Atherosclerotic rabbit aortas: expandable intraluminal grafting

Balloon-expandable intraluminal grafts that ranged in diameter from 2 to 4 mm were placed in the atherosclerotic abdominal aortas of 24 rabbits. The animals were killed 1, 3, 8, or 24 weeks after placement of the graft. All grafts retained patency without altering the luminal diameter. The small degree of neointimal thickening covering the graft's inner surface was not detectable on conventional in vivo arteriograms. Aortic atherosclerotic plaque external to the graft was markedly compressed 1 week after graft placement. The plaque regained full thickness 24 weeks after grafting when the plaque expanded outside the graft as a result of relaxation or atrophy of the surrounding arterial media.     

Expression of a functional laminin receptor (alpha 6 beta 1, very late activation antigen-6) on human eosinophils

The mechanisms responsible for the accumulation of eosinophils at sites of allergic and other inflammatory reactions are unknown, but recent studies have implicated both eosinophil and endothelial adhesion molecules in this process. However, less well studied have been the adhesive interactions between eosinophils and the subendothelial basement membrane and interstitial connective tissues. To test the hypothesis that eosinophils might interact with extracellular matrix proteins, we analyzed purified human eosinophils for the expression and function of various beta 1 integrins. Using indirect immunofluorescence and flow cytometry, purified eosinophils from mildly allergic donors were found to consistently express the integrin subunits beta 1 (CD29), alpha 4 (CD49d, very late activation antigen [VLA]-4 alpha), and alpha 6 (CD49f, VLA-6 alpha). No significant expression of the alpha 1, alpha 2, alpha 3, alpha 5, or beta 4 subunits was detected. Platelet contamination of the eosinophil preparations was excluded by light microscopy and by the inability to detect expression of platelet glycoproteins alpha v, CD41b, and CD42b. Immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of eosinophils confirmed the expression of cell-surface beta 1, alpha 4, and alpha 6. Furthermore, eosinophils purified from allergic donors were shown to adhere to plate-bound laminin, but not to type 1 or type 4 collagen. Adhesion to laminin was concentration-dependent, required divalent cations, and was completely and specifically inhibited by the anti-alpha 6 monoclonal antibody (MoAb) GoH3 and by the anti-beta 1 MoAb 33B6. Interestingly, the anti-beta 1 MoAb 18D3 (which like 33B6 blocks eosinophil binding to VCAM-1) did not inhibit eosinophil adhesion to laminin, suggesting that there are functionally distinct epitopes on the beta 1 subunit. Eosinophils purified from 4 healthy, nonallergic donors also showed alpha 6-dependent adhesion to laminin, although these cells adhered less well. These studies establish the expression of alpha 6 beta 1 on human eosinophils and document its function as a laminin receptor. Interaction of eosinophil alpha 6 beta 1 with laminin, eg, in basement membranes, may contribute to the localization of these cells at inflammatory sites in vivo.     

Transesterification of peptide esters and peptidyl resins in methanol-containing calcium acetate

The following crude peptide derivatives obtained by thermolysin catalysis in the presence of calcium acetate, were dissolved in methanol and in methanol-containing calcium acetate to determine the possible occurrence of transesterification: Z-Asn-Leu-Gly-OEt, Boc-Asn-Leu-Gly-OEt, Moz-Asn-Leu-Gly-OBzl, Moz-Asn-Leu-Gly-OtBu, Moz-Gln-Leu-Gly-OEt, Moz-Asn-lle-Gly-OEt, and Moz-Asn-Leu-Ala-OEt. Only Z-Asn-Leu-Gly-OEt and Moz-Gln-Leu-Gly-OEt were transesterified in methanol, indicating the existence of a peptide derivative-Ca²⁺ catalytic complex that may favor the reaction. In the presence of calcium acetate, all protected peptide esters except the t-butyl esters were transesterified. The transesterification of several other di- and tripeptide derivatives of different structures in methanol-containing calcium acetate was detected by HPLC and confirmed by the isolation and characterization of some of the protected peptide methyl esters obtained. Boc-Leu-Gly- and Moz-Asn-Leu-Gly-Merrifield resin were also transesterified in these solutions.     

Detecting psychosocial problems among 5-6-year-old children in preventive Child Health Care: the validity of a short questionnaire used in an assessment procedure for detecting psychosocial problems among children

BACKGROUND: An extended re-assessment of the psychometric properties of the LSPPK, an instrument aimed at identifying children with emotional and behavioural problems. METHODS: Data came from a national sample in The Netherlands of parents of 1248 children (aged 5-6 years) interviewed by child health professionals (CHP). Data were obtained regarding psychosocial problems, treatment status and scores on the LSPPK (Parent and CHP Index), and on the Child Behavior Checklist (CBCL). The scale structure, reliability, criterion and content validity and added value of the LSPPK were assessed using the CBCL and treatment status as criteria. RESULTS: The scale structure corresponded with that found originally; the LSPPK improved the prediction of problems according to the CBCL, compared to predictions using readily available risk indicators alone. Reliability varied between 0.55 and 0.69. For the LSPPK Parent Index, sensitivity varied between 0.42 and 0.50. For the CHP Index sensitivity varied between 0.60 and 0.96, but specificity varied between 0.76 and 0.79. Both indices were very sensitive for attention and social problems, but less so for other problems. CONCLUSION: The LSPPK Parent Index cannot distinguish sufficiently between children with or without serious problems. Either too many children with problems remain unnoticed or too many children without problems are labelled as a case. The LSPPK CHP Index, reflecting the CHP's interpretation of the Parent Index after interviewing the parents does not compensate adequately for the weaknesses of the Parent Index. Better assessment procedures and strategies need to be developed.     

