[Clinical characteristics of 42 patients with different subspecies of Mycobacterium abscessus complex pulmonary disease]

Objective: To compare clinical features and treatment outcomes of Mycobacterium abscessus (M.abscessus) and Mycobacterium massiliense (M.massiliense) pulmonary disease. Methods: A retrospective analysis was performed for 42 patients diagnosed with M.abscessus complex pulmonary disease for the first time in Guangzhou Chest Hospital from January to September 2021. The age of the 42 patients was 17-73 years, including 15 males and 27 females. According to the targeted next-generation sequencing, the patients were divided into M.abscessus group (28 patients, including 10 males and 18 females) and M. massiliense group (14 patients, including 5 males and 9 females). The clinical characteristics, radiological findings, drug sensitivity and clinical efficacy evaluation at 6 months of the two groups were compared. χ2 test and t-test were used for comparison between two groups. Results: The main symptoms in M. abscessus and M. massiliense groups were cough and sputum production. Radiological findings were significantly more frequent in the M. abscessus group than in the M. massiliense group, tree-in-bud sign [22/28 (78.5%) vs. 5/14], nodular bronchiectasis [27/28 (96.4%) vs. 11/14], and lesions involving more than three lung fields [23/28 (82.1%) vs. 7/14]. Both groups showed high levels of resistance to all antimicrobials. The sensitivity rate of the M. massiliense group to clarithromycin was higher than that of the M. abscessus[13/14 vs. 15/28 (53.5%)], and the success rate of treatment was significantly higher in patients with M. massiliense at the 6-month efficacy evaluation. Conclusions: The radiological findings, drug sensitivity and treatment outcomes differ between M. abscessus and M. massiliense pulmonary disease. Improving the identification of bacterial subspecies in clinical practice can effectively improve the diagnosis and treatment.

Effects of RAD51-stimulatory compound 1 (RS-1) and its vehicle, DMSO, on pig embryo culture

Pigs have become an important model for agricultural and biomedical purposes. The advent of genomic engineering tools, such as the CRISPR/Cas9 system, has facilitated the production of livestock models with desired modifications. However, precise site-specific modifications in pigs through the homology-directed repair (HDR) pathway remains a challenge. In mammalian embryos, the use of small molecules to inhibit non-homologous end joining (NHEJ) or to improve HDR have been tested, but little is known about their toxicity. The compound RS-1 stimulates the activity of the RAD51 protein, which plays a key role in the HDR mechanism, demonstrating enhancement of HDR events in rabbit and bovine zygotes. Thus, in this study, we evaluated the dosage and temporal effects of RS-1 on porcine embryo development and viability. Additionally, we assessed the effects of its vehicle, DMSO, during embryo in vitro culture. Transient exposure to 7.5 μM of RS-1 did not adversely affect early embryo development and was compatible with subsequent development to term. Additionally, low concentrations of its vehicle, DMSO, did not show any toxicity to in vitro produced embryos. The transient use of RS-1 at 7.5 μM during in vitro culture seems to be the best protocol of choice to reduce the potentially toxic effects of RS-1 while attempting to improve HDR in the pig. Direct injection of the CRISPR/Cas9 system, combined with strategies to increase the frequency of targeted modifications via HDR, have become an important tool to simplify and accelerate the production of genetically modified livestock models.

4 Aryl hydrocarbon receptor targets are upregulated in porcine blastocyst-stage embryos that were cultured invitro: A transcriptional analysis

