[The diagnostic value of hydrogen sulfide breath test for small intestinal bacterial overgrowth]

Objective: To evaluate the diagnostic value of hydrogen sulfide breath test(SBT) for small intestinal bacterial overgrowth (SIBO). Methods: College students were enrolled to complete gastrointestinal symptom scale, food frequency questionnaire, lactulose hydrogen- methane breath test (LHMBT) and SBT. Based on the correlation between hydrogen sulfide(H₂S) and hydrogen or methane gas,the receiver operating characteristic (ROC) curve of H₂S was drawn and diagnostic criteria of SBT was defined. Results: A total of 300 subjects including 84 males and 216 females with age 17-32 (21.6±2.4) years were enrolled from April 2019 to December 2019 and divided into two groups.Two hundred and three patients reported SIBO discomforts with 99 (48.8%) LHMBT positive, while 38 (39.2%) were LHMBT positive in 97 health controls. Rise of H₂S at 90 min was positively related with that of hydrogen (r=0.516, P<0.01), and H₂S levels at 90 min were positively correlated with methane (r=0.632, P<0.01). A rise in H₂S of ≥25.0 ppb or H₂S levels ≥62.5 ppb at 90 min during lactulose breath test was considered positive for SIBO, that sensitivity, specificity and accuracy were 66.4%,79.1% and 73.3% respectively. H₂S levels were significantly related to the amount of Vitamin B₁₂ intake (P=0.011). H₂S-positive subjects exhibited a constipation-predominant pattern. Conclusion: SBT is consistent with LHMBT, especially in constipation-predominant patients, which may provide a reference to the diagnosis of SIBO.

Determination of Aconitum Alkaloids in Dietary Supplements and Raw Botanical Materials by Liquid Chromatography/UV Detection with Confirmation by Liquid Chromatography/Tandem Mass Spectrometry: Collaborative Study

An interlaboratory study was conducted to evaluate a method for the determination of 3 Aconitum alkaloids, viz., aconitine, mesaconitine, and hypaconitine, in raw botanical material and dietary supplements. The alkaloids were extracted with diethyl ether in the presence of ammonia. After cleanup by solid-phase extraction to remove matrix interferences, the alkaloids were determined by reversed-phase liquid chromatography (LC)/UV detection at 235 nm with confirmation by LC/tandem mass spectrometry (MS/MS). A total of 14 blind duplicates were successfully analyzed by 12 collaborators. For repeatability, the relative standard deviation (RSDr) values ranged from 1.9 to 16.7, and for reproducibility, the RSDR values ranged from 6.5 to 33. The HorRat values were all &lt;2 with only one exception at 2.3. All collaborating laboratories had calibration curves with correlation coefficients of &gt;0.998. In addition, 6 collaborators performed the confirmation and were able to verify the identities of the alkaloids by using LC/MS/MS.

Analysis of interaction between Bmhrp28 and BmPSI in sex-specific splicing of Bombyx mori Bmdsx gene

Bombyx mori BmHRP28 and BmPSI, which belong to the family of RNA-binding proteins, have been identified binding to the female-specific exon 4 of the sex-determining gene Bmdsx pre-mRNA. However, the relationships between BmHRP28 and BmPSI still remain unclear. In this study, we carried out yeast two-hybrid (Y2H) and co-immunoprecipitation (Co-IP) analyses to address them. Y2H analysis showed that there was little or no direct binding between the BmHRP28 and BmPSI proteins. Also, the Co-IP experiments revealed that BmHRP28 and BmPSI coexisted in a multiprotein complex. Our results suggested that BmHRP28 and BmPSI form a muliprotein complex to regulate the splicing of Bmdsx pre-mRNA, but are not directly bound to each other. In an effort to find other regulatory factors in the multiprotein complex, we constructed a silkworm Y2H cDNA library of male early embryo. By Y2H screening, we identified an RNA-binding protein BmSPX, a putative component of the spliceosome, binding to BmPSI. These results indicated that BmHRP28 and BmPSI make up a spliceosome complex to regulate Bmdsx splicing and that BmSPX is another potential protein involved in this process. Our study provides some clues to better understand the mechanism of sex determination in the silkworm.

