0611 Screening for Obstructive Sleep Apnea in the Bariatric Surgery Population

Introduction

Obstructive sleep apnea (OSA) is prevalent in the bariatric surgery population and has been associated with increased perioperative risk, especially if OSA is moderate-severe (apnea-hypopnea index ≥ 15/h). Consequently, screening for OSA is recommended as part of the preoperative evaluation. Several screening tools for OSA have been developed; however, some tools lack validation and their relative performance is unclear. The purpose of this study was to compare four existing screening tools (Epworth Sleepiness Scale (ESS), STOP-BANG, NO-OSAS, and No-Apnea) with regards to the ability to identify patients with moderate-severe OSA among bariatric surgery patients.

Methods

We retrospectively reviewed data from Jan 2015 to Mar 2019 for adult patients presenting consecutively to UC San Diego for first-time bariatric surgery who had undergone a home or in-lab sleep study (within one year of the initial encounter for bariatric surgery), which is our standard of care. We compared the accuracy of the four screening tools for detecting moderate-severe OSA based on the area under the receiver operating characteristic curves (AUC). Subgroup analyses were explored based on sex, BMI, and ethnicity (Hispanic/Latino vs non-Hispanic/Latino).

Results

Of the 214 patients (83.2% female, median age 39 years) included in the study, 45.4% had moderate-severe OSA. STOP-BANG (AUC 0.75 [95%CI: 0.68 to 0.81]) and NO-OSAS (AUC 0.76 [95%CI: 0.69 to 0.82]) had similar performance (p 0.62); both performed significantly better than the ESS (AUC 0.61 [95%CI: 0.54 to 0.68]; p 0.02 for both). STOP-BANG and NO-OSAS tended to perform better in the female vs male subgroup, but this finding did not reach statistical significance.

Conclusion

STOP-BANG and NO-OSAS are superior to the ESS when screening bariatric surgery patients for moderate-severe OSA. In future analyses we will further explore if adjustments of standard cut-offs improve test characteristics (i.e. sensitivity/specificity) when screening bariatric surgery patients (analyses ongoing).

Support

None.

0690 An Evaluation Of Genioglossus Strengthening On Obstructive Sleep Apnea Treatment Outcomes

Introduction

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of pharyngeal collapse. The genioglossus is a major upper airway dilator muscle thought to be important in OSA pathogenesis. Upper airway (UA) muscle training has reported benefits in some OSA patients. Our goal was to assess the effect of upper airway muscle training on OSA outcomes.

Methods

Sixty five patients with OSA (AHI>10/h) were divided in three subgroups: 1) Treated with auto-CPAP (n=21), 2) Previously failed or refused CPAP therapy (no treatment), (n=24), 3) Currently treated with an oral appliance who still have residual OSA (AHI>10/h), (n=20). All subjects were given a custom-made tongue strengthening device. Within each group we conducted a prospective, randomized, controlled study examining the effect of upper airway muscle training. In each subgroup, subjects were randomized to UA muscle training (volitional protrusion against resistance) or sham group (negligible resistance), with 1:1 ratio over 6 weeks of treatment (twice daily for 20 min/session). In the baseline and the final visit, subjects completed home sleep testing, questionnaires (ESS, PSQI), acoustic pharynogometry, Iowa Oral Performance Instrument (IOPI), and Psychomotor Vigilance Test (PVT).

Results

Results remain blinded; 33 patients received treatment Y and 32 patients received treatment Z. To date, we have not observed a main effect of treatment group on several measures of OSA severity. Some changes in subjective measures over time were observed but difficult to interpret until unblinding occurs.

Conclusion

Treatment of OSA using upper airway muscle training exercises requires further study. Whether muscle training is a viable approach for a definable subset of OSA patients remains unclear.

Support

R01HL085188-05A1 (U.S. NIH Grant/Contract)

Outcome of Weekly Carboplatin-Paclitaxel-based Definitive Chemoradiation in Oesophageal Cancer in Patients Not Considered to be Suitable for Platinum-Fluoropyrimidine-based Treatment: A Multicentre, Retrospective Review

AIMS

Although cisplatin-fluoropyrimidine-based definitive chemoradiotherapy (dCRT) is a standard of care for oesophageal cancer, toxicity is significant and limits its use in elderly and frail patients. Weekly carboplatin-paclitaxel-based dCRT provides a viable alternative, although prospective data are lacking in the dCRT setting. Here we report the results of a national, multicentre retrospective review of outcome in patients treated with weekly carboplatin-paclitaxel-based dCRT.

