Carotid wall thickness is predictive of incident clinical stroke: the Atherosclerosis Risk in Communities (ARIC) study

Few studies have determined whether carotid artery intima-media thickness (IMT) is associated prospectively with risk of first ischemic stroke. In the Atherosclerosis Risk in Communities Study, carotid IMT, an index of generalized atherosclerosis, was defined as the mean of IMT measured by B-mode ultrasonography at six sites of the carotid arteries. The authors assessed the relation of mean IMT to stroke incidence over 6-9 years' follow-up (1987-1995) among 7,865 women and 6,349 men aged 45-64 years without prior stroke at baseline in four US communities. There were 90 incident ischemic stroke events for women and 109 for men. In sex-specific Cox proportional hazards models adjusting only for age, race, and community, the hazard rate ratios comparing extreme mean IMT values (> or =1 mm) to values less than 0.6 mm were 8.5 for women (95% confidence interval: 3.5, 20.7) and 3.6 for men (95% confidence interval: 1.5, 9.2). The relation was graded, and models with cubic splines indicated significant nonlinearity, with hazards increasing more rapidly at lower IMTs than at higher IMTs. Thus, models using linear IMT values substantially underestimate the strength of the association at lower IMTs. The strength of the association was reduced by the inclusion of putative stroke risk factors, but it remained elevated at higher IMTs. Hence, mean carotid IMT is a noninvasive predictor of future ischemic stroke incidence.

Germline mutations of the BRCA1 gene in breast and ovarian cancer families provide evidence for a genotype-phenotype correlation

Mutations in the BRCA1 gene, discovered in 1994, are associated with an 80-90% lifetime risk of breast cancer. We have analysed 60 families with a history of breast and/or ovarian cancer for germline mutations in BRCA1. Twenty-two different mutations were detected in 32 families (53%), of which 14 are previously unreported. We observed a significant correlation between the location of the mutation in the gene and the ratio of breast to ovarian cancer incidence within each family. Our data suggest a transition in risk such that mutations in the 3' third of the gene are associated with a lower proportion of ovarian cancer. Haplotype analysis supports previous data which suggest some BRCA1 mutation carriers have common ancestors; however, we have found at least two examples where recurrent mutations appear to have arisen independently.

Oral contraceptives and the risk of hereditary ovarian cancer. Hereditary Ovarian Cancer Clinical Study Group

BACKGROUND

Women with mutations in either the BRCA1 or the BRCA2 gene have a high lifetime risk of ovarian cancer. Oral contraceptives protect against ovarian cancer in general, but it is not known whether they also protect against hereditary forms of ovarian cancer.

METHODS

We enrolled 207 women with hereditary ovarian cancer and 161 of their sisters as controls in a case-control study. All the patients carried a pathogenic mutation in either BRCA1 (179 women) or BRCA2 (28 women). The control women were enrolled regardless of whether or not they had either mutation. Lifetime histories of oral-contraceptive use were obtained by interview or by written questionnaire and were compared between patients and control women, after adjustment for year of birth and parity.

RESULTS

The adjusted odds ratio for ovarian cancer associated with any past use of oral contraceptives was 0.5 (95 percent confidence interval, 0.3 to 0.8). The risk decreased with increasing duration of use (P for trend, <0.001); use for six or more years was associated with a 60 percent reduction in risk. Oral-contraceptive use protected against ovarian cancer both for carriers of the BRCA1 mutation (odds ratio, 0.5; 95 percent confidence interval, 0.3 to 0.9) and for carriers of the BRCA2 mutation (odds ratio, 0.4; 95 percent confidence interval, 0.2 to 1.1).

CONCLUSIONS

Oral-contraceptive use may reduce the risk of ovarian cancer in women with pathogenic mutations in the BRCA1 or BRCA2 gene.

The effect of acetylsalicyclic acid on platelet function

Acetylsalicylic acid (ASA, aspirin) and sodium salicylate inhibit platelet aggregation induced by collagen, antigen-antibody complexes, gamma globulin-coated particles or thrombin. These compounds suppress the release of platelet constituents, such as adenosine diphosphate (ADP) and serotonin, induced by such stimuli. Since ASA and sodium salicylate do not inhibit ADP-induced platelet aggregation, it appears that their effect on the action of the other stimuli is due to a decrease in the amount of ADP released. The administration of ASA to rabbits (in doses which inhibited collagen-induced platelet aggregation) impaired hemostasis, prolonged platelet survival, and diminished the amount of deposit formed in an extracorporeal shunt.

