A prospective randomized trial of blastocyst culture and transfer in in-vitro fertilization

The effectiveness of blastocyst culture and transfer in human in-vitro fertilization (IVF) was evaluated in a prospective randomized trial in patients having a moderate to good response to gonadotrophin stimulation. Embryos were transferred either on day 3 after culture to around the 8-cell stage in Ham's F-10 medium supplemented with fetal cord serum, or on day 5 after culture to the blastocyst stage in the sequential serum-free media G 1.2 and G 2.2. The pregnancy rates after transfer on day 3 or day 5 were equivalent, 66 and 71% respectively; however, significantly more embryos were transferred on day 3 (3.7) than on day 5 (2.2). The number of blastocysts transferred did not affect the implantation rate, and pregnancy rates when either two or three blastocysts were transferred were 68 and 87% respectively. The implantation rate of the blastocysts (50.5% fetal heart beat) was significantly higher compared to the cleavage stage embryos transferred on day 3 (30.1%). The percentage of blastocyst development was not affected by the number of 2-pronuclear embryos, or by maternal age. Irrespective of the number of blastocysts formed, pregnancy rates were similar. Furthermore, the pregnancy rate following blastocyst transfer in patients with 10 or more follicles at the time of human chorionic gonadotrophin administration was not affected by patient age. More than 60% of patients having blastocyst culture and transfer had supernumerary embryos for cryopreservation. The establishment of a pregnancy following thaw and transfer confirmed the viability of cryopreserved blastocysts cultured in the absence of serum or co-culture. The ability to transfer just two blastocysts while maintaining high pregnancy rates will therefore help to eliminate high order multiple gestations and improve the overall efficiency of human IVF.

Unwanted sexual experiences reported by nursing students: implications for nurse education and training

This study examined the nature and frequency of unwanted sexual experiences in childhood and adulthood reported by nursing students, using a questionnaire developed from the Sexual Events Questionnaire (Calam & Slade). The questionnaire was distributed to 109 second-year nursing students (90 female and 19 male) for anonymous completion. At the same time a further short questionnaire asked students about their perceptions of the first questionnaire, and how far their course had, up to the present, included consideration of issues related to sexuality. A high level of unwanted sexual experiences was reported. For example: 49 (45.0%) reported having witnessed indecent exposure; 27 (24.8%) reported someone having 'tried unsuccessfully to have sexual intercourse with you against your will'; 14 (12.8%) reported someone having 'succeeded in having sexual intercourse with you against your will'. In the second questionnaire, 74.1% thought that consideration of human sexuality had so far been included in their course either 'not at all' or 'a little', with 19.4% responding 'quite a lot' or 'very much'. It is argued that there is a particular need, for personal and professional reasons, for nursing students to have opportunities to address any unresolved effects of unwanted sexual experiences, and that within the formal curriculum there should be greater consideration of issues related to human sexuality.

Aflatoxin B1 and sulphobromophthalein binding to the dimeric human glutathione S-transferase A1-1: a fluorescence spectroscopic analysis

The binding interactions between dimeric human class alpha glutathione S-transferase A1-1 (GST A1-1) and aflatoxin B1 or sulphobromophthalein (BSP) were characterised. Aflatoxin B1 binds to GST A1-1 with a stoichiometry of 1.1 mol/mol of dimeric enzyme. The binding interaction, which can be described by a hyperbolic saturation isotherm (Kd = 8+/-2 microM), does not induce major structural changes in the enzyme, nor does it inhibit enzymatic activity. The average distance between the single tryptophan residue (Trp20) of GST A1-1 and protein-bound aflatoxin B1 was calculated to be 22.7 A by means of fluorescence resonance energy transfer. The aflatoxin-binding region, according to this calculated distance, was determined to be located in the dimer interface cleft near the crystallographic two-fold axis. Hill-plot analyses suggest that a positive co-operative interaction exists between BSP and the dimeric GST A1-1 (h = 1.6+/-0.1; K' = 14+/-0.6 microM). The binding of BSP induces a conformational change in the enzyme which is accompanied by a decrease in the molecular flexibility and in the solvent-accessible properties of the enzyme's Trp20 residue. Site-directed mutagenesis of Trp20 (Trp20-->Phe) confirms that this residue is situated in the binding environment and although it is not essential for BSP binding, it is involved in the interaction. Furthermore, the structural change associated with BSP binding alters the hyperbolic character of the glutathione saturation curve. This indicates that there may also be a cooperative interaction between glutathione and BSP or that BSP binding induces asymmetric functioning of the two enzyme subunits so that they become unequal in catalytic activity.

