Covalent binding of 7,12-dimethylbenz[a]anthracene to lymphoid and nonlymphoid tissues following oral administration to B6C3F1 mice.

Previous studies have shown that 7,12-dimethylbenz[a]anthracene (DMBA) is cytotoxic to various murine lymphoid tissues, including the spleen, thymus, mesenteric lymph nodes (MLNs), and Peyer's patches (PPs). In the present studies, we measured the amount of covalent binding of [3H]DMBA to lymphoid and nonlymphoid tissues and correlated these findings with the overall levels of [3H]DMBA (and derived substances) present in various tissues following a single oral administration to mice. Results show that [3H]DMBA was taken up relatively rapidly from the GI tract and that it was nearly completely eliminated within 24 hr via the feces. Peak plasma levels were obtained approximately 6 hr after gavage, and most organs (including brain, heart, liver, lung, kidney, spleen, and thymus) achieved their peak level of DMBA at this time. Maximal concentrations of DMBA were detected in gut-associated lymphoid tissues (i.e., PPs and MLNs) at 4 hr, during which time covalent binding of [3H]DMBA was also maximal. The time course for covalent binding was different in the liver, lung, thymus, and spleen, peaking at 6-12 hr. The amount of covalent binding of [3H]DMBA and derived metabolites in the spleen was more than twice that seen in the other tissues examined. Since the spleen has previously been found to be less sensitive to DNA fragmentation induced by DMBA than the PPs, these results suggest that covalent binding may not be the primary determinant of lymphotoxicity in these organs.     

Cervico-arthrotic myelopathies. Treatment and prognosis

The authors present 50 cases of cervical spondylotic myelopathy treated by anterior or posterior approach. To assess the severity of the pre- and postoperative neurological symptoms, they define an original ten-point classification scale taking into account gait and urinary disturbance, ability to manipulate objects and pain. With C2-C7 laminectomy, 60% of the patients are improved, essentially for walk. A few cases only (14%) are upgraded for upper limbs function. The authors conclude that this surgical treatment should be applied only when there is a multi-level narrowed canal and predominant lower limbs deficits. The efficacy of the anterior approach depends on complete removal of osteophytes. In cases with complete osteophytectomy, this surgical treatment can improve both the upper and lower limbs function and 77.8% good results are obtained. In a few cases it may be necessary to use both approach successively. Discriminant analysis applied to 12 factors shows that pre-operative scores of upper and lower limbs and sagittal diameter of spinal canal are the most important factors for neurological prognosis.     

Cat-301 immunoreactivity in the lateral geniculate nucleus and visual cortex of the strabismic amblyopic cat

Purpose: It was investigated whether alterations in neuronal structure and function occasioned by strabismic amblyopia also may be reflected in alterations in the expression on Y type neurons of a Cat-301 antibody sensitive antigen in the lateral geniculate nucleus (LGN) and cortex of our cat model of strabismic amblyopia. Methods/Results: The percentage of positively labelled cells was reduced in LGN laminae that received input from the deviated eye in strabismic amblyopic cats compared with normal cats. In the strabismic cortex, the density of immunopositive neurons was significantly reduced compared with normal, the effect being most pronounced in layer IV Conclusions: Despite previous physiological recordings indicating a decrease in X-cell associated acuity in strabismic amblyopia, the present findings imply that the changes in the early visual experience occasioned by strabismus also produce specific molecular changes in theY neuronal class.     

Bioplastique as a Complement in Conventional Plastic Surgery

This research presents reports of cases where a biocompatible and alloplastic biomaterial—Bioplastique—was used, associated with conventional plastic surgery or as a complement to it, with the aim of achieving a better final aesthetic result. Four cases are presented where Bioplastique was used in association with rhytidoplasty, rhinoplasty, and other surgical techniques. This material has shown itself to be appropriate to complement surgery; achieving a final result which would not be possible without any resort to a complement or any other hard procedure by the surgeon and is not more traumatic for the patient.     

Aortopulmonary window with patent ductus arteriosus and interrupted aortic arch: A case report

Indian Journal of Thoracic and Cardiovascular Surgery -     

State dental boards and mandatory HIV testing.

Public and professional debate over what, if any, action should be taken by state regulatory agencies regarding AIDS and the HIV status of dentists has increased in recent months. To determine if state boards had workable policies in place or were considering such policies, a telephone survey of all state boards was undertaken. All boards participated, although three provided only limited information. As of early 1992, only two boards required evidence of immunity to HVB for relicensure and none require evidence of seronegativity to HIV for relicensure. Twelve percent of the boards anticipate such requirements within two years. None have mandatory HIV testing, but 13 percent anticipate such requirements in the near future. The authors conclude that while few agencies have taken more than tentative steps toward rigorous HIV testing or restrictions, most are aware of much closer public scrutiny. More restrictions seem likely as these agencies attempt to balance public and professional rights and responsibilities.     

Effects of acute nicotine administration on the function of the human parotid gland

The effect of acute administration of nicotine on the secretory function of the human parotid gland was investigated in 4 male volunteers. After intravenous infusion of 20 micrograms nicotine/kg b.w. within 10 min in all subjects an increased salivary amylase activity and protein concentration was observed. This phenomenon is believed to be caused by a stimulation of parotid beta-adrenoceptors secondary to a nicotine-induced release of catecholamines from the adrenals.