Neuronal Redevelopment and the Regeneration of Neuromodulatory Axons in the Adult Mammalian Central Nervous System

One reason that many central nervous system injuries, including those arising from traumatic brain injury, spinal cord injury, and stroke, have limited recovery of function is that neurons within the adult mammalian CNS lack the ability to regenerate their axons following trauma. This stands in contrast to neurons of the adult mammalian peripheral nervous system (PNS). New evidence, provided by single-cell expression profiling, suggests that, following injury, both mammalian central and peripheral neurons can revert to an embryonic-like growth state which is permissive for axon regeneration. This “redevelopment” strategy could both facilitate a damage response necessary to isolate and repair the acute damage from injury and provide the intracellular machinery necessary for axon regrowth. Interestingly, serotonin neurons of the rostral group of raphe nuclei, which project their axons into the forebrain, display a robust ability to regenerate their axons unaided, counter to the widely held view that CNS axons cannot regenerate without experimental intervention after injury. Furthermore, initial evidence suggests that norepinephrine neurons within the locus coeruleus possess similar regenerative abilities. Several morphological characteristics of serotonin axon regeneration in adult mammals, observable using longitudinal in vivo imaging, are distinct from the known characteristics of unaided peripheral nerve regeneration, or of the regeneration seen in the spinal cord and optic nerve that occurs with experimental intervention. These results suggest that there is an alternative CNS program for axon regeneration that likely differs from that displayed by the PNS.

621 Robot-Assisted Radical Cystectomy: A Complete Audit Cycle of Our First 118 Cases

Aim

There are 10,200 cases of bladder cancer diagnosed every year in the UK, accounting for 3% of all new cancer diagnoses. Robot-assisted radical cystectomy (RARC) is a minimally invasive treatment option for muscle invasive and high-risk bladder cancer with a rising uptake. Between 2017 and 2019, RARC accounted for 40.6% of all cystectomies performed in the UK, increasing to 52% in 2018 to 2019. We compared our outcomes with the best practice of RARC set by the Pasadena consensus panel in 2015.

Method

A review of the prospective database of all RARC performed by two surgeons at Royal Wolverhampton Hospital between May 2013 and October 2020 was conducted. Operative and oncological outcome data were collected from Clinical Web Portal and Somerset Cancer Register and analysed using Microsoft Excel.

Results

A total of 118 RARC were performed in the study period, 50 cases were analysed in the first audit loop and 68 cases in the second. The mean age was 69 years (44 – 82), 84% were men and 70% were ASA grade II or less. Median operating time was 376 minutes (210 – 555) and the median blood loss was 250mls. 79% of urinary diversion was intra-corporeal and 84% was ileal conduit diversion. Median length of stay was 8 days; complication rate with Clavien Dindo score of III or higher was 12.7%. 86% of our patients are still alive.

Conclusions

RARC is a safe option for the radical management of bladder cancer. Our outcomes are consistent with the Pasadena consensus recommendations.

Tanycyte ablation in the arcuate nucleus and median eminence increases obesity susceptibility by increasing body fat content in male mice

Tanycytes are radial glial cells located in the mediobasal hypothalamus. Recent studies have proposed that tanycytes play an important role in hypothalamic control of energy homeostasis, although this has not been directly tested. Here, we report the phenotype of mice in which tanycytes of the arcuate nucleus and median eminence were conditionally ablated in adult mice. Although the cerebrospinal fluid-hypothalamic barrier was rendered more permeable following tanycyte ablation, neither the blood-hypothalamic barrier nor leptin-induced pSTAT3 activation in hypothalamic parenchyma were affected. We observed a significant increase in visceral fat distribution accompanying insulin insensitivity in male mice, without significant effect on either body weight or food intake. A high-fat diet tended to accelerate overall body weight gain in tanycyte-ablated mice, but the development of visceral adiposity and insulin insensitivity was comparable to wildtype. Thermoneutral housing exacerbated fat accumulation and produced a shift away from fat oxidation in tanycyte-ablated mice. These results clarify the extent to which tanycytes regulate energy balance, and demonstrate a role for tanycytes in regulating fat metabolism.

Regional Innovation Policy: Problems and Strategies in Britain and France

Britain's lagging economic performance is clearly tied to a failure on the part of British industry to innovate to the same extent as competitor economies. There is a spatial coincidence between the least innovative parts of Britain's innovation-poor economy and the traditionally depressed industrial regions. It has been suggested in government and academia that one way to help overcome both the problem of innovation lag and that of regional industrial decline is for Britain to adopt a regional innovation policy. In this paper the case for this is discussed in the context of the regional problem and in terms of problems posed by a market-led innovation process. A critical evaluation of one possible form of regional innovation policy based on the decentralisation of government research and development as carried out in France since the 1950s is presented. It is concluded that neither the present British nor French approaches are ideal but that some regionalised combination of them could be an improvement.