Perinatal mortality in a first generation immigrant population and its relation to unemployment in The Netherlands.

STUDY OBJECTIVE--To consider the association between biological and social risk factors and perinatal mortality in an ethnically mixed population in Amsterdam, The Netherlands. DESIGN--This was a matched case-control study. Cases included all registered stillborn infants and all registered liveborn infants who died within seven days of birth. Controls were selected from infants remaining alive. Each case was matched with two controls by date of registration. SETTING--Civil registry of births and deaths, Amsterdam, The Netherlands, 1975-80. PATIENTS--All 666 babies who died in the perinatal period and 1332 controls selected from the liveborn survivors. OUTCOME--Perinatal mortality. MAIN RESULTS--Perinatal mortality was independently associated with the father's and mother's employment status, maternal age, parity, and infant sex, but not with the father's or mother's country of birth. CONCLUSIONS--Employment status and not country of birth should be the main focus in studies of perinatal mortality in this population of mixed ethnicity. Future studies on selected behavioural, socio-economic, and cultural factors are needed to provide a better understanding of the causes of increased perinatal mortality among families in which the parents are unemployed.     

Applications of ultraviolet light in the preparation of platelet concentrates

Passenger lymphocytes in platelet concentrates (PCs) may induce the formation of lymphocytotoxic antibodies (LCTAbs) and subsequent refractoriness to platelet transfusions. Ultraviolet (UV) irradiation can prevent lymphocytes' acting as stimulator or responder cells in mixed-lymphocyte reactions (MLRs) and could theoretically prevent LCTAb formation in vivo. A system has been devised for the delivery of UV irradiation to PCs; platelet storage characteristics and MLRs were evaluated in UV-irradiated PCs harvested from healthy donors with the Haemonetics V50 and PCS cell separators. MLR and response to phytohemagglutinin stimulation were abolished by a dose of 3000 joules per m2 at a mean wavelength of 310 nm. Platelet aggregatory responses to adenosine diphosphate (ADP), ristocetin, collagen and epinephrine, hypotonic shock response, and pH showed no important differences when control PCs and PCs irradiated as above were compared during 5 days of storage in Fenwal PL-1240 packs. Lactate production during storage was significantly higher in UV-treated PCs (p less than 0.001), but values did not exceed 20 mmol per L. UV transmission at 310 nm in standard blood product containers, including the Fenwal PL-146, PL-1240, and PL-732, was low (less than 30%), but it was acceptable in the Delmed Cryostorage and DuPont SteriCell packs (greater than 50%). UV irradiation may provide a simple and inexpensive means of producing nonimmunogenic PCs.     

Spermatological Investigations in Patients Treated with Etretinate and Isotretinoin

Possible side effects of the retinoids etretinate and isotretinoin on the germinal epithelium were examined. 15 men received etretinate and 13 isotretinoin. After 16 weeks of treatment at therapeutic doses, no changes were observed in fundamental spermatological parameters. On the basis of examinations and data in the literature, we hold the opinion that retinoid treatment is to be considered safe from the andrological viewpoint.     

Primary lung cancer: biodistribution and dosimetry of two In-111- labeled monoclonal antibodies

This study was undertaken to measure the biokinetics and organ dosimetry of indium-111-labeled monoclonal antibodies (MoAbs) with a whole-body gamma camera imaging technique. Twenty patients with primary lung cancer were studied with two different MoAb agents (anti-carcinoembryonic antigen ZCEO25 and antiadenocarcinoma LA20207). Imaging was performed at 1, 24, 72, and 144 hours after injection. Scintigraphic whole-body retention was verified by means of comparison with the results from in vitro counting of excreta. Organ retention was verified in an abdominal phantom. The MoAb cleared slowly from the heart and lungs, the brain and spleen showed no clearance, and the liver showed increased activity over the 6-day period. Dosimetry for ZCE025 showed a dose to the liver of 1.3 rad/mCi (0.36 mGy/MBq); heart, 1.5 rad/mCi (0.40 mGy/MBq); spleen, 1.1 rad/mCi (0.29 mGy/MBq); total body, 0.49 rad/mCi (0.13 mGy/MBq); and testes, 0.39 rad/mCi (0.11 mGy/MBq). The dosimetry for LA20207 was similar.