Synthesis and biological evaluation of hydantoin derivatives as potent antiplasmodial agents

Malaria, a devastating disease, has claimed numerous lives and caused considerable suffering, with young children and pregnant women being the most severely affected group. However, the emergence of multidrug-resistant strains of Plasmodium and the adverse side effects associated with existing antimalarial drugs underscore the urgent need for the development of novel, well-tolerated, and more efficient drugs to combat this global health threat. To address these challenges, six new hydantoins derivatives were synthesized and evaluated for their in vitro antiplasmodial activity. Notably, compound 2c exhibited excellent inhibitory activity against the tested Pf3D7 strain, with an IC50 value of 3.97 ± 0.01 nM, three-fold better than chloroquine. Following closely, compound 3b demonstrated an IC50 value of 27.52 ± 3.37 µM against the Pf3D7 strain in vitro. Additionally, all the hydantoins derivatives tested showed inactive against human MCR-5 cells, with an IC50 value exceeding 100 μM. In summary, the hydantoin derivative 2c emerges as a promising candidate for further exploration as an antiplasmodial compound.

Morphinan Alkaloids from the Leaves of Alphonsea cylindrica and Their Antibacterial Properties

A phytochemical study has been carried out on CH₂Cl₂ extract of Alphonsea cylindrica leaves, resulting in the isolation of three new morphinan alkaloids. They are kinomenine (1: ), N-methylkinomenine (2: ), and hydroxymethylkinomenine (3: ). The structures of these compounds were elucidated by extensive spectroscopic analysis (1D and 2D NMR, IR, UV, HRESIMS) and comparison with the data reported in literature for similar alkaloids. Kinomenine (1: ) and N-methylkinomenine (2: ) showed weak inhibition against S. aureus (MIC values of 1: and 2:  = 500 µg/mL; pIC₅₀ values in 95% C. I. of: 1:  = 2.9 to 3.0; 2:  = 2.9 to 3.1), while kinomenine (1: ) also showed weak inhibition against E. coli (MIC values of 1:  = 500 µg/mL; pIC₅₀ value in 95% C. I. of: 1:  = 2.9) by broth microdilution method. The results obtained can be used as future referencefor the discovery of morphinans and the potential of A. cylindrica as an antibacterial source.

[Effect of electrode array type and insertion technique on the insertion force: in vitro cochlear model study]

Objective: To investigate the effect of insertion technique and electrode array type on the insertion force of electrode array, and to provide a basis for further optimizing electrode design and facilitating mini-invasive electrode insertion. Methods: Three types of electrode array from Nurotron (Standard Electrode, Slim-medium Electrode, Slim-long Electrode) were studied. from July 2019 to December 2019. These electrode arrays were inserted into the phantom models of the cochlea, manually or robot-assisted(medium speed and low speed). The real-time force during electrode array insertion was recorded by ATI Nano 17 Ti sensors and was analyzed by accessory software. Origin 2020b software was used for statistical processing. Results: The insertion force of all electrode arrays progressively increased with the insertion depth. With the manual technique, the peak force of slim-medium electrode insertion was significantly smaller than that of the standard electrode insertion((71.0±16.6) mN vs (140.9±52.7) mN, Z=3.683, P<0.01), and the peak force of the slim-long electrode insertion was between the peak force of standard electrode and slim-medium electrode(P>0.05). No difference was found in the force variation of insertion among the three electrodes(P>0.05). With medium-speed and low-speed robotic assistance, the peak force characteristics of three electrodes were similar to those with the manual technique, but the force variation of standard electrode insertion ((83.9±9.7) mN/s) at medium speed was significantly larger than that of the slim-long electrode insertion ((69.2±4.0)mN/s), and the force variation of the standard electrode insertion at low speed was significantly greater than the other two electrodes. For the same electrode, robot-assisted insertion presented significantly lower peak force and force variation than manual insertion for each type of electrode array. But there was no difference in the peak force and force variation between two-speed levels of robot assistance (P>0.05). Conclusions: The insertion force of the electrode array will be lower when a slim electrode array or robot technique is applied. Long electrode array might make manual insertion difficult or less precise. Robot assistance has advantage on force control during electrode array insertion.

[Clinical features of 141 fatal cases of coronavirus disease in Jinyintan Hospital in Wuhan, China]