The Manchester-Oxford Foot Questionnaire (MOXFQ): Development and validation of a summary index score

Objectives

The Manchester–Oxford Foot Questionnaire (MOXFQ) is a validated 16-item, patient-reported outcome measure for evaluating outcomes of foot or ankle surgery. The original development of the instrument identified three domains. This present study examined whether the three domains could legitimately be summed to provide a single summary index score.

Methods

The MOXFQ and Short-Form (SF)-36 were administered to 671 patients before surgery of the foot or ankle. Data from the three domains of the MOXFQ (pain, walking/standing and social interaction) were subjected to higher order factor analysis. Reliability and validity of the summary index score was assessed.

Results

The mean age of the participants was 52.8 years (sd 15.68; 18 to 89). Higher order principle components factor analysis produced one factor, accounting for 74.7% of the variance. The newly derived single index score was found to be internally reliable (α = 0.93) and valid, achieving at least moderate correlations (r ≥ 0.5, p < 0.001) with related (pain/function) domains of the SF-36.

Conclusions

Analyses indicated that data from the MOXFQ can be presented in summary form. The MOXFQ summary index score (MOXFQ-Index) provides an overall indication of the outcomes of foot and ankle surgery. Furthermore, the single index reduces the number of statistical comparisons, and hence the role of chance, when exploring MOXFQ data.

Responsiveness of the Manchester-Oxford Foot Questionnaire (MOXFQ) compared with AOFAS, SF-36 and EQ-5D assessments following foot or ankle surgery

The responsiveness of the Manchester-Oxford Foot Questionnaire (MOXFQ) was compared with foot/ankle-specific and generic outcome measures used to assess all surgery of the foot and ankle. We recruited 671 consecutive adult patients awaiting foot or ankle surgery, of whom 427 (63.6%) were female, with a mean age of 52.8 years (18 to 89). They independently completed the MOXFQ, Short-Form 36 (SF-36) and EuroQol (EQ-5D) questionnaires pre-operatively and at a mean of nine months (3.8 to 14.4) post-operatively. Foot/ankle surgeons assessed American Orthopaedic Foot and Ankle Society (AOFAS) scores corresponding to four foot/ankle regions. A transition item measured perceived changes in foot/ankle problems post-surgery. Of 628 eligible patients proceeding to surgery, 491 (78%) completed questionnaires and 262 (42%) received clinical assessments both pre- and post-operatively. The regions receiving surgery were: multiple/whole foot in eight (1.3%), ankle/hindfoot in 292 (46.5%), mid-foot in 21 (3.3%), hallux in 196 (31.2%), and lesser toes in 111 (17.7%). Foot/ankle-specific MOXFQ, AOFAS and EQ-5D domains produced larger effect sizes (> 0.8) than any SF-36 domains, suggesting superior responsiveness. In analyses that anchored change in scores and effect sizes to patients' responses to a transition item about their foot/ankle problems, the MOXFQ performed well. The SF-36 and EQ-5D performed poorly. Similar analyses, conducted within foot-region based sub-groups of patients, found that the responsiveness of the MOXFQ was good compared with the AOFAS. This evidence supports the MOXFQ's suitability for assessing all foot and ankle surgery.

The MOXFQ patient-reported questionnaire: assessment of data quality, reliability and validity in relation to foot and ankle surgery

Previously validated for hallux valgus surgery, the Manchester-Oxford Foot Questionnaire (MOXFQ) is here evaluated for use with different regions of the foot and ankle. The study recruited 671 consecutive patients (87.8% of those eligible), mean age 52.8 years, 64% female, who completed the MOXFQ and SF-36 general health survey before foot or ankle surgery. Surgeons completed the American Orthopaedic Foot & Ankle Society (AOFAS) scales and indicated that the patients' main regions for surgery were: Hallux 210 (31.3%), Lesser toes 119 (17.7%), Mid foot 22 (3.3%), Ankle/hind foot 311 (46.3%), Multiple/whole foot 9 (1.3%). Individual MOXFQ items were assessed in terms of response rate and floor/ceiling effects, with the validity of the three MOXFQ scales (Walking/standing, Pain, and Social interaction) being assessed in terms of item-total correlations, internal and test-retest reliability, and construct validity. MOXFQ item response rates were high (all >98%). Cronbach's alphas of >0.7 confirmed internal consistency of all three scales. Test-retest ICCs were all ≥0.89. Correlations of >0.4 obtained with related SF-36 and AOFAS scales supported a priori hypotheses. Good measurement properties are confirmed for the MOXFQ in the context of baseline assessment of patients receiving surgery for a variety of foot or ankle problems.

