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Biomedical subjects

I Lee

Publications and source records attributed to I Lee.

At least 181 records · Page 10Linked to original sources
PubMed1992

Increases in tumor response by pentoxifylline alone or in combination with nicotinamide.

Pentoxifylline (PENTO), a derivative of methylxanthine, has been reported to improve fluidity of red blood cells (RBC), and thus improve the flux of RBC through narrow capillaries. Additionally, PENTO increases 2,3-DPG levels in RBC, thereby increasing the O2 release from RBC. Nicotinamide (NA) has been known to increase tumor blood flow, reducing the hypoxic cell fractions in the tumors. The purpose of this study was to examine the effects of PENTO alone or in combination with NA (PENTO + NA) on the oxygenation and radio-response of FSaII murine fibrosarcomas of mice. We observed a significantly enhanced, radiation-induced growth delay of the FSaII tumors by the treatment of either single or multiple injections of PENTO. The combination of PENTO and NA further delayed the growth of tumors. The TCD50 of control tumors was about 56.6 Gy, whereas that of PENTO + NA treated tumors was about 31.9 Gy. Thus, TCD50 was modified by a factor of 1.8. PENTO + NA exerted no effect on the acute skin damage of C3H mice after local irradiation and the gastrointestinal death after whole body irradiation. However, PENTO + NA slightly increased the bone marrow death as demonstrated by the decrease in LD50(30) from 5.5 Gy to 5.2 Gy. The average pO2 in the saline-treated control group of FSaII tumors was 8 mmHg and it significantly increased to 19 mmHg in the PENTO + NA treated group (p less than 0.001). We concluded that the PENTO + NA treatment increased the radio-response of tumors by improving tumor oxygenation.

Animals↗
PubMed1992

Immunoglobulins in milk from cows immunized with oral strains of Actinomyces, Prevotella, Porphyromonas, and Fusobacterium.

Immunization of pregnant cows with bacteria leads to the presence of high concentrations of specific antibodies in colostrum and milk. A total of 14 cows was immunized with single strains of heat-killed oral bacteria or pools of strains of Actinomyces, Porphyromonas, Prevotella, and Fusobacterium. Two cows were treated with adjuvant alone. The mean percentages of IgG1, IgG2, IgM, and IgA in all of the milks were 83.8, 3.8, 9.3, and 3.1, respectively. ELISA and whole cell agglutination assays demonstrated high titers in the milks from the cows immunized with either individual strains or the bacterial pools. The highest titers determined by ELISA belonged to the IgG1 isotype and in several milks were 64-fold greater than titers in milk from cows treated with adjuvant alone. The concentrations of all antibodies and the titers determined by ELISA and whole cell agglutination assays markedly decreased from the first to the sixth milkings. The functional specificity of the antibodies was demonstrated by agglutination tests against a wide range of bacteria including members of Actinomyces, Fusobacterium, Porphyromonas, Prevotella, Streptococcus, Eubacterium, Propionibacterium, Peptostreptococcus, Bacteroides, Actinobacillus, Haemophilus, Capnocytophaga, and Wolinella. Minimal cross-reactions with bacteria in other genera were observed with all of the milks. High-titer milk preparations have been obtained from immunized cows, and the capacity of the bovine antibodies to agglutinate target bacteria indicates their potential usefulness in oral passive immunization studies.

Actinomyces↗
PubMed1992

Nonspecific antibacterial factors in milk from cows immunized with human oral bacterial pathogens.

Both the immunoglobulins and non-specific antibacterial factors in milk from cows immunized with pathogenic oral bacteria have the potential to influence the oral microflora during passive immunization studies. The first six milks after calving were collected from 2 cows immunized with adjuvant and from 14 cows immunized with adjuvant and heat-killed strains of periodontopathic Actinomyces, Porphyromonas, Prevotella, and Fusobacterium. Analysis of the products from the first to the sixth milks revealed that the protein and lysozyme content decreased approximately 66 and 72%, respectively; the mean specific activity of the enzyme remained relatively constant. In contrast, the mean lactoperoxidase activity increased 2.3-fold in the second milking and increased further in the fourth and sixth milkings. The mean iron-binding activity increased 1.2-fold from the first to the second milkings and then decreased 3.6-fold through the sixth milking. Cows immunized with adjuvant alone showed similar responses. Per unit volume, the milk contained approximately 150 times less lysozyme than whole human saliva obtained from six subjects but higher concentrations of lactoperoxidase and iron-binding components. Purified bovine nonspecific factors prevented the growth of the bacteria used for immunization when bacteria were tested at concentrations similar to those found in saliva and milk. Because bovine nonspecific antibacterial factors could influence both the pathogenic target bacteria and the indigenous microflora in oral passive immunization studies with bovine immunoglobulins, the presence of these proteins should be considered.

