Switching from omalizumab to mepolizumab therapy improved extra-pulmonary abdominal and cutaneous vasculitis symptoms in a patient with eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic vasculitis of small-to-medium-sized vessels. Both eosinophilic infiltration and vasculitis are thought to contribute to multi-organ damage. Some biologics have been used to reduce the required dose of corticosteroids in EGPA, but no single agent can ensure a complete control of this disease. Here, we describe a patient with anti-neutrophil cytoplasmic antibodies-negative relapsing EGPA whose asthma control was improved by omalizumab, but she continued to develop flares of abdominal and cutaneous vasculitis symptoms. After switching to mepolizumab therapy, her blood hypereosinophilia and extra-pulmonary symptoms were significantly improved. Moreover, the dose of daily maintenance corticosteroid could be tapered off. The experience from our case suggests that biologics targeting interleukin-5 may be more effective than omalizumab in the management of extra-thoracic manifestations in EGPA.

Treatment of electronic cigarette or vaping product use-associated lung injury (EVALI) by corticosteroid and low-dose pirfenidone: Report of a case

Electronic (e)-cigarette or vaping product use-associated lung injury (EVALI) is a novel and potentially lethal disease first reported in the United States. We report the case of a 56-year-old man who presented to our hospital with dyspnoea and cough lasting for 2 months after using an e-cigarette for approximately 50 puffs over 2 weeks. Physical examination revealed crackles in the left lower lung. High-resolution computed tomography (HRCT) showed consolidation and ground-glass opacities in both lungs. The baseline forced vital capacity (FVC) and diffusion capacity for carbon monoxide (DLCO) were 65.7% and 63.9% of the predicted, respectively. Lung biopsy revealed organizing pneumonia with focal fibrosis. In addition to prednisolone, he was treated with a low-dose pirfenidone (200 mg three times per day) due to the persistence of a mild cough, exertional dyspnoea and basal crackles after discharge. His symptoms and FVC significantly improved, but the recovery of the DLCO was slow. The follow-up HRCT demonstrated only minimal fibrotic changes. To our knowledge, this was the first reported case of EVALI successfully treated with a combination of corticosteroid and antifibrotic agents.

0434 Clinical Application of Computer Aided Cloud Sleep Scoring System

Introduction

According to a survey by World Sleep Society, 45% of the population suffered from sleep disorders. The best way to diagnose these patients is to use Polysomnography (PSG), recording their physiological signals throughout the night. Mostly, sleep technologists manually score sleep stages. Manual scoring is quite subjective and time-consuming. Although the technologist’s judgments are based on scoring standards of the American Academy of Sleep Medicine, fine-tuning scoring results because of different considerations in different sleep centers may be happened. In order to assess the consistency of scoring standards in sleep technologists, we tried to establish a cloud sleep scoring system and evaluate its feasibility in 4 sleep centers in southern Taiwan.

Methods

We constructed a computer-aided cloud sleep scoring system. Each sleep technologist could score the same test data of PSG online without being restricted by places and hardware equipment. After comparing scoring results of all participants, the scoring system could provide the following reports, including an overall agreement, agreement of each sleep stage and each sleep index. Besides, multi-person scoring results of each epoch with displaying physiological signals were analyzed.

Results

Seven sleep technologists from 4 hospitals in Tainan, Taiwan joined this study. Standard deviations (SDs) of each sleep stage included 2.64 in Wake stage, 6.90 in N1, 8.31 in N2, 6.87 in N3, 1.38 in REM, respectively. SDs of sleep indexes were 2.64 in sleep efficiency, 2.14 in sleep onset time, 8.35 in wake after sleep onset time, 10.03 in total sleep time, individually. The overall agreement was 89.6%. The satisfaction of this scoring system operation was 85.7%.

Conclusion

With the cloud sleep scoring system assistance, it was feasible to evaluate the scoring consistency among sleep technologists in different sleep centers.

Support

This work is supported by the Ministry of Science and Technology, Taiwan. (MOST 108-2634-F-006-012)

Murine HPV16 E7-expressing transgenic skin effectively emulates the cellular and molecular features of human high-grade squamous intraepithelial lesions

Currently available vaccines prevent HPV infection and development of HPV-associated malignancies, but do not cure existing HPV infections and dysplastic lesions. Persistence of infection(s) in immunocompetent patients may reflect induction of local immunosuppressive mechanisms by HPV, providing a target for therapeutic intervention. We have proposed that a mouse, expressing HPV16 E7 oncoprotein under a Keratin 14 promoter (K14E7 mice), and which develops epithelial hyperplasia, may assist with understanding local immune suppression mechanisms that support persistence of HPV oncogene-induced epithelial hyperplasia. K14E7 skin grafts recruit immune cells from immunocompetent hosts, but consistently fail to be rejected. Here, we review the literature on HPV-associated local immunoregulation, and compare the findings with published observations on the K14E7 transgenic murine model, including comparison of the transcriptome of human HPV-infected pre-malignancies with that of murine K14E7 transgenic skin. We argue from the similarity of i) the literature findings and ii) the transcriptome profiles that murine K14E7 transgenic skin recapitulates the cellular and secreted protein profiles of high-grade HPV-associated lesions in human subjects. We propose that the K14E7 mouse may be an appropriate model to further study the immunoregulatory effects of HPV E7 expression, and can facilitate development and testing of therapeutic vaccines.

