Neuronal antibody prevalence in children with seizures under 3 years: A prospective national cohort

OBJECTIVE

To report the prevalence of anti-neuronal antibodies in a prospective whole-nation cohort of children presenting with seizures before their third birthday.

METHODS

This was a prospective population-based national cohort study involving all children presenting with new-onset epilepsy or complex febrile seizures before their third birthday over a 3-year period. Patients with previously identified structural, metabolic, or infectious cause for seizures were excluded. Serum samples were obtained at first presentation and tested for 7 neuronal antibodies using live cell-based assays. Clinical data were collected with structured proformas at recruitment and 24 months after presentation. In addition, patients with seizures and clinically suspected autoimmune encephalitis were independently identified by a review of the case records of all children <3 years of age in Scotland who had undergone EEG.

RESULTS

Two hundred ninety-eight patients were identified and recruited and underwent autoantibody testing. Antibody positivity was identified in 18 of 298 (6.0%). The antibodies identified were GABA receptor B (n = 8, 2.7%), contactin-associated protein 2 (n = 4, 1.3%), glycine receptor (n = 3, 1.0%), leucine-rich glioma inactivated 1 (n = 2, 0.7%), NMDA receptor (n = 1, 0.3%), and GABA receptor A (n = 1, 0.3%). None of these patients had a clinical picture of autoimmune encephalitis. Seizure classification and clinical phenotype did not correlate with antibody positivity.

CONCLUSIONS

Autoimmune encephalitis is very rare in early childhood. However serum neuronal antibodies are identified in 6.4% of children presenting with seizures at <3 years of age. Antibody testing should not be a routine clinical test in early childhood-onset epilepsy because, in the absence of other features of autoimmune encephalitis, antibody positivity is of doubtful clinical significance. Antibody testing should be reserved for patients with additional features of encephalitis.

Effects of the Positive Threshold and Data Analysis on Human MOG Antibody Detection by Live Flow Cytometry

Human autoantibodies targeting myelin oligodendrocyte glycoprotein (MOG Ab) have become a useful clinical biomarker for the diagnosis of a spectrum of inflammatory demyelinating disorders. Live cell-based assays that detect MOG Ab against conformational MOG are currently the gold standard. Flow cytometry, in which serum binding to MOG-expressing cells and control cells are quantitively evaluated, is a widely used observer-independent, precise, and reliable detection method. However, there is currently no consensus on data analysis; for example, seropositive thresholds have been reported using varying standard deviations above a control cohort. Herein, we used a large cohort of 482 sera including samples from patients with monophasic or relapsing demyelination phenotypes consistent with MOG antibody-associated demyelination and other neurological diseases, as well as healthy controls, and applied a series of published analyses involving a background subtraction (delta) or a division (ratio). Loss of seropositivity and reduced detection sensitivity were observed when MOG ratio analyses or when 10 standard deviation (SD) or an arbitrary number was used to establish the threshold. Background binding and MOG ratio value were negatively correlated, in which patients seronegative by MOG ratio had high non-specific binding, a characteristic of serum that must be acknowledged. Most MOG Ab serostatuses were similar across analyses when optimal thresholds obtained by ROC analyses were used, demonstrating the robust nature and high discriminatory power of flow cytometry cell-based assays. With increased demand to identify MOG Ab-positive patients, a consensus on analysis is vital to improve patient diagnosis and for cross-study comparisons to ultimately define MOG Ab-associated disorders.

Neuronal antibody detection and improved lung cancer prediction in Lambert-Eaton myasthenic syndrome

Since approximately 50% of patients with Lambert-Eaton myasthenic syndrome (LEMS) subsequently develop small-cell lung cancer (SCLC), it is important to be able to predict cancer occurrence in these patients at neurological presentation. We aimed to determine whether circulating biomarkers were effective and objective predictors of cancer development in LEMS. We found that the presence of either SOX2, N-type voltage gated calcium channel or GABAb antibodies at LEMS diagnosis was highly sensitive (84%) and specific (87%) for the detection of SCLC. Screening for SOX2 and neuronal antibodies is a useful adjunct to clinical predictive scoring tools in predicting SCLC in LEMS.

Glutamate receptor δ2 serum antibodies in pediatric opsoclonus myoclonus ataxia syndrome

Objective

To identify neuronal surface antibodies in opsoclonus myoclonus ataxia syndrome (OMAS) using contemporary antigen discovery methodology.

Methods

OMAS patient serum immunoglobulin G immunohistochemistry using age-equivalent rat cerebellar tissue was followed by immunoprecipitation, gel electrophoresis, and mass spectrometry. Data are available via ProteomeXchange (identifier PXD009578). This generated a list of potential neuronal surface cerebellar autoantigens. Live cell-based assays were used to confirm membrane-surface antigens and adsorb antigen-specific immunoglobulin Gs. The serologic results were compared to the clinical data.

Results

Four of the 6 OMAS sera tested bound rat cerebellar sections. Two of these sera with similar immunoreactivities were used in immunoprecipitation experiments using cerebellum from postnatal rat pups (P18). Mass spectrometry identified 12 cell-surface proteins, of which glutamate receptor δ2 (GluD2), a predominately cerebellar-expressed protein, was found at a 3-fold-higher concentration than the other 11 proteins. Antibodies to GluD2 were identified in 14/16 (87%) OMAS samples, compared with 5/139 (5%) pediatric and 1/38 (2.6%) adult serum controls (p < 0.0001), and in 2/4 sera from patients with neuroblastoma without neurologic features. Adsorption of positive OMAS sera against GluD2-transfected cells substantially reduced but did not eliminate reactivity toward cerebellar sections.

Conclusion

Autoantibodies to GluD2 are common in patients with OMAS, bind to surface determinants, and are potentially pathogenic.

Active zone assembly and synaptic release

Neurotransmitter release at chemical synapses occurs when synaptic vesicles fuse to the presynaptic membrane at a specialized site termed the active zone. The depolarization-induced fusion is highly dependent on calcium ions, and, correspondingly, the transmission characteristics of synapses are thought to be influenced by the spatial arrangement of voltage-gated calcium channels with respect to vesicle release sites. Here, we review the involvement of the Drosophila Bruchpilot (BRP) protein in active zone assembly, a process that is required for the clustering of presynaptic calcium channels to ensure efficient vesicle release.

