Predictors of self-reported adherence in persons living with HIV disease

This study examined the relationships between the five dimensions of the Wilson and Cleary model of health-related quality of life and three self-reported adherence measures in persons living with HIV using a descriptive survey design. Data collection occurred in seven cities across the United States, including university-based AIDS clinics, private practices, public and for-profit hospitals, residential and day-care facilities, community-based organizations, and home care. The three dependent adherence measures studied were "medication nonadherence," "follows provider advice," and "missed appointments." The sample included 420 persons living with HIV disease with a mean age of 39 years of which 20% were women and 51% were white; subjects had a mean CD4 count of 321 mm3. HIV-positive clients with higher symptom scores, particularly depression, were more likely to be nonadherent to medication, not to follow provider advice, and to miss appointments. Participants who reported having a meaningful life, feeling comfortable and well cared for, using their time wisely, and taking time for important things were both more adherent to their medications and more likely to follow provider's advice. No evidence was found demonstrating any relationship between adherence and age, gender, ethnicity, or history of injection drug use. These findings support the need to treat symptoms, particularly depression, and to understand clients' perceptions of their environment as strategies to enhance adherence. A limitation of this study was that adherence was measured only by self-report; however, the study did expand the concept of adherence in HIV care beyond medication adherence to include following instructions and keeping appointments.

IL-4 preferentially activates a novel STAT6 isoform in mast cells

IL-4 is a pleiotropic cytokine that signals through STAT6 to direct the transactivation of multiple gene targets. In this study, we demonstrate that mast cells express a distinct STAT6 isoform. This "mast cell STAT" is a product of the STAT6 gene, but is only 65 kDa in size and appears to lack the defined C-terminal transactivation domain. Despite the presence of the conventional 94-kDa STAT6 molecule, it is the smaller isoform that associates with a consensus STAT6 binding site in extracts from IL-4-treated mast cells. This is the first evidence that STAT6 isoforms can be preferentially activated and bind to DNA in a cell-specific manner. These results imply that an additional level of specificity in the IL-4R signaling mechanism exists and may partially explain the diverse effects that IL-4 exerts on different cell types.

NF-ATc isoforms are differentially expressed and regulated in murine T and mast cells

NF of activated T cells (NF-AT) denotes a family of transcription factors that regulate the activation-dependent expression of many immunologically important proteins. At least four distinct genes encode the various family members, and several isoforms of these have been identified as well. The overlapping expression patterns and similar in vitro binding and trans-activation activities on various promoter elements of NF-AT-regulated genes suggest some redundancy in the function of these proteins. However, the phenotypic analysis of NF-AT-deficient mice supports the idea that there are tissue- and gene-specific functions as well. In this study we have characterized the expression of NF-AT cDNAs in murine mast cells. The majority of clones identified correspond to two NF-ATc isoforms that differ only in their amino-terminal sequence. Despite minimal discrepancies in the coding region, there are striking tissue- and cell type-specific differences in isoform expression patterns. Detection of NF-ATc.alpha mRNA is strictly dependent on cell activation signals in both T and mast cell lines. In contrast, the beta isoform is expressed at very low constitutive levels in both cell types but is only up-regulated in response to mast cell activation signals delivered through the FcepsilonRI or via calcium ionophores. These results demonstrate another level of regulation within the NF-AT family that can contribute to cell type-specific gene expression.

Identification of a C/G polymorphism in the promoter region of the BRCA1 gene and its use as a marker for rapid detection of promoter deletions

Reduced expression of BRCA1 has been implicated in sporadic breast cancer, although the mechanisms underlying this phenomenon remain unclear. To determine whether regulatory mutations could account for the reduced expression, we screened the promoter region by sequencing in 20 patients with sporadic disease. No mutations were detected; however, a new polymorphism consisting of a C-to-G base change within the beta-promoter was identified, with the frequency of the G allele being 0.34. Close to complete linkage disequilibrium was found between this marker and the Pro871 Leu polymorphism, situated in exon 11, which has previously been shown not to be associated with breast or ovarian cancer. This indicates that the C/G polymorphism is also unlikely to play a role in either disease. However, the strength of linkage disequilibrium between these markers permitted their use for rapid screening for genomic deletions within BRCA1. A series of 214 cases with familial breast cancer were analysed using this approach; 88/214 were heterozygous for the promoter polymorphism, thereby excluding a deletion in this region. Among the remaining patients, one hemizygous case reflecting a promoter deletion was successfully identified. Therefore, this study indicates that deletions within the beta-promoter region of BRCA1 are an uncommon event in familial breast cancer. Furthermore, it suggests that mutations within the BRCA1 promoter are unlikely to account for the reported decreased expression of BRCA1 in sporadic disease.

Intravascular gas as an incidental finding at US after blunt abdominal trauma

PURPOSE

To describe the occurrence and importance of intravascular gas at ultrasonography (US) during the initial examination of patients after blunt abdominal trauma.

MATERIALS AND METHODS

Reports of all abdominal US examinations performed at one institution for blunt trauma from October 1995 through June 1996 were reviewed. The charts of patients with intravascular gas were examined to determine the mechanism of injury, associated findings, and clinical outcome.

RESULTS

A total of 730 patients underwent abdominal US examinations during the 9 months of study; five had intravascular gas demonstrated. Two patients had portal venous gas, one had hepatic venous gas, and two had inferior vena caval gas. Four of the five patients were involved in motor vehicle accidents, and one had been assaulted. In patients in whom follow-up studies were obtained, there was no evidence of intravascular gas at US or computed tomography. No cause was found at imaging or clinical examination.

CONCLUSION

Intravascular gas may occur as a transient incidental finding after blunt abdominal trauma.

Postweaning performance of calves from Angus, Brahman, and reciprocal-cross cows grazing endophyte-infected tall fescue or common bermudagrass

Data from 403 Polled Hereford-sired calves from Angus, Brahman, and reciprocal-cross cows were used to evaluate the effects of preweaning forage environment on postweaning performance. Calves were spring-born in 1991 to 1994 and managed on either endophyte-infected tall fescue (E+) or common bermudagrass (BG) during the preweaning phase. After weaning, calves were shipped to the Grazinglands Research Laboratory, El Reno, OK and stratified to one of two winter stocker treatments by breed and preweaning forage; stocker treatments were winter wheat pasture (WW) or native range plus supplemental CP (NR). Each stocker treatment was terminated in March, calves grazed cool-season grasses, and calves were then moved to a feedlot phase in June. In the feedlot phase, calves were fed to approximately 10 mm fat over the 12th rib and averaged approximately 115 d on feed. When finished, calves were weighed and shipped to Amarillo, TX for slaughter. Averaged over calf breed group, calves from E+ gained faster during the stocker phase (P<.10), had lighter starting and finished weights on feed (P< .01), lighter carcass weights (P<.01), and smaller longissimus muscle areas (P<.05) than calves from BG. Calves from E+ were similar to calves from BG in feedlot ADG, percentage kidney, heart, and pelvic fat, fat thickness over 12th rib, yield grade, marbling score, and dressing percentage. Maternal heterosis was larger in calves from E+ for starting weight on feed (P<.01), finished weight (P<.10), and carcass weight (P<.16). These data suggest that few carryover effects from tall fescue preweaning environments exist, other than lighter, but acceptable, weights through slaughter. These data further suggest that the tolerance to E+ in calves from reciprocal-cross cows, expressed in weaning weights, moderated postweaning weight differences between E+ and BG compared to similar comparisons in calves from purebred cows.

