Correlation of idiopathic benign paroxysmal positional vertigo with cerebral small vessel disease

BACKGROUND

Benign paroxysmal positional vertigo (BPPV) is the most prevalent form of peripheral vertigo, with vascular lesions being one of its suspected causes. The older adults are particularly vulnerable to BPPV. Cerebral small vessel disease (CSVD), on the other hand, is a clinical condition that results from damage of cerebral small vessels. Vascular involvement resulting from age-related risk factors and proinflammatory state may act as the underlying factor linking both BPPV and CSVD.

AIM

The objective of this study is to explore the potential correlation between BPPV and CSVD by examining whether individuals aged 50 and older with BPPV exhibit a greater burden of CSVD.

MATERIALS AND METHODS

This retrospective study included patients aged 50 years and older who had been diagnosed with BPPV. A control group consisting of patients diagnosed with idiopathic facial neuritis (IFN) during the same time period was also included. The burden of cerebral white matter hyperintensities (WMHs) was evaluated using the Fazekas scale. An ordinal regression analysis was conducted to investigate the potential correlation between BPPV and WMHs.

RESULTS

The study included a total of 101 patients diagnosed with BPPV and 116 patients with IFN. Patients with BPPV were found to be significantly more likely (OR = 2.37, 95% CI 1.40-4.03, p = 0.001) to have a higher Fazekas score compared to the control group. Brain infarctions, hypertension, and age were all identified as significant predictors of white matter hyperplasia on MRI, with OR of 9.9 (95% CI 4.21-24.84, P<0.001), 2.86 (95% CI 1.67-5.0, P<0.001), and 1.18 (95% CI 1.13-1.22, P<0.001) respectively.

CONCLUSION

Our findings suggest that vascular impairment caused by age-related risk factors and proinflammatory status may be contributing factors to the development of BPPV in individuals aged 50 and above, as we observed a correlation between the suffering of BPPV and the severity of WMHs.

Treatment Terminations during Radiation Therapy: A Ten-Year Experience

PURPOSE/OBJECTIVE(S)

Disruptionsin cancer care adversely affect clinical outcomes, particularly when a patient does not complete the prescribed course of treatment. The impact of treatment termination (TT) during radiation therapy has not been well studied. This study addresses TT in a large multi-center department of radiation oncology over a 10-year time period.

MATERIALS/METHODS

TTs of patients undergoing radiation treatment between January 2013 and December 2022 were prospectively tracked as part of departmentalquality and safety monitoring. A TT was defined as the discontinuation of therapy at any point following consent and simulation. Causes of TTs were categorized as: hospice/death, physician choice related to toxicity, physician choice unrelated to toxicity, patient choice related to toxicity, patient choice unrelated to toxicity, progression of disease, non-cancer illness, or other. The rate of TT was calculated as a percentage of all new patients who start radiation treatments. As part of our ongoing department quality and safety program, incremental changes were made to pre-treatment evaluation and scheduling processes, collectively referred to as the "No-Fly" policy. TT rates during three iterations of this policy were compared.

RESULTS

Outof 28,707 planned treatment courses, a total of 1,467 TTs were identified (5.1%). 688 (46.9%) involved patients treated with curative intent, 770 (52.5%) with palliative intent, and 9 (0.6%) for benign disease. The rate of TT decreased from 9.3% in 2013 to 3.3% in 2022. Relative to evolutions of our No-Fly policy, the overall TT rate decreased from 8.8% under No-Fly 1 (2013-2014), to 5.2% during No-Fly 2 (2015-2018), and 4.0% with No-Fly 3 (2019-2022) (ANOVA, p<0.001). The most common sites for TT were H&N (19.3%), CNS (17.9%), and Bone Metastases (17.9%). The most common cause of TT was hospice and/or death (36.5%), 69.1% of which were in patients receiving palliative treatments. Other common causes included patient choice unrelated to toxicity (35%), physician choice unrelated to toxicity (8.8%), and progression of disease (7.6%). There were 473 TTs without radiation dose given (1.6% of planned treatments, 32.3% of TTs).

