The partial opioid agonist, buprenorphine, protects against lethal effects of cocaine.

Buprenorphine (0.3-3.0 mg/kg) produced dose-dependent protection against the lethal effects of cocaine in mice. The (+)-enantiomer of buprenorphine did not protect up to doses over 100 times greater than the lowest effective dose of its (-)-enantiomer. The protective effects were also produced by the opioid agonists morphine and methadone, but not by the opioid antagonist, naltrexone. Low doses of naltrexone (0.3-1.0 mg/kg) blocked the protective effects of buprenorphine. Protection conferred by buprenorphine was not observed in CXBK mice, a recombinant inbred strain relatively devoid of mu-opioid receptors. Thus, buprenorphine appears to protect against the lethal effects of cocaine by a process mediated by mu-opioid receptors. The present results should provide some additional safety assurance in future clinical trials with buprenorphine, especially in outpatient trials where cocaine abuse may continue along with treatment.     

Exercise conditioning and intraocular pressure

We studied the intraocular pressure response to short-term maximal aerobic exertion before and after exercise conditioning in ten healthy sedentary volunteers. Before exercise conditioning, mean intraocular pressure +/- S.E.M. decreased by 5.9 +/- 0.6 mm Hg after short-term maximal aerobic exercise, returning to baseline in a mean of 37 +/- 4 minutes. After four months of exercise conditioning, this ocular hypotensive response was significantly dampened, with a mean intraocular pressure reduction of only 1.6 +/- 0.4 mm Hg after short-term maximal aerobic exercise (P less than .01). Additionally, a significant reduction in baseline intraocular pressure occurred, with a mean intraocular pressure of 14.3 +/- 0.7 mm Hg before exercise conditioning, declining to a mean intraocular pressure of 13 +/- 0.9 mm Hg (P less than .02) after four months of physical training. Exercise conditioning may significantly reduce baseline intraocular pressure and attenuate the hypotensive response to short-term maximal aerobic exercise.     

Effects of serotonin on the internal anal sphincter: in vivo manometric study in rats.

The effects of serotonin (5-hydroxytryptamine, 5-HT) on the internal anal sphincter were studied in anaesthesized rats. Serotonin induced a dose dependent relaxation of the internal anal sphincter. Methysergide blocked this relaxation, but did not affect the rectoanal reflex. Methysergide did not antagonise the actions of cholinergic and adrenergic agonists on the internal anal sphincter. Other 5-HT antagonists such as cyproheptadine, ketanserin, chlorpromazine, amitriptyline and ergotamine failed to reduce or block the internal anal sphincter relaxation due to 5-HT, nor did they alter the rectoanal reflex. Adrenergic and cholinergic antagonists had no effect on the 5-HT-induced relaxation of the internal anal sphincter, suggesting that 5-HT acts upon the internal anal sphincter via a non-adrenergic, non-cholinergic mechanism. Tetrodotoxin reduced or blocked the relaxation of the internal anal sphincter produced by 5-HT, implying that 5-HT acts through neural pathways rather than directly on the muscle. It is concluded that although 5-HT relaxes the internal anal sphincter, it does not participate in the rectoanal reflex.     

Antenatal sonographic diagnosis of arthrogryposis multiplex congenita

Arthrogryposis Multiplex Congenita (AMC) was suspected on ultrasound examination of a fetus at 30.5 weeks of gestation. The criteria for establishing this prenatal diagnosis as well as the importance of establishing the diagnosis at any gestational age are discussed. The diagnosis of AMC was confirmed at birth in this case.     

Non-insulin-dependent diabetes mellitus in the elderly. Influence of obesity and physical inactivity

The development of hyperglycemia in the elderly is often multifactorial in etiology, and its presentation is often confounded by the advanced age of the patient, the presence of coexisting diseases and altered mental states, the absence of symptoms, and physical conditions specific to the medical care of the geriatric patient. Manifestations of macro- and microvascular complications of non-insulin-dependent diabetes mellitus (NIDDM) often herald the disease in the elderly, yet there is incomplete knowledge of the natural history of the disease and poor guidelines for its effective management in the geriatric population. Once NIDDM is diagnosed in the older patient, the propensity for these patients to develop atherosclerotic vascular complications involving every organ system and the socioeconomic sequela of the disease make treatment prudent. Coexisting risk factors for atherosclerosis, such as dyshypoproteinemia, hypertension, obesity, and cigarette smoking, should be treated vigorously, and poor diet, physical inactivity, and medications affecting glucose tolerance modified. Hyperglycemia resistant to nonpharmacologic therapy should be treated with second-generation oral sulfonylureas, and the judicious use of insulin is advised because of a heightened risk for the hazards of hypoglycemia in the elderly. The treatment of NIDDM has important implications in the elderly because of its prevalence and its association with other age-related pathophysiologic processes. Such effective treatment may have the potential to reduce morbidity and mortality and improve the quality of life of older people.     

Surface architecture of a low-temperature thermoplasticized gutta-percha.

The surface characteristics of two Ultrafil materials, Regular set (RS) and Firm set (FS) were analyzed by scanning electron microscopy (SEM). The samples of Ultrafil were obtained from both RS and FS cannules which were pre-heated to 70 degrees C. Another RS and FS samples were obtained at room temperature from un-heated cannules. Samples of standard gutta-percha points obtained from the same manufacturer were studied for comparative purposes. RS samples obtained from pre-heated and un-heated cannules exhibited rough surfaces containing randomly distributed crystal-like structures. Heated and un-heated FS samples featured smoother surfaces with fewer crystal-like structures. The gutta-percha points also exhibited smooth surfaces and absence of crystal-like structures. The consequence of the possible release of these structures from Ultrafil in a biological system is discussed.     

Hepatic actinomycosis

Primary hepatic actinomycosis is seldom seen, and almost all cases have been diagnosed by laparotomy. Treatment with high-dose parental penicillin for prolonged periods is recommended. In the past concomitant surgical drainage also has been recommended, but the nonoperative success reported here and by others suggests that surgical drainage is not essential to the treatment.