Histological evidence for the role of mechanical stress in modulating thermal denaturation of collagen

The hyperthermia and thermal denaturation literatures reveal a time-temperature equivalency when heating cells or connective tissues: thermal damage increases with increasing temperature (for the same duration) and increases with increasing duration (for the same temperature). Recent findings conversely suggest that increasing the mechanical loading on a tissue during heating decreases the thermal damage (for a given temperature and duration of heating). Surprisingly, however, there are few histological correlates of such damage. In this paper, we show that progressive light microscopic changes - swelling of collagen bands, thickening of collagen-rich layers, hyalinization, and loss of birefringence approximately - correlate very well with both increased heating times and decreased mechanical loading. Increased mechanical stress is thus thermally protective and should be considered in the design of clinical procedures that use heating to treat diseases or injuries.

Control of foot differentiation in Hydra: Phylogenetic footprinting indicates interaction of head, bud and foot patterning systems

Homeodomain transcription factor CnNK-2 seems to play a major role in foot formation in Hydra. Recently, we reported in vitro evidence indicating that CnNK-2 has autoregulatory features and regulates expression of the morphogenetic peptide pedibin. We proposed that CnNK-2 and pedibin synergistically orchestrate foot differentiation processes. Here, we further analyzed the regulatory network controlling foot formation in Hydra. By phylogenetic footprinting we compared the CnNK-2 5'-flanking sequence from two closely related species, Hydra vulgaris and Hydra oligactis. Unexpectedly, we detected a highly conserved binding site for HNF-3beta, a vertebrate Forkhead transcription factor, in the CnNK-2 5'-flanking region. The Hydra HNF-3beta homolog budhead is predominantly expressed in the apical region of the body column and early during budding. Budhead is absent from tissue expressing CnNK-2 and thought to be involved in determining tissue for head differentiation. By electrophoretic mobility shift assays we demonstrate an in vitro interaction between recombinant budhead protein and the interspecific conserved HNF-3beta binding motif in the CnNK-2 5'-flanking region. Our results strengthen the view of CnNK-2 as an important regulator during foot patterning processes. Furtheron, they point to budhead as a candidate for a transcriptional regulator of CnNK-2 and to an interaction of foot and head patterning processes in Hydra on the molecular level.

Fifty ways to leave your rubber: how men in Mombasa rationalise unsafe sex

OBJECTIVE

To explore the reasons why men who have sex with sex workers in Kenya refuse to use condoms in order to develop potential interventions that might help to overcome these barriers.

METHODS

We conducted participant observations over a period of 2 months in the bars, discos, shebeens, and guesthouses of Mombasa, Kenya, where many of the sexual transactions are initiated.

RESULTS

Analysis of the participant observations revealed at least 50 reasons for not using a condom, which we grouped into six categories: condoms are not pleasurable, condoms are defective, condoms are harmful, condoms are unnecessary, condoms are too hard to use, and external forces prohibit using condoms.

CONCLUSIONS

Some of the reasons men say they do not use condoms would be difficult to affect directly. Others are the result of gaps in knowledge and have not been impacted through better communication strategies. Finally, some of the reasons for not using condoms, such as men's weaknesses, and the loss of pleasure, could possibly be addressed through the introduction of female controlled devices. However, the most important conclusion of this paper is that men who pay for sex do so because it is pleasurable and many men do not find the male condom pleasurable. Therefore, messages targeted at men who have sex with sex workers may not be 100% successful if they only emphasise the benefits of condom use as disease control.

Control of foot differentiation in Hydra: in vitro evidence that the NK-2 homeobox factor CnNK-2 autoregulates its own expression and uses pedibin as target gene

The foot of the simple metazoan Hydra is a highly dynamic body region of constant tissue movement, cell proliferation, determination and differentiation. Previously, two genes have been shown to participate in the development and differentiation of this body region: homeodomain factor CnNK-2 and signal peptide pedibin [Dev. Biol. 180 (1996) 473; Development 126 (1999) 517; Development 122 (1996) 1941; Mech. Dev. 106 (2001) 37]. CnNk-2 functions as transcriptional regulator and is responsive to changes in the positional value while the secreted peptide pedibin serves as "extrinsic" positional signal. Exposure of polyps to pedibin increases the spatial domain of CnNK-2 expression towards the gastric region, indicating that positional signals are integrated at the cis-regulatory region of CnNK-2. In the present study, to elucidate the molecular basis of the interaction of CnNK-2 and pedibin, we characterized the 5' regulatory regions of both genes. Within the CnNK-2 5' upstream region, electrophoretic mobility shift assays showed that putative NK-2 binding motifs are specifically bound by both nuclear protein from Hydra foot and by recombinant CnNK-2, suggesting that CnNK-2 might autoregulate its own expression. This is the first indication for an autoregulatory circuit in Hydra. In addition, we also identified NK-2 binding sites in the cis-regulatory region of the pedibin gene, indicating that this gene is one of the targets of the transcription factor CnNK-2. On the basis of these results, we present a model for the regulatory interactions required for patterning the basal end of the single axis in Hydra which postulates that CnNK-2 together with pedibin orchestrates foot specific differentiation.

A comparative study of the experiences of violence of English and Swedish mental health nurses

Recent studies suggest that violence in health care environments, especially mental health care, appears to be increasing. Although there is a lack of cross-cultural studies to prove it, this increase in violence would seem to be an international phenomenon. The present study sought to compare the extent and nature of violence encountered by mental health nurses in Sweden and England. Systematic studies of violence have previously been carried out independently in both countries but this was the first attempt to compare levels of violence. Clearly defined study protocols were put in place, an operational definition of 'violence' adhered to, and random samples recruited. A specially designed questionnaire was sent to every subject (Swedish nurses n=720; English nurses n=296) enquiring about the extent of nurses' exposure to violence, the nature and severity of the violence experienced, and the effect of violence on self-esteem and job satisfaction. Significant differences were found with English nurses experiencing more violence than their Swedish counterparts. Yet support for English nurses appeared to be less good than for Swedish nurses. Reasons for the differences are discussed along with possible measures to minimise the frequency of violence against nurses and the negative effects on their work.

