The relationship between red cell distribution width, serum calcium ratio, and in-hospital mortality among patients with acute respiratory failure: A retrospective cohort study of the MIMIC-IV database

To investigate the impact of RDW/CA (the ratio of red cell distribution width to calcium) on in-hospital mortality in patients with acute respiratory failure (ARF). This retrospective cohort study analyzed the data of 6981 ARF patients from the Medical Information Mart for Intensive Care (MIMIC-IV) database 2.0. Critically ill participants between 2008 and 2019 at the Beth Israel Deaconess Medical Center in Boston. The primary outcome of interest was in-hospital mortality. A Cox proportional hazards regression model was used to determine whether the RDW/CA ratio independently correlated with in-hospital mortality. The Kaplan-Meier method was used to plot the survival curves of the RDW/CA. Subgroup analyses were performed to measure the mortality across various subgroups. After adjusting for potential covariates, we found that a higher RDW/CA was associated with an increased risk of in-hospital mortality (HR = 1.17, 95% CI: 1.01-1.35, P = .0365) in ARF patients. A nonlinear relationship was observed between RDW/CA and in-hospital mortality, with an inflection point of 1.97. When RDW/CA ≥ 1.97 was positively correlated with in-hospital mortality in patients with ARF (HR = 1.554, 95% CI: 1.183-2.042, P = .0015). The Kaplan-Meier curve indicated the higher survival rates for RDW/CA < 1.97 and the lower for RDW/CA ≥ 1.97 after adjustment for age, gender, body mass index, and ethnicity. RDW/CA is an independent predictor of in-hospital mortality in patients with ARF. Furthermore, a nonlinear relationship was observed between RDW/CA and in-hospital mortality in patients with ARF.

Association of magnesium sulfate use with mortality in critically ill patients with sepsis: a retrospective propensity score-matched cohort study

BACKGROUND

Trials have demonstrated lower rates of acute kidney injury in critically ill patients receiving magnesium supplementation, but they have yielded conflicting results regarding mortality.

METHODS

This is a retrospective cohort study based on the MIMIC-IV (Medical Information Mart in Intensive Care-IV) database. Adult critically ill patients with sepsis were included in the analysis. The exposure was magnesium sulfate use during ICU stay. The primary outcome was 28-day all-cause mortality. Propensity score matching (PSM) was conducted at a 1:1 ratio. Multivariable analyses were used to adjust for confounders.

RESULTS

The pre-matched and propensity score-matched cohorts included 10 999 and 6052 patients, respectively. In the PSM analysis, 28-day all-cause mortality rate was 20.2% (611/3026) in the magnesium sulfate use group and 25.0% (757/3026) in the no use group. Magnesium sulfate use was associated with lower 28-day all-cause mortality (hazard ratio [HR], 0.70; 95% CI, 0.61-0.79; P<0.001). Lower mortality was observed regardless of baseline serum magnesium status: for hypomagnesaemia, HR, 0.64; 95% confidence interval (CI), 0.45-0.93; P=0.020; for normomagnesaemia, HR, 0.70; 95% CI, 0.61-0.80; P<0.001. Magnesium sulfate use was also associated with lower ICU mortality (odds ratio [OR], 0.52; 95% CI, 0.42-0.64; P<0.001), lower in-hospital mortality (OR, 0.65; 95% CI, 0.55-0.77; P<0.001), and renal replacement therapy (OR, 0.67; 95% CI, 0.52-0.87; P=0.002). A sensitivity analysis using the entire cohort also demonstrated lower 28-day all-cause mortality (HR, 0.62; 95% CI, 0.56-0.69; P<0.001).

CONCLUSIONS

Magnesium sulfate use was associated with lower mortality in critically ill patients with sepsis. Prospective studies are needed to verify this finding.

