Morphometric Study and Toxicity Assessment for Horseshoe Crab Collected From Kampung Pasir Putih, Sarawak, Malaysia

In Malaysia, horseshoe crabs encountered the decreases in population, which might due to the anthropogenic factor. Hence, this study was carried out to study the morphometric characteristic and to assess the toxicity of horseshoe crabs collected by local fishermen at 2014 and 2015 from Kampung Pasir Putih, Sarawak, Malaysia. The morphometric and allometric analysis was used to study the morphometric variability between the sexes of horseshoe crabs. All the samples collected were confirmed to be Tachypleus gigas. The body weight of both sex had increased at 2015 as compared to 2014. All parameters in females were recorded high especially body weight as compared to the males. The mean body weight of females were 787.22±93.73 g and males were 298.71±29.58 g. Allometric analysis shown that the specimens collected for both sexes have a high degree of correlation between total length and body weight. However, the b values (female=0.1813; male=0.1961) shown a negative allometric growth characteristic. Due to the frequent occurrence of food poisoning after consuming horseshoe crab, toxicity analysis was carried out in this study. For toxin analyses, thin layer chromatography, high performance liquid chromatography, and liquid chromatography mass spectrometer were performed. TLC was used as a screening for TTX, HPLC was to confirm for the presence of TTX and LCMS/MS was used to quantify the amount of TTX presence. TTX was most frequent detected in the eggs with the toxicity range from 3.53 MU/g to 6.5 MU/g. In viscera caecum and soft tissue, the toxic amount range from 1.22 MU/g to 6.81 MU/g and 1.96 MU/g to 6.15 MU/g respectively. This study was inferred that the horseshoe crab T. gigas collected are non-toxic (less than 10 MU) and safe to be consumed

Investigating the maxillary buccal vestibule

AbstractBackground/purposeImproper assessment of the maxillary buccal vestibular space can contribute to the fabrication of maxillary dentures with inadequate buccal flange extensions. The purpose of this study was to determine whether a significant difference existed between the anatomic dimensions of the buccal vestibules and the corresponding buccal flanges of maxillary complete dentures in an edentulous population.Materials and methodsThe anterior, middle, and posterior depth and width of the maxillary buccal vestibules in 100 randomly selected subjects were measured with a periodontal probe. Corresponding measurements of the buccal flanges of the subjects' existing dentures were recorded. The differences between buccal vestibule widths and depths and denture flange widths and lengths were statistically compared according to site.ResultsThe difference in the mean depth between the vestibules and the flanges in the posterior area (6.4 mm and 10.3 mm, respectively) was approximately 38% (P < 0.001). The difference in the mean width between the vestibules and the flanges in the posterior area (3.3 mm and 7.9 mm, respectively) was approximately 58% (P < 0.001).ConclusionThe study revealed statistically significant differences between the anatomic depth and width of the buccal vestibules and the corresponding flange dimensions of the existing dentures

The Difference Between Two Oral Appliances in Treating Obstructive Sleep Apnea: A Case Report

Oral appliances are a range of devices that are designed to alter upper airway patency. The efficiency of these appliances for treatment of obstructive sleep apnea (OSA) has been rarely discussed. This case report describes two designs of mandibular repositioning appliances used to treat OSA. A 36-year-old man was diagnosed with mild OSA by his physician. A single-piece, soft oral appliance and a two-piece, acrylic appliance were used in this patient. Polysomnography was performed three times (baseline, and with the single-piece, and two-piece appliances). The apnea/hypopnea index was improved significantly with both appliances, but to a greater degree with the single-piece soft appliance. Our study concluded that oral appliances may assist in the management of OSA

Responses of phytoplankton community to eutrophication in Semerak Lagoon (Malaysia)

Effects of aquaculture activities on the environmental parameters and phytoplankton community structure were investigated in a semi-enclosed lagoon located at Semerak River, Malaysia. Elevated concentrations of phosphate and ammonia were observed at the aquaculture area and the inner lagoon. Relatively low dissolved oxygen, high total chlorophyll a, and high phytoplankton abundances but low species richness were recorded. Chaetoceros, Pseudo-nitzschia brasiliana, Blixaea quinquecornis, and Skeletonema blooms were observed, and some were associated with anoxia condition. Eutrophication level assessed by UNTRIX suggests that the water quality in the lagoon is deteriorating. Dissolved inorganic phosphorus and nitrogen at the impacted area were 15 and 12 times higher than the reference sites, respectively. Such trophic status indices could provide a useful guideline for optimal aquaculture management plan to reduce the environmental impact caused by aquaculture

Fracture resistance of different metal substructure designs for implant-supported porcelain-fused-to-metal (PFM) crowns

AbstractBackground/purposeThis study evaluated the fracture resistance of different metal substructure designs for implant-supported porcelain-fused-to-metal (PFM) crowns.Materials and methodsEighteen PFM crowns were fabricated using different metal substructure designs and were conventionally cemented on an implant abutment analog. The crowns were divided according to the metal substructure design for manufacturing the metal framework into three groups of six specimens each: Group A had a minimum required thickness; Group B had a conventional design; and Group C had a wrinkled design. After applying a load of 200 N at a frequency of 2 Hz with 300,000 cycles of dynamic loading, all specimens were tested for fracture resistance using compression loading on the buccal functional cusp.ResultsAmong these three groups, Groups A and B, respectively, had the minimum and maximum fracture resistance strengths. Respective data for Groups A, B, and C were 111.13 ± 27.15 kg, 236.13 ± 39.21 kg, and 188.63 ± 12.10 kg. Statistically significant differences were observed among the three groups (P < 0.05).ConclusionThese results confirm that the conventional design had the best fracture resistance, and an excessively thick porcelain layer can cause crown fracture. However, there was no obvious proof that the wrinkled design had better fracture resistance than the conventional design. Therefore, the theory that PFM can provide better support requires further corroboration