Uses and contributions of diagnostic electron microscopy in surgical pathology: a study of 20 Veterans Administration hospitals

Although the capability of electron microscopy to contribute to histopathologic diagnosis in selected instances, e.g., renal biopsies and biopsies of certain tumors, is generally recognized, its contribution in a broader range of surgical pathology accessions is not well established. To gain further information concerning this aspect of the use of electron microscopy, 7,193 surgical pathology reports, 290 (4 per cent) of which included electron microscopic findings, were analyzed; these reports represented all such accessions during the same single month at 20 VA medical centers. It was found that malignancies constituted 62 per cent of the lesions examined by electron microscopy but only 20 per cent of the total number of surgical cases examined by light microscopy. It was also found that the distribution of specimens by tissue site of origin differed considerably for specimens examined by electron microscopy and light microscopy; positive contributions of electron microscopy to diagnosis were found in 146 of the 290 electron microscopy cases (50 per cent), with higher percentages found in malignancies and in certain tissue site subsets (lower respiratory tract, soft tissue, kidney, skin, and lymph nodes with metastases); failure to examine some specimens (lung metastases to lymph nodes or other tissues and endobronchial biopsy specimens) suggests slight, but common, underutilization of electron microscopy in diagnosis.

A computer program for determining Vmax from the uncalibrated left ventricular pressure signal and its first derivative

A computer program was developed to simplify the conventional method for determining the maximal contractile element shortening velocity at zero load (Vmax) by analysis of pressure-velocity graphs during the isovolumic contraction period. From an uncalibrated left ventricular (LV) pressure signal and its first derivative (dP/dt), the graph relating developed LV pressure (Pd) to the corresponding instantaneous value of (dP/dt)/28 Pd was constructed by the computer. The segment of the graph that encompassed approximately the second half of the isovolumic contraction period, as determined by analysis of the dP/dt waveform, was then extrapolated to provide V'max on the ordinate. This V'max was compared with the conventional Vmax obtained from calibrated LV and aortic pressure signals. In 5 dogs both in the control state and during inotropic (epinephrine, propranolol) and noninotropic interventions (phenylephrine or dextran infusion), a high degree of correlation was found relating V'max and Vmax both derived by either linear (Vmax = 0.91 V'max + 0.14; r = 0.933; P less than 0.001) or exponential (Vmax = 0.99 V'max - 0.06; r = 0.959; P less than 0.001) extrapolation of the pressure-velocity graph to zero load. By use of this program, Vmax can be easily and reliably estimated from the uncalibrated LV pressure signal and its first derivative.

Diagnostic electron microscopy in the U.S. Veterans Administration

The diagnostic electron microscopy (EM) programme in the VA is described with emphasis on its central administrative aspects. There are now 45 separate diagnostic EM units, each directed by a pathologist who is initially provided with comparable resources and operates under a common administrative framework. Considerable autonomy in medical and scientific matters remains with the unit directors. Some experiences in the programme are displayed in numerical data for 1975 through 1979. Coordinated use of available EM resources for both diagnostic and research purposes is not occurring to develop better utilization. Preliminary efforts to assess the contributions of diagnostic EM in morphological diagnosis and in patient management are described.

Pathology in the Soviet Union

Five pathologists from the United States visited the Soviet Union for three weeks in April 1978 to learn of the training in and the practice of pathology in that country. The major observations of the Americans were that (1) pathology is a medical specialty in the Soviet Union, with practice limited to anatomic pathology; (2) exfoliative cytology and clinical pathology are not part of pathology; (3) interest, both clinical and experimental, in occupational, environmental, and geographic pathology is conspicuous; (4) an autopsy rate of 90% to 95% is customary; and (5) there is an organized and hierarchical framework for practice, with career patterns established early and change infrequent.

Fluorescein angiography in retrolental fibroplasia: experience from 1969-1977

Acute proliferative retrolental fibroplasia (RLF) has been studied in premature infants employing a Zeiss fundus camera and fluorescein angiography. A total of 164 angiograms have been performed on 122 infants. At the present time, angiography is reserved for studying infants with peculiar or puzzling fundus pictures. A dose of 0.1-0.4 cc of 10% sodium fluoresceinate is employed, depending on the age and the weight of the baby. Fluorescein clearly outlines the major arteriovenous shunt in the retina, which is the hallmark of acute RLF. The shunt fills with fluorescein and leaks it profusely. On regression, a fine brush border of capillaries is seen in the region where the shunt previously had been located. Study of the population susceptible to RLF reveals it to be the smallest sickest babies in the premature nursery.

Reappraisal of linoleic acid requirement of the young infant, with particular regard to use of modified cows' milk formulae

Most infants in the UK are bottle fed with cows' milk formulae that are alleged to provide less than the minimum requirement for linoleic acid, i.e. 1% of the total dietary energy. 20 term infants fed solely on a modified cows' milk formula that provided 0.55% of the energy from linoleic acid were therefore examined for evidence of deficiency. Rates of growth in length and weight, measured during the first 3 months of life, were identical with those of 20 wholly breast-fed infants. Voluntary food intakes (kcal/kg per day) followed the normal pattern. The fatty acid composition of the plasma lipids showed changes characteristic of a low intake of linoleic acid, but triene:tetraene ratios did not indicate a deficiency state, and clinical signs of deficiency were not observed. These findings suggest that the requirement for linoleic acid is substantially less than was formerly believed. The small amount of alpha-linolenic acid present in cows' milk may however exert a sparing effect on linoleic acid.

