Relatively reduced haplotype diversity in Eurasia compared to North America suggests that populations on the two continents have been affected by different historical processes.

Surgical staplers for vascular control of hepatic veins and portal structures in major hepatic resection

Phenomenal progress has occurred in the art of liver resection. Only a decade ago massive blood transfusion, liver failure, bile leak, or sepsis were alI frequent attendants of major resection, and intraoperative death from torrential bleeding from hepatic veins or vena cava was not uncommon. Now, major liver resection may be accomplished routinely without blood transfusion, and operative mortality of 0% to 2% is standard in expert hands. Uncontrolled hemorrhage remains the primary cause of intraoperative death. Mortality in the early postoperative period is usually related to delayed hemorrhage, inadequate hepatic reserve, or injury to vital blood supply or biliary drainage in the liver remnant.

Portal venous pressure changes after sequential clinical islet transplantation

BACKGROUND

Sequential pancreatic islet transplantation via the portal vein has led to insulin independence in patients with type 1 diabetes. Complications associated with the injection of islets into the portal vein have been reported; therefore, in this study we sought to further characterize changes in portal venous pressure associated with islet infusion.

METHODS

Pre- and posttransplant portal venous pressures were recorded in 50 consecutive transplant procedures in 26 patients receiving highly purified, heparinized allogeneic islet preparations via a radiologically placed portal venous cannula. Doppler ultrasound scans of the portal vein were completed within 24 hr of transplantation.

RESULTS

Posttransplant portal vein pressures rose significantly with sequential transplantation (12.4 mm Hg vs. 17.3 mm Hg, P <0.05). Portal pressure change correlated significantly with islet packed cell volume (r =0.66, P <0.001) and also with the number of islets transplanted ( r=0.49, P <0.001). Segmental portal vein thrombosis was radiologically detected after two procedures (4%).

CONCLUSION

Multiple sequential islet transplants can be safely performed via the portal vein, provided that care is taken with islet purification and attention is paid to portal venous monitoring.

A comparison of the efficacy and tolerability of brimonidine and latanoprost in adults with open-angle glaucoma or ocular hypertension: a three-month, multicenter, randomized, double-masked, parallel-group trial

BACKGROUND

Many physicians recommend either brimonidine or latanoprost as firstline therapy for chronic open-angle glaucoma or ocular hypertension. However, a search of MEDLINE indicates that there have been few head-to-head comparisons of the 2 monotherapies in a clinical setting.

OBJECTIVE

This study compared the clinical efficacy and tolerability of brimonidine 0.2% twice daily with those of latanoprost 0.005% once daily as monotherapy in patients with open-angle glaucoma or ocular hypertension.

METHODS

In this 3-month, multicenter, double-masked, parallel-group, 4-visit study, treatment-naive and previously treated patients with open-angle glaucoma or ocular hypertension and bilateral intraocular pressure (IOP) after washout of between 22 and 34 mm Hg were randomized to receive either brimonidine or latanoprost. Patients who had received previous treatment with either study drug were excluded from the study. The primary outcome measure was response rate, defined as the percentage of patients achieving > or = 20% reduction in IOP from baseline to month 3. Secondary outcome measures were mean IOP reduction from baseline to month 3 and clinical success, defined as the investigator's recommendation that the patient continue using the assigned study medication.

RESULTS

A total of 127 patients (55 treatment naive) were enrolled, 66 in the brimonidine group and 61 in the latanoprost group. After 3 months of treatment, 80% of patients in the brimonidine group and 74% of patients in the latanoprost group had achieved > or = 20% reduction in IOP from baseline. The mean reduction in IOP from baseline at month 3 was 6.8 mm Hg with brimonidine and 6.5 mm Hg with latanoprost (27.8% vs 27.0%, respectively). Among treatment-naive patients, a significantly higher percentage of brimonidine-treated patients achieved > or = 20% decrease in IOP compared with latanoprost-treated patients (88% vs 59%, respectively; P = 0.01). In previously treated patients, a higher percentage of the latanoprost group achieved > or = 20% reduction in IOP compared with the brimonidine group (88% vs 74%, respectively); however, the difference was not statistically significant. Significantly more patients in the brimonidine group achieved clinical success at month 3 compared with patients in the latanoprost group (91% vs 74%; P = 0.01).

CONCLUSIONS

At peak effect, brimonidine twice daily was as effective as latanoprost once daily in lowering IOP. In treatment-naive patients, latanoprost was associated with a significantly higher rate of nonresponse after 3 months of treatment compared with brimonidine. This suggests that brimonidine may be the more reliable choice for first-line therapy of newly diagnosed open-angle glaucoma or ocular hypertension. In previously treated patients, however, latanoprost provided greater mean IOP reduction than did brimonidine. Significantly more patients achieved clinical success with brimonidine monotherapy than with latanoprost monotherapy.

