Securing the surgical field for mobilization of right-sided colon cancer using the duodenum-first multidirectional approach in laparoscopic surgery

Background

The aim of this study was to compare the short-term outcomes of the duodenum-first multidirectional approach (DMA) in laparoscopic right colectomy with those of the conventional medial approach to assess its safety and feasibility.

Methods

This retrospective study enrolled 120 patients who had laparoscopic surgery for right-sided colon cancer in our institution between April 2013 and December 2019. Fifty-four patients underwent colectomy using the multidirectional approach; among these, 20 underwent the DMA and 34 underwent the caudal-first multidirectional approach (CMA). Sixty-six patients underwent the conventional medial approach. Complications within 30 days of surgery were compared between the groups.

Results

There were 54 patients in the multidirectional group [29 females, median age 72 years (range 36–91 years)] and 66 in the medial group [42 females, median age 72 years (range 41–91 years)]. Total operative time was significantly shorter in multidirectional approach patients than conventional medial approach patients (208 min vs. 271 min; p = 0.01) and significantly shorter in patients who underwent the DMA compared to the CMA (201 min vs. 269 min; p < 0.001). Operative time for the mobilization procedure was also significantly shorter in patients who underwent the DMA (131 min vs. 181 min; p < 0.001). Blood loss and incidence of postoperative complications did not differ. In 77 patients with advanced T3/T4 tumors, the DMA, CMA, and conventional medial approach were performed in 13, 21, and 43 patients, respectively. Total operative time and operative time of the mobilization procedure were significantly shorter in patients undergoing DMA. Blood loss and incidence of postoperative complications did not differ. R0 resection was achieved in all patients with advanced tumors.

Conclusions

The DMA in laparoscopic right colectomy is safe and feasible and can achieve R0 resection with a shorter operative time than the conventional medial approach, even in patients with advanced tumors.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10151-021-02444-5.

Frequency shift algorithm: Application to a frequency-domain multiplexing readout of x-ray transition-edge sensor microcalorimeters

In the frequency-domain multiplexing (FDM) scheme, transition-edge sensors (TESs) are individually coupled to superconducting LC filters and AC biased at MHz frequencies through a common readout line. To make efficient use of the available readout bandwidth and to minimize the effect of non-linearities, the LC resonators are usually designed to be on a regular grid. The lithographic processes, however, pose a limit on the accuracy of the effective filter resonance frequencies. Off-resonance bias carriers could be used to suppress the impact of intermodulation distortions, which, nonetheless, would significantly affect the effective bias circuit and the detector spectral performance. In this paper, we present a frequency shift algorithm (FSA) to allow off-resonance readout of TESs, while preserving the on-resonance bias circuit and spectral performance, demonstrating its application to the FDM readout of an x-ray TES microcalorimeter array. We discuss the benefits in terms of mitigation of the impact of intermodulation distortions at the cost of increased bias voltage and the scalability of the algorithm to multi-pixel FDM readout. We show that with FSA, in the multi-pixel and frequencies shifted on-grid, the line noises due to intermodulation distortion are placed away from the sensitive region in the TES response and the x-ray performance is consistent with the single-pixel, on-resonance level.

Performance and uniformity of a kilo-pixel array of Ti/Au transition-edge sensor microcalorimeters

Uniform large transition-edge sensor (TES) arrays are fundamental for the next generation of x-ray space observatories. These arrays are required to achieve an energy resolution ΔE < 3 eV full width at half maximum (FWHM) in the soft x-ray energy range. We are currently developing x-ray microcalorimeter arrays for use in the future laboratory and space-based x-ray astrophysics experiments and ground-based spectrometers. In this contribution, we report on the development and the characterization of a uniform 32 × 32 pixel array with 140 × 30 μm² Ti/Au TESs with the Au x-ray absorber. We report on extensive measurements on 60 pixels in order to show the uniformity of our large TES array. The averaged critical temperature is T_c = 89.5 ± 0.5 mK, and the variation across the array (∼1 cm) is less than 1.5 mK. We found a large region of detector's bias points between 20% and 40% of the normal-state resistance where the energy resolution is constantly lower than 3 eV. In particular, results show a summed x-ray spectral resolution ΔE_FWHM = 2.50 ± 0.04 eV at a photon energy of 5.9 keV, measured in a single-pixel mode using a frequency domain multiplexing readout system developed at SRON/VTT at bias frequencies ranging from 1 MHz to 5 MHz. Moreover, we compare the logarithmic resistance sensitivity with respect to temperature and current (α and β, respectively) and their correlation with the detector's noise parameter M, showing a homogeneous behavior for all the measured pixels in the array.

Atrophic change of the abdominal rectus muscle significantly influences the onset of parastomal hernias beyond existing risk factors after end colostomy

PURPOSE

To investigate optimal risk factors, including atrophy of the abdominal rectus muscle (ARM) for postoperative parastomal hernia (PH) in patients who underwent end colostomy at left lower quadrant.

METHODS

This single-institution retrospective study included 91 patients who underwent end colostomy between April 2004 and December 2015. The surgical and long-term outcomes among patients with or without PH were collected and compared.