Actinomyces↗
PubMed1992

Cytogenetic analysis of meningiomas.

Cytogenetic analysis of 4 cases of meningiomas from 3 male and 1 female patients is reported. One of male patients suffered from neurofibromatosis type 2. Histologically, the meningiomas were meningotheliomatous (1), transitional (2), and psammomatous (1). Chromosomal abnormalities were found in all cases with a karyotype 45,XY,-22, 45,XY,-16, 45,XX,-2, and 45,XY,t (15p;22q), respectively. Monosomy of chromosome 22 was detected only in the patient with neurofibromatosis type 2. These cytogenetic analysis demonstrates that variable clonal karyotype aberrations exist in meningiomas.

Adolescent↗
PubMed1992

Primary choriocarcinoma of the urinary bladder--a case report.

We report a primary choriocarcinoma of the urinary bladder in a 63-year-old man who presented with painless hematuria. He was diagnosed as having an invasive carcinoma and underwent a total cystectomy. The tumor was diffusely hemorrhagic and occupied the dome of the bladder. Histologically, it consisted of cyto-and syncytiotrophoblasts with extensive hemorrhage. No coexisting transitional cell carcinoma component was present. By immunohistochemistry, the tumor expressed beta-hCG and low-molecular weight cytokeratin intensely while it was negative for CEA or EMA. The post-cystectomy serum beta-hCG was 237mlU/ml, and decreased later. The pertinent literature is reviewed and diagnostic criteria are discussed.

Choriocarcinoma↗
PubMed1992

The oxygenation of murine tumor isografts and human tumor xenografts by nicotinamide.

The changes in pO2 caused by nicotinamide in the FSaII mouse tumor and three different xenografts of human tumors, HP-56, FaDu, and EO1, grown subcutaneously in the legs of mice were studied. The tumor pO2, as measured with microelectrodes, began to rise soon after the host mice were injected intraperitoneally with 500 mg/kg nicotinamide, and it increased continuously for 100-120 min. The rate and magnitude of the increase in tumor pO2 was dependent on the tumor line and also on the tumor size. In FSaII tumors, the increase in pO2 caused by nicotinamide was relatively small in the well-oxygenated small tumors (173 +/- 5 mm3) compared with that in the larger tumors (515 +/- 25 mm3). The blood perfusion in FSaII tumors as measured with the laser Doppler method was also increased by nicotinamide. The growth delay in FSaII tumors induced by X irradiation was enhanced significantly by nicotinamide. It was concluded that the enhancement of radiation damage in the experimental tumors in mice by nicotinamide, as observed in the present study and reported by others, is due to an increase in intratumor pO2, possibly as a result of an increase in blood perfusion.

Animals↗
PubMed1991

Left atrial ball thrombus: review of clinical and echocardiographic manifestations with suggestions for management.

Left atrial ball thrombus is an infrequent clinical syndrome, which can have a catastrophic outcome but can be readily treated when recognized. It is usually a complication of long-standing rheumatic mitral stenosis. Symptomatic presentation is variable: fragmentation of the thrombus followed by peripheral embolization will produce ischemia or infarction of myocardium, brain, viscera, or extremities; random, intermittent, partial, or total occlusion of the mitral valve orifice may cause syncope, pulmonary congestion, and occasionally sudden death in other patients. Embolic and obstructive phenomena may also occur together. Cardiac physical findings usually suggest mitral stenosis; variability in the intensity of the diastolic rumble is common. Two-dimensional echocardiography is the gold standard for identifying ball thrombus. Cardiac catheterization provides assessment of coronary artery status when needed. The outcome of untreated ball thrombus is unlikely to be favorable. The results of anticoagulation and thrombolysis are unpredictable and potentially as harmful as no treatment at all. Current evidence although scant suggests that prompt surgical removal of the free thrombus, often in conjunction with mitral valve repair or replacement, is the appropriate therapeutic course in most patients.