Abstract P3-12-12: Incidence of internal mammary node, sternum, and manubrium failure as detected by FDG-18 PET/CT

Introduction:

Elective radiotherapy to the internal mammary (IM) lymph nodes remains an ongoing subject of debate. While the incidence of occult IM involvement on extended mastectomy ranges from 15-65%, reported rates of IM failure are substantially lower (approximately 1%). Interest in this subject has resurfaced recently as randomized trials have shown a survival benefit to adjuvant regional node irradiation including the IM chain. The mechanism by which extended field radiotherapy leads to improved systemic outcomes has not been clearly demonstrated and the degree of benefit directly attributable to IM irradiation remains to be seen. We hypothesized that the IM lymphatic chain may provide a direct route for tumor cell dissemination into the the sternum or manubrium. As such, sternal metastases may be a manifestation of IM involvement rather than true hematogenous metastases. We sought to better elucidate patterns of failure by evaluating the incidence and timing of IM, sternal, or manubrial involvement identified by PET/CT imaging following diagnosis of metastatic breast cancer.

Patients and Methods:

Between 2007 and 2014, 96 patients with invasive breast cancer were found to have metastatic disease as diagnosed on FDG-18 PET/CT. Site of recurrence was scored as breast/chest wall, axilla/supraclav, IM chain, sternum/manubrium, or distant. IM or sternum/manubrium failure was scored as isolated (occurring without distant metastatic disease), synchronous (involved at initial diagnosis of distant metastatic disease), or metachronous (involved at any time after diagnosis of metastatic disease).

Results:

Isolated IM failures were observed in 3.1% of patients while isolated sternum/manubrium failures were recorded in 7.3% of patients. Isolated involvement of the sternum/manubrium or IM nodes occurred in 11.4%. The rate of synchronous IM failure was 11.4% with the rate of metachronous failure being 13.5%. The rate of synchronous sternum/manubrium failure was 17.7% with the rate of metachronous failure being 23.9%. The incidence of sternum/manubrium or IM involvement at the initial diagnosis of distant metastatic disease was 29.2% with the rate of involvement at any point increasing to 36.5%.

Conclusion:

The rate of internal mammary node failure by PET/CT at the time of metastatic diagnosis is higher than the incidence reported in previous trials. This discrepancy is likely due increased sensitivity of PET/CT and the difficulty of accurately assessing this region once patients have been found to have metastatic disease. Interestingly, sternum and manubrium were more often the first site of recurrence than the IM nodes. This could be due to a tropism of hematogenous metastases for these bones or could represent direct tumor cell dissemination from the internal mammary chain. This is of special interest as this region is incidentally included in the radiotherapy fields when targeting the IM nodes. Overall, our findings suggest that historic patterns of failure studies may underestimate the local benefit of internal mammary node radiotherapy.

Citation Format: Grow JL, Choudhary G, Kuo P, Livingston RB, Gonzalez VJ. Incidence of internal mammary node, sternum, and manubrium failure as detected by FDG-18 PET/CT. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-12-12.

[Very preterm births in French Polynesia: update and proposal for follow-up]

INTRODUCTION

The care of premature infants in French Polynesia is complicated by this country's geographic isolation. We undertook an evaluation of the medical care of very premature infants (VPIs) to find local solutions to this problem.

OBJECTIVES

The objectives were to determine the incidence, mortality, and the short- and long-term outcome of very preterm infants in French Polynesia.

METHODS

We retrospectively reviewed the medical charts of all infants born alive at<32 gestational age (GA) and>24 GA from January 2007 to December 2011. Perinatal characteristics and outcomes were examined by univariate and multivariate analysis.

RESULTS

In total, 204 VPIs were born during the 5-year study period, comprising 0.9% of all births. Infants less than 28 GA comprised 0.1% of all births. Sixty-two percent of mothers were of extreme age including 43% less than 25 years old. Prematurity was attributed to spontaneous preterm labor in 63% of cases and preeclampsia in 29%. Spontaneous multiple pregnancies comprised 15% of the cases. Alcohol and tobacco consumption were frequently noted (>8% and 26% mothers, respectively). Seventy-eight percent of VPIs had received prenatal steroids. Intrauterine growth was normal in 89%. Mortality occurred in 9.3% (19 patients). Mortality was higher with lower gestational age (P<0.05) and absence of prenatal steroids (P<0.05) in univariate and multivariate analysis. The primary cause of death was sepsis. Hyaline membrane disease occurred in 44% of patients, 80% of whom received surfactant therapy. In total, 16.2% newborns developed bronchodysplasia, 3.4% necrotizing enterocolitis, 3% cerebral hemorrhage, and 1.5% leukomalacia. Long-term outcome was marked by 52% of the patients lost to follow-up by 2 years of age, mostly because of geographic isolation. For the 72 patients followed-up, four developed asthma and three cerebral palsy; 70% were attending school by 3 years of age.