RESULTS

Altogether, 22 (24.2%) patients had a PH including 15 (68.2%) patients with a simultaneous incisional hernia. Univariate analysis showed that older patients (71 ± 11.9 vs. 64 ± 12.2 years, p = 0.03) and those with higher body mass index (BMI) (23.8 ± 3.8 vs. 20.9 ± 3.3 kg/m², p < 0.001) had a statistically significant relation with having PHs. Relative atrophy of left abdominal rectus muscle was more frequently found in patients with PH (ratio of left side/right side; caudal level and medial side: 0.66 vs. 0.92, p < 0.01, caudal level and lateral side: 0.95 vs. 1.03, p = 0.04). Multivariate analysis revealed that BMI > 25 kg/m² [odds ratio (OR) 9.05, 95% confidence interval (CI) 2.06-39.76, p = 0.003] and atrophy of the left lower medial portion of the abdominal rectus muscle (OR 12.85, 95% CI 2.49-66.39, p = 0.002) were independent risk factors for PHs. Neither the laparoscopic approach nor the extraperitoneal route of the colostomy was proven to correlate with a lower rate of PHs.

CONCLUSIONS

High BMI and atrophic change of ARM were significantly associated with PH development. Surgical techniques for prevention of atrophic change of ARM are expected to reduce the incidence of PHs.

Increased mobilization of c-kit+ Sca-1+ Lin- (KSL) cells and colony-forming units in spleen (CFU-S) following de novo formation of a stem cell niche depends on dynamic, but not stable, membranous ossification

Stem cells are thought to inhabit in a unique microenvironment, known as "niche," in which they undergo asymmetric cell divisions that results in reproducing both stem cells and progenies to maintain various tissues throughout life. The cells of osteoblastic lineage have been identified as a key participant in regulating the number of hematopoietic stem cells (HSCs). HSCs receive their regulatory messages from the microenvironment in the bone marrow. This would account for a reason why the localization of hematopoiesis is usually restricted in the bone marrow. To clarify the above possibility we employed a cell implantation-based strategy with a unique osteoblast cell line (KUSA-A1) derived from a C3H/He mouse. The implantation of KUSA-A 1 cells resulted in the generation of ectopic bones in the subcutaneous tissues of the athymic BALB/c nu/nu mice. Subsequently the mice obtained a greater amount of the bone marrow than normal mice, and they showed an increased number of HSCs. These results indicate that the newly generated osteoblasts-derived ectopic bones are responsible for the increase in the number of the HSC population. Furthermore, the increased number of HSCs directly correlates with both the magnitude of dynamic osteogenic process and the size of the newly generated bone or "niche."

Identification and characterization of a new pair of immunoglobulin-like receptors LMIR1 and 2 derived from murine bone marrow-derived mast cells

We have identified and characterized two mouse cDNAs in a mouse antigen-stimulated bone marrow-derived mast cell cDNA library, both of which encode type I transmembrane proteins. The genes were closely mapped in the distal region of mouse chromosome 11 and expressed not only in mast cells but also widely in leukocytes. The extracellular domains of their encoded proteins contain a single variable immunoglobulin (Ig) motif sharing about 90% identity with amino acids, showing that they comprise a pair of molecules and belong to the Ig superfamily. We named these molecules leukocyte mono-Ig-like receptor1 and 2 (LMIR1 and 2). The intracellular domain of LMIR1 contains several immunoreceptor tyrosine-based inhibition motifs (ITIMs). When cross-linked, the intracellular domain was tyrosine phosphorylated and capable of recruiting tyrosine phosphatases, SHP-1 and SHP-2 and inositol polyphosphate 5-phosphatase, SHIP. LMIR2, on the other hand, contains a short cytoplasmic tail and a characteristic transmembrane domain carrying two positively charged amino acids associated with three kinds of immunoreceptor tyrosine-based activation motif (ITAM)-bearing molecules, DAP10, DAP12, and FcRgamma. These findings suggest that a new pair of ITIM/ITAM-bearing receptors, LMIR1 and 2, regulate mast cell-mediated inflammatory responses through yet to be defined ligand(s).

[Retrogastric colon mimicking foramen of Winslow hernia or left paraduodenal hernia: case report]

We report the case of a 54-year-old woman who developed epigastralgia and vomit. Because of the abnormal gas in the epigastrium on abdominal X-ray, ileus due to foramen of Winslow hernia or left paraduodenal hernia was suspected. However, abdominal CT and barium study revealed the gas in the epigastrium to be the air in the transverse colon interposed between the stomach and pancreatic body. This anomalous interposition of the transverse colon is called retrogastric colon. The ileus was due to non-specific inflammatory duodenal stenosis. It is important to prevent misdiagnosis of retrogastric colon as lesser sac pathologic condition such as abscess, bowel perforation and internal hernia.

Diffusion-weighted echo planar imaging of the normal human cervical spinal cord

We obtained diffusion-weighted echo planar images of the human cervical cord in vivo and correlated them with histopathologic findings. Images were obtained in 17 healthy volunteers using a 1.5 T clinical MR unit. When motion-probing gradients were added perpendicular to the long axis of the cord, the white matter was hyperintense because of anisotropic diffusion. However, the gracile fasciculus was hypointense probably due to the small diameter of neural fibers and the large extracellular space.

[Usefulness of selective cerebral angiography by transradial approach]

Transradial angiography has recently emerged as an alternative to the transfemoral or transbrachial approach, especially for coronary procedures. However, there have been few studies on cerebral angiography using the transradial approach. The purpose of this study was to assess the outcomes, complications, and limitations of selective cerebral angiography via the transradial approach. Selective cerebral angiography by the right transradial approach using 100-cm-long 4-F catheters was performed in 83 patients. Using five types of catheters, the success rates of selective catheterization to the right vertebral artery, right common carotid artery, left common carotid artery, and left vertebral artery were 40/44 (91%), 68/68 (100%), 62/62 (100%), and 14/25 (56%), respectively. Puncture failed in one patient, and a guidewire could not be introduced beyond the radial artery loop in one patient. Radial artery spasm occurred in one patient, but was relieved immediately after nitroglycerin injection through the sheath with side holes. Subcutaneous bleeding occurred in six patients, but no obvious hematomas were noted. Occlusion or stenosis of the radial artery occurred in five patients, but no ischemic symptoms were observed in any of the cases. This study suggested that selective cerebral angiography can be performed safely using the transradial approach.