MATERIALS AND METHODS

In this multicentre retrospective study of nine radiotherapy centres across the UK we evaluated the outcome of patients who had non-metastatic, histologically confirmed carcinoma of the oesophagus (adenocarcinoma, squamous cell or undifferentiated; World Health Organization performance status 0-2; stage I-III disease) and had been selected to receive weekly carboplatin-paclitaxel-based dCRT as they were considered not suitable for cisplatin-fluoropyrimidine-based dCRT. dCRT consisted of carboplatin AUC 2 and paclitaxel 50 mg/m2 (days 1, 8, 15, 22, 29) and the recommended radiation dose was 50 Gy in 25 daily fractions. We assessed overall survival, progression-free survival (PFS; overall, local and distant), proportion of patients who were failure free at the response assessment (12 weeks after dCRT), treatment compliance and toxicity.

RESULTS

In total, 214 patients from nine UK centres were treated between 15 February 2013 and 19 March 2019: 39.7% of patients were ≥75 years; 18.7% ≥ 80 years. Indications for weekly carboplatin-paclitaxel-based dCRT were comorbidities (47.2%), clinician choice (36.4%) and poor tolerance/progression on cisplatin-fluoropyrimidine induction chemotherapy (15.8%). The median overall survival was 24.28 months (95% confidence interval 20.07-30.09) and the median PFS was 16.33 months (95% confidence interval 14.29-20.96). Following treatment, 69.1% (96/139) had a combined complete response on endoscopy with non-progression (complete response/partial response/stable disease) on imaging. The 1- and 2-year overall survival rates for this patient group were 81.9% (95% confidence interval 75.6-86.8%) and 50.6% (95% confidence interval 40.5-60.0%), respectively. Thirty-three per cent (n = 70) of patients experienced at least one grade 3 + acute toxicity (grade 3/4 haematological: 10%; grade 3/4 non-haematological: 32%) and there were no treatment-related deaths. 86.9% of patients completed at least four cycles of concomitant weekly carboplatin-paclitaxel-based chemotherapy and planned radiotherapy was completed in 97.7% (209/214).

CONCLUSION

Weekly carboplatin-paclitaxel-based CRT seems to be well tolerated in elderly patients and in those with comorbidities, where cisplatin-fluoropyrimidine-based dCRT is contraindicated. Survival outcomes are comparable with cisplatin-fluoropyrimidine-based dCRT.

An Under-Recognised Cause of Iatrogenic, Severe Metabolic Acidosis

Case Pyroglutamic acidosis is an uncommonly diagnosed but important cause of a high anion gap metabolic acidosis. Our case report concerns an elderly male admitted to the Intensive Care Unit (ICU) following the acute onset of coma which developed during treatment of a prosthetic joint infection. A diagnosis of pyroglutamic acidosis was ultimately made and later confirmed with laboratory testing. Blood gas analysis revealed a profound high anion gap metabolic acidosis. Treatment Treatment included withdrawal of the precipitating medications, N-acetylcysteine and sodium bicarbonate. Discussion This case highlights an unusual cause of severe metabolic acidosis caused by commonly used medications and readily reversible if recognised. This is of particular relevance in elderly, frail patients as incorrect alternate diagnoses may result in decisions which incorrectly limit critical care therapies.

Rapid healing of chronic venous ulcers following ultrasound-guided foam sclerotherapy

Objective: To measure the short term response of venous ulcers in patients treated with ultrasound-guided foam sclerotherapy (UGFS) at a two-week clinic in Honduras.

Methods: Nine females (ages 25-86; mean 48.1 years) with 13 venous ulcers and saphenofemoral junction reflux were treated with UGFS (polidocanol 3% foam; 1–4 injections; 2–11 cc; Mean Volume 5.4 cc). The dimensions of each ulcer and of the great saphenous vein (GSV) were measured before treatment and one week later.

Results: At one week follow-up 2 ulcers healed, 2 GSVs closed, and there was significant improvement in ulcer dimensions (p=0.00) and size of GSV (p=0.00).