Relationship between the red cell distribution width-to-platelet ratio and in-hospital mortality among critically ill patients with acute myocardial infarction: a retrospective analysis of the MIMIC-IV database

OBJECTIVES

We aimed to investigate the association between red cell distribution width-to-platelet ratio (RPR), and in-hospital mortality in critically ill patients with acute myocardial infarction (AMI).

DESIGN

A retrospective cohort study.

SETTING

Data were collected from the Medical Information Mart for Intensive Care database (MIMIC-IV) consisting of critically ill participants between 2008 and 2019 at the Beth Israel Deaconess Medical Centre in Boston.

PARTICIPANTS

A total of 5067 patients with AMI were enrolled from the MIMIC-IV database.

PRIMARY AND SECONDARY OUTCOME

In-hospital mortality.

RESULTS

A total of 4034 patients survived, while 1033 died. In a multiple regression analysis adjusted for age, weight and ethnicity, RPR also showed a positive correlation with in-hospital mortality (HR 1.91, 95% CI 1.42 to 2.56, p<0.0001). Moreover, after adjusting for additional confounding factors, obvious changes were observed (HR 1.63, 95% CI 1.03 to 2.57, p=0.0357). In model 2, the high ratio quartile remained positively associated with hospital mortality compared with the low ratio quartile (HR 1.20, 95% CI 1.01 to 1. 43), with a p-value trend of 0.0177. Subgroup analyses showed no significant effect modifications on the association between RPR and in-hospital mortality in the different AMI groups (p>0.05).

CONCLUSION

RPR is an independent predictor of in-hospital mortality in critically ill patients with AMI.

Acute kidney disease in hospitalized acute kidney injury patients

Background

Acute kidney injury (AKI) and chronic kidney disease (CKD) have become worldwide public health problems, but little information is known about the epidemiology of acute kidney disease (AKD)—a state in between AKI and CKD. We aimed to explore the incidence and outcomes of hospitalized patients with AKD after AKI, and investigate the prognostic value of AKD in predicting 30-day and one-year adverse outcomes.

Methods

A total of 2,556 hospitalized AKI patients were identified from three tertiary hospitals in China in 2015 and followed up for one year.AKD and AKD stage were defined according to the consensus report of the Acute Disease Quality Initiative 16 workgroup. Multivariable regression analyses adjusted for confounding variables were used to examine the association of AKD with adverse outcomes.

Results

AKD occurred in 45.4% (1161/2556) of all AKI patients, 14.5% (141/971) of AKI stage 1 patients, 44.6% (308/691) of AKI stage 2 patients and 79.6% (712/894) of AKI stage 3 patients. AKD stage 1 conferred a greater risk of Major Adverse Kidney Events within 30 days (MAKE30) (odds ratio [OR], 2.36; 95% confidence interval 95% CI [1.66–3.36]) than AKD stage 0 but the association only maintained in AKI stage 3 when patients were stratified by AKI stage. However, compared with AKD stage 0, AKD stage 2–3 was associated with higher risks of both MAKE30 and one-year chronic dialysis and mortality independent of the effects of AKI stage with OR being 31.35 (95% CI [23.42–41.98]) and 2.68 (95% CI [2.07–3.48]) respectively. The association between AKD stage and adverse outcomes in 30 days and one year was not significantly changed in critically ill and non-critically ill AKI patients. The results indicated that AKD is common among hospitalized AKI patients. AKD stage 2–3 provides additional information in predicting 30-day and one-year adverse outcomes over AKI stage. Enhanced follow-up of renal function of these patients may be warranted.