Cardiology↗
PubMed1991

Improvement in RBC flux, acidosis and oxygenation in tumour microregions by Fluosol-DA 20%.

Using laser Doppler flowmetry, we investigated the effects of Fluosol-DA 20% on RBC flux in FSaII tumours and on RBC flux in normal skin of C3H mice. The RBC flux in tumours was significantly increased; however, the RBC flux in normal skin fluctuated only slightly after the treatment with Fluosol-DA 20%. Since an increase in RBC flux by Fluosol-DA 20% may facilitate the removal of acidic metabolites from the tumours, the effects of Fluosol-DA 20% on intratumour pH was also measured. We also measured intratumour pO2 after various dosages of Fluosol-DA 20% with carbogen inhalation. We concluded that the administration of Fluosol-DA 20% selectively increased the RBC flux in tumours compared to that in normal skin. Moreover, carbogen inhalation combined with increasing dosages up to 36 ml/kg of Fluosol-DA 20% effectively enhanced tumour oxygenation in FSaII tumours.

Animals↗
PubMed1991

The prevalence and nature of podiatric problems in elderly diabetic patients.

To determine if diabetes in the elderly is associated with increased prevalence of podiatric problems, a random sample of diabetic patients (n = 74) was compared to a group of elderly non-diabetic patients (n = 79). The two groups were comparable in age (range 70-90 years), smoking habits, and consumption of alcohol. The mean duration of diabetes was 14.5 +/- 11.7 years (+/- SD), and mean serum fructosamine level was 3.3 +/- 0.66 mmol/L. The number of medical diagnoses and medications used was significantly higher in the diabetic group. Diabetic patients had modestly higher prevalence of neuropathy, vascular disease, kidney disease, and eye complications. The most common podiatric problem in both groups was elongated toenails. The prevalence of podiatric problems such as cellulitis, amputation, tinea pedia, onychomycosis, calluses, bunions, and hammer toe deformity were not increased in diabetic patients. Active foot ulcers were more common in diabetic patients (13/74 vs 5/79, P less than 0.05). It is concluded that diabetes in the elderly, unlike in young patients, increases the risk of foot problems only marginally.

Aged↗
PubMed1991

Human fibroblasts in idiopathic retroperitoneal fibrosis express HLA-DR antigens.

Idiopathic retroperitoneal fibrosis (IRF) is a rare human disease characterized by non-neoplastic fibroblastic proliferation associated with chronic inflammatory cells; its pathogenesis is obscure. We undertook an immunohistochemical study for the expression of HLA-DR antigens and other immune-related markers by retroperitoneal proliferating fibroblasts and inflammatory cells from 2 IRF patients. Patterns of immunoreactivity were compared with those expressed by human nodular fasciitis (NF) and granulation tissue. In IRF, most fibroblasts immunostained strongly for HLA-DR antigens, whereas fibroblasts in NF and granulation tissue did, not immunostain at all. The fibroblasts did not immunostain for interleukin 2 receptor, C3b receptor, CD-4, CD-8, or Leu-M1 in any of the tissue studied. Most macrophages and lymphocytes in IRF and NF immunostained Strangly for HLA-DR antigens. In IRF, the CD-4 and CD-8 immunostained T-lymphocytes appeared equally distributed. The expression of HLA-DR antigens by fibroblasts in IRF indicates that this rare disease may indeed be an immune-associated hypersensitivity disorder.

Adult↗
PubMed1990

Radiosensitization of murine tumors by Fluosol-DA 20%.

The effect of perfluorochemicals in combination with carbogen breathing on the response of SCK tumors of mice to fractionated irradiation was investigated. The SCK tumors of A/J mice were irradiated twice a day at 3 Gy per fraction (6 Gy per day), with a total dose of 18 Gy over 3 days. When the host animals were treated with an intravenous (iv) injection of 12 ml/kg of Fluosol-DA 20% before the first daily tumor irradiation and carbogen breathing during every X irradiation with Fluosol-DA 20% injection without carbogen breathing. The hypoxic cell fraction, as determined by an in vivo-in vitro cloning assay, decreased significantly, and the intratumor pO2, as determined with microelectrodes, was markedly increased by Fluosol-DA 20% injection and carbogen breathing. It was concluded that oxygenation of hypoxic cells in SCK tumors during the course of fractionated irradiation was improved by the iv injection of Fluosol-DA 20% and carbogen breathing.

