Dysplastic naevus: histological criteria and their inter-observer reproducibility

Forty melanocytic lesions were examined in a pilot study, which was followed by a final series of 100 consecutive melanocytic lesions, in order to evaluate the inter-observer reproducibility of the histological criteria proposed for the dysplastic naevus. The specimens were examined in a blind fashion by four observers. Analysis by kappa statistics showed poor reproducibility of nuclear features, while reproducibility of architectural features was acceptable, improving in the final series. Consequently, we cannot apply the combined criteria of cytological and architectural features with any confidence in the diagnosis of dysplastic naevus, and, until further studies have documented that architectural criteria alone will suffice in the diagnosis of dysplastic naevus, we, as pathologists, shall avoid this term.     

Impact of infarct artery patency on the relationship between electrocardiographic and ventriculographic evidence of acute myocardial ischaemia

Routine invasive evaluations are being abandoned, and thus simplenon-invasive methods for estimating the extent of jeoparizedmyocardium during evolving myocardial infarction are neededfor risk stratification to guide the appropriate therapeuticintervention. With this in mind the aim of the paper was toevaluate the association between ischaemic changes in the standardelectrocardiogram and the function of acutely infarcted myocardiumin relation to infarct artery patency status. Forty consecutive patients with a first acute myocardial infarction,admitted within 6 h of symptom onset and without bundle branchor fascicular block were included. Summated ST segment elevationin 11 electrocardiographic leads (aVR excluded) was measuredto the nearest 005 m V and compared to regional wall motion,estimated by the centreline method (SDIchord) and global leftventricular ejection fraction (% LVEF) after thrombolytic therapy.Acute angiographic and ST segment measurements were performedat a median 254 min (range 70–485) after the onset ofsymptoms. Patients were grouped according to infarct artery patency statusafter intravenous thrombolysis. Of the 40 patients, 27 had apatent (Thrombolysis In Acute Myocardial Infarction trial (TIMI)grade 2-3 flow) and 13 had persistently occluded (TIMI 0–1flow) infarct arteries. Anterior myocardial infarction was presentin 13 and seven patients in the two groups. In the TIMI 2-3group, the summated ST elevation did not correlate with % LVEFor SDIchord (r_s=0.08; and r_s= – 0.17, respectively). Inthe TIMI0–1 group the summated ST elevation correlatedinversely with both % LVEF and SDIchord (r_s= –0.70; andr_s= –0.56, respectively). These results show that acute summated ST segment elevationcorrelates with both global and regional left ventricular functionin patients with persistently occluded infarct arteries, thusproviding a non-invasive method for estimating the amount ofjeopardized myocardium.     

Malignant Centroblastic-Histiocytic Lymphoma of the Skin

A mixed B-cell type centroblastic lymphoma with extraordinarily many histiocytes in a 68-year-old man is reported. Multiple skin tumours were the only clinical manifestation during the first 5 months. The disease then progressed to the lymph nodes, spleen, and parenchymal organs, but the bone marrow remained unaffected until death, 11 months after the onset of signs. C3d receptors were the only surface markers of the centroblasts. The histiocytes were normal with respect to morphology, muramidase staining, and Fc and C3b receptors. This highly unusual spread from skin to lymphoid and parenchymal organs is discussed in the light of lymphoid cell kinetics.     

Calcium fluoride formation on enamel and its influence on uptake of fluoride in the apatitic lattice

abstract – Human dental enamel was exposed to a pH 4 buffer containing 150 parts /10⁶ fluoride. It was found that due to the arising degrees of saturation with respect to calcium fluoride and appetites, surface enamel dissolved coincident with a formation of calcium fluoride. The calcium fluoride redissolved while it kept the liquid saturated with respect to tiiis salt. During this second period, fluorapatite was formed while hydroxyapatite dissolved. Finally, all calcium Ouoride was dissolved and the unreacted fluoride was taken up in the apatidc lattice. The results are discussed with reference to the conditions of the oral cavity and enamel solubility experiments.     

ACTH versus prednisone and placebo in herpes zoster treatment

The effect of ACTH (Synacthen-depot®) versus prednisone and placebo in the treatment of herpes zoster (HZ) was studied in a controlled clinical trial comprising 60 consecutive patients. The treatment groups were comparable regarding sex, age and pre-entry symptom duration. The skin changes, patients' pain scores and the consumption of analgesics were monitored. Regarding objective symptoms and the development of postherpetic neuralgia there was no difference between the two treatment groups and placebo, while the ACTH group showed a decrease in pain score and consumption of analgesics during the first 4 days of the trial. Whether this finding will justify the application of ACTH in early HZ is arguable. Neither ACTH nor prednisone influenced the development of postherpetic neuralgia but this negative finding may be inaccurate due to the small number of patients in the three groups. Severe side-effects did not occur.     

