A high-density genetic map of the chromosome 13q14 atopy locus

Atopy describes a syndrome of immunoglobulin E (IgE)-mediated allergy that underlies asthma and infantile eczema. We have previously identified a locus on chromosome 13q14 that is linked to atopy and to the total serum immunoglobulin A concentration. We have therefore made a saturation genetic map of the region by typing 59 polymorphic microsatellite loci on chromosome 13q. Multipoint linkage analysis identified a 1-LOD support unit for the location of the atopy locus with a 7.5-cM region flanked by the loci D13S328 and D13S1269. The peak of linkage was at locus D13S161 with a nonparametric -log of P score of approximately 4.5. Parent of origin effects were present, with linkage primarily observed to paternally derived alleles. The genetic map of this region provides a basis for the effective identification of the chromosome 13 atopy gene.

Evidence for Msh2 haploinsufficiency in mice revealed by MNU-induced sister-chromatid exchange analysis

The role of Msh2 in chromosome stability has been investigated in a targeted mouse model for HNPCC, Msh2Delta7N. Chromosome aberration frequencies were similar in bone marrow of Msh2(+/+), Msh2(+/-)and Msh2(-/-)mice and no differential effects of in vivo X-irradiation were noted. By contrast, the induction of sister-chromatid exchanges (SCEs) by methyl nitrosourea (MNU) was reduced in Msh2(-/-)and Msh2(+/-)cells to approximately 20% and approximately 45% wild-type levels respectively indicating a phenotypic effect of haploinsufficiency of the mouse Msh2 gene.

Clonidine toxicity in an adolescent patient

Clonidine is a central acting a2-agonist used primarily as an antihypertensive agent. Recently, it has been used for the treatment of attention deficit hyperactivity disorder in children and adolescents. When taken in excess, it can produce profound CNS depression, apnea, bradycardia and hypotension. A transient period of hypertension can sometimes occur. Treatment is primarily supportive, including respiratory support, atropine for bradycardia, and fluids and dopamine for hypotension. The CNS depression sometimes responds to naloxone. Young children are very sensitive to the toxic effects of clonidine. A case of an 11 year old adolescent who took an overdose of his clonidine is described to illustrate the toxicity of this agent.

Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus)

As an integral part of the development of an artificial insemination programme in the captive koala, female reproductive physiology and behaviour were studied. The oestrous cycle in non-mated and mated koalas was characterized by means of behavioural oestrus, morphology of external genitalia and changes in the peripheral plasma concentrations of oestradiol and progestogen. The mean (+/- SEM) duration of the non-mated oestrous cycle and duration of oestrus in 12 koalas was 32.9 +/- 1.1 (n = 22) and 10.3 +/- 0.9 (n = 24) days, respectively. Although the commencement of oestrous behaviour was associated with increasing or high concentrations of oestradiol, there were no consistent changes in the morphology or appearance of the clitoris, pericloacal region, pouch or mammary teats that could be used to characterize the non-mated cycle. As progestogen concentrations remained at basal values throughout the interoestrous period, non-mated cycles were considered non-luteal and presumed anovulatory. After mating of the 12 koalas, six females gave birth with a mean (+/- SEM) gestation of 34.8 +/- 0.3 days, whereas the remaining six non-parturient females returned to oestrus 49.5 +/- 1. 0 days later. After mating, oestrous behaviour ceased and the progestogen profile showed a significant increase in both pregnant and non-parturient females, indicating that a luteal phase had been induced by the physical act of mating. Progestogen concentrations throughout the luteal phase of the pregnant females were significantly higher than those of non-parturient females. Parturition was associated with a decreasing concentration of progestogen, which was increased above that of basal concentrations until 7 days post partum.

Natural and artificial methods for inducing the luteal phase in the koala (Phascolarctos cinereus)

An experiment was conducted in which female koalas were mated for different durations of intromission and ejaculation to confirm that the luteal phase of the oestrous cycle in koalas is induced by the physical act of mating. Results showed that induction of a luteal phase in the koala usually required a complete duration of penile thrusting behaviour from the male. It is proposed that induction of a luteal phase in koalas may involve a copuloceptive reflex, triggered by the thrusting of the male's penis into the female's urogenital sinus. Although interrupted mating in koalas may be used to induce a luteal phase in preparation for an artificial insemination programme, this study showed that there is a 12.5% probability that pregnancy will result from semen prematurely emitted by the teaser male. A dose of 250 iu hCG was administered intramuscularly to eight oestrous females to determine whether it was possible to induce a luteal phase artificially. In contrast to control females, which received sterile saline injections, all females injected with hCG showed a significant increase in progestogen concentration above that of basal values, indicating that a luteal phase had been induced successfully.

