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Biomedical subjects

J Kovi

Publications and source records attributed to J Kovi.

At least 19 recordsLinked to original sources
PubMed1994

Electron microscopic findings in hepatic allograft rejection.

Orthotopic liver transplantation is today an accepted surgical procedure for patients with irreversible, end-stage liver disease. Between 1988 and 1993, seven patients (one patient twice) received liver grafts for end-stage liver disease at Howard University Hospital, Washington, DC. In conjunction with the transplant procedure, a total of 32 liver needle biopsy specimens were submitted to the pathology department. Almost half of all liver graft failures are attributed to acute, or in a lesser degree, to chronic rejection. The purpose of this study was to describe the ultrastructural findings in acute cellular rejection and to correlate the ultrastructure with the histology. The key ultrastructural features of acute cellular rejection were: a mixed cellular inflammatory infiltrate in the portal tract, bile duct damage by immunocytes with reduplication of the epithelial basement membrane, endotheliitis, and intramitochondrial crystalline inclusions. It was concluded that electron microscopic investigation significantly contributes to better understanding the immunopathologic mechanism underlying liver allograft rejection.

Graft Rejection↗
PubMed1992

Review of prostatic surgical procedures at a predominantly black hospital: a 22-year study.

This article reports the results of a pathoepidemiological study of a cohort of black men who had prostatic surgery at Howard University Hospital between 1968 and 1989. The median age of patients at diagnosis of prostate cancer increased by 8 years during the study period, indicating either a delay in seeking medical care or a true delay in onset of the disease. The trends of prevalence of biopsies with cancer in various age groups suggested a sharp rise in the incidence of prostate cancer after the age of 70. The significant increase in popularity of needle biopsy during the period 1982 to 1989 after a 7-year plateau is an indication of increased perceived value of this procedure with experience and technical improvement. The prevalence of biopsies with cancer in all successive time periods of the study showed a bimodal distribution with an early hump in the 50- to 54-year-old age group. This hump is analogous to the break in the rising incidence of breast cancer between the ages of 47 and 52 (Clemmesen hook). This similarity could be explained on the basis of hormonal dependence of the two cancers.

Adult↗
PubMed1989

Breast lesions in black women.

A number of studies compared the clinical features and demographic characteristics of black and white patients with diseases of the breast. Only a few, however, dealt with the pathology of breast lesions. In this study, the distribution of breast lesions in blacks and whites (Caucasians) in the accessioned material of the AFIP from 1980 to 1983 was described. Additionally, the distribution of estrogen and progesterone receptors in a total of 425 black patients with breast cancer at Howard University Hospital was studied and the results compared with similar data reported in white American women. In the period January 1, 1980, to January 1, 1983, there were 380 breast lesions from black patients and 3511 comparable lesions from white patients accessioned at the AFIP. A total of 159 black women and 1819 white women were diagnosed with carcinoma of breast. Black patients had 102 (79 percent) invasive duct carcinomas, and white patients had 1112 (78 percent). Black patients with invasive duct carcinoma were generally younger than white patients, as 68 percent of black patients and 53 percent of white patients were younger than 54 years. The difference in age distribution was statistically significant. Lobular carcinoma was less common in blacks than in whites. The relative ratio frequency of mucinous, medullary, and papillary carcinoma was higher in black women than in whites. Tubular carcinoma, however, was more common in whites than in blacks. Black patients had a lower incidence of ER-positive tumors and a higher incidence of ER-negative tumors compared with published data on white patients. Postmenopausal patients were more likely to be ER positive than premenopausal patients. Stratification of the data indicated a lower incidence of ER-positive and a higher incidence of ER-negative breast cancers in both premenopausal and postmenopausal patients compared with published data from institutions with predominantly white patient populations. Microscopic examination revealed a higher frequency of poorly differentiated carcinomas and fewer well- and moderately well-differentiated carcinomas than has been reported for white women with the tumor. There was a significant correlation between tumor grade and receptor positivity. Well-differentiated carcinomas were more likely ER and PR positive than poorly differentiated ones.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1988

Large acinar atypical hyperplasia and carcinoma of the prostate.

