[A case of metastatic breast cancer complicated by pulmonary tumor thrombotic microangiopathy].

Pulmonary tumor thrombotic microangiopathy is a malignancy-related complication with rapid progression and high mortality. To improve the understanding of the disease, early diagnosis and treatment are key to successful treatment. A 39-year-old patient with pulmonary hypertension transferred from another hospital was admitted to the First Affiliated Hospital of Guangzhou Medical University on September 26, 2021. The patient developed shortness of breath and progressive exacerbation over the past month. No pulmonary artery embolism was seen on computed tomography pulmonary angiography (CTPA) at the outside hospital where the breast cancer was diagnosed. Pulmonary tumor thrombotic microangiopathy was immediately considered on admission and oncological endocrine therapy was started. After treatment, the patient's dyspnoea improved, PET-CT showed significant tumor regression, and cardiac ultrasound showed a significant decrease in pulmonary artery pressure. The successful treatment experience of this case was summarized for reference.

[Tuberculosis screening in respiratory department inpatients in comprehensive medical institutions].

Objective: To explore the effect of screening tuberculosis patients in the respiratory department of general hospitals, and to provide a basis for the development of patient screening strategy. Methods: Clinical information and sputum samples of inpatients in the respiratory department of a general hospital in Longhua District, Shenzhen from December 2018 to December 2020 were collected. Sputum samples were sent to the tuberculosis laboratory of the Shenzhen Longhua Center for Chronic Disease Control (designated tuberculosis diagnosis and treatment institution) for sputum smear, liquid culture and Gene-Xpert test. Results: A total of 407 sputum samples (23 cases of suspected tuberculosis by chest imaging and 384 by clinical manifestations) were collected from 3 724 hospitalized patients. A total of 88 patients with positive etiology were detected by the three methods, and the positive rate was 21.6% (88/407), among which 15 patients with suspected tuberculosis were detected by imaging reports, and the positive rate of etiology was 19.0% (73/384) in the reported patients without imaging reports. At least 1.96% (73/3 724) of the hospitalized patients were estimated to be tuberculosis positive during the study. Pneumonia (30.1%,22/73), cough (15.1%,11/73) and pulmonary infection (15.1%,11/73) were the main characteristics in the patients with positive pathogens. Conclusions: Screening for tuberculosis among inpatients in the respiratory department of general hospitals is an effective way to detect patients who were radiographically reported to have probable tuberculosis. It is of great significance to carry out active screening in key departments of general hospitals for tuberculosis detection and control.

Trends in drug-resistant tuberculosis after the implementation of the DOTS strategy in Shenzhen, China, 2000-2013.

SETTING: The DOTS strategy has been regarded as the most cost-effective way to stop the spread of tuberculosis (TB) since its launch by the World Health Organization. OBJECTIVE: To estimate the effects of DOTS by tracking long-term trends in multidrug-resistant TB (MDR-TB). DESIGN: A retrospective cohort study was conducted from 2000 to 2013 to analyse trends in resistance to anti-tuberculosis drugs and the effect of DOTS-based treatment in Shenzhen, China, using the χ2 test. RESULTS: An overall MDR-TB rate of 4.2% was observed between 2000 and 2013, with an annual reduction of 0.16%. From 2000 to 2013, trends in resistance to isoniazid (INH), rifampicin (RMP) and MDR-TB declined significantly in new TB patients (P < 0.01), but not in retreatment cases. Sputum smear conversion rates after 2 months of treatment decreased significantly, in particular after 2007, in new and retreatment cases. CONCLUSION: INH and RMP resistance and MDR-TB rates declined significantly, suggesting that DOTS-based programmes were successful in reducing drug resistance in new cases but not in retreatment cases. The decreasing sputum smear conversion rates may have been due to an increase in the number of migrants. These two findings suggest that TB is unlikely to be completely eliminated by 2050 in Shenzhen.

Synthesis, characterization, and applications of a fluorescent probe of DNA damage.

