Search

A double blind randomised study was undertaken comparing the effects of oral mexiletine and placebo given by general practitioners at home in the early stages of suspected acute myocardial infarction, and continued for six weeks. The study comprised 216 patients. In 59 the diagnosis of acute myocardial infarction was not confirmed. Of the 72 patients with confirmed myocardial infarction treated with mexiletine, 11 (15.3%) died, compared with 19 (22.4%) of the 85 patients given the placebo, and significantly fewer of the former compared with the latter had frequent ventricular ectopics or ventricular tachycardia recorded on 24 hour electrocardiograms. Numbers of patients transferred to hospital or withdrawn from the trial because of arrhythmia or heart failure were similar in the two treated groups. Ten (13.9%) of the patients taking mexiletine had the drug withdrawn because of side effects attributed to it, compared with three (3.5%) of the group taking the placebo. A further five patients (all on mexiletine) also had treatment withdrawn because of side effects but infarction was not later confirmed. The results indicate that oral mexiletine can be given safely to patients with suspected myocardial infarction at home by their general practitioners in the absence of a positive electrocardiographic diagnosis. The frequency of ventricular tachycardia is significantly reduced; but there is no evidence of reduced mortality.

It has been shown by E. Granirer that for certain infinite amenable discrete groups G there exists a nested family of left almost convergent subsets of G on which every left invariant mean on m(G) attains as its range the entire [0,1] interval. This paper examines the range of left invariant means on L∞(G) for infinite locally compact abelian groups G and demonstrates the existence in every such group of a nested family of left almost convergent Borel subsets on which every left invariant mean on L∞ (G) attains as its range the interval [0,1]

The Snellen notation of visual acuity was not intended for a fractional expression of the proportion of full vision found. Its use in that sense gives a false impression. A series of test type, arranged on the plan of a unit of difference between the different sizes of the letters, is inferior to one arranged with the unit of proportion of one size to the letters next larger or smaller. For industrial estimations of impairment of vision an assumed zero and maximum of full vision, are necessary. Those recommended are 20/32 for the maximum and 20/320 for the zero of industrial vision. Read before the Buffalo Ophthalmological Club, Dec. 20, 1923.

n/a

Vision is a light and form sense. From the ability of the eye to discriminate detail of form is evolved the function of resolving power. The problem in medicolegal cases is the determination of the percentage loss of functional values. To determine these percentage functional disabilities, the relation between visual acuities and the associated functional losses must be established on a mathematical basis. The term “visual acuity” does not include the concept of function. Acuity notations are not fractions of vision nor are they fractional equivalents of resolving power. Comparing the successive gradations of acuity notations in the geometrical progression of Green and assuming that acuity notations express fractional ability of the form sense, it is shown that the better the acuity the poorer is functional ability—when vision is good it has relatively poor resolving power. This disproves the assumption. A method for computing the functional and proportionate value for acuity notations has been established. By this method each equal increase in the visual angle reduces visual resolving power (efficiency) by the same percentage. By application of this method to the medicolegal problem of evaluating visual disabilities, for identical degrees of damage to function identical percentage losses are established.

This paper describes the analysis, by photo–elastic methods, of a model of a design for a full-bore closure for a reactor pressure vessel.

The in vitro metabolism of progesterone-4-14C and 11-deoxycorticosterone-4-14C acetate in a rat adrenocortical carcinoma, 494 and 494-H, has been studied and compared with adrenal tissue from normal rats. An accumulation of deoxycorticosterone in the tumour tissue with an accompanying decrease of corticosterone and aldosterone, indicates a blockade in the 11-hydroxylation of deoxycorticosterone. A difference in the distribution of radioactive metabolites is observed between incubation experiments with Tumour 494 and 494-H. These findings indicate a correlation between the metabolic activity and the physiological findings in the host.

Photoelastic tests have been made on two-dimensional models of steam-turbine flanges for various combinations of the flange parameters depth, width, and bolt position. Design curves have been produced which show the relation between these flange parameters and the ratio of bolt force to pressure force necessary to produce a compressive stress at the inner edge of the flange equal to the internal pressure, this being the criterion adopted to ensure steam-tightness.Comparisons have been made between the experimentally determined stress distributions and distributions calculated by various methods. Of computer-aided methods, the English Electric Kidsgrove structural-analysis programme gave the best correspondence to the experimental results with a relatively simple idealization of the problem. When the depth of a flange exceeds the width and the bolt load acts within the inner half, the stress distribution is reliably predicted if the flange is assumed to behave as an eccentrically loaded column.

The “frozen stress” techniques of photoelasticity can give a complete knowledge of the stress, system in a solid body, but the examination of the stresses requires more time and care than in corresponding flat plate tests. In tests on tubes with transverse circular holes, sponsored by The Royal Aeronautical Society, all practicable geometrical shapes are examined and the maximum stress is measured in tension, bending and torsion. The results are comprehensive and show the inadequacy of previous results. In all cases the maximum stress occurs inside the bore of the hole. The accuracy of all the graphs of stress concentration factors is better than five per cent.

