Osteoprotegerin: a novel secreted protein involved in the regulation of bone density

A novel secreted glycoprotein that regulates bone resorption has been identified. The protein, termed Osteoprotegerin (OPG), is a novel member of the TNF receptor superfamily. In vivo, hepatic expression of OPG in transgenic mice results in a profound yet nonlethal osteopetrosis, coincident with a decrease in later stages of osteoclast differentiation. These same effects are observed upon administration of recombinant OPG into normal mice. In vitro, osteoclast differentiation from precursor cells is blocked in a dose-dependent manner by recombinant OPG. Furthermore, OPG blocks ovariectomy-associated bone loss in rats. These data show that OPG can act as a soluble factor in the regulation of bone mass and imply a utility for OPG in the treatment of osteoporosis associated with increased osteoclast activity.

The transcriptional landscape of the mammalian genome

This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5' and 3' boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.

Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies

OBJECTIVE

To determine the risk of lung cancer associated with exposure at home to the radioactive disintegration products of naturally occurring radon gas.

DESIGN

Collaborative analysis of individual data from 13 case-control studies of residential radon and lung cancer.

SETTING

Nine European countries.

SUBJECTS

7148 cases of lung cancer and 14,208 controls.

MAIN OUTCOME MEASURES

Relative risks of lung cancer and radon gas concentrations in homes inhabited during the previous 5-34 years measured in becquerels (radon disintegrations per second) per cubic metre (Bq/m3) of household air.

RESULTS

The mean measured radon concentration in homes of people in the control group was 97 Bq/m3, with 11% measuring > 200 and 4% measuring > 400 Bq/m3. For cases of lung cancer the mean concentration was 104 Bq/m3. The risk of lung cancer increased by 8.4% (95% confidence interval 3.0% to 15.8%) per 100 Bq/m3 increase in measured radon (P = 0.0007). This corresponds to an increase of 16% (5% to 31%) per 100 Bq/m3 increase in usual radon--that is, after correction for the dilution caused by random uncertainties in measuring radon concentrations. The dose-response relation seemed to be linear with no threshold and remained significant (P = 0.04) in analyses limited to individuals from homes with measured radon < 200 Bq/m3. The proportionate excess risk did not differ significantly with study, age, sex, or smoking. In the absence of other causes of death, the absolute risks of lung cancer by age 75 years at usual radon concentrations of 0, 100, and 400 Bq/m3 would be about 0.4%, 0.5%, and 0.7%, respectively, for lifelong non-smokers, and about 25 times greater (10%, 12%, and 16%) for cigarette smokers.

CONCLUSIONS

Collectively, though not separately, these studies show appreciable hazards from residential radon, particularly for smokers and recent ex-smokers, and indicate that it is responsible for about 2% of all deaths from cancer in Europe.

3H-baclofen and 3H-GABA bind to bicuculline-insensitive GABA B sites in rat brain

The presence of a novel receptor for the neurotransmitter gamma-aminobutyric acid (GABA) on peripheral autonomic nerve terminals and in mammalian brain slices has been described recently. This receptor differs from the classical GABA site as it is unaffected by recognized GABA antagonists such as bicuculline and is not sensitive to the majority of accepted GABA-mimetics such as 3-aminopropanesulphonic acid (3-APS) or isoguvacine. We propose to designate the classical site as the GABA A and the novel site as the GABA B receptor. The beta-p-chlorophenyl derivative of GABA, baclofen, is stereospecifically active at the GABA B site whereas it is devoid of activity at the classical GABA A3 site. We now report that high-affinity saturable binding of 3H-baclofen and 3H-GABA to the GABA B site can be detected in fragments of crude synaptic membranes prepared from rat brain. The results support the concept of a novel GABA receptor within the mammalian brain and show that GABA and baclofen can compete for the same recognition site.

Long-term maintenance of weight loss: current status

Intervention strategies for promoting long-term weight loss are examined empirically and conceptually. Weight control research over the last 20 years has dramatically improved short-term treatment efficacy but has been less successful in improving long-term success. Interventions in preadolescent children show greater long-term efficacy than in adults. Extending treatment length and putting more emphasis on energy expenditure have modestly improved long-term weight loss in adults. Fresh ideas are needed to push the field forward. Suggested research priorities are patient retention, natural history, assessment of intake and expenditure, obesity phenotypes, adolescence at a critical period, behavioral preference-reinforcement value, physical activity and social support, better linkage of new conceptual models to behavioral treatments, and the interface between pharmacological and behavioral methods.