Characterization of two C-type lectin-like domain (CTLD)-containing proteins from the cDNA library of Chinese mitten crab Eriocheir sinensis

Chinese mitten crab Eriocheir sinensis is one of the most important aquaculture crustacean species in China. A cDNA library was constructed from mixed tissues of E. sinensis challenged with LPS. Eight genes involved in immune response were identified from 319 single colonies. Among them, two different C-type lectin-like domain (CTLD)-containing proteins were firstly identified in Chinese mitten crab. The full-length cDNA sequences of two C-type lectin-like domain (CTLD)-containing proteins named EsCTLDcp-1 and EsCTLDcp-2 were cloned by 5' RACE. The deduced amino acid sequences of EsCTLDcp-1 and EsCTLDcp-2 possessed several conserved features of C-type lectin subfamily. The tissue distribution of EsCTLDcp-1 and EsCTLDcp-2 was examined by Real-time PCR. In the normal Chinese mitten crab, the expression of EsCTLDcp-2 was detected in all tested tissues such as haemolymph, muscle, intestine, gill, heart, gonad and hepatopancreas, whereas in muscle, intestine, gill, heart and hepatopancreas for EsCTLDcp-1. The highest expressions of EsCTLDcp-1 and EsCTLDcp-2 were both observed in hepatopancreas. LPS significantly induced the expression of EsCTLDcp-1 and EsCTLDcp-2 in the hepatopancreas at the different time points. The induced fold change of EsCTLDcp-1 and EsCTLDcp-2 increased significantly from 2 h for EsCTLDcp-1 and 4 h for EsCTLDcp-2, and reached a maximum at 12 h, then dropped at 24 h. A differential pattern was found in Chinese mitten crab challenged with Chinese mitten crab pathogen Aeromonas hydrophila. The expression of EsCTLDcp-1 increased significantly at 2 h post-challenge crabs with A. hydrophila, then decreased at 4 h and 8 h, after that increased at 12 h and 24 h. The expression of EsCTLDcp-2 was decreased at the all time points. All these data suggest a differential role of EsCTLDcp-1 and EsCTLDcp-2 in the crab innate immune response to bacterial infection.

Depinning dynamics of two-dimensional magnetized colloids on a random substrate

We perform Langevin simulations on the depinning dynamics of two-dimensional magnetized colloids on a random substrate. On increasing the magnetic field strength, we find for the first time a crossover from plastic to smectic flows as well as a crossover from smectic to elastic crystal flows above depinning. For both the smectic and elastic crystal flows, a power-law scaling relationship could be obtained between the average velocity and applied driving force. The scaling exponent is found to be larger than 1 for smectic flow. But, for the elastic crystal flow, the scaling exponent is found to be less than 1. For the plastic flow, no power-law scaling relationship between the average velocity and applied driving force can be derived and history dependence of the depinning occurs. Within the crossover from plastic to smectic flows, a sudden decrease in the critical driving force is observed, and a sudden increase is found in the critical driving force across the crossover from smectic to elastic crystal flows, accompanied by a crossing of the curves of average velocity versus driving force.

Biotransformation of podophyllotoxin to picropodophyllin by microbes

Biotransformation of podophyllotoxin (PT) by several microbial species has been investigated. Among the fungi tested, it was found that Penicillium strains can isomerize PT to picropodophyllin (PPT) in 8% yield and other strains also transform the substrate into the same product but with lower yield.

[Identification of semen Cuscutae by HPCE]

A method for identification of semen Cuscutae, a traditional Chinese herb, was developed. The proteins in semen Cuscutae were extracted under acid or basic conditions and separated by high performance capillary electrophoresis. The electrophoretograms of acidic or basic extractants from Cuscuta chinensis Lam., Cuscuta australis R. Br. and Cuscuta japonica Choisy showed significant differences, which can be used to identify the three different semen Cuscutae. The results of the identification for 13 pharmacognosical samples agreed well with those of scanning electronic microscopy and tissue microanalysis.