Human umbilical cord-derived mesenchymal stem cells and human cord blood mononuclear cells protect against cisplatin-induced acute kidney injury in rat models

Human umbilical cord-derived mesenchymal stem cells (hUCMSCs) are a promising tool to attenuate cisplatin (CP)-induced acute kidney injury (AKI). However, whether the transplantation of human cord blood mononuclear cells (hCBMNCs) exhibits similar protective effects and their potential underlying mechanisms of action remain unclear. The present study aimed to determine the protective effects of hUCMSCs and hCBMNCs transplantation therapies on an established CP-induced rat model and explore their underlying mechanisms of action. A total of 24 Sprague-Dawley rats, selected based on body weight, were randomly assigned into 4 groups: i) normal control; ii) model (CP); iii) hCBMNCs (CP + hCBMNCs); and iv) hUCMSCs (CP + hUCMSCs). hUCMSCs (2.0x10⁶ cells) and hCBMNCs (2.0x10⁶ cells) were injected into the femoral vein of rats 24 h after CP (8 mg/kg) treatment. To determine the effects of hCBMNCs and hUCMSCs on CP-induced rats, renal function assessment and histological evaluations were performed. Expression levels of high mobility group box 1 (HMGB1) and the ratio of Bax/Bcl2 in renal tissues were detected to elucidate their underlying molecular mechanisms of action. The results demonstrated that transplantation of hUCMSCs and hCBMNCs significantly improved renal function in CP-induced AKI rats, as evidenced by the enhancement of renal morphology; decreased concentrations of blood urea nitrogen and serum creatinine; and a lower percentage of apoptotic renal tubular cells. The expression of HMGB1 and the ratio of Bax/Bcl-2 were significantly reduced in the hUCMSCs and hCBMNCs groups compared with CP group. In conclusion, the present study indicated that hCBMNCs exert similar protective effects to hUCMSCs on CP-induced AKI. hUCMSCs and hCBMNCs protect against CP-induced AKI by suppressing HMGB1 expression and preventing cell apoptosis.

Novel risk models to predict acute kidney disease and its outcomes in a Chinese hospitalized population with acute kidney injury

Acute kidney disease (AKD) is a state between acute kidney injury (AKI) and chronic kidney disease (CKD), but the prognosis of AKD is unclear and there are no risk-prediction tools to identify high-risk patients. 2,556 AKI patients were selected from 277,898 inpatients of three affiliated hospitals of Central South University from January 2015 to December 2015. The primary point was whether AKI patients developed AKD. The endpoint was death or end stage renal disease (ESRD) 90 days after AKI diagnosis. Multivariable Cox regression was used for 90-day mortality and two prediction models were established by using multivariable logistic regression. Our study found that the incidence of AKD was 53.17% (1,359/2,556), while the mortality rate and incidence of ESRD in AKD cohort was 19.13% (260/1,359) and 3.02% (41/1,359), respectively. Furthermore, adjusted hazard ratio of mortality for AKD versus no AKD was 1.980 (95% CI 1.427–2.747). In scoring model 1, age, gender, hepatorenal syndromes, organic kidney diseases, oliguria or anuria, respiratory failure, blood urea nitrogen (BUN) and acute kidney injury stage were independently associated with AKI progression into AKD. In addition, oliguria or anuria, respiratory failure, shock, central nervous system failure, malignancy, RDW-CV ≥ 13.7% were independent risk factors for death or ESRD in AKD patients in scoring model 2 (goodness-of fit, P₁ = 0.930, P₂ = 0.105; AUROC₁ = 0.879 (95% CI 0.862–0.896), AUROC₂ = 0.845 (95% CI 0.813–0.877), respectively). Thus, our study demonstrated AKD was independently associated with increased 90-day mortality in hospitalized AKI patients. A new prediction model system was able to predict AKD following AKI and 90-day prognosis of AKD patients to identify high-risk patients.

