Actin and spectrin-like (Mr= 260–240 000) proteins in gregarines

In Gregarina blaberae a M_r = 47 000 and a M_r = 260–240 000 doublet polypeptides reacted in immunoblotting: i) with a polyclonal monospecific rabbit antibody to frog muscular actin, a monoclonal anti-actin antibody against chicken gizzard; and ii) with polyclonal and monoclonal antibodies to human erythrocyte β-spectrin, respectively. The M_r = 47 000 actin-like protein is associated with the ghost and a contractille cytoplasmic extract. The presence of an actin-like protein in Gregarina and Lecudina and its cellular distribution in the cortex indicated that the gliding movement might involve an actin-myosin system in contrast to previous studies. Immunofluorescence showed clear differences between the anterior part of Gregarina and Lecudina which illustrated the high cell polarity of these protozoa. The M_r = 260–240 000 doublet was detected in SDS-PAGE from G. blaberae trophozoite ghosts but not in the cytoplasmic extracts or in extracts from sexual stages, indicating that the presence of these spectrin-like proteins is stage-dependent. Visualization of the M_r = 260–240 000 by immunofluorescence showed clear species differences, with rings arranged perpendicular to the longitudinal narrow folds of G. blaberae, with longitudinal lines underlying the folds of L. pellucida and with lines separating the large folds of Selenidium pendula. The cellular distribution is consistent with a stabilizer function of the spectrin-like proteins in the scaffolding of the cortex of gregarines according to the high diversity of the cell-shape and the cell motility systems in gregarines. The presence of spectrin-like proteins in protozoa and particularly in parasites from primitive arthropods indicated that ancestral spectrin genes could the M_r = 260–240 000 form.     

Intra‐specific pollen polymorphism in Mimosa pigra (Mimosaceae)

Five different types of pollen tetrads were detected from the short and long stamens of the male and hermaphrodite flowers of the androdioecious species, Mimosa pigra L. Light (LM) and scanning electron microscopes (SEM) were used in this study to redescribe the pollen forms and to identify the various pollen types encountered. An identification key and relative percentages of these pollen types were also presented. The study showed that the long stamens of the male flowers and those of the hermaphrodite ones have five (I, II, III, IV and V) and two (I and V) pollen types respectively, whereas the short stamens of both male and hermaphrodite flowers have only one pollen type (type I). We report here the first incidence of intra‐specific pollen polymorphism in androdioecious species.     

Thyroid dysfunction in type 2 diabetics seen at the University College Hospital, Ibadan, Nigeria

Thyroid dysfunction complicates the metabolic derangement observed in Diabetes Mellitus (DM). It is necessary to recognize and treat it when present in order to achieve stability of metabolic control in these patients. The prevalence of thyroid dysfunction in type-2 diabetics in our environment is not known. This study was therefore designed to determine the prevalence of thyroid dysfunction in Type 2 diabetics seen at the Metabolic Research Unit of University College Hospital, Ibadan, Nigeria. Serum TSH, Free T3 and Free T4 assays were performed using Automated Enzyme Immunoassay platform on fresh sera from volunteers comprising 64 adult type 2 diabetics and 36, age matched, non diabetic controls; weight, height and blood pressures were measured in all subjects. In addition, past lipid profile results of type 2 diabetics were retrieved from medical records. Thyroid dysfunction was present in 19 (29.7%) of 64 type 2 diabetics and 1 (2.8%) of 36 non diabetic controls.The prevalence of thyroid dysfunction is 32.4% in females and 25.9% in males.  Secondary hypothyroidism was seen in 78.9%, sub-clinical hypothyroidism in 15.8%, and sub-clinical hyperthyroidism 5.2% of subjects with thyroid dysfunction. Abnormal lipid profiles were seen in 35.4% of euthyroid type 2 diabetics and 100% of hypothyroid type 2 diabetics. 87.5% of type 2 diabetics and 38.8% of controls were hypertensive. 7.8% of type 2 diabetics and 50% of controls were obese. The prevalence of thyroid dysfunction in type 2 is higher in type 2 diabetics than in controls. More of Type 2 diabetics were obese and more of them were hypertensive compared to controls. The approach of using TSH first in screening for thyroid dysfunction is not sufficient in type 2 diabetics. Routine screening for thyroid dysfunction should be carried out in type 2 diabetics.Keywords: Thyroid dysfunction, Diabetes, Ibadan, Nigeria.     

Prevalence and Risk Factors Associated with Entamoeba histolytica/dispar/moshkovskii Infection among Three Orang Asli Ethnic Groups in Malaysia

Background

Entamoeba histolytica/Entamoeba dispar/Entamoeba moshkovskii infection is still prevalent in rural Malaysia especially among Orang Asli communities. Currently, information on prevalence of this infection among different ethnic groups of Orang Asli is unavailable in Malaysia. To contribute to a better comprehension of the epidemiology of this infection, a cross-sectional study aimed at providing the first documented data on the prevalence and risk factors associated with E. histolytica/E. dispar/E. moshkovskii infection was carried out among three Orang Asli ethnic groups (Proto-Malay, Negrito, and Senoi) in selected villages in Negeri Sembilan, Perak, and Pahang states, Malaysia.