Objective: To describe the epidemiological characteristics and clinical features of patients with fatal coronavirus disease (COVID-19), in order to provide evidence for clinical diagnosis and treatment. Methods: In this retrospective study, we analyzed data on 141 fatal cases of confirmed COVID-19 that occurred among patients in Jinyintan Hospital in Wuhan, China, from January 20 to March 6, 2020. We analyzed their epidemiological characteristics, clinical and radiological features, laboratory results, and treatment. Results: Of the 141 patients (49 females, 92 males), the median age was 77 years (range: 24-92 years). The most likely source of exposure included the Huanan seafood market (n=3, 2%), family members (n=6, 4%), and hospital-acquired infection (n=8, 6%). The remaining 116 patients (72%) had no known source of exposure. Of the patients, 101 (72%) had chronic diseases. The most common comorbidities were hypertension, diabetes and coronary heart disease. The most common clinical manifestations were fever (n=121, 85%), dry cough (n=77, 54%), shortness of breath (n=23, 16%), and chest pain (n=15, 10%). Less common clinical manifestations included fatigue (n=7, 4%), headache (n=3, 2%), disorders of consciousness (n=2, 1%), diarrhea (n=2, 1%) and lumbago (n=1, 0.7%). In terms of laboratory tests, the absolute value of lymphocytes in most patients was reduced (n=132, 94%), but C-reactive protein (n=141, 100%), procalcitonin(n=121, 89%), serum amyloid (n=140, 99%) were significantly increased. The most common findings on imaging of the lungs were bilateral multiple mottling and ground-glass opacity (n=101, 72%), mainly in the lower lobes (n=15, 10%), with lesions being more common on the right. Other imaging findings included diffuse consolidation (n=4, 3%), ground-glass opacity and consolidation (n=20, 14%), and pneumothorax (n=1, 0.7%). All patients were treated with antibiotics and antiviral drugs. Other treatments included immunoglobulin (n=49, 35%), corticosteroids (n=45, 32%), continuous renal replacement therapy (n=24, 17%), and extracorporeal membrane oxygenation (n=12, 9%). All patients were treated with oxygen therapy. The mode of administration included invasive mechanical ventilation (n=61, 43%), noninvasive mechanical ventilation (n=65, 46%), and nasal catheter oxygen inhalation (n=15, 11%). The direct causes of death were acute respiratory distress syndrome (n=90, 64%), multiple organ failure (n=24, 17%), sudden cardiac arrest (n=11, 8%), viral myocarditis (n=8, 5%), acute myocardial infarction (n=4, 3%), cerebrovascular accident (n=3, 2%), and acute gastrointestinal bleeding (n=1, 0.7%). Conclusions: Risk factors for death due to COVID-19 included older age, male sex, and the presence of comorbidities. The most common direct causes of death were acute respiratory distress syndrome, multiple organ failure, sudden cardiac arrest, and viral myocarditis.

[Factors of hearing preservation in acoustic neuroma surgery]

Over the past 50 years, the focus of acoustic neuroma surgery has shifted from low mortality and tumor resection to retention of neurological function. Hearing preservation is another point in addition to facial nerve function preservation. Hearing preservation rates overall ranged from 2% to 93% in recent studies. Characteristics such as approach, pre-operative neurological function, tumor size, nerve of origin and fundal fluid of the internal auditory canal have been reported as possible influencing factors. This review provides a summary of recent studies and describes the prognostic factors that predict hearing preservation.

[The exploration of gene promoter methylation profiling in nasal polyp]

Objective:To explore the gene promoter methylation profiles of nasal polyp, and to analysis the promoter methylation differences between the nasal polyp and the normal nasal mucosa.Method:Total DNA of the nasal polyp tissues and normal nasal mucosa were extracted. After immunoprecipitation and whole genome amplification, the DNA was labeled with Cy3/5 and hybridized in NimbleGen hybridization chamber. For array hybridization, Roche Nimblegen CpG Promoter array was used. The slides were scanned using the Axon GenePix 4000B microarray scanner. The different genes were analyzed through pathway and verified by Real-time PCR.Result:3010 genes were found to have promoter hypermethylation in normal nasal mucosa or nasal polyp.2,62%(79/3010) of the genes had promoter hypermethylation in all the nasal polyps, which were negative in normal nasal mucosa.10.66%(321/3010) of the genes had promoter hypermethylation in normal nasal mucosa, which were negative in all the nasal polyps. Three pathways were found in the promoter hypermethylation of the nasal polyps. Fourteen pathways were found in the negative hypermethylation of the nasal polyps.Conclusion:Genes promoter methylation plays an important role in the development of nasal polyps, and the gene promoter methylation profiling may yield new some clues on the mechanism of nasal polyps.

[Personal dose monitoring of radiation workers in medical institutions at the municipal level and below in a city from 2011 to 2014]

Objective: To determine the personal dose level of radiation workers in medical institutions at the municipal level and below in a city, and to provide a scientific support for strengthening the radiation protection in the city's medical institutions. Methods: Information of the successful applicants for the "Radiation Worker Permit" from 174 medical institutions at the municipal level and below was collected from October 1, 2011 to December 31, 2014. The annual effective dose was calculated based on the personal dose monitoring report, and indicators including sex, permit application time, hospital level, type of occupational radiation, length of radiation work, blood test, and micronucleated lymphocyte rate were analyzed. Results: Of the 1 143 radiation worker permit applications submitted by medical institutions the municipal level and below in this city from 2011 to 2014, 1 123 provided at least one personal dose monitoring report. The annual effective dose of the radiation workers was 0-4.76 mSv (mean 0.31±0.40 mSv) , and the collective annual effective dose was 351.96 mSv. The annual effective dose was significantly different between radiation workers with different times of permit application, hospital levels, and types of occupational radiation (P<0.05) . Interventional radiology workers had the highest annual effective dose (0.63 mSv) , and annual effective dose was significantly different between interventional radiology workers with different lengths of radiation work (H=10.812, P<0.05) . Conclusion: The personal radiation dose of radiation workers in medical institutions at the municipal level and below in this city is maintained at a relatively low level, suggesting that the occupational environment is relatively safe for these workers. However, more focus should be placed on clinical interventional radiology workers.