A grounded theory approach towards understanding the self perceived effects of meditation on people being treated for cancer

The activities undertaken by people suffering cancer and receiving oncology treatment are known to cause high levels of anxiety. In an oncology clinic in rural Australia, nurses and volunteers promoted the use of meditation to reduce the stress caused by the terminally associated illness and its treatments. The use and self-perceived effects of meditation by cancer sufferers and their partners was explored using a grounded theory approach. Data were gathered and analysed from a series of semi-structured interviews and the findings used to generate theory regarding the use of meditation within the oncology domain. A number of theories were generated by this data and they are discussed in relation to current nursing practice and future research.

The evolution of trypanosomes infecting humans and primates

Based on phylogenetic analysis of 18S rRNA sequences and clade taxon composition, this paper adopts a biogeographical approach to understanding the evolutionary relationships of the human and primate infective trypanosomes, Trypanosoma cruzi, T. brucei, T. rangeli and T. cyclops. Results indicate that these parasites have divergent origins and fundamentally different patterns of evolution. T. cruzi is placed in a clade with T. rangeli and trypanosomes specific to bats and a kangaroo. The predominantly South American and Australian origins of parasites within this clade suggest an ancient southern super-continent origin for ancestral T. cruzi, possibly in marsupials. T. brucei clusters exclusively with mammalian, salivarian trypanosomes of African origin, suggesting an evolutionary history confined to Africa, while T. cyclops, from an Asian primate appears to have evolved separately and is placed in a clade with T. (Megatrypanum) species. Relating clade taxon composition to palaeogeographic evidence, the divergence of T. brucei and T. cruzi can be dated to the mid-Cretaceous, around 100 million years before present, following the separation of Africa, South America and Euramerica. Such an estimate of divergence time is considerably more recent than those of most previous studies based on molecular clock methods. Perhaps significantly, Salivarian trypanosomes appear, from these data, to be evolving several times faster than Schizotrypanum species, a factor which may have contributed to previous anomalous estimates of divergence times.

Portraits of menopause in the mass media

This examination of menopause as presented by the popular print media was conducted in the context of furthering our understanding of the development of attitudes toward menopause. All articles indexed under "menopause" in the Reader's Guide in the years 1981, 1982, 1985, 1986, 1989, 1990, 1993, and 1994 were located and examined. The data revealed that, although there has been an increase in the frequency of articles on menopause in the last 15 years, the media's portrayal of menopause is problematic in several respects: (a) in spite of the increased attention, the information available on menopause through the popular media is minimal and insufficient; (b) there was little variability in terms of perspective, discipline, or focus; almost all were focused on menopause as a negative experience or disease and in need of medical treatment; (c) there was considerable contradiction and inconsistency among the articles with respect to descriptions of menopause and intervention advice for menopausal women; (d) aging, stress, life-style factors, race and ethnicity, exercise and diet were, with few exceptions, ignored or trivialized.

The body mass index-mortality relationship in white and African American women

OBJECTIVE

To examine the association of body mass index to all-cause and cardiovascular disease (CVD) mortality in white and African American women.

RESEARCH METHODS AND PROCEDURES

Women who were members of the American Cancer Society Prevention Study I were examined in 1959 to 1960 and then followed 12 years for vital status. Data for this analysis were from 8,142 black and 100,000 white women. Body mass index (BMI) was calculated from reported height and weight. Associations were examined using Cox proportional hazards modeling with some analyses stratified by smoking (current or never) and educational status (less than complete high school or high school graduate).

RESULTS

There was a significant interaction between ethnicity and BMI for both all-cause (p<0.05) and CVD mortality (p<0.001). BMI (as a continuous variable) was associated with all-cause mortality in white women in all four groups defined by smoking and education. In black women with less than a high school education, there were no significant associations between BMI mortality. For high school-educated black women, there was a significant association between BMI and all-cause mortality. Among never smoking women with at least a high school education, models using the lowest BMI as the reference indicated a 40% higher risk of all-cause mortality at a BMI of 35.9 in black women vs. 27.3 in white women.

DISCUSSION

The impact of BMI on mortality was modified by educational level in black women; however, BMI was a less potent risk factor in black women than in white women in the same category of educational status.

Changes in diet and physical activity affect the body mass index of Chinese adults

OBJECTIVE

To examine the relationship between diet, particularly dietary fat intake, and body mass index (BMI).

