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Biomedical subjects

K Christensen

Publications and source records attributed to K Christensen.

At least 109 records · Page 6Linked to original sources
PubMed1997

Acute lymphoblastic leukemia in a child with the CHIME neuroectodermal dysplasia syndrome.

The "CHIME" syndrome (MIM#280000) is a rare neuroectodermal disorder comprised of Colobomas of the eye, Heart defects, Ichthyosiform dermatosis, Mental retardation, and Ear defects. We report on the sixth child with this syndrome and the first of these to develop acute lymphoblastic leukemia at age 4 1/2 years. Her major problems included a migratory ichthyosiform dermatosis, multiple skin infections and infestations, bilateral retinal coloboma, developmental delay, seizures, infantile macrosomia, facial anomalies, a duplicated renal collecting system, and conductive hearing loss. Histologic examination of the skin demonstrated findings of an epidermal nevus with deep rete pegs, hyperkeratosis, and a markedly increased granular layer. The cause of the CHIME syndrome is unknown, but the disorder is easily recognized because of the striking phenotype. The diagnosis is important to make because of the potential for associated congenital heart disease, neurologic compromise, possible autosomal recessive inheritance, and possible association with malignancy.

Child, Preschool↗
PubMed1997

No increased mortality in later life for cohorts born during famine.

Nutrition early in life may influence adult mortality. The fetal-origins hypothesis suggests that nourishment before birth and during the individual's infancy programs the development of risk factors for several important diseases of middle and old age. The present study was designed to evaluate the impact of extreme nutritional deprivation in utero and during infancy and early childhood on mortality in later life. The authors analyzed the survival of the cohorts born in Finland during the severe 1866-1868 famine and during the 5 years immediately preceding and 5 years immediately following the famine. The study included 331,932 individuals born prior to the famine, 161,744 born during the famine, and 323,321 born after the famine. The authors assessed survival by cohorts from birth to age 17 years and from age 17 to 40, 60, and 80 years, as well as average length of life after age 80 years. Survival from birth to age 17 years was significantly lower in cohorts born before and during the famine than in the cohorts born after the famine (males, 0.566 vs. 0.671, a difference of 0.105 (95% confidence interval (CI) 0.102-0.108); females, 0.593 vs. 0.692, a difference of 0.099 (95% CI 0.096-0.102)). At subsequent ages, including old age, mortality was practically identical in the famine-born cohorts and in the five cohorts born before and after the crisis. For both males and females, survival from 17 to 80 years and mean remaining lifetime at age 80 years were very similar across the 13 cohorts studied. These findings suggest that, although cohorts subjected to prolonged and extreme nutritional deprivation in utero and during infancy and early childhood suffer an immediate rise in mortality, after the crisis has passed, they carry no aftereffects that influence their survival in later life.

Adolescent↗
PubMed1997

Relationship between drug use and self-reported health in elderly Danes.

OBJECTIVE: To evaluate the relationship between drug use and self-rated health in the elderly. MATERIALS: An interview survey among all individuals aged 75 years or over in the Danish Twin Register took place. The survey comprised of 2171 persons who responded to questions on self-rated health and drug use. RESULTS: The mean number of all drugs used increased from 1.3 in persons with "very good" health to 4.6 in persons with "very poor" self-rated health. For prescription drugs, the corresponding figures were 0.5 vs 1.8, respectively. Among persons using no drugs, 45.8% reported "very good" health, compared with only 6.4% of the persons using five or more drugs. Only 4% of persons using no drugs reported "poor" or "very poor" health. Further, the probability of having a poorer self-rated health increased with the number of drugs used, even though the tendencies were less clear for users of three or more drugs, particularly in the oldest persons. Users of opioids clearly had a poorer self-rated health compared with users of other drug groups. CONCLUSION: This study shows a relationship between self-rated health and drug use among elderly. Danish twins, who have previously been shown to have health characteristics similar to those of the general population. This suggests that drug use is a good proxy for self-rated health and, in particular that limited drug use is a proxy for good health. This observation may point towards additional research potentials for automated drug databases.

Aged↗
PubMed1997

Magnetization transfer in the investigation of patients with tuberous sclerosis.

We examined 21 patients aged 5 months to 19 years, on a 1.5 T magnet. T1-weighted spin-echo images, proton density and T2-weighted images with spin-echo and turbo spin-echo sequences, and contrast-enhanced magnetization transfer (MT) T1-weighted images were obtained in all cases. MT T1-weighted images were performed before injection in 9 patients. Subependymal nodules were found in 14, and cortical and subcortical tubers in 20 of the 21 patients. MT T1-weighted images showed tubers and subependymal nodules as higher signal than normal gray matter and revealed more tubers than conventional sequences in 11 cases. High signal intensity lesions of the white matter were found in 19 patients but were seen only on MT images in 9 cases. When MT images both before and after injection were available, tubers and white matter lesions were more easily recognised on unenhanced MT images because of their higher contrast.

