High Levels of Tetrodotoxin in the Flesh, Usually an Edible Part of the Pufferfish Takifugu flavipterus, Caused by Migration from the Skin and the Regional Characteristics of Toxin Accumulation

The consumption of a pufferfish, Takifugu flavipterus or komonfugu in Japanese, formerly known as Takifugu poecilonotus, is popular in Japan. However, T. flavipterus is frequently involved in cases of tetrodotoxin (TTX) poisoning in Japan. Although victims have usually consumed inedible parts, some cases are related to consumption of flesh. To improve the risk management of pufferfish poisoning, we studied TTX level in the flesh and skin of T. flavipterus. Ninety-seven specimens obtained from the Seto Inland Sea and landed in Fukuoka Prefecture were analyzed by liquid chromatography-tandem mass spectrometry. The flesh from six specimens was toxic (>10 MU/g = 2.2 mg/kg): one was in poor condition (not freeze–thawed); three were freeze–thawed before sample preparation; and two freshly prepared and in good condition (not freeze–thawed). The fillets were divided into outer and inner portions; the TTX levels in the outer portions were notably higher. The skin of the six specimens was moderately to extremely toxic: 165 MU/g (36.3 mg/kg) in the fresh specimen not in good condition, 600–950 MU/g (132–200 mg/kg) in freeze–thawed specimens, and 4500 and 6000 MU/g (990 and 1320 mg/kg) in the two fresh specimens. We concluded that TTX in the flesh migrated from the highly toxic skin. In addition, TTX levels in the skin appeared to be regionally specific. We recommend that toxic portions of T. flavipterus are removed as soon as possible after individuals are caught, and that fish from known highly toxic areas are not consumed.

A New Inland Record of the Bull Shark Carcharhinus leucas (Müller & Henle 1839) from Peninsular Malaysia

A single specimen of a bull shark Carcharhinus leucas (Müller & Henle 1839) with c. 102 cm of total length was landed and photographed on 25 March 2019 in Sungai Mawai Lama, about 25 km inland, Kota Tinggi District, Johor, Peninsular Malaysia. This rare finding represents only the second record of C. leucas in inland Peninsular Malaysia. This shark was identified as C. leucas by the snout much shorter than the width of mouth and bluntly rounded, first dorsal fin triangular, rearward sloping, originating over or slightly behind pectoral insertion, second dorsal fin much smaller than the first dorsal fin (< 3.1:1), and lack of an interdorsal ridge. The coloration of fresh specimen: greyish back and white belly, the dark coloration on the tip of the caudal fins and second dorsal fin. This species is currently listed as a vulnerable species based on the IUCN Red List Status. Further study and monitoring are needed to assess the possibility of the importance of Sungai Mawai Lama as critical habitat of C. leucas.

Single-cell RNA sequencing of human nail unit defines RSPO4 onychofibroblasts and SPINK6 nail epithelium

Research on human nail tissue has been limited by the restricted access to fresh specimen. Here, we studied transcriptome profiles of human nail units using polydactyly specimens. Single-cell RNAseq with 11,541 cells from 4 extra digits revealed nail-specific mesenchymal and epithelial cell populations, characterized by RSPO4 (major gene in congenital anonychia) and SPINK6, respectively. In situ RNA hybridization demonstrated the localization of RSPO4, MSX1 and WIF1 in onychofibroblasts suggesting the activation of WNT signaling. BMP-5 was also expressed in onychofibroblasts implicating the contribution of BMP signaling. SPINK6 expression distinguished the nail-specific keratinocytes from epidermal keratinocytes. RSPO4+ onychofibroblasts were distributed at close proximity with LGR6+ nail matrix, leading to WNT/β-catenin activation. In addition, we demonstrated RSPO4 was overexpressed in the fibroblasts of onychomatricoma and LGR6 was highly expressed at the basal layer of the overlying epithelial component, suggesting that onychofibroblasts may play an important role in the pathogenesis of onychomatricoma.

Short Communication: The presence of Bull shark Carcharhinus leucas (Elasmobranchii: Carcharhinidae) in the fresh waters of Sumatra, Indonesia

