ACE inhibitors in HF restore canine pulmonary endothelial function and ANG II vasoconstriction

Chronic mitral regurgitation (MR) in dogs results in pulmonary congestion and increased cardiac angiotensin-converting enzyme (ACE) activity and angiotensin (ANG) II levels. ACE could contribute to altered pulmonary vasomotion in heart failure, and ACE inhibitor (ACEI) therapy may normalize pulmonary vasomotion. We evaluated pulmonary artery (PA) responses to ANG II and bradykinin (BK) in control dogs, in dogs with 4 mo of MR, in MR dogs treated with the ACEI ramipril (MR + R), and in control dogs treated with ramipril (C + R). Mean PA systolic pressure increased in MR dogs (21 +/- 4 mmHg) but was normal in MR + R dogs (13 +/- 1 mmHg). Constriction of PA rings to ANG II was depressed in MR dogs. ACEI treatment (MR + R) restored ANG II responsiveness, but peak ANG II response (3.6 +/- 0.2 g) in MR + R dogs remained lower than in C + R dogs (4.7 +/- 0.2 g). Endothelium-dependent relaxation to BK was decreased (-87 +/- 4% C, -65 +/- 4% MR; P < 0.05). Ramipril (MR + R) restored relaxation to BK. This demonstrates that pulmonary congestion results in impaired pulmonary vasomotion to ANG II and BK, which ACEIs could normalize, supporting the use of ACEIs in clinical management of chronic congestive heart failure.

Induction of fibrogenic mediators by fine and ultrafine titanium dioxide in rat tracheal explants

Respirable ambient particles [particulate matter <10 micrometer (PM(10))] are associated with both acute and chronic adverse health effects including chronic airflow obstruction. PM(10) can induce expression of inflammatory and fibrogenic mediators, but there is controversy about the types and/or sizes of particles involved and, in particular, whether ultrafine particles are the major toxic agents. To examine whether particle size affects mediator generation, we exposed rat tracheal explants, an inflammatory cell-free model of the airway wall, to various concentrations up to 500 microgram/cm(2) of fine (0.12 micrometer) or ultrafine (0.021 micrometer) titanium dioxide (anatase), maintained the explants in an organ culture in air for 1-7 days, and used RT-PCR to examine the expression of fibrogenic mediators and procollagen. No increase in gene expression was seen at 1 or 3 days, but at 5 days, ultrafine dust induced a small increase in procollagen. At 7 days, fine titanium dioxide produced significantly greater increases for platelet-derived growth factor (PDGF)-B, transforming growth factor-alpha, and transforming growth factor-beta compared with those by ultrafine dust; both dusts produced similar increases for PDGF-A; and ultrafine dust produced increases in procollagen expression, whereas fine dust had no effect. Expression levels were dose related. Both dusts produced a similar decrease in expression of PDGF receptor-alpha and a similar increase in PDGF receptor-beta. These observations suggest that ultrafine particles are intrinsically able to induce procollagen expression even in the absence of inflammatory cells; that chronic exposure to PM(10) may result in chronic airflow obstruction, in part because of ultrafine particle-mediated increases in airway wall fibrosis; and that chemically identical dusts of differing size can produce quite different patterns of gene expression in the airway wall. Differential upregulation of PDGF receptors does not appear to explain dust-induced fibrosis in this model.

Arsenic trioxide selectively induces acute promyelocytic leukemia cell apoptosis via a hydrogen peroxide-dependent pathway