CONCLUSIONS

The incidence, mortality, and morbidity of very preterm birth in French Polynesia are comparable to reports from metropolitan centers in France. Conversely, nearly one-half of the patients were lost to follow-up, precluding meaningful information on intellectual development and other outcomes. We recommend organizing a long-term follow-up network to detect cognitive sequelae and adapting such a system to the geographical residence of French Polynesian families.

Postprandial cardiac vagal tone and transient lower esophageal sphincter relaxation (TLESR)

BACKGROUND

Transient lower esophageal sphincter relaxation (TLESR) is a vagally mediated reflex that occurs most frequently after a meal. Cardiac vagal tone (CVT) decreases after a meal, and correlates with changes in gastric electrical activity. Furthermore, decreased CVT has been reported in patients with gastro-esophageal reflux disease. We therefore aimed to characterize the association between postprandial changes in CVT and the occurrence of TLESR and reflux.

METHODS

Ten healthy volunteers underwent simultaneous autonomic nervous system, gastric myoelectric activity, lower esophageal-sphincter pressure, and reflux monitoring for 30 min in the fasting state, followed by a standard meal, and a further 4 h postprandially. Results are in mean ± SEM.

KEY RESULTS

The number of TLESRs (P < 0.0001) and reflux episodes (P < 0.0001) increased after the meal, while CVT decreased (P < 0.01). Cardiac sensitivity to baroreceptor reflex (CSB) showed similar time course changes to CVT (P = 0.06). During the first postprandial hour there was a strong correlation between the number of TLESRs and reflux episodes with CVT (R(2)  = 0.51 and R(2)  = 0.50, respectively; P < 0.05). There was also an increase in the dominant power and power ratio on electrogastrography (P < 0.05) after the meal.

CONCLUSIONS & INFERENCES

In healthy volunteers, the increase in the number of TLESRs and reflux episodes after a meal occurred mostly at a time of reduced CVT. Further studies should explore whether modulation of CVT can modify frequency of TLESRs and also this relationship should be further explored in patients with reflux disease.

Hand and wrist research productivity in journals with high impact factors: a 20 year analysis

Bibliometric analyses, which study trends in research productivity, have not previously been applied to hand and wrist research. This study analyses temporal and geographic trends in hand and wrist research from 1988 to 2007. Original research articles were collected from seven English language journals selected on the basis of impact factor. Research production and quality (level of evidence) were determined by country and global region. Linear regression analysis was used to investigate trends. No significant increase in research volume was observed, but journal impact factors have risen significantly since 1988. Western Europe contributed significantly more high-quality (Level I and II) studies than the United States. Research contributions show a geographical distribution concentrated in the US and Western Europe, but considerable changes in this distribution have occurred. From 1988 to 2007, there was a relative increase in research production from Europe, Latin America and Asia, and a relative decline from the US.

Spectral collapse in ensembles of metamolecules

We report on the first direct experimental demonstration of a collective phenomenon in metamaterials: spectral line collapse with an increasing number of unit cell resonators (metamolecules). This effect, which is crucial for achieving a lasing spaser, a coherent source of optical radiation fuelled by coherent plasmonic oscillations in metamaterials, is linked to the suppression of radiation losses in periodic arrays. We experimentally demonstrate spectral line collapse at microwave, terahertz and optical frequencies.

The nitric oxide synthase inhibitor, Ng-nitro-L-arginine-methyl-ester, attenuates the delay in gastric emptying induced by hyperglycaemia in healthy humans