Toxoplasma gondii: transmission, diagnosis and prevention

Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is one of the most common parasitic infections of man and other warm-blooded animals. It has been found world-wide from Alaska to Australia. Nearly one-third of humanity has been exposed to this parasite. In most adults it does not cause serious illness, but it can cause blindness and mental retardation in congenitally infected children and devastating disease in immunocompromised individuals.

Functional annotation of a full-length mouse cDNA collection

The RIKEN Mouse Gene Encyclopaedia Project, a systematic approach to determining the full coding potential of the mouse genome, involves collection and sequencing of full-length complementary DNAs and physical mapping of the corresponding genes to the mouse genome. We organized an international functional annotation meeting (FANTOM) to annotate the first 21,076 cDNAs to be analysed in this project. Here we describe the first RIKEN clone collection, which is one of the largest described for any organism. Analysis of these cDNAs extends known gene families and identifies new ones.

Why children start smoking cigarettes: predictors of onset

We review findings from 27 prospective studies of the onset of cigarette smoking conducted since 1980. Almost 300 measures of predictors of smoking onset were examined, and 74% of them provided multivariate support for predictors of onset derived from theory and previous empirical findings. Expected relationships were strongly supported for (a) socioeconomic status, with students with compromised status being more likely to try smoking; (b) social bonding variables, particularly peer and school bonding, with less support for family bonding; (c) social learning variables, especially peer smoking and approval, prevalence estimates, and offers/availability, with less consistent support for parent smoking and approval; (d) refusal skills self efficacy; (e) knowledge, attitudes and intentions, with the expected stronger predictions from intentions than from attitudes than from knowledge; and (f) broad indicators of self-esteem. The few investigators who analyzed their data separately by age, gender, or ethnicity found many differences by these factors, though there were too few of them to detect any pattern with confidence. Though the 27 studies are far from perfect, we believe that they confirm the importance of many well-accepted predictors and raise some questions about others. In particular, family smoking, bonding and approval each received unexpectedly low support. It is not clear whether this lack of support reflects reality as it has always been, is due to a changing reality, reflects developmental changes, either in the age of subjects or the stage of onset, or is due to poor measurement and too few tests. Future prospective studies need to be theory-driven, use measures of known reliability and validity, report analyses of scale properties, and use statistical methods appropriate to the hypotheses or theories under study. Finally, we encourage more investigations of the potentially different predictors of transitions to experimental or regular cigarette smoking. This will require multi-wave studies and careful measurement of changes in smoking behavior.

Use of the automatic external defibrillator in the management of out-of-hospital cardiac arrest

The automatic external defibrillator is a simple device that can be used by nonprofessional rescuers to treat cardiac arrest. In 1287 consecutive patients with out-of-hospital cardiac arrest, we assessed the results of initial treatment with this device by firefighters who arrived first at the scene, as compared with the results of standard defibrillation administered by paramedics who arrived slightly after the firefighters. Of 276 patients who were initially treated by firefighters using the automatic defibrillator, 84 (30 percent) survived to hospital discharge (expected rate according to a logistic model, 17 percent; P less than 0.001), as compared with 44 (19 percent) of 228 patients when fire-fighters delivered only basic cardiopulmonary resuscitation and the first defibrillation was performed after the arrival of the paramedic team. Few patients with conditions other than ventricular fibrillation survived. In a multivariate analysis of characteristics that influenced survival after ventricular fibrillation, a better survival rate was related to a witnessed collapse (odds ratio, 3.9; 95 percent confidence interval, 2.0 to 7.6), younger age (odds ratio, 1.2; 95 percent confidence interval, 1.0 to 1.4), the presence of "coarse" (higher-amplitude) fibrillation (odds ratio, 4.2; 95 percent confidence interval, 1.6 to 11.0), a shorter response time for paramedics (odds ratio, 1.4; 95 percent confidence interval, 1.0 to 2.1), and initial treatment by firefighters using an automatic external defibrillator (odds ratio, 1.8; 95 percent confidence interval, 1.1 to 2.9). These findings support the widespread use of the automatic external defibrillator as an important part of the treatment of out-of-hospital cardiac arrest, although the overall impact of the use of this device on community survival rates is still uncertain.