CONCLUSION

Radiation TTs reflect major deviations from the original care plan. This large cohort study highlights the value of open departmental discourse about TTs, which prompted quality improvement changes that reduced TTs over time. Future studies addressing clinical outcomes can direct treatment decision-making and improve care for our patients.

Clinical Outcomes and Patterns of Failure in Patients with High-Risk Atypical Meningioma Treated with Single Fraction vs. Hypofractionated Gamma Knife Radiosurgery

PURPOSE/OBJECTIVE(S)

The recently completed RTOG 0539 supports fractionated radiation therapy for patients categorized as having intermediate (3 yr PFS 93.8%) or high-risk (3 yr LC 68.9%) meningiomas. Stereotactic radiosurgery (SRS) has not been widely established in the treatment of WHO grade 2 atypical meningiomas given concern that there is a greater risk of microscopic infiltration and therefore requires larger margins than safely achievable with SRS. We look to review a consecutive cohort of patients at our institution who have been diagnosed with atypical meningioma treated with either single fraction Gamma Knife SRS (GK-sfSRS) or hypofractionated Gamma Knife SRS (GK-hfSRS). We review both control rates and patterns of failure.

MATERIALS/METHODS

Patients diagnosed with intermediate or high-risk WHO grade 2 meningioma per RTOG 0539 classification, without a history of prior radiation (RT) and treated with either GK-sfSRS or GK-hfSRS between 2014 to 2021 at our institution, were included. Patient charts were reviewed, and follow-up data were analyzed for local control (LC) and failure patterns. Local failure was defined as tumor recurrence within the prescription isodose line, marginal was ≤5 mm outside the prescription isodose line, and distant was >5 mm outside of the prescription isodose line Primary outcome was LC, and secondary outcomes were overall survival (OS) and progression free survival (PFS).

RESULTS

We identified 47 pathologically confirmed WHO grade 2 meningiomas in 27 patients. 33 lesions were treated with GK-sfSRS and 14 lesions with GK-hfSRS. 6 lesions were intermediate risk, and 41 were high-risk per RTOG 0539. With a median follow up of 36 months (range 2-86 mo), the 3yr LC was 82.7%, PFS was 83.1%, and OS was 96.3%. A total of 4 patients with 8 lesions failed treatment - all with high-risk disease. All failures were local (4) or marginal (4). The 4 local failures were all from a single patient with 4 distinct meningiomas that were treated with GK-sfSRS without surgical resection. The 4 marginal failures were all in patients treated with GK-sfSRS. There were no failures in patients treated with GK-hfSRS.

CONCLUSION

Our institutional data for patients with atypical meningiomas treated with radiosurgical techniques compare favorably to the patients treated with EBRT in RTOG 0539, though longer follow-up is needed to confirm these findings. Outside of one patient, no patients developed recurrence within the prescription volume. There were 4 tumors with marginal failures, suggesting that additional dural margins than what were prescribed may be meaningful. At our institution, we are increasingly moving to hypofractionated radiosurgery with 5 mm of dural margin when using radiosurgical techniques for high-risk atypical meningioma. However, longer term follow-up is needed to validate the use of radiosurgical techniques in atypical meningioma.

Contrast enhancement by location and volume is associated with long-term outcome after thrombectomy in acute ischemic stroke

