Up-regulation of the phosphoinositide 3-kinase pathway in human lamina propria T lymphocytes.

Human intestinal lamina propria T lymphocytes (LPT), when investigated ex vivo, exhibit functional properties profoundly different from those of peripheral blood T lymphocytes (PBT). One prominent feature represents their enhanced sensitivity to CD2 stimulation when compared to PBT. Given that LPT are hyporesponsive to T cell receptor (TCR)/CD3 stimulation, an alternative activation mode, as mimicked by CD2 triggering in vitro, may be functional in mucosal inflammation in vivo. This study provides insight into signalling events associated with the high CD2 responsiveness of LPT. When compared to PBT, LPT show an increased activation of the phosphoinositide 3/protein kinase B/glycogen synthase kinase 3beta (PI3-kinase/AKT/GSK-3beta) pathway in response to CD2 stimulation. Evidence is provided that up-regulation of this pathway contributes to the enhanced CD2-induced cytokine production in LPT. Given the importance of TCR-independent stimulation for the initiation of intestinal immune responses analysis of signalling pathways induced by 'co-stimulatory' receptors may provide valuable information for therapeutic drug design.

Initial experience with larger laser sheaths for the removal of transvenous pacemaker and implantable defibrillator leads.

BACKGROUND: In a previous randomized trial, the 12F laser sheath removed pacing leads via the implant vein more successfully than traditional mechanical tools alone. Two larger sizes of laser sheath, the 14F and 16F models, were developed to extract defibrillator leads and large-diameter pacing leads implanted for the chronic. These devices use pulsed ultraviolet laser light to core though fibrotic tissue grown over the lead body to free the lead from the vasculature. A mandatory prospective registry studied the safety and effectiveness profiles of the larger laser sheaths vis-à-vis the 12F laser sheath. METHODS AND RESULTS: In this study, 863 patients underwent extraction of 1285 leads at 52 sites. Patients treated with the 14F device tended to have older leads than the 12F population; the 16F population, which comprised mostly defibrillator patients, were younger, had younger leads, and were more often male than the 12F population. Clinical success (extracting the entire lead or the lead body minus the distal electrode) was observed in 91% to 92% of cases for all device sizes. The overall complication rate was 3.6%, with 0.8% perioperative mortality. Incidence of complications was independent of laser sheath size. CONCLUSIONS: The 14F and 16F laser sheaths offer an extraction option for larger long-term transvenous pacemaker and defibrillator leads that is as safe and effective as the 12F laser sheath.

Pacemaker lead extraction with the laser sheath: results of the pacing lead extraction with the excimer sheath (PLEXES) trial.

OBJECTIVES: The purpose of this study was to evaluate the safety and effectiveness of pacemaker lead extraction with the excimer sheath in comparison to nonlaser lead extraction. BACKGROUND: Fibrotic attachments that develop between chronically implanted pacemaker leads and to the venous, valvular and cardiac structures are the major obstacles to safe and consistent lead extraction. Locking stylets and telescoping sheaths produce a technically demanding but effective technique of mechanically disrupting the fibrosis. However, ultraviolet excimer laser light dissolves instead of tearing the tissue attachments. METHODS: A randomized trial of lead extraction was conducted in 301 patients with 465 chronically implanted pacemaker leads. The laser group patients had the leads removed with identical tools as the nonlaser group with the exception that the inner telescoping sheath was replaced with the 12-F excimer laser sheath. Success for both groups was defined as complete lead removal with the randomized therapy without complications. RESULTS: Complete lead removal rate was 94% in the laser group and 64% in the nonlaser group (p = 0.001). Failed nonlaser extraction was completed with the laser tools 88% of the time. The mean time to achieve a successful lead extraction was significantly reduced for patients randomized to the laser tools, 10.1 +/- 11.5 min compared with 12.9 +/- 19.2 min for patients randomized to nonlaser techniques (p < 0.04). Potentially life-threatening complications occurred in none of the nonlaser and three of the laser patients, including one death (p = NS). CONCLUSIONS: Laser-assisted pacemaker lead extraction has significant clinical advantages over extraction without laser tools and is associated with significant risks.

Crystals of intact elongation factor Tu from Thermus thermophilus diffracting to high resolution.

The intact elongation factor Tu from the extreme thermophile Thermus thermophilus has been crystallized as a complex with the GTP analogue guanosine-5'-(beta,gamma-imido)triphosphate. The crystals are very stable in the X-ray beam and diffract to 1.9 A resolution. They exhibit space group C2, with a = 150.3(6) A, b = 99.6(3) A, c = 40.1(1) A, beta = 95.4(2) degrees, and contain one elongation factor Tu molecule per asymmetric unit.