Conclusions: Venous ulcers in patients with serve venous insufficiency responded quickly to UGFS. Long-term follow-up will be important to determine the sustainability of these results.

Morton's neuroma: clinical testing and imaging in 76 feet, compared to a control group

BACKGROUND

Morton's neuroma is a mechanically induced degenerative neuropathy.

METHODS

We compared clinical and MRI findings in 76 feet treated operatively for Morton's neuroma and 40 feet with different pathologies (controls).

RESULTS

In the 'treatment group' web space tenderness (WST) was positive in 95%, foot squeeze (SQU) in 88%, plantar percussion (PLP) in 61%, and toe tip sensation deficit (TTSD) in 67%. MRI identified neuromata in 97%. Histological examination confirmed neuroma excision in 99%. Frequency of positive tests was significantly higher in the treatment group compared to controls. MRI revealed (asymptomatic) neuromata in 10/40 (25%) feet in the control group. TTSD was similarly positive in asymptomatic and symptomatic neuromata. TTSD in association with any other test being positive, was significantly more frequent in symptomatic neuromata.

CONCLUSIONS

The diagnosis of Morton's neuroma, based on clinical and imaging findings, was accurate. Positive clinical testing was more frequent in the 'treatment' group compared to the 'control' group.

First steps towards effective methods in exploiting high-throughput technologies for the determination of human protein structures of high biomedical value

The EC 'Structural Proteomics In Europe' contract is aimed specifically at the atomic resolution structure determination of human protein targets closely linked to health, with a focus on cancer (kinesins, kinases, proteins from the ubiquitin pathway), neurological development and neurodegenerative diseases and immune recognition. Despite the challenging nature of the analysis of such targets, approximately 170 structures have been determined to date. Here, the impact of high-throughput technologies, such as parallel expression of multiple constructs, the use of standardized refolding protocols and optimized crystallization screens or the use of mass spectrometry to assist sample preparation, on the structural biology of mammalian protein targets is illustrated through selected examples.

Cellular basis of potato spindle tuber viroid systemic movement

Viroids are small, nontranslatable pathogenic RNAs that replicate autonomously and traffic systemically in their host plants. We have used in situ hybridization to analyze the trafficking pattern of Potato spindle tuber viroid (PSTVd) in tomato and Nicotiana benthamiana. When PSTVd was inoculated onto the stem of a plant, it replicated and trafficked to sink, but not source, leaves. PSTVd was absent from shoot apical meristems. In the flowers of infected plants, PSTVd was present in the sepals, but was absent in the petals, stamens, and ovary. The replicative form of PSTVd was detected in the phloem. Our data demonstrate that (i) PSTVd traffics long distance in the phloem and this trafficking is likely sustained by replication of the viroid in the phloem, and (ii) PSTVd trafficking is governed by plant developmental and cellular factors. The dependency of PSTVd and other viroids on cellular mechanisms for RNA trafficking makes them excellent tools to study such mechanisms.

Registration of stereo and temporal images of the retina

The registration of retinal images is required to facilitate the study of the optic nerve head and the retina. The method we propose combines the use of mutual information as the similarity measure and simulated annealing as the search technique. It is robust toward large transformations between the images and significant changes in light intensity. By using a pyramid sampling approach combined with simulated reannealing we find that registration can be achieved to predetermined precision, subject to choice of interpolation and the constraint of time. The algorithm was tested on 49 pairs of stereo images and 48 pairs of temporal images with success.

Development of novel monoclonal antibodies for the analysis of functional sites in FGF-2

Fibroblast growth factor 2 (FGF-2) can function as a potent mitogen, as well as a survival factor for a variety of mammalian cell types. The biological effects of FGF-2 are mediated by its interaction with two types of cellular binding sites: (1) high affinity tyrosine kinase receptors; and (2) low affinity heparan sulfate proteoglycans (HSPGs) on the cell surface. Although numerous FGF-2 antibodies have been used previously to analyze its biological actions, few studies have utilized antibodies to analyze domains within FGF-2 involved in its interactions with the two binding sites. In this report, we describe the generation and use of two monoclonal antibodies against human recombinant FGF-2 (254F1 and 256A12) that inhibit FGF-2 function. However, these antibodies appear to target preferentially different domains within the FGF-2 molecule, and therefore differentially influence the interactions of FGF-2 with its low and high affinity receptors. 254F1 is a more effective inhibitor of the high affinity, receptor tyrosine kinase binding site, whereas 256A12 appears to be a better inhibitor of the low affinity, HSPG interactions. We also demonstrate that the two antibodies are potent inhibitors of FGF-2 stimulated vascular cell proliferation, and as such have potential use in the treatment of vascular hyperproliferative diseases.

