Long-term benefits of aggressive treatment for primary colorectal cancer

The long-term follow up of 128 colorectal cancer patients is reported. Seventy-nine percent (101/128) of the patients had curative resections: 70 patients had radical lymphadenectomies with wide removal of tumor-adjacent nodes, and 31 patients had standard resections. The 5-year overall survival rates for Dukes' stage B and C patients and for all rectosigmoid cancer patients significantly favored radical resection (60% vs. 38%, 57% vs. 29%, respectively, P < 0.05). Tumor-free survival rates were also higher after radical lymphadenectomy but did not reach statistical significance. Eleven percent (14/128) of the patients required multiorgan resections, and/or preoperative radiation to render fixed cancers resectable, and these patients had a 10-year tumor-free survival rate of 45%, compared to zero % 5-year survival for the 27 patients who underwent palliative procedures (P < 0.01). These results confirm that many colorectal cancer patients will be cured with aggressive treatment and they support the need for a controlled trial for evaluation of lymphadenectomy for this disease.

Prevalence of fragile X syndrome

The much-quoted prevalence figure of 1:1,000 males for fragile X syndrome is an overestimate in a mixed ethnic population. A reexamination of the individuals from whom those data were derived using molecular diagnostic techniques demonstrates a more realistic figure of 1:4,000 males.

Prevalence of fragile X syndrome

The much-quoted prevalence figure of 1:1,000 males for fragile X syndrome is an overestimate in a mixed ethnic population. A reexamination of the individuals from whom those data were derived using molecular diagnostic techniques demonstrates a more realistic figure of 1:4,000 males.

A boy with developmental delay and a maternally inherited deletion in 15q11q13

A boy was referred at 8 weeks of age for failure to thrive. Cytogenetic and molecular studies showed that he had a large proximal deletion of the maternally derived chromosome 15q. He did not have Angelman syndrome, but at 2 years of age was severely globally delayed. He died at 2 1/2 years of age.

A comparative study of X-inactivation in Rett syndrome probands and control subjects

X-inactivation has been studied in a series of monozygotic female twins and their female relatives by a PCR method which detects methylation at the androgen receptor locus (HUMARA). The results obtained are compared to those from an earlier study employing probe M27 beta which detects locus DXS255. Analysis of X-inactivation in girls with Rett syndrome and their mothers by four different methods did not indicate a direct relationship between non-random inactivation of the X-chromosome and the presence of the disease with the exception that any skewing detected in the probands tended to favour the preferential inactivation of the paternally inherited X-chromosome. No evidence for the involvement of uniparental disomy in the etiology of the disease was found.

Maladaptive behaviour in Prader-Willi syndrome in adult life

Thirty adults with Prader-Willi syndrome (PWS) were compared with 30 adults with non-specific learning disability matched for age, sex and severity of mental retardation. Maladaptive behaviour was assessed with the Aberrant Behavior Checklist (ABC), a 58-item structured interview which rates behaviours from 0 (not a problem) to 3 (severe problem) and which yields five factors (I) irritability, agitation; (II) lethargy, withdrawal; (III) stereotypic behavior; (IV) hyperactivity, non-compliance; and (V) inappropriate speech). The PWS sample had significantly higher factor I (P < 0.001) and factor V (P < 0.05) scores. The PWS sample had mean scores above 1 for 17 ABC items; the contrast subjects had no mean scores above 1. The factor I scores for the PWS sample were similar to those of inpatients in hospital facilities for adults with mental retardation and mental illness or severely challenging behaviour. The results support previous work, and extend it by suggesting that temper tantrums, self-injury, impulsiveness, lability of mood, inactivity and repetitive speech are characteristic behaviours in PWS in adult life. Studies of the reasons for heterogeneity in behaviour are now needed.

Operative adjuncts for distal revascularization

The performance of distal arterial bypass procedures in poor outflow situations may require adjunctive techniques to maximize short- and long-term patency. The rationale and technique for the most commonly used modifications are presented along with the indications for use.

Aortofemoral bypass via transperitoneal approach

The transperitoneal route remains the most widely used approach to the infrarenal abdominal aorta. The specific indications and techniques are reviewed in full detail. Special circumstances that require modifications of the standard operative approach are presented. Finally, current and expected results of aortofemoral bypass are discussed.

