Heat- and lignosulfonate-treated canola meal as a source of ruminal undegradable protein for lactating dairy cows.

This experiment used 18 lactating Holstein cows in a 3 x 3 Latin square replicated 6 times to determine the effectiveness of processing with moist heat or moist heat combined with lignosulfonate (LSO3) for increasing the ruminal undegradable fraction of canola meal for use as a protein supplement for lactating dairy cows. Diets were formulated to be isonitrogenous and contained one of 3 forms of canola meal; untreated canola meal (UCM), heat-treated canola meal (HTCM) or heat-and LSO3-treated canola meal (LSO3CM). Total collection of urine and feces was taken from each cow during the last 5 d of each 42-d experimental period. Milk production was greater for cows fed the LSO3CM diet (36.6 kg/d) than for cows fed the UCM diet (34.8 kg/d) but did not differ from cows fed the HTCM diet (35.3 kg/d). Digestibility of crude protein was lower for cows supplemented with LSO3CM and they had reduced concentrations of ruminal ammonia N, blood urea N, and milk urea N compared with cows supplemented with UCM or HTCM. Dry matter intake and apparent digestibilities of neutral and acid detergent fiber were increased in cows fed the LSO3CM diet. Urinary N excretion (as % of N intake) was reduced in cows fed the LSO3CM diet. These results indicate that moist heat combined with LSO3 treatment of canola meal was effective in increasing the proportion of crude protein digested in the lower digestive tract of lactating cows and was therefore used more effectively as a source of protein than UCM or HTCM.

Sulfatide and Na+-K+-ATPase: a salinity-sensitive relationship in the gill basolateral membrane of rainbow trout.

We investigated the effect of salinity on the relationship between Na(+)-K(+)-ATPase and sulfogalactosyl ceramide (SGC) in the basolateral membrane of rainbow trout (Oncorhynchus mykiss) gill epithelium. SGC has been implicated as a cofactor in Na(+)-K(+)-ATPase activity, especially in Na(+)-K(+)-ATPase rich tissues. However, whole-tissue studies have questioned this role in the fish gill. We re-examined SGC cofactor function from a gill basolateral membrane perspective. Nine SGC fatty acid species were quantified by tandem mass spectrometry (MS/MS) and related to Na(+)-K(+)-ATPase activity in trout acclimated to freshwater or brackish water (20 ppt). While Na(+)-K(+)-ATPase activity increased, the total concentration and relative proportion of SGC isoforms remained constant between salinities. However, we noted a negative correlation between SGC concentration and Na(+)-K(+)-ATPase activity in fish exposed to brackish water, whereas no correlation existed in fish acclimated to freshwater. Differential Na(+)-K(+)-ATPase/SGC sensitivity is discussed in relation to enzyme isoform switching, the SGC cofactor site model and saltwater adaptation.

Green tea catechins partially protect DNA from (.)OH radical-induced strand breaks and base damage through fast chemical repair of DNA radicals.

The catechins, (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG) are believed to be active constituents of green tea accounting for the reported chemoprevention of certain cancers. The molecular mechanisms by which the measured low concentrations (ca. micromolar) of catechins in humans can reduce the incidence of carcinogenesis is not clear. Using an in vitro plasmid DNA system and radiolytically generating reactive oxygen species (ROS) under constant scavenging conditions, we have shown that all four catechins, when present at low concentrations, ameliorate free radical damage sustained by DNA. A reduction in both prompt DNA single-strand breaks and residual damage to the DNA bases, detected by subsequent incubation with the DNA glycosylases formamidopyrimidine (FPG), endonuclease III (EndoIII) and 5' AP endonuclease exonuclease III (ExoIII), was observed. EGCG was found to be the most active of the catechins, with effects seen at micromolar concentrations. Combined fast-reaction chemistry studies support a mechanism of electron transfer (or H-atom transfer) from catechins to ROS-induced radical sites on the DNA. These results support an antioxidant role for catechins in their direct interaction with DNA radicals.

The vascular activity of some isoflavone metabolites: implications for a cardioprotective role.

