Corneal D.C. recordings of slow ocular potential changes such as the ERG c-wave and the light peak in clinical work

A set-up for D.C. recordings of slow ocular potentials such as the c-wave of the electroretinogram (ERG) as well as the fast oscillation (FO), the light peak (LP) and the dark trough (DT) in both clinical and experimental work is described. It includes matched calomel half-cells connected by saline-agar bridges to a corneal contact lens on the eye and a reference chamber on the forehead, a low-drift differential-input D.C. amplifier, an A/D converter, a computer, a thermoprinter, a flexible disc memory, a plotter, and a device for light stimulation controlled by the computer.Examples of the usefulness of the set-up in clinical work are shown in the form of D.C. c-wave ERGs of normal subjects as well as of patients with vitelliform macular degeneration, choriocapillaris atrophy, and retinitis pigmentosa. The direct corneal recording of the FO and LP is demonstrated as well. The different origins of the standing potential (SP) of the eye, the ERG c-wave, the FO and the LP are reviewed briefly.     

New type of spinocerebellar degeneration syndrome in a northern Swedish population

A follow-up investigation of 24 patients with hereditary spasticity in a geographically isolated northern Swedish population, first examined by Böök (1953), was performed. Fifteen of them were dead. During the period from 1950–1972 five new cases of spastic syndromes were diagnosed in this population. The patterns of clinical symptoms and the genetic associations between the new and 24 previously reported patients with spastic syndromes were analyzed. Three of the five new cases had a specific syndrome. This starts in the first years of life with ataxia, which is followed by dysarthria, spasticity and jerky intention tremor. Initially the patients are mentally normal, but there seems to be slight mental deterioration through the years. The disorder is a progressive spinocerebellar degeneration with autosomal recessive inheritance.     

Management of appendiceal masses.

OBJECTIVE: To evaluate the outcome of patients treated for appendiceal abscess, and managed either conservatively or surgically, and to describe the short and long-term outcome as well as incidence of interval appendicectomy in those treated conservatively. DESIGN: Retrospective study. SETTING: University hospital, Sweden. PATIENTS: Ninety-three patients with the diagnosis of appendiceal abscess, 50 treated conservatively and 43 who were operated on, with a mean age of 46 (14-93) years. Mean (range) follow-up for patients operated on was 65 (11-135) and for those treated conservatively 66 (6-136) months. MAIN OUTCOME MEASURES: Course of acute disease, recorded complications, recurrence of appendicitis and incidence of interval appendicectomy during follow-up. RESULTS: The duration of pain before admission was 4 (0.5-82) days for those operated on and 7 (2-60) days for those treated conservatively. A palpable mass was more common in the conservatively managed group. Complications were common among patients who were operated on. No interval appendicectomies were done during the second half of the study period. 4 of the patients treated conservatively (8%) had an underlying tumour diagnosed at follow-up. CONCLUSIONS: Operative management of patients with appendiceal masses seems to be associated with a high risk of postoperative complications and the risk of a more extensive surgical procedure. If possible, a conservative approach should be advocated. Because of inaccurate radiological imaging during the acute phase and the risk of an underlying malignancy, routine follow-up is necessary. Routine interval appendicectomy cannot be recommended.     

MRI of transplanted pancreatic islets.

A promising treatment method for type 1 diabetes mellitus is transplantation of pancreatic islets containing beta-cells. The aim of this study was to develop an MR technique to monitor the distribution and fate of transplanted pancreatic islets in an animal model. Twenty-five hundred purified and magnetically labeled islets were transplanted through the portal vein into the liver of experimental rats. The animals were scanned using a MR 4.7-T scanner. The labeled pancreatic islets were clearly visualized in the liver in both diabetic and healthy rats as hypointense areas on T2*-weighted MR images during the entire measurement period. Transmission electron microscopy confirmed the presence of iron-oxide nanoparticles inside the cells of the pancreatic islets. A significant decrease in blood glucose levels in diabetic rats was observed; normal glycemia was reached 1 week after transplantation. This study, therefore, represents a promising step toward possible clinical application in human medicine.     

Tracers for aerosol ventilation scintigraphy: Tc-99m versus In-113m

113mIn has been proposed as a suitable tracer for aerosol ventilation scintigraphy in combination with 99mTc pulmonary perfusion scintigraphy. The high energy (393 keV) of 113mIn allows it to be detected in the presence of 99mTc, but degrades the spatial resolution which can be achieved. We have compared the resolution obtained with 99mTc and 113mIn in phantom experiments and in aerosol ventilation scans in 14 patients with airways disease. The resolution at the distances from the collimator encountered in lung scintigraphy was 10-20 mm for 99mTc and 15-40 mm for 113mIn. Aerosol ventilation images were abnormal in all patients. The 99mTc images showed peripheral defects and frequently central hot spots reflecting increased local aerosol deposition. In the 113mIn images, the lower resolution had a smoothing effect, the central hot spots were less striking, and the distribution of activity appeared more uniform, some detail was lost in the periphery. It is suggested that 113mIn is useful for ventilation scintigraphy in the diagnosis of pulmonary embolism, but that 99mTc is the tracer of choice if aerosol ventilation scintigraphy is used to study airways disease.     

