Niazi and Saxena first observed that vitamin A has an inhibitory and modifying influence on tail regeneration in Bufo andersonii tadpoles. A positive relationship was later found between the inhibiting influence of vitamin A and the developmental stage of the regenerating tail in the same species. There have been several subsequent reports on the effects of vitamin A and its derivatives on limb development and regeneration. Thus in regenerating amphibian limbs, application of retinoids produces pattern duplication in the proximodistal and anteroposterior axes of the limb, and local application of retinoic acid to the anterior side of developing chick limbs causes duplications in the anteroposterior axis of limb. Here we show that vitamin A can cause limb development when applied to amputated tail stumps of the tadpoles of the marbled balloon frog Uperodon systoma (Anura Microhylidae). This is the first report of homeotic transformation mediated through vitamin A in vertebrates.

Biofilms form a complex layer with defined structures, that attach on biotic or abiotic surfaces, are tough to eradicate and tend to cause some resistance against most antibiotics. Several studies confirmed that biofilm-producing bacteria exhibit higher resistance compared to the planktonic form of the same species. Antibiotic resistance factors are well understood in planktonic bacteria which is not so in case of biofilm producing forms. This may be due to the lack of available drugs with known resistance mechanisms for biofilms. Existing antibiotics cannot eradicate most biofilms, especially of ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species). Insects produce complex and diverse set of chemicals for survival and defense. Antimicrobial peptides (AMPs), produced by most insects, generally have a broad spectrum of activity and the potential to bypass the resistance mechanisms of classical antibiotics. Besides, AMPs may well act synergistically with classical antibiotics for a double-pronged attack on infections. Thus, AMPs could be promising alternatives to overcome medically important biofilms, decrease the possibility of acquired resistance and treatment of multidrug-resistant pathogens including ESKAPE. The present review focuses on insect-derived AMPs with special reference to anti-biofilm-based strategies. It covers the AMP composition, pathways and mechanisms of action, the formation of biofilms, impact of biofilms on human diseases, current strategies as well as therapeutic options to combat biofilm with antimicrobial peptides from insects. In addition, the review also illustrates the importance of bioinformatics tools and molecular docking studies to boost the importance of select bioactive peptides those can be developed as drugs, as well as suggestions for further basic and clinical research.

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In this study the effects of vitamin A on tadpoles of Polypedates maculatus with an amputated tail were investigated. After amputation of half the tail at the hindlimb‐bud stage, tadpoles were exposed to vitamin A (palmitate) 10 IU/ml solution for 24 hr (Group I), 48 hr (II), 72 hr (III), 96 hr (IV), 120 hr (V) or 144 hr (VI). Vitamin A was deleterious to survival of the tadpoles since 10, 30 and 30% tadpoles died from Group IV, V and VI, respectively before the emergence of forelimbs. Regeneration of the tail was abnormal in 91.7% of the tadpoles. Vitamin A induced homeotic transformation of the amputated tail to hindlimbs in 11.6% of the animals. Normal limb development was suppressed partially or completely in 48.3% tadpoles. These results indicate that in addition to traumatic effects, vitamin A can lead to homeotic transformation of the tail into hindlimbs and can also interfere with normal development of limbs.

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Neuropsychopharmacological studies have been conducted on the chloroform fraction extracted from the seeds of Syzygium cuminii L., on experimental animals. The extract was found to produce alteration in general behaviour pattern, reduction in spontaneous motility, hypothermia, potentiation of pentobaritone hypnosis, analgesia, reduction in exploratory behavoiur pattern, muscle relaxant action, and suppression of aggressive behavoiur. The extract also caused suppression of conditioned avoidance response and showed antagonism to amphetamine group toxicity. These observations suggest that the extract of the seeds of S. cuminii possesses a potent CNS depressant action.

Blood was analyzed from eighty (forty males and forty females) adult individuals of Polypedates teraiensis to establish reference ranges for its hematological and serum biochemical parameters. The peripheral blood cells were differentiated as erythrocytes, lymphocytes, eosinophils, neutrophils, monocytes, basophils, and thrombocytes, with similar morphology to other anurans. Morphology of blood cells did not vary according to sex. The hematological investigations included morphology and morphometry of erythrocytes, morphometry of leucocytes, packed cell volume (PCV), hemoglobin content (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), erythrocyte or red blood cell (RBC) count, leukocyte or white blood cell (WBC) count, differential leukocyte count, and neutrophil to lymphocyte (N/L) ratio. Besides, protein, cholesterol, glucose, urea, uric acid, and creatinine content of blood serum were assayed. Hematological parameters that differed significantly between sexes were RBC count, length and breadth of RBC, neutrophil %, N/L ratio, area occupied by basophils, and diameter of large lymphocyte and eosinophils. The level of glucose, urea, and creatinine in blood serum also significantly differed between sexes.

The present paper describes a sequential study of the leukocyte profiles and the changes in morphometry and morphology of erythrocytes in the tadpoles of Polypedates teraiensis during their development and metamorphosis, that is, transfer from an aquatic mode to a terrestrial mode of life. Blood smears of 21 different stages (Gosner stage 26 to 46) of tadpoles were investigated. Population of erythrocytes was heterogeneous in population represented by various forms (oval, elliptical or rounded cells, comma shaped, teardrop shaped, schistocytes, senile erythrocytes, crenulated RBCs). Correlation between various morphometric values of erythrocytes was determined with different developing stages of tadpoles. Amongst the leucocytes, the lymphocytes were the most abundant cells followed by neutrophils. Neutrophils and monocytes showed varied morphologic forms. The percentage of lymphocytes and neutrophils showed a negative whereas percentage of eosinophil, basophil, and monocytes showed a positive correlation with the developmental stages of tadpoles. Blood platelets were also observed, which were rounded in shape and found in aggregates.