The Stilbene Synthase Family in Arachis: A Genome-Wide Study and Functional Characterization in Response to Stress

Peanut (Arachis hypogaea) and its wild relatives are among the few species that naturally synthesize resveratrol, a well-known stilbenoid phytoalexin that plays a crucial role in plant defense against biotic and abiotic stresses. Resveratrol has received considerable attention due to its health benefits, such as preventing and treating various human diseases and disorders. Chalcone (CHS) and Stilbene (STS) Synthases are plant-specific type III Polyketide Synthases (PKSs) that share the same substrates and are key branch enzymes in the biosynthesis of flavonoids and stilbenoids, respectively. Although resveratrol accumulation in response to external stimulus has been described in peanut, there are no comprehensive studies of the CHS and STS gene families in the genus Arachis. In the present study, we identified and characterized 6 CHS and 46 STS genes in the tetraploid peanut and an average of 4 CHS and 22 STS genes in three diploid wild species (Arachis duranensis, Arachis ipaënsis and Arachis stenosperma). The CHS and STS gene and protein structures, chromosomal distributions, phylogenetic relationships, conserved amino acid domains, and cis-acting elements in the promoter regions were described for all Arachis species studied. Based on gene expression patterns of wild A. stenosperma STS genes in response to different biotic and abiotic stresses, we selected the candidate AsSTS4 gene, which is strongly induced by ultraviolet (UV) light exposure, for further functional investigation. The AsSTS4 overexpression in peanut hairy roots significantly reduced (47%) root-knot nematode infection, confirming that stilbene synthesis activation in transgenic plants can increase resistance to pathogens. These findings contribute to understanding the role of resveratrol in stress responses in Arachis species and provide the basis for genetic engineering for improved production of valuable secondary metabolites in plants.

A novel soybean hairy root system for gene functional validation

Agrobacterium rhizogenes-mediated transformation has long been explored as a versatile and reliable method for gene function validation in many plant species, including soybean (Glycine max). Likewise, detached-leaf assays have been widely used for rapid and mass screening of soybean genotypes for disease resistance. The present study combines these two methods to establish an efficient and practical system to generate transgenic soybean hairy roots from detached leaves and their subsequent culture under ex vitro conditions. We demonstrated that hairy roots derived from leaves of two (tropical and temperate) soybean cultivars could be successfully infected by economically important species of root-knot nematodes (Meloidogyne incognita and M. javanica). The established detached-leaf method was further explored for functional validation of two candidate genes encoding for cell wall modifying proteins (CWMPs) to promote resistance against M. incognita through distinct biotechnological strategies: the overexpression of a wild Arachis α-expansin transgene (AdEXPA24) and the dsRNA-mediated silencing of an endogenous soybean polygalacturonase gene (GmPG). AdEXPA24 overexpression in hairy roots of RKN-susceptible soybean cultivar significantly reduced nematode infection by approximately 47%, whereas GmPG downregulation caused an average decrease of 37%. This novel system of hairy root induction from detached leaves showed to be an efficient, practical, fast, and low-cost method suitable for high throughput in root analysis of candidate genes in soybean.

Engineering Resistance against Sclerotinia sclerotiorum Using a Truncated NLR (TNx) and a Defense-Priming Gene

The association of both cell-surface PRRs (Pattern Recognition Receptors) and intracellular receptor NLRs (Nucleotide-Binding Leucine-Rich Repeat) in engineered plants have the potential to activate strong defenses against a broad range of pathogens. Here, we describe the identification, characterization, and in planta functional analysis of a novel truncated NLR (TNx) gene from the wild species Arachis stenosperma (AsTIR19), with a protein structure lacking the C-terminal LRR (Leucine Rich Repeat) domain involved in pathogen perception. Overexpression of AsTIR19 in tobacco plants led to a significant reduction in infection caused by Sclerotinia sclerotiorum, with a further reduction in pyramid lines containing an expansin-like B gene (AdEXLB8) potentially involved in defense priming. Transcription analysis of tobacco transgenic lines revealed induction of hormone defense pathways (SA; JA-ET) and PRs (Pathogenesis-Related proteins) production. The strong upregulation of the respiratory burst oxidase homolog D (RbohD) gene in the pyramid lines suggests its central role in mediating immune responses in plants co-expressing the two transgenes, with reactive oxygen species (ROS) production enhanced by AdEXLB8 cues leading to stronger defense response. Here, we demonstrate that the association of potential priming elicitors and truncated NLRs can produce a synergistic effect on fungal resistance, constituting a promising strategy for improved, non-specific resistance to plant pathogens.

