Enzootic calcinosis in Toggenburg goats in New Zealand

CASE HISTORY

Necropsies on Toggenburg goats culled from a small farm in the Manawatū district of New Zealand, performed at Massey University (Palmerston North, NZ) over a period of 29 years (1991-2019), revealed soft tissue mineralisation, particularly of cardiovascular tissues. The farm spans 10 acres and runs between 15 and 30 Toggenburg goats. The goats are predominantly on pasture comprising a variety of types.

PATHOLOGICAL FINDINGS

Necropsies were performed on all adult goats (n = 45) that died or were euthanised. Histopathology was performed on 42 goats (93%), of which 33 (73%) included sufficient tissues diagnostically relevant to soft tissue mineralisation. The most significant gross findings were in various arteries, with the aorta most commonly affected, followed by the heart and lungs. The aortic intima showed prominent, multifocal to coalescing, raised, wrinkled, white plaques. Microscopically there were multiphasic lesions of mineralisation, chondroid, and osseous metaplasia in the elastic arteries, aorta, heart and lungs. A lumbar vertebra from one goat had prominent, basophilic, fibrillar, tangled matrix lining Haversian canals and lamellae.

LABORATORY FINDINGS

Blood samples were collected from 15 adult goats in the affected herd and from 10 adult Toggenburg goats from an unaffected herd. Samples were collected by jugular venipuncture at 2-month intervals for 12 months (April 2018-March 2019). Concentrations of calcium, phosphorus, 25-hydroxyvitamin D2 and D3 (25OHD2, 25OHD3) in serum were analysed. The concentration of total 25OHD in serum was 34.2 (95% CI = 18.9-49.4) nmol/L (p < 0.001) higher in goats from the affected herd than in goats from the unaffected herd. Serum 25OHD2 concentration was 46.2 (95% CI = 39.2-53.2) nmol/L higher (p < 0.001) in goats from the affected herd compared to the unaffected herd. Serum Ca concentrations in affected goats were 0.101 (95% CI = 0.005-0.196) mmol/L higher (p = 0.039) than unaffected goats, but remained within the reference range. There was no evidence of a difference in serum 25OHD3 and P concentration between the herds.

VEGETATION SURVEY

All paddocks on the property were surveyed every 2 months along evenly spaced line transects, and then further traversed perpendicularly to form a grid. No known calcinogenic species were identified. Known plant sources of vitamin D identified on the farm included mushrooms (species not defined), Dactylis glomerata, lichen, pine pollen, and algae.

DIAGNOSIS

Soft tissue mineralisation and enzootic calcinosis.

CLINICAL RELEVANCE

Veterinarians are alerted to the possibility of either enzootic calcinosis in goats and the potential occurrence of calcinogenic plants in New Zealand; or chronic vitamin D toxicosis of non-plant origin.

Community-wide versus school-based targeted deworming for soil-transmitted helminth control in school-aged children in Vietnam: the CoDe-STH cluster-randomised controlled trial

Background

Soil-transmitted helminth (STH) infection control programs typically consist of school-based preventive chemotherapy (PC) targeted to school-aged children. STH reservoirs in untreated community members contribute to ongoing transmission in children. The CoDe-STH (Community Deworming against STH) trial, conducted in Dak Lak province, Vietnam, between October 2019 and November 2020, aimed to determine whether community-wide mass drug administration (MDA) is more effective than school-based targeted PC in reducing STH prevalence and intensity in children.

Methods

In this two-arm cluster randomised controlled trial, 64 primary schools were randomly assigned 1:1 to receive either school-based targeted PC ("school arm") or community-wide MDA ("community arm"). A single dose of albendazole 400 mg was used for deworming. The primary outcome was hookworm prevalence in schoolchildren, measured using quantitative real-time PCR. We also measured infection intensity for Necator americanus only, using qPCR cycle threshold (Ct) values converted into eggs per gram of faeces (EPG). Analysis was by intention to treat. The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12619000309189).

Findings

The analysis included 4955 children in the school arm and 5093 children in the community arm. N. americanus was the dominant STH species. The relative reduction in hookworm prevalence was not significantly different between the school arm (30.1%, 95% confidence interval [CI] 20.5-36.9) and the community arm (34.6%, 95% CI 19.9-49.4). Due to lower baseline prevalence than expected, the study was underpowered to detect a difference in prevalence reduction between the study arms. The community arm showed significantly greater relative reduction in N. americanus infection intensity (56.0%, 95% CI 39.9-72.1) compared to the school arm (3.4%, 95% CI -24.7 to 31.4). The community arm also showed greater relative reduction in prevalence of moderate-to-heavy intensity (≥2000 EPG) N. americanus infections (81.1%; 95% CI 69.7-92.6) compared to the school arm (39.0%, 95% CI 13.7-64.2).

Interpretation

Although no impact was seen on overall prevalence, community-wide MDA was more effective in lowering N. americanus infection intensity in schoolchildren compared to school-based targeted PC, measured 12 months after one round of albendazole deworming with high coverage.

Funding

National Health and Medical Research Council, Australia (APP1139561).

Combining mutation and horizontal gene transfer in a within-host model of antibiotic resistance

Antibiotics are used extensively to control infections in humans and animals, usually by injection or a course of oral tablets. There are several methods by which bacteria can develop antimicrobial resistance (AMR), including mutation during DNA replication and plasmid mediated horizontal gene transfer (HGT). We present a model for the development of AMR within a single host animal. We derive criteria for a resistant mutant strain to replace the existing wild-type bacteria, and for co-existence of the wild-type and mutant. Where resistance develops through HGT via conjugation we derive criteria for the resistant strain to be excluded or co-exist with the wild-type. Our results are presented as bifurcation diagrams with thresholds determined by the relative fitness of the bacteria strains, expressed in terms of reproduction numbers. The results show that it is possible that applying and then relaxing antibiotic control may lead to the bacterial load returning to pre-control levels, but with an altered structure with regard to the variants that comprise the population. Removing antimicrobial selection pressure will not necessarily reduce AMR and, at a population level, other approaches to infection prevention and control are required, particularly when AMR is driven by both mutation and mobile genetic elements.

Source attributed case-control study of campylobacteriosis in New Zealand

BACKGROUND

Following an initial reduction in human campylobacteriosis in New Zealand after the implementation of poultry food chain-focused interventions during 2006-2008, further decline has been relatively small. We report a year-long study of notified campylobacteriosis cases, incorporating a case control study combined with a source attribution study. The purpose was to generate up-to-date evidence on the relative contributions of different sources of campylobacteriosis in New Zealand.

