Effects of Kaempferia parviflora Wall. Ex. Baker and Sildenafil Citrate on cGMP Level, Cardiac Function, and Intracellular Ca2+ Regulation in Rat Hearts

ABSTRACT:: Although Kaempferia parviflora extract (KPE) and its flavonoids have positive effects on the nitric oxide (NO) signaling pathway, its mechanisms on the heart are still unclear. Because our previous studies demonstrated that KPE decreased defibrillation efficacy in swine similar to that of sildenafil citrate, the phosphodiesterase-5 inhibitor, it is possible that KPE may affect the cardiac NO signaling pathway. In the present study, the effects of KPE and sildenafil citrate on cyclic guanosine monophosphate (cGMP) level, modulation of cardiac function, and Ca transients in ventricular myocytes were investigated. In a rat model, cardiac cGMP level, cardiac function, and Ca transients were measured before and after treatment with KPE and sildenafil citrate. KPE significantly increased the cGMP level and decreased cardiac function and Ca transient. These effects were similar to those found in the sildenafil citrate-treated group. Furthermore, the nonspecific NOS inhibitor could abolish the effects of KPE and sildenafil citrate on Ca transient. KPE has positive effect on NO signaling in the heart, resulting in an increased cGMP level, similar to that of sildenafil citrate. This effect was found to influence the physiology of normal heart via the attenuation of cardiac function and the reduction of Ca transient in ventricular myocytes.     

Sodium fluoride mouthrinse used twice daily increased incipient caries lesion remineralization in an in situ model

Objectives

To investigate the remineralizing effects of fluoride mouthrinses used at different times and frequency in addition to fluoride toothpaste.

Methods

A randomized crossover single blinded study comprised 4 experimental phases of 21 days each. Twelve orthodontic volunteers were fixed with an orthodontic bracket containing an artificial carious enamel slab, which was from the same tooth in all 4 phases, and were randomly assigned to the following groups: (1) brushing with F toothpaste 2× per day (F- brush), (2) F- brush + rinsing with 0.05% NaF (F- rinse) after lunch, (3) F- brush + F-rinse before bedtime, and (4) F- brush + F- rinse 2× per day. Mean mineral gain after each phase was determined from mineral density profiles obtained using Micro-CT.

Results

The mean mineral gain in all treatments with F- brush and F-rinse were significantly greater than those in F- brush (p < 0.05). Moreover F- rinse 2× per day increased lesion remineralization more than F- rinse once a day.

Conclusions

The twice-daily use of 0.05% NaF mouthrinse combined with twice-daily regular use of fluoride toothpaste resulted in the greatest remineralization of incipient caries. These data indicate that rinsing frequency is a factor affecting the effectiveness of fluoride mouthrinse.

Clinical significance

The rinsing frequency of NaF mouthrinse, when used with fluoride toothpaste, also affects the remineralization. This finding, if confirmed by a clinical study, would lead to a new recommendation for fluoride mouthrinse used in high caries risk patients who could benefit from using it twice a day.     

Effects of sildenafil citrate on defibrillation efficacy

Introduction: Although fatal arrhythmia and sudden death have been reported in patients taking sildenafil citrate, its effect on defibrillation efficacy has not been investigated. The aim of this study was to test the hypothesis that sildenafil citrate increases the shock strength required to successfully defibrillate during ventricular fibrillation (VF).
Methods and Results: A total of 26 pigs (20–25 kg) were randomly assigned into three groups. In each group, the defibrillation threshold (DFT) was determined at the beginning of the study using a three-reversal up/down protocol. Each shock (RV-SVC, biphasic) was delivered after 10 seconds of VF. Group 1 (n = 10) received 50 mg and group 2 (n = 10) received 100 mg of sildenafil citrate intravenously at a rate of 2 mL/minute for 50 minutes. Group 3 (n = 6) received 100 mL of saline intravenously at the same rate as in group 1. The DFT was determined again after the drug (drug-DFT) and saline (saline-DFT) administration. For 100-mg sildenafil citrate infusion, the DFT (483 ± 39 V, 18 ± 3 J) was significantly (P < 0.003 and P < 0.01, respectively) higher than the control-DFT (407 ± 123 V, 13 ± 7 J). This sildenafil citrate infusion increased the DFT ∼19% by voltage, and ∼38% by total energy. After 50-mg sildenafil citrate infusion, the DFT (454 ± 28 V, 15 ± 2 J) was not different than the control DFT (449 ± 28 V, 15 ± 2 J). Saline infusion (391 ± 18 V, 12 ± 1 J) did not alter the control DFT (399 ± 22 V, 12 ± 1 J).
Conclusion: The 100-mg sildenafil citrate infusion, representing a supra-therapeutic plasma level, significantly increased the DFT. This finding indicates that VF occurring during supra-therapeutic sildenafil citrate treatment would require a stronger shock to successfully defibrillate.     