The aim of this study was to determine whether the nitric oxide (NO) synthase inhibitor, N(g)-nitro-L-arginine-methyl-ester (L-NAME), reverses the effects of acute hyperglycaemia on gastric emptying and antropyloroduodenal (APD) motility. The study had a four-way randomized crossover (hyperglycaemia vs euglycaemia; L-NAME vs placebo) design in a clinical laboratory setting. Seven healthy volunteers [four males; age 30.3 +/- 3.8 years; body mass index (BMI) 23.6 +/- 1.2 kg m(-2)] were the study subjects. After positioning a transnasal manometry catheter across the pylorus, the blood glucose concentration was maintained at either 15 or 5 mmol L(-1) using a glucose/insulin clamp. An intravenous infusion of L-NAME (180 microg kg(-1 )h(-1)) or placebo (0.9% saline) was commenced (T = -30 min) and continued for 150 min. At T = -2 min, subjects ingested a drink containing 50 g of glucose made up to 300 mL with water. Gastric emptying was measured using 3D ultrasound, and APD motility using manometry. Hyperglycaemia slowed gastric emptying (P < 0.05), and this effect was abolished by L-NAME. L-NAME had no effect on gastric emptying during euglycaemia. Hyperglycaemia suppressed fasting antral motility [motility index: 3.9 +/- 0.8 (hyperglycaemia) vs 6.5 +/- 0.6 (euglycaemia); P < 0.01]; l-NAME suppressed postprandial antral motility [motility index: 3.6 +/- 0.2 (L-NAME) vs 5.1 +/- 0.2 (placebo); P < 0.001]. Postprandial basal pyloric pressure was higher during hyperglycaemia (P < 0.001), and lower after administration of L-NAME (P < 0.001). Slowing of gastric emptying induced by hyperglycaemia is mediated by NO, and may involve the modulation of tonic pyloric activity.

Towards the lasing spaser: controlling metamaterial optical response with semiconductor quantum dots

We report the first experimental demonstration of compensating Joule losses in metallic photonic metamaterial using optically pumped PbS semiconductor quantum dots.

[Intestinal fistula: an unusual complication of necrotizing enterocolitis in the preterm infant]

Intestinal fistula is a rare complication in necrotizing enterocolitis (NEC) and is typically associated with a colonic stricture. We report the case of a preterm infant with severe NEC, who developed an ileocolic fistula followed by the appearance of a colonic stricture after surgical treatment. This report shows how complex the outcome of NEC can be: a contrast enema should be done in NEC when the clinical or biological outcome is not favorable, in order not to delay the diagnosis of intestinal fistula.

Are concerns over right laparoscopic donor nephrectomy unwarranted?

OBJECTIVE

To examine the ability of several large, experienced transplantation centers to perform right-sided laparoscopic donor nephrectomy safely with equivalent long-term renal allograft function.

SUMMARY BACKGROUND DATA

Early reports noted a higher incidence of renal vein thrombosis and eventual graft loss. However, exclusion of right-sided donors would deprive a significant proportion of donors a laparoscopically harvested graft.

METHODS

A retrospective review was performed among 97 patients from seven centers performing right-sided laparoscopic donor nephrectomy. Surgical and postoperative demographic factors were evaluated. Complications were identified and long-term renal allograft function was compared with historical left-sided laparoscopic donor nephrectomy cohorts.

RESULTS

Right laparoscopic donor nephrectomy was performed for varying reasons, including multiple left renal arteries or veins, smaller right kidney, or cystic right renal mass. Mean surgical time was 235.0 +/- 66.7 minutes, with a mean blood loss of 139 +/- 165.8 mL. Conversion was required in three patients secondary to bleeding or anatomical anomalies. Mean warm ischemic time was limited at 238 +/- 112 seconds. Return to diet was achieved on average after 7.5 +/- 2.3 hours, with mean discharge at 54.6 +/- 22.8 hours. Two grafts were lost during the early experience of these centers to renal vein thrombosis. Both surgical and postoperative complications were limited, with few long-term adverse effects. Mean serum creatinine levels were higher than open and left laparoscopic donor nephrectomy on postoperative day 1, but at all remaining intervals the right laparoscopic donors had equivalent creatinine values.

CONCLUSIONS

These results confirm that right laparoscopic donor nephrectomy provides similar patient benefits, including early return to diet and discharge. Long-term creatinine values were no higher than in traditional open donor or left laparoscopic donor cohorts. These results establish that early concerns about high thrombosis rates are not supported by a multiinstitutional review of laparoscopic right donor nephrectomies.

Can seizures be the only manifestation of transient ischemic attacks? A report of four cases

Several studies have investigated the frequency of epileptic seizures following ischemic strokes and transient ischemic attacks (TIAs). Little attention has been paid to the possibility that seizures may be precipitated by TIAs. We examined if seizures can be the only symptom of a TIA and how often this might occur. We performed a retrospective analysis of clinical charts and electroencephalograms of 160 consecutive patients evaluated for a first-ever seizure from January 1997 to December 1999 at Belluno General Hospital. From January to May 2000, 19 more first-ever seizure patients were evaluated directly. Four patients (2%) had seizures in the presence of important risk factors for ischemic stroke (atrial fibrillation in two patients, atrial fibrillation and ventricular mural thrombus in one patient, hemodynamically significant left carotid stenosis in one patient). Seizures were not accompanied by other neurological deficits or brain lesions on CT or MRI. As risk factors for brain ischemia are frequent in the general population not developing seizures, our results do not prove that the occurrence of seizures was more than casual in these patients. Yet they indicate that in a small percentage of patients, seizures can occur in a context highly suggestive of TIA, with no other focal deficits.