Characteristics of GABAB receptor binding sites on rat whole brain synaptic membranes

1 Saturable binding of (+/-)-[3H]-baclofen and [3H]-gamma- aminobutyric acid ([3H]-GABA) to rat brain crude synaptic membranes has been examined by means of a centrifugation assay. 2 The binding of [3H]-baclofen could be detected in fresh or previously frozen tissue and was dependent on the presence of physiological concentrations of Ca2+ or Mg2+ although a lower affinity Na+ -dependent component could also be observed. Both components probably reflect binding to receptor recognition sites. 3 The saturable portion of bound [3H]-baclofen formed 20.3 +/- 6.9% of total bound ligand. This could be displaced by GABA (IC50 = 0.04 microM), (-)-baclofen (0.04 microM) and to a much lesser extent by (+)-baclofen (33 microM). Isoguvacine, piperidine-4-sulphonic acid and bicuculline methobromide were inactive (up to 100 microM) and muscimol was only weakly active (IC50 = 12.3 microM). 4 Saturable binding of [3H]-GABA increased on adding CaCl2 or MgSO4 (up to 2.5 mM and 5.0 mM respectively) to the Tris-HCl incubation solution. This binding (GABAB site binding) was additional to the bicuculline-sensitive binding of GABA (GABAA site binding) and could be completely displaced by (-)-baclofen (IC50 = 0.13 microM). 5 Increasing the Ca2+ concentration (0 to 2.5 mM) increased the binding capacity of the membranes without changing their affinity for the ligand. 6 The binding of [3H]-GABA to GABAB sites could be demonstrated in fresh as well as previously frozen membranes with a doubling of the affinity being produced by freezing. Further incubation with the non-ionic detergent Triton-X-100 (0.05% v/v) reduced the binding capacity by 50%. 7 The pharmacological profile of displacers of [3H]-GABA from GABAB sites correlated well with that for [3H]-baclofen displacement. A correlation with data previously obtained in isolated preparations of rat atria and mouse vas deferens was also apparent. 8 It is concluded that [3H]-baclofen or [3H]-GABA are both ligands for the same bicuculline-insensitive, divalent cation-dependent binding sites in the rat brain.

Treatment of giardiasis

Giardia lamblia is both the most common intestinal parasite in the United States and a frequent cause of diarrheal illness throughout the world. In spite of its recognition as an important human pathogen, there have been relatively few agents used in therapy. This paper discusses each class of drugs used in treatment, along with their mechanism of action, in vitro and clinical efficacy, and side effects and contraindications. Recommendations are made for the preferred treatment in different clinical situations. The greatest clinical experience is with the nitroimidazole drugs, i.e., metronidazole, tinidazole, and ornidazole, which are highly effective. A 5- to 7-day course of metronidazole can be expected to cure over 90% of individuals, and a single dose of tinidazole or ornidazole will cure a similar number. Quinacrine, which is no longer produced in the United States, has excellent efficacy but may be poorly tolerated, especially in children. Furazolidone is an effective alternative but must be administered four times a day for 7 to 10 days. Paromomycin may be used during early pregnancy, because it is not systematically absorbed, but it is not always effective. Patients who have resistant infection can usually be cured by a prolonged course of treatment with a combination of a nitroimidazole with quinacrine.

Bicuculline-insensitive GABA receptors on peripheral autonomic nerve terminals

The action of gamma-aminobutyric acid (GABA) and related compounds on rat isolated atria and mouse and guinea pig isolated vas deferens has been studied. GABA depressed the evoked but not basal release of [3H]noradrenaline from atria (IC50 4 micro M) and reduced the twitch responses of the vas deferens (IC50 3 micro M) in a dose-dependent manner. These depressant effects were not prevented by recognized GABA antagonists such as bicuculline and picrotoxin. Numerous GABA analogues, in particular 3-aminopropanesulphonic acid, failed to mimic the action of GABA. However, beta-p-chlorophenyl GABA (baclofen) was stereospecifically active. Other related beta-substituted derivatives were also active but to a lesser degree than GABA. Pretreatment of the vas deferens with the neuronal GABA uptake inhibitors 2,4-diaminobutyric acid or cis-3-aminocyclohexanecarboxylic acid potentiated the action of GABA. These data suggest the presence of a bicuculline-insensitive GABA receptor on autonomic nerve terminals. Preliminary observations indicate a lack of chloride ion dependence in the action of GABA at this site.

