THE INCIDENCE AND GENETICS OF METACHROMATIC LEUCODYSTROPHY IN NORTHERN SWEDEN

The purpose of this study was to investigate the incidence and genetics of metachromatic leuco-dystrophy (MLD). A series of 13 cases of late infantile MLD and 2 cases of juvenile MLD was collected from the northern part of Sweden and studied together with their relatives. The series was considered to be adequately representative of the true occurrence of MLD during the period 1955–1965. The incidence rate for late infantile MLD was estimated to be about 1 per 40 000. The MLD patients were highly concentrated to the south-west part of Norrland. From the family analysis it was concluded that late infantile MLD is most probably transmitted by an autosomal recessive gene.     

Range of movement of mandible in children

Abstract— The range of movement of the mandible was studied in 103 boys and girls aged 7 years, in 110 boys and girls aged 10 years, and in 60 women aged 20 years. The mobility of the mandible was estimated by repeated direct measurement of the maximal opening capacity, and in the 10-year-old children and the women also by measurement of maximal protrusion and lateral movement. The method for recording the mobility of the mandible proved to be precise. Lateral movement of the mandible to the right was greater than to the left both in children and adults. No difference in opening capacity or maximal protrusion was found between the boys and the girls, while lateral movement was somewhat larger in the boys. The mean maximal opening capacity was 46 mm in the 7-year-old children, 51 mm in the 10-year-old children, and 51 mm in the adult women. Maximal protrusion and lateral movement was, on the average, 9–10 mm in the 10-year-old children and in the adult women. The investigation suggests that in girls the range of movement of the mandible has reached adult level by 10 years. The opening capacity in children was found to be positively correlated with body height and body weight. Both in children and adults relatively high positive correlations were found between opening capacity, protrusion, and lateral movement.     

Attempts to predict prognosis of pulpotomy in primary molars Bacteriologic and histologic examination

Abstract— In connection with therapeutic pulpotomy in primary mandibular molars, samples for bacteriologic examination were taken from the orifice of the distal root canal immediately before application of calcium hydroxide paste. Of samples from 60 teeth examined, half gave growth in broth media. No correlation was found between the results of bacteriologic examinations and the outcome of treatment as judged on histologic grounds. In a further 40 pulpotomized primary mandibular molars the tissue removed from immediately above the orifice of the distal root canal was studied histologically. Of these biopsy specimens from teeth where the pulp had been exposed during excavation of caries, but which had not produced clinical evidence of pulpitis, only 5 appeared free from inflammation. Biopsy specimens from the successfully treated s cases showed very moderate inflammatory changes but no certain correlation between the condition of the extirpated tissue and the result of treatment could be demonstrated. The investigation shows that bacteriologic contamination of the wound surface during operation cannot be the dominant cause of failure. It is instead more likely that the outcome of the pulpotomy depends on the extent to which microorganisms in superficial parts of the pulp have damaged the pulpal tissue in the root canals.     

Abolition of Diaphragmatic Pacing by Nonsurgical Retraction of a Left Ventricular Lead

This report describes the nonsurgical elimination of intractable diaphragmatic stimulation by partial withdrawal of a left ventricular (LV) pacing lead (in the coronary venous system) with resultant preservation of LV pacing. The procedure entailed the use of a deflectable catheter in the right atrium for ensnaring the LV lead. At the 3-month follow-up, the absence of diaphragmatic stimulation was associated with a satisfactory LV pacing threshold and dramatic clinical improvement from effectual biventricular pacing.     

Characterization of the prostanoid receptors and of the contractile effects of prostaglandin F2a in human pial arteries

The contractile and relaxant effects of various prostanoids were studied on isolated human pial arteries. Contractions were elicited with the following order of potency: U46619?U44069>PGB₂>PGF_2a>PGE₂?PGD₂>PGF_1a≥TXB₂, indicating that prostanoid-induced contractions probably are mediated by a thromboxane-sensitive receptor. Relaxation of PGF_2a-contracted arteries was induced with the order of potency: PGE₂> PGE₁>PGD₂?PGD₁. Vessels contrated by K⁺ were relaxed only by PGE,. Since PGI₂ was previously found to be more potent than all the prostanoids tested in the present study, relaxant responses are probably mediated via a PGI₂-sensitive receptor. The roles of free extracellular and cellularly bound calcium for the contractile effects of PGF_2a and K⁺ were estimated by incubating the arteries for various times in calcium-free medium containing 10^-5 M EGTA. Incubation for 5–10 min abolished K⁺-induced contractions, whereas after 40 min of incubation PGF_2a still induced contractions that reached 70% of control. The PGF_2a-induced contraction was biphasic in 8 out of 10 preparations. The second phase could be eliminated by increasing the EGTA-concentration to 10^-4 M, as well as by nifedipine pretreatment. In calcium-free, high K⁺ medium calcium-induced contractions were elicited at lower concentrations in the presence of PGF_2a. The results suggest that PGF_2a-induced contractions in human pial arteries are relatively independent of free extracellular calcium. PGF_2a may promote trans-membrane influx of calcium, as well as release calcium from seemingly superficially located cellular stores.