[Ophthalmic surgical robot-assisted retinal puncture and injection for submacular hemorrhage caused by polypoid choroidal vasculopathy: a case report]

A 65-year-old man presented with decreased visual acuity in the left eye for 1 month. The diagnosis of hemorrhagic retinal detachment (submacular hemorrhage), which was caused by idiopathic polypoid choroidal vasculopathy, was confirmed by the ultra-wide-angle fundus examination, optical coherence tomography, and B-ultrasound. A vitrectomy combined with an ophthalmic surgical robot-assisted retinal puncture and injection was performed. The recombinant tissue plasminogen activator was injected accurately by the ophthalmic surgical robot between the retinal nerve epithelium and retinal pigment epithelium through a micro-injection needle. During the 2-month follow-up, the subretinal hemorrhage was significantly regressive, the visual acuity of the left eye was improved from hand movement to 0.1, and no other complications were observed.

[Characteristics of primary ocular symptoms in children with optic pathway glioma at different ages]

Objective: To investigate the characteristics of initial ocular symptoms in children with optic pathway glioma (OPG) at different age stages. Methods: A retrospective case series study was conducted. Clinical data of 16 children with OPG who were diagnosed and treated in the Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University from April 2017 to July 2021 were collected. The initial ocular symptoms, clinical manifestations of the eyes and nervous system, imaging and histopathological features were analyzed, and the differences in initial ocular symptoms between infants and young children aged≤36 months and older children aged>36 months were compared. Results: Of all 16 children included, 9 were male and 7 were female. The onset age was 15.0 (6.3, 56.5) months, and the diagnosis age was 48.0 (11.3, 78.0) months. There were 11 infants and young children, and 5 older children. Eye symptoms were the initial manifestation in 11 cases, including 8 cases of infants and young children (5 cases presented with irregular nystagmus, 2 cases with strabismus, and 1 case with failure to chase visual target), and 3 cases of older children (2 cases presented with decreased vision and 1 case with optic disc edema). The imaging findings showed that optic chiasm-involved OPG accounted for the highest proportion, with 3 cases in older children and 8 cases in infants and young children. Among the 8 children with optic chiasm-involved OPG who underwent surgical treatment, 5 were diagnosed with pilocytic astrocytoma according to histopathological results. Seven children had useful vision saved after treatment, and 1 child had visual loss accompanied by cognitive impairment due to surgery after 4 years of nystagmus. Conclusion: OPG in children often manifests as initial ocular symptoms, with irregular nystagmus being more common in infants and young children, and vision loss being the main symptom in older children.

[Effect of intestinal obstruction stent combined with neoadjuvant chemotherapy on the pathological characteristics of surgical specimens in patients with complete obstructive colorectal cancer]

