ABSTRACT
A new species, Euconocephalus narayanpurensis Kumar & Chand sp. nov., from India is described in this paper. The new species is similar to the African species Euconocephalus lineatipes (Bolívar, 1890), but differs from the latter in the smaller size, more acute humeral sinus, the narrowly rounded apex of elytra and convex male last abdominal tergite. A key to the Indian species of Euconocephalus Karny, 1907 is also provided.
Subject(s)
Orthoptera , Male , Animals , Animal Distribution , IndiaABSTRACT
A new species, Xestophrys bengalensis sp. nov., from the West Bengal state of India is described in this paper. The new species is superficially similar to the Indonesian species Xestophrys javanicus lombockensis Carl, 1908, but differs from the latter in the smaller size, anterior femur unarmed on the external margin, and hind femur with two spines on the internal margin. A key to the species of Xestophrys Redtenbacher, 1891 is also provided.
Subject(s)
Orthoptera , Animals , Animal Distribution , IndiaABSTRACT
OBJECTIVE: Three-dimensional computed tomography reconstruction of the face has recently been presented as a newer diagnostic tool in coronavirus disease 2019 associated mucormycosis. This study was conducted to compare three-dimensional computed tomography reconstruction with conventional two-dimensional computed tomography in coronavirus disease 2019 associated mucormycosis. METHODS: A total of 123 mucormycosis patients underwent three-dimensional computed tomography reconstruction after a comprehensive clinical investigation. The involvement of the facial skeleton was noted. RESULTS: The anterior maxillary wall was most commonly involved (9.8 per cent). Involvement of the lateral maxillary wall was noted in 6.5 per cent of patients. Sixty-seven patients (54.5 per cent) underwent endoscopic surgery, 22 (17.9 per cent) underwent open surgical procedures, and 12 (9.8 per cent) had combined endoscopic and open surgical procedures. In 21 patients (17.1 per cent), open surgery was performed in the first instance based on additional three-dimensional computed tomography findings, and revision surgical procedures were avoided. CONCLUSION: Three-dimensional computed tomography of the face was found to be superior in determining the extent of disease. It reduces delays in diagnosis, facilitates surgical planning and minimises the need for multiple surgical procedures.
Subject(s)
COVID-19 , Mucormycosis , Humans , Mucormycosis/diagnostic imaging , COVID-19/diagnostic imaging , Tomography, X-Ray Computed/methods , Maxilla , EndoscopyABSTRACT
More than one hundred years after its description, a male specimen of Liara(Unalianus)heteracanthus(Redtenbacher, 1891) was collected at a new locality in the Mizoram State, India. Opportunity is taken to redescribe and illustrate this specimen.
Subject(s)
Orthoptera , Animal Distribution , Animals , India , MaleABSTRACT
The first-in-class inhibitor of ALK, c-MET and ROS1, crizotinib (Xalkori), has shown remarkable clinical efficacy in treatment of ALK-positive non-small cell lung cancer. However, in neuroblastoma, activating mutations in the ALK kinase domain are typically refractory to crizotinib treatment, highlighting the need for more potent inhibitors. The next-generation ALK inhibitor PF-06463922 is predicted to exhibit increased affinity for ALK mutants prevalent in neuroblastoma. We examined PF-06463922 activity in ALK-driven neuroblastoma models in vitro and in vivo In vitro kinase assays and cell-based experiments examining ALK mutations of increasing potency show that PF-06463922 is an effective inhibitor of ALK with greater activity towards ALK neuroblastoma mutants. In contrast to crizotinib, single agent administration of PF-06463922 caused dramatic tumor inhibition in both subcutaneous and orthotopic xenografts as well as a mouse model of high-risk neuroblastoma driven by Th-ALK(F1174L)/MYCN Taken together, our results suggest PF-06463922 is a potent inhibitor of crizotinib-resistant ALK mutations, and highlights an important new treatment option for neuroblastoma patients.
