An animal model for colon cancer metastatic cell line with enhanced metastasizing ability. Establishment and characterization

We have developed an animal model for colon cancer metastasis and produced a metastasizing tumor after using a microinjection technique to inject SW480 cells into the cecal wall of athymic nude mice during "minilaparotomy." After the metastatic foci formed in murine lung, an in vitro primary culture was performed and a new metastatic cancer cell line, which was designated as CC-ML3, was established. The studies included: 1) the comparison between SW 480 and CC-ML3 in morphology, growth kinetics, seeding and plating efficiency, and karyotype; and 2) carcino-embryonic antigen determination, origination, and metastatic ability of CC-ML3. The results showed that CC-ML3 was significantly different from SW480 in vitro and possessed a high metastatic potential in vivo. This newly developed animal model may thus be useful for studying the biology and pathogenesis of metastasis of human colonic cancer.

Human papillomavirus type-related DNA and c-myc oncogene alterations in colon cancer cell lines

Although squamous-cell epithelium is the most frequent target site of human papillomavirus (HPV) infection, a similar infection is demonstrated in columnar epithelial cells in this paper. The papillomavirus expression in three cell lines was detected in colorectal adenocarcinoma of Chinese patients. The HPV-16 and HPV-18 DNA sequences were found in colorectal cancer cell lines, which might suggest the correlation of HPV to the etiology of colorectal cancers. In addition, c-myc oncogene was identified by amplification in all three colorectal cancer cell lines, but only normal germ-line fragments were found in control tissue. The correlation between HPV and c-myc, and the implications of these findings in colorectal cancers are also discussed.

Identification and functional characterization of Epstein-Barr virus DNA polymerase by in vitro transcription-translation of a cloned gene

In order to identify the gene encoding the Epstein-Barr virus (EBV) DNA polymerase, a portion of the BamHI-A fragment containing the fifth leftward open reading frame (BALF5) of the EBV genome was cloned into SP6 and T7 promoter-containing vectors for in vitro transcription-translation. The RNA synthesized in vitro was used to program rabbit reticulocyte lysates, which were analyzed for the synthesis of the putative polymerase polypeptide (110 kDa) and assayed directly for EBV DNA polymerase activity. The polypeptide synthesized by the full-length BALF5 genomic fragment had a molecular mass of 110 kDa. 5'-truncated BALF5 with the first and second ATGs deleted produced 95- and 83-kDa polypeptides, respectively. All three translation products were enzymatically active and displayed resistance to high salt concentrations. The identity of the largest polypeptide as the viral polymerase was established by (i) immunoprecipitation with EBV-positive sera from patients with nasopharyngeal carcinoma and by a rabbit polyclonal antiserum prepared with a synthetic peptide derived from the DNA sequence of BALF5; (ii) identification of a polypeptide of identical size (110 kDa) immunoprecipitated from superinfected Raji cell extracts by these antibodies; and (iii) salt-resistant enzymatic activity which was neutralized by the rabbit EBV antiserum. Thus, BALF5 encodes a functional polymerase identical to that induced in superinfected Raji cells.

Renal osteodystrophy

The term "renal osteodystrophy" is used to include skeletal disorders of patients with chronic renal failure: osteitis fibrosa, osteomalacia, osteosclerosis, osteoporosis and the frequently associated extraskeletal calcifications. It is the chronic glomerular disease with phosphate retention and resultant hyperphosphatemia on one hand and deficient 1,25 (OH)2 D3 and resultant hypocalcemia on the other to induce secondary hyperparathyroidism. The three most common causes of chronic renal failure in our patients are chronic glomerulonephritis, diabetic nephropathy, hypertensive nephropathy in decreasing frequency, polycystic renal disease occurs in five patients. Other miscellaneous causes include nephrotic syndrome, chronic pyelonephritis, systemic lupus erythematosus, periarteritis nodosa, interstitial nephritis and renal stones. The bone changes are similar in primary and secondary hyperparathyroidism and the incidence of brown tumor is about 3% in the former and 1.5 to 1.7% in the latter. We present one among the 94 dialyzed patients who has long-standing severe chronic renal failure from polycystic kidney disease and develops brown tumor in the mid ulna after 7 years on maintenance hemodialysis. The incidence of brown tumor in our series is about 1.1%. Because of increased longevity of the dialyzed patients, brown tumor from secondary hyperparathyroidism is now more commonly observed. Hyperphosphatemia with serum calcium-phosphate products exceeding plasma solubility of 60 to 75 mg/dl may induce soft tissue and vascular calcification. This explains the much higher incidence of soft tissue calcification in secondary than primary hyperparathyroidism; two of our patients with generalized Monckeberg's type arterial calcification and multiple periarticular calcifications in five patients have been observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Perspectives on health effects of electric and magnetic fields

Some epidemiological studies have fostered concern about cancers caused by electric and magnetic fields associated with distribution and use of electric power. At present, there is no scientific consensus as to which factors, the electric field and/or magnetic field, are biologically important. Similarly, there is no clear indication whether higher field levels are of greater risk than lower level fields. The complex scientific issues attending health effects of power-frequency electric and magnetic fields would be most effectively resolved through interdisciplinary research involving investigators from biological, medical and engineering research communities. A critical need, at present, is a significant increase in federal funding for research on interaction mechanisms and animal studies, while maintaining efforts in epidemiology but with greater emphasis on confounding factors and known cancer-causing agents.