Proceedings of resources for optimal care of acute care and emergency surgery consensus summit Donegal Ireland

BACKGROUND

Opportunities to improve emergency surgery outcomes exist through guided better practice and reduced variability. Few attempts have been made to define optimal care in emergency surgery, and few clinically derived key performance indicators (KPIs) have been published. A summit was therefore convened to look at resources for optimal care of emergency surgery. The aim of the Donegal Summit was to set a platform in place to develop guidelines and KPIs in emergency surgery.

METHODS

The project had multidisciplinary global involvement in producing consensus statements regarding emergency surgery care in key areas, and to assess feasibility of producing KPIs that could be used to monitor process and outcome of care in the future.

RESULTS

Forty-four key opinion leaders in emergency surgery, across 7 disciplines from 17 countries, composed evidence-based position papers on 14 key areas of emergency surgery and 112 KPIs in 20 acute conditions or emergency systems.

CONCLUSIONS

The summit was successful in achieving position papers and KPIs in emergency surgery. While position papers were limited by non-graded evidence and non-validated KPIs, the process set a foundation for the future advancement of emergency surgery.

Genome-wide analysis of expansin superfamily in wild Arachis discloses a stress-responsive expansin-like B gene

Expansins are plant cell wall-loosening proteins involved in adaptive responses to environmental stimuli and various developmental processes. The first genome-wide analysis of the expansin superfamily in the Arachis genus identified 40 members in A. duranensis and 44 in A. ipaënsis, the wild progenitors of cultivated peanut (A. hypogaea). These expansins were further characterized regarding their subfamily classification, distribution along the genomes, duplication events, molecular structure, and phylogeny. A RNA-seq expression analysis in different Arachis species showed that the majority of these expansins are modulated in response to diverse stresses such as water deficit, root-knot nematode (RKN) infection, and UV exposure, with an expansin-like B gene (AraEXLB8) displaying a highly distinct stress-responsive expression profile. Further analysis of the AraEXLB8 coding sequences showed high conservation across the Arachis genotypes, with eight haplotypes identified. The modulation of AraEXLB8 expression in response to the aforementioned stresses was confirmed by qRT-PCR analysis in distinct Arachis genotypes, whilst in situ hybridization revealed transcripts in different root tissues according to the stress imposed. The overexpression of AraEXLB8 in soybean (Glycine max) composite plants remarkably decreased the number of galls in transformed hairy roots inoculated with RKN. This study improves the current understanding of the molecular evolution, divergence, and gene expression of expansins in Arachis, and provides molecular and functional insights into the role of expansin-like B, the less-studied plant expansin subfamily.

Ex vitro hairy root induction in detached peanut leaves for plant-nematode interaction studies

BACKGROUND

Peanut (Arachis hypogaea) production is largely affected by a variety of abiotic and biotic stresses, including the root-knot nematode (RKN) Meloidogyne arenaria that causes yield losses worldwide. Transcriptome studies of wild Arachis species, which harbor resistance to a number of pests and diseases, disclosed several candidate genes for M. arenaria resistance. Peanut is recalcitrant to genetic transformation, so the use of Agrobacterium rhizogenes-derived hairy roots emerged as an alternative for in-root functional characterization of these candidate genes.

RESULTS

The present report describes an ex vitro methodology for hairy root induction in detached leaves based on the well-known ability of peanut to produce roots spontaneously from its petiole, which can be maintained for extended periods under high-humidity conditions. Thirty days after infection with the A. rhizogenes 'K599' strain, 90% of the detached leaves developed transgenic hairy roots with 5 cm of length in average, which were then inoculated with M. arenaria. For improved results, plant transformation, and nematode inoculation parameters were adjusted, such as bacterial cell density and growth stage; moist chamber conditions and nematode inoculum concentration. Using this methodology, a candidate gene for nematode resistance, AdEXLB8, was successfully overexpressed in hairy roots of the nematode-susceptible peanut cultivar 'Runner', resulting in 98% reduction in the number of galls and egg masses compared to the control, 60 days after M. arenaria infection.

