Induction of ovarian tumors by heavy ion irradiation in B6C3F1 mice

Six-week-old B6C3F1 mice were exposed to 0.439 Gy heavy ion irradiation as a 290 MeV/u carbon-ion beam (LET 10 keV/micron) at 2 cm from the upper proximal point of a spread Bragg beam and autopsied 13.5 months after the irradiation. In males total tumor incidences, mainly liver tumors, were 37.0% in irradiated group and 25.0% in control (P>0.05). In females the total tumor incidences were 32.3%, mainly ovarian tumors, in the irradiated group and 0% in the controls. These results indicate that heavy ion irradiation induces ovarian tumors in females but does not target any organ in males.

No susceptibility of colon tissue implanted into the glandular stomach of rats to N-nitroso-N-methylurea carcinogenesis

The present study was undertaken to determine the response of colonic mucosa implanted into the stomach fundus in 6-week-old male F344 rats to oral administration of N-nitroso-N-methylurea (MNU). In graft + MNU, 15% animals had tumors in the implanted colon tissue whereas a 26% incidence of gastric tumors was observed for the pyloric mucosa. In MNU alone, 30% of rats demonstrated gastric tumors. In graft alone 10% of tumors were observed in the grafted site but none in the pylorus. Thus while graft tissue may intrinsically have an elevated risk of tumor development, no susceptibility to MNU was observed in the present study.

Effects of azoxymethane on X-ray induced intestinal metaplasia in Donryu rats

The present study was undertaken to determine the effect of azoxymethane (AOM) administration on intestinal metaplasia induced by X-irradiation in male Donryu rats. Five-week-old animals were X-irradiated with two doses of 10 Gy each at a 3-day interval or three X-ray doses of 10 Gy at a 2-day interval and then received AOM injections i.m. at a dose of 15 mg/kg body weight once weekly for 3 weeks, 6 months after irradiation. Alkaline phosphatase positive foci were decreased after AOM treatments, but aberrant crypt like-foci appeared within areas of intestinal metaplasia. In contrast no induction was observed in normal-appearing gastric mucosa.

Hepatitis C virus infection in acquired aplastic anemia

Hepatitis-associated aplastic anemia (HAAA) is an uncommon disorder that usually is not due to hepatitis A or B virus infection. Hepatitis C virus (HCV) seropositivity is infrequently observed in aplastic anemia (AA) patients who have not been extensively transfused. However, HCV seropositivity may not be detected until several weeks or months after viral infection and AA patients may exhibit defective humoral immunity. Therefore, we evaluated sera from AA patients for the presence of HCV viremia using a reverse transcriptase polymerase chain reaction (RT-PCR) based assay and several serologic assays for HCV antibodies. Serum samples from 90 AA patients who presented to the UCLA Medical Center between March 1984 and February 1990 were analyzed. Overall, 17 patients were found to have HCV viremia by RT-PCR assay, of whom 14 had a positive second-generation HCV enzyme immunoassay (EIA-2) and only 6 were EIA-1 reactive. The frequency of HCV viremia increased with the duration of time between diagnosis and sample procurement, and the number of blood products transfused prior to sampling (P = 0.026). No patient who received fewer than 20 U of blood products or who was sampled less than 20 days after diagnosis had a positive HCV RT-PCR result. Of four patients with hepatitis-associated AA (HAAA), one who was sampled 23 days after diagnosis had hepatitis C viremia and a reactive EIA-2 assay. Therefore, the high frequency of HCV viremia in this patient population is most likely due to transfusion with contaminated blood products prior to the introduction of routine blood donor screening for HCV.

The effects of dilution on the outcome of pooled plasma testing with HIV type 1 (HIV-1) RNA genome amplification as compared to the outcome of individual-unit testing with other HIV-1 markers

BACKGROUND

Proposed testing of large plasma pools with genome amplification technology (GAT) for detection of transfusion-transmissible viruses may have unanticipated complications not associated with individual unit testing. One such potential complication, the effect of dilution resulting from pool formation, was the subject of the present study.

