The Perception of Color by Cattle and its Influence on Behavior

Experiments have suggested that cattle can only discriminate long wavelengths of light (colored red) from short (blue) or medium (green) wavelengths, and not short from medium wavelengths; however, stimuli were inadequately balanced for intensity. In this study, an initial group of calves was trained to discriminate light sources by intensity, and the intensities of short, medium, and long wavelength lights were then varied to determine when the calves perceived them to be isoluminant. A new group of calves was tested for their ability to discriminate between the three isoluminant sources and were able to discriminate between long and short or medium wavelengths (mean correct choice 82 and 89%, respectively) but had limited ability to discriminate between the short and medium wavelengths (three out of seven calves could just discriminate in the first eight tests, but thereafter they all selected at random). The response to three stimuli--novel, fearful, and their handler--was video-recorded in isoluminant short, medium, and long wavelengths and movement was assessed by image analysis. In the fear test (a loud noise behind them), the calves negotiated a barrier and concealed themselves more rapidly in the medium (58 s) than the short wavelength (95 s) light. They performed fewest movements in the medium wavelength light compared with the short and long wavelength lights in the novel stimulus and fear tests. They had stronger movement in the long than the short or medium wavelength light in the novel arena test and in response to the handler, and they took least time to reach the handler in the long wavelength.

The locomotion of dairy cows on floor surfaces with different frictional properties

The locomotion of dairy cows was evaluated on floors with a smooth epoxy resin surface or with a surface-applied bauxite aggregate of mean diameter 0.5, 1.2, or 2.5 mm (coefficients of static friction, mu 0.35, 0.42, 0.49, and 0.74, respectively). Locomotion was recorded as cows walked to receive a food reward. Cows on the floor with least friction walked rapidly (0.85 m/s), with frequent, short steps. At the start of the supporting phase the upper limbs were more vertical. Joint arcs during this phase were reduced. Cows on 0.5-mm aggregate also walked rapidly (0.84 m/s); they had the least vertical limb angles and long steps but held the hoof more vertical, probably to offset any increased slip risk. On floors with larger aggregate, cows decreased speed and step frequency but maintained long steps, keeping their upper forelimbs more vertical to reduce the supporting limb phase. It is concluded that on a low friction floor (mu < 0.4), cows walk quickly with frequent, short steps. As mu increases to 0.5, step length increases and the number of steps decreases to maintain speed at increased friction, producing an optimal coefficient of friction between 0.4 and 0.5. Further increases in mu may increase the hanging limb phase at the expense of the supporting limb phase, to reduce friction, while maintaining a long stride to expedite arrival at the reward.

Challenges with studies investigating longevity of dental restorations--a critique of a systematic review

OBJECTIVES

A systematic review is a method of evaluating the published and unpublished literature relating to a specific area or topic. The objectives of this paper are to identify and discuss problems encountered in synthesising the available literature; and to make recommendations for the future conduct and reporting of clinical trials that aim to determine the longevity of dental restorations.

DATA SOURCES

Studies were identified by a wide search of published and unpublished material in any language using a large number of general and specialist data bases, hand searching of key dental journals and searching of abstracts from conference proceedings.

STUDY SELECTION

Pre-defined inclusion criteria based on objective outcome measures of restoration longevity and study designs were applied to determine study selection.

CONCLUSIONS

A review of the longevity of dental restorations completed recently encountered substantial problems in designing an appropriate protocol to address this issue. The review found that many of the factors reported previously as affecting restoration longevity could not be confirmed using the agreed systematic review protocol that incorporated an objective study design. Further, the multiplicity of study designs, and reporting methods found in the literature made meta-analyses impossible. A proforma is proposed in order to aid the design of future research into the longevity of restorations.