[Delineation of calf arteries using 2D-TOF MR angiography without contrast medium: efficacy of cardiac gating and leg warming]

We evaluated the image quality of non-contrast enhanced 2D-TOF MRA of the calf and the efficacy of cardiac gating and leg warming. In 10 healthy volunteers, MRA was carried out under the following four conditions: (a) usual MRA, (b) MRA with cardiac gating, (c) MRA after leg warming and (d) MRA with cardiac gating after leg warming. Although MRA with cardiac gating was not suitable, MRA after leg warming was well suited to the imaging of calf arteries. The image quality of MRA with cardiac gating after leg warming was the same as that of MRA after leg warming.

[Delineation of the white and gray matter of the normal human cervical spinal cord using diffusion-weighted echo planar imaging]

To delineate the white and gray matter of the normal human cervical spinal cord, diffusion-weighted echo planar imaging (DW-EPI) was performed in 11 healthy volunteers. Three axial (X-, Y- and Z-axis) anisotrophic diffusion-weighted images were obtained on a 1.5T superconducting clinical unit using a single-shot DW-EPI sequence. On X- and Y-axis DWIs the white and gray matter could be well differentiated: the former showed high intensity and the latter low intensity. Anterior columns were clearly visible, whereas posterior columns were not. On Z-axis DWI the white and gray matter could not be differentiated at all, because both showed low intensity. In conclusion, DW-EPI can clearly delineate the white and gray matter of the cervical spinal cord, and this technique will be useful to evaluate white matter disorders such as ischemic or demyelinating disease.

[Delineation of calf deep veins using 2D-TOF MR venography without contrast media: efficacy of tourniquet and leg-warming]

We evaluated the imaging quality of 2D-TOF MR venography of the lower part of the leg and the efficacy of a tourniquet around the knee and leg-warming. In 8 healthy volunteers, MR venography was carried out under the following four conditions: (a) usual MR venography, (b) MR venography with tourniquet around the knee, (c) MR venography after leg-warming and (d) MR venography with tourniquet after leg-warming. Our results suggested that MR venography with tourniquet after leg-warming is best suited for imaging the veins of the leg. We also compared the diagnostic image quality of MR venography and conventional contrast venography in 7 patients with varices. The results showed no significant differences between the two methods. We conclude that MR venography with tourniquet after leg-warming is a technique that provides reliable information about the veins of the leg.

[The usefulness of radiotherapy in the management of intracranial meningioma: a review of 29 patients]

Twenty-nine patients with intracranial meningiomas were treated with a high-energy linear accelerator (4-10 MV. X rays and electron beams) between 1980 and 1992 at the Hiroshima Prefectural Hiroshima Hospital. We investigated the relationships between tumor size and tumor response, histological type and tumor response, and grade of operation using Simpson's classification and recurrence rate. Meningiomas were greatly reduced between 1 month and 46 months after radiotherapy, the average being 14 months. In the group with a tumor size of less than 5 cm2, 3 patients obtained CR, 5 patients NC and 1 patient PD. Tumor response was 89% in the group with a combination of CR with NC. In the group with a tumor size of 5 to 20 cm2, 2 patients obtained PR, 1 patient NC and 1 patient PD. Tumor response was 75% in the group with a combination of PR with NC. In the group with a tumor size of more than 20 cm2, 3 patients showed NC, 3 patients PD. Tumor response was 50% in the group with NC. In the group with a tumor size of less than 20 cm2, tumor response was 85%. In the group with a tumor size of more than 20 cm2, it was 50%. Though there were no statistically significant differences between the two groups, a tumor size of less than 20 cm2 had a tendency to be more responsive than one of more than 20 cm2. The response of meningioma of the transitional type was worse than that of the meningothelial type and fibroblastic type. Fourteen patients after Simpson grade II or III operation were free of recurrence. The results of this study support the role of radiotherapy for meningioma which is less than 20 cm2, and also for treatment after Simpson grade II or III operation.

Insulinoma: correlation of short-TI inversion-recovery (STIR) imaging and histopathologic findings

We studied the value of short-TI inversion-recovery (STIR) imaging for the localization of pancreatic insulinoma. Four patients (three women and one man aged 35-65 years) with surgically proven insulinoma were included in this study. All patients were examined by MR imaging with spin echo (SE) and STIR sequences. The STIR images were compared with the histopathologic findings in each case. In two patients, the tumors were markedly hyperintense on STIR images, and a 5-mm insulinoma was depicted only by this imaging method in one of the two. In the other two patients, 10-mm insulinomas were only slightly hyperintense on STIR images. The latter tumors had a higher content of collagen fibers than the former, indicating that the amount of collagen influences the signal intensity of insulinoma. Despite some limitations, STIR imaging is a useful noninvasive method for the localization of pancreatic insulinoma.

CT of thrombosed renal vein presenting as a hyperdense mass

We report a patient with focal renal vein thrombosis that presented as a hyperdense mass mimicking a hyperdense cyst or a pelvic or parenchymal tumor. The lesion was described as a well-defined round hyperdense mass in the right renal sinus on noncontrast CT and was surgically proven to be acute thrombosis of the renal vein. Renal vein thrombosis should be considered in the differential diagnosis of a hyperdense mass in the renal sinus even if the patient has no underlying renal abnormality.