METHODS

The study approach included: • A case-control study of notified cases (aged six months or more) sampled in a major urban centre (Auckland, every second case) and a mixed urban/rural area (Manawatū/Whanganui, every case), between 12 March 2018 and 11 March 2019. • Source attribution of human campylobacteriosis cases sampled from these two regions over the study period by modelling of multilocus sequence typing data of Campylobacter jejuni and C. coli isolates from faecal samples of notified human cases and relevant sources (poultry, cattle, sheep).

RESULTS

Most cases (84%) were infected with strains attributed to a poultry source, while 14% were attributed to a cattle source. Approximately 90% of urban campylobacteriosis cases were attributed to poultry sources, compared to almost 75% of rural cases. Poultry consumption per se was not identified as a significant risk factor. However specific risk factors related to poultry meat preparation and consumption did result in statistically significantly elevated odds ratios.

CONCLUSIONS

The overall findings combining source attribution and analysis of specific risk factors indicate that poultry meat remains a dominant pathway for exposure and infection.

Cost-benefit analyses of supplementary measles immunisation in the highly immunized population of New Zealand

As endemic measles is eliminated from countries through increased immunisation, the economic benefits of enhanced immunisation programs may come into question. New Zealand has suffered from outbreaks after measles introductions from abroad and we use it as a model system to understand the benefits of catch up immunisation in highly immunised populations. We provide cost-benefit analyses for measles supplementary immunisation in New Zealand. We model outbreaks based on estimates of the basic reproduction number in the vaccinated population (R_v, the number of secondary infections in a partially immunised population), based on the number of immunologically-naïve people at district and national levels, considering both pre- and post-catch up vaccination scenarios. Our analyses suggest that measles R_v often includes or exceeds one (0.18-3.92) despite high levels of population immunity. We calculate the cost of the first 187 confirmed and probable measles cases in 2014 to be over NZ$1 million (∼US$864,200) due to earnings lost, case management and hospitalization costs. The benefit-cost ratio analyses suggest additional vaccination beyond routine childhood immunisation is economically efficient. Supplemental vaccination-related costs are required to exceed approximately US$66 to US$1877 per person, depending on different scenarios, before supplemental vaccination is economically inefficient. Thus, our analysis suggests additional immunisation beyond childhood programs to target naïve individuals is economically beneficial even when childhood immunisation rates are high.

Characterisation by multilocus sequence and porA and flaA typing of Campylobacter jejuni isolated from samples of dog faeces collected in one city in New Zealand

AIMS

To investigate the prevalence of Campylobacter spp. and C. jejuni in dog faecal material collected from dog walkways in the city of Palmerston North, New Zealand, and to characterise the C. jejuni isolates by multilocus sequence typing (MLST) and porA and flaA antigen gene typing.

METHODS

A total of 355 fresh samples of dogs faeces were collected from bins provided for the disposal of dog faeces in 10 walkways in Palmerston North, New Zealand, between August 2008-July 2009. Presumptive Campylobacter colonies, cultured on modified charcoal cefoperazone deoxycholate plates, were screened for genus Campylobacter and C. jejuni by PCR. The C. jejuni isolates were subsequently characterised by MLST and porA and flaA typing, and C. jejuni sequence types (ST) were assigned.

RESULTS

Of the 355 samples collected, 72 (20 (95% CI=16-25)%) were positive for Campylobacter spp. and 22 (6 (95% CI=4-9)%) were positive for C. jejuni. Of the 22 C. jejuni isolates, 19 were fully typed by MLST. Ten isolates were assigned to the clonal complex ST-45 and three to ST-52. The allelic combinations of ST-45/flaA 21/porA 44 (n=3), ST-45/flaA 22/porA 53 (n=3) and ST-52/ flaA 57/porA 905 (n=3) were most frequent.

CONCLUSIONS

The successful isolation of C. jejuni from canine faecal samples collected from faecal bins provides evidence that Campylobacter spp. may survive outside the host for at least several hours despite requiring fastidious growth conditions in culture. The results show that dogs carry C. jejuni genotypes (ST-45, ST-50, ST-52 and ST-696) that have been reported in human clinical cases.

CLINICAL RELEVANCE

Although these results do not provide any evidence either for the direction of infection or for dogs being a potential risk factor for human campylobacteriosis, dog owners are advised to practice good hygiene with respect to their pets to reduce potential exposure to infection.

Clinical trials in surgical infection

Change is needed

Influence of blanketing and season on vitamin D and parathyroid hormone, calcium, phosphorus, and magnesium concentrations in horses in New Zealand

The aims of the study were to determine the effect of season and blanketing on vitamin D synthesis in horses and examine the interaction between vitamin D and other analytes involved in calcium homeostasis. Twenty-one healthy horses at pasture were included; 5 were covered with standard horse blankets including neck rugs. Blood samples were collected for 13 mo and analyzed for 25-hydroxyvitamin D2 (25OHD2) and 25-hydroxyvitamin D3 (25OHD3), 1,25-dihydroxyvitamin D (1,25[OH]2D), ionized calcium (iCa), total calcium (tCa), phosphorus (P), total magnesium (tMg), and parathyroid hormone (PTH). Grass and hay samples were collected and analyzed for vitamin D, calcium, phosphorus, and magnesium. Climate data were also collected. The serum concentration of 25OHD3 in horses was either undetectable or below the detection limit of the assay, and the main form of 25OHD was 25OHD2. No differences in serum 25OHD2, 1,25(OH)2D, iCa, tCa, P, tMg, and PTH (P ≥ 0.05) concentrations were seen between the 2 groups. Associations were seen between iCa and PTH (P < 0.05), iCa and tMg (P < 0.05), and dietary vitamin D and 25OHD2 (P < 0.05). A strong seasonal trend was seen in serum 25OHD2 (P < 0.0001), which was higher during spring and summer when the amount of sunshine and UV radiation was higher. Parathyroid hormone and 1,25(OH)2D showed opposing trends with PTH higher in winter whereas 1,25(OH)2D was higher in summer. The results suggest that dietary vitamin D may be necessary for horses to fulfill their vitamin D requirements; however, further research is required to determine the contribution of vitamin D3 synthesis in the skin to the vitamin D status of the horse.

Estimating Bacterial Pathogen Levels in New Zealand Bulk Tank Milk

Zoonotic bacteria such as Campylobacter, Listeria, and Shiga toxin-producing Escherichia coli have been found in bulk tank milk in many countries, and the consumption of raw milk has been implicated in outbreaks of disease in New Zealand. Fecal contamination at milking is probably the most common source of pathogenic bacteria in bulk tank milk. Raw milk was collected from 80 New Zealand dairy farms during 2011 and 2012 and tested periodically for Campylobacter, E. coli O157, Listeria monocytogenes, and Salmonella. Milk quality data such as coliform counts, total bacterial counts, and somatic cell counts also were collected. By treating the total bacterial count as a proxy for fecal contamination of milk and utilizing farm and animal level prevalence and shedding rates of each pathogen, a predictive model for the level of pathogenic bacteria in bulk tank raw milk was developed. The model utilizes a mixture distribution to combine the low level of contamination inherent in the milking process with isolated contamination events associated with significantly higher pathogen levels. By simulating the sampling and testing process, the predictive model was validated against the observed prevalence of each pathogen in the survey. The predicted prevalence was similar to the observed prevalence for E. coli O157 and Salmonella, although the predicted prevalence was higher than that observed in samples tested for Campylobacter.