Low concentrations of As(2)O(3) (</=1 micromol/L) induce long-lasting remission in patients with acute promyelocytic leukemia (APL) without significant myelosuppressive side effects. Several groups, including ours, have shown that 0.5 to 1 micromol/L As(2)O(3) induces apoptosis in APL-derived NB4 cells, whereas other leukemic cells are resistant to As(2)O(3) or undergo apoptosis only in response to greater than 2 micromol/L As(2)O(3). In this report, we show that the ability of As(2)O(3) to induce apoptosis in leukemic cells is dependent on the activity of the enzymes that regulate cellular H(2)O(2) content. Thus, NB4 cells have relatively low levels of glutathione peroxidase (GPx) and catalase and have a constitutively higher H(2)O(2) content than U937 monocytic leukemia cells. Glutathione-S-transferase pi (GSTpi), which is important for cellular efflux of As(2)O(3), is also low in NB4 cells. Moreover, As(2)O(3) further inhibits GPX activity and increases cellular H(2)O(2) content in NB4 but not in U937 cells. Selenite pretreatment of NB4 cells increases the activity of GPX, lowers cellular H(2)O(2) levels, and renders NB4 cells resistant to 1 micromol/L As(2)O(3). In contrast, concentrations of As(2)O(3) that alone are not capable of inducing apoptosis in NB4 cells induce apoptosis in the presence of the GPx inhibitor mercaptosuccinic acid. Similar effects are observed by modulating the activity of catalase with its inhibitor, aminotriazol. More important from a therapeutic point of view, U937 and HL-60 cells, which require high concentrations of As(2)O(3) to undergo apoptosis, become sensitive to low, clinically acceptable concentrations of As(2)O(3) when cotreated with these GPx and catalase inhibitors. The induction of apoptosis by As(2)O(3) involves an early decrease in cellular mitochondrial membrane potential and increase in H(2)O(2) content, followed by cytochrome c release, caspase 3 activation, DNA fragmentation, and the classic morphologic changes of apoptosis.

Retrovirus-mediated herpes simplex virus thymidine kinase gene therapy approach for hepatocellular carcinoma

The therapeutic effect of herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV) system on hepatocellular carcinoma was studied in this experiment. The tk-containing retroviral recombinants were used to infect hepatoma cells (BEL-7402) and the cells were treated with ganciclovir (0-1000 microg/ml). The results showed that HSV-tk gene could be efficiently transferred in vitro into hepatoma cells and stably expressed. The growth potential of the tk-containing cells was significantly inhibited by GCV (P<0.01) as compared to the non-tk-containing cells. The antitumor effect of HSV-tk/GCV system was also produced ex vivo in tk-containing tumor of nude mice as characterized by a marked decrease in tumor growth after GCV treatment contrary to a progressive enlargement of non-tk-containing tumors. Although the histological examination demonstrated that the efficiency of the gene transfer was less than 30%, the killing effect of HSV-tk/GCV system on hepatocellular carcinoma was still significantly generated. The proper mechanism of HSV-tk gene therapy on hepatic tumor referred as "bystander effect" in therapeutic approach has not been found in this study and required to be explored further.

[Ultrasonic and CT diagnosis of large upper abdominal mass]

OBJECTIVE

To assess accuracy of ultrasonic (US) and CT diagnosis of big mass in the upper abdomen.

METHODS

Data from 38 clinically and pathologically confirmed cases were retrospectively analyzed and accuracy of their preoperative US and CT diagnosis compared.

RESULTS

US diagnosis was correct in 3 of 9 (33.3%) cases with a mass in the liver, in 16 of 21 (76.2%) cases with a mass in the adrenal gland and in 2 of 4 cases with a mass in the kidney. In contrast, CT diagnosis was correct in 2 of 9 (22.2%) cases with a mass in the liver, in 4 of 18 (22.2%) cases with a mass in the adrenal gland and none in a case with a mass in the kidney. In 4 cases with a mass in the spleen, neither US nor CT diagnosis was correct.

CONCLUSION

Because organs in the upper abdomen are closely located with each other, correct imaging localization of big mass in this region is not without difficulty. In this series, accuracy of diagnosis with US and CT is comparable, but for localizing tumor in the adrenal gland, US imaging seems superior. US and CT are both incapable of accurately diagnosing large mass in the spleen.

