Biomanufacturing in low Earth orbit for regenerative medicine

Research in low Earth orbit (LEO) has become more accessible. The 2020 Biomanufacturing in Space Symposium reviewed space-based regenerative medicine research and discussed leveraging LEO to advance biomanufacturing for regenerative medicine applications. The symposium identified areas where financial investments could stimulate advancements overcoming technical barriers. Opportunities in disease modeling, stem-cell-derived products, and biofabrication were highlighted. The symposium will initiate a roadmap to a sustainable market for regenerative medicine biomanufacturing in space. This perspective summarizes the 2020 Biomanufacturing in Space Symposium, highlights key biomanufacturing opportunities in LEO, and lays the framework for a roadmap to regenerative medicine biomanufacturing in space.

High-gain cryogenic amplifier assembly employing a commercial CMOS operational amplifier

We have developed a cryogenic amplifier for the measurement of small current signals (10 fA-100 nA) from cryogenic optical detectors. Typically operated with gain near 10(7) V/A, the amplifier performs well from DC to greater than 30 kHz and exhibits noise level near the Johnson limit. Care has been taken in the design and materials to control heat flow and temperatures throughout the entire detector-amplifier assembly. A simple one-board version of the amplifier assembly dissipates 8 mW to our detector cryostat cold stage, and a two-board version can dissipate as little as 17 μW to the detector cold stage. With current noise baseline of about 10 fA/(Hz)(1/2), the cryogenic amplifier is generally useful for cooled infrared detectors, and using blocked impurity band detectors operated at 10 K, the amplifier enables noise power levels of 2.5 fW/(Hz)(1/2) for detection of optical wavelengths near 10 μm.

Gq-mER signaling has opposite effects on hypothalamic orexigenic and anorexigenic neurons

Two populations of cells within the hypothalamus exert opposite actions on food intake: proopiomelanocortin (POMC) neurons decrease it, while neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurons increase it. 17β-Estradiol (E2) is a potent anorexigenic hormone that exerts both genomic and non-genomic, rapid actions on these metabolic neurons. This review focuses on the rapid membrane effects of E2 in both POMC and NPY/AgRP neurons and how these combined effects mediate the anorexigenic effects of this steroid.

Survival, Differentiation, and Migration of High-Purity Mouse Embryonic Stem Cell-derived Progenitor Motor Neurons in Fibrin Scaffolds after Sub-Acute Spinal Cord Injury

Embryonic stem (ES) cells can be differentiated into many neural cell types that hold great potential as cell replacement therapies following spinal cord injury (SCI). Coupling stem cell transplantation with biomaterial scaffolds can produce a unified combination therapy with several potential advantages including enhanced cell survival, greater transplant retention, reduced scarring, and improved integration at the transplant/host interface. Undesired cell types, however, are commonly present in ES-cell derived cultures due to the limited efficiency of most ES cell induction protocols. Heterogeneous cell populations can confound the interaction between the biomaterial and specific neural populations leading to undesired outcomes. In particular, biomaterials scaffolds may enhance tumor formation by promoting survival and proliferation of undifferentiated ES cells that can persist after induction. Methods for purification of specific ES cell-derived neural populations are necessary to recognize the full potential of combination therapies involving biomaterials and ES cell-derived neural populations. We previously developed a method for enriching ES cell-derived progenitor motor neurons (pMNs) induced from mouse ES cells via antibiotic selection and showed that the enriched cell populations are depleted of pluripotent stem cells. In this study, we demonstrate the survival and differentiation of enriched pMNs within three dimensional (3D) fibrin scaffolds in vitro and when transplanted into a sub-acute dorsal hemisection model of SCI into neurons, oligodendrocytes and astrocytes.

Precise Measurement of Lunar Spectral Irradiance at Visible Wavelengths

We report a measurement of lunar spectral irradiance with an uncertainty below 1 % from 420 nm to 1000 nm. This measurement uncertainty meets the stability requirement for many climate data records derived from satellite images, including those for vegetation, aerosols, and snow and ice albedo. It therefore opens the possibility of using the Moon as a calibration standard to bridge gaps in satellite coverage and validate atmospheric retrieval algorithms. Our measurement technique also yields detailed information about the atmosphere at the measurement site, suggesting that lunar observations are a possible solution for aerosol monitoring during the polar winter and can provide nighttime measurements to complement aerosol data collected with sun photometers. Our measurement, made with a novel apparatus, is an order of magnitude more accurate than the previous state-of-the-art and has continuous spectral coverage, removing the need to interpolate between filter passbands.

The membrane estrogen receptor ligand STX rapidly enhances GABAergic signaling in NPY/AgRP neurons: role in mediating the anorexigenic effects of 17β-estradiol

Besides its quintessential role in reproduction, 17β-estradiol (E2) is a potent anorexigenic hormone. E2 and the selective Gq-coupled membrane estrogen receptor (Gq-mER) ligand STX rapidly increase membrane excitability in proopiomelanocortin (POMC) neurons by desensitizing the coupling of GABAB receptors to G protein-coupled inwardly rectifying K(+) channels (GIRKs), which upon activation elicit a hyperpolarizing outward current. However, it is unknown whether E2 and STX can modulate GABAB signaling in neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurons. We used single-cell RT-PCR and whole cell patch clamping with selective pharmacological reagents to show that NPY/AgRP cells of mice express the GABAB-R1 and -R2 receptors and are hyperpolarized by the GABAB agonist baclofen in an E2-dependent manner. In males, E2 rapidly attenuated the coupling of GABAB receptors to GIRKs, which was blocked by the general PI3K inhibitors wortmannin and LY-294002 or the selective p110β subunit inhibitor TGX-221. The ERα-selective agonist propyl pyrazole triol mimicked the effects of E2. STX, in contrast, enhanced the GABAB response in males, which was abrogated by the estrogen receptor (ER) antagonist ICI 182,780. In gonadectomized mice of both sexes, E2 enhanced or attenuated the GABAB response in different NPY/AgRP cells. Coperfusing wortmannin with E2 or simply applying STX always enhanced the GABAB response. Thus, in NPY/AgRP neurons, activation of the Gq-mER by E2 or STX enhances the GABAergic postsynaptic response, whereas activation of ERα by E2 attenuates it. These findings demonstrate a clear functional dichotomy of rapid E2 membrane-initiated signaling via ERα vs. Gq-mER in a CNS neuron vital for regulating energy homeostasis.

