Platelet kinetics in patients with idiopathic thrombocytopenic purpura and moderate thrombocytopenia

We studied ten normal subjects and 20 patients with stable, untreated idiopathic thrombocytopenic purpura (ITP) and platelet counts in the range of 35,000 to 110,000/microL. The diagnosis was made by clinical criteria. Platelet-associated IgG was increased in all nine of the nine patients studied. Autologous platelets were labeled with chromium 51 and reinfused for measurement of mean cell life and platelet production rate. Mean cell life was calculated by two methods, weighted mean and multiple hit, with excellent agreement between the two. As expected, mean cell life was significantly reduced in ITP patients as compared to the normal subjects (2.9 days v. 8.0 days, P less than .001). However, mean platelet production rates in ITP patients and normal subjects, 3.5 and 3.8 X 10(9) platelets/k/d respectively, were not significantly different. Platelet production rate was above and below the normal range (2 to 5.6 X 10(9) platelets/k/d) in two and four patients, respectively. We conclude that the rate of platelet production is not increased in most patients with ITP who have platelet counts greater than 35,000/microL. We did find that platelet size was increased in eight of the 12 patients in whom it was measured, including two of the patients with low platelet production.     

Is the secretion of atrial natriuretic peptide in man under neural control?

AIMS: Previous work has described short-term variation in the circulating plasma level of atrial natriuretic peptide (ANP), but the mechanism remains unknown. Our aim was to investigate the role of cardiac innervation in this variability. METHODS AND RESULTS: Blood samples were obtained from the right atrium via a pulmonary artery flotation catheter every 2 min over a 90 min period. Seven patients who underwent cardiac transplantation by the standard biatrial technique (partial innervation) and ten patients who underwent transplantation by the bicaval technique (total denervation) were studied. ANP levels were measured by radioimmunoassay. The median ANP levels were somewhat higher in the biatrial group compared to the bicaval group [470 (150-1095) vs. 216 (100-605) pg. ml(-1); median (range); P = ns], and both were much higher than normal levels in the pulmonary artery (40 (24, 56) pg ml(-1); median and interquartile range). In both transplant groups circulating plasma ANP levels showed considerable variability. The median number of 'peaks' and 'troughs', as counted by visual inspection, were not significantly different between the two groups. Computer analysis identified 12-16 and 6-15 'pulses' in the biatrial and bicaval group, respectively. Further analysis revealed that pulse amplitude, height and area were significantly higher in the biatrial compared to the bicaval group. CONCLUSION: It would appear that variability of circulating plasma levels of ANP is preserved despite complete or partial cardiac denervation, and so a neural mechanism does not appear to account for such variation.     

Exploring the utility of whole‐exome sequencing as a diagnostic tool in a child with atypical episodic muscle weakness

The advent of whole‐exome next‐generation sequencing (WES) has been pivotal for the molecular characterization of Mendelian disease; however, the clinical applicability of WES has remained relatively unexplored. We describe our exploration of WES as a diagnostic tool in a 3½‐year old female patient with a 2‐year history of episodic muscle weakness and paroxysmal dystonia who presented following a previous extensive but unrevealing diagnostic work‐up. WES was performed on the proband and her two parents. Parental exome data was used to filter potential de novo genomic events in the proband and suspected variants were confirmed using di‐deoxy sequencing. WES revealed a de novo non‐synonymous mutation in exon 21 of the calcium channel gene CACNA1S that has been previously reported in a single patient as a rare cause of atypical hypokalemic periodic paralysis. This was unexpected, as the proband's original differential diagnosis had included hypokalemic periodic paralysis, but clinical and laboratory features were equivocal, and standard clinical molecular testing for hypokalemic periodic paralysis and related disorders was negative. This report highlights the potential diagnostic utility of WES in clinical practice, with implications for the approach to similar diagnostic dilemmas in the future.     

Significance of IGFBP-4 in the Development of Fetal Growth Restriction

Background: Fetal growth restriction (FGR) is a leading cause of perinatal mortality and morbidity. Animal studies suggest dysregulation of IGF-binding protein (IGFBP)-4 is significant in the development of FGR, although human data are lacking. We postulated that IGFBP-4 is expressed at the maternal fetal interface and plays a role in regulating IGF bioavailability. Thus, maternal serum levels of IGFBP-4 may be associated with complications of abnormal placental growth and development including FGR. Methods: Circulating levels of IGFBP-4 and its protease, pregnancy-associated plasma protein-A (PAPP-A), were examined in healthy pregnancies. Their expression in villi and bed as possible sources of the circulating products were examined by immunohistochemistry. From the large Ottawa and Kingston (OaK) Birth Cohort, a nested case-control study was conducted to examine circulating levels of IGBP-4, PAPP-A, IGF-I, and IGF-II by Western blot in early gestation in 36 women who went on to develop FGR and 36 controls having normal-weight babies. Results: IGFBP-4 was elevated in early pregnancy compared with nonpregnant women and women in later pregnancy, consistent with the presence of abundant extravillous trophoblasts and decidual cells that highly expressed IGFBP-4. High expression of PAPP-A was observed in extravillous trophoblasts and decidual cells in early pregnancy but hardly detectable in the circulation at this time, suggesting maternal circulating PAPP-A originates more likely from syncytiotrophoblasts. Increased IGFBP-4 in the maternal circulation in early pregnancy was associated with the development of FGR [0.48 (0.28-0.74) in control vs. 1.22 (0.66-1.65) in FGR; odds ratio = 22 (95% confidence interval = 2.7-181)]. No difference was observed in circulating PAPP-A, IGF-I and IGF-II in the FGR vs. control group. Conclusion: Our findings support the role of IGFBP-4 in regulating IGF bioavailability and provide new clues for the prevention and treatment of FGR, raising the possibility of clinical use of IGFBP-4 as an early biomarker for this condition.     