Non-laxative CT colonography with barium-based faecal tagging: is additional phosphate enema beneficial and well tolerated?

OBJECTIVE

The purpose of this study was to investigate the efficacy and tolerance of an additional phosphate enema prior to non-laxative CT colonography (CTC).

METHODS

71 patients (mean age 80 years, 28 male, 43 female) underwent non-laxative CTC following 4 oral doses of diluted 2% w/w barium sulphate. Patients were invited to self-administer a phosphate enema 2 h before CTC. An experienced observer graded the volume of retained stool (1 (nil) to 4 (>75% bowel circumference coated)), retained fluid ((1 (nil) to 4 (>50% circumference obscured)), retained stool tagging quality (1 (untagged) to 5 (≥75% to 100%) tagged) and confidence a polyp ≥6 mm could be excluded (yes/no) for each of six colonic segments. Tolerance of the enema was assessed via questionnaire. Data were analysed between those using and not using the enema by Mann-Whitney and Fisher's exact test. 18/71 patients declined the enema.

RESULTS

There was no reduction in residual stool volume with enema use compared with non-use either overall (mean score 2.6 vs 2.7, p = 0.76) or in the left colon (mean 2.3 vs 2.4, p = 0.47). Overall tagging quality was no different (mean score 4.4 vs 4.3, p = 0.43). There was significantly more retained left colonic fluid post enema (mean score 1.9 vs 1.1, p<0.0001), and diagnostic confidence in excluding polyps was significantly reduced (exclusion not possible in 35% segments vs 21% without enema, p = 0.006). Of 53 patients, 30 (56%) found the enema straightforward to use, but 4 (8%) found it unpleasant.

CONCLUSION

Phosphate enema use prior to non-laxative CTC leads to greater retained fluid, reducing diagnostic confidence, and is not recommended.

Cultivation of 'Candidatus Liberibacter asiaticus', 'Ca. L. africanus', and 'Ca. L. americanus' associated with huanglongbing

A new medium designated Liber A has been designed and used to successfully cultivate all three 'Candidatus Liberibacter spp.,' the suspect causative agents of huanglongbing (HLB) in citrus. The medium containing citrus vein extract and a growth factor sustained growth of 'Ca. Liberibacter spp.' for four or five single-colony transfers before viability declined. Colonies, positive for 'Ca. L. asiaticus' by a 16s-based rDNA real-time polymerase chain reaction (RT-PCR) assay and sequencing, were irregular-shaped, convex, and 0.1 to 0.3 mm after 3 to 4 days. Suspect 'Ca. L. asiaticus' and 'Ca. L. americanus' cells were observed in infected tissue and on agar culture by scanning electron microscopy. The cells were ovoid to rod shaped, 0.3 to 0.4 by 0.5 to 2.0 microm, often with fimbriae-like appendages. Two strains of 'Ca. L. asiaticus' and one of 'Ca. L. americanus' grown on Liber A medium were pathogenic on citrus and could be isolated from noninoculated tissues of inoculated trees and seedlings 9 and 2 months later, respectively. The identity was confirmed by RT-PCR and 16s rDNA sequencing. This is the first report of the cultivation and pathogenicity of 'Ca. L. asiaticus' and 'Ca. L. americanus' associated with symptoms of HLB.

Qdot nanobarcodes for multiplexed gene expression analysis

We report a quantum dot (Qdot) nanobarcode-based microbead random array platform for accurate and reproducible gene expression profiling in a high-throughput and multiplexed format. Four different sizes of Qdots, with emissions at 525, 545, 565, and 585 nm are mixed with a polymer and coated onto the 8-mum-diameter magnetic microbeads to generate a nanobarcoded bead termed as QBeads. Twelve intensity levels for each of the four colors were used. Gene-specific oligonucleotide probes are conjugated to the surface of each spectrally nanobarcoded bead to create a multiplexed panel, and biotinylated cRNAs are generated from sample total RNA and hybridized to the gene probes on the microbeads. A fifth streptavidin Qdot (655 nm or infrared Qdot) binds to biotin on the cRNA, acting as a quantification reporter. Target identity was decoded based on spectral profile and intensity ratios of the four coding Qdots (525, 545, 565, and 585 nm). The intensity of the 655 nm Qdot reflects the level of biotinylated cRNA captured on the beads and provides the quantification for the corresponding target gene. The system shows a sensitivity of < or =10(4) target molecules detectable with T7 amplification, a level that is better than the 10(5) number achievable with a high-density microarray system, and approaching the 10(3)-10(4) level usually observed for quantitative PCR (qPCR). The QBead nanobarcode system has a dynamic range of 3.5 logs, better than the 2-3 logs observed on various microarray platforms. The hybridization reaction is performed in liquid phase and completed in 1-2 hours, at least 1 order of magnitude faster than microarray-based hybridizations. Detectable fold change is lower than 1.4-fold, showing high precision even at close to single copy per cell level. Reproducibility for this proof-of-concept study approaches that of Affymetrix GeneChip microarray, with an R(2) value between two repeats at 0.984, and interwell CV around 5%. In addition, it provides increased flexibility, convenience, and cost-effectiveness in comparison to conventional gene expression profiling methods.