Step-sections of 429 whole prostate glands were studied. Large acinar atypical hyperplasia was graded as mild, moderate, and severe based on the degree of cellular anaplasia. The relationship between atypical hyperplasia and prostatic carcinoma was investigated. There was a strong association between prevalence and grade of atypical hyperplasia and prostatic carcinoma in patients up to 60 years old. Beyond the age of 60 no association was detected. In the younger age groups (36 to 60 years) atypical hyperplasia was found in 86.8% of prostates with carcinoma, but only in 37.9% of benign glands. Corresponding figures for the over-60 age group were 68.8% and 65.1%, respectively. A biologic explanation of the association between atypical hyperplasia and carcinoma in the younger age groups has been proposed. It was suggested that these men with atypical hyperplasia, particularly with severe atypical hyperplasia, have a greater risk for developing prostatic carcinoma.

Adult↗
PubMed1987

The role of diet in prostate cancer.

This is a one-to-one, age- and race-matched case-control study involving 55 histologically confirmed black prostate cancer patients and 55 controls who were seen at three major hospitals in Washington, DC from 1982 to 1984. Personal interviews were conducted to obtain the number of times food items of specified serving size were consumed per week by cases and controls; the subjects were grouped according to the age periods 30-49 and 50 years and older. We then calculated the average daily consumption of each of 18 nutrients per 1,000 calories. There was a significant negative association between linoleic acid (p less than 0.04) for the 50 years and older group, thiamin (p less than 0.05) for those 30-49 years old, riboflavin (p less than 0.03) for the 50 and older group, and iron (p less than 0.05) for those 30-49 years old. The results of this study suggest that the intake of thiamin and iron (in subjects 30-49 years old), linoleic acid and riboflavin (in subjects 50 years and over) could be protective because control subjects consumed more of these nutrients than did the cases.

Adult↗
PubMed1986

Dissemination of prostatic carcinoma: an autopsy study.

Autopsy protocols at Howard University Hospital (HUH), Washington, DC, for the period of 1930 to 1985 were reviewed. The patient population of the hospital is predominantly black. Necropsy cases with adenocarcinoma of the prostate were tabulated according to the presence or absence of metastasis and the site of the metastatic lesion. A comparison was made with a similar racially unselected (predominantly white) series (Massachusetts General Hospital).The most commonly involved organs by secondary carcinoma of the prostate were, in descending order of frequency, lymph nodes, bones, bladder, lung, liver, and kidneys. In comparison with the MGH unselected series, the distribution of metastatic sites was significantly different (P < .0001). In the HUH series, kidney and adrenal gland metastases were more common than in the control series. The seminal vesicles were more frequently involved in the MGH series. In the HUH series, 76 percent of bone metastases occurred in the vertebrae, while the comparable figure for the MGH series was 40 percent.

Humans↗
PubMed1985

Ductal spread in prostatic carcinoma.

The histologic appearances of ductal invasion were studied in 139 cases of prostatic adenocarcinoma diagnosed in the Department of Pathology, Howard University Hospital, during the period January 1980 through October 1983. Intraductal spread was found in almost half (48%) of the prostatic glands examined. Ductal spread was associated with the local extent (P less than 0.001) rather than with the grade of the tumor (P less than 0.01). Three distinct patterns of ductal penetration were recognized. The duct wall was completely destroyed in microinvasion. In foci of ductal permeation the integrity of the basement membrane was generally preserved, and the duct wall was infiltrated mainly by solitary tumor cells. When the tumor spread was by extension in continuity within the duct wall, the neoplastic cells appeared to grow between the pre-existing epithelial layers. It was concluded that prostatic carcinoma cells have the ability to penetrate the wall of benign ducts and progressively replace the normal epithelial elements. In this process the general framework of the affected duct appears to be preserved.

Adenocarcinoma↗
PubMed1985

Nutrition and prostate cancer: a case-control study.

This one-to-one, age- and race-matched case-control study involved 181 histologically confirmed black prostate cancer patients and 181 controls seen at three major hospitals in Washington, DC, during the period 1979-1982. Personal interviews were conducted to obtain the number of times food items of specified serving size were consumed per week by cases and controls during the age periods 30-49 and 50 years and older. Then the average daily consumption of each of 18 nutrients per 1,000 calories was calculated. There was risk enhancement associated with increased intake of proteins, total fat, saturated fat, oleic acid, and vitamin A during the age period 30-49 years. The association was highly significant for vitamin A and approached statistical significance for the other four nutrients. A hypothesis based on disturbance of the zinc-retinol binding protein-vitamin A axis was put forward to explain the relative risk enhancement effect of vitamin A on prostate cancer.

Adult↗
PubMed1984

Sclerosing lobular hyperplasia manifesting as a palpable mass of the breast in young black women.