DESIGN

Prospective study of adults who participated in the 1989 and 1991 China Health and Nutrition Survey.

SUBJECTS

3484 adults aged 20-45 at baseline (1989) survey.

MEASUREMENTS

Measurement of dietary intake with replicated 24 h dietary recalls. Anthropometric measurements. Measurements of physical activity, smoking habit and socio-economic factors.

RESULTS

Change in fat intake was positively associated with change in BMI in men (beta=0.00036, P=0.0001), and change in physical activity level was inversely associated with change in BMI in women (beta=-0.12, P=0.02). Energy intake, physical activity and major socio-economic factors were related to BMI in cross-sectional analysis.

CONCLUSIONS

Diet is becoming an increasingly important determinant of body weight in this population, where fat and energy consumption has been increasing steadily during the past decade.

Peptide length preferences for rat and mouse MHC class I molecules using random peptide libraries

MHC class I molecules bind short peptides for presentation to CD8+ T cells. The determination of the three-dimensional structure of various MHC class I complexes has revealed that both ends of the peptide binding site are composed of polar residues conserved among all human and murine MHC class I sequences, which act to lock the ends of the peptide into the groove. In the rat, however, differences in these important residues occur, suggesting the possibility that certain rat MHC class I molecules may be able to bind and present longer peptides. Here we have studied the peptide length preferences of two rat MHC class Ia molecules expressed in the TAP2-deficient mouse cell line RMA-S: RT1-A1c, which carries unusual key residues at both ends of the groove, and RT1.Aa which carries the canonical residues. Temperature-dependent peptide stabilization assays were performed using synthetic random peptide libraries of different lengths (7-15 amino acids) and successful stabilization was determined by FACS analysis. Results for two naturally expressed mouse MHC class I molecules revealed different length preferences (H2-Kb, 8-13-mer and H2-Db, 9-15-mer peptides). The rat MHC class Ia molecule, RT1-Aa, revealed a preference for 9-15-mer peptides, whereas RT1-A1c showed a more stringent preference for 9-12-mer peptides, thereby ruling out the hypothesis that unusual residues in rat MHC molecules allow binding of longer peptides.

Body weight change and carotid artery wall thickness. The Atherosclerosis Risk in Communities (ARIC) Study

The impact of weight change in adulthood on cardiovascular disease is controversial. This study examined the association of change in body weight, from young adulthood to middle age, with average carotid artery intimal-medial wall thickness by B-mode ultrasound measured in middle age. Participants were 13,282 men and women aged 45-64 years from the baseline examination of the Atherosclerosis Risk in Communities (ARIC) Study (1987-1989). Weight change was calculated as the difference between weight at the baseline examination and self-reported weight at age 25. White men gained a mean of 9.7 kg; black men, 10.1 kg; white women, 12.0 kg; and black women, 20.8 kg. Weight change was positively, albeit modestly, associated with intimal-medial thickness in black men and white men and in white women, but not in black women. Adjusted for age, examination center, smoking, education, sports activity level, height, and body mass index at age 25, the differences in intimal-medial thickness associated with a 10-kg increment in weight change were 0.016 (95% confidence interval 0.010 to 0.022) mm in white men, 0.008 (95% confidence interval 0.001 to 0.015) mm in black men, 0.013 (95% confidence interval 0.009 to 0.017) mm in white women, and 0.002 (95% confidence interval -0.002 to 0.006) mm in black women. These findings support the hypothesis that weight gain in adulthood promotes atherosclerotic changes in white men and women and in black men.

Nocturnal oxygen and hypercapnic ventilatory response in patients with congestive heart failure

Patients with congestive heart failure and Cheyne-Stokes respiration have a low arterial oxygen saturation, especially during sleep, which can be increased by breathing oxygen. Chronic alterations in blood gases are known to modulate the hypercapnic ventilatory response (HCVR). We therefore evaluated whether the HCVR is influenced by nocturnal nasal oxygen in patients with heart failure and Cheyne-Stokes respiration. Twenty patients with chronic congestive heart failure and a left ventricular ejection fraction < or = 35% (mean 18.3% +/- SD 6.0%) as well as 25 healthy control subjects were studied. The patients were assigned to 1 week each of nocturnal nasal oxygen and room air with a flow of 41 min-1 in a randomized cross-over fashion. After each week resting ventilation and HCVR were evaluated by the rebreathing technique. Breathing oxygen during the night for 1 week increased the basal nocturnal oxygen saturation from 92.5% +/- 1.6% to 96.5% +/- 0.9% (P < 0.000,01) and reduced Cheyne-Stokes respiration. HCVR was 1.22 +/- 0.90 l min-1 mmHg-1 after nocturnal room air and did not differ from that in the control subjects (1.31 +/- 0.62 l min-1 mmHg-1). In the patients HCVR decreased to 0.91 +/- 0.52 l min-1 mmHg-1 after nocturnal oxygen (P = 0.019). There were no significant changes with nocturnal oxygen in resting minute ventilation, respiratory rate or end-tidal PCO2. We conclude that nocturnal nasal oxygen reduces HCVR in patients with congestive heart failure and Cheyne-Stokes respiration.