Serine-protease inhibition during islet isolation increases islet yield from human pancreases with prolonged ischemia

BACKGROUND

Islet isolation from the pancreatic tissue matrix remains highly variable. Recent evidence suggests that intrinsic human pancreatic proteases, including trypsin, may inhibit effective collagenase enzymatic activity during islet isolation, thereby impairing the isolation success. In this study we have hypothesized that serine protease inhibition applied during pancreatic digestion, could improve yield and/or functional viability of islets isolated from human pancreases.

METHODS

Twelve organ donor pancreases with 12.9+/-0.6 hr cold storage (mean+/-SEM) were perfused via their ducts with Liberase-HI enzyme in the presence (n=6) or absence (n=6) of 0.4 mM Pefabloc. All were then gently dissociated and their purified islets separated with Ficoll density gradient centrifugation.

RESULTS

Donor-related factors (age, gender, cold storage time, body mass index, and pancreas weight) did not differ significantly between the two experimental groups. Pefabloc supplementation did not affect the digestion time, islets remaining trapped in exocrine tissue, or final islet purity. Islet recovery was increased in the Pefabloc-treated group (mean+/-SEM yield 323.8+/-80.8 x 10(3) islet equivalents vs. 130.8+/-13.6 x 10(3) islet equivalents, P<0.05). Cellular composition, DNA and insulin content, and insulin secretory activity of the isolated islets was similar.

CONCLUSIONS

Inhibition of intrinsic protease activity within pancreases after prolonged cold storage improves isolation of viable islets.

Bile leak from duct of Luschka after liver transplantation

BACKGROUND

We report a case of bile leak from an accessory duct of Luschka during cholecystectomy during liver transplantation.

METHODS

Radiological findings suggested that the collection was septated. An intra-operative cholangiogram was obtained by cannulation of the accessory hepatic duct.

RESULTS

An infected biloma with Clostridium perfringens was drained surgically. The bile leak that emanated from the gall bladder fossa was found to communicate with an accessory right hepatic duct draining a segmental duct in the right liver lobe. The bile leak resolved completely after direct suture of the accessory duct.

CONCLUSIONS

Excessive use of electrocautery to the liver bed during donor cholecystectomy may injure subcapsular ducts in the gallbladder fossa. In liver transplantation, dissection should be kept close to the serosal lining of the gall bladder, preserving the areolar tissue in the gall bladder bed, to avoid injury to the duct of Luschka.

Patterns of morphological, biochemical, and molecular evolution in the Oeneis chryxus complex (Lepidoptera: Satyridae): a test of historical biogeographical hypotheses

Surveys of allozyme allele frequency and mitochondrial DNA (mtDNA) sequence variation were employed to test historical biogeographical hypotheses on the origin and unique distribution of the synchronized biennial, high-altitude butterflies of the Oeneis chryxus complex in western North America. Populations of O. c. stanislaus and O. ivallda from the central and northern Sierra Nevada are indistinguishable by use of allozyme allele frequency data, possessed nearly identical mtDNA cytochrome oxidase subunit 1 (COI) haplotypes, and were found to be relatively distantly related to O. c. chryxus from the Snake Range in eastern Nevada. However, individuals of O. ivallda from Piute Pass in the southern Sierra Nevada are more variable, with some individuals sharing mtDNA characteristics with O. c. chryxus. We find little support for the hypothesis proposed by W. Hovanitz in 1940 that O. c. stanislaus invaded the central Sierra Nevada from across the Great Basin and displaced O. ivallda, but cannot reject the hypothesis that ancestral Oeneis dispersed across the Great Basin to California. This result is congruent with hypotheses of dispersal across the Great Basin for the origin of some Sierran alpine organisms.

Novel approaches toward early diagnosis of islet allograft rejection

BACKGROUND

The inability to diagnose early rejection of an islet allograft has previously proved to be a major impediment to progress in clinical islet transplantation. The need to detect early rejection will become even more relevant as new tolerance-inducing protocols are evaluated in the clinic. We explored three novel approaches toward development of early diagnostic markers of islet rejection after islet allotransplantation.

METHODS

(a) Canine islet allograft transplant recipients were immunosuppressed for 1 month, then therapy was withdrawn. Serum glutamic acid decarboxylase antigen (GAD65), an endogenous islet protein, was monitored daily with a CO2 release assay. (b) Rodent islets were genetically engineered to express a unique foreign protein (beta-galactosidase) by using adenoviral vectors, and after allograft transplantation, the viral-specific protein was measured in serum using optical luminescence. (c) Rodents receiving islet allografts were immunosuppressed temporarily, and daily glucose tolerance tests were followed until graft failure occurred.

