Inguinal hernia repair in patients with artificial urinary sphincter after radical prostatectomy

PURPOSE

Stress urinary incontinence (UI) often develops after radical prostatectomy for prostate cancer, and in those patients with moderate-to-severe stress UI an artificial urinary sphincter (AUS) is implanted. Inguinal hernias (IHs) often occur after radical prostatectomy. As the prevalence of AUS implantation increases, it is possible to encounter patients with IHs undergoing AUS implantation (IHA). This study investigated our treatment and discussed an appropriate approach for IHAs.

METHODS

We retrospectively investigated patients who underwent IH repair with AUS implantation at our hospital from January 2018 to March 2023. We classified IHAs into Types A-D based on the positions of the IHs and AUS devices (the positions of the control pump, pressure-regulating balloon, and connecting tube). The hernia and control pump were ipsilateral in Types A and B, whereas the hernia and pressure-regulating balloon were ipsilateral in Types A and C.

RESULTS

This study included 12 IHs of 11 patients. The median patient age was 77 years. We conducted open repair in nine patients with all types and laparoscopic repair in two patients with Type B. The median operation times for unilateral and bilateral repairs were 96 and 182 min, respectively. There were no complications with AUS or hernia surgeries.

CONCLUSION

IHA has its own characteristics, and multidisciplinary knowledge thereof will help surgeons safely perform IH surgery.

[A Case of Esophageal Cancer with Multiple Lung Metastases Resected after Stent Placement and Chemotherapy]

A 70-year-old man was diagnosed with middle and lower thoracic esophageal squamous cell carcinoma. A computed tomography(CT)scan revealed multiple pulmonary metastases. The clinical stage was T3N1M1, Stage Ⅳb. After esophageal stent placement was performed to alleviate strong stenotic symptoms, cisplatin/5-fluorouracil(CDDP/5-FU)therapy was introduced, and 8 courses were completed. Four additional courses of 5-FU monotherapy were then administered. Following systemic chemotherapy, CT scans showed no evidence of lung metastases. About a year after the initial treatment, the patient underwent a thoracoscopic esophagectomy. Postoperatively, he was followed up without treatment and has remained alive for 1 year and 4 months without any recurrence.

A case of conservatively managed gastric perforation at a recurrent hiatal hernia site after laparoscopic paraesophageal repair

INTRODUCTION AND IMPORTANCE

Gastric perforation due to a hiatal hernia is a rare cause of acute abdominal pain that often requires surgical intervention. Conservative management for this condition is an effective option in certain cases, although fewer reports of this exist. Herein, we report a unique case of gastric perforation caused by a recurrent hiatal hernia that was successfully treated with conservative management.

CASE PRESENTATION

A 74-year-old man developed a high fever and an elevated inflammatory response on the third day after a laparoscopic paraesophageal hernia repair using a mesh. Computed tomography confirmed the recurrence of the hiatal hernia, with gastric fundal prolapse into the mediastinum and surgical emphysema in the gastric wall. This was followed by a gastric perforation within the mediastinum. The patient was treated using an ileus tube through the perforation site.

CLINICAL DISCUSSION

In similar cases, if the clinical symptoms are mild, there are no signs of serious infection, and the perforation remains in the mediastinum and can be appropriately drained, conservative treatment is considered an option.

CONCLUSION

Under favorable conditions, conservative management can be an option for gastric perforation in patients with recurrent hiatal hernias, which is a serious potential postoperative complication.

Beneficial effects of balloon pulmonary angioplasty on clinical outcomes in patients with residual pulmonary hypertension after pulmonary endarterectomy

Background

Although pulmonary endarterectomy (PEA) is an established surgical treatment for chronic thromboembolic pulmonary hypertension (CTEPH), a part of patients after PEA show residual pulmonary hypertension, leading to limited exercise capacity. Recently, several studies have indicated that balloon pulmonary angioplasty (BPA) improves hemodynamics, exercise capacity and prognosis in inoperable CTEPH patients. However, the effects of BPA in patients with residual pulmonary hypertension after PEA remain to be elucidated.

