The value of prophylactic R2 lymph node dissection for gastric cancer

Three hundred and eleven patients with an R2 lymph node dissection for gastric cancer were reviewed in order to examine the efficacy of prophylactic R2 lymph node dissection. In 246 patients, who were all macroscopically determined to have either N0 or N1 lymph node metastasis at the time of operation, 30 showed histologic lymph node metastasis in the N2 group. When the 5-year survival rates in the 61 patients with histologic N2 lymph node metastasis were compared according to the macroscopic evaluation of lymph node metastasis at the time of operation, 30 patients who were determined to have either N0 or N1 lymph node metastasis showed a better prognosis than the 31 patients who were determined to have N2 lymph node metastasis (p < 0.01). Therefore, prophylactic R2 lymph node dissection contributes to an improved prognosis for gastric cancer patients who are found to macroscopically have either N0 or N1 lymph node metastasis on the basis of an intra-operative evaluation.

Expression of tenascin in odontogenic tumours

We investigated the expression of tenascin in a series of odontogenic tumours (n = 63) of epithelial and epithelial-ectomesenchymal origin by using immunohistochemical methods. A heterogeneity of expression of tenascin was observed in odontogenic tumours. The heterogeneity was most prominent in odontogenic tumours not forming calcified tissues. In these ameloblastomas and adenomatoid odontogenic tumours, tenascin was mainly localised at the epithelial tumour cell-mesenchymal tissue interface. In the calcifying epithelial odontogenic tumour, ameloblastic fibroma and odontoma, a widespread stromal immunoreactivity was observed which was, however, unreactive in the calcified masses. The stellate reticulum-like cells and granular cells of ameloblastoma also showed a positive immunoreactivity for tenascin. The results of the present study suggest that expression of tenascin in the stromal tissue of odontogenic tumours differs according to the potential of forming calcified masses by the tumour cells irrespective of tumour cell morphology.

Development of the blood-retinal barrier in vitro: formation of tight junctions as revealed by occludin and ZO-1 correlates with the barrier function of chick retinal pigment epithelial cells

To elucidate the molecular mechanisms of the blood-retinal barrier (BRB), we examined chick retinal tissues histochemically using antibodies against tight junction proteins such as ZO-1, 7H6 antigen, and occludin. Retinal pigment epithelial (RPE) cells in situ in chickens and late chick embryos expressed all of the tight junctional proteins examined, showing that tight junctions seal the cell borders of chick RPE cells in vivo. On the other hand, RPE cells isolated from late chick embryos and transferred in vitro did not express occludin, ZO-1 and 7H6 antigen. The effects of differentiation-inducing agents, such as retinoic acid, dexamethasone and dimethyl sulfoxide (DMSO) were tested. Only DMSO induced an increase in transepithelial electrical resistance (TER) in a time-dependent manner. Under supplementation with DMSO, immunofluorescently demonstrable occludin and ZO-1 were induced progressively at cell borders in parallel with the increase in TER that occurred with decreases in inulin and dextran permeability. Electron microscopically tight junction-like junctional apparatus were induced in RPE cells. These results indicated that tight junctions of RPE cells play an important role in the formation of the BRB.

A possible mechanism for the cytotoxicity of a polyacetylenic alcohol, panaxytriol: inhibition of mitochondrial respiration