Legume-derived isoflavones such as genistein, diadzein and equol have been associated with a reduction in risk of cardiovascular disease. In the current study, we explore the vascular activity of several isoflavone metabolites namely dihydrodaidzein, cis and trans-tetrahydrodaidzein and dehydroequol for potential cardioprotective properties. Rat isolated aortic rings were used. 17beta-oestradiol, equol, and all four of the metabolites studied significantly antagonized contractile responses to noradrenaline. The direct vasodilatory action of these compounds were examined and in contrast to 17beta-oestradiol, the vasodilatory effect of which was demonstrated to be endothelium independent, the dilatory action of all four compounds could be inhibited by endothelium denudation. Further, the dilatory action of both dihydrodaidzein and cis-tetrahydrodaidzein were inhibited by the nitric oxide synthase inhibitor, N(omega)-nitro-L-arginine (NOLA), by the soluble guanylate cyclase inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and by 40 mM KCl. Dilatory responses to dehydroequol and trans-tetrahydrodaidzein, on the other hand, were inhibited by 40 mM KCL but not by NOLA nor ODQ. Finally, we examined the protective potential of these compounds in inhibiting endothelium damage by oxidized low density lipoprotein (ox-LDL). Trans-tetrahydrodaidzein was at least 10 fold more potent than 17beta-oestradiol in protecting against ox-LDL induced damage. We conclude that the isoflavone metabolites, dihydrodaidzein, cis- and trans-tetrahydrodaidzein and dehydroequol, may potentially represent a novel series of cardioprotective therapeutics.

Mental health literacy: an impediment to the optimum treatment of major depression in the community.

BACKGROUND: Mental health literacy refers to the knowledge and beliefs about mental disorders which aid their recognition, management and prevention. This study examined the mental health literacy and experience of depression in a random and representative community population. METHODS: The experience of depression and mental health literacy of 3010 subjects from a random and representative population were determined on the basis of responses to the mood module of the PRIME-MD and questions about a vignette of a person with features of major depression. RESULTS: Those with major depression had significantly more personal experience of depression than those with other depressions and those who were not depressed, but there were few significant differences between the groups in terms of mental health literacy. Of those with major depression, 40% considered anti-depressants helpful, but 40% also considered they were harmful. CONCLUSIONS: There is a considerable impediment to the recognition and management of major depression and a need for further community education programs.

Suicidal ideation and health-related quality of life in the community.

OBJECTIVE: To examine the health-related quality of life of people with suicidal ideation in the general community. DESIGN: A Health Omnibus Survey of a random, representative sample of the South Australian population in 1998, conducted by experienced interviewers. SUBJECTS: 3010 people over the age of 15 years. OUTCOME MEASURES: The survey included questions about utilisation of health services and the Short-form Health-related Quality of Life (SF-36) and Assessment of Quality of Life (AQoL) instruments. Suicidal ideation was determined in response to a direct question. RESULTS: 79 (2.6%) subjects reported suicidal ideation in the past two weeks. Compared with those without suicidal ideation, subjects with suicidal ideation reported significantly greater use of general practitioners, psychiatrists, psychologists, social workers and outpatient clinics (P<0.001), community health services and other counsellors (P<0.01), and more hospital admissions (P<0.05). Those subjects also scored significantly poorer on all subscales of both instruments (P<0.001), to the extent that they were below the 4th percentile on the role-emotional and mental health dimensions of the SF-36 and the social relationships, psychological wellbeing and overall scores of the AQoL. CONCLUSIONS: Suicidal ideation is associated with poor health-related quality of life. These results in a random and representative community sample add support to the need to improve targeting of those with suicidal ideation on a population basis with a view to earlier intervention.

Major depression and its associated morbidity and quality of life in a random, representative Australian community sample.

OBJECTIVE: The objective of this study is to describe health services utilisation and morbidity, including health-related quality of life, in those with major depression in a random and representative sample of the population. METHOD: Data were gathered in a Health Omnibus Survey of the South Australian population. Major depression was delineated on the basis of responses to the Primary Care Evaluation of Mental Disorders. Information about use of health services and absence from usual functioning was collated, and two measures of health-related quality of life, the Short-form Health Status Questionnaire and the Assessment of Quality of Life were also administered. Results of those with major depression were compared with those who had other depressive syndromes and those who had no depression. RESULTS: Those with major depression reported significantly greater use of all health services and poorer functioning in terms of carrying out their normal duties. Similarly, their health-related quality of life was significantly poorer than those with other depressive syndromes, which in turn was significantly poorer than those who were not depressed. Only one-fifth of those with major depression were currently taking antidepressants. CONCLUSIONS: These results are consistent with international studies. In addition to the potential for alleviating the depressive symptomatology of individuals, it is evident that even a modest improvement in functioning with appropriate treatment would have the potential to benefit the Australian community by one billion dollars a year.