Nurses' attitudes towards cost-effectiveness and quality of care

OBJECTIVE

To describe nurses' attitudes toward cost-effectiveness in nursing practice and its perceived effects on quality of care, and to examine the influence of role, education, and experience on these attitudes.

DESIGN

A comparative, descriptive design was used.

SETTING

Two community hospitals in the midwest.

SUBJECTS

Registered nurses and licensed practical nurses.

MEASUREMENTS AND MAIN RESULTS

Blaney Hobson Nursing Attitude Scale was used to measure nurses' attitudes toward cost-effectiveness. Demographic information was obtained by asking open-ended questions. Scores ranged from 30 to 96, with a mean score of 65.57 (SD = 13.58).

CONCLUSIONS

Nurses with greater than 10 years experience had more positive attitudes than nurses with 10 years or less experience. Nurses in administration/management positions had more positive attitudes than did staff nurses. No significant correlation was found between education level and attitudes toward cost-effectiveness. The major concern of participants was that quality of care would suffer due to cost containment efforts. The majority of participants agreed that education in cost containment and budgetary issues should begin in basic nursing school and should be included in employer orientation programs.

Disproportionate fetal growth and fingerprint patterns

Fingerprint whorl patterns are formed during fetal life. In a group of 180 term infants, those with more fingerprint whorls tended to have a small abdominal circumference (P = 0.09) and high ratio of head to abdominal circumference (P = 0.008). These associations were independent of the relation between the whorl counts of the mothers and their infants. We also found an independent correlation between the babies' whorl count and the combination of increasing subscapular (P = 0.03) and decreasing triceps (P = 0.02) skinfold thicknesses of the mothers. Whorl patterns are associated with adult hypertension; maternal nutritional status may influence their common origin during fetal development.

Cell-to-cell movement of potato spindle tuber viroid

Viroids are non-translatable, autonomously replicating circular RNAs that infect only plants. An important component of the viroid infection process is cell-to-cell movement; however, there is virtually no information available about the pathways and mechanisms of this process. In this study, potato spindle tuber viroid (PSTVd) has been used as a model system to investigate the mechanism of viroid cell-to-cell transport. Infectious RNA transcripts were produced from PSTVd cDNA clones in vitro, labeled with the nucleotide-specific fluorescent dye TOTO-1 iodide, and used for micro-injection. When injected into symplasmically isolated guard cells of mature tomato and tobacco leaves, PSTVd remained in the injected cells; in contrast, PSTVd injected into symplasmically connected mesophyll cells moved rapidly from cell to cell. A 1400 nt RNA containing only vector sequences was unable to move out of the injected mesophyll cells, but when PSTVd was fused to this transcript, the fusion RNA moved from cell to cell. At the DNA level, PSTVd cDNA also appears able to mediate cell-to-cell movement of plasmid DNA. These data indicate that (i) PSTVd moves from cell to cell via plasmodesmata, and (ii) this movement may be mediated by a specific sequence or structural motif.

Psychosocial outcome of children evaluated for short stature

OBJECTIVE

To assess the psychosocial functioning of adults who were evaluated as children for short stature and were not treated with human growth hormone.

DESIGN

Inception cohort study.

SETTING

Hospital-based pediatric endocrinology clinic.

PARTICIPANTS

From 1975 to 1980, medical record review indicated that 181 of the children referred to our clinic for concerns about short stature were non-growth hormone deficient. In 1992 and 1993, we were able to recruit 35 of these patients for a follow-up study. Eligible subjects were at least 18 years of age at the time of follow-up.

MAIN OUTCOME MEASURES

Standardized self-report questionnaires assessed various domains of psychosocial adjustment. Also, a brief test of intellectual functioning was administered and subjects underwent a semistructured in-person interview to evaluate pragmatic functioning and experiences associated with short stature.