Objective: To compare the effects of three treatment options: emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery, on the pathological characteris- tics of surgically-resected specimens from patients with completely obstructive colorectal cancer. Methods: This was a retrospective cohort study analyzing clinicopathological data of patients with complete obstructive colorectal cancer who were admitted to the General Surgery Department of Beijing Chaoyang Hospital, Capital Medical University, between May 2012 and August 2020. The inclusion criteria were diagnosed with complete colorectal obstruction, pathologically confirmed as adenocarcinoma, resectable on imaging assessment, and without distant metastasis, combined with the patients' clinical manifestations and imaging examination findings. Patients with multiple colorectal cancers, refusal to undergo surgery, and concurrent peritonitis or intestinal perforation before stenting of the intestinal obstruction were excluded. Eighty-nine patients with completely obstructive colorectal cancer were enrolled in the study and were divided into emergency surgery group (n=30), stent-surgery group (n=34), and stent-neoadjuvant chemotherapy- surgery group (n=25) according to the treatment strategy. Differences in the pathological features (namely perineural infiltration, lymphovascular infiltration, tumor deposits, specimen intravascular necrosis, inflammatory infiltration, abscesses, mucus lake formation, foreign body giant cells, calcification, and tumor cell ratio) and biomolecular markers (namely cluster of differentiation (CD)34, Ki67, Bcl-2, matrix metalloproteinase-9, and hypoxia-inducible factor alpha) were recorded. Pathological evaluation was based on the presence or absence of qualitative evaluation of pathological features, such as peripheral nerve infiltration, vascular infiltration, and cancer nodules within the specimens. The evaluation criteria for the pathological features of the specimens were as follows: Semi-quantitative graded evaluation based on the proportion of tissue necrosis, inflammatory infiltrates, abscesses, mucus lake formation, foreign body giant cells, calcification, and tumor cells in the field of view within the specimen were classified as: grade 0: not seen within the specimen; grade 1: 0-25%; grade 2: 25%-50%; grade 3: 50%-75%; and grade 4: 75%-100%. The intensity of cellular immunity was classified as none (0 points), weak (1 point), moderate (2 points), and strong (3 points). The two evaluation scores were then multiplied to obtain a total score of 0-12. The immunohistochemical results were also evaluated comprehensively, and the results were defined as: negative (grade 0): 0 points; weakly positive (grade 1): 1-3 points; moderately positive (grade 2): 4-6 points; strongly positive (grade 3): 7-9 points; and very strong positive (grade 4): 10-12 points. Normally-distributed values were expressed as mean±standard deviation, and one-way analysis of variance was used to analyze the differences between the groups. Non-normally-distributed values were expressed as median (interquartile range: Q1, Q3). A nonparametric test (Kruskal-Wallis H test) was used for comparisons between groups. Results: The differences were not statistically significant when comparing the baseline data for age, gender, tumor site, American Society of Anesthesiologists score, tumor T-stage, N-stage, and degree of differentiation among the three groups (all P>0.05). The differences were not statistically significant when comparing the pathological characteristics of the resected tumor specimens, such as foreign body giant cells, inflammatory infiltration, and mucus lake formation among the three groups (all P>0.05). The rates of vascular infiltration were 56.6% (17/30), 41.2% (15/34), and 20.0% (5/25) in the emergency surgery, stent-surgery, and stent- neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences between the groups (χ²=7.142, P=0.028). Additionally, the rate of vascular infiltration was significantly lower in the stent-neoadjuvant chemotherapy-surgery group than that in the emergency surgery group (P=0.038). Peripheral nerve infiltration rates were 55.3% (16/30), 41.2% (14/34), and 16.0% (4/25), in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (χ²=7.735, P=0.021). The infiltration peripheral nerve rates in the stent-neoadjuvant chemotherapy-surgery group were significantly lower than those in the emergency surgery group (P=0.032). The necrosis grade was 2 (1, 2), 2 (1, 3), and 2 (2, 3) in the emergency surgery, stent- surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=10.090, P=0.006). Post hoc comparison revealed that the necrosis grade was higher in the stent-surgery and stent-neoadjuvant chemotherapy-surgery groups compared with the emergency surgery group (both P<0.05). The abscess grade was 2 (1, 2), 3 (1, 3), and 2 (2, 3) in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=6.584, P=0.037). Post hoc comparison revealed that the abscess grade in the emergency surgery group was significantly lower than that in the stent-surgery group (P=0.037). The fibrosis grade was 2 (1, 3), 3 (2, 3), and 3 (2, 3), in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=11.078, P=0.004). Post hoc analysis revealed that the fibrosis degree was higher in both the stent-surgery group and the stent- neoadjuvant chemotherapy-surgery group compared with the emergency surgery group (both, P<0.05). The tumor cell ratio grades were 4 (3, 4), 4 (3, 4), and 3 (2, 4), in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, with statistically significant differences (H=8.594, P=0.014). Post hoc analysis showed that the tumor cell ratio in the stent-neoadjuvant chemotherapy-surgery group was significantly lower than that in the emergency surgery group (P=0.012). The CD34 grades were 2 (2, 3), 3 (2, 4), and 3 (2, 3) in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups, respectively, and the difference was statistically significant (H=9.786, P=0.007). Post hoc analysis showed that the CD34 grades in the emergency surgery, stent-surgery, and stent-neoadjuvant chemotherapy-surgery groups were 2 (2, 3), 3 (2, 4), and 3 (2,3), respectively. Post hoc analysis revealed that the CD34 concentration was higher in the stent-surgery group than that in the emergency surgery group (P=0.005). Conclusion: Stenting may increase the risk of distant metastases in obstructive colorectal cancer. The stent-neoadjuvant chemotherapy-surgery treatment model promotes tumor cell necrosis and fibrosis and reduces the proportion of tumor cells, vascular infiltration, and peripheral nerve infiltration, which may help decrease local tumor infiltration and distant metastasis in completely obstructive colorectal cancer after stent placement.