Genome sequence, comparative analysis and haplotype structure of the domestic dog

Here we report a high-quality draft genome sequence of the domestic dog (Canis familiaris), together with a dense map of single nucleotide polymorphisms (SNPs) across breeds. The dog is of particular interest because it provides important evolutionary information and because existing breeds show great phenotypic diversity for morphological, physiological and behavioural traits. We use sequence comparison with the primate and rodent lineages to shed light on the structure and evolution of genomes and genes. Notably, the majority of the most highly conserved non-coding sequences in mammalian genomes are clustered near a small subset of genes with important roles in development. Analysis of SNPs reveals long-range haplotypes across the entire dog genome, and defines the nature of genetic diversity within and across breeds. The current SNP map now makes it possible for genome-wide association studies to identify genes responsible for diseases and traits, with important consequences for human and companion animal health.

The virtual courtroom: a view of justice. Project to prepare witnesses or victims with learning disabilities to give evidence

PURPOSE

With the advent of 'The Youth Justice and Criminal Evidence Act 1999' passed by Parliament in August 1999, vulnerable witnesses can for the first time give evidence to the court with the support of 'special measures'. People with a learning disability fall into the category of vulnerable witnesses, and the purpose of this paper is to describe the development of the virtual courtroom, a virtual reality (VR) and multimedia based training platform to prepare this group of people for such an eventuality.

METHOD

A user-centred design methodology was adopted, with a user group being formed of students and adults with learning disabilities. This group, working together with facilitators, experts on the new act, and experienced designers of VR based training systems, designed and implemented the virtual courtroom.

RESULTS

The virtual courtroom model has been produced using the Realimation Virtual Reality software tool. The next stage of the project is to design and develop three multimedia-based scenarios showing a variety of situations in which a person with a learning disability could give evidence in court.

CONCLUSION

One of the recommendations in the 'Speaking up for justice' report, suggested that the Home Office develop further material to assist vulnerable witnesses to prepare for their attendance at court. The virtual courtroom provides one of the first and most innovative of such solutions.

Minding the gap: some theory-practice disjunctions in nursing education research

Nursing and nurse education are currently experiencing 'turbulence' as a result of the rapid, unpredictable and often divergent forces in the macro- and micro-institutional settings. Research-based knowledge seeks to 'smooth-over' this 'turbulence', which the literature cites as 'gaps' between the rhetorical ideals and practical realities. This paper deconstructs three influential ENB-sponsored research projects. It is argued that these research reports introduce forms of 'Utopianism', reinserting theory-practice gaps they sought to close down. Finally, as a result of the idealism revealed by the deconstruction, five key issues for future development in nursing research are discussed. These issues are of significance to educationalists since educational policy and practice in nursing are often developed from research findings.

Screening methods for thyroid hormone disruptors

The U.S. Congress has passed legislation requiring the EPA to implement screening tests for identifying endocrine-disrupting chemicals. A series of workshops was sponsored by the EPA, the Chemical Manufacturers Association, and the World Wildlife Fund; one workshop focused on screens for chemicals that alter thyroid hormone function and homeostasis. Participants at this meeting identified and examined methods to detect alterations in thyroid hormone synthesis, transport, and catabolism. In addition, some methods to detect chemicals that bind to the thyroid hormone receptors acting as either agonists or antagonists were also identified. Screening methods used in mammals as well as other vertebrate classes were examined. There was a general consensus that all known chemicals which interfere with thyroid hormone function and homeostasis act by either inhibiting synthesis, altering serum transport proteins, or by increasing catabolism of thyroid hormones. There are no direct data to support the assertion that certain environmental chemicals bind and activate the thyroid hormone receptors; further research is indicated. In light of this, screening methods should reflect known mechanisms of action. Most methods examined, albeit useful for mechanistic studies, were thought to be too specific and therefore would not be applicable for broad-based screening. Determination of serum thyroid hormone concentrations following chemical exposure in rodents was thought to be a reasonable initial screen. Concurrent histologic evaluation of the thyroid would strengthen this screen. Similar methods in teleosts may be useful as screens, but would require indicators of tissue production of thyroid hormones. The use of tadpole metamorphosis as a screen may also be useful; however, this method requires validation and standardization prior to use as a broad-based screen.