STUDY DESIGN AND METHODS

Specimens from three plasma donor HIV type 1 (HIV-1) seroconversion panels were tested with a quantitative HIV-1 RNA GAT assay (lower detection limit, 400 copies). GAT results were compared to HIV-1 p24 antigen and anti-HIV-1/2 enzyme immunoassay results. Effects of dilution on the detection of GAT-positive panel specimens were assessed by terminal dilution with pooled volunteer-donor EDTA plasma samples.

RESULTS

Low HIV-1 RNA copy numbers (755 and 890 copies/0.1-mL input) that were detectable in two individual plasma specimens before HIV-1 p24 antigen were subsequently undetectable by GAT upon dilution with an equal volume of nonreactive plasma from a single donor. HIV-1 RNA at higher copy numbers (15,500 copies/0.1-mL input) in an HIV-1 p24 antigen-reactive and anti-HIV-1/2-nonreactive specimen was undetectable when diluted to 1-in-50 (1-in-50). Terminal dilution of seven HIV-1 RNA-containing plasma panel specimens indicated a proportional loss of HIV-1 RNA detectability with increasing dilution.

CONCLUSION

GAT for detection of HIV-1 RNA in individual specimens was more sensitive than other HIV markers. For pooled plasma testing, GAT-independent constraints, such as effects of dilution, may preclude the use of GAT detection as a replacement for individual unit testing with HIV serologic assays.

Cell kinetics of hemopoietic colony-forming units in spleen (CFU-S) in young and old mice

The growth potential of the hemopoietic progenitor cells from young and old mice is similar. Previous studies of their cell-kinetics showed no significant differences between them when measured by the incorporation of tritiated thymidine ([3H]TdR). A different approach for exploring stem-cell kinetics in aged animals is provided by another method; the incorporation of bromodeoxyuridine (BrdUrd) during DNA synthesis followed by exposure to near-ultraviolet light (near-UV) kills BrdUrd labelled cells in DNA-synthesis (S-phase). This BrdUrd-near UV cytocide (BUUV) reveals the size of cycling fractions at the level of hemopoietic progenitor cells; it also demonstrates the velocity of the cells entering S-phase when cells are labeled by a continuous infusion of BrdUrd by an osmotic pump, followed by an appropriate colony-assay for each progenitor cell. We compared the cell kinetics of young and old hemopoietic progenitor cells (CFU-S) by this approach. Osmotic pumps were implanted subcutaneously in the backs of young (2 months) and old (22 months) male C57BL/6CrSlc mice for 2, 4, 8, 12, and 16 days to continuously infuse BrdUrd at a flow-rate of 1 mg/h per kg. Cells were harvested from femoral marrow of the infused mice, plated in non-coated bacterial plates, and exposed to a single dose of near-UV at 4000 J/m2. After BUUV cytocide, bone-marrow cells were assayed for 8- and 13-day CFU-S colonies. In the 8-day colonies, the cytocide fraction of CFU-S from young mice increased rapidly, whereas the fraction from old mice showed flatter curves. Both curves reached a plateau at 52.6% for young, and 43.9% for old mice, and then converged 4 days after labeling. In the 13-day colonies, the curve for the aged was much flatter than that for the young; however, the plateaus in both young and old are similar, but at much lower values than earlier, i.e. 24.5% and 16.0%, respectively. The size of the cycling fraction of progenitor cells was close in the two groups during the steady-state cell-cycle. However, the velocity of the cell cycle at a progenitor level was very different, old mice being much slower. Further, within the progenitors, the cell cycle was much slower in the primitive ones and became faster when the stem cells differentiated into mature progenitor cells.