Contrast enhancement (CE) on brain non-contrast computed tomography (NCCT) is common after endovascular thrombectomy (EVT) in patients with acute ischemic stroke (AIS), but its association with clinical outcomes is not well established. The current study aimed to investigate this relationship. We retrospectively reviewed consecutive patients with acute ischemic stroke who had hyperdensity on NCCT immediately after EVT for anterior circulation large vessel occlusion (LVO) from January 2016 to December 2019. We used ASPECTS combined with volume measurement by 3D reconstruction to estimate the extent and location of CE. Multivariable regression analysis was conducted to explore the risk factors associated with clinical outcome. In this study, 113 of 158 (71.52%) anterior circulation AIS-LVO patients had hyperdensity on brain NCCT. After strict inclusion and exclusion criteria, a total of 64 patients were enrolled in the final analysis. In logistic regression analysis, CE-ASPECTS, CE volume, CE at the caudate nucleus, M4 and M6 region were associated with 3-month poor functional outcome after adjusting for confounding factors. The conventional variable model was used for reference, including age, initial NIHSS, the procedure time, stent retriever passes, recanalization status and baseline ASPECTS, with AUC of 0.73. When combined with the above-named variables (conventional variables + CE-ASPECTS + CE volume + CE at caudate nucleus + CE at M4 region + CE at M6 region), the predictive power was significantly improved, with AUC of 0.87 (95% CI 0.78-0.95). The spatial location and volume of CE on NCCT obtained immediately after EVT were independent and strong predictors for poor outcome at 3-months in patients with AIS after excluding definite hemorrhage by 24-h follow up CT.

Salvianolic Acids for Injection alleviates cerebral ischemia/reperfusion injury by switching M1/M2 phenotypes and inhibiting NLRP3 inflammasome/pyroptosis axis in microglia in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

After cerebral ischemia/reperfusion injury, pro-inflammatory M1 and anti-inflammatory M2 phenotypes of microglia are involved in neuroinflammation, in which activation of NLRP3 inflammasome and subsequent pyroptosis play essential roles. Salvianolic Acids for Injection (SAFI) is Chinese medicine injection which composed of multiple phenolic acids extracted from Radix Salviae Miltiorrhizae, and has been reported to generate neuroprotective effects after cerebral ischemic insult in clinical and animal studies.

AIM OF THE STUDY

The present study was designed to investigate whether SAFI exerts neuroprotective effects by switching microglial phenotype and inhibiting NLRP3 inflammasome/pyroptosis axis in microglia.

MATERIALS AND METHODS

The middle cerebral artery occlusion/reperfusion (MCAO/R) model in rats and oxygen-glucose deprivation/reoxygenation (OGD/R) model in co-cultured primary neurons and primary microglia were utilized. The neuroprotective effect of SAFI was evaluated through measuring neurological deficit scores, neuropathological changes, inflammatory factors, cell phenotype markers, and related proteins of NLRP3 inflammasome/pyroptosis axis.

RESULTS

The results showed that SAFI treatment was able to: (1) produce a significant increase in neurological deficit scores and decrease in infarct volumes, and alleviate histological injury and neuronal apoptosis in cerebral cortex in MCAO/R model; (2) increase neuronal viability and reduce neuronal apoptosis in the OGD model; (3) reshape microglial polarization patterns from M1-like phenotype to M2-like phenotype; (4) inhibit the activation of the NLRP3 inflammasome and the expression of proteins related to NLRP3 inflammasome/pyroptosis axis in vivo and in vitro.

CONCLUSION

These findings indicate that SAFI exert neuroprotective effect, probably via reducing neuronal apoptosis, switching microglial phenotype from M1 towards M2, and inhibiting NLRP3 inflammasome/pyroptosis axis in microglia.

Kv1.3 channel blockade alleviates cerebral ischemia/reperfusion injury by reshaping M1/M2 phenotypes and compromising the activation of NLRP3 inflammasome in microglia