Alterations in replication timing of X-chromosome bands in Rett syndrome

A cytogenetic study has been carried out on 30 girls affected with Rett syndrome, 35 of their family members and 25 unrelated healthy control females. Karyotyping at the 850 band level revealed no detectable chromosome abnormalities in either the affected girls or their families. Observations on the sequence of the appearance of early replicating bands on both the active and the inactive X-chromosome demonstrated the same replication patterns in all of the groups investigated with the exception that band Xp21 appeared with greater frequency in the Rett syndrome cells. A degree of variation was detected both between and within the subjects when the timing of the latest bands to replicate was investigated for the active X, but the same consensus order was obtained for all groups. A comparable number of elongated X-chromosomes was found in the girls with Rett syndrome (8%) when compared to their mothers (12%) when synchronized cells were treated with a short pulse of BrdU. If a disturbance in X-inactivation does contribute to the aetiology of Rett syndrome, it is at a level which is not detected by observations on the relative timing of replication of chromosome bands.

A clinical, cytogenetic, and molecular study of 40 adults with the Prader-Willi syndrome

A clinical, cytogenetic, and molecular study has been carried out on 40 adults with a firm diagnosis of Prader-Willi syndrome. A cytogenetically detectable deletion was observed in 58% while further subjects had a deletion which was detectable by molecular methods only, giving a total of 76%. Four cases of maternal uniparental disomy (UPD) were all female. Three of them were heterodisomic while the fourth was isodisomic. Two male probands were heterozygous at all loci tested yet did not have UPD. Although methylation studies showed that one of them had a single band using probe PW71, the other one had two bands. Psychiatric studies suggest that females with maternal UPD are indistinguishable psychologically from those with a paternal deletion in 15q11q13.

X inactivation patterns in female monozygotic twins and their families

X inactivation studies have been carried out on 22 pairs of female monozygotic twins, one set of female monozygotic triplets, and their mothers and singleton sisters, using the probe M27 beta. Forty-eight per cent of the twins, 55% of their mothers, and 42% of their singleton sisters showed skewed X inactivation. Two of the triplets and their mother had random X inactivation, while the third triplet showed skewed X inactivation. Their singleton sister was homozygous with M27 beta. Of the twins, six pairs showed skewed X inactivation in favour of the same X chromosome, one pair showed skewed X inactivation favouring opposite X chromosomes, in seven pairs one twin showed skewed X inactivation while her co-twin showed random X inactivation, and in eight pairs both twins were random. A higher frequency of skewed pattern of X inactivation was not observed in the monozygotic twins when compared to a series of non-twin females (mothers and singleton sisters) and, so, the results in this study do not lend support to the theory that skewed X inactivation predisposes to the twinning process.

Environmental health. Nappies: the bottom line

Increasing use of disposable nappies presents a major environmental hazard. Manufacturing processes consume vast amounts of resources; disposal is a significant pollution problem, although laundering nappies too generates pollution. Teresa Webb believes parents should be presented with the comparable facts about nappies, to enable them to make an informed choice.

Sister chromatid exchange in families with Angelman or Prader-Willi syndrome

Using estimation of numbers of sister chromatid exchanges arising in 15q11q13 as a measure, comparisons of the stability of the Prader-Willi syndrome critical region have been made. The groups studied included probands with Prader-Willi or Angelman syndromes either with or without a cytogenetically visible deletion in 15q11q13, their parents, specifically those parents who had passed on the homologue which had become deleted, and a control group. No significant differences were found between any of the four groups, indicating that there was no increase in the instability of the PWSCR region as measured by sister chromatid exchange.

A male with a de novo translocation involving loss of 15q11q13 material and Prader-Willi syndrome

A male proband is described who carries a de novo translocation between chromosomes Y and 15 associated with Prader-Willi syndrome. In situ hybridisation and molecular studies were used to show loss of the paternally derived 15q11q13 region in the translocated chromosome. Lack of further symptoms indicate that this region was lost with no apparent deletion of the Y chromosome.

Family studies in Prader-Willi syndrome

Clinical, cytogenetic and molecular studies have been undertaken in the families of 52 probands with Prader-Willi syndrome. The maternal age at the birth of a proband with a deletion in 15p11q13 was on average 8 years less than that of the mothers of probands with uniparental disomy (UPD), the paternal age was on average 7 years less. Seven probands with UPD were all female, as were 7 patients who had neither a detectable chromosomal abnormality nor UPD. Cytogenetic and molecular polymorphisms in proximal chromosome 15 indicated that for probands with a 15q11q13 deletion, inheritance of both the maternal and the intact paternal homologue is random in their unaffected sublings. Pigmentation studies suggest that probands who have a deletion in 15q11q13 have lighter colouring than other family members implying that D15S12 may not be imprinted.