Cytokines in alcoholic liver disease

Cytokines are low-molecular-weight mediators of cellular communication produced by multiple cell types in the liver, with the Kupffer cell critically important. Inflammatory cytokines such as tumor necrosis factor, interleukin-1, and interleukin-8, and hepatic acute-phase cytokines such as interleukin-6 play a role in modulating certain metabolic complications in alcoholic liver disease and probably play a role in the liver injury of alcoholic liver disease. Two potential inducers of cytokine production in alcoholic liver disease are endotoxin and reactive oxygen species generated after ethanol metabolism. Cytotoxic cytokines likely induce liver cell death by both necrosis and apoptosis in alcoholic liver disease. Anticytokine therapy has been highly successful in attenuating cell injury/death in a variety of toxin-induced models of liver injury, including alcohol-related liver injury. Anticytokine therapy has been used successfully in humans in disease processes such as Crohn's disease and rheumatoid arthritis. There is an emerging rationale for use of anticytokine therapy in alcoholic liver disease, with the goal of maintaining beneficial effects of cytokines and inhibition of the deleterious effects of these potentially toxic agents.

Gender differences in social support and physical health

A large body of prospective data has accumulated linking social support to health, and most social scientists agree that low levels of support are associated with poor physical and mental health. Unfortunately, most of the research has been limited to White men. When women and people of color are included in the designs, the relationships between social support and physical health are more complicated. Prospective population-based studies provide evidence that low support is associated with increased risk of mortality in women. However, in several studies, results indicated that, for specific age groups, women with high social support have increased risk of mortality. Factors that may contribute to the observed gender differences in the social support-physical health relationship are discussed. Future research should include adequate numbers of women and more sophisticated measures of social support to move the field forward.

GABA receptor multiplicity. Visualization of different receptor types in the mammalian CNS

Receptors for GABA in the mammalian brain are not homogeneous. A clear separation exists between receptors which recognize the antagonist bicuculline and a population which does not. These two classes have been designated GABAA and GABAB sites respectively. Within the GABAA category there may also be many subtypes which exhibit subtle pharmacological differences. Numerous centrally-active agents influence GABAA site function generally via an allosteric interaction. By comparison very few substances currently available interact with GABAB sites. The GABAA and GABAB sites show many contrasting characteristics not least of which is their distribution pattern within the rat brain. Autoradiographic analysis has indicated that although both receptors may be present within many regions, in some areas only one type is present. For example, GABAA sites only are present in the lamina molecularis of the olfactory bulb and granule cell layer of the cerebellum whereas GABAB sites are present in the interpeduncular nucleus without any evidence of GABAA sites. In the spinal cord GABAB sites are unevenly distributed with high densities in laminae I-IV. GABAA sites are more uniformly distributed throughout the dorsal and ventral horns. In conclusion, there is now good evidence for multiple GABA receptors and the way is open to determine the functional significance of the GABAB receptor in relation to the now classical GABAA site.

Health problems in a large cohort of Americans traveling to developing countries

BACKGROUND

Millions of Americans visit developing countries each year, however, little is known about their health during travel. This study describes health problems in a large cohort of American travelers during and after their trip.

METHODS

A 2-year survey of 784 travelers (95% follow-up) was conducted for persons traveling for < or = 90 days. At the pretravel visit, travelers were given a postcard to record adverse health events. Following travel, standardized telephone interviews were performed for any positive responses, or if the card was not returned. All travelers were contacted 2 months after return to determine late occurring illness and compliance with antimalarials.