After cerebral ischemia/reperfusion injury, pro-inflammatory M1-like and anti-inflammatory M2-like phenotypes of microglia are involved in neuroinflammation, in which NLRP3 inflammasome plays an essential role. Kv1.3 channel has been recognized as neuro-immunomodulatory target, but it is not clear as to its role in the neuroinflammation after cerebral ischemic injury. The current study aimed to investigate the issue. Middle cerebral artery occlusion/reperfusion (MCAO/R) model in rats and oxygen-glucose deprivation/ reoxygenation (OGD/R) in primary microglia were utilized to mimic disease state of ischemic stroke. Treatment with PAP-1, a Kv1.3 channel blocker, produced a significant improvement in neurological deficit scores and a decrease in infarct volume in MCAO/R model. An increased number of M2-like phenotypic microglia and a reduced number of M1-like phenotypic microglia were observed by immunofluorescent staining in the in vivo model, which was further validated by flow cytometry in vitro. Western blot showed that PAP-1 treatment profoundly reduced cleavage of caspase-1 and IL-1β in vivo and in vitro. Furthermore, PAP-1 administration reduced the number of NLRP3⁺/Iba1⁺ cells and NLRP3 protein levels in vivo, while reduced mRNA and protein expression levels of NLRP3 in vitro. Reduced mRNA expression levels of IL-1β in vitro and protein level of IL-1β in vivo were also observed. Taken together, our findings suggested that Kv1.3 channel blockade effectively alleviated cerebral ischemic injury, possibly by reshaping microglial phenotypic response from M1 towards M2, compromising the activation of NLRP3 inflammasome in microglia, and inhibiting release of IL-1β.

[Prognostic analysis of patients with myasthenia gravis after extended thymectomy]

Objective: To identify the long-term outcome of patients with myasthenia gravis (MG) after extended thymectomy, and to analyze the prognostic factors. Methods: The medical data and follow-up results in 72 patients with MG who underwent extended thymectomy in Department of Thoracic Surgery, Anhui Provincial Hospital Affiliated with Anhui Medical University from January 2006 to October 2015 were retrospectively reviewed and analyzed. There were 32 male and 40 female patients, aging from 10 to 70 years with a mean age of 39.5 years. The outcome-related factors including gender, age while being operated on, duration of preoperative period, whether taking steroid before operation, modified Osserman classification, pathology type of thymus were analyzed by χ(2) test and multivariate regression analysis. Results: All patients were followed up from 6 to 75 months (median 37 months). Among them, 21 patients (29.2%) achieved complete stable remission, 18 patients (25.0%) experienced pharmacological remission, 20 patients (27.8%) improved, 9 patients (12.5%) reminded stable and 4 patients (5.6%) deteriorated. Both univariate and multicariate analysis revealed that duration of preoperative period (OR=22.871, 95% CI: 2.813 to 185.917, P=0.003) and Osserman classification (OR=0.103, 95% CI: 0.014 to 0.774, P=0.027) showed significantly associated with the surgical curative effect. Conclusions: Extended thymectomy is an efective measure for MG. The duration of preoperative period and Osserman classification are prognostic factors for thymectomized MG. Those patients with generalized MG or whose duration of preperative period is less than 6 months are likely to have better prognosis.

Role of surgery in the management and prognosis of limited-stage small cell carcinoma of the esophagus

Small cell carcinoma of the esophagus (SCCE) is a rare, highly aggressive tumor characterized by early dissemination and a poor prognosis. Surgery, chemotherapy, and radiotherapy have been used alone or in combination for the treatment of this rare disease. The aim of this retrospective study was to analyze the role of surgery in the management of limited-stage SCCE at a high-volume center. We retrospectively evaluated 73 patients with limited-stage SCCE who received an esophagectomy at our center from January 1994 to December 2011. The clinical characteristics, median survival times (MSTs), overall survival (OS), and relevant prognostic factors were analyzed. The overall MST was 23.0 months, and the 1-, 2-, 3-, and 5-year OS rates were 61.6%, 47.9%, 22.7%, and 10.6%, respectively. The MST for patients without lymph node involvement (33.0 months) was greater than the MST for patients with lymph node involvement (17.0 months) (P = 0.014). Similarly, patients who underwent radical resection had a greater MST (25.0 months) than patients who underwent palliative resection (7.0 months) (P = 0.004). Patients who received chemotherapy had a greater MST (27.0 months) than patients who did not receive chemotherapy (13.0 months) (P = 0.021). Survival analysis confirmed that a radical operation, chemotherapy, and lymph node involvement were independent prognostic factors. This study suggests that radical resection combined with chemotherapy should be recommended for patients with limited-stage SCCE, especially patients with negative regional lymph nodes. A lack of lymph node metastasis was a good prognostic factor because patients without lymph node involvement had greater OS.