Comparison of ground reaction forces and contact times between 2 lateral plyometric exercises in professional soccer players

There are no studies which have examined the differences in kinetics between lateral plyometric exercises and the selection of these exercises is largely based on the experience and observation of coaches. This study aimed to compare ground reaction forces (GRF) and contact times (GCT) between 2 lateral plyometric exercises: lateral alternative leg hopping (HOP), and speed lateral footwork (SPEED). 16 professional male soccer players (age: 24.6±5.5 years; and BMI: 21.7±2.2 kg.m - 2) participated in this within-participant repeated measures study. 3-dimensional GRF data were measured by force platform. Our study revealed significant differences between the 2 lateral plyometric exercises in all kinetics parameters (F=573.7, P<0.01). HOP produced significantly longer GCT (0.45 s vs. 0.23 s, P<0.01, large effect), significantly higher values (P<0.05, large effect) in peak force (3.31 vs. 2.47 Body Weight [BW]), peak rate of force development (0.94 vs. 0.29 BW/s), and impulse (0.76 vs. 0.31 BW.s) except for peak force in the medial-lateral (P<0.05, medium effect) and impulse in the anterio-posterior direction (not significant, small effect). Therefore, SPEED is an exercise that aims to increase step frequency because of its short GCT (< 0.25 s) while HOP increases leg strength and power.

Long-term ovariectomy decreases serotonin neuron number and gene expression in free ranging macaques

The serotonin system responds to the ovarian steroids, estradiol (E) and progesterone (P), in women and female animal models. In macaques, ovarian steroid administration to ovariectomized (Ovx) individuals improves serotonin neural function through actions on pivotal serotonin-related genes and proteins, such as TPH2 (tryptophan hydroxylase 2), SERT (serotonin reuptake transporter), and the 5HT1A autoreceptor. In addition, ovarian steroid administration reduces gene and protein expression in the caspase-independent pathway and reduces DNA fragmentation in serotonin neurons. This study examines the hypothesis that long-term ovariectomy will lead to a loss of serotonin neurons and compromised gene expression in serotonin neurons. Female Japanese macaques were ovariectomized or tubal ligated (n=5/group) at 3 years of age and returned to their natal troop. After 3 years, the animals were collected, administered a fenfluramine challenge to determine global serotonin availability, and then euthanized. Fev, TPH2, SERT, and 5HT1A expression were examined with digoxigenin in situ hybridization (ISH) and quantitative image analysis. Cell number, positive pixel area, and average pixel density were determined. In the Ovx group, Fev, TPH2, SERT, and 5HT1A showed a significant decease in average and total cell number and positive pixel area. The reduction in Fev-positive neurons suggests that there were fewer serotonin neurons in Ovx animals compared to ovary-intact animals. The decrease in TPH2 in the Ovx animals was consistent with earlier results in 5-month Ovx animals, but it may be due to the decrease in cell number rather than a decrease in expression on an individual cell basis. The decrease in SERT and 5HT1A in long-term Ovx differed from previous studies in short-term Ovx. In summary, long-term ovarian steroid loss resulted in fewer serotonin neurons and overall lower Fev, TPH2, SERT, and 5HT1A gene expression. This may be due to serotonin cell death or to a negative impact on a long-term developmental process in young female macaques.

Sensitivity of an immunomagnetic-separation-based test for detecting Escherichia coli O26 in bovine feces

The sensitivity of a test for cattle shedding Escherichia coli serogroup O26 was estimated using several fecal pats artificially inoculated at a range of concentrations with different E. coli O26 strains. The test involves the enrichment of fecal microflora in buffered peptone water, the selective concentration of E. coli O26 using antibody-coated immunomagnetic-separation beads, the identification of E. coli colonies on Chromocult tryptone bile X-glucuronide agar, and confirmation of the serogroup with E. coli serogroup O26-specific antisera using slide agglutination. The effective dose of E. coli O26 for an 80% test sensitivity (ED(80)) was 1.0 x 10(4) CFU g(-1) feces (95% confidence interval, 4.7 x 10(3) to 2.4 x 10(4)). Differences in test sensitivity between different E. coli O26 strains and fecal pats were also observed. Individual estimates of ED(80) for each strain and fecal pat combination ranged from 4.2 x 10(2) to 4.8 x 10(5) CFU g(-1). These results suggest that the test is useful for identifying individuals shedding a large number of E. coli O26 organisms or, if an appropriate number of individuals in a herd are sampled, for identifying affected herds. The study also provides a benchmark estimate of sensitivity that can be used to compare alternative tests for E. coli O26 and a methodological approach that can be applied to tests for other pathogenic members of the Enterobacteriaceae and other sample types.

Prevalence and virulence factors of Escherichia coli serogroups O26, O103, O111, and O145 shed by cattle in Scotland

A national survey was conducted to determine the prevalence of Escherichia coli O26, O103, O111, and O145 in feces of Scottish cattle. In total, 6,086 fecal pats from 338 farms were tested. The weighted mean percentages of farms on which shedding was detected were 23% for E. coli O26, 22% for E. coli O103, and 10% for E. coli O145. The weighted mean prevalences in fecal pats were 4.6% for E. coli O26, 2.7% for E. coli O103, and 0.7% for E. coli O145. No E. coli O111 was detected. Farms with cattle shedding E. coli serogroup O26, O103, or O145 were widely dispersed across Scotland and were identified most often in summer and autumn. However, on individual farms, fecal shedding of E. coli O26, O103, or O145 was frequently undetectable or the numbers of pats testing positive were small. For serogroup O26 or O103 there was clustering of positive pats within management groups, and the presence of an animal shedding one of these serogroups was a positive predictor for shedding by others, suggesting local transmission of infection. Carriage of vtx was rare in E. coli O103 and O145 isolates, but 49.0% of E. coli O26 isolates possessed vtx, invariably vtx1 alone or vtx1 and vtx2 together. The carriage of eae and ehxA genes was highly associated in all three serogroups. Among E. coli serogroup O26 isolates, 28.9% carried vtx, eae, and ehxA-a profile consistent with E. coli O26 strains known to cause human disease.

Stress and weight gain in parents of cancer patients

OBJECTIVE

To investigate the effects of chronic stress on weight changes and related behavioral changes in parents with a child who had just been diagnosed with cancer compared to parents with healthy children.

DESIGN

Longitudinal case-control study with assessments occurring over a three-month period following the child's diagnosis of cancer.

SUBJECTS

In total, 49 parents of healthy children and 49 parents of cancer patients aged 19-58.

MEASUREMENTS

Body weight, diet, physical activity, self-reported mood and stress.

RESULTS

Parents of cancer patients were more likely to gain weight, and experienced significantly greater weight gain over the 3 months than parents of healthy children. The magnitude of weight gain was related to the degree of psychological distress that the parents experienced. Parents of cancer patients reported lower levels of physical activity and lower caloric intake than parents of healthy children, with the most marked differences between groups occurring in the area of physical activity.

CONCLUSION

Findings suggest that a major stressor, such as a child's diagnosis of cancer, is associated with weight gain. Further research is needed to determine how long these weight gains persist and whether other types of stress also produce weight gains. Such studies should focus not only on the effect of stress on eating behavior but also on physical activity.