Extraction and colorimetric determination of azadirachtin-related limonoids in neem seed kernel

A colorimetric method was developed for the determination of total azadirachtin-related limonoids (AZRL) in neem seed kernel extracts. The method employed acidified vanillin solution in methanol for the colorization of the standard azadirachtin or neem seed kernel extracts in dichloromethane. Through the investigation of various factors influencing the sensitivity of detection, such as the concentration of vanillin, acid, and the time required for the formation of color, optimum conditions were selected to perform the assay. Under the optimum conditions, a good linearity was found between the absorbance at 577 nm and the concentration of standard azadirachtin solution in the range of 0.01-0.10 mg/mL. In addition, different extraction procedures were evaluated using the vanillin assay. The HPLC analysis of the extracts indicated that if the extractions were performed in methanol followed by partitioning in dichloromethane, approximately 50% of the value determined by the vanillin assay represents azadirachtin content.

[Inhibitory effects of recombinant human neurotrophin-4/5 protein on neurotoxicity caused by arsenic trioxide]

OBJECTIVE

To study preliminarily the inhibitory effects of recombinant human neurotrophin (hNT)-4/5 protein on neurotoxicity caused by arsenic trioxide (As(2)O(3)).

METHODS

Nerve cells of the chicken embryonic forebrain and PC12 cells were co-cultured with recombinant hNT-4/5 protein and As(2)O(3) (0 - 16 micromol/L) for 24 and 48 hours, respectively, to observe the survival of nerve cells and the outgrowth of PC12 cells, with clone expression and recombination techniques.

RESULTS

There was significant difference in survival rate of nerve cells between the experimental and control groups (P < 0.01) after co-culture for 48 hours, and survival rate and number of neuron outgrowth increased with the concentration of hNT-4/5 protein.

CONCLUSION

Recombinant hNT-4/5 protein could inhibit neurotoxicity caused by As(2)O(3), which provided a basis to find an anti-toxic factor in the environment by genetic engineering.

Myosin I contributes to the generation of resting cortical tension

The amoeboid myosin I's are required for cellular cortical functions such as pseudopod formation and macropinocytosis, as demonstrated by the finding that Dictyostelium cells overexpressing or lacking one or more of these actin-based motors are defective in these processes. Defects in these processes are concomitant with changes in the actin-filled cortex of various Dictyostelium myosin I mutants. Given that the amoeboid myosin I's possess both actin- and membrane-binding domains, the mutant phenotypes could be due to alterations in the generation and/or regulation of cell cortical tension. This has been directly tested by analyzing mutant Dictyostelium that either lacks or overexpresses various myosin I's, using micropipette aspiration techniques. Dictyostelium cells lacking only one myosin I have normal levels of cortical tension. However, myosin I double mutants have significantly reduced (50%) cortical tension, and those that mildly overexpress an amoeboid myosin I exhibit increased cortical tension. Treatment of either type of mutant with the lectin concanavalin A (ConA) that cross-links surface receptors results in significant increases in cortical tension, suggesting that the contractile activity of these myosin I's is not controlled by this stimulus. These results demonstrate that myosin I's work cooperatively to contribute substantially to the generation of resting cortical tension that is required for efficient cell migration and macropinocytosis.