Subject(s)
Lactams, Macrocyclic/therapeutic use , N-Myc Proto-Oncogene Protein/antagonists & inhibitors , Neuroblastoma/drug therapy , Protein Kinase Inhibitors/therapeutic use , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Aminopyridines , Anaplastic Lymphoma Kinase , Animals , Cell Line, Tumor , Cell Proliferation/drug effects , Clinical Trials as Topic , Crizotinib , Lactams , Lactams, Macrocyclic/pharmacology , Mice, Inbred BALB C , Mice, Nude , Mutation/genetics , N-Myc Proto-Oncogene Protein/metabolism , Neuroblastoma/pathology , PC12 Cells , Protein Kinase Inhibitors/pharmacology , Pyrazoles/pharmacology , Pyrazoles/therapeutic use , Pyridines/pharmacology , Pyridines/therapeutic use , Rats , Receptor Protein-Tyrosine Kinases/genetics , Receptor Protein-Tyrosine Kinases/metabolism , Xenograft Model Antitumor AssaysABSTRACT
Recently, germline and somatic heterozygous mutations in the platelet-derived growth factor receptor ß (PDGFRB) have been associated with familial infantile myofibromatosis (IM), which is characterized by soft tissue tumors, and overgrowth syndrome, a disease that predisposes to cancer. These mutations have not been functionally characterized. In the present study, the activity of three PDGFRB mutants associated with familial IM (R561C, P660T and N666K) and one PDGFRB mutant found in patients with overgrowth syndrome (P584R) was tested in various models. The P660T mutant showed no difference with the wild-type receptor, suggesting that it might represent a polymorphic variant unrelated to the disease. By contrast, the three other mutants were constitutively active and able to transform NIH3T3 and Ba/F3 cells to different extents. In particular, the germline mutant identified in overgrowth syndrome, P584R, was a stronger oncogene than the germline R561C mutant associated with myofibromatosis. The distinct phenotypes associated with these two mutations could be related to this difference of potency. Importantly, all activated mutants were sensitive to tyrosine kinase inhibitors such as imatinib, nilotinib and ponatinib. In conclusion, the PDGFRB mutations previously identified in familial IM and overgrowth syndrome activate the receptor in the absence of ligand, supporting the hypothesis that these mutations cause the diseases. Moreover, imatinib seems to be a promising treatment for patients carrying these mutations. To our knowledge, these are the first confirmed gain-of-function point mutations of PDGFRB in human cancer.
Subject(s)
Growth Disorders/genetics , Imatinib Mesylate/pharmacology , Mutation , Myofibromatosis/congenital , Receptor, Platelet-Derived Growth Factor beta/genetics , Animals , Blotting, Western , Cell Line , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Proliferation/genetics , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/metabolism , Female , Growth Disorders/metabolism , Humans , MCF-7 Cells , Mice , Mice, Inbred BALB C , Mice, Knockout , Mutagenesis, Site-Directed , Myofibromatosis/genetics , Myofibromatosis/metabolism , NIH 3T3 Cells , Neoplasms, Experimental/genetics , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Oncogenes/genetics , Protein Kinase Inhibitors/pharmacology , Receptor, Platelet-Derived Growth Factor beta/metabolism , SyndromeABSTRACT
Our earlier studies showed that lactational exposure to lead (Pb) caused irreversible neurochemical alterations in rats. The present study was carried out to examine whether gestational exposure to Pb can cause long-term changes in the brain cholinergic system and behavior of rats. The protective effect of calcium (Ca) supplementation against Pb toxicity was also examined. Pregnant rats were exposed to 0.2% Pb (Pb acetate in drinking water) from gestational day (GD) 6 to GD 21. The results showed decrease in body weight gain (GD 6-21) of dams, whereas no changes were observed in offspring body weight at different postnatal days following Pb exposure. Male offspring treated with Pb showed marginal alterations in developmental landmarks such as unfolding of pinnae, lower and upper incisor eruption, fur development, eye slit formation and eye opening on postnatal day (PND) 1, whereas significant alterations were found in the righting reflex (PNDs 4-7), slant board behavior (PNDs 8-10) and forelimb hang performance (PNDs 12-16). Biochemical analysis showed decrease in synaptosomal acetylcholinesterase (AChE) activity and an increase in acetylcholine (ACh) levels in the cortex, cerebellum and hippocampus on PND 14, PND 21, PND 28 and in the four-month age group of rats following Pb exposure. Significant deficits were also observed in total locomotor activity, exploratory behavior and open field behavior in selected age groups of Pb-exposed rats. These alterations were found to be maximal on PND 28, corresponding with the greater blood lead levels observed on PND 28. Addition of 0.02% Ca to Pb reversed the Pb-induced impairments in the cholinergic system as well as in behavioral parameters of rats. In conclusion, these data suggest that gestational exposure to Pb is able to induce long-term changes in neurological functions of offspring. Maternal Ca administration reversed these neurological effects of Pb later in life, suggesting a protective effect of calcium in Pb-exposed animals.
