Preparation and in-vitro evaluation of mesoporous biogenic silica nanoparticles obtained from rice and wheat husk as a biocompatible carrier for anti-cancer drug delivery.

In this study, mesoporous silica nanocarriers were synthesized from natural sources such as rice and wheat husk for drug delivery application. First, the biogenic silica in cereals husk was extracted by acid leaching and then converted to sodium silicate as a silica precursor. Mesoporous silica nanoparticles were then synthesized by adding sodium silicate to the template mixture by continuous and discrete modes during the sol-gel process. The effects of natural sources type and precursor addition method on nanocarriers' morphological and physicochemical properties were investigated by XRD, FT-IR, BET and SEM analysis. Our results showed rice husk-based spherical nanocarriers were more crystalline with slit-shaped pores, while wheat husk-based nanocarriers had been composed of spherical nanoparticles with narrow cylindrical pores. The results also showed that by adding the precursor discretely, their hydrophilicity, particle size and pore size increased compared with the continuous mode, probably due to the high initial concentration of the precursor in the reaction mixture. Doxorubicin (Dox), as a model anticancer drug was loaded into the nanocarriers, and the drug release behavior was studied at two different pH values (7.4 and 5.4). In general, the accumulated released drug at pH 5.4 was approximately twice as much as pH 7.4 due to the higher solubility of doxorubicin at acidic environment. Also, the accumulated released drug at pH 5.4 for nanocarriers which had been synthesized by discrete mode, was higher than continuous mode, due to the larger pore diameter of them. The biocompatibility and cytotoxicity of nanocarriers and Dox-loaded nanocarriers were also investigated on the HFF-2 and MCF-7 cell lines, respectively. Moreover, apoptosis, as the mechanism of cell death, was evaluated by morphological study of the MCF-7 cells. Within acceptable toxicity limits and apoptosis induction, the Dox-loaded nanocarriers, especially discrete mode synthesized nanocarriers, exhibited high-efficiency anticancer effect on the MCF-7 cell line.

Correction to: Morphological reflections of evolutionary adaptations in the tongue of the white-headed duck.

The affiliation of the third author has been incorrectly published in the original publication of the article. The correct affiliation is provided in this erratum.

Morphological reflections of evolutionary adaptations in the tongue of the white-headed duck.

During an organism's evolution, functional adaptations help species to become better suited to their ecological niches. From the morphological aspect, these adaptations are reflected in the anatomical specializations of different organs. Specializations of the lingual organ is a critical adaptation of birds, such as the white-headed duck (Oxyura leucocephala), that enables their nutritional requirements to be met. For optimal use of the available food resources, the white-headed duck utilizes three methods of food collection, namely pecking, grazing and filter-feeding. Since this species is classified as endangered, we conducted the present study on two carcasses of the white-headed duck (death due to natural causes) employing routine histological methods, light microscopy and scanning electron microscopy. Our results show that the tongue of this bird shares some similarities and some differences with the tongue of other members of the family Anatidae. The results confirm that it is better adapted to the filter-feeding method rather than to other types of food intake. This adaptation is reflected by anatomical specializations of its lingual structures, including the stair-like outline shape, bi-sectional lingual body, a deep median sulcus, lateral conical papillae, mucus secreting glands, lack of serous secreting glands, cartilaginous skeleton and the triangular fibromuscular structure of the lingual body. The so-called triangular structure and cartilaginous skeleton are the major structures involved in the lingual motions during the filter-feeding method. The presence of the triangular structure and its connection with the cartilaginous skeleton and lingual mucosa have not previously been reported in any species of birds.

Morphological study of the European hedgehog (Erinaceus europaeus) tongue by SEM and LM.

The hedgehog tongue is a tactile and taste organ which carries out various functions. Detailed functional and morphological studies are required to clearly define the relationship of the hedgehog tongue with taste, food palatability, mastication and swallowing of food, as well as the production of sounds. The aim of this study was to determine the relationship between the morphological characteristics of the European hedgehog tongue and the lifestyle of this animal, as well as to compare findings with the results of studies on other vertebrates. Gross and micro-anatomical light and scanning electron microscopy studies revealed that the hedgehog tongue could be divided in three areas, namely the apex, body and root. A keratinized stratified squamous epithelium, which was smooth on the ventral surface but bore four types of papillae on the dorsal surface, lined the tongue. Three types of these papillae were found to have gustatory functions and to express their activity in close relation with the salivary glands. These simple conical filiform papillae were situated caudally and distributed one after the other without a break. The dome-shaped fungiform papillae on the apex, with the highest distribution rate on the apex edge, were small, but those on the body and root were large. The three circular vallate papillae were arranged in a triangular shape. The foliate papillae with a few tiny projections, found in a shallow furrow, were situated between the root and the body. Most of the nerve fibers observed in different sections of the tongue tissue were of the unmyelinated type, confirming that the main task of the hedgehog tongue was its gustatory function.

Polymelia with unhealed navel in an Iranian indigenous young fowl.