Diagnosis of Pneumocystis carinii pneumonia: improved detection in sputum with use of monoclonal antibodies

With the dramatic increase in the frequency of Pneumocystis carinii pneumonia associated with human immunodeficiency virus infection, there has been a need for more rapid and less invasive diagnostic techniques. Recent studies have shown that examination of induced sputum can establish the diagnosis of P. carinii pneumonia in about 55 percent of cases. To assess whether a recently developed indirect immunofluorescent stain using monoclonal antibodies was more sensitive than Giemsa or toluidine blue O stains in detecting P. carinii in sputum, we undertook two prospective studies. Of 63 patients at one institution from whom sputum specimens were obtained, 49 were ultimately given a diagnosis of P. carinii pneumonia, 46 of them by staining of sputum. The sensitivity of the three stains in detecting P. carinii was 45 of 49 (92 percent) for immunofluorescence; 37 of 49 (76 percent) for Diff-Quik (a Giemsa-type stain); and 39 of 49 (80 percent) for toluidine blue O. There were no false positive immunofluorescent stains. In a similar study of a series of 25 patients at another institution, a diagnosis of P. carinii pneumonia was made in 23 of 25 patients by staining of induced sputum. We conclude that examination of induced sputum is a rapid, sensitive, and inexpensive method for diagnosing P. carinii pneumonia and that indirect immunofluorescence is a practical and highly sensitive staining technique for establishing this diagnosis.

Are retinal arteriolar abnormalities related to atherosclerosis?: The Atherosclerosis Risk in Communities Study

The objective of this study was to describe associations of retinal arteriolar abnormalities with clinical and subclinical manifestations of atherosclerosis and a broad group of risk factors for vascular disease. A biracial population of 8772 adults (aged 48 to 72 years) living in 4 communities was examined from 1993 to 1995 were studied for that purpose. Retinal arteriovenous nicking and focal arteriolar narrowing were determined by light-box grading of a 45 degrees fundus photograph by use of a standardized protocol. Diameters of arterioles and venules were measured in digitized photographs, and a summary arteriolar-to-venular ratio was derived as an index of generalized arteriolar narrowing. Focal arteriolar narrowing was associated only with hypertension. Generalized arteriolar narrowing was associated with carotid plaque but not with any other evidence of atherosclerosis, either clinical (cardiovascular disease or stroke) or subclinical (carotid or popliteal artery thickness or lower limb obstructive disease), or with plasma cholesterol. It was also associated with smoking, with inflammatory markers (white blood cell count, fibrinogen, and reduced albumin), and with the triglyceride and high density lipoprotein cholesterol changes associated with inflammation. Arteriovenous nicking was inconsistently associated with subclinical atherosclerosis. It was not associated with cardiovascular disease, stroke, or plasma cholesterol. Arteriovenous nicking was associated with markers of inflammation and vascular endothelial dysfunction (von Willebrand factor and factor VIII). Arteriolar narrowing and nicking appear to be related to hypertension and inflammatory factors. Nicking may also be related to endothelial dysfunction. Results suggest that these arteriolar changes are pathologically distinct from atherosclerosis. Including their measurement in population studies may permit evaluation of the independent contribution of arteriolar disease to various ischemic diseases of the heart, brain, and other organs.

Abdominal wall strength, bulging, and hernia after TRAM flap breast reconstruction

