London Archive of Longitudinal Growth Data

An Archive of longitudinal growth data, accessible to research workers under the usual safeguards, has been set up in the Department of Growth and Development. The present S.I.R. database contains seven British and one Indian study. The Archive is open to receive other contributions if researchers wish.     

Computerized potential distribution mapping: a new intraoperative mapping technique for ventricular tachycardia surgery

This study evaluated potential distribution mapping as a method for localizing the site of origin of ventricular tachycardia (VT). In contrast to conventional activation time maps, potential distribution maps require less editing and thus can be more automated and rapidly processed for interpretation of multiple beats of VT. As a series of potential distribution maps during VT is required for detailed analysis, an on-line computerized system was designed to display potential distribution maps sequentially at 1-ms intervals as a color movie. Potential distribution maps and activation time maps were constructed from 182 epicardial and endocardial unipolar electrodes during 12 episodes of reproducible monomorphic VT in 9 dogs four to six days after experimental myocardial infarction (mean cycle length, 162 +/- 21 ms). At the onset of each depolarization during VT, a potential minimum abruptly developed on the surviving epicardium and another on the surviving endocardium of the left ventricle, both immediately adjacent to the subendocardial infarct. These two minima on the initial potential distribution maps corresponded to the sites of earliest epicardial and endocardial activation breakthrough recorded on the activation time maps. These two minima subsequently expanded or moved into the adjacent area and coincided with the spread of activation fronts on the epicardial and endocardial surfaces. Thus, the rapid display of sequential, computerized potential distribution maps of multiple beats of VT provides a dynamic means of identifying the site of origin of VT, and therefore should facilitate intraoperative mapping.     

Infarction of a growth hormone-secreting macroadenoma during a TRH test

Pituitary infarction occurring immediately after TRH injection (200 micrograms) is reported in a patient with gigantism due to a growth hormone-secreting pituitary macroadenoma. Evidence of infarction was seen in CSF and in serial CT scans. Regression of symptoms and sign of acromegaly, abolition of abnormal growth hormone secretion, and virtually complete anterior and partial posterior pituitary failure rapidly followed. The infarction was probably initiated by a hypertensive response to TRH. TRH testing in acromegalic subjects may require smaller doses of TRH to avoid unwanted pressor responses.     

Comparison of catheter surface morphologies

The surface morphologies of different generic types of Foley catheter have been investigated using scanning electron microscopy (SEM). The characteristic features of each material are illustrated and it is shown that distinct differences exist between the inner and outer surfaces of latex-based catheters; these differences are attributed to the methods of manufacture. The possible relations between morphology and performance in situ are discussed.     

Psychosocial problems among survivors of Hodgkin's disease

The psychosocial problems that develop in long-term survivors of Hodgkin's disease were examined in a cross-sectional survey of 403 patients. The average age at treatment was 27 years and at interview was 36 years. The median time since treatment was 9 years. Sixty percent of the patients were treated for stage I or II disease and 40% for stage III or IV. Eighty-two percent of the patients had never relapsed, and 98% were free of disease at the time of interview. The study investigated the type and frequency of problems by means of a self-administered questionnaire using standard survey items to assess disruption in three areas of life: sense of well-being, family relationships, and employment. Results indicate that energy had not returned to patients' satisfaction in 37% of the cases. This was influenced by age, time since therapy, stage of disease, and type of treatment. Patients with self-reported energy loss were more likely to be depressed. Moderately high divorce rates (32%), problems with infertility (18%), and less interest in sexual activity (20%) were reported. Employment patterns favored men returning to work, and number of hours worked was highly correlated with less depression, younger age, and return of energy. Difficulties at work were reported by 42% of the cases. The interaction of treatment, biologic, psychosocial, and functional variables is described.     

Long-term treatment sequelae following external beam irradiation for adenocarcinoma of the prostate: analysis of RTOG studies 7506 and 7706