A polyacetylenic alcohol, panaxytriol, isolated from Panax ginseng C. A. Meyer inhibits both tumor cell growth in vitro and the growth of B16 melanoma transplanted into mice. Our preliminary studies indicated that panaxytriol localizes to the mitochondria in human breast carcinoma cells (Breast M25-SF). This study focused on the effects of panaxytriol on mitochondrial structures and function in Breast M25-SF. The results indicate that panaxytriol rapidly inhibits cellular respiration and disrupts cellular energy balance in Breast M25-SF. At concentrations between 11.3 and 180 microM, panaxytriol causes a dose-dependent inhibition of the conversion of the tetrazolium (MTT assay) by mitochondrial dehydrogenase within 2 h. A 1-h treatment with 180 microM panaxytriol causes a significant loss of rhodamine-123 from cells with mitochondria prestained with rhodamine-123 (by flow cytometry). Specific toxic changes were observed by electron microscopy in the mitochondria of Breast M25-SF within 1 h after treatment with more than 180 microM panaxytriol. These data indicate that 180 microM panxytriol rapidly disrupts cellular energy balance and respiration in Breast M25-SF and suggest that panaxytriol may lower cellular ATP concentrations. After treatment with 180 microM panaxytriol, cellular ATP levels were 40% of those in control cells after 1 h. ATP depletion preceded the loss of cellular viability. Neither ATP depletion nor cytolysis was found in human erythrocytes that have no mitochondria. Thus, ATP depletion resulting from a direct inhibition of mitochondrial respiration is a critical early event in the cytotoxicity of panaxytriol.

Type II citrullinemia associated with neutropenia

A 37-year-old Japanese man was admitted with delirium and hyperammonemia. He was diagnosed as having type II citrullinemia because of an elevated citrulline level on amino acid analysis and very low hepatic argininosuccinate synthetase activity. He also showed a low neutrophil count and a low serum level of granulocyte colony-stimulating factor. Reduced production of this cytokine and/or impairment of its feedback regulation by the neutrophil count may have played a role in the neutropenia of this patient.

Immunohistochemical detection of the laminin receptor polypeptide, a putative precursor of 67-kda-laminin receptor, in human lung-cancer

Laminin receptor polypeptide was immunodetected in human lung cancer with a polyclonal antibody raised against a 20-mer peptide of the putative high-affinity laminin receptor of 67 kDa (Wewer et al: Cancer Res 47: 5691-5698, 1987). As a result, immunoreactivity was recognized specifically in cancer cells both in freshly-prepared cell samples and in paraffin-embedded tissue specimens. It was shown that immunodetection of the laminin receptor polypeptide with this antipeptide antibody could be applied to diagnostic use for lung cancer. The results also suggest that the laminin receptor polypeptide is not necessarily a membrane-associated protein and may function without further processing to the 67 kDa-laminin receptor.

[Problems of national health insurance reimbursement revision, especially for laboratory tests]

The reimbursement fees for laboratory tests are lowered at every revision of Health Insurance Reimbursement (HIR), carried out every 2 years. This leads to the financial trouble for laboratory operation in university hospitals as well as general hospitals. Medical care costs in Japan account for 6% of GNP and is not as high as that in advanced countries such as USA, Canada, and Germany. The Central Pharmaceutical Affairs Councils gives manufacturing and sales approval for in-vitro diagnostics after examination of the applied documents. The Committee on Application of Medical Care Remuneration in the Japan Medical Association decides the following; Propriety of reimbursement establishment for new in-vitro diagnostics, reimbursement fees for new in-vitro diagnostics, propriety of reimbursement establishment for medical devices and propriety of reimbursement for new drugs. The MOSS (Market-Oriented, Sector-Selective) approach was initiated also in the in-vitro diagnostics field in January 1985 the target of which is to abolish the economic barrier and relax regulations in Japan. The Ministry of Health and Welfare lowered the reimbursement fees based on actual prices in commercial laboratories, which is very low because of price dumping through excess competition. In future, we would like to propose additional reimbursement fees for in-house emergency tests. Furthermore, we would like to request the judgment fee for diagnosis of myelogram, immunoelectrophoresis and isoenzymes for which clinical laboratory physicians play a role.