Natural and artificial methods for inducing the luteal phase in the koala (Phascolarctos cinereus)

An experiment was conducted in which female koalas were mated for different durations of intromission and ejaculation to confirm that the luteal phase of the oestrous cycle in koalas is induced by the physical act of mating. Results showed that induction of a luteal phase in the koala usually required a complete duration of penile thrusting behaviour from the male. It is proposed that induction of a luteal phase in koalas may involve a copuloceptive reflex, triggered by the thrusting of the male's penis into the female's urogenital sinus. Although interrupted mating in koalas may be used to induce a luteal phase in preparation for an artificial insemination programme, this study showed that there is a 12.5% probability that pregnancy will result from semen prematurely emitted by the teaser male. A dose of 250 iu hCG was administered intramuscularly to eight oestrous females to determine whether it was possible to induce a luteal phase artificially. In contrast to control females, which received sterile saline injections, all females injected with hCG showed a significant increase in progestogen concentration above that of basal values, indicating that a luteal phase had been induced successfully.

Comparison of cytogenetic damage in cultured cells from cobalt-60 gamma-radiation and the Auger emitter zinc-65

PURPOSE

To assess the ability of the Auger-emitting nuclide, zinc-65 (65Zn), relative to gamma-irradiation, to cause chromosomal aberrations in cultured rat prostate cells.

MATERIALS AND METHODS

Rat prostate adenocarcinoma cells in culture were exposed to doses of 1, 2, 3 or 5 Gy of external gamma-irradiation for 24h or incubated with 0.7, 1.5, 1.8 or 2.8 MBq of 65Zn for 24 h. The uptake by and clearance from cells of 65Zn was measured. Metaphase spreads prepared from washed cells were scored for chromatid- and chromosome-type aberrations.

RESULTS

Following exposure to 65Zn or gamma-irradiation, chromatid-type damage was more commonly observed than chromosome-type aberrations. The relationship between induced chromatid damage and gamma dose (to 3 Gy) was best fitted by a second-order polynomial function, while the activity response relationship for chromatid damage caused by 65Zn appeared to be best fitted by a straight line. Measurements of the uptake of 65Zn by cells showed that average concentrations within cells were about 100 times the concentration in the culture medium. Assuming uniform distribution of 65Zn within cells, with 36% in the nucleus, the dose was estimated as 0.70 Gy per MBq added 65Zn, with Auger electrons contributing most (93%) of the dose. Assuming that 20% of cellular zinc was localized in the nucleus, based on previous measurements, the dose to the nucleus was calculated as 0.44 Gy per MBq added 65Zn. RBE values for chromatid damage induced by 65Zn compared to gamma-radiation range from about 1 to 3 based on a uniform dose throughout the cell and from about 2 to 5 based on 20% of 65Zn in the cell nucleus.

CONCLUSION

The observed radiotoxicity of 65Zn is consistent with its behaviour as an Auger-emitting radionuclide that is localized to some extent in the nucleus.

Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus)

As an integral part of the development of an artificial insemination programme in the captive koala, female reproductive physiology and behaviour were studied. The oestrous cycle in non-mated and mated koalas was characterized by means of behavioural oestrus, morphology of external genitalia and changes in the peripheral plasma concentrations of oestradiol and progestogen. The mean (+/- SEM) duration of the non-mated oestrous cycle and duration of oestrus in 12 koalas was 32.9 +/- 1.1 (n = 22) and 10.3 +/- 0.9 (n = 24) days, respectively. Although the commencement of oestrous behaviour was associated with increasing or high concentrations of oestradiol, there were no consistent changes in the morphology or appearance of the clitoris, pericloacal region, pouch or mammary teats that could be used to characterize the non-mated cycle. As progestogen concentrations remained at basal values throughout the interoestrous period, non-mated cycles were considered non-luteal and presumed anovulatory. After mating of the 12 koalas, six females gave birth with a mean (+/- SEM) gestation of 34.8 +/- 0.3 days, whereas the remaining six non-parturient females returned to oestrus 49.5 +/- 1. 0 days later. After mating, oestrous behaviour ceased and the progestogen profile showed a significant increase in both pregnant and non-parturient females, indicating that a luteal phase had been induced by the physical act of mating. Progestogen concentrations throughout the luteal phase of the pregnant females were significantly higher than those of non-parturient females. Parturition was associated with a decreasing concentration of progestogen, which was increased above that of basal concentrations until 7 days post partum.