ABSTRACT
Activating mutations in the platelet-derived growth factor (PDGF) receptor alpha (PDGFRA) have been described in patients with gastrointestinal stromal tumors or myeloid malignancies associated with hypereosinophilia. These patients respond well to imatinib mesylate, raising the question as to whether patients with a PDGF receptor mutation in other tumor types should receive a tyrosine kinase inhibitor treatment. We characterized 10 novel somatic point mutations in PDGFRA that have been reported in isolated cases of glioblastoma, melanoma, acute myeloid leukemia, peripheral nerve sheath tumors and neuroendocrine carcinoma. The PDGFRA transmembrane domain mutation V536E stimulated Ba/F3 cell growth and signaling via ERK and STAT5 in the absence of ligand. This mutant, identified in glioblastoma, was strongly inhibited by imatinib. Modeling suggested that the mutation modulates the packing of the transmembrane domain helices in the receptor dimer. By contrast, two mutations in highly conserved residues affected the receptor traffic to the cell surface or kinase activity, thereby preventing the response to PDGF. The other mutations had no significant impact on the receptor activity. This functional analysis matched the predictions of SIFT and PolyPhen for only five mutations and these algorithms do not discriminate gain from loss of function. Finally, an E996K variant that had been identified in a melanoma cell line was not expressed in these cells. Altogether, several newly identified PDGFRA mutations do not activate the receptor and may therefore represent passenger mutations. Our results also underline the importance of characterizing novel kinase alterations in cancer patients.
Subject(s)
Neoplasms/genetics , Point Mutation , Receptor, Platelet-Derived Growth Factor alpha/genetics , Amino Acid Sequence , Flow Cytometry , Glycosylation , Humans , Molecular Sequence Data , Protein Transport , Receptor, Platelet-Derived Growth Factor alpha/chemistry , Sequence Homology, Amino AcidABSTRACT
Rice blast is one of the important diseases of rice which can be effectively managed by the deployment of resistance genes. Pi-ta is one of the major blast resistant genes effective against pathogen populations in different parts of India. We analysed allelic variants of Pi-ta from 48 rice lines selected after phenotyping of 529 rice landraces across three eco-geographical blast hot spot regions. Besides, Pi-ta orthologue sequences of 220 rice accessions belonging to wild and cultivated species of rice were also included in the study for a better evo-devo perspective of the diversity present in the gene and the selection pressures acting on this locus. We obtained high nucleotide variations (SNPs and insertion-deletions) in the intronic region. We also identified 64 haplotypes based on nucleotide polymorphism in these alleles. Pi-ta orthologues of Indian landraces were scattered in eight major haplotypes indicating its heterogenous nature. We identified a total of 47 different Pi-ta protein variants on the basis of deduced amino acid residues amongst the orthologues. Five unique and novel Pi-ta variants were identified for the first time in rice landraces exhibiting different reaction types against the Magnaporthe oryzae population. A high value of Pi(non/syn) was observed only in the leucine-rich domain of the alleles cloned from Indian landraces, indicating strong selective forces acting on this region. The detailed molecular analysis of the Pi-ta orthologues provides insights to a high degree of inter- and intraspecific relationships amongst the Oryza species. We identified rice landraces possessing the effective alleles of this resistance gene which can be used in future blast resistance breeding programmes.