[Acquired pure red cell aplasia associated with relapsed non-Hodgkin's lymphoma: a case report-improvement of PRCA after acute hepatitis]

A 47-year-old male patient was admitted because of anemia. He had been diagnosed as non-Hodgkin's lymphoma (Follicular mixed, B cell type, stage ISA) by splenectomy two years before. Bone marrow examination on admission revealed lymphoma cell infiltration and marked decrease in erythroid cells. These findings confirmed relapsed lymphoma with acquired pure red cell aplasia. After several courses of combination chemotherapy, lymphoma cells disappeared from bone marrow, but PRCA was not improved. In this case there were two times remission of PRCA. At first time, acute B type hepatitis occurred during the chemotherapy, anemia improved transiently. At the second time, mild acute hepatitis associated with herpes zoster occurred. Twenty days after hepatic injury, PRCA was improved, and continued in remission state till present day. To disclose the mechanism of PRCA in this case, erythroid colony assay of marrow cells was performed. This showed the presence of inhibitory factor in patient's serum at PRCA state, that was considered to be related to the occurrence of PRCA. These findings suggest that the improvement of PRCA was associated with the changes on immunological condition after acute hepatitis in this case.

An approach for acute disruption of large arteries in patients with advanced cervical cancer: endoluminal balloon occlusion technique

OBJECTIVE

To test the feasibility of an intraluminal balloon occlusion technique for the control of sudden arterial disruption from cervical branches in patients with advanced malignancy.

BACKGROUND

A sudden disruption of large cervical arteries is a devastating complication of advanced cervical malignancy and local infection.

METHODS

Three patients with this complication underwent endoluminal balloon occlusion before surgical management. A double-lumen balloon catheter was introduced from the femoral artery to the bleeding point. Angiographic examination of the intracranial cross-filling could be performed by the injection of contrast medium from the opposite carotid artery, and consciousness levels could be directly confirmed under unilateral carotid occlusion.

RESULTS

Resection of the carotid or innominate artery was safely performed in all the patients. No neurologic complications occurred. Bleeding did not recur during follow-up (range 5-32 months).

CONCLUSIONS

This experience, although limited, suggests that surgical intervention to control cervical arterial bleeding with intraluminal balloon occlusion prevents excessive bleeding, decreases the risk of damage to the central nervous system, and improves the outcome in these critically ill patients.

Natural history of a spontaneous dissecting aneurysm of the proximal superior mesenteric artery: report of a case

We report herein the case of a 44-year-old man in whom an asymptomatic dissecting aneurysm was found in the proximal part of the superior mesenteric artery (SMA) during a preoperative evaluation for colon cancer. The patient was managed conservatively with blood pressure control during the perioperative period of the colon resection as the false lumen of the dissecting aneurysm was revealed to be completely occluded by thrombus. The thrombus in the false lumen continued to be absorbed until 1 month after surgery. The patient is currently well 4 years after his operation without any evidence of recurrence of the aneurysm.

Reinitiation of spermatogonial mitotic differentiation in inactive old BDF1 mouse seminiferous tubules transplanted to W/Wv mouse testis

The seminiferous epithelia of old mice (33 mo of age) are composed of spermatogonia and Sertoli cells. Histochemical examination using the anti-c-kit monoclonal antibody demonstrated that the number of differentiating type A spermatogonia decreases with age. To elucidate the differential activity of old mouse spermatogonia, we transplanted extremely thin seminiferous epithelia of old BDF, mice into W/Wv mouse testes and examined whether or not they could reinitiate differentiation. Artificially cryptorchid mice were used as the control. At 2 wk after transplantation, spermatocytes and round spermatids were detected in transplanted seminiferous tubules of the control, whereas the most advanced spermatogenic cells in those of old mice were spermatocytes. At 4 wk after transplantation, although elongated spermatids were detected in transplanted tubules of the control, haploid cells (spermatids) were still undetectable in those derived from old mice. Thus, meiosis was never restored, although spermatogonia of old mice can reinitiate differentiation into spermatocytes under suitable testicular conditions. Since it has been reported in several mammalian species that age-related changes in the testicular microenvironment lead to the gerontal cessation of spermatogenesis, the present results suggest that both a defective extratubular environment and a defective intratubular environment may cause the cessation of spermatogenesis in old BDF, mice.