CONCLUSIONS

This methodology proved to be more practical and cost-effective for functional validation of peanut candidate genes than in vitro and composite plant approaches, as it requires less space, reduces analysis costs and displays high transformation efficiency. The reduction in the number of RKN galls and egg masses in peanut hairy roots overexpressing AdEXLB8 corroborated the use of this strategy for functional characterization of root expressing candidate genes. This approach could be applicable not only for peanut-nematode interaction studies but also to other peanut root diseases, such as those caused by fungi and bacteria, being also potentially extended to other crop species displaying similar petiole-rooting competence.

Inductively coupled plasma emission spectroscopic and flame photometric analysis of goat epididymal fluid

AIM

The elemental composition of the epididymal luminal fluid (ELF) in adult goat (Capra indica) was investigated.

METHODS

ELF was collected by micropuncture from twelve sites along the epididymal duct. The elemental contents was analyzed with inductively coupled plasma (ICP) emission spectroscopy, a microanalytical technique that can simultaneously measure many elements in minute volumes of sample. The Na and K concentrations were determined by flame photometry.

RESULTS

ICP spectroscopy showed the presence of copper, calcium, nickel, iron, magnesium, chromium, titanium and zinc in ELF, with fluctuating levels at different sites along the length of the epididymis. Cadmium, cobalt, lead and manganese were not found. The Na+/K+ ratio was seen to be higher at the initial segments of the epididymis and lower at the distal.

CONCLUSION

It is proposed that the observed characteristic distribution of elements in ELF may have far reaching implications in sperm maturation and storage known to occur in the epididymis.

Plant natural products active against snake bite--the molecular approach

The article surveys the substances identified in plants reputed to neutralize the effects of snake venoms. Protective activity of many of them against the lethal action of the venom of the jararaca (Bothrops jararaca) snake was confirmed by biological assays. It was shown that all belong to chemical classes capable of interacting with macromolecular targets--receptors and enzymes. In a few cases it has been shown that exogenous natural micromolecules can mimic the biological activity of endogenous macromolecules. From the evidence presented, it can be inferred that micromolecules which neutralize the action of snake venoms mechanistically replace endogenous antitoxic serum proteins with venom neutralizing capacity such as produced by some animals.

Anti-inflammatory and immunologically active polysaccharides of Periandra mediterranea

Three polysaccharides, glucans with mean M(r)'s of 1.5 x 10(5), 3.6 x 10(4) and 2.1 x 10(4), were isolated from dried roots of Periandra mediterranea by fractionation on Sephacryl S-300 HR and Sephadex G-25. Chemical and spectroscopic studies indicated that they have a highly branched glucan type structure composed of alpha-(1-->4) linked D-glucopyranose residues with both (3-->4) and (4-->6) branching points. The polysaccharides enhance phagocytosis in vivo, and exhibit anti-inflammatory activity.

Ganoderma lucidum: partial characterization of spore and whole body antigenic extracts

This study focused on the characterization of antigenic/ allergenic profiles of Ganoderma lucidum spore and whole body preparations. Whole body G. lucidum contained higher protein to carbohydrate ratio whereas it was less than one for spore extract. Isoelectric focusing showed 12 and 11 bands in acidic pH range (pI 3.5-6.5) for G. lucidum spore and whole body, respectively, while SDS-PAGE showed 8 and 23 fractions, respectively, in molecular weight range of 12.8-75.0 kD. The prominent protein fractions of G. lucidum spores were 19.4, 22.8 and 23.8 kD, whereas for G. lucidum whole body, 13.2, 14.7, 18. 7, 21.5 and 23.5 constituted major fractions. Immunoblotting with 41 individual serum samples revealed 21.8, 23.8, 19.4 and 20.0 kD to be major allergenic protein fractions of G. lucidum spores. The same using G. lucidum whole body and 26 individual serum samples identified several fractions of 17.0, 17.5, 18.5, 22.0, 23.8, 42.0, 44.0, 56.0 and 69.0 kD as major allergens. The compiled data suggest that there are common as well as specific allergenic components in two G. lucidum extracts studied.