Perinatal events in the development of asthma

Many potential factors are likely involved in the pathogenesis of asthma. These include prenatal, peripartum, and postnatal influences. Prenatally, genetic endowment, maternal smoking, in utero allergen sensitization, and alterations in maternal immune function, especially at the placental level, may increase the risk for asthma and atopy. In the peripartum period, suspected factors include obstetric practices (eg, the use of prostaglandins, hormones, and other agents) and prematurity. Postnatally passive smoke exposure, neonatal or early childhood infections and breast-feeding are under increasing scrutiny as to their possible role in the development of asthma. Despite the volumes of work already reported, much more is left to be done to sort out the complex interrelationships of these and other as yet unsuspected influences on the development of asthma.

Review of health consequences from high-, intermediate- and low-level exposure to organophosphorus nerve agents

Short and long-term health effects from exposure to organophosphorus (OP) military and insecticidal nerve agents are evaluated based on the abundant scientific literature published over five decades on health effects in humans (from human experimentation and occupational exposures) and in laboratory animals. Four distinct health effects are identified: acute cholinergic toxicity; organophosphate-induced delayed neuropathy (OPIDN); subtle long-term neuropsychological and neurophysiological effects; and a reversible muscular weakness called 'intermediate syndrome'. Some effects are subtle and difficult to differentiate from health effects caused by other diseases or occupational exposures. Each effect has data suggesting threshold exposure levels below which it is unlikely to be clinically detectable. Therefore, meaningful interpretation of human and animal studies requires rigid exposure characterization. Because precise exposure levels are often difficult to reconstruct, a system for characterizing exposure is proposed based upon observed initial acute signs and symptoms, as high-level (definitive cholinergic poisoning); intermediate-level (threshold cholinergic effects including miosis, rhinorrhea or clinically measurable depression of cholinesterase); and low-level (no immediate clinical signs or symptoms) exposure. Threshold exposure levels for known long-term effects from OP nerve agent are at or above intermediate-level exposure. Long-term health effects seen at intermediate-level exposures or in many survivors of high-level exposure are subtle, detectable in exposed populations but not individuals, and not reported in individuals experiencing low-level exposure alone. Co-exposure to other pharmaceutical agents may promote or protect against health effects from OP nerve agents, but qualitatively they are the same effects seen with OP nerve agents alone. Thus, the system for characterizing exposure based on initial acute effects is also useful for evaluating health outcomes from co-exposure to OP nerve and other agents.

Who cares for junior medical officers?

Recent changes in the way that some hospitals are run have created particular problems for junior medical staff. Here we describe a new system of managing such staff, under evaluation at a large Sydney teaching hospital, which seems to be working well and which has been positively appraised by the Postgraduate Medical Council and the Australian Council on Healthcare Standards.

Difficulties in detecting parathyroid hypertensive factor in the rat

1. Parathyroid hypertensive factor (PHF) has been implicated in the pathogenesis of several forms of hypertension. We aimed to establish a PHF bioassay using spontaneously hypertensive rat (SHR) plasma. 2. Spontaneously hypertensive rats were confirmed hypertensive and their plasma was dialysed and injected into anaesthetized normotensive rats. 3. Haemodynamic responses to injected SHR plasma were uninterpretable during pentobarbital anaesthesia due to blood pressure (BP) fluctuation. Under halothane anaesthesia, BP was stable but did not rise following SHR plasma injection. Using filtered, undialysed plasma and a different brand of pentobarbital, no consistent BP response was observed following SHR plasma injection. 4. We were unable to detect PHF in the SHR.

Does gestational hypertension become pre-eclampsia?

OBJECTIVE

To determine the likelihood of progression from gestational hypertension (GH) to pre-eclampsia (PE) in hypertensive pregnant women and whether this change can be identified in advance by available clinical and laboratory measures.

DESIGN

A retrospective analysis and a prospective study.

SETTING

St George Hospital, Sydney, a teaching hospital of the University of New South Wales delivering 2500 women per year.

POPULATION

Eight hundred and forty-five women with new hypertension in the second half of pregnancy, managed by a uniform protocol (661 in the retrospective analysis, 184 in the prospective study).

METHODS

Clinical and laboratory data at initial presentation were compared among women with GH who developed PE and those who remained with a diagnosis of GH until delivery. Data predictive for progression from GH to PE were analysed by logistic regression analysis.

MAIN OUTCOME MEASURED

Progression from GH to PE.

RESULTS

In the retrospective analysis, 416 women initially presented as having GH and 62 (15%) progressed to PE. In the prospective study, 112 women initially presented with GH and 29 (26%) progressed to PE, giving an overall progression of 17%. In both studies, women who developed PE from GH presented earlier than those who remained with GH until delivery. In multiple logistic regression analyses prior miscarriage and early gestation at presentation were associated with increased likelihood of progressing from GH to PE.

CONCLUSION

Approximately 15-25% of women initially diagnosed with GH will develop PE and this is more likely with earlier presentation or if the woman has had a prior miscarriage. Women with gestational hypertension diagnosed after 36 weeks of gestation have only about 10% risk of developing PE. These data should help stratify the risks of mildly hypertensive pregnant women being managed as outpatients in their third trimester.

Review of health consequences from high-, intermediate- and low-level exposure to organophosphorus nerve agents

Short and long-term health effects from exposure to organophosphorus (OP) military and insecticidal nerve agents are evaluated based on the abundant scientific literature published over five decades on health effects in humans (from human experimentation and occupational exposures) and in laboratory animals. Four distinct health effects are identified: acute cholinergic toxicity; organophosphate-induced delayed neuropathy (OPIDN); subtle long-term neuropsychological and neurophysiological effects; and a reversible muscular weakness called 'intermediate syndrome'. Some effects are subtle and difficult to differentiate from health effects caused by other diseases or occupational exposures. Each effect has data suggesting threshold exposure levels below which it is unlikely to be clinically detectable. Therefore, meaningful interpretation of human and animal studies requires rigid exposure characterization. Because precise exposure levels are often difficult to reconstruct, a system for characterizing exposure is proposed based upon observed initial acute signs and symptoms, as high-level (definitive cholinergic poisoning); intermediate-level (threshold cholinergic effects including miosis, rhinorrhea or clinically measurable depression of cholinesterase); and low-level (no immediate clinical signs or symptoms) exposure. Threshold exposure levels for known long-term effects from OP nerve agent are at or above intermediate-level exposure. Long-term health effects seen at intermediate-level exposures or in many survivors of high-level exposure are subtle, detectable in exposed populations but not individuals, and not reported in individuals experiencing low-level exposure alone. Co-exposure to other pharmaceutical agents may promote or protect against health effects from OP nerve agents, but qualitatively they are the same effects seen with OP nerve agents alone. Thus, the system for characterizing exposure based on initial acute effects is also useful for evaluating health outcomes from co-exposure to OP nerve and other agents.

