Three births after preimplantation genetic diagnosis for cystic fibrosis with sequential first and second polar body analysis

OBJECTIVE

The purpose of this study was to determine the accuracy and feasibility of sequential polar body removal and analysis for preimplantation genetic diagnosis of mendelian disorders.

STUDY DESIGN

Three couples with risk factors for cystic fibrosis had preimplantation genetic diagnosis with the use of sequential polar body analysis. After stimulation, oocytes were harvested and the first polar bodies were removed and analyzed on the day of aspiration. The following day, after fertilization, the second polar bodies were aspirated. Only embryos known to have inherited the normal maternal allele were transferred.

RESULTS

All three couples had successful pregnancies resulting in the births of unaffected infants.

CONCLUSIONS

Preimplantation diagnosis with the use of sequential polar body removal is feasible and can prevent the establishment of genetically abnormal pregnancies for couples at risk.

Age, hypertension, and cardiac responses to beta-agonist in humans

OBJECTIVES

To evaluate the effects of hypertension on heart rate and left ventricular responses to beta-agonist in young and older subjects, as well as the modulating effect of the arterial baroreflex on these responses.

METHODS

Isoproterenol (INN, isoprenaline) alone was infused in 14 young normotensive subjects (mean age, 30 +/- 2 years), 18 older normotensive subjects (mean age, 60 +/- 2 years), 11 young hypertensive subjects (mean age, 36 +/- 1 years), and 17 older hypertensive subjects (mean age, 59 +/- 1 years); isoproterenol combined with ganglionic blockade (trimethaphan [INN, trimetaphan]) was administered to eight young normotensive subjects and eight young hypertensive subjects. Isoproterenol was infused at three to four incremental rates, each rate for 8 minutes. Left ventricular responses were assessed by echocardiography.

RESULTS

Isoproterenol caused similar increases in heart rate in all four groups. With ganglionic blockade, heart rate responses were enhanced but were similar in the young normotensive and hypertensive subjects. In young subjects, hypertension did not affect left ventricular responses to isoproterenol alone, whereas older hypertensive subjects showed some blunting of left ventricular responses compared with older normotensive subjects. With ganglionic blockade, young hypertensive subjects also showed mild blunting of left ventricular responses.

CONCLUSION

These results show that, in humans, hypertension does not lead to a decrease in chronotropic responses to infusion of the beta-agonist isoproterenol and causes only a modest decrease in left ventricular responses.

Influence of sepsis on the plasma elimination pharmacokinetics of diaspirin crosslinked hemoglobin in rats

Septic shock is characterized by abnormalities in microcirculatory O2 delivery (QO2) and profound tissue O2 debt. Administration of crosslinked hemoglobin may be a means of augmenting the QO2 and tissue O2 availability. Sepsis is associated with hemodynamic and metabolic alterations which may affect the pharmacokinetics of crosslinked hemoglobin. The objective of this study was to determine the effect of sepsis on the plasma elimination of diaspirin crosslinked hemoglobin (DCLHb). Twenty-four hours after the induction of sepsis by cecal ligation and perforation, septic (n = 9) and sham rats (n = 8) received an intravenous infusion of 300 mg of DCLHb and arterial blood samples were taken at regular intervals to determine free plasma hemoglobin concentration. DCLHb elimination in septic and sham rats was consistent with first-order elimination kinetics. The half life (t1/2) for septic rats was 4.2 +/- 0.7 h and was significantly shorter than the t1/2 of non-septic rats (5.4 +/- 0.9 h). In all rats, free plasma hemoglobin returned to basal levels by 24 hours after DCLHb administration. The volume of distribution for DCLHb in the septic and non-septic rats was not significantly different and suggests that DCLHb is not influenced by altered gut permeability. Despite significant changes in some elimination parameters the differences were small. Consequently, dosing regimens for this compound may not need to be altered in sepsis.

Preimplantation diagnosis of common aneuploidies by the first- and second-polar body FISH analysis

PURPOSE

A low pregnancy rate in in vitro fertilization (IVF) patients of advanced maternal age may be caused by aneuploidies originating from non disjunction in the first or second meiotic divisions. We introduced genetic testing of oocytes by sampling and fluorescent in situ hybridization (FISH) analysis of the first and second polar bodies, to avoid fertilization and transfer of aneuploid oocytes in IVF patients of advanced maternal age.