RESULTS

Travelers had a mean age of 44 years, a median duration of 19 days, and visited 123 countries. An illness was reported by 64% (1.6 illnesses per traveler). Ill travelers were more often female, and traveled longer than those who were not ill; depending upon destination, each day of travel increased by 3 to 4% the chance of becoming ill. Diarrhea was most common, occurring in 46%; 34% met a strict definition for traveler's diarrhea. Respiratory illness occurred in 26%, skin disorders in 8%, acute mountain sickness in 6%, motion sickness in 5%, accidents and injuries in 5%, and isolated febrile episodes in 3%. Medical care was sought by 8% of all travelers and 12% of those reporting illness. On return, 26% of travelers were ill, 56% of whom became ill after return. Diarrhea, respiratory illness, skin disorders, and febrile syndromes were most common, and 46% of those who were ill sought medical care. Complete compliance with antimalarials was 80%. Noncompliant individuals usually discontinued medications on return. Side effects were reported by 4% of those taking chloroquine, 11% of those taking chloroquine plus proguanil, and 14% of those taking mefloquine, with half of these neuropsychiatric. The incidence of documented malaria was 3.8 cases per 1,000 travelers.

CONCLUSIONS

Many travelers experience adverse health events during and after travel to the developing world. Attention to the prevention and therapy of traveler's diarrhea, prophylaxis of malaria, management of respiratory illness, personal safety, and access to medical care during travel, and, recognition of clinical syndromes after return, will help to improve the traveler's health.

Effect of a serogroup A meningococcal conjugate vaccine (PsA-TT) on serogroup A meningococcal meningitis and carriage in Chad: a community study [corrected]

BACKGROUND

A serogroup A meningococcal polysaccharide-tetanus toxoid conjugate vaccine (PsA-TT, MenAfriVac) was licensed in India in 2009, and pre-qualified by WHO in 2010, on the basis of its safety and immunogenicity. This vaccine is now being deployed across the African meningitis belt. We studied the effect of PsA-TT on meningococcal meningitis and carriage in Chad during a serogroup A meningococcal meningitis epidemic.

METHODS

We obtained data for the incidence of meningitis before and after vaccination from national records between January, 2009, and June, 2012. In 2012, surveillance was enhanced in regions where vaccination with PsA-TT had been undertaken in 2011, and in one district where a reactive vaccination campaign in response to an outbreak of meningitis was undertaken. Meningococcal carriage was studied in an age-stratified sample of residents aged 1-29 years of a rural area roughly 13-15 and 2-4 months before and 4-6 months after vaccination. Meningococci obtained from cerebrospinal fluid or oropharyngeal swabs were characterised by conventional microbiological and molecular methods.

FINDINGS

Roughly 1·8 million individuals aged 1-29 years received one dose of PsA-TT during a vaccination campaign in three regions of Chad in and around the capital N'Djamena during 10 days in December, 2011. The incidence of meningitis during the 2012 meningitis season in these three regions was 2·48 per 100,000 (57 cases in the 2·3 million population), whereas in regions without mass vaccination, incidence was 43·8 per 100,000 (3809 cases per 8·7 million population), a 94% difference in crude incidence (p<0·0001), and an incidence rate ratio of 0·096 (95% CI 0·046-0·198). Despite enhanced surveillance, no case of serogroup A meningococcal meningitis was reported in the three vaccinated regions. 32 serogroup A carriers were identified in 4278 age-stratified individuals (0·75%) living in a rural area near the capital 2-4 months before vaccination, whereas only one serogroup A meningococcus was isolated in 5001 people living in the same community 4-6 months after vaccination (adjusted odds ratio 0·019, 95% CI 0·002-0·138; p<0·0001).

INTERPRETATION

PSA-TT was highly effective at prevention of serogroup A invasive meningococcal disease and carriage in Chad. How long this protection will persist needs to be established.

FUNDING

The Bill & Melinda Gates Foundation, the Wellcome Trust, and Médecins Sans Frontères.

Cytokines and alcoholic liver disease

It is clear that cytokines cause metabolic disturbances that are similar to known complications of AH. TNF appears to be a proximal mediator of multiple types of experimental liver injury and TNF activity is elevated in ALD, as are the levels of certain other cytokines. On the other hand, low physiologic amounts of cytokines appear to be important for liver regeneration (and perhaps are beneficial to the organism as a whole). Goals for evaluation of anticytokine therapy in ALD will be: (1) determining the timing and type of the particular anticytokine employed (such as, immediate administration of antibody followed by an inhibitor of cytokine production), (2) appropriate monitoring of drug effects on cytokine metabolism as well as liver function and outcome, and (3) maintenance of the regenerative or positive physiologic effects of cytokines while blocking the cytolytic effects. Thus, we predict that ultimate anticytokine therapy will be directed at conserving the positive growth-enhancing effects of cytokines while attenuating their cytolytic effects.