Association of involvement in psychological self-regulation with longer survival in patients with metastatic cancer: an exploratory study

There have been numerous anecdotal claims that when patients are dedicated users of a variety of psychological self-regulation strategies, including relaxation, mental imaging, cognitive restructuring and meditation, such dedication may have a life-prolonging effect. Our aim was to test this possibility more rigorously, in patients with metastatic cancer.A prospective, longitudinal, correlative study was carried out on 22 patients with varying kinds of medically incurable metastatic cancer. The intervention was one year of weekly group psychological therapy. Extensive verbal data (patients' written homework and therapists' notes) were collected over the year. The extent of each patient's involvement with psychological work was estimated following a qualitative analysis of these data. Patients were classed as showing high, moderate, or low involvement on the basis of a quantitative rating of categories defined by the analysis. These three subgroups did not differ significantly in their expected median survival duration as estimated from independent quantitative predictions by a large panel of oncologists who analyzed the patients' medical charts at time of study entry.A significant relationship was found between degree of involvement in psychological work and survival duration. Results are presented as Kaplan-Meier survival curves (Fig. 2;P = 0. 006, Log Rank test) and as a graphic display of the median survival of each of the three groups (Fig. 3). The main likely confounders (medical status, age, quality of life, and attendance at therapy) were similar across subgroups and did not change the relation between psychological work and survival duration. Limitations in the design are discussed. However, the strong effects observed support clinical observations that dedicated involvement in psychological self-regulation may prolong the life of some patients with metastatic cancer.

The effect of applying sodium fertilizer on the rate of digestion of perennial ryegrass and white clover incubated in rumen liquor, with implications for ruminal tympany in cattle

A high herbage K:Na ratio increases the risk of ruminal tympany in cattle, which may relate to digestion rate. Experiment 1 examined whether in vitro digestibility of ryegrass was affected by NaCl fertilizer or by Na concentration in artificial saliva. Fertilizer Na increased grass digestibility, but Na in artificial saliva decreased it, probably due to the energy cost of sodium exclusion from bacteria. Increased herbage digestibility with fertilizer Na is therefore not due to additional Na, but may relate to increased water-soluble carbohydrates. Experiment 2 examined whether NaCl fertilizer applied at 35 or 70 kg Na ha(-1)to ryegrass and white clover affected in vitro gas production. Sodium fertilizer increased maximum gas output from grass and rate of production, confirming the increase in grass digestibility recorded previously, but in clover it had the opposite effect, thereby potentially reducing ruminal tympany in cows fed a high legume diet.

Effects of a computerized treatment simulation on patient expectations for orthognathic surgery

One hundred forty-six patients, ranging in age from 15 to 50 and presenting with a moderate to severe dentofacial disharmony requiring orthodontics and orthognathic surgery, were randomly assigned to 2 preparation strategy groups: standard presurgical consultation with or without a computerized treatment simulation presentation. The demographic profiles of the 2 groups were similar. Viewing a treatment simulation did not have a significant effect on the anticipation of social/interpersonal or general health problems in the first month after surgery. These 2 areas of concern were significantly related to psychological well-being. Psychologically distressed patients, whether or not they saw a simulation, expected significantly more problems in social/interpersonal relations and in general health during the first month after surgery. A treatment simulation presentation did affect patients' overall expectations of problems in the first month after surgery and their concerns about symptom recovery. However, the impact of the presentation was related to the patient's psychological well-being. In the standard presurgical consultation group, the average anticipated level of overall problems and discomfort during recovery was significantly higher for patients who reported elevated psychological distress than for those who did not. In the treatment simulation group, the average level of concern was similar for those patients who reported distress and those who did not. Preparation strategy was not significantly related to the long-term expectation of improvement after treatment. Long-term expectation of treatment improvement was related to psychological distress and gender. Men tended to report similar expectations regardless of psychological well-being, while women who were distressed anticipated significantly more improvement overall, in self-image, and in general health after treatment than women who were not distressed.

Effects of agronomic treatments on structure and function of ammonia-oxidizing communities

The aim of this study was to determine the effects of different agricultural treatments and plant communities on the diversity of ammonia oxidizer populations in soil. Denaturing gradient gel electrophoresis (DGGE), coupled with specific oligonucleotide probing, was used to analyze 16S rRNA genes of ammonia oxidizers belonging to the beta subgroup of the division Proteobacteria by use of DNA extracted from cultivated, successional, and native deciduous forest soils. Community profiles of the different soil types were compared with nitrification rates and most-probable-number (MPN) counts. Despite significant variation in measured nitrification rates among communities, there were no differences in the DGGE banding profiles of DNAs extracted from these soils. DGGE profiles of DNA extracted from samples of MPN incubations, cultivated at a range of ammonia concentrations, showed the presence of bands not amplified from directly extracted DNA. Nitrosomonas-like bands were seen in the MPN DNA but were not detected in the DNA extracted directly from soils. These bands were detected in some samples taken from MPN incubations carried out with medium containing 1,000 microg of NH(4)(+)-N ml(-1), to the exclusion of bands detected in the native DNA. Cell concentrations of ammonia oxidizers determined by MPN counts were between 10- and 100-fold lower than those determined by competitive PCR (cPCR). Although no differences were seen in ammonia oxidizer MPN counts from the different soil treatments, cPCR revealed higher numbers in fertilized soils. The use of a combination of traditional and molecular methods to investigate the activities and compositions of ammonia oxidizers in soil demonstrates differences in fine-scale compositions among treatments that may be associated with changes in population size and function.