[Production and characterization of monoclonal antibody against colon cancer associated antigen in Chinese]

Although many monoclonal antibodies have been made in human colon cancer, none of them are from the Chinese species. Recently, a colon cancer cell line CC-M2 established from a Chinese patient has been completely characterized and used as immunogen to produce monoclonal antibodies. Monoclonal antibodies were produced by standard hybridoma technique. The fusion rate was 95.8%. An isotype IgG1 of high proliferation named as Sam-2 was used in this study. The titers were measured around 10(4). Further studies on MoAb Sam-2 through indirect immunofluorescent and immunoperoxidase tests revealed its good specificity and sensitivity in colorectal cancer tissue. In CEA study, the result indicated that Sam-2 may react on a non-CEA related antigen. For further clinical application, the antigen was identified as a glycoprotein by chemical resistant test. In preliminary studies using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting techniques, Sam-2 could recognize two closed antigens or a dimer antigen with molecular weight 25.2 and 27 Kd respectively.

Perianal Paget's disease--report of 4 cases

Over the past nine years (from 1981 to 1989), four patients with perianal Paget's disease were treated. All were male with an average age of 58.5 years. Clinically, perianal Paget's disease manifests as a slowly enlarging eczematous, and sharply demarcated perianal skin rash that may be oozing or itching. In the characteristic pathology finding, Paget's cells appear as large, rounded signet-ring cells with abundant mucin stain positive cytoplasm in the basal layer of the acanthotic epidermis. All but one, who suffered from primary sweat gland carcinoma, had underlying rectal adenocarcinoma. The first two cases expired soon after a delayed diagnosis of terminal underlying malignancy. Only in the later two cases was there a preoperative suspicion of perianal Paget's disease. There is often a delay in diagnosis due to clinical ignorance. Patients with persisting perianal skin rash should be biopsied frequently. If perianal Paget's disease is diagnosed, the underlying malignancy should be surveyed and managed thoroughly.

Changes in intratumor pH by two heatings

It is a known fact that pH in rodent tumors decline significantly upon heating most likely due to breakdown of the tumor blood circulation. We recently observed that tumor blood vessels become thermotolerant after being heated with a sublethal thermal dose. The purpose of the present study was to reveal whether heating can reduce intratumor pH when the tumor vessels are thermotolerant. When the SCK tumors of A/J mice were heated at 42.5 degrees C for 1 h, the tumor vessels became most thermotolerant at 18 h postheating, as measured with the 86Rb uptake method. The intratumor pH in the control SCK tumors was 7.05 +/- 0.14 (SD), and it significantly decreased to 6.70 +/- 0.08 (P less than 0.001) after heating at 44.5 degrees C for 1 h. However, when the tumor vessels were thermotolerant, i.e., 18 h after heating at 42.5 degrees C for 1 h, reheating at 44.5 degrees C for 1 h could not reduce the intratumor pH. We concluded that such a failure to increase tumor acidity by a second heating at temperatures as high as 44.5 degrees C was due to vascular thermotolerance developed by the first heating.

Effects of hydralazine on the blood flow in RIF-1 tumors and normal tissues of mice

Hydralazine is a peripheral vasodilator used as an antihypertensive agent. Hydralazine has been reported to potentiate tumor damage by hyperthermia as well as by hypoxic-cell-specific drugs through the reduction of tumor blood flow and pO2. In the present study, we investigated the changes in blood perfusion caused by hydralazine in S.C. RIF-1 tumors and normal tissues in C3H mice using the 86Rb uptake technique and laser Doppler flowmetry. The tumor blood flow was decreased significantly by an intravenous administration of 0.5-10.0 mg/kg hydralazine, as determined by both uptake of 86Rb and laser Doppler flowmetry. The tumor pO2 was also decreased significantly by the injection of hydralazine. On the other hand, the uptake of 86Rb was increased significantly in the skin and muscle by hydralazine. The changes seen in the skin and muscle after injection of hydralazine as assessed by laser Doppler flowmetry were similar to those assessed by uptake of 86Rb, indicating a significant increase in blood circulation in these tissues. Uptake of 86Rb remained unchanged in the kidney and decreased in the liver and spleen in the presence of hydralazine in a dose-dependent manner at 0.5-10.0 mg/kg. The decline in uptake of 86Rb in normal tissues strongly suggests that hydralazine decreases the blood flow in these normal tissues. Thus the recent proposal to use hydralazine to increase the antitumor activity of heat or certain drugs needs to be reexamined.

Extralobar pulmonary sequestration of the left retroperitoneum

This paper presents an extralobar pulmonary sequestration in the left retroperitoneum in an eight year old girl. The clinical and diagnostic features included abdominal pain, an abdominal mass, elevated VMA, and radiological manifestations simulating a left adrenal mass. A laparatomy was performed. Extralobar pulmonary sequestration of the left retroperitoneum is fairly uncommon. An eight year old girl was admitted with abdominal pain, elevated urinary VMA and an abdominal mass. The radiological manifestations simulated a left adrenal mass. At surgery an extralobar pulmonary sequestration was detected.

