Histology Course Research Articles

Angiographic and Histologic Course after Implantation of Balloon Expandable Intravascular Stents in Miniswine Coronary Arteries: Short‐ and Mid‐Term Observations

Sixteen balloon expandable Medtronic Wiktor tantalum stents were implanted in the major coronary arteries of six minipigs, which were maintained on a normal diet and given 500 mg aspirin per day. Angiographic and histologic examinations were performed 6 and 26 weeks after implantation. Angiographically reviewed, stenting increased the inner diameter of the coronary arteries from 2.61 ± 0.44 to 3.02 ± 0.34 mm (n = 16, P ≤ 0.001). Six weeks later, this value was reduced from 2.98 ± 0.35 to 2.33 ± 0.46 mm (n = 9, P ≤ 0.05), and between 6 and 26 weeks, an increase from 2.17 ± 0.44 to 2.93 ± 0.40 mm occurred (n = 6, P ≤ 0.05). Histologic evaluation at 26 weeks after stent implantation revealed an increase of the cross‐sectional area of the total vessel from 4.30 ± 1.09 to 5.50 ± 1.67 mm2 (n = 9; P ≤ 0.01). This was due to widening of the total vessel and intimal proliferation, which amounted to 1.19 ± 0.46 mm2 within the stented segment, as compared to 0.03 ± 0.03 mm2 in control sections (P ≤ 0.01). The areas of free vessel lumen, media muscularis, and adventitia remained unchanged. In 15 of the 16 hislologically examined coronary arteries, the internal elastica was fractured at the site of stent implantation. Twelve stents had also penetrated through the external elastica without evidence of wall hemorrhage. Thirteen out of 16 stents were angiographically followed, of which 12 were patent at the final reangiography. In one animal, acute thrombosis of the stented vessel after guidewire induced coronary artery spasm caused chronic right heart failure due to right ventricular myocardial infarction. Sudden death occurred in another pig 2 hours after successful implantation of three grossly oversized stents (inner vessel diameter: 2.4 ± 0.2 mm, stent diameter 3.2 ± 0.5 mm). Autopsy revealed extensive dissections of the media with subsequent vessel occlusion. It is concluded that Medtronic Wiktor stents can be placed easily, even in more distal or curved coronary arteries. Despite antiaggregational medication, intimal proliferation is observed early after implantation, reaches a maximum at about 6 weeks, and is followed by a regression 26 weeks poststenting. At 26 weeks follow‐up, the free vessel lumen at the stent site was not significantly reduced as compared to control segments. Proper adjustment of internal vessel diameter and stent diameter is necessary to prevent major dissections and thrombotic occlusions.

Acute and chronic bacterial prostatitis due to E. coli

Inoculation of Escherichia coli (serotype O:6) into the bladder of male and female Mastomys (Praomys) natalensis produced severe prostatitis. In this rodent both male and female animals possess a well developed prostatic gland. The histologic and microbiologic course of the prostatic infection resembled strongly the human disease. Acute bacterial prostatitis was followed by the development of chronic bacterial or nonbacterial prostatitis. The infection persisted in some animals for up to six months. Prostatitis was observed histologically in all animals sacrificed six months postinfection. Animals responded to the infection with a rise of anti-lipopolysaccharide antibodies. No major morphologic differences were detected in the histologic pattern of the inflammatory process between animals with positive and negative bacterial cultures and between male and female animals.

Induction of Renal Tumors in Cynomolgus Monkeys (Macaca fascicularis) by Prenatal Exposure to 1,2-Dimethylhydrazine

Nephroblastomas were induced at an early age in two of six cynomolgus monkeys by prenatal exposure to 1,2-dimethylhydrazine. In one, the tumor of the right kidney had metastasized into the lower lobes of the lungs. By their histologic structure, development, and clinical course, the induced nephroblastomas were analogous to the Wilms' tumors often found in children.