Triggering learning in midwifery

The delivery of the head with or without forceps may have been quite easy, but more commonly there has been a little difficulty in completing the extension of the head. The hairy scalp slides with reluctance. When the forehead has appeared it is necessary to press back the perineum to deliver the face. Fat cheeks eventually emerge. A double chin has hooked over the posterior commissure, to which it remains tightly opposed. Restitution seldom occurs spontaneously for the head seems incapable of movement as a result of friction with the girdle of contact at the vulva... time passes. The child's face becomes suffused. It endeavours unsuccessfully to breathe. Abdominal efforts by the mother or by her attendants produce no advance, gentle traction is equally unavailing... Usually equanimity forsakes the attendants. They push, they pull. Alarm increases. Eventually, by greater strength of muscle or some infernal struggle, the difficulty seems to be overcome... It dawns upon the attendants that their anxiety was not ill founded.

The development of a problem-based curriculum in midwifery

Making use of best available evidence has clearly become an important part of midwifery practice. As educational programmes are preparing the practitioners of the future, it is believed that midwifery education should also be informed by evidence. At Thames Valley University, a BSc Midwifery curriculum, using the principles of problem-based learning, has been implemented following a review of both appropriate research and evaluation. This article explains the process undertaken in preparation for the course as well as the proposed means of ongoing evaluation.

Thermal stabilization of collagen fibers by calcification

Mineralized collagenous tissue is known to be more stable than soft collagenous tissue both mechanically and thermally. We find that the denaturation temperature of collagen in bone scanned in differential scanning calorimetry at 5 degrees C/min is 155 degrees C, 90 degrees C higher than that in skin. Furthermore, when the bone is partially demineralized with citrate, a discrete intermediate denaturation temperature appears at 113 degrees C, indicating that the mineral is retained at preferential binding sites in the collagen until it is completely leached out. It is shown by electron microscopy that these sites are located in the overlap regions of the collagen fibrils. Collagen in bovine hide can be synthetically mineralized in vitro by impregnation with calcium acid phosphate solution, followed by raising the pH, causing the phosphate to precipitate. Some of the collagen in this synthetically calcified tissue has an elevated denaturation temperature, 104 degrees C. This temperature compares favorably with collagen that is tanned with chromium oxide-sulfate complexes. Calcium phosphate in synthetically mineralized hide, hydroxyapatite in bone, and chromium oxide-sulfate complexes in leather might share the same mechanism of thermal stabilization.

Characteristics of mitotic cells in developing and adult testes with observations on cell lineages

This report describes characteristics of dividing cells, primarily in developing (10-40 day) rat testis and relates the structure of the dividing cells to the structure of interphase cells. Mitotic cells were characterized in seven zones. Dividing Sertoli cells were seen prior to day 15 and possessed distinct characteristics as compared with dividing germ cells. Myoid cells showed morphological characteristics of precursor myoid cells; 'clear cells' self-replicated in the myoid cell layer; adult-type Leydig cells, some containing lipid, differentiated early (10th-15th postnatal days) from fibroblast-like cells of the multilayered tubule wall and later (15th-25th postnatal days) from dividing differentiated and semi-differentiated Leydig cells within the lymphatic space; fibroblastic cells arose from cells with similar morphological characteristics; semi-differentiated Leydig cells divided, and differentiated Leydig cells in the lymphatic space self-renewed; undifferentiated perivascular cells most likely gave rise to Leydig cells, pericytes; arteriolar smooth muscle cells and vascular endothelial cells arose from division of the pre-existing respective cell types. Fetal Leydig cells appeared to remain but, with time, they appeared to lose their lipid. The data suggest that (1) early recruitment of Leydig cells from undifferentiated peritubular fibroblast-like cells, (2) later mitosis of differentiated and semi-differentiated Leydig cells primarily in the interstitium but also in the perivascular region, and (3) the continued presence of pre-existing Leydig cells from the fetus constitute the adult population. Leydig cell division in the adult mouse was documented. This study provides the necessary information for the recognition of cell divisions to study of cell lineages among testis cells.