Coronary vascular responses to nitroglycerin following aorta-coronary saphenous vein grafting in dogs

Phasic coronary arterial flow responses to nitroglycerin were evaluated in 15 open-chest greyhounds before and after aorta-coronary saphenous vein grafting. Coronary flow was measured with electromagnetic probes proximal and distal to the vein graft site. Simultaneous measurements of branchiocephalic flow, aortic and left atrial pressure, left ventricular pressure, and dp/dt were made. Grafts were placed during normothermic hemodilution cardiopulmonary bypass and induced ventricular fibrillation. Before grafting, intravenous nitroglycerin (0.6 mg.) elicited an abrupt rise in diastolic coronary flow which decreased as aortic pressure fell and systolic coronary flow increased. However, after grafting, nitroglycerin elicited no change in diastolic coronary flow, whereas systolic coronary flow increased and aortic pressure fell. In 6 control dogs treated similarly except for aorta-coronary grafting, coronary flow responses to nitroglycerin were unchanged. These acute experiments suggest that, in dogs with aorta-coronary saphenous vein grafts, the coronary dilating effect of nitroglycerin is virutally abolished.

Leukocyte migration test in Crohn's disease, ulcerative colitis, and ankylosing spondylitis using Crohn's colon homogenate, mitochondrial, and microsomal fractions

Leukocytes from 33 patients with Crohn's disease, 20 patients with ulcerative colitis, and 20 patients with ankylosing spondylitis were tested for evidence of abnormal migration in the presence of preparations of colon from a patient with Crohn's disease. None of the patients was on treatment with immunosuppressive drugs. The test was also performed with leucocytes from 12 health subjects. Significant alteration was seen in the Crohn's disease group, particularly when the antigen used was mitochondrial or microsomal fraction of colon mucosa, whereas the patients in the ulcerative colitis group showed reactivity only with the whole colon homogenate and not with the subcellular fractions. The ankylosing spondylitis group showed no statistical difference from the normal controls with any of the antigens.

Reversal of severe fatty hepatic infiltration after intestinal bypass for morbid obesity by calorie-free amino acid infusion

Hepatic fatty infiltration complicating jejunoileal bypass can be massive and may require restoration of gastrointestinal continuity. This fatty infiltration appears to be caused by protein depletion associated with adequate or high carbohydrate intake. The present study has shown that calorie-free amino acid alimentation can reverse these changes. In three of thirteen patients who underwent 12 inch to 6 inch jejunoileal bypass procedures, symptomatic hepatomegaly developed with near total replacement of hepatocytes by massive fatty infiltration. After undergoing liver scan, liver biopsy, and liver function tests, the patients were started on a peripheral infusion of 2L per day of a 4.25 per cent crystalline amino acid solution, allowing for fat mobilization while preserving body protein stores. All oral intake was withheld except for water. At the end of a fourteen to twenty-one day infusion period, serum albumin levels increased by 1 gm in all patients. Decreases in liver volume of 83, 45, and 40 per cent occurred. During the infusion period ketonuria was 4 plus in all patients indicating active lipolysis. Weight loss was impressive (17, 19, and 40 pounds). All patients showed marked symptomatic improvement, and postinfusion liver biopsy specimens showed a return to near normal architecture. Maintenance of normal liver size by a high-protein, low-carbohydrate diet was observed in a five to seven month follow-up period. In contrast to previous studies using standard hyperalimentation solutions, the use of calorie-free amino acid solutions reverses the hepatic fatty infiltration seen after intestinal bypass by mobilization of fat. This fat mobilization does not occur as readily in the presence of large amounts of glucose.

An evaluation of the rosette inhibition test in Crohn's disease

Serial rosette inhibition tests were performed on nine patients with Crohn's disease undergoing immunosuppressive therapy in an attempt to estimate the minimum amount of drug necessary to maintain immunosuppression. The rosette inhibition titre was found to be higher in immunosuppressed patients than in normal subjects. However, there was no consistent correlation of the rosette inhibition titre with the degree of activity of the disease. The test is therefore not sufficiently discriminative to be used as a basis on which to control drug dosage.

Cellular hypersensitivity to mitochondrial antigens in diabetes mellitus and its relationship to the presence of circulating autoantibodies

Leucocyte migration tests with rat liver mitochondria have been performed in eighteen patients with juvenile diabetes mellitus and in fifteen healthy controls. Leucocytes from normal subjects showed no inhibition of leucocyte migration, whereas inhibition occurred in twelve out of eighteen diabetics. The active component appeared to be in the inner membranes of the mitochondria in seventeen patients, whilst leucocytes from one patient showed inhibition to outer membrane fragments.

Leucocyte migrations tests were performed in a further thirty-five patients, again using rat liver mitochondria as antigen, and sera from these patients was investigated for the presence of tissue autoantibodies. In those patients having a positive leucocyte migration test there was a higher incidence of circulating antibodies than in the group where white cells showed no inhibition but this did not reach statistical significance.

Mixed-lymphocyte reaction as a measure of immunological competence of lymphocytes from patients with Crohn's disease

Peripheral blood lymphocytes from 12 patients with Crohn's disease and from a group of normal volunteers have been tested for transformation under stimulation of allogeneic cells in a mixed lymphocyte culture and by phytohaemagglutinin (PHA) in vitro. There was a significant depression of transformation in the mixed lymphocyte culture where lymphocytes from the Crohn's disease patients constituted the responding population. With PHA stimulation, no difference in transformation was seen between the patients and the control group. This is interpreted as indicating a depression in cellular immunity in Crohn's disease.