Low Temperature Fluorescence Imaging of Freeze-trapped Human Cervical Tissues

We characterized the fluorescence intensity distribution within the epithelia and stroma of frozen human cervical tissues at the following excitation-emission wavelength pairs: 440, 525 nm and 365, 460 nm. The intensities at both excitation-emission wavelength pairs are significantly lower in the epithelia of severely dysplastic tissues, relative to that in normal and inflammatory tissues. Furthermore, there are small differences in (1) the epithelial intensity of severe dysplasia and mild dysplasia at 440, 525 nm and (2) the stromal intensity of inflammatory and severely dysplastic tissues at 365, 460 nm. A comparison of the ratio of intensities at 440, 525 nm and 365, 460 nm between the epithelia of each tissue type indicates that this ratio is lowest in severely dysplastic tissues. It is interesting to note that the epithelial and stromal intensities are comparable at 365, 460 nm; however, at 440, 525 nm, the epithelial intensity is more than a factor of two less that that of the stroma for all tissue types.

Optimizing the therapeutic approach in tinea capitis of childhood with itraconazole

BACKGROUND

Tinea capitis is the most common dermatophytosis of childhood with increasing incidence. Whereas griseofulvin is considered by many as the mainstay of treatment, newer oral antifungal agents, including fluconazole, itraconazole and terbinafine have demonstrated higher efficacy, resulting in shorter treatment durations.

OBJECTIVES

We aimed to determine the optimum regimen for the treatment of childhood tinea capitis with itraconazole.

METHODS

A mycological culture outcome-dependent combination of a 28-day continuous and facultative additional 14-day courses with itraconazole was used in 42 children (20 girls; 22 boys) aged 12-140 months (mean 66) with tinea capitis due to Microsporum canis (n = 26) and Trichophyton violaceum (n = 16). The drug was given orally according to the patients' body weight (50 mg daily for < 20 kg; 100 mg daily for > or = 20 kg) over 4 weeks. Direct microscopy and fungal culture as a parameter for efficacy were repeated 2 weeks after termination of treatment. Assessment of efficacy was based on the evaluation of results from light microscopy and culture at 8 weeks after initiation of treatment, and in the case of a further positive mycological culture at 14 and 20 weeks, respectively. A positive fungal culture at these times resulted in an additional course for 2 weeks with the initially chosen itraconazole dosage.

RESULTS

In 34 of 42 patients a single 4-week course of itraconazole resulted in a complete mycological cure of lesions as demonstrated by light microscopy and mycological culture. Four of 42 patients had to be treated by a second itraconazole course for 2 weeks, and four children received a third course of itraconazole for 2 weeks until all lesions showed negative direct microscopy and mycological culture. No abnormal haematological or biochemical results occurred. Apart from transient, completely reversible indigestion in two children, no side-effects were observed.

CONCLUSIONS

A culture-based 28-day continuous therapeutic regimen plus facultative cultural outcome-dependent additional 14-day courses of a body weight-adapted dosage of itraconazole in tinea capitis due to M. canis and T. violaceum is discussed; this offers the advantage of an effective therapy with complete negative direct microscopy as well as negative cultural results, within a shorter active treatment period (cf. previous studies with continuous administration of itraconazole).

Lack of functional Pit-1 and Pit-2 expression on hematopoietic stem cell lines

Hematopoietic stem cells (HSC) are an important target for retroviral gene transfer. However, transduction efficiency in these HSC is extremely low compared to fibroblasts or more mature hematopoietic cells. This infection block was analyzed in the HSC line FDC-Pmix. The infection frequency with the amphotropic murine leukemia virus (MLV-A) is more than 100-fold lower in FDC-Pmix cells as compared to fibroblasts. Pseudotyping with the env of the 10A1 strain (MLV-10A1), which uses both the amphotropic receptor (Pit-2) and the receptor for gibbon ape leukemia virus (Pit-1), did not improve the infection efficiency. Vectors pseudotyped with VSV G protein were found to overcome the infection block in FDC-Pmix, confirming that the block is at the level of virus binding and possibly penetration. Accordingly, we could not detect virus binding of MLV-A or MLV-10A1 to FDC-Pmix cell lines. Northern blot analysis was performed to detect whether the defect is at the level of transcription. Surprisingly, similar levels of Pit-2 receptor transcripts were detected in all cell types. The overexpression of rat Pit-2 DNA in CHO but not in FDC-Pmix cells improved amphotropic infection frequency after introducing rat Pit-2 DNA into the cells. Taken together these results show that the inefficient infection of FDC-Pmix is due to a lack of functional receptors. Either the receptor protein is incorrectly processed in these cells or a cofactor is missing in FDC-Pmix cells that is necessary for efficient binding and/or penetration.

Feelings of professional fulfilment and exhaustion in mental health personnel: the importance of organisational and individual factors

BACKGROUND

Mental health personnel are at high risk for mental illness, burnout and suicide. Previous studies of this group of professionals have indicated the importance of organisational factors in explaining burnout, or exhaustion, and work satisfaction. This study looks more systematically at the contribution of organisational and individual factors to work-related exhaustion and to professional fulfillment, an expanded version of job satisfaction.

METHODS

A cross-sectional study of 1, 051 psychiatrists and mental health nurses in the city of Stockholm was carried out by postal questionnaire with a previously validated instrument. Multiple and logistic regressions were used to identify predictors of exhaustion and professional fulfillment.

RESULTS

Organisational characteristics were found to be more important than individual characteristics in predicting exhaustion and professional fulfillment in mental health professionals.

CONCLUSIONS

The results indicate that the psychosocial work environment and well-being of mental health professionals can be improved by concentrating on organisational factors such as efficiency, personal development and goal quality.

Controlled temperature tissue fusion: argon laser welding of rat intestine in vivo. Part one

BACKGROUND AND OBJECTIVE

Thermal denaturation of proteins is recognized as a rate process governed by the local temperature-time response. Since rate processes are exponential with temperature, laser-assisted tissue welding was performed with and without temperature feedback control (TFC) to investigate the efficacy of temperature feedback in enhancing the photothermal welding process in vivo.