Reduction in free-radical-induced DNA strand breaks and base damage through fast chemical repair by flavonoids.

This paper provides evidence that dietary flavonoids can repair a range of oxidative radical damages on DNA, and thus give protection against radical-induced strand breaks and base alterations. We have irradiated dilute aqueous solutions of plasmid DNA in the absence and presence of flavonoids (F) in a "constant *OH radical scavenging environment", k of 1.5 x 10(7) s(-1) by decreasing the concentration of TRIS buffer in relation to the concentration of added flavonoids. We have shown that the flavonoids can reduce the incidence of single-strand breaks in double-stranded DNA as well as residual base damage (assayed as additional single-strand breaks upon post-irradiation incubation with endonucleases) with dose modification factors of up to 2.0+/-0.2 at [F] < 100 microM by a mechanism other than through direct scavenging of *OH radicals. Pulse radiolysis measurements support the mechanism of electron transfer or H* atom transfer from the flavonoids to free radical sites on DNA which result in the fast chemical repair of some of the oxidative damage on DNA resulting from *OH radical attack. These in vitro assays point to a possible additional role for antioxidants in reducing DNA damage.

Suicidal ideation in a random community sample: attributable risk due to depression and psychosocial and traumatic events.

OBJECTIVE: To determine the attributable risk for suicidal ideation of depression and psychosocial and traumatic events in a random and representative population. METHOD: Data were gathered from a random and representative sample of 2501 South Australians. Suicidal ideation and clinical depression were determined by the general health questionnaire (GHQ-28) and the short-form health survey (SF-12) respectively, and information regarding psychosocial stressors and traumatic events was collated. These data were subjected to univariate and multivariate analyses to determine the population-attributable risks for suicidal ideation. RESULTS: Overall, 5.6% of men and 5.3% of women had suicidal ideation. Univariate analyses demonstrated a significant attributable risk for suicidal ideation for depression and the majority of the psychosocial and traumatic events. Multivariate analysis demonstrated that clinical depression remained significantly associated with suicidal ideation, with a population-attributable risk of 46.9%. Because of the small number of people in the population who experience both suicidal ideation and specific events, multivariate analysis could not be applied to individual events. However, even when the psychosocial events were summed, they no longer remained significantly associated with suicidal ideation, whereas the summation of traumatic events remained significant, with a population-attributable risk of 38.0%. CONCLUSIONS: These results confirm the importance of traumatic events as significant factors in contributing to suicidal ideation. However, of even greater importance is that they indicate, unequivocally, the magnitude of the contribution of clinical depression to suicidal ideation, with the population-attributable risk of depression indicating that elimination of mood disorders would reduce suicidal ideation by up to 46.9%.

Cholinergic strategies for Alzheimer's disease.

Alzheimer's disease is a devastating degenerative disorder of the central nervous system that results in gradual deterioration of cognitive function and severe alteration of personality. Degeneration of neurons in the nucleus basalis Meynert, the origin of the major cholinergic projections to the neocortex, occurs early in the course of the disease, and is correlated with the cognitive decline. This link between cholinergic dysfunction in the basal-cortical system and cognitive deficits has focused scientific efforts on developing tools to elucidate the neurobiological role of the cholinergic system in cognition and to develop therapeutic interventions in the disorder. An important step in understanding the mechanisms underlying cognitive dysfunction has been the development of in vivo rodent models that mimic some of the features of Alzheimer's disease. Acute excitotoxic or immunotoxic lesions of the nucleus basalis in rodents have revealed a role of the basal-cortical system in attention, learning and memory. More recent advances in developing mouse gene technology offer newer models to systematically examine the underlying neuropathological cascade leading to dysfunctions in mnemonic processing. Using in vivo rodent models, several cholinergic enhancement strategies have been tested and proven to be effective in alleviating lesion-induced cognitive deficits, including neuropharmacological approaches (acetylcholinesterase inhibitors), neurotrophic factor administration (nerve growth factor), and transplantation of cholinergic-enriched fetal grafts. Successful results have also been obtained using ex vivo gene transfer to deliver nerve growth factor or acetylcholine to compromised regions of the basal-cortical system. Gene therapy may be of particular interest for clinical applications, because this approach provides a method for topographically restricted and selective delivery of therapeutic genes and their products to afflicted areas of the brain. Advanced techniques in molecular biology (e.g., exogenous regulatable gene transfer) and newly developed tools of modern neuroscience (e.g., neural precursor cells) will be important contributions for deciphering the biological bases of neuronal degeneration and for refining therapeutic strategies for Alzheimer's disease.