Cathepsin D in human reproductive tissues: cellular localization in testis and epididymis and surface distribution in different sperm conditions

Mammalian sperm surface antigens are acquired either during spermatogenesis or sperm maturation in the epididymis. These antigens, many of which are hydrolytic enzymes, are actively synthesized and secreted by the resident epithelial cells and adsorbed to the sperm membrane as part of posttesticular sperm modification. In this study, we aimed to investigate the expression of cathepsin-D (CAT-D) in human reproductive tissues and its distribution on the sperm surface in different sperm conditions. Immunohistochemical results revealed the expression of CAT-D in the somatic Sertoli and Leydig cells without showing any immunoreactivity in any germ cells, despite their engagement of the acrosomal system. A strong immunoreactivity of anti-CAT-D was also detected in the epididymal epithelium, chiefly in the principal cells, which are known to actively synthesize and secrete proteins into the epididymal lumen. The absence of CAT-D in the clear cells was unexpected because these cells are known to engage the endosomal machinery. We further showed that CAT-D was anchored on the sperm surface confined to the postacrosomal region without any lateral redistribution within the membrane during sperm capacitation. However, the enzyme underwent changes to be an active form of a 29/30-kd doublet during sperm capacitation. Using CAT-D as a marker, we were able to demonstrate here localization of the enzyme in human reproductive tissues, as well as reveal membrane modification in human sperm during maturation and capacitation processes.     

<Emphasis Type="Italic">DI*A</Emphasis> and <Emphasis Type="Italic">DI*B</Emphasis> Allele Frequencies Among Southern Thai Blood Donors

Diego (DI) blood group genotyping is clinically important in Asian populations. Data of Diego blood type among southern Thais is still unknown. This study aimed to report DI*A and DI*B allele frequencies in southern Thai blood donors and to estimate potential risk of Di^a incompatibility and alloimmunization in Thai populations. DNA samples obtained from 427 southern Thai blood donors were genotyped for DI*A and DI*B alleles by polymerase chain reaction with sequence-specific primer. DI*A and DI*B allele frequencies among southern Thais were 0.0047 and 0.9953. Their frequencies were similar to those among American Native, Italian, Filipino, Alaska Native/Aleut and Hawaiian/Pacific Islander populations; while, the frequencies significantly differed from central and northern Thai, Southeast Asian, Brazilian, Southern Brazilian, Brazilian Japanese descendants, Japanese, Han Chinese, Chinese, and Korean populations (P < 0.05). The Di^a incompatibility among southern Thais (0.93%) was lower than among central Thais (3.49%), corresponding to a significantly lower probability of Di^a alloimmunization (P < 0.05). This is the first report of DI*A and DI*B allele frequencies among southern Thais, which is beneficial for not only creating information for estimating risk of alloimmunization, but also providing antigen-negative red cell donors to prevent both alloimmunization and adverse transfusion reactions.     

