Proprioception of the shoulder joint in healthy, unstable, and surgically repaired shoulders

Shoulder proprioception was measured in 90 subjects who were assigned to three experimental groups: group 1 (n = 40), healthy college-age subjects; group 2 (n = 30), patients with anterior instability; and group 3 (n = 20), patients who have had surgical reconstruction. Kinesthesia and joint position sense were measured with a specially designed proprioception testing device. The results revealed no significant differences in proprioception between dominant and nondominont shoulders in group 1 for any test condition. Significant differences (p < 0.05) were revealed between the unstable and uninvolved shoulder for both kinesthesia and joint position sense in group 2. No significant mean differences were revealed between the surgical and contralaterol shoulder in group 3 under any test condition. This series of studies provides evidence that proprioceptive deficits caused by partial deafferentiation result when copsuloligomentous structures are damaged. Reconstructive surgery appears to restore some of these proprioception characteristics.     

Research review: a computer-based diagnostic model for individual case review

A previous study found that Iliad, a diagnostic expert system, detects diagnostic errors missed by peer review organization (PRO) review. That study used volunteer physicians from an institution as gold standard reviewers, however. The article discusses a second experiment employing Utah PRO (UPRO) review physicians as gold standards. Iliad was compared with the Unified Clinical Data Set used by the UPRO and was found to detect otherwise unsuspected diagnostic errors. The confirmation rate of Iliad flags was much higher in the earlier study, however. No agreement was found between institution and UPRO physicians, but there was agreement between a unique physician (who was both an institution and UPRO physician) and each of the two groups. Because Iliad screens for potential diagnostic errors to be confirmed or denied by gold standard physician review, the different types of physicians in the two experiments might have been the cause.     

Juxta-articular synovial cyst of the shoulder

A case of an unusual synovial cyst with both intra- and extraosseous components found in the proximal humerus of a patient with osteoarthritis is presented. The importance of this lesion is that it should be recognized as a manifestation of the underlying osteoarthritis and does not represent a more serious primary lesion.     

Ontario, Canada, High School Teachers as Enforcers in the War on Drugs: What Their Students See and Say

This paper examines how high school teachers interact with students on the subject of marijuana. Results, based on 49 focus groups with 278 high school students in Ontario, Canada, reveal three basic assumptions of the students: 1) only some teachers can actually tell when a student is high on marijuana; 2) many teachers have tried marijuana or continue to use it; and 3) individual teachers vary in how they respond to students who are high. Results suggest that changes in the relationship between marijuana and authority account in large part for the seeming reluctance of so many teachers to exercise their mandate to discipline students who use marijuana. The reasons for this are twofold: 1) many teachers do not see use of marijuana of and by itself as a threat to their authority; and 2) teachers who choose to confront users run the risk of having their authority and independence of action undermined once they report infractions to administrators who have authority over teachers and students alike.     

Effects of RSR13, a synthetic allosteric modifier of hemoglobin, alone and in combination with dizocilpine, on outcome from transient focal cerebral ischemia in the rat

This study examined the effect of a pharmacologically induced rightward shift in the partial pressure of oxygen at which 50% of hemoglobin is saturated (P50) on outcome from transient focal cerebral ischemia in the rat. Halothane anesthetized rats (n=20 per group) were given saline or a single 15-min infusion of 150 mg/kg RSR13 (2-[4-[[3,5-dimethylanilino) carbonyl]methyl]phenoxy]-2-methylproprionic acid) intravenously before or 30 min after onset of 75 min of middle cerebral artery filament occlusion (MCAO). Seven days later, severity of hemiparesis and cerebral infarct size were examined. RSR13 alone did not significantly improve outcome. Conscious normothermic rats (n=12 per group) were also given RSR13 (150 mg/kg) or 0.9% NaCl intravenously and subjected to 75 min of MCAO with 7 days of recovery. Again, RSR13 alone did not significantly reduce infarct size or improve neurologic score. A dose-response curve for dizocilpine (MK-801) was then constructed in conscious normothermic rats subjected to 75 min of MCAO. Dizocilpine (0.5 mg/kg i.v.) caused a 90% reduction in mean infarct size while 0.25 mg/kg reduced infarct size by 48%. Other rats were then subjected to 75 min of MCAO after being given dizocilpine (0.25 mg/kg i.v.; n=18) or RSR13 (150 mg/kg i.v. )+dizocilpine (0.25 mg/kg i.v.; n=15). RSR13+dizocilpine resulted in smaller cortical infarct volume (8+/-14 mm3 vs. 34+/-37 mm3, p<0.02) and total cerebral infarct volume (46+/-28 mm3 vs. 81+/-60 mm3, p<0. 05) compared to dizocilpine alone, respectively. We conclude that a pre-ischemic peak increase in P50 of approximately 25 mmHg alone is insufficient to reduce focal ischemic injury, but may be advantageous when used in conjunction with other neuroprotective agents.     