In vivo nuclear magnetic resonance study of the osmoregulation of phosphocholine-substituted beta-1,3;1,6 cyclic glucan and its associated carbon metabolism in Bradyrhizobium japonicum USDA 110

A phosphocholine-substituted beta-1,3;1,6 cyclic glucan (PCCG), an unusual cyclic oligosaccharide, has been isolated from Bradyrhizobium japonicum USDA 110 (D. B. Rolin, P. E. Pfeffer, S. F. Osman, B. S. Swergold, F. Kappler, and A. J. Benesi, Biochim. Biophys. Acta 1116:215-225, 1992). Data presented here suggest that PCCG synthesis is dependent on the carbon metabolism and that osmotic regulation of its biosynthesis parallels regulation of membrane-derived oligosaccharide biosynthesis observed in Escherichia coli (E. P. Kennedy, M. K. Rumley, H. Schulman, and L. M. G. van Golde, J. Biol. Chem. 251:4208-4213, 1976) and Agrobacterium tumefaciens (G. A. Cangelosi, G. Martinetti, and E. W. Nester, J. Bacteriol. 172:2172-2174, 1990). Growth of B. japonicum USDA 110 cells in the reference medium at relatively low osmotic pressures (LO) (65 mosmol/kg of H2O) caused a large accumulation of PCCG and unsubstituted beta-1,3;1,6 cyclic glucans (CG). Sucrose and polyethylene glycol, nonionic osmotica, reduce all growth rates and inhibit almost completely the production of PCCG at high osmotic pressures (HO) above 650 and 400 mosmol/kg of H2O), respectively. We used in vivo 13C nuclear magnetic resonance spectroscopy to identify the active osmolytes implicated in the osmoregulation process. The level of alpha,alpha-trehalose in B. japonicum cells grown in autoclaved or filter-sterilized solutions remained constant in HO (0.3 M sucrose or 250 g of polyethylene glycol 6000 per liter) medium. Significant amounts of glycogen and extracellular polysaccharides were produced only when glucose was present in the autoclaved HO 0.3 M sucrose media. The results of hypo- and hyperosmotic shocking of B. japonicum USDA 110 cells were monitored by using in vivo 31P and 13C nuclear magnetic resonance spectroscopy. The first observed osmoregulatory response of glycogen-containing cells undergoing hypoosmotic shock was release of P(i) into the medium. Within 7 h, reabsorption of P(i) was complete and production of PCCG was initiated. After 12 h, the PCCG content had increased by a factor of 7. Following the same treatment, cells containing little or no glycogen released trehalose and failed to produce PCCG. Thus the production of PCCG/CG in response to hypoosmotic shocking of stationary-phase cells was found to be directly linked to the interconversion of stored glycogen. Hyperosmotic shocking of LO-grown stationary-phase cells with sucrose had no effect on the content of previously synthesized CG/PCCG. The PCCG/CG content and its osmotically induced biosynthesis are discussed in terms of carbon metabolism and a possible role in hypoosmotic adaptation in B. japonicum USDA 110.

A comparison of two semi-quantitative surgical keratometers: the modified Hyde ruler and the Barrett keratoscope with "astigmatic dial"

The Hyde astigmatic ruler is an inexpensive, semiquantitative, hand-held, surgical keratometer that we modified by geometrically calculating the correct shape of its ellipses. The Barrett keratoscope is a cheap, disposable, qualitative keratometer that, unlike the Hyde ruler, produces a bright corneal image. We designed a transparent overlay, or "astigmatic dial," to use with the keratoscope. This overlay determines the magnitude of astigmatism and sets the distance the keratoscope is held from the cornea by direct comparison with the corneal image. Using a model cornea, we compared our modified Hyde ruler with the Barrett keratoscope and astigmatic dial to determine the accuracy of measurement provided by each. Both instruments had good predictive values for the true astigmatism; however, the Barrett keratoscope/astigmatic dial provided more consistent measurements of the astigmatism. We believe the keratoscope and dial provide a cheap, convenient, and accurate alternative to the more expensive microscope-mounted keratometers.

Progressive dissociation of pectin

The structural organization of alkaline soluble peach pectin was investigated over size ranges extending from micrometers to tenths of nanometers. Analysis was by electron microscopy and high-performance anion-exchange chromatography (HPAEC). Superimposed and individual circular microgels in the micrometer size range were isolated from mesocarp tissue of cell walls and visualized by rotary shadowing. Dilute NaCl and 50% aqueous glycerol disaggregated these microgels into rods, segmented rods, and kinked rods, which collectively comprised the internal gel network of the microgels. Image analysis of the shadowed specimens before and after disaggregation followed by curve fitting of the smoothed distributions revealed a multimodal distribution of lengths. HPAEC revealed that the multimodal aggregates were stable for the most part to further dissociation by increasing ionic strength.