Randomised trial of management of hypertensive pregnancies by Korotkoff phase IV or phase V

BACKGROUND

There is debate about whether diastolic blood pressure should be recorded as the fourth (muffling, K4) or fifth (disappearance, K5) Korotkoff sound in pregnancy. We compared maternal and fetal outcomes and the likelihood that episodes of severe hypertension would be recorded when hypertensive pregnancies were managed according to either K4 or K5.

METHODS

220 pregnant women with diastolic hypertension (K4 > or =90 mm Hg) after the 20th week of gestation were enrolled in a prospective randomised study at two obstetric units in Australia; they were randomly assigned management with K4 (n=103) or K5 (n=117) for the remainder of the pregnancy. Clinical management was according to a uniform department protocol. Analysis was by intention to treat. All the women completed the trial.

FINDINGS

An episode of severe hypertension (systolic > or =170 mm Hg, diastolic > or =110 mm Hg, or both) was more likely to be recorded with use of K4 than with use of K5 (39 [38%] vs 30 [26%] women, p=0.051), mainly because of a greater likelihood that severe diastolic hypertension would be recorded (34 [33%] vs 20 [17%], p=0.006). The frequency of severe systolic hypertension and simultaneous severe systolic and diastolic hypertension did not differ between groups. Pregnancy was prolonged by an average of 2 weeks in both groups, and there were no significant differences between the groups in laboratory data, requirements for antihypertensive treatment, birthweight, fetal growth retardation, or perinatal mortality. There was no eclampsia or significant maternal morbidity in either group.

INTERPRETATION

A change from use of K4 to K5 would mean that one fewer case of severe diastolic hypertension would be recorded for every six hypertensive pregnancies, but all other episodes of severe hypertension would be recorded with similar frequency. Since the K4/K5 difference is smaller in hypertensive than in normotensive pregnant women and since K5 is closer to the actual intra-arterial pressure and more reliably detected, universal adoption of K5 to record diastolic blood pressure in hypertensive pregnancy should be considered.

Accuracy of automated blood pressure recorders in pregnancy

Automated blood pressure recorders are used with increasing frequency by pregnant women, mostly without proper evaluation of their accuracy. We compared blood pressures (BP) recorded by 2 automated noninvasive devices, the Spacelabs 90207 ambulatory blood pressure monitor and the OMRON HEM 705 CP portable self-initiated device, with blood pressures recorded by routine sphygmomanometry in 79 pregnant women either considered 'at risk' for preeclampsia or with mild hypertension in pregnancy. The Spacelabs device tended to overestimate systolic BP by a mean 11 (SD=8) mmHg and diastolic BP by 5 (SD=7) mmHg for phase 5 pressure (p<0.001) but was similar to routine BPs for diastolic phase 4 pressures. The OMRON device tended to underestimate diastolic (phase 4) pressure by 4 (SD=6) mmHg (p<0.001) but gave similar systolic and diastolic (phase 5) pressures to routine sphygmomanometry. However, for both devices there was considerable individual patient variability in accuracy. When using these devices to record a limited number of blood pressure recordings, as in this study, we suggest that individual comparison with mercury sphygmomanometry be made in each pregnant woman before accepting the validity of these recordings.

Atoxoplasma (Apicomplexa: Eimeriorina: Atoxoplasmatidae) in the greenfinch (Carduelis chloris)

Merozoites of an Atoxoplasma species were present within parasitophorous vacuoles in the cytoplasm of leucocytes in the blood vessels in the small intestine of the greenfinch (Carduelis chloris). The merozoites indented the nucleus of the leucocytes. Merozoites, macrogametes, and microgamonts were present in the epithelial cells of the intestines. No merogony was observed. Experiments provided circumstantial evidence linking disporocystid-octozoic oocysts with the blood and intestinal infections.

Urinary calcium/creatinine ratio as a predictor of preeclampsia

Hypocalciuria has been associated with preeclampsia (gestational hypertension with proteinuria or other maternal organ dysfunction) but not usually with pure gestational hypertension or normal pregnancy. We hypothesized that hypocalciuria would be a marker of emerging preeclampsia in women presenting with gestational hypertension who later developed preeclampsia. Eighty-one women with de novo hypertension in the second half of pregnancy (n = 81) were enrolled prospectively. At first assessment, calcium/creatinine ratio was determined in a spot urine. Patients were followed until delivery and were classified subsequently according to the occurrence of preeclampsia. Gestational hypertensive patients who became preeclamptic (n = 31) had lower urinary calcium/creatinine ratios at presentation (ratio = 0.07, interquartile range [IQR] = 0.04-0.11) than women who remained as gestational hypertensives (n = 50; ratio = 0.17, IQR = 0.08-0.21; P = .002). Intact plasma parathyroid hormone (PTH) concentrations were similar between groups. Using a receiver operator curve, the best threshold value for the development of preeclampsia was a calcium/creatinine ratio of 0.10, which yielded a sensitivity of only 68% and a specificity of 70%. A low calcium/creatinine ratio preceded the emergence of preeclampsia by 12 (7-24) (median [IQR]) days among a group of women with gestational hypertension. Though this implies primary or secondary disturbances of renal calcium handling even before preeclampsia is clinically apparent, this measurement does not have sufficient sensitivity to recommend its use as a screening test for the emergence of preeclampsia.

Becoming a primary care nurse practitioner: challenges of the initial year of practice

The transition from student to primary care practitioner is exciting and challenging and offers seemingly limitless opportunities. This article presents results of a model generated from a longitudinal study of 35 newly graduated primary care nurse practitioners during their first year of practice. Stages of development include laying the foundation (recuperating from school, negotiating the bureaucracy, looking for a Job, and worrying); launching (feeling real, getting through the day, battling time, and confronting anxiety); meeting the challenge (increasing competence, gaining confidence, and acknowledging system problems); and broadening the perspective (developing system savvy, affirming oneself, and upping the ante). Anticipatory guidance is offered for new graduates and their mentors and colleagues. Mentors can provide crucial information about appropriate expectations and create key structures to facilitate new practitioners' needs for consultation and advice.

The effect of HLA-DR genes on susceptibility to and severity of ankylosing spondylitis

OBJECTIVE

To analyze the effect of HLA-DR genes on susceptibility to and severity of ankylosing spondylitis (AS).

METHODS

Three hundred sixty-three white British AS patients were studied; 149 were carefully assessed for a range of clinical manifestations, and disease severity was assessed using a structured questionnaire. Limited HLA class I typing and complete HLA-DR typing were performed using DNA-based methods. HLA data from 13,634 healthy white British bone marrow donors were used for comparison.