Qigong and L-1 straining maneuver oxygen system requirements with and without positive pressure breathing

Based on the characteristics of respiration and the intrathoracic pressure in Qigong (Q-G) maneuvering, it has been theorized that the Q-G maneuver may lessen the lack of coordination between aircraft oxygen apparatus and anti-G maneuvers and may be more compatible with positive pressure breathing (PPB). In an experiment intended to test this hypothesis, 5 male volunteers, trained in Q-G and L-1 maneuvers, performed the Q-G and the L-1 maneuvers without and with (PPB) at 4 and 6 kPa, respectively, with 14 respiratory parameters being measured. The results demonstrated that, when performing Q-G maneuver, the maximal expiratory flow rate averaged 1.175-1.645 L.s-1, the inspiratory peak flow, 1.003-1.297 L.s-1. Both these values were markedly lower than those of the L-1 maneuver, and matched well the performance of current aircraft oxygen apparatus. From the blood pressure and heart rate values, it is evident that PPB can further promote the blood pressure-raising effect of the Q-G maneuver, and alleviate pilots' fatigue.

The characteristics and significance of intrathoracic and abdominal pressures during Qigong (Q-G) maneuvering

In order to investigate the mechanism of raising the blood pressure by the Qigong (Q-G) maneuver, the changes of esophageal and gastric pressures were determined during this maneuver, and the data were compared with those from the L-1 maneuver. Eight subjects performed the Q-G maneuver at +1 Gz; their esophageal pressures (mean +/- S.D.) were -6.7 +/- 2.1 mm Hg in the inspiratory phase and 0.1 +/- 3.7 mm Hg in the expiratory phase; intragastric pressures (mean +/- S.D.) were 69.5 +/- 20.2 mm Hg and 63.4 +/- 22.6 mm Hg, respectively. In 22 centrifuge runs at +4.0 to 7.5 Gz and during Q-G maneuvering, 5 subjects had esophageal pressures of -9.0 +/- 3.3 mm Hg in the inspiratory phase and 1.6 +/- 7.2 mm Hg in the expiratory phase, and gastric pressures of 140.6 +/- 23.2 mm Hg and 138.7 +/- 29.5 mm Hg, respectively. The results showed that during Q-G maneuvering, even with a high-G load, the thoracic pressure remained negative or at low pressures while gastric pressures were remarkably raised. They both fluctuated little during respiration; therefore, a relatively large and constant pressure gradient between abdominal and thoracic pressures was maintained. Here lies the significant characteristic of blood pressure raising by the Q-G maneuver. It might possess theoretical significance for further study and development of anti-G maneuvers.

Prenatal exposure to methadone affects central cholinergic neuronal activity in the weanling rat

The effect of prenatal exposure to methadone via maternal osmotic minipumps was studied on brain regional acetylcholine (ACh) turnover and dopamine (DA), norepinephrine (NE), serotonin (5-hydroxytryptamine, 5-HT) and their metabolites in 21-day-old female and male rats. ACh content was not affected in any region studied. However, the turnover rate of ACh (TRAch) was increased significantly in the striata and parietal cortices of both sexes. Two gender-specific changes were observed: a profound decrease in hypothalamic TRACh in the females and an increase in hippocampal TRACh in the males. No changes were observed in TRACh in the medulla-pons or the frontal cortex of either sex. The reduction in TRACh was accompanied by a threefold increase in DA content in the hypothalamus of the methadone-exposed females. No other changes were observed in DA, NE, or 5-HT, save for increased 5-HT content in the medulla-pons of the male methadone-exposed rats. Thus, prenatal methadone exposure produces several lingering changes in cholinergic function, many of which were not apparent in the immediate postnatal period. Although striatal ACh content was no longer reduced in methadone-exposed rats, striatal cholinergic function remains disrupted. It remains to be proven whether these differences are a direct effect of methadone exposure or are a consequence of neonatal withdrawal.

The characteristics and theoretical basis of the Qigong maneuver

We have made a systematic experimental study since we proposed the Qigong (Q-G) maneuver in 1986. The purpose of this article is to summarize our 5-year research project. It describes the theoretical problems of the Q-G maneuver, including the mechanism of blood pressure elevation induced by the Q-G maneuver, analysis of the maneuver elements and their respective contribution, the theory and method of muscular contraction in the Q-G maneuver, and the theory and practice of seated posture in the anti-G maneuver. We also describe the characteristics of the Q-G maneuver in five aspects.