Developing supernumerary limbs is a rare congenital condition that only a few cases have been documented. Depending on the cause and developmental conditions, they may be single, multiple or complicated, and occur as a syndrome or associated with other anomalies. Polymelia is defined as the presence of extra limb(s) which have been reported in human, mouse, chicken, calf and lamb. It seems that the precise mechanism regulating this type of congenital malformations is not yet clearly understood. While hereditary trait of some limb anomalies was proven in human and the responsible genetic impairments were found, this has not been confirmed in the other animals especially the birds. Regarding the different susceptibilities of various vertebrate species to the environmental and genetic factors in embryonic period, the probable cause of an embryonic defect in one species cannot be generalized to the all other species class. The present study reports a case of polymelia in an Iranian indigenous young fowl and discusses its possible causes.

Morphological development of testes in ostrich (Struthio camelus) embryo.

Although the histological structure of ostrich testis has been studied, very little information is currently available on the embryonic development of this organ. The aim of this study was to determine the sequence of the histological changes in diverse components of the testis in ostrich embryo from embryonic day (E) 20 to E42. The main findings were categorized into four histological features, i.e., development of sex cords, interstitial tissue and rete ducts, and the appearance of defective septa. While the lumen of sex cords, tunica albuginea, capsular rete ducts and Leydig cell precursors appeared at E26, the filum-shaped defective septa were visible at E36. The emersion of the lumen in the primary sex cords and formation of capsular rete ducts in the ostrich embryo is considerably different from that in other birds. However, tunica albuginea and Leydig cell precursors appeared in a similar pattern to those of other birds. An interesting observation was that the primordial germ cell (PGC)-like cells were completely distinct, while the capsular rete ducts were formed by trapping of some Sertoli cell aggregations in the tunica albuginea. This suggests that similar to the primary sex cords, the capsular rete ducts may originate from the Sertoli cell aggregations which had corralled some PGCs. Stereological estimations in the ostrich embryo testis showed the major proportion of testis is occupied by the seminiferous tubules, which is unlike the fowl embryo testis.

Microanatomical study of testis in juvenile ostrich (Struthio camelus).

The majority of investigations on the testis, as the main organ of male reproductive system, have been performed in mammalian species, with few studies on bird species. Thus, the structure of the ostrich testis remains largely unknown. The aim of this study was to investigate the microanatomical characteristics of the testis in five juvenile ostriches. A stereological study was performed according to the Delesse principle. The mean volume fraction of the seminiferous tubules was 0.569, and the mean volume of the seminiferous tubules in an average testis was 1.04 cm(3). The Paraffin-embedded sections were stained with hematoxylin and eosin, Masson's trichrome, Alcian blue, and periodic acid-Schiff stains. Histological studies revealed that the spermatogonial stem cells and Sertoli cells were localized inside the seminiferous tubules, close to the basement membrane. Inside the tubules a few meiotic cells up to the spermatozoa stage were located in a centripetal manner. Outside the tubules, one to three layers of euchromatic peritubular myoid cells were present, surrounded by loose interstitial connective tissue. A thick tunica albuginea contained many myoid cells and some rete ducts, with the latter extending from the hilus to the free surface of the testis. Straight seminiferous tubules were distributed in the lateral surfaces and hilar portions of the capsule but were rare in the free surface. These capsular rete ducts may participate in testicular fluid transit from the distal tubules through the capsule.

Frequency of caseous lymphadenitis (CLA) in sheep slaughtered in an abattoir in Tabriz: comparison of bacterial culture and pathological study.

From January to February 2008, 468 sheep carcasses (335 male and 133 female) in a Khosroshahr (suburb of Tabriz, East Azerbaijan province, Iran) abattoir were randomly selected for inspection. The aim of the study was to estimate the frequency of caseous lymphadenitis (CLA) in sheep and to compare the results of bacterial cultures and histopathology of suspected cases. The mean age of the population was 2.5 years. One hundred ninety-seven cases containing 153 (77.7%) males and 44 (22.3%) females had prominent enlargement of one of the lymph nodes (i.e., prescapular, prefemoral, inguinal, supramammary, or midiastinal); these were removed with the surrounding tissue for further evaluation. For confirmed diagnosis of CLA, samples were sent for microbiology and pathology analysis. Standard bacteriological culture methods for isolation of Corynebacterium pseudotuberculosis and tissue preparations for histopathological sections were performed. To evaluate the effect of age on the frequency of CLA, animals were categorized in four groups: under 1, 1-2, 2-3, and over 3 years of age. Based on the results, in 59 (12.60%) carcasses C. pseudotuberculosis was isolated, and in 94 (20.08%) of the cases histopathological studies revealed pathognomonic signs (lamellated exudates or onion ring) of CLA. The frequency of CLA based on bacteriological culture was 12.60% and on histopathological study 20.08%. In 37 (18.8%) of the carcasses, both bacteriological and histopathological studies confirmed CLA. The frequency of CLA following microscopic examination (20.08%) presented a more precise diagnosis compared to bacteriological culture (12.60%) and macroscopic evaluation of the lymph nodes (P < 0.05). Furthermore, there was a positive correlation rate between the bacteriological culture and histopathological study (r = 0.196, P = 0.006). The prescapular lymph node had the highest infection rate with 54 (1.70 ± 0.97) and supramammary lymph node had the lowest with two (0.07 ± 0.41) (P < 0.05). There was an increase in CLA detection with increasing age (P < 0.05), the mean age of animals with a positive CLA test were 2.92 years and in the oldest age group 31 (47%) cases had the highest infection.