Circadian rhythm of calciotropic hormones, serum calcium, phosphorus and magnesium during the shortest and longest days of the year in horses in New Zealand

A study was conducted to determine the circadian rhythms and trends of vitamin D metabolites including 25-hydroxyvitamin D₃ , 25-hydroxyvitamin D₂ , 1,25-dihydroxyvitamin D and parathyroid hormone, in addition to serum calcium, phosphorus and magnesium concentrations in horses over 48 h on the shortest and longest days of the year in 2013. Five healthy adult horses (Equus caballus) were on a constant pasture feeding regimen, and blood samples were collected from each horse every 3 h over a 48-h period, starting at 07:00 PM on day one and finishing at 07:00 PM on day three, for the measurement of calciotropic hormones and electrolytes. There was a significant difference between the serum concentration of calciotropic hormones, iCa, tCa, P and tMg between the shortest (winter) and longest (summer) days of the year in horses. Serum concentration of 25OHD₃ was very low and mostly undetectable. Serum iCa, 1,25(OH)₂ D and PTH concentrations clearly showed a circadian rhythm on the longest days of the year and serum tCa, P and tMg concentrations showed a diurnal pattern on the longest days (summer) of the year. None of the analytes showed any circadian rhythm on the shortest days (winter) of the year. The result of this study could have significant relevance to equine athletes travelling to international equestrian competitions and facing a huge time and seasonal differences that might affect their ability to adjust their circadian rhythms to new time zones.

The uncovering of ESE-1 in human neutrophils: implication of its role in neutrophil function and survival

Epithelium-specific Ets transcription factor 1 (ESE-1) is a member of the E26 transformation-specific family of transcription factors that has an epithelial-restricted constitutive expression but is induced by inflammatory stimuli in non-epithelial cells. Here we report that ESE-1 is constitutively expressed in human, but not in murine, neutrophils and that ESE-1 is modestly upregulated in septic patient neutrophils. In normal human neutrophils, ESE-1 was detected at both RNA and protein levels but was found to be an unstable nuclear protein ex vivo. ESE-1 transcription was also induced during all-trans retinoic acid-mediated HL-60 differentiation, a human promyelocytic cell line often used as an in vitro model of human neutrophils. Elf3-/- mice had normal neutrophils but a reduced number of circulating B-lymphocytes. These findings indicate a potential role of ESE-1 in regulating human neutrophil differentiation and function, and that it has different roles in the immune system of different species.

Effects of hyperandrogenemia and increased adiposity on reproductive and metabolic parameters in young adult female monkeys

Many patients with hyperandrogenemia are overweight or obese, which exacerbates morbidities associated with polycystic ovary syndrome (PCOS). To examine the ability of testosterone (T) to generate PCOS-like symptoms, monkeys received T or cholesterol (control) implants (n = 6/group) beginning prepubertally. As previously reported, T-treated animals had increased neuroendocrine drive to the reproductive axis [increased luteinizing hormone (LH) pulse frequency] at 5 yr, without remarkable changes in ovarian or metabolic features. To examine the combined effects of T and obesity, at 5.5 yr (human equivalent age: 17 yr), monkeys were placed on a high-calorie, high-fat diet typical of Western cultures [Western style diet (WSD)], which increased body fat from <2% (pre-WSD) to 15-19% (14 mo WSD). By 6 mo on WSD, LH pulse frequency in the controls increased to that of T-treated animals, whereas LH pulse amplitude decreased in both groups and remained low. The numbers of antral follicles present during the early follicular phase increased in both groups on the WSD, but maximal follicular size decreased by 50%. During the late follicular phase, T-treated females had greater numbers of small antral follicles than controls. T-treated monkeys also had lower progesterone during the luteal phase of the menstrual cycle. Although fasting insulin did not vary between groups, T-treated animals had decreased insulin sensitivity after 1 yr on WSD. Thus, while WSD consumption alone led to some features characteristic of PCOS, T + WSD caused a more severe phenotype with regard to insulin insensitivity, increased numbers of antral follicles at midcycle, and decreased circulating luteal phase progesterone levels.

Elevated androgens during puberty in female rhesus monkeys lead to increased neuronal drive to the reproductive axis: a possible component of polycystic ovary syndrome

BACKGROUND

Hyperandrogenemia is associated with several clinical disorders in which both reproductive dysfunction and metabolic changes may coexist [i.e. polycystic ovary syndrome (PCOS), obesity and congenital adrenal hyperplasia]. Moreover, there is growing evidence that the elevated levels of circulating androgens in obese girls may lead to an increased neuroendocrine drive to the reproductive axis, similar to that associated with PCOS.

METHODS

To test whether androgen exposure in the childhood and adolescent period could lead to pubertal alterations in LH secretory patterns, female rhesus monkeys received subcutaneous testosterone implants prepubertally beginning at 1 year of age, maintaining a 3.7-fold increase (P = 0.001) in circulating testosterone levels over cholesterol-implant controls (n = 6/group) into the post-pubertal period. In early adulthood, pulsatile secretion of LH was measured over 12 h during the early follicular phase of a menstrual cycle, and responsiveness of the pituitary to gonadotrophin-releasing hormone was determined. In addition, ultrasounds were performed to assess ovarian morphology and glucose tolerance testing was performed to assess insulin sensitivity.

RESULTS

The timing of menarche was similar between groups. Testosterone-treated animals had a significantly greater LH pulse frequency during the early follicular phase compared with controls (P = 0.039) when measured at 5 years of age. There was a larger LH response to GnRH when testosterone-treated animals were 4 years of age (P = 0.042), but not when the animals were 5 years old (P = 0.57). No differences were seen in insulin sensitivity or ovarian morphology, and the groups showed similar rates of ovulation in early adulthood.

CONCLUSIONS

Exposure to increased levels of androgens over the course of pubertal development appears to trigger physiological changes in the neural drive to the reproductive axis that resemble those of obese hyperandrogenemic girls in early adulthood and are characteristic of PCOS.

Humane killing of fishes for scientific research: a comparison of two methods

Two killing methods were compared on the clupeid, bony bream Nematolosa erebi and it was found that ice-slurry immersion was more humane than benzocaine overdose. The use of ice-slurry for killing N. erebi should be accepted as a standard humane method and considered similarly for other warm-water species.