The incidence of postoperative abdominal bulge, hernia, and the ability to do sit-ups was reviewed in a series of 268 patients who had undergone free TRAM (FTRAM) or conventional TRAM (CTRAM) flap breast reconstruction. Minimum follow-up was 6 months. Patients were divided into four groups: unilateral FTRAM (FT1P; n = 123), double-pedicle bilateral FTRAM (FT2P; n = 45), single-pedicle CTRAM (CT1P; n = 40), and double-pedicle or bilateral CTRAM (CT2P; n = 60). The incidence of abdominal bulges (3.8 percent) and hernia (2.6 percent) was similar in the four groups. Synthetic mesh, however, was required for reinforcement of donor site closure twice as often in the CTRAM patients. The ability to perform sit-ups was greatest in the FT1P group (63.0 percent), slightly lower in the CT1P group (57.1 percent), still lower in the FT2P group (46.2 percent), and lowest in the CT2P group (27.1 percent; p = 0.0005). Patients reconstructed with an FTRAM flap were more likely to be able to do sit-ups (58.3 percent) than were those reconstructed with a CTRAM flap (38.2 percent; p = 0.0074). Patients who had only one muscle pedicle used were more likely to be able to do sit-ups (61.7 percent) than were those who had two muscle pedicles used (35.6 percent; p = 0.0003). We conclude that the incidence of abdominal bulge or hernia is relatively independent of the type of TRAM flap used and the number of muscle pedicles harvested. On the other hand, postoperative abdominal strength, as measured by the ability do sit-ups, is influenced significantly by both of these factors.

Relationships of cerebral MRI findings to ultrasonographic carotid atherosclerosis in older adults : the Cardiovascular Health Study. CHS Collaborative Research Group

Cerebral magnetic resonance imaging (MRI) has demonstrated a high prevalence of infarct-like lesions, white matter hyperintensities, and evidence of cerebral atrophy in older adults. While these findings are generally believed to be related to ischemia and atherosclerosis, their relationship to atherosclerosis in the carotid arteries remains to be explored. Study subjects were part of the multicenter Cardiovascular Health Study, a cross-sectional study of 3502 women and men >/=65 years of age undergoing cranial MRI and carotid ultrasonography. MRI infarcts were detected in 1068 participants (29.3%) and measurable carotid plaque in 2745 (75.3%). MRI infarcts, ventricular and sulcal widening, and white matter score were strongly associated with carotid intimal-medial thickness (IMT) and stenosis degree after adjustment for age and sex (all P<0. 01). Associations with plaque characteristics were less strong and less consistent; MRI infarcts were weakly associated only with surface irregularity, and ventricular size was weakly associated only with lesion density (both P<0.04). In contrast, sulcal widening was strongly related to plaque characteristics, with scores being higher in those with heterogeneous and irregular plaque (both P<0. 009). Adjustment for other risk factors, and for carotid IMT/stenosis, removed associations of MRI findings with plaque characteristics except for weak relationships remaining between MRI infarcts and surface irregularity and between sulcal score and heterogeneous plaque (both P<0.03). MRI abnormalities show strong and consistent relationships with increasing carotid IMT and stenosis degree but less strong associations with plaque characteristics, especially after adjusting for IMT and stenosis.

Characteristics and crystal structure of bacterial inosine-5'-monophosphate dehydrogenase

IMP dehydrogenase (IMPDH) is an essential enzyme that catalyzes the first step unique to GTP synthesis. To provide a basis for the evaluation of IMPDH inhibitors as antimicrobial agents, we have expressed and characterized IMPDH from the pathogenic bacterium Streptococcus pyogenes. Our results show that the biochemical and kinetic characteristics of S. pyogenes IMPDH are similar to other bacterial IMPDH enzymes. However, the lack of sensitivity to mycophenolic acid and the Km for NAD (1180 microM) exemplify some of the differences between the bacterial and mammalian IMPDH enzymes, making it an attractive target for antimicrobial agents. To evaluate the basis for these differences, we determined the crystal structure of the bacterial enzyme at 1.9 A with substrate bound in the catalytic site. The structure was determined using selenomethionine-substituted protein and multiwavelength anomalous (MAD) analysis of data obtained with synchrotron radiation from the undulator beamline (19ID) of the Structural Biology Center at Argonne's Advanced Photon Source. S. pyogenes IMPDH is a tetramer with its four subunits related by a crystallographic 4-fold axis. The protein is composed of two domains: a TIM barrel domain that embodies the catalytic framework and a cystathione beta-synthase (CBS) dimer domain of so far unknown function. Using information provided by sequence alignments and the crystal structure, we prepared several site-specific mutants to examine the role of various active site regions in catalysis. These variants implicate the active site flap as an essential catalytic element and indicate there are significant differences in the catalytic environment of bacterial and mammalian IMPDH enzymes. Comparison of the structure of bacterial IMPDH with the known partial structures from eukaryotic organisms will provide an explanation of their distinct properties and contribute to the design of specific bacterial IMPDH inhibitors.