RESULTS

Few significant differences between the study sample and standardization samples were found on measures of psychosocial and intellectual functioning. Within-group childhood height during the first evaluation appointment was not significantly associated with most adult measures of psychosocial adjustment. Shorter adult stature was significantly associated with lower educational achievement, lower self-esteem, and greater emotional distress.

CONCLUSIONS

The absence of significant psychosocial distress or impairment in these subjects brings into question one basis for hormonal treatment for non-growth hormone deficient short stature; that short stature in childhood is likely to lead to psychological dysfunction in adulthood. The results, however, also suggest that shorter stature in adulthood may constitute a psychosocial stressor, increasing vulnerability across several domains.

The in vivo and in vitro characterisation of an engineered human antibody to E-selectin

BACKGROUND

E-selectin is an endothelial cell specific adhesion molecule that is believed to play an important role in the early stages of leukocyte extravasation.

OBJECTIVES

Here we describe the construction and evaluation of an engineered human monoclonal antibody that blocks E-selectin function.

RESULTS

SPLAT-1 is an engineered human monoclonal antibody that has a very similar affinity for E-selectin as its murine parent antibody. In vitro SPLAT-1 blocks the binding of human leukocytes to E-selectin and does not mediate antibody-dependent cellular cytotoxicity (ADCC) or complement-mediated lysis of endothelial cells. In vivo, SPLAT-1 inhibits the recruitment of leukocytes to cytokine-inflamed human skin grafted on to SCID mice and has a long circulating half-life in primates. It does not appear to provoke an immune response in primates even on repeat administration.

CONCLUSIONS

SPLAT-1 has the characteristics of a antibody suitable for human therapy studies.

Cryptosporidium parvum oocysts recovered from water by the membrane filter dissolution method retain their infectivity

Cryptosporidium parvum oocysts infectious to neonatal BALB/c mice were processed by the cellulose-acetate membrane (CAM) filter dissolution method to determine if the procedure that utilizes acetone incubation and alcohol centrifugations alters their viability (determined by in vitro excystation) or infectivity (determined by infectivity bioassay). In addition, most oocysts with altered viability by desiccation, heat inactivation, and snap freezing that were processed by the CAM filter dissolution method were nonrefractile, unstained oocyst ghosts. The remaining organisms, oocyst shells, were lightly stained with the acid-fast stain. Infectious oocysts retained their infectivity and nonviable oocysts (oocyst shells) retained their morphology when processed by the CAM dissolution method. Infectious oocysts, oocyst shells, and oocyst ghosts produced positive reactions of similar intensity in direct immunofluorescence antibody staining, utilizing the MERIFLUOR Cryptosporidium/Giardia test kit. Cryptosporidium oocysts recovered from finished drinking water by the CAM dissolution method can be subjected to testing for their viability and infectivity.

Diagnosis of subclinical cryptosporidiosis in captive snakes based on stomach lavage and cloacal sampling

The applicability of stomach lavage and cloacal swab techniques for diagnosis of subclinical cryptosporidiosis were tested in eight captive snakes subclinically infected with Cryptosporidium serpentis. Two feeding regimes were employed. The snakes were first fed 7 days prior to stomach and cloaca sampling, and then 3 days prior to sampling, and the oocysts were detected by fluorescein labeled monoclonal antibody (mAb) and by acid-fast stained (AFS) direct wet smear (DWS). The overall sensitivity of AFS DWS was 95% for stomach samples and 57% for cloacal samples, with false-negativity of 5% and 43%, respectively. A significant relationship (P < 0.01) was found between stomach and cloacal samples when mAb were used for oocyst detection. Stomach sampling was diagnostically superior to cloacal sampling for identifying snake subclinical cryptosporidiosis. Based on gastric aspirates, cryptosporidial infection was diagnosed in all eight animals, and only in two or four snakes when cloacal swab material was processed by AFS or by mAb, respectively. Feeding snakes 3 days prior to sampling facilitated diagnosis based on stomach samples; however, it did not improve diagnosis when cloacal samples were used. The fraction of oocyst-positive stomach samples was significantly higher (P < 0.05) for snakes fed 3 days prior to gastric lavage when compared with the fraction of positive samples of snakes fed 7 days prior to lavage. If subclinical cryptosporidiosis is suspected in a non-eating snake patient, force-feeding and stomach lavage, 3 days after the meal, is recommended.