Aim

In the present study, we investigated comprehensive efficacy of BPA on hemodynamics, exercise capacity and right ventricular function in those with residual pulmonary hypertension after PEA.

Methods

From October 2010 to February 2019, 227 patients with CTEPH underwent PEA in our institution. Right heart catheterization after PEA (median follow up period from PEA to right heart catheterization 39 [10.5, 90] months) showed that 55 patients showed residual PH (mean pulmonary artery pressure (mPAP)≥25mmHg), and 38 of them referred to BPA (mean age 57 years old, male 8 (21%)) due to residual symptoms. In 29 out of 38 patients (76%) who completed BPA and underwent follow-up right heart catheterization, we examined hemodynamics, exercise capacity and right ventricular function before and after BPA. Follow-up examination was performed 3 months after last BPA session.

Results

In this study population (N=29), PEA significantly improved mPAP (47±7 to 38±10 mmHg), pulmonary vascular resistance (PVR, 14.6±4.6 to 9.2±4.6 WU) and right ventricular ejection fraction measured by magnetic resonance imaging (26.6±11.3 to 38.4±6.8%) (Figure). Median period from PEA to first BPA procedure was 42 [13.5, 94] months. Total session number during study period was 160 sessions, and mean session number of BPA was 5.5±1.5 per patient. Follow-up study revealed that BPA additionally improved mPAP (38±10 to 27±8 mmHg) and PVR (9.2±4.6 to 5.1±2.2 WU) (Figure). Similarly, 6-minute walk distance (393±125 to 452±125 m) and peak VO2 (16.4±3.8 to 18.1±4.6 ml/min/kg, p<0.05) were increased, and WHO functional class also significantly improved by BPA (I/II/III/IV, 0/21/8/ 0 to 1/27/1/0, p<0.01). In addition, right ventricular ejection fraction (38.4±6.8 to 44.2±7.1%) was increased after BPA (Figure). There were no procedure-related deaths and major lung injuries requiring oral intubation during study period. 3-year survival in patients after BPA was 100% (median follow-up period after last BPA session, 32 [18, 46] months).

Conclusion

In CTEPH patients with residual pulmonary hypertension after PEA, additional BPA significantly improved hemodynamics, right ventricular function, exercise capacity and residual symptoms without severe complications, leading to good prognosis. These results suggest that combination therapy of PEA and BPA could be an effective therapeutic option for post PEA patients with residual symptoms and exercise limitation.

Figure 1

Funding Acknowledgement

Type of funding source: None

Self-expandable Metal Stent as a Bridge to Surgery for Colorectal Cancer: Safety and Oncological Outcomes

BACKGROUND/AIM

Self-expandable metal stent (SEMS) as a bridge to surgery (BTS) for obstructive colorectal cancer (CRC) raises concerns regarding the short-term as well as oncological outcome. The present study aimed to investigate the safety of SEMS placement and risk factors of worse short-term and oncological outcomes as BTS.

PATIENTS AND METHODS

Twenty-four patients with obstructive CRC who underwent SEMS placement as BTS were included. Success rate of SEMS placement and 2-year relapse-free survival (RFS) rates in stage II/III BTS patients were assessed.

RESULTS

Technical and clinical success rates for SEMS placement were 100% and 87.5%, respectively. In Multivariate analyses, longer tumour length, longer interval to surgery, and angular positioning were risk factors related with the complication of stent placement. Two-year RFS rates were significantly higher in the no-complication than in the complication group (100% vs. 75%, log-rank test, p<0.01).

CONCLUSION

A long tumour length, long interval between SEMS insertion and surgery, and angular positioning of the SEMS were identified as risk factors for SEMS-related complications. Moreover, SEMS insertion and/or surgery complications were associated with worse oncological outcome in CRC patients.