Transcaecal ileal diversion in the management of the 'at risk' distal colonic anastomosis

Transcaecal ileal diversion has been used in association with primary resection and anastomosis to defunction an elective distal colonic anastomosis in 10 patients and to allow on-table colonic lavage with subsequent colonic defunction in 11 patients presenting as an emergency with distal colonic obstruction. Post-operative wound sepsis occurred in four patients (19%) with a clinical anastomotic leak in one patient. The median hospital stay was 14 (10-19) days. Transcaecal ileal diversion is simple to perform. It may facilitate primary resection and anastomosis in both the elective and emergency situation without increasing morbidity, mortality or the hospital stay.

Pectin microgels and their subunit structure

High-performance size exclusion chromatography revealed that alkaline-extracted peach fruit pectin dissolved in 0.05 M NaNO3 comprised a hierarchy of at least four aggregated, macromolecular-sized species. Each of the three largest species was found to be comparable in length to the three smallest subunits of an interconnecting gel network visualized by transmission electron microscopy of pectin, rapidly dried from solution. The interconnecting subunits of the gel network were rods or segmented rods and the integrated network formed a circular gel about 1 micron in diameter. Shadowed samples prepared from 5 and 50 mM NaCl or aqueous glycerol solutions produced images of partially dissociated subunits.

Use of cytogenetic methods to determine mutagenic changes in the blood of pharmacy personnel and nurses who handle cytotoxic agents

Lymphocytes of subjects from throughout the United Kingdom were studied over a two-year period beginning in January 1985 to determine the level of chromosomal damage produced by environmental exposure to cytotoxic agents. A small pilot study was conducted to determine the expected background level of chromosomal aberrations. Four groups of subjects were then recruited: pharmacy personnel who reconstituted the drugs under recommended conditions, nurses who did not reconstitute the drugs but worked on units where patients received cytotoxic chemotherapy, unexposed office workers from the same geographic location as the pharmacy personnel and nurses (negative control), and patients receiving cytotoxic drugs (positive control). Subjects completed questionnaires about smoking, viral illnesses, radiation exposure, and medication use in the past 12 months; pharmacy personnel were asked the numbers of times (1) they had handled specific drugs and (2) spills had occurred with these drugs. Lymphocytes from subjects were incubated for 48 hours, and first-division metaphases were examined for chromosome and chromatid aberrations; damage was measured as the number of aberrations per 100 cells. For a blood sample to be included in the analysis, at least 100 metaphase divisions had to be examined. Data were analyzed for 50 pharmacy staff members, 11 nurses, 12 controls, and 6 patients. Metaphase divisions in cells of the pharmacy personnel and nurses indicated no significant difference in chromosomal damage compared with the unexposed office workers. When the pharmacy, nurse, and control groups were pooled into a nonpatient group and compared with the patient group, significantly greater damage was observed in the patient group.(ABSTRACT TRUNCATED AT 250 WORDS)

An investigation of ring and dicentric chromosomes found in three Turner's syndrome patients using DNA analysis and in situ hybridisation with X and Y chromosome specific probes

We have studied three patients with features of Turner's syndrome, two with a 45,X/46,X,r(?) and the third with a 45,X/46,X,dic?(Y) karyotype. Because Turner's syndrome patients with a mosaic karyotype containing a Y chromosome are known to have a high risk of developing gonadal tumours, we used DNA analysis and in situ hybridisation with X and Y specific probes to identify the chromosomal origin of the rings and dicentric chromosomes in the three index patients. Both ring chromosomes were shown to be of X origin, while the dicentric was composed of Y chromosome material. We discuss the importance of using a combination of molecular and cytogenetic analyses in such cases.

Acetylated alpha-tubulin in microtubules during mouse fertilization and early development