Hippocampal grafts of acetylcholine-producing cells are sufficient to improve behavioural performance following a unilateral fimbria-fornix lesion.

Lesions of the septohippocampal pathway produce cognitive deficits that are partially attenuated by grafts of cholinergic-rich tissue into denervated target regions or by systemic administration of cholinomimetic drugs. In the present study, fibroblasts engineered to produce acetylcholine were used to test the hypothesis that restoration of hippocampal acetylcholine in rats with septohippocampal lesions is sufficient to improve cognitive processing post-damage. Rats received unilateral grafts of acetylcholine-producing or control fibroblasts into the hippocampus immediately prior to an aspirative lesion of the ipsilateral fimbria-fornix. Some rats with fimbria-fornix lesions were implanted with acetylcholine-producing or control fibroblasts into the neocortex, another major target of the basal forebrain cholinergic system, to determine if the site of acetylcholine delivery to the damaged brain is critical for functional recovery. Rats were tested in a hidden platform water maze task, a cued water maze task and activity chambers between one and three weeks post-grafting. Compared to unoperated controls, rats with fimbria fornix lesions only were significantly impaired in hidden platform water maze performance. Hippocampal grafts of acetylcholine-producing cells reduced lesion-induced deficits in the water maze, whereas hippocampal control grafts and cortical grafts of either cell type were without effect. Locomotor activity and cued water maze performance were unaffected by the lesion or the implants. Taken together, these data indicate that water maze deficits produced by fimbria fornix lesions, which disrupt a number of hippocampal neurotransmitter systems, can be attenuated by target specific replacement of acetylcholine in the hippocampus and that this recovery occurs in the absence of circuitry repair.

The Health of the Nation Outcome Scales in psychiatric hospitalisation: a multicentre study examining outcome and prediction of length of stay.

OBJECTIVE: The Health of the Nation Outcome Scales (HoNOS) is a reliable instrument, useful in detecting change in symptoms and functioning during psychiatric hospitalisation. The present study examines its utility in predicting length of stay of patients in six private psychiatric hospitals in four Australian States. METHOD: The HoNOS was administered on admission and discharge in six private psychiatric hospitals in Australia. RESULTS: There were significant differences in total score and in all sub-scales between admission and discharge. There were no significant associations between total HoNOS scores and length of stay, either for individual hospitals or for specific diagnosis-related groups. There were only very weak associations, of doubtful practical clinical significance, between length of stay of all patients and individual HoNOS sub-scales. CONCLUSION: While the HoNOS is of some value in providing a readily administered and understood measure for clinicians, on the basis of these findings it is unlikely to be of utility in predicting length of stay or in offering a 'gate-keeping' service in decision-making in regard to the allocation of resources for individual patients.

In situ disappearance of amino acids from grass silages in the rumen and intestine of cattle.

Nineteen grass silages were evaluated using the in situ rumen and mobile nylon bag techniques to determine the amino acid (AA) composition of rumen-undegradable protein and the possibility of predicting the concentrations of individual AA presented to the duodenum from the dietary AA profiles. All feeds and residues from the nylon bags were analyzed for diaminopimelic acid to correct for contamination by microbial proteins. All essential AA behaved similarly; the initial feed had the highest concentrations, and the material remaining in the mobile nylon bag had the lowest concentrations. The reduction in the concentration of methionine between the 12-h rumen residue and the residue in the mobile nylon bag was significant. With the exception of arginine (r2 = 0.76) and serine (r2 = 0.82), the relationship was poor between the concentrations of AA in the grass silage and those in the residue in the nylon bag following 12 h of rumen incubation. The lack of reliable relationships between concentrations of individual AA in the silages and concentrations of AA in the 12-h rumen residue indicated that degradability characteristics of AA in grass silage were not alike. This poor relationship was likely the reason that prediction equations could not be developed between the AA composition of the initial feed and the pattern of AA presented to the duodenum following 12 h of rumen incubation. The AA composition of the rumen-undegradable portion of grass silages differs from the AA composition of grass silages.