Gender differences in balance performance at the time of retirement

BACKGROUND

Impairments in balance performance are a commonly accepted risk factor for falling in older people. Since there is a higher reported incidence of falling in women, it is of interest to test whether this correlates with poorer balance performance in women than men at the time of retirement in order to plan health promotional strategies. The purpose of this study was to investigate whether any gender differences exist in balance performance in people approaching retirement age.

METHODS

Ninety-seven healthy volunteers (44 males, 53 females) planning to retire shortly were enrolled in the study (age range 50-67 years). Balance assessments during quiet standing were performed under various conditions; feet together eyes open, feet together eyes closed and single limb stance eyes open. The range of centre of pressure displacement in both the anterior-posterior and medial-lateral planes was collected for each task using a force platform.

FINDINGS

For several of the balance tasks the men exhibited a statistically significant larger range of centre of pressure displacement than the women (P<0.01). However, after normalising the data for height, no gender differences were seen. Over half of the group failed to complete all three single limb stance trials on both limbs.

INTERPRETATION

When the data was normalised for height, no differences were found in static balance performance between men and women of retirement age. A number of participants demonstrated balance impairments whilst performing the single limb stance likely to affect functional activities. Health promotional messages should be targeted equally at men and women.

Implications of high-molecular-weight oligomers of the binary toxin from Bacillus sphaericus

The mosquito-larvicidal binary toxin produced by Bacillus sphaericus is composed of BinB and BinA, which have calculated molecular weights of 51.4 and 41.9 kDa, respectively. NaOH extracts of B. sphaericus spores were analyzed using SDS-PAGE. Stained gels showed bands with molecular weights corresponding to those of BinB and BinA as well as two additional bands at 110 and 125 kDa. The matrix-assisted laser desorption/ionization mass spectrum of the purified 110 and 125 kDa bands showed two peaks at 104,160 and 87,358 Da that are assigned to dimers of BinB and BinA, respectively. Mass spectral analysis of trypsin-digested 110 and 125 kDa bands showed peaks at 51,328, 43,523, 43,130, and 40,832 Da that assigned to undigested BinB, two forms of digested BinB and digested BinA, respectively. Dynamic light scattering studies showed a solution of the purified 110 and 125 kDa bands was comprised almost entirely (99.6% of total mass) of a particle with a hydrodynamic radius of 5.6+/-1.2 nm and a calculated molecular weight of 186+/-38 kDa. These data demonstrate that the binary toxin extracted from B. sphaericus spores can exist in solution as an oligomer containing two copies each of BinB and BinA.

Distribution of Escherichia coli O157 in bovine fecal pats and its impact on estimates of the prevalence of fecal shedding

The distribution of Escherichia coli O157 in bovine feces was examined by testing multiple samples from fecal pats and determining the density of E. coli O157 in immunomagnetic separation (IMS)-positive fecal samples. The density of E. coli O157 in bovine feces was highly variable, differing by as much as 76,800 CFU g(-1) between samples from the same fecal pat. The density in most positive samples was <100 CFU g(-1), the limit of reliable detection by IMS. Testing only one 1-g sample of feces per pat with IMS may result in a sensitivity of detection as low as 20 to 50%. It is therefore probable that most surveys have greatly underestimated the prevalence of E. coli O157 shedding in cattle and the proportion of farms with shedding cattle. The sensitivity of the detection of E. coli O157 in bovine feces can be as much as doubled by testing two 1-g samples per pat rather than one 1-g sample.

Temporal shedding patterns and virulence factors of Escherichia coli serogroups O26, O103, O111, O145, and O157 in a cohort of beef calves and their dams

This study investigated the shedding of Escherichia coli O26, O103, O111, O145, and O157 in a cohort of beef calves from birth over a 5-month period and assessed the relationship between shedding in calves and shedding in their dams, the relationship between shedding and scouring in calves, and the effect of housing on shedding in calves. Fecal samples were tested by immunomagnetic separation and by PCR and DNA hybridization assays. E. coli O26 was shed by 94% of calves. Over 90% of E. coli O26 isolates carried the vtx(1), eae, and ehl genes, 6.5% carried vtx(1) and vtx(2), and one isolate carried vtx(2) only. Serogroup O26 isolates comprised seven pulsed-field gel electrophoresis (PFGE) patterns but were dominated by one pattern which represented 85.7% of isolates. E. coli O103 was shed by 51% of calves. Forty-eight percent of E. coli O103 isolates carried eae and ehl, 2% carried vtx(2), and none carried vtx(1). Serogroup O103 isolates comprised 10 PFGE patterns and were dominated by two patterns representing 62.5% of isolates. Shedding of E. coli O145 and O157 was rare. All serogroup O145 isolates carried eae, but none carried vtx(1) or vtx(2). All but one serogroup O157 isolate carried vtx(2), eae, and ehl. E. coli O111 was not detected. In most calves, the temporal pattern of E. coli O26 and O103 shedding was random. E. coli O26 was detected in three times as many samples as E. coli O103, and the rate at which calves began shedding E. coli O26 for the first time was five times greater than that for E. coli O103. For E. coli O26, O103, and O157, there was no association between shedding by calves and shedding by dams within 1 week of birth. For E. coli O26 and O103, there was no association between shedding and scouring, and there was no significant change in shedding following housing.

Detection of Escherichia coli serogroups O26, O103, O111 and O145 from bovine faeces using immunomagnetic separation and PCR/DNA probe techniques

AIMS

The aim of this study was to isolate Escherichia coli O26, O103, O111 and O145 from 745 samples of bovine faeces using (i) immunomagnetic separation (IMS) beads coated with antibodies to lipopolysaccharide, and slide agglutination (SA) tests and (ii) PCR and DNA probes for the detection of the Verocytotoxin (VT) genes.

METHODS AND RESULTS

IMS-SA tests detected 132 isolates of presumptive E. coli O26, 112 (85%) were confirmed as serogroup O26 and 102 had the VT genes. One hundred and twenty-two strains of presumptive E. coli O103 were isolated by IMS-SA, 45 (37%) were confirmed as serogroup O103 but only one of these strains was identified as Verocytotoxin-producing E. coli (VTEC). Using the PCR/DNA probe method, 40 strains of VTEC O26 and three strains of VTEC O103 were isolated. IMS-SA identified 21 strains of presumptive E. coli O145, of which only four (19%) were confirmed as serogroup O145. VTEC of this serogroup was not detected by either IMS-SA or PCR/DNA probes. E. coli O111 was not isolated by either method.

CONCLUSION

IMS beads were 2.5 times more sensitive than PCR/DNA probe methods for the detection of VTEC O26 in bovine faeces.

SIGNIFICANCE AND IMPACT OF THE STUDY

IMS-SA is a sensitive method for detecting specific E. coli serogroups. However, the specificity of this method would be enhanced by the introduction of selective media and the use of tube agglutination tests for confirmation of the preliminary SA results.

Applied technique for increasing calicivirus detection in shellfish extracts

AIMS

Optimal detection of enteric RNA viruses in clinical, environmental, and food products using reverse transcription-PCR (RT-PCR) when inhibitory substances in extracted sample materials are present.