Fluoride and enamel solubility

abstract — The present paper deals with the solubility of enamel and the influence of fluoride on the degree of saturation with respect to hydroxyapatite. Enamel surfaces were exposed to 8 ml buffer at various pH values. The buffers were analyzed at suitable intervals for calcium, phosphate, fluoride and pH and the ionic activity products for fluorapatite, hydroxyapatite, calcium fluoride, brushite and octacalcium phosphate were calculated. It was found that the buffers were supersaturated with respect to fluorapatite and remained unsaturated with respect to the other salts investigated. Under these conditions fluorapatite was formed while hydroxyapatite dissolved, the system thus tending toward equilibrium at which the liquid phase is saturated concurrently with respect to both apatites. It is suggested that at least a part of the solubility reducing effect of fluoride is due to fluoride rendering the liquid phase supersaturated with respect to fluorapatite. This results in formation of fluorapatite, rendering the liquid phase unsaturated with respect to hydroxyapatite.     

High-Dose Survival in the Lymphocytic Choriomeningitis Virus Infection Is Accompanied by Suppressed DTH but Unaffected T-Cell Cytotoxicity

Provided that intracerebral inoculation is applied, an increase in the virus dose from 10(2) to 10(4) LD50 of lymphocytic choriomeningitis virus (LCMV) leads to strikingly reduced mortality. To analyse the background for this autointerference, we measured several virologic and immunologic variables in mice infected with these doses of virus. In the high-dose mice we found generally higher organ virus titres and serum interferon titres than in the low-dose mice. Since we could demonstrate that virus-specific T-cell cytotoxicity in spleen, peripheral blood, and meningeal exudate was similar after intracerebral infection with large and small virus doses, and since the LCMV infection in the brain qualitatively and quantitatively was independent of the size of virus inoculum, the explanation for the survival of the high-dose animals is obviously not lack of possibilities for interaction between cytotoxic T cells and infected sensitive targets in the central nervous system. On the other hand, high doses of virus caused a clear suppression of the LCMV-specific delayed-type hypersensitivity (DTH). In addition, when splenocytes from high-dose animals were transferred either intravenously or locally into the footpad of newly virus-challenged mice, DTH was markedly suppressed as compared with the response after transfer of spleen cells from low-dose mice. We therefore conclude that autointerference in the LCMV infection is due to a selective suppression of Td function. Large amounts of persistent virus late after infection with high doses of virus suggest a central role for Td function also in virus clearance. Finally, our results indicate the existence of two subsets of K,D region-restricted T cells, one mediating cytotoxicity and the other mediating DTH. This possibility is discussed.     

Increased hepatic microsomal activity after halothane anaesthesia in children

The effect of anaesthesia and surgery on microsomal enzyme activity was studied in 19 children aged 4-9 years, scheduled for tonsillectomy. The children were randomly allocated to either halothane or ketamine anaesthesia. Antipyrine clearance was measured before and 4 days after surgery by a salivary one-sample technique. Statistically significant (p less than 0.001) increases in antipyrine clearance was found in children who received halothane anaesthesia. The antipyrine clearance was increased by a mean of 26% 4 days after surgery, compared with a pre-operative control measurement. No significant change in antipyrine clearance was observed in children who received ketamine anaesthesia. There was also a significant difference in antipyrine clearance changes after surgery between the two groups (p less than 0.05). Halothane has enzyme-inducing properties after a single exposure in children, while a single dose of ketamine does not.     

Reduction of body doses in rotational panoramic radiography by means of reduced beam width in combination with rare earth intensifying screens

Abstract – The absorbed doses in the body of a Rando-Alderson phantom were measured in rotational panoramic radiography (OP-5) with LiF-700 crystals using conventional intensifying screens and standard collimator, as well as rare earth intensifying screens and a collimator slit of reduced width. The reduction of the absorbed doses obtained by using the latter combination was calculated. The reduction range in different regions was 0–50%. The greatest reduction was obtained in the cranial part of the phantom. In the caudal part little or no reduction was observed, probably because leakage radiation contributes substantially to the absorbed doses in this area. The average dose equivalent was calculated for organs in which measurements were made in several locations. The reduction was about 50% for these organs except for the gonads (8%). Compared to the estimated average annual dose equivalent originating from the natural background radiation sources, the dose equivalent resulting from this X-ray examination was very small except in the thyroid gland. In this organ the dose equivalent from one exposure corresponded to 36 days of natural background radiation, but it could be reduced to 18 days by using rare earth intensifying screens in combination with reduced beam width.