[Case Report of Long-Term Clinical Efficacy of Paclitaxel plus Bevacizumab Combination Therapy for Stage Ⅳ AdvancedBreast Cancer]

A 50-year-old woman had noted a mass in her right breast 2 years ago but did not consult a hospital. She consulted our hospital because the mass increased in size and also reddened. The tumor measured 10 cm in diameter and was palpable in the whole right breast. A core needle biopsy was performed, and invasive ductal carcinoma was diagnosed. CT showed multiple lung and liver metastases and bone scintigraphy showed bone metastases in a rib. Because the lung and liver metastases were life-threatening, paclitaxel(PTX)chemotherapy was administered weekly. Biomarkers analysis revealed ER(+), PgR(+), HER2(2+), HER2 FISH 1.27, Ki-67 30%, and bevacizumab (Bev) was added from 2 courses. After 4 courses of chemotherapy, the multiple lung and liver metastases were found to be significantly reduced on CT. Toxicities included alopecia, hypertension, and proteinuria. At this time, 3 years after the treatment started, PTX plus Bev combination therapy was also administered.

Detection of Second Primary Malignancies of the Esophagus and Hypophraynx in Oral Squamous Cell Carcinoma Patients

Objective

To assess the usefulness of modified esophagogastroduodenoscopy (EGD) for the detection of second primary malignancies of the esophagus or hypopharynx in patients with oral squamous cell carcinoma and determine the association between the oral lesion subsite and esophageal or hypopharyngeal lesion occurrence.

Study Design

Retrospective review.

Methods

In total, 166 patients with oral squamous cell carcinoma without any established symptoms of esophageal or hypopharyngeal squamous cell carcinoma underwent modified EGD based on the Valsalva maneuver and U-turn method, image-enhanced endoscopy, and chromoendoscopy using Lugol's iodine for diagnosis. All suspected lesions were biopsied to determine the clinical stages and duplication rates. Odds ratios for the occurrence of duplicate lesions according to the oral lesion subsite were determined.

Results

In total, 37 esophageal and 16 hypopharyngeal lesions were detected. According to the Union for International Cancer Control/American Joint Committee on Cancer classification (2009), 75.7% and 5.4% esophageal lesions were classified as stage IA and IB, respectively, and 50% and 18.8% hypopharyngeal lesions as stage II and stage I, respectively. Approximately 59.1% and 50% esophageal and hypopharyngeal lesions, respectively, were successfully treated by endoscopic resection. Oral lesions involving the floor of the mouth were more frequently accompanied by second primary malignancies of the esophagus or hypopharynx.

Conclusions

Modified EGD is an effective noninvasive technique for early diagnosis and treatment of second primary malignancies of the esophagus and hypopharynx in patients with oral squamous cell carcinoma. In particular, patients with floor of the mouth lesions need close monitoring for hypopharyngeal and esophageal lesions.

Level of Evidence

3b.

[A Case of HER2 Positive Occult Breast Cancer Presenting as Swollen Axillary Lymph Nodes]

Occult breast cancer, which develops as a metastatic lesion with no primary tumor detected in the breast, is a rare breast cancer. A 68-year-old female patient particularly complained of the presence of a right axillary mass. The mass in the right axilla was palpable, but no tumor was found in both the breasts on palpation, ultrasound examination, or MRI. Partial breast resection and axillary lymph node dissection were performed following a diagnosis of invasive ductal carcinoma by core needle biopsy. There was no mammary gland tissue present around the tumor due to the pathology of the disease, and the tumor was diagnosed as occult breast cancer. As the cancer was ER negative and HER2 positive, treatment with a combination of FEC, docetaxel, and trastuzumab was initiated. Radiotherapy, which irradiated the right supraclavicular fossa and the right mammary gland, was administered. No disease recurrence and mammary tumor has been reported in the patient till date. Treatment of occult breast cancer generally includes local therapy such as radiation and surgery. However, in the present case, we did not operate upon the breast; instead we treated the right breast and the right supraclavicular fossa with radiation therapy. As the tumor was HER2 positive, we reasoned that local control of disease would be likely if treatment with chemotherapy and trastuzumab was performed effectively.

Comparative analysis of avascular areas in superficial esophageal squamous cell carcinomas using in vivo and ex vivo magnifying endoscopy

BACKGROUND AND STUDY AIMS

 An avascular area (AVA), one of the microvasculature changes in superficial esophageal cancers, appears when a tumor demonstrates a bulky growth pattern. We aimed to compare endoscopic and histopathological findings by observing formalin-fixed AVA specimens using magnifying endoscopy.