METHODS AND RESULTS

We adapted a device for detection of RNA viruses in plant tissues and insects to detect a calicivirus strain (San Miguel sea lion virus, serotype 17) in water and oyster tissue extracts. This single, compartmentalized tube-within-a-tube (TWT) device for RT-PCR-nested PCR was compared to a conventional protocol of RT-PCR-nested PCR. In the presence of 100 mg of shellfish tissue extract equivalent, this TWT device decreases the calicivirus assay detection limit 10-fold over that of conventional RT-PCR-nested PCR while maintaining an identical detection limit of viral nucleic acid suspended in water. Both the conventional and TWT methods estimated the total particle-to-infectious particle ratio for this strain of calicivirus at approximately 40 : 1.

CONCLUSIONS

We believe that the TWT device with appropriate RT-PCR primers will decrease the detection limit for other calicivirus strains and RNA viruses in shellfish tissue extracts.

SIGNIFICANCE AND IMPACT OF THE STUDY

We believe that the TWT approach is applicable to other situations where RT and/or PCR inhibitory materials are present or nucleic acid targets of bacteria or viruses are at low levels in extracts of food products or clinical specimens.

Clinical measurement of muscle tone using a velocity-corrected modified Ashworth scale

OBJECTIVE

To develop a new form of the modified Ashworth scale (MAS) for muscle-tone assessment that combines the MAS score with the passive muscle-stretching velocity during the assessment of muscle tone, resulting in a measure that has higher intertester reliability than the MAS.

DESIGN

Twenty-two volunteer subjects with spinal cord injuries at a tertiary care outpatient and inpatient spinal cord injury rehabilitation center affiliated with a university were recruited for this study.

RESULTS

A decision tree in which V-MAS scores were obtained was developed. The data obtained from three independent raters, when adjusted by means of the V-MAS, showed an excellent interrater reliability.

CONCLUSIONS

Results indicated that the V-MAS is a more reliable measure. In addition, the resulting units of the V-MAS, ranging from 0 to 1, are of the same form as pendulum test data. The V-MAS method is quite simple to use because the rater need only measure the angular range and duration of the passive movement to calculate average velocity during the MAS assessment in addition to the normal MAS rating of muscle tone.

WHO activities for prevention of deafness and hearing impairment in children

This paper gives an overview of WHO activities in the global campaign for the prevention of deafness and hearing impairment, focusing particularly on children. It discusses the size of the problem and the causes and consequences of deafness and hearing impairment. It emphasizes the inadequate state of our knowledge of this subject in developing countries and the importance of collecting valid data. It describes the public health route to prevention of deafness and hearing impairment, especially through primary ear and hearing care, and outlines the World Health Organization's aims and activities for prevention of deafness and hearing impairment.

Management of radiated reoperative wounds of the cervicothoracic spine: the role of the trapezius turnover flap

Reoperation for malignant disease of the cervicothoracic spine can lead to compromised wound healing secondary to poor tissue quality from previous operations, heavily irradiated beds, and concomitant steroid therapy. Other complicating factors include exposed dura and spinal implants. Introducing well-vascularized soft tissue to obliterate dead space is critical to reliable wound healing. The purpose of this study was to determine the efficacy of the trapezius turnover flap in the management of these complex wounds. This study is a retrospective review of all patients undergoing trapezius muscle turnover flaps for closure of complex cervicothoracic wounds after spinal operations for metastatic or primary tumors. Six patients (3 male/3 female) were operated over an 18-month period (mean patient age, 43 years). Primary pathologies included radiation-induced peripheral nerve sheath tumor (N = 2), chondrosarcoma (N = 1), nonsmall-cell lung cancer (N = 1), paraganglioma (N = 1), and spindle cell sarcoma (N = 1). Trapezius muscle turnover flaps were unilateral and based on the transverse cervical artery in every patient. Indication for flap closure included inability to perform primary layered closure (N = 3), open wound with infection (N = 2), and exposed hardware (N = 1). All patients had previous operations of the cervicothoracic spine (mean, 5.8 months; range 2-9 months) for malignant disease and prior radiation therapy. Exposed dura was present in all patients, and 2 patients had dural repairs with bovine pericardial patches. Spinal stabilization hardware was present in 4 patients. All patients underwent perioperative treatment with systemic corticosteroids. All flaps survived, and primary wound healing was achieved in each patient. The only wound complication was a malignant pleural effusion communicating with the back wound, which was controlled with a closed suction drain. All wounds remained healed during the follow-up period. Four patients died from progression of disease within 10 months of surgery. The trapezius turnover flap has been used successfully when local tissue conditions prevent primary closure, or in the setting of open, infected wounds with exposed dura and hardware. The ease of flap elevation and minimal donor site morbidity make it a useful, single-stage reconstructive option in these difficult wounds.

Inhibition of Vesivirus infections in mammalian tissue culture with antisense morpholino oligomers

Caliciviruses infect and cause disease in animals and humans. They are nonenveloped, positive-stranded RNA viruses with a genome of approximately 7.5 kb that encodes viral proteins in three open reading frames (ORF). Antisense oligomers targeting one of the three ORF of caliciviruses of the genus Vesivirus significantly inhibit viral replication in tissue culture. Porcine kidney and African green monkey kidney cells were infected with Vesivirus isolates SMSV-13 and PCV Pan-1. Phosphorodiamidate morpholino oligomers (PMO) with sequence complementary to the AUG translation start site regions of ORF1, ORF2, and ORF3 were evaluated for their effect on viral titer. Scrape-loading delivered PMO to 50%-70% of the cells of the two cell lines, as measured by fluorescence microscopy and flow cytometry. A PMO targeting ORF3 caused a significant increase in viral titer. A PMO targeting ORF2, a scrambled PMO control sequence, and an unrelated PMO antisense sequence did not alter viral titer. Various PMO sequences antisense to an upstream region of ORF1 were effective in reducing viral titer up to 80% in a dose-dependent and sequence-specific manner. The extent of viral titer reduction was proportional to the delivery of PMO to cells. These observations demonstrate that antisense PMO can disrupt caliciviral gene function in a nucleic acid sequence-specific manner and are potentially effective antiviral agents.