Human umbilical cord blood mononuclear cells protect against renal tubulointerstitial fibrosis in cisplatin-treated rats

Currently, there is no effective method to prevent renal interstitial fibrosis after acute kidney injury (AKI). In this study, we established and screened a new renal interstitial fibrosis rat model after cisplatin-induced AKI. Our results indicated that rats injected with 4 mg/kg cisplatin once a week for two weeks after firstly administrated with 6.5 mg/kg loading dose of cisplatin could set up a more accurate model reflecting AKI progression to renal interstitial fibrosis. Then, we investigated the effects and possible mechanisms of human umbilical cord blood mononuclear cells (hUCBMNCs) on renal tubular interstitial fibrosis after cisplatin-induced AKI. In rats injected with hUCBMNCs for four times, level of matrix metalloproteinase 7 (MMP-7) in serum and urine, urinary albumin/creatinine ratio, tubular pathological scores, the relative collagen area of the tubulointerstitial region, endoplasmic reticulum dilation and the mitochondrial ultrastructural damage were significantly improved. The level of reactive oxygen species, α-smooth muscle actin (α-SMA), [NOD]-like pyrin domain containing protein 3 and cleaved-Caspase 3 in renal tissue decreased significantly. However, in rats injected with hUCBMNCs for two times, no significant difference was discovered in MMP-7 levels and urinary albumin/creatinine ratio. Although expression of α-SMA and the percentage areas of collagen staining in tubulointerstitial tissues were ameliorated in rats injected with hUCBMNCs for two times, the effects were significantly weaker than those in rats injected with hUCBMNCs for four times. Taken together, our study constructed a highly efficient, duplicable novel rat model of renal fibrosis after cisplatin-induced AKI. Multiple injections of hUCBMNCs may prevent renal interstitial fibrosis after cisplatin-induced AKI.

Human umbilical cord blood mononuclear cells protect against renal tubulointerstitial fibrosis in cisplatin-treated rats

Currently, there is no effective method to prevent renal interstitial fibrosis after acute kidney injury (AKI). In this study, we established and screened a new renal interstitial fibrosis rat model after cisplatin-induced AKI. Our results indicated that rats injected with 4 mg/kg cisplatin once a week for two weeks after firstly administrated with 6.5 mg/kg loading dose of cisplatin could set up a more accurate model reflecting AKI progression to renal interstitial fibrosis. Then, we investigated the effects and possible mechanisms of human umbilical cord blood mononuclear cells (hUCBMNCs) on renal tubular interstitial fibrosis after cisplatin-induced AKI. In rats injected with hUCBMNCs for four times, level of matrix metalloproteinase 7(MMP-7)in serum and urine, urinary albumin/creatinine ratio, tubular pathological scores, the relative collagen area of the tubulointerstitial region, endoplasmic reticulum dilation and the mitochondrial ultrastructural damage were significantly improved. The level of reactive oxygen species, α-smooth muscle actin (α-SMA), [NOD]-like pyrin domain containing protein 3 and cleaved-Caspase 3 in renal tissue decreased significantly. However, in rats injected with hUCBMNCs for two times, no significant difference was discovered in MMP-7 levels and urinary albumin/creatinine ratio. Although expression of α-SMA and the percentage areas of collagen staining in tubulointerstitial tissues were ameliorated in rats injected with hUCBMNCs for two times, the effects were significantly weaker than those in rats injected with hUCBMNCs for four times. Taken together, our study constructed a highly efficient, duplicable novel rat model of renal fibrosis after cisplatin-induced AKI. Multiple injections of hUCBMNCs may prevent renal interstitial fibrosis after cisplatin-induced AKI.

[Classification of cardiac amyloidosis: an immunohistochemical analysis]

