- PublicationRecognition of deglycosylated larval proteins of Gnathostoma spinigerum by a monoclonal antibody and human gnathostomiasis antiserum(1999-01-01) P. Uparanukraw; T. Harnnoi; A. Dantrakool; N. Morakote; W. Chaicumpa; Chiang Mai University; Mahidol UniversityThe study on the recognition of35S-labelled somatic antigens of Gnathostoma spinigerum advanced third-stage larva (aL3) has revealed that the mAb GN6/24 immunoprecipitated 26- and 24-kDa proteins from the undigested and N-glycosidase F-digested larval extracts, respectively. The recognition of the deglycosylated form of the glycoprotein indicated that the mAb reacted with the peptide epitope on the 26-kDa protein. Human gnathostomiasis antiserum immunoprecipitated most of the N-glycosidase F-digested larval proteins including the deglycosylated 26-kDa protein.
- PublicationThyroid cartilage and vocal fold reduction: A new phonosurgical method for male-to-female transsexuals(2000-01-01) S. Kunachak; S. Prakunhungsit; K. Sujjalak; Mahidol UniversityTo date, there is a paucity of literature on surgery to alter vocal pitch in male-to-female transsexuals. The currently available pitch-raising surgical techniques yield neither a good long-term result nor a high enough pitch to simulate a female voice. We investigated a new procedure to alter vocal pitch in 6 male-to-female transsexuals. The principle is to shorten and increase tension on both vocal folds by composite resection of a vertical strip of the anterior thyroid cartilage along with a segment of vocal fold. This resulted in a satisfactory pitch alteration from an average of 147 Hz before operation to 315 Hz afterward. In addition to a marked pitch elevation, all patients were particularly pleased with the softness of the voice and the simultaneous loss of the prominentia laryngea (Adam's apple). The longest follow-up was 6 years. In conclusion, thyroid cartilage and vocal fold reduction is an effective method for long-term alteration of voice in male-to-female transsexuals.
- PublicationThe permeability of the dentine and other tissues that are exposed at the tip of a rat incisor(2000-01-01) K. Vongsavan; N. Vongsavan; B. Matthews; Mahidol University; University of Bristol, Faculty of Medicine and DentistryThe tissues that form the incisal surface of a rat incisor include dentine, an atubular calcified tissue which lines the last-formed dentine, and calcified pulp remnants. The permeability of these tissues was investigated in vitro and in vivo using Evans blue dye. The incisal surface was prepared by etching it with acid or removing 1 mm by fracturing or with a diamond disc followed by etching. In some cases, 1.5-3.0 mm was removed to expose the soft tissue of the pulp. The dye was applied for 30 min, then longitudinal sections of the crown were cut and examined microscopically to determine the extent to which the dye had diffused into the underlying tissues. In only those teeth in which the dye had been applied direct to the pulpal soft tissue could any be detected below the exposed tooth surface. In previous experiments, it was found that both cat and human dentines were freely permeable to Evans blue when they were tested in vitro. It is concluded that the dentine and other tissues that form the incisal surface of a rat incisor are less permeable than cat or human dentine. © 2000 Elsevier Science Ltd.
- PublicationRadiofrequency catheter ablation: 5 years experience at Siriraj Hospital(2000-11-01) Ongkarn Raungratanaamporn; Kiertuai Bhuripanyo; Charn Sriratanastavorn; Rungroj Krittayaphong; Jarupim Soongswang; Suphachai Chaithiraphan; Mahidol UniversityBetween February 1995 to May 2000, 626 consecutive patients underwent radiofrequency catheter ablation for various types of cardiac arrhythmia. The mean age was 41 years, range 1-85 years. Mapping and ablation were guided by intracardiac electrogram and anatomical approaches. The initial success, compliction, recurrent and final success rates are shown below :-WPW AVRT AT AFI AVNRT PVC VT AF Initial success (%) 95 100 83 91 100 89 95 81 Complication (%) 2.1 4.6 7.1 8.8 6.0 7.7 1.4 25 Recurrence (%) 9 4 13 6 1 11 11 6 Final success (%) 93 99 77 88 100 89 91 75 Conclusion, RFCA is an effective treatment and should be considered as first line treatment for certain tachyarrhythmia.
