Non-random involvement of chromosome 13 in patients with persistent or relapsed disease after bone-marrow transplantation for chronic myeloid leukemia

Chronic myeloid leukemia (CML) patients with persistent or relapsed disease following bone-marrow transplantation (BMT) usually show both clonal and non-clonal cytogenetic changes in addition to the Philadelphia (Ph) translocation. These changes are presumably due to conditioning prior to transplantation and are generally not thought to be of clinical significance. We have examined the additional cytogenetic changes found in Ph+ve cells after BMT in 47 CML patients. Forty patients showed clonal changes. The involvement of each chromosome was compared statistically with expected values assuming that further chromosome changes are random and related to chromosome size. In clones that comprised 50% or more of the Ph+ve metaphases, chromosome 13 was involved in 12 of 22 clones (55%); this was highly significant when compared with the theoretical expected value of 3.2 (14.5%) (P < 0.001). The chromosome 13 rearrangements comprised both translocations and deletions. By means of FISH with a panel of 13q YAC clones, the breakpoints in 6 of these patients were investigated, but no common site of translocation was identified. The YAC panel was then used on material from 6 patients with chromosomal deletions. A common region of deletion was identified at 13q12-14, suggesting the presence of one or more tumor suppressor genes. We conclude that chromosome 13 deletions are non-randomly overrepresented in Ph+ve metaphases following BMT for CML. Genes Chromosomes Cancer 27:278-284, 2000.

Fusion of ETV6 to the caudal-related homeobox gene CDX2 in acute myeloid leukemia with the t(12;13)(p13;q12)

The t(12;13)(p13;q12) is a rare, recurrent translocation reported in a range of hematological malignancies. We have analyzed the molecular basis of this lesion in three patients with acute myeloid leukemia (AML), two of whom were known to have chromosome 12 breakpoints within the ETV6 gene. Fluorescence in situ hybridization (FISH) with ETV6 cosmids indicated that this gene was also disrupted in the third patient, while the normal ETV6 allele was retained. 3' rapid amplification of cDNA ends (RACE) polymerase chain reaction (PCR) from bone marrow mRNA of this individual identified a novel sequence fused to ETV6 that was homologous to a region just upstream of the mouse CDX2 homeobox gene, the human homologue of which has previously been mapped to chromosome 13q12. PCR primers designed to amplify an ETV6-CDX2 fusion identified two major transcripts from this patient. First, a direct in-frame fusion between exon 2 of ETV6 and exon 2 of CDX2, and second, a transcript that had an additional sequence of unknown origin spliced between these same exons. Surprisingly, apparently normal CDX2 transcripts, usually expressed only in intestinal epithelium, were also detectable in cDNA from this patient. Neither normal nor fusion CDX2 mRNA was detectable in the two other patients with a t(12;13), indicating that this translocation is heterogeneous at the molecular level. Reverse transcription-PCR analysis showed that CDX2 mRNA, but not ETV6-CDX2 mRNA, was strongly expressed in 1 of 10 patients with chronic myeloid leukemia in transformation, suggesting that deregulation of this gene may be more widespread in leukemia. CDX2 is known to regulate class I homeobox genes and its expression in hematopoietic cells may critically alter the balance between differentiation and proliferation.

Chromosomal breakage analysis in dyskeratosis congenita peripheral blood lymphocytes

Dyskeratosis congenita (DC) is a rare inherited disorder characterized by reticulate skin pigmentation, nail dystrophy and mucosal leucoplakia. Bone marrow failure occurs in the majority of cases and there is a predisposition to malignancy. Following conflicting reports of increased spontaneous and induced chromosomal breakage in DC lymphocytes, we examined chromosomal breakage with and without clastogen treatment in 10 DC patients from six different families. Peripheral blood cultures were stimulated with phytohaemagglutinin and treated with three clastogenic agents and gamma-irradiation. There was no significant difference in the chromosomal breakage in DC lymphocytes with or without exposure to bleomycin, DEB, MMC or gamma-irradiation. DC can therefore be distinguished from Fanconi's anaemia in which lymphocytes show increased spontaneous and clastogen-induced chromosomal breakage.

Investigation into the effect of proteoglycan molecules on the tribological properties of cartilage joint tissues

The aim of this research was to investigate the role of the hydrophilic properties of the proteoglycan molecules within the cartilage matrix, on the tribological properties of joint tissues in the mixed and boundary lubricating regime. Bovine articular cartilage, bovine meniscus and bovine cartilage that had been degraded to remove the chondroitin sulphate from its proteoglycans were studied in order to investigate differences in their friction and compression responses. The tissues were tested on a sliding friction rig under nominal contact stresses of 0.5 and 4 MPa. The compression tests were carried out under a 0.8 MPa contact stress. The compression tests showed the cartilage and meniscus deforming at the same rates, but the degraded cartilage deformed more quickly to reach its equilibrium position in a shorter period of time. The friction tests carried out at a constant load revealed the friction of the meniscus rising more rapidly with loading time than the cartilage. The degraded cartilage followed an almost identical curve as the untreated cartilage. Although the reduced proteoglycan content of the degraded cartilage substantially altered the biphasic compression response, it did not have an effect on the frictional properties of the tissue.