Antilipopolysaccharide factor (ALF) of mud crab Scylla paramamosain: molecular cloning, genomic organization and the antimicrobial activity of its synthetic LPS binding domain

Antilipopolysaccharide factors (ALFs) are small basic proteins that can bind and neutralize lipopolysaccharide (LPS) and have broad spectrum antimicrobial activities. In this study, we describe the isolation of the full-length cDNA encoding for ALF peptide (ALFSp) of mud crab, Scylla paramamosain by sequencing a hemocyte cDNA library and using the rapid amplification cDNA end (RACE) method. A full-length ALFSp cDNA of 614 bp contains an open reading frame (ORF) of 372 bp, encoding 123 amino acid protein with 26 residues signal sequence. The calculated molecular mass of the mature protein is 11.18 kDa. The highly two conserve cysteine residues and putative LPS binding domain were observed in ALFSp peptide. Comparison of amino acid sequences revealed that ALFSp shared high identity with other known ALFs and had an overall similarity of 65, 64, 63, 61 and 59% to those of Fenneropenaeus chinensis, Litopenaeus vannamei, Marsupenaeus japonicus, Limulus polyphemus, and Tachypleus tridentatus, respectively. A neighbour-joining tree showed a clear differentiation of each species and also indicated that ALF from S. paramamosain, Carcinus maenas and Callinectes sapidus are closely related phylogenetically. The genomic DNA sequence of ALFSp gene consists of 1075 bp containing three exons and two introns. Tissue distribution analysis revealed that ALFSp was abundantly expressed in hemocytes, intestine, and muscle but not in eyestalk. The synthetic ALFSp peptide containing putative LPS binding domain revealed a strong antimicrobial activity against several bacteria especially on the growth of Gram-positive bacteria, Micrococcus luteus and Gram-negative bacteria, Vibrio harveyi suggested that ALFSp could play an essential role in defense mechanism in S. paramamosain.     

Epidemiology of Malaria in Thailand

Background : In spite of significant achievements in malaria control in the past two decades, about 150,000 malaria cases still occur in Thailand each year. Although most short-term visitors to Thailand stay in malaria-free areas, an increasing number of more adventurous travelers are exposed to the disease.
Method : Since 1987, the Malaria Division of the Thai Ministry of Public Health has maintained a computerized database that includes all malaria cases recorded at malaria clinics, government health institutions, and private hospitals nationwide. In this article, we analyze the 1992 data.
Results : The provinces of Trad, Tak, and Kanchanaburi had the highest incidence of locally transmitted cases. Trad Province was also responsible for the highest number of imported cases. The highest incidence rate was found to be 426.5 per 1000 persons per year in a group of villages in Maesod District, Tak Province. Districts and provinces with ≥ 20 cases per 1000 persons per year are listed in this report. Peak transmission seasons and species prevalence of different endemic areas are described. Analysis of case investigation, a part of this database, indirectly supported the presence of mefloquine resistant Plasmodium falciparum strains on the Thai-Cambodian border.
Conclusions : This paper describes the characteristics of malaria in different parts of Thailand and pinpoints areas with significant transmission. However, in accordance with the present policy of the Thai national malaria control program, we do not recommend chemoprophylaxis, but we do strongly encourage personal protection, early diagnosis, and prompt treatment.     

Bioavailability and pharmacokinetic comparison between generic and branded azithromycin capsule: a randomized, double-blind, 2-way crossover in healthy male Thai volunteers

