The benefits of supplementary fat in feed rations for ruminants with particular focus on reducing levels of methane production

Methane (CH₄), a highly potent greenhouse gas, has repeatedly been identified as a significant contributor to global warming. In this connection, ruminants, animals that produce large quantities of methane, have been singled out as an area for reduction with regard to their emissions to the atmosphere. In an analysis of recently published data, we identify the underlying mechanisms of methane production in ruminants and focus on the efficacy of different fat sources in terms of their ability to reduce methane production. Specific attention has been placed on in vivo studies involving cattle and sheep, as well as studies based on a large number of animals (>10), recorded over a longer period (>21 days), and employing reliable techniques for the quantification of methane production. Data clearly indicate that supplementary fat, given to ruminants inhibits methane production, with medium-chain fatty acids (laurin, myristic acid) as well as poly-unsaturated fatty acids (linoleic and especially linolenic acid) having a significant effect. It is also apparent that conflicting findings between individual published trials can largely be resolved when one takes into consideration differences in experimental design, the composition of the basic feeds, the fat sources used, and the number of animals involved.

Nature and quality of antipsychotic prescribing practice in UK psychiatry of intellectual disability services

BACKGROUND

Antipsychotics are perceived to be over-used in the management of behavioural problems in people with an intellectual disability (ID). Published guidelines have set good practice standards for the use of these drugs for behavioural indications. We sought to identify the range of indications for which antipsychotic drugs are prescribed in people with ID and to audit clinical practice against the standards.

METHOD

Data were collected from the clinical records of individuals with ID who were under the care of mental health services in the UK, and prescribed an antipsychotic drug.

RESULTS

The sample comprised 2319 patients from 39 clinical services. Twenty-seven per cent of the patients had a diagnosis of a psychotic illness (ICD-10 F20-29) and 27% an affective illness (ICD-10 F30-39). The proportion who did not have a psychiatric diagnosis ranged from 6% of those with borderline/mild ID to 21% of those with severe/profound ID. Overall, the most common indications for prescribing an antipsychotic drug were comorbid psychotic illness, anxiety and agitation, and a range of behavioural disturbances. The prevalence of use of antipsychotic drugs to manage challenging behaviour in the absence of concomitant mental illness increased with the severity of ID and accounted for almost half of prescriptions in those with severe/profound ID. Adherence to the audit standards related to documentation of clinical indications and review of efficacy was high. Side effect monitoring was less assiduous.

CONCLUSIONS

In clinical practice, most prescriptions for antipsychotic drugs in people with ID are consistent with the evidence base and the overall quality of prescribing practice, as measured against recognised standards, is good, although in some patients potentially remedial side effects may not be detected and treated.

FMRI activation in language areas correlates with verb generation performance in children

Functional MRI mapping of language areas in children frequently employs a covert verb generation task. Because responses are not monitored, the relationship between fMRI activation and task performance is unknown. We compared fMRI activation during covert and overt verb generation to performance during the overt task. 15 children, ages 11-13 years, listened to concrete nouns and responded with related verbs covertly and overtly. A clustered fMRI acquisition allowed for recording of overt responses without motion artifacts. Region of interest analysis was also performed in areas that exhibited correlation between activation and performance during overt verb generation in left inferior frontal and left superior temporal gyri (along with their right hemisphere homologues). Regression analysis determined that during both covert and overt generation, left hemisphere regions showed positive correlations with average counts of verbs generated during the overt task. These results suggest that increased verb generation performance leads to increased activation. In addition, overt performance may be used as an estimator of covert performance.