RESULTS

(a) Although serum monitoring of GAD65 antigen demonstrated elevated levels preceding loss of graft function in preliminary studies, the effect was not reproducible in all animals. (b) Genetically engineered rodent islets demonstrated normal insulin kinetics in vitro (insulin stimulation index 2.57+/-0.2 vs. 2.95+/-0.3 for control islets, P=ns), and purified viral protein products had a stable half-life of 8 hr in vivo. After islet allotransplantation, there were two peak elevations in serum viral proteins, confirming that an intra-islet "sentinel signal" could be detected serologically during acute rejection. There was no lead-time ahead of hyperglycemia, however. (c) Daily sequential intravenous glucose tolerance (IVGT) tests demonstrated evidence of allograft dysfunction (decline in KG) with a 2-day lead time to hyperglycemia (2.58+/-0.3 vs. 1.63+/-0.2%/min, respectively, P<0.001), with an accuracy of 89%, sensitivity of 78%, and specificity of 95%.

CONCLUSIONS

Of the three diagnostic tests, metabolic assessment with an abbreviated IVGT was the most effective method of demonstrating early islet dysfunction due to rejection.

Pancreatic islet transplantation in the treatment of diabetes mellitus

This chapter reviews current developments and future directions in clinical islet transplantation. With the recent introduction of glucocorticoid-free immunosuppressive therapies and improved methods for islet isolation, the success of the procedure has increased substantially. Challenges ahead include progress with international multicentre trials, development of single donor protocols, progress in clinical tolerance based therapies to lower overall risk of immunosuppression, and ultimately finding an alternative source to provide effective therapy for more patients with diabetes. Recent advances in stem cell biology and xenotransplantation may soon provide this opportunity.

Clinical outcomes and insulin secretion after islet transplantation with the Edmonton protocol

Islet transplantation offers the prospect of good glycemic control without major surgical risks. After our initial report of successful islet transplantation, we now provide further data on 12 type 1 diabetic patients with brittle diabetes or problems with hypoglycemia previous to 1 November 2000. Details of metabolic control, acute complications associated with islet transplantation, and long-term complications related to immunosuppression therapy and diabetes were noted. Insulin secretion, both acute and over 30 min, was determined after intravenous glucose tolerance tests (IVGTTs). The median follow-up was 10.2 months (CI 6.5-17.4), and the longest was 20 months. Glucose control was stable, with pretransplant fasting and meal tolerance-stimulated glucose levels of 12.5+/-1.9 and 20.0+/-2.7 mmol/l, respectively, but decreased significantly, with posttransplant levels of 6.3+/-0.3 and 7.5+/-0.6 mmol/l, respectively (P < 0.006). All patients have sustained insulin production, as evidenced by the most current baseline C-peptide levels 0.66+/-0.06 nmol/l, increasing to 1.29+/-0.25 nmol/l 90 min after the meal-tolerance test. The mean HbA1c level decreased from 8.3+/-0.5% to the current level of 5.8+/-0.1% (P < 0.001). Presently, four patients have normal glucose tolerance, five have impaired glucose tolerance, and three have post-islet transplant diabetes (two of whom need oral hypoglycemic agents and low-dose insulin (<10 U/day). Three patients had a temporary increase in their liver-function tests. One patient had a thrombosis of a peripheral branch of the right portal vein, and two of the early patients had bleeding from the hepatic needle puncture site; but these technical problems were resolved. Two patients had transient vitreous hemorrhages. The two patients with elevated creatinine levels pretransplant had a significant increase in serum creatinine in the long term, although the mean serum creatinine of the group was unchanged. The cholesterol increased in five patients, and lipid-lowering therapy was required for three patients. No patient has developed cytomegalovirus infection or disease, posttransplant lymphoproliferative disorder, malignancies, or serious infection to date. None of the patients have been sensitized to donor antigen. In 11 of the 12 patients, insulin independence was achieved after 9,000 islet equivalents (IEs) per kilogram were transplanted. The acute insulin response and the insulin area under the curve (AUC) after IVGTT were consistently maintained over time. The insulin AUC from the IVGTT correlated to the number of islets transplanted, but more closely correlated when the cold ischemia time was taken into consideration (r = 0.83, P < 0.001). Islet transplantation has successfully corrected labile type 1 diabetes and problems with hypoglycemia, and our results show persistent insulin secretion. After a minimum of 9,000 IEs per kilogram are provided, insulin independence is usually attained. An elevation of creatinine appears to be a contraindication to this immunosuppressive regimen. For the subjects who had labile type 1 diabetes that was difficult to control, the risk-to-benefit ratio is in favor of islet transplantation.

Portal blood flow and liver regeneration in auxiliary partial orthotopic liver transplantation in a canine model

Functional competition has been shown to lead to a detrimental outcome in auxiliary liver transplantation. We evaluated the interaction in auxiliary partial orthotopic liver transplantation between the native liver and the graft in terms of portal flow and regeneration. The need for diversion of the portal flow to the graft was also assessed. Reduced-size liver grafts were transplanted orthotopically after partial hepatectomy in beagles. There were two groups: the preserved group, where portal inflow to the native liver was preserved, and the ligated group, where it was interrupted. Portal flow was measured serially and liver regeneration was evaluated on postoperative day 5. Functional competition was not observed in the preserved group. On the other hand, ligation of the native liver portal vein had no obviously detrimental effects on the remnant native liver. This leads to the conclusion that the portal vein to the native liver can be safely ligated to prevent functional competition.