Guidelines for treatment of head injury in adults. Opinions of a group of neurosurgeons

There are a number of parallel activities world wide to devise guidelines for the treatment of head injuries. A Group of neurosurgeons from various European countries worked on guidelines during three informal meetings, which may serve as a base for discussion of national or local protocols. Three levels of certainty were distinguished: Measures that must be taken which such a high degree of certainty, that they have not seriously been challenged-principles. Measures, that should be taken, as there is reasonable evidence in the literature about its efficacy-recommendations and measures that may be taken, but proof of its efficacy is lacking-optional measures. Protocols based on these guidelines are felt to help young neurosurgeons in training, define neurosurgical needs for other specialities and enhance the general efficacy of care for the head injured patient including multiple injuries.

Controversies in thromboembolic disease during pregnancy: a critical review

OBJECTIVE

To critically appraise the body of literature concerning strategies for the prevention of thromboembolism during pregnancy.

DATA SOURCES

We used the Medline data base and reference lists of articles to identify all English-language papers examining thromboembolism during pregnancy.

METHODS OF STUDY SELECTION

We identified 156 articles in the obstetric literature and 29 articles in the medical literature that referenced nonpregnant populations. Together, these articles form the primary data base on which most recommendations are based.

DATA EXTRACTION AND SYNTHESIS

There are no level 1 trials (large randomized trials with definitive results) in the obstetric literature examining the efficacy of thromboembolism prophylaxis during pregnancy. There are only two level 2 trials (small randomized trials with uncertain results because of moderate to high alpha or beta error) that address prophylactic strategies in pregnant women with histories of thromboembolism or the antiphospholipid antibody syndrome. The remainder of the published trials are observational, some prospective but predominantly retrospective. Many of the recommendations from consensus panels regarding prophylactic strategies in pregnancy were based on level 1 trials in nonpregnant populations.

CONCLUSION

Although women with a history of thromboembolic disease are at appreciable risk of recurrence during pregnancy, the exact incidence is unknown and there are no adequate efficacy trials demonstrating that prophylactic regimens are effective. Heparin is the anticoagulant of choice in pregnancy; however, changes in metabolism and clearance make adequate dosing problematic. Expert consensus panels disagree over the optimal management of pregnant women at risk for thromboembolism. Randomized controlled trials during pregnancy are needed if any progress is to be made in combating this lethal disorder.

Computerised transient hyperaemic response test--a method for the assessment of cerebral autoregulation

A simple bedside test has been developed to assess the state of autoregulation in subarachnoid haemorrhage patients. Transcranial Doppler was used to measure blood flow velocity in the middle cerebral artery after a brief common carotid compression. Acceleration of blood flow postcompression was interpreted as evidence of intact cerebral autoregulation. A program using the Windows environment was designed for signal analysis of the transient hyperaemic response test (THRT). The flow velocity signal from the TCD was recorded, carotid compression and release automatically detected and the test results immediately displayed and stored in a database. The program was verified in 614 tests; 552 of them were analysed off-line using previously recorded data and 62 on-line during the examination. A significant correlation was found between the results of computerised testing and the patient's neurological state.

Assessment of cerebral autoregulation with ultrasound and laser Doppler wave forms--an experimental study in anesthetized rabbits

The aim of the study was to correlate changes in transcranial Doppler blood flow velocity wave form in the basilar artery with cortical red blood cell flux measured with a laser Doppler flowmeter during hemorrhage-induced hypotension in anesthetized and ventilated New Zealand rabbits. Although systolic flow velocity and flux exhibited an autoregulatory threshold at 45 mm Hg, diastolic flow velocity started to fall when mean arterial blood pressure fell below 65 mm Hg. The difference between the mean arterial blood pressure at which diastolic blood flow velocity decreases and the pressure at which mean flux decreases is the difference between systolic and diastolic blood pressure. The increasing divergence between systolic and diastolic flow velocities was reflected in an increase in the amplitude of blood flow velocity pulsations and pulsatility indices. An increase in flux pulsatile wave form was noted as cerebral resistive vessels dilated with hypotension.