[Functional outcomes of 100 patients with adenocarcinoma of the esophagogastric junction undergoing Cheng's GIRAFFE(®) reconstruction after proximal gastrectomy]

Objective: To investigate the functional outcomes and postoperative complications of Cheng's GIRAFFE reconstruction after proximal gastrectomy. Methods: A descriptive case series study was conducted. Clinical data of 100 patients with adenocarcinoma of the esophagogastric junction who underwent Cheng's GIRAFFE reconstruction after proximal gastrectomy in Cancer Hospital of University of Chinese Academy of Sciences (64 cases), Zhejiang Provincial Hospital of Chinese Medicine (24 cases), Lishui Central Hospital (10 cases), Huzhou Central Hospital (1 case) and Ningbo Lihuili Hospital (1 case) from September 2017 to June 2021 were retrospectively analyzed. Of 100 patients, 64 were males and 36 were females; the mean age was (61.3 ± 11.1) years and the BMI was (22.7±11.1) kg/m(2). For TNM stage, 68 patients were stage IA, 24 were stage IIA and 8 were stage IIB. Postoperative functional results and postoperative complications of radical gastrectomy with Giraffe reconstruction were analyzed and summarized. Gastroesophageal reflux disease questionnaire (RDQ) score and postoperative endoscopy were used to evaluate the occurrence of reflux esophagitis and its grade (grade N, grade A, grade B, grade C, and grade D from mild to severe reflux). The continuous data conforming to normal distribution were expressed as (mean ± standard deviation), and those with skewed distribution were presented as median (Q1, Q3). Results: All the 100 patients successfully completed R0 resection, including 77 patients undergoing laparoscopic surgery and 23 patients undergoing laparotomy. The Giraffe anastomosis time was (38.6±14.0) min; the blood loss was (73.0±18.4) ml; the postoperative hospital stay was 9.5 (8.2, 13.0) d; the hospitalization cost was (6.0±0.3) ten thousand yuan. Fourteen cases developed perioperative complications (14.0%), including 7 cases of pleural effusion or pneumonia, 3 cases of anastomotic leakage, 2 cases of gastric emptying disorder, 1 case of gastrointestinal hemorrhage and 1 case of anastomotic stenosis, who were all improved and discharged after symptomatic management. Patients were followed up for (33.3±1.6) months. Eight patients were found to have reflux symptoms by RDQ scale six months after surgery, and 11 patients (11/100,11.0%) were found to have reflux esophagitis by gastroscopy, including 6 in grade A, 3 in grade B, and 2 in grade C. All the patients could control their reflux symptoms with behavioral guidance or oral PPIs. Conclusion: Cheng's GIRAFFE reconstruction has good anti-reflux efficacy and gastric emptying function; it can be one of the choices of reconstruction methods after proximal gastrectomy.

[Clinical features and prognostic factors in adult acute myeloid leukemia patients with FLT3-ITD and CEBPA gene co-mutation]

目的

研究FLT3-ITD及CEBPA双等位基因突变(CEBPAdm)共突变成人急性髓系白血病(AML)患者的临床特征及预后。

方法

对2016年1月至2018年9月就诊于郑州大学第一附属医院的初治成人AML患者的临床资料进行回顾性研究，比较分析其临床特点及预后。基因突变检测采用直接测序法。

结果

①接受基因突变检测的非M₃且资料完整患者599例，检出FLT3-ITD基因突变阳性（FLT3-ITD⁺）且CEBPAdm阳性（CEBPAdm⁺）患者19例（A组），FLT3-ITD⁺且CEBPAdm⁻患者84例（B组），FLT3-ITD⁻且CEBPAdm⁺患者95例（C组），未检出任何已知基因突变患者70例（D组），共计268例。②A、B、C、D四组间性别、PLT、FAB分型、诱导治疗方案、融合基因突变情况差异均无统计学意义（P值均>0.05）；而发病年龄、初诊时WBC、HGB含量、外周血原始幼稚细胞比例、骨髓原始幼稚细胞比例差异均有统计学意义（P值均<0.05）。组间两两比较，A组较B、C、D组性别、年龄、HGB含量、PLT、FAB分型差异无统计学意义（P值均>0.05）。A组初诊时外周血WBC、外周血原始幼稚细胞比例、首疗程诱导治疗后微小残留病（MRD）水平高于B、C、D各组。③A、B、C、D组首疗程化疗后完全缓解（CR₁）率分别为50.0%、32.4%、59.8%、39.0%（P=0.003），复发率分别为55.6%、50.0%、21.1%、40.0%（P<0.001），中位总生存时间分别为6.25、3.0、15.5、10.5个月（P<0.001），中位无进展生存时间分别为5.0、4.0、10.0、6.7个月（P=0.032）。