[The exploration of VEGF-B methylation in the nasal polyp]

Objective:The objective of this study is to investigate the methylation status of vascular endothelial cell growth factor B (VEGF-B) gene and to indentify the roles in pathogenesis,development and classification of nasal polyps.Method:The methylation status of VEGF-B gene of 28 nasal polyp tissues and 12 samples of inferior turbinate tissues were detected by methylationspecific-polymerase chain reaction (MS-PCR) and gene sequencing.Result:There was significant statistic diference between nasal polyp tissue group and control group (χ ²=4.096,P<0.05). The results of gene sequencing suggest that the VEGF-B gene promoter were hypomethylation status in the nasal polyps.Conclusion:Methylation status of VEGF-B promoter may play an important role in the pathogenetic mechanism of nasal polyps.

Enzyme-containing spin membranes for rapid digestion and characterization of single proteins

Proteolytic digestion is an important step in characterizing protein sequences and post-translational modifications (PTMs) using mass spectrometry (MS). This study uses pepsin- or trypsin-containing spin membranes for rapid digestion of single proteins or simple protein mixtures prior to ultrahigh-resolution Orbitrap MS analysis. Centrifugation of 100 μL of pretreated protein solutions through the functionalized membranes requires less than 1 min and conveniently digests proteins into large peptides that aid in confirming specific protein sequence variations and PTMs. Peptic and tryptic peptides from spin digestion of apomyoglobin and four commercial monoclonal antibodies (mAbs) typically cover 100% of the protein sequences in direct infusion MS analysis. Increasing the spin rate leads to a higher fraction of large peptic peptides for apomyoglobin, and MS analysis of peptic and tryptic peptides reveals mAb PTMs such as N-terminal pyroglutamate formation, C-terminal lysine clipping and glycosylation. Relative to overnight in-solution digestion of mAbs, spin digestion yields higher sequence coverages. Spin-membrane digestion followed by infusion MS readily differentiates a mAb to the Ebola virus from a related antibody that differs by addition of a single amino acid.

[A combination use of endoscope and microscope in cerebral pontine angle surgery]

Objective: To evaluate the application of combination use of microscope and endoscope in cerebral pontine angle (CPA) surgery. Methods: A total of 72 patients undergone lateral skull base surgeries via endoscope under microscopic control from January 2006 to January 2015 was reviewed respectively. The patients including 35 males and 37 females were composed of 22 cases of vestibular swannnomas, 45 cases of cranial neuropathy and 5 cases of CPA chelesteatoma. Twenty cases of vestibular swannnomas, 15 cases of cranial neuropathy and 2 cases of CPA chelesteatoma undergone the surgery via retrosigmoid approach, while other cases undergone the surgery via retrolabyrinthine approach. Surgical procedures were accomplished under the control of microscope and different angular endoscope with imaging fusion. The surgical results were evaluated according to subjective and objective criteria, and all patients were followed up for 15 years. Results: The symptoms was disappeared in the cranial neuropathy patients, without facial paralysis, complication of other nerves or hearing loss. Twenty-two patients with vestibular schwannomas got total tumor removal without facial palsy or neurological deficits; useful hearing was preserved in 16 of 22 patients (72.7%), and no tumor recurrence was found during 1-5 years follow-up. There was also no facial palsy or other complications in 5 cases of CPA chelesteatoma, which gained completely surgical removal; useful hearing was preserved in 3 of 5 cases of these patients and no recurrence was occurred during 1-1.5 years follow-up. Conclusions: A combination use of endoscope and microscope could combine advantages and avoid disadvantages of two techniques. It can provide better exposure with minimal invasion in CPA surgery, and is especially applicable in surgery for cranial neuropathy, vestibular schwannoma and CPA cholesteatoma, which should be performed through retrosigmoid approach and retrolabyrinthine approach.

Changes in rumen protozoal community by condensed tannin fractions of different molecular weights from a Leucaena leucocephala hybrid in vitro

AIMS

To evaluate the effects of condensed tannins (CTs) fractions of differing molecular weights (MWs) from a Leucaena leucocephala hybrid-Rendang on the rumen protozoal community in vitro.

METHODS AND RESULTS

The effects of unfractionated CTs (F0) and CT fractions of different MWs (F1 > F2 > F3 > F4 > F5) on protozoal population and community were evaluated in vitro using rumen microbes and ground guinea grass as the substrate. Higher-MW CT fractions F1 and F2 significantly (P < 0·05) decrease the number of ciliate protozoa. The real-time PCR analysis showed that the total protozoa was significantly (P < 0·05) lower in F0 and all CTs with fractions F1 and F2 having the lowest value. High-throughput sequencing of the partial 18S rRNA gene showed that the genus Entodinium significantly (P < 0·05) decreased with increasing MWs of CT, whereas Anoplodinium-Diplodinium were significantly (P < 0·05) increased. Inclusion of the highest MW CT fraction F1 decreased the relative abundance of the minor genera such as Eudiplodinium and Polyplastron compared to the control and CT fractions F2-F5.

