Adolescents With Breakthrough COVID-19 Infections Requiring Hospitalization: A Multicenter Retrospective Study.

Background Vaccines have the most important role in the battle against the COVID-19 pandemic. With the widespread use of vaccines, COVID-19 has remarkably declined. Adolescents were vaccinated after approvals for this age group, which was later than adults, and a nationwide vaccination program was implemented in August 2021 in Turkey for adolescents ≥12 years of age. Therefore, we aimed to determine the effects of the COVID-19 nationwide adolescent vaccination program on adolescent hospitalizations due to COVID-19 and multisystem inflammatory syndrome in children (MIS-C) by comparing two periods, including the vaccination period (VP) and the pre-VP (PVP). The second aim of this study is to compare the clinical features and disease severity of vaccine-breakthrough COVID-19 hospitalizations with unvaccinated individuals in the VP. Methods A retrospective multicenter study was conducted to determine and compare the number of hospitalizations due to COVID-19 and MIS-C between the VP (September 1, 2021, to August 31, 2022) and PVP (September 1, 2020, to August 31, 2021). We also compared the characteristics, risk factors, and outcomes of breakthrough infections of adolescents aged 12-18, which required hospitalization with the same age group of unvaccinated hospitalized individuals during the VP. Results During the study period, 3967 children (0-18 years) were hospitalized in the PVP and 5143 (0-18 years) in the VP. Of them, 35.4% were adolescents (12-18 years) in the PVP, and this rate was 18.6% in the VP; relative risk was 0.6467 (95% confidence interval [CI]: 0.6058-0.6904; p < 0.001). Patients with breakthrough COVID-19 were older (201 vs. 175 months, p < 0.001) and less commonly hospitalized for COVID-19 (81.5% vs. 60.4%, p < 0.001, odds ratio [OR]: 0.347 [95% CI: 0.184-0.654]). The majority of these infections were asymptomatic and mild (32% vs.72.9%: p < 0.001, OR: 5.718 [95% CI: 2.920-11.200]), and PICU admission was less frequently required (p = 0.011, OR: 0.188 [95% CI: 0.045-0.793]). Most breakthrough COVID-19 infections occurred within three months after the last vaccine dose (54.2%). Conclusions This study demonstrated a significant decrease in adolescent hospitalizations due to COVID-19 and MIS-C after implementing COVID-19 vaccines in Turkey. Breakthrough cases were less severe and mostly occurred three months after the last dose. This study emphasizes the importance of COVID-19 vaccines and that parents' decisions may be changed, particularly those who hesitate to or refuse vaccination.

The Role of Adenovirus in Hepatitis of Unknown Etiology Among Children in Turkey, July 2022 to January 2023.

BACKGROUND: In the first half of 2022, the increase in cases of severe acute hepatitis in children with no epidemiological link and unknown cause has aroused concern worldwide. In this study, we aimed to determine the frequency of adenovirus in children with hepatitis of unknown origin in Turkey. METHODS: In this study, which was conducted with the participation of 16 centers from Turkey, between July 2022 and January 2023, 36 pediatric patients under the age of 18 who met the definition of acute hepatitis were included. RESULTS: Twenty (55,6%) of patients were female and 16 (44,4%) were male, with a mean age of 41.55 ± 39.22 (3-192) months. The most common symptoms were fever (66.7%), weakness (66.7%), loss of appetite (66.7%), fatigue (61.1%), vomiting (61.1%), and diarrhea (47.2%). Six (16 %) children had acute hepatic failure. Eight of the 15 children (46%) had respiratory viral infections (rhinovirus/enterovirus, n = 4; rhinovirus + parainfluenza, n = 1; parainfluenza, n = 1, SARS-CoV-2 n = 2). Adenovirus was detected in 16 (44%) patients. Adenovirus and coinfections were detected in 7 patients. History of diarrhea and fatigue in the last month was significantly higher in the adenovirus group ( P = 0.023 and 0.018). One child who had both adenovirus and rhinovirus infection required liver transplantation; all others recovered with supportive care. CONCLUSION: There were no deaths in our series; however, the number of cases, etiology, and severity of the clinical course may have differed between countries owing to differences in case definitions, laboratory facilities, or regional genetic differences.