结论

FLT3-ITD及CEBPAdm共突变成人AML患者初诊时外周血WBC高，外周血原始幼稚细胞比例高，首疗程诱导化疗后MRD水平高，CR₁率低，复发率高，中位总生存时间、中位无进展生存时间短，预后不佳。

[Preliminary efficacy analysis of Cheng's Giraffe reconstruction after proximal gastrectomy in adenocarcinoma of esophagogastric junction]

Objective: To investigate the safety and feasibility of proximal partial gastrectomy with Cheng's Giraffe esophagogastric reconstruction for the treatment of early Siewert II adenocarcinoma of esophagogastric junction (AEG). Methods: Indication of Cheng's Giraffe esophagogastric reconstruction: (1) Siewert II AEG or Siewert III AEG with diameter < 4 cm; (2) preoperative staging as cT1-2N0M0. A descriptive case series study was carried out. Clinical data of 34 patients with Siewert II AEG undergoing proximal partial gastrectomy and Cheng's Giraffe esophagogastric reconstruction at Department of Abdominal Surgery of Zhejiang Cancer Hospital and Department of Gastrointestinal Surgery, The First Affiliated Hospital of Zhejiang University of Traditional Chinese Medicine from February to July 2018 were retrospectively collected and analyzed, including 14 cases in IA stage, 11 cases in IIA stage and 8 cases in IIB stage. Brief procedure of Cheng's Giraffe esophagogastric reconstruction was as follows: Firstly, 12 cm long tubular stomach was formed by longitudinal incision 4 cm away from the great curvature of the stomach. Secondly, the gastric fundus and His angle were formed. Finally, the distance from His angle to esophagal-tubular gastric anastomosis should be more than 5 cm. The reflux disease questionare (RDQ) scores, radionuclide gastric emptying scintigraphy, and 24-hour multichannel intraluminal (MII)-pH monitoring technology were used to evaluate postoperative gastric emptying and gastroesophageal reflux. Result: All 34 patients successfully completed proximal partial gastrectomy with Cheng's Giraffe esophagogastric reconstruction, including 13 cases by open surgery and 21 cases by laparoscopic surgery. The operation time was (144.6±39.8) minutes, the blood loss during operation was (35.4±17.2) ml. No laparoscopic case was converted to open surgery and no postoperative complication was observed. The postoperative hospital stay was (8.4±2.5) days. The postoperative RDQ score was 4.4±3.1 one month after operation, and 3.3±2.5 six months after operation. Gastric-half emptying time was (67.0±21.5) minutes, and the residual ratio was (52.2±7.7)% in 1 hour, (36.4±3.1)% in 2 hours and (28.8±3.6)% in 3 hours at postoperative 1-month. The 24-hour MII-pH monitoring at postoperative 2-month revealed the frequency of acid reflux was (12.6±7.9) times, frequency of non-acid reflux was (19.6±9.7) times, DeMeester score was 5.8±2.9. Conclusion: Cheng's Giraffe esophagogastric reconstruction is safe and feasible in the treatment of Siewert type II AEG, and has good dynamic and anti-reflux effects.

[Bone remodeling in patients with juvenile condylar resorption after stabilization splint treatment]

Objective: To investigate bone remodeling in patients with different types of juvenile condylar resorption after stabilization splint treatment using cone-beam CT (CBCT). Methods: Fifty-nine juvenile condylar resorption patients (114 sides of condyle) treated with stabilization splint from January 2012 to May 2018 in Department of Temporomandibular Joint, Stomatological Hospital of Chongqing Medical University were selected as splint group, while twenty-four patients (48 sides of condyle) who underwent natural remodeling without stabilization splint treatment after 6-12 months were severed as control group. Pre-and post-treatment CBCT was taken for all patients. There were three types of condyles (including type Ⅰ, type Ⅱ and type Ⅲ) before treatment and four types of condyles (including progression, no changes, stable without new bone and remodeled with new bone) after treatment. Progression and no change were considered as poor curative effect, and stable without new bone and remodeled with new bone were considered to be effective. The vertical distance of the condylar height was measured and compared before and after treatment in the two groups. Results: Significant difference in treatment outcome was found in types Ⅰ and Ⅱ between the splint group and the control group (Z=-2.874, P=0.004; Z=-3.874, P=0.000), and no significant difference was found in type Ⅲ between the two groups (Z=-0.617, P=0.537). The difference of condylar progression percentage [splint group: 43% (15/35), control group: 80% (16/20)] was statistically significant between the two groups in type Ⅱ (χ(2)=7.139, P=0.011), and no significant difference was found in types Ⅰ and Ⅲ between the two groups (χ(2)=0.103, P=0.748; χ(2)=1.249, P=0.540). In two groups, the condylar height difference before and after treatment in type Ⅱ condylar resorption was statistically significant (P<0.05). Conclusions: Stabilization splint treatment was effective in patients with different types of juvenile condylar resorption, especially in type Ⅰ. However, it was difficult to reverse the height reduction of the condylar bone regardless of treatment.