Screening of polyacetylenic alcohols in crude drugs using the ELISA for panaxytriol

Polyacetylenic alcohols such as panaxytriol, panaxynol and panaxydol isolated from the roots of Panax ginseng C. A. MEYER have antiproliferative activity against various cultured tumor cells. Anti-panaxytriol antibody was obtained by immunizing rabbits with panaxytriol-bovine serum albumin conjugates. Although the antibody reactivity was directed mainly toward panaxytriol, there was a slight cross-reactivity with other polyacetylenic compounds. The antibody was, therefore, used for screening a large number of crude drugs for polyacetylenic compounds such as panaxytriol. Methanol-extracts from 31 crude drugs were examined. Significant reactivity was observed in 15 methanol-extracts from Aralieaceae, Compositae and Umbelliferae as reported by other investigators. Three out of the 15 crude drugs were selected for determination of the potent cross-reactive compounds. Four kinds of cross-reactive compounds were isolated by silica gel column chromatography, monitoring each fraction using the enzyme-linked immunosorbent assay (ELISA). Among them, panaxynol and heptadeca-1,8-diene-4,6-diyne-3,10-diol were identified from Saposhnikoviae Radix. Falcarindiol was newly identified from Peucedani Radix. A new polyacetylenic alcohol, 9,10-epoxy-16-hydroxy-octadeca-17-ene-12,14-diyne-1-al, was also isolated from Foeniculi Fructus. All these polyacetylenic alcohols inhibited the growth of a human gastric adenocarcinoma cell line, MK-1 cells, in a dose-dependent manner. These results indicate that the antibody against panaxytriol is an effective tool for "screening" antiproliferative polyacetylenic compounds.

Evaluation of albumin concentration in rabbit anterior chamber with laser flare-cell meter

To find an appropriate way of using Kowa's laser flare-cell meter in evaluating the anterior chamber albumin concentration, we characterized the relationship among the flare intensity determined with the flare-cell meter in terms of photon count/ms (flare value), flare value converted to albumin concentration, and anterior chamber albumin concentration in drug-treated rabbit eyes. Flare measurement was done in rabbits that received intravenous administration of fluorescein isothiocyanate-labeled albumin and instillation of prostaglandin E1, pilocarpine, or tropicamide. Flare value, anterior chamber fluorescence, plasma fluorescence, and plasma albumin concentration were determined. Anterior chamber albumin concentration was calculated from the plasma albumin concentration and the corrected aqueous/plasma fluorescence ratio. The correlation between the flare value converted to albumin concentration (Albequiv) and the anterior chamber albumin concentration (Albac) had two phases: 1) Linear correlation was found when the flare value was below 100 photon count/ms: Albac = 0.53 Albequiv - 0.006, r = 0.98; 2) When the flare value was above 100 photon count/ms, the correlation was lower and had a different slope. In this condition, the Albac was correlated better with the flare value itself: Albac = 0.0042 [flare value] + 0.17, r = 0.88. The results suggested that anterior chamber albumin concentration is evaluated quantitatively from the converted flare value when the flare value is below 100 photon count/ms and from the flare value itself when the flare value is above that level.

Immunohistochemical expression of tenascin in normal stomach tissue, gastric carcinomas and gastric carcinoma in lymph nodes

The immunohistochemical expression of tenascin was examined in the normal adult mucosa of the stomach, primary tumours and lymph node metastases of gastric cancer patients. In normal gastric tissue tenascin was expressed in the muscularis mucosae, muscularis propria and vessel walls, however it was not expressed in either the mucosal connective tissue or the stromal tissue in the submucosal layer. In gastric cancer, tenascin was expressed in 35 of 85 primary tumours, and in 8 of 25 metastases in lymph nodes. Tenascin was located in the fibrous stroma surrounding foci of cancer. The expression of tenascin in the primary tumour did not correlate with the depth of invasion, lymph node metastasis or prognosis. Tenascin appears during the process of either malignant transformation or tumour progression in gastric cancer, and the positive expression of tenascin may be useful as a stromal marker for the early detection of gastric cancer.

Cataracts after bone marrow transplantation: long-term follow-up of adults treated with fractionated total body irradiation

PURPOSE

To determine the risk of, and risk factors for, developing cataracts after bone marrow transplantation.