Lymphokine requirement for the generation of natural killer cells from CD34+ hematopoietic progenitor cells

We have established a cell culture system without stromal cells that allows the CD34+ hematopoietic progenitor cells (HPC) to differentiate into natural killer (NK) cells. CD34+Lin (CD3, CD16, CD56)- cells were purified using fluorescence-activated cell sorting from normal adult bone marrow (BM) and cultured for 28 days in medium supplemented with interleukin-2 (IL-2) and stem cell factor (SCF). NK (CD3-CD16-CD56+) cells were generated in a dose-dependent manner in response to SCF. NK cells originated from CD34+CD33+Lin- cells, but they were barely detectable in cultures of CD34+CD33-Lin- cells. However, on addition of IL-3, an induced differentiation of NK cells from CD34+CD33-Lin- cells was observed, although at a lower frequency. Supplementing of the cell cultures with SCF alone or both SCF and IL-3 for the first 7 days followed by IL-2 for the next 21 days is essential for production of NK cells from CD34+CD33+Lin- cells and from CD34+CD33-Lin- cells, respectively. These data provide direct evidence that NK cells arise from CD34+HPC and show the minimum lymphokine requirement for their differentiation.

Atypical appearance of adrenal pseudocysts

We report 2 cases of adrenal pseudocysts that resulted from hemorrhage into a normal adrenal gland and that showed atypical imaging features on computerized tomography and ultrasonography. The presence of a solid component within the mass and/or central calcification, which is unlike the typical features of adrenal pseudocyst, suggested a diagnosis of adrenal tumor. The solid component diminished on computerized tomography in 26 days in case 1 and in 16 days in case 2, which seemed to represent resolving hematoma. The atypical appearance of these adrenal pseudocysts, especially the changeable pattern of the solid component within the mass, should be kept in mind to ensure a correct preoperative diagnosis.

Human primitive hematopoietic progenitor cells are more enriched in KITlow cells than in KIThigh cells

To clarify the phenotypes of various classes of human hematopoietic progenitor cells, we used a multicolor staining protocol in conjunction with CD34 and a newly developed mouse antihuman c-kit proto-oncogene product (KIT) monoclonal antibody (MoAb). We characterized three cell fractions in CD34+ cells that express KITlow and KIThigh cells in addition to KIT- cells. A clonogenic assay showed that most granulocyte-macrophage colony-forming cells (GM-CFC) were present in CD34+KIThigh populations, whereas erythroid burst-forming cells (BFU-E) were detected mainly in the CD34+KITlow population. CD34(+)-KIT- fraction contained a small number of BFU-E. Morphologic analysis showed that blast-like cells were more enriched in the CD34+KITlow fraction. KITlow cells contained CD34+CD38- cells that were considered to be very primitive progenitor cells, as determined by a replating assay. To clarify the biologic differences between both fractions, we examined the more primitive progenitor cell functions by assessing long-term culture-initiating cells (LTC-IC) on the stromal cells. At week 2, more CFC recovered from the culture in the fraction initiated with a CD34+KIThigh population. However, more LTC-IC were present during weeks 5 to 9 in the CD34+KITlow population. These results indicate that primitive progenitors are more enriched in the KITlow population and that the KIThigh population contains many GM-committed progenitor cells. We also showed that anti-KIT MoAb inhibited the ability of CD34+ cells to generate CFC on the stromal layer in the LTC system. This suppressive effect was more evident in the generation of BFU-E by CD34+KITlow cells. Moreover, we confirmed that CD34+KIThigh cells emerged from CD34+KITlow cells during coculture with allogeneic stromal cells or from liquid culture in the presence of stem cell factor (SCF), interleukin-6, and erythropoietin. These results emphasize the pivotal role of the KIT and SCF interaction in hematopoiesis and indicate that KITlow cells are more primitive than KIThigh cells.

Expression of c-kit mRNA and protein during the differentiation of human hematopoietic progenitor cells

To investigate how c-kit and c-kit ligand play a role in the function of hematopoietic stem cells, we determined the expression of c-kit in sorted human hematopoietic stem cells, CD34+CD33- cells and CD34+CD33+ cells. CD34+ cells constituted approximately 1% of the population of gated bone marrow cells and contained colony-forming cells. Two-color analysis by a fluorescence-activated cell sorter (FACS) revealed that about one-third to one-half of the total CD34+ cell population were positive for the CD33 antigen. To analyze the relative accumulation of c-kit mRNA in sorted cells, we used the reverse transcription-polymerase chain reaction (RT-PCR) method, followed by Southern blot analysis. There was a linear relationship between the amount of input RNA and products amplified in the range of 10(3) to 10(5) cells. Using this procedure, we carried out an analysis of c-kit mRNA expression in CD34+CD33-, CD34+CD33+, CD34-CD33+, and CD34-CD33- cells. Enhanced expression for c-kit mRNA was observed solely in CD34+CD33- cells. In contrast, flow cytometry shows that c-kit protein was expressed most abundantly in CD34+CD33+ cells. Colony-forming cells were generated on a human stromal cell layer for 5 weeks initiated with CD34+CD33- cells but not with CD34+CD33+ cells. During co-culture with stromal cells, CD34+CD33- cells differentiated into CD34+CD33+ cells. From these findings, it is concluded that CD34+CD33+ cells are direct progenies of CD34+CD33- cells. In this differentiation pathway, the expression of c-kit mRNA decreased and the c-kit protein increased.

