Unexpected dipivaloylation of 9-lithiated fluorene: formation of 1-(fluoren-9-ylidene)-2,2-dimethylpropyl pivalate

Treatment of 9-lithiated fluorene with pivaloyl chloride provided ap-9-pivaloylfluorene, (1), the major product, and a minor product ultimately identified as the title compound, C(23)H(26)O(2), (2). The latter was also formed directly, but slowly, from 9-lithiated-(1) treated with pivaloyl chloride. Although (1) exists exclusively as its less sterically restricted ap rotamer, its sp(2)-hybridized anion sterically impedes reaction at the 9-position from either face. While 9-lithiated-(1) is exclusively, but slowly, 9-methylated with methyl iodide, reaction with pivaloyl chloride, also slow, leads only to the O-acylated product, (2). The protons of the tert-butyl-C=C moiety approach a proton on the fluorene ring to well within the sum of their van der Waals radii, resulting in significant molecular compression, strain and distortion. For example, distortion in the moiety C=C(O)(C) is exhibited by the enlargement of C=C-C angle to 130.6 (2) degrees at the expense of the corresponding 'equivalent' C=C-O angle, which is compressed to 116.46 (19) degrees.

An evaluation of a network for professional development in child and adolescent mental health in rural and remote communities

In 1998 a telemedicine network was established in South Australia and the Northern Territory to deliver educational material to professionals working in child and adolescent mental health in remote areas. The network involved a wide range of health professions, from psychiatrists to psychologists and social workers. The first 12 months of network activity were evaluated by quantitative and qualitative techniques. Four sources of data were used: an activity log, questionnaires, interviews and action research. A total of 36 telemedicine sessions were held, ranging in duration from 45 to 90 min (average 56 min) and involving a total of 45 different professionals, who participated an average of four times each (range 1-15). The most common types of session were case discussions (47%), followed by specialist seminars (36%) and administrative and introductory sessions (17%). The benefits of the network included: networking and peer support; improved efficiency and reduced travel costs; and improved efficiency of health services. The problems included: costs; lack of access to technical support; and the need for staff induction and training.

Transforming growth factor beta1 is expressed in the jejunum after experimental Cryptosporidium parvum infection in humans

Biopsies from volunteers challenged with Cryptosporidium parvum were examined for transforming growth factor beta1 (TGF-beta1). None of the prechallenge biopsies exhibited TGF-beta. Seven of 12 volunteers with oocyst shedding expressed TGF-beta versus 2 of 13 volunteers without detected oocysts. The association of TGF-beta expression with oocyst excretion and the timing of symptoms suggests that TGF-beta mediates intestinal healing.

Perioperative and late stroke rates of carotid endarterectomy contralateral to carotid artery occlusion : results from a randomized trial

BACKGROUND AND PURPOSE

Several previous studies have reported the benefits of carotid endarterectomy (CEA) contralateral to carotid occlusion with mixed results, but none of these were randomized except for the North American Symptomatic Carotid Endarterectomy Trial. The purpose of this study was to analyze the results of surgery in patients with contralateral carotid artery occlusion in a randomized trial in which randomization was done according to the method of closure.

METHODS

In 399 CEAs (357 patients) that were randomized into primary closure versus patching, 49 had contralateral occlusion. Strokes were designated as ipsilateral if they arose from the same CEA side and contralateral if they arose from the occluded side. A Kaplan-Meier analysis was used to estimate perioperative strokes and stroke-free survival in patients with contralateral occlusion (group A) versus those without contralateral occlusion (group B).

RESULTS

Demographic characteristics and mean follow-up for both groups were similar (group A, 40 months; group B, 33 months). Group A had a higher incidence of contralateral transient ischemic attacks (TIAs) (12.2% versus 0.9%; P<0.0001), contralateral strokes (2% versus 0%; P=0.025), and combined contralateral TIAs/strokes (14.3% versus 0.9%; P<0.0001). The rates for perioperative and all strokes (operative and late) were 2% and 4. 1% (2% ipsilateral and 2% contralateral strokes) for group A and 2. 9% and 3.4% (all ipsilateral) for group B (P=0.60 and 0.85, respectively). The rates for perioperative and all TIAs were 0% and 14.3% for group A versus 2.6% and 6.3% for group B (P=0.918 and P=0. 08, respectively). The rates for perioperative and all neurological events (TIA and stroke) were 2% and 18.4% for group A and 5.4% and 9. 7% for group B (P=0.27 and 0.113, respectively). The cumulative stroke-free survival rates at 5 years were 84% for group A and 77% for group B (P>0.1). The cumulative stroke-free survival rates at 5 years for symptomatic and asymptomatic patients in group A and group B were also similar. The perioperative and late deaths were similar for both groups (group A, 8%; group B, 14%).

CONCLUSIONS

Group A had a higher incidence of contralateral TIAs and strokes than group B; however, the perioperative and all late stroke rates and survival rates of CEA were comparable in patients with and without contralateral occlusion.