METHODS

Three hundred and sixty-three IVF patients 34 years and older participated in the study. Using micromanipulation procedures, the first and second polar bodies were removed following their extrusion from the oocytes and studied by FISH, using probes specific for chromosomes 13, 18, and 21 to detect oocytes with common aneuploidies.

RESULTS

Of a total of 538 IVF cycles, 3250 oocytes were available for FISH analysis, with conclusive FISH results in 2742 oocytes (84.3%). As many as 1102 (40%) of oocytes were predicted to be aneuploid and not transferred. Of 1640 embryos predicted to be normal, 1145 were transferred in 467 treatment cycles, resulting in 107 pregnancies (23%), from which 67 healthy children have been born, 32 pregnancies spontaneously aborted, and 15 pregnancies are ongoing after being confirmed normal by prenatal diagnosis.

CONCLUSIONS

Preimplantation diagnosis by first- and second-polar body FISH analysis allows us to avoid the age-related risk of common aneuploidies in IVF patients of advanced maternal age.

Techniques to evaluate elderly human muscle function: a physiological basis

Elderly persons appear to exhibit muscle weakness and a slowing in their speed of muscle movement. Objective quantification of these characteristics requires reliable and practical tests to assess the muscle contractile characteristics of elderly people. This review discusses the advantages and limitations of voluntary and electrically stimulated muscle testing techniques used to assess the strength, speed, and fatigability of elderly muscle with a brief explanation of the physiological basis. This review presents the practice and theory underlying the scientific measurement of elderly human muscle function, bridging the gap between the practical issues of measurement and the physiological significance of such measurements.

Poly(vinyl alcohol) synthetic polymer foams as scaffolds for cell encapsulation

Poly(vinyl alcohol) (PVA) foams were used as scaffolds in hollow fiber membrane-based cell encapsulation devices. The surrounding permselective membrane serves as an immunoisolation barrier while allowing metabolites and other small molecules to be freely transported. The internal matrix defines the microenvironment for the encapsulated cells. PC12 cell-containing devices represent one possible strategy for safe transplantation of dopamine-secreting cells for the treatment of dopamine-deficient diseases such as Parkinson's disease. PC12 cells--a dopamine-secreting cell line--were encapsulated with PVA foam as a matrix material in the lumen of these hollow fibers. In this work, we demonstrate the presence of the PVA matrix increased the catecholamine secretion efficiency of the cells as compared to devices containing a chitosan matrix. Devices were implanted in vivo into rodent striatum and device output of catecholamines was measured preimplant and post-explant. Evoked stores of dopamine remained constant (preimplant vs explant) for devices encapsulated with the foam matrix and increased with devices encapsulated with chitosan matrix. Cell proliferation within devices was inhibited in the presence of the foam matrix. Cell viability and distribution was significantly improved with the inclusion of the foam matrix in both in vitro and in vivo studies. In comparison to chitosan--a typical matrix material for PC12 cells--addition of a foam-type matrix altered the encapsulated cell microenvironment and resulted in more efficient secretion of catecholamines and improved distribution within the device resulting in smaller necrotic regions and a lower rate of cell proliferation.

Detection of translocations involving the Y-chromosome in prospective prenatal screening of common chromosomal aneuploidies by FISH

In the application of the fluorescence in situ hybridization (FISH) technique for prospective prenatal screening of common aneuploidies involving the autosomes 13, 18, and 21, and sex chromosomes, six cases of inconsistency between the results of FISH analysis and the results of karyotyping of cultured amniocytes have been observed, including two cases of translocation involving the Y-chromosome and chromosome 15 in a total of 904 cases of amniocentesis studied. In one case, the translocation was of maternal origin, and in the other, of paternal origin. In both cases, the couples decided to continue the pregnancy and normal babies were delivered. The data show the usefulness of applying the FISH technique in prospective prenatal screening of common trisomies for the possible detection of rare chromosome rearrangements involving the Y-chromosome.