A content analysis of obstetrics and gynecology scholarship: implications for women's health

In the context of studying the medicalization of women, we sought insight into the reflexive and mutually influential relationships between the prevailing social agenda and the formal knowledge base by analyzing the content, purpose and funding source of the scholarly work published in the three major, English-language obstetrics and gynecology journals. Our analysis of the 6103 articles published in 1975, 1980, 1985, 1990, and 1993 led us to the conclusion that, rather than responding to changing social needs and life-styles, the obstetrics and gynecology specialty has continued to emphasize the reproductive nature of women rather than the health and well-being requirements of non-pregnant and non-fertile women. The social values and attitudes toward women inferred from the priorities evident in these data are ideologically consistent with the view that women's primary role is that of reproduction. The implied importance of certain themes and the consequent allocation of resources may serve to perpetuate the politically oppressive view of women as biologically motivated and determined.

Symptomatic zinc deficiency in breast-fed term and premature infants

Two 3-month-old exclusively breast-fed infants, one born at full-term and the other born prematurely, developed symptomatic zinc deficiency manifested by an acrodermatitis enteropathica-like eruption. Inadequate breast milk zinc was demonstrated in both cases. A rapid clinical response followed oral zinc supplementation after which their serum zinc levels returned to normal. The infants remained asymptomatic following cessation of zinc therapy. Reports of similar cases suggest that in a group of infants breast milk does not meet their nutritional zinc requirements. Inadequate breast milk zinc is thought to result from a defect in transfer of zinc from maternal serum to breast milk.

Efficient generation of major histocompatibility complex class I-peptide complexes using synthetic peptide libraries

The use of synthetic random peptide libraries is a powerful technology for the study of many aspects of antigen presentation and peptide selection by major histocompatibility complex (MHC) molecules. Here we have used them in conjunction with a recombinant system to determine the peptide binding motifs of three classical class I MHC molecules of the laboratory rat: RT1-Aa, RT1-Au, and RT1-A1c. Described is a method for producing large amounts of soluble class I heavy and light chains in bacteria. Refolding RT1-Aa heavy chain (HC) with rat beta2-microglobulin (beta2m) in the presence of a specific peptide and the subsequent purification of the complex yielded conformationally correct material. This was assessed by gel chromatography, SDS-polyacrylamide gel electrophoresis, isoelectric focussing gel electrophoresis, enzyme-linked immunosorbent assay, and fluorescence-activated cell sorter analysis employing a previously unreported method utilizing a His-Tag affinity silica. By refolding RT1-Aa HC and rat beta2m around a random nonapeptide library and subjecting the resulting complex to acid elution of the bound peptides and pool sequencing, the peptide binding motif for this MHC class I molecule was determined. Results corresponded well with those previously determined from naturally bound peptides and in addition gave a clear and unambiguous signal for the C-terminal anchor residue. This method was then applied to determine the previously undescribed binding motifs for RT1-Au and RT1-A1c. For both molecules, the whole motif was confirmed from naturally bound peptides. We propose this method as an alternative way to obtain the whole class I MHC peptide motif, particularly when a specific antibody is unavailable and/or natural expression of the class I molecule of interest is low.