Use of the Cornell net carbohydrate and protein system and rumen-protected lysine and methionine to reduce nitrogen excretion from lactating dairy cows.

A study was carried out to determine whether the addition of rumen-protected Lys and Met to ration formulations allowed a reduction in dietary crude protein (CP) without jeopardizing total milk or milk protein yields. Eighteen multiparous Holstein cows were randomly assigned to treatment sequences in a replicated 3 x 3 Latin square design. Total mixed rations were balanced according to degradation and rates of passage of protein and carbohydrates using the Cornell Net Carbohydrate and Protein System. Rations differed in percentages of CP (18.3, 16.7, and 15.3% for rations 1, 2, and 3, respectively), but energy was held constant. Rations 2 and 3 were supplemented with rumen-protected Lys and Met. Milk, blood, and rumen fluid samples were taken during the 2nd and 3rd wk of each 28-d experimental period. Total collection of urine and feces occurred during the last 5 d of each experimental period. Cows fed ration 1 had a higher milk yield (34.2 vs. 32.8 kg/d) and DMI than did cows fed rations 2 or 3, but milk protein output was not different among groups. Nitrogen efficiency, milk N as a percentage of intake N, improved as percentages of CP in the rations were reduced. Blood urea N values were 15.9, 12.9, and 10.0 mg/dl for cows fed rations 1, 2, and 3, respectively. Apparent digestibilities of CP and urinary N excretion decreased as the percentages of CP in the rations decreased. Results indicated that it is possible to make more efficient use of CP by using rumen-protected amino acids. This procedure may result in less than maximum milk yield, but milk protein output can be maintained.

Cytotoxic aldehydes as possible markers for childhood cancer.

Concentrations of 22 known aldehydes (byproducts of lipid peroxidation), 5 acyloins, free and total carnitine and acylcarnitines were measured in plasma and urine obtained from pediatric patients with various forms of cancer before any treatment, and following treatment with doxorubicin or daunorubicin. Aldehydes, before the initiation of chemotherapy, were significantly elevated in cancer patients compared to controls. Aldehydes such as hexanal, heptanal, and malondialdehyde were strikingly higher in samples from cancer patients, while trans 4-cis-4-decenal was the prominent aldehyde in the blood of controls. In addition, in each form of cancer the pattern of aldehydes appeared to be unique when compared to controls, or to others forms of cancer. In cancer patients receiving chemotherapy there was a general trend toward a reduction 24 h after both the first and after the fifth doxorubicin dose. These changes however were not significant statistically due to large inter-patient variation. Free and total plasma carnitine levels remained in the normal range, and there were no abnormal acylcarnitines detected in urine. Possible hypotheses to explain the elevations in aldehydes, and the reasons for the changed aldehyde profiles in different forms of cancer are discussed.

Neural precursor cells: applications for the study and repair of the central nervous system.