Characteristics of heat flow in optical fiber devices that use integrated thin-film heaters

We describe the analysis of heat flow in a type of tunable optical fiber grating that uses thin-film resistive heaters microfabricated on the surface of the fiber. The high rate of heat loss from these microstructures and the relatively low thermal diffusivity of the glass yield unusual thermal properties. Approximate one-dimensional analytical calculations capture important aspects of the thermal characteristics of these systems. Comparison with experimental results that we obtained from devices with established designs validates certain features of the computations. This modeling also establishes the suitability of integrated thin-film heaters for several new types of tunable fiber grating devices.

Liver transplantation improves cirrhosis-associated impaired oral glucose tolerance

BACKGROUND

Thirty-five percent to 80% of cirrhotic patients have impaired glucose tolerance (IGT) or diabetes mellitus (DM). Diabetic cirrhotics have higher morbidity and mortality than nondiabetics. Therefore, it would be worthwhile to determine whether liver transplantation improves glucose homeostasis in these patients.

METHOD

A total of 26 patients awaiting liver transplantation were evaluated for impaired glucose homeostasis by fasting blood glucose and/or oral glucose tolerance tests (OGTT). Five patients underwent transplant surgery within 1 year of OGTT and had a repeat OGTT 3-6 months after transplantation.

RESULTS

Sixty-five percent (17/26) of the patients had abnormal glucose homeostasis. Twenty-three percent (6/26) met American Diabetes Association criteria for DM, and another 42.3% (11/26) had IGT. All patients had normal HbA1C levels. After transplantation, the 2-hr blood glucose improved in four patients and the mean 2-hr glucose level was reduced (204 +/- 94 vs. 132 +/- 53 mg/dl [mean +/- SD, P=0.051]).

CONCLUSION

Liver transplantation can reverse cirrhosis-associated impaired glucose tolerance.

Bcl-2 leads to expression of anti-DNA B cells but no nephritis: a model for a clinical subset

Transgenic mice expressing anti-DNA antibodies have been extensively studied as a model for understanding B cell regulation in systemic lupus erythematosus (SLE). BALB/c mice transgenic for the R4A-gamma2b heavy chain of an anti-double-stranded DNA (dsDNA) antibody produce two populations of high-affinity anti-dsDNA B cells, one deleted, and the other anergized. We generated double-transgenic BALB / c mice expressing both the R4A-gamma2b heavy chain and the anti-apoptotic bcl-2 gene in the B cell compartment to study whether bcl-2 overexpression differentially affected anergic and deleted B cells. The double-transgenic mice (R4A/bcl-2) express elevated serum titers of both high- and low-affinity anti-dsDNA antibodies and display rescue of autoreactive B cells that are normally either deleted or anergized. Despite the presence of anti-dsDNA antibodies in their serum, R4A/bcl-2-transgenic mice do not develop nephritis, demonstrating that overexpression of bcl-2 is not by itself sufficient to allow disease progression. This phenotype resembles that of some SLE patients who have high titers of anti-DNA antibodies without nephritis.

Crossreactive B cells are present during a primary but not secondary response in BALB/c mice expressing a bcl-2 transgene

While it is clear that multiple genetic factors lead to autoimmune diseases such as systemic lupus erythematosus (SLE), it appears that an environmental stimulus is also required to trigger the disease in susceptible individuals. We have previously demonstrated that B cells making crossreactive antibodies that bind to both phosphorylcholine (PC), a component of pneumococcal cell wall polysaccharide, and double stranded DNA (dsDNA) can be found in BALB/c mice immunized with PC coupled to a protein carrier. While these B cells are normally eliminated in vivo by apoptosis, they can be recovered ex vivo by fusion with a cell line overexpressing the anti-apoptotic gene bcl-2. This observation led us to ask whether in vivo expression of bcl-2 might abrogate immunologic tolerance during an ongoing immune response. In the present study, we have examined BALB/c mice that constitutively express a bcl-2 transgene in the B cell compartment. Bcl-2 transgenic BALB/c mice have an expanded B cell number, but display no evidence of anti-dsDNA antibodies in the serum even following immunization with PC coupled to a protein carrier. Crossreactive anti-DNA, anti-PC B cells can be recovered by hybridoma technology late in the primary response, but do not appear in the memory B cell compartment. Thus, in vivo expression of bcl-2 can rescue B cell autoreactivity in the primary immune response, but is not sufficient for activation of these B cells or for their maintenance in the memory compartment.