- PublicationComparison of general and regional anesthesia for cesarean section: Success rate, blood loss and satisfaction from a randomized trial(1999-07-01) Jariya Lertakyamanee; Thitima Chinachoti; Thara Tritrakarn; Jarinya Muangkasem; Achra Somboonnanonda; Thrathip Kolatat; Mahidol UniversityObjective: A prospective randomized trial was organized to compare the effectiveness of general and regional anesthesia for cesarean section (C/S). Method: Three hundred and forty-one patients were randomized into the general anesthesia group (GA), epidural anesthesia group (EA) and spinal anesthesia group (SA). The effectiveness of interest was success rate, blood loss and patient satisfaction. Result: We found that the success rates of EA and SA were lower than GA. Success in EA should be improved by using an epidural catheter to add more local anesthetic drug instead of a single shot; and the surgeon should allow more time for the block to work adequately. Success is SA should be improved by using bupivacaine instead of lidocaine. GA resulted in significantly more blood loss, lower postoperative hematocrit, and higher proportion of patients who had postoperative hematocrit <30 per cent than EA and SA. The patients' satisfaction scores were not different among the 3 techniques. This meant that, given adequate explanation and perioperative care, Thai women were satisfied with regional anesthesia. Conclusion: Regional anesthesia is a better choice of anesthesia for C/S than general anesthesia. However, the availability of different techniques and ability to change the technique when needed were very useful and important. If GA is chosen, all safety procedures must be followed. Oxygen supplement and endotracheal intubation facilities must be available in all techniques. Guidelines of anesthesia for C/S at a national level should be agreed upon, including the type of personnel, monitoring equipment and postoperative care.
- PublicationCharacterization of specific monoclonal antibodies for detection of mefloquine in body fluids(2000-09-01) Sakalin Trisirivanich; Juntra Laothavorn; Kesara Na-Bangchang; Srisin Khusmith; Mahidol UniversitySpecific monoclonal antibodies (MAbs) to mefloquine conjugated to bovine serum albumin (mefloquine-BSA) were produced by hybridoma technology. The mefloquine-BSA was synthesized by converting mefloquine into hemisuccinate followed by convalently linked to bovine serum albumin (BSA) and coupling with N,N′ disuccinimidyl carbonate (DSC). The conjugate was purified by Sephadex G-75 gel filtration using 0.01M PBS pH 7.2. An average of 19.34 molecules of mefloquine were conjugated to each molecule of protein determined by differential UV absorption spectra of hapten and protein carrier. Sixteen monoclones producing antibody specific to mefloquine were screened by indirect ELISA using homologous antigens. The specificity of MAbs was determined by reacting with BSA and the structurally related antimalarial drug, quinine. Three, three, five and two MAbs belonged to IgG1, IgG2a, IgG2b and IgG3, respectively. Most of the MAbs slightly reacted with quinine-BSA due to the closely related structure of mefloquine to quinine. The selected MAb designated 11F9(G5)G9 which showed no cross reaction with quinine-BSA gave high reactivity with blood samples from malaria patients previously treated with mefloquine when compared to normal blood by indirect ELISA. The preliminary results indicated that such specific MAb could be used as antibody probe for detection of mefloquine in biological fluids.
- PublicationDetection of HBV genome by gene amplification method in HBsAg negative blood donors(1999-05-01) Pisamai Bodhiphala; Pimol Chiewsilp; Somchai Chaturachumroenchai; Prasong Pruksananonda; Mahidol University; Charoen Krung Pracharak Hospital; Samitivej Hospital (Sukhumvit)The incidence of post-transfusion hepatitis has been reduced greatly by screening blood donors for hepatitis B surface antigen (HBsAg). However, hepatitis B virus infection still accounts for a certain number of cases of post-transfusion hepatitis. The purpose of this study was to detect HBV DNA in the HBsAg negative blood samples by using nested PCR with two primer pairs specific to core region. Two hundreds blood samples from HBsAg negative donors, and 14 samples from HBsAg positive donors were provided by the blood bank of Ramathibodi Hospital. The results showed that HBV DNA was detected in all 14 HBsAg positive blood samples and in 7 (3.5%) of 200 HBsAg negative blood samples. This study showed that the absence of HBsAg in otherwise apparently healthy individuals may not be enough to ensure lack of circulating HBV. The more sensitive ELISA technique is still in need. Otherwise, the safety of blood transfusion can be enhanced by careful selection of blood donors and careful consideration of risks and benefit of the patients who need blood transfusions.
- PublicationPrevalence and clinical characteristics of fragile X syndrome at Child Development Clinic, Ramathibodi Hospital(2000-01-01) Nichara Ruangdaraganon; Thanyachai Sura; Noppawan Sriwongpanich; Pornprot Limprasert; Tasanawat Sombuntham; Nittaya Kotchabhakdi; Mahidol University; Prince of Songkla University; Rachanukul HospitalFragile X syndrome, the most common cause of inherited mental retardation, is an X-linked genetic disorder caused by an expanded CGG repeat in the fragile X mental retardation 1 gene. It is characterized by mental retardation, behavioral features, and physical features, such as a long face with large protruding ears and macro-orchidism. A screening for the syndrome was conducted in a representative sample of pediatric patients, who had developmental delay or mental retardation with unknown cause, at the Child Development Clinic, Ramathibodi Hospital. The DNA test was performed on all patients using PCR and southern blot techniques. Five positive cases were detected from 114 screened subjects, and more four cases confirmed among other family members. Two of five positive families initially denied a family history of mental retardation. Among 9 cases of fragile X syndrome, four had hyperactivity and two had autistic like behavior. More than half had rather a long face or prominent ears. Three boys had macro-orchidism.