Invitro-produced (IVP) porcine embryos are developmentally delayed compared with those derived invivo. Thus, efforts have been made to modify the current medium for IVP of porcine embryos in an attempt to shift the abundance of target transcripts towards the invivo level. The objective of the current study was to identify differences in mRNA abundance that may account for reduced developmental competence in IVP embryos and to determine whether alterations to maturation and culture media directed the transcriptional profiles of IVP embryos towards an invivo state. Following AI of gilts, an oviduct and tip of the uterine horn were flushed on Day 2 to recover 4-cell stage embryos; these were cultured for 4 days in MU3, generating IVM and invitro-cultured (IVC) blastocyst-stage embryos. On Day 6, the gilts were killed, and the contralateral horns were flushed to obtain invivo-derived (IVV) blastocyst-stage embryos. The third group of blastocyst-stage embryos, referred to as invitro-matured and cultured (IVMC), were created by aspirating cumulus–oocyte complexes from slaughterhouse-derived ovaries, maturing and fertilizing invitro, and culturing for 6 days in MU3. Total RNA was extracted from pools of 10 blastocyst-stage embryos with 3 replicates per group. First- and second-strand cDNA was synthesised and sequenced by using the Illumina platform (Illumina Inc.). After removal of adapters and reads that mapped to porcine rRNA genes and the PhiX genome, reads were mapped to the Sus scrofa genome by using STAR (version 2.7.1a) with default options. Pairwise comparisons were performed to test for differential expression of genes by using the Bioconductor package DESEqn 2. Transcripts were differentially abundant (false discovery rate <0.05) between IVV and IVC embryos (2,450), between IVV and IVMC embryos (3,045), and between IVC and IVMC embryos (262). Pathways related to cell cycle were downregulated in IVC and IVMC compared with IVV embryos, and pathways related to amino acid transport in metabolism were upregulated in IVC and IVMC compared with IVV embryos. Of particular interest, message for cytochrome P450 family 1 subfamily A member 1 (CYP1A1) was only present in the IVC (956 reads) and IVMC (381 reads) embryos but not in the IVV embryos (0 reads). The aryl hydrocarbon receptor (AHR) promotes transcription of CYP1A1, which encodes a monooxygenase involved in xenobiotic metabolism. Moreover, abundance of 12 other AHR targets was increased in IVC and IVMC embryos (false discovery rate <0.05) compared with IVV embryos. Thus, production of porcine embryos invitro may activate AHR, resulting in altered transcriptional profiles and reduced competence. This research was funded by USDA-NIFA (2019-67011-29543).

[The clinical characteristics of 89 cases of non-tuberculous mycobacterium pulmonary disease complicated with tracheobronchial lesions]

Objective: To explore the clinical characteristics of non-tuberculous mycobacterium(NTM) pulmonary disease complicated with tracheobronchial lesions. Methods: From January 2014 to December 2018, there were 1 006 patients who were admitted to Guangzhou Chest Hospital for the first time and received examination by bronchoscopy. A total of 89 patients with complete data were selected, including 40 males and 49 females, aged 20 to 85 years, with 46 patients (52%) aged 60 years or older. The clinical symptoms and signs of the patients were analyzed with chest imaging, bronchoscopy and pathological examination results. Comparisons between groups were made by Chi-square test and t test. Results: The number of patients with NTM complicated with tracheobronchial lesions accounted for 8.9%(89/1 006) of those hospitalized with NTM and received bronchoscopy during the same period. Clinical symptoms included cough and sputum (89/89), different degrees of hemoptysis or blood sputum (52/89), and shortness of breath (50/89). Chest CT showed that 72 cases (72/89, 81%) had lung lesions involving more than 3 lung fields, and 83 cases (93%) had bronchiectasis and 63 cases (63/89, 71%) with cavities. Pulmonary atelectasis was shown in 45 cases (45/89, 51%). By bronchoscopy, 39 cases (39/89, 44%) were diagnosed as tuberculous lesions involving bilateral upper bronchi, while lesions of the right lower bronchus was found in 27 cases (27/89, 30%).The percentage of patients with multilobar bronchial involvement was 50.6%(45/89). The morphological characteristics of the bronchial lesions included scar stenosis or atresia in 63 cases (63/89, 71%), hyperemia and edema in 46 cases (46/89, 52%), and multiple types of lesions in 48 cases (48/89, 54%). Conclusions: Patients with NTM lung disease complicated with tracheobronchial inflammatory lesions did not have specific manifestations clinically. Lung lesions are extensive, often accompanied by bronchiectasis and cavity formation. Endoscopic changes were mostly manifested as multilobar tracheobronchial involvement characterized by scar stenosis, congestion and edema, mainly involving bilateral upper bronchi and the right lower bronchus.