Concentration and detection of caliciviruses in water samples by reverse transcription-PCR

Human caliciviruses (HuCVs) cause waterborne outbreaks of gastroenteritis. Standard indicators of a safe water supply do not adequately predict contamination of water by viruses, including HuCVs. We developed a method to concentrate and detect HuCVs in water samples by using a cultivable primate calicivirus (Pan-1) as a model. Viable Pan-1 was seeded in different types of water and then filtered with a 1MDS filter, eluted with beef extract (BE), and reconcentrated by polyethylene glycol (PEG) precipitation. The viruses in the final samples were tested by plaque assay or by reverse transcription (RT)-PCR following extraction of the RNA with Trizol. Pan-1 was more sensitive to high-pH treatment than poliovirus was; a pH 9.0 BE solution was found to recover 35% more viable Pan-1 than a pH 9.5 BE solution recovered. Pan-1 was recovered from small volumes of deionized, finished, ground, and surface waters at efficiencies of 94, 73, 67, and 64%, respectively, when samples were assayed after elution without further concentration. When larger volumes of water (up to 40 liters) were tested after elution and concentration with PEG, 38, 19, and 14% of the seeded Pan-1 were recovered from finished, ground, and surface waters, respectively. The limit of detection of Pan-1 by RT-PCR was estimated to be 0.75 to 1.5 PFU in 40 liters of finished water. This method may be adapted for monitoring HuCVs in drinking water and other types of water for public health safety.

Expression of the virulence-related Sca (Mn2+) permease in Streptococcus gordonii is regulated by a diphtheria toxin metallorepressor-like protein ScaR

The acquisition of transition metal ions by pathogenic bacteria is crucial to their growth and survival within the human host, however, the mechanisms of metal ion homeostasis in streptococci are unknown. The scaCBA operon in the human oral bacterium Streptococcus gordonii encodes the components of an ABC-type transporter for manganese (Mn2+). Production of substrate-binding lipoprotein ScaA was increased approximately fivefold in cells cultured in low Mn2+ medium (< 0.1 microM Mn2+), but not in iron (Fe2+/Fe3+)-limited medium, and was enhanced in the presence of human saliva or serum. mRNA analysis revealed that under low Mn2+ conditions, levels of scaCBA transcript (2.6 kb) were increased > 20-fold. The Mn2+-responsive transcriptional regulator of the sca operon was purified and characterized as a 215-amino-acid residue polypeptide, designated ScaR, with 26% identity to the Corynebacterium diphtheriae diphtheria toxin repressor (DtxR). Inactivation of scaR in S. gordonii DL1 (Challis) resulted in constitutive derepression of sca operon transcription. Expression of tpx, located immediately downstream of scaA and encoding a putative thiol peroxidase, was not subject to ScaR regulation. Purified ScaR protein bound to the scaC promoter region in vitro in the presence of Mn2+ (Kd approximately 80 nM) and, to a lesser extent, in the presence of Ni2+ or Zn2+. The metalloregulator protein binding region was localized by DNA protection analysis to a 46 bp sequence encompassing the -35 and -10 promoter signatures. This sequence was well conserved within the promoters of corresponding virulence-related permease operons in other streptococci. The results identify a new Mn2+-sensing regulator of Mn2+ transport in streptococci, important for Mn2+ homeostasis during infection of the human host.

Intrarater reliability of manual passive movement velocity in the clinical evaluation of knee extensor muscle tone

OBJECTIVE

To quantify the relationship between therapist-applied velocity of passive movement during a manual muscle test of muscle tone and the level of muscle tone represented by the relaxation index of the pendulum test.

DESIGN

Comparison of therapist-applied passive limb movement velocity during a manual muscle test with the same subject's level of muscle tone measured by the pendulum test. Three different therapists tested each subject. The relation between the velocity scores and pendulum test scores both intratherapist and intertherapist were assessed statistically by means of analysis of variance and correlation coefficients.

SETTING

A university-affiliated tertiary care outpatient and inpatient spinal cord injury rehabilitation center.

PARTICIPANTS

Twenty-two volunteer subjects with spinal cord injuries.

MAIN OUTCOME MEASURES

Passive knee angular displacement data were collected during both manual knee muscle testing and pendulum tests by using an electrogoniometer.

RESULTS

The therapists produced significantly different movement velocities during the manual muscle tests (p < .05). A significant correlation (p < .001) was found between pendulum test scores and passive velocities, indicating that in higher levels of muscle tone, the greater stretch reflex present provided greater resistance against the therapist force and subsequently decreased the velocity of the passive stretching.

CONCLUSIONS

Measurement of average velocity during passive stretching by itself can be used to evaluate muscle tone.

The use of pedicled expanded flaps for aesthetic resurfacing of the burned face

Reconstruction of extensive, deep burns of the face is a challenging problem in plastic surgery. The authors report the use of tissue expanders placed in the upper chest for facial resurfacing after burn injuries in 4 patients. The expanders are hyperinflated. The flap is then advanced upward to resurface an aesthetic unit of the face with the pedicle intact. The pedicle is divided 2 weeks later. The method of reconstruction allows a large area of facial resurfacing to be performed without fear of flap loss or flap retraction impairing the cosmetic result. This technique has the disadvantage of being a staged procedure and cannot be performed in those with burns of the upper chest.

Vortex flow and transverse flux screening at the bose glass transition

We study the vortex phase diagram in untwinned YBCO crystals with columnar defects. These randomly distributed defects are expected to induce a "Bose glass" phase of localized vortices exhibiting a vanishing resistance and Meissner effect for magnetic fields H( perpendicular) transverse to the columns. We directly observe the transverse Meissner effect using a Hall probe array. As predicted, the Meissner state breaks down at temperatures T(s) that decrease linearly as H( perpendicular) increases. However, T(s) lies far below the conventional melting temperature T(m) determined by a vanishing resistivity, suggesting a regime where vortices are effectively localized even when rotated off the columnar defects.

An atomic force microscopy investigation of bioadhesive polymer adsorption onto human buccal cells

Atomic force microscopy (AFM) was used to examine the buccal cell surface in order to image the presence of adsorbed bioadhesive polymers identified from previous work. Isotonic saline solution (5 ml) containing either polycarbophil (pH 7.6), chitosan (pH 4.5) or hydroxypropyl methylcellulose (pH 7.6) (0.5% w/v) was exposed to freshly collected buccal cells (ca. 48x10(4) cells/test) for 15 min at 30 degrees C. The cells were then rinsed with a small volume of double distilled water, allowed to air-dry on a freshy cleaved mica surface and imaged using contact mode AFM. Untreated cells showed relatively smooth surface characteristics, with many small 'crater-like' pits and indentations spread over cell surfaces. Cells that had been treated with all the investigated polymers appeared to have lost the crater and indentation characteristic and gained a higher surface roughness. These results suggest that polymer chains had adsorbed onto the cell surfaces. Quantitative image analysis of cell topography showed significant increases (P<0.05) in arithmetic roughness average (R(a)) for all the investigated polymer treated cells surfaces with respect to untreated control specimens. The changes in surface topography indicate the presence of adsorbed polymer, confirming previous work. This study demonstrates the suitability of AFM as a powerful and sensitive technique for detecting and imaging bioadhesive polymers present on mucosal cell surfaces.