Antitumour activity of 3-nitropropionic acid from Phomopsis sp. and optimization of fermentation conditions

In this study, 3-nitropropionic acid (3-NPA) was separated and purified from endophytic fungi belonging to Phomopsis sp. and its cytotoxicity was determined by MTT assay. Treatment with 3-NPA for 24 h resulted in a dose-dependent apoptosis in MCF-7 cells. Through quantitative detection of the genes that are closely related to the Bcl-2 signalling pathway, there was an increased expression of p53 and Bax and a decreased expression of Bcl-2, which indicated apoptosis in these cells. Meanwhile, the overexpression of PARA (poly ADP-ribose polymerase) and apoptosis inducing factor (AIF) also suggested that 3-NPA induced cellular apoptosis through a caspase-3-independent pathway in caspase-3-deficient MCF-7 cells. The fermentation condition was also improved to produce more 3-NPA: glucose as a carbon source and yeast extract as a nitrogen source, fermentation for 8 days at 32°C and a solution environment of pH 5·0. Under these conditions, the yield of 3-NPA was increased to 529 mg l(-1) compared with 410 mg l(-1) under traditional fermentation conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

3-Nitropropionic acid is a mitochondrial inhibitor and has some useful bioactivities such as antibacterial activity. In this paper we found that 3-NPA also has obvious cytotoxicity, so we studied its antitumour activity and tried to determine the antitumour molecular mechanism, opening a new perspective for potential antitumour prodrug development. As 3-NPA is often obtained from natural products with a low yield, in order to overcome the disadvantage of an endophytic fungi source of 3-NPA, we optimized the fermentation conditions for 3-NPA in Phomopsis sp. to obtain the maximum production of 3-NPA.

Controllability of vortex domain structure in ferroelectric nanodot: fruitful domain patterns and transformation paths

Ferroelectric vortex domain structure which exists in low-dimensional ferroelectrics is being intensively researched for future applications in functional nanodevices. Here we demonstrate that adjusting surface charge screening in combination with temperature can provide an efficient way to gain control of vortex domain structure in ferroelectric nanodot. Systematical simulating experiments have been conducted to reveal the stability and evolution mechanisms of domain structure in ferroelectric nanodot under various conditions, including processes of cooling-down/heating-up under different surface charge screening conditions, and increasing/decreasing surface charge screening at different temperatures. Fruitful phase diagrams as functions of surface screening and temperature are presented, together with evolution paths of various domain patterns. Calculations discover up to 25 different kinds of domain patterns and 22 typical evolution paths of phase transitions. The fruitful controllability of vortex domain structure by surface charge screening in combination with temperature should shed light on prospective nanodevice applications of low-dimensional ferroelectric nanostructures.

[Changes in cyclin expression during proliferation and differentiation of CD34(+) cells derived from fetal liver induced by thrombopoietin]

In order to elucidate the intrinsic mechanism underlying proliferation and differentiation of megakaryocytes during ontogenesis, CD34(+) cells were isolated from human fetal liver (FL) with a high-gradient magnetic sorting system (MACS) and were incubated in liquid suspension with 50 and 100 ng/ml of thrombopoietin (TPO) and in MegaCult(Tm) -C semi-solid culture system with 0, 12.5, 25, 50, 100, and 200 ng/ml of TPO. The cell number, colony number of CFU-Mk, platelet-associated antigen phenotype, and DNA ploidy of CD41(+) cells were examined from d 0 to d 12 in culture. The expression patterns of cyclins B1, D1, and D3 were also analyzed by using immunoblot and flow cytometry. TPO stimulated proliferation of CD34(+) cells of FL from 1 x 10(5)/ml to 13.12 +/-4.06 10(5)/ml with 95% of CD41a(+) cells and 3% of CD34(+) cells after 12 d of culture. Most of the megakaryocytes (MKs) derived from FL were in 2 N ploidy class, and few in 4 N ploidy class, but no megakaryocytes ploidy class was higher than 4 N. The effect of TPO on the formation of CFU-Mk colonies from FL derived CD34(+) cells is shown in a dose-response curve. The expression of cyclin B1 increased progressively and the high level of cyclin B1 was maintained in FL CD34(+) cells induced by TPO during 12 d of culture. A high level of cyclin B1 appeared on FL derived MKs of G1 phase at d 12. The expression of cy-of cyclins D1 and D3 gradually increased in FL CD34(+) cells, which was induced by TPO during the initial 6-day incubation. Afterwards, the level of cyclins D1 and D3 decreased progressively, particularly in MKs which were in G2+M phases. These data suggest that (1) TPO induced proliferation and differentiation of FL derived CD34(+) cells through upregulation of cyclin B1 in G2+M phases and cyclins D1 and D3 in all phases of cell cycle, and (2) Continuing high level of cyclin B1 and decreases of cyclins D1 and cyclin D3 on MKs in G2+M phases may contribute to a retardation of MK endoreduplication.