CONCLUSION

CTs of differing MWs could reduce and alter the rumen protozoa population in vitro. This effect was more pronounced for higher-MW CTs.

SIGNIFICANCE AND IMPACT OF THE STUDY

The high MW CTs should be considered as a feed supplement in the ruminant diet to reduce the protozoal population which are known to be associated with methanogens as a means to mitigate methane production in the rumen.

Hyperphagia in male melanocortin 4 receptor deficient mice promotes growth independently of growth hormone

KEY POINTS

Loss of function of the melanocortin 4 receptor (MC4R) results in hyperphagia, obesity and increased growth. Despite knowing that MC4Rs control food intake, we are yet to understand why defects in the function of the MC4R receptor contribute to rapid linear growth. We show that hyperphagia following germline loss of MC4R in male mice promotes growth while suppressing the growth hormone-insulin-like growth factor-1 (GH-IGF-1) axis. We propose that hyperinsulinaemia promotes growth while suppressing the GH-IGF-1 axis. It is argued that physiological responses essential to maintain energy flux override conventional mechanisms of pubertal growth to promote the storage of excess energy while ensuring growth.

ABSTRACT

Defects in melanocortin-4-receptor (MC4R) signalling result in hyperphagia, obesity and increased growth. Clinical observations suggest that loss of MC4R function may enhance growth hormone (GH)-mediated growth, although this remains untested. Using male mice with germline loss of the MC4R, we assessed pulsatile GH release and insulin-like growth factor-1 (IGF-1) production and/or release relative to pubertal growth. We demonstrate early-onset suppression of GH release in rapidly growing MC4R deficient (MC4RKO) mice, confirming that increased linear growth in MC4RKO mice does not occur in response to enhanced activation of the GH-IGF-1 axis. The progressive suppression of GH release in MC4RKO mice occurred alongside increased adiposity and the progressive worsening of hyperphagia-associated hyperinsulinaemia. We next prevented hyperphagia in MC4RKO mice through restricting calorie intake in these mice to match that of wild-type (WT) littermates. Pair feeding of MC4RKO mice did not prevent increased adiposity, but attenuated hyperinsulinaemia, recovered GH release, and normalized linear growth rate to that seen in pair-fed WT littermate controls. We conclude that the suppression of GH release in MC4RKO mice occurs independently of increased adipose mass, and is a consequence of hyperphagia-associated hyperinsulinaemia. It is proposed that physiological responses essential to maintain energy flux (hyperinsulinaemia and the suppression of GH release) override conventional mechanisms of pubertal growth to promote the storage of excess energy while ensuring growth. Implications of these findings are likely to extend beyond individuals with defects in MC4R signalling, encompassing physiological changes central to mechanisms of growth and energy homeostasis universal to hyperphagia-associated childhood-onset obesity.

Molecular Weight, Protein Binding Affinity and Methane Mitigation of Condensed Tannins from Mangosteen-peel (Garcinia mangostana L)

The objectives of this study were to determine the molecular weight of condensed tannins (CT) extracted from mangosteen (Garcinia mangostana L) peel, its protein binding affinity and effects on fermentation parameters including total gas, methane (CH₄) and volatile fatty acids (VFA) production. The average molecular weight (M_w) of the purified CT was 2,081 Da with a protein binding affinity of 0.69 (the amount needed to bind half the maximum bovine serum albumin). In vitro gas production declined by 0.409, 0.121, and 0.311, respectively, while CH₄ production decreased by 0.211, 0.353, and 0.549, respectively, with addition of 10, 20, and 30 mg CT/500 mg dry matter (DM) compared to the control (p<0.05). The effects of CT from mangosteen-peel on in vitro DM degradability (IVDMD) and in vitro N degradability was negative and linear (p<0.01). Total VFA, concentrations of acetic, propionic, butyric and isovaleric acids decreased linearly with increasing amount of CT. The aforementioned results show that protein binding affinity of CT from mangosteen-peel is lower than those reported for Leucaena forages, however, the former has stronger negative effect on IVDMD. Therefore, the use of mangosteen-peel as protein source and CH₄ mitigating agent in ruminant feed requires further investigations.

Obesity and sex influence insulin resistance and total and multimer adiponectin levels in adult neutered domestic shorthair client-owned cats