The effect of prenatal methadone exposure on development and nociception during the early postnatal period of the rat

The effects of prenatal exposure to methadone via Alzet osmotic minipump on early postnatal development and on nociceptive behavioral endpoints were assessed in Sprague-Dawley rat pups during the first three postnatal weeks. This treatment regimen appeared to produce no maternal toxicity, with dams developing and maintaining dependence upon methadone through parturition. Methadone-exposed dams exhibited a withdrawal syndrome consisting of wet-dog shakes, diarrhea, vocalizations and irritability when challenged with naloxone 24 h postpartum. Pups exhibited a similar withdrawal syndrome following naloxone challenge consisting of mouthing and licking, hyperactive response to touch and vocalizations 24 h postpartum. Although no significant difference in litter size was evident in methadone-treated litters, a 16% pup mortality rate was observed in these litters. Prenatal methadone-exposed pups exhibited a significant body weight reduction at birth that resolved by postnatal day 2 (P2) in males and P4 in females. Methadone-exposed pups exhibited significant developmental delay in the expression of the negative geotaxic response to a morphine challenge while, conversely, 21-day-old pups exhibited a significantly reduced analgesic response to this challenge. These studies indicate that this method of prenatal exposure to methadone can produce dependence in the dam and offspring without substantial mortality, induce developmental delay and alter analgesic responses to opiate challenge in exposed pups during the preweanling period.

The effect of M1 muscarinic blockade on behavior and physiological responses following traumatic brain injury in the rat

Dicyclomine (1 mg/kg or 10 mg/kg), scopolamine (1 mg/kg), or saline was administered intraperitoneally to rats 15 min prior to moderate fluid percussion brain injury. A variety of reflexes and responses were measured up to 60 min following injury, and body weight and several neurological measures were taken daily up to 10 days following injury. All 3 antimuscarinic treatments reduced the duration of transient behavioral suppression as assessed by these measures. It appears that blockade of the M1 muscarinic receptor can attenuate transient behavioral suppression associated with concussive brain injury. Thus, stimulation of M1 muscarinic receptors may mediate components of reversible traumatic unconsciousness following cerebral concussion. No differences were observed between saline and antimuscarinic treatments in the incidence or duration of apnea following injury. Scopolamine pretreatment significantly elevated heart rate prior to injury, but had no significant effect on the responses of heart rate and blood pressure to experimental concussion. Both doses of dicyclomine significantly reduced resting heart rate, but unlike scopolamine, significantly enhanced the cardiovascular response to fluid percussion injury. Antimuscarinic treatment significantly reduced body weight loss and certain motor deficits, including beam balance and beam walk performance, following concussive head injury. Scopolamine and both doses of dicyclomine appeared to be equally effective in reducing long-term deficits. Data from these experiments indicate that at least some of the long-term behavioral deficits following moderate levels of brain injury may involve the binding of acetylcholine to M1 muscarinic receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

A preliminary report on a new anti-G maneuver

Inspired by Traditional Chinese Medicine and Qigong, we designed a new anti-G maneuver, the Q-G Maneuver, which has proved promising. This maneuver consists of volition mobilization, stepwise tensing of leg and abdominal muscles, and maintenance of a shallow thoracic respiration throughout. It was tested on 24 pilots on the ground and 3 pilots on a centrifuge. All pilots were monitored with heart level blood pressure, oximetry, ear lobe pulse, CO2 concentration in exhaled gas, EEG and ECG; in centrifuge runs, peripheral vision was also monitored. Blood pressure was maintained at 180-240 mm Hg for more than 30 s without fatigue. On the centrifuge, the pilots tolerated a G load 2.25-3.0 G higher than without the maneuver, without any visual disturbance. Oximetry readings were 96-97%, and there was no evidence of hyperventilation. The ear lobe pulse was even enhanced during G load with the maneuver. Follow-up visits to 18 out of 24 pilots with 455 inflight applications of the maneuver showed that the maneuver is feasible and can be used effectively during high-G load.