"Going solid": a model of system dynamics and consequences for patient safety

Rather than being a static property of hospitals and other healthcare facilities, safety is dynamic and often on short time scales. In the past most healthcare delivery systems were loosely coupled-that is, activities and conditions in one part of the system had only limited effect on those elsewhere. Loose coupling allowed the system to buffer many conditions such as short term surges in demand. Modern management techniques and information systems have allowed facilities to reduce inefficiencies in operation. One side effect is the loss of buffers that previously accommodated demand surges. As a result, situations occur in which activities in one area of the hospital become critically dependent on seemingly insignificant events in seemingly distant areas. This tight coupling condition is called "going solid". Rasmussen's dynamic model of risk and safety can be used to formulate a model of patient safety dynamics that includes "going solid" and its consequences. Because the model addresses the dynamic aspects of safety, it is particularly suited to understanding current conditions in modern healthcare delivery and the way these conditions may lead to accidents.

Encephalocraniocutaneous lipomatosis syndrome in a child: association with multiple high flow cerebral arteriovenous fistulae. Case report and review

SUMMARY

We describe the case of a three-year-old Danish boy born at term by Cesarean due to cardiac insufficiency in the last trimestre of intra-uterine life for which he is being treated with cardiac drugs. At birth, he was noted to have bilateral ocular malformations on the upper eyelids, and diffuse scalp lipoma and alopecia. Due to the retarded growth (score - 3D) he had a MRI and angiography which demonstrated a high flow fistula on the basilar tip artery and another one on the MCA branch treated by endovascluar approach. Intracranial arachnoid cysts, dysplastic cortex, ventricular enlargement and lipoma were noted too, establishing the diagnosis of Encephalocraniocutaneous Lipomatosis Syndrome, a rare disease, especially in bilateral presentation. To our knowledge this is the first observation of ECCL associated with intracranial pial arteriovenous fistulas.

Genetic characterization of orf viruses isolated from various ruminant species of a zoo

In the present study, an outbreak of proliferative dermatitis in musk ox (Ovibos moschatus), Sichuan takin (Budorcas taxicolor tibetana) and domestic Shetland sheep (Ovis aries) in a zoo is described. Skin lesions consisted of severe, persistent, multifocal, proliferative dermatitis in musk ox, and mild, transient, focal, dermatitis in the Sichuan takin and Shetland sheep. Parapoxviruses were isolated from skin lesions, and characterized by restriction enzyme analysis and partial gene sequencing. The results of this investigation indicate that the outbreak of proliferative dermatitis was due to infection by a single parapoxvirus, which is genetically closely related to other orf virus (ORFV) strains but distant to bovine papular stomatitis virus (BPSV) and pseudocowpox virus (PCPV).

The role of error in organizing behaviour. 1990

During recent years the significance of the concept of human error has changed considerably. The reason for this has partly been an increasing interest of psychological research in the analysis of complex real life phenomena, and partly the changes of modern work conditions caused by advanced information technology. Consequently, the topic of the present contribution is not a definition of the concept or a proper taxonomy. Instead, a review is given of two professional contexts for which the concept of error is important. Three cases of analysis of human-system interaction are reviewed: (1). traditional task analysis and human reliability estimation; (2). causal analysis of accidents after the fact, and (3). design of reliable work conditions in modern sociotechnical systems. It is concluded that "errors" cannot be studied as a separate category of behaviour fragments; the object of study should be cognitive control of behaviour in complex environments.

Muscle recruitment by the min/max criterion -- a comparative numerical study

This paper introduces the min/max criterion for simulation of muscle recruitment in multiple muscle systems. The criterion is introduced and justified by comparison to two known criterion types: the polynomial criterion and the soft saturation criterion. The comparison is performed on a planar three-muscle elbow model performing a dumbbell curl. A generalized form of the soft saturation criterion is introduced, and it is shown that the min/max criterion can be interpreted as the limit of the classical criteria when the exponents in their mathematical expressions approach infinity. We finally show how the min/max criterion can be cast into a form that allows for efficient and robust numerical solution by linear programming. It is concluded that the min/max criterion possesses a number of attractive physiological as well as algorithmic advantages.

