Assessment of Photoinduced Frontal Polymerization Processes for a Stable 1K System

Frontal polymerization (FP) has attracted increasing interest in recent years in various applications. This polymerization method can be very promising for the polymerization of thick materials with high fillers content in the range of 50–80% (weight) by local application of a reasonable amount of energy. In this work, recent advances in controllable and predictive behavior for photoinduced frontal photopolymerization are reported. Here, tert-butyl peroxybenzoate (Luperox-P) is selected to initiate thermal polymerization at depth because its high polymerization ability and its decomposition temperature is in a promising range, i.e., neither extremely high (monomer decomposition) nor very low (storage stability issues). Thermal imaging experiments are used to follow the temperatures in the samples in real time. The number of cured layers and the depth of cure are also determined. This paper investigates various factors such as the contents of both photo and thermal initiators, the light intensity, the fiber contents, the irradiation time, etc., resulting in a statistical design of experiments with the factors: 1) content of Luperox P and 2) the irradiation time used to investigate the influence on photoinduced frontal polymerization. Markedly, FP appears to be fully controllable for a storage-stable, tunable 1K system.     

Chemokine production by human vascular smooth muscle cells: modulation by IL-13

1. The production of chemokines by vascular smooth muscle cells (SMC) is implicated in the pathogenesis of atherosclerosis, although the factors regulating chemokine production by these cells are incompletely characterized.
2. We describe the differential stimulation of interleukin-(IL)-8, monocyte chemoattractant protein (MCP)-1 and regulated on activation normal T-cell expressed and secreted (RANTES) synthesis following treatment of human vascular SMC with IL-1α or tumour necrosis factor α (TNFα). Under basal conditions, cultured SMC release very low amounts of IL-8, MCP-1 and RANTES as assessed by specific ELISA. Concentration-response studies with IL-1α or TNFα revealed that each stimulus induced a similar amount of MCP-1. In contrast approximately three fold more IL-8 was induced by IL-1α than by TNFα whereas significant RANTES production was induced only by TNFα. These findings point to a divergence in the regulation of synthesis of the different chemokines in response to IL-1α or TNFα stimulation.
3. The T-cell derived cytokines IL-10 and IL-13 were also found to have differential effects on chemokine production by SMC. IL-13, but not IL-10, significantly enhanced IL-8 and MCP-1 release in response to IL-1α or TNFα. This increase in chemokine release appeared to be accounted for by increased mRNA expression.
4. These findings provide support for the concept that smooth muscle cells can have an active role in a local immune response via the production of chemokines which can be selectively modulated by T-cell derived cytokines.

     

Intraoperative measurement of javid shunt flow with transit-time ultrasound

Transit-time ultrasound methods were used to measure blood flow in 37 patients undergoing carotid endarterectomy. Internal carotid flow before (ICF^bef) and after (ICF^aft) endarterectomy was measured with a 6 mm perivascular probe, and Javid shunt flow (SF) was measured with a clamp-on probe. For the entire group ICF^bef averaged 117±67 ml/min and ICF^aft was 173±67 ml/min. Shunt flow averaged 123±51 ml/min. The differences between ICF^bet and ICF^aft and between SF and ICF^aft were significant (ANOVA,p<0.01) but the difference between ICF^bef and SF was not. The relationship between ICF^bef and SF appeared to define two groups of patients. Those in whom SF was greater than ICF^bef (SF > ICF^bef) had more stenosis evident on preoperative arteriograms (64.7%±14.55% maximum single diameter stenosis) and a greater average increase in ICF (151%±159%) than those with SF ICF^bef (43.3%±20.9% stenosis and 34%±54% increase in ICF), suggesting that the relationship between SF and ICF^bef defines groups with different hemodynamic responses. The similarity between SF and ICF^bef indicates that Javid shunt flow offers adequate protection from cerebral ischemia. A practical benefit of the shunt clamp-on flow probe is the ability afforded to recognize shunt occlusions.Presented at the Twelfth Annual Meeting of the Southern California Vascular Surgical Society, Coronado, Calif., September 17–19, 1993.     

