Integrable Atomtronic Interferometry

High sensitivity quantum interferometry requires more than just access to entangled states. It is achieved through the deep understanding of quantum correlations in a system. Integrable models offer the framework to develop this understanding. We communicate the design of interferometric protocols for an integrable model that describes the interaction of bosons in a four-site configuration. Analytic formulas for the quantum dynamics of certain observables are computed. These expose the system's functionality as both an interferometric identifier, and producer, of NOON states. Being equivalent to a controlled-phase gate acting on 2 hybrid qudits, this system also highlights an equivalence between Heisenberg-limited interferometry and quantum information. These results are expected to open new avenues for integrability-enhanced atomtronic technologies.

The difficulty to model Huntington's disease in vitro using striatal medium spiny neurons differentiated from human induced pluripotent stem cells

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by an expanded polyglutamine repeat in the huntingtin gene. The neuropathology of HD is characterized by the decline of a specific neuronal population within the brain, the striatal medium spiny neurons (MSNs). The origins of this extreme vulnerability remain unknown. Human induced pluripotent stem cell (hiPS cell)-derived MSNs represent a powerful tool to study this genetic disease. However, the differentiation protocols published so far show a high heterogeneity of neuronal populations in vitro. Here, we compared two previously published protocols to obtain hiPS cell-derived striatal neurons from both healthy donors and HD patients. Patch-clamp experiments, immunostaining and RT-qPCR were performed to characterize the neurons in culture. While the neurons were mature enough to fire action potentials, a majority failed to express markers typical for MSNs. Voltage-clamp experiments on voltage-gated sodium (Nav) channels revealed a large variability between the two differentiation protocols. Action potential analysis did not reveal changes induced by the HD mutation. This study attempts to demonstrate the current challenges in reproducing data of previously published differentiation protocols and in generating hiPS cell-derived striatal MSNs to model a genetic neurodegenerative disorder in vitro.

Dermal peptide delivery using enhancer molecules and colloidal carrier systems - part V#: Influence of enhancers on the permeation of PKEK through snake skin

In a previous study, it was shown, that shed snake skin is a good alternative model membrane for the human stratum corneum (SC). In this study, the influence of the enhancers dimethyl sulfoxide (DMSO), 1,2-propanediol, 1,3-butanediol, 1,2-pentanediol, 1,2-hexanediol and 1,2-octanediol in a concentration of 10 % on the permeation of l-prolyl- l-lysyl-l-α-glutamyl-l-lysin (PKEK) through shed snake skin was conducted. Pharmacokinetic parameters (diffusion coefficient, permeation coefficient, t-lag, Flux) were calculated. All examinations were performed on the skin of an individual and thus allowed a very good comparability of the data. All enhancers have overcome the shed snake skin and could be proven in the acceptor. DMSO does not affect the permeability of the membrane. Nevertheless, PKEK permeates faster in the presence of DMSO than PKEK being used alone. PKEK permeated the same, no matter if an auxiliary material was added or not. Without their addition, in all other enhancers no significant difference towards permeation could be determined.

Stainless steel surface functionalization for immobilization of antibody fragments for cardiovascular applications

Stainless steel 316 L material is commonly used for the production of coronary and peripheral vessel stents. Effective biofunctionalization is a key to improving the performance and safety of the stents after implantation. This paper reports the method for the immobilization of recombinant antibody fragments (scFv) on stainless steel 316 L to facilitate human endothelial progenitor cell (EPC) growth and thus improve cell viability of the implanted stents for cardiovascular applications. The modification of stent surface was conducted in three steps. First the stent surface was coated with titania based coating to increase the density of hydroxyl groups for successful silanization. Then silanization with 3 aminopropyltriethoxysilane (APTS) was performed to provide the surface with amine groups which presence was verified using FTIR, XPS, and fluorescence microscopy. The maximum density of amine groups (4.8*10(-5) mol/cm(2)) on the surface was reached after reaction taking place in ethanol for 1 h at 60 °C and 0.04M APTS. On such prepared surface the glycosylated scFv were subsequently successfully immobilized. The influence of oxidation of scFv glycan moieties and the temperature on scFv coating were investigated. The fluorescence and confocal microscopy study indicated that the densest and most uniformly coated surface with scFv was obtained at 37 °C after oxidation of glycan chain. The results demonstrate that the scFv cannot be efficiently immobilized without prior aminosilanization of the surface. The effect of the chemical modification on the cell viability of EPC line 55.1 (HucPEC-55.1) was performed indicating that the modifications to the 316 L stainless steel are non-toxic to EPCs.