STUDY DESIGN/MATERIALS AND METHODS

An automated system was developed for temperature feedback controlled laser irradiation. An experimental device incorporating co-aligned laser delivery and temperature detection was used to perform argon laser welded (with and without TFC) enterotomies. The weld strength and histology of laser welded and control sutured enterotomies were compared in an in vivo rat model. Animals (n = 41) were sacrificed at 1, 3, 7, and 21 days postoperatively, and the anastomotic site was removed for bursting/leaking pressure measurements and histological examination.

RESULTS

Laser-welded (with and without TFC) and control sutured anastomoses in surviving animals healed comparably. Some laser-welded anastomoses without TFC ruptured spontaneously (4 out of 15) leading to the animals' death within the first 24-36 hours postoperatively. None of the animals in the other groups had this problem (control suture 0/6; laser with TFC 1 leak/8). The bursting/leaking pressures of the laser welded anastomoses were not significantly different than those of the sutured controls.

CONCLUSION

TFC improves the quality of laser-welded rat intestinal anastomoses in vivo in the critical first postoperative 36 hours.

Controlled temperature tissue fusion: Ho:YAG laser welding of rat intestine in vivo. Part two

BACKGROUND AND OBJECTIVE

Temperature feedback control (TFC) during laser-assisted tissue welding was implemented to eliminate exponential increases in the rate of denaturation associated with rapidly increasing temperatures. This study was undertaken to investigate and compare the weld strengths and healing responses of laser welded enterotomies with and without TFC using a cw Ho:YAG laser and to examine the effects of wavelength on weld strength and histology. The Ho:YAG experimental results were compared with a similar study using cw argon ion laser irradiation.

STUDY DESIGN/MATERIALS AND METHODS

An automated system was developed for temperature feedback controlled laser irradiation. An experimental device incorporating co-aligned laser delivery and temperature detection was used to perform cw Ho:YAG laser-welded enterotomies (with and without TFC). The weld strength and histology of laser welded and control sutured enterotomies were compared in an in vivo rat model (Ho:YAG, n = 42; argon, n = 41). Animals were sacrificed at 1, 3, 7, and 21 days postoperatively and the anastomotic site was removed for bursting/leaking pressure measurements and histological examination.

RESULTS

Argon and Ho:YAG laser-welds with and without TFC and the control sutured anastomoses healed comparably, although wound abscesses were more prevalent in the Ho:YAG group leading to delay in mucosal healing. Laser-welded anastomoses without TFC were associated with more spontaneous ruptures and leaks (argon: 4/6 ruptures; Ho:YAG: 1/4 leak, 2/4 ruptures, & 1/3 stenosis) during the survival period than those with TFC (argon: 1/3 leak; Ho:YAG: 1/5 rupture). Bursting pressures of the Ho:YAG welds were weaker at 1 week than the argon welds, but by 3 weeks, laser welds and suture anastomoses were equally strong.

CONCLUSION

From the spontaneous failure rates encountered, it is believed that TFC improves the quality and stability of laser-assisted enterotomy closures in surviving animals. However, TFC does not provide a satisfactory method to identify completion of a weld.

Autofluorescence patterns in short-term cultures of normal cervical tissue

Fluorescence spectroscopy has potential to improve cervical precancer detection. The relationship between tissue biochemistry and fluorescence is poorly understood. The goal of this study was to characterize normal cervical autofluorescence, using fresh tissue short-term tissue cultures and epithelial cell suspensions. Transverse, short-term tissue cultures were prepared from 31 cervical biopsies; autofluorescence images were obtained at 380 and 460 nm excitation. Fluorescence excitation-emission matrices were measured from normal, precancerous and cancerous cervical cell suspensions. Observed fluorescence patterns contrast those reported for frozen-thawed tissue, and were placed into groups with (1) bright epithelial and weak stromal fluorescence; (2) similar epithelial and stromal fluorescence; and (3) weak epithelial and bright stromal fluorescence. The average ages of women in the groups were 30.9, 38.0 and 49.2 years. Epithelial fluorescence intensity was similar in Groups 1 and 2, but weaker in Group 3. Stromal intensity was similar in Groups 2 and 3, but weaker in Group 1. The ratio of epithelial to stromal fluorescence intensity was significantly different for all groups. EEMs of cell suspensions showed peaks consistent with tryptophan, reduced form of nicotinamide adenine dinucleotide (phosphate) and flavin adenine dinucleotide. Short-term tissue cultures represent a novel, biologically appropriate model to understand cervical autofluorescence. Our results suggest a biological basis for the increased fluorescence seen in older, postmenopausal women.

Changes in collagen I and collagen III metabolism in patients with generalized atopic eczema undergoing medium-dose ultraviolet A1 phototherapy

Fourteen patients suffering from acute, exacerbated atopic eczema were screened for changes in collagen I and collagen III metabolism in serum (n = 11), urine (n = 11) and skin biopsies (n = 9) before and after medium-dose ultraviolet (UV) A1 phototherapy (15 exposures of 50 J/cm2 over a 3-week period, total dose 750 J/cm2). Mature collagen I and, to a lesser extent, mature collagen III were found to be decreased after the therapy in skin samples from the irradiated patients. As markers of collagen I degradation, the cross-links pyridoline and deoxypyridoline were analysed in urine using high-performance liquid chromatography. Both cross-links were found to be mildly increased after UVA1 phototherapy, without reaching statistical significance. As markers of de novo collagen synthesis we screened for the procollagen I-carboxyterminal peptide (PICP) and procollagen III-aminoterminal peptide (PIIINP) levels in serum and skin. The ratio of PICP to PIIINP in serum dropped significantly after the UVA1 phototherapy, suggesting a different impact of UVA1 on the two collagens. These findings were paralleled by a diminished ratio of PICP to PIIINP in tissue samples. Staining for matrix metalloproteinase 1 (MMP-1) and its specific counterpart, tissue inhibitor of MMP-1 (TIMP-1), showed slight increases for both proteins by therapeutic UVA1; this was also seen in serum for TIMP-1 but not MMP-1. In our study, high-energy UVA1 doses induced changes of the skin collagens in patients with atopic eczema which are measurable by their metabolites in serum and urine.