Predicting surgical outcome for pain relief and return to work

BACKGROUND

We evaluated a new psychological test (Paindex) for identifying and quantifying psychological factors associated with poor surgical outcome, and predicting the degree of pain relief and return to work.

METHOD

This test was administered to 120 randomly selected patients before carpal tunnel and laminectomy surgeries.

RESULTS

This test correctly predicted the probability of pain relief and return to work in 46 of the 50 laminectomy patients (92%), and 63 of the 70 carpal tunnel patients (90%). The overall test sensitivity was 86% and the specificity 94%.

CONCLUSION

These findings indicate that this can be a useful adjunctive test for identifying psychological problems that could have a bearing on the decision to operate and then problems that could occur after surgery, particularly in cases where the extent and degree of pain and disability are judged to be considerably in excess of the objective medical findings.

Predicting surgical outcome for pain relief and return to work

BACKGROUND

We evaluated a new psychological test (Paindex) for identifying and quantifying psychological factors associated with poor surgical outcome, and predicting the degree of pain relief and return to work.

METHOD

This test was administered to 120 randomly selected patients before carpal tunnel and laminectomy surgeries.

RESULTS

This test correctly predicted the probability of pain relief and return to work in 46 of the 50 laminectomy patients (92%), and 63 of the 70 carpal tunnel patients (90%). The overall test sensitivity was 86% and the specificity 94%.

CONCLUSION

These findings indicate that this can be a useful adjunctive test for identifying psychological problems that could have a bearing on the decision to operate and then problems that could occur after surgery, particularly in cases where the extent and degree of pain and disability are judged to be considerably in excess of the objective medical findings.

The inhibition of antigen-induced eosinophilia and bronchoconstriction by CDP840, a novel stereo-selective inhibitor of phosphodiesterase type 4

1. The novel tri-aryl ethane CDP840, is a potent and selective inhibitor of cyclic AMP phosphodiesterase type 4 (PDE 4) extracted from tissues or recombinant PDE 4 isoforms expressed in yeast (IC50S: 4-45 nM). CDP840 is stereo-selective since its S enantiomer (CT 1731) is 10-50 times less active against all forms of PDE 4 tested while both enantiomers are inactive (IC50S: > 100 microM) against PDE types 1, 2, 3 and 5. 2. Oral administration of CDP840 caused a dose-dependent reduction of interleukin-5 (IL-5)-induced pleural eosinophilia in rats (ED50 = 0.03 mg kg-1). The eosinophils in pleural exudates from CDP840-treated animals contained higher levels of eosinophil peroxidase (EPO) than cells from control animals, suggesting a stabilizing effect on eosinophil degranulation. CDP840 was approximately equi-active with the steroid dexamethasone in this model and was 10-100 times more potent than the known PDE 4-selective inhibitors rolipram and RP73401. The activity of CDP840 was not influenced by adrenalectomy, beta-sympathomimetics or beta-sympatholytics. 3. Antigen-induced pulmonary eosinophilia in sensitized guinea-pigs was reduced dose-dependently by CDP840 (0.01-1 mg kg-1, i.p.) and intracellular EPO levels were significantly higher. CDP840 was more potent in these activities than CT1731 or rolipram and comparable in potency to RP73401. 4. Rolipram or CDP840 were less active than dexamethasone in preventing neutrophil accumulation, or exudate formation in carrageenan-induced pleurisy in rats and thus do not exhibit general anti-inflammatory activity. 5. In sensitized guinea-pigs, aerosols of the antigen ovalbumin caused a dose-dependent bronchoconstriction demonstrated by an increase in pulmonary inflation pressure. Administration of CDP840 (0.001-1.0 mg kg-1, i.p.), 1 h before antigen challenge, resulted in dose-dependent reduction in response to antigen. This activity was not due to bronchodilatation since higher doses of CDP840 (3 mg kg-1) did not significantly change the bronchoconstrictor response to histamine. Rolipram was approximately 10 times less active than CDP840 in preventing antigen-induced bronchoconstriction. 6. These results confirm the observations that selective PDE 4 inhibitors reduce antigen-induced bronchoconstriction and pulmonary eosinophilic inflammation. CDP840 is more potent than rolipram in inhibiting native or recombinant PDE 4. Unlike the recently described potent PDE 4 inhibitor RP73401, CDP840 is more active than rolipram in the rat IL-5 model following oral administration. The novel series of tri-aryl ethanes, of which CDP840 is the lead compound, could be the basis of an orally active prophylactic treatment for human asthma.