Event adjudication and data monitoring in an intensive care unit observational study of thromboprophylaxis

BACKGROUND

The objective of this report is to describe the roles, responsibilities and recommendations of a 3-member Event Adjudication Committee (EAC) and a 5-member data monitoring committee (DMC) for a prospective multicenter observational study of critically ill patients with renal insufficiency examining the bioaccumulation and bleeding risk associated with dalteparin thromboprophylaxis.

METHODS

The EAC reviewed bleeding events to adjudicate whether they were major or minor and whether they were related to dalteparin (uncertain, unlikely, or likely). The DMC reviewed all bleeds deemed by the EAC as uncertain or likely due to dalteparin then recommended either to continue or suspend enrolment pending review by the steering committee, or requested more information.

RESULTS

Consensus on bleeding severity was achieved for all cases. At the second planned interim analysis, the EAC recommended to the DMC and steering committee that the EAC should stop adjudicating whether bleeding was related to dalteparin since attribution was challenging in this population with numerous bleeding risk factors; moreover, no bleeding rates were available from prior studies or historical or concurrent controls.

CONCLUSIONS

Adjudication of whether an outcome can be attributed to an intervention in an open-label, uncontrolled observational study gives a potentially misleading impression of research oversight without methodological face validity. In this study, the EAC recommended modification of the adjudication process, and the DMC recommended continuing enrolment to achieve the target sample size.

Fact and theory in recovery from the aphasias

Clinical evidence has suggested that the form of an aphasia--and perhaps potential for recovery therefrom--can be related to an exceedingly wide range of variables. Such anatomico-physiological considerations as size, depth, location and nature (e.g. penetrating missile injury, stroke, tumour, closed head injury) of the injury are frequently held to be crucial correlates, as are associated neurological deficits (e.g. presence of hemiplegia, sensory and visual field defects). Subject variables, such as age, sex and 'handedness" (including familial handedness), complicate the picture still further, as may differences in education personality and cognitive style. Given a multidimensional problem of this magnitude the first objective of theory is to indicate putative constrainst on patterns of impaired performance. Studies of the normal population--that is, the population from which cases of brain injury are later drawn--may, we believe, aid in the elucidation of individual differences seen after injury. A more detailed knowledge of the range of possibilities concerning cerebral specialization of function and variations in task strategies seems to be required. In this context we shall review some recent reports on dichotic listening and split visual field experiments with both normal and brain-damaged subjects and also consider the role that linguistic descriptions of aphasic impairment could play in suggesting retraining procedures appropriate to the individual patient.

Acquired dyslexia: patterns of deficit and recovery

These preliminary results are concerned with the quantitative description of recovery of function and the shape of the recovery curve. Four patients, in whom dylexia was the salient residual symptom of cerebral damage, are described. Individual differences in the pattern of dyslexic error and the time course of recovery are discussed; and recovery--as measured by longitudinal studies of performance in reading tasks--is analysed in terms of a model which takes into account rate of learning and the eventual asymptote. It is suggested that these or analogous techiques may be relevant both for the design of remedial programmes and for problems of prognosis.

Pulsatile gonadotropin-releasing hormone stimulation of gonadotropin subunit transcription in rat pituitaries: evidence for the involvement of Jun N-terminal kinase but not p38

We investigated whether Jun N-terminal kinase (JNK) and p38 mediate gonadotropin subunit transcriptional responses to pulsatile GnRH in normal rat pituitaries. A single pulse of GnRH or vehicle was given to female rats in vivo, pituitaries collected, and phosphorylated JNK and p38 measured. GnRH stimulated an increase in JNK phosphorylation within 5 min, which peaked 15 min after GnRH (3-fold). GnRH also increased p38 phosphorylation 2.3-fold 15 min after stimulus. Rat pituitary cells were given 60-min pulses of GnRH or media plus the JNK inhibitor SP600125 (SP, 20 microM), p38 inhibitor SB203580 (20 microM), or vehicle. In vehicle-treated groups, GnRH pulses increased LHbeta and FSHbeta primary transcript (PT) levels 3-fold. SP suppressed both basal and GnRH-induced increases in FSHbeta PT by half, but the magnitude of responses to GnRH was unchanged. In contrast, SP had no effect on basal LHbeta PT but suppressed the stimulatory response to GnRH. SB203580 had no effect on the actions of GnRH on either LH or FSHbeta PTs. Lbeta-T2 cells were transfected with dominant/negative expression vectors for MAPK kinase (MKK)-4 and/or MKK-7 plus a rat LHbeta promoter-luciferase construct. GnRH stimulated a 50-fold increase in LHbeta promoter activity, and the combination of MKK-4 and -7 dominant/negatives suppressed the response by 80%. Thus, JNK (but not p38) regulates both LHbeta and FSHbeta transcription in a differential manner. For LHbeta, JNK is essential in mediating responses to pulsatile GnRH. JNK also regulates FSHbeta transcription (i.e. maintaining basal expression) but does not play a role in responses to GnRH.

The origins and sequelae of abnormal neuroendocrine function in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common clinical disorder characterized by ovulatory dysfunction and hyperandrogenaemia. A neuroendocrine hallmark of PCOS is persistently rapid LH (GnRH) pulsatility, which favours pituitary synthesis of LH over that of FSH and contributes to the increased LH concentrations and LH : FSH ratios typical of PCOS. Inadequate FSH levels contribute to impaired follicular development, whereas elevated LH levels augment ovarian androgen production. Whereas luteal phase elevations in progesterone normally slow GnRH pulse frequency, women with PCOS do not experience normal progesterone-mediated slowing, due in part to impaired hypothalamic progesterone sensitivity. This reduction in hypothalamic progesterone sensitivity appears to be mediated by elevated androgens because sensitivity can be restored with the androgen receptor blocker flutamide. The ovulatory and hormonal abnormalities associated with PCOS generally present during puberty, typically associated with hyperandrogenaemia. Along with elevated LH concentration and pulsatility, some girls with hyperandrogenaemia have impaired hypothalamic progesterone sensitivity similar to that seen in adult women with PCOS. We propose that peripubertal hyperandrogenaemia may lead to persistently rapid GnRH pulse frequency via impaired hypothalamic feedback inhibition. The subsequent abnormalities in gonadotropin secretion, androgen production and ovulatory function may support progression towards the adult PCOS phenotype.

The effect of a selective cyclooxygenase-2 (COX-2) inhibitor on the proliferation rate of retinoblastoma cell lines

PURPOSE

To examine the effect of nepafenac, a selective cyclooxygenase-2 (COX-2) inhibitor, on the proliferation rate of two human retinoblastoma (Rb)cell lines.

METHODS

Two human Rb cell lines (WERI-RB and Y79) were cultured. COX-2 expression in these cell lines was verified by immunocytochemical analysis of cytospin sections and Western blotting. An MTT-based proliferation assay was used to compare Rb cell growth with and without amfenac, the active metabolite of nepafenac. The averaged results per condition were recorded. The Student's t-test was used to compare results from the cells cultured with and without amfenac.

