Histogram analysis of diffusion kurtosis imaging of deep brain nuclei in Parkinson's disease with different motor subtypes

AIM

To evaluate the diagnostic and differential efficacy of diffusion kurtosis imaging (DKI) histogram analysis for different motor subtypes of Parkinson's disease (PD).

MATERIALS AND METHODS

Seventy PD patients including 40 with postural instability and gait disorder (PIGD) and 30 with tremor-dominant (TD) and 36 healthy controls (HC) were enrolled prospectively and underwent MRI examinations. The regions of interest (ROI) in the deep brain nuclei were delineated and features were extracted on the map of mean kurtosis (MK), axial kurtosis (Ka), and radial kurtosis (Kr), respectively. The differences in histogram features between PD patients and HC and between patients with PIGD and TD were compared. The areas under the curve (AUCs) were calculated to evaluate the diagnostic efficacy of all histogram features. The correlations between histogram features and clinical indicators were evaluated.

RESULTS

Some DKI histogram features were significantly different between PD patients and HC, and also different between patients with PIGD and TD (all p<0.05). MK of the substantia nigra pars reticulate (SNprkurtosis), Ka of the substantia nigra pars compacta (SNpc) 50 percentile (SNpcP50), and Kr of SNpc 90th percentile showed the highest AUC for distinguishing patients with PIGD from HC. MK-SNpc 10th percentile, Ka-SNpc 25th percentile, and Kr of the head of the caudate nucleus (CN) 90th percentile had the highest AUC for distinguishing patients with TD from HC. MK of the putamen 10th percentile combined with Ka of the bilateral red nucleus RNkurtosis yielded the highest diagnostic performance with an AUC of 0.762 for distinguishing patients with PIGD from TD. Certain DKI histogram features were correlated with Hoehn-Yahr (H&Y) stage, Mini Mental State Examination (MMSE) score, tremor score, and PIGD score (all p<0.05).

CONCLUSION

DKI histogram analysis was useful to diagnose and discriminate different motor subtypes of PD. Certain DKI histogram features correlated with clinical indicators.

The characteristics of thoracic aortic dissection in autopsy-diagnosed individuals: An autopsy study

Thoracic aortic dissection (TAD) is the most common cause of sudden cardiac death associated with aortic diseases. The age of TAD victims in forensic studies is significantly younger than hospitalized patients with TAD, while only a few studies have been conducted on autopsy-diagnosed TAD deceased. A retrospective study was conducted at the Medicolegal Center of Sun Yat-sen University from 1999 to 2019 to address the characteristics of TAD victims. A total of 200 deceased from spontaneous rupture of TAD were assessed, with 165 (82.5%) males and 175 (87.5%) Stanford type A deceased. Our main results showed that compared with patients with TAD diagnosed during their lifetime, individuals diagnosed with TAD until an autopsy showed an earlier onset (43.80 years old) and less accompanied hypertension (<50%). Sudden death was the initial symptom of 32 decedents. Instead of chest/back pain (40 decedents), abdominal pain (59 decedents) was the most common initial symptom, and 42 decedents presented with no accompanying pain. A higher proportion of abdominal pain and the painless symptom was associated with a higher risk of misdiagnosis. Women showed a more atypical clinical presentation and rapid progression than men. Younger decedents showed more pronounced left heart changes. The present study implicated the TAD individuals diagnosed until an autopsy as a particular entity, indicating the urgent need for further investigation on early diagnosis and pathogenesis of patients with TAD with atypical pain and painless or with younger age to reduce the burden of TAD-related sudden death.

Gadolinium deposition in the brain is related to various contrast agents: a matched case-control study

AIM

To assess the relationship between gadolinium deposition in the brain and various gadolinium-based contrast agents (GBCAs) and to explore confounding variables.