Auditory cortex accesses phonological categories: an MEG mismatch study

The studies presented here use an adapted oddball paradigm to show evidence that representations of discrete phonological categories are available to the human auditory cortex. Brain activity was recorded using a 37-channel biomagnetometer while eight subjects listened passively to synthetic speech sounds. In the phonological condition, which contrasted stimuli from an acoustic /dae/-/tae/ continuum, a magnetic mismatch field (MMF) was elicited in a sequence of stimuli in which phonological categories occurred in a many-to-one ratio, but no acoustic many-to-one ratio was present. In order to isolate the contribution of phonological categories to the MMF responses, the acoustic parameter of voice onset time, which distinguished standard and deviant stimuli, was also varied within the standard and deviant categories. No MMF was elicited in the acoustic condition, in which the acoustic distribution of stimuli was identical to the first experiment, but the many-to-one distribution of phonological categories was removed. The design of these studies makes it possible to demonstrate the all-or-nothing property of phonological category membership. This approach contrasts with a number of previous studies of phonetic perception using the mismatch paradigm, which have demonstrated the graded property of enhanced acoustic discrimination at or near phonetic category boundaries.

Documented head injury in early adulthood and risk of Alzheimer's disease and other dementias

BACKGROUND

The association between antecedent head injury and AD is inconsistent.

OBJECTIVE

To examine the association between early adult head injury, as documented by military hospital records, and dementia in late life; and to evaluate the interaction between head injury and APOE epsilon4 as risk factors for dementia.

METHODS

The study had a population-based prospective historical cohort design. It included men who were World War II Navy and Marine veterans, and were hospitalized during their military service with a diagnosis of either a nonpenetrating head injury or another unrelated condition. In 1996 to 1997, military medical records were abstracted to document the occurrence and details of closed head injury. The entire sample was then evaluated for dementia and AD using a multistage procedure. There were 548 veterans with head injury and 1228 without head injury who completed all assigned stages of the study. The authors estimated risk of dementia, specifically AD, using proportional hazards models.

RESULTS

Both moderate head injury (hazard ratio [HR] = 2.32; CI = 1.04 to 5.17) and severe head injury (HR = 4.51; CI = 1.77 to 11.47) were associated with increased risk of AD. Results were similar for dementia in general. The results for mild head injury were inconclusive. When the authors stratified by the number of APOE epsilon4 alleles, they observed a nonsignificant trend toward a stronger association between AD and head injury in men with more epsilon4 alleles.

CONCLUSIONS

Moderate and severe head injuries in young men may be associated with increased risk of AD and other dementias in late life. However, the authors cannot exclude the possibility that other unmeasured factors may be influencing this association.

Use of lipid lowering drugs for primary prevention of coronary heart disease: meta-analysis of randomised trials

OBJECTIVE

To summarise the effect of primary prevention with lipid lowering drugs on coronary heart disease events, coronary heart disease mortality, and all cause mortality.

DESIGN

Meta-analysis.

IDENTIFICATION

Systematic search of the Medline database from January 1994 to June 1999 for English language studies examining drug treatment for lipid disorders (use of the MeSH terms "hyperlipidemia" and "anticholesteremic agents," keyword searches for individual drug names, and a search strategy for identifying randomised trials to capture relevant articles); identification of older studies through systematic reviews and hand search of bibliographies.

INCLUSION CRITERIA

All randomised trials of at least one year's duration that examined drug treatment for patients with no known coronary heart disease, cerebrovascular disease, or peripheral vascular disease and that measured clinical end points, including all cause mortality, coronary heart disease mortality, and non-fatal myocardial infarctions.

DATA EXTRACTION

Review of the articles and extracted relevant data by two authors separately, with disagreements resolved by consensus.