Islet transplantation in seven patients with type 1 diabetes mellitus using a glucocorticoid-free immunosuppressive regimen

BACKGROUND

Registry data on patients with type 1 diabetes mellitus who undergo pancreatic islet transplantation indicate that only 8 percent are free of the need for insulin therapy at one year.

METHODS

Seven consecutive patients with type 1 diabetes and a history of severe hypoglycemia and metabolic instability underwent islet transplantation in conjunction with a glucocorticoid-free immunosuppressive regimen consisting of sirolimus, tacrolimus, and daclizumab. Islets were isolated by ductal perfusion with cold, purified collagenase, digested and purified in xenoprotein-free medium, and transplanted immediately by means of a percutaneous transhepatic portal embolization.

RESULTS

All seven patients quickly attained sustained insulin independence after transplantation of a mean (+/-SD) islet mass of 11,547+/-1604 islet equivalents per kilogram of body weight (median follow-up, 11.9 months; range, 4.4 to 14.9). All recipients required islets from two donor pancreases, and one required a third transplant from two donors to achieve sustained insulin independence. The mean glycosylated hemoglobin values were normal after transplantation in all recipients. The mean amplitude of glycemic excursions (a measure of fluctuations in blood glucose concentrations) was significantly decreased after the attainment of insulin independence (from 198+/-32 mg per deciliter [11.1+/-1.8 mmol per liter] before transplantation to 119+/-37 mg per deciliter [6.7+/-2.1 mmol per liter] after the first transplantation and 51+/-30 mg per deciliter [2.8+/-1.7 mmol per liter] after the attainment of insulin independence; P<0.001). There were no further episodes of hypoglycemic coma. Complications were minor, and there were no significant increases in lipid concentrations during follow-up.

CONCLUSIONS

Our observations in patients with type 1 diabetes indicate that islet transplantation can result in insulin independence with excellent metabolic control when glucocorticoid-free immunosuppression is combined with the infusion of an adequate islet mass.

Ogilvie's syndrome associated with acute cytomegaloviral infection after liver transplantation

Ogilvie's syndrome, or acute colonic pseudo-obstruction, is a rare complication following liver transplantation. We describe two cases in which the onset of Ogilvie's syndrome is strongly temporally associated with acute cytomegaloviral (CMV) infection in immunosuppressed liver transplant recipients. The pseudo-obstruction resolved rapidly in both cases following treatment with intravenous ganciclovir. Acute CMV infection therefore appeared to be causally linked to pathogenesis of Ogilvie's syndrome in these two cases. This association has not been described previously to our knowledge, and should be considered in any transplant patient presenting with Ogilvie's syndrome.

Living related liver transplantation from donors with the left-sided gallbladder/portal vein anomaly

The presence of a left-sided gallbladder poses a unique challenge for living related liver donation. Associated anomalies include segment IV atrophy, absence of portal vein bifurcation, and abnormal intrahepatic portal branches to segments II and III. The complex is rare, but is more frequent in Japan. Of 379 living related liver transplants from our institution, the complex has been encountered on four occasions (incidence: 1.1%), and we herein review our experience. Anomalies were identified preoperatively (by computed tomography and ultrasound) in all instances. One donor was turned down because there was no common portal trunk to segment II and III branches. Three donors underwent successful retrieval using a modified technique. There were no complications in the donors or recipients relating to the complex. Thus, living related liver retrieval can be achieved safely in the presence of the left-sided gallbladder/portal anomaly complex, but technical modifications are required.

Penicillium peritonitis in an adolescent receiving chronic peritoneal dialysis

A 19-year-old female on chronic peritoneal dialysis developed acute peritonitis; multiple peritoneal fluid and catheter tip cultures yielded Penicillium species. She promptly responded to catheter removal and intravenous amphotericin B, followed by oral fluconazole, without further recurrences 1 year later. This is the first reported case of Penicillium peritonitis in the pediatric population. We review the microbiology and clinical spectrum of this disease, as well as the few previous reported cases in adults.

Level and perceived stability of self-esteem prospectively predict depressive symptoms during psychoeducational group treatment

OBJECTIVES

To investigate the combined roles of level and perceived stability of self-esteem in prospectively predicting depression.

DESIGN

Symptoms of depression and anxiety were measured both before and after psychoeducational treatment for depression; level and perceived stability of self-esteem were measured before treatment.

METHOD

Participants were 26 adults (16 female), age range 21-75 years.