Characterization of four newly established human colorectal adenocarcinoma cell lines from Chinese patients

Four colon adenocarcinoma cell lines, CC-M2, CC-M3, CC-M4, and CC-M2NM, have been established from surgical specimens of 18 unselected patients without the use of "feeder" cells and additional growth factors (e.g., insulin, hydrocortisone, etc.) in the culture medium. The methods of primary cultivation of tissue explants are described. Studies of determination of morphology, growth curve, plating efficiency, chromosomal analysis, CEA and beta-HCG synthesis, and tumorigenicity, were done to characterize the cell lines. Significant variations have been found in one of the four cell lines, both in vitro and in vivo studies. There are distinct phenotypes in the established cell lines which may be useful in studying the cell differentiation and progression of colorectal cancer.

Cancer of the auricle

Thirty-five patients with carcinoma of the auricle seen in Veterans General Hospitals, Taipei and Taichung from January 1970 to December 1988 were reviewed retrospectively. There were 28 men and 7 women. More cases occurred in the 7th and 8th decades with an average of 64 years (median 67) and ranged from 29 to 91 years. The most common manifestations at diagnosis were exophytic mass (86%) and/or ulcerative lesion (29%). Histologically, basal cell carcinoma outnumbered squamous cell carcinoma 17 to 14. The remaining 4 cases consisted of 2 melanomas, 1 sweat gland adenocarcinoma and 1 unclassified sarcoma. Eighty-eight percent (15/17) of basal cell carcinoma presented at early stage without regional lymph node or distant metastasis. They were mainly treated by surgery. One patient with multifocal lesions suffered from marginal recurrence. The 2 and 5-year survival rates were 94% and 86% respectively. Half of our 14 patients with squamous cell carcinoma had local extensive tumor but no lymph node or distant metastasis was found at the time of diagnosis. Local recurrence occurred in 4 patients, one case associated with lung metastasis. The local control rate of combined surgery and irradiation in squamous cell carcinoma was 100% (4/4), superior than that of operation alone 67% (6/9) or radiotherapy alone (0/1). The actual 2 and 5-year survival rates were 85% and 64% respectively. Our 4 patients with different pathology other than basal cell or squamous cell carcinoma had high rate of regional lymph nodes or distant metastases, presenting poor prognosis. The overall treatment failure for carcinoma of the auricle was 23% (8/35) but reduced to 14% after salvage treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of pancreatic amylase by dietary carbohydrate in chronic alcoholic rats

The nutritional adequacy of dietary ingredients is essential for optimal food consumption and growth of animals. Dietary carbohydrate levels regulate pancreatic amylase synthesis. Ethanol diets with 36% of total calories from ethanol and 11% from carbohydrate are nutritionally inadequate, whereas a 26% ethanol diet made isocaloric to the 36% alcohol diet by the addition of maltose-dextrins provides all nutrients in amounts recommended for normal growth. Young rats fed the modified ethanol diet for 3 months consume 101.4 ml of diet daily compared to 66.5 ml by those on the 36% ethanol diet. Increased food consumption results in (a) similar amounts of alcohol consumption (3.6 vs. 3.3 g/day), (b) a threefold enhancement in carbohydrate intake (5.1 vs. 1.7 g/day), and (c) a normal growth rate (6.7 vs. 3.1 g/day). Both the acinar content of amylase (20.2 +/- 0.3 micrograms/mg of protein) and the acinar response to cholecystokinin-octapeptide in 36% ethanol diet-fed rats are significantly reduced compared to those of 26% ethanol diet-fed rats (34.1 +/- 5.6 micrograms/mg of protein). These results confirm (a) the nutritional adequacy of the 26% ethanol diet compared to the 36% ethanol diet, and (b) that carbohydrate inadequacy, and not ethanol consumption per se, is the primary cause of pancreatic amylase insufficiency in chronic alcoholic rats.

[Sensory action potentials of ring finger in the diagnosis of carpal tunnel syndrome]

Amplitudes and latencies of sensory action potentials (SAPs) recorded over the index, middle, little and ring fingers by antidromic stimulation of the median or ulnar nerve at wrist were measured in 65 normal adults and 78 patients with clinically and electrophysiologically verified carpal tunnel syndrome. In the normal adults, there was no significant difference among the SAP latencies of the index, middle, ring and little fingers. Among these 65 normal adults, the difference between median and ulnar SAPs of ring finger was less than 0.4 msec in 64 subjects, but 0.7 msec in one. In the patient group, the median distal sensory latency of the ring finger was significantly longer than that of the ulnar nerve which was recorded over the ring and little fingers. Six cases (7.7%) of 78 patients diagnosed as CTS by conventional electrophysiological studies was false negative by using the ring finger sensory action potential study. It is suggested that the SAP study of the ring finger by stimulation of the median and ulnar nerves at the wrist can not replace the conventional electrodiagnostic methods for the diagnosis of carpal tunnel syndrome.

