Interactions in human casein systems: self-association of nonphosphorylated human beta-casein

Since caseins were originally defined as phosphoproteins, nonphosphorylated beta-casein, comprising nearly 5% of the total beta-casein in the isoelectric precipitate from human milk, appears to be unique. Despite the relatively small amount present, its properties suggest that it may play an important role in micelle formation and structure. It has a partial specific volume, v, of 0.749 +/- 0.008 and an absorbance, E1% 1 cm,280 nm of 6.2 +/- 0.2. Sedimentation and viscosity data yield a solvation of 3 g H2O/g protein and an axial ratio of about 5 for the monomer. This would be consistent with a prolate ellipsoid of 10 nm length and 2 nm width. Equilibrium in the system is attained quite slowly and the temperature-dependent polymerization was found to be reversible. With calcium, the solubility behavior reflects an increased hydrophobicity and lower electrostatic repulsion in the molecule. There is essentially no strong calcium binding to this protein but there is evidence which strongly suggests that calcium binds to nonphosphate groups at higher concentrations. Increasing the temperature from 4 to 37 degrees C causes an apparent conformational change and an increase in protein aggregation which is further increased by addition of NaCl at 37 degrees C until a limiting size is reached at about 0.1 M NaCl. This limiting size polymer contains about 75 monomers and is nearly spherical with a radius of about 12 nm and a solvation of 1.5 g H2O/g protein. Laser light scattering measurements on the solution in 0.25 M NaCl revealed a relatively homogeneous particle size with a corrected diffusion coefficient, D20,w, of 2.8 X 10(-7) cm2/s.     

Histochemical studies on the distribution of 5-nucleotidase in the germinating pollen grains ofEschscholtzia californica cham.

The present paper incorporates a detailed study on the distribution of 5-nucleotidase in the germinating pollen grains ofEschscholtzia califomica. The intense activity of this enzyme has been found in the wall of pollen grains and pollen tubes and small positive granules in the lumen of both in the pollen grains and pollen tubes. The presence of this enzyme in the wall is presumably connected with the permeability and transport process and growth regulation of the pollen tubes.     

Histological and histoenzymological studies of medulla oblongata of Taphozous melanopogon Temminck (a Microchiroptera).

The paper deals with the histological and histoenzymological studies of the medulla oblongata of Taphozous melanopogon Temminck (a microchiropteran bat). Three phosphatases, namely acid phosphatase (ACP), thiamine pyrophosphatase (TTP) and glucose-6-phosphatase (G-6-P) were studied. All the enzymes were seen in all the neurons. The large neurons of the different nuclei are more strongly positive for ACP than the small neurons. Further, the areas which contain dense populations of neurons are more strongly stained than the area containing scattered neurons. TPP and G-6-P distributions are almost parallel to that of ACP. The functions of these enzymes in synthesis and secretory processes were discussed.     

Acute pharmacogenetic activation of medial prefrontal cortex excitatory neurons regulates anxiety-like behaviour

The medial prefrontal cortex (mPFC) is implicated in anxiety-like behaviour. In rodent models, perturbations of mPFC neuronal activity through pharmacological manipulations, optogenetic activation of mPFC neurons or cell-type specific pharmacogenetic inhibition of somatostatin interneurons indicate conflicting effects on anxiety-like behaviour. In the present study we examined the effects of pharmacogenetic activation of Ca²⁺/calmodulin-dependent protein kinase α (CamKIIα)-positive excitatory neurons on anxiety-like behaviour. We used clozapine-N-oxide (CNO) to pharmacogenetically activate virally delivered CamKIIα-hM3Dq-DREADD in mPFC excitatory neurons. The effects of acute CNO or vehicle treatment on anxiety-like behaviour in the open field and elevated plus maze tests were examined in rats virally infected with either CamKIIα-hM3Dq-DREADD or CamKIIα-GFP. In addition, the effects of acute CNO treatment on the expression of the neuronal activity marker c-Fos were examined in the mPFC as well as downstream target neuronal circuits using immunohistochemistry. Acute pharmacogenetic activation of mPFC excitatory neurons evoked a significant decrease in anxiety-like behaviour selectively on the elevated plus maze task, but not the open field test. Acute CNO treatment resulted in enhanced c-Fos-immunopositive cell number in the infralimbic, prelimbic and cingulate subdivisions of the mPFC. This was also accompanied by enhanced c-Fos-immunopositive cell number in multiple downstream circuits of the mPFC in CNO-treated hM3Dq animals. Acute pharmacogenetic activation of mPFC excitatory neurons reduces anxiety-like behaviour in a task-specific fashion accompanied by enhanced c-Fos expression in the mPFC and multiple target circuits implicated in the regulation of anxiety-like behaviour.     

Glycine at hypoglossal motor nucleus: genioglossus activity, CO(2) responses, and the additive effects of GABA.