METHODS AND MATERIALS

Four hundred and ninety-two adults who underwent bone marrow transplantation in Seattle were followed for 2 to 18 (median, 6) years. Before transplantation, patients received a preparative regimen of chemotherapy plus total body irradiation (TBI) (n = 407) or chemotherapy alone, without TBI (n = 85). TBI was administered in a single dose of 10 Gy (n = 74) or in fractionated doses totaling 12-15.75 Gy (n = 333). The risk of cataracts was determined for groups of patients with respect to the type of preparative regimen received and other pretransplant and posttransplant variables.

RESULTS

One hundred and fifty-nine patients (32%) developed cataracts between 0.5 to 11 (median, 2.3) years after transplantation. The probability of cataracts at 11 years after transplantation was 85%, 50%, 34%, and 19% for patients receiving 10 Gy of single-dose TBI, > 12 Gy fractionated TBI, 12 Gy fractionated TBI, and no TBI, respectively (p < 0.0001). Among those developing cataracts, the severity was greater in patients after single-dose TBI (59% probability of surgical extraction) than after > 12 Gy fractionated TBI, 12 Gy fractionated TBI, or no TBI (33%, 22% and 23%, respectively). Patients given corticosteroids after transplant had a higher probability of cataracts (45%) than those without steroids (38%) (p < 0.0001). In a proportional hazards regression model, the variables that were correlated with an increased probability of cataracts were single-dose TBI (relative risk (RR) = 2.46) and steroid therapy (RR = 2.34), while a decreased probability of cataracts was correlated with a nonTBI preparative regimen (RR = 0.41). The yearly hazard of developing cataracts in recipients of single-dose TBI was highest during the third year after transplantation, while in recipients of fractionated TBI, the hazard was distributed among years one through seven. The probability of cataracts in all groups reached a plateau at 7 years after transplantation, after which the development of cataracts was extremely unlikely.

CONCLUSION

TBI is the major risk factor for developing cataracts after BMT. Single-dose TBI results in the highest risk of cataracts. However, the risk of cataracts in recipients of fractionated-TBI is significantly higher than in patients who receive no TBI. In addition to TBI, steroid therapy is an independent risk factor for cataracts after BMT.

[Coronary arteritis of Kawasaki disease unresponsive to high-dose intravenous gammaglobulin successfully treated with plasmapheresis]

Kawasaki disease (KD) is characterized by marked activation of immune system and generalized vasculitis including coronary arteritis, and the intravenous gammaglobulin therapy is recommended as the first line of the choices. However, in some fulminant cases the coronary arteritis progresses rapidly and extensively in the early phase of the disease despite of the aggressive high-dose gammaglobulin administration. Recent observations indicated that the vasculitis begins at the endothelial cells which are activated by several inflammatory cytokines and are adhered to by cytokine-activated cytotoxic immune cells. Thus, it is important for the prevention of coronary arteritis and the resultant coronary aneurysm to reduce the inflammatory cytokines in the plasma. We reported here a 4-year-old girl with coronary arteritis which began on the 3rd day of the disease. The patient was fulfilled the revised criteria of KD at the hospital admission. As the initial intravenous gammaglobulins (400 mg/kg/day for 3 consecutive days and the subsequent 1 g/kg single intravenous infusion) revealed ineffective, which was judged by echocardiography in the persistence of brightness of the slightly widened coronary artery, and by laboratory data, we conducted therapeutic approach of plasmapheresis (replacement of plasma with 5% albumin in saline) on 8-10th days of KD. Fever was down to normal range soon after the first plasmapheresis, and after the second pheresis CRP was reduced, and finally on the 10th day echocardiography demonstrated marked improvement of inflamed coronary artery. The precise mechanism of the effective plasmapheresis is to be investigated, but it is possible that the removal of inflammatory cytokines from the plasma ceased the subsequent endothelial cell damage and coronary arteritis.(ABSTRACT TRUNCATED AT 250 WORDS)