PATIENTS AND METHODS

 A prospective analysis was conducted on 16 patients with superficial esophageal cancer, including AVA, who underwent endoscopic submucosal dissection (ESD). Magnifying endoscopy and blue laser imaging were used to identify AVAs. After the ESD, the AVA width was measured on formalin-fixed specimens using magnifying endoscopy, and AVA thickness and depth were determined after hematoxylin and eosin staining using microscopy.

RESULTS

 Mean AVA widths of M1, M2, and M3/SM-lesions were 0.434, 0.578, and 0.835 mm, respectively (M1 vs. M2, P = 0.16; M2 vs. M3/SM-, P  = 0.07). Mean AVA thicknesses of M1, M2, and M3/SM-lesions were significantly different (0.176, 0.518, and 0.800 mm; M1 vs. M2, P < 0.01; M2 vs. M3/SM-, P  < 0.05). There was a significant correlation between AVA width and thickness.

CONCLUSIONS

 AVA size can be measured accurately on formalin-fixed specimens with magnifying endoscopy. AVA thickness can be useful for determining tumor depth.

Case of Superficial Cancer Located at the Pharyngoesophageal Junction Which Was Dissected by Endoscopic Laryngopharyngeal Surgery Combined with Endoscopic Submucosal Dissection

Aims. In order to determine the indications of transoral surgery for a tumor located at the pharyngoesophageal junction, the trumpet maneuver with transnasal endoscopy was used. Its efficacy is reported here. Material and Methods. An 88-year-old woman complaining of dysphagia, diagnosed with cervical esophageal cancer, and hoping to preserve her voice and swallowing function was admitted to our hospital. Conventional endoscopy showed that the tumor had invaded the hypopharynx. When inspecting the hypopharynx and the orifice of the esophagus, we asked the patient to blow hard and puff her cheeks with her mouth closed (trumpet maneuver). After the trumpet maneuver, the pharyngeal mucosa was stretched out. The pedicle of the tumor arose from the left-anterior wall of the pharyngoesophageal junction, so we decided to perform endoscopic resection. Result. Under general anesthesia, the curved laryngoscope made it possible to view the whole hypopharynx, including the apex of the piriform sinus and the orifice of the esophagus. The cervical esophageal cancer was pulled up to the hypopharynx. Under collaboration between a head and neck surgeon and an endoscopist, the tumor was resected en bloc by endoscopic laryngopharyngeal surgery combined with endoscopic submucosal dissection. Conclusion. Transnasal endoscopy using the trumpet maneuver is useful for a precise diagnosis of the pharyngoesophageal junction. Close collaboration between head and neck surgeons and endoscopists can provide good results in treating tumors of the pharyngoesophageal junction.

Salvage chemoradiotherapy for locally advanced esophageal carcinomas

'Salvage chemoradiotherapy (CRT)' was introduced in 2005 to treat thoracic esophageal carcinomas deemed unresectable based on the intraoperative findings. The therapeutic concept is as follows: the surgical plan is changed to an operation that aims to achieve curability by the subsequent definitive CRT. For this purpose, the invading tumor is resected as much as possible, and systematic lymph node dissection is performed except for in the area around the bilateral recurrent nerves. The definitive CRT should be started as soon as possible and should be performed as planned. We hypothesized that this treatment would be feasible and provide good clinical effects. We herein verified this hypothesis. Twenty-seven patients who received salvage CRT were enrolled in the study, and their clinical course, therapeutic response, and prognosis were evaluated. The patients who had poor oral intake because of esophageal stenosis were able to eat solid food soon after the operation. The radiation field could be narrowed after surgery, and this might have contributed to the high rate of finishing the definitive CRT as planned. As a result, the overall response rate was 74.1%, and 48.1% of the patients had a complete response. No patient experienced fistula formation. The 1-, 3-, and 5-year overall survival rates were 66.5%, 35.2%, and 35.2%, respectively. Salvage CRT had clinical benefits, such as the fact that patients became able to have oral intake, that fistula formation could be prevented, that the adverse events associated with the definitive CRT could be reduced, and that prognosis of the patients was satisfactory. Although the rate of recurrent nerve paralysis was relatively high even after the suspension of aggressive bilateral recurrent nerve lymph node dissection, and the rate of the progressive disease after the definitive CRT was high, salvage CRT appears to provide some advantages for the patients who would otherwise not have other treatment options following a non-curative and residual operation.