Risk factors and segment-specific carotid arterial enlargement in the Atherosclerosis Risk in Communities (ARIC) cohort

BACKGROUND AND PURPOSE

B-mode ultrasound imaging affords the opportunity to quantify both intimal-medial thickness (IMT) and lumen diameter of extracranial carotid arteries in ambulatory populations. Since the relation of IMT to lumen diameter may be complex, we asked whether cardiovascular disease risk factors (previously shown to be associated with greater arterial IMT) are related to smaller lumen diameters.

METHODS

We used B-mode ultrasound to quantify lumen diameter, interadventitial diameter, and IMT of the extracranial carotid arteries and assessed the relationship of these measures to body mass index, smoking, low-density lipoprotein (LDL) and high-density lipoprotein cholesterol, hypertension, and diabetes in 6088 male and 7493 female participants in the Atherosclerosis Risk in Communities (ARIC) cohort.

RESULTS

Smoking, hypertension, and LDL cholesterol were consistently related to greater IMT in the common and internal carotid arteries of men and women, as has been previously reported. In the internal carotid artery, smoking, hypertension, and LDL cholesterol were consistently related to smaller lumens. In the common carotid artery, body mass index, smoking, and hypertension were related to significantly larger, and LDL cholesterol to smaller, lumens. Thus, only LDL cholesterol was consistently associated with smaller lumens in both the common and internal carotid arteries.

CONCLUSIONS

Risk factors relate positively to IMT in both the common and internal carotid arteries and inversely with lumen diameter in the internal carotid artery, in parallel with their relation to clinical events. However, their association with lumen diameters of the common carotid artery in population-based samples is more complex, and in some cases adverse levels of risk factors may be associated with larger lumens.

Cloning and characterization of the t(X;11) breakpoint from a leukemic cell line identify a new member of the forkhead gene family

Chromosome translocations involving 11q23 are associated with a number of different types of leukemia. These translocations fuse a gene encoding a putative transcription factor, HTRXI, to genes on other chromosomes. We report cloning and sequencing the t(X;11) breakpoint region from a cell line established from an infant with acute lymphocytic leukemia. The gene AFXI, on the X chromosome, is expressed in a variety of cell types. Sequence analysis indicates a high degree of homology between AFXI and the forkhead family of transcription factors. The high degree of identity within the forkhead region and the lack of homology outside that region suggest that AFXI represents a novel forkhead family member. It is predicted that a chimeric fusion protein with altered DNA binding activity will be the result of the translocation.

Developmental capacity, energy metabolism and ultrastructure of mature oocytes from prepubertal and adult sheep

Development to the blastocyst stage was assessed for oocytes obtained from prepubertal and adult sheep matured and fertilized in vitro. The proportion of cleaved oocytes reaching the blastocyst stage was significantly lower for oocytes derived from prepubertal sheep than for those from adult sheep (7.4% and 24.6% respectively). There were no differences in the metabolism of glucose, glutamine or pyruvate between oocytes matured in vivo and in vitro, or of glucose or pyruvate between oocytes from prepubertal and adult sheep. Glutamine metabolism by mature oocytes from prepubertal sheep was significantly lower than that by oocytes from adult sheep. Ultrastructural studies revealed no differences in the morphology of cytoplasmic organelles of oocytes matured in vitro from prepubertal and adult sheep, but differences in the volume fraction and size of mitochondria and cortical granules were observed. These data suggest that mature oocytes from prepubertal sheep do not possess the developmental potential of their adult-derived counterparts, and this phenomenon may be associated with metabolic and ultrastructural anomalies.

Beriplex P/N reverses severe warfarin-induced overanticoagulation immediately and completely in patients presenting with major bleeding

In an open non-randomized study, 10 patients with major bleeding and an Internationalized Normal Ratio (INR) greater than 14 were treated with 5 mg of intravenous vitamin K and 30 iu/kg of a single concentrate containing factors II, VII, IX and X (Beriplex P/N; Aventis Behring). The levels of these factors before and immediately after treatment were 4.7, 1.6, 8.5 and 1.1 iu/dl and 94, 30, 66 and 91 iu/dl respectively. The median INR before treatment was greater than 20 and, after treatment, 1.1. All patients had a satisfactory clinical response with immediate cessation of bleeding, and no thromboembolic complications occurred.