A deficiency in DNA repair and DNA-PKcs expression in the radiosensitive BALB/c mouse

We have studied the efficiency of DNA double strand break (DSB) rejoining in primary cells from mouse strains that show large differences in in vivo radiosensitivity and tumor susceptibility. Cells from radiosensitive, cancer-prone BALB/c mice showed inefficient end joining of gamma ray-induced DSBs as compared with cells from all of the other commonly used strains and F1 hybrids of C57BL/6 and BALB/c mice. The BALB/c repair phenotype was accompanied by a significantly reduced expression level of DNA-PKcs protein as well as a lowered DNA-PK activity level as compared with the other strains. In conjunction with published reports, these data suggest that natural genetic variation in nonhomologous end joining processes may have a significant impact on the in vivo radiation response of mice.

Loss of heterozygosity in spontaneous and X-ray-induced intestinal tumors arising in F1 hybrid min mice: evidence for sequential loss of APC(+) and Dpc4 in tumor development

Min (multiple intestinal neoplasia) mice carry a mutant allele of the murine Apc (adenomatous polyposis coli) locus and are predisposed to intestinal adenoma formation in the intestinal tract. Early studies have shown complete loss of function of Apc by whole chromosome loss on the tumor-sensitive C57BL/6J genetic background and in AKR x B6 F1 hybrids. Gamma-radiation-induced chromosomal losses focus the critical region on wt Apc, but because of the limited number of polymorphic markers used, no other critical regions of loss on chromosome 18 were identified. Using intestinal tumors arising spontaneously and induced by X-rays in CBA/H x C57BL/6J F1 hybrid mice and high-resolution microsatellite loss of heterozygosity (LOH) techniques, we provide mapping data for wt Apc loss, which confirms and extends earlier observations. In addition, high-frequency loss events at the Dpc4 locus were found in both spontaneous and radiation-induced tumors. These data identified LOH of Dpc4 as a critical secondary event following complete functional loss of Apc. LOH across the Trp53 genomic region of chromosome 11 was not observed. No LOH was recorded for the Mom1 candidate gene Pla2g2a or for 9 out of 10 polymorphic markers from the Mom1 genomic region on murine chromosome 4. One marker mapping distal to Pla2g2a showed LOH in a small minority of spontaneous tumors. These data support the contention that Mom1 does not act as a classical tumor suppressor. Overall, our data indicates a significant role for Dpc4 mutation in intestinal tumor progression in the mouse and provides further evidence for the importance of interstitial chromosome losses in radiation tumorigenesis.

A randomized controlled trial of strapping to prevent post-stroke shoulder pain

OBJECTIVE

To determine whether strapping the shoulder in hemiplegic stroke patients: (1) prevents the development, or reduces the severity, of shoulder pain, (2) preserves range of movement in the shoulder, and (3) improves the functional outcomes for the arm and patient overall.

DESIGN

A prospective, randomized, single-blind controlled trial of shoulder strapping versus no strapping.

SETTING

Care of the elderly wards in a teaching hospital, Christchurch, New Zealand.

SUBJECTS

All patients admitted with an acute hemiplegic stroke, who had persisting weakness of shoulder abduction.

INTERVENTION

The treatment group had their affected shoulder strapped for six weeks from randomization in addition to standard physiotherapy.

MAIN OUTCOME MEASURES

All subjects were assessed at entry (week 0), at end of the treatment phase (week 6) and two months later (week 14). A visual analogue scale (VAS) was used to assess shoulder pain severity whereas shoulder range of movement to the point of pain (SROMP) assessed passive range of movement and pain. Functional Independence Measure (FIM), Motor Assessment Scale (MAS) and Rankin Disability Index measured functional outcomes.

RESULTS

Ninety-eight subjects participated (49 strapped, 49 controls). Intention to treat analysis showed no significant difference in pain, range of movement or functional outcomes after the intervention phase or at the final assessment. However there were trends for less pain at six weeks (VAS, p = 0.11) and better final upper limb function (MAS, p = 0.16) in strapped patients. Skin reactions were uncommon (6.1%). The presence of neglect or sensory loss, but not subluxation, at baseline was independently associated with poor outcome. Range of movement was lost early (mean difference SROMP between hemiplegic and contralateral shoulders at baseline = 15.2 degrees (95% CI 10.9-19.5)) and continued throughout the study. Shoulder strapping did not alter the rate at which range of movement was lost.

