Ultrastructural, lectin histochemical and immunohistological observations on Merkel cell tumors

The clinicopathological and ultrastructural findings of 10 cases of Merkel cell tumor (MCT) are presented. Three patients died rapidly due to tumor dissemination. The tumor cells in eight out of the 10 cases were positive for neuron-specific enolase, however, all were negative for the ten polypeptide hormones examined, as well as for the argentaffin and argyrophil reactions. One of the patients had suffered from chronic lymphocytic leukaemia. Particularly in this case, but also in the others, the differentiation of MCT from a malignant lymphoma necessitated immuno-histological, lectin histochemical and ultrastructural studies. The focal peanut agglutinin positivity of the tumor cells in 6 out of the 10 MCTs seems to be a characteristic feature of these cells.     

Transluminal angioplasty of the iliac and femoral arteries: follow-up results without anticoagulation

With the advent of the angiographic balloon catheter, transluminal angioplasty has become a more effective procedure for the alleviation of symptoms of peripheral ischemia. In the past two and a half years we have performed this procedure on over 208 iliac and femoral arteries. One hundred twenty iliac arteries were dilated. Of these, 86% remained patent at one year and 83% at two years. Eighty-eight femoral arteries were dilated. Of these, 75% remained patent at one year and 67% at two years. These vessel survival rates are slightly less than those following surgery. However, the morbidity from transluminal angioplasty is very low and the mortality is essentially zero.     

Small bowel function in acute lymphoblastic leukaemia

Small bowel function before, during, and after treatment for acute lymphoblastic leukaemia was studied in 26 children. A significant impairment of D-xylose absorption was found during treatment. Permeability studies showed a significant decrease in mannitol and a significant increase in lactulose concentrations; five of 20 children tested had evidence of lactose malabsorption, three of whom were symptomatic. Intestinal function abnormalities were greater in children whose methotrexate treatments were separated by 7 day than by 16 day intervals. Only five (19%) children had no abnormal tests. Abnormalities of small bowel function may be treatment induced and this has implications for morbidity from gastrointestinal symptoms, impairment of the mucosal barrier, and malabsorption of both nutrients and drugs leading to malnutrition and suboptimal drug concentrations.     

Dose-dependent changes in the antigenicity of bacterial endotoxin exposed to ionizing radiation

The antigenic properties of the highly purified US reference standard endotoxin (RSE) exposed to varying doses of ionizing radiation were studied with double immunodiffusion, immunoelectrophoresis and immunoblotting. Rabbit RSE antisera identified 2 distinct major antigenic components for untreated RSE: one related to the O-polysaccharide side chain ("O-antigenic specificity"), the other to the R-core. Based on a serologic cross-reactivity of R-core of RSE (Escherichia coli 0113) with the R-core of the lipopolysaccharide from E. coli 0111, the core type of E. coli 0113 was identified as coli R3. Increasing exposure of RSE to ionizing radiation progressively destroyed all antigenic reactivities: at lower doses of radiation the rate of elimination differed for the 2 antigen classes. The O-polysaccharide was more sensitive to gamma-radiation than the R-core and the O-antigenicity was lost before that of the R-core. Endotoxin molecules containing incomplete R-core (radiation-induced or mutant) did not react with the RSE antiserum.     

Use of laser-UV for inactivation of virus in blood products

Inactivation of virus by UV radiation was examined as a potential method for sterilization of blood products. Samples of attenuated poliovirus, platelets and plasma were uniformly irradiated with a XeCl excimer laser that delivered 40 nsec pulses of UV at 308 nm (UVB308). Intensities and exposure does were varied from 0.11 to 1.40 MW/cm2 and 0.51 to 56.0 J/cm2, respectively. In studies conducted with low intensity UVB308 (less than or equal to 0.17 MW/cm2), using exposure doses greater than or equal to 10.8 J/cm2, it was possible to inactivate poliovirus by 4 to 6 log10. Platelets irradiated with doses less than or equal to 21.5 J/cm2 exhibited minimal damage as assessed by aggregation activity and spontaneous release of serotonin. Examination of the coagulation activity of irradiated plasma indicated that exposure doses less than or equal to 21.5 J/cm2 resulted in less than 20% increase in prothrombin and partial thromboplastin times. The use of UVB308 at a higher intensity (1.4 MW/cm2) over a similar range of exposure doses did not enhance viral inactivation but did result in increased damage to platelet and plasma proteins. These results demonstrate that at 308 nm there exists a "window of efficacy" for exposure doses between 10.8 and 21.5 J/cm2 and peak intensities less than or equal to 0.17 MW/cm2 in which a hardy virus is significantly inactivated and platelets and plasma proteins are, by functional criteria, minimally affected. Increased viral inactivation cannot be accomplished with higher UV intensities and will require additional or alternate measures.     

The tiny parathyroid adenoma

In the past 11 years we have operated on three patients with "tiny" parathyroid adenomas (less than 60 mg). Two of these adenomas were virtually indistinguishable visually from the normal glands. (The third adenoma was found only after fixation and permanent sections.) Despite frozen-section diagnoses of "probable hyperplastic tissue" in two cases, these small hyperplastic glands proved confusing at operation. This was especially true of the hyperactive gland embedded within mediastinal tissue that, on initial examination of gross material, had been missed by surgeons and pathologists alike and was discovered only on permanent serial sections. The preoperative laboratory data did not vary substantially from that of other hyperparathyroid patients with larger adenomas; in each case two or more endocrinologists had agreed that parathyroidectomy was indicated and had referred these patients for operation. Permanent microscopic sections confirmed the diagnosis of parathyroid adenoma in all three patients. The clinical and laboratory postoperative data strongly indicate that these small adenomas, masquerading as normal-sized glands, were responsible for the hypercalcemia. These tiny adenomas should be added to the other anatomic and pathologic variations of the parathyroid glands that can prove confusing at operation.