RESULTS

Four studies met eligibility criteria. Drug treatment reduced the odds of a coronary heart disease event by 30% (summary odds ratio 0.70, 95% confidence interval 0.62 to 0.79) but not the odds of all cause mortality (0.94, 0.81 to 1.09). When statin drugs were considered alone, no substantial differences in results were found.

CONCLUSIONS

Treatment with lipid lowering drugs lasting five to seven years reduces coronary heart disease events but not all cause mortality in people with no known cardiovascular disease.

Organic secretion by striated ducts

In addition to their role in electrolyte homeostasis, striated ducts in the parotid and submandibular glands of many mammalian species engage in secretion of organic products. This secretion usually is in the form of serous-like granules that lack substructure. Usually, the granules are in the 2.0-2.5 mm range, but granules smaller than 0.1 mm and larger than 12 mm have been observed. In mustelids, striated duct cells contain rhomboidal crystalloids in their apical cytoplasm; in dogs and at least two bat species, the apical plasmalemma is festooned with perpendicularly-oriented rods. Rather than granules, the supranuclear cytoplasm of duct cells in a number of species contains spherical or oblong vesicles. These may convey glycoproteins to the luminal surface where they are incorporated into the glycocalyx or the plasma membrane. Certain vesicles appear to be involved in the uptake of foreign proteins introduced retrogradely into the main excretory duct or of altered proteins produced by acinar cells in streptozotocin-induced diabetes.

Lipid screening in women

Evidence of the benefits of lowering cholesterol in various populations continues to grow, but questions persist about screening and treatment of lipid disorders in women. In this paper, we review the distinct features of the epidemiology of lipids and coronary heart disease in women and data from recent long-term treatment trials specific to women. Although data from primary prevention trials in women remain sparse, recent trials demonstrating benefits of cholesterol reduction across a broad range of cholesterol levels and cardiac risk in men and women bolster the conclusion that benefits may extend to asymptomatic women who are otherwise at high risk for coronary disease. Periodic lipid screening beginning in middle age will identify most women who are at high enough risk to merit drug therapy or more intensive individual lifestyle interventions. More detailed consideration of age, diabetes, blood pressure, specific lipid levels, or the ratio of total cholesterol to high-density lipoprotein cholesterol, and other risk factors can more accurately estimate individual risk of coronary heart disease and identify high-risk women most likely to benefit from lipid reduction. Advice about healthy diet, weight control, and physical activity can benefit all women, but authorities differ on the benefits of routine lipid screening in low-risk younger women.

Experience-dependent changes in cerebral activation during human REM sleep

The function of rapid-eye-movement (REM) sleep is still unknown. One prevailing hypothesis suggests that REM sleep is important in processing memory traces. Here, using positron emission tomography (PET) and regional cerebral blood flow measurements, we show that waking experience influences regional brain activity during subsequent sleep. Several brain areas activated during the execution of a serial reaction time task during wakefulness were significantly more active during REM sleep in subjects previously trained on the task than in non-trained subjects. These results support the hypothesis that memory traces are processed during REM sleep in humans.

The locomotion of dairy cows on concrete floors that are dry, wet, or covered with a slurry of excreta

Six dairy cows were trained to individually walk down a concrete aisle for a food reward. Their locomotion was then examined in a switchback experiment as the floor surface of the aisle was changed from dry to wetted concrete or concrete covered by shallow (5 cm) or deep (12.5 cm) slurry from cattle excreta. The static and dynamic frictional coefficients were measured by a tribometer, but did not give a clear indication of the risk of slipping. Cow locomotion was measured over the second half of the aisle, and limb angles recorded as the cow passed a video camera. Wetting the floor did not affect the walking or stepping rate, but it reduced the arc made by the joints of the hindlimb during the supporting phase. Slurry caused the cows to keep their legs more vertical at the end of the support phase, probably to aid lifting the limb out of the slurry. It also caused the cows to place their forelimbs down less vertically at the start of the support phase, probably because of the reduced risk of slip in the slurry. When the floor was covered with either the deep or, to a lesser extent, the shallow slurry, the cows' walking and stepping rates were reduced, and on the floor covered with deep slurry their step length was increased. Therefore slurry reduces the cow's walking speed and alters limb angles during the support phase, producing a different walking pattern from cows on dry or wetted concrete.