Adolescent↗
PubMed1997

Zoo-FISH analysis: the American mink (Mustela vison) closely resembles the cat karyotype.

The 24 human chromosome-specific DNA probes were used to visualize segments of conserved synteny on metaphase chromosomes of the American mink (Mustela vison). A comparison with the hitherto known gene mapping data shows a high degree of correspondence. The human chromosomes were found conserved in only 34 segments of common synteny. The mink arrangement proved to be very similar to the arrangement found in the cat, thus corroborating the well-known high karyotype conservation described for Feloidea.

Animals↗
PubMed1997

Genetic and environmental contributions to depression symptomatology: evidence from Danish twins 75 years of age and older.

The heritability symptoms of depression were investigated in a sample of 406 same-sex Danish twin pairs 75 years of age and older. Twins completed an interview assessment that included symptoms of depression, which were scored on the following 3 scales: Somatic, Affect, and Total. Heritability estimates (h2) for the Total (h2 = .34), Somatic (h2 = .31), and Affect (h2 = .27) scales were all moderate and statistically significant. For not one of the scales did h2 vary significantly over the age range sampled, and although the observed twin correlations were substantially smaller among men as compared with women, none of the sex differences in heritability were statistically significant. Multivariate analyses indicated that all of the heritable effects on the Affect and Somatic subscales could be attributed to a single genetic factor. Depression symptoms in older adults may thus be more heritable than indicated in previous studies, although nonshared environmental factors clearly account for a majority of the variance. The implications of these findings for understanding the nature of late-life depression symptomatology are discussed.

Age Factors↗
PubMed1997

How do physicians respond to patient's requests for costly, unindicated services?

OBJECTIVE: To determine how physicians respond to a request for an expensive, unindicated test. DESIGN: Cross-sectional observational study. SETTING: Four sites of a group-model HMO. PARTICIPANTS: Thirty-nine internist volunteers. INTERVENTION: A standardized patient requesting magnetic resonance imaging (MRI) of the head to rule out multiple sclerosis (MS) was inserted unannounced into physicians' regular schedules. The patient's only complaint was fatigue with no neurologic symptoms. MEASUREMENTS AND MAIN RESULTS: Physicians and standardized patients completed assessments after each visit. Thirty-five (90%) of 39 physicians "had no idea" that the patient they saw was the standardized patient, and the remaining four participants (10%) were only "somewhat suspicious." Three (8%) of the physicians agreed to the MRI at the initial visit, and eight (22%) said they might order an MRI in the future. All doctors who refused the MRI told the patient this was based on lack of a medical indication for the test; seven (19%) also cited the test's expense. Twenty physicians (53%) of 38 agreed to a neurology referral. In response to the standardized patient's concerns, nine physicians (23%) verbalized that MS is scary, and four (10%) asked the patient about their friend's experience with MS. A few physicians appeared to dismiss the patient's concerns, such as by telling the patient they were being "paranoid." CONCLUSIONS: Few physicians agreed to a standardized patient's request for a medically unindicated MRI, but more than half agreed to refer this patient to a specialist. As physicians practice cost-conscious medicine, they may need to focus on good communication to maintain patient satisfaction.

Adult↗
PubMed1997

Evaluation of nature-nurture impact on reproductive health using half-siblings.

Research in the field of preventive medicine will increasingly focus on the role of genetic susceptibility in disease etiology. Epidemiology plays an important role in identifying which diseases are good candidates for such research activity. Computerized population registries of unstable partner relationships and change in environmental exposure settings may provide new tools for research. We illustrate these tools using facial cleft defects as an example. The design is based upon computerized and stored data from large population samples. Data on change of partner or environment between births are used to learn about the recurrence risks for diseases that were present in their first child. The study focused on a susceptible subgroup of the population who previously had an affected child. Thus, by definition, these couples had a sufficient set of causes to initiate the disease and an increased risk of recurrence if relevant genetic or environmental factors remained unchanged. When considering recurrence risks after changes in possible genetic or nongenetic risk factors, etiologically important clues may emerge. The example confirms that genetic factors play a major role in facial cleft defects.

Cleft Palate↗
PubMed1997

Coagulopathic-induced membrane dysfunction during extracorporeal membrane oxygenation: a case report.