Successful management of acute myocarditis with biventricular assist devices and cardiac transplantation

Acute, fulminant myocarditis invariably culminating in death within hours to days has been reported in humans.1,2 This report describes a patient who presented with acute fulminant myocarditis and circulatory collapse; she required support for 23 days with circulatory mechanical assist devices followed by cardiac transplantation. This unique clinical experience enabled us to study the histologic course of fulminant myocarditis in humans, to compare and apply laboratory data derived from the murine myocarditis model to patient care and to evolve recommendations for the management of this devastating condition.

The retrospective analysis of the histological course by use of GPT integration value in anti HBe positive cases with abnormal GPT

The retrospective analysis of the histological course by use of GPT integration value in anti HBe positive cases with abnormal GPT

Morphometric and ultrastructural analyses of melanocytes, nevus cells, and melanoma cells.

Cytological atypia, revealed in the course of routine light microscopy, is considered a valuable indicator of malignancy in melanocytic lesions. A clear definition of the term cytological atypia, however, is lacking. Therefore, by morphometric analysis of ultrathin sections of 11 malignant melanomas (7 invasive, 3 in situ, and 1 lentigo maligna melanoma) and 10 compound nevi, we evaluated the discriminating power of the various facets of cytological atypia, i.e., nuclear area, area of the nucleolus, area of the total cell, and nuclear irregularity. In each case, at least 50 intraepidermal melanocytic cells were examined. The two-sided U-test showed significant differences between intraepidermal nevus and melanoma cells, with regard to the mean values (mean) and standard deviations (s) of the nuclear area (mean and s, p = 0.00011), area of the nucleolus (mean, p = 0.00043; s, p = 0.00011), and area of the total cell (mean, p = 0.00011; s, p = 0.00093). However, only the mean values and standard deviations of the nuclear area allowed a clear distinction in each individual case. The area of the nucleus can be estimated in the course of routine histology. We therefore think that the size and variation of the nuclear area should be considered in the histological differential diagnosis between malignant melanomas and benign nevi.

Urachal carcinoma: evaluation with computed tomography.

The computed tomographic (CT) findings in 7 patients with urachal carcinoma were reviewed. Computed tomography was useful in establishing an initial diagnosis, determining the tumor extent, and visualizing tumor recurrence. The embryology, histology, and clinical course of urachal carcinoma are reviewed.

Angiosarcomas in lymphedematous limbs.

The clinical and histopathological features of four cases of angiosarcoma in congenital, post-traumatic, and post-hysterectomy lymphedematous limbs are reported. A good correlation between histologic and ultrastructural findings and clinical course was observed.

Leukocyte Scintigraphy with 111ln in Acute and Chronic Osteomyelitis of Experimental Animals

Studies on 28 New Zealand white rabbits with experimentally induced osteomyelitis show that 111ln-leukocyte scans turn negative when inflammation changes from the acute stage (histologically represented mainly by granulocytes and only small development of collageneous fibres) into the chronic stage (histologically showing marked lymphoplasmacytic infiltration and increased development of connective tissue). Falsely negative scans (i. e. cold lesions) are due to marked medullar necroses accompanied by diminished development of an abscess wall and reduced concentration of granulocytes within the necroses. Truly negative scans (i. e. cold lesions) are seen in chronic osteomyelitis with extended medullar fibrosis accompanied by reduced blood flow in comparison to the normal medullar bone of the contralateral side. The histological course of experimental osteomyelitis in rabbits is in some respect comparable with the stages of osteomyelitis in man and allows to predict the result of the leukocyte scan.

Histological course of alcoholic hepatitis: Influence of abstinence, sex and extent of hepatic damage

The factors influencing the histological evolution of alcoholic hepatitis without cirrhosis have been evaluated in 26 patients (14 males and 12 females) submitted to repeated liver biopsies over a mean period of 1.7 years (1-3). Drinking habits during follow-up were checked by inquiries to patients and relatives and by serial determination of ethanol in urine. At the end of the follow-up, 9 patients (34.6%) had progressed to cirrhosis, 5 (19.2%) still had alcoholic hepatitis and 12 (46.1%) had normal liver or only minimal changes. Nine patients continued drinking heavily, 4 reduced their daily intake markedly and 13 stopped drinking. Improvement of liver lesions was observed in 9 of the abstainers and in 3 non-abstainers that had markedly reduced their alcohol consumption. Among the 9 patients with persistent heavy alcohol consumption, 5 developed cirrhosis and 4 still showed alcoholic hepatitis in their last biopsy. Cirrhosis also developed over 1-2 years in 4 females who had stopped drinking, indicating a marked influence of sex on the course of alcoholic hepatitis. Progression of the disease to cirrhosis despite abstinence occurred in a high proportion of women (4/7) but not in men (0/6). These observations indicate that discontinuation of heavy alcohol consumption often results in improvement of liver lesion in patients with alcoholic hepatitis. However, the risk of progression to cirrhosis remains elevated in women.