RESULTS

A significant association between DR1 and AS was found, independent of HLA-B27 (overall odds ratio [OR] 1.4, 95% confidence interval [95% CI] 1.1-1.8, P = 0.02; relative risk [RR] 2.7, 95% CI 1.5-4.8, P = 6 x 10(-4) among homozygotes; RR 2.1, 95% CI 1.5-2.8, P = 5 x 10(-6) among heterozygotes). A large but weakly significant association between DR8 and AS was noted, particularly among DR8 homozygotes (RR 6.8, 95% CI 1.6-29.2, P = 0.01 among homozygotes; RR 1.6, 95% CI 1.0-2.7, P = 0.07 among heterozygotes). A negative association with DR12 (OR 0.22, 95% CI 0.09-0.5, P = 0.001) was noted. HLA-DR7 was associated with younger age at onset of disease (mean age at onset 18 years for DR7-positive patients and 23 years for DR7-negative patients; Z score 3.21, P = 0.001). No other HLA class I or class II associations with disease severity or with different clinical manifestations of AS were found.

CONCLUSION

The results of this study suggest that HLA-DR genes may have a weak effect on susceptibility to AS independent of HLA-B27, but do not support suggestions that they affect disease severity or different clinical manifestations.

Ambulatory blood pressure monitoring in pregnancy: what is normal?

OBJECTIVE

Noninvasive 24-hour ambulatory blood pressure monitoring holds great promise as a useful tool in the management of hypertensive pregnancies and pregnancies considered "at risk" for development of preeclampsia. The purpose of this study was to define ambulatory blood pressure monitoring parameters throughout normal pregnancy, including women considered at risk for development of hypertension who continued to have a completely normal pregnancy.

STUDY DESIGN

Two hundred seventy-six 24-hour ambulatory blood pressure monitoring studies were made cross-sectionally with use of a Spacelabs 90207 device (validated for use in pregnancy), at one or more of 9 to 17, 18 to 22, 26 to 30, and >30 weeks' gestation. Upper limits of normal were defined as the mean plus 2 SDs for awake and sleep ambulatory blood pressure monitoring results at each stage.

RESULTS

Average awake upper limits of normal were 130/77, 132/79, 133/81, and 135/86 mm Hg at the four stages of pregnancy, respectively. Systolic blood pressure fell significantly by 12% to 14% (p < 0.0001) and diastolic blood pressure by 18% to 19% (p < 0.0001) during sleep at all stages of pregnancy. Awake ambulatory blood pressure monitoring systolic measurements were 11 to 12 mm Hg higher than "clinic" measurements (p < 0.001) and diastolic measurements were 5 to 11 mm Hg higher (p < 0.0001) throughout pregnancy. Maximum blood pressure variability ranged from 8 to 13 mm Hg.

CONCLUSIONS

The upper limits of normal ambulatory blood pressure monitoring-derived measurements rise slightly as pregnancy progresses. Awake measurements are higher than "clinic" measurements recorded under relaxed conditions by a clinical researcher. The diurnal blood pressure fall and variabilities are similar during pregnancy to those seen in nonpregnant subjects. These data should provide valuable references for further studies of ambulatory blood pressure monitoring in high risk pregnancies.

A genome-wide screen for susceptibility loci in ankylosing spondylitis

OBJECTIVE

To localize the regions containing genes that determine susceptibility to ankylosing spondylitis (AS).

METHODS

One hundred five white British families with 121 affected sibling pairs with AS were recruited, largely from the Royal National Hospital for Rheumatic Diseases AS database. A genome-wide linkage screen was undertaken using 254 highly polymorphic microsatellite markers from the Medical Research Council (UK) (MRC) set. The major histocompatibility complex (MHC) region was studied more intensively using 5 microsatellites lying within the HLA class III region and HLA-DRB1 typing. The Analyze package was used for 2-point analysis, and GeneHunter for multipoint analysis.

RESULTS

When only the MRC set was considered, 11 markers in 7 regions achieved a P value of < or =0.01. The maximum logarithm of odds score obtained was 3.8 (P = 1.4 x 10(-5)) using marker D6S273, which lies in the HLA class III region. A further marker used in mapping of the MHC class III region achieved a LOD score of 8.1 (P = 1 x 10(-9)). Nine of 118 affected sibling pairs (7.6%) did not share parental haplotypes identical by descent across the MHC, suggesting that only 31% of the susceptibility to AS is coded by genes linked to the MHC. The maximum non-MHC LOD score obtained was 2.6 (P = 0.0003) for marker D16S422.

CONCLUSION

The results of this study confirm the strong linkage of the MHC with AS, and provide suggestive evidence regarding the presence and location of non-MHC genes influencing susceptibility to the disease.

The role of germline polymorphisms in the T-cell receptor in susceptibility to ankylosing spondylitis

The role of germline polymorphisms of the T-cell receptor A/D and B loci in susceptibility to ankylosing spondylitis was investigated by linkage studies using microsatellite markers in 215 affected sibling pairs. The presence of a significant susceptibility gene (lambda > or = 1.6) at the TCRA/D locus was excluded (LOD score < -2.0). At the TCRB locus, there was weak evidence of the presence of a susceptibility gene (P = 0.01, LOD score 1.1). Further family studies will be required to determine whether this is a true or false-positive finding. It is unlikely that either the TCRA/D or TCRB loci contain genes responsible for more than a moderate proportion of the non-MHC genetic susceptibility to ankylosing spondylitis.

The effect of HLA-DR genes on susceptibility to and severity of ankylosing spondylitis

OBJECTIVE

To analyze the effect of HLA-DR genes on susceptibility to and severity of ankylosing spondylitis (AS).

METHODS

Three hundred sixty-three white British AS patients were studied; 149 were carefully assessed for a range of clinical manifestations, and disease severity was assessed using a structured questionnaire. Limited HLA class I typing and complete HLA-DR typing were performed using DNA-based methods. HLA data from 13,634 healthy white British bone marrow donors were used for comparison.

RESULTS

A significant association between DR1 and AS was found, independent of HLA-B27 (overall odds ratio [OR] 1.4, 95% confidence interval [95% CI] 1.1-1.8, P = 0.02; relative risk [RR] 2.7, 95% CI 1.5-4.8, P = 6 x 10(-4) among homozygotes; RR 2.1, 95% CI 1.5-2.8, P = 5 x 10(-6) among heterozygotes). A large but weakly significant association between DR8 and AS was noted, particularly among DR8 homozygotes (RR 6.8, 95% CI 1.6-29.2, P = 0.01 among homozygotes; RR 1.6, 95% CI 1.0-2.7, P = 0.07 among heterozygotes). A negative association with DR12 (OR 0.22, 95% CI 0.09-0.5, P = 0.001) was noted. HLA-DR7 was associated with younger age at onset of disease (mean age at onset 18 years for DR7-positive patients and 23 years for DR7-negative patients; Z score 3.21, P = 0.001). No other HLA class I or class II associations with disease severity or with different clinical manifestations of AS were found.

CONCLUSION

The results of this study suggest that HLA-DR genes may have a weak effect on susceptibility to AS independent of HLA-B27, but do not support suggestions that they affect disease severity or different clinical manifestations.