Cystic fibrosis newborn screening: impact on reproductive behavior and implications for genetic counseling.

OBJECTIVE: To evaluate the impact of newborn screening for cystic fibrosis (CF) on the reproductive knowledge and behavior of CF families and to determine if heterozygote detection with the immunoreactive trypsinogen (IRT) method in conjunction with DNA analysis (IRT/DNA) influences knowledge and attitudes about reproduction in false-positive families. METHODS: The Wisconsin CF Neonatal Screening Project investigated 650 340 infants from 1985 to 1994 in a comprehensive randomized controlled trial to study both benefits and risks of newborn screening and to determine if early diagnosis would improve the prognosis of children with CF. Assessments of reproductive knowledge, attitudes, and behaviors of 135 families of children diagnosed as having CF in both the early treatment group and control groups were made 3 months after diagnosis using a questionnaire which was completed by 100 families. The same questionnaire was administered 1 year later to evaluate retention of information. It was completed by 71 families. A follow-up assessment tool was also administered in 1994 and responses obtained from 73 families. Knowledge, attitudes, and behavior among false-positive families were also assessed at the time of the sweat test in 206 families who experienced IRT screening and 109 families tested with the IRT/DNA method. Follow-up assessments were completed 1 year later in 106 IRT families and 63 IRT/DNA families. RESULTS: In families with a CF child, 95% initially understood that there was a 1 in 4 risk in subsequent pregnancies, and there was good retention of this information 1 year later. At the 1994 assessment, 52% of families had not yet conceived more children, but 74% of these already had children. In the couples in whom CF was diagnosed in the first child, 70% (95% confidence interval = 54% to 85%) conceived more children. There were 43 subsequent pregnancies in 31 families. Prenatal diagnosis was used by 26% of the families (8/31) for 21% of the pregnancies (9/43). There were 3 pregnancies with CF detected, all of which were carried to term. In the false-positive groups, >95% of families initially understood that their child definitely did not have CF. There was no difference between false-positive IRT and IRT/DNA groups, and the information was retained at 1 year. Follow-up assessment 1 year after negative sweat tests revealed that 7% of the IRT and 10% of the IRT/DNA families still thought about the results often or constantly. When asked whether the experience of screening affected feelings about having more children, an affirmative response was obtained in 4% of IRT families but in 17% of IRT/DNA families. One year later, more than half of the false-positive IRT/DNA families did not understand that they were at increased risk of having a child with CF. CONCLUSIONS: We conclude that CF neonatal screening does not have a significant impact on the reproductive behavior of most families and that prenatal diagnosis is not used by the majority of CF families. IRT/DNA testing experiences seem to affect attitudes about having more children, and some parents are confused about the implications of the results, even with genetic counseling. However, persistent concerns about the sweat test result are limited. Questions raised by this study confirm the need for more research regarding the process of genetic counseling and its impact on reproductive attitudes and behavior in the newborn screening setting.

Bacterial carriers and virus-like-particles as antigen delivery devices: role of dendritic cells in antigen presentation.

Replicating attenuated strains of intracellular bacteria like Salmonella typhimurium, Listeria monocytogenes or Mycobacterium bovis Bacille Calmette Guérin (BCG), and non-replicating virus-like-particles (VLP) consisting, for instance, of the VP1-surface component of polyoma virus offer great potential as heterologous carriers delivering foreign protein antigens for immune recognition. Moreover, attenuated S. typhimurium and L. monocytogenes strains hold also great promise as delivery vehicles for DNA vaccines. Polyoma virus-specific VLP consisting of VP1-pentamers are also of interest as carrier devices for eukaryotic expression plasmids. At first sight these different replicating and non-replicating types of vehicles have little in common, but from an immunological point of view viable bacteria and non-viable VLP are both well suited for evoking protective immune responses via several routes of vaccine administration. As these antigen carriers generate humoral and cell-mediated immunity, the heterologous antigens are not only targeted to appropriate pathways of major histocompatibility (MHC) class I and class II antigen processing and presentation, but also generate an adequate cytokine milieu for promoting antigen-specific responses. The most prominent advantage of these carrier devices is presented by their capacity to directly target antigenic proteins or DNA vaccines to immature dendritic cells (DC) along their maturation pathway. Mature DC are the key antigen presenting cell population which efficiently mediates antigen transport to organised lymphoid tissues for the initiation of T cell responses. In general, uptake of these diverse antigen delivery systems by antigen presenting cells (APC) finally lead to efficacious immune responses in the control of pathogenic microorganisms and tumours.