[CT findings of invaginated mesentery in adult intussusception]

The CT findings of invaginated mesentery in adult intussusception were analyzed in 12 patients (three patients with four small bowel intussusceptions and nine patients with nine large bowel intussusceptions). In all small bowel intussusceptions, the neck was located near the superior mesenteric artery and vein (SMA & SMV) and showed a medial opening, and the vessels in the neck showed a continuity to the left side of SMA & SMV. In most of the large bowel intussusceptions, the neck was located distant from SMA & SMV, and the vessels in the neck did not show continuity to SMA & SMV. The difference in CT findings between small and large bowel intussusception is attributed to the difference in mesenteric anatomy; the small bowel and its mesentery move freely in the peritoneal cavity, whereas the large bowel is partially fixed to the retroperitoneum.

CD4dull+ hematopoietic progenitor cells in murine bone marrow

CD4+ cells comprise approximately 3% to 6% of murine bone marrow (BM) cells. The majority are CD4dull+, but there are two distinct sub populations: CD4 brightly positive Gr-1- cells (CD4hiGr-1-) and CD4+ Gr-1+ cells (CD4loGr-1lo). CD4hiGr-1- cells are considered to be mature T cells by cell surface antigen expression and morphology. CD4loGr-1lo cells, which comprise approximately 0.6% of the BM cells, express small amount of B220 and Thy1 antigens. Interestingly, colony-forming units (CFU)-spleen and CFU-C are not enriched in this population. However, when injected into lethally irradiated mice, CD4loGr-1lo cells were shown to differentiate into T-cell, B-cell, and myelo-monocyte lineages when assayed 26 weeks after transplantation. Furthermore, donor-derived CD4loGr-1lo cells were present in the recipients' BM at least 16 weeks after transplantation. These observations suggest that murine CD4loGr-1lo cells in BM have self-renewal capability and retain the ability to differentiate into at least three lineages in long-term hematopoiesis.

[CT and MR imaging anatomy of the fascia in the pelvic extraperitoneal space]

CT and MRI anatomy of the fascia in the pelvic extraperitoneal space has not been established. CT and some MR imagings of nine patients who received irradiation to the pelvis and of eleven patients who received transarterial infusion for urinary bladder carcinoma were studied about the anterior and posterior attachment sites of the coccygeus muscle, the sacrouterine ligament and the lateral ligament. Observing the course of the inferior gluteal artery, the author set up three axial levels; (a), (b) and (c) levels, where the artery passes in front of the piriformis muscle, just gets over the coccygeus muscle and over the sacrospinous ligament, respectively. At (b) and (c) levels, the posterior attachment site of the sacrouterine ligament was the coccygeus muscle and the posterior attachment site of the lateral ligament was the sacrouterine ligament. By these ligaments, the pelvic extraperitoneal space was divided into three compartments; the prevesical, the perivesical and the perirectal spaces. The prevesical space was limited by the coccygeus muscle and the sacrouterine ligament posteriorly, the perivesical space was limited by the sacrouterine ligament and the lateral ligament posteriorly, and the perirectal space was surrounded by the sacrouterine ligament and the coccygeus muscle. On the coronal image through the level slightly posterior to the anus, the sacrouterine ligament attached to the levator ani muscle at a lateral third like a screen. On the basis of these results, new axial and coronal models of the pelvis extraperitoneal space are presented, which are useful for understanding the location and spread of the lesion.

Enrichment of interleukin-2-responsive natural killer progenitors in human bone marrow

Natural killer (NK) cells can be cultured in interleukin-2 (IL-2)-containing medium from selected human bone marrow (BM) cells obtained after the elimination of mature T and NK cells. To isolate and characterize IL-2-responsive NK progenitors in the selected BM cells, we investigated the expression of IL-2 receptors (IL-2R) on these cells. Neither CD25 (IL-2R alpha) nor IL-2R beta antigen was observed on the selected BM cells before culture. However, CD25+ cells without detectable levels of IL-2R beta antigen appeared 24 hours after culture in IL-2-containing medium. Cells were sorted from each fraction of the selected BM cells 24 hours after culture after staining with anti-CD33, anti-CD34, and anti-CD25 monoclonal antibodies. The generation of NK cells (CD3- CD56+ cells) and NK activity were observed only from the CD33-/CD34-/CD25+ cell fraction after culture in IL-2-containing medium. The frequency of IL-2-responsive NK progenitors relative to the fraction was 1/231 (95% confidence range, 1/156 to 1/289), which corresponded to the frequency relative to the total number of selected BM cells when the frequency relative to the CD33-/CD34-/CD25+ cell-fraction was converted according to the percentage of these cells in the total number of selected BM cells. These results indicated that IL-2-responsive NK progenitors were enriched in the CD33-/CD34-/CD25+ cell fraction.