The kinetics of vascular thermotolerance in SCK tumors of A/J mice

Development of thermotolerance has been observed in diverse biological systems. Despite the important role of blood circulation in heat-induced tissue damage, little is known about vascular thermotolerance. The kinetics of vascular thermotolerance in SCK tumors of A/J mice was investigated in this study. A single heating at 43.5 degrees C or 44.5 degrees C for 1 hr caused marked damage in tumor vasculature, as demonstrated by a marked decrease in Rb-86 uptake (% of injected dose/g of dried tissue). The tumor vasculature became resistant or tolerant to subsequent heatings at those temperatures when the tumors were preheated at 42.5 degrees C for 1 hr. Vascular thermotolerance became significant at 5 hr and reached its maximum at 18 hr after preheating at 42.5 degrees C. When the vascular thermotolerance was at its peak, heating at temperatures as high as 44.5 degrees C for 1 hr could not reduce the tumor blood flow. The vascular thermotolerance decayed considerably but not completely at 72 hr after the preheating. The vascular thermotolerance may exert a profound implication on the response of tissues, including tumors, to multiple heatings.

The Epstein-Barr virus immediate-early gene product, BMLF1, acts in trans by a posttranscriptional mechanism which is reporter gene dependent

In DNA cotransfection experiments, the Epstein-Barr virus immediate-early gene product, BMLF1, stimulated the chloramphenicol acetyltransferase (CAT) activity of both latent and productive EBV promoters linked to CAT. This BMLF1-induced increase in CAT activity was out of proportion to the effect on CAT mRNA, suggesting a posttranscriptional mechanism. Furthermore, when growth hormone was used as a reporter gene instead of CAT, BMLF1 no longer functioned. Thus, the BMLF1 effect was reporter-gene dependent. The effect of the BMLF1 gene product does not then appear to be directed at promoter activation, but instead may function to increase the level of an as yet unidentified protein(s) required for Epstein-Barr virus infection.

Monoclonal antibody against rat renal cell tumor-associated antigen as a new tool for the analysis of renal tumorigenesis

A monoclonal antibody, NR-2 MAb, against one of the rat renal cell tumor-associated antigens was developed. NR-2 MAb belonged to IgM class and recognized a polypeptide of 81,000 daltons designated as NR-2 antigen, which is of non-glycoprotein nature with a pI of 4.6. NR-2 MAb was employed to probe the histogenesis of renal cell tumors in rats treated with N-ethyl-N-hydroxyethylnitrosamine followed by trisodium nitrilotriacetate monohydrate. Immunohistochemical analysis indicated that NR-2 antigen was expressed in simple hyperplasia, adenomatous hyperplasia and renal cell tumors. Both clear cells and basophilic cells of the simple hyperplasia showed equally strong positive reactions with NR-2 MAb, whereas the vacuolated epithelium was negative. Furthermore, the proximal tubules in nontumorous areas also expressed NR-2 antigen, suggesting that the hyperplastic lesions which eventually lead to renal cell tumors may derive from epithelia of proximal tubules and not directly from vacuolated epithelium. Such NR-2 antigen-positive epithelia of proximal tubules seem to be initiated cells. NR-2 MAb also cross-reacted with preneoplastic liver lesions.

The Epstein-Barr virus (EBV) BZLF1 immediate-early gene product differentially affects latent versus productive EBV promoters

The Epstein-Barr virus (EBV) BZLF1 gene product is thought to mediate the disruption of latent EBV infection. We have examined the regulatory effects of BZLF1 by studying its transactivating effects on seven different EBV promoters. We find that whereas the BZLF1 gene product increases the activity of the two early promoters, BMLF1 and BMRF1, it decreases the activity of three latent promoters (the BamHI-C and BamHI-W Epstein-Barr nuclear antigen promoters and the latent membrane protein promoter). The BZLF1-induced changes in promoter-directed chloramphenicol acetyltransferase activity occur in EBV-negative as well as EBV-positive cell lines and are accompanied by a similar change in chloramphenicol acetyltransferase mRNA. Deletion analysis of the BamHI Z fragment indicates that in a portion of the amino-terminal half of the BZLF1 gene product (amino acids 24 to 86) is not essential for positive transactivating effects but is required for down-regulating effects. Thus, different domains of the same EBV immediate-early gene product can either increase the function of EBV promoters active in productive infection or decrease the function of key promoters active in latent infection.

Synergistic inhibition of Epstein-Barr virus: transformation of B lymphocytes by alpha and gamma interferon and by 3'-azido-3'-deoxythymidine

We analyzed the effects of 3'-azido-3'deoxythymidine (AZT) and alpha and gamma interferon (IFN-alpha and IFN-gamma) on transformation of human umbilical cord lymphocytes (HUCLs) by Epstein-Barr virus (EBV). B lymphocytic outgrowth from HUCLs infected with EBV was monitored by focus formation; the presence of EBV genomes in transformed foci was confirmed by in situ cytohybridization and EBV nuclear antigen. The 50% inhibitory doses for preventing focus formation were 0.14 microM for AZT, 10 units (U)/mL for IFN-alpha, and 1 U/mL for IFN-gamma. To determine whether inhibition resulted from direct cytotoxic effects, we assessed the viability of nontransformed HUCLs exposed to the agents for 30 d. The nontoxic doses were 1 microM for AZT, 30 U/mL for IFN-alpha, and 3 U/mL for IFN-gamma. Combining IFN-alpha or IFN-gamma with AZT or IFN-alpha with IFN-gamma at nontoxic doses showed synergistic decreases in numbers of transformed foci. Transformation of HUCLs by EBV was sensitive to, but not abolished by, these agents at doses below those required for cell killing.