The spectrum of pathology in central core disease

Central core disease is a congenital myopathy with muscle weakness defined pathologically by the presence of extensive areas in muscle fibres that are devoid of oxidative enzyme activity. The gene responsible has been shown to be the ryanodine receptor 1 on chromosome 19q13 and mutations have now been identified in several patients. Some cases with the morphological defect remain molecularly undefined, particularly those studied before molecular studies were available. We have studied three families with congenital onset, each with a dominantly inherited mutation in a C-terminal exon of the ryanodine receptor 1. They illustrate the spectrum of pathology that can be observed in patients with the myopathic features of central core disease. We show that extensive fibrosis and fat may be present, type 1 fibre uniformity may occur in the absence of cores; cores may be central or peripheral, single or multiple; and that an appearance of multiple focal minicores might cause a diagnostic pathological dilemma. In addition, we show the value of immunocytochemistry in identifying cores, in particular the use of antibodies to desmin and gamma-filamin.

Capacitation status and fertility of fresh and frozen-thawed ram spermatozoa

The effect of cryopreservation on the capacitation status and fertility of ram spermatozoa was observed. After the chlortetracycline staining technique was validated for ram spermatozoa, it was applied to fresh or long-term frozen-stored spermatozoa. Fresh spermatozoa displayed mainly the F pattern (non-capacitated; 61.3%), becoming B pattern (capacitated; 54%) and AR pattern (acrosome reacted; 41%) with incubation (6 h at 37 degrees C). In contrast, frozen spermatozoa displayed the B pattern (65.9%), becoming the AR pattern (64.2%) with incubation. This demonstrates that cryopreservation may cause membrane changes in ram spermatozoa functionally equivalent to capacitation. The differences in capacitation status did not affect in vitro fertilization rates between fresh and frozen spermatozoa, but pregnancy rates at Day 18 after intrauterine artificial insemination were higher for fresh than for frozen spermatozoa. This difference was not evident at Day 50, possibly as a result of the high embryonic loss between Days 18 and 50 when fresh unincubated and frozen incubated spermatozoa were inseminated. Further research is necessary to determine what part of the cryopreservation process is responsible for the membrane changes in ram spermatozoa.

Normal fertility in ewes after cervical insemination with frozen-thawed spermatozoa supplemented with seminal plasma

The effect of seminal plasma (SP) on the motility, capacitation status, penetration through cervical mucus and fertility of frozen-thawed ram spermatozoa was examined. In the presence of SP, motility of frozen-thawed spermatozoa was better (P<0.001) and there were more uncapacitated and less acrosome-reacted cells in comparison with controls (P<0.001). Frozen thawed spermatozoa were also better able to penetrate cervical mucus after addition of SP. Addition of SP increased the percentage of ewes pregnant after insemination of frozen-thawed (39/94, 41.5% v. 51/92, 55.4%; P<0.05) but not fresh spermatozoa (34/55, 61.8% v. 42/58, 72.4% for 0 v. 30% SP in the resuspension medium). Moreover, SP improved pregnancy rates after cervical (14/50; 28% v. 25/49; 51%; P<0.05) but not intrauterine insemination (25/44; 56.8 v. 26/43; 60.5%) with frozen-thawed spermatozoa. In a second experiment, pregnancy rates were 30/45 (66.7%), 9/37 (24.3%) and 24/40 (60.0%) for ewes inseminated with frozen-thawed spermatozoa in the uterus (control), cervix without SP and cervix after supplementation with SP, respectively (P<0.01 for unsupplemented v. supplemented spermatozoa). These experiments demonstrate that impaired function of cryopreserved spermatozoa can be overcome by addition of SP, resulting in normal fertility after cervical AI.

Clinical follow-up after bilateral risk reducing ('prophylactic') mastectomy: mental health and body image outcomes

BACKGROUND

In Manchester, approximately 120 women at > or = 1:4 lifetime risk of breast cancer have considered preventative surgery since 1992. Women treated within the Manchester protocol receive two genetic counselling sessions, a psychological assessment and a surgical consultation pre-operatively and annual follow-up post-operatively. The vast majority of women have breast reconstruction.