Methods/Findings

Faecal samples were examined by formalin-ether sedimentation and trichrome staining techniques. Of 500 individuals, 8.7% (13/150) of Proto-Malay, 29.5% (41/139) of Negrito, and 18.5% (39/211) of Senoi were positive for E. histolytica/E. dispar/E. moshkovskii, respectively. The prevalence of this infection showed an age-dependency relationship, with higher rates observed among those aged less than 15 years in all ethnic groups studied. Multivariate analysis confirmed that not washing hands after playing with soils or gardening and presence of other family members infected with E. histolytica/E. dispar/E. moshkovskii were significant risk factors of infection among all ethnic groups. However, eating with hands, the consumption of raw vegetables, and close contact with domestic animals were identified as significant risk factors in Senoi.

Conclusions

Essentially, the findings highlighted that E. histolytica/E. dispar/E. moshkovskii parasites are still prevalent in Malaysia. Further studies using molecular approaches to distinguish the morphologically identical species of pathogenic, E. histolytica from the non-pathogenic, E. dispar and E. moshkovskii are needed. The establishment of such data will be beneficial for the public health authorities in the planning and implementation of specific prevention and control strategies of this infection in different Orang Asli ethnic groups in Malaysia.     

Optimisation of growth medium for the production of cyclodextrin glucanotransferase from Bacillus stearothermophilus HR1 using response surface methodology

Cyclodextrin glucanotransferase (CGTase) activity was observed when the bacterium was grown in the medium at various initial pH values, containing carbon, nitrogen, phosphorus and mineral salt sources at 50 °C for 24 h in the shake flasks. The optimisation of this growth medium was carried out using response surface methodology. The design contains a total of 32 experimental trials involving 10 star points and 6 replicates at the centre points. The design was employed by selecting sago starch, peptone from casein, K₂HPO₄, CaCl₂ and initial pH as five independent variables in this study. The optimal calculated values of tested variables for maximal production of CGTase were found to be comprised of: sago starch, 16.02 g/l; peptone from casein, 20 g/l; K₂HPO₄, 1.4 g/l; CaCl₂, 0.2 g/l and initial pH, 7.54 with a predicted CGTase activity of 14.20 U/ml. These predicted optimal parameters were tested in the laboratory and the final CGTase activity obtained was very close to the predicted value at 14.80 U/ml.     

Vocalisation Repertoire of Female Bluefin Gurnard (Chelidonichthys kumu) in Captivity: Sound Structure,Context and Vocal Activity

Fish vocalisation is often a major component of underwater soundscapes. Therefore, interpretation of these soundscapes requires an understanding of the vocalisation characteristics of common soniferous fish species. This study of captive female bluefin gurnard, Chelidonichthys kumu, aims to formally characterise their vocalisation sounds and daily pattern of sound production. Four types of sound were produced and characterised, twice as many as previously reported in this species. These sounds fit two aural categories; grunt and growl, the mean peak frequencies for which ranged between 129 to 215 Hz. This species vocalized throughout the 24 hour period at an average rate of (18.5 ± 2.0 sounds fish^-1 h^-1) with an increase in vocalization rate at dawn and dusk. Competitive feeding did not elevate vocalisation as has been found in other gurnard species. Bluefin gurnard are common in coastal waters of New Zealand, Australia and Japan and, given their vocalization rate, are likely to be significant contributors to ambient underwater soundscape in these areas.     

Quantifying the ultrastructure changes of air-dried and irradiated human amniotic membrane using atomic force microscopy: a preliminary study

Air-dried and sterilized amnion has been widely used as a dressing to treat burn and partial thickness wounds. Sterilisation at the standard dose of 25 kGy was reported to cause changes in the morphological structure as observed under the scanning electron microscope. This study aimed to quantify the changes in the ultrastructure of the air-dried amnion after gamma-irradiated at several doses by using atomic force microscope. Human placentae were retrieved from mothers who had undergone cesarean elective surgery. Amnion separated from chorion was processed and air-dried for 16 h. It was cut into 10?×?10 mm, individually packed and exposed to gamma irradiation at 5, 15, 25 and 35 kGy. Changes in the ultrastructural images of the amnion were quantified in term of diameter of the epithelial cells, size of the intercellular gap and membrane surface roughness. The longest diameter of the amnion cells reduced significantly after radiation (p?<?0.01) however the effect was not dose dependent. No significant changes in the shortest diameter after radiation, except at 35 kGy which decreased significantly when compared to 5 kGy (p?<?0.01). The size of the irradiated air-dried amnion cells reduced in the same direction without affecting the gross ultrastructure. At 15 kGy the intercellular gap decreased significantly (p?<?0.01) with Ra and Rq, values reflecting surface roughness, were significantly the highest (p?<?0.01). Changes in the ultrastructure quantified by using atomic force microscope could complement results from other microscopic techniques.     

Ecomorph Evolution in <Emphasis Type="Italic">Myotis</Emphasis> (Vespertilionidae,Chiroptera)

The genus Myotis is unique among mammals in its high taxonomic diversity and global distribution. Their phylogenetic relationships reflect biogeographic affinities rather than phenotypes. Myotis diverged from other bats in the early Miocene, with a subsequent split between Old and New World lineages about 19 million years ago. Similar ecomorphs (‘Leuconoe’ [near-water hunters], ‘Myotis’ [gleaners], ‘Selysius’ [aerial hawkers]) emerged independently in different lineages of Myotis. We retrieved the probable ancestral ecomorph for each lineage. Phenetic diversity was estimated from the analysis of body and skull traits. It seems that evolution of Myotis fluctuated between ‘Leuconoe’, ‘Selysius’, and larger ‘Myotis’.