There is evidence for glycine and GABA(A)-receptor-mediated inhibition of hypoglossal motoneurons in vitro. However, comparable studies have not been performed in vivo, and the interactions of such mechanisms with integrative reflex respiratory control have also not been determined. This study tests the hypotheses that glycine at the hypoglossal motor nucleus (HMN) will suppress genioglossus (GG) muscle activity, even in the presence of hypercapnic respiratory stimulation, and the effects of glycine will be blocked by strychnine. We also determined whether coapplication of glycine and muscimol (GABA(A)- receptor agonist) to the HMN is additive in suppressing GG activity. Twenty-four urethane-anesthetized, tracheotomized, and vagotomized rats were studied. Diaphragm and GG activities, the electroencephalogram, and blood pressure were recorded. Microdialysis probes were implanted into the HMN for delivery of artificial cerebrospinal fluid (control), glycine (0.0001-10 mM), or muscimol (0.1 microM). Increasing glycine at the HMN produced graded suppression of GG activity (P < 0.001), although the GG still responded to stimulation with 7% inspired CO(2) (P = 0.002). Strychnine (0.1 mM) reversed the glycine-mediated suppression of GG activity, whereas combined glycine and muscimol were additive in GG muscle suppression. It remains to be determined whether the recruitment of such glycine and GABA mechanisms explains the periods of major GG suppression in behaviors such as rapid eye movement sleep.     

Experimental zygomycosis in rabbits: Clinicopathological studies

Zygomycosis was produced experimentally in 20 New Zealand white rabbits (Oryctolagus cuniculus) by intra-nasal administration of spores of Absidia corymbifera. Infected animals showed dullness, depression, coughing and mucopurulent nasal discharge, but no mortality. Haematology revealed no significant change in Hb and PCV, but leukocytosis due to neutrophilia in the initial stages of the experiment. There was a significant increase in serum total proteins, creatinine, AST, ALT, total Igs and CICs. A. corymbifera specific IgM and IgG antibodies were detected in the sera of the infected animals. Gross lesions consisted of pneumonic consolidations of the antero-ventral lobes of the lungs. Microscopically, histology showed formation of pyogranulommas in the lungs. Fungal elements typical of A. corymbifera were demonstrated in the tissues upto 15 days after infection by special stains and confirmed by indirect immunoperoxidase. Re-isolation of the fungus from lungs was also achieved consistently up to 15 days only. It was concluded that intra-nasal instillation of A. corymbifera in rabbits produced significant clinico-pathological alterations with the lesions confined mainly to the lungs. In the present study, neither systemic dissemination of the disease occurred nor were kidneys site of predilection as reported earlier. This revised version was published online in August 2006 with corrections to the Cover Date.     

Production of hand-made cloned buffalo (<Emphasis Type="Italic">Bubalus bubalis</Emphasis>) embryos from non-viable somatic cells

Use of non-viable somatic cells for hand-made cloning (HMC) can enable production of cloned animals from tissues obtained from elite or endangered dead animals. Buffalo skin fibroblast cells were rendered non-viable by heat treatment and used for HMC. Although fusion (93.6 ± 1.72 vs 67.1 ± 2.83%) and cleavage (90.3 ± 1.79 vs 65.8 ± 1.56%) rate was lower (P < 0.001) than that for controls, blastocysts could be successfully produced. However, blastocyst rate (34.1 ± 2.43 vs 6.9 ± 2.18%, P < 0.001) and total cell number of blastocysts (TCN, 221.3 ± 25.14 vs 151.1 ± 21.69, P < 0.05) were lower and apoptotic index (4.8 ± 1.06 vs 10.9 ± 1.21) was higher (P < 0.001) than that of controls. In another experiment, ear tissue of slaughterhouse buffaloes was preserved in mustard oil at room temperature for 48 h following which somatic cells were harvested by enzymatic digestion and used for HMC. Although fusion (96.8 ± 1.48 vs 84.2 ± 3.19%), cleavage (89.6 ± 3.59 vs 77.2 ± 3.99%), and blastocyst rate (36.9 ± 7.45 vs 13.1 ± 6.87%) were lower (P < 0.01), TCN (223.0 ± 27.89 vs 213.3 ± 28.21) and apoptotic index (3.97 ± 0.67 vs 5.22 ± 0.51) of blastocysts were similar to those of controls. In conclusion, HMC can be successfully used for production of blastocysts from non-viable cells and from cells obtained from freshly slaughtered buffaloes. This can pave the way for the restoration of farm or wild animals by HMC if somatic cells could be obtained within a few hours after their death.     

Propensity of <Emphasis Type="Italic">Withania somnifera</Emphasis> to Attenuate Behavioural,Biochemical, and Histological Alterations in Experimental Model of Stroke

The present study was designed to evaluate the beneficial effects of Withania somnifera (WS) pre-supplementation on middle cerebral artery occlusion (MCAO) model of ischemic stroke. Ischemic stroke was induced in the rats by inserting intraluminal suture for 90 min, followed by reperfusion injury for 24 h. The animals were assessed for locomotor functions (by neurological deficit scores, narrow beam walk and rotarod test), cognitive and anxiety-like behavioural functions (by morris water maze and elevated plus maze test). MCAO animals showed significant impairment in locomotor and cognitive functions. Neurobehavioural changes were accompanied by decreased acetylcholinesterase activity, increased oxidative stress in terms of enhanced lipid peroxidation and lowered thiol levels in the MCAO animals. In addition, MCAO animals had cerebral infarcts and the presence of pycnotic nuclei. Single-photon emission computerized tomography (SPECT) of MCAO animals revealed a cerebral infarct as a hypoactive area. On the other hand, pre-supplementation with WS (300 mg/kg body weight) for 30 days to MCAO animals was effective in restoring the acetylcholinesterase activity, lipid peroxidation, thiols and attenuated MCAO induced behavioural deficits. WS significantly reduced the cerebral infarct volume and ameliorated histopathological alterations. Improved blood flow was observed in the SPECT images from the brain regions of ischemic rats pre-treated with WS. The results of the study showed a protective effect of WS supplementation in ischemic stroke and are suggestive of its potential application in stroke management.