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Biomedical subjects

Jianlong Zhao

Publications and source records attributed to Jianlong Zhao.

8 recordsLinked to original sources

Personalized functional topography-based multisite brain age prediction modeling reveals divergent neurodevelopment in major depression.

Major depressive disorder (MDD) is associated with widespread alterations in functional brain networks across the lifespan. However, heterogeneity in atypical brain development among patients with MDD remains largely uncharacterized. Using a multisite resting-state functional MRI dataset consisting of 1,105 MDD patients and 1,065 healthy controls, we constructed a harmonized multicenter brain age prediction model based on individualized functional topography and identified two patient subgroups with positive or negative brain age gaps (BAGs). In patients with a positive BAG (BAG+), expansion of the salience network (SAL) into the dorsolateral prefrontal and ventrolateral prefrontal cortices, in addition to contraction of the sensorimotor and dorsal attention networks (DAN), contributes to accelerated brain aging. Conversely, in the negative BAG (BAG-) group, SAL expansion into the orbitofrontal cortex (OFC) and contraction of the visual and sensorimotor networks (SMN) were linked to delayed brain development. These subgroups also exhibited distinct neurodevelopmental trajectories. Clinically, BAG+ patients showed stronger associations between higher-order network topography and mood symptoms, whereas BAG- patients exhibited links between visual/default mode network topography and insomnia. At the molecular level, both groups showed enrichment of genes related to synaptic signaling but displayed distinct expression patterns and divergent expression trajectories in key neurodevelopmental gene sets. Notably, antidepressant treatment modulated the brain in ways that were specific to each subgroup. These findings reveal heterogeneous neurodevelopmental profiles in MDD with distinct biological and clinical signatures, offering insights into personalized precision medicine for this disorder.

Humans↗

A novel method based on ligase detection reaction for low abundant YIDD mutants detection in hepatitis B virus.

A novel method based on ligase detection reaction (LDR) coupled with polymerase chain reaction (PCR) was used in this study to detect low abundant YIDD mutants in hepatitis B virus (HBV), which was able to detect 10(2) mutants from 10(8) wild type copies in plasmids and 10(3) from 10(7) in clinical serum samples. Direct sequencing and microarray hybridization were selected for sensitivity comparison together with this assay. By direct sequencing, 6 of 50 clinical specimens infected with HBV were found to be YIDD and the others to be YMDD, while by microarray hybridization, 28 specimens were detected to contain both YMDD and YIDD, and the others contained YMDD only, and with this assay, 31 specimens containing both YMDD and YIDD were detected with the others containing YMDD only, which indicated that the assay was relatively more sensitive.

Journal Article↗

Optical and electrochemical detection techniques for cell-based microfluidic systems.

The ability to fabricate microfluidic systems with complex structures and with compatible dimensions between the microfluidics and biological cells have attracted significant attention in the development of microchips for analyzing the biophysical and biochemical functions of cells. Just as cell-based microfluidics have become a versatile tool for biosensing, diagnostics, drug screening and biological research, detector modules for cell-based microfluidics have also undergone major development over the past decade. This review focuses on detection methods commonly used in cell-based microfluidic systems, and provides a general survey and an in-depth look at recent developments in optical and electrochemical detection methods for microfluidic applications for biological systems, particularly cell analysis. Selected examples are used to illustrate applications of these detection systems and their advantages and weaknesses.

Biosensing Techniques↗

A low temperature bonding of quartz microfluidic chip for serum lipoproteins analysis.

A low-temperature bonding method for microfabrication of quartz microfluidic chips has been developed. The bonding process involved two steps: pre-bonding and post-annealing at low temperature. The bonding quality was evaluated by measuring the shear force at bonding interface and the electrical properties of the chips. Shear force of 5.66 MPa (566 N/cm(2)) was obtained in a bonded chip after a post-annealing at 200 degrees C for 6 h. We owe the strong bonding strength to the formation of Si-O-Si bonds at the bonding interface during the post-annealing stage. The bonding procedures were not sensitive to surrounding and could be performed in a routine laboratory without clean room conditions. The performance of the fabricated microfluidic chips was tested by capillary zone electrophoresis (CZE) of serum lipoproteins with laser-induced fluorescence (LIF). The low-density (LDL) and high-density (HDL) lipoproteins in the serum was separated completely by using tricine buffer with methylglucamine.

Cold Temperature↗

Study of hepatitis B virus gene mutations with enzymatic colorimetry-based DNA microarray.