Objective: To evaluate the sensitivity and specificity of immunohistochemistry (IHC) in the classification of cardiac amyloidosis on endomyocardial biopsy (EMB) and heart allograft. Methods: Twenty cardiac tissues from 19 patients at Fuwai Hospital from January, 1990 to April, 2017 with histopathologic features of amyloidosis and Congo red staining positivity were included. IHC was performed with monoclonal antibodies against AA amyloid and polyclonal antibodies against transthyretin (ATTR), λ-light chain (AL-λ), κ-light chain (AL-κ), ApoAⅠ, ApoAⅡ, ApoA Ⅳ and β(2)-microglobin. The extent of interstitial staining was evaluated by light microscopy, and three patterns were recognized; these included diffuse pericellular pattern, discrete pericellular pattern, and nodular pattern. Two patterns of vascular deposition were also noted, including arterial pattern and venous pattern. Endocardial involvement was also assessed and recorded. Results: Nineteen cases were divided into three groups according to the pattern of proteins expression in specimens. The first group (5 cases) only showed single protein expression on EMB. The second group (6 cases) showed more than one protein expression, but one of them was intensely stained or any staining of any protein together with ApoA Ⅳ co-staining. The third group (8 cases) also showed more than one protein expression and all of them had intense staining. Amyloid deposits were successfully subtyped as AL-λ, ATTR, AL-κ and ApoAⅠby IHC in the former two groups with the sensitivity of 11/19. In the third group, amyloid deposits could not be subtyped by immunohistochemistry due to their poor specificity. The pericellular pattern tended to favor AL over ATTR amyloidosis and vascular deposition tended to favor ATTR. Conclusions: Amyloid deposits can be reliably subtyped in diagnostic cardiac specimens using IHC. The co-deposition of chaperon proteins, the distribution of amyloid proteins and clinical features are also auxiliary to subtype cardiac amyloidosis.

[The clinical characteristics, diagnosis and treatment of patients with gout in China]

Objective: To investigate the demographic characteristics, clinical features, diagnosis and treatment of patients with gout in China. Methods: Clinical data of 6 814 patients with gout from 100 hospitals in 27 provinces, municipalities or autonomous regions in China were collected and analyzed. Results: (1) The ratio of male to female in patients with gout was 14.7∶1. The mean age of onset was (48.8±15.1) years old. Mean serum urate level was (526.7±132.3) μmol/L. Patients' education background was of U-shaped distribution; (2) Hypertension was the most common comorbidity [15.8%(1 079/6 814)], then overweight or obesity [51.9%(3 536/6 814)]; (3) Alcohol and high-purine food intake were dominant triggering factors in men. The diagnosis of gout was made after onset in majority of patients with cardinal symptom arthralgia. Most patients had the disease less than 5 years, and the longer the course, the more flares in the previous year of entry; (4) Febuxostat was the mostly used urate-lowering medication. 20.7%(1 412/6 814), 10.8%(739/6 814) and 3.9%(265/6 814) of patients were followed up in 4 weeks, 12 weeks and 24 weeks after registration, and 18.9%(267/1 412), 29.1%(215/739) and 38.1%(101/265) of them reached the control target of serum urate levels, respectively. After treatment, patients' liver function was not affected, but serum creatinine levels decreased significantly. Conclusions: The proportion of gout patients who reach target serum urate level is very low. Further steps including education and survey need to be carried on.

[Analysis on clinical characteristics and prognosis of patients with mitral valve prolapse]

Objective: To evaluate the clinical characteristics and prognosis of patients with mitral valve prolapse (MVP). Methods: We retrospectively analyzed the clinical characteristics and prognosis of 148 MVP patients who underwent mitral valve surgery in Fuwai hospital from January 2012 to December 2015.The patients were divided into mucoid degeneration group (52 cases) and without mucoid degeneration group(19 cases) according to pathological examination of leaflets and chordate. Results: The clinical symptoms of MVP patients included dyspnea (59.5%(88/148)), chest distress and pain (52.7%(78/148)), and palpitations (36.5% (54/148)). Mitral valve repair was performed in 144 cases (97.3%), and mitral valve replacement was performed in 4 cases (2.7%). Posterior leaflet prolapse was the most common form of MVP (68.9%, 102/148). Pathological examination revealed myxomatous degeneration in 73.2% patients (52/71), fibrosis in 8.5% patients (6/71), and fibrinoid necrosis in 8.5% patients (6/71). Patients with mucoid degeneration had less atrial fibrillation before surgery (5.8%(3/52) vs. 42.1%(8/19), P<0.01), smaller preoperative left atrium diameter ((43.2±6.5) mm vs. (48.2±8.9) mm, P<0.05), more posterior leaflet prolapse (94.2%(49/52) vs. 63.2%(12/19), P<0.01), redundant chordae (26.9%(14/52) vs. 0, P<0.05) and leaflet thickening (76.9%(40/52) vs. 52.6%(10/19), P<0.05) when compared with patients without mucoid degeneration.Echocardiography examination at the postoperative follow-up of 39.0(22.3, 57.0) months revealed smaller left atrium diameter((38.5±7.1) mm vs. (45.3±8.3) mm, P<0.01), left ventricular end-diastolic diameter ((48.9±6.2) mm vs. (57.5±7.6) mm, P<0.01), reduced left ventricular ejection fraction ((61.2±7.1)% vs. (65.1±6.2)%, P<0.01) and less moderate or severe mitral regurgitation (1.4%(2/148) vs. 100.0%(148/148), P<0.01) compared with the corresponding preoperative values. Conclusions: Dyspnea is the main symptom, and mucoid degeneration characterized by redundant chordae and leaflet thickening are the main pathological features of MVP patients.The surgical treatment of MVP patients is related with satisfactory outcome results.