[Changes of serum Krebs von den Lungen-6 levels in interstitial lung disease associated with dermatomyositis and secondary Sjögren's syndrome: a case report]

Interstitial lung diseases (ILDs) are a diverse group of pulmonary disorders characterized by various patterns of inflammation and fibrosis in the interstitium of the lung. The underlying pathogenesis of ILDs is complex and associated with multiple rheumatologic conditions, such as systemic sclerosis, rheumatoid arthritis, pollymyositis and dermatomyositis, Sjögren's syndrome, and systemic lupus erythematosus. As the disease progresses, excessive pulmonary fibrosis impairs alveolar gas exchange and damages pulmonary function. The common methods to diagnose ILDs, such as clinical manifestations, pulmonary function test, and radiological examinations are not specific for ILDs and not able to diagnose ILDs at the early stage due to their low sensitivity. So, the easy way is important to diagnose ILDs. One important biomarker for ILDs is the high-molecular-weight glycoprotein, Krebs von den Lungen-6(KL-6). KL-6 encoded by the MUC1 gene is a mucin-like glycoprotein with high molecular weight and expressed predominantly on the cell surface of type II alveolar epithelial cells, and is detectable in the serum of patients with ILDs. We here report a case of ILDs associated with dermatomyositis and secondary Sjögren's syndrome. A 60-year-old woman was admitted to our hospital with the chief complaints of debilitation, dry mouth, dyspnea and astasia. ILDs associated with dermatomyositis and secondary Sjögren's syndrome was diagnosed clinically when the following criteria were satisfied: (1) development of dyspnea within 2 months of presentation, (2) pulmonary dispersion dysfunction, (3) bilateral infiltrative shadows on chest high resolution computed tomography (HRCT). She was treated with prednisone 50 mg/d prior to admission, but the result of therapy was not good. In our hospital she was treated with intravenous methylprednisolone and cyclophosphamide and oral hydroxychloroquine sulfate. Subsequently, her serum KL-6 levels gradually decreased after treatment, pulmonary diffuse function improved, and the improvement in the clinical manifestation and HRCT findings were observed. Nevertheless, the combination treatment of glucocorticoid and cyclophosphamide had contributed to the favourable outcomes. In conclusion, detection of serum KL-6 levels in ILDs associated with connective tissue diseases may be beneficial to making a definitive diagnosis, predicting the prognosis and monitoring the disease activity, which would be of great help in clinical practice. However, a well-designed clinical study with more patients and a longer follow-up period are required to arrive at a more conclusive judgment on the role of serum KL-6 in patients with ILDs.

Changes of snoring sound after relocation pharyngoplasty for obstructive sleep apnoea: the surgery reduces mean intensity in snoring which correlates well with apnoea-hypopnoea index

OBJECTIVE

To investigate objective changes of snoring after surgery in patients with obstructive sleep apnoea (OSA) and correlate these with changes in the apnoea-hypopnoea index (AHI).

DESIGN

Prospective case series.

SETTING

A novel measurement, Snore Map, was used to analyse full-night snore sounds in terms of the maximal/mean intensity, peak/mean frequency, snoring index and energy type (Snore Map type, 0-4). Snore sound was classified into three bands according to frequency energy spectrum: B1 (40-300 Hz), B2 (301-850 Hz) and B3 (851-2000 Hz).

PARTICIPANTS

Thirty-four male and two female OSA patients (mean age, 39 years; mean AHI, 53.1/h; mean body mass index, 26.8 kg/m(2) ) with favourable anatomic structure were consecutively enrolled.