Adjunctive treatment of congenital pigmented nevi with phenol chemical peel

The purpose of this study was a retrospective evaluation of the treatment of congenital pigmented nevi using the phenol chemical peel technique. Patients were treated with standard Baker formula in the operating room under general anesthesia or intravenous sedation with continuous electrocardiogram monitoring. A total of 20 patients were reviewed (13 girls and 7 boys, mean age 3.8 years). Eight patients had nevi located on the face, five patients had trunk lesions, and three patients had lesions on the thighs. Two patients had nevi located on both the face and the trunk, and two patients had involvement of the face, trunk, and thigh. Three of the above patients had the classic "bathing trunk" distribution of the nevi. A test area was peeled in four patients, and in five patients preoperative biopsies were performed to rule out malignancy before initiation of therapy. An average of 2.6 treatments were performed per patient. Two patients had adjunctive dermabrasion to increase the depth of peel and to contour surface irregularities. The length of follow-up ranged from 6 to 84 months with a mean of 28 months. Healing of the wounds occurred within 2 to 3 weeks postoperatively. Seventy-five percent of patients had satisfactory cosmetic improvement in the appearance of the lesions following treatment. Four patients had recurrence of the pigmentation after an initial lightening response, three of whom had their nevi subsequently excised. There was no incidence of hypertrophic scarring or cardiac and/or renal complications. There was one death from complications of leptomeningeal melanocytosis. Chemical peeling of congenital pigmented nevi is an acceptable alternative method of therapy for those lesions that are too large for excision and primary closure or for lesions in which excision would result in unacceptable scars in areas such as the face.

Burkholderia cepacia is resistant to the antimicrobial activity of airway epithelial cells

There has been much interest recently in the antimicrobial properties of cationic peptides called beta-defensins from epithelial cells. Human beta-defensin (hBD)-1 and -2 have been particularly implicated in cystic fibrosis (CF) patients, where their inhibition by high salt concentrations may explain in part the susceptibility of the CF lung to bacterial infection. In this work, we have employed a simple co-culture system using the 16-HBE human bronchial epithelial cell line to assess growth inhibitory activity against Pseudomonas aeruginosa and Burkholderia cepacia. In medium alone, P. aeruginosa proliferated more than 100,000-fold, whereas in the presence of 16-HBE cells or 16-HBE-conditioned medium, bacterial proliferation was less than 100-fold. Raising the salt concentration of cell-free 16-HBE conditioned medium to approximately 200 mM significantly reduced this growth inhibitory activity. In contrast, there was no evidence of epithelial-derived growth inhibitory activity against two strains of B. cepacia. RT-PCR analysis indicated expression of the hBD-2 mRNA in 16-HBE cells, but not hBD-1. These data demonstrate for the first time that B. cepacia is resistant to epithelial-derived antimicrobial substances and argue against them being important in the defense against this organism in the lung.

Development of a reverse transcription polymerase chain reaction procedure for the detection of marine caliciviruses with potential application for nucleotide sequencing

A reverse transcription polymerase chain reaction (RT-PCR) procedure is described for the detection of marine caliciviruses including vesicular exanthema of swine virus (VESV), San Miguel sea lion virus (SMSV), bovine Tillamook virus (BCV Bos-1) and caliciviruses (CV) isolated from dolphin (Cetacean CV), gorilla (Primate CV) and rattlesnake (Reptile CV) using primers (1F and 1R) designed from the capsid-coding region of the viral genome. These primers were compared with those described by Neill, J.D. and Seal, B.S., 1995: Development of PCR primers for specific amplification of two distinct regions of the genomes of San Miguel sea lion and vesicular exanthema of swine viruses, Mol. Cell. Probes 9, 33-38 (Hel1/Hel2), which had been designed from the 2C-like region of the calicivirus genome. Both sets proved to be extremely useful diagnostic tools for all of the known marine calicivirus serotypes with the exception of three: SMSV-8 and -12 and mink CV suggesting that these three caliciviruses may belong to a different group. Neither of the two primer sets reacted with strains of the vesicular disease viruses of foot-and-mouth disease (FMD), swine vesicular disease (SVD) or vesicular stomatitis (VS) nor with two feline caliciviruses (FCV). The 1F/1R primer set has the advantage over the Hel1/Hel2 set in that it generates a larger PCR product for nucleotide sequence investigations and so provides greater opportunity for identifying molecular differences between the viruses.

An in vitro mucosal model predictive of bioadhesive agents in the oral cavity

The formulation of a drug/carrier complex that can be distributed and retained for extended periods within the oral cavity would be advantageous in the treatment of local conditions. In this study, an in vitro system was developed to investigate the binding of bioadhesive macromolecules to buccal epithelial cells, without having to alter their physicochemical properties by the addition of 'marker' entities. In this innovative approach a lectin binding inhibition technique, involving an avidin-biotin complex and a colourmetric detection system, was used to evaluate polymer binding. 0.5% w/v polymer solutions in saline (pH 7.6) were left in contact with a standardized number of freshly collected human buccal cells for 15 min. The cells were then exposed to 10 mg L(-1) biotinylated lectin from Canavalia ensiformis followed by 5 mg L(-1) streptavidin peroxidase. The inhibition of lectin binding (i.e. by 'masking' of the binding site on the cell surface by the attached bioadhesive polymer) was measured and expressed as a percentage reduction in the rate of o-phenylenediamine oxidation over 1 min. From the wide range of polymer solutions screened, chitosan gave the greatest inhibition of lectin binding to the surface of buccal cells, while methylcellulose, gelatin, Carbopol 934P and polycarbophil also produced a substantial reduction. Lectin binding inhibition was also observed for a selected number of polymer solutions when screened at pH 6.2. The presence of bound chitosan, polycarbophil and Carbopol 934P on the buccal cell surface was confirmed using direct staining techniques. It was concluded that this assay can be used to detect polymer binding to the cells present on the buccal mucosa, and the information gained used in the development of retentive drug/polymer formulations.

The British Diabetic Association Cohort Study, I: all-cause mortality in patients with insulin-treated diabetes mellitus

AIMS

To assess mortality in patients with diabetes incident under the age of 30 years.

METHODS

A cohort of 23 752 diabetic patients diagnosed under the age of 30 years from throughout the United Kingdom was identified during 1972-93 and followed up to February 1997. Following notification of deaths during this period, age- and sex-specific mortality rates, attributable risks and standardized mortality rates were calculated.

RESULTS

The 23 752 patients contributed a total of 317 522 person-years of follow-up, an average of 13.4 years per subject. During follow-up 949 deaths occurred in patients between the ages of 1 and 84 years, 566 in males and 383 in females. All-cause mortality rates in the patients with diabetes exceeded those in the general population at all ages and within the cohort were higher for males than females at all ages except between 5 and 15 years. The relative risk of death (standardized mortality ratio, SMR), was higher for females than males at all ages, being 4.0 (95% CI 3.6-4.4) for females and 2.7 (2.5-2.9) for males overall, but reaching a peak of 5.7 (4.7-7.0) in females aged 20-29, and of 4.0 (3.1-5.0) in males aged 40-49. Attributable risks, or the excess deaths in persons with diabetes compared with the general population, increased with age in both sexes.