[Surgical pathology analysis of the causes of failure of 48 bioprosthetic heart valves in 40 Chinese cases]

OBJECTIVE

To investigate the pathological changes and related factors leading to failure of bioprosthetic valves.

METHODS

The surgical explanted bioprosthetic valves in Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College from January 2006 to December 2014 were retrospectively reviewed. Calcification, cusp tears, pannus and infectious endocarditis of bioprosthetic valves were evaluated by gross examination, X ray photography and histopathological analysis. Meanwhile, the age and the site at implantation, and the tissue type of bioprosthetic valves, the implantation duration were obtained by chart review and used to be analyzed with the modes of valve failure. U test, χ(2) test and Fisher exact test were used to analyze the data.

RESULTS

Total 48 bioprosthetic valves were collected from 40 cases with 26 females. Their age at the time of implantation was 12 to 71 years (median 58 years). The tissue types of bioprosthesis included 24 bovine pericardial valves and 24 porcine aortic valves respectively. The implantation sites included mitral in 29 valves, aortic in 14 valves and tricuspid in 5 valves. The implantation duration ranged from 5 days to 27 years (mean (111±77) months). The study showed that the commonest mode of valve failure was structural valve deterioration (32 valves, 66.7%). The fewer modes of valve failure were infectious endocarditis (9 valves, 18.7%) and non-structural valve deterioration (7 valves, 14.6%). No thrombosis was found in this series. The degree of calcification was correlated positively with implantation duration (r=0.52, P=0.000). The implantation duration of bovine pericardial valves was longer than that of porcine aortic valves ((146±74) months vs. (77±68) months, Z=-3.24, P=0.001). Porcine aortic valves had a higher incidence of cusp tears than bovine pericardial valves (66.7% vs. 16.7%, χ(2)=12.34, P=0.000) despite they had a relatively lower incidence of calcification (41.7% vs. 75.0%, χ(2)=5.37, P=0.019). For the age at the time of implantation, the patients ≤60 years old had more calcification of bioprosthetic valves compared with those >60 years old (45.1% vs. 2/17, χ(2)=5.51, P=0.019) whereas the patients ≤60 years old had fewer cusp tears (12.9% vs. 58.8%, P=0.002). Infectious endocarditis was found more frequently in the valves failure within 5 years than those failure after 5 years (6/14 vs. 8.8%, P=0.006).

CONCLUSIONS

Structural valve deterioration is the principle cause of bioprosthetic valve failure while infectious endocarditis mainly involves the valves failure in early and middle terms after surgery. The mode of valve failure in the patients ≤60 years old is different from that in the patients >60 years old at the time of implantation. More calcification would occur in bioprosthetic valve in the younger patients.

