Three dimensional microelectrodes enable high signal and spatial resolution for neural seizure recordings in brain slices and freely behaving animals

Neural recordings made to date through various approaches—both in-vitro or in-vivo—lack high spatial resolution and a high signal-to-noise ratio (SNR) required for detailed understanding of brain function, synaptic plasticity, and dysfunction. These shortcomings in turn deter the ability to further design diagnostic, therapeutic strategies and the fabrication of neuro-modulatory devices with various feedback loop systems. We report here on the simulation and fabrication of fully configurable neural micro-electrodes that can be used for both in vitro and in vivo applications, with three-dimensional semi-insulated structures patterned onto custom, fine-pitch, high density arrays. These microelectrodes were interfaced with isolated brain slices as well as implanted in brains of freely behaving rats to demonstrate their ability to maintain a high SNR. Moreover, the electrodes enabled the detection of epileptiform events and high frequency oscillations in an epilepsy model thus offering a diagnostic potential for neurological disorders such as epilepsy. These microelectrodes provide unique opportunities to study brain activity under normal and various pathological conditions, both in-vivo and in in-vitro, thus furthering the ability to develop drug screening and neuromodulation systems that could accurately record and map the activity of large neural networks over an extended time period.

Hendra in the Hunter Valley

In June 2019 the first equine case of Hendra virus in the Hunter Valley, New South Wales, Australia was detected. An urgent human and animal health response took place, involving biosecurity measures, contact tracing, promotion of equine vaccinations and investigation of flying fox activity in the area.

No human or additional animal cases occurred. Equine vaccination uptake increased by over 30-fold in the surrounding region in the three months following the case. Black flying fox and grey-headed flying fox species were detected in the Valley. The incident prompted review of Hendra virus resources at local and national levels.

This event near the “horse capital of Australia”, is the southernmost known equine Hendra case. Management of the event was facilitated by interagency collaboration involving human and animal health experts. Ongoing One Health partnerships are essential for successful responses to future zoonotic events.

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In June 2019 the southernmost known equine case of Hendra virus was detected in the Hunter Valley, Australia.

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This signified an increase in potential equine and human populations at risk of infection.

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Interagency collaboration between animal and human health experts is essential in managing Hendra virus spillover events.

Peripheral neuron plasticity is enhanced by brief electrical stimulation and overrides attenuated regrowth in experimental diabetes

Peripheral nerve regrowth is less robust than commonly assumed, particularly when it accompanies common clinical scenarios such as diabetes mellitus. Brief extracellular electrical stimulation (ES) facilitates the regeneration of peripheral nerves in part through early activation of the conditioning injury response and BDNF. Here, we explored intrinsic neuronal responses to ES to identify whether ES might impact experimental diabetes, where regeneration is attenuated. ES altered several regeneration related molecules including rises in tubulin, Shh (Sonic hedgehog) and GAP43 mRNAs. ES was associated with rises in neuronal intracellular calcium but its strict linkage to regrowth was not confirmed. In contrast, we identified PI3K-PTEN involvement, an association previously linked to diabetic regenerative impairment. Following ES there were declines in PTEN protein and mRNA both in vitro and in vivo and a PI3K inhibitor blocked its action. In vitro, isolated diabetic neurons were capable of mounting robust responsiveness to ES. In vivo, ES improved electrophysiological and behavioral indices of nerve regrowth in a chronic diabetic model of mice with pre-existing neuropathy. Regrowth of myelinated axons and reinnervation of the epidermis were greater following ES than sham stimulation. Taken together, these findings identify a role for ES in supporting regeneration during the challenges of diabetes mellitus.

A novel alternating current multiple array electrothermal micropump for lab-on-a-chip applications

The AC electrothermal technique is very promising for biofluid micropumping, due to its ability to pump high conductivity fluids. However, compared to electroosmotic micropumps, a lack of high fluid flow is a disadvantage. In this paper, a novel AC multiple array electrothermal (MAET) micropump, utilizing multiple microelectrode arrays placed on the side-walls of the fluidic channel of the micropump, is introduced. Asymmetric coplanar microelectrodes are placed on all sides of the microfluidic channel, and are actuated in different phases: one, two opposing, two adjacent, three, or all sides at the same time. Micropumps with different combinations of side electrodes and cross sections are numerically investigated in this paper. The effect of the governing parameters with respect to thermal, fluidic, and electrical properties are studied and discussed. To verify the simulations, the AC MAET concept was then fabricated and experimentally tested. The resulted fluid flow achieved by the experiments showed good agreement with the corresponding simulations. The number of side electrode arrays and the actuation patterns were also found to greatly influence the micropump performance. This study shows that the new multiple array electrothermal micropump design can be used in a wide range of applications such as drug delivery and lab-on-a-chip, where high flow rate and high precision micropumping devices for high conductivity fluids are needed.