Transesophageal echocardiography detection of an esophageal sarcoma mimicking aortic dissection

This report shows that transesophageal echocardiography can detect thoracic pathology, in this case esophageal sarcoma, as well as cardiac and aortic abnormalities. Transesophageal echocardiography can help differentiate cardiac from aortic or other intrathoracic pathology when the patient's history and physical examination do not provide enough information.

Apolipoprotein E polymorphism in cerebrovascular disease

OBJECTIVES

The aim of this study was to investigate the relationship between the apo E genotype with acute cerebral infarction and primary intracerebral haemorrhage and to examine the relationship of the apo E genotype with mortality following acute stroke.

MATERIALS AND METHODS

We studied 592 cases of acute stroke and 289 healthy control subjects clinically free of cerebrovascular disease. Pathological type of stroke was determined by cranial computed tomography and the subtype of cerebral infarction classified according to the Oxfordshire Community Stroke Project Classification (OCSP). Apo E genotype was determined using polymerase chain reaction.

RESULTS

There was no difference in apo E genotype frequency between cases and controls (chi2 = 3.58, 5 d.f., P = 0.60). Apo E genotypes were not related to the pathological type of stroke (cerebral infarction, CI, n = 532 and primary intracranial haemorrhage, PICH, n = 60, (chi2 =3.738, 4 d.f., P=0.44) nor with the Oxfordshire Community Stroke Project Classification subtypes of cerebral infarction, lacunar infarction, LACI (n = 169), total anterior circulation infarction, TACI (n = 117), partial anterior circulation infarction, PACI (n = 173), posterior circulation infarction, POCS (n = 54) and including those cerebral infarcts which could not be classified (n= 19), chi2 =31.1, 20 d.f., P=0.153). At the time of the analysis, 243 cases (41.0%) had died. The median follow-up (including death) was 851 days. There was no relationship between time to death and apo E genotype in cases of either CI or PICH.

CONCLUSION

In this population, there was no relationship between the apolipoprotein E polymorphism and the pathogenesis of cerebral infarction or primary intracerebral haemorrhage. Apo E genotype was not related to all-cause mortality following stroke.

Effects of load carriage on heart rate, blood pressure and energy expenditure in children

Fifteen male primary school children, aged 10 years, were selected to carry school bags of 10, 15 and 20% of their own body weights, where 0% body weight was used as a control. Maximum oxygen uptake (VO2max) tests were conducted on a motorized treadmill using a continuous incremental protocol. During the load carrying test, subjects walked on a treadmill at 1.1 m s(-1) for 20 min at each load condition. Blood pressures were measured before, immediately following, and at 3 and 5 min after every trial. Heart rate and expired VO2 were recorded before, during and 5 min after walking using a cardiopulmonary function system. The results showed a significant difference in oxygen uptake, energy expenditure and the recovery of blood pressure rise for between 10 and 20% body weight load conditions. The carrying weight of a school bag for children could be recommended as 10% of body weight because it was not significantly different from 0% load in the metabolic cost.

Absolute structure determination of the highly biologically active bisdehydrodoisynolic acids

In a project designed to relate the unexpected in vivo and in vitro properties exhibited by (+)- and (-)-bisdehydrodoisynolic acid with their absolute stereochemical structure, an X-ray crystal-structure analysis was undertaken of the highly estrogenic, poorly binding (-) enantiomer. (1) and (13)C NMR spectra are also reported for the first time. The crystal structure shows the cis juxtaposition of the carboxyl and ethyl groups, which are separated by a large torsion angle, and that only the carbon atom holding the carboxyl group is out of the plane in which the remainder of the fused three-ring moiety lies. The crystal structure, which unequivocally characterizes the (-) enantiomer as cis-13(S),14(R) and, implicitly, the (+) enantiomer as cis-13(R),14(S), will be useful in continued studies aimed at explaining the selective estrogen receptor modulation (SERM) of these enantiomers which, in some cases, produces significantly different end-organ effects compared to those of estradiol, in both males and females, affording the promise of a variety of therapeutic and pharmacologic applications.

Relationship of MRI and clinical staging to outcome in invasive bladder cancer treated by radiotherapy

AIM

To compare MRI and clinical staging of invasive bladder cancer prospectively and identify additional prognostic features on MRI before radiotherapy.

METHODS AND MATERIALS

143 patients with a pathological diagnosis of transitional cell carcinoma underwent MRI (1.0 T) of the abdomen and pelvis before radical radiotherapy. Tumour size, site, degree of infiltration, presence of adenopathy and hydronephrosis were assessed and an appropriate radiological stage assigned. Following radiotherapy all patients received regular cystoscopic follow-up. Date of first relapse and date of death were recorded.

RESULTS

The median follow-up was 2.8 years for survivors. Those patients upstaged from T2a clinically to T3b on MRI had a significantly worse outcome (P = 0.0078). In univariate analysis a number of MRI features were significantly associated with adverse outcome: tumour size, circumferential tumour extent, and presence of hydronephrosis (all P < 0.05). After adjustment for clinical T stage and histological grade, all these MRI features and the MRI T stage were found to confer additional prognostic information in predicting early disease relapse and death (P < 0.05).