31P nuclear magnetic resonance evaluation of rat liver preserved in UW solution

A persistent problem in orthotopic liver transplantation is primary nonfunction (PNF) of the hepatic allograft. In an attempt to reduce the incidence of graft failure, the feasibility of pretransplant assessment of graft viability was investigated by 31P nuclear magnetic resonance (NMR) spectroscopy. The level of adenosine triphosphate (ATP) was measured as an indicator of liver function by 31P NMR spectroscopy after a 30 min normothermic reperfusion following cold-storage in University of Wisconsin (UW) solution. The mean +/- SD beta-ATP/Pi ratio after preservation for 0, 12, 24 or 48 h was 1.40 +/- 0.34, 0.85 +/- 0.27, 0.64 +/- 0.14 and 0.38 +/- 0.09, respectively. Significance was observed between 12h and 24h and between 12h and 48h of preservation. These results correlated well with the morphological changes in endothelial cells and sinusoidal lining cells examined by transmission electron microscopy. It is suggested strongly that microcirculatory disturbances due to endothelial cell injury impairs the recovery of ATP levels after reperfusion, and that ATP determination by 31P NMR spectroscopy, as a non-invasive modality, may help in the prediction of PNF after liver transplantation.

Surgical trends in the treatment of diseases of the lumbar spine in Utah's Medicare population, 1984 to 1990

Chronic low back pain is a major source of disability in this country. The rate of surgical treatment for back disorders varies between small geographic areas in the northeastern United States. A statewide database was utilized to determine rate of surgery for mechanical low back problems in Utah's Medicare population from 1984 to 1990. The average surgery rate for Medicare enrollees was 274.7 per 100,000, and the Utah laminectomy and discectomy rates were at least 20% higher than the U.S. average. Back surgery rates rose by 55% over the study period, primarily because of increasing rates of surgery for spinal stenosis. There was statistically significant variation in surgery rates among regions in the state, with the highest region having a rate 50% greater than the lowest region. Rates of surgery for spinal stenosis had more variation than those for herniated disc surgery. There was no significant correlation between the number of surgeons performing back surgery and the rate of surgery. The variation and increase in back surgery rates in Utah's Medicare population are likely related to changes in the use of surgery for treatment of spinal stenosis and not to an increase in the number of back surgeons. Further investigation is needed to understand better the reasons for the observed increase in back surgery rates.

Hereditary hemorrhagic telangiectasia showing severe anemia which was successfully treated with estrogen

Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease) is a bleeding disorder attributed to a vascular developmental abnormality. It is transmitted as an autosomal dominant trait. A 63-year-old female was admitted because of repeated episodes of severe anemia which resulted from bleeding of telangiectases in the gastric mucosa. Conventional therapies including endoscopical microwave coagulation and ethanol injection were not effective. The persistent anemia necessitated frequent blood transfusion. Estrogen was orally administrated and blood transfusion became unnecessary. Thus, estrogen therapy should be considered as one of the effective treatments for recurrent severe anemia due to hereditary hemorrhagic telangiectasia.

Proliferating cell nuclear antigen (PCNA) expression in oral squamous cell carcinoma - an aid to conventional histological grading?

Proliferating cell nuclear antigen (PCNA) is a well known marker for cell proliferation. It tends to accumulate in the late G1 and S-phase of the cell cycle. A monoclonal antibody (MoAb) against PCNA is now available and it can react with paraffin-embedded specimens. In the present study, PCNA immunohistochemical staining of 36 cases of oral cancer specimens obtained from surgery were investigated. The results showed differing nuclear staining patterns for PCNA in normal, hyperplastic and dysplastic epithelium, early cancer and 3 levels of differentiation for squamous cell carcinoma of the oral cavity. It appears that PCNA can be a useful marker in delineating normal epithelium and hyperplastic epithelium from dysplasia in the oral cavity. The use of PCNA staining may further emphasize the conventional histopathological grading of well-differentiated, moderately-differentiated and poorly-differentiated oral squamous cell carcinoma but is still dependent on basic criteria as observed without immunostaining. PCNA expression for all grades of squamous cell carcinoma are present at the deep, infiltrative margins.