In this study, we estimated insulin sensitivity and determined plasma concentrations of total-, low-molecular-weight (LMW), and high-molecular-weight (HMW) adiponectin and leptin in 72 domestic shorthair, neutered, client-owned cats. Glucose tolerance was assessed with an intravenous glucose tolerance test and body fat percentage (BF%) was measured with dual-energy x-ray absorptiometry. Total adiponectin was measured with 2 different ELISAs. Low-molecular-weight and HMW adiponectin plasma concentrations were determined by Western blot analysis after sucrose-gradient velocity centrifugation, and the adiponectin multimer ratio [SA = HMW/(HMW + LMW)] was calculated. Differences in glucose tolerance, leptin, total adiponectin, and multimer ratio among lean (BF% <35; n = 26), overweight (35 <BF% <45; n = 28), and obese (BF% >45; n = 18) cats as well as between male (n = 34) and female (n = 38) neutered cats were evaluated by linear regression and 2-way ANOVA. Sex and age were included as covariates for analysis of BF%, whereas BF%, fat mass, and lean body mass were covariates for analysis of sex differences. Increased BF% was negatively correlated with multimer ratio (SA, r = -45; P < 0.002), whereas no differences were found in total adiponectin concentrations among BF% groups (P > 0.01). Male cats had indices of decreased insulin tolerance and significantly lower total adiponectin concentrations than did female cats (mean ± SEM, 3.7 ± 0.4 vs 5.4 ± 0.5 μg/mL; P < 0.02). Altered SAs could contribute to an obesity-associated decreasing glucose tolerance in cats, and low total adiponectin concentrations may relate to increased risk of diabetes mellitus in neutered male cats.

Hypothalamic distribution of somatostatin mRNA expressing neurones relative to pubertal and adult changes in pulsatile growth hormone secretion in mice

The age-associated decline in growth hormone (GH) secretion may be a consequence of the reduction in the number of GH-releasing hormone (GHRH) positive neurones. However, it remains unclear whether an alteration in the number or distribution of somatostatin (SST) neurones contributes to this change. In the present study, we characterised the role of SST in modulating the change in pulsatile GH secretion in male C57Bl/6J mice throughout puberty and into early adulthood. We assessed pulsatile GH secretion in mice at 4, 8 and 16 weeks of age. These ages correspond to early pubertal, early adulthood and adulthood, respectively. We show an elevation in peak, total and pulsatile GH secretion coinciding with periods of rapid linear growth. Using in situ hybridisation and morphometric methods, we mapped the distribution of Sst mRNA expression within the mouse brain relative to this change in pulsatile GH secretion. The results obtained show that altered pulsatile GH secretion in male mice from 4-16 weeks of age does not coincide with a significant change in the number of Sst mRNA expressing neurones or an abundance of Sst mRNA expression throughout the arcuate nucleus (ARC) and periventricular nucleus (PeV). Rather, we observed a progressive decline in Sst mRNA expressing neurones within subnuclei of the paraventricular nucleus at this time. We conclude that structural changes in Sst expression within the PeV and ARC may not reflect the observed decline in pulsatile GH secretion in mice from puberty into early adulthood.

Epistatic interactions of AKT1 on human medial temporal lobe biology and pharmacogenetic implications

AKT1 controls important processes in medial temporal lobe (MTL) development and plasticity, but the impact of human genetic variation in AKT1 on these processes is not known in healthy or disease states. Here, we report that an AKT1 variant (rs1130233) previously associated with AKT1 protein expression, prefrontal function and schizophrenia, affects human MTL structure and memory function. Further, supporting AKT1's role in transducing hippocampal neuroplasticity and dopaminergic processes, we found epistasis with functional polymorphisms in BDNF and COMT--genes also implicated in MTL biology related to AKT1. Consistent with prior predictions that these biologic processes relate to schizophrenia, we found epistasis between the same AKT1, BDNF and COMT functional variants on schizophrenia risk, and pharmacogenetic interactions of AKT1 with the effects on cognition and brain volume measures by AKT1 activators in common clinical use--lithium and sodium valproate. Our findings suggest that AKT1 affects risk for schizophrenia and accompanying cognitive deficits, at least in part through specific genetic interactions related to brain neuroplasticity and development, and that these AKT1 effects may be pharmacologically modulated in patients.

The decline in pulsatile GH secretion throughout early adulthood in mice is exacerbated by dietary-induced weight gain

The transition between puberty and adulthood is accompanied by a slowing in linear growth. Although GH is a key factor that drives somatic development into adulthood, early adulthood coincides with a reduction in circulating levels of GH. To this extent, a pathological decline in postpubertal GH secretion is detrimental to attainment of peak lean muscle mass and bone mass and promotes adiposity and increases susceptibility to the development of obesity in adulthood. Here we characterized pulsatile GH secretion in C57BL/6J mice at 12 and 16 wk of age. Deconvolution analysis of these measures reveals a reduction in pulsatile GH secretion between 12 and 16 wk of age. Dietary intervention with high-fat feeding at 8 wk of age results in a significant increase in adiposity, the development of glucose intolerance, and hyperinsulinemia. We show the exacerbation of the age-associated decline in pulsatile GH secretion in high-fat-fed mice after 4 wk of dietary intervention (at 12 wk of age), and a further suppression of pulsatile GH secretion by 8 wk of dietary intervention (at 16 wk of age). Suppressed pulsatile secretion of GH did not coincide with an elevation in circulating free fatty acids. Rather, we observed increased hepatic triglyceride content and an eventual decrease in circulating levels of IGF-I. Given the established role of GH in maintaining healthy aging, we anticipate that an advancing of the age-associated decline in pulsatile GH secretion as a consequence of dietary-induced weight gain may have long-term ramifications on adult health.