The association between depressive symptoms and health status in patients with chronic pulmonary disease

This study evaluated the association between depressive symptoms and health related quality of life (HRQoL) in patients with chronic pulmonary disease using both general and disease-specific HRQoL measures. A cross-sectional analysis of HRQoL measures completed by patients enrolled in the Department of Veteran Affairs Ambulatory Care Quality Improvement Project. 1252 patients with chronic pulmonary disease screened positive for emotional distress and returned the Hopkins Symptom Checklist-20 (SCL-20). 733 of 1252 had a score of 1.75 or greater on the SCL-20 indicating significant depressive symptoms. Depressive symptoms were associated with statistically significantly worse general and pulmonary health as reflected by lower scores on all sub-scales of both the Medical Outcomes Short Form-36 and the Seattle Obstructive Lung Disease Questionnaire. In fact, 11% to 18% of the variance in physical function sub-scales was attributed to depressive symptoms alone. Patients with chronic pulmonary disease and depressive symptoms reported significantly more impaired functioning and worse health status when compared to those patients without depressive symptoms. Because there are highly effective treatments for depression, selective screening of patients with chronic pulmonary disease for depression may identify a group that could potentially benefit from treatment interventions.

Reduction in glial immunity and neuropathology by a PAF antagonist and an MMP and TNFalpha inhibitor in SCID mice with HIV-1 encephalitis

The effects of anti-inflammatory drugs on glial immunity and neuropathology were determined in a severe combined immune deficiency (SCID) mouse model of HIV-1 encephalitis. HIV-1-infected human monocyte-derived macrophages (MDM) are stereotactically inoculated into basal ganglia resulting in a multinucleated giant cell encephalitis. A platelet activating factor antagonist and a matrix metalloproteinase inhibitor, which also inhibits tumor necrosis factor alpha release, were administered to animals at the time of the MDM inoculation. The drugs administered in combination markedly reduced brain inflammation, astrogliosis and microglia activation. These findings demonstrate that reduction of brain inflammatory responses, independent of viral replication, can affect HIVE pathology in an animal model system of disease.

The efficacy of potent anti-retroviral drug combinations tested in a murine model of HIV-1 encephalitis

Development of anti-retroviral regimens with enhanced efficacy against brain HIV-1 is essential if viral eradication is to be achieved. To address this, a severe combined immune deficiency mouse model of HIV-1 encephalitis was used to assay the effect of protease-containing and protease-sparing drug regimens on viral replication in brain macrophages. Here, HIV-1-infected human monocyte-derived macrophages (MDM) are inoculated into basal ganglia, causing a multinucleated giant cell encephalitis reminiscent of human disease. Drugs were administered at the time of MDM inoculation and continued until sacrifice. Immunohistochemical tests evaluated ongoing viral replication, glial immunity, and neuronal survival. Treatment with ddI/d4T decreased the numbers of infected cells by 75%, while ddI/d4T/amprenavir or ZDV/3TC/ABC diminished infection by 98%. Triple drug regimens decreased astrogliosis by > or = 25%. This small-animal model may be used to screen drug regimens that affect ongoing HIV-1 replication within its brain sanctuary.

Human factors in a dynamic information society: where are we heading?

Society is becoming increasingly dynamic and integrated owing to the extensive use of information technology. This has several implications that pose new challenges to the human factors profession. In an integrated society, changes and disturbances propagate rapidly and widely and the increasing scale of operations requires also that rare events and circumstances are considered during systems design. In this situation, human factors contributions should be increasingly proactive, not only responding to observed problems, but also, they should be based on models of adaptive human behaviour in complex, dynamic systems. The paper suggests some methodological issues to consider for human factors analyses by designers, evaluators and teachers.