RESULT

The Y79 cell line showed a higher proliferative rate than the WERI-RB cell line. Both cell lines were negative for COX-2 expression by immunocytochemical analysis; however, both cell lines were positive for COX-2 expression by Western blot. When amfenac was added to both of the cell lines, a statistically significant reduction in proliferation was observed in both cell lines. The two Rb cell lines were positive for COX-2 only in the Western blot, indicating that they probably express low levels of COX-2, which was undetectable by immunocytochemical analysis.

CONCLUSION

The selective, anti-COX-2 molecule amfenac inhibited proliferation of both tested Rb cell lines. Further trials should be undertaken to study the effect of selective COX-2 inhibitors on Rb.

Difficulty of perceptual spatiotemporal integration modulates the neural activity of left inferior parietal cortex

The integration of spatial and temporal information is a prerequisite for skilled movements. Likewise, spatial and temporal information must be integrated to predict the potential collision (or otherwise) of two moving objects. In a previous blocked functional magnetic resonance imaging (fMRI) study [Neuroimage 20 (2003) S82] we showed that collision judgments (relative to size judgments) provoked a significant increase in neural activity in the left inferior parietal cortex (supramarginal gyrus). This result suggests that this region is involved in the integration of perceptual spatiotemporal information in addition to its known involvement in programming skilled actions. To further investigate the impact of the integration of temporal and spatial information on the left parietal cortex we conducted an event-related fMRI study in which we varied the difficulty of the collision (and the size) judgment tasks parametrically. Reaction times and error rates were used as behavioral measures of increasing task demands. There was a significant linear increase in reaction times and error rates during the collision and the size tasks over the four levels of task difficulty. A linear increase of the blood oxygen level-dependent signal in the left inferior parietal cortex was found only for the collision, not for the size, conditions. Neural activation in the left inferior parietal cortex thus paralleled the increasing demands on spatiotemporal integration. This result confirms that the left supramarginal gyrus integrates spatial and temporal information irrespective of motor demands.

Regulation of gonadotropin subunit gene transcription

Reproductive function in mammals is regulated by the pituitary gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH and FSH are secreted by the gonadotrope cell and act on the gonad in a sequential and synergistic manner to initiate sexual maturation and maintain cyclic reproductive function. The synthesis and secretion of LH and FSH are regulated mainly by the pulsatile release of the hypothalamic decapeptide hormone gonadotropin-releasing hormone (GnRH). The control of differential LH and FSH synthesis and secretion is complex and involves the interplay between the gonads, hypothalamus and pituitary. In this review, the transcriptional regulation of the gonadotropin subunit genes is discussed in a physiologic setting, and we aimed to examine the mechanisms that drive those changes.

Testosterone stimulates follicle-stimulating hormone beta transcription via activation of extracellular signal-regulated kinase: evidence in rat pituitary cells

This study investigated whether estradiol (E2) or testosterone (T) activate extracellular signal-regulated kinase (ERK) and calcium/calmodulin-dependent kinase II (Ca/CaMK II), as indicated by enzyme phosphorylation in rat pituitaries. In vivo studies used adult female rats given E2, T, or empty silastic capsules (vehicle controls). Twenty-four hours later, the rats were given a single pulse of GnRH (300 ng) or BSA-saline (to controls) and killed 5 min later. GnRH stimulated a two- to three-fold rise in activated Ca/CaMK II, and E2 and T had no effect on Ca/CaMK II activation. In contrast, both GnRH and T stimulated threefold increases in ERK activity, with additive effects seen following the combination of GnRH+T. E2 had no effect on ERK activity. In alpha T3 clonal gonadotrope cells, dihydrotestosterone did not activate ERK alone but enhanced and prolonged the ERK responses to GnRH, demonstrating direct effects on the gonadotrope. Thus, the ERK response to GnRH plus androgen was enhanced in both rat pituitary and alpha T3 cells. In vitro studies with cultured rat pituitary cells examined the effect of GnRH+/-T in the presence of the mitogen-activated protein (MAP) kinase kinase inhibitor, PD-098059 (PD). Results showed that PD suppressed ERK activational and FSH beta transcriptional responses to T. These findings suggest that one site of T regulation of FSH beta transcription is through the selective stimulation of the ERK pathway.

A functional magnetic resonance imaging study of local/global processing with stimulus presentation in the peripheral visual hemifields

When stimuli are presented in the left or right visual fields, hemispheric specialization for global and local processing in occipital areas is attenuated. Using functional magnetic resonance imaging, we investigated how this attenuation is compensated for when information must cross the corpus callosum to reach the areas specialized for global and local processing. We presented hierarchically nested letters (e.g. a large E made of smaller E's) to the right or the left visual hemifield while subjects fixated centrally. In half the trials, subjects indicated whether the global aspect and in the other half whether the local aspect of the stimulus matched a pre-specified target letter. Visual hemifield presentations showed the expected contralateral activations of occipital cortex. The main effects of locally or globally directed attention did not show any differential occipital activations, but the right anterior cingulate cortex was activated differentially during local processing. Region-of-interest-based analyses showed increased neural activity in left posterior occipital cortex during local processing when stimuli were presented in the left hemifield. During global processing with stimulus presentation to the right hemifield, the right posterior occipital cortex was activated. Activation of right anterior cingulate cortex during local processing is likely to reflect the suppression of global processing precedence in order to select correctly the local stimulus level. The activations in left (local) and right (global) occipital areas are likely to reflect the top-down augmentation of stimulus information that has been degraded by callosal crossing in order to access the hemisphere specialized for local or global processing.

Gonadotropin-releasing hormone stimulation of gonadotropin subunit transcription: evidence for the involvement of calcium/calmodulin-dependent kinase II (Ca/CAMK II) activation in rat pituitaries

The intracellular pathways mediating GnRH regulation of gonadotropin subunit transcription remain to be fully characterized, and the present study examined whether calcium/calmodulin-dependent kinase II (Ca/CAMK II) plays a role in the rat pituitary. Preliminary studies demonstrated that a single pulse of GnRH given to adult rats stimulated a transient 2.5-fold rise in Ca/CAMK II activity (as determined by an increase in Ca/CAMK II phosphorylation), with peak values at 5 min, returning to basal 45 min after the pulse. Further studies examined the alpha, LHbeta, and FSHbeta transcriptional responses to GnRH or Bay K 8644+KCl (BK+KCl) pulses in vitro in the absence or presence of the Ca/CAMK II-specific inhibitor, KN-93. Gonadotropin subunit transcription was assessed by measuring primary transcripts (PTs) by quantitative RT-PCR. In time-course studies, both GnRH and BK+KCl pulses given alone increased all three subunit PTs after 6 h (2- to 4-fold). PT responses to GnRH increased over time (3- to 8-fold over basal at 24 h), although BK+KCl was ineffective after 24 h. KN-93 reduced the LHbeta and FSHbeta transcriptional responses to GnRH by 50-60% and completely suppressed the alphaPT response. In contrast, KN-93 showed no inhibitory effects on basal transcriptional activity or LH or FSH secretion. In fact, KN-93 tended to increase basal alpha, LHbeta, and FSHbeta PT levels and enhance LH secretory responses to GnRH. These results reveal that Ca/CAMK II plays a central role in the transmission of pulsatile GnRH signals from the plasma membrane to the rat alpha, LHbeta, and FSHbeta subunit genes.