Characterisation of [3H]gabapentin binding to a novel site in rat brain: homogenate binding studies

The binding characteristics of [3H]gabapentin, the radiolabelled analogue of the novel anticonvulsant gabapentin (1-(aminomethyl)cyclohexaneacetic acid) were studied using purified synaptic plasma membranes prepared from rat cerebral cortex. In 10 mM HEPES buffer [3H]gabapentin bound to a single population of sites with high affinity (KD = 38 +/- 2.8 nM) with a maximum binding capacity of 4.6 +/- 0.4 pmol/mg protein, reaching equilibrium after 30 min at 20 degrees C. This novel site was unique to the central nervous system with little or no specific [3H]gabapentin being measurable in a range of peripheral tissues. Binding was potently inhibited by a range of gabapentin analogues and 3-alkyl substituted gamma-aminobutyric acid (GABA) derivates although GABA itself and the selective GABAB receptor ligand baclofen, were only weakly active. Gabapentin itself (IC50 = 80 nM) and 3-isobutyl GABA (IC50 = 80 nM) which also has anticonvulsant properties, showed the highest affinity for the binding site. Of a wide range of other pharmacologically active compounds only the polyamines spermine and spermidine influenced [3H]gabapentin binding, with both compounds producing a maximum of 50% inhibition of specific binding. Magnesium ions produced a similar pattern of inhibition but the effect of the polyamines and magnesium ions were not additive. The data provide evidence for the existence in brain of a novel binding site that may mediate the anticonvulsant effects of gabapentin and other potential anticonvulsant compounds.

Management of renovascular disease: a review of renal artery stenting in ten studies

To evaluate the efficacy and safety of renal artery stents in renovascular disease, we identified 10 descriptive studies containing sufficient information for systematic evaluation. No randomized comparisons of stenting with angioplasty or with surgery were found. Overall, stents were placed in 416 renal arteries in 379 patients, mean age 64 years (range 27-84), 56% male. Of the stenoses, 97% were atheromatous (inter-study range 71-100%), 80% ostial (22-100%) and 31% bilateral (12-87%). The clinical indication for stenting was usually hypertension with or without mild renal impairment. Radiological indications for stenting were: narrowing of > or = 50% (in 9/10 studies) as a result of elastic recoil (58%) or dissection (2%) at the time of angioplasty; restenosis some time after angioplasty (15%); or as a primary procedure (25%). Technical success was reported in 96-100% of procedures. Restenosis (> or = 50% narrowing), evaluated in 312/416 (75%) arteries, generally between 6 and 12 months, was 16% overall. Hypertension was cured by stenting (DBP < or = 90 mmHg on no treatment) in 34/379 (9%) overall and in 34/207 (16%) of those whose renal function was normal initially. Six of 379 (1.6%) patients died within 30 days of stenting, but in only two (0.5%) was death judged to be procedure-related. Complications, other than those which led to dialysis, occurred in 42/379 (13%) patients, one third requiring intervention, ranging from blood transfusion to a surgical bypass procedure. Renal function as judged by serum creatinine concentration (SCC) improved in 26%, stabilized in 48% and deteriorated in 26% of patients whose renal function was impaired initially (SCC > 133 mumol/l). In one study, with average baseline SCC > 200 mumol/l, successful stenting slowed the rate of progression of renal failure when renal function was deteriorating beforehand. Nine of 379 (2.4%) patients, including 7/14 (50%) whose SCC was > or = 400 mumol/l initially, required dialysis after stenting. Stenting should be offered by specialist centres as a secondary procedure for unsuccessful angioplasty, or restenosis following angioplasty, to patients with renovascular disease and uncontrolled hypertension, advancing renal failure or pulmonary oedema.