Co-evolution of rat TAP transporters and MHC class I RT1-A molecules

The genes for rat major histocompatibility complex (MHC) class I molecules are associated either with those for the A allele of the transporter associated with antigen processing (TAP-A), which can transport peptides with basic carboxy-terminal residues, or with those for TAP-B, which cannot [1-5]. To explore whether these associations have a functional basis, we compared the sequences of 13 rat MHC class la RT1-A cDNAs from nine MHC haplotypes. Of seven TAP-A- linked RT1-A molecules, six possess strongly acidic F pockets, and these bind a high proportion of peptides with basic carboxy-terminal residues. The F pockets of TAP-B-linked molecules, by contrast, were more basic. Furthermore, we identified six positions at the 'righthand end' of the peptide-binding groove, at which a majority of TAP-B-linked molecules diverge from the consensus sequence for class la molecules whereas, at these positions, all the TAP-A-linked molecules reflect the consensus sequence. Our results suggest that the linked rat class la and TAP genes have co-evolved to maximize the supply of appropriate peptides to the presenting molecules.

The effect of age on the association between body-mass index and mortality

BACKGROUND

The effect of age on optimal body weight is controversial, and few studies have had adequate numbers of subjects to analyze mortality as a function of body-mass index across age groups.

METHODS

We studied mortality over 12 years among white men and women who participated in the American Cancer Society's Cancer Prevention Study I (from 1960 through 1972). The 62,116 men and 262,019 women included in this analysis had never smoked cigarettes, had no history of heart disease, stroke, or cancer (other than skin cancer) at base line in 1959-1960, and had no history of recent unintentional weight loss. The date and cause of death for subjects who died were determined from death certificates. The associations between body-mass index (defined as the weight in kilograms divided by the square of the height in meters) and mortality were examined for six age groups in analyses in which we adjusted for age, educational level, physical activity, and alcohol consumption.

RESULTS

Greater body-mass index was associated with higher mortality from all causes and from cardiovascular disease in men and women up to 75 years of age. However, the relative risk associated with greater body-mass index declined with age. For example, for mortality from cardiovascular disease, the relative risk associated with an increment of 1 in the body-mass index was 1.10 (95 percent confidence interval, 1.04 to 1.16) for 30-to-44-year-old men and 1.03 (95 percent confidence interval, 1.02 to 1.05) for 65-to-74-year-old men. For women, the corresponding relative risk estimates were 1.08 (95 percent confidence interval, 1.05 to 1.11) and 1.02 (95 percent confidence interval, 1.02 to 1.03).

CONCLUSIONS

Excess body weight increases the risk of death from any cause and from cardiovascular disease in adults between 30 and 74 years of age. The relative risk associated with greater body weight is higher among younger subjects.

Frankenstein's nurse! What are schools of nursing creating?

The research presented in this paper examines the socialisation of nursing students under the current educational arrangements and the way in which it creates nurses who assign high status to technological expertise and its manipulation, while regarding many of the traditional, more 'basic', nursing skills as being of low status. Such a professional outlook has serious implications for areas of nursing practice where technology is largely inappropriate and where care of the body dominates practice (such as in aged care). In a longitudinal study which followed student nurses from neophyte to graduand status, results showed that intentions to work in aged care decrease as students progress through their pre-service programs. At the same time, however, these students come to regard areas that require a manipulation of technology, such as is perceived in surgical wards and intensive care, as the 'real' role of nursing. Structures which guide students through the socialisation process, (i.e. the curriculum and teaching staff) were examined regarding their contribution to the establishment and maintenance of this culture. The findings of this study have important implications for the future of quality nursing in areas like aged care--as well as for the future success of nursing in its quest to be regarded as a 'true', autonomous profession.

Vertical translocation. Part II. Outcomes after surgical treatment of rheumatoid cervical myelopathy

This is a prospective observational study in 116 patients with rheumatoid arthritis and vertical translocation who underwent cervical spine surgery after developing symptomatic myelopathy. These patients, whose mean age was 62 years, had suffered from rheumatoid arthritis for almost 25 years. Surgery was performed via a combination of anterior (67 transoral decompressions) and posterior approaches. Surgical morbidity was recorded in 39% of patients, with a 30-day mortality rate of 10.3%, which was largely related to poor preoperative neurological grade. Neurological improvement of at least one Ranawat class was observed in 55 patients. Univariate analysis revealed the following clinical variables to be associated with a good neurological outcome (Ranawat class): younger age and good preoperative muscle power. Significant radiological variables included the degree of vertical translocation as measured by the Redlund-Johnell method and the preoperative spinal cord area. The degree of transgression in the foramen magnum did not significantly affect neurological outcome. Neither the anterior nor the posterior atlantodens interval predicted neurological recovery. Multiple logistic regression models were constructed based on the preliminary evidence of the authors' univariate analysis and these confirmed the importance of preoperative neurological function, spinal cord area, and the degree of vertical translocation in influencing the final neurological grade.