Pharmacokinetics of propofol during conscious sedation using target-controlled infusion in anxious patients undergoing dental treatment

Infusion of propofol by a target-controlled infusion (TCI) system is effective in achieving conscious sedation for anxious patients presenting for dental surgery. It is a common clinical observation that anxious patients require more anaesthetic drugs than non-anxious individuals. In study 1 we have defined blood propofol concentrations necessary for conscious sedation in both anxious (n = 23) and non-anxious (n = 18) patients. The pump performance of the TCI system, using Gepts' pharmacokinetic model, was evaluated in these two patient groups. Subsequently, clearance of propofol was compared in the two groups. Mean measured venous serum propofol concentrations obtained between 20 and 35 min after the optimal sedation level was reached were 1.6 (SD 0.2) micrograms ml-1 in the anxious patients compared with 1.7 (0.3) micrograms ml-1 in the control group (study 1) and 1.4 (0.27) micrograms ml-1 in study 2. The pump systematically overpredicted measured propofol concentrations in both groups (study 1). There was no significant difference in propofol clearance between the two groups. In study 2, an optimized set of microconstants was derived which should more accurately predict the pharmacokinetic profile of the anxious population and this set was tested prospectively in another group of 12 anxious dental patients. Bias and precision with the optimized kinetic set were significantly less than the values obtained in study 1. We conclude that there was no significant pharmacokinetic differences between anxious and non-anxious subjects receiving subanaesthetic doses of propofol for conscious sedation.

Early life and later determinants of adult disease: a 50 year follow-up study of the Newcastle Thousand Families cohort

The relative contribution of socioeconomic, behavioural and biological factors operating in fetal and infant life, childhood and adulthood to risk for cardiovascular disease, respiratory diseases and non-insulin-dependent diabetes in middle age has become an important research issue. All 1142 babies born in Newcastle upon Tyne in May and June 1947 were recruited into a prospective cohort study of child health (the 'Thousand Families' study) and followed in great detail to the age of 15 y, with a brief further follow up at age 22 y. Children from poorer families were at greatest risk of severe respiratory tract infection in infancy. Children from professional and managerial families were on average taller and heavier throughout childhood than those from semi- and unskilled manual social classes. Repeated infections in early childhood greatly increased the risk of developing chronic respiratory disease by age 15 y. This paper outlines a new investigation designed to trace surviving members of this cohort and to chart the relationships between their socioeconomic circumstances, lifestyles, experiences and health from birth through to the present day. Existing data on socioeconomic circumstances and infections in infancy and childhood, infant nutrition, birthweight and physical development to age 22 y will be linked to information gained from a new study. This comprises a postal questionnaire survey of study members' adult health, socioeconomic circumstances and lifestyle, and a hospital based clinical examination including heart and lung function, glucose tolerance, blood lipids and anthropometric measurements at age 49-51 y. Out of a target sample of 979 people for whom sufficient data are available on the first year of life, 866 (88%) have been traced and 649 are still resident in the North of England. Those study members who have been traced are highly representative of the original cohort. The Thousand Families cohort provides a unique opportunity for detailed epidemiological study because of the wealth of data available on infant and childhood socioeconomic and family circumstances, all of which was collected prospectively. In addition, there has been comparatively little loss to follow-up since 1948.

Developing a medical school alcohol policy

The health and lifestyle problems of medical students and doctors give cause for concern on several fronts. We have developed a health policy for staff and students in Newcastle Medical School. This policy presents integrated recommendations relating to six key areas, i.e. alcohol, physical activity, sexual health, stress, occupational health and safety, and diet. The methods used to develop recommendations in relation to alcohol are described here. They were adopted by the working groups developing recommendations in the other areas. There were four key stages to policy development: establishing an information base; preparing a draft policy for consultation; consulting staff and students, and finalizing the policy. Consultation was a slow and challenging process but led to substantial revisions to the policy, enhancing its acceptability and likely success. The final policy includes a 3-year implementation plan setting out actions, resource implications and key players. Our policy, which has been adopted by the medical school and will soon be implemented, includes recommendations regarding changes to the school environment, training and education needs for staff and students, and access to services for those with alcohol related problems. Health policies should be developed in other medical schools and our approach offer a possible model.