Growth inhibition of leukemic cells by (-)-epigallocatechin gallate, the main constituent of green tea

In this report, we presented the results that EGCG, the main constituent of the polyphenols present in Japanese green tea inhibited growth of leukemic cell lines of both human and mice. The proliferation of human leukemic cell lines and mouse NFS60 cell line was inhibited by EGCG. Sensitivity of each line to EGCG was different, and more than 50% of DNA synthesis was reduced in all the cell lines in the presence of 50 microM EGCG. On the other hand, normal hematopoietic progenitor cells retained their natural function of supplying mature cells of various lineages in the presence of less than 10 microM EGCG in vitro. Even in the presence of 100 microM EGCG, half the colonies containing all the lineages of cells were developed. All the dead cells of each line showed characteristics of apoptosis, which might be due to inhibition by EGCG of growth factors' signaling. Besides anticarcinogenic activity, EGCG is expected to have a new function for leukemia therapy without side effects.

Tricuspid valve endocarditis in a non-drug addict associated with peliosis hepatis

A 31-year-old woman was admitted because of persistent remittent fever. Tricuspid valve endocarditis due to Staphylococcus aureus was identified as the cause of fever. The patient had no history of intravenous drug abuse, oral contraceptives or predisposing cardiac disease. Huge hepatomegaly was found without any signs of congestive heart failure. Liver enzyme abnormalities were not detected throughout the entire course of therapy. The liver biopsy specimen revealed peliosis hepatis. Treatment with panipenem/betamipron was successful, although recurrent septic pulmonary embolism occurred. The cause of the huge hepatomegaly encountered in the present case may be attributable to peliosis due to severe infection.

Hepatitis C virus-related liver damage is related to cold activation of complement

A high positivity of cold activation of complement has been reported in Japanese patients having hepatitis B virus-negative chronic hepatitis. Although the cause of cold activation of complement is unknown, the involvement of hepatitis C virus (HCV) has been suspected. We studied the positivity of cold activation of complement in 253 patients, including 93 patients with chronic hepatitis C infection who received 6MU natural interferon-alpha per day for 24 continuous weeks. Cold activation was positive in 38% of patients with chronic hepatitis C and in 46% of patients with liver cirrhosis C. We did not detect cold activation in asymptomatic HCV carriers; patients with chronic hepatitis B, liver cirrhosis B, or alcohol-related liver damage; or in the controls. Cold activation was also negative in HCV-RNA-negative patients who responded completely to interferon-alpha, and in HCV-RNA-positive patients who responded partially whose serum alanine transaminase levels were normalized after interferon treatment. In the patients who had a relapse of hepatitis C after interferon treatment, positivity of cold activation increased sharply. We conclude that HCV-associated liver damage is related to the development of cold activation of complement. Cold activation is useful for monitoring the response to interferon in patients with chronic hepatitis C infection.

Effect of (-)-epigallocatechin gallate on leukemic blast cells from patients with acute myeloblastic leukemia

Information on the anti-carcinogenic effect of EGCG, the main constituent of the polyphenols present in Japanese green tea leaves, has recently been accumulating. In this report, we evaluate the effect of EGCG on leukemic blast cells from AML patients. The results showed that EGCG inhibited the proliferation of AML cells in all cases examined. Since AML cells might proliferate by autocrine or paracrine growth mechanisms, we also examined the effect of EGCG on the production of GM-CSF from AML cells. Although EGCG did not directly inhibit the production of GM-CSF, it did inhibit the effect of TNF-alpha or TPA, both of which stimulated AML cells to produce GM-CSF. On the other hand, the modulation of receptors for growth factors might play a role in the proliferation or carcinogenesis of AML cells. We also found that EGCG inhibited the modulation of c-kit, a receptor for stem cell factor, on leukemic cells. These findings suggested that EGCG might be available as a new therapeutic tool for AML patients.