Beta2-microglobulin in hypertensive pregnancies

Beta2-Microglobulin (beta2-m) is a polypeptide that is freely filtered and then mostly reabsorbed and degraded in the proximal renal tubule. Beta2-m is a marker of glomerular filtration (GFR) in renal failure, whereas urinary beta2-m is a marker of proximal renal tubular dysfunction. Preeclampsia (PE) (ie, de novo hypertension in pregnancy with accompanying renal, cerebral, or liver disease or thrombocytopenia) often has renal involvement characterized by proteinuria, decreasing glomerular filtration, or renal tubular dysfunction. The aim of this study was to determine whether serum beta2-m concentration or urinary beta2-m excretion were greater in women with PE than in women with gestational hypertension (GH) (ie, isolated de novo hypertension in the second half of pregnancy) and normal pregnant women. Seventy-five pregnant women (35 with PE, 22 with GH, and 18 normotensives) were studied prospectively. Serum creatinine and beta2-m concentrations, 24-hour proteinuria, and fractional excretion (FE) of beta2-m were measured. Preeclamptics had similar serum creatinine but higher serum beta2-m (3.26+/-0.99 mg/L) than gestational hypertensives (2.44+/-0.77 mg/L; P = 0.016), and both groups had higher serum beta2-m than controls (1.62+/-0.54 mg/L; P = 0.001). FE of beta2-m was similar amongst groups (PE: 0.27%; interquartile range [IQR]: 0.20-0.86; GH: 0.21%; IQR: 0.11-0.40; controls: 0.26%, IQR: 0.12-0.69). PE is characterized by higher serum beta2-m but similar serum creatinine to GH. Because FE beta2-m is similar in these groups, this implies reduced filtering of beta2-m in PE rather than altered tubular handling of beta2-m. Further studies are now necessary to assess whether measurement of serum beta2-m is helpful in the clinical management of the hypertensive disorders of pregnancy.

Susceptibility to ankylosing spondylitis in twins: the role of genes, HLA, and the environment

OBJECTIVE

To determine the relative effects of genetic and environmental factors in susceptibility to ankylosing spondylitis (AS).

METHODS

Twins with AS were identified from the Royal National Hospital for Rheumatic Diseases database. Clinical and radiographic examinations were performed to establish diagnoses, and disease severity was assessed using a combination of validated scoring systems. HLA typing for HLA-B27, HLA-B60, and HLA-DR1 was performed by polymerase chain reaction with sequence-specific primers, and zygosity was assessed using microsatellite markers. Genetic and environmental variance components were assessed with the program Mx, using data from this and previous studies of twins with AS.

RESULTS

Six of 8 monozygotic (MZ) twin pairs were disease concordant, compared with 4 of 15 B27-positive dizygotic (DZ) twin pairs (27%) and 4 of 32 DZ twin pairs overall (12.5%). Nonsignificant increases in similarity with regard to age at disease onset and all of the disease severity scores assessed were noted in disease-concordant MZ twins compared with concordant DZ twins. HLA-B27 and B60 were associated with the disease in probands, and the rate of disease concordance was significantly increased among DZ twin pairs in which the co-twin was positive for both B27 and DR1. Additive genetic effects were estimated to contribute 97% of the population variance.

CONCLUSION

Susceptibility to AS is largely genetically determined, and the environmental trigger for the disease is probably ubiquitous. HLA-B27 accounts for a minority of the overall genetic susceptibility to AS.

Knowledge generation for the HIV-affected family

PURPOSE

To examine the current literature about HIV-affected families in regard to knowledge development and priorities for future research.

SIGNIFICANCE

The current view of HIV focuses largely on HIV-infected individuals. There is a paucity of relevant research and a need to make explicit the priorities for knowledge generation about HIV-affected families.

SCOPE

HIV family literature, 1980-1996, was reviewed and categorized and serves as the context for presenting future priorities for knowledge generation about HIV-affected families. Priorities identified were designing and testing family-level services; determining epidemiology of the phenomenon of HIV family caregiving; who gives care and why, what caregivers do, the outcomes of caregiving, quality of family care, and relationships

CONCLUSIONS

A critical need is to address in-depth the problems that have limited knowledge development about HIV-affected families. This explication of issues and questions to understand HIV-affected families can stimulate future research.

Randomized, double-blind comparison of hirulog versus heparin in patients receiving streptokinase and aspirin for acute myocardial infarction (HERO). Hirulog Early Reperfusion/Occlusion (HERO) Trial Investigators

BACKGROUND

Thrombolytic therapy improves survival after myocardial infarction through reperfusion of the infarct-related artery. Thrombin generated during thrombolytic administration may reduce the efficacy of thrombolysis. A direct thrombin inhibitor may improve early patency rates.

METHODS AND RESULTS

Four hundred twelve patients presenting within 12 hours with ST-segment elevation were given aspirin and streptokinase and randomized in a double-blind manner to receive up to 60 hours of either heparin (5000 U bolus followed by 1000 to 1200 U/h), low-dose hirulog (0.125 mg/kg bolus followed by 0.25 mg x kg(-1) x h(-1) for 12 hours then 0.125 mg x kg(-1) x h(-1)), or high-dose hirulog (0.25 mg/kg bolus followed by 0.5 mg x kg(-1) x h(-1) for 12 hours then 0.25 mg x kg(-1) x h(-1)). The primary outcome was Thrombolysis In Myocardial Infarction trial (TIMI) grade 3 flow of the infarct-related artery at 90 to 120 minutes. TIMI 3 flow was 35% (95% CI, 28% to 44%) with heparin, 46% (95% CI, 38% to 55%) with low-dose hirulog, and 48% (95% CI, 40% to 57%) with high-dose hirulog (heparin versus hirulog, P=.023; heparin versus high-dose hirulog, P=.03). At 48 hours, reocclusion had occurred in 7% of heparin, 5% of low-dose hirulog, and 1% of high-dose hirulog patients (P=NS). By 35 days, death, cardiogenic shock, or reinfarction had occurred in 25 heparin (17.9%), 19 low-dose hirulog (14%), and 17 high-dose hirulog patients (12.5%) (P=NS). Two strokes occurred with heparin, none with low-dose hirulog, and two with high-dose hirulog. Major bleeding (40% from the groin site) occurred in 28% of heparin, 14% of low-dose hirulog, and 19% of high-dose hirulog patients (heparin versus low-dose hirulog, P<.01).

CONCLUSIONS

Hirulog was more effective than heparin in producing early patency in patients treated with aspirin and streptokinase without increasing the risk of major bleeding. Direct thrombin inhibition may improve clinical outcome.

A linkage study across the T cell receptor A and T cell receptor B loci in families with rheumatoid arthritis

OBJECTIVE

To examine whether the T cell receptor (TCR) A or TCRB loci exhibit linkage with disease in multiplex rheumatoid arthritis (RA) families.

METHODS

A linkage study was performed in 184 RA families from the UK Arthritis and Rheumatism Council Repository, each containing at least 1 affected sibpair. The microsatellites D14S50, TCRA, and D14S64 spanning the TCRA locus and D7S509, Vbeta6.7, and D7S688 spanning the TCRB locus were used as DNA markers. The subjects were genotyped using a semiautomated polymerase chain reaction-based method. Two-point and multipoint linkage analyses were performed.