RESULTS

More stable self-esteem was associated with greater depressive symptomatology at treatment completion, particularly among participants who began treatment with the lowest self-esteem. Effects were specific to symptoms of depression in contrast with anxiety.

CONCLUSION

These results suggest that a stable, well-consolidated negative self-concept is associated with prolonged depression and a poor response to psychosocial interventions.

Construct and concurrent validity of the Hopkins Verbal Learning Test-revised

The present investigation examined the validity of the revised Hopkins Verbal Learning Test (HVLT-R). In a principal components analysis with varimax rotation, measures of new learning and delayed recall loaded on a single factor distinguishable from measures related to general cognitive function and visual memory. The HVLT-R also correlated most strongly with other tests of verbal memory and relatively weakly with a test of general intelligence. Group comparisons showed that normal controls performed better than age- and education-matched patients with probable Alzheimer's disease (AD) or vascular dementia (VaD). Discriminant function analyses and Bayesian statistics revealed high classification accuracies for dementia patients versus controls. When scores on the HVLT-R and other neuropsychological tests were subjected to discriminant function analyses, performance on the HVLT-R delayed recognition task was found to be the most useful in discriminating patients with AD from those with VaD. We conclude that the HVLT-R is a valid test of verbal learning and memory that is best suited for use with elderly patients suspected of dementia.

Intraductal collagenase delivery into the human pancreas using syringe loading or controlled perfusion

Effective intraductal delivery of the enzyme collagenase into the pancreas is crucial to the subsequent ability to isolate viable islets. Most clinical islet transplant centers load the enzyme into the pancreas by retrograde injection using a syringe following cannulation of the pancreatic duct. An alternative approach is to perfuse the pancreas via the pancreatic duct with collagenase solution using a recirculating perfusion device system. This provides control over perfusion pressures and collagenase temperature. This study reports on our evaluation of the delivery of Liberase-HI into the pancreas of 14 consecutive adult multiorgan cadaveric donors. Alternate glands were procured and processed using an identical protocol with the exception of collagenase delivery. The first group of pancreases was loaded using the perfusion technique where cold (4 degrees C) Liberase-HI was perfused at 80 mmHg for 5 min after which the pressure was increased to 180 mmHg. The collagenase solution was then slowly warmed to 35 degrees C, transferred to the dissociation chamber and mechanically dissociated, and then purified using discontinuous gradients of Ficoll. Pancreases in the second group were loaded with collagenase (28-32 degrees C) using the syringe technique before mechanical dissociation and purification. There were no significant differences in pancreas cold ischemia, donor age, body mass index, maximum blood glucose, or serum amylase of the donors between the two groups. Mean collagenase digestion time in the digestion chamber was not different between the two groups; however, the amount of undigested tissue remaining after dissociation was significantly higher in the syringe-loaded group (15.3 +/- 2.6 g vs. 4.6 +/- 2.1 g, mean +/- SEM, p < 0.05). Postdigestion recovery of islets was 471 +/- 83 x 10(3) IE in the perfusion group compared with 391 +/- 57 x 10(3) IE for the syringe-loaded group. Postpurification recovery was higher in the perfused group (379 +/- 45 vs. 251 +/- 28 x 10(3) IE, p < 0.05, two-tailed paired t-test). No difference in in vitro islet viability was observed between the two groups following glucose perifusion with the calculated stimulation index of 4.6 +/- 0.6 for the perfusion group and 4.2 +/- 0.7 for the syringe-loaded group. Controlled perfusion via the pancreatic duct allows the effective delivery of the enzyme achieving maximal distension to all regions of the pancreas leading to an increased recovery of the islets with no detrimental effect on subsequent in vitro islet function.

Cytomegalovirus (CMV) retinitis activity is accurately reflected by the presence and level of CMV DNA in aqueous humor and vitreous

To evaluate the potential of ocular and systemic specimens to provide markers of active cytomegalovirus (CMV) retinitis, we examined the relationship between virologic and clinical aspects of CMV infections in AIDS patients with CMV retinitis. CMV polymerase chain reaction (PCR) analysis of 74 aqueous humor and vitreous specimens indicated that ocular specimens can provide accurate markers to differentiate active and inactive CMV retinitis (aqueous or vitreous PCR, P<.001). Moreover, these markers were superior to extraocular measures, including plasma PCR (P=.08) and blood and urine CMV cultures (P=.05). A direct correlation was identified between the quantity of CMV DNA in aqueous humor or vitreous specimens and the corresponding surface area of active CMV retinitis (r2=.69 and.44, respectively). Thus, qualitative and quantitative PCR-based analyses of aqueous humor can provide valuable markers of CMV retinitis activity. Such assays could provide rapid and reliable tools to assist in management of patients with CMV retinitis in whom the view of the retina is obscured.

Biliary complications in pediatric living related liver transplantation

BACKGROUND

The goal of this study was to evaluate cause and outcome of biliary complications occurring after pediatric living related liver transplantation (LRLT).