Effects of cigarette smoke on nitric oxide synthase expression in the rat lung

To examine the effects of cigarette smoke on nitric oxide synthase (NOS) gene expression and protein production, groups of rats were exposed to smoke once only or daily and were sacrificed after 1, 2, 7, or 28 days of exposure. NOS-1, NOS-2, and NOS-3 mRNAs in whole lung were quantified using reverse transcription polymerase chain reaction (RT-PCR), and NOS protein levels were determined by Western blots. Neither NOS-1 gene expression nor protein levels changed with smoke exposure. Levels of NOS-2 expression were more than doubled in smokers at Day 1 and decreased to control values during 1 month with daily smoke exposure, while protein levels did not change. NOS-3 expression was increased approximately 35% after 2 days of smoke exposure and remained increased to 28 days, whereas protein levels were increased by approximately 60% at Day 7 and remained elevated. In situ hybridization showed that NOS-2 was diffusely expressed in the lung parenchyma, airways, and vessels, and that NOS-3 was strongly expressed in vascular endothelium. Protein distribution, as determined by immunohistochemical staining, was identical to mRNA tissue distribution, and these distributions were not changed by smoke. We conclude that smoke exposure induces a rapid but transient increase in transcription of NOS-2, and a sustained increase in transcription and translation of NOS-3; up-regulation of NOS occurs within the anatomic compartment where these genes are normally expressed. These findings indicate that cigarette smoke can directly and rapidly affect NOS expression, and thus potentially affect the function of the pulmonary vasculature.

[Study on laser flash spectroscopy of laser-induced interaction of DNA and polynucleotides with SO4*-]

The interactions of DNA and polynucleotides (poly[G],poly[A] and poly[C]) with SO4*- were investigated by 248 nm laser flash photolysis. The results show that, the reactions of poly[G] or poly[A] with SO4*- yield predominantly the corresponding one-electron-oxidated base radicals. With poly[C], it is suggested that SO4*- radical reacts predominantly by addition to the base moiety to produce C5-yl and C6-yl sulphate radical adducts,and subsequently H-abstraction yields C2'-sugar radical. The predominant species resulting from the reaction of DNA with SO4*- is DNA guanyl radical.

Dynamic Surface Tension Measurement with a Dynamic Wilhelmy Plate Technique

An experimental method called dynamic Wilhelmy plate technique (DWPT) for studying dynamic surface tension was designed in this study. A diffusion-controlled model corresponding to the initial and boundary conditions of this method was proposed. Dynamic surface tension of Triton X-100 and SDS was measured with this technique and analyzed with the proposed model. The calculated diffusion coefficients for the short- and long-time approximations are 3.7 x 10(-6) and 0.97 x 10(-6) cm(2)/s for Triton X-100 and 4.6 x 10(-6) and 0.79 x 10(-6) cm(2)/s for SDS, respectively. The predicted dynamic surface tension with these diffusion coefficients for the simultaneously generated aqueous/air interfaces is in good agreement with the drop mass technique. Another diffusion controlled model that considers the energy barrier at the aqueous/air interface was also proposed in this study. The calculated energy barriers are in the range of 4.1-5.7 RT for Triton X-100 and 6.5-8.0 RT for SDS. Copyright 1999 Academic Press.

[Rapid determination of saccharin sodium in ice cream by high performance liquid chromatography (HPLC)]

This is a method for the rapid determination of saccharin sodium in ice cream by HPLC. A radial compression C18 cohumn, 100 mm x 8 mm i.d., and ultraviolet detector at 220 nm were applied to the determination without extraction. The solution of samples would be determined after they were treated with the solution of copper sulfate and sodium hydroxide in water. The detectable amount was 0.38 mg/kg, the coefficient of variation CV was 1.72%, and the recovery was 96.25%-101.75%.

[Histopathology studies on 8,673 cases of ocular adnexal hyperplastic lesions and tumors]

OBJECTIVE

To study the histopathologic classification of ocular adnexal hyperplastic lesions and tumors according to the histogenesis and the anatomic sites.

METHOD

To analyze retrospectively the pathologic specimens of 8,673 cases of ocular adnexal hyperplastic lesions and tumors between 1961 - 1997.

RESULTS

There were 7,265 benign cases (83.77%), and 1,408 malignant cases (16.23%). Classification by anatomic sites: eye lid 5,313 cases (61.26%), orbit 1,484 cases (17.11%) and epibulbar 1,876 cases (21.63%). Classification by histogenesis: (1) Primary tumor 6,679 cases: epitheliogenic 2,481 cases (37.15%), mesenchymal 753 cases (11.27%), lympho-hematopoietic 102 cases (1.53%), neurogenic 1,542 cases (23.09%), congenital abnormal embryogenetic 1,767 cases (26.46%), uncertain resource tumor 34 cases (0.50%). (2) Secondary tumor 13 cases; (3) Metastatic tumor 9 cases; (4) Non-tumor lesion 1,972 cases.