Reversal by glucose of pancreatic amylase insufficiency in chronic alcoholic rats

Carbohydrate consumption regulates pancreatic amylase synthesis in rats. The Lieber-DeCarli 36% alcohol diet employed in chronic alcohol studies and the isocaloric control diet contain 11 and 47% of total calories from carbohydrates, respectively. Young rats fed ad libitum the 36% ethanol diet for 2 weeks obtained 1.2 g/day of carbohydrate, whereas those pair-fed with control diet received 5.8 g/day. Rats fed the 36% ethanol diet and given an intramuscular injection of a solution of 1.5 g of glucose daily for 2 weeks received twofold greater amounts of carbohydrate than saline-injected controls (2.7 versus 1.2 g). These changes in carbohydrate intake produced proportionate changes in pancreatic amylase levels. The secretory responses to cholecystokinin-octapeptide (CCK8) of acini from control and glucose-injected rats were significantly higher compared with those in the saline-injected or noninjected alcohol groups. The blood alcohol levels in glucose-injected rats were markedly reduced compared with other alcohol groups (71.7 versus 274.9 mg/dl) despite similar amounts of ethanol ingestion daily (2.4 g) in the three groups. In vitro experiments with acini from rats fed a nutritionally optimal diet revealed that high pharmacologic concentrations of ethanol, while inducing basal secretion, inhibited CCK8-stimulated amylase secretion. These results indicate that: (a) the amount of alcohol consumption does not correlate with either the levels of blood alcohol or of pancreatic amylase; (b) the carbohydrate availability in rats regulates pancreatic amylase levels despite significant levels of alcohol in blood; (c) blood alcohol levels observed in vivo may not affect synthetic and secretory processes of amylase in pancreatic acini.

Structural determinants for transcriptional activation by cAMP-responsive DNA elements

A transcriptional cAMP-responsive enhancer element (CRE) consisting of the 8-base pair (bp) palindrome, 5' TGACGTCA 3', is found in several eukaryotic genes. We analyzed the effects on gene transcription of point mutations within the CRE, the influence of the bases surrounding the CRE, and the requirements for transcriptional synergism of tandemly repeated CREs. When inserted as an oligonucleotide with restriction enzyme linker sites, the 8-bp CRE itself is as active in conferring cAMP responsivity on an enhancerless chloramphenicol acetyltransferase reporter plasmid as is a single copy of the choriogonadotropin alpha (CG alpha), twice repeated 18-bp sequence containing the CRE. Point mutations in the first (T to A), fourth (C to G), or eighth (A to T) positions of the CRE, when contained within the CG alpha 18-bp sequence, each inhibited transcriptional activity greater than 90%. However, the identical eighth position A to T mutation occurs in the cAMP-responsive sequence of the vasoactive intestinal peptide (VIP) gene, and that mutant sequence in the context of the adjacent bases of the native VIP sequence is maximally cAMP responsive when inserted in the reporter plasmid. The substantially reduced activity of the core 8-bp CRE when synthesized as a cassette including the adjacent bases of the rat glucagon or bovine parathyroid hormone gene further emphasizes the restrictive influence of particular surrounding sequences. Active oligonucleotides containing the 8-bp palindrome and different but equally permissive contexts have comparable properties in transfected reporter genes and gel mobility-shift assays. The pair of tandemly repeated 18-bp elements containing the CRE in the CG alpha gene synergistically stimulate transcription either with paired native CREs or when one native CRE is paired with one mutant CRE, suggesting the presence of cooperative interactions. Tandem insertion of more than two 18-bp sequences, or insertion of additional sequences between the two CREs, inhibits transcription. These observations indicate that the contexts of the bases adjacent to CREs exert profound influences on the transcriptional activities mediated by the cAMP-responsive elements.

Comparison of two bromovinyl nucleoside analogs, 1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil and E-5-(2-bromovinyl)-2'-deoxyuridine, with acyclovir in inhibition of Epstein-Barr virus replication

The effect of 1-beta-D-arabinofuranosyl-E-5-(2-bromovinyl)uracil (BV-araU), a new antiviral drug, on Epstein-Barr virus (EBV) was studied and compared with those of E-5-(2-bromovinyl)-2'-deoxyuridine (BVdU) and acyclovir (ACV). BV-araU effectively inhibited EBV replication both in superinfected Raji cells and in virus producer P3HR-1(LS) cells, as determined by density gradient centrifugation, in situ cytohybridization with an EBV DNA probe, and cRNA-DNA hybridization. The 50% effective doses for viral DNA replication were 0.26, 0.06, and 0.3 microM for BV-araU, BVdU, and ACV, respectively. The relative efficacy on the basis of the in vitro therapeutic index was BVdU (6,500) greater than BV-araU (1,500) greater than ACV (850). Synthesis of EBV-induced polypeptides with molecular weights of 145,000 and 140,000 was inhibited by these drugs. Kinetic analysis of reversibility of inhibition of EBV DNA replication after removal of the drugs indicated that BV-araU, like BVdU, has a more prolonged inhibitory effect than ACV. These results indicate that the 2' OH group in the arabinosyl configuration of BV-araU results in marked reduction in anti-EBV activity while slightly diminishing cytotoxicity.