METHODS

A database of 205 pediatric patients (71 male and 134 female) undergoing 208 LRLT from June 1990 to April 1996 was reviewed.

RESULTS

The overall incidence of bile duct complications was 13.9% (29 patients). There were 19 bile leaks, 7 anastomotic strictures, 8 intrahepatic biliary complications, and the bile duct was ligated inadvertently in 2 cases. Logistic regression analysis revealed hepatic artery thrombosis, ABO incompatible transplantation, intrapulmonary shunting in recipients, mode of artery reconstruction, and cytomegalovirus infection were all significant risk factors for biliary complications.

CONCLUSIONS

Avoidance of ABO incompatible transplantation where possible, routine use of microvascular techniques for hepatic artery reconstruction to minimize the risk of artery thrombosis, earlier transplantation for patients with intrapulmonary shunt, and prophylaxis against cytomegalovirus infection should all reduce the rate of biliary complications after LRLT in pediatric recipients.

Auxiliary partial orthotopic liver transplantation from living donors: significance of portal blood flow

BACKGROUND

Auxiliary liver transplantation has several advantages over standard orthotopic liver transplantation. However, functional competition has been reported even in auxiliary partial orthotopic liver transplantation (APOLT). We evaluated herein the interaction in APOLT between the native liver and the graft in terms of portal blood flow and regeneration. The need for diversion of the portal blood flow to the graft was also assessed.

METHODS

A total of 15 patients received APOLT from living donors. Portal blood flow to the native liver was preserved in 6 patients, and the portal vein to the native liver was preemptively transected at the time of transplantation in 9 patients.

RESULTS

Of the patients with preservation of the portal blood flow to the native liver, two showed inadequate graft portal blood flow just after operation, and in the other three patients the graft portal blood flow decreased or the graft atrophied after deterioration of the graft function. In the patients with preemptive transection of the portal vein to the native liver, optimal graft portal blood flow was obtained, and the native liver, supplied only by arterial inflow, supported a small-for-size graft until the graft regenerated. The damage to the native liver was minimal.

CONCLUSIONS

Functional competition may occur in APOLT with preservation of the portal blood flow to the native liver, whereas preemptive transection of the native liver portal vein is a safe procedure and effectively prevents the portal steal phenomenon.

Heat shock protein 72 production in liver tissue after experimental total hepatic inflow occlusion

BACKGROUND

The pathogenesis of hepatic ischaemia-reperfusion injury is incompletely understood. This study examined the effects of reperfusion with congested portal blood on ischaemia-reperfusion injury of the liver following Pringle's manoeuvre, as monitored by heat shock protein (HSP) 72 production in rat liver tissue.

METHODS

Rats were randomized to three groups. In group 1 hepatic ischaemia with portal congestion was induced by Pringle's manoeuvre for 15 min; in group 2 Pringle's manoeuvre was applied for 15 min with an extracorporeal portasystemic shunt; and in group 3 the superior mesenteric vein was occluded for 15 min. The production of HSP72 in liver tissue was measured by Western blotting at 48 h after each intervention. Conventional parameters for hepatic function were examined at 1, 3 and 48 h after reperfusion.

RESULTS

There was marked HSP72 expression in group 1, but not in group 2 or 3, showing that a combination of liver ischaemia and reperfusion of congested portal blood is required to induce strong expression of HSP72 in the tissue. On the other hand, biochemical parameters were raised equally in both groups 1 and 2, reflecting a similar degree of ischaemic hepatocyte injury.

CONCLUSION

The additional stress impact of temporary portal occlusion upon ischaemia-reperfusion injury of the liver was clearly detected by in situ hepatic HSP72 production in this study.

Growth and quality of life after living-related liver transplantation in children

Fifty-six consecutive pediatric recipients surviving more than 3 yr after living-related liver transplantation (LRLT) were evaluated in terms of growth, quality of life (QOL) and need for maintenance immunosuppression. Significant improvement in Z-score for height and weight were observed at last follow-up, ranging from 3 to 6 yr after transplantation, although catchup height gain lagged behind recovery in weight (height: -1.77 pre-transplant to -0.77 post-transplant, p<0.001; weight: -1.12 pre-transplant to -0.18 post-transplant, p<0.0001). 82% (46) recipients have remained in good health and have an excellent QOL as assessed in the most recent 6 months; these children lead similar daily lives to normal healthy children, with daily school attendance and full participation in activities including gymnastics and hiking. 3.6% (2) recipients attended school regularly but were unable to participate in sporting activities. 14% (8) recipients remain home or hospital-bound due to persistent complications in the past 6 months, with only minimal school attendance. Less than 10% of recipients were taking steroids by 2 yr post-transplantation, although approximately half of the children were receiving low-dose maintenance steroids at 1 yr. The mainstay immunosuppressant was tacrolimus, with 68% (38) recipients receiving daily therapy, 8.9% (5) alternate-day, 8.9% (5) twice a week, and 5.4% (3) a single dose weekly or alternate weeks. 7.1% (4) recipients were withdrawn completely from all immunosuppressants, including tacrolimus, for various reasons. 8.9% (5) patients have needed multiple immunosuppressive agents over the last 6 months. In conclusion, LRLT restores growth and offers excellent quality of life in pediatric recipients. The majority of recipients require minimal, steroid-free, immunosuppression by 2 yr post-transplant, but the occasional recipient still needs intensive longterm immunosuppression.