Genotyping hepatitis C virus isolates from Spain, Brazil, China, and Macau by a simplified PCR method

An improved and simplified method of genotyping was developed for classifying hepatitis C virus (HCV) isolates into the five common genotypes, i.e., I/1a, II/1b, III/2a, IV/2b, and V/3a, by PCR with genotype-specific primers deduced from the core gene. Sense and antisense primers, specific for each of the five common genotypes, were designed by comparison of 319 core gene sequences from HCV isolates of various genotypes from genetic groups 1 to 9. In the first round of PCR, a sequence of 433 bp representing nucleotides 319 to 751 was amplified with universal primers. The second round of PCR was performed with respective sense and antisense primers in two separate reactions, one for the amplification of genotypes I/1a and II/1b and the other for the amplification of genotypes III/2a, IV/2b, and V/3a. The specificity of genotyping was confirmed with a panel of 191 serum samples containing HCV isolates whose core gene sequences were known: 110 serum samples infected with HCV of the five common genotypes and 81 serum samples infected with HCV of other genotypes. The use of sense and antisense primers for genotype II/1b (primers 389 and 492) abolished the cross-reaction of the antisense primer for genotype II/1b (primer 133) with some HCV isolates of genotype I/1a found by our original method. The new method was used for genotyping 130 HCV isolates from Spain, 53 from Brazil, 106 from China, and 30 from Macau. A total of 329 bp of the NS5b region (nucleotides 8279 to 8607) of five isolates from Spain and five isolates from Macau which could not be classified as any of the five common HCV genotypes or genotype 2c were sequenced, and the sequences were compared with those of HCV isolates of known genotypes; two isolates from Spain were deduced to be of genotype 4d and one was deduced to be of genotype 1d, while the remaining two isolates from Spain had novel genotypes in genetic group 2; however, all five isolates from Macau were of genotype 6a.

Secretory granule formation and synthesis pathway of secretory proteins in parotid gland cells

The cytochemical technique for endogenous peroxidase and an immunocytochemical method with protein A-gold were used to investigate the formation of the secretory granule substructure in acinar cells of the gerbil parotid glands in normal conditions and after treatment with the ionophore monensin. In untreated animals and 90 min after treatment with monensin, peroxidase activity was seen in rER, in transport vesicles close to the condensing vacuoles, and in the dense core of condensing vacuoles and secretory granules, whereas the Golgi cisternae remain unreactive. At 45 or 60 min after stimulation with monensin, the condensing vacuoles and the immature granules in the trans Golgi area did not exhibit dense cores and their content appeared similar to the peripheral portion of the mature secretory granules. These observations suggest that, in Mongolian gerbil parotid acinar cells, some substances such as peroxidase may be transported from the rER directly to the condensing vacuoles.

Hyperattenuating insulinoma at unenhanced CT

We report a case with insulinoma that showed higher attenuation than normal pancreatic parenchyma on precontrast CT. Pathology of the surgical specimen revealed the presence of psammoma bodies, which were responsible for hyperattenuation. It is worthwhile to obtain precontrast CT in patients suspected of having insulinoma.