Wisconsin Stillbirth Service Program: II. Analysis of diagnoses and diagnostic categories in the first 1,000 referrals.

The Wisconsin Stillbirth Service Program has provided a mechanism for the collection and analysis of unbiased and representative information concerning stillborn infants. Generated diagnoses and diagnostic categories within the first 1,000 referrals (including 789 stillbirths) is summarized here. Among all referred stillborns, 24.5% were found to have an identifiable intrinsic fetal cause of death. Specific diagnoses were extraordinarily heterogeneous, with about 85 different processes identified with this group. No single diagnosis was found in more than 1 1/2% of the evaluated stillborns. Distribution by classes of fetal causes (as a percent of all fetal causes in stillborns) included malformation syndromes in 44%, single malformations and defined sequences in 34%, disruptions in 10%, and dysplasias in 3%. The heterogeneity of syndromic causes is illustrated, examples of previously undescribed syndromic processes provided and the problems experienced in generating specific diagnoses discussed. Specific single malformations, sequences, disruptions, and dysplasias are also tabulated and illustrated. Distribution by etiologic categories (as a percent of all fetal causes in stillborns) included defined sporadic conditions in 29%, cytogenetic aberration in 25%, presumed multifactorial processes in 12%, Mendelian disorders in 5%, and environmental events in less than 4%. A fourth of all fetal causes could not be sufficiently defined to allow for certainty in assigning a specific etiologic category. The materials summarized provide reference data regarding the frequency of classes and categories of fetal diagnoses generated from an unbiased and non-selected series of stillborns.

Achondroplasia: unexpected familial recurrence.

We review six families in which recurrence of achondroplasia, inexplicable through autosomal dominant inheritance, has occurred. The clinical and radiographic characteristics of affected individuals in these families are identical to those usually seen in achondroplasia. Family histories and parental characteristics likewise seemed not to set this group apart from others with achondroplasia. While various mechanisms for these occurrences of achondroplasia in family members related through unaffected relatives can be postulated, the hypothesis that these recurrences were simply the result of two independent chance events cannot, at least for the moment, be excluded.

Fetal disruptions: assessment of frequency, heterogeneity, and embryologic mechanisms in a population referred to a community-based stillbirth assessment program.

The Wisconsin Stillbirth Service Project (WiSSP) is a community-based program for the investigation of the cause of fetal death. From its inception in 1983 through July 1988, 629 referrals were made to WiSSP. All referrals were assessed for the presence of disruptional characteristics, and 23 were found to have major or primary disruptive effects. Most of these were either early amnion disruption/limb-body wall disruption (treated as a single group, since analysis suggests a continuum of clinical characteristics) and twin-twin disruptions. Therefore, disruptions accounted for 3.6% of all referrals (including liveborn and miscarriage referrals) to WiSSP. When only stillborn fetuses are considered, approximately 2.4% appear to have died because of disruptions. This makes disruptions one of the most frequent, identifiable causes of late intrauterine death. We estimate that 0.6-1.4% of all stillborn fetuses die because of early amnion disruption/limb-body wall disruption which, when taken with previous estimates of the frequency of such problems in early miscarriages and liveborn infants, suggests that these disruptions result in a 95% prenatal mortality rate. We suggest a unified model of likely pathogenetic mechanisms which may help explain the continuum of multisystem involvement seen in those with early amnion disruption/limb body wall disruption. In addition, 3 patients with atypical disruptions are reviewed who exemplify the difficulty and importance of differentiating disruptional and malformational processes.

Validation of radiographic criteria for the diagnosis of Down syndrome in stillborn infants.

We assessed the utility of radiographic findings as aids to the diagnosis of Down syndrome (DS) in stillborn infants. The iliac index may help to confirm the diagnosis of DS in stillborn infants in whom it is suspected clinically, but in whom it cannot be confirmed cytogenetically. It also can serve as a screening procedure to select stillborns in whom fluorescent in situ hybridization of fixed tissues should be completed. An iliac index of 59 degrees differentiates between control and affected stillborns with the highest accuracy, but false positives persist above 55 degrees, and false negatives are common below 64 degrees. We recommend that a conservative cutoff value of 55 degrees be used if the radiographic data serve as the principal means of diagnosing DS in stillborn infants. A cutoff value of 64 degrees may be appropriate if the radiographic data are used to screen stillborn infants for fluorescent in situ hybridization studies.