[Kidney-pancreas transplantation. Clinical results in 23 consecutive patients]

Immunosuppressive approaches to combined kidney-pancreas tx include quadruple therapy with either antilymphocyte globulin (ATG) or OKT3 for a short period (7-14 days) immediately after transplantation. Maintenance therapy with prednisone, azathioprine and cyclosporin is then used to ensure the long-term survival of the graft. This study reports 23 cases of combined kidney-pancreas tx under ATG induction (n = 7) and OKT3 induction (n = 16). Both groups had maintenance therapy with azathioprine, prednisone and cyclosporin. The follow-up was 12 months. Graft loss was 3 out of 7 vs 1 out of 16 (p < 0.05) for the kidney and 3 out of 7 vs 3 out of 16 for the pancreas in ATG treated vs OKT3 treated patients respectively. There were two deaths in the ATG group and one in the OKT3 group; two patients died with functioning graft, one in each group. The one year actuarial survival was 87% for graft and patient, 83% for kidney and 77% for pancreas. Combined kidney-pancreas tx with ATG or OKT3 have a similar outcome. OKT3 allows a longer period before the onset of rejection. There is a trend in survivals which suggests a better survival in OKT3 treated recipients. Infections and other complications were similar in ATG and OKT3 patients.

Overexpression of bcl-2 alters usage of mutational hot spots in germinal center B cells

Bcl-2 is an anti-apoptotic gene important in B cell development. In order to study how apoptosis regulates somatic hypermutation and selection of B cell clones in the germinal center, we examined the antibody response to phosphorylcholine (PC) in transgenic mice overexpressing bcl-2 in the B cell compartment. The anti-PC antibody response is dominated by the S107V1 variable region heavy chain gene. We, therefore, analyzed S107V1-encoded heavy chains from germinal center cells. The proportion of germinal center sequences that were mutated, and the frequency of mutations did not differ significantly between the two groups of mice. No significant differences were found in the clustering of replacement mutations in the complementarity determining regions (CDRs) and in replacement to silent (R:S) mutation ratios. A significant difference between bcl-2 transgenic mice and controls, however, was found in the targeting of mutations to oligonucleotide motifs presumed to be mutational "hot spots." While non-transgenic mice displayed the expected clustering of mutations in hot spots, mutations from bcl-2 transgenic mice lacked this pattern. This observation suggests that the mechanism for somatic hypermutation includes two distinct functions, a non-specific mutational apparatus and a mechanism to target mutation to hot spots, and that in certain circumstances these functions may be uncoupled.

Evaluation of potential genotoxicity of pulsed electric and electromagnetic fields used for bone growth stimulation

Medical devices emitting pulsed electric and electromagnetic fields have been found to be effective for a number of clinical applications including stimulation of bone and tissue growth. To determine whether pulsed fields of the type used in these clinical applications present a mutagenic hazard, electric and electromagnetic fields at two exposure levels were tested in the Ames test, CHO cell chromosomal aberration assay, BALB/3T3 cell transformation assay and unscheduled DNA synthesis assay in primary rat hepatocytes. For both field types, initial and independent repeat studies were performed for each assay at both clinical and supra clinical doses. In all assays, the results show a lack of cytotoxic, transforming and mutagenic activity. The data suggest that pulsed electric and electromagnetic fields of the type and dose levels used in bone growth stimulation lack mutagenic and transforming activity.

Studies on the structure, regulation, and pathogenic potential of anti-dsDNA antibodies

Studies of anti-double-stranded (anti-ds)DNA antibodies have provided insights into how and why these antibodies arise in systemic lupus erythematosus. In this review we discuss the experimental approaches that have been used by our laboratory to study these autoantibodies. Structure/function analyses including site-directed mutagenesis have helped characterize the molecular genetics of anti-dsDNA antibodies, and more recently peptide libraries have been used to define molecular motifs that these antibodies bind. Most of the pathogenic anti-dsDNA antibodies observed in lupus are somatically mutated. We demonstrated in vitro and in vivo that anti-bacterial antibodies can mutate to acquire specificity for dsDNA. Furthermore, using a fusion partner constitutively expressing bcl-2, NSO(bcl-2), we have shown the existence of anergic or preapoptotic B cells making antibodies that cross-react with both bacterial antigen and dsDNA. Whether defects in the regulation of these antibodies might contribute to serum expression of anti-dsDNA antibodies in some individuals remains unknown. A major emphasis of this review is the regulation of anti-dsDNA antibodies in a transgenic mouse model harboring the gene for the heavy chain of a pathogenic anti-dsDNA antibody. Nonautoimmune transgenic mice effectively regulate autoreactive B cells by anergy and deletion, while their autoimmune counterparts do not. The vast majority of anergic B cells expressing high-affinity transgenic anti-dsDNA antibody fail to display allelic exclusion of the heavy chain. We postulate that this may be one mechanism that allows them to escape deletion. Comparative studies on light chain usage in both the autoimmune and the nonautoimmune transgenic mouse strains have demonstrated that within the autoreactive B-cell population, there are subsets that are differentially regulated. Ultimately transgenic animals making pathogenic autoantibodies may provide us with a system for testing novel therapies for autoimmune disease.