[Long-term prognosis of chronic heart failure in the elderly]

To elucidate the predictors of the mortality rate in the elderly with chronic heart failure (HF), 120 consecutive patients (mean age, 75.2 +/- 7.8 years) with heart failure (NYHA I-II) were analyzed prospectively for 5 years. [Methods] Left ventricular ejection fraction (EF), left ventricular diastolic and systolic dimension (LVDD and LVDS) and wall thickness (WT) were measured by echocardiogram. Venipuncture for measurement of ANP and norepinephrine (NE) was done in supine position after 30 minute rest. [Results] 1) HF was associated with hypertension (47.5%), ischemic heart disease (34%), valvular disease (15%) and atrial fibrillation (AF, 23%). 2) 15 and 11 patients died for cardiac and non-cardiac events, respectively. 3) There was no difference in mean ages, gender, blood pressure, plasma-NE, EF, LVDD, LVDS, WT and AF between cardiac death and control groups. However, plasma ANP was higher in cardiac death group (173 pg/ml) than in control group (76 pg/ml) (p < 0.01). 4) Cox proportional hazard regression model revealed that ANP was an independent predictor for cardiac death (p < 0.005). We conclude that only plasma ANP level predicts long-term prognosis of chronic heart failure in the elderly.

[Primary myelofibrosis with severe bone pain]

An 80-year-old man was admitted with bone pain, affecting both lower limbs and the dorsa of the feet, in September, 1991. Primary myelofibrosis was diagnosed. Bilateral x-ray films of the tibia, fibula, femur and vertebra revealed osteoporosis, but this was considered an unlikely source of the bone pain. The bone pain subsequently disappeared, but then became severe in both lower limbs and the dorsa of the feet and was accompanied by leukemic transformations in February, 1992. He died of aspiration pneumonia in July, 1992. Autopsy revealed microfractures with osteoporosis and infiltration of leukemic cells in the periosteum of the left tibia, which may have caused the bone pain. This case provides useful information to analyze the cause of bone pain in patients with myelofibrosis.

Hyaluronan and chondroitin sulfate in rabbit tears

The concentrations of hyaluronan (HA) and chondroitin sulfate (CS) in rabbit tears were determined using high performance liquid chromatography. The tears were taken from both normal eyes and eyes with a corneal epithelial defect. The concentration of CS was 7.61 times higher than that of HA in the tears of normal eyes. When the concentration of CS isomers was compared, the highest concentration was observed in chondroitin 6-sulfate (C6S), followed by chondroitin 4-sulfate (C4S) and chondroitin (C0S), in that order. When the corneal epithelium was removed from the left eye using a trephine and microscissors, a significant increase was detected in the concentrations of HA and C6S in tears of the left eye one day after removal, whereas no change was observed in those of the right eye. In addition, a significant positive correlation was observed between the increased amount of HA concentration and the healing rate of the corneal epithelium. These results suggest that the increase of HA concentration in tears is associated with spontaneous corneal epithelial healing.

Delayed enhancement of peripheral zone of neurofibromas at magnetic resonance imaging

It is well known that bizonal histologic appearance characteristic of neurofibromas are reflected on magnetic resonance (MR) images. We report a case in which a delayed enhanced MR image showed that the entire mass enhanced homogeneously resulting in loss of zonal distinction on early enhanced MR image.

[Infection in elderly leukemic patients]

Febrile episodes occurring in 29 elderly patients (mean age 75 years) with leukemia, from 1988 to 1993, were reviewed. A febrile episode was defined as a temperature of 38 degrees C or greater for at least 6 hours. The number of febrile episodes was 64. The average was 2.2 febrile episodes per patient. Seventy-two percent of febrile episodes occurred when the patients had neutropenia below 100/microliters, while 16% occurred with neutropenia of 101/microliters to 500/microliters. Causative microorganisms were identified in 48% of total febrile episodes. The most common infectious site was the urinary tract which accounted for 25% of total episodes. Pneumonia and septicemia accounted for 22% of total episodes, respectively. Gram-positive cocci were responsible for 66% of microbiologically documented febrile episodes, while 21% were caused by gram-negative bacilli. Gram-positive cocci, particularly staphylococcus aureus, coagulae-negative staphylococcus and enterococci increased compared with a decade ago in our department. Granulocyte colony-stimulating factor (G-CSF) was used 12 times for infection. No significant difference in fever amelioration was seen between G-CSF and non-G-CFS cases.