BACKGROUND: Azithromycin is a semisynthetic azalide antibiotic with extensive tissue penetration and a prolonged t(12). It is used once daily for 3 days in the treatment of a number of bacterial infections. However, based on a literature search, information concerning its pharmacokinetic properties, including the relative bioavailability of a newly developed generic capsule formulation compared with an established branded one in the Thai population, has not been reported. OBJECTIVE: The aim of this study was to compare the relative bioavailability and other pharmacokinetic properties of a newly developed generic capsule formulation of azithromycin with those of an established branded formulation in healthy male volunteers in Thailand. METHODS: A randomized, double-blind, 2-way crossover study was performed in healthy male Thai volunteers under fasting conditions with a washout of 30 days between the study periods. A single dose of 2 x 250-mg azithromycin capsules was orally administered, and blood samples were collected over a period of 120 hours. Plasma azithromycin concentrations were determined using a validated high-performance liquid chromatography method with fluorescence detection after derivatization with 9-fluorenylmethyloxycarbonyl chloride. A plasma concentration-time curve was generated for each volunteer from which the C(max), T(max), AUC(0-Iast), AUC(0-infinity), t(1/2), and kappa(e) were determined using noncompartmental analysis. Bioequivalence was defined using regulatory requirements set forth by Thailand, Association of Southeast Asian Nations, and the US Food and Drug Administration (bioequivalence acceptance range, 0.80-1.25). RESULTS: A total of 14 volunteers completed the study. The mean age of volunteers was 20.8 years (range, 19-23 years), and the mean body weight was 62.8 kg (range, 50.6-70.0 kg). The mean (SD) T(max), C(max), AUC(0-last), and AUC(0-infinity) values after administration of the generic and branded formulations were 1.46 (0.41) versus 1.54 (0.41) hours, 425.23 (208.45) versus 431.75 (198.16) ng/mL, 3919.77 (1549.65) versus 4344.79 (1654.98) ng . h/mL, and 4027.05 (1839.13) versus 4515.53 (2203.87) ng . h/mL, respectively. The relative bioavailability of the generic and branded formulations were 1.00 (0.17). The mean (SD) t1/2 values after administration of the generic and branded formulations were 26.43 (10.92) and 28.10 (13.13) hours, respectively. The analysis of variance results of the natural logarithm (In) -transformed values found no significant effect of formulation, period, or sequence on the studied pharmacokinetic parameters. The 90% CIs of the treatment ratios for the Intransformed values of C(max), AUC(0-last), and AUC(0-infinity) were 0.82 to 1.11, 0.91 to 1.06, and 0.91 to 1.08, respectively. All were within the standard bioequivalence acceptance range of 0.80 to 1.25. No adverse events were reported in this study. CONCLUSIONS: In this small study in a selected population of healthy male Thai volunteers, the C(max) and AUC were not statistically significantly different between generic and branded formulations of a single, 2 x 250-mg dose of azithromycin capsules. The generic and branded formulations were found to be bioequivalent. Both formulations were well tolerated.     

The cycle for a Siphoviridae-like phage (VHS1) of Vibrio harveyi is dependent on the physiological state of the host

In a previous report, we isolated Vibrio harveyi (VH) 1114 together with its bacteriophage, VHS1, from a black tiger shrimp-rearing pond. The VHS1 has its lysogenic relationship to the VH1114 host as either true lysogen (TL) or pseudolysogen (PL). The characters of TL are based on the extrachromosomal existence of the VHS1 phage genome in the VH host which also simultaneously produces the VHS1 phage particles and is resistant to super-infection. The original VH1114 host exhibits a clear plaque after infection with VHS1 phage. The PL, on the other hand, exhibits a turbid plaque and does not possess the phage genome but shows toleration to the phage infection. Maintaining the PL in artificial seawater (ASW) for 1h causes the PL to be sensitive to VHS1 infection and results in clear plaques as in the original clone. A chloramphenical-added-ASW treated pseudolysogen clone (PLC), however, prevented VHS1 infection. It is postulated that the infection of VHS1 phage is regulated with a phage binding receptor which supposed to be inducible.     

Biphasic effects of Morus alba leaves green tea extract on mice in chronic forced swimming model

In this study, the effects of an aqueous extract of Morus alba leaves green tea (ME) on mouse behaviors (depression, anxiety, climbing activity and thermal response), muscle coordination and muscle strength were studied. Male IRC mice received a single intraperitoneal injection of either the ME, desipramine or diazepam. Thirty minutes after injection, the mice were tested in all experimental models. A significant antidepressant-like effect could be detected in the animals receiving either 100 or 200 mg/kg ME. The effect of 200 mg/kg ME in decreasing the immobility time was comparable to 10 mg/kg desipramine. With higher dose (1000 mg/kg), a significant increase in immobility time could be observed. In the elevated plus maze, no increase in time in the open arm could be observed in mice treated with ME at either 100 or 200 mg/kg. However, high doses of ME (500 or 1000 mg/kg) decreased both time in the open arm and the number of entries in the maze. No change in thermal response could be seen in mice treated with ME at doses up to 500 mg/kg, however, at 1000 mg/kg, the response time to heat was increased significantly. The ME at either 500 or 1000 mg/kg also decreased muscle coordination, strength and climbing activity significantly when compared with the control. This study suggests that ME possesses an antidepressant- without an anxiolytic-like effect, however, at high doses, the extract might show the sedative effect and alter other functions such as muscle strength, animal activity in the maze and pain response.