Pulmonary hypertension: considerations in the liver transplant candidate

Pulmonary hypertension is a potentially lethal complication of end-stage liver disease with a prevalence of 2%. In the setting of liver transplantation, the prevalence may be as high as 12%. Given the potential importance of this syndrome to the transplantation community, the purpose of this review is to summarize the current state of understanding of portopulmonary hypertension and to suggest potential management strategies for (1) liver transplant candidates with suspected pulmonary hypertension and (2) intraoperative pulmonary hypertension following liver allograft reperfusion.

Pulmonary hypertension: considerations in the liver transplant candidate

Pulmonary hypertension is a potentially lethal complication of end-stage liver disease with a prevalence of 2%. In the setting of liver transplantation, the prevalence may be as high as 12%. Given the potential importance of this syndrome to the transplantation community, the purpose of this review is to summarize the current state of understanding of portopulmonary hypertension and to suggest potential management strategies for (1) liver transplant candidates with suspected pulmonary hypertension and (2) intraoperative pulmonary hypertension following liver allograft reperfusion.

Postischemic injury, delayed function and Na+/K(+)-ATPase distribution in the transplanted kidney

We evaluated the postischemic renal injury in 22 patients undergoing renal transplantation. Renal tissue obtained 45 to 60 minutes after reperfusion of the allograft was stained with specific antibodies against the delta subunit of Na+/K(+)-ATPase, fodrin and ankyrin. The distribution of each cytoskeletal protein was analyzed by laser confocal microscopy. Subsequent allograft function was assessed on two occasions, 1 to 3 and 36 hours post-reperfusion, respectively. Recipients were divided into two groups: those who achieved a normal GFR on post-transplant day 3 (group 1, N = 12) and those with persistent hypofiltration (group 2, N = 10). Patients of both groups exhibited impaired sodium reabsorption and isosthenuria one to three hours postoperatively, but these abnormalities persisted on day 3 only in group 2 subjects with persistent hypofiltration. Abnormalities of Na+/K(+)-ATPase, ankyrin and fodrin were confined to proximal tubule cells and were marked only in the subjects of group 2. They consisted of redistribution of each cytoskeletal protein from the basolateral membrane to the cytoplasm. We conclude that postischemic injury to a renal allograft results in a loss of polarity of proximal tubule cells. We propose that ensuing impairment of proximal sodium reabsorption could activate tubuloglomerular feedback, thereby contributing to the protracted hypofiltration that characterizes this form of postischemic, acute renal failure.

The incidence of renal failure in one hundred consecutive heart-lung transplant recipients

Between March 1981 and November 1992, 100 heart-lung transplantations were performed at our institution. We report on the renal function in the 67 patients who survived a minimum of 6 months posttransplantation, and who were aged more than 10 years at the time of transplant. Renal function was determined by serial measurement of serum creatinine. Mean serum creatinine increased from 0.96 +/- 0.03 mg/dL at baseline to 1.55 +/- 0.07 mg/dL at 6 months posttransplantation, to 1.88 +/- 0.11 mg/dL at the end of follow-up (mean follow-up, 50.0 months; range, 6 to 140 months). The decline in renal function was biphasic, with a rapid decrease in the first 6 months, followed by a much slower decline. Three patients developed end-stage renal failure. This compares with 14 of 416 cardiac transplant recipients at Stanford who developed end-stage renal failure over the same period. We conclude that in our large series at a single center the incidence of renal impairment and end-stage renal failure is low and similar between heart-lung and heart transplant patients.

Novel method for isolating mammalian cells defective in fluid-phase endocytosis

A new method for isolating mutants defective in fluid-phase endocytosis has been developed based on the observation that endocytosed horseradish peroxidase can be made lethal to cells. The method was used to isolate a mutant from Chinese hamster ovary cells, termed HRP-1, that was temperature-sensitive for viability and had a 70% reduction in the rate of horseradish peroxidase endocytosis at the restrictive temperature. At high temperature, HRP-1 cells were also defective in the secretory path and their Golgi complex disappeared at the resolution of fluorescence microscopy. These properties are similar to two previously described mutants of CHO cells, DS28-6 and V.24.1. In complementation tests, mutants HRP-1, DS28-6, and V.24.1 all appeared to be in the same complementation group.

Laser surgery procedures in the operational KC-135E aviation environment

The operational aviation and space environments present a potential for surgical trauma to aircrew and passengers. Current wound care techniques for trauma in the aviation and space medicine environment focus on classical surgical management of wounds. Medical lasers used in these environments can provide rapid control of bleeding wounds, reduce aircraft environmental contamination from body fluids and secretions, and foster rapid triage of injured personnel. Self-contained and reusable medical lasers have the potential to reduce the material supply of medical kits in the aviation and space environment. A miniaturized carbon dioxide laser was used to establish protocols and procedures for use on operational military KC-135E aircraft. Laser surgery was performed to demonstrate laser efficacy and safety in flight.