Magnetic resonance imaging of the pediatric airway

OBJECTIVE

To determine the role of magnetic resonance imaging (MRI) and how it relates to endoscopy as well as to other imaging modalities in the evaluation of pediatric airway disorders.

DESIGN

A review study of children with various distal airway disorders over a 3-year period. Surgical procedures as well as all diagnostic imaging modalities were reviewed and analyzed with respect to clinical outcome.

SETTING

Academic tertiary care children's hospitals.

PATIENTS

Forty-nine children between the ages of 1 week and 14 years with the signs and symptoms of distal airway disorders.

INTERVENTIONS

Forty-five of 49 children underwent airway endoscopy. Fourteen children also underwent fluoroscopy and 4 underwent echocardiography. When indicated, open surgical repair was performed and used to verify findings in 32 cases.

RESULTS

Magnetic resonance imaging was the most accurate modality in defining extrinsic airway abnormalities. The findings of echocardiography were incorrect in 2 of 4 cases, and fluoroscopy, although accurate for tracheal narrowing and tracheomalacia, often could not elucidate that exact cause or missed left mainstem bronchial compression. Furthermore, tracheal narrowing to 50% or greater on MRI correlated 100% with the need for surgical intervention.

CONCLUSIONS

Magnetic resonance imaging is a useful modality that has allowed us to accurately diagnose extrinsic pediatric tracheal abnormalities. In certain cases, MRI scans can be obtained prior to endoscopy. In those cases, definitive endoscopy and open repair are performed at the same procedure instead of at 2 separate procedures (ie, one for diagnostic endoscopy and the other for definitive repair).

Porcine model of airway mucosal injury

PURPOSE

The development of a reliable animal model of laryngeal or tracheal stenosis has been limited by lack of reproducibility, high morbidity and mortality, and cumbersome technique. The small size of previously proposed models has limited the development of innovative reconstructive techniques.

MATERIALS AND METHODS

Eleven of 15 post-weanling commercial piglets underwent injury by a sharpened metal rod to the anterior half of the subglottic region at repeated intervals under endoscopic guidance. Four of 15 animals did not undergo injury and served as control for normal subglottic growth over time. Each airway was sized by endotracheal tube (ETT) passage and endoscopic photography over time, and the degree of total stenosis was estimated in comparison to the control animals.

RESULTS

The first two animals underwent daily injury and expired from copious granulation tissue. Eight additional animals developed symptomatic subglottic stenosis manifested by audible stridor and intercostal retractions while undergoing injury every third day. Photographs documented the size of the stenosis to be greater than 50% (40% by ETT sizing) with a mean of three injuries in a mean time of 18 days.

CONCLUSION

The porcine model shows a high degree of tolerance with minimal morbidity and consistent reliable results in an animal model of airway stenosis that is suitable for further innovative studies.

Liver tumor ablation techniques

Despite advances in surgical technique, patients with primary and secondary liver tumors remain a difficult management problem, as most tumors are unresectable at presentation. Alternative therapies, involving the in situ destruction of liver tumors, have recently come under scrutiny as palliative options. Percutaneous ethanol injection and cryosurgery have been advocated, but both have associated technical difficulties and adverse effects. Novel liver tumor ablation techniques have recently been developed that work via the induction of localized hyperthermia. There is mounting evidence to support a hypothesis that cancer cells are more selectively sensitive to heat than are normal cells, due to the poor blood supply of neoplastic tissue and the decreased vasodilatation capacity of the neovascular bed. These ablative modalities induce a variable degree of tumor necrosis in unresectable tumors, and therefore may provide useful palliation. Clinical trials are needed to determine the true nature and degree of any palliative benefit. In addition, the determinants of treatment efficacy and the predictability of the necrotic zone must be better understood before these techniques can be contemplated as alternatives to liver resection for cure.