71 Removal of hypotaurine from porcine embryo culture medium decreases message for pro-apoptotic genes but does not affect development at low oxygen tension

Hypotaurine (HT) is a routine additive to embryo culture medium, acting primarily as an oxygen radical scavenger. However, the practice of culturing embryos at ~5% O2 has been widely adopted because this is more physiologically relevant to the oxygen tensions detected in the oviduct and uterus. Thus, the utility of HT may be diminished as fewer oxygen radicals are produced during culture at 5% O2. The objective here was to determine the effects of removing HT from our porcine embryo culture medium (MU2) on the development of embryos incubated at a lower oxygen tension (5% O2) compared with atmospheric oxygen (~20% O2). Porcine cumulus-oocyte complexes were aspirated, matured, and fertilized with standard procedures from our laboratory. Presumptive zygotes were cultured in 1 of 4 conditions: MU2 with 5mM HT at 5% O2 (low O2 +HT; control), MU2 without HT at 5% O2 (low O2 −HT), MU2 with 5mM HT at 20% O2 (high O2 +HT), or MU2 without HT at 20% O2 (high O2 −HT). The percentage of presumptive zygotes that developed to the blastocyst stage on Day 6 and total number of nuclei in the blastocysts were determined. The RNA was extracted from pools of 30 blastocysts, and cDNA was synthesised for quantitative PCR for genes associated with HT synthesis, oxidative stress, and apoptosis. Damage to DNA was assessed by TUNEL staining of Day 6 blastocysts. Data were analysed for normality by using a Shapiro-Wilk test, and differences between means were detected by using 2-way ANOVA followed by Tukey’s honest significant difference test with P<0.05 considered significant. Embryos cultured with high O2 −HT had significantly decreased blastocyst development compared with all other groups (26.2±2.5% v. 36.9-41.7±3.3-4.3%). Embryos cultured with low O2 −HT had significantly more nuclei than those cultured with high O2 +HT (50.5±1.5v. 45.5±1.2). Notably, differences in blastocyst development (41.7±3.3% v. 36.9±3.3%) or total number of nuclei (50.0±1.8v. 50.5±1.5) were not detected between embryos cultured with low O2 +HT or low O2 −HT. The abundance of messages for genes involved in HT synthesis (cysteine sulfinic acid decarboxylase [CSAD]) and oxidative stress (superoxide dismutase 1 [SOD1] and glutathione peroxidase 6 [GPX6]) did not differ between groups. Contrarily, messages for 2 pro-apoptotic markers (BCL2 associated agonist of cell death [BAD] and caspase 3 [CASP3]) were significantly increased in embryos cultured with +HT regardless of oxygen tension; however, percentages of DNA-damaged nuclei in blastocysts after TUNEL staining were not different between groups (5.4-6.5±0.5-1.0%). These results indicate that HT is not necessary for porcine pre-implantation development at 5% O2 but is beneficial at atmospheric oxygen tension. Further investigation is required to confirm if HT promotes apoptosis in pre-implantation embryos. This research was supported by Food for the 21st Century at the University of Missouri and R01 HD080636.