Evaluation of 601 children with multisystem inflammatory syndrome (Turk MISC study).

PURPOSE: Due to its link with the 2019 coronavirus, the multisystem inflammatory syndrome in children (MISC) has garnered considerable international interest. The aim of this study, in which MISC patients were evaluated multicenter, and the data of the third period of the Turk-MISC study group, to compare the clinical and laboratory characteristics and outcomes of MISC patients who did and did not require admission to an intensive care unit (ICU). METHODS: This retrospective multicenter observational study was carried out between June 11, 2021, and January 01, 2022. The demographics, complaints, laboratory results, system involvements, and outcomes of the patients were documented. RESULTS: A total of 601 patients were enrolled; 157 patients (26.1%) required hospitalization in the intensive care unit (ICU). Median age was 8 years (interquartile range (IQR) 4.5-11.3 years. The proportion of Kawasaki disease-like features in the ICU group was significantly higher than in the non-ICU group (56.1% vs. 43.2% p = 0.006). The ICU group had considerably lower counts of both lymphocytes and platelets (lymphocyte count 900 vs. 1280 cells × µL, platelet count 153 vs. 212 cells × 103/ µL, all for p< 0.001). C-reactive protein, procalcitonin, and ferritin levels were significantly higher in the ICU group (CRP 164 vs. 129 mg/L, procalcitonin 9.2 vs. 2.2 µg/L, ferritin 644 vs. 334 µg/L, all for p< 0.001). Being between ages 5-12 and older than 12 increased the likelihood of hospitalization in the ICU by four [95% confidence intervals (CI)1.971-8.627] and six times (95% CI 2.575-14.654), respectively, compared to being between the ages 0-5. A one-unit increase in log D-dimer (µg/L) and log troponin (ng/L) was also demonstrated to increase the need for intensive care by 1.8 (95% CI 1.079-3.233) and 1.4 times (95% CI 1.133-1.789), respectively.     Conclusion: By comparing this study to our other studies, we found that the median age of MISC patients has been rising. Patients requiring an ICU stay had considerably higher levels of procalcitonin, CRP, and ferritin but significantly lower levels of lymphocyte and thrombocyte. In particular, high levels of procalcitonin in the serum might serve as a valuable laboratory marker for anticipating the need for intensive care. WHAT IS KNOWN: • Lymphopenia and thrombocytopenia were an independent predictor factors in patients with MISC who needed to stay in intensive care unit. • The possibility of the need to stay in the intensive care unit in patients with MISC who had Kawasaki disease-like findings was controversial compared with those who did not. WHAT IS NEW: • A one-unit increase log D dimer and log troponin was demonstrated to require for intensive care unit by 1.8 and 1.4 times, respectively. • Serum procalcitonin levels had the best performance to predict stay in the intensive care unit stay.

Effects of thiamethoxam on brain structure of Bombus terrestris (Hymenoptera: Apidae) workers.

Neonicotinoids are the most widely used pesticide compared to other major insecticide classes known worldwide and have the fastest growing market share. Many studies showed that neonicotinoid pesticides harm honeybee learning and farming activities, negatively affect colony adaptation and reduce pollination abilities. Bumblebees are heavily preferred species all over the world in order to ensure pollination in plant production. In this study, sublethal effects of the neonicotinoid insecticide thiamethoxam on the brain of Bombus terrestris workers were analyzed. Suspensions (1/1000, 1/100, 1/10) of the maximum recommended dose of thiamethoxam were applied to the workers. 48 h after spraying, morphological effects on the brains of workers were studied. According to area measurements of ICC's of Kenyon cells, there was a significant difference between 1/10 dose and all groups. On the other hand, areas of INC's of Kenyon cells showed a significant difference between the control group and all dose groups. Neuropil disorganization in the calyces increased gradually and differed significantly between the groups and was mostly detected at the highest dose (1/10). Apart from optic lobes, pycnotic nuclei were also observed in the middle region of calyces of mushroom bodies in the high dose group. Also, the width of the lamina, medulla and lobula parts of the optic lobes of each group and the areas of the antennal lobes were measured and significant differences were determined between the groups. The results of the study revealed that sublethal doses of thiamethoxam caused some negative impacts on brain morphology of B. terrestris workers.