Significant late intestinal and urinary morbidity from external beam irradiation for adenocarcinoma of the prostate has been a constant concern of both the urologist and the radiation oncologist. We analyzed two large Radiation Therapy Oncology Group trials (7506 and 7706) using primary irradiation in the treatment of local or locoregional adenocarcinoma of the prostate to assess morbidity via the Radiation Therapy Oncology Group scoring scheme (grade 1-5). One thousand twenty patients were treated in total with a minimum follow-up of 7 years in the surviving patients. There was a 3.3% incidence of intestinal complications defined as grade 3 toxicity or more with .6% of patients experiencing bowel obstruction or perforation. Urinary complications defined as grade 3 toxicity or more were found in 7.7% of patients with only 0.5% experiencing morbidity that would require a major surgical intervention such as laparotomy, cystectomy, or prolonged hospitalization. Intestinal and urinary complications were evaluated in reference to several parameters that might have an impact on their incidence (i.e., previous laparotomy, stage of disease, hypertension, positive lymph nodes, previous transurethral resection, total dose, and energy of accelerator used). Only total dose (greater than 70 Gray) was found to have a significant impact on the incidence of the urinary complications. None of these factors had a significant impact on the incidence of intestinal complications. These data from two large multi-institutional trials represent a fair estimate of the actual incidence of major intestinal and urinary complications from external beam irradiation in the management of local and locoregional adenocarcinoma of the prostate. Since the incidence of these major complications remains very low, we believe that external beam irradiation remains an excellent alternative to radical prostatectomy in the management of these patients.     

A study of the mechanism of selenite-induced hypomethylated DNA and differentiation of Friend erythroleukemic cells

Sodium selenite is a good inducer of hemoglobin production inFriend erythroleukemic cells (FELC). At a concentration of 20µM 70-80% of the cells produce hemoglobin and the DNAis hypomethylated. What is the mechanism for sodium selenitealteration of the DNA methylation pattern? Experiments withmethionine adenosyltransferase (the enzyme that synthesizesadenosylmethionine) showed little effect of selenite on theactivity of this enzyme in vitro or in vivo. Therefore, FELCare able to synthesize S-adenosyhnethionine in the presenceof sodium selenite. When sodium selenite was added to an invitro assay for DNA methylase, the enzyme was non-competitivelyinhibited by 80% at 20 µM selenite with a K₁ of 6 µM.DNA methylase isolated from control and selenite-treated FELCwas purified through a DEAE-Sephacel column and no differencein activity was found. In the presence of selenite, DNA methylaseis very sensitive to selenite inhibition, but removal of theselenite restores activity. However, DNA synthesized by FELCgrown in the presence of selenite (no DNA methylase activity)was found to be hypomethylated. These results suggest that DNAmethylase activity is inhibited in FELC grown in the presenceof sodium selenite.     

Effect of thymectomy on blood T-cell subsets in myasthenia gravis

We studied peripheral blood mononuclear T-cell subsets in 23 patients with myasthenia gravis who had undergone thymectomy at least one year before study. An increase in the T4+/T8+ (helper-inducer/suppressor-cytotoxic cell) ratio was seen, similar to that previously reported in nonthymectomized patients with myasthenia gravis. Six patients were studied before and after thymectomy and no consistent alteration in the pattern of T-cell subsets was detected. We were not able to demonstrate a quantitative effect of thymectomy on peripheral blood mononuclear T-cell subsets in patients with myasthenia gravis.     

Limiting dilution analysis of age- and gender-related differences in autoantibody production against bromelain-modified RBC

Cultured peritoneal cells from untreated mice, after 3 days of in vitro culture, produce autoantibodies against bromelain-treated isologous erythrocytes. The autoantibody response varies with both age and gender. The effects of age and gender were demonstrated by culturing peritoneal cells using limiting dilution techniques. In neonatal mice there were no precursor cells that differentiated into autoantibody secretors. Cells from female mice gave higher responses than cells from males, and the effect was more pronounced in cells from older mice and cultures to which lipopolysaccharide/dextran sulfate (LPS/DS) had been added. Various cell separation and cell mixing experiments indicated that a non-B-cell, nonadherent cell was involved in the higher autoimmunity detected in the presence of LPS/DS in female and older mice. It is thus possible that low autoimmune responses are due to the absence or unresponsiveness of accessory cells rather than potentially autoimmune B-cells.     

Delayed presentation of unstable cervical spine injury with minimal symptoms

Emergency physicians are less likely to suspect the presence of a severe or unstable cervical spine injury in patients who have been ambulatory since the traumatic episode. We present the case of a man with multiple cervical fractures and a 75% anterior subluxation of C6 and C7 who did not seek medical care for six weeks after falling from a height. Previous reports of delayed or occult cervical spine injuries are reviewed. Physicians must aggressively search for injuries whenever a history of neck pain is present or a strong mechanism of injury exists, even if the patient has been ambulatory for days or weeks following the injury.