An examination of nonresponse in a work environment questionnaire mailed to psychiatric health care personnel

Nonresponse to surveys, which seems to plague work environment studies and studies of health care personnel in particular, may pose problems of generalizability and validity. The aim of this study was to provide an estimate of nonresponse error in a self-administered survey concerning the work environment of psychiatric health care personnel. A random sample of 10% of the original survey population (N = 693) was selected to participate in a telephone follow-up of a postal survey that had a response rate of 51%. There were no differences between the responders and nonresponders to the postal survey on the exposure or outcome variables. There was no evidence of nonresponse bias in this study, although recall bias may have been a problem. In those cases in which generalizability is deemed important, it is recommended that nonresponse studies be regularly carried out when response rates are less than 100%.

An examination of nonresponse in a work environment questionnaire mailed to psychiatric health care personnel

Nonresponse to surveys, which seems to plague work environment studies and studies of health care personnel in particular, may pose problems of generalizability and validity. The aim of this study was to provide an estimate of nonresponse error in a self-administered survey concerning the work environment of psychiatric health care personnel. A random sample of 10% of the original survey population (N = 693) was selected to participate in a telephone follow-up of a postal survey that had a response rate of 51%. There were no differences between the responders and nonresponders to the postal survey on the exposure or outcome variables. There was no evidence of nonresponse bias in this study, although recall bias may have been a problem. In those cases in which generalizability is deemed important, it is recommended that nonresponse studies be regularly carried out when response rates are less than 100%.

Violence in mental health care: the experiences of mental health nurses and psychiatrists

Violence against mental health service personnel is a serious workplace problem and one that appears to be increasing. This study aimed to ascertain the extent and nature of violence against mental health nurses and psychiatrists, and to identify what support, if any, they received following exposure to violence. Mental health staff working within five West Midlands Trusts in the United Kingdom were surveyed using a postal questionnaire to investigate the extent and nature of violence they encountered in their daily work. There was an overall response rate of 47%, which included a response rate for psychiatrists of 60% (n=74) and for mental health nurses of 45% (n=301). Though both groups experienced violence at work, nurses were found: to have been exposed to violence significantly more during their career; to have been a victim of violence within the previous 12 months of the survey; and to have suffered a violent incident involving physical contact. Whilst a higher proportion of nurses than psychiatrists received some support following a violent incident, a large proportion of both groups did not receive any, although most felt in need of it. The implications of this study for training and management are discussed.

Individual and organizational well-being in psychiatric nursing: a cross-cultural study

Although health care systems around the world are undergoing rapid changes, there is an absence of comparative studies of how these changes affect nurses' well-being and work life. The purpose of this study was (i) to identify and describe possible differences between the psycho-social work environments of English and Swedish mental health nurses, and (ii) to attempt to explain these differences. 1016 psychiatric nurses from Stockholm (Sweden) and Birmingham (England) responded to a postal questionnaire on their psycho-social work environment and feelings of professional fulfillment, mental energy and work-related exhaustion. The study was given ethical clearance in Stockholm and Birmingham. Results indicated that while the English nurses rated their organizational well-being more favourably, Swedish psychiatric nurses reported greater individual well-being than their counterparts. Multiple regression analyses indicated that self-esteem was important for explaining mental energy and work-related exhaustion, but less so for explaining professional fulfillment, which was predicted primarily by organizational factors. When controlling for self-esteem, which was higher amongst the Swedish nurses, the differences in professional fulfillment and mental health were no longer significant. Reasons for the differences in self-esteem and experiences of the workplace are discussed. Low response rate may have contributed to a selection bias.

Activation of caspase-3 in axotomized rat retinal ganglion cells in vivo

Recently, we have shown that inhibition of caspase-3-like caspases is the most effective treatment strategy to protect adult rat retinal ganglion cells from secondary death following optic nerve transection. In the present study, we localized active caspase-3 in axotomized retinal ganglion cells in vivo and demonstrated a co-localization of the active p20 fragment and TUNEL-staining in some of these cells. In line with this, we detected an enhanced cleavage and activity of caspase-3 protein in retinal tissue after lesion, while caspase-3 mRNA expression remained unchanged. These data suggest caspase-3 as an important mediator of secondary retinal ganglion cell death following axotomy in vivo.

Making family-centred care a reality

The role of families in caring for their sick children has evolved over the last century. Where once they were banned from hospitals, families now play an integral part in the care of their children, whether in hospital or at home.

Computer-controlled bipolar endotubal sterilization is successful in a rabbit model

OBJECTIVE

To determine the efficacy of a computer-controlled bipolar endotubal catheter system designed to accomplish safe, effective, and inexpensive female sterilization in preventing pregnancy in a rabbit model.

DESIGN

Prospective controlled study.

SETTING

University animal care facility.

ANIMAL(S)

Sixty healthy virginal female New Zealand white rabbits.

INTERVENTION(S)

Rabbits were assigned to the following groups: [1] endotubal radiofrequency minimal energy (95 degrees C) treatment; [2] endotubal radiofrequency maximal energy (105 degrees C) treatment; [3] endouterine radiofrequency (105 degrees C) treatment; [4] nonsurgical control; [5] laparotomy-only control; [6] endotubal radio-frequency sham control; and [7] external Kleppinger forceps bipolar cautery control. Rabbits were mated at 4 or 12 weeks after treatment.

MAIN OUTCOME MEASURE(S)

Pregnancy outcomes in treated animals and nontreated controls.

RESULT(S)

No pregnancies were observed in any of the uterine horns in which minimal or maximal energy was delivered to the fallopian tubes or uterus, although pregnancy occurred in one horn as a result of the delivery of energy below the radiofrequency minimum of 95 degrees C. The outcomes of the treatment groups were significantly different from those of the nonsurgical and sham surgical control groups.

CONCLUSION(S)

With adequate tissue heating, 100% sterilization efficacy was achieved with a new, computer-controlled bipolar catheter, whereas pregnancies occurred in all untreated control groups. If human studies support these results, the goal of a safe, effective means of transcervical sterilization may be realized.

A comparative study of the perceptions of British mental health nurses and psychiatrists of their work environment

This comparative study of the perceptions of mental health nurses and psychiatrists about aspects of their work environment was undertaken in the West Midlands in England. The aim of the study was to ascertain the extent to which the environment in which mental health professionals' work impacts on their own mental and physical well-being. Seventy-four psychiatrists and 301 mental health nurses responded to a postal questionnaire. Analysis of data indicated that significant differences exist between nurses and psychiatrists in their working conditions, their physical working environment, their sources of support with a work-related problem, and the effects of their work on their own mental and physical health. The main recommendation derived from this study was to improve communication between mental health professionals and their managers by giving more structured feedback and guidance about one's work performance. This may help to alleviate the mental strain many mental health professionals experience in their work.