Characteristics of a widespread community cluster of H275Y oseltamivir-resistant A(H1N1)pdm09 influenza in Australia

Background. Oseltamivir resistance in A(H1N1)pdm09 influenza is rare, particularly in untreated community cases. Sustained community transmission has not previously been reported.

Methods. Influenza specimens from the Asia–Pacific region were collected through sentinel surveillance, hospital, and general practitioner networks. Clinical and epidemiological information was collected on patients infected with oseltamivir-resistant viruses.

Results. Twenty-nine (15%) of 191 A(H1N1)pdm09 viruses collected between May and September 2011 from Hunter New England (HNE), Australia, contained the H275Y neuraminidase substitution responsible for oseltamivir resistance. Only 1 patient had received oseltamivir before specimen collection. The resistant strains were genetically very closely related, suggesting the spread of a single variant. Ninety percent of cases lived within 50 kilometers. Three genetically similar oseltamivir-resistant variants were detected outside of HNE, including 1 strain from Perth, approximately 4000 kilometers away. Computational analysis predicted that neuraminidase substitutions V241I, N369K, and N386S in these viruses may offset the destabilizing effect of the H275Y substitution.

Conclusions This cluster represents the first widespread community transmission of H275Y oseltamivir-resistant A(H1N1)pdm09 influenza. These cases and data on potential permissive mutations suggest that currently circulating A(H1N1)pdm09 viruses retain viral fitness in the presence of the H275Y mutation and that widespread emergence of oseltamivir-resistant strains may now be more likely.

Cognitive impairment in multiple sclerosis can be predicted by imaging early in the disease

BACKGROUND

Cognitive impairment is common in multiple sclerosis (MS) and adds significantly to the burden of the disease. The ability to predict future cognitive impairment from imaging obtained at disease onset has not been investigated.

METHODS

62 patients imaged within 3 months of a clinically isolated syndrome were assessed neuropsychologically 7 years later. Baseline and periodic MRI measures of lesions, atrophy and normal-appearing white and grey matter were regressed against neuropsychological scores to explore the best predictors of cognitive outcome.

RESULTS

28 patients had developed clinically definite MS at follow-up and a further nine met revised McDonald criteria for MS. Deficits in speed of information processing and executive function were the most common abnormalities. Poor performance correlated with high anxiety ratings. Baseline T(1) lesion metrics predicted executive deficits, and new T(2) lesions at the 3-month follow-up predicted slowed information processing. An increase in myo-inositol concentration in normal-appearing white matter over the first 3 years was associated with poor executive function.

CONCLUSIONS

MRI variables obtained at the onset of a clinically isolated syndrome can predict future development of cognitive abnormalities. Our findings may have implications in monitoring and treating patients.

Fertilization state of Ascaris suum determined by electrorotation

Electrorotation is a non-invasive technique that is capable of detecting changes in the morphology and physicochemical properties of microorganisms. The first detailed electrorotation study of the egg (ovum) of a parasitic nematode, namely Ascaris suum is described to show that electrorotation can rapidly differentiate between fertilized and non-fertilized eggs. Support for this conclusion is by optical microscopy of egg morphology, and also from modelling of the electrorotational response. Modelling was used to determine differences in the dielectric properties of the unfertilized and fertilized eggs, and also to investigate specific differences in the spectra of fertilized eggs only, potentially reflecting embryogenesis. The potential of electrorotation as an investigative tool is shown, as undamaged eggs can be subjected to further non-destructive and destructive techniques, which could provide further insight into parasite biology and epidemiology.