Sequential analysis of hematopoietic reconstitution achieved by transplantation of hematopoietic stem cells

We confirmed that murine hematopoietic stem cells express the c-kit molecule but not lymphohematopoietic lineage markers. These lineage marker-negative c-kit-positive (Lin- c-kit+) cells were further divided according to the uptake of rhodamine-123 (Rh-123). Approximately 1,000 Lin- c-kit+ rhodamine-123dull cells, which contained 4.0 +/- 1.3 and 12.5 +/- 1.9 day 8 and day 12 spleen colony-forming units (CFU-S), respectively, rescued the 100% of lethally irradiated mice. One third of these cells formed colonies in the presence of interleukin-3 plus erythropoietin. The time course of the hematopoietic reconstitution of this primitive hematopoietic stem cell fraction was investigated by using Ly-5 congenic mice. Although myeloid cells and B lymphocytes were detected in the peripheral blood 2 to 3 weeks after transplantation, T lymphocytes were not detected until 4 weeks after transplantation. It is generally assumed that myeloid cells and B lymphocytes grow in the bone marrow and that T lymphocytes must pass through the thymus. For the first 2 to 3 weeks after transplantation, donor-type T lymphocytes were not dominant in the thymus, and most donor type cells were CD4/CD8 double-negative or double-positive (including CD4low and CD8low). Four weeks after transplantation, donor-type T lymphocytes were dominant and the ratio of CD4/CD8 cells had recovered to the normal pattern. However, significant numbers of T lymphocytes were detected in the peripheral blood at this stage. Sequential analysis of hematopoietic reconstitution from primitive stem cells demonstrates that myeloid and B-lymphoid lineages occurred earlier than that of the T-lymphoid lineages.

In vivo and in vitro stem cell function of c-kit- and Sca-1-positive murine hematopoietic cells

c-kit is expressed on hematopoietic stem cells and progenitor cells, but not on lymphohematopoietic differentiated cells. Lineage marker-negative, c-kit-positive (Lin-c-kit+) bone marrow cells were fractionated by means of Ly6A/E or Sca-1 expression. Lin-c-kit+Sca-1+ cells, which consisted of 0.08% of bone marrow nucleated cells, did not contain day-8 colony-forming units-spleen (CFU-S), but 80% were day-12 CFU-S. One hundred cells rescued the lethally irradiated mice and reconstituted hematopoiesis. On the other hand, 2 x 10(3) of Lin-c-kit+Sca-1- cells formed 20 day-8 and 11 day-12 spleen colonies, but they could not rescue the lethally irradiated mice. These data indicate that Lin-c-kit+Sca-1+ cells are primitive hematopoietic stem cells and that Sca-1-cells do not contain stem cells that reconstitute hematopoiesis. Lin-c-kit+Sca-1+ cells formed no colonies in the presence of stem cell factor (SCF) or interleukin-6 (IL-6), and only 10% of them formed colonies in the presence of IL-3. However, approximately 50% of them formed large colonies in the presence of IL-3, IL-6, and SCF. Moreover, when single cells were deposited into culture medium by fluorescence-activated cell sorter clone sorting system, 40% of them proliferated on a stromal cell line (PA-6) and proliferated for more than 2 weeks. In contrast, 15% of the Lin-c-kit+Sca-1-cells formed colonies in the presence of IL-3, but no synergistic effects were observed in combination with SCF plus IL-6 and/or IL-3. Approximately 10% proliferated on PA-6, but most of them degenerated within 2 weeks. The population ratio of c-kit+Sca-1+ to c-kit+Sca-1- increased 2 and 4 days after exposure to 5-fluorouracil (5-FU). These results are consistent with the relative enrichment of highly proliferative colony-forming cells by 5-FU. These data show that, although c-kit is found both on the primitive hematopoietic stem cells and progenitors, Sca-1+ cells are more primitive and respond better than Sca-1- cells to a combination of hematopoietic factors, including SCF and stromal cells.

Expression and function of adhesion molecules on human hematopoietic stem cells: CD34+ LFA-1- cells are more primitive than CD34+ LFA-1+ cells

Advances in fluorescence-activated cell sorter technology have brought about multicolor analysis of cell phenotypes. To clarify the phenotypes of human hematopoietic stem cells (HSCs), we initially prepared novel antibodies against CD34 and labeled one of them (4A1) with allophycocyanin (APC). With this, we analyzed the phenotypes of CD34+ HSCs and showed that primitive HSCs or CD34+CD33- cells expressed adhesion molecules such as CD43, CD44, CD11a, CD11c, CD18, and leukocyte adhesion molecule (LAM-1). The more primitive hematopoietic cells or CD34+CD38- cells also expressed CD11a and CD18 with an incidence of 20% to 30%. To clarify the role of adhesion molecules in HSCs, we examined the colony forming capacity after long-term culture with allogeneic irradiated stromal layers. Among CD34+CD33- cells, CD18+ cells gave rise to colony-forming cells (CFCs) on stromal layers, but reached a maximum at week 2, after which the number of generated CFCs decreased. On the other hand, CD18- cells generated less CFCs than CD18+ cells at 2 to 3 weeks, but increased after 4 weeks of culture. When CD18 or CD11a antibody was added to a coculture system of CD34+CD33- cells with stromal layers, the number of generated CFCs decreased significantly compared with the no antibody control. Leukocyte function-associated antigen-1 (LFA-1) (CD11a/CD18) was expressed on some populations of hematopoietic cells and contributed to the proliferation by interacting with stromal cells. However, more primitive cells capable of reconstituting hematopoiesis did not express LFA-1. These data provide a rationale for the administration of anti-LFA-1 antibody after bone marrow transplantation for reducing the graft failure.