MAIN OUTCOME MEASURES

Parameters of polysomnographies and Snore Maps at baseline and six months after operation were compared. Statistical significance was set at P < 0.05.

RESULTS

Thirty-two patients completed this study. The mean reduction in the total-snoring index was insignificant but there were significant decreases in total mean intensity, total peak frequency, total mean frequency and Snore Map type after surgery. There were also significant decreases in the mean intensity in all three bands, the snoring index in B2/B3 and the mean frequency in B1 postoperatively. Changes in the total mean intensity, total mean frequency, B2 mean intensity and B3 snoring index positively correlated with change in the AHI.

CONCLUSIONS

Relocation pharyngoplasty significantly decreases both the snoring sound intensity and snoring frequency. These reductions are directly proportional to the improvement of OSA.

Tensor renormalization group study of classical XY model on the square lattice

Using the tensor renormalization group method based on the higher-order singular value decomposition, we have studied the thermodynamic properties of the continuous XY model on the square lattice. The temperature dependence of the free energy, the internal energy, and the specific heat agree with the Monte Carlo calculations. From the field dependence of the magnetic susceptibility, we find the Kosterlitz-Thouless transition temperature to be 0.8921(19), consistent with the Monte Carlo as well as the high temperature series expansion results. At the transition temperature, the critical exponent δ is estimated as 14.5, close to the analytic value by Kosterlitz.

Identification and characterization of microRNA from chicken adipose tissue and skeletal muscle

MicroRNA (miRNA) is small noncoding RNA that is extensively expressed in organisms. Different types play important roles in various biological processes, such as growth and development. In this study, we identified 47 miRNA in chicken adipose tissue and skeletal muscle, of which 38 were known chicken miRNA, 4 were known miRNA homologous to other species, and 5 were potentially novel miRNA. The target genes from adipose tissue and skeletal muscle were predicted. The expression assay indicated that the 10 selected miRNA were differentially expressed in different developmental stages. Both miRNA-133a and miR-1a were muscle-related, whereas miR-122 was adipose-related miRNA. Certain identified miRNA may be essential to growth and development of chicken adipose tissue and skeletal muscle. Further studies of these miRNA will help to understand their functions in growth and development of adipose tissue and skeletal muscle of poultry.

Correlation between IL-3 receptor expression and growth potential of human CD34+ hematopoietic cells from different tissues

CD123 (alpha-subunit of IL-3 receptor) expression on primitive and committed human hematopoietic cells was studied by multicolor sorting and single-cell culture. The sources of cells included fetal liver (FLV), fetal bone marrow, umbilical cord blood, adult bone marrow and mobilized peripheral blood. Three subsets of CD34+ cells were defined by the levels of surface CD123: CD123negative, CD123low, and CD123bright. Coexpression of lineage markers showed that a majority of CD34+CD123bright cells were myeloid and B-lymphoid progenitors, while erythroid progenitors were mainly in the CD34+CD123negative subset. The CD34+CD123low subset contained a heterogeneous distribution of early and committed progenitor cells. Single CD34+ cells from the CD123 subsets were cultured in a cytokine cocktail of stem cell factor, interleukin 3 (IL-3), IL-6, GM-CSF, erythropoietin, insulin-like growth factor-1, and basic fibroblast growth factor. After 14 days of incubation, a higher cloning efficiency (CE) was observed in the CD34+CD123negative and CD34+CD123low fractions (37+/-23% and 44+/-23%, respectively) than in the CD34+CD123bright fraction (15+/-21%). Using previously published criteria that colonies containing dispersed, translucent cells (dispersed growth pattern, DGP) were derived from primitive cells and that colonies composed solely of clusters were from committed cells, early precursors were distributed evenly in the CD34+CD123negative and CD34+CD123low subsets. When CD38 and CD90 (Thy-1) were used for further characterization of CD34+ cells from FLV, CE increased from 37+/-23% in CD123negative to 70+/-19% in CD123negativeCD38- and from 44+/-23% in CD123low to 66+/-19% in CD123lowCD38-. No significant increase in CE or DGP progenitors was observed when CD34+ cells were sorted by CD90 and CD123. We concluded that: A) high levels of CD123 were expressed on B-lymphoid and myeloid progenitors; B) early erythroid progenitors had little or no surface CD123, and C) primitive hematopoietic cells are characterized by CD123negative/low expression.