An open-label pilot study of cannabis-based extracts for bladder dysfunction in advanced multiple sclerosis

The majority of patients with multiple sclerosis (MS) develop troublesome lower urinary tract symptoms (LUTS). Anecdotal reports suggest that cannabis may alleviate LUTS, and cannabinoid receptors in the bladder and nervous system are potential pharmacological targets. In an open trial we evaluated the safety, tolerability, dose range, and efficacy of two whole-plant extracts of Cannabis sativa in patients with advanced MS and refractory LUTS. Patients took extracts containing delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD; 2.5 mg of each per spray) for eight weeks followed by THC-only (2.5 mg THC per spray) for a further eight weeks, and then into a long-term extension. Assessments included urinary frequency and volume charts, incontinence pad weights, cystometry and visual analogue scales for secondary troublesome symptoms. Twenty-one patients were recruited and data from 15 were evaluated. Urinary urgency, the number and volume of incontinence episodes, frequency and nocturia all decreased significantly following treatment (P <0.05, Wilcoxon's signed rank test). However, daily total voided, catheterized and urinary incontinence pad weights also decreased significantly on both extracts. Patient self-assessment of pain, spasticity and quality of sleep improved significantly (P <0.05, Wilcoxon's signed rank test) with pain improvement continuing up to median of 35 weeks. There were few troublesome side effects, suggesting that cannabis-based medicinal extracts are a safe and effective treatment for urinary and other problems in patients with advanced MS.

An AC electroosmotic micropump for circular chromatographic applications

Flow rates of up to 50 microm s(-1) have been successfully achieved in a closed-loop channel using an AC electroosmotic pump. The AC electroosmotic pump is made of an interdigitated array of unequal width electrodes located at the bottom of a channel, with an AC voltage applied between the small and the large electrodes. The flow rate was found to increase linearly with the applied voltage and to decrease linearly with the applied frequency. The pump is expected to be suitable for circular chromatography for the following reasons: the driving forces are distributed over the channel length and the pumping direction is set by the direction of the interdigitated electrodes. Pumping in a closed-loop channel can be achieved by arranging the electrode pattern in a circle. In addition the inherent working principle of AC electroosmotic pumping enables the independent optimisation of the channel height or the flow velocity.

Analysis of parasites by electrorotation

AIMS

The application of the AC electrokinetic technique of electrorotation for studying eukaryotic parasite transmission stages is reviewed. Electrorotation is a noninvasive technique that utilizes electrically energized microelectrode structures within micro-fluidic chambers to probe the physiological structure of micro-organisms. Application of the technique to the transmission life cycle stages of three separate genera of protozoan parasites, Cryptosporidium, Giardia and Cyclospora, and one nematode genus Ascaris, each of significant public health importance, is described.

METHODS AND RESULTS

Standard electrorotation apparatus, consisting of micro-fabricated electrodes in a fluidic chip, quadrature sinusoidal signal generator, microscope and image capture system, was used to study each organism. Spectra of cellular rotation rate were recorded as a function of applied electric field frequency and compared with standardized biological tests, where appropriate, to illustrate the effectiveness and versatility of the electrorotation technique.

CONCLUSIONS

Electrorotational determination of the viability of individual G. intestinalis cysts, Cryptosporidium parvum and Cyclospora cayetanensis oocysts has been achieved. The sporulation state of Cyclospora cayetanensis oocysts was also readily determined, as was the fertilization state of A. suum ova.

SIGNIFICANCE AND IMPACT OF THE STUDY

Electrorotation is a simple, noninvasive and versatile analytical technique suited to a wide range of particle types and capable of incorporation into integrated Lab-on-a-chip devices.

Fresh garlic: a possible vehicle for Salmonella Virchow

A sustained increase in Salmonella enterica serovar Virchow notifications in South Eastern Australia between September 1997 and May 1998 instigated a case-control study and environmental investigations. Cases were defined as having locally acquired culture-confirmed S. Virchow phage-type 8 infection and diarrhoeal disease. Matched controls were selected by progressive digit dialling based on cases' telephone numbers. An exposure and food history questionnaire was administered by telephone. Phage typing and pulse field gel electrophoresis were performed on case and environmental isolates. Thirty-two notifications of S. Virchow infection met the case definition, 37% reported bloody diarrhoea and S. Virchow was isolated from blood in 13% of cases. Twelve patients were admitted to hospital and one died. Fresh garlic (OR 4.1, 95% CI 1.3-12.8) and semi-dried tomatoes (OR 12.6, 95% CI 1.5-103.1) were associated with these cases. The associations remained significant after adjusting for sex and age. S. Virchow (PT 8) was cultured from two brands of semi-dried tomatoes associated with cases in two different states. We provide sufficient evidence for semi-dried tomatoes and fresh garlic to be considered as potential risk foods in future Salmonella outbreak investigations.