[Clinical significance of FOXM1 and Gli-1 protein expression in high-grade ovarian serous carcinoma]

Objective: To investigate the different expression and prognostic significance of forkhead box M1 (FOXM1) and Gli-l in ovarian high grade serous carcinoma (HGSC). Methods: The expressions of FOXM1 and Gli-1 in 94 cases of HGSC and 20 cases of normal fallopian tube tissues were detected by immunohistochemistry. Kaplan-Meier analysis and Cox multivariate survival analysis were used to assess the relationship of the FOXM1 and Gli-1 levels with age, International Federation of Gynecology and Obstetrics (FIGO) stage, omental metastasis, and residual foci and prognosis of HGSC. Results: The positive rates of FOXM1 and Gli-1 expression in HGSC were 79.8% (75/94) and 77.7% (73/94), respectively, both significantly higher than those of the normal controls (P<0.05). The expressions of FOXM1 and Gli-1 were significantly correlated with FIGO stage, and both of their positive rates in stage Ⅲ-Ⅳpatients were significantly higher than those in stage Ⅰ-Ⅱ cases (P<0.001). The expressions of FOXM1 in HGSC were positively correlated with Gli-1.Kaplan-Meier analysis revealed that the 5-year overall survival rates of FOXM1- and Gli-1-positive groups were 8.0% and 6.8%, significantly lower than 36.8% and 38.1% of the FOXM1- and Gli-1-negative groups, respectively (P<0.05 for both). Cox multivariate survival analysis revealed that FIGO stage and overexpression of FOXM1 protein were independent prognostic factors of HGSC patients (P<0.05 for both). Conclusions: The overexpression of FOXM1 and Gli-1 proteins participate in the carcinogenesis of HGSC, and are significantly associated with FIGO stage. The protein expression of FOXM1 is positively correlated with Gli-1 in HGSC. Expression of FOXM1 protein and FIGO stage are independent prognostic factors of HGSC.

A multiplex touchdown PCR for detection of Streptococcus pneumoniae, Haemophilus influenzae type b and Mycobacterium tuberculosis complex in sputum samples

Rapid and accurate detection of Streptococcus pneumoniae (Sp), Haemophilus influenzae type b (Hib) and Mycobacterium tuberculosis complex (MTBC) in sputum by conventional methods remains problematic. Primers based on capsular polysaccharide biosynthesis gene (cpsA), the region II of the capsulation locus (cap), the insertion sequence IS6110 were designed for Sp, Hib, MTBC respectively. These primers were incorporated in a multiplex touchdown PCR assay for simultaneous detection of Sp, Hib and MTBC. The multiplex touchdown PCR assay was evaluated using standard strains and clinical sputum samples. The multiplex touchdown PCR assay showed 100% specificity in identifying Sp, Hib, MTBC from pure culture of standard strains. The sensitivities of the multiplex touchdown PCR assay were 94%, 98%, 98% for detection of Sp, Hib and MTBC respectively based on culture results while evaluated using 492 consecutive qualified clinical sputum samples; the specificities were all 100%. This highly sensitive and specific multiplex touchdown PCR assay offers a rapid and simple method for detection of Sp, Hib and MTBC in clinical sputum samples.

Enhanced osseointegration of titanium implant through the local delivery of transcription factor SATB2

Titanium implants are widely used in dentistry and orthopedic surgery. Nevertheless, bone regeneration around the implant is a relatively slow process, after placement. This study assessed whether SATB2 can enhance osseointegration of a titanium implant. To determine the effect of SATB2 in implant integration, two different viruses encoding SATB2 (PBABE-Satb2 virus or RCAS-Satb2 virus) were locally administered to the bone defect prior to titanium implant placement in our established transgenic TVA mice. Seven and 21 days post implantation, the femurs were isolated for quantitative real-time RT-PCR, H&E staining, immunohistochemical (IHC) staining, and microcomputed tomography (microCT) analysis. Quantitative real-time RT-PCR results demonstrated that the in vivo overexpression of SATB2 enhanced expression levels of potent osteogenic transcription factors and bone matrix proteins. We also found that 21 days after implantation, there were no significant differences in the expression levels of SATB2, Osx, Runx2, COLI, OC, and BSP between the RCAS-Satb2 group and the RCAS group. Histological analysis showed that SATB2 overexpression significantly enhanced new bone formation and bone-to-implant contact after implantation. IHC staining analysis revealed that forced expression of SATB2 increased the number of BSP-positive cells surrounding the implant. MicroCT analysis demonstrated that in vivo overexpression of SATB2 significantly increased the density of the newly formed bone surrounding the implant. These results conclude that in vivo overexpression of SATB2 significantly accelerates osseointegration of titanium implants and SATB2 can serve as a potent molecule in promoting tissue regeneration.