RESULTS

Nonparametric single-marker likelihood odds (LOD) scores were 0.49 (P = 0.07) for D14S50, 0.65 (P = 0.04) for TCRA, 0.07 (P = 0.29) for D14S64, 0.01 (P = 0.43) for D7S509, 0.0 (P = 0.50) for Vbeta6.7, and 0.0 (P = 0.50) for D7S688. By multipoint analysis, there was no evidence of linkage at TCRB (LOD score 0), and the maximum LOD score at the TCRA locus was 0.37 (at D14S50). The presence of a susceptibility locus (LOD score < -2.0) was excluded, with lambda > or = 1.8 at TCRA and > or = 1.4 at TCRB.

CONCLUSION

These linkage studies provide no significant evidence of a major germline-encoded TCRA or TCRB component of susceptibility to RA.

Purification and partial amino acid sequences of two distinct albumins from turtle plasma

Two putative albumins, denoted Alb-1 (apparent molecular mass of 67 kDa) and Alb-2 (68 kDa), were purified from plasma of the emydid turtle (Trachemys scripta). Concentrations in serum or plasma were determined by radioimmunoassay using 125I-labeled Alb-1. In juvenile turtles (less than 2 years of age), serum concentrations of Alb-1 and Alb-2 were 2.72 +/- 0.23 mg/ml and 1.68 +/- 0.22 mg/ml, respectively, while concentrations in plasma pooled from adult turtles were 4.2 mg/ml and 2.6 mg/ml, respectively. The two albumins are immunologically distinct from one another as determined by both radioimmunoassay with 125I-labeled Alb-1 and Western blot analysis with antichicken albumin antiserum. Determination of the amino acid compositions of Alb-1 and Alb-2, and of albumin purified from plasma of the common snapping turtle (Chelydra serpentina), suggested that Alb-1 is more similar to albumins of other animals than is Alb-2. This was also indicated by Western blot analysis and by determining the N-terminal amino acid sequences of Alb-1 (40 residues) and Alb-2 (15 residues). Thus, it appears that two distinct forms of albumin are synthesized by T. scripta, possibly as a result of gene duplication and divergence.

Low-molecular-weight heat shock proteins in a desert fish (Poeciliopsis lucida): homologs of human Hsp27 and Xenopus Hsp30

The heat shock response of a fish which inhabits a highly stressful environment (Poeciliopsis lucida, a minnow from river systems of the Sonoran desert in northwestern Mexico) was investigated. Cells derived from this fish exhibited a typical heat shock response when exposed to elevated temperature, synthesizing high levels of 90 kDa, 70 kDa, and 30 kDa heat shock proteins (Hsp90, Hsp70, and Hsp30), as well as lower amounts of other heat shock proteins. Additional small heat shock proteins (sHSPs), including Hsp27, were induced after a prolonged heat shock at a time when synthesis of Hsp70 and Hsp30 was decreasing. Characterization of cDNA clones for hsp27 and hsp30 revealed that both are members of the alpha-crystallin/sHSP superfamily but belong to separate lineages within this gene family. The multiple isoforms of P. lucida Hsp30 appear to be members of a multigene family and are most closely related to salmon and Xenopus Hsp30s. In contrast, Hsp27 is highly similar to mammalian and avian sHSPs; it was synthesized as three isoforms which represented differentially phosphorylated forms of a single polypeptide. In Poeciliopsis, the various sHSPs may each perform a subset of the roles attributed to mammalian sHSPs. The conservation of phosphorylation sites in Hsp27 may indicate an involvement in signal transduction to the actin cytoskeleton. The hsp30 genes appear to have diverged more rapidly than the corresponding hsp27 genes; the various members of the Hsp30 family may function as molecular chaperones and, in this role, may be less evolutionarily constrained. Finally, the presence of these two classes of sHSP in a single taxon indicates that these two lineages arose by gene duplication early in the evolution of vertebrates and raises questions about the fate of homologs of Hsp30 in mammals and of Hsp27 in Xenopus.

Susceptibility to ankylosing spondylitis in twins: the role of genes, HLA, and the environment

OBJECTIVE

To determine the relative effects of genetic and environmental factors in susceptibility to ankylosing spondylitis (AS).

METHODS

Twins with AS were identified from the Royal National Hospital for Rheumatic Diseases database. Clinical and radiographic examinations were performed to establish diagnoses, and disease severity was assessed using a combination of validated scoring systems. HLA typing for HLA-B27, HLA-B60, and HLA-DR1 was performed by polymerase chain reaction with sequence-specific primers, and zygosity was assessed using microsatellite markers. Genetic and environmental variance components were assessed with the program Mx, using data from this and previous studies of twins with AS.

RESULTS

Six of 8 monozygotic (MZ) twin pairs were disease concordant, compared with 4 of 15 B27-positive dizygotic (DZ) twin pairs (27%) and 4 of 32 DZ twin pairs overall (12.5%). Nonsignificant increases in similarity with regard to age at disease onset and all of the disease severity scores assessed were noted in disease-concordant MZ twins compared with concordant DZ twins. HLA-B27 and B60 were associated with the disease in probands, and the rate of disease concordance was significantly increased among DZ twin pairs in which the co-twin was positive for both B27 and DR1. Additive genetic effects were estimated to contribute 97% of the population variance.

CONCLUSION

Susceptibility to AS is largely genetically determined, and the environmental trigger for the disease is probably ubiquitous. HLA-B27 accounts for a minority of the overall genetic susceptibility to AS.

Improved methods of assessing proteinuria in hypertensive pregnancy

OBJECTIVE

To determine whether use of an automated urinalysis device will improve the accuracy of detecting proteinuria, and whether spot urine protein to creatinine ratio will provide accurate quantitation of proteinuria in hypertensive pregnant women.

DESIGN

Prospective studies assessing the accuracy of both detection and quantitation of proteinuria.

SETTING

Antenatal ward and pregnancy day assessment unit of St George Hospital, a teaching hospital in Sydney, Australia.

POPULATION

Hypertensive pregnant women admitted to hospital or day assessment unit for management of their hypertensive disorders.

METHODS

1. Routine dipstick urinalysis and 2. urinalysis by an automated device (Clinitek 100 Ames) on a midstream urine sample were compared with measurement of protein concentration on that sample (n = 103). In a third study, the protein:creatinine ratio on a midstream (spot) urine sample was compared with protein excretion over the subsequent 24 hours (n = 100).

MAIN OUTCOME MEASURES

Relations between urine protein concentrations and 1. dipstick urinalysis and 2. automated urinalysis; 3. Positive and negative predictive values of spot protein:creatinine ratio for true proteinuria (> or = 300 mg/day).

RESULTS

Automated urinalysis improved the percentage of true positive urinalyses from 48% with visual urinalysis to 74% (P = 0.02). True negatives were 98% to 100% for both methods. Spot urine protein:creatinine ratio correlated well with subsequent 24-hour urine proteinuria (r = 0.93, P < 0.001). A protein:creatinine ratio > 30 mg protein/mmol creatinine was the optimum discriminant value for true proteinuria, with sensitivity 93%, specificity 92%, positive predictive value 95% and negative predictive value 90%.