GH does not modulate the early fasting-induced release of free fatty acids in mice

Fasting results in the mobilization of adipose stores and the elevation of levels of free fatty acids (FFA). In humans, this process is driven by a release in GH. Little is known regarding the role of GH in modulating this process during early stages of fasting in the mouse. Confirmation of the role of GH in modulating FFA release in the fasting mouse is of particular importance given the frequent use of mouse models to study metabolic mechanisms. Here, we correlate the initial release of FFA throughout fasting in mice with pulsatile GH secretion. Observations illustrate the rapid release of FFA in response to food withdrawal. This does not correlate with a rise in GH secretion. Rather, we observed a striking loss in pulsatile secretion of GH throughout the first 6 h of fasting, suggesting that GH does not modulate the initial release of FFA in the mouse in response to fasting. This was confirmed in GH receptor knockout mice, in which we observed a robust fasting-induced rise in FFA. We further illustrate the dynamic relationship between the orexigenic and anorexigenic hormones ghrelin and leptin during fasting in the mouse. Our findings show an initial suppression of leptin and the eventual rise in circulating levels of acyl-ghrelin with fasting. However, altered acyl-ghrelin and leptin secretion occurs well after the rise in FFA and the suppression of GH secretion. Consequently, we conclude that although acyl-ghrelin and leptin may modulate the physiological response to drive food intake, these changes do not contribute to the initial loss of pulsatile GH secretion. Rather, it appears that the suppression of GH secretion in fasting may occur in response to an elevation in fasting levels of FFA or physiological stress. Observations highlight a divergent role for GH in modulating FFA release between man and mouse.

Development of a method for the determination of pulsatile growth hormone secretion in mice

Measures of pulsatile GH secretion require frequent collection and analysis of blood samples at regular intervals. Due to blood volume constraints, repeat measures of circulating levels of GH in mice remain challenging. Consequently, few observations exist in which the pulsatile pattern of GH secretion in mice have been characterized. To address this, we developed a technique for the collection and analysis of circulating levels of GH at regular and frequent intervals in freely moving mice. This was achieved through the development of a sensitive assay for the detection of GH in small (2 μl) quantities of whole blood. The specificity and accuracy of this assay was validated following guidelines established for single-laboratory validation as specified by the International Union of Pure and Applied Chemistry. We incorporated an established method for tail-clip blood sample collection to determine circulating levels of GH secretion in 36 whole blood samples collected consecutively over a period of 6 h. Resulting measures were characterized by peak secretion periods and interpulse stable baseline secretion periods. Periods characterized by elevated whole blood GH levels consisted of multicomponent peaks. Deconvolution analysis of resulting measures confirmed key parameters associated with pulsatile GH secretion. We show a striking decrease in pulsatile GH secretion in mice after 12-18 h of fasting. This model is necessary to characterize the pulsatile profile of GH secretion in mice and will significantly contribute to current attempts to clarify mechanisms that contribute to the regulation of GH secretion.

Cloning, expression and protective capacity of 37 kDa outer membrane protein gene (ompH) of Pasteurella multocida serotype B:2

The major outer membrane protein (OmpH) of 4 local Malaysian strains of Pasteurella multocida serotype B:2 were characterized in comparison to ATCC strains. Three major peptide bands of MW 26, 32 and 37 kDa were characterized using SDSPAGE. Two of these fragments, the 32 kDa and 37 kDa were observed to be more reactive with a mouse polyclonal antiserum in all of the local isolates as well as the ATCC strains in a Western blot. However, the 32 kDa fragment was found to cross react with other Gram negative bacteria. Therefore, the 37 kDa OmpH was selected as vaccine candidate. The 37 kDa ompH gene of the isolated strain 1710 was cloned into an Escherichia coli expression vector to produce large amounts of recombinant OmpH (rOmpH). The 37 kDa ompH gene of strain 1710 was sequenced. In comparison to a reference strain X-73 of the ompH of P. multocida, 39bp was found deleted in the 37 kDa ompH gene. However, the deletion did not shift the reading frame or change the amino acid sequence. The rOmpH was used in a mice protection study. Mice immunized and challenged intraperitoneally resulted 100% protection against P. multocida whilst mice immunized subcutaneously and challenged intraperitoneally only resulted 80% protection. The rOmpH is therefore a suitable candidate for vaccination field studies. The same rOmpH was also used to develop a potential diagnostic kit in an ELISA format.

Use of propranolol in infantile haemangioma among Chinese children

OBJECTIVE

To describe the use of propranolol as first-line treatment or as single therapy to control the proliferating phase of infantile haemangioma in Chinese children.

DESIGN

Retrospective study.

SETTING

Regional hospital, Hong Kong.

PATIENTS

Children 3 years old or younger with facial haemangioma who took oral propranolol between 1 December 2008 and 1 December 2009.

RESULTS

There were 12 such patients, all of whom underwent prior clinical evaluation before starting the treatment. Ten patients had a solitary facial haemangioma and two had multiple haemangiomas. The mean age of symptom onset was 12 days. The mean age for starting propranolol treatment was 7 months, and in all cases a clinical response was observed within 7 days. Five (41%) of the patients had complete resolution 2 to 6 months after starting medication, at which time they were 5 to 12 months old. Two of them had a recurrence of the haemangioma within 8 weeks of stopping the drug, but responded to a second treatment course. In these two patients, the propranolol dosage had been tailed down rapidly and the therapy was of a shorter duration than in those without recurrence. The remaining seven patients are still taking propranolol and responding satisfactorily. Hypotension was observed in two patients, one of whom tolerated a lower dose and in the other, therapy was reinitiated at her older age. No serious side-effect was encountered in the remaining patients.