Synergistic effect of IL-3 and IL-6 on highly enriched murine hemopoietic progenitors

It has been reported that interleukin 6 (IL-6) acts on hemopoietic stem cells in synergism with interleukin 3 (IL-3), but it has not yet been clarified whether IL-6 acts directly on the stem cells or not. To investigate the mechanism of the synergism between IL-3 and IL-6, we sorted hemopoietic stem cells from untreated murine bone marrow cells using a two-laser fluorescence-activated cell sorter (FACS). Cells negative for the lymphohemopoietic lineage (lineage-negative, Lin-), with a high affinity to wheat germ agglutinin (WGA+), and showing a low expression of Thy-1 antigen (Thy-1low) were sorted and analyzed by in vitro and in vivo colony formation. This fraction was 0.4% of the total mononuclear bone marrow cells. Approximately 25% of these Lin-WGA+Thy-1low cells showed in vitro colony formation, whereas approximately 1% of them formed day-8 and day-12 spleen colonies. Thus, it appears that the Lin-WGA+Thy-1low cells were a highly enriched stem cell population. By FACS clone sorting, single cells were isolated from the enriched stem cell fraction and cultured in semisolid or liquid culture systems. Addition of IL-6 to methylcellulose medium containing IL-3 did not significantly increase the number of colonies. It is thus suggested that the target cells of IL-3 and IL-6 are the same as those of IL-3. The secondary colony-forming ability of primary colonies that developed in the presence of IL-6 and IL-3 was higher than that of colonies formed in the presence of IL-3 alone. In correspondence with this finding, the numbers of myeloid colonies and spleen colony-forming units (CFU-S) were increased by the incubation of these sorted cells for 7 days with IL-6 and IL-3 when compared with the effect of IL-3 alone. Therefore, it is concluded that IL-6 acts directly on hemopoietic stem cells to enhance their proliferation.

[Reevaluation of US and CT findings in adult intussusception]

Computed tomographic (CT) and ultrasonographic (US) findings of 10 adult patients with 11 intussusceptions were retrospectively analyzed. Through close scrutiny of wall structures of intussusceptums and mesenteric fat, new features of adult intussusceptions were found: 1. The returning walls were thicker than the entering walls in 10 of 11 intussusceptums. 2. The neck of the returning wall was thicker than its head in eight of nine intussusceptums. 3. Longitudinal compression of the wall and venous congestion resulting from an inside out turning of the wall structure were thought to be the cause of thickening of the returning wall. 4. Invaginated mesenteric fat tended to be located at the head (apex) in two of seven intussusceptions, making differentiation from intussusception caused by lipoma difficult. 5. The leading masses were detectable as apical soft tissue density masses in eight of 10 intussusceptions. These findings contradict those of previous reports on adult intussusceptions.

Enrichment and characterization of murine hematopoietic stem cells that express c-kit molecule

The proto-oncogene c-kit encodes a transmembrane tyrosine kinase receptor for stem cell factor (SCF). The c-kit/SCF signal is expected to have an important role in hematopoiesis. A monoclonal antibody (ACK-2) against the murine c-kit molecule was prepared. Flow cytometric analysis showed that the bone marrow cells that expressed the c-kit molecule (approximately 5%) were B220(B)-, TER119(erythroid)-, Thy1negative-low, and WGA+. A small number of Mac-1(macrophage)+ or Gr-1(granulocyte)+ cells were c-kit-low positive. Colony-forming unit in culture (CFU-C) and day-8 and day-12 CFU-spleen (CFU-S) existed exclusively in the c-kit-positive fraction. About 20% of the Lin(lineage)-c-kit+ cells were rhodamine-123low and this fraction contained more day-12 CFU-S than day-8 CFU-S. On the basis of these findings, murine hematopoietic stem cells were enriched with normal bone marrow cells. One of two and one of four Thy-1lowLin-WGA+c-kit+ cells were CFU-C and CFU-S, respectively. Long-term repopulating ability was investigated using B6/Ly5 congenic mice. Eight and 25 weeks after transplantation of Lin-c-kit+ cells, donor-derived cells were found in the bone marrow, spleen, thymus, and peripheral blood. In peripheral blood, T cells, B cells, and granulocyte-macrophages were derived from donor cells. Injection of ACK-2 into the irradiated mice after bone marrow transplantation decreased the numbers of day-8 and day-12 CFU-S in a dose-dependent manner. Day-8 spleen colony formation was completely suppressed by the injection of 100 micrograms ACK-2, but a small number of day-12 colonies were spared. Our data show that the c-kit molecule is expressed in primitive stem cells and plays an essential role in the early stages of hematopoiesis.

In vivo stem cell function of interleukin-3-induced blast cells

The treatment of mice with high doses of 5-fluorouracil (5-FU) results in an enrichment of primitive hematopoietic progenitors. Using this procedure, we obtained a new class of murine hematopoietic colonies that had very high secondary plating efficiencies in vitro and could differentiate into not only myeloid cells but also into lymphoid lineage cells. The phenotypes of interleukin-3 (IL-3) induced blast colony cells were Thy-1-positive and lineage-marker-negative. We examined whether these blast colony cells contained primitive hematopoietic stem cells in vivo and could reconstitute hematopoietic tissues in lethally irradiated mice. Blast colony cells could generate macroscopic visible spleen colonies on days 8 and 12, and 5 x 10(3) blast cells were sufficient to protect them from lethally irradiation. It was shown that 6 or 8 weeks after transplantation of 5 x 10(3) blast cells, donor male cells were detected in the spleen and thymus of the female recipients but not in the bone marrow by Southern blot analysis using Y-encoded DNA probe. After 10 weeks, bone marrow cells were partially repopulated from donor cells. In a congenic mouse system, donor-derived cells (Ly5.2) were detected in the thymus and spleen 6 weeks after transplantation. Fluorescence-activated cell sorter analyses showed that B cells and macrophages developed from donor cells in the spleen. In the thymus, donor-derived cells were found in CD4, CD8 double-positive, single-positive, and double-negative populations. Reconstitution of bone marrow was delayed and myeloid and lymphoid cells were detected 10 weeks after transplantation. These results indicate that IL-3-induced blast cells contain the primitive hematopoietic stem cells capable of reconstituting hematopoietic organs in lethally irradiated mice.