METHODS

The study group included 87 patients with multiple enhanced brain magnetic resonance imaging (MRI) examinations of which 48 patients were in the linear GBCA group (33 patients in gadopentetate dimeglumine group and 15 patients in gadobenate dimeglumine group) and 39 patients in the macrocyclic GBCA group (22 patients in gadobutrol group and 17 patients in gadoterate meglumine group). The control group included 87 normal participants who were matched regarding age, sex, MRI machine and imaging sequences to the study cohort. T1 signal intensity (SI) ratios of the dentate nucleus to the pons (DN/pons) and of the globus pallidus to the frontal white matter (GP/FWM) in both groups were calculated and compared. The relationships between SI ratios and confounding variables were analysed.

RESULTS

Significant differences were detected between two linear GBCA groups and control groups in T1 SI ratios of the DN/pons and GP/FWM (all p<0.001). There were no differences for two the macrocyclic GBCA groups compared with matching control groups (all p>0.05). T1 SI ratios of the linear GBCA group were significantly higher than those of the macrocyclic GBCA group (p<0.001). In the linear GBCA group, the T1 SI ratios of the DN/pons correlated moderately positively with the number of GBCA administrations (r=0.643, p<0.001), and MRI machine and sequence used.

CONCLUSIONS

Increased T1 SI could be observed after repeated administrations of linear GBCA. T1 SI of the DN correlated with the number of linear GBCA administrations, and detection might be affected by MRI machine and sequence.

[Hydroxyfasudi attenuates lipopolysaccharide induced endothelial dysfunction via suppressing the expression of Rho-associated coiled-coil protein kinase 1, connexin 43 and caveolin 1]

Objective: To investigate the effect and mechanism of hydroxyfasudi (HF), a specific Rho kinase inhibitor, on lipopolysaccharide(LPS)induced endothelial dysfunction. Methods: A total of 24 male Sprague Dawley rats were randomly divided into control group(n=6), HF group(n=6), LPS group(n=6) and LPS + HF group(n=6) with random number table method. There was no special treatment in control group. HF (30 mg/kg) was injected intraperitoneally in HF group. LPS (1 mg/kg) were injected intravenously in LPS group. In LPS+ HF group, HF (30 mg/kg) was injected intraperitoneally, followed by intravenous LPS injection (1 mg/kg) 30 minutes later. All rats were sacrificed after 8 hours, and aortic tissue was extracted. RT-PCR was performed to detect mRNA levels of Rho-associated coiled-coil protein kinase (ROCK)1, connexin (Cx)43 and caveolin (Cav)1. The protein levers of ROCK1, Cx43 and Cav-1 were assessed by Western blot and immunohistochemical staining respectively. Results: (1) RT-PCR experiments showed that mRNA levels of ROCK1(2.67±0.03 vs. 1.00±0.04), Cx43(1.73±0.03 vs. 1.00±0.08), and Cav1(1.85±0.04 vs. 1.0±0.03) in LPS group were significantly higher than in control group(all P<0.05). mRNA levels of ROCK1(0.38±0.02), Cx43(0.58±0.02), and Cav1(0.27±0.01) in LPS + HF group were significantly lower than in LPS group(all P<0.05). (2)Western blot analysis showed that protein levels of ROCK1(3.46±0.82 vs. 2.19±0.56), Cx43(0.33±0.09 vs.0.11±0.06), and Cav1(3.45±0.74 vs. 2.25±0.91) in LPS group were significantly higher than in control group(all P<0.05). Protein levels of ROCK1(1.09±0.52), Cx43(0.01±0.06), and Cav1(2.06±0.40) in LPS + HF group were significantly lower than in LPS group(all P<0.05). (3) Immunohistochemical staining showed that protein levels of ROCK1(84.1±0.953.7±2.9), Cx43(99.1±2.1 vs. 46.2±0.8), and Cav1(167.0±6.4 vs. 84.9±1.0) in LPS group were significantly higher than in control group(all P<0.05). Protein levels of ROCK1(30.4±0.6), Cx43(21.4±1.3), and Cav1(55.8±2.8) in LPS + HF group were significantly lower than in LPS group(all P<0.05). Conclusion: HF attenuates LPS induced endothelial dysfunction probably via suppressing the expression of ROCK1, Cx43 and Cav1.