Changes in Trypanosoma cruzi phospholipid turnover induced by parasite contact with cell membranes

To investigate the possibility that cell contact could initiate a series of signals in both the host cell and the flagellate protozoan Trypanosoma cruzi, we studied [32P]-phospholipid turnover during parasite interaction with cellular membranes in vitro. Lipid alterations were produced in the parasite during the initial period of contact with the plasma membranes of human erythrocytes. In the presence of calcium an increment in phosphatidylethanolamine was observed with a concomitant decrease in phosphatidic acid fractions, whereas these modifications were not observed in the absence of calcium. There was an evident decrease in phosphatidylcholine and a shift in the phosphatidylinositol/lysophosphatidylethanolamine fraction among the phospholipids of major turnover in the absence or presence of calcium. Among the minor labeled species, lysophosphatidylcholine reached levels that duplicated control values, whereas the amounts of lysophosphatidylinositol, phosphatidylinositol 4-phosphate, and phosphatidylinositol 4,5-bisphosphate diminished by over 50%. All of these variations indicate that the parasite's contact with plasma membranes induces changes involving T. cruzi phospholipids and suggest the participation of these compounds in the activation of intracellular mechanisms that might be important during the life cycle of this parasite.

Ganglioside treatment of acute Trypanosoma cruzi infection in mice promotes long-term survival and parasitological cure

Ganglioside treatment of mice during their acute infection with Trypanosoma cruzi promoted long-term survival and clearance of parasites from the bloodstream and organs. Additionally, such treatment completely prevented the clinical manifestations of the infection, and progression into the chronic stages of the disease, for at least 18 months post-infection. Trypanosoma cruzi must invade nucleated cells to survive and reproduce within the mammalian host, and it has been suggested that ganglioside treatment inhibits the parasite's phospholipase A2 enzymes (PLA2), which are involved in membrane destabilization. However, since total brain gangliosides were not toxic to the parasite, either in xenic or axenic cultures, it seems unlikely that their action in vivo relates to their inhibition of PLA2. Other possible mechanisms of action are discussed.

Fomes pectinatis: an aeroallergen in India

This work is focused on the aerobiology and allergenicity of Fomes pectinatis in India. The atmospheric concentration of Fomes basidiospores was recorded and the antigens were prepared from spore (FSE) and whole body (FWBE) materials. The intradermal (ID) and prick (PT) skin tests were conducted on 172 patients having respiratory allergy. The period from July to October has been recorded as having a higher concentration of Fomes spores. The maximum counts (67 spores/m3) were observed from the North Delhi site in the month of July, 1989, compared with 550 spores/m3 in the South Delhi site. Marked skin positivity (2+ and above) varied from 9.8% to FSE to 22% to FWBE. Nine out of twelve ID positive patients (2+ to 3+) to FSE also gave PT positive response. For FWBE, similar ID and PT response was obtained in 80% of cases. The soluble protein content of FSE was 0.37 mg/ml, whereas, for FWBE it was 0.70 mg/ml. It was observed through ELISA that almost all patients had significantly raised FP specific IgE levels in their sera. The current study, therefore, indicates that Fomes pectinatis may be a prevalent aeroallergen in India.

Rat sperm surface mannosidase is first expressed on the plasma membrane of testicular germ cells

In previous publications (Tulsiani et al., Biochem J 1993; 290:427-436 and Tulsiani et al., Dev Biol 1995; 167:584-595), we reported that sperm surface mannosidase is present in rat testis and is modified during spermatogenesis and sperm maturation. The present studies were directed towards examining the origin of alpha-D-mannosidase activity present on fertile spermatozoa. Mixed germ cells prepared after sequential enzymatic digestions of rat testis were separated by unit gravity sedimentation using 2-4% linear bovine serum albumin gradient. Fractions enriched in spermatocytes, round spermatids, and condensed/elongated spermatids (> 95% pure cells) were separately pooled and assayed for [3H]Man9-mannosidase activity before (intact) and after lysis with Triton X-100. Interestingly, the cells contained a significant level of alpha-D-mannosidase activity. Approximately 70% of the total [3H]Man9-mannosidase activity present in the detergent-solubilized germ cell extract cross-reacted with anti-rat sperm mannosidase, and 25% of the activity cross-reacted with anti-Golgi mannosidase I. This result indicates that most of the mannosidase activity present in the germ cell extract is antigenically similar to the enzyme present on the cauda spermatozoa. Using cell fractionation techniques, we obtained evidence suggesting that the germ cell-associated mannosidase activity is an integral component of the plasma membranes. Taken together, these results indicate that sperm surface mannosidase is first expressed on the testicular germ cells.