A novel dodecadepsipeptide, cereulide, is an emetic toxin of Bacillus cereus

A vacuole-formation substance, cereulide of Bacillus cereus, is an emetic toxin in animals. Both oral administration and intraperitoneal injection of cereulide caused dose-dependent emesis in Suncus murinus, a new animal model of emesis. Vagotomy or a 5-HT3 receptor antagonist completely abolished this emetic effect. Therefore, cereulide causes emesis through the 5-HT3 receptor and stimulation of the vagus afferent. We also found that our purified cereulide caused swelling of mitochondria of HEp-2 cells.

Local response of the primate retinal microcirculation to increased metabolic demand induced by flicker

PURPOSE

To study the response of the macular circulation to a local increase in metabolic demand created by a flickering source of illumination.

METHODS

Laser-targeted angiography (release of a fluorescent dye from heat-sensitive liposomes using a laser pulse) was used to study, in subhuman primates, changes in hemodynamic parameters of the retinal circulation that were induced by a flickering source of illumination. Changes in the macular macrocirculation were compared with those in the macular microcirculation and were evaluated at various distances from the foveola.

RESULTS

In response to monochromatic light flicker, the blood flow in retinal arteries increased by 30%. The response of the microcirculation was not homogeneous. It showed a maximum increase in the mid-perifoveal region where there is an increase in ganglion cells and nerve fibers. Interestingly, the maximum change in the index representing capillary blood flow exceeded the blood flow change in the artery (P < 0.08).

CONCLUSIONS

A stimulus expected to cause increased metabolic demand results in a regulatory response by the retinal microcirculation. This response shows spatial variations that correspond with known variations in retinal anatomy. The authors propose that a redistribution of blood can occur between the capillary layers to fulfill high metabolic demands by neuronal tissue remote from the choroid.

Aberrant expression of gap junction proteins (connexins) is associated with tumor progression during multistage mouse skin carcinogenesis in vivo

To elucidate what changes in the expression of gap junction proteins (connexins) occur at what stages during multistage mouse skin carcinogenesis in vivo, we immunohistochemically and morphometrically analyzed the expression of connexin 26 (Cx26) and connexin 43 (Cx43) in papillomas, well-, moderately- and poorly-differentiated squamous cell carcinomas, as well as in squamous cell carcinomas at invasion sites and those metastasized into lymph nodes in female CD-1 mice as a result of treatment with dimethylbenz[a]anthracene and 12-O-tetradecanoylphorbol-13-acetate. In papillomas, no clear reduction of the two connexins was observed; however, Cx26 and Cx43 were frequently co-localized in the same gap junction plaques, whereas the two kinds of Cxs were differentially expressed in normal and surrounding non-tumorous epidermis. In squamous cell carcinomas, the expression of both Cx26 and Cx43 significantly decreased compared with surrounding non-tumorous epidermis and papillomas. The Western blot analysis confirmed that both Cx26 and Cx43 proteins were reduced in squamous cell carcinomas compared with papillomas. Furthermore, the expression of Cx26 was reduced as cancer cells became morphologically less differentiated, while that of Cx43 did not change. Squamous cell carcinomas at invasive sites showed clear reduction of Cx26 and Cx43. In squamous cell carcinomas metastasized into lymph nodes, Cx26 was expressed, but few carcinoma cells expressed Cx43. The localization of E-cadherin on the plasma membrane between cancer cells was maintained even at invasive and metastatic sites. Our data suggest that quantitative and qualitative changes in connexin expression are associated with tumor progression, including the loss of differentiation, and invasion and metastasis, during multistage mouse skin carcinogenesis.