Sclerosing lobular hyperplasia is defined as a lesion of the breast characterized solely by prominent hyperplasia of the lobules and sclerosis of the intralobular stroma. The extra-lobular connective tissue may or may not be fibrosed. To ascertain the frequency of this condition, the histologic sections of all benign breast lesions diagnosed at Howard University Hospital between January 1, 1980, and June 30, 1982, were reviewed. The patient population of the hospital is almost entirely black. Among a total of 590 benign breast lesions, 18 cases of sclerosing lobular hyperplasia were found. The mean age of the patients was 28.3 years. The patients generally complained of a painless or slightly tender lump in the breast, of one or two month's duration. The masses appeared finely nodular and varied in size from 0.8 X 1.2 cm to 3.5 X 5.0 cm. Some microscopic sections from patients with sclerosing lobular hyperplasia revealed incipient (lobule-sized) fibroadenoma. On re-examination of the available sections of 101 fibroadenomas, 47 (46.5 per cent) were found to be surrounded by breast tissue exhibiting focal sclerosing lobular hyperplasia. Apparently, sclerosing lobular hyperplasia is often overgrown by fibroadenoma, and the presenting symptoms are those of the dominant tumor rather than those of the preceding condition.

Adenofibroma↗
PubMed1983

Virilizing lipid cell tumor of the ovary: light and electron microscopic studies.

Lipid cell tumor of the ovary is among the rarest tumors belonging to the virilizing group of ovarian neoplasms. A lipid cell tumor of the ovary is described in an 18-year-old woman with secondary amenorrhea, hirsutism, and frank virilization. Current diagnostic features, preoperative and postoperative androgen determinations, and histomorphological and ultrastructural studies are presented. Prompt diagnosis and treatment are emphasized in this potentially malignant and disfiguring androgenic tumor that is readily amenable to surgery.

Adenoma↗
PubMed1983

Ultrastructure of the gonads in the testicular feminization syndrome.

The testicular feminization syndrome is a form of familial male pseudohermaphroditism transmitted by an X-linked gene. The karyotype is 46XY. Affected patients resemble normal females phenotypically. To date, only eight cases of this syndrome have been studied by electron microscope. This study reports the ultrastructural appearance of the gonads in two additional patients. The presence of mature interstitial cells with a rich endoplasmic reticulum suggests that the pathologic defect is not due to a lack of androgenic hormone production by the testes but is caused by peripheral end-organ resistance.

Adolescent↗
PubMed1982

Cancer of the prostate and aging: an autopsy study in black men from Washington, DC, and selected African cities.

Age-related changes of arteries, veins, glands, and stroma in the prostate of black men from Washington, DC, and from Ibadan, Nigeria, and Accra, Ghana, West AFrica, were studied in a total of 795 consecutive, unselected prostate specimens removed at autopsy during a 7-year period (1973-1980). Except for age group 80 and over, aging changes in the prostate were more severe in all age groups in black men from Washington, DC, than in black men from Ibadan and Accra (P less than 0.01). However, when the intensity of age-dependent alterations was compared in either US or African black men with carcinoma and with no carcinoma, no significant differences were found. These findings do not support the idea that the aging process per se increases susceptibility to cancer.

Adult↗
PubMed1981

Mixed mesodermal tumor of urinary bladder: a light and electron microscopic study.

Light and ultrastructural findings in a mixed mesodermal tumor of the urinary bladder are reported. The mesenchymal component of the tumor contained undifferentiated mesenchymal cells and cells with chondroblastic differentiation. The neoplastic chondrocytes displayed an abundance of cytoplasmic microfilaments and had a scalloped cell surface.

Aged↗
PubMed1981

Ultrastructure of intestinal lymphatics in Crohn's disease.

The fine structure of intestinal lymphatics in four patients with Crohn's disease and in two control subjects is described. Although obstructed lacteals are considered to be of major importance in the pathogenesis of regional enteritis, no detailed electron microscopic studies of lymphatic capillaries in this disease could be found. Even though both open and closed intercellular junctions were observed in the normal intestinal lymphatics, only closed junctions were noted in the mucosal and submucosal lymphatic capillaries in patients with regional enteritis. A heavy accumulation of protein rich lymph at the abluminal surface of lymphatic capillaries was consistently seen. None of the control lymphatics showed a similar alteration. The described fine structural changes indicate a decreased permeability of the lymphatic wall. Reduced lymphatic permeability could be a contributing element in the development of submucosal edema, a major microscopic feature of Crohn's disease.

Adult↗