Morphodynamic interpretation of acute coronary thrombosis, with special reference to volcano-like eruption of atheromatous plaque caused by coronary artery spasm

Routine autopsy studies of hearts with coronary thrombosis, collected over a period of eleven years, showed unique morphologic features of rupture of soft atheromatous plaques. These features include: (1) irregular luminar outline: angulation, invagination, upheaval, and/or wrinkles, (2) wavy outline of atheromatous cavity, (3) volcano-like rupture with seepage or gushing of semiliquid atheromatous contents into lumen, (4) cholesterol crystals arranged in rheologic vector direction, (5) rupture of deeper intimal fibrous tissue, (6) one or multiple intimal upheavals, (7) focal thickening of contracted media, (8) vestige of volcano-like eruption with organized thrombus, and (9) old thrombotic occlusion with wavy appearance of thick intimal fibrous tissue. The authors present a dynamic model of vasoconstriction or artery spasm that accounts for these features and the rupture of soft atheromatous plaques.

Cavernous hemangioma of the thoracic spinal cord

A 25-year-old woman presented with a four-year history of progressive right-lower-extremity weakness and atrophy and a left hemisensory deficit was found. Metrizamide-enhanced spinal CT scan showed an intramedullary lesion at the level of T1-T2; this had expanded the cord in fusiform fashion but showed no evidence of a cystic component. Surgical resection was performed and the pathological diagnosis was cavernous hemangioma. Two and one-half years later, her left hemisensory deficit was worsening and a spinal MRI showed high signal intensity mass in the region of the previous surgery consistent with chronic hematoma which was re-evacuated with some improvement in the patient's neurological condition.

Anti-human immunodeficiency virus agent 3'-azido-3'-deoxythymidine inhibits replication of Epstein-Barr virus

We show that the anti-human immunodeficiency virus agent, 3'-azido-3'-deoxythymidine (AZT), which suppresses infectivity and cytopathic effects of human immunodeficiency virus, also effectively inhibits Epstein-Barr virus (EBV) DNA replication. However, AZT has no effect on four other human herpesviruses: cytomegalovirus, varicella-zoster virus, and herpes simplex virus types 1 and 2. The combination of acyclovir and AZT, while it is not synergistic, has an additive effect against EBV replication. AZT may prove to be a useful drug for treatment of coinfections with human immunodeficiency virus and EBV.

What is expected of CT in the evaluation of stroke?

This study was based on 5042 cranial CT examinations in a 2-year period. 19.8% of all cranial CT scans were performed for confirmation or evaluation of clinically suspected stroke. 87% of the clinical diagnoses of stroke were confirmed by CT scan. Intracranial hemorrhage made up a small percentage in this study. The establishment of this diagnosis was a valuable service in the patients' management. Brain tumor may rarely present clinical symptoms mimicking stroke and may have a normal CT initially.

Effect of acyclic pyrimidines related to 9-[(1,3-dihydroxy-2-propoxy)methyl]guanine on herpesviruses

A series of pyrimidines related to the potent antiherpetic agent 9-[(1,3-dihydroxy-2-propoxy)methyl]guanine (1, BW B759U), all containing the same acyclic chain, have been synthesized. Some of the compounds were derivatives of the naturally occurring bases, cytosine, uracil, and thymine; others included compounds in which the 5-position of the cytosine and uracil moieties were substituted by bromo, iodo, fluoro, methyl, and amino groups. Other variations of the cytosine derivatives were the 5-aza, 2-mercapto, 4-methylamino, 4-dimethylamino, and isocytosine congeners. A 4-aminopyrimidine adduct was also made. Antiviral testing showed that 1-[(1,3-dihydroxy-2-propoxy)methyl]cytosine (18, BW A1117U) was equivalent to the guanine analogue in potency against human cytomegalovirus and Epstein Barr virus. Other compounds in the series were largely inactive in antiviral screening against the herpesviruses.

Microwave-induced thermoelastic pressure wave propagation in the cat brain

This paper presents direct measurements of acoustic pressure wave propagation in cat brains irradiated with pulsed 2.45-GHz microwaves. Short rectangular microwave pulses (2 microseconds, 15 kW peak power) were applied singly through a direct-contact applicator located at the occipital pole of a cat's head. Acoustic pressure waves were detected by using a small hydrophone transducer, which was inserted stereotaxically into the brain of an anesthetized animal through a matrix of holes drilled on the skull. The measurements clearly indicate that pulsed microwaves induce acoustic pressure waves which propagate with an acoustic wave velocity of 1523 m/s.