Mechanisms of gastrointestinal copper absorption in the African walking catfish: copper dose-effects and a novel anion-dependent pathway in the intestine

In mammals, copper (Cu) absorption occurs mostly in the small intestine, and some of the Cu transporters involved in its uptake have been characterised. In fish, however, the regions of the gut involved in Cu absorption and the membrane transport mechanisms responsible for gastrointestinal Cu uptake are unknown. Everted gut sacs and isolated perfused intestine of Clarias gariepinus were used to explore Cu absorption (at 22 degrees C). Gut sacs exposed to 100 micromol l(−1) mucosal solution Cu ([Cu](m)) showed that Cu was mostly (70 %) absorbed in the middle and hind intestine. Most of the accumulated Cu was located in the mucosa. In perfused intestines, cumulative Cu absorption from the mucosal solution to the serosal perfusate was greatest at 10 micromol l(−1) [Cu](m) and decreased at higher values of [Cu](m), while tissue accumulation of Cu showed a dose-dependent elevation. Absorption efficiency therefore declined with increasing Cu dose, and basolateral transport was the limiting factor in Cu uptake. Serosal applications of the P-type ATPase inhibitor vanadate (100 micromol l(−1)) or the anion transport inhibitor DIDS (100 micromol l(−1)) caused threefold increases in net Cu uptake (at [Cu](m)=10 micromol l(−1)). The vanadate effect was explained by a reduction in transepithelial potential rather than inhibition of Cu-ATPase, but the DIDS effect was not. Transepithelial potential, water transport and tissue [Cu] were not affected by DIDS, but tissue [K(+)] was elevated. Removal of Cl(−) simultaneously from both the mucosal and serosal solutions caused a 10-fold reduction in the rate of Cu uptake, while removal of Cl(−) from the mucosal solution only completely abolished Cu absorption to the serosal perfusate. Transepithelial potential effects are discussed. We conclude that Cu absorption occurs mostly in the intestine and is normally driven by a basolateral Cu/anion symport that prefers Cl(−).

Early postsurgery experience of prostate cancer patients and spouses

PURPOSE

The authors describe the experience of men with prostate cancer and their spouses in the early recovery period after surgery.

DESCRIPTION OF STUDY

As part of a longitudinal qualitative study, semistructured interviews were held with 34 patients who had prostate cancer and their spouses 8 to 10 weeks after surgery.

RESULTS

Five components of experience emerged from the interviews: 1) hearing news about the extent of their cancer after surgery influenced how patients viewed their cancer experience and, in many cases, their recovery; 2) men placed great emphasis on recovering their physical capacity quickly; 3) couples connected with each other through working out care routines and managing periods of irritability; 4) couples described a range of responses to surgery side effects and complications; and 5) the meaning of cancer varied for couples, with most seeing the experience as a temporary disruption.

CLINICAL IMPLICATIONS

Physicians, nurses, social workers, and other health professionals working with patients before and after prostatectomies may assist couples to prepare better for the early recovery period by being both sensitive to the men's need to recover physical capacity quickly while helping them to understand that recovery takes time. Accurate information about expected periods of irritability, side effects, and possible complications would diminish the likelihood of distress during this period.

To tell or not to tell: patterns of disclosure among men with prostate cancer

This paper draws on the results of a longitudinal, qualitative study of men with prostate cancer (treated with prostatectomy) and their spouses. Interviews were conducted separately and simultaneously with men and their spouses, at three points in time (pre-surgery, 8-10 weeks post-surgery and 11-13 months post-surgery). The primary focus in the paper is on men's responses to questions about their decisions to share information (or not) with others about their diagnosis and ongoing medical situation. Most men with prostate cancer avoided disclosure about their illness where possible, and placed great importance on sustaining a normal life. Factors related to limiting disclosure included men's low perceived need for support, fear of stigmatization, the need to minimize the threat of illness to aid coping, practical necessities in the workplace, and the desire to avoid burdening others. This study contributes to an understanding of disclosure issues related to prostate cancer, and raises issues about how best to be helpful to men, given their tendency to minimize the impact of illness, and the need for support.