The importance of seeing it coming: a functional magnetic resonance imaging study of motion-in-depth towards the human observer

Despite their crucial biological relevance, the neural structures differentially activated by the detection of optic flow towards the observer remain to be elucidated. Here, we deploy functional magnetic resonance imaging with normal volunteers to locate the areas differentially activated when motion towards the observer is detected. Motion towards the observer, compared with motion away, showed significant activations (P<0.05, corrected for multiple comparisons), as assessed using statistical parametric mapping, in the lateral inferior occipital cortex bilaterally and in right lateral superior occipital cortex. The areas implicated do not extend into area V5 or subdivisions thereof.Our data suggest that the representations of motion towards the observer implicate perceptual and attentional mechanisms acting at early stages of visual processing in extrastriate cortex. From the standpoint of efficient biological engineering, it makes sense that such crucially important functions as object motion towards the observer would be computed in early visual processing areas. Further studies will be required to determine the extent to which the effects we observed in lateral occipital cortex reflect differential attention to different types of motion, as contrasted with the derivation of explicit representations of motion towards the observer.

Task instructions influence the cognitive strategies involved in line bisection judgements: evidence from modulated neural mechanisms revealed by fMRI

Manual line bisection and a perceptual variant thereof (the Landmark test) are widely used to assess visuospatial neglect in neurological patients, but little is known about the cognitive strategies involved. In the Landmark test, one could explicitly compare the lengths of the left and right line segments; alternatively, one could compute the centre of mass of the display. We here investigate with functional MRI if these cognitive strategies modulate the neural mechanisms underlying judgements whether pre-transected horizontal lines are correctly bisected (the Landmark test) in normal volunteers. Functional neuroimaging (fMRI) was carried out in 12 healthy volunteers who judged: (a) whether the line segments on either side of the transection mark were of equal length, and (b) whether the transection mark was in the centre of the line. Line centre judgements were made significantly faster than line length comparisons. Increased neural activity common to both strategies was observed in inferior parietal lobes bilaterally and right temporooccipital cortex. Further activations, most likely reflecting general task demands like response selection and motor control, were found in the precentral gyrus bilaterally, supplementary motor area bilaterally, right anterior cingulate, right dorsolateral prefrontal cortex, cerebellar vermis, and right thalamus and right putamen. Explicit length comparisons (relative to line centre judgements) differentially activated left superior posterior parietal cortex, with a tendency toward activation of the equivalent area on the right, while the reverse comparison revealed differential activation in the lingual gyrus bilaterally and anterior cingulate cortex. The activations observed in inferior parietal cortex during task performance using either strategy are consistent with the results of lesion studies. The differential activation of superior posterior parietal cortex following length instructions suggests that explicit comparisons of spatial extent were implicated. The differential activation of bilateral occipital cortex following centre judgements suggests that the centre of a line is extracted at an early stage of visual processing.

Ecological condition of central Australian arid-zone rivers

Australian arid-zone rivers are known to be ecologically variable and go through "boom and bust" cycles based on highly variable and unpredictable flow regimes. They are facing increasing pressure from land and water resources development and, whilst they are considered to be still in relatively good condition, no studies have yet been carried out to verify this. Such baseline studies are crucial if we are to assess any ecological changes in response to development and management interventions. The ecological condition of four of these endorheic rivers (Georgina, Diamantina, Cooper-Thomson and Bulloo) flowing into the Lake Eyre and Bulloo Basins in central Australia was assessed using several criteria (level of human influence, habitat condition, water chemistry and aquatic macroinvertebrate composition). Using criteria based on the level of human influence, most of the sites were assessed to be relatively unimpacted (reference) condition. The most discernible and widespread impact was riparian and bank damage by stock access. However, the level of this impact was considered to be only moderate. Most aquatic macroinvertebrates found in the area are considered to be opportunistic and tolerant of a wide range of environmental conditions, but with their life histories known to be linked to flow conditions. Their trophic guild was dominated by collectors and predators. The AusRivAS modelled observed to expected values of macroinvertebrate composition indicated that there were differences in ecological condition between sites (e.g. different waterholes) and between times (e.g. seasons and years). Overall, 75% of sites were assessed to be good condition with the remainder being mildly impaired. Water chemistry of the sites was characterised by high spatial and temporal variability with low conductivity and alkaline pH, relatively high turbidity, total nitrogen and total phosphorus, and wide-ranging dissolved oxygen. Given the high variability in water quality and ecological condition within a catchment, there was little evidence of any overall difference in these factors between the catchments. However, given that the hydrology of each river system is distinctly different, one might expect some differences in ecological structure and function at finer scale. Periods of hydrological isolation (eg. to allow natural dryouts) as well as the maintenance of natural connectivity (eg. instream, overbank and floodplain wetting) are both necessary for the maintenance of ecological integrity of these systems.

Gonadotropin subunit transcriptional responses to calcium signals in the rat: evidence for regulation by pulse frequency

Alterations in the frequency of calcium influx signals to rat pituitary cells can regulate the expression of gonadotropin subunit mRNAs in a differential manner, producing effects that are similar to those previously found for GnRH. The present study was conducted to investigate whether this reflects a transcriptional response to calcium pulse frequency, as determined by alterations in primary transcript (PT) expression. Perifused rat pituitary cells were given pulses of the calcium channel-activator Bay K 8644 (BK; with 10 mM KCl in the injectate) for 6 h. The response to alterations in pulse dose was examined by giving pulses of 1, 3, or 10 microM BK at 60-min intervals. Maximal increases in LHbeta and FSHbeta PTs were obtained with the 3-microM BK pulse dose and with the 10-microM dose for alpha. To investigate the effect of calcium pulse frequency, 3-microM BK pulses were given at intervals of 15, 60, or 180 min. Alpha PT was selectively stimulated by 15-min pulses and LHbeta by 15- and 60-min pulses of BK. In contrast, FSHbeta PT was maximally stimulated by the slower, 180-min pulse interval. These findings reveal that pulsatile increases in intracellular calcium stimulate alpha, LHbeta, and FSHbeta transcription in a differential manner. Thus, intermittent changes in intracellular calcium appear to be important in the transmission of GnRH pulse signals from the plasma membrane to the gene, and they may mediate the differential actions of pulse frequency on gonadotropin subunit gene expression.