alpha-Tubulin in the microtubules of mouse oocytes and embryos is acetylated in a specific spatial and temporal sequence. In the unfertilized oocyte, a monoclonal antibody to the acetylated form of alpha-tubulin is bound predominantly at the poles of the arrested metaphase meiotic spindle. The labeling intensity of the spindle microtubules is weaker as observed by immunofluorescence using oocytes double-labeled for total tubulin and acetylated alpha-tubulin, and as measured by immuno high-voltage electron microscopy (immunoHVEM) with colloidal gold; cytasters are not acetylated. At meiotic anaphase, the spindle becomes labeled, and by telophase and during second polar body formation only the meiotic midbody is acetylated. The sperm axoneme retains its acetylation after incorporation though the interphase microtubules are not detected. First mitosis follows a pattern similar to that observed at the second meiosis and during interphase only the mitotic midbodies are acetylated. After treatment with cold, colcemid, or griseofulvin, the remaining stable microtubules are acetylated, but immunoHVEM observations suggest that these fibers might not have been acetylated prior to microtubule disruption. Taxol stabilization does not alter acetylation patterns. Acetylated microtubules are not necessarily old microtubules since acetylated fibers are observed at 30 sec after cold recovery. These results show the presence of acetylated microtubules during meiosis and mitosis and demonstrate a cell-cycle-specific pattern of acetylation, with acetylated microtubules found at the centrosomes at metaphase, an increase in spindle labeling at anaphase, and the selective deacetylation of all but midbody microtubules at telophase.

Simultaneous trisomy 9q3 and monosomy 5p in two children with der(5),t(5;9)(p15.1;q34.13): report of an extended family

We present a family segregating for t(5;9)(p15.1;q34.13). Two cases with der(5),t(5;9), resulting in a partial duplication 9q34.13----qter and partial deletion of 5p15.12----pter, were ascertained. The phenotypes were consistent with features of both the cri du chat and trisomy 9q3 syndromes.

Comparison of the effectiveness of midazolam and diazepam in lipid emulsion as sedation during upper gastrointestinal endoscopy

In a study of 101 patients undergoing upper gastrointestinal endoscopy, 90% of patients had complete amnesia for the procedure after intravenous midazolam (average dose 10 mg), but only 61% had complete amnesia after intravenous diazepam in lipid emulsion (average dose 18.4 mg) (P = 0.0006). However, when assessed by two different tests, recovery within the first hour was significantly more rapid after diazepam (P less than 0.0001). Prolonged sedation (over 20 hours after injection) was reported occasionally by patients who had received either drug. Thus, as with patients who have been sedated with diazepam, those who have been sedated with midazolam should also be advised to avoid driving or operating machinery for at least 24 hours after injection.

Long-term high fibre, low fat diet in gestational diabetes

A 30-year-old Caucasian who developed gestational diabetes in her first pregnancy requiring 58 U insulin daily and who subsequently adopted a high fibre, low fat diet and who was able to maintain normal glucose tolerance throughout a second pregnancy is reported.

A periodic cytoskeletal lattice in striated muscle

The axial periodicities of electron density in striated muscle fibers extend over four orders of magnitude, ranging from the sarcomere repeat (2000-3000 nm) to a residue repeat in the alpha-helix of structural proteins (0.15 nm). A prevailing idea about the regular arrangement of structures in the contractile apparatus maintains that long-range axial spacings, related to the organization of sarcomere repeats, are essentially independent of the short-range periodicities with molecular dimensions. This is a central theme of the sliding filament hypothesis but is only supported by evidence from measured spacings near the upper and lower limits in the spectrum of dimensions, leaving a wide gap in resolved structural information extending from about 460 down to 50 nm. Several independent morphological methods show an electron-dense cross-striation of low amplitude with a pseudo-period of 230 nm, out of phase with the sarcomere repeat, in myofibrils of frog twitch fibers. Averaged images of embedded muscle fibers indicate that the sarcomere repeat contains five symmetrical pairs of these striations, which are coordinated with discrete repeats of the major molecular periods in the thick and thin filaments, in register within A and I bands. The pseudo-period therefore correlates short-range molecular repeats in the filaments with long-range registry of the sarcomere repeats in myofibrils. This raises the interesting possibility that the 230-nm pseudo-periodicity identifies a replicated axial structure in myofibrils that integrates the organization of the major structural proteins into the sarcomere repeat. The density distribution in sarcomeres of isolated unstained myofibrils also establishes that symmetrical pairs of striations with intrinsically low amplitudes are independently distorted out of uniform register in stretched sarcomeres. This behavior is consistent with the properties of N lines. The out-of-phase arrangement of 230-nm striations in the sarcomere repeat of twitch fibers should produce special diffraction effects in the region of the gap in the spectrum of periodicities recorded from muscle, with maxima at spacings extending from 200 to 80 nm. Correspondence between the diffraction spectrum of myofibril models containing a 230-nm spaced axial pseudo-period and the observed very low-angle X-ray diffraction spacings from living muscle (Huxley and Brown, 1967) suggests that the 230-nm pseudo-periodicity is a regular detectable component of striated muscle, resembling the structure of naturally occurring leptomeric fibrils in extrafusal and intrafusal fibers (Karlson and Andersson-Cedergren, 1968).(ABSTRACT TRUNCATED AT 400 WORDS)