The longitudinal relation between brain lesion load and atrophy in multiple sclerosis: a 14 year follow up study

BACKGROUND

Studies have suggested that T2 lesion activity is prominent in early relapsing-remitting multiple sclerosis, whereas brain atrophy, while seen early, appears more evident in later progressive disease. The temporal relation between these processes remains unclear.

OBJECTIVE

To explore the association between changing brain lesion loads and subsequent tissue atrophy in multiple sclerosis.

METHODS

28 subjects with clinically probable or definite multiple sclerosis (mean age 46.0 years; 17 female and 11 male) were followed for 14 years after first onset of symptoms. T2 lesion loads were estimated soon after symptom onset and at around five, 10, and 14 years later. Disease related atrophy was estimated at the 14 year follow up by comparing brain tissue volumes (proportional to total intracranial volumes) determined in the multiple sclerosis group with data from 29 normal control subjects (mean age 36.7 years; 16 female, 13 male) using multiple linear regression analyses to allow for differences in age and sex distributions.

RESULTS

Change in lesion load in the first five years was more closely correlated to disease related brain atrophy at 14 years than later changes in lesion load, although the correlation was only moderate (Spearman correlation = -0.528, p = 0.004).

CONCLUSIONS

From this, it appears that early rather than later focal lesion accumulation relates to subsequent brain atrophy, but factors unconnected directly with lesion formation probably also play a significant role in determining such atrophy.

Precise estimate of fundamental in-vivo MT parameters in human brain in clinically feasible times

A methodology is presented for extracting precise quantitative MT parameters using a magnetisation-prepared spoiled gradient echo sequence. This method, based on a new mathematical model, provides relaxation parameters for human brain in-vitro and in-vivo. The in-vivo parameters have been obtained from three different regions of normal white matter: occipital white matter, frontal white matter and centrum semiovale; two regions of normal grey matter: cerebral cortex and cerebellum, and from five regions with MS lesions. All this has been achieved using MT images collected within a timeframe that is clinically feasible. We hope that this new technique will shed light on the properties and dynamics of water compartments within the brain.

Paediatric day stay tonsillectomy service: development and audit

Day stay paediatric tonsillectomy is well established in many parts of the world but not in Australia. This audit presents the protocol and results of the first one hundred and twenty-five patients managed this way at our hospital. Patients assessed as being at low risk of postoperative complications were offered the procedure as a day patient. All patients had a standardized relaxant anaesthetic technique with an intraoperative opioid and antiemetics. The patients were observed for six hours postoperatively in the Day Stay Unit and contacted the day following surgery to assess any problems. The overall incidence of postoperative vomiting was 15.6%. Two patients required overnight admission. One child was re-admitted on day four for delayed postoperative haemorrhage. Forty-four of the first forty-nine patients' parents were contacted four to six weeks later to assess their experiences of the process. Although approximately three-quarters of the parents rated their child's pain as moderate or severe at some stage, all but one felt the analgesic regimen was good or adequate. Eighty per cent were satisfied with having the surgery as a day stay procedure.

Quantitative 1H MRS imaging 14 years after presenting with a clinically isolated syndrome suggestive of multiple sclerosis

clinically isolated syndromes (CIS) are events suggestive for emerging multiple sclerosis (MS). A majority of patients develop MS within months or years whilst others remain clinically isolated. The goal of this study was to investigate whether biochemical metabolites detectable by 'H magnetic resonance spectroscopy (MRS) may serve to distinguish between these two groups. We investigated 41 patients 14 years after presentation with a CIS and 21 controls with combined quantitative short echo 'H MRS and magnetic resonance imaging (MRI) and assessed disability according to the Expanded Disability Status Scale (EDSS). At follow-up, 32 had developed MS, and 9 still had CIS. Compared with controls, MS patients demonstrated significantly higher concentrations of myo-inositol (Ins) in normal appearing white matter (NAWM) and lesions. Lesions also demonstrated a reduced N-acetyl-aspartate (NAA) level and an increase in choline-containing compounds (Cho). The NAWM Ins concentration was correlated with EDSS (r = 0.48, p = 0.005). MS normal appearing cortical grey matter (CGM) exhibited a decreased NAA. Patients who remained CIS did not differ significantly from controls in any MRS measure. Metabolite changes in normal appearing white and grey matter in MS indicate diffuse involvement of the entire MS brain, which was not seen in the persisting CIS patients. Elevated Ins in MS NAWM appeared functionally relevant It may indicate glial cell proliferation or gliosis.