Antioxidants increase lipopolysaccharide-stimulated TNF alpha release in murine macrophages: role for altered TNF alpha mRNA stability

Through their effects on gene activation, antioxidants have been reported to modulate cellular expression of several proinflammatory cytokines and adhesion molecules, an effect mediated by preventing translocation of the transcription factor nuclear factor-kappa B (NF-kappa B) into the nucleus. In addition, modulation of the intracellular redox state may have profound effects on cell activation and subsequent gene expression distinct from effects on NF-kappa B; these effects may account for the divergent effects of antioxidants on cytokine gene expression in various reports. In the present studies, we evaluated the effect of the antioxidant, pyrrolidine dithiocarbamate (PDTC), on murine and human myeloid cell tumor necrosis factor alpha (TNF alpha) gene and protein expression. PDTC-enhanced LPS-induced TNF alpha secretion in cells derived from a murine macrophage cell line (J774.1), as well as in primary murine peritoneal macrophages by 4-fold. The effect was both stimulus and species dependent, as TNF alpha secretion was attenuated by PDTC in human THP-1 cells and in murine cells stimulated with zymosan. Northern analysis demonstrated that these effects were evident at the level of mRNA expression. Electrophoretic mobility shift assays confirmed the down-regulatory effect of PDTC on human myeloid NF-kappa B activation, whereas in murine cells no such inhibitory effect was evident. Evaluation of TNF alpha mRNA stability in murine cells demonstrated that the potentiating effect of PDTC on TNF alpha mRNA expression was due to an increase in mRNA half-life from 37 to 93 min. Together, these data suggest that the effect of antioxidants on gene expression are both stimulus and species dependent and illustrate a novel mechanism whereby redox manipulation might modulate TNF alpha expression in vivo.

Hypothalamic dysfunction

A pulsatile GnRH stimulus is required to maintain gonadotropin synthesis and secretion. The frequency and amplitude of GnRH pulses determine gonadotropin subunit gene expression and secretion of pituitary LH and FSH. Rapid frequency (more than 1 pulse per h) GnRH pulses favor LH while slower frequencies favor FSH secretion. During ovulatory cycles, an increase in GnRH frequency during the follicular phase favors LH synthesis prior to the LH surge, while following ovulation, luteal steroids slow GnRH pulses to favor FSH synthesis. Thus, a changing frequency of GnRH stimulation of the gonadotrope is one of the mechanisms involved in differential gonadotropin secretion during ovulatory cycles. In hypothalamic amenorrhea a majority of women exhibit a persistent slow frequency of LH (GnRH) pulses, which reflects excess hypothalamic opioid tone and can be temporarily reversed by opioid antagonists. At the other end of the spectrum, in polycystic ovarian syndrome, LH (GnRH) pulses are persistently rapid and favor LH synthesis, hyperandrogenism and impaired follicular maturation. Administration of progesterone can slow GnRH pulse secretion, favor FSH secretion and induce follicular maturation. Thus, the ability to change the pattern of GnRH secretion is an important factor in the maintenance of cyclic ovulation, and loss of this function leads to anovulation and amenorrhea.

Thyrotrophin (TSH)-secreting pituitary macroadenoma with cavernous sinus invasion

Thyrotrophin (TSH)-secreting pituitary adenomas, although rare, should be recognised as a possible cause of normal or elevated serum TSH in the presence of elevated serum free thyroid hormone levels. Clinical hyperthyroidism may be mild or absent. Early recognition provides the best chance for surgical cure. We report a patient with a TSH-secreting pituitary tumour with cavernous sinus invasion. This case illustrates that multiple modalities of treatment are often necessary and complementary in achieving control of tumour growth and hormonal hypersecretion when these tumours are diagnosed late.

Source control in the management of sepsis

The process of surgical decision making is based on both general principles that are amenable to evaluation using rigorous techniques of clinical research and the intangible element of surgical judgment that seeks to apply those principles to the care of an individual patient. The role of surgical judgment is inescapable, even though it is intrinsically subjective and recalcitrant to objective evaluation, for a host of factors modify the application of principle in each patient, and render the circumstances of a given problem sufficiently distinctive, that evidence must be tempered with common sense. We have tried to provide, through an evidence-based approach to a series of questions, the rationale for the basic principles that should guide the clinician in initiating or modifying source control, recognizing that sound clinical judgement demands, at times, that these be set aside. In the individual patient, evidence of clinical improvement is the most important marker of the approach selected. Evaluation of the adequacy of source control in the critically ill patient can be difficult. As with other modes of anti-infective therapy, effective source control measures are expected to result in clinical improvement, reflected in: Resolution of clinical signs of sepsis or systemic inflammation. Bacteriological resolution. Evidence of reversal of the metabolic sequelae of infection, with normal progression of wound healing, reflected in the formation of granulation tissue, and epithelialization. Radiographic evidence of control of an infectious focus. Prevention of further organ dysfunction, and resolution of existing organ dysfunction. Survival. Evaluation of the adequacy of source control may necessitate planned reoperation. The adequacy of débridement of necrotizing soft-tissue infections can be assessed by repeat exploration under general anesthesia, continuing the process until there is evidence of healthy granulation tissue throughout the wound. Planned reexploration is also indicated for patients with diffuse intestinal ischemia to ensure bowel viability. The appropriate interventions to determine the adequacy of source control are dictated by the clinical circumstances. A residual or recurrent abscess can usually be demonstrated by CT or ultrasound examination, while resolution of an abscess cavity can be monitored using sinograms. The diagnosis of persistent or evolving tissue necrosis is guided by the clinical setting. Retroperitoneal necrosis can be detected by CT, while sigmoid ischemia following aortic aneurysmectomy can be evaluated by sigmoidoscopy. Occasionally diagnostic peritoneal lavage assists in establishing a diagnosis of gut ischemia; the lavage fluid appears bloody with established ischemia. The diagnosis of an infected foreign body requires an appropriate history and is supported by recurrent bacteremia or by positive cultures drawn retrograde through an indwelling vascular or peritoneal dialysis catheter. Finally, ongoing contamination from a breach of the gastrointestinal tract can be documented by appropriate contrast studies. The general principles that guide the use of source control techniques in the management of the patient with severe sepsis or septic shock are readily articulated. Their implementation in practice, however, is more complex, and does not, as a rule, lend itself to simple algorithms that are applicable in all cases. Moreover evidence-based support for these principles is weak. In the final analysis, the elusive process of experienced surgical judgement is invaluable for all but the most straightforward problems.

