On-chip rapid drug screening of leukemia cells by acoustic streaming.

Rapid and personalized single-cell drug screening testing plays an essential role in acute myeloid leukemia drug combination chemotherapy. Conventional chemotherapeutic drug screening is a time-consuming process because of the natural resistance of cell membranes to drugs, and there are still great challenges related to using technologies that change membrane permeability such as sonoporation in high-throughput and precise single-cell drug screening with minimal damage. In this study, we proposed an acoustic streaming-based non-invasive single-cell drug screening acceleration method, using high-frequency acoustic waves (>10 MHz) in a concentration gradient microfluidic device. High-frequency acoustics leads to increased difficulties in inducing cavitation and generates acoustic streaming around each single cell. Therefore, single-cell membrane permeability is non-invasively increased by the acoustic pressure and acoustic streaming-induced shear force, which significantly improves the drug uptake process. In the experiment, single human myeloid leukemia mononuclear (THP-1) cells were trapped by triangle cell traps in concentration gradient chips with different cytarabine (Ara-C) drug concentrations. Due to this dual acoustic effect, the drugs affect cell viability in less than 30 min, which is faster than traditional methods (usually more than 24 h). This dual acoustic effect-based drug delivery strategy has the potential to save time and reduce the cost of drug screening, when combined with microfluidic technology for multi-concentration drug screening. This strategy offers enormous potential for use in multiple drug screening or efficient drug combination screening in individualized/personalized treatments, which can greatly improve efficiency and reduce costs.

[Clinical features of 23 cases of AIDS complicated by tuberculosis].

OBJECTIVE: To discuss the clinical features, treatment and prognosis of patients with AIDS complicated by tuberculosis(TB). METHODS: The clinical features of 23 patients with AIDS complicated by tuberculosis admitted from 1997 to July 2004 were retrospectively analyzed. RESULTS: Of the 23 patients, most (94.3%) were young or middle-aged, and 11 (47.8%) died within half a year. The main HIV transmission was via sexual contact in 15 (65.2%) patients. Loss of body weight by 5 - 15 kg was present in all patients, cough for over 1 month in 15 (65.2%), and multiple opportunistic infections were complicated in most cases. Out of the 23 cases, 14 (60.9%) showed only pulmonary TB, and 8 (34.8%) showed lymph node TB. In 12 cases with infiltrated pulmonary TB, X-ray showed bilateral infiltration and no cavity formation was found. Slightly positive PPD test was found in 2 (8.7%) cases, and positive acid-fast bacilli was detected in sputum in 1 case (4.4%). The pre-treatment CD(4)(+) cell number in 23 patients was much lower than that in AIDS patients without complicated TB (P < 0.05). The pre-treatment CD(4)(+) cell number in patients died shortly after diagnosis was much lower than that in survived patients (P < 0.05). The HIV RNA level in the 23 patients was much higher than that in patients without complication of TB (P < 0.05). The mortality in patients treated with therapy against both TB and HIV was much lower than that in patients untreated or treated only with anti-TB therapy (P < 0.05). CONCLUSIONS: For patients with AIDS complicated by TB, the high negative rate in PPD test and the atypical chest X-ray manifestations are common. However, lymph node TB is quite common with high mortality. The pre-treatment CD(4)(+) level decreases significantly, and is associated with mortality. The TB bacilli may accelerate HIV virus duplication. It is suggested that the patients be treated with a combination of anti-TB and anti-HIV therapies.

[Clinical and chest X-ray characteristics of 5 cases with severe acute respiratory syndrome in children in Shenzhen area].

OBJECTIVE: To explore clinical and chest X-ray features of SARS in children to facilitate correct diagnosis. METHODS: Clinical manifestations and chest X-ray findings in five children suffering from SARS admitted for treatment in the hospital between February and May, 2003 in Shenzhen area were analyzed. The diagnosis was confirmed by epidemiological, clinical, laboratory and radiological examinations. Among the 5 cases, 1 was a boy and the others were girls at the age of 4 to 13 years. RESULTS: Of the 5 SARS children, 3 presented a history of close contact with SARS patients. Fever was the initiative symptom, 4 had a body temperature of over 38 degrees C with the highest being 40 degrees C; fever sustained from 4 to 7 days with an average of 5.6 days. All the 5 cases developed nonproductive cough; on auscultation, both moist and dry rales could be heard in 3 out of the 5 cases. Mean total white count of peripheral blood was (2.96 - 6.9) x 10(9)/L, and was < 5.0 x 10(9)/L in 4 cases. SARS associated coronavirus specific RNA fragment was found positive by RT-PCR in 1 case; 1 case was positive for both IgM and IgG antibodies to the virus; 1 case was positive for only IgM antibody and another 2 cases were positive for only IgG antibody. IgG and IgM antibodies to Mycoplasma pneumoniae and Chlamydia pneumoniae as well as blood culture for bacteria were all negative. Findings on chest X-ray examination: 4 cases showed presence of patchy or macular opacities with cord-like shadows in unilateral lung plates while 1 case each showed ground-glass-like opacity and migratory changes; 1 case showed interstitial changes in the lungs in the form of irregular reticular lattice and cord-like shadows. Two cases received CT scanning and macular-patchy or spotty shadows were seen all over the lung. The shortest time for absorption of foci in the lungs was 7 days while the longest was 33 days with a mean of 15 +/- 6 days. None of the cases had any signs of fibrosis in the lungs. All the 5 cases were completely cured and discharged 7 to 40 days (mean 18 +/- 11 days) after admission. CONCLUSION: Compared with adult cases with SARS, children with SARS had milder symptoms and signs. Presence of unilateral patchy shadow in lungs represented the main chest X-ray findings.