Wilson ratio of fermi gases in one dimension

We calculate the Wilson ratio of the one-dimensional Fermi gas with spin imbalance. The Wilson ratio of attractively interacting fermions is solely determined by the density stiffness and sound velocity of pairs and of excess fermions for the two-component Tomonaga-Luttinger liquid phase. The ratio exhibits anomalous enhancement at the two critical points due to the sudden change in the density of states. Despite a breakdown of the quasiparticle description in one dimension, two important features of the Fermi liquid are retained; namely, the specific heat is linearly proportional to temperature, whereas the susceptibility is independent of temperature. In contrast to the phenomenological Tomonaga-Luttinger liquid parameter, the Wilson ratio provides a powerful parameter for testing universal quantum liquids of interacting fermions in one, two, and three dimensions.

Degeneration of retinal layers in multiple sclerosis subtypes quantified by optical coherence tomography

BACKGROUND

Optical coherence tomography can be used to assess retinal degeneration in multiple sclerosis (MS). Thinning of the retinal nerve fibre layer and macular thickness have been well characterized, but newer devices allow quantification of all retinal layers.

OBJECTIVES

The objective of this study was to evaluate the thickness of the paramacular retina, peripapillary retinal nerve fibre layer, and deeper paramacular layers in MS patient subgroups, using state-of-the-art optical coherence tomography.

METHODS

Using a Heidelberg Engineering Spectralis device, we performed paramacular volumetric retinal scans and circular peripapillary fibre-layer scans, manually segmenting different retinal layers into single horizontal foveal scans in 95 patients with definite MS (42 relapsing-remitting, 41 secondary progressive, 12 primary progressive), plus 91 age- and sex-matched controls.

RESULTS

Even without a history of optic neuritis, all MS subgroups had significant thinning of the peripapillary retinal nerve fibre layer, the paramacular retinal thickness and the retinal ganglion cell- and inner plexiform layer. Only in primary progressive MS was the inner nuclear layer significantly reduced.

CONCLUSIONS

Our findings indicate a primary retinal pathology involving the inner nuclear layer in primary progressive MS. Results in eyes without history of optic neuritis suggest possible subclinical episodes of optic neuritis or retrograde trans-synaptic degeneration of retinal ganglion cells and their axons.

Rapid detection, enrichment and propagation of specific T cell subsets based on cytokine secretion

T cell lines with defined cytokine profiles are an invaluable tool for assessing the control of immune responses both in vitro and in vivo. Production of such cell lines can be complex and time-consuming. Here we present a powerful technique to assay the cytokines produced by T cells activated polyclonally or with specific antigens. This paper presents a detailed methodology for the identification and isolation of cytokine-producing T cells activated with the artificial superantigen, CytoStim, or viral and fungal antigens. These cells can be analysed for different cytokines simultaneously, or cultured further to rapidly establish T cell lines making known cytokine types. We highlight the enumeration, isolation and phenotype of interleukin-17-producing T cells, and the rapid generation of virus-specific Th1 T cell lines.

V600E BRAF mutations are alternative early molecular events in a subset of KIT/PDGFRA wild-type gastrointestinal stromal tumours

BACKGROUND

A small subset (10-15%) of gastrointestinal stromal tumours (GISTs) lack mutations in KIT and PDGFRA (wild-type GIST). Recently, a novel BRAF exon 15 mutation (V600E) was detected in imatinib-naive wild-type high-risk intestinal GISTs (4%). However, the frequency and distribution of BRAF mutations within the spectrum of GISTs, and whether they might represent secondary events acquired during tumour progression, remain unknown.

METHODS

69 GISTs (39 KIT mutants, 2 PDGFRA mutants and 28 wild-type) were analysed for mutations in BRAF exon 15 and KRAS exon 2. To assess the stage at which these mutations might occur in GIST, a considerable number of incidental gastric (n = 23) and intestinal (n = 2) tumours were included.

RESULTS

BRAF mutations (V600E) were detected in 2 of 28 wild-type GISTs (7%), but in none of the 41 KIT/PDGFRA mutants. No KRAS mutation was detected. The two BRAF-mutated GISTs measured 4 mm in diameter and originated in the gastric body and the jejunum in two men (mean age, 76 years). Both tumours were mitotically inactive KIT-positive spindle-cell GISTs that were indistinguishable histologically from their more common KIT-mutated counterparts.

CONCLUSION

BRAF mutations represent an alternative molecular pathway in the early tumorigenesis of a subset of KIT/PDGFRA wild-type GISTs and are per se not associated with a high risk of malignancy. Mutations in KIT, PDGFRA and BRAF were mutually exclusive in this study. Results from this and a previous study indicate that BRAF-mutated GISTs show a predilection for the small bowel (four of five tumours), but this needs further evaluation in larger studies.