Comparison of open and arthroscopic subacromial decompression

We retrospectively reviewed 68 patients (70 shoulders) who underwent either open or arthroscopic acromioplasty performed by a single surgeon (JPI) for chronic impingement syndrome in the presence of an intact rotator cuff. Group 1 consisted of 24 shoulders that had open acromioplasty and group 2 consisted of 46 shoulders that had arthroscopic acromioplasty. The minimum follow-up was 12 months for both groups. There was no statistical difference in mean postoperative shoulder scores between the operative groups. However, there were more excellent results in the open group as compared with the arthroscopic group (54.2% vs 41.9%, respectively). In addition, there was a higher percentage of poor results in group 2 as compared with group 1 (27.9% vs 16.6%, respectively). Arthroscopic acromioplasty was associated with shorter hospital stays and faster achievement of maximal pain relief as compared with open acromioplasty. Examination of postoperative radiographs often revealed subacromial calcifications. These calcifications were more frequent after arthroscopic acromioplasty and were associated with a worse result.     

Homosexual foot fetishism

262 respondents from an organization for homosexual foot fetishists provide information from a broader sample than clinical cases and allow examination of the effects of sexual preference on fetishism. Data show a wide range of feet/footwear objects to be arousing. Such interests were often associated with particular types of men, yet interests were subject to change over time. Fetishistic arousal rested on both sensual and symbolic aspects of the fetish. Symbolically, it was the theme of masculinity that made male feet/footwear arousing, showing parallels to femininity evoked by female feet/footwear for male heterosexual fetishists. For many of the respondents, fetishism did not seem to be a substitute for living persons. Respondents had intimate relationships and were able to incorporate their fetish interests into stable relationships and less intimate ones. Considerable involvement in sadomasochistic practices was also found as was involvement in the gay world. Finally, nothing about a fetishistic interest seemed to preclude the development of subcultural forms around the practice.     

Lay people's evaluations of health: are there variations between different subgroups?

STUDY OBJECTIVE--To elicit lay concepts of health and to see whether these are related to various sociodemographic factors, as has been suggested by previous smaller studies. DESIGN AND SETTING--A total of 196 people aged 18 and over were selected, as a representative sample of the general population, from the electoral registers of Walsall and Dudley in the West Midlands. Respondents were interviewed in their own homes in the autumn of 1989. MEASUREMENTS--Open ended and structured questions were used to elicit concepts of health. The three main stages consisted of an unprompted section in which respondents were asked to describe the features of good or poor health in themselves or others; a prompted section in which they were asked to rate 37 health statements using a series of categories from "very important" to "not at all important"; and a section in which they were asked to indicate which of six groups of statements, each representing a particular concept of health, best represented their own notions of health. RESULTS--Health was seen as multidimensional. Irrespective of whether respondents addressed health in self or health in others, or good or poor health, the biomedical dimension remained an important one. The manner by which concepts of health are elicited may provide some explanation as to why so many and varied concepts are alleged to be held by different subgroups of the population (notably different social classes). CONCLUSIONS--The differences found in this study between models of health employed by different subgroups of the general population have not been as great as has previously been suggested in the published reports. This is encouraging for those using existing health status measurements.     

Relating health education research to health policy

This paper argues that research in health education is being driven by a set of implicit values that emphasize formality, rigor and objectivity, and that relatively little attention is being paid to the ways in which research findings are subsequently used. A critique of a detached and formal research perspective is developed around the problems of 'pure' knowledge and the potential incompatibility between this and policy-making processes. In this light, it is suggested that the pursuit of academic research rigor at the expense of practical utility is hindering the development of a stronger research-policy link. The paper then goes on to suggest that in adopting a sharper political orientation, health education research could legitimately become less concerned with the restrictive nature of academic formalism with research. The nature of this type of research, the potential it has as well as its limitations are subsequently explored.     

5-HT 2C receptor sensitivity during treatment with selective serotonin re-uptake inhibitors

We studied the effect of repeated treatment with selective serotonin re-uptake inhibitors (SSRIs) on the sensitivity of brain 5-HT(2C) receptors, by measuring the decrease in slow wave sleep (SWS) that follows administration of meta-chlorophenylpiperazine (mCPP) (7.5 mg orally). mCPP significantly lowered SWS both in patients taking SSRIs and in a group of healthy controls. There was, however, no difference in the response between the two groups. The results do not support the suggestion that repeated SSRI treatment alters the sensitivity of 5-HT(2C) receptors in the human brain. The present study, however, cannot exclude the possibility that a decrease in 5-HT(2C) receptor sensitivity was offset by higher plasma levels of mCPP in the SSRI-treated group.