INVITED REVIEW: Inhibitors of myostatin as methods of enhancing muscle growth and development

With the increasing demand for affordable, high-quality meat, livestock and poultry producers must continually find ways to maximize muscle growth in their animals without compromising palatability of the meat products. Muscle mass relies on myoblast proliferation during prenatal or prehatch stages and fiber hypertrophy through protein synthesis and nuclei donation by satellite cells after birth or hatch. Therefore, understanding the cellular and molecular mechanisms of myogenesis and muscle development is of great interest. Myostatin is a well-known negative regulator of muscle growth and development that inhibits proliferation and differentiation in myogenic cells as well as protein synthesis in existing muscle fibers. In this review, various inhibitors of myostatin activity or signaling are examined that may be used in animal agriculture for enhancing muscle growth. Myostatin inhibitors are relevant as potential therapies for muscle-wasting diseases and muscle weakness in humans and animals. Currently, there are no commercial myostatin inhibitors for agriculture or biomedical purposes because the safest and most effective option has yet to be identified. Further investigation of myostatin inhibitors and administration strategies may revolutionize animal production and the medical field.

Mild heat stress enhances differentiation and proliferation of Japanese quail myoblasts and enhances slow muscle fiber characteristics

The objective of this study was to investigate the effect of mild heat stress on muscle fiber hyperplastic and hypertrophic growth in quail primary myogenic cells to better understand the mechanisms leading to increased skeletal muscle development in avian embryos incubated at a higher temperature. Compared to control cultures maintained at 37°C, incubation at 39°C enhanced myotube length (P < 0.01) and diameter (P < 0.001) at 3 days after differentiation (D3). This enlargement of the myotubes incubated at 39°C can be explained by differences in the fusion index (56.7 vs. 46.2%, P < 0.05) and nuclei number per myotube (18.1 vs. 10.8, P < 0.001) compared to the control cells at D3. Additionally, a higher density of myotubes at D3 in cultures exposed to a higher temperature were related to higher levels of Pax-7 (P < 0.05) compared to the control cells incubated continuously at 37°C. These results indicated a higher proliferative capacity in cells exposed to mild heat stress compared to the control cells. On the other hand, mild heat stress enhanced protein levels of slow myosin heavy chain isoform (P < 0.01) and cytochrome c oxidase subunit IV (P < 0.01) compared to the control cells at D3. These discrepancies in protein expression indicated maintenance of slow muscle fiber type characteristics in myotubes incubated at 39°C. Our results suggest that mild heat stress plays a significant role in myogenic mechanisms related to muscle mass and development.

Safety of high doses of urokinase and reteplase for acute ischemic stroke

BACKGROUND AND PURPOSE

ET is considered in selected patients with AIS with persistent arterial occlusion after receiving IVT. Limited data exist on the safety of IA high doses of UK and RT for ET. We investigated any correlation between IA doses of UK or RT and safety outcomes in patients who underwent ET.

MATERIALS AND METHODS

We identified all patients from our stroke registry who received UK or RT for ET from 1998 to 2008. Demographics, baseline National Institutes of Health Stroke Scale scores, recanalization rates, rates of attempted MT, mortality, SICH, and discharge modified Rankin Scale scores were collected.

RESULTS

Of 197 patients; 72 received UK and 125 received RT. More than 90% of patients in both groups had received prior IVT. The median IA dose of UK was 200,000 U (range, 25,000-1,500,000 U) and of RT was 2 mg (range, 1-8 mg). Concurrent MT was attempted in 59.7% of UK-treated patients and 72.0% of RT-treated patients, with SICH rates of 4.2% and 8.0%, respectively. Logistic regression adjusting for prior IVT and MT revealed no correlation between SICH and doses of UK (OR, 1.00; 95% CI, 0.99-1.00; P = .94) or RT (OR, 0.803; 95% CI, 0.48-1.33; P = .39). There was no correlation between mortality and doses of UK (OR, 1.00; 95% CI, 0.99-1.00; P = .51) or RT (OR, 1.048; 95% CI, 0.77-1.42; P = .75).

CONCLUSIONS

High IA doses of UK and RT may be safe when given with or without MT in patients with AIS despite receiving a full dose of intravenous recombinant tissue plasminogen activator. These results need prospective validation.