Murine leukemia virus recombinants that use phosphate transporters for cell entry induce similar spongiform encephalomyelopathies in newborn mice

Amphotropic Moloney-murine leukemia virus recombinants (Mo-AmphoV) induce a severe spongiform encephalomyelopathy in newborn mice. We show here that a coisogenic recombinant with a 10A1-MuLV host range (Mo-10A1V) also induces a neurodegenerative disease, clinically characterized by mild tremor and ataxia. Spongiform lesions are most severe in the metencephalon and mesencephalon but extend into the prosencephalon and spinal cord. Significantly, the quality of histopathology was indistinguishable between Mo-AmphoV and Mo-10A1V, probably reflecting a final common pathogenic pathway. Common receptor use thus may be an important determinant in the pathogenicity of these viruses. These results have implications for the clinical use of retroviral pseudotypes that use phosphate transporters for cell entry.

Predictors of a healthy workplace for Swedish and English psychiatrists

BACKGROUND

Few studies have attempted to analyse the organisational aspects of the workplace that may affect the well-being of psychiatrists and even fewer have offered insights into what a positive workplace might look like. This study provides an outline of such a workplace, with reference to individual and organisational factors. In addition, a comparison is made between two European cities to check for cultural differences.

METHOD

Three hundred and eighty psychiatrists from Stockholm and Birmingham responded to a previously tested questionnaire on their work environment.

RESULTS

Predictors of a positive workplace for psychiatrists were: high self-esteem, satisfactory support with work-related problems, lower perceived workload, positive view of leadership, low work-related exhaustion and having a sense of participation in the organisation. There were few cultural differences.

CONCLUSIONS

Measures should be taken to improve leadership skills for managers, to offer more support for work-related problems, and to allow psychiatrists to participate more in the organisation.

Near-infrared Raman spectroscopy for in vitro detection of cervical precancers

In this study, we investigate the potential of near-infrared Raman spectroscopy to differentiate cervical precancers from normal tissues, inflammation and metaplasia and to differentially diagnose low-grade and high-grade precancers. Near infrared Raman spectra were measured from 36 biopsies from 18 patients in vitro. Detection algorithms were developed and evaluated relative to histopathologic examination. Algorithms based on empirically selected peak intensities, ratios of peak intensities and a combination of principal component analysis for data reduction and Fisher discriminant analysis for classification were investigated. Spectral peaks were tentatively identified from measured spectra of potential chromophores. Empirically selected normalized intensities can differentiate precancers from other tissues with an average sensitivity and specificity of 88 +/- 4% and 92 +/- 4%. Ratios of unnormalized intensities can differentiate precancers from other tissues with a sensitivity and specificity of 82% and 88% and high-grade from low-grade lesions with a sensitivity and specificity of 100%. Using multivariate methods, intensities at eight frequencies can be used to differentiate precancers from all other tissues with a sensitivity and specificity of 82% and 92% in an unbiased test. Raman algorithms can potentially separate benign abnormalities such as inflammation and metaplasia from precancers. Comparison of tissue spectra to published and measured chromophore spectra indicate that the most likely primary contributors to the tissue spectra are collagen, nucleic acids, phospholipids and glucose 1-phosphate. These results suggest that near-infrared Raman spectroscopy can be used for cervical precancer diagnosis and may be able to accurately separate samples with inflammation and metaplasia from precancer.

Controlled radiofrequency endotubal sterilization

STUDY OBJECTIVE

A safe, effective, inexpensive method of transcervical tubal sterilization could have a major impact on women's health. In this study, we evaluated the efficacy of a new radiofrequency catheter prototype designed for endotubal sterilization using animal models.

SETTING

Animal research laboratory.

DESIGN

Prospective observational study.

METHOD

The optimal energy delivery to create a complete circumferential transmural thermal lesion in the tube was determined in 114 in vitro acute studies using porcine and bovine fallopian tubes. A study was then initiated with eight mini-pigs. Thirty-four lesions were made in the fallopian tubes using computer-controlled power delivery. Three weeks later the animals were euthanized and evaluated.

MEASUREMENTS AND MAIN RESULTS

A hydrosalpinx was evident in 8/11 of the tubes with separate proximal and distal cautery, implying occlusion at each of these sites. Complete occlusion of the tubes was seen at 12/22 sites evaluated by histology. Narrowing was seen in 9/22, and 1/22 was open.

CONCLUSION

The endotubal cautery prototype creates a reproducible lesion, but did not always cause complete closure of the tube in this preliminary study. However, based on our results, we hypothesize that a radiofrequency catheter can be developed for minimally invasive transcervical sterilization.

Physiological and pathological factors of human breast disease that can influence optical diagnosis

The 'normal' human female breast is a very complex organ that changes considerably during development, pregnancy and menopause. In addition, it is an excretory organ that, during lactation, discharges various metabolites and certain drugs that can be optically active. Optical diagnosis of breast cancers requires detection of differential concentrations of 1) various absorbers and scatterers or 2) native or exogenous fluorophores to distinguish cancers from surrounding 'normal' and benign breast tissues. The differential concentrations are due to the biology of the cancer cells and the host responses to the cancer growth. For most patients, the cancer will be intermixed with a complex 3-dimensional array of 'normal' breast tissue and benign breast lesions. This complexity will challenge the optical biopsy investigator but, with the recent advances in our understanding of light transport, optical diagnostic techniques and devices can be developed to complement and supplement current breast cancer screening techniques.

Entry of amphotropic and 10A1 pseudotyped murine retroviruses is restricted in hematopoietic stem cell lines

Although transduction with amphotropic murine leukemia virus (MLV) vectors has been optimized successfully for hematopoietic differentiated progenitors, gene transfer to early hematopoietic cells (stem cells) is still highly restricted. A similar restriction to gene transfer was observed in the mouse stem cell line FDC-Pmix compared with transfer in the more mature myeloid precursor cell line FDC-P1 and the human erythroleukemia cell line K562. Gene transfer was not improved when the vector was pseudotyped with gp70SU of the 10A1 strain of MLV, which uses the receptor of the gibbon ape leukemia virus (Pit1), in addition to the amphotropic receptor (Pit2). Although 10A1 and amphotropic gp70SU bound to FDC-P1, K562, and fibroblasts, no binding to FDC-Pmix cells was detected. This indicates that FDC-Pmix cells lack functional Pit2 and Pit1 receptors. Pseudotyping with the vesicular stomatitis virus G protein improved transduction efficiency in FDC-Pmix stem cells by 2 orders of magnitude, to fibroblast levels, confirming a block to retroviral infection at the receptor level.