CD34+ cells derived from fetal liver contained a high proportion of immature megakaryocytic progenitor cells

Endoreplication and maturation of the megakaryocyte (MK) may be retarded or delayed during ontogenesis. In this study, CD34+ cells were isolated from both human fetal liver and adult bone marrow and incubated with thrombopoietin (TPO). The cell number, morphological characteristics, platelet-associated antigen phenotype, maturation stage and DNA ploidy of CD41+ cells were examined from day 0 to day 12 in culture. 1) TPO stimulated the proliferation of fetal liver (FL)-derived CD34+ cells with a mean 73.14-fold increase of CD41+ cells after 12 d in culture. Adult BM-derived CD34+ cells increased only slightly, with a mean 8.18-fold increase of CD41+ cells. 2) Although the membrane phenotype of both FL CD34+-derived MKs and BM CD34+ -derived MKs analyzed with CD41a, CD42a, CD61 and CD34 were similar, all FL CD34+-derived MKs were in maturation stage I and II and in low ploidy (<4N) class. By comparison, BM CD34+ MKs possessed 15% MKs in maturation stage III and IV and with 23% MKs in high ploidy class ( > 4N). 3) Most of cultured FL-derived CD34+ cells did not have a well developed demarcation system (DM) and numerous alpha-granules after 12 d incubation. von Willebrand factor (vWF) appeared earlier on the cultured BM-derived CD34+ cells than on FL-derived CD34+ cells. 4) The expression of both cyclin E and cyclin B1 progressively increased in FL CD34+ cells induced by TPO during 12 d in culture. 5) The expression of cyclin D1 gradually decreased in FL CD34+ cells induced by TPO over 12 d incubation. 6) Immunocytochemical analysis showed that cyclin D3 was detected only in cytoplasm of cultured FL-derived CD34+ cells, whereas in both cytoplasm and nuclei of cultured BM-derived CD34+ cells. These data suggest that FL-derived CD34+ cells contain a high proportion of immature megakaryocytic progenitor cells. It further suggests that TPO can push these progenitor cells into proliferation by upregulating the expression of cyclins B1 and E, and drive a high proportion of cells into megakaryocytic lineage.

Selective induction of apoptosis of NB4 cells from G2+M phase by sodium arsenite at lower doses

Apoptosis of NB4 cells induced by sodium arsenite and arsenate was studied using flow cytometry and DNA gel electrophoresis in order to investigate their effects on cell cycle and determine the relationship between apoptosis and cell cycle. In this study, we found that: 1) at low doses, sodium arsenite selectively induced apoptosis of NB4 cells in G2+M phase of cell cycle after its being arrested in G2 phase. With increment of the cells blocked in G2 phase, dUTP-specifically labeling cells in G2+M phase increased without concomitant increment of dUTP-labeling cells in other two phases of cell cycle; 2) at high doses, extensive apoptosis was induced in NB4 cells from all phases of cell cycle without cell cycle preference and cell cycle blockade; 3) sodium arsenite-induced apoptosis of NB4 cells occurred in the presence of bcl-2 expression as the unapoptotic cells; 4) sodium arsenite with As3+ induced apoptosis of NB4 cells more strongly than sodium arsenate with As5+ did although both of them affected NB4 cells in the same pattern. These results not only suggested that both arsenite and arsenate induced apoptosis of NB4 cells through 2 different mechanisms--at low doses, arsenical might directly induce apoptosis through regulation of cell cycle checkpoint, while at high doses they might directly induce it, but also indicated that bcl-2 might not play an important role in arsenite or arsenate-induced apoptosis of NB4 cells, whereas chemical valence of As in a compound might be related to efficiency in arsenical induction of apoptosis.