CONCLUSIONS

This is the first study from the UK of young patients diagnosed with diabetes that is large enough to calculate detailed age-specific mortality rates. This study provides a baseline for further studies of mortality and change in mortality within the United Kingdom.

The British Diabetic Association Cohort Study, II: cause-specific mortality in patients with insulin-treated diabetes mellitus

AIMS

To measure cause-specific mortality, by age, in patients with insulin-treated diabetes incident at a young age.

METHODS

A cohort of 23 752 patients with insulin-treated diabetes diagnosed under the age of 30 years, from throughout the United Kingdom, was identified during 1972-93 and followed to February 1997. Death certificates have been obtained for deaths during the follow-up period and cause-specific mortality rates and standardized mortality ratios by age and sex are reported.

RESULTS

During the follow-up period 949 deaths occurred and at all ages mortality rates were considerably higher than in the general population. Acute metabolic complications of diabetes were the greatest single cause of excess death under the age of 30 years. Cardiovascular disease was responsible for the greatest proportion of the deaths from the age of 30 years onwards.

CONCLUSIONS

Deaths in patients with diabetes diagnosed under the age of 30 have been reported and comparisons drawn with mortality in the general population. To reduce these deaths attention must be paid both to the prevention of acute metabolic deaths and the early detection and treatment of cardiovascular disease and associated risk factors.

Anti-inflammatory actions of interleukin-13: suppression of tumor necrosis factor-alpha and antigen-induced leukocyte accumulation in the guinea pig lung

The Th2 cytokine interleukin (IL)-13 is believed to play an important role in the development of allergy, although it has also been ascribed anti-inflammatory roles in several experimental models. In this study, we have examined the effects of human recombinant IL-13 on eosinophilic lung inflammation in the guinea pig. IL-13 (1 to 100 ng, given by intratracheal instillation) did not elicit airway eosinophil recruitment. A pronounced accumulation of eosinophils, as well as monocyte/macrophages, was elicited by intratracheal instillation of guinea pig tumor necrosis factor alpha (gpTNF-alpha). Intratracheal administration of IL-13 (1 to 100 ng) given immediately prior to exposure to gpTNF-alpha resulted in a dose-related suppression of eosinophil and monocyte/macrophage accumulation in the airways, as assessed by bronchoalveolar lavage (BAL) and eosinophil peroxidase activity in whole-lung homogenates. IL-13 treatment also reduced BAL fluid (BALF) leukocyte accumulation induced by subsequent aerosol antigen challenge of sensitized guinea pigs. Antigen challenge also resulted in elevated levels of immunoreactive eotaxin and eosinophil-stimulating activity in BALF, although only the latter was reduced significantly by IL-13 instillation prior to challenge. In contrast to the suppressive effects of IL-13, instillation of human recombinant IL-4 (100 ng) alone elicited an increase in BALF monocyte/macrophage numbers, and IL-4 was unable to inhibit gpTNF-alpha-induced leukocyte accumulation. Hence, IL-13 (but not human IL-4) exhibits an anti-inflammatory action in the airways of gpTNF-alpha- or antigen-challenged guinea pigs, by mechanisms that may involve the decreased generation of eosinophil-stimulating activity in the airways.

Multicenter evaluation of electrical stimulation systems for walking

OBJECTIVE

To test the long-term benefits of several noninvasive systems for functional electrical stimulation (FES) during walking.

DESIGN

Forty subjects (average years since injury, 5.4) were studied in four centers for an average time of 1 year. Gait parameters were tested for all subjects with and without FES. Thus, subjects served as their own controls, since the specific effect of using FES could be separated from improvements resulting from other factors (e.g., training).

SETTING

Subjects used the devices in the community, but were tested in a university or hospital setting.

PATIENTS

Subjects with spinal cord injury (n = 31) were compared to subjects with cerebral damage (n = 9).

MAIN OUTCOME MEASURES

Gait parameters (speed, cycle time, stride length). Acceptance was studied by means of a questionnaire.

RESULTS

Some initial improvement in walking speed (average increase of >20%) occurred, and continuing gains were seen (average total improvement, 45%). The largest relative gains were seen in the slowest walkers (speeds of <0.3 m/sec). Acceptance of the FES systems was good and improved systems have been developed using feedback from the subjects.

CONCLUSIONS

Based on the improvements in speed and the acceptance of these FES systems, a greatly increased role for FES in treating gait disorders is suggested.

Complete nucleotide sequence and genomic organization of a primate calicivirus, Pan-1

The primate calicivirus, Pan-1, was originally isolated from several primate species. It displayed typical calicivirus morphology by electron microscopy. We determined the genomic sequence of Pan-1 by cDNA cloning and direct RNA sequencing. Pan-1 shares a similar genomic organization and a high degree of sequence identity with feline caliciviruses. The Pan-1 genome contains 8,304 nucleotides, plus a poly-A tail, and is longer than any other calicivirus strains with a completely known sequence. The extra sequences of Pan-1 include a unique 424-nucleotide sequence at the 5' end of ORF1, additional amino acids at the N-terminus of the capsid, and a longer 3' UTR.

Inositol polyphosphate-mediated iron transport in Pseudomonas aeruginosa

It has previously been shown that myo-inositol hexakisphosphate (myo-InsP6) mediates iron transport into Pseudomonas aeruginosa and overcomes iron-dependent growth inhibition. In this study, the iron transport properties of myo-inositol trisphosphate and tetrakisphosphate regio-isomers were studied. Pseudomonas aeruginosa accumulated iron (III) at similar rates whether complexed with myo-Ins(1,2,3)P3 or myo-InsP6. Iron accumulation from other compounds, notably D/L myo-Ins(1,2,4,5)P4 and another inositol trisphosphate regio-isomer, D-myo-Ins(1,4,5)P3, was dramatically increased. Iron transport profiles from myo-InsP6 into mutants lacking the outer membrane porins oprF, oprD and oprP were similar to the wild-type, indicating that these porins are not involved in the transport process. The rates of reduction of iron (III) to iron (II) complexed to any of the compounds by a Ps. aeruginosa cell lysate were similar, suggesting that a reductive mechanism is not the rate-determining step.

Genomic mapping of a calicivirus VPg

We identified a primate calicivirus (Pan-1) VPg in Pan-1-infected cells. The Pan-1 VPg was associated with both genomic and subgenomic RNAs. RNase digestion of Pan-1 RNA yielded a residual protein of 16 kDa. The N-terminal sequence of Pan-1 VPg was determined by direct amino acid sequencing and mapped to a region of the genome equivalent to picornavirus VPgs. Alignment of this protein sequence with similar regions of other calicivirus genomes allowed identification of conserved amino acid motifs and potential boundaries of the calicivirus VPg genes. Proteinase K treatment abolished the infectivity of Pan-1 RNA, suggesting that Pan-1 VPg is required for RNA infectivity.