Sublethal effects of thiamethoxam on immune system cells in the workers of Bombus terrestris (Hymenoptera: Apidae).

Neonicotinoids harm especially bumblebees and other species in agricultural areas all over the world. The toxic effect of thiamethoxam from the neonicotinoid group has been little studied especially on bees. This research aimed to evaluate the effects of thiamethoxam on the immune system cells of Bombus terrestris workers. Different ratios of 1/1000, 1/100 and 1/10 of the recommended maximum application dose of thiamethoxam formed the experimental groups. Ten foraging workers were used for each dose and control groups. Contamination was ensured by spraying the prepared suspensions at different ratios to the bees for 20 s at a pressure of 1 atm. The effects of thiamethoxam on the structures of immune system cells of bumblebees and the amount of these cells were investigated after 48 h of exposure. In general, anomalies such as vacuolization, cell membrane irregularities and cell shape changes were detected in prohemocyte, plasmatocyte, granulocyte, spherulocyte and oenocytoid in each dose group. Hemocyte area measurements in all groups were examined comparatively between groups. In general, granulocyte and plasmatocyte sizes were decreased, while spherulocyte and oenocytoid were increased. It was also determined that there was a significant decrease in the amount of hemocytes in the 1 mm3 hemolymph as dose increased. The results of the study revealed that sublethal doses of thiamethoxam negatively affected hemocytes and their amounts of B. terrestris workers.

Immunogenicity, efficacy, and safety of CoronaVac and Pfizer/BioNTech mRNA vaccines in patients with psoriasis receiving systemic therapies: A prospective cohort study.

BACKGROUND AND OBJECTIVES: Evidence of immune response to COVID-19 vaccine in psoriasis patients on biological agents is lacking. This study aimed to evaluate SARS-CoV-2 antibody levels following vaccination with CoronaVac or Pfizer/BioNTech mRNA in patients using biological agents or methotrexate, high-titer antibody levels achievement rate, and impact of medications on immunogenicity. METHODS: This noninterventional, prospective cohort study included 89 patients and 40 controls vaccinated with two doses of inactivated (CoronaVac) or Pfizer/BioNTech mRNA vaccines. Anti-spike and neutralising antibodies were analysed before and three to six weeks after the second dose. Adverse effects and symptomatic COVID-19 were assessed. RESULTS: Median anti-spike and neutralising antibody titers after CoronaVac were significantly lower in patients than controls (57.92 U/mL vs 125.4 U/mL, and 1/6 vs 1/32, respectively, p < 0.05). Patients were less likely to achieve high-titer anti-spike antibody levels (25.6 % vs 50 %). Infliximab was associated with attenuated vaccine response. Pfizer/BioNTech vaccine induced comparable median anti-spike (2,080 U/mL vs 2,976.5 U/mL,) and neutralising antibody levels (1/96 vs 1/160) in patients and controls, respectively (p > 0.05). High-titer anti-spike and neutralising antibodies development rates were comparable among patients and controls (95.2 % vs 100 %, and 30.4 % vs 50.0 %, respectively, p > 0.05). Nine (10.1 %) COVID-19 cases- all mild - were identified. Psoriasis flare was seen in 6.74 %, mostly after Pfizer/BioNTech vaccine. CONCLUSION: Psoriasis patients treated with biological agents and methotrexate developed similar response to mRNA vaccine but weaker response to inactivated vaccine. Infliximab reduced response to the inactivated vaccine. Adverse effects were more frequent with mRNA vaccine, but none was severe.

Evaluation of possible COVID-19 reinfection in children: A multicenter clinical study.