Glycation in food and metabolic transit of dietary AGEs (advanced glycation end-products): studies on the urinary excretion of pyrraline

Pyrraline [epsilon-(2'-formyl-5'-hydroxymethyl-pyrrolyl)-L-norleucin] belongs to the group of AGEs (advanced glycation end-products) formed in the final stage of the Maillard reaction in foods and in vivo. As it is generally accepted that AGEs are pathophysiologically relevant in aging and in diseases such as diabetes and uraemia, physiological consequences resulting from the ingestion of dietary AGEs are discussed, but balance studies for well defined AGEs are still lacking. The aim of our study was to investigate the influence of nutrition on the urinary excretion of pyrraline. After the first day without dietary restrictions, seven healthy volunteers were asked, starting on the morning of day 2, to ingest a diet virtually free of Maillard compounds (i.e. no cooked or roasted foods, no bakery products, no coffee, etc.). Dietary control was stopped on the morning of day 5. We collected 24 h urine samples for these 5 days, which were analysed for free pyrraline by reverse-phase HPLC with UV detection at 297 nm. We found that urinary excretion of free pyrraline was directly affected by the composition of the diet, decreasing from 4.8+/-1.1 mg/day on day 1 to levels of 1.6, 0.4 and 0.3 mg/day on days 2, 3 and 4 respectively, followed by a significant increase to 3.2+/-1.4 mg/day on the 5th day. The results of this work prove, for the first time, that urinary excretion of pyrraline is strongly dependent on its dietary intake. Thus the influence of nutrition should be taken into consideration in studies directed to the physiological role of glycation compounds.

An ex vivo perfusion model to evaluate hyperacute rejection in a discordant pig-to-human combination

Inadequate supplies of human organs for transplantation have evoked an escalating interest in human xenotransplantation. Hyperacute rejection precludes use of discordant organs. We have developed an ex vivo perfusion model in order to evaluate hyperacute rejection in a pig-to-human combination. Pig kidneys (n = 6) perfused with human blood deteriorated rapidly and rejection was seen after 70 (60–87) min (median, 95% confidence interval). Kidneys perfused with pig blood survived 300 (216–360) min, corresponding to the upper time limit of the model. Increases in prostaglandin E₂ and 6-keto-prostaglandin F_1α indicated endothelial activation. Sequential blood samples revealed a strong progressive inflammatory response with reduced leukocyte and platelet counts, granulocyte activation indicated by increased myeloperoxidase, and complement activation, shown by an increase in C3 activation products and the terminal SC5b-9 complement complex. A significant role for classical pathway activation was indicated by formation of C1rs-C1 inhibitor complexes and activation of C4, whereas factor B was not significantly activated. Biopsies at rejection demonstrated hyperacute rejection with inflammatory changes involving the vessels as well as the nephrons. Where the inflammatory markers could be studied in pig blood, activation was less than in human blood. The present discordant xenotransplant model is a valuable adjunct for evaluation of changes occurring in the human blood perfusate as well as in the pig kidney during hyperacute rejection.

Temperature-controlled radiofrequency catheter ablation with a 10-mm tip electrode creates larger lesions without charring in the porcine heart

BACKGROUND

Radiofrequency catheter ablation of atrial flutter, atrial fibrillation or ventricular tachycardia may be favoured by large lesions. We compared lesions created in unipolar mode using 10-mm/8 F electrodes with those of 4-mm/7 F catheters.

METHODS

Ablations were first performed in porcine hearts in vitro (70 degrees C, 60 s, tangential catheter tip-tissue orientation). Anaesthetized pigs were thereafter ablated with 10- or 4-mm catheters in the right atrial free wall (RAFW), inferior vena cava-tricuspid valve (IVC-TV) isthmus and left ventricle (LV).

RESULTS

In vitro, lesion length doubled and lesion volume tripled using the 10-mm catheter. Average power supply was 69 (SD12) (10-mm tip) versus 26 (SD7) W (4-mm tip). In vivo, lesion length increased by 50% and lesion volume fivefold. Charring at the lesion surface or sudden impedance rises were not observed in vivo. Histologically, coagulation necrosis and minor haemorrhages were found. One RAFW lesion (10-mm) showed a dissection approaching the epicardium. Fibrinous platelet clots or overt thromboses covered the endocardial surface in half of all lesions. Three 10-mm electrode isthmus lesions extended to the right descending posterior artery and one LV lesion to the left anterior descending artery, but there was no damage to the arterial walls. Following six ablations with the 10-mm electrode and two with the 4-mm tip, injury to the adjacent lung tissue of 0.5 to 6.0 mm depth was found (p = 0.22).

CONCLUSION

RF ablation using 10-mm/8 F electrodes created significantly larger lesions. 10-mm electrodes appeared safe in the porcine IVC-TV isthmus and LV, but not in the RAFW.