Affective exchanges between young autistic children and their mothers

This study examined autistic children's social behavior, affect, and use of gaze during naturalistic interactions with their mothers. Sixteen autistic children, 30 to 70 months of age, and 16 normal children, matched on receptive language, participated. Children and their mothers were videotaped during three situations: a free-play period, a more structured period during which communicative demand was made on the child, and a face-to-face interaction. In all three situations, autistic and normal children did not differ in the frequency or duration of gaze at mother's face. In the one condition (face-to-face interaction) during which affective expressions were coded, autistic and normal children also were not found to differ significantly in the frequency or duration of smiles displayed, and neither group displayed frowns. However, autistic children were much less likely than normal children to combine their smiles with eye contact in a single act that conveyed communicative intent. Autistic and normal children were not found to differ in the percentages of smiles they displayed to social versus nonsocial events. However, when autistic children's responses to mother's smiles specifically were examined, it was found that they were much less likely to smile in response to mother's smiles than were normal children. Finally, it was found that mothers of autistic children displayed fewer smiles and were less likely to smile in response to their children's smiles, when compared with mothers of normal children. These findings suggest that the autistic child's unusual affective behavior may negatively affect the behavior of others.

Differentiation of central cholecystokinin receptor binding sites using the non-peptide antagonists MK-329 and L-365,260

Cholecystokinin (CCK) receptor binding was measured in rodent and primate brain and spinal cord using 125I-Bolton Hunter CCK-8 (125I-BH-CCK) and the selective non-peptide CCK antagonists MK-329 and L-365,260. In homogenate binding studies, L-365,260 displayed nanomolar affinity for CCK-B receptors in the cerebral cortex of several species including man (pIC50 congruent to 8.2) but showed low affinity for CCK-A receptors in the rat pancreas (pIC50 congruent to 6.3). By contrast, the CCK-A antagonist MK-329 showed the reverse selectivity (cortex: pIC50 congruent to 6.9, pancreas: pIC50 = 9.6). In autoradiographs of rat and monkey brain. 125I-BH-CCK binding was localized regionally with high levels being detected in the cerebral cortex, basal ganglia and some mid- and hindbrain nuclei. Specific 125I-BH-CCK binding was also localized to the substantia gelatinosa of the rat, monkey and human spinal cord. L-365,260 inhibited binding to most areas of the brain, but in the rat medial nucleus tractus solitarii and the monkey nucleus tractus solitarii. dorsomedial nucleus and infundibular hypothalamic nuclei together with the dorsomedial aspects of the caudate nucleus, where CCK-A sites are present, L-365,260 failed to displace all 125I-BH-CCK binding. In the primate spinal cord, L-365,260 was a relatively weak inhibitor of 125I-BH-CCK binding (pIC50 congruent to 6.0) whereas MK-329 showed high affinity for the CCK-A sites present there (pIC50 congruent to 9.6).(ABSTRACT TRUNCATED AT 250 WORDS)

High prevalence and abundant atypical genotypes of Toxoplasma gondii isolated from lambs destined for human consumption in the USA

Little information is available on the presence of viable Toxoplasma gondii in tissues of lambs worldwide. The prevalence of T. gondii was determined in 383 lambs (<1 year old) from Maryland, Virginia and West Virginia, USA. Hearts of 383 lambs were obtained from a slaughter house on the day of killing. Blood removed from each heart was tested for antibodies to T. gondii by using the modified agglutination test (MAT). Sera were first screened using 1:25, 1:50, 1: 100 and 1:200 dilutions, and hearts were selected for bioassay for T. gondii. Antibodies (MAT, 1:25 or higher) to T. gondii were found in 104 (27.1%) of 383 lambs. Hearts of 68 seropositive lambs were used for isolation of viable T. gondii by bioassay in cats, mice or both. For bioassays in cats, the entire myocardium or 500g was chopped and fed to cats, one cat per heart and faeces of the recipient cats were examined for shedding of T. gondii oocysts. For bioassays in mice, 50g of the myocardium was digested in an acid pepsin solution and the digest inoculated into mice; the recipient mice were examined for T. gondii infection. In total, 53 isolates of T. gondii were obtained from 68 seropositive lambs. Genotyping of the 53 T. gondii isolates using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) revealed 57 strains with 15 genotypes. Four lambs had infections with two T. gondii genotypes. Twenty-six (45.6%) strains belong to the clonal Type II lineage (these strains can be further divided into two groups based on alleles at locus Apico). Eight (15.7%) strains belong to the Type III lineage. The remaining 22 strains were divided into 11 atypical genotypes. These results indicate high parasite prevalence and high genetic diversity of T. gondii in lambs, which has important implications in public health. We believe this is the first in-depth genetic analysis of T. gondii isolates from sheep in the USA.