METHODS

Since 1996, mental health and body image have been assessed in women attending annual follow-up using self-report questionnaires: the 28-item General Health Questionnaire (GHQ) and 10-item Body Image Scale (BIS). Women with high scores are assessed by clinical interview together with a proportion who have no significant problems.

RESULTS

Between 1995 and 1999, 76 women completed surgery. Ten were awaiting post-operative review and 60 (91%) attended for follow-up of whom 45 (75%) were interviewed. Questionnaire data were available for 52 (79%) women, mean age 40.8 years (range 27-58). Six women were gene mutation carriers and of these three had had breast cancer. One additional patient was affected but had not been genetically tested. Eight (17%) of 47 women with assessments in the first post-operative year scored in the 'caseness' range on the GHQ: the mean GHQ score was 3.8 (S.D. 6.7), range 0-25. Results were comparable with those for women attending the Family History Clinic for risk assessment. The mean score on the BIS was 5.1 (S.D. 5.5), range 0-25, comparable with scores for women undergoing conservative surgery for breast cancer. Twenty-one percent of women reported no negative change in body image following surgery (i.e. zero questionnaire summary scores) and the majority of changes reported were of minor degree (item scores 0 or 1). The most frequently reported changes were in sexual attractiveness (55%), feeling less physically attractive (53%) and self-consciousness about appearance (53%): a third of women felt less feminine to a minimal degree. These results appeared stable over time. A minority of women had more serious psychological or body image concerns, usually in relation to surgical complications: they received further psychiatric intervention.

CONCLUSIONS

For the majority of women there is no evidence of significant mental health or body image problems in the first 3 years following Bilateral Prophylactic Mastectomy (BPM), but women who have complications warrant additional psychological help. Careful pre-operative preparation and long-term monitoring are advocated in this new field of cancer prevention.

Potentiation of methicillin activity against methicillin-resistant Staphylococcus aureus by diterpenes

Totarol is a diterpene compound extracted from the totara tree. Totarol and eight other diterpenes were found to potentiate methicillin, one reducing the minimum inhibitory concentration of methicillin against resistant Staphylococcus aureus 256-fold. Totarol did not inhibit the synthesis of DNA or peptidoglycan in S. aureus, but reduced the respiration rate by 70%. Under potentiation conditions, diterpenes had only a slight effect on the respiration rate, but had a significant effect on expression of PBP 2a. We conclude that the primary staphylococcal target for totarol is the respiratory chain, but that potentiation of methicillin by diterpenes is by interference with PBP 2a expression.

Integration of sperm sexing technology into the ART toolbox

Sex-sorting of mammalian spermatozoa has applications for genetic improvement of farm animals, in humans for the control of sex-linked disease, and in wildlife as a captive management strategy and for the re-population of endangered species. Considerable research has been undertaken worldwide on the Beltsville sperm sexing technology, the only effective method for pre-selection of sex of offspring. The combination of this method with assisted reproductive technologies has resulted in the birth of offspring in a wide range of animals, including cattle, the only livestock species in which sperm sexing is used commercially. Major improvements in the efficiency of sorting, in particular the development of high speed sorting (15 million X and Y spermatozoa per hour) have led to the production of offspring using conventional and low dose AI and the successful cryopreservation of sorted spermatozoa in cattle, sheep, horses and elk. A major limitation remains the short viable lifespan of sorted spermatozoa in the female genital tract, in most species necessitating sperm deposition deep in the uterus, and close to the expected time of ovulation, for acceptable fertility after in vivo insemination. Special deep uterine insemination technology has been employed to produce offspring in pigs and horses using low sperm doses. Considerable attention has been paid to reduction of the damage and capacitation-like changes to spermatozoa that result from flow cytometric sorting and from freezing and thawing. However, high-purity sorting of liquid-stored or frozen-thawed spermatozoa for immediate use, or re-cryopreservation for later use, does not reduce its fertilizing capacity in vitro, allowing its combination with in vitro fertilization or juvenile in vitro embryo transfer to produce blastocysts, and offspring in sheep and cattle after embryo transfer. Further research into sorting and preservation methods that incorporate strategies to prevent destabilization of sperm membranes may improve the fertilizing lifespan of flow cytometrically sorted spermatozoa. With continued improvement in sorting instrumentation and biological handling, sorting efficiency should reach a point where commercially acceptable pregnancy rates may be achieved in a number of species after conventional or deep uterine insemination.