Viability of Giardia intestinalis cysts and viability and sporulation state of Cyclospora cayetanensis oocysts determined by electrorotation

Electrorotation is a noninvasive technique that is capable of detecting changes in the morphology and physicochemical properties of microorganisms. Electrorotation studies are reported for two intestinal parasites, Giardia intestinalis and Cyclospora cayetanensis. It is concluded that viable and nonviable G. intestinalis cysts can be differentiated by this technique, and support for this conclusion was obtained using a fluorogenic vital dye assay and morphological indicators. The viability of C. cayetanensis oocysts (for which no vital dye assay is currently available) can also be determined by electrorotation, as can their sporulation state. Modeling of the electrorotational response of these organisms was used to determine their dielectric properties and to gain an insight into the changes occurring within them. Electrorotation offers a new, simple, and rapid method for determining the viability of parasites in potable water and food products and as such has important healthcare implications.

Operation Safe Haven: an evaluation of health surveillance and monitoring in an acute setting

From May to June 1999, 3,920 ethnic Albanians from Kosovo arrived in Australia as part of Operation Safe Haven. These people were evacuated from refugee camps in the former Yugoslav Republic of Macedonia. Initial processing in Australia occurred at East Hills Reception Centre, and accommodation for the duration of stay was provided in eight Haven Centres in five States. The arrival of a large number of refugees in a short time frame is unprecedented in Australia. A health surveillance system was developed and critical health data were collected to assess health status and needs, plan care, monitor for potential outbreaks of communicable diseases, track service use, to meet international reporting requirements and document our response to this crisis. In this article the health surveillance system is evaluated and suggestions are offered for the formulation of specific guidelines necessary for health surveillance in acute settings.

Evaluating the potential for opportunistic vaccination in a Northern Territory hospital

OBJECTIVE

To evaluate the potential for opportunistic vaccination and a simple intervention aimed at improving vaccination coverage for children in hospital.

METHODS

Hospital records were reviewed for children under 7 years, discharged from paediatric wards (PW) and the emergency department (ED) for 4 weeks before and after an intervention (423 and 446 children, respectively). This comprised the education of staff and the introduction of prompts to record vaccination status.

RESULTS

Documentation of vaccination status increased in the PW (63-90%) and the ED (24-46%), as did the adequacy of detail recorded (51-77% and 8-36%, respectively). Opportunistic vaccination increased from zero of 84 opportunities during the first audit to six of 139 following the intervention. All but one vaccine was given in the PW. Opportunistic vaccination improved when documentation identified a need for vaccination (P = 0. 02).

CONCLUSION

There were numerous missed opportunities to vaccinate children in hospital, especially in the ED. Simple prompts improved documentation of vaccination status and the detail of information recorded. Despite improved documentation, opportunistic vaccination failed to improve in the ED. Improving documentation of vaccination status is not sufficient in itself to improve opportunistic vaccination.

A South Australian Salmonella Mbandaka outbreak investigation using a database to select controls

Between April and June 1996, 15 persons with Salmonella enterica serovar Mbandaka infection were reported in South Australia (population 1.6 million) compared with 12 over the previous five years. To identify a possible source for the infections a case control study was conducted.

METHODS

Trained interviewers asked 15 cases and 45 controls about their consumption of 105 foods. Controls were matched to case residential location and age. They were selected from a previously constructed database of 3,014 randomly selected South Australian households.

RESULTS

Thirteen of the 15 cases ate 'generic' or 'retail store' brands of peanut butter produced by the same factory in another state, compared with five of the 45 controls (p < 0.01). Salmonella Mbandaka was isolated from three opened jars of peanut butter from case households, and from three unopened jars from retail outlets. Further investigation implicated roasted peanuts from a third Australian state as the source of the Salmonella contamination.

DISCUSSION

This is the first recorded outbreak of salmonellosis resulting from the consumption of peanut butter. The SA outbreak investigation comprised a matched case control study to identify possible common food sources. Such investigations need be conducted rapidly to maximise public health benefits, and the utility of selecting controls from a population based database can improve timeliness.