BACKGROUND: Although it was originally unknown whether there would be cases of reinfection of coronavirus disease 2019 (COVID-19) as seen with other coronaviruses, cases of reinfection were reported from various regions recently. However, there is little information about reinfection in children. METHODS: In this study, we aimed to investigate the incidence and clinical findings of reinfection in pediatric patients who had recovered from COVID-19. We retrospectively evaluated all patients under 18 years of age with COVID-19 infection from a total of eight healthcare facilities in Turkey, between March 2020 and July 2021. Possible reinfection was defined as a record of confirmed COVID-19 infection based on positive reverse transcription-polymerase chain reaction (RT-PCR) test results at least 3 months apart. RESULTS: A possible reinfection was detected in 11 out of 8840 children, which yielded an incidence of 0.12%. The median duration between two episodes of COVID-19 was 196 (92-483) days. When initial and second episodes were compared, the rates of symptomatic and asymptomatic disease were similar for both, as was the severity of the disease (p = 1.000). Also, there was no significant difference in duration of symptoms (p = 0.498) or in hospitalization rates (p = 1.000). Only one patient died 15 days after PCR positivity, which resulted in a 9.1% mortality rate for cases of reinfection in pediatric patients. CONCLUSION: We observed that children with COVID-19 were less likely to be exposed to reinfection when compared with adults. Although the clinical spectrum of reinfection was mostly similar to the first episode, we reported death of a healthy child during the reinfection.

Turkish Healthcare Workers' Personal and Parental Attitudes to COVID-19 Vaccination From a Role Modeling Perspective.

Introduction As in many other countries, healthcare workers (HCWs) have been identified as the priority group for vaccination in Turkey for they are in close contact with not only patients with COVID-19 to whom they provide treatment but also asymptomatic individuals with COVID-19 infection while inoculating COVID-19 vaccines. As a result of this prioritization, they will always be in the limelight and regarded as role models for personal and parental acceptance of COVID-19 vaccines. Methods Turkish healthcare workers (n=1,808) were contacted and invited to fill out an online questionnaire between December 27, 2020, and January 14, 2021, in order to reveal their approaches to COVID-19 vaccines and vaccination. Results Most of the participants had moderate concerns of having severe COVID-19. Anxiety on the adverse effects of COVID-19 vaccines was more prevalent in females and among 36- to 50-year-old healthcare workers and less frequent in physicians, nurses, and midwives and in those with a higher level of knowledge about COVID-19 vaccines. Strict anti-vaccination tendency was higher in professional categories other than physicians, nurses, and midwives. Females, physicians, nurses, midwives, healthcare workers aged 51 and over, healthcare workers having children, married healthcare workers, and healthcare workers who use scientific journals and World Health Organization (WHO) announcements as sources of information were more inclined to accept COVID-19 vaccines. The elimination of COVID-19 vaccine hesitancy in healthcare workers would be possible if people around them, physicians, and ministers or high officials get vaccinated but will persist in 19% of the healthcare workers. More than half of the healthcare workers thought vaccination against COVID-19 should not be mandatory. The Pfizer-BioNTech vaccine was the most preferred COVID-19 vaccine (37.3%). The reasons for this preference were the trustworthiness of the country of origin, the manufacturer company, the Turkish origin of its developers, the vaccine's being the first to receive emergency validation, and its non-Indian, non-Russian, and non-Chinese origin. Parental vaccine refusal and hesitancy were present in 15.6% and 31.9% of the healthcare workers, respectively. The mistrust in COVID-19 vaccines among Turkish healthcare workers was directed toward not only pharmaceutical companies but also health authorities and academicians because of their unconvincing, conflicting, or vague statements and toward certain countries known for their production of low-quality merchandise in the past. Conclusion The parental COVID-19 vaccine hesitancy of 32% of the healthcare workers is unacceptably high for role modeling against anti-vaccine movement and should be diminished by implementing necessary measures as soon as possible.

COVID-19 severity and SARS-Cov-2 vaccine safety in pemphigus patients.