Persistent lower abdominal pain induced by long peritoneal shunt catheter

Persistent abdominal pain directly induced by a peritoneal catheter of a ventriculoperitoneal shunt, which is associated with no other complications such as bowel perforation, pseudocyst or infection, has not been previously reported. A 65-year-old woman with hydrocephalus developed persistent lower abdominal pain radiating to the perineal area after shunt insertion. Radiography suggested that the distal end of a peritoneal catheter was located in a cul-de-sac of the pelvis. Otherwise, all studies were negative for shunt infection, fluid collection, or other abdominal and pelvic events. The patient's pain resolved completely after surgery in which the peritoneal catheter was shortened. In the presence of unexplained, persistent lower abdominal pain after shunt placement, the need to shorten the peritoneal catheter should be considered.

Long-term follow-up of giant serpentine MCA aneurysm treated with EC-IC bypass and proximal occlusion

Giant serpentine aneurysms are a rare but important subset of giant aneurysms, with unique management considerations. We present long-term follow-up clinical and imaging features of a giant serpentine middle cerebral artery lesion treated with extracranial-intracranial bypass and proximal occlusion more than a decade earlier. Calcification of the obliterated aneurysm sac and durability of this management strategy are demonstrated.

[Studies on the active constituents of sichuan liang shan rhododendron L. I. Determination of two flavonoids in leaves, extracts and jinjuan liquors]

A reversed-phase HPLC method for the separation and determination of the two flavonoids: quercetin and kaempferol is described. The column was 25 cm x 4.6 mm i.d., packed with Zorbax SB-C18(5 microns). The mobile phase was a mixture of MeOH-H2O (60:40, V/V). The flow rate was 0.7 mL/min. UV detection was performed at 360 nm. External standard was used and the calibration curves showed good linearity over the range of 6.0-100 mg/L, r = 0.9995-0.9998, and detection limits were 3.3-6.2 mg/L. The recoveries were 96.0% and 97.3% for quercetin and kaempferol respectively. The relative standard deviations of the method were 2.1%-4.5%. The method is simple, fast, sensitive and accurate and can be applied to the analysis of quercetin and kaempferol. It provides a scientific basis for industrial production and quality control of Jinjuan liquor preparations for clinical uses.

[Determination of tetramethylpyrazine in animal serum and cerebrospinal fluid by high performance liquid chromatography]

A reversed-phase high performance liquid chromatographic (RP-HPLC) method for the determination of the tetramethylpyrazine(TMP) in Chuanxiong extract, the animal(mouse) serum and cerebrospinal fluid has been developed. The TMP was separated on an ODS column Zorbax SB-C18(4.6 mm i.d. x 250 mm, 5 microns) at room temperature and detected by using UV detector at 270 nm. The mobile phase was methanol-water (50:50, V/V) containing 0.2 mmol/L of NH4H2PO4 flowing at a rate of 0.8 mL/min and 20 microL samples were injected. The detection limit of TMP was 1 mg/L and the calibration curve is linear between 5 and 500 mg/L with a correlation coefficient (r) of 0.999. The recovery of TMP ranged 98%-103%. The extract of Chuanxiong and pretreated serum and cerebrospinal fluid sample are stable for a week at room temperature.

Metabolism of 2,4,5,2',5'-pentachlorobiphenyl in the rat. Qualitative and quantitative aspects

The metabolism of 2,4,5,2',5'-pentachloro [14C] biphenyl (5-CB) was studied in the male rat. Following iv administration of 5-CB (0.6 mg/kg), 84% of the total dose was excreted within 7 days and 89% of the radioactivity excreted was in the form of 5-CB metabolites. Mass spectral and proton nuclear magnetic resonance analysis or chemical methods in conjunction with mass spectral analysis were used to identify the metabolites. The major metabolite was identified as 3'-hydroxy 5-CB. One minor metabolite was identified as the 3',4'-dihydrodiol of 5-CB and a second minor metabolite was tentatively identified as 3',4'-dihydroxy-5-CB. The relative amounts of 5-CB and its metabolites excreted in the urine and feces were also determined.