CONCLUSION

The classification is helpful to the histopathologic diagnosis and the study about the detailed distribution of common ocular adnexal hyperplastic lesions and rare tumors, and it also increases the pathologic diagnostic data in North China.

Apoptosis and growth inhibition in malignant lymphocytes after treatment with arsenic trioxide at clinically achievable concentrations

BACKGROUND

Arsenic trioxide (As2O3) can induce clinical remission in patients with acute promyelocytic leukemia via induction of differentiation and programmed cell death (apoptosis). We investigated the effects of As2O3 on a panel of malignant lymphocytes to determine whether growth-inhibitory and apoptotic effects of As2O3 can be observed in these cells at clinically achievable concentrations.

METHODS

Eight malignant lymphocytic cell lines and primary cultures of lymphocytic leukemia and lymphoma cells were treated with As2O3, with or without dithiothreitol (DTT) or buthionine sulfoximine (BSO) (an inhibitor of glutathione synthesis). Apoptosis was assessed by cell morphology, flow cytometry, annexin V protein level, and terminal deoxynucleotidyl transferase labeling of DNA fragments. Cellular proliferation was determined by 5-bromo-2'-deoxyuridine incorporation into DNA and flow cytometry and by use of a mitotic arrest assay. Mitochondrial transmembrane potential (delta psi(m)) was measured by means of rhodamine 123 staining and flow cytometry. Protein expression was assessed by western blot analysis or immunofluorescence.

RESULTS

Therapeutic concentrations of As2O3 (1-2 microM) had dual effects on malignant lymphocytes: 1) inhibition of growth through adenosine triphosphate (ATP) depletion and prolongation of cell cycle time and 2) induction of apoptosis. As2O3-induced apoptosis was preceded by delta psi(m) collapse. DTT antagonized and BSO enhanced As2O3-induced ATP depletion, delta psi(m) collapse, and apoptosis. Caspase-3 activation, usually resulting from delta psi(m) collapse, was not always associated with As2O3-induced apoptosis. As2O3 induced PML (promyelocytic leukemia) protein degradation but did not modulate expression of cell cycle-related proteins, including c-myc, retinoblastoma protein, cyclin-dependent kinase 4, cyclin D1, and p53, or expression of differentiation-related antigens.

CONCLUSIONS

Substantial growth inhibition and apoptosis without evidence of differentiation were induced in most malignant lymphocytic cells treated with 1-2 microM As2O3. As2O3 may prove useful in the treatment of malignant lymphoproliferative disorders.

Measurement of four tumor marker antigens in the sera of pregnant women

We sought to determine the maternal serum levels of four tumor-associated antigens during the three trimesters of pregnancy in healthy women. CEA, CA 228, CA 15-3, and Her2/neu oncogene product p105 assay values were determined for 90 healthy pregnant women during the three trimesters of pregnancy at five participating evaluation sites. Results were compared to means and cut-off values determined for healthy nonpregnant women. Differences in assay values in the 1st and 3rd trimester were analyzed for statistical significance (Student's t-test). CEA, CA 228 and CA 15-3 assay values in general were found to be within the normal range. CA 15-3 and Her2/neu p105 serum assay values were above the cut-off (3.3% and 8.2%, respectively) and were significantly elevated in the 3rd trimester as compared to the 1st trimester of pregnancy (P < 0.05 and P < 0.001, respectively). CEA and CA 228 may be of potential value in monitoring pregnant women with malignant disease. Normal elevations in 3rd trimester serum Her2/neu p105 and CA 15-3 assay values should be considered when monitoring a pregnant patient with malignant disease.