[An outbreak of Pontiac fever due to Legionella pneumophila serogroup 7. II. Epidemiological aspects]

From August 20 to 22, 1994, an outbreak of acute febrile illness occurred in a Training Center building of a company in Shibuya-ku, Tokyo. All 43 trainees attended in two groups and 2 Center staffs were attacked. Illness was self- limiting, generally lasting three days. Though strains of legionellae, isolated from the water of the cooling tower located at the top of the building, were identified as Legionella pneumophila by microplate DNA-DNA hybridization, they failed to agglutinate with antisera against L. pneumophila serogroups 1 through 6. Two strains were sent to the Centers for Disease Control, Atlanta, Georgia, USA, and determined as serogroup 7 of the species. Since the clinical courses agreed with the definition of Pontiac fever by Glick et al. and seroconversion in a patient against the cooling tower strain (EY3698)from 1:16 to 1:256 was determined by indirect fluorescent antibody technique, the epidemic of acute febrile illness was concluded as an outbreak of Pontiac fever due to L. pneumophila serogroup 7. The cooling tower was a cylindrical open style, with volumetric flow rate of 130 liter/min, and was used for air- conditioning exclusively to the third floor of the building. The building equipped no air-inlet, and indoor-air of the training room exchanged at every break time through windows of 168 cm in height and 72 cm in width. The cooling tower was not operated for five days before the Group A trainees checked in the Center on 18 August followed by Group B trainees on 19 August. It was speculated that high atmospheric temperature and stagnation of cooling water during this period would lead L. pneumophila to overly multiply, which could be a source of infection by flowing in through opened windows to the training rooms.

[An outbreak of Pontiac fever due to Legionella pneumophila serogroup 7. I. Clinical aspects]

In August 1994, an epidemic of acute febrile illness occurred at the Education Center Building of a company in Shibuya-ku, Tokyo. All 43 trainees attended in two groups and 2 staff members of the Center fell ill. The 45 patients came to one of our hospitals in two groups, and 35 patients were treated. The patients were 4 males and 31 females, and the average age was 29.0 years. The duration until falling ill was 36 to 90 hours after entering the Center. Symptoms were fever, lumbago arthralgia, headache, dyspnea, general fatigue, etc. Physical examination revealed slightly injected mucosa of the pharynx in a patient who complained of a sore throat. On laboratory examination, leukocytosis with a left shift of the nucleus and elevation of serum CRP levels were found. Erythromycin (600 mg, daily) and nonsteroidal antiinflammatory drugs (NSAIDs) were given by mouth to almost every patient. Two patients were hospitalized. The illness was self-limited, generally lasting from two to five days. Strains of legionellae isolated from the water of the cooling tower located at the top of the Center, were identified as L. pneumophila serogroup 7. Since seroconversion in a patient against the cooling tower strain from 1:16 to 1:256 was determined and the clinical courses agreed with the definition of Pontiac fever by Glick et al, we concluded that the epidemic was an outbreak of Pontiac fever due to L. pneumophila serogroup 7. Pontiac fever is considered to be one of the community-acquired diseases. Thus, we have to note that Pontiac fever may be misdiagnosed as we examine patients who complain of the symptoms noted above.

Loss of serum HCV RNA at week 4 of interferon-alpha therapy is associated with more favorable long-term response in patients with chronic hepatitis C

To determine the virological factors associated with a favorable long-term response to interferon-alpha (IFN) therapy in chronic hepatitis C virus (HCV) infection, 61 Japanese patients with chronic HCV infection were treated with IFN for 24 weeks (780 million units in total) and followed for 8 to 16 months after cessation of therapy. Ten patients dropped out because of severe side effects. Of the 51 patients who completed IFN therapy, 23 showed complete and sustained response (CR --> SR), 13 complete response with early relapse (CR --> Rel), and 15 no response to IFN (NR). For the pretreatment serum HCV RNA level, 20/23 who had CR --> SR had < 10(6) eq/ml compared to 3/13 CR --> Rel and 1/15 NR (P < 0.01). Serologically defined HCV type 2 infection was also associated with a better opportunity to develop CR --> SR compared to CR --> Rel of NR (P < 0.01). Loss of serum HCV RNA at week 4 of IFN therapy was also associated with a more favorable long-term response [17/19 CR --> SR were HCV RNA negative compared to 3/11 CR --> Rel (P < 0.01) and 2/13 NR (P < 0.01)]. In contrast, normalization of serum alanine aminotransferase (ALT) levels at week 4 was found in 9/19 CR --> SR compared to 8/11 CR --> Rel (P = NS), and 0/13 in NR (P < 0.01). Six months after cessation of IFN therapy, 3/25 CR --> SR patients were HCV RNA positive despite normalization of serum ALT levels. These data indicated that in addition to pretreatment serum HCV RNA levels and HCV type, the kinetics of response to IFN (at week 4) were also predictive of subsequent long-term response to IFN in patients with chronic HCV infection.