Intraspinal and behavioral consequences of nerve growth factor-induced nociceptive sprouting and nerve growth factor-induced hyperalgesia compared in adult rats

Intraspinal and behavioral events were studied in adult rats with nociceptive nerves that were undergoing collateral sprouting into adjacent denervated skin. This sprouting, which is driven by endogenous nerve growth factor (NGF), did not cause hyperalgesia. For comparison, we studied an exogenous NGF administration that induced hyperalgesia but was too brief to evoke sprouting. When nociceptive nerves sprouted in skin, back-labeling with wheat germ agglutinin-conjugated horseradish peroxidase revealed that their projections sprouted in the cord. The sprouted peripheral nerves now activated more c-Fos-containing interneurons, which stimulus-response studies showed was not due to an increased afferent discharge. We attribute the interneuron recruitment to synaptogenesis following the intraspinal sprouting. Nociceptive stimulation of dorsal skin reflexly activates underlying cutaneous trunci muscle (CTM). When a nociceptive field expanded by nerve sprouting, so did the area of the evoked CTM reflex: this implies a recruitment of CTM motoneurons. We interpret this "matching" of response to stimulus as an adaptive phenomenon ensured by an adaptive intraspinal sprouting of the nociceptive projections. Neither the intraspinal changes nor the reflex changes occurred if peripheral sprouting was blocked by systemic anti-NGF treatment, indicating that the role of endogenous NGF was only in that sprouting. No comparable adaptive events occurred during NGF-induced hyperalgesia. Neither nociceptive fields nor CTM reflexes were affected; however there was a recruitment of c-Fos-expressing interneurons. This recruitment was not explained by peripheral sensitization, and, because sprouting was not involved here, we attribute the recruitment to "synaptic unmasking," i.e., an increased effectiveness of the preexisting excitatory circuitry.

Bipolar radiofrequency catheter ablation creates confluent lesions at larger interelectrode spacing than does unipolar ablation from two electrodes in the porcine heart

AIMS

Radiofrequency catheter ablation of atrial flutter and fibrillation may be favoured by large, elongated lesions. We compared bipolar ablation with unipolar ablation from one or two electrodes in the porcine heart.

METHODS AND RESULTS

In vitro, confluent lesions were reliably created by a 'dielectrode' catheter (energy delivered simultaneously (in parallel) from two 4 mm electrodes spaced 1 mm apart, towards an indifferent electrode), and a 'bipolar' catheter (energy delivered (in series) between two 4 mm electrodes spaced 5 mm apart). Sixteen anaesthetized pigs were randomized to standard unipolar (4), dielectrode (6) or bipolar (6) ablation. Two radiofrequency current deliveries of 30 s duration (70 degrees C) were administered to the inferior vena cava-tricuspid valve isthmus and two to the right atrial free wall in all animals. After 4 h, the lesions were examined macroscopically and histologically. Mean (SD) endocardial lesion length x width x depth measured 7.4 (2.4) x 5.4 (2.2) x 2.8 (0.8) mm in the standard unipolar mode, 10.2 (1.4) x 6.3 (0.7) x 3.3 (1.1) mm in the dielectrode mode and 14.0 (3.6) x 6.0 (1.7) x 3.8 (1.2) mm in the bipolar mode. Thus lesion length increased significantly through the three groups (P < 0.001), while width and depth did not.

CONCLUSION

Both dielectrode and bipolar ablation were feasible in porcine right atrial ablation, and created longer lesions than the standard unipolar mode. By allowing a larger interelectrode distance, bipolar ablation created the longest lesions and may be favourable when linear lesions are necessary.

Immunoglobulin prolongs survival of pig kidneys perfused ex vivo with human blood

Intravenous immunoglobulin (IVIG) (Octagam), was used to determine the effect on hyperacute rejection in an ex vivo xenograft model. Six pig kidneys were perfused with IVIG and fresh human AB blood, and six control pig kidneys were simultaneously perfused with albumin and blood from the same donation. The survival of the IVIG-perfused xenografts (median, 6.5 h) was significantly (P = 0.03) longer than the albumin-perfused xenografts (median, 3.5 h). Complement was activated in both groups. The administration of IVIG to the perfused blood resulted in immediate and significantly higher complement activation in the fluid phase as compared with the albumin group. At rejection the fluid phase complement activation was higher in the IVIG group than in the albumin group for C1rs/C1inh complexes, C4bc, Bb and TCC. At the time of rejection both the albumin and the IVIG group demonstrated interstitial tubular haemorrhage, vasculitis or necrosis of glomerular capillaries and glomerular microthrombi. IgM, C1q, C3c, C4 and fibrin were located in arteries and glomeruli and IgG in the interstitium in both groups at rejection. The fluid phase findings are consistent with a modulatory effect of IVIG on complement activation by deviating the classical pathway activation towards the fluid phase. The prolonged survival of the IVIG-perfused kidneys suggests that IVIG may be useful to dampen hyperacute rejection.