A prospective, longitudinal study of the relationship of psychological work to duration of survival in patients with metastatic cancer

This study is a prospective, longitudinal investigation of the psychological factors associated with the duration of survival in patients with metastatic cancers of various kinds who were receiving group psychotherapy. A correlative approach rather than an experimental (trials) design was used in the study because our aim was to relate the psychological attributes of each individual to survival rather than to test the efficacy of the intervention. Twenty-two patients with medically incurable metastatic cancer of various kinds received weekly group psychotherapy for up to 1 year, the great majority remaining well enough to attend the group for at least 8 months. During this time, they provided extensive verbal data, through written homework, and from notes taken by the therapists at interviews and during group sessions. These data were subjected to detailed qualitative analysis, as a result of which a number of psychological themes were defined. A quantitative rating was assigned to the data for each theme in each individual patient through team discussions. The scores for the individual themes were summed to produce a 'total psychological score', representing the degree of each patient's involvement with psychological self-help work. The values for each patient were then related to his or her survival duration. Cox regression analyses showed that this composite score, and five of six major themes, were significantly related to survival duration. These themes were: ability to act and change; willingness to initiate change; application to self-help work; relationships with others; and quality of experience. In contrast, there was no relationship between survival and four standard psychometric measures taken at the onset of therapy. However, results on a 5-point scale measuring the subject's expectancy that psychological efforts would affect the disease showed a strong relationship to survival. To control for differences in severity of disease as a factor possibly influencing psychological work, the analyses were repeated, using the survival duration predicted for each patient by a panel of oncologists as a covariate. Closely similar results were obtained. Limitations on the interpretation of the results are discussed. Within these limits, it appears that there is a strong association between longer survival and psychological factors related to the involvement of cancer patients in psychological self-help activities. While causality cannot be inferred, reasons are given for believing that this is not a result of the disease influencing the patients' psychology, but rather the converse.

Distribution of glucocorticoid and mineralocorticoid receptors and 11beta-hydroxysteroid dehydrogenases in human and rat ocular tissues

PURPOSE

The administration of glucocorticoids as topical or systemic medications may lead to the development of ocular hypertension through the induction of morphologic and biochemical changes in the trabecular meshwork leading to a reduction in the facility of aqueous outflow. Glucocorticoids exert their physiological effects by binding to and activating glucocorticoid and mineralocorticoid receptors. The activity of glucocorticoids is critically regulated at a prereceptor level by the two isozymes of 11beta-hydroxysteroid dehydrogenase. The purpose of this study was to determine the distribution of glucocorticoid target receptors and the isozymes of 11beta-hydroxysteroid dehydrogenase (11 beta-HSD) that regulate the activity of glucocorticoids at a prereceptor level in human and rat ocular tissues.

METHODS

Horizontal sections of normal adult human and rat eyes were cut and hybridized with 35S-labeled cRNA probes specific for the glucocorticoid receptor, mineralocorticoid receptor, and 11beta-HSD types 1 and 2 using in situ hybridization. Immunohistochemical analysis of glucocorticoid and mineralocorticoid receptors using monoclonal antibodies was carried out on rat eye tissue sections. Whole rat eyes were homogenized and the activity of 11beta-HSD types 1 and 2 in the eye assessed as the percentage conversion of tritiated corticosterone to tritiated 11-dehydrocortico-sterone when corticosterone was added to the homogenate.

RESULTS

In the rat ocular tissues mRNAs encoding glucocorticoid receptor, mineralocorticoid receptor, and 11beta-HSD types 1 and 2 were detected in nonpigmented ciliary epithelium, trabecular meshwork, corneal epithelium and endothelium, and anterior lens epithelium. Immunohistochemistry confirmed the presence of glucocorticoid and mineralocorticoid receptors at these sites. Activity of both isozymes of 11beta-HSD was demonstrated in homogenized rat eyes (percentage conversion of tritiated corticosterone to 11-dehydrocorticosterone; mean +/- SD, 11beta-HSD 1 = 15% +/- 5.3%, 11beta-HSD 2 = 7.9% +/- 2.8%). In both human and rat eyes, expression of mRNAs encoding glucocorticoid receptor and 11beta-HSD type 1 was high in the trabecular meshwork and lens epithelium, whereas expression of mRNAs encoding the mineralocorticoid receptor and 11beta-HSD type 2 was high in nonpigmented ciliary epithelium and corneal epithelium and endothelium.