Novel polymeric nanoparticles targeting the lipopolysaccharides of Pseudomonas aeruginosa

Considering outburst of various infectious diseases globally, nanoparticle assisted targeted drug delivery has emerged as a promising strategy that can enhance the therapeutic efficacy and minimize the undesirable side effects of an antimicrobial agents. Molecular imprinting is a newly developed strategy that can synthesize a drug carrier with highly stable ligand-like 'cavity', may serve as a new platform of ligand-free targeted drug delivery systems. In this study, we use the amphiphilic lipopolysaccharides, derived from Pseudomonas aeruginosa as imprinting template and obtained an evenly distributed sub-40 nm polymeric nanoparticles by using inverse emulsion method. These molecularly imprinted nanoparticles (MIPNPs) showed specific binding to the lipopolysaccharide as determined by fluorescence polarization and microscale thermophoresis. MIPNPs showed selective recognition of target bacteria as detected by flow cytometry. Additionally, MIPNPs exhibited the in vivo targeting capabilities in both the keratitis model and meningitis model. Moreover, the photosensitizer methylene blue-loaded MIPNPs presented significantly strong inhibition of bacterial Growth, compared to non-imprinted controls for in vitro model of the photodynamic therapy. Our study shows an attempt to design a magic bullet by molecular imprinting that may provide a novel approach to generate synthetic carrier for targeting pathogen and treatment for a variety of infectious human diseases.

Familial hypercholesterolaemia with tuberous and tendinous xanthomas: case report and mutation analysis

Xanthomas are important clinical manifestations of disordered lipid metabolism, which are mostly found in patients with familial hypercholesterolaemia (FH), an inherited disorder that is predominantly caused by mutations in the low-density lipoprotein receptor gene (LDLR). Tuberous and tendinous xanthomas with wide distribution and large size are rare; however, they may indicate the severity of FH, and tend to be found in homozygous FH. In this study, we investigated the clinical and genetic aspects of a young patient with FH presenting with multiple large masses in various locations. The lesions on the elbows and buttocks were locally excised and subsequently confirmed by biopsy to be xanthomas. Genetic analysis further confirmed that the patient was compound heterozygous for two mutations in both alleles of the LDLR gene. This rare case of compound heterozygous FH presenting with multiple large and widely distributed xanthomas provides a better understanding of FH and xanthomas.

[Immunohistochemical study on ANP in the atria of electrocution]

By the immunohistochemical staining for ANP with LSAB method and the analysis of areas and grays of ANP with computer image analysis, it was found that the ANP granulus in right atria of electrocution were obviously depleted, compared with that in the control groups. The results showed that depletion of ANP granules in right atria could be used as a reference for the forensic diagnosis of electrocution and might benefit for the clinical therapy to the patients suffering from electric injuries.

Construction, expression, and characterization of recombinant hirudin in Escherichia coli

The mutant gene of HV2-K47 was obtained by polymerase chain reaction-directed mutagenesis and expressed in Escherichia coli. Many elements that could affect its expression level were compared. The product was purified to homogeneity via three chromatographic steps--ion exchange, gel filtration, and reverse phase chromatography--on the AKTA Explorer System. The anti-thrombin activity of HV2-K47 is much higher than that of recombinant HV2. Some properties and expression conditions were investigated systematically, which would be useful for further studies of hirudin and other small proteins.

[Changes of leukocyte rheologic characteristics and cell adhesion molecules in patients with multiple organ failure after severe trauma]

OBJECTIVE

To explore the changes of leukocyte rheologic characteristics and of cell adhesion molecule in patients with multiple organ failure (MOF) after severe trauma.

METHODS

By using the erythrocyte deformability apparatus, platelet and thrombus adhesion dual-purpose apparatus and enzyme-linked immunosorbent assay (ELISA), We measured the leukocyte deformability (LD), leukocyte adhesion function (LAF), leukocyte CD18 expression, soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule (sVCAM-1) concentration in 36 MOF patients, 31 trauma patients, and 35 to be controls.