Community outbreak of psittacosis in a rural Australian town

BACKGROUND

Health authorities in Victoria, Australia were notified of three men from a rural town with atypical pneumonia, admitted to hospital over 8 days. Initial serological testing suggested Chlamydia psittaci as the cause. We did a case-control study to find risk factors for psittacosis.

METHODS

We searched for cases of pneumonia or severe flu-like illness through family physicians and the regional hospital. We selected three controls per case from the region's electoral roll. We collected blood for serological tests and administered questionnaires to all cases and controls.

FINDINGS

We found 16 cases of psittacosis and one died. Most cases were clustered within a small geographical area, with a median age of 58 years (range 23-76), 15 (94%) of whom were male. Keeping, handling, or feeding domestic or wild birds was not associated with illness. Cases spent a median of 17.5 h per week in their garden, compared with a median of 5.2 h for controls (p=0.04) and were more likely to have mowed lawns during the 3 weeks before onset of illness than controls (odds ratio 4.81 [95% CI 1.08-33.37]).

INTERPRETATION

We showed that psittacosis outbreaks are not limited to direct contact with birds and pose new challenges for disease control. Modifications may be needed to work outdoors to decrease the risk of psittacosis.

A prolonged outbreak of Campylobacter infection at a training facility

Campylobacter outbreaks are rarely detected despite Campylobacter being the most common food-borne illness notified to public health authorities. We report a prolonged outbreak of Campylobacter occurring over a three month period at a training facility. Seventy-eight cases were detected, 16 of which were confirmed Campylobacter infections. In seven affected groups of people using the facility, the attack rate ranged between 19% and 67%. An investigation of one sporting group showed that illness was associated with consumption of cucumber served at a self-serve salad bar. Six people attending the facility in other weeks also reported illness after eating only at the salad bar. Transmission of Campylobacter ceased after changes were instituted to food preparation and storage in the facility kitchen.

Hypoplasia of the epiglottis: case report and review

We report an infant born with a hypoplastic epiglottis and present the first in vivo photograph of the condition. Absence or hypoplasia of the epiglottis is a rare anomaly. Previously reported cases either died shortly after birth due to multiple congenital anomalies or details of the outcome were lacking. The clinical effects of hypoplastic epiglottis are discussed.

Clinical features that differentiate hantavirus pulmonary syndrome from three other acute respiratory illnesses

To elucidate the early clinical characteristics of hantavirus pulmonary syndrome (HPS), we compared the clinical features of 24 cases of HPS with those of cases of bacteremic pneumococcal pneumonia (n = 30), influenza (n = 33), or unexplained adult respiratory distress syndrome (ARDS, n = 21). On admission, patients with HPS were less likely than outpatients with influenza to have reported sore throat (OR = 0.02, P < .01) and cough (OR = 0.1, P = .01) and were less likely than patients with pneumococcal pneumonia to have lobar infiltrates detected by chest roentgenography (OR = 0, P < .01). Multivariate discriminant analysis revealed that three clinical characteristics at admission (dizziness, nausea or vomiting, and absence of cough) and three initial laboratory abnormalities (low platelet count, low serum bicarbonate level, and elevated hematocrit level) served to identify all patients with HPS and to exclude HPS in at least 80% of patients with unexplained ARDS. These findings warrant further study and should facilitate the early recognition of patients with HPS, who may benefit from early critical-care intervention.

Laryngoscopic diagnosis of laryngeal sarcoid

Sarcoidosis is usually a multisystem granulomatous disease, and it sometimes affects the larynx and causes symptoms of dysphonia, dyspnea, and dysphagia. Laryngeal sarcoid has a characteristic appearance at direct or indirect laryngoscopy: the supraglottic tissues are symmetrically affected with a pale, diffusely swollen appearance somewhat like that of epiglottitis. Five cases of laryngeal sarcoid are presented. Three photographs taken at direct laryngoscopy, and one at indirect laryngoscopy, document and emphasize the typical appearance of the supraglottic tissues. The appearance of this uncommon condition is sufficiently characteristic to suggest the diagnosis, which can finally be confirmed only by biopsy.

User-space protocols deliver high performance to applications on a low-cost Gb/s LAN

Two important questions in high-speed networking are firstly, how to provide Gbit/s networking at low cost and secondly, how to provide a flexible low-level network interface so that applications can control their data from the instant it arrives.

We describe some work that addresses both of these questions. The Jetstream Gbit/s LAN is an experimental, low-cost network interface that provides the services required by delay-sensitive traffic as well as meeting the performance needs of current applications. Jetstream is a combination of traditional shared-medium LAN technology and more recent ATM cell- and switch-based technology.