Subject(s)
Disease Resistance/genetics , Magnaporthe/pathogenicity , Plant Diseases/genetics , Plant Proteins/genetics , Receptors, Cytoplasmic and Nuclear/genetics , Amino Acid Sequence , Base Sequence , Genetics, Population , Haplotypes , Immunity, Innate/genetics , India , Introns , Magnaporthe/genetics , Oryza , Plant Diseases/microbiology , Plant Proteins/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Sequence Analysis, DNAABSTRACT
The pyramidal neurons in the hippocampus are extremely neuroplastic, and the complexity of dendritic branches can be dynamically altered in response to a variety of stimuli, including learning and stress. Recently, the teneurin family of proteins has emerged as an interneuronal and extracellular matrix signaling system that plays a significant role in brain development and neuronal communication. Encoded on the last exon of the teneurin genes is a new family of bioactive peptides termed the teneurin C-terminal-associated peptides (TCAPs). Previous studies indicate that TCAP-1 regulates axon fasciculation and dendritic morphology in the hippocampus. This study was aimed at understanding the molecular mechanisms by which TCAP-1 regulates these changes in the mouse hippocampus. Fluoresceinisothiocyanate (FITC)-labeled TCAP-1 binds to the pyramidal neurons of the CA2 and CA3, and dentate gyrus in the hippocampus of the mouse brain. Moreover, FITC-TCAP-1 co-localizes with ß-dystroglycan upon binding to the plasma membrane of cultured immortalized mouse E14 hippocampal cells. In culture, TCAP-1 stimulates ERK1/2-dependent phosphorylation of the cytoskeletal regulatory proteins, stathmin at serine-25 and filamin A at serine-2152. In addition, TCAP-1 induces actin polymerization, increases immunoreactivity of tubulin-based cytoskeletal elements and causes a corresponding increase in filopodia formation and mean filopodia length in cultured hippocampal cells. We postulate that the TCAP-1 region of teneurin-1 has a direct action on the cytoskeletal reorganization that precedes neurite and process development in hippocampal neurons. Our data provides novel evidence that functionally links the teneurin and dystroglycan systems and provides new insight into the molecular mechanisms by which TCAP-1 regulates cytoskeletal dynamics in hippocampal neurons. The TCAP-dystroglycan system may represent a novel mechanism associated with the regulation of hippocampal-function.
Subject(s)
Contractile Proteins/metabolism , Cytoskeleton/metabolism , Dystroglycans/metabolism , Microfilament Proteins/metabolism , Nerve Tissue Proteins/metabolism , Pyramidal Cells/metabolism , Stathmin/metabolism , Tenascin/metabolism , Animals , Blotting, Western , Filamins , Fluorescent Antibody Technique , Hippocampus/physiology , MAP Kinase Signaling System/physiology , Mice , Neurogenesis/physiologyABSTRACT
Children with chronic kidney disease (CKD) suffer from growth failure due to a multitude of confounding factors. Among these include nutritional deficiencies, metabolic acidosis, anemia, and growth hormone resistance. Each of these variables contributes independently to increased morbidity and mortality in this population. Psychosocial well being is also adversely affected. Every effort should be made by the nephrology team to optimize treatment of these variables when managing children with CKD.
Subject(s)
Child Nutrition Disorders/etiology , Growth Disorders/etiology , Kidney Diseases/complications , Bone Diseases, Metabolic/etiology , Bone Diseases, Metabolic/prevention & control , Child , Child Nutrition Disorders/prevention & control , Chronic Disease , Growth Disorders/drug therapy , Growth Disorders/prevention & control , Human Growth Hormone/therapeutic use , Humans , Nutritional Requirements , Recombinant Proteins/therapeutic useABSTRACT
PURPOSE: Well-functioning vascular access is essential for the provision of adequate CRRT. However, few data exist to describe the effect of catheter size or location on CRRT performance in the pediatric population. METHODS: Data for vascular access site, size, and location, as well as type of anticoagulant used and patient demographic data were gathered from the ppCRRT registry. Kaplan-Meier curves were generated and then analyzed by log-rank test or Cox Proportional Hazards model. RESULTS: Access diameter was found to significantly affect circuit survival. None of the 5 French catheters lasted longer than 20 hours. Seven and 9 French, but not 8 French, catheters fared worse than larger diameter catheters (p=0.002). Circuits associated with internal jugular access survived longer than subclavian or femoral access associated circuits (p<0.05). Circuit survival was also found to be favorably associated with the CVVHD modality (p<0.001). CONCLUSIONS: Functional CRRT circuit survival in children is favored by larger catheter diameter, internal jugular vein insertion site and CVVHD. For patients requiring catheter diameters less than 10 French, CRRT circuit survival might be optimized if internal jugular vein insertion is feasible. Conversely, when a vascular access site other than the internal jugular vein is most prudent, consideration should be given to using the largest diameter catheter appropriate for the size of the child. The CVVHD modality was associated with longer circuit survival, but the mechanism by which this occurs is unclear.
Subject(s)
Catheterization, Central Venous , Catheterization, Peripheral , Hemofiltration , Kidney Failure, Chronic/therapy , Registries , Renal Dialysis , Adolescent , Adult , Catheters, Indwelling , Child , Child, Preschool , Cohort Studies , Humans , Infant , Infant, Newborn , Proportional Hazards Models , United StatesABSTRACT
Size-resolved cloud condensation nuclei (CCN) spectra measured for various aerosol types at a non-urban site in Germany showed that CCN concentrations are mainly determined by the aerosol number size distribution. Distinct variations of CCN activation with particle chemical composition were observed but played a secondary role. When the temporal variation of chemical effects on CCN activation is neglected, variation in the size distribution alone explains 84 to 96% of the variation in CCN concentrations. Understanding that particles' ability to act as CCN is largely controlled by aerosol size rather than composition greatly facilitates the treatment of aerosol effects on cloud physics in regional and global models.