Hasan V, Widodo MS. 2020. Short Communication: The presence of Bull shark Carcharhinus leucas (Elasmobranchii: Carcharhinidae) in the fresh waters of Sumatra, Indonesia. Biodiversitas 21: 4433-4439. A single subadult specimen of Bull shark Carcharhinus leucas was photographed and captured by local fisherman using casting net on June 2020 in the upper Indragiri River, Riau Province, Indonesia. Carcharhinus leucas are one of only a few species of elasmobranchs that live in both marine and freshwater environments. This species currently listed as a near-threatened species based on the IUCN Red List Status. Singel specimen identified as C. leucas by the coloration of fresh specimen: white belly and greyish back, first dorsal fin high, tip of second dorsal and caudal fins black. Meristic characters measurement results as follows: total length 102 cm; fork length 86.3 cm; preanal length 65.1 cm; pre pelvic length 51.9 cm; pre pectoral length 22.5 cm; pre-orbital length 8.3 cm; head length 25 cm; pre-first dorsal length 29.4 cm; pre-second dorsal length 56 cm, and pre-caudal length 78.1 cm. This photo is considered as the third record from freshwaters of Sumatra after in the Batang Hari River, Jambi Province in 1997, and in the Musi River, South Sumatra Province in 2019. The photographic records indicate that a single specimen of C. leucas was found in the upper Indragiri River recorded more than 150 km inland. These results enhanced the understanding of C. leucas distribution in Sumatra freshwaters. Monitoring is needed to assess the possibility of the importance of the upper Indragiri River as a migration route, nursery, and growth ground of C. leucas. Studying small scale habitat use of C. leucas is challenged by their preferred habitats in freshwaters environments with fast-changing environmental conditions. Water conditions in the upper Indragiri River, namely salinity 0‰, temperature 25-27°C, dissolved oxygen 3.9-11.1 mg/l, are ideal for A. leucas habitat.

Redescription of Tetragonurus pacificus (Teleostei: Stromateoidei: Tetragonuridae), based on specimens collected from Taiwan and Tarawa Atoll

The rare squaretail Tetragonurus pacificus Abe 1953 was described on the basis of a single poor-condition specimen obtained from the stomach of a yellowfin tuna collected from west of the Solomon Islands. A fresh specimen of T. pacificus was recently collected from southwestern Taiwan and its morphology and the fresh coloration are herein described in detail. In addition, a juvenile specimen collected from the southern Pacific Ocean was found in the museum collection. The species is characterized by dorsal-fin spines 10–11; longitudinal scale rows along body axis 72–80; and predorsal scales 17–20. The present specimen collected from off southwestern Taiwan represents the northernmost record of the species from the Pacific Ocean.

Amphicnemis rigiketit sp. nov. from Sarawak, with notes on Amphicnemis remiger Laidlaw, 1912 (Odonata: Zygoptera: Coenagrionidae)

Amphicnemis rigiketit sp. nov. is described from southwestern Sarawak (holotype ♂ in forest around stream, near road from Kota Samarahan to Siburan, Samarahan Division, Sarawak, Malaysian Borneo, 21 ii 2018, deposited in the Natural History Museum, London). The new species is allied to A. remiger Laidlaw, 1912. The female of A. remiger is described for the first time and a description of the male from a fresh specimen is provided along with notes on variation.

Desquamative Gingivitis: A Sign of Mucocutaneous Disorder

Desquamative gingivitis is characterized by erythematous gingiva, desquamation and erosion of the gingival epithelium.It is a clinical manifestation of various disorders that can manifest as a desquamative lesion of gingiva rather than a disease entity.It is seen mainly in adults, especially women, although rare cases have been observed in children. Failure to evaluate properly and systematically a patient with a clinical condition consistent with desquamative gingivitis can lead to unpleasant outcomes. Clinical features may be symptomatic to asymptomatic with complaints ranging from burning sensation to intense pain.Lesions are found in skin, genitalia, or oral mucosa, although confined to gingiva alone in some patients.Diagnosis and treatment planning depends on history,clinical features,histopathology and immunofluorescence. Correct diagnosis of mucocutaneous disorders where DG is a presenting manifestation involves taking a careful history and thorough intra-oral examination. A definitive diagnosis depends on taking an incisional biopsy from perilesional site and sending a fresh specimen for immunostaining.

Histopathological Features of Lymph Nodes of Tuberculous Lymphadenitis Patients: Experience of 50 cases in Bangladesh

Background: Tuberculous lymphadenitis is common manifestation of extra-pulmonary tuberculosis in Bangladesh. Objective: The purpose of the present study was to see the histopathological features of tuberculous lymphadenitis patients. Methodology: This cross sectional study was done at the Department of Pathology at Banghabandhu Sheikh Mujib Medical University (BSMMU), Dhaka from January 2009 to March 2011 for a period of nearly two years. All the patients irrespective of age and sex with the clinical features suggestive of tuberculous lymphadenitis and later on proved to be the same histologically were selected for the study purposively. Relevant information was recorded in a prescribed data sheet and histomorphological findings were recorded accordingly. In cases where fresh specimen was available, caseous portion of lymph node was sent for culture. FiteFaraco staining was also done on lymph node sections in all cases. Result: A total number of 50 tuberculous lymphadenitis patients were recruited for this study of which well formed granuloma was detected in 34(68.0%) cases followed by ill defined and combination of well and ill defined which were 8(16.0%) cases in each. Among 34 well defined cases coalescing and discrete were found in 6(17.6%) cases in each. However, both types were found in 22(64.7%) cases.Conclusion: In conclusion well formed granuloma is most commonly found in tuberculous lymphadenitis with combined variety of coalescing and discrete histopathologic featuresBangladesh Journal of Infectious Diseases 2016;3(2):40-42