Jetstream frames contain a channel identifier so that the network driver can immediately associate an incoming frame with its application. We have developed such a driver that enables applications to control how their data should be managed without the need to first move the data into the application's address space. Consequently, applications can elect to read just a part of a frame and then instruct the driver to move the remainder directly to its destination. Individual channels can elect to receive frames that have failed their CRC, while applications can specify frame-drop policies on a per-channel basis.

Measured results show that both kernel- and user-space protocols can achieve very good throughput: applications using both TCP and our own reliable byte-stream protocol have demonstrated throughputs in excess of 200 Mbit/s. The benefits of running protocols in user-space are well known- the drawback has often been a severe penalty in the performance achieved. In this paper we show that it is possible to have the best of both worlds.

The correlation of placental protein 14 concentrations in uterine flushing and endometrial morphology in the peri-implantation period

The relationship between the concentrations of placental protein 14 (PP14) in uterine flushing and the endometrial morphology in the mid-luteal phase was assessed in a prospectively designed study involving the precise timing of all samples by the luteinizing hormone (LH) surge. A total of 29 regularly cycling women with unexplained infertility or recurrent miscarriage were studied. To flush the uterine cavity, 10 ml of physiological saline solution was used immediately prior to sampling of an endometrial specimen for morphological study, in the mid-luteal phase. PP14 concentrations were measured by radioimmunoassay in uterine flushings and plasma samples; the endometrium was assessed by the use of histological dating criteria and morphometric techniques. PP14 levels in uterine flushings were correlated with endometrial dating and volume fraction measurement of the glands. They were consistently below the sensitivity of the assay with histological dating of < day LH +5, or when the glandular lumen occupied < 20% of the gland. In contrast, PP14 concentrations in plasma were not related to histological dating or morphometric analyses, and did not differ in patients with normal endometrial development (20.8 ng/ml) and in those with retarded endometrial development (22.5 ng/ml). The presence of detectable concentrations of PP14 in uterine flushing was significantly associated with normal histological dating. Uterine flushing may therefore provide a reliable, non-invasive alternative to endometrial biopsy in the evaluation of endometrial function in the peri-implantation period.

Concentration of endometrial protein PP14 in uterine flushings throughout the menstrual cycle in normal, fertile women

OBJECTIVE

To determine the variation in concentration of endometrial protein PP14 in uterine flushings throughout the menstrual cycle comparing this to concentrations in plasma samples.

DESIGN

Precise timing of all samples by the luteinising hormone surge.

SETTING

Jessop Hospital for Women, Sheffield.

SUBJECTS

Twenty-three regularly cycling, previously fertile volunteer women.

INTERVENTIONS

Observational study; 10 ml of physiological saline was used to flush the uterine cavity once or serially in the cycle of the study.

MAIN OUTCOME MEASURES

The measurement of PP14 levels by radioimmunoassay in uterine flushings and plasma samples.

RESULTS

In uterine flushing, PP14 levels were not detectable in significant amounts in the proliferative phase and the early luteal phase; after day LH + 6, the concentration rises rapidly with a doubling time of only 6.6 to 14.6 h in the midluteal phase. In the late luteal phase, the concentrations in uterine flushing were over a hundred times higher than the corresponding plasma samples.

CONCLUSIONS

The measurement of PP14 in uterine flushings is likely to be of greater value than the measurement in plasma samples; it may provide a valuable alternative to the evaluation of endometrial function.

Placental protein 14 levels in uterine flushing and plasma of women with unexplained infertility

OBJECTIVES

To measure concentrations of placental protein 14 (PP14) in uterine flushings and plasma samples obtained from patients with unexplained infertility and to compare the results of those of normal fertile women.

DESIGN

Prospective study.

SETTING

Infertility and gynaecology outpatient clinics at the Jessop Hospital for Women, Sheffield, United Kingdom.

PATIENTS

Sixteen patients with unexplained infertility and 12 normal fertile women who had been previously sterilized.

INTERVENTIONS

Daily monitoring of luteinizing hormone (LH) to detect the LH surge; uterine flushings and blood samples were obtained on days 7, 10, and 12 after the LH surge.

MAIN OUTCOME MEASURES

The measurement of PP14 concentration in uterine flushings and plasma samples throughout the luteal phase.