The neural basis of vertical and horizontal line bisection judgments: an fMRI study of normal volunteers

Bisection of horizontal lines is used as a clinical test of spatial cognition in patients with left visuospatial neglect after right hemisphere lesions. Bisection of vertical lines has also been employed, albeit less frequently. Interestingly, normal subjects often bisect horizontal lines too far left and vertical lines too high. We used fMRI to investigate whether vertical/horizontal stimulus orientation interacts with the neural mechanisms associated with line bisection judgments (the Landmark task). For control of orientation per se, subjects performed a visual detection task with the same stimuli. Statistical analysis of evoked BOLD responses employed SPM99. The Landmark task increased neural activity (P < 0.05, corrected) in the superior and inferior parietal lobes bilaterally, though predominantly on the right; early visual processing areas bilaterally; and cerebellar vermis, left cerebellar hemisphere, anterior cingulate, and prefrontal cortex bilaterally. Vertical lines (relative to horizontal lines and vice versa) increased neural activity in early visual processing areas, consistent with differential retinotopic stimulation. In addition, vertical lines activated right parietooccipital and superior posterior parietal cortex bilaterally. No significant interactions between the neural mechanisms associated with task and stimuli were observed. Increased neural activation in parietal and parietooccipital cortex associated with vertical lines may reflect increased attentional demands associated with this stimulus orientation. The right hemispheric dominance observed in posterior parietal during the Landmark task irrespective of stimulus orientation is consistent with lesion studies. Our results suggest that the behavioral patterns observed in normal subjects and neurological patients result from different stimulus effects rather than differential task demands.

Regulation of gonadotropin subunit transcription after ovariectomy in the rat: measurement of subunit primary transcripts reveals differential roles of GnRH and inhibin

The aim of this study was to determine if the changes in gonadotropin subunit gene expression following ovariectomy reflect transcriptional and/or posttranscriptional regulation by GnRH or inhibin. Subunit transcription rates were determined by recently developed quantitative RT-PCR for subunit primary transcripts (as an indicator of gene transcription), which allow us to measure both mRNA and PT from RNA extracted from a single pituitary. Following ovariectomy, LHbeta PT concentrations increased 2- to 3-fold between 72 h and 7 d, paralleling changes in serum LH and LHbeta mRNA. In contrast, serum FSH, FSHbeta mRNA, and FSHbeta PT concentrations were 6- to 9-fold greater 12-24 h after ovariectomy followed by an additional 2.5-fold increase at 72 h. Although alpha RNA was elevated at 72 h after ovariectomy, alpha-primary transcript did not change. GnRH antagonist prevented the increase in LHbeta-PT at 72 h, but had no effect on the increase in FSHbetaPT at 12 h and was only partially effective at 72 h. The acute GnRH-independent increase in FSHbeta-primary transcript after ovariectomy could be duplicated by the administration of inhibin antiserum to intact rats; inhibin-alpha antiserum did not affect LHbeta-primary transcript, but increased FSHbeta-primary transcript concentrations 8- to 11-fold. The half-disappearance rates of LHbeta and FSHbeta primary transcripts were measured after GnRH blockade or administration of recombinant human inhibin A. The half-disappearance times for LHbeta and FSHbeta primary transcripts following GnRH blockade were 13 and 17 min, respectively; the mRNAs did not change. The effects of inhibin were specific for FSHbeta; 60 min after inhibin FSHbeta-primary transcript was undetectable with a half-disappearance time of 19 min, additionally FSHbeta mRNA levels also fell with a half-life of 94 min. In conclusion, these data support previous evidence that GnRH regulates gonadotropin gene expression primarily at the level of transcription. However, the acute increase in FSHbeta-primary transcript after ovariectomy or immunoneutralization of inhibin-alpha, and the rapid fall in FSHbeta-primary transcript following rh inhibin, provide novel evidence that inhibin suppresses FSHbeta gene transcription in addition to its action in regulating FSHbeta mRNA stability.

Synergistic induction of IL-10 by hypertonic saline solution and lipopolysaccharides in murine peritoneal macrophages

BACKGROUND

Liver injury after ischemia/reperfusion is an important cause of morbidity in surgical patients. We have shown that the preconditioning of animals that were subjected to liver ischemia/reperfusion with hypertonic saline solution (HTS) prevented injury by inhibiting Kupffer cell tumor necrosis factor (TNF) production. We postulated that the induction of anti-inflammatory interleukin-10 (IL-10) by HTS might contribute to protection.

METHODS

Murine thioglycolate--elicited peritoneal exudative macrophages (PEMs) were used to model the effects of HTS on IL-10 release from Kupffer cells. Cells were preconditioned with 500 mOsm HTS (or isotonic saline medium) for 2 hours and then stimulated with lipopolysaccharide (LPS; 1 microg/mL) or vehicle for 4 hours under isotonic conditions. TNF-alpha and IL-10 were measured in the culture supernatant by enzyme-linked immunosorbent assay; TNF, IL-10, and SOCS-3 messenger RNA expression were assessed by Northern blot. NF-kappa B activation was examined by electrophoretic mobility shift assay and Western blot for I kappa B degradation.

RESULTS

In the absence of LPS, isotonic medium--and HTS-pretreated PEMs produced little IL-10 (24.9 +/- 66.0 and 0 pg/mL, respectively); however, stimulation of PEMs with LPS increased IL-10 (134.9 +/- 72.2 pg/mL). Preconditioning with HTS significantly augmented LPS-induced IL-10 production, resulting in a 2-fold increase in IL-10 compared with the isotonic solution LPS group (270.7 +/- 106.8 pg/mL; P <.01). HTS alone increased IL-10 mRNA levels and markedly augmented levels induced by LPS alone. To determine whether IL-10 accounted for HTS-induced TNF inhibition, cells from IL-10 knockout animals were studied. A lack of IL-10 did not reverse the inhibitory effect of HTS on LPS-induced TNF. NF-kappa B activation was the same in HTS-and isotonic solution--pretreated groups after LPS.

CONCLUSIONS

HTS augments IL-10 induction by LPS at the gene level. Although TNF is reduced, it is not causally related to increased IL-10 or altered NF-kappa B signaling. HTS might exert its beneficial effects by independently modulating pro- and anti-inflammatory molecules, accounting for the potent immunomodulation exerted by HTS in vivo.

Spatial Cognition: Where We Were and Where We Are

Some highlights of the ongoing study of visuospatial cognition from Descartes to the advent of functional neuroimaging are reviewed. We emphasize that parietal cortex contains multiple representations of space, appropriate to the demands of perception and action in near and far space. Converging evidence from the behavioral effects of relatively focal brain lesions on different aspects of spatial cognition and from the locus of maximal physiological activation when normal volunteers perform spatial tasks is described. Clinical pathologies of spatial attention, including visual extinction, simultanagnosia, and unilateral neglect, are examined for the light they cast on the basic functions of brain circuits involving the parietal lobes.