This report is based on a study of the tain that the visual acuity had reached its records of 172 cases of perforating ocular injuries of patients who were admitted to the wards of the Wilmer Ophthalmological Institute during the years 1935 to 1942, inclusive. The selection of these 172 cases was made from a total of approximately 275 both public and private ward patients. Some records were discarded either be­ cause they were incomplete or because there was an inadequacy of postoperative follow-up observation. Also discarded were the records of all patients with perforating ocular injuries who had re­ ceived definitive treatment before coming to the hospital, or in whom examination had been so long postponed that the out­ come was determined before treatment could be instituted. The study does not include nonperforating injuries, or cases of subconjunctival scleral rupture. Cases of retained intraocular foreign bodies are included. Of the 275 records which were reviewed, 47, or 17 percent, were dis­ carded because enucleation was performed without any attempt being made at repair, it being considered that the eyes were hopelessly lost. Figures including these 47 enucleated eyes, however, appear later in the discussion of the influence of the length of the laceration on recovery, and in the computation of the incidence of sympathetic ophthalmia. In this study there are no rigid speci­ fications of minimal postoperative ob­ servation; thus there are included all records in which it seemed reasonably cer

THIS INVESTIGATION was undertaken to study the differences between the ocular and the subcutaneous inflammatory responses following heterologous tumor transplantation, and to determine whether such differences could account for the superiority of the ocular route as a transplantation site. That such differences do occur appears to have been taken as self-evident in many of the published reports dealing with the ocular transplantation of tumors. For example, Smirnova 1 assumed that the "agents of defense" could not act in the: anterior chamber but presented no evidence to support this hypothesis. Greene 2 stated that the eye differs from other transplantation sites in the rapidity and intensity of foreign-body reactions. Greene, furthermore, concluded that these differences account for the success of transplants in the ocular area. On the other hand, Morris and associates 3 described destruction of tumor heterotransplants in the eye by lymphocytes, plasma cells, and, occasionally, foreign body giant cells.

SummaryThe introduction of an interference-fit pin in a circular hole in a flat plate is found to result in a reduction in the stress concentration factor at the hole boundary under tension applied to the plate. The S.C.F. decreases rapidly with increase in the ratio of interference stress to applied tension, and decreases also with increase in the ratio of hole diameter to width of plate. Very little difference in the S.C.F. is found for different ratios of Young's modulus of pin and plate.

It is now more than 25 years since Coker and Filon first developed photoelasticity as a practicable method of exploring the stress distribution in certain types of engineering components. All engineers must be familiar with the striking photographs of fringe patterns obtained by their method in stressed plates of various shapes viewed in a polariscope. In those early days observations were made on Xylonite models and the method was only applicable to components in which stress distribution was of a two-dimensional type. Moreover, with the apparatus then available investigations were somewhat difficult and many engineers at that time were very distrustful of the results obtained from what was, to them, a little understood laboratory technique.

The optically sensitive coating technique is used to determine the post-elastic behaviour of a large plate with an interference fit pin. An aluminium alloy exhibiting a small degree of work-hardening was chosen and this is thought to be similar in behaviour to a lightly cold-worked mild steel. Theoretical analysis of an idealized material indicates that work-hardening has a significant effect on the spread of plastic regions.

SummaryThe elastic stress distribution around a circular hole in a flat bar under simple tension, when the hole is filled by a push-fit pin, was investigated photoelastically. Over a range of values of the ratio of hole diameter to width of bar, and for pins of differing Young's moduli, the effect of the pin was sensibly the same, namely, to reduce the maximum tension on the hole boundary by about 15 per cent, as compared with that in the unfilled hole.The maximum shear stress on the boundary was unaltered.

The African rodent Mastomys spontaneously develops gastric argyrophil carcinoids. The tumor cells showed a varying degree of argyrophilia. The most strongly argyrophilic cells showed an OPT-induced fluorescence suggesting the presence of histamine. In addition, electron microscopy showed that these strongly argyrophil cells contained numerous cytoplasmic granules, similar to the endocrine-like cells in the oxyntic gland area of the rat and mouse stomach. The bulk of tumor cells, however, were weakly argyrophil, conceivably due to the scarcity of cytoplasmic granules. These granules resembled those of many polypeptide hormone-producing tumors, such as bronchial carcinoids and medullary thyroid carcinoma. Chemical analysis revealed the presence of histamine and histidine decarboxylase in extracts from tumor tissue. These observations agree with previous findings of numerous histamine-containing (OPT-fluorescent), argyrophilic, endocrine-like cells in the oxyntic mucosa of the rat and mouse stomach. In search for the parent cell of the gastric carcinoid of the Mastomys, histofluorescence techniques, in combination with light and electron microscopy, were used. 1. The OPT-method for the fluorescence microscopic demonstration of histamine revealed a small population of fluorescent cells scattered in the epithelium of the oxyntic and pyloric mucosa. 2. The fluorescent cells were argyrophilic after silver-staining according to Grimelius. In the pyloric gland area, however, most of the argyrophilic cells were non-fluorescent. 3. The Falck-Hillarp fluorescence technique revealed that the argyrophil cells had the capacity to accumulate dopamine after injecting animals with the precursor DOPA. This was also true for the tumor cells. 4. The pyloric gland area was rich in 5-hydroxytryptamine-containing endocrine-like cells as revealed by their formaldehyde-induced fluorescence and by the positive argentaffin staining of their cytoplasmic granules at the electron microscopic level. 5. Ultrastructurally, the epithelium of the oxyntic gland area contained scattered endocrine-like cells with numerous cytoplasmic granules. Based on the morphology of their cytoplasmic granules, at least two different cell types could be distinguished, probably representing two types of histamine-containing cells. It is suggested that a common progenitor of the two types of histamine-containing argyrophil endocrine-like cells in the oxyntic gland area of the Mastomys stomach represents the parent cell of the tumor.