[Radiologic manifestations of peritoneal mesothelioma]

We report four cases of histologically proved peritoneal mesothelioma and describe the radiographic (mainly CT and angiographic) findings. There were three malignant diffuse tumors and one benign localized tumor. In one case, the lesion extended to the omentum and entrapped the fat tissue, and differentiation from peritonitis carcinomatosa was difficult. In the other three cases, reflecting necrotic change within the tumor, CT showed hypodensity throughout most of the mass. In two cases with hemorrhage, CT showed hyperdensity in the center of the mass. Angiography showed slight or medium neovascularity in the periphery of the tumor, but most of the tumor was avascular. Angiography was helpful for topographic diagnosis, but it was difficult to make a specific diagnosis or differentiate between malignant and benign types. We emphasize that it is important to consider peritoneal mesothelioma in the differential diagnosis when a mass of unknown origin is found in the abdomen, particularly when it is accompanied by necrosis and hemorrhage.

Effects of interleukin 3, interleukin 6, and granulocyte colony-stimulating factor on sorted murine splenic progenitor cells

In order to examine the effect of recombinant growth factors on hemopoietic stem cells, these cells were enriched using wheat germ agglutinin (WGA) and monoclonal antibodies for lineage markers (Lin) such as B220, L3T4, Lyt-2, asialo GM1, Mac-1, and AL-21. Spleen colony-forming units (CFU-S) and in vitro colony-forming units were highly enriched in the fraction of WGA+Lin- spleen cells. To eliminate committed progenitor cells, spleen cells of 5-fluorouracil (5-FU)-treated mice were used. By this treatment, day-8 CFU-S disappeared but day-14 CFU-S were preserved. Day-14 CFU-S were also contained in the fraction of WGA+Lin- cells, which made up about 0.5% of total nucleated spleen cells. Moreover, this fraction contained primitive stem cells that could reconstitute the hemopoiesis of irradiated mice. Sorted WGA+Lin- spleen cells obtained from male 5-FU-treated mice were injected into lethally irradiated female mice. Southern hybridization using a mouse Y chromosome-specific probe showed that the bone marrow, spleen, and thymus of the recipients was reconstituted by male mouse-derived cells. When sorted WGA+Lin- spleen cells of the 5-FU-treated mice were cultured in vitro in the presence of recombinant interleukin 3 (IL-3), interleukin 6 (IL-6), and granulocyte colony-stimulating factor (G-CSF), colony formation was observed only in wells with IL-3, whereas unfractionated spleen cells formed colonies in the presence of IL-3, IL-6, or G-CSF. However, IL-6 but not G-CSF acted synergistically on enriched hemopoietic stem cells in the presence of IL-3. These data suggest that G-CSF or IL-6 did not affect primitive stem cells independently but showed the effect on these cells indirectly or synergistically with IL-3.

Target cells for granulocyte colony-stimulating factor, interleukin-3, and interleukin-5 in differentiation pathways of neutrophils and eosinophils

To study the relationship between hematopoietic factors and their responsive hematopoietic progenitors in the differentiation process, both purified factors and enriched progenitors are required. We isolated total CD34+ cells, CD34+,CD33+ cells, and CD34+,CD33- cells individually from normal human bone marrow cells by fluorescence-activated cell sorter (FACS), and examined the effects of granulocyte colony-stimulating factor (G-CSF), interleukin-3 (IL-3), and IL-5 on in vitro colony formation of these cells. CD34+,CD33+ cells formed granulocyte colonies in the presence of G-CSF. Both CD34+,CD33+ cells and CD34+,CD33- cells formed granulocyte/macrophage colonies in the presence of IL-3. Eosinophil (Eo) colonies were only formed by CD34+,CD33- cells in response to IL-3, but scarcely formed by CD34+ cells in the presence of IL-5. We performed the two-step cultures consisting of the primary liquid culture for 6 days and the secondary methylcellulose culture, and serially examined changes in phenotypes of ,he cells cultured in the primary culture. CD34-,CD33+ cells derived from CD34+,CD33+ cells by preincubation with G-CSF or IL-3 formed Eo colonies in the presence of IL-5 but not IL-3. CD34-,CD33+ cells derived from CD34+,CD33- cells by preincubation with IL-3 also formed Eo colonies by support of IL-5 as well as IL-3. Both CD34+ cells gradually lost the CD34 antigen by day 6 of incubation with G-CSF or IL-3. Loss of this antigen was well-correlated with acquisition of susceptibility to IL-5. It was concluded that G-CSF supported the neutrophil differentiation of committed colony-forming cells, IL-3 supported that of both committed and multipotent colony-forming cells. G-CSF and IL-3 also supported the early stage of E. differentiation; IL-5 supported the late stage of that.

[Radiologic diagnosis of pleural mesothelioma]

Five cases of pleural mesothelioma (3 benign and 2 malignant) were evaluated with chest radiograph and CT. A case of benign localized mesothelioma growing within the major fissure, and a case of diffuse malignant mesothelioma encircling the descending thoracic aorta are included among the five cases. Pleural mesotheliomas present a variety of roentgenographic manifestations depending upon the histologic type, the site of origin, and the direction of the extension, and can easily be misdiagnosed as lung tumor, aortic aneurysm, or mediastinal tumor. It is emphasized that pleural mesothelioma should be considered as a differential diagnosis when a mass lesion is found in the mediastinum, hilar region, interlobar fissure, or near the chest wall.