Disease problems in shrimp sector in Khulna district of Bangladesh: a question of sustainability

Disease is the main restraining factor for the development of shrimp sector in Bangladesh. Both brackish water shrimp bagda (Penaeus monodon) and freshwater prawn golda, (Macrobrachium rosenbergii) farming in Bangladesh have been facing disease problem. A study on disease outbreak in both brackish water and freshwater small-scale shrimp farms (gher) in Khulna district was carried out through interviewing randomly selected 3-5% of shrimp farmers with a structured questionnaire during March to December, 2002. The study showed that 97% bagda farming ghers and 80% golda farming ghers were affected by disease. White spot disease was the severe disease for bagda, whereas, antenna rot was the main disease for freshwater prawn. Change of water and liming were carried out as control measures of disease for bagda shrimp farming, while it was only liming for golda farming. A small number of shrimp farmers (15%) used chemicals for treatment of shrimp diseases. Development of suitable farming technology to prevent disease contamination and innovation of proper treatments for diseases are required to overcome the disease problems for sustainable shrimp farming in Bangladesh.

Methylation of tumor associated genes in tissue and plasma samples from liver disease patients

To investigate whether aberrant hypermethylation in plasma DNA could be used as diagnosis makers for hepatocellular carcinoma (HCC), we performed methylation-specific PCR (MSP) to check the methylation status of five tumor associated genes in 36 cases of

Study on regional differences in soil-water characteristics and their relevance to aquaculture productivity and fish disease

A total of 45 ponds used for fish polyculture were investigated in three zones of Bangladesh to identify the differences among the zones in respect to aqua-ecology, culture practices, fish productivity and health management. Four hundred and fifty fish from three zones were clinically examined by naked eye and histopathology. Out of total number of fish examined, 45 fish from Dhaka zones were examined for parasites and bacteria in addition to histopathology. Faded and haemorrhagic gill, skin, fin, scale loss and lesions were observed during fish examination. Aeromonas spp. Pseudomonas spp. and Streptococcus spp. were isolated respectively from 56%, 46% and 39% affected fish. Among the five water quality parameters analyzed, the highest average hardness and alkalinity respectively were recorded in Rajshahi (156 ppm and 142 ppm) followed by Dhaka (146 ppm and 132 ppm) and Chittagong (81 ppm and 90 ppm). The highest average pH was recorded in Mymensingh (7.52) followed by Rajshahi (7.13) and Chittagong (7.05). Water holding capacity of soil in Rajshahi zone was poor compared to other zones and farmers were found to be reluctant to fish farming.

Health and disease status of Thai pangas, Pangasius hypophthalmus cultured in rural ponds of Mymensingh, Bangladesh

Thai pangas, Pangasius hypophthalmus is one of the important aquaculture species in Bangladesh. Over the last few years spectacular development has been taking place in Thai pangas farming in Mymensingh district. Due to availability of easy breeding and culture techniques as well as quick return, more and more people are converting their rice fields into pangas farms overnight. The present study was carried out to examine health and disease status of Thai pangas mainly through clinical, histopathological and bacteriological techniques. In addition, for collecting primary data on disease and health status of Thai pangas and the resultant socioeconomic impacts on rural households, questionnaire interview and participatory rural appraisal tools were used with selected farming households in three upazilas of Mymensingh district. The most prevalent diseases as reported by the farmers were red spot, followed by anal protrusion, tail and fin rot, pop eye, dropsy and gill rot. Other conditions like cotton wool type lesion, ulceration and white spot were reported but with lower incidence. Four isolates of Aeromonas hydrophila were recovered from kidney and lesion of diseased fish. Hemorrhage over the body especially near mouth and caudal region was noticed in the fishes associated with aeromonad infection. Internally, kidney, liver and spleen became swollen and enlarged. The isolates varied with their pathogenicity. All the four isolates were sensitive to Nitrofurantoin, Cotrimoxazole and Tetracycline but were resistant to Amoxycilline. An attempt was made to treat diseased fish with extracts from neem leaf, garlic and turmeric. Recovery of infection was monitored through mortality and histopathology. General histopathological changes of different organs were also studied. Extract from neem (Azadirachta indica) leaf gave better result. Telangiectasis, lamellar hypertrophy and hyperplasia hemorrhage, lamellar fusion, necrosis of lamellar epithelial cells, presence of parasites and their cysts were the major pathology of gills. Hemorrhagic lesion, pyknotic nuclei and melanomacrophage centers (MMC) were found in the liver of fish. Major pathologies in kidney of fish included presence of MMC, necrotic and ruptured kidney tubules, severe haemopoietic necrosis, and hemorrhage. The economic loss due to disease in Thai pangas farming was estimated from the difference between expected production and actual production. On an average, Thai pangas farmers of Mymensingh incur a loss of Tk. 23,104/ha/cycle due to fish disease (3.6% of expected total production). The loss, however, varied with location and size of farms, type of farmers and management practices. The study also highlighted fish health management related problems and recommended further work for the development of user-friendly farmer-oriented fish health management packages.