Effect of temporary occlusion of the hepatic vein on dual blood in the liver: evaluation with spiral CT

PURPOSE

To evaluate the contribution of hepatic veins to the dual blood supply in the liver under temporary hepatic venous occlusion.

MATERIALS AND METHODS

Selected hepatic veins in 23 patients with liver tumors were temporarily occluded with a balloon catheter. Computed tomography (CT) arteriography, CT during arterial portography (CTAP), or both were performed with a spiral technique with and without temporary occlusion of a hepatic vein.

RESULTS

After hepatic vein occlusion, a well-demarcated, wedge-shaped area of hypoattenuation was seen at CTAP and/or hyperattenuation was seen at CT arteriography in the following regions: left lobe (left hepatic vein), ventral part of the anterior segment and the medial segment except for the ventromedial part (middle hepatic vein), dorsal part of the anterior segment and the ventral part of the posterior segment (right hepatic vein), and dorsocaudal part of the right lobe (inferior right hepatic veins).

CONCLUSION

After hepatic venous occlusion, the portal veins become draining veins and the occluded area is supplied with arterial blood alone.

Detection of anti-hepatitis C virus using chemiluminescence

To determine if chemiluminescence can be used in an enzyme immunoassay (EIA) format to test for hepatitis C virus (HCV) antibody and to compare sensitivity and specificity of chemiluminescence to a licensed anti-HCV EIA method, random volunteer donor samples were evaluated. One thousand and seventy-four random volunteer donor samples were collected during a 2-week period. Two aliquots of each sample were tested for anti-HCV. One aliquot was tested using a licensed anti-HCV 2.0 EIA test. The second aliquot was tested using the research anti-HCV chemiluminescence assay. Confirmatory testing was done using Recombinant Immuno Blot Assay (RIBA) 2.0 HCV and HCV RNA. Of the 1074 samples, eight were found to be reactive for anti-HCV. Seven were positive by the anti-HCV 2.0 EIA and the chemiluminescence system. The eighth sample was chemiluminescence reactive, but EIA negative; when tested by an unlicensed EIA 3.0 HCV test, RIBA 3.0 HCV test and an HCV-RNA assay, the sample was still negative. The same sample was also tested by RIBA 2.0 HCV and showed a reactive band to SOD. The chemiluminescence assay has a 100% sensitivity and 99.9% specificity compared to EIA and can be used as an alternative to EIA for detecting antibodies to HCV.

Production of term offspring by in vitro fertilization using old mouse spermatozoa

We successfully produced offspring of old male BDF1 mice using in vitro fertilization. Although 7 old male mice (33 months of age) were infertile and revealed frequent degeneration in the seminiferous epithelia, 4 of them had spermatozoa in the caudae epididymides. The IVF rate of their sperm with eggs from young ICR mice was very high (82.0%). The production rate of offspring was also satisfactory (61.6%). The present study indicates that the IVF method is useful for producing offspring of aged male mice.

Congenital ossification of the stapedius tendon: diagnosis with CT

PURPOSE

To describe the features of congenital ossification of the stapedius tendon at thin-section computed tomography (CT).

MATERIALS AND METHODS

Thin-section CT scans, clinical records, and surgical findings were retrospectively evaluated in nine ears of five patients with surgically proved congenital ossification of the stapedius tendon. Thin-section CT scans of 50 control ears were also reviewed.

RESULTS

On thin-section CT scans, a linear area of soft-tissue attenuation was demonstrated between the monopod stapes and the pyramidal eminence (nine ears), as well as thickening of the stapes footplate (two ears). In the 50 control ears, the normal stapes tendon was not clearly seen on thin-section CT scans.

CONCLUSION

At CT, a linear area of soft-tissue attenuation that extends from the pyramidal eminence to the monopod stapes is suggestive of congenital ossification of the stapedius tendon or a bony bar adjacent to it.