Explosive school-based measles outbreak: intense exposure may have resulted in high risk, even among revaccinees

Several studies have pointed out that L-selectin on CD34-positive cells plays a role in haematopoietic reconstitution after peripheral blood stem cell (PBSC) transplantation. Since it is known that a decrease in L-selectin expression in lymphocytes and granulocytes can be induced by a variety of stress situations, we have investigated in this study whether the freeze-thawing procedure, used in PBSC transplantation, would affect L-selectin expression on CD34+ stem cells. Flow cytometry was performed by labelling the cells with anti-CD34 (HPCA2 PE) and anti-CD62L (FMC46 FITC). The leucapheresis procedure itself caused a slight decrease of L-selectin expression on CD34 cells in 11 out of 12 cases (mean decrease of the percentage of positive cells 11.9; range 6-23). A much larger decrease was found upon freeze-thawing: a mean of 39% (range 4-78% in 27 cases) compared to fresh material. To determine if L-selectin expression might be up-regulated after cryopreservation, thawed transplant samples (n = 11) were incubated at 37 degrees C in RPMI with 10% FCS at 5% CO2. Already early in the course of incubation two CD34-positive populations appeared in the blast region, characterized by either a low or high forward scatter. Simultaneous viability staining with the DNA dye 7-Amino Actinomycin D and the DNA/RNA dye Syto16 revealed that the population with low forward scatter was apoptotic while the population with the high forward scatter was non-apoptotic. The latter population is considered to be most relevant for transplantation. In this population an increase of L-selectin expression after overnight incubation was observed in 8/11 samples up to values of 46-120% of the values of the fresh nonfrozen samples. In addition, the mean fluorescence intensity was significantly increased in 10/11 cases. Kinetic experiments with shorter incubation times revealed that only part of the leucapheresis samples (two out of 8) showed an increase of L-selectin expression within 4 h. In addition, a decrease of L-selectin expression was found upon CD34 purification from fresh leucapheresis material by magnetic isolation (decrease ranging from 59 to 92%, n = 5). In contrast to frozen samples, L-selectin reappearance was seen already within 4 h of incubation in all samples. Both the loss of L-selectin expression on CD34 cells occurring upon freeze-thawing, the emergence of apoptosis, as well as the recovery of L-selectin expression on non-apoptotic cells varies largely between individual leucapheresis samples, and therefore it is concluded that such processes should be considered when correlations with clinical outcome after transplantation are made.     

Fusion between retinal rod outer segment membranes and model membranes: a role for photoreceptor peripherin/rds

Peripherin/rds plays an essential role in the maintenance of photoreceptor rod cell disk membrane structure. The purification of this protein to homogeneity [Boesze-Battaglia, K., et al. (1997) Biochemistry 36, 6835-6846] has allowed us to characterize the functional role of peripherin/rds in the maintenance of rod outer segment (ROS) membrane fusion processes. Utilizing a cell-free fusion assay system, we report that the fusion of R18-labeled ROS plasma membrane (R18-PM) with disk membranes or peripherin/rds-enriched large unilammellar vesicles (LUVs) is inhibited upon trypsinolysis of peripherin/rds. To understand this phenomenon, we tested the ability of a series of overlapping synthetic C-terminal peripherin/rds peptides to mediate model membrane fusion. Within the 63 amino acid long region of the C-terminus, we identified a minimal 15 residue long amino acid sequence (PP-5), which is necessary to promote membrane fusion. PP-5 was able to inhibit R18-PM disk membrane fusion and promoted ANTS/DPX contents mixing in a pure vesicle system. This peptide (PP-5) promoted calcium-induced vesicle aggregation of phosphatidylethanolamine:phosphatidylserine LUVs. FTIR analysis confirmed the structural prediction of this peptide as alpha-helical. When modeled as an alpha-helix, this peptide is amphiphilic with a hydrophobicity index of 0.75 and a hydrophobic moment of 0.59. PP-5 has substantial biochemical and functional homology with other well-characterized membrane fusion proteins. These results demonstrate the necessity for peripherin/rds in ROS membrane fusion, specifically the requirement for an intact C-terminal region of this protein.     