The biological and functional significance of the sperm acrosome and acrosomal enzymes in mammalian fertilization

The mammalian spermatozoon undergoes continuous modifications during spermatogenesis, maturation in the epididymis, and capacitation in the female reproductive tract. Only the capacitated spermatozoa are capable of binding the zona-intact egg and undergoing the acrosome reaction. The fertilization process is a net result of multiple molecular events which enable ejaculated spermatozoa to recognize and bind to the egg's extracellular coat, the zona pellucida (ZP). Sperm-egg interaction is a species-specific event which is initiated by the recognition and binding of complementary molecule(s) present on sperm plasma membrane (receptor) and the surface of the ZP (ligand). This is a carbohydrate-mediated event which initiates a signal transduction cascade resulting in the exocytosis of acrosomal contents. This step is believed to be a prerequisite which enables the acrosome reacted spermatozoa to penetrate the ZP and fertilize the egg. This review focuses on the formation and contents of the sperm acrosome as well as the mechanisms underlying the induction of the acrosome reaction. Special emphasis has been laid on the synthesis, processing, substrate specificity, and mechanism of action of the acid glycohydrolases present within the acrosome. The hydrolytic action of glycohydrolases and proteases released at the site of sperm-zona binding, along with the enhanced thrust generated by the hyperactivated beat pattern of the bound spermatozoon, are important factors regulating the penetration of ZP. We have discussed the most recent studies which have attempted to explain signal transduction pathways leading to the acrosomal exocytosis.

Sensitization to Ganoderma lucidum in patients with respiratory allergy in India

Although human sensitization to basidiomycete Ganoderma has been reported in New Zealand, North America and Europe, hypersensitivity due to this fungi is not known in India, in spite of its prevalence in the atmosphere. We have studied the atmospheric concentration of Ganoderma in different localities within Delhi and the sensitization level to this fungi amongst the Indian population. Aerobiological sampling, using a Burkard personal slide sampler, was carried out in Delhi for 2 consecutive years (October 1989-September 1991). The sampler was operated at 10 day regular intervals for 10 min to trap the spores. The peak season for Ganoderma is recorded from July to September with highest average monthly catch of 336 spores/m3 in September 1991 from south Delhi. Antigenic extracts were prepared from both, the spores and whole body of Ganoderma lucidum. The results of intradermal skin tests conducted on 172 patients revealed that 28.48% and 17.44% of patients showed marked skin reactivity to spore and whole body extracts, respectively. A significant correlation (r = 0.963, P < 0.01) was found between intradermal and skin-prick tests. More than 80% of the intradermal test positive patients had significantly (P < 0.01) elevated IgE antibodies to the fungi in question. Thus, sensitization to Ganoderma lucidum has been reported for the first time in the atopic population of India.

Rejuvenation of epididymal principal cells by prolactin under androgen deficiency

Influence of prolactin on the ultrastructure of principal cells lining the epididymal epithelium was investigated in Wistar rats. Orchidectomy produced degenerative changes suggesting that structural integrity of principal cell is maintained by factors originating in the testis. The atrophic changes in the principal cell of ordhidectomised rats were significantly reversed when prolactin was administered to these animals. The number of cells that responded were found to increase with the dose of prolactin injected. On the otherhand, bromocryptine treatment did not appreciably change the ultrastructure of principal cells in orchidectomised rats. Results suggest that prolactin may have a rejuvenating epididymal principal cells in androgen deficient states.

Impact of prolactin on epididymal lipid profile in castrated rats

Prolactin treatment to castrated rats led to accumulation of triacylglycerol and esterified cholesterol. There was no appreciable drift in epididymal cholesterol: phospholipid ratio between the prolactin treated and control animals. However, further analysis of phospholipids showed a build up of phosphatidyl inositol, phosphatidyl choline and phosphatidyl ethanolamine but a drop in the levels of phosphatidyl serine and sphingomyelin in prolactin treated castrated rats as compared to those castrated animals injected with vehicle alone. Changes in phospholipids reported above were prominently seen in the group of castrated rats that received 100 micrograms oPRL/100 g body weight but not in those animals which received either lower or higher doses of the hormone. Interestingly, bromocryptine treatment in castrated rats produced a general depletion in the levels of all lipid classes studied in the epididymis. It is suggested that this may be due to impaired synthesis and/or increased breakdown of lipids in this organ.