CONCLUSIONS

Glucocorticoid target receptors and the enzymes regulating glucocorticoid activity at these receptors are present in mammalian ocular tissues, which regulate aqueous humor formation and outflow. Alteration in the number or affinity of receptors or in the activity of regulatory enzymes may alter the susceptibility of certain individuals to the effects of glucocorticoids on intraocular pressure.

Frictional properties of cattle hooves and their conformation after trimming

The conformation of the hooves of nine heifers obtained from an abattoir was measured and their coefficient of static friction (mu) was determined for movement in forward, backward and sideways directions. The hooves were trimmed by the Dutch method and their conformation and p were measured again. Trimming increased mu, and decreased the length of the digit and the angle between it and the floor. The value of mu was considerably greater for movement in a forward or backwards direction than sideways. The relationship between the value of mu for sideways movement and hoof conformation was examined by using 52 lower limbs from a variety of cattle breeds. Although mu was greater for Belgian blue than other cattle breeds, there were no relationships between mu and hoof conformation, including a measure of the roughness of the sole.

Long-term stability of surgical open-bite correction by Le Fort I osteotomy

Skeletal changes greater than those observed in untreated adults have been noted beyond 1 year post-surgery in adult patients who had surgical correction of a long face deformity. The stability of skeletal landmarks and dental relationships from 1 to >3 years post-surgery was examined in 28 patients who had undergone surgery of the maxilla only, and in 26 patients who had undergone 2-jaw surgery to correct >2 mm anterior open bite. Although the average changes in almost all landmark positions and skeletal dimensions were less than 1 mm, point B moved down >2 mm and face height increased >2 mm in one-third of the maxilla-only group and in 40% of the 2-jaw group (>4 mm in 10% and 22% respectively). Overbite decreased 2-4 mm in only 7% of the maxilla-only and 12% of the 2 groups, with no changes >4 mm, because in three-fourths of the patients with an increase in anterior face height, further eruption of the incisors maintained the overbite relationship. In the maxilla-only group, mandibular length (Co-Pg) showed >2 mm long-term change in 45% of the patients, two-thirds of whom showed an increase rather than a decrease in length. In the 2-jaw group, no patients showed a decrease in Co-Pg length and one-third had an increase. For both groups, changes in overjet were smaller and less frequent than changes in mandibular length.

Acute tubulointerstitial nephritis attributable to indinavir therapy

Indinavir sulfate has been reported to cause asymptomatic crystalluria and nephrolithiasis in patients with human immunodeficiency virus (HIV) infection. Patients taking indinavir may present with asymptomatic crystalluria, nephrolithiasis with frank renal colic and obstruction, flank pain in the absence of nephrolithiasis, and dysuria or urgency. Asymptomatic crystalluria has been described as benign. Discontinuation of the drug has not been recommended in the absence of nephrolithiasis. We report two HIV-positive patients receiving indinavir who developed acute interstitial nephritis with foreign body giant cell reaction on renal biopsies. Both patients had asymptomatic crystalluria, although crystals were associated with clumps of white blood cells (WBCs) on urinalysis in one patient. Both cases show that the inflammatory response was significant enough to lead to tubular injury and acute renal impairment. Our findings suggest that asymptomatic crystalluria attributable to indinavir may illicit an inflammatory response with acute renal insufficiency, warranting monitoring of renal function, especially in patients with crystalluria.

Quantitative analysis of ammonia oxidising bacteria using competitive PCR

Culture-based methods for enumeration, such as most probable number (MPN) methodologies, have proved inefficient due to difficulties in the isolation and cultivation of ammonia oxidising bacteria in the laboratory. Biases are associated with the isolation of bacteria in selective media and organisms cultivated in the laboratory may not be truly representative of those in the environment. In this study, we developed a competitive PCR (cPCR)-based method based on the amplification of 16S rRNA genes specific for the beta-subgroup proteobacterial ammonia oxidising bacteria for enumeration of these organisms. Populations in both agricultural soils and estuarine sediments were quantified by traditional MPN and by cPCR. The numbers of ammonia oxidisers for both sample types were significantly underestimated by conventional MPN and were 1-3 orders of magnitude lower than those obtained by cPCR. Higher numbers of ammonia oxidisers found in fertilised plots in agricultural soils by the cPCR technique were not observed in MPN estimates. It was necessary to construct a separate standard curve for each sample type as differences in DNA extraction, quantity and purity had a significant bearing on the ease of PCR of both competitor and target DNA.