Wisconsin Stillbirth Service Program: I. Establishment and assessment of a community-based program for etiologic investigation of intrauterine deaths.

Although stillbirth is a common event, few programs have previously been established for the comprehensive etiologic investigation of intrauterine death. Fewer still have been prospective, unbiased in ascertainment, and consistent in protocol utilization. The Wisconsin Stillbirth Service Program was established in 1983 as a unique model for the investigation of the causes of stillbirth. This community-based, University-supported model for health care delivery is here described. Through it more than a thousand infants have been etiologically investigated. We demonstrate that a community-based program of stillbirth assessment can succeed, that compliance with recommended protocols is high and that a specific primary cause of fetal death can be demonstrated in about 40% of referrals. A majority of the established causes of intrauterine death are fetal etiologies. Furthermore, it appears that there are no substantial referral biases. Lack of such biases, together with the prospective, protocol driven nature of the program provides a unique population upon which to base estimates of the frequency of various etiologic diagnoses and classes and categories of cause.

Cardiac lead extraction with a novel locking stylet.

Extraction of chronically implanted pacing and defibrillator leads is facilitated by using specialized locking stylets placed in the lead to allow application of traction and to stabilize the lead during sheath dissection of fibrotic tissue. We report the initial multicenter series of cases using a novel lead locking device (LLD). In 57 consecutive patients presenting at 6 institutions for lead extraction, 99 leads were treated using the LLD. After removing the pulse generator, leads were severed, the inner coil dilated and an LLD was successfully inserted and locked in the inner lumen of 95/99 (96 %) leads. With traction applied to the LLD, a variety of sheaths were advanced over the lead body to separate it from adhesions. In 97/99 (98 %) leads, all or most of the lead was removed via the implant vein; 2 leads were removed via the femoral vein. No major complications were observed. The LLD deploys safely and reliably, and provides stable support for advancement of dissecting sheaths.

Effects of 308 nanometer excimer laser energy on 316 L stainless-steel stents: implications for laser atherectomy of in-stent restenosis.

PURPOSE: To determine the effects of the incidental exposure of stents to pulsed 308 nanometer ultraviolet excimer laser energy. METHODS: Five types of 316 L stainless-steel coronary stents were subjected to two types of study. First, for endurance testing, sixty stents were deployed in 3.0Eth 4.0 mm polymer tubes in three geometries. Up to 1,000 laser pulses were delivered while advancing a 2.0 mm eccentric catheter through the lumen of the stent. These stents were next subjected to 400 million simulated heartbeats and then analyzed for metal etching and fatigue. Second, six additional stents were irradiated with 1,000 pulses underwater and then analyzed for particulates, anions and cations liberated from the stent. RESULTS: Photomicroscopy revealed surface etching on a number of stents. Two stent models exhibited multiple strut fractures at the strut joints in both test samples and controls. In no case was a break observed at the site of laser-stent interaction. Breakage frequency was not significantly different between lazed stents and controls. Lazed stents produced a mean of 14 micrograms of sodium and 4 micrograms of iron more than controls. No excess particulates were detected. CONCLUSION: Under model conditions typical of clinical use, excimer laser treatment does not alter stainless-steel stent endurance or liberate clinically significant material from the stent.

Biophysical bases for delayed and aberrant motor development in young children with achondroplasia.

Achondroplasia, the most common skeletal dysplasia, is characterized by delayed and aberrant motoric development in childhood. Delays and aberrancy are secondary to the anatomical differences inherent in people with achondroplasia. We present a photographic essay documenting biophysical differences, aberrant pre-orthograde movement strategies, and selected adaptive techniques. A parental questionnaire assessed the presence of, predominance, and ages at which various types of pre-orthograde locomotion were observed. Fine and gross motor skills were assessed contemporaneously by use of the Denver Developmental Screening Test in 93 children with achondroplasia and were found to be more delayed than previously reported. Physicians, therapists, early-childhood educators, and parents should recognize that aberrant does not mean maladaptive and that different development is not defective development.

Excimer laser assisted angioplasty for the treatment of critical limb ischemia.