CONCLUSIONS

Use of an automated urinalysis device improved accurate detection of proteinuria, particularly reducing false positive tests. A random urine protein:creatinine ratio provides an accurate and rapid quantitation of proteinuria in hypertensive pregnant women. This should improve clinical care, especially when managing hypertensive pregnant women as outpatients.

Extraneous lipid contamination in single-volume proton MR spectroscopy: phantom and human studies

PURPOSE

To determine the degree of extraneous lipid contamination in defined volumes of interest studied with single-volume proton MR spectroscopy.

METHODS

Single-volume proton MR spectroscopy was performed on a fat/water phantom and in three volunteers using the stimulated-echo acquisition mode (STEAM) and point-resolved spectroscopy (PRESS) localization methods. Three different volumes of interest (8, 27, and 64 cm3) were examined at echo times of 20, 135, and 270 for the STEAM sequences and 135 and 270 for the PRESS acquisitions in both the phantom and the volunteers (volumes of interest were placed adjacent to but not encompassing fat-containing structures, such as the scalp and retroorbital fat). The degree of lipid contamination was then correlated with measurements of the section profiles.

RESULTS

The PRESS method resulted in less extraneous lipid contamination in both phantom and volunteer studies. The STEAM method had the highest level of lipid contamination signal in phantom and human studies. In the volunteers, volumes of interest abutting fat-containing structures obtained with PRESS or STEAM sequences showed no lipid contamination. However, the STEAM sequences showed lipid signal in the volume of interest adjacent to orbital fat whereas the PRESS sequences did not. These observations are supported by the section profile studies, which showed that the actual volume excited by the STEAM sequence was 7% to 32% larger than that originally selected, while with PRESS the actual excited volume was 12% to 16% smaller than that originally selected.

CONCLUSION

In our MR unit, short-echo-time STEAM sequences (< or = 135 milliseconds) resulted in extraneous lipid contamination in phantom and human studies adjacent to the orbits. PRESS sequences showed no lipid contamination in volumes abutting fat structures in phantoms or humans. These results correlated closely with the configuration of the section profiles. Although these findings might be dependent on the MR unit used, our study could help determine extraneous lipid contamination for other MR units.

Measuring venous capacitance and blood flow in pregnancy

Forearm or calf venous plethysmography has been used in pregnant women to examine the effects of pregnancy on the vascular system and more recently to measure blood flow changes in response to intra-arterial infusion of vasoactive substances. To examine the assumption that venous capacitance and blood flow measurements are the same in the forearm and calf, venous plethysmography was conducted simultaneously on the forearm and calf in normal (NP) and hypertensive pregnant women (HTP) in their third trimester and in normal nonpregnant women (N). All studies were made on the right forearm and calf with subjects in the left lateral recumbent position. There was no significant difference between venous capacitance in the forearm (median: 124 x 10(3)mL/100mL/mmHg for both NP and HTP) and leg (134 [NP] and 106 [HTP] x 10(3)mL/100mL/mmHg) for both pregnant groups but venous capacitance in the nonpregnant group was greater in the leg than arm (174 versus 112 x 10(3)mL/100mL/mmHg, p < 0.001). Blood flow was similar in the leg and forearm (median 4.9 versus 3.9mL/100mL/min respectively) in nonpregnant women. Forearm blood flow was also similar to calf flow in NP women (6.2 versus 4.3mL/100mL/min respectively) but greater than calf blood flow in HTP (9.7 versus 5.3mL/100mL/min, p < 0.01). Using left lateral recumbency, forearm and calf vein capacitances are similar in pregnant women, in contrast to nonpregnant women. Blood flow is higher in the forearm than the calf only in hypertensive pregnant women. These observations should be borne in mind when interpreting studies of regional blood flow in pregnancy.

Second Australian National Blood Pressure Study (ANBP2). Australian Comparative Outcome Trial of ACE inhibitor- and diuretic-based treatment of hypertension in the elderly. Management Committee on behalf of the High Blood Pressure Research Council of Australia

The Second Australian National Blood Pressure Study (ANBP2) is a comparative outcome trial being conducted in general practices throughout Australia of ACE inhibitor- and diuretic-based treatment in 6000 hypertensive patients aged 65-84 years. The study is using a prospective randomised open-label design with blinding of endpoint assessments. The primary objective is to determine whether there is any difference in total cardiovascular events (fatal and non-fatal) over a five year treatment period between the two treatment regimens. Eligible hypertensive patients (average sitting blood pressure at the 2nd and 3rd screening visits > 160 mm Hg systolic and/or > 90 mm Hg diastolic) may be either untreated or previously treated and should have no history of recent cardiovascular morbidity or serious intercurrent illness. Patients are randomised to one of the treatment arms with randomisation stratified for practice and for age. Following randomisation each patient's blood pressure is managed by his/her general practitioner according to guidelines relevant to each treatment arm. Over 700 patients have now been randomised with recruitment intended to be complete by the end of 1997.

The renin-angiotensin-aldosterone system in pre-eclampsia

Pre-eclampsia is characterised physiologically by plasma volume contraction, intravascular coagulation and intense vasoconstriction. It was originally thought that the renin-angiotensin-aldosterone (RAA) system would be overactive but studies have shown a more complex picture. Plasma renin activity (PRA) and concentration (PRC) and plasma angiotensin II (AII) and aldosterone concentrations (PAC) are reduced compared to normal pregnancy. Total renin concentration is normal and plasma concentrations of high molecular weight angiotensinogen are increased in pre-eclampsia though total angiotensinogen is normal. PRA and PRC respond appropriately to physiologic stimuli in pre-eclampsia except for impaired renin release following frusemide, possibly due to prostacyclin deficiency. Although plasma AII concentrations are reduced there is heightened pressor sensitivity to infused AII--the mechanism(s) for this are unknown. PAC is reduced but the ratio PAC-PRC is twofold greater in pre-eclampsia than normal pregnancy. This does not appear to be due to changes in potassium, atrial natriuretic peptide, dopamine or ACTH, and may be another manifestation of increased (adrenal) sensitivity to AII in pre-eclampsia. There is an inverse relationship between the plasma active renin to prorenin ratio and the clinical severity of the pre-eclampsia. Understanding the mechanisms producing these changes in the RAA system in pre-eclampsia will give strong clues to the overall pathogenesis of this disorder.

Glucocorticoids and hypertension in man

Abnormalities of cortisol production or metabolism are involved in the genesis of hypertension in Cushing's syndrome, apparent mineralocorticoid excess and liquorice abuse and possibly in chronic renal failure and essential hypertension. We have studied the physiological mechanisms by which cortisol raises blood pressure in short term studies of cortisol administration in normal men. Cortisol induced hypertension cannot be explained by increases in vasopressor or decreases in vasodepressor hormone concentrations, or by any increase in sympathetic nervous activity. The hypertension is accompanied by substantial sodium retention but a significant component of the blood pressure rise is sodium independent. The hypertension is characterized by an increase in cardiac output but a rise in output is not essential for the rise in blood pressure. Our working hypothesis is that cortisol induced hypertension is a consequence of increases in renal vascular resistance.