Recovery from doxacurium infusion administered to produce immobility for more than four days in pediatric patients in the intensive care unit

Doxacurium was administered by titrated infusion to 14 pediatric patients for 4.7-12.3 days after laryngotracheal reconstruction to produce minimum spontaneous movement and less than five posttetanic movements of the first toe after stimulation of the posterior tibial nerve. Recovery was documented by stimulation of the ulnar nerve with 2 Hz for 2 s (train-of-four [TOF]) at intervals of 1 min and measurement of the ratio of the fourth to the first response (TOF ratio) at the adductor pollicis. During spontaneous recovery, the TOF ratio was between 0.4 and 0.7 for 0.6-3.3 h, mean (SEM) 2.2 (0.31) h. The TOF ratio equaled 1 between 4.7 and 23.0 h, mean (SEM) 11.0 (2.1) h after termination of doxacurium infusion. In six of the patients, weakness and decreased coordination were noted for a few days to weeks postoperatively. There were no complications related to impairment of upper airway function or ventilation in those patients who had recovery of neuromuscular transmission to the extent of TOF ratio equal to 1 prior to extubation or in those patients in whom weakness or lack of coordination was noted after tracheal extubation.

High yield of rodent islets with intraductal collagenase and stationary digestion--a comparison with standard technique

Intraductal distention of the pancreas with collagenase followed by stationary warm incubation improves the recovery of islets of Langerhans in the rat, but controlled studies are needed for valid comparison with standard isolation methods. We have modified Gotoh's technique of stationary digestion for high-yield isolation in the rat (Stationary). The method is subjected herein to rigorous blinded comparison with the standard chopped tissue (Chopped) technique, based on Lacy et al., as performed in our laboratory for over 10 yr. Islet recovery was determined by a single observe 'blinded' to the method of isolation used, and only intact islets of diameter > or = 100 microns were included. Stationary gave 719 +/- 114 islets per pancreas (mean +/- SD, n = 21 isolations) vs. 487.5 +/- 69 for Chopped (n = 36 isolations), a 47.5% increment in yield (p < 0.0001). In vitro islet perifusion showed no statistical difference in stimulation index (SI) or stimulated area under the curve (SAUC) between the two methods, but Stationary showed a trend towards improved phase II insulin release. In vivo function was assessed by isogeneic transplantation of 2,000 islets beneath the renal capsule of streptozotocin diabetic recipients (65 mg/kg Sigma); Stationary recipients (n = 7) became normoglycemic (< or = 8 mmol/L) by 3.3 +/- 4.8 days vs. 1.6 +/- 1.5 days for Chopped recipients (p = 0.4 ns, mean +/- SEM). IVGTT performed at 1 mo posttransplant gave K-values for Stationary of 2.64 +/- 0.8 vs. 2.62 +/- 0.8 for Chopped (mean +/- SD, p = 0.9 ns, n = 6, unpaired t-test), which were not distinguishable from normal control rats (2.59 +/- 0.8) (p = 0.9 ns, n = 10). Graft function remained stable until graft bearing nephrectomy induced hyperglycemia uniformly within 1 day. Graft histology showed a healthy well-preserved structure on light microscopy, with well-granulated beta cells on EM. Economic costs of rat, collagenase, and Ficoll were 26% ($50.82) lower per recipient for Stationary. We conclude that modified stationary digestion significantly improves islet recovery with excellent in vitro and in vivo function, and is cost effective.

Is early response to portoenterostomy predictive of long-term outcome for patients with biliary atresia?

PURPOSE

Therapy for biliary atresia (BA) typically involves portoenterostomy (PE). In light of the development of liver transplantation (LT) as an option for therapy in infancy, the authors reviewed their experience to determine factors that might predict the requirement for LT.

METHODS

Cases of BA diagnosed between September 1980 and September 1994 were reviewed. Responses to PE were rated as poor (PR; death or LT by 3 years), temporary (TR; LT > 3 years), or good (GR; anicteric).

RESULTS

Twenty-nine patients were identified; 24% were native indian or Inuit. Twenty-three had PE; 11 responded. Seven (32%) became anicteric and continue to do well (GR). Four (18%) required LT after age 3 (TR). Twelve patients had PR; 3 underwent LT (average age, 1.3 years), 4 are listed for LTX, and 5 died by age 2.8 years. (Six patients did not have PE; 2 died in infancy and 4 had LT.) All transplant recipients are well. Factors associated with PR were older age at time of surgery (67 +/- 7 days v 51 +/- 4 days in the GR group), nadir of AST (273 +/- 84 U/Lv 70 +/- 26 U/L in the GR group), and number of post-PE complications (3.6 v per patient v 1 per patient in the GR group). TR was differentiated from GR by bilirubin nadir (46 +/- 10 mumol/Lv 14 +/- 3 mumol/L, respectively) and rate of bilirubin decline (2.6 +/- 1.5 mumol/L/d v 10.8 +/- 3.0 mumol/L/d, respectively). (P < .05 for all comparisons.)

CONCLUSION

Outcomes are comparable to those of North American series, but the incidence is lower overall and is higher among natives. Factors that correlate with outcome include age at time of surgery, post-PE complications, postoperative decline and rate of decline of bilirubin and AST. The latter had not been reported previously and may prove useful in planning therapy for partial responders after PE.