CONCLUSIONS

No significant benefit with shoulder strapping was demonstrated and reasons for this are discussed. Range of movement in the hemiplegic shoulder is lost very early and any preventive treatments need to begin within the first 1-2 days after a stroke.

Optimal outcome measures, research priorities, and international cooperation

The participants in the Eriksholm Workshop on "Measuring Outcomes in Audiological Rehabilitation Using Hearing Aids" debated three issues that are reported in this article. First, it was agreed that the characteristics of an optimal outcome measure vary as a function of the purpose of the measurement. Potential characteristics of outcome self-report tools for four common goals of outcome measurement are briefly presented to illustrate this point. Second, 10 important research priorities in outcome measurement were identified and ranked. They are presented with brief discussion of the top five. Third, the concept of generating a brief universally applicable outcome measure was endorsed. This brief data set is intended to supplement existing outcome measures and to promote data combination and comparison across different social, cultural, and health-care delivery systems. A set of seven core items is proposed for further study.

Somatic cell hybrids for high-density mapping of chromosome 2 breakpoints in radiation-induced myeloid leukemia cell lines from inbred mice

Chromosome 2 (chr 2) deletions are recurrent abnormalities in acute myeloid leukemia (AML) induced by ionizing radiation in the mouse. The localization of deletion sites has proven extremely useful in providing information on the molecular mechanisms of leukemogenesis. The models available for the study of AML are mostly represented by inbred mouse strains, in which the molecular resolution of breakpoints is problematic. In this study, we have examined five leukemic cell lines exhibiting hemizygous chr 2 loss, derived from CBA, C3H, or (C57BLxCBA/H) F1 mice in which AML had been induced by a whole-body dose of radiation. By application of a somatic cell hybridization technique, we have generated interspecific cell hybrids retaining the deleted murine chr 2 homologue. This strategy permitted a very detailed genetic analysis allowing the utilization of any genetic marker on chr 2 without a requirement for polymorphism. Somatic cell hybrid clones were subjected to a high-density polymerase chain reaction-based microsatellite screening using 62-106 informative markers for each cell line. Detailed maps accurately defining chr 2 breakpoints were obtained. The identification of critical breakpoint markers allowed the construction of partial yeast artificial chromosome contigs across chr 2 breakpoints. These maps represent an essential resource for cloning of the breakpoint regions.

The X-ray structure of a chitinase from the pathogenic fungus Coccidioides immitis

The X-ray structure of chitinase from the fungal pathogen Coccidioides immitis has been solved to 2.2 A resolution. Like other members of the class 18 hydrolase family, this 427 residue protein is an eight-stranded beta/alpha-barrel. Although lacking an N-terminal chitin anchoring domain, the enzyme closely resembles the chitinase from Serratia marcescens. Among the conserved features are three cis peptide bonds, all involving conserved active site residues. The active site is formed from conserved residues such as tryptophans 47, 131, 315, 378, tyrosines 239 and 293, and arginines 52 and 295. Glu171 is the catalytic acid in the hydrolytic mechanism; it was mutated to a Gln, and activity was abolished. Allosamidin is a substrate analog that strongly inhibits the class 18 enzymes. Its binding to the chitinase hevamine has been observed, and we used conserved structural features of the two enzymes to predict the inhibitors binding to the fungal enzyme.

Metacarpal morphometry using a semi-automated technique in the assessment of osteoporosis and vertebral fracture risk