CONCLUSION

Propranolol was useful as first-line or single-agent treatment of facial infantile haemangioma in Chinese children, and gave rise to minimal side-effects. Although recurrence of infantile haemangioma occurred after propranolol was tailed off rapidly after a relatively short duration, an optimal treatment duration and tapering schedule has not yet been defined. Nevertheless, patients responded well to second courses of propranolol therapy.

Observation of dynamic samples using simple coverslip fluidics

The ability to observe samples undergoing controlled fluid flow under the microscope is important for studying biochemical processes and motion dynamics. We describe here a simple method to achieve this using coverslips shaped using a fiber scribe. Testing showed good directional flow control within the test range of 0-1 ml/min flow rate and an ability to sustain a flow rate up to approximately 1 ml/min. Testing with a sealed T-channel coverslip demonstrated the ability to construct fluid network branches with this scheme. We also demonstrated the usefulness of this procedure in motion dynamic studies of Dunaliella algae swimming under fluid flow.

Immunological profiles of immune restoration disease presenting as mycobacterial lymphadenitis and cryptococcal meningitis

OBJECTIVES

A proportion of HIV patients beginning antiretroviral therapy (ART) develop immune restoration disease (IRD). Immunological characteristics of IRD were investigated in a cohort of HIV patients beginning therapy in Kuala Lumpur, Malaysia.

METHODS

Peripheral blood mononuclear cells were collected at weeks 0, 6, 12, 24 and 48 of ART from five patients experiencing IRD [two with cryptococcal and three with Mycobacterium tuberculosis (Mtb) disease], eight non-IRD controls who had begun ART with CD4 T-cell counts of <100 cells/microL and 17 healthy controls. Leukocytes producing interferon-gamma (IFNgamma) were quantified by enzyme-linked immunospot assay after stimulation with purified protein derivative (PPD), early secretory antigenic target-6 (ESAT-6), Cryptococcus neoformans or Cytomegalovirus antigens. Plasma immunoglobulin (IgG) antibodies reactive with these antigens were assessed by enzyme-linked immunosorbent assay. Proportions of activated (HLA-DR(hi)) and regulatory (CD25 CD127(lo) and CTLA-4(+)) CD4 T-cells were quantified by flow cytometry.

RESULTS

Plasma HIV RNA declined and CD4 T-cell counts rose within 8-27 weeks on ART. Mtb IRD patients displayed elevated IFNgamma responses and/or plasma IgG to PPD, but none responded to ESAT-6. Cryptococcal IRD occurred in patients with low baseline CD4 T-cell counts and involved clear IFNgamma and antibody responses to cryptococcal antigen. Proportions of activated and regulatory CD4 T-cells declined on ART, but remained higher in patients than in healthy controls. At the time of IRD, proportions of activated CD4 T-cells and regulatory CD4 T-cells were generally elevated relative to other patients.

CONCLUSIONS

Cryptococcal and Mtb IRD generally coincide with peaks in the proportion of activated T-cells, pathogen-specific IFNgamma responses and reactive plasma IgG. IRD does not reflect a paucity of regulatory CD4 T-cells.

Anatomical study on the morphology and blood supply of the falciform ligament and its clinical significance

The purpose of this study was to understand the clinical significance of the morphology and blood supply of the falciform ligament in laparoscopic surgery. The structure, blood vessel distribution and anastomoses of the falciform ligament were observed in 20 cases of living laparoscopy, 30 cadaveric specimens injected with latex and five cadaveric specimens with Indian ink and hyaline. The falciform ligament was formed by two sides of peritoneum and its length, largest and smallest width were 8.3+/-1.6 cm, 4.9+/-0.8 cm and 1.1+/-0.3 cm, respectively. The left inferior phrenic artery and middle segment artery of the liver formed a vessel that arched and gave off 6-12 branches to the falciform ligament. The veins of the falciform ligament drained into the left inferior phrenic vein, and were not accompanied by any artery. In conclusion, the vessels of the falciform ligament anastomose with multiple vessels and form a significant pathway of the collateral circulation in the liver. The falciform ligament is an important landmark in laparoscopic surgery.

First-episode psychosis in the military: a comparative study of prodromal symptoms

OBJECTIVE

The objective of this study is to provide a retrospective description of prodromal symptoms of young military servicemen with first-episode psychosis, and a comparison with first-episode non-psychotic disorders.

METHOD

Thirty consecutive servicemen presenting with first-episode psychosis were studied. Thirty-four randomly selected servicemen from 123 with non-psychotic disorders served as comparison. A combination of unstructured and semistructured interviews with the patient and other informants was used to describe the prodromal symptoms.