[In vitro growth characteristics of rIL3 stimulated megakaryocytic progenitor cells (CFU-MK) of fetal liver]

In this study, plasma clot and methycellulose semi-solid and liquid culture technigues were employed to observe the in vitro growth characteristics of proliferation and differetiation of 4-5 months fetal liver and adult bone marrow CFU-MKs. Fetal liver MK colonies in plasma clot in the presence of rIL3 or Meg-CSA were larger (usually with > 50 cells/colony) than that of the adult (usually with < 50 cells/colony). The number (36.40 +/- 16.60/1 x 10(5) cells) of fetal liver Mk colonies in presence of 2 ng/ml rIL3 was larger than that (10.05 +/- 2.81/1 x 10(5) cells) of human adult bone marrow MK colonies (P < 0.01). In contrast, the major DNA ploidy classes of megakaryocytes derived from fetal liver CFU-MK were those of 2N and 4N cells and the major DNA ploidy classes of megakaryocytes derived from human adult bone marrow were those of 8N and 4N cells. The mean (5.45 +/- 0.86) of the ploidy of the former was lower than that (10.13 +/- 1.30) of the latter (P < 0.01). The same results were obtained with the presence of 10% Meg-CSA. These present results indicated that CFU-MK in fetal liver has a high ability of proliferation and low capacity of differentiation (polyploidization). Interestingly, the number of fetal liver MK colonies increased in the range of rIL3 concentration from 0.5 ng/ml to 2 ng/ml. At higher rIL3 concentration (2-8 ng/ml), the colony growth showed a steady decrease from the maximum value instead of an increase. However, in the same range of rIL3 concentration, the numbers of adult bone marrow MK colonies numbers and fetal liver CFU-GM colonies increased steadily and finally reached to a plateau. Furthermore, both fetal liver and adult bone marrow MK colonies showed dose-dependent response in the range of Meg-CSA concentration from 5% to 25%. In addition, there was no difference on DNA ploidy distributions of megakaryocytes derived from fetal liver CFU-MK between rIL3 and Meg-CSA as growth factors. Moreover, the DNA ploidy distribution of fetal liver derived megakaryocytes stimulited by rIL3 could not be changed by addition of rIL6 (100 u/ml). In summary, the above data suggest that CFU-MK in the fetal liver undergoes some intrinsic cellular modification in order to suit the need of ontogensis.

Developmental change of megakaryocyte maturation and DNA ploidy in human fetus

Megakaryocytes in fetal livers obtained from 30 water-balloon aborted normal fetuses of 3 to 6 months' gestation, in the bone marrow from the same 30 fetuses, and another 9 fetuses of 7 to 8 months' gestation and in the normal bone marrow of adults were analyzed by immunocytochemical staining for size and maturation stage distribution and by flow cytometry for ploidy distribution simultaneously. In human fetuses, megakaryocytes showed a shift during ontogenesis from smaller towards larger size and from less mature towards a more mature stage with advancement of gestation. This was accompanied by a significant progressive shift to higher ploidy. However, the proportions (78.64%) of hypoploidy (< or = 8N) megakaryocytes in bone marrow of 7-8 months' gestation fetuses was still much higher than that (33.32%) in human adults (p < 0.05), with the proportion of hyperploidy (> or = 16N) megakaryocytes lower than that (67.86%) in human adults. This result indicated that megakaryocyte polyploidization may be retarded or inhibited during development.