RESULTS

Levels of PP14 in uterine flushings of patients with unexplained infertility were significantly lower than those of normal fertile women on days LH +10 and LH +12. No significant differences were observed between the two groups in PP14 levels in uterine flushings on day LH +7 and plasma samples on days LH +7, LH +10, and LH +12.

CONCLUSIONS

Patients with unexplained infertility have reduced concentrations of PP14 in uterine flushings but not in plasma samples as compared with normal fertile women. Placental protein 14 measurement in uterine flushings may be a more valuable method of assessing endometrial function in infertile patients than plasma levels of the protein.

[Integration of a nursing model into a local community service center]

Four years ago, maternal/child health nurses from the Metro CLSC in Montreal found themselves in a crisis situation. They were unable to evaluate their work--which consisted of varying tasks and the need for these nurses to be everywhere at the same time. A need to reflect on the situation prompted the team to meet for three hours twice monthly to analyze the problems and establish a plan of action. A nurse-counsellor guided the initial process. A post-natal home visit was chosen as an example for discussion. The group conceded that each member of the perinatal team had a different philosophy and nursing approach. The team consisted of nurses of various ages, experiences and educational backgrounds. Some nurses felt more comfortable expressing themselves in English while others preferred French. At times this group diversity hindered the communication of ideas as well as the ability to reach a consensus about required practice changes. The McGill Nursing model from McGill University was chosen and integrated into the team's practice. The author presents this model and outlines it's advantages and disadvantages. She illustrates this model with the use of an ecomap designed by Wright and Leahy (1984). This nursing model addresses the use of forces within each individual as well as the family. Since it takes into account the extended family, it allows a global approach to care. The article focuses on the essential elements of integrating the model, including it's development and how it was accepted by these nurses. According to the author, the process of changing to this model is dynamic and continuous.(ABSTRACT TRUNCATED AT 250 WORDS)

An analysis of the variation of plasma concentrations of placental protein 14 in artificial cycles

OBJECTIVE

To analyze the factors affecting the variation of plasma concentration of placental protein 14 (PP14) in artificial cycles.

DESIGN

The effects of different hormone replacement therapy (HRT) regimens were examined in a crossover design.

SETTING

Jessop Hospital for Women, Sheffield, United Kingdom.

PATIENTS

Eighteen women with premature ovarian failure: 6 associated with Turner's syndrome and 12 with idiopathic premature ovarian failure.

INTERVENTIONS

Four different HRT regimens; 36 study cycles.

MAIN OUTCOME MEASURES

Plasma PP14 concentrations on days 1, 15, 19, and 29 of the artificial cycles.

RESULTS

In cycles treated with a standard HRT, the levels were similar to those of the natural cycle. Subjects with Turner's syndrome did not have elevated PP14 levels, whereas the majority (9/12 [75%]) of those with idiopathic premature ovarian failure had elevated levels on day 29 of the cycle. Levels of PP14 were reduced when either the doses of estradiol valerate were reduced to 1/3 or the doses of progesterone (P) were reduced to 1/5 of the standard HRT.

CONCLUSIONS

Plasma levels of PP14 are dependent not only on P stimulation but also on adequate estrogen priming.

Stationary vs. mapping manometry in evaluating dysphagia

Two methods are used to assess esophageal motility. The mapping technique uses catheter withdrawal at 1 cm steps until the entire esophagus is evaluated. A simpler method is commonly used that involves keeping the catheter stationary for the entire evaluation. We compared these 2 techniques in 30 patients referred for the evaluation of dysphagia. Emphasis was placed on the distal 10 cm of the esophagus because this is the primary location of esophageal motility disorders. There was excellent correlation between techniques for mean distal amplitude (r = 0.945), mean distal duration (r = 0.942), and percentage of non-peristaltic contractions (r = 0.967). The overall manometry diagnosis was similar by both methods in 27 (90%) patients. Three patients had different manometry diagnoses resulting from use of the two techniques. However, the change in diagnosis was only clinically important in one patient in whom the mapping technique identified a segmental motility disorder that had been missed by the stationary technique. Stationary manometry had a 94% sensitivity and 93% specificity rate for identifying motility disorders compared to mapping manometry. We conclude that stationary manometry is a simple and accurate method for evaluating esophageal pressures and distal disorders. Only those patients with normal results of stationary studies may benefit by further mapping to identify rare segmental motility disorders.