[Pulmonary alveolar proteinosis associated with myelodysplastic syndrome]

A 57-year-old man with myelodysplastic syndrome developed dyspnea on exertion in September 1993. Chest X-ray film showed diffuse infiltrative shadows in the middle and lower lung fields on both sides. The infiltrates were prominent in the perihilar regions but less so in the periphery, consistent with a "bat wing pattern." Milky fluid was obtained by bronchoalveolar lavage. The specimens obtained from transbronchial lung biopsy were compatible with the pathological findings of pulmonary alveolar proteinosis with amorphous periodic acid-Sciff-positive materials in the alveolar spaces. Impaired function of alveolar macrophages was demonstrated from their abnormally low phagocytosis of FITC-labeled latex beads. Whole lung lavage under general anesthesia was done twice, but the patient died because of progression of respiratory failure.

[A case of malignant lymphoma arising from chronic pyothorax; usefulness of magnetic resonance imaging (MRI) for diagnosis]

A 79-year-old man had a history of pneumothorax induced to treat pulmonary tuberculosis when he was 40 years old, and of chronic pyothorax when he was 60 years old. He was admitted to our hospital because of chest pain and swelling of the right lateral chest wall. Soft tissues of the chest wall and rib had been destroyed, and a fistula had formed at the skin. The diagnosis was confirmed by examination of a biopsy specimen from the chest wall tumor. The tumor was successfully treated by radiation therapy. 67Ga scintigraphy, CT, and MRI were useful for diagnosis and follow up. Pyothorax and the tumor could be distinguished only with MRI.

Murine spleen stromal cell line SPY3-2 maintains long-term hematopoiesis in vitro

The hematopoietic microenvironment (HIM) of mouse spleen predominantly induces the differentiation of hematopoietic progenitors into erythroid lineage in vivo. However, the mechanisms of this phenomenon have not been fully explored because of the lack of an adequate in vitro system mimicking the spleen hematopoiesis. To reconstruct the HIM of mouse spleen in vitro, we established spleen stromal cell lines from a three-dimensional (3D) spleen primary culture in collagen gel matrix. Of these, SPY3-2 cells were negative for preadipocytic and endothelial markers, had a fibroblastoid morphology, and were not converted to adipocytes in the presence of 1 mumol/L hydrocortisone. They supported the maintenance and multilineal differentiation of hematopoietic progenitor cells for more than 8 weeks in vitro. The differentiated hematopoietic cells in the coculture medium were predominantly monocytes rather than granulocytes. Furthermore, erythropoiesis was predominantly induced in the presence of 2 U/mL erythropoietin and continued for more than 12 weeks. The number of burst-forming units-erythroid (BFU-E) was increased 10 times after 3 weeks of coculture, which was followed by pronounced production of erythroid cells in the coculture after week 4. SPY3-2 expressed high levels of c-kit ligand and low levels of granulocyte macrophage colony-stimulating factor and interleukin-3, and these molecules were all involved in this long-term erythropoiesis. Thus, the clonal SPY3-2 cell line will provide a novel HIM in vitro analogous to that of mouse spleen in vivo. These results suggest that 3D collagen gel culture may facilitate the establishment of functioning stromal cell lines of hematopoietic organ.