Two decades after the clinical introduction of percutaneous transluminal angioplasty (PTA), controversy still exists about the role of PTA for the treatment of occlusive disease in the femoropopliteal and infragenicular arteries. For the patient with critical limb ischemia (CLI), where diffuse disease and long occlusions are the rule, the results with PTA have not been optimal. Surgical revascularization has long been considered the gold standard for this patient population, but this procedure is associated with significant morbidity and mortality and up to 37% of patients may be poor surgical candidates. With advances in laser catheter design and refinement of recanalization techniques, improved results have been seen with laser assisted angioplasty of complex peripheral arterial disease. There has been renewed interest in excimer laser angioplasty for the treatment of patients with long total occlusions and diffuse disease who otherwise would have limited options for treatment. Excimer laser assisted angioplasty has been shown to be a successful approach to the treatment of long occlusions in the superficial femoral artery. Data from the recently completed Laser Angioplasty for Critical Limb Ischemia Phase 2 Trial (LACI) suggest that this is a viable treatment strategy for patients with CLI who are otherwise not good candidates for bypass surgery.

Next generation catheters for excimer laser coronary angioplasty.

In response to the need for maximising debulking in complex lesions, three new excimer laser coronary angioplasty catheter designs have been introduced. The eccentric laser catheter features a fibreoptic bundle disposed opposite the guide-wire lumen at the catheter tip and a torque mechanism that allows the user to rotate the fibre bundle toward the lesion mass. Residual lumens 50% larger than the catheter tip diameter have been obtained when multiple passes were made, with each pass performed using a different tip rotation. A recent case series utilising this catheter in restenosed stents resulted in larger lumens and lower 6-month restenosis rates. The optimal spaced (OS) laser catheter features a fibre bundle placed concentrically around the guide-wire lumen. The 61 microm diameter core fibres are spaced at a nominal centre-to-centre distance of 90 microm, resulting in a 40% increase in ablative area as compared to previous concentric catheter designs. In vitro testing and clinical evaluation demonstrated OS catheters routinely achieve an ablated area > or =90% of the catheter tip size. The 0.9 mm catheter features a high-density fibre pack composed of 65 fibres. Peripheral dead space has been minimised to maximise penetration of calcified plaque. When combined with laser parameters of up to 80 mJ/mm2, and 80 Hz pulse repetition rate, the catheter demonstrated improved hard tissue and calcified tissue penetration in vitro. Clinical evaluation in Canada revealed a 94% lesion recanalisation rate in high-grade stenoses with angiographic evidence of calcification, chronic total occlusions, and lesions which have failed balloon angioplasty.

Laser wavemeter with solid Fizeau wedge interferometer.

A Fizeau wavemeter using a solid Fizeau wedge interferometer that is suitable for determining the wavelength of pulsed or cw laser light has been modeled and investigated experimentally. Accuracy of a few parts in 10(6) over a wide wavelength range can be achieved with careful design. Experimental accuracy of 2 parts in 10(6) was demonstrated over a range of 40 nm.

Continuing education in genetics for Adoption workers in Wisconsin.

In response to 1982 legislation and 1984 changes in the Wisconsin Adoption Records Laws requiring the collection of a medical-genetic history at the time of termination of parental rights, a continuing education program in genetics was conducted for adoption workers in 1984 and 1985. The education program provided 14 workshops in five locations throughout the state and consisted of a variety of formats and levels of training. In all, 164 participants were trained at least at the introductory level with approximately 40 of these individuals taking part in the advanced levels of training. Evaluations of the training by participants and by a sample of the agency supervisors of trainees ranked the program very highly. A review of genetic history forms completed in post-training sessions verified the expectation that training was beneficial. Trained workers completing the medical-genetic history forms scored somewhat higher than untrained workers and much higher than parents who completed the forms without professional guidance. Medical-genetic history forms completed by birth fathers as part of step-parent adoptions contained little to no useful information about the birth father's genetic background.

Modulation of phospholipase D stimulation in c-src transfected mesangial cells.

Stimulation of rat mesangial cells with platelet-derived growth factor BB (PDGF-BB) enhanced phospholipase D (PLD) activity in a concentration dependent manner. Mesangial cells overexpressing the tyrosine kinase pp60c-src (c-Src) were used to determine the effect of this non transforming protooncogene on PLD activation. Overexpression of c-Src interfered with PDGF-BB-mediated activation of PLD. This modulation was dependent on the tyrosine kinase activity of c-Src, since overexpression of tyrosine kinase-negative mutants of c-Src did not affect PLD activation. No effect of c-Src overexpression was observed, when PLD was activated by ATP or guanosine 5'-3-O-(thio)triphosphate (GTP gamma S). The results indicate that the tyrosine kinase c-Src specifically interfered with PDGF-mediated but not with ATP- or GTP gamma S-mediated PLD activation.