Neither uniparental disomy nor skewed X-inactivation explains Rett syndrome

The locus DXS255 was studied using the probe M27 beta in ten probands with Rett syndrome and in eight of their families. No evidence of uniparental disomy of the X chromosome was detected, as all informative probands had inherited an allele from each of their parents. Differential methylation of a CCGG site within the DXS255 locus as shown by digestion with MspI/HpaII, revealed moderate skewing of X-inactivation favouring the maternal allele in two of the probands. Random X-inactivation was present in all mothers tested and in two unaffected sisters. Three of four unaffected siblings had inherited the same maternal allele at DXS255.

Molecular mechanisms in Angelman syndrome: a survey of 93 patients

Angelman syndrome (AS) results from a lack of maternal contribution from chromosome 15q11-13, arising from de novo deletion in most cases or rarely from uniparental disomy. These families are associated with a low recurrence risk. However, in a minority of families, more than one child is affected. No deletion has been found in these families, except one. The mode of inheritance in these families is autosomal dominant modified by imprinting. Sporadic cases, with no observable deletion, therefore pose a counselling dilemma as there could be a recurrence risk as high as 50%. We present a series of 93 AS patients, showing the relative contribution of these different genetic mechanisms. Eighty-one AS patients were sporadic cases while 12 cases came from six families. Sixty cases had deletions in 15q11-13 detected by a set of highly polymorphic (CA)n repeats markers and conventional RFLPs. Ten sporadic cases plus all 12 familial cases had no detectable deletion. In addition, two cases of de novo deletions occurred in a chromosome 15 carrying a pericentric inversion. In one of these the AS child had a cousin with Prader-Willi syndrome (PWS) arising from a de novo deletion in an inv(15) inherited from his father. One case arose from a maternal balanced t(9;15)(p24;q15) translocation. There were three cases of uniparental disomy. Five patients were monoallelic for all loci across the minimal AS critical region, but the presence of a deletion cannot be confirmed. In familial cases, all affected sibs inherited the same maternal chromosome 15 markers for the region 15q11-13. Two cases were observed with a de novo deletion starting close to the locus D15S11 (IR4-2R), providing evidence for the development of classical AS with smaller deletions. Cytogenetic analysis proved limited in its ability to detect deletions, detecting only 42 out of 60 cases. However, cytogenetic analysis is still essential to detect chromosomal abnormalities other than deletions such as inversions and balanced translocations since both have an increased risk for deletions. A staged diagnostic strategy based on the use of highly informative (CA)n repeat markers is proposed.

Difference in methylation patterns within the D15S9 region of chromosome 15q11-13 in first cousins with Angelman syndrome and Prader-Willi syndrome

Abnormalities of chromosome region 15q11-13 are associated with Angelman syndrome (AS) and Prader-Willi syndrome (PWS). Differences between the methylation patterns of the region of chromosome 15q11-13 which hybridizes to the highly conserved DNA, DN34, in normal individuals and in patients with AS and PWS have been described. We report on a family in which first cousins are affected by AS and PWS as a result of a familial paracentric inversion of 15q11-q13. The results of the studies on this family demonstrate the differences in the methylation patterns in the 2 conditions and the phenomenon of genomic imprinting, whereby genetic information is expressed differently dependent on the parent of origin.

Information transmission in bilingual, bicultural contexts: a field study of community health nurses and interpreters

The purpose of this article is to present the findings made in a field study of nurses and interpreters who were working in a county health department. Informed by the qualitative research method of grounded theory, analysis of 37 semistructured interviews revealed three types of interactions among nurses, interpreters, and clients. In these situations, the interpreter worked as a voice box, an excluder, or a collaborator. Collaborative interactions allowed both interpreters and community health nurses to establish the most effective rapport with clients. Rapport, in turn, facilitated client assessment and the planning and delivery of nursing services. Implications for community health nursing practice include providing opportunities for interpreters to establish a rapport with clients. Research implications include the development of strategies that promote collaboration between community health nurses and interpreters. Theoretically, such strategies would enhance client outcomes.

Is skewed X inactivation responsible for symptoms in female carriers for adrenoleucodystrophy?

A study of X inactivation in 12 female carriers for adrenoleucodystrophy showed no evidence that skewed patterns are related to clinical manifestation. Other possible mechanisms to explain manifestation in females are considered.