GABA, GABA transporters, GABA(A) receptor subunits, and GAD mRNAs in the rat parabrachial and K?lliker-Fuse nuclei

Enzymes are increasingly being used to perform regio- and enantioselective reactions in chemoenzymatic syntheses. To utilize enzymes for unphysiological reactions and to yield novel products, a broad substrate spectrum is desirable. Thiamin diphosphate (ThDP)-dependent enzymes vary in their substrate tolerance from rather strict substrate specificity (phosphoketolases, glyoxylate carboligase) to more permissive enzymes (transketolase, dihydroxyacetone synthase, pyruvate decarboxylase) and therefore differ in their potential to be used as biocatalysts. We give an overview of the known substrate spectra of ThDP-dependent enzymes and present examples of multi-enzyme or chemoenzymatic approaches which involve ThDP-dependent enzymes as biocatalysts to obtain pharmaceutical compounds as ephedrine and glycosidase inhibitors, sex pheromones as exo-brevicomin, 13C-labeled metabolites, and other intermediates as 1-deoxyxylulose 5-phosphate, a precursor of vitamins and isoprenoids.     

Identified hair follicle afferent boutons in the spinal cord of the cat are enriched with L-glutamate-like immunoreactivity

Hair follicle afferent boutons in the spinal dorsal horn of the cat were examined for L-glutamate enrichment. Two hair follicle afferent axons were labelled intra-axonally with horseradish peroxidase, and post-embedding immunogold reactions of L-glutamate were performed on thin sections containing horseradish peroxidase-labelled boutons. Quantitative analysis showed that hair follicle boutons were associated with immunogold reactions for L-glutamate which were almost twice as dense as average values for dorsal horn tissue. Further analysis revealed that hair afferent boutons displayed 2.3-times the average gold particle density associated with post-synaptic dendrites and 3-times the average immunogold density for L-glutamate of structures which were known to be immunoreactive for GABA. This enrichment of L-glutamate in identified hair afferent terminals supports the idea that the amino acid is a neurotransmitter of hair follicle primary afferent axons.     

Influence of upper airway pressure changes on respiratory frequency

Influences of pressure changes within the upper airway on respiratory frequency were studied in anesthetized rabbits. These reflex effects were investigated in two ways: (1) by applying sustained negative or positive pressures to isolated upper airway in vagally intact animals during tracheostomy breathing, and (2) by briefly occluding the nasal airways of vagotomized animals at end expiration. Negative pressure applied to isolated upper airway decreased the respiratory frequency (P less than 0.01). Decrease in respiratory frequency correlated with magnitude of pressure change. In contrast, positive pressures produced an increase in respiratory frequency (P less than 0.05). But, the increase in frequency correlated poorly with magnitude of positive pressure change. A post-stimulus effect lasting several breaths was seen following the release of both negative and positive pressures (P less than 0.01). Nasal occlusion in vagotomized animals was associated with an increase in Ti and Ttot of the first nasally occluded breath (P less than 0.05). Increase in Ti was not associated with an increase in peak diaphragmatic activity. This would result in decreased inspiratory load on the upper airway patency maintaining muscles by reducing the mean inspiratory pressure. Hence, these reflex responses to airway pressure could play a functional role in the maintenance of upper airway patency.     

Long-term course of tear gland function in patients with keratoconjunctivitis sicca and Sj?gren''s syndrome

The reliability and validity of a Confidence of Dental Hygienist in Child Management Scale were examined. Forty-eight dental hygiene students, nine dental staff, and thirty-one dentists were subjects for the reliability and validity scale. The acceptable level of the reliability on the Scale was shown by internal consistency and stability. The confidence scores of the clinician's group were significantly higher than the confidence scores of the students. The reliability and validity of the Confidence Scale were established. Next, we evaluated the effect of behavioral science training, using videotape feedback and role playing on twelve dental hygiene students. Six students received the training, the other six students, the controls, had no training. The confidence scores of the training group were significantly higher than those of the control group, demonstrating that the training was effective for dental hygiene students.     

The effect of an acetylcholine analog on the activity of the angiotensin-converting enzyme in the lung, kidney and plasma of the arterial and renal venous blood of rats

Angiotensin-converting enzyme (ACE) activity after i.v. carbachol administration increased in the renal cortex and decreased in the renal venous plasma. Carbachol did not affect the pulmonary ACE activity. The renal ACE pool seems to be more sensitive to cholinergic effect than the pulmonary one.     

Holography and the possibility of its use in applied anatomy

The article deals with some methods of holography (holograms with inclined reference beam, in three-dimensional media after Yu. N. Denisiuk, holographic interferometry) as applied to studying anatomical objects. Approximate optical schemes and photographic copies of holograms of separate objects are presented. The comparative analysis of different methods enabled the authors to recommened for practical use the method of obtaining holograms in three-dimensional media for documentation of anatomical investigation and storage of information, holographic method of obtaining contour maps of the surface for quantitative characteristics of individual properties of the object and the method of double exposure for studying static and dynamic deformities.