OBJECTIVES: To establish a modified microarray method for detecting HBV gene mutations in the clinic. DESIGN AND METHODS: Site-specific oligonucleotide probes were immobilized to microarray slides and hybridized to biotin-labeled HBV gene fragments amplified from two-step PCR. Hybridized targets were transferred to nitrocellulose membranes, followed by intensity measurement using BCIP/NBT colorimetry. RESULTS: HBV genes from 99 Hepatitis B patients and 40 healthy blood donors were analyzed. Mutation frequencies of HBV pre-core/core and basic core promoter (BCP) regions were found to be significantly higher in the patient group (42%, 40% versus 2.5%, 5%, P < 0.01). Compared with a traditional fluorescence method, the colorimetry method exhibited the same level of sensitivity and reproducibility. CONCLUSIONS: An enzymatic colorimetry-based DNA microarray assay was successfully established to monitor HBV mutations. Pre-core/core and BCP mutations of HBV genes could be major causes of HBV infection in HBeAg-negative patients and could also be relevant to chronicity and aggravation of hepatitis B.

Colorimetry↗

Detection of gyrA and parC mutations associated with ciprofloxacin resistance in Neisseria gonorrhoeae by use of oligonucleotide biochip technology.

An oligonucleotide biochip that specifically detects point mutations in the gyrA and parC genes of Neisseria gonorrhoeae was designed and subsequently evaluated with 87 untreated clinical specimens. The susceptibilities of the N. gonorrhoeae strains were tested to determine the prevalence of ciprofloxacin-resistant strains in Anhui Province, People's Republic of China. Conventional DNA sequencing was also performed to identify mutations in gyrA and parC and to confirm the biochip data. The study demonstrates that all of the point mutations in the gyrA and parC genes of N. gonorrhoeae were easily discriminated by use of the oligonucleotide biochip. Fifteen different alteration patterns involved in the formation of ciprofloxacin resistance were identified by the biochip assay. Double mutations in both Ser91 and Asp95 of the GyrA protein were seen in all nonsensitive isolates. Double mutations in Ser91 and Asp95 of GyrA plus mutation of Glu91 or Ser87 of the ParC protein lead to significant high-level resistance to ciprofloxacin in N. gonorrhoeae isolates. The results obtained by use of the oligonucleotide biochip were identical to those obtained by use of DNA sequencing. In conclusion, the oligonucleotide biochip technology has potential utility for the rapid and reliable identification of point mutations in the drug resistance genes of N. gonorrhoeae.

Anti-Infective Agents↗

Generation of concentration gradient by controlled flow distribution and diffusive mixing in a microfluidic chip.

We have developed a simple method to generate a concentration gradient in a microfluidic device. This method is based on the combination of controlled fluid distribution at each intersection of a microfluidic network by liquid pressure and subsequent diffusion between laminas in the downstream microchannel. A fluid dynamic model taking into account the diffusion coefficient was established to simulate the on-chip flow distribution and diffusion. Concentration gradients along a distance of a few hundred micrometers were generated in a series of microchannels. The gradients could be varied by carefully regulating the liquid pressure applied to the sample injection vials. The observed concentration gradients of fluorescent dyes generated on the microfluidic channel are consistent with the theoretically predicted results. The microfluidic design described in this study may provide a new tool for applications based on concentration gradients, including many biological and chemical analyses such as cellular reaction monitoring and drug screening.

Journal Article↗

[Influence of labeled primer and labeled dUTP assays on the signal intensity of the chip for the detection of HBV gene polymorphism].

BACKGROUND: To evaluate the influence of assays with primer labeled with fluorochrome (Cy5) and dUTP labeled with Cy5 on the signal intensity of the chip for detection of hepatitis B virus (HBV) gene polymorphism. METHODS: The P-region and pre-C/C-region of HBV gene were amplified by polymerase chain reaction (PCR) with Cy5 labeled primer or Cy5 labeled dUTP. The amplicons of the two assays were hybridized with chips, scanned and analyzed by computer software for the detection of HBV gene polymorphism. RESULTS: The signal intensity of assay with Cy5 labeled dUTP was slightly higher than that of assay with Cy5 labeled primer, but non?specific signal intensity of the assay with Cy5 labeled dUTP was higher. The result of 42 samples showed that there was no significant difference between the two assays, and that both had a good repeatability and CV value (15%-20%). CONCLUSIONS: The assay with Cy5 labeled primer may replace the assay with Cy5 labeled dUTP as a routine method to detect HBV gene polymorphism, and it is simpler and cheaper.

DNA, Viral↗