Effect of intracerebral norepinephrine depletion on outcome from severe forebrain ischemia in the rat

Manipulations of plasma catecholamine concentrations influence outcome from ischemic brain insults. It has been suggested that these effects are mediated by influences on brain catecholamine concentrations. This study examined whether major changes in brain norepinephrine concentrations can alter outcome from severe forebrain ischemia. Sprague-Dawley rats were administered 50 mg/kg i. p. N-(chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) or were left untreated (control). One week later, these rats were subjected to either 7 or 8 min of normothermic forebrain ischemia (bilateral carotid occlusion and MABP=30 mmHg) and allowed to recover for 4 days. Histologic damage was then evaluated. In other control and DSP-4-treated animals, hippocampal microdialysate norepinephrine concentrations were measured before, during and after 8 min of forebrain ischemia. Norepinephrine concentrations were also determined in brain homogenates from non-ischemic DSP-treated and control rats. A 95% depletion of norepinephrine was observed in brain homogenates from non-ischemic DSP-4-treated rats compared with control. During ischemia, microdialysate norepinephrine concentrations increased in control but not in DSP-4-treated rats (P=0.002). For plasma, intra-ischemic epinephrine concentrations increased 8-10-fold and returned to baseline values post-ischemia with no differences between groups. Plasma norepinephrine values remained unchanged in both groups. Histologic damage resulting from either 7 or 8 min of ischemia in hippocampal structures, caudoputamen, and neocortex was similar between DSP-4-treated and control groups. This study could not identify any effect of major changes in brain norepinephrine concentrations on ischemic brain damage. These data indicate that peripheral catecholamine effects on near-complete forebrain ischemic outcome are unlikely to be mediated by effects on central catecholamine concentrations.     

Second-generation peptidomimetic inhibitors of protein farnesyltransferase demonstrating improved cellular potency and significant in vivo efficacy.

The synthesis and evaluation of analogues of previously reported farnesyltransferase inhibitors, pyridyl benzyl ether 3 and pyridylbenzylamine 4, are described. Substitution of 3 at the 5-position of the core aryl ring resulted in inhibitors of equal or less potency against the enzyme and decreased efficacy in a cellular assay against Ras processing by the enzyme. Substitution of 4 at the benzyl nitrogen yielded 26, which showed improved efficacy and potency and yet presented a poor pharmacokinetic profile. Further modification afforded 30, which demonstrated a dramatically improved pharmacokinetic profile. Compounds 26 and 29 demonstrated significant in vivo efficacy in nude mice inoculated with MiaPaCa-2, a human pancreatic tumor-derived cell line.     

Tobacco industry scientific advisors: serving society or selling cigarettes?

According to industry documents, the tobacco industry has executed a "brilliantly conceived" strategy to "creat[e] doubt" in the public's mind about whether cigarette smoking is in fact a serious cause of disease. A component of this strategy has been the funding of scientific research "into the gaps in knowledge in the smoking controversy." Grant review and selection are performed by a group of independent scientists. Knowledgeable observers believe that the existence of this research funding program in general, and the Scientific Advisory Board in particular, is intended by the industry to reinforce doubts in the public mind about the severity of the hazards posed by smoking. Because the Advisory Board has never taken a public stance against the industry's position that the causal relationship between smoking and disease remains unproven, I polled these scientists to determine whether they believed that smoking is a cause of lung cancer. Despite repeated opportunities, only four of 13 board members responded, all affirmatively; two others have expressed their judgment that smoking causes lung cancer in their professional publications. Thus, over half of the Board members, and the Board as a whole, have not gone on record as rejecting the industry's "party line." It might be hoped that the American scientists would follow the lead of the members of a similar body of scientists in Australia who have taken a strong and public stand against the industry position that smoking is not an established cause of disease.     

The effects of the anti-smoking campaign on cigarette consumption.

The impact of the anti-smoking campaign on the consumption of cigarettes is measured by fitting cigarette demand functions to pre-campaign dat, projecting "ahead" as if the campaign had not occurred, and then comparing these predictions with realized consumption. The analysis suggests that major "events" in the campaign (e.g., the Surgeon General's Report) caused immediate though transitory decreases of 4 to 5 per cent in annual per capita consumption. However, the cumulative effect of persistent publicity supported by other public policies, has been substantial: in the absence of the campaign, per capita consumption likely would have exceeded its actual 1975 value by 20 to 30 per cent. This is a conservative indication of the effectiveness of the campaign, for it ignores other potentially important and desirable behavior changes, such as the shift to low "tar" and nicotine cigarettes.