Radiofrequency current ablation of porcine right atrium: increased lesion size with bipolar two catheter technique compared to unipolar application in vitro and in vivo

Interruption of atrial flutter and fibrillation by RF catheter ablation may be favored by large, elongated lesions. We administered RF current in unipolar and bipolar mode in porcine right atrium. Bipolar ablation was performed between the tip electrodes of two serially coupled catheters. With 4-mm tip electrodes in vitro, lesion length increased from a mean (SD) of 7.9 (1.2) mm at 3 mm-interelectrode distance (i.e.d.) to 13.3 (3.3) mm at 9-mm IED, but decreased at 12-mm IED due to nonconfluent lesions (P < 0.0001). With 4 mm distal electrodes and 8 mm IED, bipolar lesions were 65% longer than corresponding unipolar ablations. Switching to bipolar mode increased the lesion length more than increasing electrode tip length to 6 mm in unipolar mode. Power and temperature controlled ablation created equally sized lesions. Twelve anesthetized pigs were randomized to unipolar or two catheter bipolar temperature controlled ablation of the right atrial free wall. Bipolar ablation created confluent lesions with endocardial length x width of 13.5 (5.8) x 7.3 (3.7) mm, unipolar ablation 6.4 (2.8) x 4.6 (1.4) mm (P < 0.001 when comparing length and P = 0.013 for lesion width). The atrial lesions in both groups were transmural and extended into hilar lung lesions with maximal depth of 3.0 (1.1) and 2.6 (1.0) mm, respectively (P = 0.44). Five bipolarly and four unipolarly ablated pigs developed right diaphragmal paresis. We conclude that bipolar ablation may be preferable in situations where large, elongated lesions are favorable. The two catheter technique is feasible in porcine right atrium. Both bipolar and unipolar ablation of the porcine right atrial free wall may frequently be complicated by injury to the phrenic nerve and adjacent lung tissue.

Development of a biodegradable ureteric stent: surface modification and in vitro assessment

The aim of the present study was to develop a short bioresorbable ureteric stent and to characterize the chosen polymers with respect to surface modification, biocompatibility, and loading of a biologically active compound. As materials for the stent, poly(D,L-lactide) and poly(D,L-lactide-co-glycolide) were chosen. Degradation experiments were carried out and analytical data were obtained by contact angle measurement, X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy in the attenuated reflection mode (FTIR-ATR). Gas loading technology was used to incorporate biologically active compounds, and biocompatibility of the polymers was assessed by in vitro cellular assays, applying measures such as cell morphology, proliferative activity, and membrane integrity. Our results indicate that surface modification of bioresorbable polymers is a suitable and efficient approach to improve the surface properties. Incorporation of biologically active compounds was possible without loss of activity, and in vitro assessment of cellular responses demonstrated the biocompatibility of the chosen polymers and modifications.

Premorbid social functioning in schizophrenia and bipolar disorder: similarities and differences

OBJECTIVE

This research examined social functioning in childhood and adolescence among patients with schizophrenia and patients with bipolar disorder compared with healthy subjects and investigated the relation between premorbid adjustment and risk factors for psychosis.

METHOD

Maternal recall was used to assess the premorbid adjustment of patients with schizophrenia (N = 70) and patients with bipolar disorder (N = 28) recruited from a survey of consecutive hospital admissions for psychosis and of healthy comparison subjects (N = 100) drawn from the same catchment area.

RESULTS

The patients with schizophrenia had significantly poorer premorbid adjustment in childhood and adolescence than the comparison subjects and were impaired in both sociability and school adjustment. The patients with bipolar disorder exhibited poorer social impairment in adolescence than the comparison subjects, though to a lesser degree than the schizophrenic subjects, but functioned well at school. There were significant linear trends in the risk of psychosis with worsening premorbid functioning, which was most marked in the schizophrenic group, and a specific linear relation between low birth weight and poor premorbid adjustment among the schizophrenic patients.

CONCLUSIONS

Impaired premorbid social functioning is not specific to schizophrenia and is seen also in bipolar disorder. The data support the view that poor premorbid social adjustment is one manifestation of vulnerability to adult psychotic disorders. These results are consistent with other findings pointing to early developmental deficits in patients who subsequently develop psychosis.

Safety of rapid-rate transcranial magnetic stimulation: heart rate and blood pressure changes

We examined the influence of rapid-rate transcranial magnetic stimulation on heart rate and blood pressure in 13 healthy volunteers. In a first series three different cortical magnetic stimuli were applied: over C3, C4 and Fz (10/20 system), in a second series additionally over Pz. We also used a stimulus over the brachial plexus and a sham stimulus. Five stimuli of each location were applied with a Cadwell high speed magnetic stimulator using a focal point circular coil. Stimulus train duration was 500 ms, stimulus frequency 20 Hz. Stimulus strength was 70-90% of maximum stimulator output, 20% of maximum stimulator output above subjects' individual motor threshold. The subjects assessed stimulus inconvenience immediately after stimulation. ECG and blood pressure (Finapres) were recorded continuously during the 1 h test. In all subjects there was a clearly marked autonomic response with heart rate acceleration and decrease in blood pressure after all stimuli. There was no difference in responses between cortical stimuli. Blood pressure decrease after sham stimulation was significantly smaller than after cortical stimulation, it was more marked after brachial plexus stimulation. Autonomic reaction correlates well with subjective estimation of stimulus inconvenience. We conclude the observed effect of rapid-rate transcranial magnetic stimulation to be associated to rather an unspecific arousal reaction than to a direct stimulation of autonomic cortex areas. We did not observe any clinically relevant side-effects.