ABSTRACT
Synthesis of [2]catenane 6 has been successfully achieved by the combination of Pd complex 1 and pyridines 2 and 3 at a molar ratio of 2:1:1 in D20. A mixture of square molecule 4 (prepared from 1 and 2) and macrocycle 5 (obtained from 1 and 3), in which the final ratio of 1, 2, and 3 was kept 2:1:1 reorganizes in D2O/CD3OD (1:1) to form 6 within one day. However, the same mixture in D2O shows the formation of novel [3]catenane 7 along with the [2]catenane. In order to make 7, the theoretical ratio of components 1, 2, and 3 should be 3:1:2. Thus, deliberately maintaining such ratio of the above-mentioned molecules, a higher proportion of the [3]catenane is observed in D2O as found from 1H NMR spectra of the system. Reorganization of the twelve components to form [3]catenane is supported by studies with the DOSY method. This method is a first attempt to separate, from a mixture, either catenanes or any other supramolecular self-assembly structures. CSI-MS studies further support the assigned catenane super structures 6 and 7. All the results indicate that the [2]catenane is thermodynamically the most stable structure, while the [3]catenane is a meta-stable self-assembly.
Subject(s)
Pyridines/chemistry , DNA/chemistry , Magnetic Resonance Spectroscopy/methods , Molecular Conformation , Organometallic Compounds/chemical synthesis , Organometallic Compounds/chemistry , Palladium/chemistry , Platinum/chemistry , Pyridines/chemical synthesisABSTRACT
The aim of this study was to evaluate the efficacy and side-effects of tacrolimus in pediatric transplant patients previously receiving cyclosporin A (CsA). This study was a retrospective chart review strengthened by a concomitant patient interview. Eleven pediatric cardiac or renal transplant patients, who had been converted from CsA to tacrolimus from October 1995 to January 1999 at The Cleveland Clinic Foundation, were included; there were six renal and five cardiac transplant patients. Each chart was reviewed to assess transplanted organ function pre- and post-conversion. For the six renal transplant patients, creatinine levels and biopsy findings were evaluated. For the five cardiac transplant patients, cardiac catheterization and routine biopsy data were analyzed likewise. Epstein Barr virus (EBV) status was also evaluated in each patient. In addition, each parent or patient was interviewed to ascertain dates of transplant, current medications, and side-effects. The patients' ages ranged from 6 to 20 yr (mean age 14.6 yr). All patients had been converted to tacrolimus. Eight patients were converted for treatment of refractory rejection, two were converted because of CsA-associated side-effects, and one patient was converted empirically for a history of multiple previous transplant rejections. Seven out of eight patients who received tacrolimus for rejection therapy improved. One patient had complete resolution of gingival hyperplasia. Another patient who previously developed hemolytic uremic syndrome on CsA had no further evidence of hemolysis. Four patients were weaned off steroid therapy. Despite conversion, two renal transplant patients progressed to chronic rejection. Five patients exhibited no side-effects. Side-effects experienced included transient hyperglycemia in conjunction with steroid use, headaches, and tremors that subsided rapidly. Four of 11 patients developed post-transplant lymphoproliferative disease (PTLD). Fortunately, reducing the dose of tacrolimus and/or surgical resection of the mass (if present), eradicated the disease. In conclusion, conversion therapy successfully provides an alternate treatment for acute rejection. It also enabled some patients to discontinue steroid therapy, maximizing growth potential. PTLD is a severe, potentially life-threatening complication that needs to be recognized and monitored closely. In conclusion, tacrolimus has been shown to be a very effective agent for the treatment of refractory organ rejection, but must be used cautiously.