RESULTS

The most common prodromal psychotic symptoms were social withdrawal (83%); anxiety (77%); sleep disturbance (77%); disturbance in attention, concentration or memory (73%); deterioration in studies in school (70%); depressed mood (63%); odd behaviour (53%); and anger or irritability (53%). Common symptoms found in first-episode psychosis and non-psychotic patients included sleep disturbance, anxiety, depressed mood and anger or irritability. Common symptoms that were associated with the psychotic prodrome were social withdrawal (p < 0.001), deterioration in school results (p < 0.001) and disturbance in attention, concentration or memory (p < 0.001). The psychotic prodrome was also associated with apathy (p < 0.001), odd behaviour (p < 0.001), doing nothing (p = 0.004) and thought blocking (p = 0.04).

CONCLUSION

Cognitive disturbances and attenuated negative symptoms appear to be more specific to the psychotic prodrome in young patients with first-episode psychosis.

Improved high performance liquid chromatographic analysis of omeprazole in human plasma

A simple high-performance liquid chromatographic method was developed for the determination of omeprazole in human plasma. Omeprazole and the internal standard, chloramphenicol, were extracted from alkalinized plasma samples using dichloromethane. The mobile phase was 0.05 M Na2HPO4-ACN (65:35, v/v) adjusted to pH 6.5. Analysis was run at a flow rate of 1.0 ml/min at a detection wavelength of 302 nm. The method was specific and sensitive with a detection limit of 2.5 ng/ml at a signal-to-noise ratio of 4:1. The limit of quantification was set at 5 ng/ml. The calibration curve was linear over a concentration range of 5-1280 ng/ml. Mean recovery value of the extraction procedure was about 96%, while the within and between day coefficient of variation and percent error values of the assay method were all less than 14%.

Adjusting to military life--servicemen with problems coping and their outcomes

A small proportion of servicemen enlisting for compulsory National Service in Singapore experience problems adjusting to military life. This paper aims to profile the servicemen who experience such problems. There is a paucity of literature addressing this issue internationally and none published locally. Servicemen who were referred to the Psychological Medicine Branch of the Singapore Armed Forces within six months of enlistment were retrospectively studied. In the work year July 1995 to June 1996, 77 cases were seen. The main classes of diagnoses were stress-related disorders, anxiety, mood and psychotic disorders. The main stressor was problems adapting to the military environment. There were 10 cases of parasuicide, significantly less than US Army statistics. At Operationally Ready Date, 20.7% were able to hold a combat vocation, similar to the US Army situation. This paper hopes to document the local figures and act as a reference for evaluating future therapies and policies.

A community based study of prostatic symptoms in Singapore

PURPOSE

We describe the prevalence of prostatic symptoms, bother and related quality of life, as well as health seeking behavior in men 40 years old or older in Singapore.

MATERIALS AND METHODS

A community based cross-sectional study was conducted in men 40 years old or older in Queenstown, Singapore. The International Prostate Symptom Score for benign prostatic hyperplasia was used to score symptom severity objectively. Results obtained were compared to those from United States, Scottish and Japanese populations.

RESULTS

The prevalence of moderate to severe symptomatology was 10% after age adjustment to match the 1990 Singapore population. The most prevalent symptoms were frequency (22.5% of cases) and nocturia (21.5%) with consistently lower prevalence for bother (6.9% for frequency and nocturia). The prevalence of prostatic symptoms was approximately 3 or more times less than in the Scottish, United States and Japanese populations, while the prevalence of bother was approximately 10 times less. For symptomatic individuals there was poor correlation between symptom severity and bother scores. Bother scores correlated better with quality of life scores (r = 0.50) and were more closely associated with health seeking behavior (p = 0.03) than symptom severity scores (r = 0.39, p = 0.07).

CONCLUSIONS

The prevalence of prostatic symptoms, severity and bothersomeness were all relatively low in Singapore. Bother was not analogous to symptom severity and should be considered independently in clinical decision making.

Strategies for reducing the frequency of preeclampsia in pregnancies with insulin-dependent diabetes mellitus

The object of this study was whether improving glycemic control and maintaining normal glycosylated hemoglobin (HbA1c) through pregnancy can reduce the frequency of preeclampsia. One hundred and twenty-three complete medical records of pregnant insulin-dependent diabetics (IDDM) managed at Yale-New Haven Hospital from 1983 to 1993 were reviewed. Serial HbA1c measurements and the occurrence of preeclampsia were recorded. Based on the change of HbA1c values through the pregnancy, glycemic control was categorized into four groups: group 1, high to normal; group 2, high to high; group 3, normal to normal; group 4, normal to high. The association between HbA1c change and the incidence of preeclampsia was analyzed by chi-square test and Fisher's exact test. Among 123 IDDM pregnancies, 40 (32.5%) developed preeclampsia. High HbA1c levels at any time in IDDM pregnancies were associated with an increased incidence of preeclampsia (group 1 or 2 or 4 versus group 3). Reducing HbA1c by improving glycemic control both before and during pregnancy resulted in a significantly lower incidence of pre-eclampsia (group 3 versus groups 1+2+4, p < 0.05). The best strategy for reducing the frequency of preeclampsia in IDDM pregnancies is by improving glycemic control before pregnancy.