Polypectomy of adenomas in the prevention of colorectal cancer: 10 years' follow-up of the Telemark Polyp Study I. A prospective, controlled population study

BACKGROUND

The efficacy of polypectomy in preventing colorectal cancer (CRC) has never been demonstrated in a controlled, prospective study. This must be done by randomization within a population with a high prevalence of colorectal polyps, and the feasibility and safety of endoscopic screening examination is a prerequisite for this type of study.

METHODS

The present study is a randomized, controlled study of the feasibility and safety of flexible sigmoidoscopic screening of a normal population sample of 799 men and women aged 50-59 years, findings at 2 and 6 years' colonoscopic follow-up, and the appearance of clinical colorectal cancer (CRC) after 10 years.

RESULTS

The attendance rate was high, and there were no complications. After 10 years 1 of 400 in the screening group had developed CRC (in the group of 76 (19%) not attending for screening examination). Four of 399 controls developed CRC.

CONCLUSIONS

Poor yield of polyps at follow-up, slow growth of in situ polyps, and no clinical CRC among screenees after 10 years provides support to infrequent or no colonoscopic follow-up after initial polypectomy in individuals with otherwise average risk of CRC.

When to suspect and how to diagnose pulmonary lymphangioleiomyomatosis

The objective of this study was to present clinical and radiological data of eight women with histologically proven lymphangioleiomyomatosis (LAM) diagnosed between 1984 and 1994, and to suggest a diagnostic strategy when LAM is suspected. A review of case reports, including results of biopsies, lung function and radiological procedures was undertaken. The mean age of the women at start of symptoms was 36 years, and the mean age at time of diagnosis 42 years. The most frequent presenting complaint was dyspnea, either in conjunction with pneumothorax (3), chylothorax (2) or on exertion (2). All patients had airflow limitation and markedly reduced gas transfer. Five patients had 16 episodes of pneumothorax. In seven patients multiple cysts were observed on the surface of the lung during thoracotomy while computerized tomography (CT) scans revealed numerous cysts evenly distributed throughout the lung parenchyma. The procedures that confirmed the diagnosis included transbronchial lung biopsy (4), open lung biopsy (2), thoracoscopy (1), thoracotomy (3) and autopsy (1). Three specimens had to be revised before the histological diagnosis was confirmed. It was concluded that the important clues to a diagnosis of LAM are recurrent episodes of pneumothoraces in fertile women, progressive air-flow limitation, markedly reduced gas transfer and characteristic findings on thoracic CT scans. A specific request to the pathologist to stain lung tissue specimens for smooth muscle cells is mandatory.

Cardiac findings in generalized lipodystrophy

The cardiac findings in eight patients, two of whom were female, with total lipodystrophy (Berardinelli-Seip's disease) are reported. One of them had the acquired form of the disease. Four patients died at a mean age of 32 years. As far as we know, at least three of them most likely died for cardiac reasons, one shortly after recovering from an attempted suicide. All eight patients had hypertrophic hearts, mostly with deranged diastolic, but also systolic, function. One had pulmonary hypertension. We conclude that generalized lipodystrophy is a serious disease with cardiac affection leading to cardiac dysfunction and early death. There is no specific cardiac treatment, and the treatment should be according to the general guidelines for patients with hypertrophic, dysfunctioning hearts.

HLA-DR matching reduces rejection rate in heart transplantation

We have studied the influence of serological matching for ten HLA-DR antigens on the occurrence of acute cellular rejection in heart transplantation by correlating the findings in routine endomyocardial biopsies taken during the first posttransplant year with the results of HLA typing of all recipients of a first cardiac graft and their donors during 1983-1994 at our center. We found that recipients of HLA-DR matched hearts had a lower frequency of acute cellular rejection, especially so for the moderate/severe rejection grades. Also, rejection appeared earlier in the DR-mismatched combinations. Whether the mismatch was for one or two DR antigens did not make a significant difference, neither could we demonstrate any influence of HLA-A or -B mismatches. The survival of DR-matched cardiac grafts tended to be higher at 1 year than DR-mismatched grafts, but the difference did not reach statistical significance.

Insight and psychotic illness. Cross-sectional and longitudinal associations

BACKGROUND

Insight has recently re-emerged as an important aspect of psychopathology amenable to empirical study. We sought to examine the relationship between various aspects of insight into illness and clinical, sociodemographic and neuropsychological variables.

METHOD

From an inner-London catchment area population, 150 in-patients with recent onset of psychosis were assessed on a variety of measures, including the Present State Examination (PSE). Subjects were followed up for a mean of four years and reassessed.

RESULTS

High IQ was associated with better insight as rated on the PSE, while gender, ethnicity and a diagnosis of schizophrenia appeared to be unrelated. At follow-up, similar associations were found, as well as correlations with attitudes to treatment and a more elaborate measure of insight. Cerebral ventricular enlargement and tests of frontal lobe function did not correlate with insight, but there was a curious, strong association with left-handedness at both assessment points. Initial insight correlated significantly but weakly with insight at follow-up.