Human constant regions influence the antibody binding characteristics of mouse-human chimeric IgG subclasses

Although antibody affinity is primarily determined by immunoglobulin variable region structure human IgG antibodies of the four subclasses specific for the same antigen have been shown to differ in their affinity. To explore the influence of the immunoglobulin constant region on functional antibody affinity, a set of V region identical mouse-human chimeric IgG subclasses specific for TAG72 (tumour-associated glycoprotein) were studied. Biomolecular interaction analysis (BIA) was used to determine the binding kinetics of whole IgG subclasses and F(ab')2 fragments. Despite identical V regions, binding kinetics differed for the four subclasses. The apparent dissociation rate constants of the intact immunoglobulins ranked IgG4 < IgG3 < IgG2 < IgG1. In contrast, analysis of the binding characteriztics of the F(ab')2 fragments derived from IgG1, IgG2 and IgG4 revealed identical binding kinetics. The structure of the constant regions of the humanized IgG subclass antibodies clearly influenced functional antibody affinity, as has been described for the murine IgG subclasses. The exact mechanism for this phenomenon remains obscure but such differences should be taken into account when designing or choosing antibodies for therapeutic use.

Psychological adjustment of children evaluated for short stature: a preliminary report

Since synthetic growth hormone became available in the mid-1980s, there has been debate about its use for non-growth-hormone-deficient short children. Justification for this use of growth hormone often is based on a presumed association of short stature with significant psychosocial maladjustment. However, systematic evaluation of psychosocial functioning in short children has been limited, and our understanding of this area is scant. In this study, we have used a combination of interview and self-report measures to examine self-esteem, personality characteristics, affective functioning, coping style, and stature-related stresses in 41 children (5 to 16 years) referred to a pediatric endocrinology service because of short stature. Parent-report and child measures of self-esteem and psychological functioning indicated no evidence of maladjustment in comparison with norms. Furthermore, within the subject sample, the degree of short stature was not related to poor psychological functioning. We found limited evidence linking increased age with increased distress, suggesting that short stature may pose greater difficulties for children as they enter adolescence. Taken as a whole, however, the results do not support the contention that short stature is generally associated with psychosocial maladjustment in children referred for evaluation of their short stature.

Protein kinase C phosphorylates two of the four known syndecan cytoplasmic domains in vitro

The transmembrane heparan sulfate proteoglycans of the syndecan family are implicated to participate in several cellular reactions which are dependent on protein kinase C. We have used an in vitro assay to assess whether any of the Peptides corresponding to the complete cytoplasmic domains of rat syndecans 1 through 4 were used as substrates for the enzyme. The syndecan-2 (fibroglycan) and syndecan-3 (N-syndecan) peptides were both found to be phosphorylated by protein kinase C with Kms of 15 +/- 3 microM and 85 +/- 25 microM, respectively, while the syndecan-1 and -4 peptides were not phosphorylated under the conditions used. The sites of in vitro phosphorylation for syndecans-2 and -3 were localized to ser-197 and ser-339, respectively. Thus, among 13 available sites (serines and threonines) in the four peptides, two were selectively modified by the enzyme. The specificity and the kinetics of the reactions indicate that the cytoplasmic domains of syndecan-2 and -3 are likely to be physiological substrates for protein kinase C.

Use of peptide combinatorial libraries in drug design: the identification of a potent serotonin reuptake inhibitor derived from a tripeptide cassette library

BACKGROUND

Medicinal chemistry traditionally requires the identification of biologically active molecules by synthesizing and screening each purified substrate. Further progress in drug discovery then requires definition of the structure-activity relationship of the lead compound. More recently, combinatorial chemistry has emerged as a way to examine structure-activity relationships by screening a large mixture of compounds synthesized in a predictably random manner, without the labor-intensive costs of molecular isolation and purification. We set out to use this approach to examine the structural requirements for peptide binding to serotonin and dopamine transporters.