An experiment in teaching histology and cell biology.

An experiment in teaching a course of histology and cell biology was undertaken at Tel Aviv University Medical School. Teachers were selected from different fields and formed a group which heard and discussed each lecture. Almost all teachers never had taught the subject and were free from bonds to the ‘orthodox’ ways of teaching histology. The course aimed at teaching morphology in relation to function, stressing understanding more than memorising, and relating the two-dimensional appearances of sections to three-dimensional structure.The course consisted of frontal lectures, microscopical and EM labs and small-group lab sessions in which students performed various techniques and discussed them. These sessions aimed at understanding and discussing limitations of the techniques and why and when they could be useful, and not at teaching the techniques themselves.The course was successful (judged by student evaluation and by the student knowledge of the subject, as reported by teachers or pathology and othe...

Microfiches as an aid to teaching histology.

A set of six colour microfiches and an atlas of black-and-white prints of the photomicrographs used in the microfiches have been prepared by the author and have been used for teaching an Histology course to medical students for 4 years. Students reaction to them and their use has been gauged by voluntary questionnaires. Of students who responded, 78% found the microfiches made the course easier for them; 76% like the microfiches because they can use them for home study; 77% find them useful for class discussion; 62% like them because of their colour reproduction. A small group of fifteen students, who failed the Histology course the year prior to the introduction of microfiches and subsequently repeated the course, felt they could revise better with the help of the microfiches. Also they felt the course was clearer. Comparison of the examination results of the students for the 4 years preceding the introduction of microfiches with those of the 4 years since, shows an improvement in mean percentage achieved together with a decrease in the standard deviation (s.d.).

The Challenge of Education and Training in Pathology: The Basle Response

The aim of pregraduate teaching is to form young physicians who are masters in theart of observation and of biological reasoning, two faculties for which pathology is particularly suitable as a teaching instrument. In Basle we teach general pathology in the 3rd year in lecturesand in coordinated histology courses which are programmed. Thus, the student following his booklet with sketches, works up some slides, each step guided by questions which he has to answer in order to go on. In the 4th year the same schedule is followed for special pathology, which in the 6th year is applied at autopsy demonstrations. At these demonstrations a clinician first discusses the clinical history with the students thus preparing the questions which the pathologist has to answer by demonstrating his findings on color television. In other courses the students receive the clinical data and a week later a real clinico-pathological conference is held. Finally pathology is taught in small groups with fresh and formalin-fixed specimens. A great number of audiovisual courses are at the disposition of the students. We use them exclusively for repetition and not for initial teaching. The most important thing for a young pathologist is to learn how to work up biopsies including the knowledge where to find necessary help in the literature, an understandingof the clinical problems, and the precise final diagnois. In doing autopsies he must be able to understand and answer the clinical questions as well as to see the scientific problems. The programme spans 5 years including 1 in clinical work. During the 4 years in pathology the young pathologist, according to a schedule, rotates from one specialist to the other working up the biopsies under supervision. The attendance of several slide seminars organized by the society of pathology is compulsory. The young pathologist does about 300 autopsies and learns how to work up autopsies of junior colleagues. For self-education we prepared audiovisual courses with microscopic sets of slides. The main point in postgraduate education is the conviction of all permanent members of a department that teaching is one of our most important tasks, since with a thorough education of the next generation we are significantly helping to produce better pathologists.