Metacarpal morphometry represents a potentially cheap and widely available non-invasive assessment of skeletal status. In two cross-sectional studies, we compared the performance characteristics of a semiautomated technique (the Teijin Bonalyzer) with an in-house manual measurement, and with measures of skeletal strength at other sites. The metacarpal cortical index (mCI) was measured on hand radiographs of 178 osteoporotic women using both the Teijin Bonalyzer and a digitizing tablet. Measurements on the latter were consistently lower than with the Bonalyzer except for mCI (0.443+/-0.080 vs 0.364+/-0.060, p<0.001), although correlation coefficients between these two methods were highly significant (r = 0.62-0.83, p<0.001). The reproducibility errors of metacarpal bone mineral density (mBMD) were constant (1.1-1.2%) whilst those for mCI showed a marked operator-dependency (2.0-7.9%). In 379 elderly community-dwelling women, Bonalyzer mCI and mBMD showed a significant decline with age (r = -0.30 and -0.27 respectively, p<0.05). Both mCI and mBMD correlated significantly with forearm BMD (r = 0.50 and 0.57 respectively, p<0.001) and hip BMD (r = 0.48 and 0.53 respectively, p<0.001). After adjustment for age and weight, hip BMD demonstrated the best discrimination for prevalent vertebral fractures as judged by the gradient of risk for a 1 SD decrease in measurement (odds ratio (OR) 2.17, 95% CI 1.56-3.01). Similar but smaller gradients of risk were shown by Bonalyzer mCI (OR 1.32, 95% CI 1.00-1.75), mBMD (OR 1.35, 95% CI 1.02-1.78) and forearm BMD (OR 1.39, 95% CI 1.08-1.80). MCI, and in particular mBMD, may be useful assessments of bone mass and fracture risk. In our study, it is comparable to peripheral assessment of skeletal status by forearm densitometry.

Voluntary ethanol drinking during the first three postnatal weeks in lines of rats selectively bred for divergent ethanol preference

BACKGROUND

Using a procedure first developed by Hall (1979), we examined ethanol self-administration in preweanling pups from Wistar rats and in lines of rats selectively bred for divergent ethanol preference (alcohol-preferring P, alcohol-nonpreferring NP, high-alcohol-drinking HAD-1 and -2, and low-alcohol-drinking LAD-2) to determine if factors contributing to high and low alcohol intakes are present early in development.

METHODS

From postnatal days 5 to 20, nondeprived male and female rat pups received 30 min daily access to either water or a 15% (v/v) ethanol solution. In each daily session, pups were placed in a heated chamber containing Kimwipes soaked with a water or ethanol solution. Pups were weighed before and after each session, and intake levels were calculated as a percentage of body weight change.

RESULTS

Similar to previous reports, Wistar pups exhibited over a 2-fold higher level of ethanol ingestion than water on postnatal days 9 through 14, with ethanol intakes approaching 3 g/kg body weight. When the drinking patterns of the selected lines were examined, only the HAD replicate lines showed a comparable preference for ethanol versus water during the preweanling period. The ethanol consumption of P, NP, and LAD lines was not consistently distinguishable from water intake levels. To reveal whether early ethanol exposure would influence later ethanol drinking behavior, a subset of HAD and LAD rat pups received free-choice ethanol access upon weaning. Although the divergent ethanol preference between high- and low-alcohol-drinking lines was evident within the first 4 days of access (>4 g/kg/day for HAD; <2 g/kg/day for LAD), preweanling ethanol exposure did not alter the acquisition or maintenance of ethanol drinking in either line.

CONCLUSIONS

Overall, these results suggest that (a) the enhanced ethanol ingestion observed during the middle portion of the preweanling period is a robust phenomenon and generalizes across nonselected strains of rats, (b) selective breeding for divergent alcohol preference has arrested this age-specific effect in all but the HAD lines of rats, and (c) early ethanol exposure does not alter genetic dispositions for later high or low alcohol preference.

Physical map and characterization of transcripts in the candidate interval for familial chondrocalcinosis at chromosome 5p15.1

The gene for familial chondrocalcinosis (MIM 118600; gene symbol CCAL2) has been localized to a 0.8-cM interval on the short arm of chromosome 5, between the polymorphic microsatellite markers D5S416 and D5S2114. We have undertaken the physical and transcript mapping of this interval, as well as regions telomeric to the interval, in an attempt to define ultimately the gene for this disorder. The physical map is composed of YAC, BAC, PAC, and cosmid resources and spans a physical distance of approximately 0.3 Mb. Using cDNA selection, we have identified eight novel transcripts in and around the interval; two of the selected transcripts reside in the candidate interval. We have also more precisely placed several expressed sequence tags (ESTs) that were previously mapped by radiation hybrid analysis and were reported to reside in or near the candidate interval. Two of the ESTs analyzed overlap with the selected cDNAs that reside in the candidate interval. All of the selected cDNAs are expressed partial transcripts, as determined by Northern blot analysis, and using RT-PCR analysis, we have determined that the cDNAs that reside in the candidate interval are expressed in cartilage and synovium, tissues that are presumably relevant to the chondrocalcinosis phenotype.