There are safety concerns in the treatment of pemphigus patients with immunosuppressants, particularly rituximab (RTX), in times of the COVID-19 pandemic. In the beginning, the reports were more pessimistic. However, few reports have recently pointed to manageable courses in this patient group. Therefore, we investigated the disease characteristics and demographic features of pemphigus patients in the period of the COVID-19 pandemic. We aimed to investigate the impact of immunosuppressants on the course of COVID-19 in pemphigus patients. Also, we tried to find out the rate of flares due to COVID-19 and SARS-Cov-2 vaccines. This multicenter study included 247 patients with pemphigus from three tertiary dermatology clinics with the specialized outpatient clinic for autoimmune blistering diseases. Patients were asked standardized questions in person or via telephone calls. Also, demographic data were collected from patients' files. Two hundred forty-four of 247 patients took the survey between August and September 2021. The data of three patients were obtained from the National Health System. We collected the data of all pemphigus patients who visited the clinics at least once in the past 3 years. Among 51 patients having COVID-19, 40 had a non-serious disease, whereas 11 required hospitalization. One patient died because of COVID-19 infection. The number of patients is limited, and data depends mainly on patients' statements. RTX treatment does not require additional safety cautions than other immunosuppressives.

Multisystem inflammatory syndrome in children associated with COVID-19 in 101 cases from Turkey (Turk-MISC study).

AIM: Multisystem inflammatory syndrome in children (MIS-C) may cause shock and even death in children. The aim of this study is to describe the clinical features, laboratory characteristics and outcome of children diagnosed with MIS-C in 25 different hospitals in Turkey. METHODS: The retrospective study was conducted between 8 April and 28 October 2020 in 25 different hospitals from 17 cities. Data were collected from patients' medical records using a standardised form. Clinical and laboratory characteristics and outcomes according to different age groups, gender and body mass index percentiles were compared using multivariate logistic regression analysis. RESULTS: The study comprised 101 patients, median age 7 years (interquartile range (IQR) 4.6-9.3); 51 (50.5%) were boys. Reverse-transcriptase polymerase chain reaction (PCR) assay was positive in 21/100 (21%) patients; 62/83 (74.6%) patients had positive serology for SARS-CoV-2. The predominant complaints were fever (100%), fatigue (n = 90, 89.1%), and gastrointestinal symptoms (n = 81, 80.2%). Serum C-reactive protein (in 101 patients, median 165 mg/L; range 112-228), erythrocyte sedimentation rate (73/84, median 53 mm/s; IQR 30-84) and procalcitonin levels (86/89, median 5 µg/L; IQR 0.58-20.2) were elevated. Thirty-eight patients (37.6%) required admission to intensive care. Kawasaki disease (KD) was diagnosed in 70 (69.3%) patients, 40 of whom had classical KD. Most patients were treated with intravenous immunoglobulin (n = 92, 91%) and glucocorticoids (n = 59, 58.4%). Seven patients (6.9%) died. CONCLUSION: The clinical spectrum of MIS-C is broad, but clinicians should consider MIS-C in the differential diagnosis when persistent fever, fatigue and gastrointestinal symptoms are prominent. Most patients diagnosed with MIS-C were previously healthy. Immunomodulatory treatment and supportive intensive care are important in the management of cases with MIS-C. Glucocorticoids and intravenous immunoglobulins are the most common immunomodulatory treatment options for MIS-C. Prompt diagnosis and prompt treatment are essential for optimal management.

COVID-19 associated multisystemic inflammatory syndrome in 614 children with and without overlap with Kawasaki disease-Turk MIS-C study group.

