Dental students on instruction in local anaesthesia

In order to find out how dental students feel about their education in the application of local anaesthesia, a questionnaire was distributed via e-mail among all dental students in the Netherlands. A total of 397 completed questionnaires were analyzed statistically. At all 3 dental schools in the second year instruction in theoretical aspects of local anaesthesia began. Practical teaching began in the second or third study year. A preclinical training model was used by 15% of the students in Amsterdam, 20% of the students in Nijmegen and 35% of the students in Groningen. When they administered their first injection in a human, a fellow dental student in 91-98% of all cases, 24-74% of the students felt that they were insufficiently prepared. 35-52% of the students said that they would also like to receive instruction in intraligamentary anaesthesia in the dental curriculum. Other changes in the curriculum were also frequently suggested, especially the introduction of preclinical training models (29%, 55% and 56% for Groningen, Nijmegen and Amsterdam respectively).     

Up-regulation of platelet-derived growth factor by peripheral-blood leukocytes during experimental allergic encephalomyelitis

In multiple sclerosis (MS) and its animal model, experimental allergic encephalomyelitis (EAE), clinical disease is associated with infiltration of the central nervous system (CNS) by immune cells. Subsequent remission with remyelination has been linked to an increased occurrence of oligodendrocyte progenitor (O2A) cells. Platelet-derived growth factor (PDGF) and fibroblast growth factor-2 (FGF-2) are key growth factors for O2A cells, yet little is known about their relevance in EAE and MS. We analyzed the expression of PDGF, FGF-2, and their receptors by peripheral-blood leukocytes (PBLs) and lymphocyte subsets during MBP-induced EAE. Strong up-regulation of PDGF, but not FGF-2, was observed in PBLs, with the highest expression after the disease maximum. T, NK, and NKT cells expressed PDGF, which is a novel observation because thus far only monocytes/macrophages have been reported to express PDGF. These results extend the idea that growth factors may contribute to improved CNS tissue repair, including PDGF, which is secreted by lesion-homing immune cells. The production of PDGF by lymphocytes may have potential therapeutic value when activating or modulating T-cell responses in demyelinating diseases.     

A molecular analysis of prokaryotic and viral DNA sequences in prostate tissue from patients with prostate cancer indicates the presence of multiple and diverse microorganisms

BACKGROUND: Inflammation, both acute and chronic, is a common feature of prostate histology. While inflammation has been proposed to play an important role in both benign and malignant growth of the prostate, the stimuli for this inflammation remain poorly characterized. Infectious pathogens are potential stimuli for prostatic inflammation. METHODS: Universal eubacterial PCR was used to test 170 prostate tissue core samples from 30 cancer patients for 16S rDNA gene sequences. Positive PCR products (n=64, 37%) were cloned and sequenced. For comparison, tissue samples from 30 patients were cultured using standard clinical microbiological techniques. DNA samples from 200 additional patients were tested by organism-specific PCR for the presence of Chlamydia trachomatis, Propionibacterium acnes, Trichomonas vaginalis, BK virus, Epstein-Barr virus, human cytomegalovirus, human papillomavirus, and xenotropic murine leukemia-related virus. RESULTS: 16S sequencing results indicated the presence of 83 distinct microorganisms. Microbiological culture isolated markedly fewer species. In general, organism-specific PCR failed to detect multiple organisms previously reported as common in the prostate. There was no significant association between the presence of particular species of bacteria and histologic evidence of acute or chronic inflammation. CONCLUSIONS: Most prostates from men undergoing prostatectomy (87%) contain bacterial DNA from one or more species. However, the majority of individual tissue core samples were negative, suggesting regional heterogeneity in the presence of bacteria and a lack of a generalized or ubiquitous prostatic flora. Culture results suggest either the "unculturable" nature of species present in the prostate or that 16S rDNA sequences were derived from non-viable bacteria.     

Alpha-fetoprotein levels in different strains of mice during development.

The levels of alpha-fetoprotein (AFP) were measured at birth and at 7 days of age in plasma from Q, C3H/He-mg/Crc, BALB/c/Crc, A/Crc, CBA/Ca/Crc and C57BL/Mcl mice, and in adult blood samples and amniotic fluid at 14 days' gestation from Q, C3H and BALB/c mice. The AFP levels in amniotic fluid and neonatal plasma were significantly higher in BALB/c mice than in the other strains tested, but by postnatal day 7, C57BL and C3H mice had the highest plasma levels. It seems therefore that the genetic mechanisms controlling the synthesis of AFP prenatally may be distinct from those concerned with its reduction after birth. At 6 weeks of age the level in C3H mice was somewhat higher than in BALB/c, and more than double that in Q mice. An attempt to increase AFP levels in response to galactosamine-induced liver damage was successful only in Q adult mice. When amniotic fluids and day 0 plasma from several strains of mice were tested by polyacrylamide gel electrophoresis, no differences in AFP mobility were detected. Preliminary studies were also carried out to see if the administration of sodium butyrate, claimed to delay the timing of the fetal to adult haemoglobin switch in some mammalian species, could also affect the rate of synthesis of AFP during fetal life.     