[Esophageal perforations]

An oesophageal perforation is a serious condition with high morbidity and mortality. During the latest decades an increased number of traumatic perforations as well as wide use of endoscopic procedures have increased the incidence of oesophageal perforation. An early diagnosis and treatment is important for the prognosis. Cervical and selected thoracic perforations can be treated conservatively although the majority should be operated. Primary closure can be performed if done before 24 hours have elapsed, while later treatment is controversial. Drainage of the mediastinum and pleural space, as well as diversion of saliva and gastric content is important. The literature is reviewed in relation to etiology, diagnosis, treatment and prognosis.

[Benign esophageal perforations treated at a department of thoracic surgery]

Between January 1, 1980 and December 31, 1994, 37 patients with benign oesophageal perforation underwent different kinds of treatment. The overall mortality was 30%. When diagnosed less than 12 hours after the perforation the mortality was 21%, between 12 and 24 hours. Reinforced primary repair gave the best results without any deaths in seven cases where it was performed. Oesophageal perforation is a serious condition, and it is important to know the symptoms. If there is any suspicion of the condition, an oesophageal X-ray with watersoluble contrast medium should be performed on liberal indication. When diagnosed the patient should be transferred to a Department of Thoracic Surgery immediately. Only few patients can be treated conservatively and most should be operated with reinforced primary suture and drainage.

Controlled temperature tissue fusion: argon laser welding of canine intestine in vitro

BACKGROUND AND OBJECTIVE

Thermal denaturation of proteins is recognized as a rate process governed by the local temperature-time response and is believed to be the principal mechanism for photothermal tissue welding. Since rate processes are exponential with temperature, feedback control of tissue surface temperature is hypothesized to create a quasi-constant rate of denaturation that will enhance the tissue welding process.

STUDY DESIGN, MATERIALS AND METHODS

Controlled temperature tissue welding of severed edges of fresh canine jejunum was performed in vitro by remote sensing of tissue surface temperature with an infrared sensor. A hardware controlled temperature feedback system opened and closed a shutter located in the beam path of an argon ion laser to provide constant temperature welding.

RESULTS

Strong tissue fusion was not possible at or below a surface temperature of 70 degrees C, but was accomplished at 80 degrees, 90 degrees, and 95 degrees, and 100 degrees C. Fusion was achieved with thermal coagulation of the collagenous submucosa and mucosal tissues. The bursting strength of welds created at 90 degrees C and 95 degrees C were significantly stronger than those performed at 80 degrees C.

CONCLUSION

Laser-assisted intestinal anastomoses created in vitro are optimally strong at 90-95 degrees C feedback control temperatures.

Controlled temperature tissue fusion: argon laser welding of canine intestine in vitro

BACKGROUND AND OBJECTIVE

Thermal denaturation of proteins is recognized as a rate process governed by the local temperature-time response and is believed to be the principal mechanism for photothermal tissue welding. Since rate processes are exponential with temperature, feedback control of tissue surface temperature is hypothesized to create a quasi-constant rate of denaturation that will enhance the tissue welding process.

STUDY DESIGN, MATERIALS AND METHODS

Controlled temperature tissue welding of severed edges of fresh canine jejunum was performed in vitro by remote sensing of tissue surface temperature with an infrared sensor. A hardware controlled temperature feedback system opened and closed a shutter located in the beam path of an argon ion laser to provide constant temperature welding.

RESULTS

Strong tissue fusion was not possible at or below a surface temperature of 70 degrees C, but was accomplished at 80 degrees, 90 degrees, and 95 degrees, and 100 degrees C. Fusion was achieved with thermal coagulation of the collagenous submucosa and mucosal tissues. The bursting strength of welds created at 90 degrees C and 95 degrees C were significantly stronger than those performed at 80 degrees C.

CONCLUSION

Laser-assisted intestinal anastomoses created in vitro are optimally strong at 90-95 degrees C feedback control temperatures.

Development of a multivariate statistical algorithm to analyze human cervical tissue fluorescence spectra acquired in vivo

BACKGROUND AND OBJECTIVE

A general multivariate statistical algorithm has been developed to analyze the diagnostic content of cervical tissue fluorescence spectra acquired in vivo.

MATERIALS AND METHODS

The primary steps of the algorithm are to: (1) preprocess the data to reduce inter-patient and intra-patient variation of tissue spectra within a diagnostic category, without a priori information, (2) dimensionally reduce the preprocessed fluorescence emission spectrum with minimal information loss and use it to select the minimum number of the original emission variables of the fluorescence spectrum required to achieve classification with negligible decrease in predictive ability, and (3) assign a posterior probability to the diagnosis of each sample, so that samples with relative uncertain diagnosis can be reevaluated by a clinician. The algorithm was tested retrospectively and prospectively on cervical tissue spectra acquired from 476 sites from 92 patients at 337 nm excitation.

RESULTS

The algorithm based on the entire fluorescence spectrum differentiates squamous intraepithelial lesions (SILs) from normal squamous epithelia and inflammation with an average sensitivity and specificity of 88% +/- 1.4 and 70% +/- 1, respectively. The average sensitivity and specificity of the identical algorithm based on intensity selected at only two emission wavelengths is 88% +/- 1.4 and 71% +/- 1.4, respectively.

CONCLUSION

The multivariate statistical algorithm based on both types of spectral inputs at 337 nm excitation has a similar sensitivity and significantly improved specificity relative to colposcopy in expert hands.

Spectroscopic diagnosis of cervical intraepithelial neoplasia (CIN) in vivo using laser-induced fluorescence spectra at multiple excitation wavelengths

BACKGROUND AND OBJECTIVE

The diagnostic contribution of cervical tissue fluorescence spectra acquired in vivo at 380 and 460 nm excitation were analyzed using a general multivariate statistical algorithm.