Synovial cysts of the lumbar spine: CT evaluation

Seven cases of surgically proven intraspinal synovial cysts are reported. Computed tomographic (CT) scans demonstrated a series of low-density masses adjacent to the facet joints; in three cases, a dense rim indicated a calcified wall on the cyst; in one, the wall was partially calcified; and in three the mass appeared to be filled with gas. In all of these cases, there was severe degenerative facet disease at the same level as the synovial cyst. In six patients, the cysts were unilateral, while one was bilateral; seven cysts were located at the level of L4-L5, and one at L3-L4. We conclude from this study that the intraspinal synovial cyst can be identified reliably by the CT scan.

Novel acyclic adenosine analogs inhibit Epstein-Barr virus replication

The effect of three new acyclic adenosine analogs, (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [(S)-HPMPA], 9-(2-phosphonylmethoxyethyl)adenine (PMEA), and (S)-9-(2,3-dihydroxypropyl)adenine [(S)-DHPA], on Epstein-Barr virus (EBV) replication was studied. Both (S)-HPMPA and PMEA but not (S)-DHPA effectively inhibited EBV DNA replication in virus-producer P3HR-1 cells and in latently infected Raji cells superinfected with P3HR-1 virus, as determined by cRNA-DNA hybridization and density gradient centrifugation. The 50% effective doses for inhibiting virus replication were 0.08 and 1.1 microM for (S)-HPMPA and PMEA, respectively. Both drugs were cytostatic but not cytotoxic to the cells at a concentration as high as 100 microM. These results indicate that (S)-HPMPA and PMEA are potent and selective anti-EBV agents in vitro.

Doppler microwave. A clinical assessment of its efficacy as an arterial pulse sensing technique

A new Doppler microwave device designed for noninvasive arterial pulse detection by assessment of arterial wall motion was clinically evaluated. Carotid pulse tracings obtained with the microwave device were compared with simultaneously obtained intra-aortic pressure pulse waves. Ease and quality of the recording were also evaluated in 25 consecutive patients undergoing echocardiography. In 92% of the patients tested, good quality carotid pulse tracings could be obtained. T1/2 values and systolic time intervals were calculated from these recordings and correlated well with the known disease states of these patients, which ranged from aortic stenosis and aortic insufficiency to chronic heart failure. Finally, microwave tracings were faithful reproductions of invasive recordings of arterial pressures when compared on the basis of left ventricular ejection times and pulse contour.

Two strains of Epstein-Barr virus (B95-8 and a P3HR-1 subclone) that lack defective genomes induce early antigen and cause abortive infection of Raji cells

The heterogeneity of Epstein-Barr virus (EBV) obtained from P3HR-1 cells has permitted derivation of a distinct subclone of P3HR-1 (L. Heston, M. Rabson, N. Brown, and G. Miller, Nature (London) 295:160-163, 1982). We have analyzed the biologic properties and genomic structure of this subclonal virus (clone 13) compared with those of parental P3HR-1 and B95-8 viruses. Synthesis of EBV compared with those of parental P3HR-1 and B95-8 viruses. Synthesis of EBV proteins in Raji cells superinfected with virus derived from P3HR-1, clone 13, and B95-8 was analyzed both by fluorography of radiolabeled proteins and by immunoblotting. Highly concentrated preparations of clone 13 and B95-8 virus induced most of the spectrum of EBV proteins in Raji cells with the exception of the 145,000-, 140,000-, and 110,000-molecular-weight proteins, which were either undetectable or reduced. Moreover, both clone 13 and B95-8 viruses also induced the same patterns of early antigen diffuse components as the parental P3HR-1 virus did. However, only P3HR-1 virus could induce EBV DNA synthesis in superinfected Raji cells, as determined both by buoyant density centrifugation and by in situ cytohybridization with biotinylated recombinant EBV DNA probes. Defective heterogeneous molecules present in P3HR-1 virus have been implicated in early antigen induction after superinfection of Raji cells. Therefore, Southern blots of clone 13, P3HR-1, and B95-8 viruses were hybridized to recombinant EBV fragments representing the sequences contained within the defective molecules in P3HR-1. The parental P3HR-1 contained the previously described defective molecules. No evidence for defective molecules was found in clone 13 or B95-8 viruses. These data indicate that concentrated preparations of both clone 13 and B95-8 viruses can induce abortive infection in Raji cells, but while the defective molecules are not needed for induction of early antigen diffuse components, they may be required for the induction of viral DNA synthesis.

Differential effects of acyclovir and 9-(1,3-dihydroxy-2-propoxymethyl)guanine on herpes simplex virus and Epstein-Barr virus in a dually infected human lymphoblastoid cell line

We investigated the effects of acyclovir and 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG) on a lymphoblastoid cell line dually infected with Epstein-Barr virus and herpes simplex virus (HSV) type 1. The numbers of Epstein-Barr virus genomes were reduced during 70 days of treatment with either drug. Both drugs suppressed HSV replication in a dose-related manner. In the continued presence of the drugs, HSV developed resistance, rapidly to acyclovir and much more slowly to 30 microM DHPG. Analysis of HSV glycoprotein C production and viral DNA showed that treatment with 100 microM DHPG eliminated HSV production, curing the cell line of HSV persistent infection.