Pharmacological screening of plants recommended by folk medicine as snake venom antidotes; IV. Protection against jararaca venom by isolated constituents

Fifteen compounds, isolated from plants reputed as snake venom antidotes, belonging to different classes of natural products, were shown to protect mice to a significant degree against the lethal action of the venom of Bothrops jararaca snakes. Administration was by the oral route, one hour prior to envenomation. The substances are nitrogen-free, low-molecular-weight compounds for which some kind of biodynamic activity has previously been reported. The fact that they are mostly trivial, naturally-occurring compounds should explain why plants used as snake-bite antidotes are so widely distributed over the plant kingdom.

Pharmacological Screening of Plants Recommended by Folk Medicine as Snake Venom Antidotes; IV. Protection against Jararaca Venom by Isolated Constituents1

Fifteen Compounds, isolated from plants reputed as snake venom antidotes, belonging to different classes of natural products, were shown to protect mice to a significant degree against the lethal action of the venom of BOTHROPS JARARACA snakes. Administration was by the oral route, one hour prior to envenomation. The substances are nitrogen-free, low-molecular-weight compounds for which some kind of biodynamic activity has previously been reported. The fact that they are mostly trivial, naturally-occurring compounds should explain why plants used as snake-bite antidotes are so widely distributed over the plant kingdom.

Survey of airborne culturable and non-culturable fungi at different sites in Delhi metropolis

A two year aerobiological survey for culturable and non-culturable fungi was conducted at human height at five different sites in Delhi metropolis. Burkard Personal Volumetric Sampler for petriplates and slide exposures were used for sampling the air. With simultaneous petriplate and slide exposure a total of 98 fungal forms were recorded. Cladosporium contributed for 25-40% of total airborne fungi followed by Ustilago (smuts) (24%) Aspergillus flavus (10-13%), Alternaria (11%) and A. niger (8%). Basidiomycetes contributed 7-13% at different sites. The frequency of occurrence of these types varied from 50-98%. In general fungal concentration was high from July to April with low counts in winter (January) and dry and hot summer (May-June). Quantitative variations in the spore counts were found to be statistically significant within the same urban locality.

Modulation in activity of some epididymal glycosidases by prolactin

Activity of glycosidases in the epididymis was influenced by several factors originating in the testis. Activities of all the three glycosidases studied viz., beta-glucosidase, beta-galactosidase and alpha-mannosidase were found to be significantly lower in the epididymis of orchidectomized animals than in sham operated rats. However, an enhanced activity of epididymal beta-galactosidase and alpha-mannosidase was noticed in prolactin treated orchidectomized rats compared to orchidectomized rats given vehicle alone. On the other hand, activity of these two enzymes in bromocriptine treated orchidectomized rats was even lower than that found in orchidectomized rats given vehicle. Neither prolactin nor bromocriptine treatment had any significant influence on the epididymal beta-glucosidase. The results suggest a selective but definite action of prolactin on epididymal glycosidases.

The effect of ovine prolactin on the epididymal sialic acid concentration in male rats

1. Previous experiments have shown that the level of sialic acid in the epididymis is influenced by factors originating in the testis. 2. To exclude interference from these factors, both orchidectomized and duct-ligated rats were used to study the potential role of prolactin in the epididymis. 3. When ovine prolactin was injected in orchidectomized rats, a dose-related increase in the level of sialic acid was observed in the epididymis. 4. That this action of prolactin is independent of androgen was confirmed by studies using bromocriptine, which decreases circulating endogenous prolactin. 5. The physiological role(s) of epididymal sialic acid production in response to prolactin remain to be established.

Effect of blood flow rate and donor vessel diameter on the patency of carotid venous bypass grafts in dogs

A saphenous vein graft was implanted from the right subclavian to the right common carotid artery in seven dogs (group I) and between the right and left common carotid arteries in another seven dogs (group II). The recipient artery was ligated proximally to augment blood flow through the graft. Immediately after the anastomoses were completed, the average blood flow through the graft was 32 +/- 25 mL/min in group I and 122 +/- 22 mL/min in group II. At sacrifice 30 days later, angiography showed that all grafts in group I were thrombosed, whereas six (87.5%) of seven grafts in group II were patent. These findings suggest that a larger donor vessel diameter and higher graft flow rates may improve patency in venous bypass grafts that are 3 to 5 mm in diameter.