- PublicationDevelopment of metal-resin composite restorative material. Part 3. Flexural properties and condensability of metal-resin composite using Ag-Sn irregular particles.(2000-01-01) S. Urapepon; K. Kakuta; H. Ogura; C. Suchatlampong; A. Rittapai; Mahidol UniversityPowder-liquid type metal-resin composites, using Ag-Sn irregular particles as the filler, 4-META as coupling agent and UDMA + TEGDMA as resin matrix, were experimentally prepared under 9 different conditions (three different particle sizes and three different filler contents). The flexural strength and flexural modulus were measured. Three different irregular particle size MRCs without redox-initiator at 94% filler content, as well as amalgam, conventional hybrid composite and Ag-Sn spherical particle MRC were evaluated for condensability. The flexural strength of the Ag-Sn irregular particle MRC was significantly influenced by both the filler particle size and filler contents (p < 0.01). It increased when either the filler content increased or the particles size decreased. The highest flexural strength (97.6 MPa) was obtained from the condition of particles size < 20 microns and 94% filler content. The flexural modulus was significantly influenced by filler content and it increased with increasing filler content. The condensability of the Ag-Sn irregular particle MRC was lower than that of amalgam but much higher than presently available conventional composites and spherical particle MRC.
- PublicationThe role of prostacyclin (PGI2) and thromboxane A2(TXA2) in pathogenesis of dengue hemorrhagic fever (DHF)(1999-12-01) Chawalit Preeyasombat; Suporn Treepongkaruna; Arporn Sriphrapradang; Lulin Choubtum; Mahidol UniversityIn previous studies it has been demonstrated that the levels of plasma 6 keto-prosta-glandin F1α (6-K-PGF1), the stable metabolite of PGI2were elevated in DHF patients during shock. In this study it is hypothesized that excessive PGI2production plays a very important role in developing serious clinical manifestations of dengue shock syndrome (DSS) patients. In addition, an attempt was made to determine whether TXA2has any significant role in such patients. Plasma 6-K-PGF1and thromboxane B2(TXB2), the stable metabolites of TXA2were determined in 43 normal healthy children (NC) and 54 DHF patients without shock (DHF-N) and 33 DHF patients with shock (DHF-S). Subjects aged between 2 and 14 years. Plasma 6-K-PGF1and TXB2were measured by radioimmunoassay and the ratio of TXB2/6-K-PGF1were also calculated. In 43 NC the values of plasma TXB2, 6-K-PGF1and TXB2/6-K-PGF1ratio were (mean ± SE) 372.3 ± 17.1, 150.1 ± 2.4 and 2.52 ± 0.12 pg/ml, respectively. In 54 DHF-N patients the corresponding values were 409.1 ± 16.0, 278.4 ± 11.6 and 1.54 ± 0.06 pg/ml; whereas those in 33 DHF-S patients were 254.3 ± 26.2, 349.1 ± 20.5 and 0.757 ± 0.073 pg/ml, respectively. Plasma 6-K-PGF1levels of DHF-N and DHF-S patients were significantly greater than those in normal children (p < 0.001, p < 0.01 respectively). The plasma 6-K-PGF1levels seem to be greater in DHF-S patients than in the DHF-N patients, however the difference in values were not statistically significant (p > 0.05). These findings indicate that plasma PGI2level is significantly increased in DHF particularly during shock. Plasma TXB2levels of DHF-N had no significant statistical difference from those of NC (p > 0.05); however, those in DHF-S patients were significantly lowered (p < 0.001) than those of NC and DHF-N patients. The findings suggest the important role of TXA2to compensate for excessive PGI2secretion in DHF patients. The failure or inadequate TXA2production may eventually lead to shock. The ratios were significantly reduced in both DHF-N and DHF-S patients when compared to those of NC (p < 0.001 both). The ratio in DHF-S patients was also significantly lowered than that in DHF-N patients (p < 0.001). It is suggested that the imbalance between TXA2and PGI2production exists during DHF infection. The more reduction of plasma TXA2/PGI2ratio leads to more overt and serious clinical manifestations of the disease.