Suppression of superoxide anion production by interleukin-10 is accompanied by a downregulation of the genes for subunit proteins of NADPH oxidase

Interleukin-10 (IL-10) inhibited the production of superoxide anion (02-) by both unactivated and interferon-gamma (IFN-gamma)-activated human monocytes. Simultaneous addition of IL-10 with IFN-gamma at the start of incubation was necessary for an optimal inhibitory effect. The degree of inhibition was substantially comparable to that of IL-4, and the combination of suboptimal concentrations of IL-10 and IL-4 produced an additive effect. A similar effect was also obtained when viral IL-10 (vIL-10) was used instead of IL-10. The inhibitory effect of IL-10 was accompanied by the reduced accumulation of transcripts for heavy chain subunit of cytochrome b558 (gp9l-phox) and 47-kD cytosolic factor (p47-phox), components of the O2--generating NADPH oxidase system. Reduction of the mRNAs was distinct within 24 hours. On the other hand, the induced O2- production by human monocytic leukemia cell lines (THP-1 and HL60) was not inhibited by IL-10. The amount of gp9l-phox and p47-phox mRNAs remained unchanged even in the presence of excess amount of IL-1O. Taken together, these results suggest that IL-10 inhibits 02- production by downregulation of the gp9l-phox and p47-phox genes in human monocytes.

High incidence of a polymorphic variant of erythrocyte membrane protein, Band 3-Memphis, on a western Japanese island

Band 3 is the major membrane protein of erythrocytes, which binds membrane skeletal proteins, glycolytic enzymes, and hemoglobin and transports various kinds of anions. Band 3-Memphis is a variant of Band 3, the amino terminal fragment of which depicts a slow electrophoretic mobility on sodium dodecyl sulfate-polyacrylamide gel. The frequency of Band 3-Memphis varies among populations, with a higher frequency among the Japanese. We investigated the frequency of Band 3-Memphis in a western Japanese island which is relatively isolated from the main islands, finding that the frequency of Band 3-Memphis of the inhabitants of this island is significantly higher than the frequency of the Japanese based on the survey in Kyushu Island. This indicates that there may be differences of population in the frequency of Band 3-Memphis in Japan and that Band 3-Memphis may be a good marker to genetically differentiate each population.

Expression of the c-kit ligand and interleukin 6 genes in mouse bone marrow stromal cell lines

The expression of c-kit ligand and interleukin 6 (IL-6) genes in mouse bone marrow-derived stromal cell lines was examined using quantitative polymerase chain reaction (PCR) analysis based on the design of an internal DNA control. The stromal cells studied included the 14F1.1 endothelial-adipocytes that support long-term hemopoiesis and two additional cell lines (MBA-1, MBA-13) which do not have this function. All the cell lines expressed c-kit ligand gene constitutively, and this expression was not increased by lectins. On the other hand, the expression of the IL-6 gene was markedly induced in all the lines by lipopolysaccharide (LPS) and by phorbol 12-myristate 13 acetate (PMA). The constitutive expression of c-kit ligand in 14F1.1 cells was the lowest among the three cell lines studied and could be increased by stimulation with IL-4. Thus, we observed some quantitative differences among the cell lines in their expression of cytokine genes. However, the unique capacity of 14F1.1 cells to support in vitro hemopoiesis cannot thus far be explained solely on the basis of the ability of these cells to secrete cytokines which are not produced by other stromal cell lines. c-kit ligand may be necessary, but its presence alone is not sufficient for 14F1.1 cells to support prolonged hemopoiesis.

IL-10 inhibits prostaglandin E2 production by lipopolysaccharide-stimulated monocytes

Since IL-10 has recently been shown to exhibit pleiotropic effects on human monocytes, it was of interest to determine the effect of this cytokine on prostaglandin E2 (PGE2) production by monocytes. Recombinant IL-10 (rIL-10) did not significantly affect PGE2 production by lipopolysaccharide (LPS)-unstimulated monocytes, but efficiently inhibited PGE2 production by LPS-stimulated monocytes. The inhibition by rIL-10 was achieved in a dose-dependent manner. Recombinant IL-4 also inhibited PGE2 production at the same degree as rIL-10. Viral IL-10 inhibited PGE2 production by monocytes in a similar fashion as did human rIL-10. Endogenously produced IL-10 was also shown to inhibit PGE2 production by LPS-stimulated monocytes. Kinetic studies showed that the inhibition by rIL-10 on PGE2 production was observed at least 3 h after LPS stimulation. Taken together, these results indicate that IL-10 may play an important role in modulating immunological responses via down-regulation of PGE2 production by monocytes.