Multisystemic inflammatory syndrome (MIS-C) diagnosis remains difficult because the clinical features overlap with Kawasaki disease (KD). The study aims to highlight the clinical and laboratory features and outcomes of patients with MISC whose clinical manifestations overlap with or without KD. This study is a retrospective analysis of a case series designed for patients aged 1 month to 18 years in 28 hospitals between November 1, 2020, and June 9, 2021. Patient demographics, complaints, laboratory results, echocardiographic results, system involvement, and outcomes were recorded. A total of 614 patients were enrolled; the median age was 7.4 years (interquartile range (IQR) 3.9-12 years). A total of 277 (45.1%) patients with MIS-C had manifestations that overlapped with KD, including 92 (33.3%) patients with complete KD and 185 (66.7%) with incomplete KD. Lymphocyte and platelet counts were significantly lower in patients with MISC, overlapped with KD (lymphocyte count 1080 vs. 1280 cells × µL, p = 0.028; platelet count 166 vs. 216 cells × 103/µL, p < 0.001). The median serum procalcitonin levels were statistically higher in patients overlapped with KD (3.18 vs. 1.68 µg/L, p = 0.001). Coronary artery dilatation was statistically significant in patients with overlap with KD (13.4% vs. 6.8%, p = 0.007), while myocarditis was significantly more common in patients without overlap with KD features (2.6% vs 7.4%, p = 0.009). The association between clinical and laboratory findings and overlap with KD was investigated. Age > 12 years reduced the risk of overlap with KD by 66% (p < 0.001, 95% CI 0.217-0.550), lethargy increased the risk of overlap with KD by 2.6-fold (p = 0.011, 95% CI 1.244-5.439), and each unit more albumin (g/dl) reduced the risk of overlap with KD by 60% (p < 0.001, 95% CI 0.298-0.559). CONCLUSION: Almost half of the patients with MISC had clinical features that overlapped with KD; in particular, incomplete KD was present. The median age was lower in patients with KD-like features. Lymphocyte and platelet counts were lower, and ferritin and procalcitonin levels were significantly higher in patients with overlap with KD. WHAT IS KNOWN: • In some cases of MIS-C, the clinical symptoms overlap with Kawasaki disease. • Compared to Kawasaki disease, lymphopenia was an independent predictor of MIS-C. WHAT IS NEW: • Half of the patients had clinical features that overlapped with Kawasaki disease. • In patients whose clinical features overlapped with KD, procalcitonin levels were almost 15 times higher than normal. • Lethargy increased the risk of overlap with KD by 2.6-fold in MIS-C patients. • Transient bradycardia was noted in approximately 10% of our patients after initiation of treatment.

Comparison of body wall histologic structure of two medicinal leeches Hirudo sulukii and Hirudo verbana (Hirudinida: Hirudinidae).

In this study, it was aimed to determine secretory cell types using histochemical properties of secretory cells and epidermis histology in the body wall of two medicinal leech species, Hirudo verbana and Hirudo sulukii. In addition, areas of epidermis epithelial cells, secretory cell types, and secretion areas of secretory cells stained with histochemical stains were statistically compared in both species. Epidermis is composed of single layer of cylindrical epithelium and secretory cells. The cuticle layer covers the epithelial layer. Some Type 1 cells within and close to the epidermis were determined as pear-shaped secretory cells. Type 2a and Type 2b secretory cells were found in large groups in the inner parts of the body wall, especially around muscles. While Type 1 cells were stained weakly with PAS and AB, Type 2b cells were stained darker than Type 2a cells. Statistical calculations showed that areas of epithelial and secretory cells were generally larger in H. sulukii than in H. verbana. Therefore, H. sulukii was thought to be a more resistant species compared to H. verbana. As secretion areas of secretory cells reacting with PAS and AB stains were generally larger in H. sulukii, it was concluded that mucus composition between the two species has different concentration.

Public interest in dermatologic symptoms, conditions, treatments, and procedures during the COVID-19 pandemic: Insights from Google Trends.