[The study of castor oil sulphate synthesis process by infrared spectroscopy]

The castor oil sulphate synthesis process was studied by infrared spectroscopy. Based on the determination of iodone value the reaction mechanism was discussed. Both the duplicated bond and the hydroxide ion in castor oil took part in sulphate reaction and a hydrolysis also took place in the castor acid.

A brief history of antibiotic science

As the greatest achievement in the history of microbiology, the story of antibiotic is an extremely inspired chapter in its history. Like the developmental process of other sciences, antibiotic reveals a history of first accumulating experience, followed by the stage of interpretation of the phenomena as other experimental study. Meantime, there is no end to the discovery of new antibiotics. Currently, the scope and province of antibiotic research is expanding both in its profundity and coverage.

[Determination of erythrocyte immune functions and its significance in primary lung cancer patients.]

BACKGROUND

To explore the erythrocyte immune state and its clinical significance in the lung cancer patients.

METHODS

The RBC-C3bRR , RBC-ICR and CIC in plasma were detected by Guo-Feng's method in 24 lung cancer patients and 22 normal adults as control.

RESULTS

RBC-C3bRR in patients with lung cancer was significantly lower than that in the control group ( P < 0. 01) , and the value of CIC was remarkably higher in cancer patients than that in the control group ( P < 0. 01) . The red cell immunological function was remarkably improved after operation.

CONCLUSIONS

Detection of erythrocyte immune state in the lung cancer patients might be helpful to make the diagnosis , judge the curative effects and monitor the prognosis.

Growth induction of hepatic stimulator substance in hepatocytes through its regulation on EGF receptors

The cytosolic liver-specific growth factor-hepatic stimulator substance (HSS) has been shown to be able to amplify the rat hepatocyte proliferation responded to EGF. In order to get more insight into the mechanism, the regulatory effect of HSS on EGF-receptor (EGF-R) and the receptor phosphorylation at molecular level was studied. HSS partially purified from weanling rat liver was given to cultured hepatocytes and its influence on EGF-R specific binding and internalization as well as mRNA expression were investigated. The results showed that preincubation of hepatocytes with HSS could lead to an increase in [125I]-EGF binding to its receptors and inhibit EGF-induced receptor down-regulation. Furthermore, the over-expression of EGF-R mRNA stimulated by HSS was seen during 2-12 h after the incubation. Additionally, it was demonstrated with human hepatoma SMMC-7721 cells in Western blot that the EGF-R expression and the receptor autophosphorylation were increased with dose/time-dependency after HSS treatment. These results strongly suggest that the mechanism of HSS action on hepatocyte growth might be related to its modulation on EGF-R and receptor-mediated signaling transduction.

[Clinical practice of spherical allogeneic biological membranous implant in the eye socket]

OBJECTIVE

To investigate the effect of implantation of spherical allogeneic biological material implant after eyeball enucleation.

METHODS

A spherical allogeneic biological material implant was implanted in the eye socket after eyeball enucleation in 50 cases including stage I in 48 cases and stage II in 2 cases.

RESULTS

After operation, the motility of installed artificial eyes was good in 49 cases, the orbit and eyelids were full in all the cases. In the follow-up of 4 - 24 months (mean, 8 months), the conjunctival wound and muscular tissue were adherent firmly to the biological material, and there were no postoperative infection, no dislocation and shift of the implant.

CONCLUSION

The spherical allogeneic biological membranous implant is an ideal material for the implantation in the eye socket after enucleation.

[The clinical features of myocardial infarction in patients younger than 35 years and over 45 years of age]

OBJECTIVE

To investigate the clinical features and the characteristics of coronary angiography in young patients with myocardial infarction.

METHODS

27 patients younger than 35 years with myocardial infarction were studied with respect to their history, habit of smoking and drinking and body weight index. Comparison was made between the left ventricular ejection fraction with ultrasound method and X-ray heart/chest ratio in patients with or without thrombolytic therapy. Selective coronary angiography was performed in 23 of the 27 patients.