Subject(s)
Graft Rejection/drug therapy , Graft Survival/drug effects , Heart Transplantation/immunology , Immunosuppressive Agents/therapeutic use , Kidney Transplantation/immunology , Tacrolimus/therapeutic use , Adjuvants, Immunologic/administration & dosage , Adolescent , Adult , Child , Female , Graft Rejection/immunology , Graft Rejection/prevention & control , Heart Transplantation/physiology , Herpesvirus 4, Human/immunology , Humans , Kidney Transplantation/physiology , Living Donors , Male , Retrospective Studies , Tacrolimus/adverse effects , Time Factors , Treatment OutcomeABSTRACT
Microorganisms may produce substances that disrupt the interaction between platelets and vascular endothelium, which has been associated with atypical hemolytic uremic syndrome (HUS). We present the first reported case of Fusobacterium necrophorum bacteremia that presented initially with atypical HUS. Antimicrobial therapy eradicated the patient's bacteremia, and plasmapheresis restored platelet-endothelial homeostasis. Understanding the pathophysiologic mechanisms involved in atypical HUS would guide the development of more precise therapies.
Subject(s)
Bacteremia/complications , Fusobacterium Infections/complications , Fusobacterium necrophorum , Hemolytic-Uremic Syndrome/etiology , Adult , Anti-Bacterial Agents , Bacteremia/drug therapy , Bacteremia/microbiology , Drug Therapy, Combination/therapeutic use , Female , Fusobacterium Infections/drug therapy , Hemolytic-Uremic Syndrome/therapy , Humans , PlasmapheresisABSTRACT
Complexation of the ligand 1 with Pd(NO3)2 leads to the self-assembly of a very stable M2L4 type macrotricyclic cage that encapsulates a nitrate ion inside its cavity.
ABSTRACT
The stability constants of Cu(II) complexes that consist of either an oxaaza macrocycle with two triamine moieties linked by dioxa chains, or two macrocyclic ligands with a polyamine chain which are connecting the 2 and 9 positions of phenanthroline, have been determined by means of potentiometric measurements. The results are compared to those reported for other ligands with a similar molecular architecture. Of the complexes that contain phenanthroline in their macrocycle, the Cu(II) ion of the complex with the smallest and most rigid macrocycle (L3) has an unsaturated coordination sphere, while in the complex with the largest macrocycle (L5) the Cu(II) ion is coordinatively almost saturated. These results are corroborated by the crystal structure of the [CuL5](ClO4)2 complex. The affinity of the ligands and the complexes towards nucleic acids was studied by measuring the changes in the melting temperature, which showed that the affinity of the macrocyclic ligands towards double-stranded DNA or RNA is generally smaller than that of their linear analogues that bear a similar charge, with a strong preference for polyA-polyU, a model for RNA. However, the complexes of two of the changed macrocyclic ligands which contain a phenanthroline unit (L4, L5) showed a distinctly larger increase in their melting temperature deltaTm with DNA (polydA-polydT), which is reversed again in favor of RNA upon metallation to the dinuclear copper complex with L5. Experiments with supercoiled plasmid DNA showed a particularly effective cleavage with a mononuclear Cu(II) complex that contains a phenanthroline unit (L6). Related ligands showed less activity towards DNA, but not so towards the biocidic bis(p-nitrophenyl)phosphate (BNPP). In both cases (with DNA and BNPP) the activity seemed to increase with decrease of coordinative saturation of the Cu(II) ion, with the exception of one particular ligand (L6). Experiments with radical scavengers in the DNA experiments showed some decrease in cleavage, which indicates the participation of redox processes.
Subject(s)
Copper/chemistry , Polyamines/chemistry , Ribonucleases/chemistry , Binding Sites , Crystallography, X-Ray , DNA/chemistry , Hydrolysis , Ligands , Molecular Conformation , Nitrophenols/chemistry , Potentiometry , RNA/chemistry , Solutions , TemperatureABSTRACT
Split aliquots of pooled buffalo semen samples were processed before freezing 1) by washing twice with Tris-citric acid buffer by centrifugation and re-suspension to the original volume in the same buffer, or 2) or by passage through a G-15 Sephadex column. The effect of these procedures on progressive motility, percentages of live spermatozoa, sperm abnormalities and intact acrosomes and release of glutamate oxatoacetate transaminase (GOT) into the medium were assessed after extension, after equilibration and after 18 to 24 h or 15 d of frozen storage. Prior to extension, gel filtration reduced sperm concentration and enhanced progressive motility, whereas washing produced little effect on these attributes. Except in the case of GOT release, which was significantly (P < 0.05) lower after the washing of semen (34.3 +/- 16.40) than the filtering of semen (45.7 +/- 12.35), the 2 procedures did not cause significant effects (P > 0.05). Damage to spermatozoa due to freeze-processing was also similar in the 2 treatments, and the extent of beneficial effect in improved motility and live spermatozoan numbers after thawing was also similar.