Interstitial microwave antennas for thermal therapy

This paper presents a new microwave antenna design with improved heating at the tip for interstitial hyperthermia and thermocoagulation. Temperature distribution patterns surrounding a conventional insulated antenna and the new sleeved coaxial slot radiator are measured in a saline phantom under transient and steady-state conditions. The new design provides an improved steady-state temperature distribution over the active region of the radiator. In contrast to the cold zone at the tip of a conventional insulated antenna the new sleeved coaxial slot antenna provides maximal (sixfold greater) power deposition at its tip.

Metabolic activation of 9([2-hydroxy-1-(hydroxymethyl)ethoxy]methyl)guanine in human lymphoblastoid cell lines infected with Epstein-Barr virus

9-([2-Hydroxy-1-(hydroxymethyl)ethoxy]methyl)guanine (BW B759U) is more potent and has a more prolonged inhibitory effect against Epstein-Barr virus (EBV) in vitro than does acyclovir (ACV). To assess the mechanism of this difference, we first compared the extent of phosphorylation of the two drugs in superinfected Raji cells. BW B759U is phosphorylated to levels 100-fold higher than is ACV. In addition, lower levels of phosphorylation of BW B759U and ACV were observed in uninfected Raji cells. Studies on the kinetics of formation of BW B759U triphosphate in superinfected Raji cells indicated that drug-phosphorylating activity was detected as early as 3 h after superinfection; this activity was steadily maintained for the first 7 h, followed by a burst of activity between 7 and 10 h and a doubling of phosphorylation between 10 and 25 h. During the superinfection cycle, the pool sizes of deoxyribonucleoside and ribonucleoside triphosphates were increased and reached their maxima at 10 h after infection. The maximal amount of triphosphorylated drug in a virus producer cell, P3HR-1 (LS), was obtained at 21 h after drug treatment. During long-term drug treatment, approximately 44 and 77% reduction in EBV genome copies per cell was observed on days 3 and 7, respectively. In a separate experiment, after treatment of P3HR-1 (LS) cells with BW B759U for 36 h, 4.2 pmol of BW B759U triphosphate per 10(6) cells was achieved. After the cells were released into drug-free medium, drug triphosphate was rapidly decreased to 11% of the original level in 1 day. Thereafter, the decrease was slow but steady, down to 0.22 pmol/10(6) P3HR-1 cells by 5 days. We calculated that 0.22 pmol of BW B759U triphosphate per 10(6) cells represents a cellular concentration of 0.22 microM, which is theoretically enough to inhibit EBV replication. This is based upon a comparison with the 50% effective dose of BW B759U (0.05 microM) for inhibition of genome replication and a Ki of 0.08 microM for BW B759U triphosphate inhibition of EBV DNA polymerase.

Ependymoma of filum terminale: metrizamide-enhanced CT evaluation

Two cases of surgically proven myxopapillary ependymomas of filum terminale are reported. In both, myelography and metrizamide-enhanced computed tomographic (CT) scans were performed. An intramedullary tumor in the lower thoracic spine, soft-tissue masses in the neural foramina and enlarged bony spinal canal in the lower thoracic and upper lumbar spine were noted in one case and, in the other, an intradural extramedullary tumor at T12-L1 level. Both patients had normal cranial CT scans, and both presented with similar symptoms--low back pain and weakness and paresthesia of leg or legs for up to 3 years' duration. Myelography and metrizamide-enhanced CT scans were performed in order to evaluate disc disease in one patient and spinal stenosis in the other. Ependymoma was an incidental finding, which was then removed by surgical resection. Pathology confirmed the diagnosis.

Sequential detection of different antigens induced by Epstein-Barr virus and herpes simplex virus in the same Western blot by using dual antibody probes

A dual antibody probing technique that permitted a color-coded identification of polypeptides representing different classes of Epstein-Barr virus (EBV) antigens as well as differentiation of the polypeptides induced by different herpesviruses in the same Western blot was developed. When the nitrocellulose sheet was probed first with monoclonal antibody against EBV early antigen diffuse component (EA-D) and then stained with 4-chloro-1-naphthol, four polypeptides specific for EA-D were identified by purple bands. Subsequently, the same nitrocellulose sheet was reprobed with human serum containing antibodies against EBV early antigen, viral capsid antigen, and nuclear antigen and stained with 3,3'-diaminobenzidine. Several brown bands corresponding to early, viral capsid, and nuclear antigen polypeptides were detected. The dual antibody probing technique was used in an analysis to differentiate polypeptides resulting from either EBV or herpes simplex virus infection, either in cells infected by individual virus or in a cell line dually infected by both viruses. On the basis of different colored bands in different lanes of the same gel, 20 polypeptides with molecular weights ranging from 31,000 to 165,000 were identified as herpes simplex virus-specific proteins. These results suggested that the dual antibody probing technique may be applicable in clinical diagnosis for detecting antigens and antibodies derived from different pathogens.