The effects of hair density of beef cattle on Haematobia irritans horn fly populations

We show the relationships that exist between the amount of hair and quantity of sebum on cattle skin and the population density of the horn fly, Haematobia irritans. Brahman and Chianina steers had means of 2390 and 1587 hairs per cm2, respectively, significantly more than the mean number of hairs on Angus, Brahman x Angus Crossbred, Charolais, and Red Poll steers. The Chianina steers had > 30% more sebum present on their skin and hair (0.58g/929 cm2) than the Angus, Charolais, and Red Poll steers at the Beef Cattle Research Station Savoy, Arkansas. The Brahman steers had a significantly greater amount of sebum present on the skin (1.51 g/929 cm2) than the Crossbred and purebred Angus steers (0.55 and 0.25 g/929 cm2, respectively) at the South Central Family Farms Research Centre Booneville, Arkansas. The Brahman and Chianina steers had means of 61.9 and 17.0 horn flies per steer, respectively, during the fly season, whereas the Angus, Crossbred, Charolais and Red Poll steers had fly season means that ranged from 76.9 to 265.8 flies per steer. Regression analysis showed that an increase of 100 hairs per cm2, was associated with a reduction of 11 horn flies in the Angus II, 5 in Angus I, 20 in Charolais, 37 in Red Poll, and 0.4 in Chianina steers at the Savoy Station and a reduction of 6.6 horn flies for the Angus, Brahman, and Crossbred steers at the Booneville Centre. Regardless of cattle breed, an increase of 1.0 g of sebum per 929 cm2 output by the steer was associated with 478.5 additional hairs per cm2 on the animal. Each increase of 0.25 g of sebum per 929 cm2 resulted in a decrease of 9.2 horn flies per steer. We conclude that some of the factors responsible for fly-resistance in cattle are hair density and the corresponding amount of sebum present on cattle skin and hair.

Isolation and characterisation of the NBR2 gene which lies head to head with the human BRCA1 gene

To study the regulation of BRCA1 gene expression and the potential importance of dysregulation of this gene in breast and ovarian cancer, we have examined the 5' region of the human BRCA1 gene in detail. We have identified a new gene, NBR2, which is partially related to the NBR1 gene (formerly known as 1A1-3B and mapping directly adjacent to the pseudo-BRCA1 gene) and which lies head to head with the BRCA1 gene. The physical distance between the transcription start sites of the NBR2 and BRCA1 genes is 218 bp, suggesting that regulation of the expression of both genes may be co-ordinated through a bi-directional promoter. The NBR2 gene contains five exons spanning a genomic region of approximately 30 kb between the BRCA1 and pseudo-BRCA1 genes. Northern analysis showed that the NBR2 gene is expressed in all the tissues examined. The NBR2 cDNA contains an open reading frame of 112 amino acids and is predicted to encode a protein of approximately 12 kDa. Single-strand conformation polymorphism (SSCP) analysis of the NBR2 gene failed to identify any mutations in either breast or ovarian cancer, suggesting that if the NBR2 gene is involved in the development of these cancers, other mechanisms for tumorigenesis may exist. Hybridisation of NBR2 probes to zoo blots showed that the NBR2 gene is present in human and other primates. No hybridisation to DNA from other species was observed, suggesting that genomic elements controlling BRCA1 expression may differ between species.

Withdrawal of nifedipine capsules: jeopardizing the treatment of acute severe hypertension in pregnancy? Australasian Society for the Study of Hypertension in Pregnancy

Short-acting oral nifedipine has been withdrawn from the Australian market because of reports of its adverse effects after long-term treatment in non-pregnant patients with heart disease. This will have a major impact on the treatment of acutely hypertensive pregnant women, in whom the drug has proven to be safe, effective and easy to administer. Should pregnant women be forced to use less suitable agents, thus threatening their own and their babies' health?

Effects of diet on measurement of nitric oxide metabolites

1. The present study investigated whether a low nitrate/nitrite diet could minimize variability in the measurement of endogenous plasma and urine nitric oxide (NO) metabolites, nitrate and nitrite (NOx) in normal subjects. 2. Nitrate and nitrite concentrations were measured in plasma and urine as indicators of NO production in six subjects during a free diet and then during a low nitrate/nitrite diet for 6 days. 3. The plasma concentration and 24 h urine NOx/creatinine ratio were significantly lower on the low nitrate/nitrite diet than on the free diet (P < 0.01). Nitric oxide production appeared to vary greatly within and between subjects, but these variations were substantially decreased by the fourth day of a low nitrate/nitrite diet. 4. Human plasma and urine NOx measurements should be determined after a low nitrate/nitrite diet for at least 4 days.

Purification, partial characterization and peptide sequences of vitellogenin from a reptile, the tuatara (Sphenodon punctatus)

Vitellogenin (Vg), a major precursor to egg yolk proteins, was purified from plasma of an estradiol-treated female tuatara (Sphenodon punctatus) by MgCl2-EDTA precipitation and DEAE-cellulose chromatography. The amino acid composition of tuatara Vg is similar to that of other vertebtate Vgs and contains a large proportion of serine (13.7 mol/100 mol of total amino acid). The amino acid sequences of the N-terminus of mature Vg (33 residues) and of several trypsin- and CNBr-generated peptides were determined. Six peptide sequences obtained from tuatara Vg could be aligned with Vg sequences from other vertebrates. Reduced and non-reduced forms of tuatara Vg have the same apparent molecular mass (approximately 218 kDa) when resolved by SDS-PAGE, indicating that inter-chain disulfide bonds are not a feature of the molecule in this species. Western blot analysis with anti-tuatara Vg antiserum indicated that at least some epitopes are shared among Vgs of turtle, alligator and tuatara.

Feasibility of conducting cardiovascular outcome research in Australian general practice: results from the ANBP2 pilot study. Australian National Blood Pressure Study

1. The present study aimed to determine the feasibility of conducting a 5 year cardiovascular outcome trial of the treatment of 6000 elderly hypertensive patients in Australian general practices. 2. General practitioners (GPs) were invited to participate by mail and personal follow-up. Patient records were reviewed to identify subjects for a blood pressure (BP) screening programme. Blood pressure was measured on three occasions and eligible subjects were included if the average BP was > or = 160 mmHg systolic or > or = 90 mmHg diastolic if systolic BP was > or = 140 mmHg. 3. Seven hundred and forty-one GPs were approached and 89 were enrolled in the study (12% of mail invites and 75% of those receiving a personal contact). In 16 practices where screening was completed, 82,000 records were reviewed to identify 4% patients eligible for screening. Twenty-two per cent of eligible subjects attended screening. Of 1938 subjects screened, 180 (9%) had BP > or = 160/90 mmHg. Forty-seven per cent of subjects (n = 916) were receiving antihypertensive therapy and 184 (20%) were withdrawn from therapy. One hundred and sixteen (63%) of these subjects had BP return to study entry levels within 6 weeks. Fifty-seven newly diagnosed and 81 previously treated subjects were randomized (7% of the screened population). 4. Based on the high participation rate of GPs, the response rate of patients to attend a BP screening programme and the 7% randomization to screening ratio for entry into the study, the ANBP2 pilot study has demonstrated that it is feasible to recruit subjects from Australian general practices to a cardiovascular outcome trial.