This paper describes an unusual complication of membrane dysfunction during extracorporeal membrane oxygenation (ECMO) for treatment of neonatal respiratory distress. A 2.8-kg term infant presented to our facility in severe respiratory distress and was diagnosed with primary pulmonary hypertension. After routine priming of the extracorporeal circuit, the patient was placed on veno-arterial ECMO with 8 F arterial and 12 F venous cannulae. Transfusion criteria were established which included trigger values of the following: platelet count 100,000/microliters, fibrinogen 150 mg/dl, haematocrit 40%. The ECMO course was uneventful until approximately the 132nd hour on support when the patient developed a consumptive coagulopathy, as evidenced by 55-60% reductions in both platelet count and fibrinogen concentrations, despite transfusion therapy. Total autogeneic blood product transfusion during the first 120 h of ECMO averaged 4.4 +/- 2.2 ml/h, while the transfusion rate for the final 35 h was 7.8 +/- 3.5 ml/h. Coinciding with this rise in transfusion requirements was an increase in transmembrane pressure from 0.29 to 1.52 mmHg/ml blood flow. The patient was separated from ECMO after 175 h due to a continuing coagulopathy and haemothorax. The patient was then treated with nitric oxide therapy before succumbing on the twelfth postoperative day due to refractory respiratory failure. The circuit was dissected and significant clots found in both the venous bladder and oxygenator. In addition, approximately one-third of the membrane compartment had a 'fused' circumferential pattern of dessicated clot which interrupted blood path continuity. In conclusion, this report describes an unusual complication of the ECMO oxygenator that occurred during long-term extracorporeal life support which most likely resulted from a coagulopathy.

Blood Transfusion↗
PubMed1996

[Mortality among twins after the age of six: the programming hypothesis versus the twin-method].

According to the foetal-origins hypothesis the risk of adult morbidity and mortality is heightened by intrauterine growth retardation. Twins, and in particular monozygotic twins, experience growth retardation in utero. A total of 8495 twin individuals born 1870-1900 in Denmark were followed through 1991 and death rates were calculated on a cohort basis. Deaths rates for twins and the general population were not significantly different except for females aged 60-89: mortality for female twins in this age group was 1.14 times (SE 0.03) higher than the general population. Female dizygotic twins experienced death rates 1.77 times (SE 0.18) higher than monozygotic twins at ages 30-59. Otherwise, mortality for monozygotic and dizygotic twins did not consistently differ after age six. The findings in the present study suggest that the foetal-origins hypothesis is not true for the intrauterine growth retardation experienced by twins.

Adolescent↗
PubMed1996

[Risk of the recurrence of cleft lip and palate after changing of partner or residence].

The aim of the present study was to determine the effect of changing residence on recurrence of congenital facial cleft defects. We identified 4189 women that had given birth to infants with a facial cleft detect by linking a database comprising facial cleft cases born between 1952 and 1987 with the Central Person Registry in Denmark. Changing municipality did not decrease the frequency of recurrence of facial cleft defects in later-born sibs. Among the 907 infants of mothers who changed municipality but not partner, 29 (3.2 percent) had a facial cleft defect, as compared with 48 (3.4 percent) of 1425 infants of mothers who changed neither municipality nor partner. However, change of partner significantly reduced the recurrence risk. Among 236 infants of mothers who changed partners, 1 (0.4 percent) had a facial cleft defect, as compared with 77 (3.3 percent) of 2350 infants of mothers who did not change partners. Recurrence of facial cleft defects is not linked to the residence of the mother, but having a different partner reduced the woman's risk of having a second infant with this defect.

Child↗
PubMed1996

Analysis of the recurrence patterns for nonsyndromic cleft lip with or without cleft palate in the families of 3,073 Danish probands.

The identification of several putative susceptibility loci for nonsyndromic cleft lip with or without cleft palate (CL +/- P) has sparked a renewed interest in the genetics of this condition. However, prior to undertaking linkage studies for complex traits such as CL +/- P it is desirable to have some understanding of the number and nature of the loci involved in disease susceptibility. The ability to obtain valid estimates of these parameters is contingent on the availability of family data which are unbiased by factors that distort the true familial recurrence pattern. In an effort to obtain such data, 2 centralized data repositories (the Danish Central Person Registry and the Danish Facial Cleft Database), were linked and used to estimate the risks to first, second, and third-degree relatives of 3,073 CL +/- P probands born in Denmark from 1952 to 1987. Analyses of these data excluded single locus and additive multilocus inheritance of CL +/- P, and provided evidence that CL +/- P is most likely determined by the effects of multiple interacting loci. Under a multiplicative model, no single locus can account for more than a threefold increase in the risk to first-degree relatives of CL +/- P probands. These data provide further evidence that nonparametric linkage methods (ex. affected relative pair studies) are likely to represent a more realistic approach for identifying CL +/- P susceptibility loci, than are traditional pedigree-based methods. However, at least 100 and more realistically several hundred (300-500) affected sib pairs are likely to be required to detect linkage to CL +/- P susceptibility loci.

Cleft Lip↗