A nine-year-old boy developed paralytic left esotropia secondary to an intracranial lesion. He also exhibited total loss of function of the left fifth and seventh cranial nerves. Extraocular muscle surgery in this situation was felt to be dangerous to the operated eye. The degree of risk however could not be determined from published reports. Surgery was performed and was complicated by severe corneal ulceration. Use of a therapeutic contact lens presumedly helped in finally achieving a satisfactory result.

An examination of land mobile frequency coordination practices points up the fact that the FCC has been far more aggressive and innovative than the private sector. In addition to discussing some cause and effect implications of these respective actions and inactions, this paper describes a practical mini-computer system which one user organization has attempted to develop as a means of demonstrating the viability of self-regulation, by the private land mobile community, of the frequency management function.

On the basis of our study of 12 cases of granular cell tumors in the brains of rats of different inbred strains, it seems that granular cell tumors are not rate in the central nervous system of untreated, aging BN/Bi rats. In none were metastases found. Awareness of the occurrence of these tumors in the central nervous system of these rats may stimulate further studies into the cellular origin of granular cell tumors that form in the central nervous system of the rat and might help to elucidate the origin of these tumors in general.

Problems in rock fracture and pore collapse were studied with the intent of understanding mechanisms of and developing models for rubble formation, permeability enhancement, and wave propagation. Results are reported for studies on explosive-induced fracture and fluid flow in a gas-bearing sandstone at confining pressures to simulate in situ conditions; explosive-induced fracture in a brittle plastic with multiple charges fired both simultaneously and sequentially; the effect of several intermediate-strain rates on strength and fracture in limestone; and development and testing of a theoretical model for yielding and pore collapse in porous rocks. The specific technical objectives of the project is to understand the physical mechanisms and develop models for the creation of fractured material or rubble and the enhancement of permeability by underground high-explosive detonations. This understanding will benefit in situ energy and resource technologies that use high explosives to achieve or enhance recovery of underground resources.

Argyrophilic carcinoids were found in 2 Syrian hamsters (Mesocricetus auratus). A solitary neoplasm was located in the glandular stomach of a 25.5-month-old animal that had ingested for 12 months laboratory chow to which arecoline and calcium hydroxide [Ca(OH)2] had been added. In the other hamster, a primary carcinoid of the pancreas had metastasized to the mesenteric lymph nodes and liver; this was in a 22-month-old animal that had ingested for 16 months chow containing added snuff and Ca(OH)I. It is not known whether the carcinoids were spontaneous or induced by the treatment. Argyrophilic carcinoids have previously been reported in only one other rodent species.

In comparison with other rodents, the mastomys is unique as regards the patterns of neoplastic and non-neoplastic diseases that it develops, some of which may constitute suitable animal models for corresponding diseases of man. Among the spontaneous diseases commonly encountered in necropsies of 600 mastomys maintained in a closed colony were: (1) degenerative joint disease of diarthroses and interventricular disks, which develops regularly in the second year of life; (2) renal disease, a type of immune-complex glomerulonephritis, affecting approximately 80% of mastomys in the age bracket 18-36 months; (3) thymomas and thymic hyperplasia affecting 30% of mastomys by the time they are 2 years old or older; (4) a combination of thymoma and polymyositis in a mastomys showing serum-globulin reactivity, presumably auto-antibody against striated muscle; (5) beginning before the age of 1 year, replacement of the normal cell population of the lymphoid tissues by plasma cells, and intense plasma cell infiltration at many other organ and tissue sites; (6) haematopoietic neoplasms, without leukaemic blood, in 10% of mastomys; and (7) histamine-producing argyrophilic carcinoid tumours of the glandular stomach in approximately 60% of old male and 30% of old female mastomys. Additionally, other neoplasms not infrequently encountered in mastomys rarely occur in other rodent species; conversely some neoplasms commonly found in other rodents, including especially tumours of the lung and mammary gland and leukaemia, are rare or absent in mastomys.