Gene expression profile in the liver tissue of geese after overfeeding

Geese form a fatty liver after feeding on a carbohydrate-rich diet, possibly as an evolutionary adaptation to accumulate reserves for migration. To gain insight into the gene-regulation processes of hepatic steatosis in geese, we examined the profile of transcriptional expression in goose fatty liver and control liver by suppression subtractive hybridization and measured the levels of serum biochemical variables. We found 107 genes whose expression was different between the treatment and control groups. The main functions of these genes are metabolic processes, including the metabolism of carbohydrates, amino acids, and lipids. Twenty-four genes were classified using the Kyoto Encyclopaedia of Genes and Genomes pathways. Twelve genes that related to metabolic and cellular processes were confirmed by quantitative RT-PCR. A specific positive effect of feeding was observed on the expression of genes involved mainly in unsaturated fatty acids and triglyceride synthesis, and a negative effect was observed on genes involved in β-oxidation, cholesterol metabolism, and glycolysis. The results could serve as an important reference for the development of goose breeding for fatty liver production and human liver disease research.

A comparative study on SWCNT and DWCNT field-effect transistors

Field-effect transistors have been fabricated using single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs), and their electrical transport properties have been studied comparatively. While a semiconducting SWCNT exhibits better field-effect characteristics than a DWCNT counterpart, the DWCNT shows more complicated response to external gate modulation. Depending on the nature of the two shells of a DWCNT, i.e., whether the shell is semiconducting (S) or metallic (M), a DWCNT device can be described as either S-S, or S-M, or M-S, or M-M. It was found that the S-S and M-M or M-S devices show similar field-effect characteristics to those found in SWCNT devices. But for S-M DWCNT devices, distinct field-effect characteristic was found and attributed to the combined effects of intershell interactions and screening by free carriers of the inner metallic shell. The S-M DWCNT devices thus provide a perfect system for studying the important intershell interaction, and information on the effect of this interaction on the electrical properties of a multi-walled carbon nanotube can be obtained by a comparative study of S-M DWCNT and S-SWCNT devices.

DIP: The Database of Interacting Proteins: 2001 update

The Database of Interacting Proteins (DIP; http://dip.doe-mbi.ucla. edu) is a database that documents experimentally determined protein-protein interactions. Since January 2000 the number of protein-protein interactions in DIP has nearly tripled to 3472 and the number of proteins to 2659. New interactive tools have been developed to aid in the visualization, navigation and study of networks of protein interactions.

Serotonin-like immunoreactive fibers in the medial dorsal accessory group and the anterior fornical nucleus of the magnocellular neurosecretory system in the rat

The area lateral to the stria medullaris and the fornix at the level of the interventricular foramen, an area known to be occupied by the medial dorsal accessory group and the anterior fornical nucleus of the magnocellular neurosecretory system, was found to be studded with serotonin (5-HT)-like immunoreactive (LI) varicosities. Double immunostaining with antisera against 5-HT and oxytocin (OXY) proved that the 5-HT-LI varicosities were in close proximity to the OXY-LI neurons in the medial dorsal accessory group and the anterior fornical nucleus. These nuclei were distributed more densely with 5-HT-LI varicosities than other cell groups in the magnocellular neurosecretory system.