Coronavirus disease 2019 (COVID-19) pandemic had substantial effect both on daily life and medical practice. Internet data have been used to analyze the trends in public interest in various medical conditions and treatments. The aim of this study is to analyze the public interest in dermatologic symptoms, conditions, treatments, and procedures during the COVID-19 pandemic. Google Trends was queried for a total of 120 dermatological search queries. Three periods of 2020 ([March 15-May 9], [May 10-July 4], and [July 5-October 31]) were compared with the previous 4 years (2016-2019). A significantly decreased interest in skin cancers and certain dermatologic conditions (eg, pityriasis rosea and scabies) was observed throughout the study period. Whereas a significant increase of interest in dry skin, hair shedding, oily hair, atopic dermatitis, and hand eczema was detected during the study. An initial decrease in interest was followed by a significant increase for acne, comedones, melasma, rosacea, botox, dermaroller, and peeling. The study demonstrated a significant impact of the COVID-19 pandemic on the public interest in dermatology. The present results would help to create healthcare policies and information sources, which can meet the public demand. The reasons for the observed trends and their effect on patient outcomes might be of interest for future studies.

Netherton syndrome: Temporary response to dupilumab.

Netherton syndrome (NS) is an orphan disease characterized by congenital ichthyosis, hair abnormalities, and atopy, with limited treatment options. We achieved temporary improvement only during the initial 6 weeks of treatment with dupilumab, which differs from the sustained improvement observed in 2 other recently published cases. Although the clinical presentation of atopy and increased pre-allergic cytokines in NS patients suggest that dupilumab may be beneficial, larger studies are required.

Acute generalized exanthematous pustulosis due to ceftriaxone: Report of a pediatric case with recurrence after positive patch test.

Acute generalized exanthematous pustulosis (AGEP) is seen uncommonly in children and sometimes shows atypical clinical features in this population. Patch testing can be used effectively in children for the confirmation of the culprit drug in cases of multiple drug use. Here, we report a rare, pediatric case of ceftriaxone-induced AGEP confirmed by patch testing with subsequent recurrence of the skin eruption.

Histopathological analysis of carbaryl-induced toxicity in the spleen of Levantine frog, Pelophylax bedriagae (Anura: Ranidae).

This study describes the histopathological effects of carbaryl in the spleen of Levantine frog, Pelophylax bedriage. Due to its primary role in immune system, it is important to research the toxic effects of pesticides, which play an important role in environmental pollution, on spleen. To that end, adult frogs were exposed to carbaryl for 96 h. Experimental groups contained low dose, (0.05 mg/g), medium dose (0.1 mg/g) and high dose (0.2 mg/g). After following exposure to carbaryl, the frogs were euthanised and dissected. In low-dose group, there were no important changes in spleen tissue. In medium-dose group, prominence in haemorrhage just below the capsule and an increase in the melanomacrophage number were determined. In high-dose group, in addition to increases in the melanomacrophages, separations in capsule, haemorrhage below capsule and within splenic tissue, sinusoidal enlargement, congestion in dilated sinusoid, hypertrophic plasma cells and fibrosis were determined as important histological lesions in exposed frogs. This study clearly showed that carbaryl caused important histopathological damages in splenic tissue of Pelophylax bedriagae. In view of these findings, it can be said that this insecticide has the capacity to disrupt spleen' functions.

Histopathological study of toxic effects of carbaryl on digestive tract of Bufotes variabilis (Anura: Bufonidae).

Due to the negative effects of pesticide usage in environment, i.e., decline in amphibian populations, this study was designed to examine histopathologic changes following carbaryl exposure for 96 h in the digestive tract of variable toad, Bufotes variabilis. After exposure to single doses of carbaryl (low dose 50 µg/g, medium dose 100 µg/g, and high dose: 200 µg/g), the toads were euthanized and dissected and digestive tract samples were quickly removed. Histopathology revealed esophageal vacuolization and necrosis in esophageal cells. Hemorrhage was also observed in the esophagus. In the stomach, necrosis in the glandular epithelium, congested blood vessels, edema among gastric glands, dilated tips of the mucosal epithelial layer, gastric glandular atrophy, and hemorrhage were found. In the intestine, edema within villi, hemorrhage, inflammation, vacuolization, and necrosis in epithelial cells of villi were detected. This study clearly showed that carbaryl caused adverse effects on the digestive tract of B. variabilis in all dose groups.