Low “penetrance” of phylogenetic knowledge in mitochondrial disease studies

An up-to-date view of the worldwide mitochondrial DNA (mtDNA) phylogeny together with an evaluation of the conservation of each site is a reliable tool for detecting errors in mtDNA studies and assessing the functional importance of alleged pathogenic mutations. However, most of the published studies on mitochondrial diseases make very little use of the phylogenetic knowledge that is currently available. This drawback has two inadvertent consequences: first, there is no sufficient a posteriori quality assessment of complete mtDNA sequencing efforts; and second, no feedback is provided for the general mtDNA database when apparently new mtDNA lineages are discovered. We demonstrate, by way of example, these issues by reanalysing three mtDNA sequencing attempts, two from Europe and another one from East Asia. To further validate our phylogenetic deductions, we completely sequenced two mtDNAs from healthy subjects that nearly match the mtDNAs of two patients, whose sequences gave problematic results. (c) 2005 Elsevier Inc. All rights reserved.

Origin, genetic diversity, and population structure of Chinese domestic sheep

To characterize the origin, genetic diversity, and phylogeographic structure of Chinese domestic sheep, we here analyzed a 531-bp fragment of mtDNA control region of 449 Chinese autochthonous sheep from 19 breeds/populations from 13 geographic regions, to

Phylogenetic analysis of snow sheep (Ovis nivicola) and closely related taxa

Based on mitochondrial cytochrome b gene sequence analysis, the history of true sheep ( Ovis) began approximately 3.12 million years ago ( MYA). The evolution of Ovis resulted in three generally accepted genetic groups: Argaliforms, Moufloniforms, and Pac

Application of the phylogenetic analysis in mitochondrial disease study

Mitochondrial disease currently received an increasing concern. However, the case-control design commonly adopted in this field is vulnerable to genetic background, population stratification and poor data quality. Although the phylogenetic analysis could

Association of pro staglandin-endoperoxide synthase 2 (PTGS2) polymorphisms and Alzheimer's disease in Chinese

Cyclooxygenase-2 (COX-2, encoded by the gene prostaglandin-endoperoxide synthase 2, PTGS2) is a key enzyme in the conversion of arachidonic acid to prostaglandins. The prostaglandins produced by COX-2 are involved in inflammation and pain response in diff

Absence of association between SERPINE2 genetic polymorphisms and chronic obstructive pulmonary disease in Han Chinese: a case-control cohort study

Background: Recent studies have proposed that the serine protease inhibitor E2 (SERPINE2) was a novel susceptibility gene for chronic obstructive pulmonary disease (COPD) in Caucasians. However, this issue still remained controversial. Additional evidence

Revealing the History of Sheep Domestication Using Retrovirus Integrations

The domestication of livestock represented a crucial step in human history. By using endogenous retroviruses as genetic markers, we found that sheep differentiated on the basis of their "retrotype" and morphological traits dispersed across Eurasia and Afr

Polymorphisms of the estrogen receptor alpha (ESR1) gene and the risk of Alzheimer's disease in a southern Chinese community

Background: Alzheimer's disease (AD) is a neurodegenerative disease with a higher prevalence in women. Expression of estrogen receptor 1 (ESR1) gene has been identified throughout the brain. Owing to the putative neuroprotective effects of estrogen, estro

Mitochondrial control region sequence variation within the argali wild sheep (Ovis ammon): evolution and conservation relevance

The phylogenetic relationship of several subspecies of Ovis ammon were analyzed by comparing DNA sequences within the entire mitochondrial D-loop region. Five putative subspecies of ammon (dalai-lamae, darwini, hodgsoni, sairensis and adamerzi) were sampled from four provinces in China [Xinjiang, Qinghai, Gansu and Xizang (Tibet)] and two (servertzovi and nigrimontana) from Uzbekistan. The argalis sampled represent most of the currently recognized putative Subspecies of argali. Analysis of mtDNA sequences revealed high variability within ammon (7.7%), ranging from 2.4 to 11.5%. MaxiMUM-Parsimony tree indicated that nigrimontana from Uzbekistan diverged First, followed by severtzovi from Uzbekistan. The dispersal of argalis into China gave rise to three clades, suggesting that the argali originated in Western Asia and then dispersed throughout the central Asian highlands on a southeastward course. Among the Chinese argalis, mtDNA analysis places dalailamae genetically closer to hodgsoni than to darwini. Severtzovi and.. nigrimontana are two separate subspecies and genetically distinct from the Chinese argali.

Pseudomitochondrial genome haunts disease studies

The accidental amplification of nuclear mitochondrial pseudogenes (NUMTs) can pose a serious problem for mitochondrial disease studies. This report shows that the mutation spectrum left by spurious amplification of a NUMT can be detected because it usuall