Determinants of survival in liver resection for colorectal secondaries

All 72 resections for colorectal liver secondaries during the period 1971-1984 were analysed retrospectively. Liver tumours were single in 35 (49 per cent), unilateral in 55 (76 per cent) and associated with extrahepatic disease in 12 (18 per cent) patients. Operative mortality was 5.6 per cent. With respect to the disease in the liver, the presence or absence of four or more metastases was the predominant prognostic determinant with a 5 year survival rate of 20 per cent in patients with less than four liver tumours, and no 3 year survivor among patients with four or more tumours. When the number of liver tumours was less than four, the prognosis in patients with unilateral disease was not significantly better than in patients with bilateral disease (P = 0.19). No other liver disease variable seemed to play any role in the prognosis. Extrahepatic disease was associated with a poor prognosis and no 5 year survivor. The length of the tumour-free resection margin was the only treatment variable that varied with the outcome: a resection margin of less than 10 mm was followed by a poor survival. Variables that did not influence survival included uni- or bilateral disease, liver tumour volume, tumour size, type of liver resection, Dukes' classification, differentiation of the primary tumour and synchronous or metachronous disease. It is concluded that resection for liver colorectal secondaries is indicated when there are less than four liver tumours, even if bilateral, no extrahepatic disease is present, and a resection margin of at least 10 mm can be obtained. It should not be performed unless all of these requirements are met.     

Visual half-field tests of lateralized letter presentations: differences between preliterate and literate children

In the present study, hemispheric differences in global and analytic processing were investigated in preliterate and literate children, using the "dual-letter" matching task paradigm (Navon, 1977). The stimuli consisted of lateralized visual presentations of large uppercase letters made up of small uppercase letters. The task of the subject was to decide on each trial if the large or small letters were the same or not. Vocal reaction time (VRT) and error-frequency were used as dependent measures. In Experiment 1, 28 right-handed 8-years old children participated. The children were split into a preliterate and a literate group depending on teachers evaluations, and on scores on a reading test. The results showed longer VRTs for the preliterate children when the stimuli were initially presented to the right hemisphere and especially when the subjects were required to match the small letters. These results were followed up in Experiment 2, where the preliterate subjects were split into "fast" and "slow" readers. The results showed that the "slow" readers were more impaired in processing the letter stimuli when the stimuli were initially presented to the right hemisphere. It is concluded that hemispheric asymmetry for letter processing interacts with the development of normal reading ability in children.     

Interleukin 2 and gamma interferon production, interleukin 2 receptor expression, and DNA synthesis induced by tularemia antigen in vitro after natural infection or vaccination.

The T-cell response induced by Francisella tularensis antigen in sensitized subjects was characterized in vitro by measuring DNA synthesis in whole-blood and mononuclear cell cultures, interleukin 2 (IL-2) and gamma interferon (IFN-gamma) production, and IL-2 receptor expression. Correlations between these variables were estimated. The strengths of the responses were compared in 21 subjects naturally infected 2 years ago, 6 subjects vaccinated 5 to 6 years ago, and 13 control subjects with no history of infection or vaccination. Subjects with a history of natural infection synthesized more DNA in both whole-blood and mononuclear cell cultures, secreted more IL-2 and IFN-gamma, and expressed more IL-2 receptors than control subjects did. All these responses differed highly significantly (P less than 0.001) from those of the control subjects. The vaccinees exhibited somewhat lower responses than the naturally immunized subjects did, but the vaccinees could be distinguished from the control subjects by their DNA synthesis, receptor expression, and IFN-gamma production (P less than 0.01 to 0.001). The vaccinees showed a lower response, in terms of DNA synthesis and IL-2 secretion (P less than 0.05), than the infected group did but responded in a manner similar to that of this group, with respect to receptor positivity and IFN-gamma secretion (P greater than 0.10). The correlations between all the T-cell functions were good, with highly significant correlations (P less than 0.001) between whole-blood DNA synthesis and IL-2 and IFN-gamma secretion and between the two lymphokines (P less than 0.001). The results not only increase our knowledge of the T-cell response to tularemia antigen but also give an alternative approach to DNA synthesis measurement for the quantitation of T-cell responses. The results for the low-responding sensitized subjects seem to indicate that the parameters were comparable in sensitivity.