Impaired endothelin-1 release in tilt-induced syncope

The neurohumoral events associated with neurocardiogenic syncope remain unclear. The simultaneous assessment of changes in endothelium-dependent and independent hormones and in autonomic balance in patients with tilt-induced syncope has been incompletely studied. Forty-six healthy subjects aged between 21 and 83 years (mean +/- SEM 47 +/- 3) underwent a 30-minute head-up tilt test at 60 degrees. Fourteen subjects (10 females and 4 male subjects) exhibited syncope at 16 +/- 2 minutes into the tilt. Hemodynamics were recorded every 5 minutes and blood samples for the measure of catecholamines, endothelin-1 (ET-1), and angiotensin-II (AT-II), were drawn at baseline, and 5, 10, 15, and 30 minutes into the tilt and immediately before syncope. Heart rate variability was analyzed by 5-minute segments during the test. Both catecholamines and ET-1 levels increased consistently in response to head-up tilt in subjects able to tolerate the test. Epinephrine increased to a greater extent before syncope. In contrast, ET-1 failed to increase at any time during the tilt and just before syncope. AT-II increased at 30 minutes into the tilt only in the control group. Finally, power in high-frequency bands decreased less in the group with syncope. Thus, compared with subjects able to tolerate a head-up tilt test, patients with syncope exhibit a greater increase in adrenomedullary activation, no significant increase in ET-1 levels, and a blunting in the decrease of vagal tone before syncope. The lack of increase in ET-1 during tilt may play a role in the inability to support orthostatic stress.

Quality of life after pouch excision

BACKGROUND

Pouch excision is a devastating experience for patients having restorative proctocolectomy for ulcerative colitis.

METHODS

The quality of life among patients having pouch excision for ulcerative colitis was compared with that in those having proctocolectomy and ileostomy for ulcerative colitis using a validated standardized self-administered questionnaire.

RESULTS

After pouch excision patients (n = 9) had more troublesome bowel symptoms (mainly from liquid stoma output) than those in the proctocolectomy group (n = 14) (mean(s.d.) score 5.64(0.92) versus 6.13(0.37), P = 0.03). However, the mean scores for the other parameters (systemic symptoms, functional, social and emotional impairment) did not differ significantly.

CONCLUSION

Patients having pouch excision for ulcerative colitis have more liquid ileostomy loss but a comparable quality of life to those treated by standard proctocolectomy and ileostomy.

Cluster analysis applied to building-related illness

Identifying remediable causes of occupant symptoms in building-related illness is frequently difficult. This is particularly true when the building-wide prevalence of symptoms is comparable to that reported in non-problem buildings. This analysis applied an epidemiological approach to an assessment of a problem building, allowing investigators to visually identify an area of apparent increased symptom density. A cluster analysis approach permitted biostatistical confirmation of the visual cluster. Building-related symptom reporting was statistically significantly associated with a prior physician diagnosis of dust and/or mold allergy. The likely etiology of building occupant symptoms was identified within the region implicated by the cluster analysis. This approach may be useful to focus building evaluations on both the likely physical source and general characteristics of suspect etiologic agents.

Physician-assisted suicide: reflections on Oregon's first case

The authors analyze Oregon's first reported assisted suicide of Mrs. A as a real life application of the Oregon Death with Dignity Act. They critique the effectiveness of the Act's safeguards as illustrated by the case of Mrs. A. They point out that the Act does not require that physicians be adequately trained in palliative care in order to participate in assisted suicide. Most physicians do not have such training. Without it, they are not able to effectively present alternatives to patients requesting assisted suicide. Most physicians also lack the expertise to assess patients' decision-making capacity. Nor does the Act ensure that physicians will be in a position to assess coercion of patients' decisions. The Act requires physicians to report only minimal information about their cases, and there are no enforcement provisions to see that even this is done. Under the Act, a good faith standard rather than the more usual negligence standard immunizes physicians from civil or criminal liability even when they act negligently. The authors demonstrate that the Act protects physicians more than patients, and encourages secrecy. The authors conclude that secrecy will need to be replaced by openness to permit the kind of examination the practice of assisted suicide warrants.

Combination neurohormonal blockade with ACE inhibitors, angiotensin II antagonists and beta-blockers in patients with congestive heart failure: design of the Randomized Evaluation of Strategies for Left Ventricular Dysfunction (RESOLVD) Pilot Study

BACKGROUND

The Randomized Evaluation of Strategies for Left Ventricular Dysfunction (RESOLVD) Pilot Study is a trial of combination neurohormonal blockade using an angiotensin II antagonist (candesartan), an angiotensin-converting enzyme inhibitor (enalapril) and a beta-blocker (metoprolol) in patients with congestive heart failure (CHF).

OBJECTIVES

Primary objectives of stage I are to determine the efficacy (via the 6 min walk test) and safety of candesartan alone, and in combination with enalapril, versus enalapril alone. Secondary objectives are to determine the effect of the above combinations on neurohormones, ventricular function, quality of life and symptoms. Stage II objectives are similar, evaluating the effect of the addition of metoprolol or placebo to the above medication(s).