CONCLUSIONS

The assessment of insight in psychosis has concurrent validity and is a distinct aspect of psychotic phenomenology. It may, in part, have a neuropsychological basis.

Risk factors for early and late mortality in surgical treatment of coronary artery disease

A total of 1025 patients who had coronary bypass surgery at the Surgical Department A, Rikshospitalet, Oslo, between 1982 and 1986, were analysed for factors associated with early mortality and long-term survival. The cumulative follow-up time accounted for 6553 patient-years; the median follow-up was 6.45 years and ranged from the day of admission to 10 years. In total, 31 patients (3%) died within 30 days of surgery. Some 30 possible risk factors were analysed. Univariate analysis followed by a multivariate analysis defined six independent risk factors for early mortality. These were lack of sinus rhythm, previous heart surgery, mitral regurgitation, left main stem stenosis, unstable angina, and an elevated left ventricular end-diastolic pressure. Estimation of attributable risk showed that these factors could identify all patients who died early. Independent risk factors for late death were: lack of sinus rhythm, resection of a left ventricular aneurysm, left main stem stenosis, New York Heart Association (NYHA) class IV on admission, an elevated end-diastolic pressure, and prolonged cross-clamping time. The attributable risk analysis showed that independent risk factors for total mortality explained only about half of the patients who died. This appeared to be because of the competing effect of non-cardiac mortality. Results of the study show that risk factors for early mortality are good indicators for the outcome of coronary artery bypass surgery, identifying all deaths, whereas long-term mortality cannot be predicted. Stratification of independent risk factors allows a better comparison of mortality in different centres, and also better quality control of bypass surgery.

[An answer to an inquiry on diffuse panbronchiolitis. Now it has found its way here!]

Diffuse panbronchiolitis (DPB) is a disease characterised by chronic inflammation in the region of respiratory bronchioles. The condition has mainly been observed in Japanese patients, though isolated cases have been reported from other countries. In a review published in Läkartidningen (37/94), the question was raised of why this disease had not been seen in Scandinavia, and whether this might be the result of missed diagnosis. The diagnostic criteria were listed, and the question was posed of whether (Scandinavian) physicians existed who had encountered patients with chronic sinusitis, persistent cough and inexplicable nodular changes in lung x-rays. As a direct result of this enquiry, the present article reports what may well be the first Scandinavian patient to fulfil all the diagnostic criteria of DPB. The patient responded with improved lung function and normalised blood gases to a combined treatment regimen comprising immunosuppression (cyclophosphamide and prednisolone) and nebulised antibiotics (gentamicin).

Effects of combined radiofrequency and direct current energy catheter ablation on ventricular myocardium in pigs

When radiofrequency catheter ablation of ventricular arrhythmias is unsuccessful, an option may be to combine it with direct current energy. We therefore investigated the effects of such a combination. Radiofrequency energy was delivered in a bipolar or unipolar fashion to the left and right ventricles through an ablation catheter with a tip electrode 2 mm long, using a temperature-guided radiofrequency generator. Radiofrequency ablation was followed by a single cathodal direct current shock (66 J) with the ablation catheter positioned similarly in six closed-chest pigs. In a control group (six animals) only direct current ablation was performed, with one or two energy applications (66 J) in each ventricle. Two of six animals in the radiofrequency/direct current group died due to perforation in the follow-up period, 1 and 3.5 h after the direct current ablation, respectively. Gross pathological examination of the hearts revealed transmural lesions in all animals. In the radiofrequency/direct current group four lesions were perforated, three of which were located in the left ventricle. There was a significant increase in the number of perforations in the radiofrequency/direct current group compared to the control group, where perforation was never observed. Haemorrhagic pericardial fluid was found in five of the six animals in the radiofrequency/direct current group compared to none in the control group. These findings show that myocardial ablation with radiofrequency energy followed by direct current energy in the same session may have a high complication rate.

Power and temperature guided radiofrequency catheter ablation of the right atrium in pigs

The aim of the present study was twofold: to assess the safety of ablating the atrial free wall using RF current; and to assess the effect of a single dose of intravenous heparin followed by aspirin once daily to prevent thrombus formation after RF ablation. Temperature and power guided catheter ablation were evaluated. Twenty pigs were randomized to power or temperature guided unipolar RF catheter ablation. Ten animals received a bolus of heparin (150 U/kg) followed by 150-mg aspirin daily, and ten served as controls. A mid-sternal thoracotomy was performed 5-7 days later. The ability of a lesion to resist an increased transmural atrial pressure was examined by inflating a cuff around the pulmonal artery. Transmural lesions were found in all animals. Right atrial pressure was increased from 5 to 30 mmHg with no sign of perforation. In 11 of 20 (55%) animals, 1-3 lesions were found in the lungs (diameter 4-18 mm). The localization of these lesions corresponded to the lesions in the atria. There were no differences in the energy delivery modes with regard to the number of animals with lung lesions. Lesions with thrombus formation were found in four animals in the heparin/aspirin group and in nine animals in the control group. The incidence of thrombi was significantly smaller in the treatment group. There were no differences between temperature and power guided catheter ablation with regard to the size of the atrial lesions or to the incidence of thrombus formation. Transmural lesions induced in the right atrium by RF energy are resistant to increases in transmural pressure. However, lung tissue overlying the ablated target may be injured by the RF energy delivered. The combination of a single dose intravenous heparin followed by aspirin daily may reduce the incidence of thrombus formation.

