Vital apicoectomy of the teeth: a 1-4 week histopathological study in Macaca mulatta

Several studies have reported devitalization of teeth following surgical procedures in the area of the root apices. The purpose of this investigation was to observe the 1-4-week wound healing pattern in monkey dental tissues following intentional vital apicoectomy (IVA). Two adult Macaca mulatta were used in this study. All of the teeth were surgically transected within the apical one-third with a bur. The soft tissues were then closed. At death, a maxillary and a mandibular quadrant for 1, 2, 3 and 4 weeks following surgery were obtained after vascular perfusion. Each quadrant was demineralized in EDTA, processed, serially sectioned at 7 microns and alternately stained with hematoxylin and eosin, Preece's modified trichome, and McKay's bacterial stains. Examination of sequential IVA cuts showed an initial disruption of the pulpal neurovascular supply resulting in pulpal necrosis. The pulpal tissues underwent a process of replacement with PDL-like connective tissues and deposition of cementum on all cut dentin surfaces of the tooth roots as well as in some of the pulp chambers. No abscesses, external resorption or ankylosis were found.     

Trochanteric sciatic neuropathy

A patient with severe weakness, atrophy, and sensory loss of the right leg had a focal right sciatic neuropathy. The sciatic nerve was enlarged at the level of the lesser trochanter, excessively firm, and multistranded; its stimulation threshold was focally increased. Biopsied fascicles had reduplicated perineurial leaflets, many Renaut bodies, and an abnormal unimodal spectrum of small-diameter fibers. We postulate that the lesion was induced by the combination of an underlying prominent lesser trochanter and sitting on hard benches.     

The Clinical Course of Epilepsy and Its Psychosocial Correlates: Findings from a U.K. Community Study

As part of a large community-based study, we retrospectively examined the clinical course of epilepsy in an unselected population of people who had a recent history of seizures or were receiving antiepileptic drugs (AEDs). Clinical information was collected from medical records, and information about psychosocial functioning was obtained by means of postal questionnaires sent to identified subjects. The response rate to the postal questionnaire was 71%. There were some deficiencies in the recording of clinical data, which is not unusual since data were taken from records held by primary physicians rather than from hospital clinics. Nevertheless, findings regarding the clinical course of epilepsy corresponded to those of earlier studies. Fifty-seven percent of the sample had had at least a 2-year seizure-free period and 46% of subjects were currently in a remission of at least 2-year duration. There was a clear relationship between current seizure frequency and levels of anxiety and depression, perceived impact of epilepsy, perceived stigma, and marital and employment status. The relationship of seizure frequency and other clinical variables to psychosocial function was explored by multivariate analysis techniques. The amount of variation in scores on the various measures of function accounted for by the clinical variables was small. The most important predictor was current seizure activity, which was the first variable to enter the regression analyses for six of the eight measures of psychosocial function considered. Age at epilepsy onset also emerged as a significant predictor for depression, stigma, and marital status. In individuals with epilepsy in remission, there was little evidence that psychosocial functioning was associated with length of remission, a finding which may in part reflect the nature of this study population. The results indicate that there are several more important predictors of psychopathology and social dysfunction in epilepsy and suggest several implications for treatment interventions.     

Difficulties Generated by Allergies

Allergies have recently been related to the development of speech, language and hearing problems in students. Diagnosis and treatment is compounded by multiple complaints or the absence of complaints. If an unrecognized allergic hearing loss is operating, individuals sometimes are considered to be mentally incompetent or emotionally disturbed. In our analyses, articulation and hearing loss were found predominantly in conjunction with allergic rhinitis, and vocal quality problems were associated with bronchial asthma. These findings suggest that school health professionals should be aware of the possibility of an allergy disorder when dealing with young students who have learning, articulation, hearing or vocal quality problems.     

Hydrolysis and solvent-dependent 2'----5'and 3'----5' acyl migration in prodrugs of 9-beta-D-arabinofuranosyladenine

As a prerequisite to quantitative in vivo studies to further explore the promising topical activity of the 2',3'-di-O-acetyl derivative of 9-beta-D-arabinofuranosyladenine (ara-A) against herpes virus infections, the kinetics of solution degradation of the 2',3'-di-O-acetyl derivative and the 2'-,3'-, and 5'-monoacetates were investigated. The rates of aqueous solution hydrolysis were found to be consistent with rank order predictions based on a consideration of substituent effects. Preliminary in vivo hydrolysis data, however, do not correlate with such predictions, indicating a need for more systemic studies of the effect of molecular structure on enzyme-catalyzed hydrolysis. An important reaction of the 2'-3'-diester and the 3'-monoester in aqueous solution, in addition to ester hydrolysis, is 3'----5' acyl migration. 2'----5' Acyl migration does not occur in water but is the predominant migration pathway in organic solvents, as verified by studies in acetonitrile. 1H NMR spectroscopy was employed to study the dependence of the conformation of the sugar ring on the solvent environment. Although a change in the equilibrium between the C(2')endo and C(3')endo conformational states does occur, it is not a dramatic change and cannot explain the solvent selectivity observed in the acyl migration kinetics.     

Possible site of zinc control of hepatoma cell division in Wistar rats

The effect of zinc on the growth of a transplantable DAB hepatoma in young male Wistar rats was determined. Both a zinc deficiency (less than 0.5 microgram/g feed) as well as high levels of dietary zinc (500 micrograms/g feed) significantly reduced tumor growth. Both high- and low-zinc diets resulted in reduced activity of the salvage pathway of thymidine synthesis as well as reduced 32PO4 incorporation into DNA and diminished DNA polymerase activity. Blockage of the de novo pathway of DNA synthesis by the folate antagonist methotrexate (MTX) resulted in greatly increased flux through the thymidine salvage pathway and increased DNA polymerase activity but decreased 32PO4 incorporation in the transplantable hepatomas in Wistar rats fed normal zinc diets (50 micrograms/g feed). MTX had the effect of reducing all these activities in the groups fed low- and high-zinc diets. These data suggested a site of action of zinc associated with the salvage pathway of thymidine synthesis.