RESULTS

All of the 27 patients were male. 81.5% of them had smoking index more than 100, 55.5% drinking index more than 150, 51.9% family history of hypertension and 72.2% low blood level of HDL cholesterol. Most of the cardiac accidents took place in the night and morning. 17.4% of the patients had angiographically normal coronary arteries and 30.0% mild stenosis (no significant stenosis). 39.1%, 8.7% and 4.4% of the patients had one-vessel, two-vessel and three- vessel disease respectively. The frequency of patients with left ventricular ejection fraction less than 0.5 was 6.0% in patients with thrombolytic therapy and 33.3% without.

CONCLUSION

47.8% of the patients younger than 35 years with myocardial infarction has no or no significant stenosis of the coronary arteries. Heavy smoking is the most important one of relative factors for young patients with myocardial infarction. Other factors include low blood level of HDL cholesterol, drinking index of more than 150 and family history of hypertension in order. Thrombolysis treatment helps to maintain ventricular performance.

Malignant cells can be sensitized to undergo growth inhibition and apoptosis by arsenic trioxide through modulation of the glutathione redox system

Arsenic trioxide (As2O3) induces clinical remission in acute promyelocytic leukemia (APL) with minimal toxicity and apoptosis in APL-derived NB4 cells at low (1 to 2 micromol/L) concentration. We examined the basis for NB4 cell sensitivity to As2O3 to identify experimental conditions that would render other malignant cells responsive to low concentrations of As2O3. The intracellular glutathione (GSH) content had a decisive effect on As2O3-induced apoptosis. Highly sensitive NB4 cells had the lowest GSH and the sensitivity of other cell lines was inversely proportional to their GSH content. The t(14;18) B-cell lymphoma cell line had low GSH levels and sensitivity to As2O3 at levels slightly higher than in APL cells. Experimental upmodulation of GSH content decreased the sensitivity to As2O3. Ascorbic acid and buthionine sulfoxide (BSO) decreased GSH to a greater extent, and rendered malignant cells more sensitive to As2O3. As2O3-induced apoptosis was not enhanced by ascorbic acid in normal cells, suggesting that the combination of ascorbic acid and As2O3 may be selectively toxic to some malignant cells. Ascorbic acid enhanced the antilymphoma effect of As2O3 in vivo without additional toxicity. Thus, As2O3 alone or administered with ascorbic acid may provide a novel therapy for lymphoma.

[CT findings of metastatic and primary neoplasms of the kidney: a comparative study]

OBJECTIVE

To study CT findings of renal metastases and compare them with primary renal cell carcinoma.

METHODS

CT features of eleven cases of renal metastases and one hundred cases of primary renal cell carcinoma confirmed by histopathology were studied and compared. The metastastic tumors arised from lung carcinoma in 6 cases, esophagus carcinoma in 2 cases and one in each of adrenal cortical carcinoma, testis seminoma and unknown primary tumor.

RESULTS

Renal metastases accounted for 3.7% of all malignant tumors of the kidney. The ratio of renal metastases to second primary renal carcinoma was 1:1. On CT, the renal metastases appeared as diffusely invasive, ill-definded mass (63.6%), 18.2% of the neoplasms were multiple, without or less exophytic (81.8%) and without or with minimal enhancing on postcontrast scan (100%). The tumor invaded the pelvocalyceal system (72.7%). In contrast, the primary renal cell carcinomas were nodular, rounded or lobulated and more exophytic mass with well-defined border and regular contours (87.0%). Moderate to high enhancing postcontrast (80.7%) was observed with obvious necrosis (60.2%), foci of calcification (15.0%) and invasion of the renal vein and inferior vena cava (7.0%).

CONCLUSION

Contrast-enhanced CT is helpful in the differential diagnosis of renal metastases from primary renal cell carcinoma. But for those showing single, more exophytic mass with well-defined border and intense enhancing postcontrast, the correct diagnosis depends on histopathology.