Effect of treatment with fluosol and mannitol during temporary middle cerebral artery occlusion in cats

Four groups of seven cats each were subjected to 6 hours of temporary middle cerebral artery (MCA) occlusion followed by reperfusion. During the first 30 minutes of the occlusion, Group 1 received 20% Fluosol-DA (FDA) and Group 2 received 20% FDA and mannitol; Group 3 received 20% FDA and mannitol 30 minutes before the occlusion, and Group 4 (control) received an infusion of saline solution during the first 30 minutes of occlusion. All cats breathed 100% oxygen throughout the occlusion and during 2 hours of reperfusion. Blood pressure, PaO2, and pH remained stable for 8 hours. PaO2 increased from an average base line level of 102 +/- 15 (SD) torr to 520 +/- 45 torr in Group 1, 450 +/- 41 torr in Group 2, 480 +/- 28 torr in Group 3, and 396 +/- 151 torr in Group 4 during the administration of 100% oxygen. The average fluorocrit during occlusion was 6% in Groups 1, 2, and 3. The 24-hour mortality rate was 71% in Group 1, 43% in Group 2, 29% in Group 3, and 14% in Group 4; a midline shift and herniation were present after each fatal infarct. The survivors were sacrificed 10 days after the occlusion. There was a trend toward improvement of neurological function at sacrifice in Groups 2 and 3 compared with Groups 1 and 4. The infarct areas on coronal sections were 2.4 times larger in Group 1 (FDA only) than in Group 4 (control) (P less than 0.05). There was no significant difference in infarct size between Group 4 and Group 2 or 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Measurement of lactate accumulation by in vivo proton NMR spectroscopy during global cerebral ischemia in rats

In vivo 1H NMR spectral editing techniques were used to monitor cerebral lactate production during remotely controlled temporary forebrain ischemia in rats. The lactate/N-acetylaspartate (NAA) ratio correlated with survival after ischemia and subsequent reperfusion. The lactate/NAA ratio that predicted death after ischemia in rats was estimated to be approximately 1.3.

Comparison of lactate concentration determinations in ischemic and hypoxic rat brains by in vivo and in vitro 1H NMR spectroscopy

An experimental protocol for the quantitation of lactate is demonstrated for in vivo 1H NMR surface coil spectroscopy. The in vivo lactate concentration can be calculated by comparing the in vivo and in vitro ratios of lactate and N-acetylaspartate (NAA) NMR signals. With this protocol, approximately 25% of lactate present in the hypoxic or ischemic rat brain is observed by NMR.

Thyroid epididymal relationship. II. Influence of hyperthyroidism on epididymal lipids

The influence of experimentally induced hyperthyroidism on the lipid composition of the caput and cauda epididymides has been studied in pubertal and adult rats. Thyroxine treatment did not alter the major lipid classes in the epididymis. However, regional and age-related fluctuations in the concentration of mono-, di- and triacylglycerols have been observed. While the diacylglycerols increase, mono- and triacylglycerols were found to decrease, suggesting an inverse relationship between these fractions. Among the phospholipid fractions, phosphatidylcholine and phosphatidylethanolamine were reduced. The changes in epididymal lipid profiles give an indication that the epididymis may be yet another site responsible for fertility disturbances in hyperthyroid males. The withdrawal of thyroxine from hyperthyroid animals returned the epididymal lipid profiles to normal levels. This indicates that the effects of thyroxine in the epididymis are temporary and reversible following thyroxine withdrawal.

Thyroid-epididymal relationship. I. Influence of hypothyroidism on epididymal lipids

The influence of thyroidectomy on the lipid composition of caput and cauda epididymides have been studied. The analysis was conducted in epididymal tissues free from fluids and sperm. A general tendency towards accumulation of epididymal lipids was observed in hypothyroid rats. Hypothyroidism also brought about a differential regional response, which may be age-related. The existence of a relationship between triacylglycerols, phospholipids and diacylglycerols has been suggested. Since immediate thyroxine replacement to thyroidectomised rats maintained epididymal lipids at control levels, it is concluded that hypothyroidism has a definite influence on the epididymal lipid composition.

Influence of hypothyroidism on epididymal enzymes involved in carbohydrate metabolism. Studies in pubertal and adult rats

The influence of thyroidectomy on key epididymal enzymes of the Embden-Meyerhof and pentose phosphate pathway have been studied in pubertal and adult animals in relation to the serum hormone profile. Age related differences in the response of epididymal segments were observed with respect to hexokinase activity, although the other 2 key enzymes of the Embden-Meyerhof pathway (6-PFK and PK) were suppressed in all regions of the epididymis in both pubertal and adult rats. The enzymes involved in the pentose phosphate pathway (G-6-PDH and 6-PGDH) remained unaltered. The serum hormone profile revealed that while FSH and testosterone titres were reduced, LH and Prl were unaltered. Replacement of T4 in thyroidectomized animals maintained serum hormone levels and the activities of the enzymes studied at control levels. It is inferred that thyroid hormones may be one part of a complex mechanism that controls carbohydrate metabolism in the epididymis.