A modification of the Kernahan "Y" classification in cleft lip and palate deformities

The search for a universally accepted system of classifying cleft lip and palate deformities has yielded many models of varying complexity. Recently, there has been a trend toward symbolic classification systems that allow members of the cleft team to quickly assess the nature of the deformity. The existing systems, however, have limitations. These include inadequate description of the cleft lip deformity and complexity of nomenclature. A modification of Kernahan's striped Y classification is proposed that addresses these problems. This system was applied to 150 cleft patients, and it was found that it was able to describe all varieties of clefts encountered. In contrast, the Kernahan system could only describe 74.7 percent of the patients adequately.

Long-term follow-up of cranial bone graft in dorsal nasal augmentation

A follow-up of 363 cranial bone grafts for nasal reconstruction is presented. The main indications for the surgery were congenital, posttraumatic, or postrhinoplasty deformity. The results were satisfactory in the vast majority of cases. The complications associated with the grafts and with the donor site are discussed, as are the methods to treat and prevent these complications from occurring.

Response of single species biofilms and microcosm dental plaques to pulsing with chlorhexidine

The aim of this study was to determine the effect of pulsing chlorhexidine gluconate, at concentrations commonly used in mouthwashes, on Streptococcus sanguis biofilms and microcosm dental plaques in vitro. Biofilms were grown on bovine enamel and nutrients were supplied in the form of artificial saliva. Pulsing experiments were carried out on steady-state biofilms using 0.05 or 0.2% chlorhexidine solutions delivered twice daily for 1 min. In a separate study, the enamel discs on which the biofilms were formed were pre-treated with chlorhexidine and pulsed directly after inoculation and then at regular intervals. With both concentrations of chlorhexidine used, a c.2 log10 reduction in the viable counts of S. sanguis was achieved with the initial pulse, but as pulsing continued, the bacterial population recovered, albeit not to the previous level. A c.1 log10 reduction in the total viable counts of the microcosm plaques was seen after the first pulse with 0.2% chlorhexidine. The total count then recovered rapidly and, after the fifth pulse, the total viable counts were not significantly different from those before pulsing. The total counts then remained at a similar level throughout the course of the experimental runs. Pre-treatment of the enamel discs with 0.2% chlorhexidine before inoculation produced viable counts of c.10(5) cfu/mm2, a 1 log10 reduction compared with untreated discs. After pulsing with 0.2% chlorhexidine at 8 h, a 3 log10 reduction was seen in the total aerobic and anaerobic counts, but again the viable counts subsequently increased despite twice-daily chlorhexidine pulsing. Regardless of the nature of the biofilm, pulsing initially achieved substantial kills, but the viability of the biofilms subsequently increased despite continued pulsing. Chlorhexidine was effective at reducing the viability of microcosm plaques when it was applied to the substratum before exposure to bacteria and subsequently pulsed on to the biofilms.

Isolation of reptilian calicivirus Crotalus type 1 from feral pinnipeds

Ten virus isolates were obtained from three species of marine mammals sampled on San Miguel Island (California, USA) and 1,200 km north on Rogue Reef (Oregon, USA) during tagging operations in 1986-87. Seven of these 10 were derived from 30 sampled Steller sea lion (Eumetopias jubatus pups, while two of 10 were isolated from one of 19 sampled California sea lion (Zalophus californianus californianus pups, and the remaining isolate was derived from 30 sampled northern fur seal (Callorhinus ursinus) pups. All 10 isolates were identified as belonging to a single serotype, reptilian calicivirus Crotalus type 1 (RCV Cro-1), previously isolated from both healthy and diseased snakes and frogs in a California zoologic collection. The marine samples also showed that nine of 30 Steller sea lion pups, one of 19 California sea lion pups and zero of 30 fur seal pups were producing type specific neutralizing antibodies to RCV Cro-1. This represents the first reported instance of the isolation from marine sources of calicivirus originally isolated from a terrestrial species.

Partial characterization of the genome of nine animal caliciviruses

Caliciviruses (CVs) include at least 42 distinct serotypes. Seventeen CV serotypes have been isolated from marine sources and are called San Miguel sea lion caliciviruses (SMSVs). CVs also have been isolated from reptiles, primates, and other terrestrial animals. Nucleotide sequences from portions of genome of prototype strains for six SMSV serotypes, the reptile CV, Cro-1, the cetacean CV, Tur-1, and the primate CV, Pan-1, are presented. cDNA products of the polymerase (all strains characterized) and capsid (SMSV-17) regions were produced by reverse transcription-polymerase chain reaction using Pan-1 primers. Comparisons of nucleotide and amino acid identity among these and published CV sequences indicated that the nine characterized CVs fall into a phylogenetic group that includes SMSV-1 and SMSV-4 and that is more closely related to other characterized animal CVs than to most human CVs. The phylogenetic analysis also indicated that distinct genera exist among the Caliciviridae. SMSV-17 and SMSV-4 are predicted to be closer to each other than other caliciviruses of known serotype; 574 (82%) of the 704 amino acids in the SMSV-17 and SMSV-4 capsid genes were identical.

In vitro isolation and characterization of a calicivirus causing a vesicular disease of the hands and feet

We report that a calicivirus of oceanic origin, San Miguel sea lion virus serotype 5 (SMSV-5), is a human pathogen. This biotype was isolated originally from blisters on the flippers of northern fur seals (Callorhinus ursinus) and replicates readily in primate and human cell lines. It infects a phylogenetically diverse array of hosts (poikilotherms to primates) and induces type-specific neutralizing antibodies in exposed humans. Group antibody against a pooled antigen of SMSV-5 and two other serotypes was also observed in 18% of 300 blood donors from a population in the northwestern United States. The human calicivirus isolate designated SMSV-5 Homosapien-1 (SMSV-5 Hom-1) was recovered from a laboratory worker with systemic illness, including vesicular lesions on all four extremities. We believe this newly described human disease represents a paradigmatic shift in calicivirus disease recognition.

Calicivirus emergence from ocean reservoirs: zoonotic and interspecies movements

Caliciviral infections in humans, among the most common causes of viral-induced vomiting and diarrhea, are caused by the Norwalk group of small round structured viruses, the Sapporo caliciviruses, and the hepatitis E agent. Human caliciviruses have been resistant to in vitro cultivation, and direct study of their origins and reservoirs outside infected humans or water and foods (such as shellfish contaminated with human sewage) has been difficult. Modes of transmission, other than direct fecal-oral routes, are not well understood. In contrast, animal viruses found in ocean reservoirs, which make up a second calicivirus group, can be cultivated in vitro. These viruses can emerge and infect terrestrial hosts, including humans. This article reviews the history of animal caliciviruses, their eventual recognition as zoonotic agents, and their potential usefulness as a predictive model for noncultivatable human and other animal caliciviruses (e.g., those seen in association with rabbit hemorrhagic disease).