Repeated high-intensity Wingate cycle bouts influence markers of lymphocyte migration but not apoptosis

Studies have shown significant changes in lymphocytes during continuous exercise, but little has been shown on the effect of repeated high intensity bouts. This study was designed to examine the effect of repeated intermittent bouts on lymphocyte subset cell count, apoptosis, and migration. A series of 6 Wingate anaerobic cycle tests were performed by participants (N = 8) with blood samples attained before, immediately following, and after a designated recovery period (excess postexercise oxygen consumption (EPOC)) to observe lymphocyte changes. Lymphocyte subsets (CD4+, CD4/CD45RA+, CD8+, CD8+/CD45RA+, CD19+) were assessed for apoptosis (annexin V+) and cellular migration (CX(3)CR1). Our results indicate that the CD8+ and CD8+/CD45RA+ subsets were significantly influenced by the repetitive Wingate cycling protocol such that cell counts increased with exercise, and then decreased at EPOC termination (p = 0.016). The observed postexercise decrease in CD8+ and CD8+/CD45RA+ cells was accompanied by a significant change in the CX(3)CR1 cell migration receptor (p = 0.019), but not apoptosis (p = 0.87). This indicates that with repetitive high-intensity cycling, the response in CD8+ cells following the bout is likely due to cell migration rather than cell death.     

Polyclonal rearrangements of the T-cell receptor β-chain in fatal angioimmunoblastic lymphadenopathy

Genomic rearrangement of germline T-cell antigen receptor (TcR) and immunoglobulin (Ig) genes was studied by Southern blot analysis in seven patients with angioimmunoblastic lymphadenopathy (AILD). In three cases clinically suspected of transformation into malignant lymphoma, hybridization with the TcRβ probe showed markedly dimished intensity in the 11.5 kb germline band after Eco RI digestion and normal germline configuration after Hind III and Bam HI digestion, indicating polyclonal T cell rearrangements. A clonal rearrangement of the TcRβ gene was detected in only one case at initial biopsy. No monoclonal rearrangement of Ig genes was observed. These data show that in some cases of AILD disease progression is indicated by polyclonal TcR rearrangements and not by outgrowth of a malignant clone, supporting the concept of AILD as an immunoregulatory disorder.     

In vivo thorax 3D modelling from costovertebral joint complex kinematics

Background

The costovertebral joint complex is mechanically involved in both respiratory function and thoracic spine stability. The thorax has been studied for a long time to understand its involvement in the physiological mechanism leading to specific gas exchange. Few studies have focused on costovertebral joint complex kinematics, and most of them focused on experimental in vitro analysis related to loading tests or global thorax and/or lung volume change analysis. There is however a clinical need for new methods allowing to process in vivo clinical data. This paper presents results from in vivo analysis of the costovertebral joint complex kinematics from clinically-available retrospective data.

Methods

In this study, in vivo spiral computed tomography imaging data were obtained from 8 asymptomatic subjects at three different lung volumes (from total lung capacity to functional residual capacity) calibrated using a classical spirometer. Fusion methods including 3D modelling and kinematic analysis were used to provide 3D costovertebral joint complex visualization for the true ribs (i.e., first seven pairs of ribs).

Findings

The 3D models of the first seven pairs of costovertebral joint complexes were obtained. A continuous kinematics simulation was interpolated from the three discrete computerized tomography positions. Helical axis representation was also achieved.

Interpretation

Preliminary results show that the method leads to meaningful and relevant results for clinical and pedagogical applications. Research in progress compares data from a sample of healthy volunteers with data collected from patients with cystic fibrosis to obtain new insights about the costovertebral joint complex range of motion and helical axis assessment in different pathological conditions.     

Clinical dynamics of varicose disease in patients with high degree of venous reflux during conservative treatment and after surgery: 7-year follow-up

183 patients (195 limbs) with primary femoral vein reflux were evaluated to relate valvular insufficiency and clinical results of elastic compression (68 limbs), saphenectomy (75 limbs), and valvuloplasty (52 limbs). Duplex scanning and calculating of Reflux Volume Index (RI) were performed before surgery and up to nine years of follow-up. Strong correlation between hemodynamic changes and results of treatment was found. Reulceration and recurrence were found in 74% of extremities with increasing leakage and in 14% of extremities with stable valve function. All 38 extremities with improved valvular function were free of ulcers and recurrent varicose veins. The success of surgical treatment in extremities with primary femoral vein reflux is associated with valvular function improvement. Elastic compression alone has poor clinical and hemodynamic results. Valvuloplasty significantly improves the results of surgical treatment.Presented at The 16th Annual Congress of The Phelbology Society of America, New York, New York, March 1996.     

Structural changes at microtubule ends accompanying GTP hydrolysis: Information from a slowly hydrolyzable analogue of GTP, guanylyl (α,β)methylenediphosphonate

Microtubules are dynamic polymers that interconvert between periods of slow growth and fast shrinkage. The energy driving this nonequilibrium behavior comes from the hydrolysis of GTP, which is required to destabilize the microtubule lattice. To understand the mechanism of this destabilization, cryo-electron microscopy was used to compare the structure of the ends of shrinking microtubules assembled in the presence of either GTP or the slowly hydrolyzable analogue guanylyl (α,β)methylenediphosphonate (GMPCPP). Depolymerization was induced by cold or addition of calcium. With either nucleotide, we have observed curled oligomers at the ends of shrinking microtubules. However, GDP oligomers were consistently more curved than GMPCPP oligomers. This difference in curvature between depolymerizing GDP and GMPCPP protofilaments suggests that GTP hydrolysis is accompanied by an increase in curvature of the protofilaments, thereby destabilizing the lateral interactions between tubulin subunits in the microtubule lattice.