Effect of thyroxine treatment on epididymal carbohydrate metabolism in the pubertal rat

The influence of thyroxine treatment on key enzymes involved in the glycolytic and HMP shunt pathways was studied in the caput, corpus and cauda epididymides of pubertal rats, and related to the serum hormone profile. The activity of 6-phosphofructokinase and pyruvate kinase was significantly increased in all 3 segments of the epididymis, but the HMP shunt pathway was suppressed. Thyroxine treatment was found to depress the serum levels of testosterone, LH and FSH, although an increase in prolactin levels was observed. Withdrawal of hormone treatment resulted in the restoration of normal activity of 6-phosphofructokinase and pyruvate kinase and restoration of normal serum hormone levels. However, the activity of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase increased following withdrawal of treatment. It is concluded that hyperthyroidism exerts an influence on epididymal enzymes involved in carbohydrate metabolism.

Effect of adrenalectomy and corticosterone replacement on epididymal carbohydrate metabolism--studies on mature male rats

The effect of adrenalectomy and corticosterone replacement on epididymal enzymes involved in obligatory steps of glycolysis and pentose phosphate pathway were studied along with serum hormonal profiles. Adrenalectomy was found to elevate serum prolactin while the gonadotropins and testosterone were unaltered. In caput epididymal tissue enzymes of the pentose phosphate pathway. Glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities were increased after adrenalectomy. However, in corpus epididymal tissue the key enzymes viz. hexokinase, 6-phosphofructokinase and pyruvatekinase of the glycolytic pathway were elevated leaving the pentose phosphate pathway unaffected. Adrenalectomy was also found to favour glycolysis of the epididymal spermatozoa. The possible direct effect of prolactin is discussed to explain the enzymatic changes in epididymis. Corticosterone replacement was found to maintain the enzyme activities along with serum prolactin and corticosterone at control levels. In conclusion, it is suggested that the adrenalectomy induced changes in enzyme activities could be due to the direct effect of prolactin.

Epididymal carbohydrate metabolism in experimental hypercorticosteronism: studies on mature male rats

Corticosterone induced changes in serum hormonal profiles and the key enzymes involved in glycolytic and pentose phosphate pathways were studied in caput, corpus and cauda epididymides of mature male rate (200-250 g body weight). Corticosterone (3.5 mg/100 g body weight sc. for 20 days) treatment was found to depress serum testosterone and prolactin while the gonadotrophins were unaltered. Enzymes of both the glycolytic and pentose phosphate pathways were significantly decreased in caput epididymidis. But in corpus and cauda epididymides only the glycolytic enzymes were reduced. Withdrawal of treatment (for 20 days), resulted in restoration of the glycolytic enzymes to normalcy. Tge serum hormonal profiles were also found to be within the normal range. The pentose phosphate pathway in caput epididymidis showed a significant increase in enzyme activities following withdrawal of treatment. From the present investigation it is clear that hypercorticosteronism had a definite influence on epididymal enzymes involved in carbohydrate metabolism.

Effect of hormonal steroids on lactate dehydrogenase activity and its isozymes in the coagulating gland of castrated male rats

The effect of castration and treatment with testosterone propionate, androstenedione and oestradiol-17 beta on the coagulating gland LDH activity and its isozymes were studied. Castration reduced the total LDH activity and administration of testosterone propionate alone was able to restore it back to sham operated control levels. Regarding LDH isozymes, the LDH3 and LDH4 responded very similarly to testosterone and oestradiol. LDH5 was significantly increased only in the androgen treated groups. The post-castration decrease in total M-subunits was restored to sham operated control levels in the testosterone propionate treated group. This was mainly contributed by the LDH3, LDH4 and LDH5 isozymes. The changes observed due to testosterone propionate and androstenedione treatments have been attributed to the rejuvenation of tissue from the castration induced losses. The oestradiol induced events have been associated with the growth of fibro muscular layers observed under similar experimental conditions.