Transfection of interferon-gamma gene in a mouse bone marrow stromal preadipocyte cell line causes apoptotic cell death

It has been reported that bone marrow and serum of patients with aplastic anemia or chronic myeloproliferative disorders contain an abnormal concentration of cytokines. In the present study, we tried to isolate mouse bone marrow stromal cell lines that were stably transformed with a variety of cytokine genes and that expressed them constitutively. From mouse bone marrow stromal cell lines MBA-1, MBA-13, and 14F1.1, we isolated clones secreting interleukin-3 (IL-3), IL-4, granulocyte-macrophage colony-stimulating factor (GM-CSF), or granulocyte (G)-CSF. Interferon-gamma (IFN-gamma)-producing stable transformants could not be established from 14F1.1 cells in spite of repeated transfection trials. At early stages of transfection, 14F1.1 cells did secrete IFN-gamma; however, exogenously added mouse IFN-gamma could not inhibit 14F1.1 cell growth. We discovered that chromosomal DNA isolated from 14F1.1 after transfection with the mouse IFN-gamma gene was fragmented. This is characteristic of cells undergoing apoptotic cell death. DNA fragmentation was also observed in 14F1.1 cells transfected with the human IFN-gamma gene. These results indicate that intracellular IFN-gamma induces apoptotic cell death of 14F1.1 stromal cells.

Long-term survival of human myeloid progenitor cells induced by a mouse bone marrow stromal cell line

Mouse endothelial-adipocyte cell line (14F1.1), which induces proliferation of mouse stem cells in culture, is also capable of supporting long-term survival in culture of human myeloid progenitor cells; colony forming unit-granulocyte/macrophage (CFU-GM) was recovered from cultures incubated with the 14F1.1 cell line after over a month of incubation. The CFU-GM population increased beyond the input number, whereas, in control cultures initiated without stromal cells, the number of progenitors gradually declined. Addition of a relatively low concentration of human colony-stimulating factors (CSFs) into the cultures promoted the formation of "cobblestone areas," where mouse stroma and human hemopoietic cells closely interacted. 14F1.1 supernatant alone did not support the survival of human CFU-GM but synergized with the function of human granulocyte-macrophage colony-stimulating factor (GM-CSF) to stimulate adherent macrophage proliferation.

Effects of interleukin 4 on stromal cell-associated bone marrow culture

We examined the effect of murine interleukin 4 (IL-4) on in vitro hemopoiesis associated with an endothelial-adipose cell line derived from a murine bone marrow stroma and termed 14F1.1. The addition of IL-4 to the co-culture led to the rapid disappearance of hemopoietic progenitors, and when greater than or equal to 20 U/ml IL-4 was added, this effect became remarkable. The stimulation of 14F1.1 cells by IL-4 before the start of co-culture accelerated the disappearance of hemopoietic progenitors, although continuous stimulation by IL-4 was needed. When IL-4 was added to the co-culture 2 weeks after initial incubation, the myeloid lineage progenitor cells disappeared within 1 week. When we examined whether the inhibitory activity on hemopoiesis was induced by 14F1.1 cells stimulated with IL-4, we found no distinct inhibitory activity in the 14F1.1-cell supernatant, but there was a slight increase in colony-stimulating activity. Colony formation of bone marrow cells seeded on top of 14F1.1 cells but separated by a thin 'empty' agar layer was enhanced by IL-4-treated 14F1.1 cells. We also noted the disappearance of the 'cobblestone' area, which had been the site of active hemopoiesis in this culture, together with the disappearance of any granulocyte-macrophage colony-forming units (CFU-GM), thereby implying that IL-4 alters the interaction between hemopoietic progenitors and stromal cells.