CONCLUSION

This study demonstrates that MRI before radiotherapy provides valuable additional prognostic information compared to clinical staging.

Jockey injuries in the United States

CONTEXT

In the sport of horse racing, the position of the jockey and speed of the horse predispose the jockey to risk of injury.

OBJECTIVE

To estimate rates of medically treated injuries among professional jockeys and identify patterns of injury events.

DESIGN

Cross-sectional survey from data compiled by an insurance broker. Information on the cause of injury, location on the track, and body part injured was evaluated.

SETTING

Official races at US professional racing facilities (n = 114) from January 1, 1993, through December 31, 1996.

PARTICIPANTS

A licensed jockey population of approximately 2700 persons.

MAIN OUTCOME MEASURES

Annual injury incidence rates per 1000 jockey-years, as well as injury type, cause, and location on the track.

RESULTS

A total of 6545 injury events occurred during official races between 1993 and 1996 (606 per 1000 jockey-years). Nearly 1 in 5 injuries (18.8%) was to the jockey's head or neck. Other frequent sites included the leg (15.5%), foot/ankle (10.7%), back (10.7%), arm/hand (11.0%), and shoulder (9.6%). The most frequent location where injuries occurred was entering, within, or leaving the starting gate (35.1%), including 29.5% of head injuries, 39.8% of arm/hand injuries, and 52.0% of injuries to the leg/foot. Most head injuries resulted from being thrown from the horse (41.8%) or struck by the horse's head (23.2%). Being thrown from the horse was the cause of 55.1% of back and 49.6% of chest injuries.

CONCLUSIONS

Our data suggest that jockeys have a high injury rate. Efforts are needed to reduce the number of potential injury events on the track and to improve protective equipment so events do not lead to injury.

Balance control, flexibility, and cardiorespiratory fitness among older Tai Chi practitioners

BACKGROUND

Tai Chi Chuan (TTC) exercise has beneficial effects on the components of physical condition and can produce a substantial reduction in the risk of multiple falls. Previous studies have shown that short term TCC exercise did not improve the scores in the single leg stance test with eyes closed and the sit and reach test. There has apparently been no research into the effects of TCC on total body rotation flexibility and heart rate responses at rest and after a three minute step test.

METHODS

In this cross sectional study, 28 male TCC practitioners with an average age of 67.5 years old and 13.2 years of TCC exercise experience were recruited to form the TCC group. Another 30 sedentary men aged 66.2 were selected to serve as the control group. Measurements included resting heart rate, left and right single leg stance with eyes closed, modified sit and reach test, total body rotation test (left and right), and a three minute step test.

RESULTS

Compared with the sedentary group, the TCC group had significantly better scores in resting heart rate, three minute step test heart rate, modified sit and reach, total body rotation test on both right and left side (p < 0.01), and both right and left leg standing with eyes closed (p < 0.05). According to the American Fitness Standards, the TCC group attained the 90th percentile rank for sit and reach and total body rotation test, right and left.

CONCLUSION

Long term regular TCC exercise has favourable effects on the promotion of balance control, flexibility, and cardiovascular fitness in older adults.

Interferon-gamma expression in jejunal biopsies in experimental human cryptosporidiosis correlates with prior sensitization and control of oocyst excretion

To investigate the role of interferon (IFN)-gamma in human cryptosporidiosis, jejunal biopsies from experimentally infected volunteers and chronically infected AIDS patients were examined for IFN-gamma expression by in situ hybridization. IFN-gamma expression was compared with oocyst excretion, baseline serum anti-Cryptosporidium antibody, and symptoms. IFN-gamma mRNA was detected in biopsies from 13 of 26 volunteers after experimental infection but not in biopsies taken before C. parvum exposure or in biopsies from patients with AIDS-associated cryptosporidiosis. After challenge, 9 of 10 volunteers with baseline C. parvum antibody produced IFN-gamma, compared with 4 of 16 volunteers without baseline antibody (P<.01). Furthermore, IFN-gamma mRNA was detected in 9 of 13 volunteers who did not excrete oocysts, compared with 4 of 13 with organisms (P<.05). Thus, expression of IFN-gamma in the jejunum was associated with prior sensitization and absence of oocyst shedding. IFN-gamma production may explain the resistance to infection noted in sensitized persons but may not be involved in control of human primary infection.

What do GPs need to know? The use of knowledge in general practice consultations

In the course of the consultation in primary care, the general practitioner integrates knowledge of different types that are drawn from different sources. As a consequence of the way practitioners develop expertise, this use of knowledge is often hidden from the conscious mind of the practitioner and often hidden from direct observation. On the other hand, understanding of this use of knowledge is crucial to several necessary developments of the profession of general practice. A method involving collaboration between researcher and practitioner sheds new light on this knowledge-in-use.