Fish tank or swimming granuloma caused by Mycobacterium marinum is an opportunist pathogen commonly found in aquatic environments. We present a 16 year-old boy with frequent exposure to aquarium water who had several nodules (sprotrichoid forms) on his right hand.Pervious studies showed that fish tank granuloma is a rare skin infection (0.27 per 100,000 population in one year). However, taking proper history and considering the patient’s signs and symptoms could be helpful in diagnosis and treatment.

BACKGROUND AND OBJECTIVES: Formaldehyde in food or the environment poses significant health risks, as it is a known carcinogen that can cause respiratory issues skin irritation, and long-term exposure can lead to serious diseases such as cancer. It can be found around us, such as in food and water. A novel gold electrode modified with fish albumin has been developed for the detection of formaldehyde, aligning with green chemistry principles. Fish albumin, which contains amino acids such as glycine, lysine, and histidine, can react with formaldehyde. This reactivity suggests that fish albumin is a viable and environmentally friendly material for use in formaldehyde sensors. The objectives of this study were to make albumin-modified electrodes used for formaldehyde detection applied for the fish in case fishermen generally use formaldehyde to preserve the fish they bring ashore. This formaldehyde helps maintain the freshness of the fish during the handling and transportation process.METHODS: The fish albumin was used from the self-extraction of snakehead fish (Channa striata) using water as a solvent. Fish albumin was mixed with paraffin in a definite ratio, then heated on the hot plate and stirred until homogenized. The liquid was poured into a small glass tube, with one of the ends connected to gold. The electrode was ready to be used after the liquid became solid. All performances for formaldehyde detection used the cyclic voltammetry technique. The potential measurement was between 0 volt and +1.8 volt with a 100 millivolt per second scan rate.FINDINGS: The electrode works well in acidic conditions by showing a significant formaldehyde signal compared to alkaline and neutral conditions. The linear analysis range was 0.1 ~ 3 millimolars with a detection limit of 4.07 micromolars, and the sensitivity was 20.365 microampere millimolars per square millimeter. This electrode was used to determine the formaldehyde concentration in the interference of methanol, ethanol, glycerol, and glucose. This method was also applied to the real samples and simultaneously compared to the standard method (Nash method) for formaldehyde detection.CONCLUSION: The electrode exhibits excellent performance with high sensitivity and selectivity for formaldehyde detection under acidic conditions. The electrode also features a low detection limit, allowing for precise formaldehyde measurement. Methanol, ethanol, glucose, and glycerol do not interfere with detection. Additionally, the electrode demonstrates good repeatability and delivers accuracy comparable to the standard Nash method, making it a promising alternative for formaldehyde detection. The benefit of the proposed method is that no reagent is added to samples.

Lead is one of the heavy metal that is very toxic for environment and organisms. Lead can inhibits many physiological processes and it is so dangerous for body tissues. In this study, four groups of fish (carassius auratus) 35 in each, were used for experiment. Group 1 was as control, in group 2 fishes were exposed to lead acetate at concentration of 8.5 mg/l, fishes in group 3 and 4 were also exposed to lead acetate in the same concentration of group 2 supplemented with vitamin B1(thiamine) at doses 30mg/l and 60mg/l, for 21 days respectively. Tissue specimens including gill, brain, kidney and liver were fixed in 10% buffered formalin, and stained with H&E. Results of histopathological findings evaluated with two non parametric Kruskal - Wallis Test and Mann - Whitney Test. Histopathology of brains of fishes in group two, showed hyperemia, privascular edema, prineuronal edema and ischemic cell changes. According to Mann - Whitney Test, hyperemia and edema lesions, the difference between group 2 and 4 was significant. This result showed some efficacy of thiamine at concentration of 60mg/l in prevention of brain lesions caused by lead poisoning. Histopathology of kidneys revealed hyperemia, degenerative and necrotic changes, swelling of epithelial cells, hyperplasia of melanomacrophage centers, intranuclear inclusion bodies in epithelial cells. In kidney, goup 2 and 3 showed significant difference in swelling of epithelial cells, intranuclear inclusion bodies and degenerative necrotic changes according to Mann - Whitney test. In liver, hyperemia, hyperplasia of melanomacrophage centers, hepatocellular vacular degeneration and intranuclear inclusion bodies were observed. In liver, the difference of hyperemia were significant in group 2 and 4. Considering the histopathological findings and based on Mann-Whitney test, non of lesions revealed significant difference in gill. According to the result of this experiment, it seems that thiamine has some degrees of protective effects on lead poisoning lesions in brain, kidney and liver of Goldfish, and it seems that the thiamine has a dose depended role dose on lead poisoning in fish.

The environmental pollution is a major problem for human kind. Water systems are usually confronting with the problems resulting from the different pollutants which kerosene and other oil products are very important material. The present study was under taken to study clinical and histopathological changes of exprimental Kerosene poisoning in gold fish (Carassius aurats).In this study 136 healthy gold fish were selected, and divided into a groups (One control and three experiment groups). Kerosene in amount of 10, 100, and 250ppm was added in to the water of groups 1,2 and 3 respectively. Duration of the trial was 21, day. Clinical signs in experiment groups included ataxia, anorexia. incresed mucus secretion, skin, ulcers and constipation. Fish of control showed no changes. Afetr necropsy and preparing the, tissue sections, from the gills, histopathological examination revealed hypermia, Hemorrhage, Infilteration of mononuclear in flammatory cells, fibrinous exudate and necrosis of Lamella in experiment groups but there lesions were more severe in fish of group 3.

Goldfish rearing is common in most countries of the world. In this study, 150 specimens of Goldfish were taken from four fish farms (12 pools) seasonally and selectively, and transferred alive in the bacteriological laboratory of Inland Waters Aquaculture Research Center. The bacteria were isolated from professional test and biochemical methods. The results showed that Goldfish and pool water bacteria isolations were included Enterobacteriaceae, Pseudomonas sp., Aeromonas sp., Sterptococcus sp., Vibrio sp., Mycobacterium sp. In different seasons of the year, the highest and lowest abundance of bacteria in Goldfish, respectively, belonged to the genus Pseudomonas spp. (33/6%) and Streptococcus spp. (7/3%).