RESULTS

The leukocyte filtration index (LFI), leukocyte adhesion rate (LAR), leukocyte CD18 expression, and sICAM-1 and sVCAM-1 concentration were significantly higher in MOF patients than in controls and trauma patients (F = 68.45 - 116.20, q = 12.161 - 21.374, P < 0.00), and the changes of these indicators in MOF deaths were more obvious than those in MOF survivors (t = 6.920 - 11. 665, P < 0.00). The LFI and LAR in MOF patients were positively related to leukocyte CD18 expression, sICAM-1, and sVCAM-1 concentration (r = 0.691 - 0.844, P < 0.001); LFI was positively related to LAR (r = 0.711, P < 0.001).

CONCLUSION

The abnormalities of leukocyte rheologic characteristics and CAMs might be closely related to the occurrence of MOF and the severity of pathologic changes.

Re-design of Smith predictor systems for performance enhancement

In this paper, a new design for Smith Predictor systems is presented. It employs a deliberately mismatched model to enhance performance over a perfectly matched system while using a simple primary controller. The design methodology is formulated in the frequency domain as an optimization problem and it turns out that an approximate solution can be obtained using the linear least squares method. To improve the performance further, a modified Smith Predictor system structure is also proposed, and it reduces the system into one involving second-order dynamics for the primary controller design. Illustrative simulation of several typical processes are included.

[Cerebrovascular diseases complications after cardiac surgery]

OBJECTIVE

To assess morbidity, mortality, sorts, risk factors, prevention and treatment of patients with cerebrovascular disease complication (CVDC) undergoing cardiopulmanary bypass (CPB).

METHODS

We retrospectively reviewed 10,173 cases of CPB surgery, analysed risk factors of CVDC after CPB surgery in comparison with controls.

RESULTS

After CPB surgery, the general morbidity of neurological complications (NC) was 1.44% (146/10,173), of which CVDC accounted for 59.58% (87/146). In the CVDC group, cerebral embolism accounted for 39.09%, cerebral infarction 28.74%, cerebral haemorrhage 11.49%, prosthetic valve endocarditis (PVE) with CVD 10.34%, and others 10.35%. Death occurred in 44 patients of the NC group, in which CVDC went to 47.72% (21/44). Aortic clump time and CPB time were greatly longer in the CVDC group than controls (P < 0.01).

CONCLUSIONS

The main postoperative neurological complications after CPB surgery are CVDC, most of which are ischemic cerebrovascular disease. Postoperative CVDC correlates with longer aortic clump time and CPB time during the operation.

Presenilin mutations associated with Alzheimer disease cause defective intracellular trafficking of beta-catenin, a component of the presenilin protein complex

The presenilin proteins are components of high-molecular-weight protein complexes in the endoplasmic reticulum and Golgi apparatus that also contain beta-catenin. We report here that presenilin mutations associated with familial Alzheimer disease (but not the non-pathogenic Glu318Gly polymorphism) alter the intracellular trafficking of beta-catenin after activation of the Wnt/beta-catenin signal transduction pathway. As with their effect on betaAPP processing, the effect of PS1 mutations on trafficking of beta-catenin arises from a dominant 'gain of aberrant function' activity. These results indicate that mistrafficking of selected presenilin ligands is a candidate mechanism for the genesis of Alzheimer disease associated with presenilin mutations, and that dysfunction in the presenilin-beta-catenin protein complexes is central to this process.

Fast full search equivalent encoding algorithms for image compression using vector quantization

Three fast search routines to be used in the encoding phase of vector quantization (VQ) image compression systems are presented. These routines, which are based on geometric considerations, provide the same results as an exhaustive (or full) search. Examples show that the proposed algorithms need only 3-20% of the number of mathematical operations required by a full search and fewer than 50% of the operations required by recently proposed alternatives.