The frequency of histologically dysplastic nevi in 199 pediatric patients

Many uncertainties surround the definition, frequency, and significance of dysplastic nevi in children. Consequently the management of dysplastic nevi in the pediatric population has been largely derived from the studies of adults. Biopsies are usually performed on this young age group because of lesion change or abnormal appearance. One might therefore assume that the frequency of histologically diagnosed dysplastic nevi would be higher in children than in adults. We decided to attempt to verify this assumption by determining the frequency of dysplastic nevi diagnosed histologically in the pediatric population. To do this we reviewed 199 cutaneous pathology reports of nevi removed from patients less than 18 years old and submitted to a community-based dermatopathology laboratory. The diagnosis of dysplastic nevus was made based on histologic criteria recommended by the World Health Organization Melanoma Program. We found that 3 of 199 nevi submitted for histologic analysis met the histologic criteria for dysplastic nevus. There were no melanomas. Our data suggest that there is an extremely low frequency of histologically confirmed dysplastic nevi within the general pediatric population.

Evaluation of antiretroviral drug efficacy for HIV-1 encephalitis in SCID mice

OBJECTIVES

To compare the efficacy of the nucleoside reverse transcriptase inhibitors (NRTIs) abacavir, zidovudine (AZT), lamivudine (3TC), didanosine (ddI), and stavudine (d4T) to inhibit viral replication in brain macrophages. A severe combined immunodeficiency (SCID) mouse model of HIV-1 encephalitis (HIVE) was used to monitor spreading viral infection in the CNS.

BACKGROUND

The development of antiretroviral therapies with CNS efficacy against neuroinvasive virus is important if eradication of HIV-1 can be achieved within critical "hidden reservoirs."

METHODS

HIV-1-infected human monocyte-derived macrophages (MDMs) (after a single round of viral replication) were inoculated into the caudate and putamen of SCID mice. This resulted in the spreading of viral infection with a concomitant multinucleated giant cell encephalitis (astrogliosis, microglial activation, and neuronal injury). NRTIs were administered to animals at the time of intracerebral MDM inoculations and continued until the time of sacrifice. Antiretroviral effects were assessed by viral load and percentages of infected MDMs.

RESULTS

In brains of SCID mice with HIVE, abacavir and lamivudine reduced HIV-1 p24 antigen-positive cells by 80% and 95%, respectively, whereas both decreased viral load by approximately 1 log. Zidovudine, didanosine, and stavudine showed variable effects.

CONCLUSION

Abacavir and lamivudine showed significant antiretroviral activity in SCID mice with HIVE when compared with other NRTIs. The extrapolation of these results to humans with HIV-1 dementia awaits future investigations.

Outcome of nursing home care for residents with alcohol use disorders

OBJECTIVES

To describe the outcome of nursing home (NH) care for a previously established cohort of residents with active, inactive or no alcohol use disorder (AUD), and to examine demographic variables, health services utilization, mortality and drinking behaviors in this group.

DESIGN

Retrospective cohort study with participant interviews at NH admission and 3 years later.

SETTING

Urban Veterans Affairs (VA) Medical Center and Nursing Home Care Unit (NHCU).

PARTICIPANTS

Patients older than age 50 admitted consecutively to a VA NHCU between July 1991 and February 1993 who completed a structured interview, N = 117.

MAIN OUTCOME MEASURES

AUD as determined by DSM-III-R criteria. Demographics, health services utilization and mortality as abstracted from the VA medical record.

RESULTS

Health service utilization as measured by care episodes was not significantly different in the three groups (active, inactive and no AUD), but subjects with AUD had documented health services use related to alcoholism, including hospitalizations for alcohol-related illness, placements in long-term care facilities to control drinking and death from alcohol-related causes. The mean age at death was significantly younger for study participants with active or inactive AUD compared to those with no AUD: 67.7, 70.4 and 77.9 years, respectively (p < 0.004). Of the 21 participants with active AUD at NHCU entry, 11 resumed drinking after discharge and six still met criteria for active AUD 3 years later.

CONCLUSIONS

The subset of NHCU patients with active AUD continued to incur alcohol-related hospitalizations and institutionalizations following NHCU discharge and suffered early mortality relative to their peers. Effective models of care for this subset of patients should be sought.