Managing aphthous ulcers: laser treatment applied

The recurrent aphthous ulcer is a common oral ulcerative condition. Therapies are pharmaceutical in nature, remain palliative and do not alleviate pain. Carbon dioxide laser therapy was used to treat a minor form of the ulcer (canker sore); the laser therapy reduced or eliminated the pain and inflammation with normal wound healing.

Effect of membrane fatty acyl composition on LDL metabolism in Hep G2 hepatocytes

The mechanism by which dietary cis-unsaturated fatty acids lower plasma levels of low-density lipoprotein (LDL) cholesterol is unknown. Since plasma membrane incorporation of dietary cis-unsaturated fatty acids is known to alter the function of plasma membrane associated proteins, perhaps by increasing membrane fluidity, we examined LDL receptor function in Hep G2 hepatocytes that were unmodified, enriched with the cis-unsaturated fatty acids oleate or linoleate, or enriched with the saturated fatty acids stearate or palmitate. Hepatocytes enriched in cis-unsaturated fatty acids exhibited augmented LDL binding, uptake, and degradation in comparison to unmodified cells. In contrast, Hep G2 hepatocytes enriched in saturated fatty acids had decreased LDL binding, uptake, and degradation. Enrichment with oleate or linoleate resulted in a decrease in the calculated fatty acyl mole-weighted melting point of the plasma membrane and an increase in plasma membrane fluidity, as measured by the steady-state fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene incorporated into the plasma membrane. Conversely, stearate or palmitate enrichment resulted in an increased plasma membrane fatty acyl mole-weighted melting point and decreased plasma membrane fluidity. LDL binding, uptake, and degradation varied with plasma membrane fluidity in a highly correlated manner. Thus, one mechanism by which dietary cis-unsaturated fatty acids lower LDL cholesterol may possibly involve an alteration in membrane lipid composition or membrane fluidity that promotes enhanced LDL receptor function, thereby leading to increased hepatic clearance of LDL.

Plasma membrane enrichment with cis-unsaturated fatty acids enhances LDL metabolism in U937 monocytes

The mechanism by which dietary cis-unsaturated fatty acids lower low density lipoprotein (LDL) cholesterol is unknown. Because cis-unsaturated fatty acids incorporated into cell membranes increase membrane fluidity and, as a result, can alter membrane-dependent cell functions, we examined LDL binding, uptake, and degradation in upregulated U937 monocytes enriched in membrane oleate, a monounsaturated fatty acid, and membrane linoleate, a polyunsaturated fatty acid. The same parameters were also examined in upregulated U937 monocytes enriched in membrane stearate, a saturated fatty acid, and in upregulated, unmodified U937 monocytes. Monocytes enriched in cis-unsaturated fatty acids exhibited augmented LDL binding, internalization, and degradation compared with both stearate-enriched monocytes and unmodified monocytes. The molar potency of linoleate in augmenting LDL metabolism was 50% greater than that of oleate. Enrichment with oleate and linoleate resulted in a decrease in the fatty acyl mole-weighted melting point of the plasma membrane and an increase in plasma membrane fluidity, as indicated by a reduction in the steady-state fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene incorporated into the membrane. Stearate-enriched monocytes exhibited a slight increase in the plasma membrane fatty acyl mole-weighted melting point and essentially no change in plasma membrane fluidity. Thus, one mechanism by which cis-unsaturated fatty acids lower LDL cholesterol may involve alteration in membrane lipid composition and physical properties, thereby leading to an increase in cellular clearance of this atherogenic lipoprotein.

Insulin receptors on erythrocytes and hepatocytes from streptozotocin induced diabetic rats

Insulin receptors on hepatocytes and erythrocytes were studied in rats two and eight weeks after the injection of streptozotocin (50 mg/kg) to see if erythrocyte insulin receptors change parallel with hepatocyte insulin receptors in response to hypoinsulinemia. Insulin binding to hepatocytes increased two (14.0 +/- 2.5% v.s. 7.7 +/- 0.7%; P less than 0.025) and eight weeks (15.9 +/- 1.9% v.s. 6.6 +/- 1.1%; P less than 0.005) after the streptozotocin injection. Scatchard analysis revealed that this increase was due to a rise in both the receptor concentration and affinity. The number of receptors was comparable in the two- and eight-week-streptozotocin rats while the increase in the affinity was more pronounced in the latter group. Insulin binding to the erythrocytes was also increased in both two- (5.0 +/- 0.7% v.s. 4.2 +/- 0.6%) and eight-week- (4.3 +/- 0.6% v.s. 2.7 +/- 1.2%) streptozotocin rats. This increase was due to a rise in the receptor concentration rather than the affinity. However, compared to hepatocytes, these changes were inconsistent and statistically not significant. Furthermore, no correlation was obtained between the binding and plasma insulin concentration. These results indicate that insulin receptors on rat erythrocytes are less sensitive to a change in the plasma insulin concentration and do not always reflect accurately the receptor state on hepatocytes.