DESIGN

Randomized, two-stage trial consisting of a three-way comparison (stage I), followed by a 3 x 2 partial factorial design (stage II).

SETTING

Sixty out-patient clinics in five countries.

PATIENTS

Patients with symptoms of CHF (New York Heart Association functional classes II to IV), ejection fraction less than 40% and 6 min walk distance of 500 m or less.

INTERVENTIONS

In stage I, 770 patients are randomized to receive candesartan alone, enalapril alone, or candesartan plus enalapril. After five months (end of stage I), patients are assessed for eligibility to be randomized in stage II. Those who are not candidates for randomization to beta-blocker or placebo are followed on their stage I medications until the end of the study. In stage II, patients are randomized to receive metoprolol or placebo for a further six months in addition to their stage I medications. Endpoints are measured at baseline, end of stage I (week 20) and end of stage II (week 46). STUDY STATUS: The study has recently completed follow-up in both stages. The findings from this study will be used to design a large scale mortality study that will help further define the role of neurohormonal blockade in patients with CHF.

Family dynamics of families with mental health problems in Finland

This study forms part of the International Family Dynamics Project. Its purpose was describe the family functioning of families with mental health problems on the basis of Barnhill's framework for healthy family systems. The sample consisted of 160 families in which one family member had mental health problems. Both the patients and their relatives took part. The data were collected by questionnaires, i.e. The Family Dynamics Measure and The Family Dynamics Questionnaire. According to the results, mental health patients described family functioning as fairly poor, while relatives described it as fairly good. However, patients' and relatives' perceptions of family functioning did not differ significantly. There were some statistically significant differences between patients' and relatives' perceptions of different family dynamics dimensions. Relatives reported more mutuality (P = 0.006) and clearer communication (P = 0.009) than patients. Older mental health patients reported more isolation than patients under 30. Relatives who mentioned some serious illness in the family reported more role conflict than those who didn't. No differences were found by gender, family structure or education. The results indicated that the mental health problems of a single family member did not impair family dynamics. The study showed that the resources and functioning of families are fairly good in spite of the illness in the family.

Low levels of cardiovascular risk factors and coronary heart disease in a UK Chinese population

OBJECTIVE

To compare the prevalence of cardiovascular risk factors and coronary heart disease in Chinese and Europid adults.

DESIGN

Population based, cross sectional survey.

SETTING

Newcastle upon Tyne, UK, 1991-93.

SUBJECTS

Altogether 380 Chinese and 625 Europid adults, aged 25-64 years.

MAIN OUTCOME MEASURES

Fasting lipid levels, blood pressure, body mass index (BMI), the proportions who smoked, and the prevalence of coronary heart disease based on the Rose angina questionnaire and major electrocardiographic abnormalities on resting 12 lead electrocardiogram (Minnesota codes 1.1-1.2). All figures were age adjusted to the 1991 England and Wales population.

RESULTS

Altogether 183 and 197 Chinese, and 310 and 315 Europid men and women respectively were seen. Compared with Europid men, Chinese men had a lower mean total cholesterol concentration (5.1 versus 5.6 mmol/l, p < 0.001) and LDL cholesterol (3.2 versus 3.6 mmol/l, p < 0.001); lower BMI values (23.8 versus 26.1 kg/m-2, p < 0.001); and smoked less (23% versus 35%, p < 0.01)). Compared with Europid women, Chinese women also had lower mean lipid levels (total cholesterol: 4.9 versus 5.4 mmol/l p < 0.001, LDL cholesterol: 2.8 versus 3.1 mmol/l p < 0.001); BMI values (23.5 versus 26.1 kg/m-2, p < 0.001); and far fewer were smokers (1.4% versus 33%, p < 0.001). Chinese women, however, had higher mean systolic (121 versus 117 mmHg, p > 0.05) and diastolic (75 versus 68 mmHg, p < 0.001) blood pressures. The prevalence of coronary heart disease was significantly lower in Chinese than Europid men (4.9% versus 16.6%, p < 0.001) but not significantly different in women (7.3% versus 11.1%, p = 0.16).

CONCLUSION

Strategies for UK Chinese are needed to maintain this favourable risk factor profile and prevent any potential increase in the risk of coronary heart disease associated with increasing acculturation.