MATERIALS AND METHODS

The primary steps of the algorithm are to: (1) preprocess data to reduce interpatient and intrapatient variation of tissue spectra from the same diagnostic category, without a priori information, (2) dimensionally reduce the pre-processed spectral data using Principal Component Analysis, and (3) develop a probability based classification scheme based on logistic discrimination using the diagnostically useful principal components. The algorithm was tested on cervical tissue spectra acquired from 165 sites at 380 nm excitation and from 147 sites at 460 nm excitation. A retrospective and prospective estimate of the algorithm's performance was determined.

RESULTS

At 460 nm excitation, (1) SILs can be differentiated from normal squamous tissues with an average sensitivity and specificity of 91% +/- 1.3 and 75.5% +/- 1, respectively; furthermore, (2) high grade SILs can be differentiated from low grade SILs with an average sensitivity and specificity of 80% +/- 4 and 76% +/- 5, respectively. In addition, using tissue spectra at 380 nm excitation, SILs can be differentiated from normal columnar epithelia and inflammation with an average sensitivity and specificity of 77% +/- 1 and 72% +/- 9, respectively.

CONCLUSIONS

Fluorescence spectra at multiple excitation wavelengths are essential for the detection and differential diagnosis of SILs at colposcopy.

In vivo autofluorescence of an unpigmented melanoma in mice. Correlation of spectroscopic properties to microscopic structure

Recently, fluorescence spectroscopy and imaging have been under investigation for in vivo diagnosis of several types of superficial cancer, including primary melanomas of the skin. Here we report on a detailed investigation of the autofluorescence properties of a K1735P melanoma implanted intradermally in the ears of syngeneic C3H/HeN mice. Although this tumour can produce melanin in some cases, it appeared as an unpigmented lesion in our experiments. Excitation-emission maps in the wavelength range of 360-700 nm were recorded from tumours and normal ears. The control ears and the tumour-bearing ears showed fluorescence in a broad range of excitation and emission wavelengths. Valleys of decreased fluorescence were observed in the 385-425 nm range and could be related to absorption of the excitation light by haemoglobin, oxyhaemoglobin and a third unknown absorber. The spectroscopic differences between the malignant melanoma and the control skin could be related to either differences in blood oxygenation or the tissue dimensions. However, no spectroscopic features were detected reflecting intrinsic differences between the melanoma and normal tissue.

Corneal photocoagulation with continuous wave and pulsed holmium: YAG radiation

In this study, the effectiveness of pulsed and continuous wave (CW) holmium: YAG lasers in coagulating in vitro pig corneas was analyzed. With the CW laser, irradiance and exposure time were varied; irradiance, from 162 to 324 W/cm2 and exposure time, from 200 to 800 ms. With the pulsed laser, number of pulses and radiant exposure were varied; number of pulses per lesion, from 4 to 30 and radiant exposure, from 10 to 25 J/cm2. Laser-induced corneal damage was determined by analyzing histological cross sections of each lesion. Depth and diameter of the lesions were plotted against the varying laser parameters. Light and birefringent photomicrographs of typical lesion histology show that the pulsed laser significantly damaged superficial layers of the cornea and could not achieve the coagulation depths produced by the CW laser. Additional histology demonstrates that minimal surface damage (intrastromal coagulation) occurred when the CW laser beam was delivered with a sapphire-tipped contact probe. The results provide empirical data on the sensitivity of each parameter in producing a range of coagulation end points. In addition, the experimental results describe trends between the parameters of either laser and the extent of coagulation.

Combined ultrasound and fluorescence spectroscopy for physico-chemical imaging of atherosclerosis

This paper describes a combined ultrasonic and spectroscopic system for remotely obtaining physico-chemical images of normal arterial tissue and atherosclerotic plaque. Despite variations in detector-tissue separation, R, fluorescence powers corresponding to pixels in the image are converted to the same set of calibrated units using distance estimations from A-mode ultrasound reflection times. An empirical model, validated by Monte Carlo simulations of light propagation in tissue, is used to describe changes in fluorescence power as a function of R. Fluorescence spectra of normal and atherosclerotic human aorta obtained with this system are presented as a function of R. To compensate for changes in fluorescence power with R, the empirical model was used in each case to calculate the fluorescence power at a constant reference value of R(Rref = 1.67 mm). Prior to compensation, tissue fluorescence power decreased more than a factor of two as R was increased from 2.5 to 5 mm. Following compensation, the fluorescence power varied less than +/- 10% of the average compensated peak. The chemical composition of each sample was determined by fitting its fluorescence spectrum (in calibrated units) to a model of tissue fluorescence incorporating structural protein and ceroid fluorescence, as well as structural protein and hemoglobin attenuation. Parameters of the fit were used to classify tissue type. Without compensation for distance variation, classification of tissue type was frequently incorrect; however, with compensation, predictive value was high. A 1-D chemical image of a section of human aorta containing both normal and atherosclerotic regions obtained with this system is also presented. After compensation for detector-sample separation, tissue classifications along the cross-section closely resemble those obtained from histology. Regions of elevated ceroid concentration and intimal thickening are clearly observable in the resultant chemical image. The potential value of this type of system in the diagnosis and treatment of coronary artery disease is discussed.

Lifetime testing of sapphire and sculpted silica fiber scalpels

BACKGROUND AND OBJECTIVE

Sapphire and sculpted silica fiber scalpels were evaluated for performance as they aged. Performance was determined by measuring their useful lifetime, forward transmission, incision depth, and the thermal coagulation thickness at the sides and bottom of the incision. STUDY DESIGN/MATERIALS, AND METHODS: Aging was performed with a chicken breast model. Performance measurements were made at periodic intervals. Sapphire scalpels were cooled with air or saline.

RESULTS

The air-cooled, frosted sapphire scalpels had the longest useful lifetime, whereas the saline-cooled, frosted sapphire scalpels had the shortest. Aging deteriorated the forward transmission of the sculpted silica fiber scalpels the most. Little difference was found between the averages of all incision measurements. Two of the saline-cooled, frosted sapphire scalpels fractured during the aging process.

CONCLUSION

Aging influences the scalpel lifetime, but there was no evidence that the aging process significantly affected the incision size.