Adenocarcinoma↗
PubMed1989

Massive left atrial thrombus: a possible paraneoplastic complication of breast carcinoma.

We describe a patient with long-standing rheumatic mitral valve disease, left atrial dilatation, and a precommissurotomy history of left atrial thrombus. Following operation she was maintained on daily aspirin as an antithrombotic measure. For 6 years she had no evidence, echocardiographically, of left atrial thrombus. She underwent surgery for apparently nonmetastatic breast cancer in early 1986. In May 1986 the left atrium was echocardiographically clear. At approximately the same time, recurrence was found at the suture line. In October 1987, two metastatic lung lesions and a very large left atrial mass were detected by computed tomography. The atrial mass was surgically removed and found to be a thrombus. There was a striking temporal correlation between dissemination of carcinoma and development of a massive atrial thrombus.

Atrial Fibrillation↗
PubMed1989

Expression of ras oncogene p21 during human fetal development as determined by monoclonal antibodies RAP-5, Y13-259, and DWP.

In this report we describe the expression of the ras proto-oncogene p21 protein in various tissues during normal fetal development. Conventional, formalin fixed and paraffin-embedded sections of normal organs were examined from fetuses ranging 9 to 42 weeks of gestation. Immunohistochemical localization of ras p21 was accomplished using the broadly reactive, mouse monoclonal antibodies RAP-5 and Y13-259. The monoclonal antibody DWP, which is specific for a mutated form of ras p21 having a valine/cysteine at amino acid position 12, was also used. Detectable expression of the p21 protein was seen at different time periods during fetal development depending on the tissue. The expression of ras p21 (as detected by RAP-5 and Y13-259) was noted in a wide range of cell types and tissues; intense immunostaining was noted in epithelial cells of the gastrointestinal tract, exocrine and endocrine pancreas, renal tubules and transitional urotheliem, as well as in other tissues. This immunostaining generally, but not invariably, corresponded with patterns previously reported in benign and/or malignant neoplasms of adult tissues. In most instances ras p21 expression, when present, occurred during periods of rapid growth in given organ systems. However, some actively proliferating fetal tissues such as thymus and spleen, failed to express detectable ras p21 suggesting that factors other than cell cycle may influence its expression. No reactivity with DWP was noted in any of the tissues, suggesting that the mutated forms detected by this monoclonal antibody are not expressed during normal human embryogenesis. These data show that there is regulated expression, and broad distribution of this gene product in normal developing human fetal tissue.

Antibodies, Monoclonal↗
PubMed1989

Immunohistochemical analysis of normal and mutated ras oncogene p21 expression in human pulmonary and pleural neoplasms.

In this study we examined 214 cases of primary human pulmonary neoplasms for the expression of a mutated form of the ras oncogene p21 product, recognized by the monoclonal antibody (MCA) DWP. Adjacent serial sections from these same cases had previously been used to demonstrate the frequency of ras p21 expression using the broadly reactive anti-ras p21 MCA RAP-5. Confirmation of the increased expression of p21 was accomplished using MCA Y13-259. The use of adjacent tissue sections from these cases allows the direct comparison of the expression of the mutated and non-mutated forms of ras p21. If reactivity with DWP would prove to be significantly more restrictive than that of the "pan" ras MCAs, RAP-5 and Y13-259, it would lend support to the possibility that DWP (and similar MCAs which detect other specific mutations) could be used to define subsets of these neoplasms based on their specific ras p21 phenotype. Since one would anticipate that the valine/cysteine substitution at position 12 of the ras p21 would occur at only low frequencies in human tumors, our results with DWP are consistent with this hypothesis. As previously reported, RAP-5 reacted with a high proportion of lung tumors (100/214 or 47%). In this report, we demonstrate the selective expression of the mutation recognized by the MCA DWP in only 5% of these same tumors (13/214), and that the expression of this mutated form is not restricted to any of the conventional histological subclasses of pulmonary neoplasms.

Antibodies, Monoclonal↗