Spontaneous Immunoglomerulonephritis in Wistar Rats

A strain of rats bred at the Nuclear Study Center of Mol (C.E.N.) develops a nephropathy characterized by granular deposition of immunoglobulin and complement in the renal glomeruli and tubules. We have attempted to specify the complement activation pathways (classical or alternate) in this disease by looking for their initial components (C1q, C3 and C4) in tissue lesions. The immunohistologic and histologic course of the disease has been followed in male and female rats. Immunohistologic results show that glomerular and tubular injury in CEN Wistar rats may be mediated by the classical pathway of complement activation. Histologic data demonstrate that the tubular, glomerular, and interstitial lesions appear in both sexes, but are more extensive and develop earlier in male rats. The lipopigments found in tubular cells suggest a lysosomal dysfunction which might contribute to the progress of the disease.

The medical teacher's viewpoint.

A problem concerned with the teaching of histology is outlined. Television is found to be useful as part of the strategy for dealing with the problem.During recent months the Charing Cross Television Unit made twenty programmes to supplement the Department of Anatomy's histology course. The programmes were viewed by the students each week throughout the course and are now available for private study in the library.

Endodermal germ cell carcinoma (endodermal sinus tumor) of the vagina in infant girls

An endodermal sinus tumor (endodermal germ cell carcinoma) was diagnosed in a 1-year-old girl in the vagina after hemorrhage; the tumor was completely removed by radical abdominal surgery. Postoperative polychemotherapy was performed for two years with Actinomycin D, Adriamycin, Vincristin, and Cyclophosphamide. The infant is now tumor-free for 26 months, showing almost normal somatic and psychic development. The characteristic histological patterns and clinical course of this strongly malignant tumor are demonstrated, based on 25 published case reports of endodermal sinus tumors in the vagina of little girls (aged 5-26 months). This neoplasm in early infancy has to be separated from the clear-cell adenocarcinoma of the vagina which occurs after puberty in adolescent girls and young women, and is induced by stilbestrol therapy to the mother during early pregnancy.

Clinical Relevance of Histological Grading of Cancer of the Larynx

Primary biopsies from 52 patients with cancer of the larynx were examined by two pathologists working independently. The malignancy of each case was graded twice with an interval of 1--1 1/2 month according to a histological scoring system elaborated by Jacobsson. The reproducibility of the system was found poor for individual prognostic purposes and no connection between histological grade and clinical course was demonstrated.

Asymptomatic primary biliary cirrhosis: Presentation, histology, and short-term course in d-penicillamine trial

Asymptomatic primary biliary cirrhosis: Presentation, histology, and short-term course in d-penicillamine trial

Review of Medical Histology

The problem of relevance continues to bedevil the presentation of medical histology courses. Students are not likely to understand the value of the subject until its applications become visible, and this may occur in divided and irregular doses at odd times, and even long after the course is completed. Curricula, as they expand in content and get compressed in time, may produce some unforeseen and undesirable gaps in knowledge. The introduction to this small but useful volume states its authors' intent to present in concise from (227 easy-to-read pages) the fundamentals of histology necessary for a modern medical curriculum. They have succeeded admirably. Students need more histology than this, but it should come by means of observation, discussion, and application, not through reading textbooks. The text may seem too brief, but the expressed and fulfilled objective is to make drawings and diagrams complement, not duplicate, information. Obviously, great care and

Genetic associations between myasthenia gravis and the HL-A system.

HL-A antigens were determined in 159 myasthenic patients, 112 of whom were females and 47 males. Fifty-seven patients were thymectomized. The relationship between 23 different HL-A antigens and myasthenia gravis (MG) with reference to sex, age at onset, clinical course of MG, thymus histology, and auxiliary diseases of the patients, as well as the significance of these antigens to 245 relatives of myasthenics, were analysed. The frequencies of HL-A1 and HL-A8 were highly significantly higher in myasthenic patients than in normal Finnish controls. The increase of HL-A1 is secondary and due to a strong linkage disequilibrium between HL-A8 and HL-A1. HL-A8 appeared most often in females with onset of MG before the age of 35 years, and inpatients with thymus hyperplasia. No significant HL-A deviations were found in males or in females with later onset of disease. In seven thymoma patients the occurrence of W10 antigen was almost significantly increased.