Taking MAD to the extreme: ultrafast protein structure determination

Multiwavelength anomalous diffraction data were measured in 23 min from a 16 kDa selenomethionyl substituted protein, producing experimental phases to 2.25 A resolution. The data were collected on a mosaic 3 x 3 charge-coupled device using undulator radiation from the Structural Biology Center 19ID beamline at the Argonne National Laboratory's Advanced Photon Source. The phases were independently obtained semiautomatically by two crystallographic program suites, CCP4 and CNS. The quality and speed of this data acquisition exemplify the opportunities at third-generation synchrotron sources for high-throughput protein crystal structure determination.

The effects of raloxifene on tibia histomorphometry in ovariectomized rats

Tissue-specific estrogen agonists may be useful in protecting against osteoporosis and the increased risk of coronary heart disease in postmenopausal women with minimal undesired effects on reproductive tissues. The actions of the mixed estrogen agonist/antagonist raloxifene on selected estrogen target tissues were determined in ovariectomized (OVX) rats immediately postovariectomy. Five groups of 75-day-old Sprague-Dawley rats were studied; baseline controls, sham-operated controls, OVX controls, OVX animals treated with estrogen (0.1 mg 17 alpha-ethynyl estradiol/kg.day), and OVX animals treated with raloxifene (3 mg/kg.day). Fluorochrome labels were given on days 1, 28, and 34. The baseline controls were killed on day 2, and the remaining groups on day 35. Ovariectomy increased tibial longitudinal growth rate as well as measurements related to radial growth and cancellous bone turnover. Ovariectomy decreased cancellous bone area and uterine weight, and increased serum cholesterol, bone elongation, and radial bone growth. Estrogen treatment prevented these changes in OVX rats. Raloxifene prevented cancellous osteopenia as well as the changes in radial bone growth, bone resorption, and blood cholesterol, but was less effective in reducing cancellous bone formation and did not prevent uterine atrophy. These findings suggest that raloxifene is a target-specific, mixed estrogen agonist/antagonist. At the concentration studied, raloxifene had potent estrogenic activity on bone resorption and serum cholesterol, a lesser effect on bone formation, and minimal activity on uterine wet weight.

Effect of olfactory bulb ablation on spread of a neurotropic coronavirus into the mouse brain

Previous results suggested that, after intranasal inoculation, mouse hepatitis virus (MHV), a neurotropic coronavirus, entered the central nervous system (CNS) via the olfactory and trigeminal nerves. To prove this hypothesis, the effect of interruption of the olfactory pathway on spread of the virus was studied using in situ hybridization. Unilateral surgical ablation of this pathway prevented spread of the virus via the olfactory tract on the side of the lesion. MHV RNA could be detected, however, at distal sites on the operated side, indicating that the virus spread via well-described circuits involving the anterior commissure from the control (intact) side of the brain. Viral transport via the trigeminal nerve was not affected by removal of the olfactory bulb, showing that the surgical procedure was specific for the olfactory pathway. These results prove conclusively that MHV gains entry to the CNS via a transneuronal route, and spreads to additional sites in the brain via known neuroanatomic pathways.

Birth of a male lamb derived from an in vitro matured oocyte fertilised by intracytoplasmic injection of a single presumptive male sperm

The developmental competence of in vitro matured ovine oocytes, cytoplasmically injected with single male or female chromosome-bearing sperm, was investigated. Eighty-five unsorted, 92 'female-sorted' and 74 'male-sorted' ram sperm were injected into in vitro matured sheep oocytes and, two to four hours later, placed into the oviducts of 28 oestrous sheep. The sperm were separated according to sex by analysis of their DNA content with a flow cytometer. One pregnancy was diagnosed by ultrasound after 55 days and a 3 kg male lamb was born after 150 days gestation. This lamb was derived from an oocyte injected with 'male-sorted' sperm.