Symmetry of cerebral blood flow and cognitive responses to hypoglycaemia in humans

A low blood glucose level is associated with impairment of higher cerebral function and an increase in cerebral blood flow. This study examined whether there are differences in the physiological responses to hypoglycaemia between the cerebral hemispheres. Eight healthy men participated in two hyperinsulinaemic glucose clamp studies: after 60 min at 4.5 mmol/l, blood glucose was either lowered to 2.0 mmol/l and "clamped" there for 60 min (hypoglycaemia) or continuously maintained at 4.5 mmol/l (euglycaemia). Cardiac output, middle cerebral artery velocity (transcranial Doppler) and cerebral blood flow (133-xenon inhalation) were measured during the studies. Neuropsychological tests were used to determine whether hypoglycaemia caused differential impairment of hemispheric cognitive function. Hypoglycaemia was associated with symmetrical impairment of cognitive function in both cerebral hemispheres and a rise in cardiac output (from 5.5 [0.2] to 8.7 [0.2] l.min-1, p < 0.0001, mean [standard error]), middle cerebral artery velocity (from 55 [2.6] to 64 [2.8] cm.s-1, p < 0.002), and global cerebral blood flow (from 56 [2.6] to 69 [2.9] ml.100 g-1.min-1, p < 0.005 compared to pre-insulin values). There were no differences in the blood flow response during hypoglycaemia between hemispheres and the increase in blood flow did not correlate with either the change in cardiac output or rise in plasma catecholamine levels. After 120 min of hyperinsulinaemic, euglycaemia, global cerebral blood flow rose significantly above baseline (from 58 [2.4] to 63 [2.2] ml.100 g-1.min-1, p < 0.05). In conclusion, using the techniques described, the physiological and cognitive responses of each cerebral hemisphere to hypoglycaemia were symmetrical.(ABSTRACT TRUNCATED AT 250 WORDS)

The hyperaemic response to a transient reduction in cerebral perfusion pressure. A modelling study

A mathematical model of cerebral blood flow and the cerebrospinal fluid circulation is described which permits the study of phenomena caused by dynamic changes in cerebrovascular autoregulatory or cerebrospinal fluid compensatory reserves. A transient decrease in cerebral perfusion pressure was produced by carotid artery compression. Comparison of the computer simulations with clinical and experimental data, reported elsewhere, suggests that the transient hyperaemic response (THR) is proportional to the strength of the autoregulatory response. The relationships between the magnitude and time course of the THR, and the period and level of reduction in CPP were studied. This model suggests that simple clinical tests based on the examination of THR using transcranial Doppler velocity measurements are of potential value for the non-invasive assessment of the autoregulatory reserve.

Technological Change in Fences and European Pastoral Heritage in Semi-Arid New South Wales

Despite increasing attention to conservation of natural resources and Aboriginal heritage, relics of the European pastoral industry in the semi-arid rangelands have been neglected. Fences are ubiquitous relics of the pastoral industry and show a rich variety in styles, techniques and technological change. Examples from Wilcannia in western New South Wales illustrate the variety that can be found. Legislation in New South Wales prohibits disturbance of relics (items > 50 years old) but has not been applied. The key step is assessing the significance of the item or place. Criteria adopted under The Burra Charter are listed and briefly discussed. Costs of conservation should be borne by society, not individual graziers; and grazier cooperation is essential for conserving cultural heritage.

Reversible cortical blindness as a complication of rheumatoid arthritis of the cervical spine

A case is presented in which a patient with rheumatoid damage to the cervical spine causing cervical cord and vertebral artery compression sustained transient cortical blindness with a partial left hemiparesis. Magnetic resonance imaging revealed anterior subluxation of middle cervical vertebrae, separation of the odontoid peg with resultant atlantoaxial subluxation, and proliferative pannus formation. The patient was almost symptom-free after transoral decompression and posterior cervical fusion.

Preventive care in diabetes mellitus. Current practice in urban health-care system

Early identification and treatment of complications of diabetes mellitus may reduce the severity of the complications. As part of a program to reduce these complications in the Denver Department of Health and Hospitals patient population, our study determined how frequently preventive care, e.g., fundoscopic examinations, referral to an ophthalmologist, foot examinations, and assessment of cardiovascular risk factors, was provided to diabetic patients. With the use of billing records to identify a large sample of diabetic patients, a chart review of 544 patients was conducted. During the study year, the mean +/- SE number of visits to primary-care clinics was 5.7 +/- 0.22, with 86.4% having at least one visit. Most diabetic patients were seen by primary-care physicians; only 9% received care in a specialized diabetes clinic. Despite frequent primary-care visits, most diabetic patients in this county health-care system did not have documentation of care to detect complications of diabetes mellitus, and referral services for detection and treatment of these complications were infrequently used. Moreover, among patients seen on greater than or equal to 10 occasions in a primary-care setting, preventive care was not provided to 30% of the patients. Preventive care does not appear to be a regular part of a primary-care visit for most of the diabetic patients in this study.