We have designed and generated a 90-mer oligonucleotide that contains a single adduct of benzo[a]pyrene diol epoxide (BPDE) and that is fluorescently labeled. The known amount of BPDE adduct in a given length of DNA makes this probe a useful standard for DNA damage assay. The BPDE-90-mer was fluorescently labeled with tetramethylrhodamine to allow for high sensitivity detection with laser-induced fluorescence (LIF). The binding of both double-stranded and single-stranded BPDE-90-mer with three anti-BPDE antibodies was studied using affinity capillary electrophoresis (CE). Formation of antibody complex with BPDE-90-mer results in a shift in migration time from that of the unbound BPDE-90-mer. Affinity CE/LIF studies suggest that antibody 8E11 has high-affinity suitable for immunoassay of BPDE-DNA adducts. A competitive immunoassay using the fluorescent probe and CE/LIF is demonstrated for the analysis of BPDE-DNA adducts in A549 human lung carcinoma cells incubated with 2.5, 5, and 10 microM BPDE for 2 h. The design of the 90-mer probe is flexible to substitute different DNA damage types with relative ease. The fluorescent 90-mer is composed of six shorter oligonucleotides. The sequence of the two center oligonucleotides may be changed depending on the desired DNA lesion measurement. By inserting different damaged oligonucleotides, a variety of DNA damage systems can be investigated using the same CE/LIF approach.

Detection of DNA adducts of benzo[a]pyrene using immunoelectrophoresis with laser-induced fluorescence. Analysis of A549 cells.

Detection of benzo[a]pyrene diol epoxide (BPDE)-damaged DNA in a human lung carcinoma cell line (A549) has been performed using free zone affinity capillary electrophoresis with laser-induced fluorescence (LIF). Using BPDE as a model carcinogenic compound, the speed, sensitivity and specificity of this technique was demonstrated. Under free zone conditions, an antibody bound adduct was baseline-resolved from an unbound adduct in less than 2 min. The efficiencies of separation were in excess of 6 x 10(5) and 1 x 10(6) plates per meter for the antibody-bound and unbound adducts, respectively. Separation using a low ionic strength buffer permitted the use of a high electric field (830 V/cm) without the loss of resolving power. Using LIF detection, a concentration detection limit of roughly 3 x 10(-10) M was achieved for a 90-mer oligonuleotide containing a single BDPE. The use of formamide in the incubation buffer to enhance denaturing of DNA did not affect the stability of the complex between the antibody and the adducts. Using a fluorescently labeled BPDE-modified DNA adduct probe, a competitive assay was established to determine the levels of BPDE-DNA adducts in A549 cells.

[Study on the relationship of metallothionein and antioxidases in protective mechanism of cardiomyocytes].

AIM: To study the relationship of Metallothionein (MT) and antioxidases in hypoxia/reoxygenation (H/R) and hypoxic preconditioning (HPC). METHODS: H/R and HPC model of rat cultured cardiomyocytes were established. Then the contents of MT and relevant changes of activities of antioxidases (SOD, CAT, GSHpx) of cardiomyocytes were determined while pretreated with the treatment: HPC. Zn2+ inducing MT or MT antibody. RESULTS: In HPC and Zn2+ induced groups, all the contents of MT and the activities of antioxidases were obviously higher than those in H/R (P < 0.05, P < 0.01 respectively). While using MT, the activities of SOD were progressively increased than control (P < 0.05), CAT and GSHpx activities were lower than control (P < 0.01), but were significantly higher than those in I/R group (P < 0.01). In MT antibody groups, the activities of antioxidase were decreased extremely. CONCLUSION: MT has effects on the cardiomyocytes protective role of HPC. And can afford more capacity for cardiomyocytes to tolerate the H/R damage by the mechanism of increasing the activities of antioxidase.

Detection of duck hepatitis B virus DNA fragments using on-column intercalating dye labeling with capillary electrophoresis-laser-induced fluorescence.

A rapid on-column DNA labeling technique is used to detect viral restriction DNA fragments by capillary electrophoresis-laser induced fluorescence detection. Intercalating dyes such as POPO3 or ethidium homodimer-2 are incorporated into the detection buffer. The cationic dyes migrate into the capillary during electrophoresis and bind to the oppositely migrating DNA fragments. A post-column sheath-flow fluorescence detector is used in the experiment. Excellent labeling efficiency is achieved at minimal background fluorescence by diluting the dyes to between 1 x 10(-7) M and 5 x 10(-7) M in a buffer with low ionic strength relative to the running buffer within the capillary. This dilute sheath-flow buffer allows stacking of dye molecules inside the capillary when an electric field is applied. Calibration curves using a series of DNA size markers (between 72 and 1353 base pairs) were linear over an order of magnitude in DNA concentration. Sensitivity also increased linearly with fragment length, and detection limits ranged from 4 x 10(-14) M to 5 x 10(-13) M for the size-standards. Analysis of cloned viral DNA using duck hepatitis B virus demonstrated a concentration detection limit of 3.9 x 10(-16) M. Last, the technique produced very high separation efficiency, 14 x 10(6) theoretical plates which is greater than 47 x 10(6) plates m-1, for the duck hepatitis B viral genome.