A combination of gene transfer and intracerebral transplantation techniques has been used in studies of CNS development to provide the most compelling evidence to date that the broad diversity of cell types that exist in the CNS arises from single precursor cells. Although the factors that influence cellular differentiation in vivo remain to be clarified, work conducted in vitro with neural precursors has demonstrated that environmental signals (both soluble factors and substrate molecules) play a pivotal role in these decisions. In particular, FGF-2 appears to be one of the prominent influential factors involved in CNS development (see Temple & Qian, 1995). The generation of immortalized precursor populations that are capable of differentiating into multiple CNS cell types in vivo has significant implications for the treatment of neural dysfunction. Such cells may be manipulated toward a lineage that synthesizes factors of interest and used in grafting strategies to replace substances that are lost after injury or in neurodegenerative disease. Alternatively, precursor cells may be directed to a neuronal lineage and used to functionally repair damaged neural systems. Finally, genetic modification of precursor populations provides a method for introducing therapeutic gene products both into discrete regions of the brain and into widely dispersed areas of the CNS. In considering applications to human disease, it has been reported that nestin is expressed in human neuroepithelial cells (Tohyama et al., 1992), suggesting the existence of neural precursors. Recently, such precursors were in fact isolated by two separate groups (Kirschenbaum et al., 1994; Sabaté et al., 1995) and shown to be amenable to gene transfer and to successfully survive transplantation into the brain of experimental animals (Sabaté et al., 1995). Such findings encourage the possibility that precursor cells from the human CNS may be utilized in cell replacement or gene therapy strategies directed toward human neurodegenerative disorders. While immortalization techniques have been essential for generating large quantities of precursor cells for study and transplantation, the genetic modification of cells may alter vital cellular properties. Thus, the ability to induce the proliferation of nonimmortalized neural populations in vitro with the use of growth factors (see section on CNS precursor cells above) provides an important alternative approach for developing perpetual neural cell lines. Recent work with such growth factor-responsive precursor cells has suggested their therapeutic potential in the CNS, as evidenced by the finding that FGF-2-responsive cells can successfully engraft and express transgenes in the adult brain (Gage et al., 1995; Sabaté et al., 1995; Suhonen et al., 1996). Continuing studies with these cells will provide additional insight into the properties of primary CNS stem cells and increase the range of precursor populations that are useful for exploring the development, function, and plasticity of the CNS.

Gene therapy in neurology.

Many methods of gene transfer to the brain are under study for the treatment of the central nervous system manifestations of a number of diseases. One strategy employs vectors--typically genetically altered viruses--for the delivery of exogenous genes directly to a host's brain cells in situ. Alternatively, transplanting cells--of either neural or nonneural origin--that intrinsically secrete missing or therapeutic gene produces, or which are genetically engineered ex vivo to do so, may provide another strategy. Nonmigratory cells implanted into small, discrete anatomic sites are well suited for disease processes whose pathology is very focal. Neural cells that have the capacity to migrate in the central nervous system provide more powerful vehicles for delivering factors to disease involving pathology that is widely disseminated, extensive, multifocal, or even global (e.g., many neurogenetic diseases). Both neural and nonneural cell types have been successfully engineered to produce a variety of neurotransmitter synthetic enzymes, metabolic enzymes, and neurotrophic factors. Impressive results with genetically modified cells in animal models of central nervous system disease encourage the continued development of gene therapy strategies for treating neural dysfunction.

Long-term survival of transplanted basal forebrain cells following in vitro propagation with fibroblast growth factor-2.

The intracerebral transplantation of freshly dissected fetal tissue containing cholinergic neurons of the developing basal forebrain has been reported to reverse lesion-induced or age-related cognitive deficits in animal models of cholinergic neuronal degeneration. Grafts of cultured fetal neurons, however, have generally shown poor cellular survival and limited therapeutic benefit. We tested the hypothesis that recent advances in the identification of growth factors that promote the survival and propagation of fetal precursor cells in vitro would improve the long-term survival of cultured neurons following intracerebral implantation. Dissociated cells from gestational Day 14 rodent basal forebrain were grown in chemically defined media supplemented with 20 ng/ml basic fibroblast growth factor. Two weeks postplating, numerous cells were present in the cultures and showed immunoreactive labeling for a variety of markers, including glutamic acid decarboxylase, neuron-specific enolase, neurofilament proteins, glial fibrillary acidic protein and, occasionally, choline acetyltransferase. To determine if cultured basal forebrain cells would survive intracerebral implantation, the cells were implanted homotypically into the nucleus basalis magnocellularis. To enhance the potential for graft survival in vivo, cells were also implanted into the nucleus basalis magnocellularis following an ibotenic acid lesion and into the denervated frontal cortex. Animals sacrificed between 2 weeks and 7 months following transplantation showed good and comparable graft survival in all sites. Immunocytochemical analysis revealed that representative populations of cells observed in vitro survived for prolonged periods in vivo, even in sites distal from their normal cellular targets. Thus, neuronal populations expanded in vitro can successfully survive and maintain cellular phenotypes post-transplantation. These results suggest a potential for isolating and growing specific neuronal populations in vitro for intracerebral transplantation.