RESULTS

We screened a tripeptide cassette library for serotonin and dopamine reuptake inhibition using cloned transporter assay systems. The method has afforded a number of tripeptide pharmacophores with inhibitory IC50 values ranging from 10 microM to < 1 microM in the dopamine and serotonin reuptake systems. The conformation of one of these tripeptides, N-acetyl-D-Trp-L-Phe-D-Lys-CONH2 (which inhibits serotonin uptake with an IC50 of 10 microM) was compared to that of the serotonin uptake inhibitor s-fluoxetine, and was shown to be more similar in conformation to fluoxetine than was an analogous tripeptide containing L-Lys (IC50 > 50 microM).

CONCLUSIONS

We have identified five tripeptides with inhibitory IC50 values of < 10 microM in the serotonin reuptake system. One tripeptide was predicted to have pharmacophore features similar to that of fluoxetine, a selective and potent non-peptide serotonin reuptake inhibitor. Our results suggest that tripeptides derived from combinatorial libraries will help to define the important structural elements of pharmacophores.

Apocrine chromhidrosis involving the areolae in a 15-year-old amateur figure skater

Apocrine chromhidrosis is a rare disease frequently localized to the face or axillae, and rarely has been reported to occur around the breasts. We report a 15-year-old amateur figure skater who displayed localized chromhidrosis around her areolae. The most common precipitating event was exercise. She was treated topically with capsaicin cream 0.025% with a subsequent decrease in symptomatology.

Autoregulatory circuits in myeloma. Tumor cell cytotoxicity mediated by soluble CD16

BACKGROUND

Multiple myeloma remains an incurable malignancy due to marked resistance of the tumor to standard doses of chemotherapy. Treatment approaches, using chemotherapeutic dose escalation and hematopoietic stem cell support have resulted in significant augmentation of tumor mass reduction such that complete remissions are effected in approximately 50% of patients. These remissions are however, often not durable. In the setting of minimal residual disease, therefore, adjunctive immunotherapy may be useful.

METHODS

Peripheral blood mononuclear cells were studied from 28 untreated patients with multiple myeloma (MM). Mononuclear cell CD16 (FcR gamma III) expression was determined by flow cytometry. The effect of lymphocyte-derived soluble CD16, isolated by affinity chromatography, on MM cell growth and differentiation was assessed. MM cell proliferation, viability, immunoglobulin production and gene expression was studied.

RESULTS

Data are presented indicating that cells expressing CD16 are increased in untreated patients with IgG-secreting myeloma. The predominant phenotype of these cells is CD8+ or CD56+. These CD16+ cells can produce a soluble form of the Fc receptor (sFcR, sCD16) that can bind to surface Ig on cultured human IgG-secreting myeloma cells and effect suppression of tumor cell growth and Ig secretion. This effector function is accompanied by concomitant suppression of c-myc as well as IgH and IgL gene transcription. Finally, prolonged exposure to sCD16 causes myeloma tumor cell cytolysis.

CONCLUSIONS

sCD16 and possibly other soluble FcR are candidate molecules for adjunctive immunotherapy of myeloma, once complete responses have been effected by intensive cytotoxic therapy, now possible in up to 50% of newly diagnosed patients.

Isotype choice for chimeric antibodies affects binding properties

Construction of a series of chimeric antibodies (murine variable region and human constant region) derived from the murine antibody BIRR1, which recognizes intercellular adhesion molecule 1 (ICAM-1), has revealed differences in the relative binding abilities of the chimeric antibody to antigen. The chimeric antibodies show a ranking of their ability to compete with BIRR1 for antigen on the surface of cells with the order BIRR1 = cIgG1 (100%) > cIgG4 (30%) > cIgG2 (10%) as demonstrated by solid-phase competitive enzyme-linked immunosorbent assay. Papain digestion yielded Fab fragments that were purified to homogeneity. Competitive enzyme-linked immunosorbent assay showed that the chimeric and murine Fab binding constants were equivalent. A solution-phase binding assay (analyzed by size exclusion high performance liquid chromatography) between the intact mAbs and recombinant soluble ICAM-1 further established that the binding constants involving the Fab arms of the two antibodies were equivalent. In summary, the murine and chimeric anti-ICAM-1 antibodies bind cellular ICAM-1 with equivalent affinities but with differing avidities.