Exome sequencing in familial corticobasal degeneration

BackgroundCorticobasal degeneration (CBD) is a neurodegenerative, sporadic disorder of unknown cause. Few familial cases have been described.ObjectiveWe aim to characterize the clinical, imaging, pathological and genetic features of two familial cases of CBD.MethodsWe describe two first cousins with CBD associated with atypical MRI findings. We performed exome sequencing in both subjects and in an unaffected first cousin of similar age.ResultsThe cases include a 79-year-old woman and a 72-year-old man of Native American and British origin. The onset of the neurological manifestations was 74 and 68 years respectively. Both patients presented with a combination of asymmetric parkinsonism, apraxia, myoclonic tremor, cortical sensory syndrome, and gait disturbance. The female subject developed left side fixed dystonia. The manifestations were unresponsive to high doses of levodopa in both cases. Extensive bilateral T1-W hyperintensities and T2-W hypointensities in basal ganglia and thalamus were observed in the female patient; whereas these findings were more subtle in the male subject. Postmortem examination of both patients was consistent with corticobasal degeneration; the female patient had additional findings consistent with mild Alzheimer's disease. No Lewy bodies were found in either case. Exome sequencing showed mutations leading to possible structural changes in MRS2 and ZHX2 genes, which appear to have the same upstream regulator miR-4277.ConclusionsCorticobasal degeneration can have a familial presentation; the role of MRS2 and ZHX2 gene products in CBD should be further investigated.     

Hyperhomocysteinemia exacerbates the development of intimal hyperplasia in Sprague-Dawley rats: Alleviation by rosiglitazone

The amino acid intermediate homocysteine (Hcy) is formed during the metabolism of methionine to cysteine. Hyperhomocysteinemia (HHcy) is recognized as an independent risk factor for coronary atherosclerosis. The circulating levels of total Hcy (tHcy) can increase due to intake of foods rich in methionine or deficiencies of vitamins such as folate, pyridoxine and cyanocobalamin, which are required for the metabolism of Hcy. In addition, mutations in the genes coding for Hcy metabolizing enzymes can contribute to an increase in tHcy levels. Clinical and epidemiological studies have shown that an elevated level of tHcy measured in serum or plasma is a strong predictor of cardiovascular disease risk, which appears to be greatest in patients who have HHcy following a methionine load. Intimal hyperplasia (IH) (intima/media [I/M] ratio) is the universal response of a vessel to injury and may result in vasoconstriction when left unattended. The effect of dietary HHcy on balloon catheter-injured carotid artery and its modulation (if any) by the peroxisome proliferator-activated receptor agonist gamma rosiglitazone was evaluated in 12-week-old female Sprague-Dawley rats fed either a control diet or a diet containing 1% L-methionine. Once the rats were established on the diet, the group that was fed 1% L-methionine was further subdivided and either given an aqueous preparation of 3 mg/kg/day rosiglitazone or the vehicle via oral gavage for one week. This was followed by surgically injuring the left carotid artery using a Maverick Over-The-Wire catheter (2.0 mm × 20 mm, 3.2F; Boston Scientific, USA). The rats were continued on their respective diets and drug regimen for 21 days postsurgery. On day 22 of the procedure, the rats were sacrificed for collection of blood, the carotid arteries and liver for biochemical and histological evaluation. Compared with controls there was a significant increase in both tHcy levels and I/M ratio in the rats fed 1% L-methionine (5.4±0.28 μM versus 32.8±3.01 μM, P<0.002; and 0.175±0.05 versus 1.05±0.23, P<0.005, respectively). The effect of rosiglitazone in rats fed the control diet was not prominent. On the other hand, administration of rosiglitazone to the rats on the 1% L-methionine diet significantly reduced the levels of serum tHcy (16.6±2.1 μM versus 32.8±3.01 μM, P<0.001); however, the tHcy levels remained significantly elevated compared with animals on the control diet (P<0.002). The group receiving the L-methionine diet plus rosiglitazone had an inhibition in the development of IH compared with those receiving the L-methionine diet alone (I/M of 0.278±0.041 versus 1.05±0.23, P<0.01). Moreover, the development of IH in the group receiving the L-methionine diet plus rosiglitazone treatment was not significantly different from that observed in the group on the control diet without rosiglitazone (0.278±0.041 versus 0.175±0.05, respectively). These findings may have important implications in deciphering the molecular mechanisms involved in the augmentation of IH in HHcy and modulation of this process by rosiglitazone.     

社区医护干预预防产后抑郁症的研究

[目的]调查产后抑郁症患者的现状及需求,探讨预防措施。[方法]定性与定量研究相结合,定性采用专题小组讨论和半结构性访谈,12人参加专题讨论、9人半结构性访谈;定量研究随机抽取本市各社区产后42d的产妇776例行问卷调查。[结果]产妇月子期间常发生头疼、恶心、焦虑、恐惧、失眠以及照顾新生儿困难;半结构性访谈中有1产妇处于产后抑郁症的临界,EPDS量表测定为12分;776例产妇月子里有身心健康问题者692例,求助者91.0%,其中需要社区护理人员帮助的71.7%,实际寻求帮助仅12.7%。[结论]预防产后抑郁症应实行社区医护人员培训与产后访视人员的准入制度,采取社区医护干预的三级预防,同时拓展社区产后保健服务的内涵。