Development of granulomas and vascular fibrocellular proliferation in the lungs of pigs receiving long-term lipid-based parenteral nutrition

The lungs of pigs receiving long-term total parenteral nutrition (TPN) have been studied. A total of 20 pigs were tentatively infused with TPN through central venous catheters for 7 weeks. To secure adequate nutrition and gastrointestinal absorbance of nutrients, an additional full oral diet was given to eight of these animals. Fifteen control animals received Ringer solution through central venous catheters in addition to the oral diet. All animals infused with TPN for 7 weeks developed lung granulomas, a finding not observed in control animals. No lung granulomas were seen in three TPN animals sacrificed after 3 to 5 weeks owing to illness. All TPN animals also developed tissue reactions suggesting long-standing lung vascular inflammation. Similar vascular changes were seen in seven control animals that had bacterial infection or endotoxemia. The total amount of neutral fat in lung homogenate tended to increase in animals given TPN, and the linoleic acid content was significantly increased. In conclusion, long-term TPN caused lung granulomas in pigs. Vascular damage seemed to be accelerated by bacterial infection as well as by the TPN. The tissue reactions presumably involved long-term activation of monocytes/macrophages.

Single lung transplantation as treatment for end-stage pulmonary sarcoidosis: recurrence of sarcoidosis in two different lung allografts in one patient

Three patients have undergone single lung transplantation in our hospital because of respiratory failure as a result of sarcoidosis. Two patients survived the postoperative period. Obliterative bronchiolitis developed in one of these patients, and recurrence of sarcoidosis in the transplanted lung necessitated contralateral single lung transplantation. Nine months later the first transplant became necrotic and infected and had to be removed. The postoperative course was uncomplicated. However, transbronchial biopsy specimens 10 months after retransplantation show sarcoid changes also in the second transplant, but without any signs of cellular rejection.

Simultaneous occurrence of primary choroidal and cutaneous malignant melanoma and skin metastasis

This case report describes the clinical and histopathological findings in a 65-year-old woman enucleated for a malignant choroidal melanoma. Simultaneously, an excision was performed of a cutaneous melanoma together with a satellite nodule presumed to be a metastasis from the cutaneous, superficial spreading melanoma. Six months later, chemotherapy for liver metastasis was given without effect. There were no signs of dysplastic nevus syndrome. A 39-year-old cousin, however, had been enucleated for a malignant choroidal melanoma. This sporadic case might suggest a common etiologic factor in the pathogenesis of multicentric melanomas.

The effect of temperature-guided radiofrequency ablation of ventricular myocardium

The safety and feasibility of temperature-guided radiofrequency (RF) ablation of ventricular myocardium were assessed in an open-chest animal model. RF ablation was performed in the ventricles of 19 pigs using ablation catheters with a tip electrode of 2 or 4 mm length. The energy was delivered in a bipolar (2 mm tip electrode only) or unipolar configuration. Set temperature ranged from 60 to 90 degrees C. Pulse duration was 30 s. Histological examination showed coagulation necrosis with a haemorrhagic zone. However, lesions with a deep cleavage were found after five unipolar (2 mm tip electrode) energy applications. No such lesions were found after unipolar energy applications with a 4 mm tip electrode. During or shortly after ablation, premature ventricular beats and non-sustained VT were frequently observed and in some instances ventricular fibrillation. In the bipolar mode we found a positive correlation between lesion area/volume and peak temperature with a correlation coefficient of 0.48 and 0.56, respectively (P < 0.05). However no correlation was found between lesion size and applied energy. In the unipolar configuration there was no correlation between lesion size and these parameters. Median depth and area were: bipolar: 4.0 mm/23.5 mm2, unipolar (2 mm tip electrode): 3.5 mm/12.2 mm2, unipolar (4 mm tip electrode): 4.0 mm/15.7 mm2. We conclude that in a beating heart it is difficult to predict lesion size from temperature or energy.

Single lung transplantation. Morphological surveillance by transbronchial biopsy

Seven cases of single lung transplantation are reported. The recipients were all below 60 years of age and severely disabled with end-stage lung disease. Transplantation was performed according to ABO blood group compatibility and negative lymphocytotoxic cross-match between donor and recipient irrespective of HLA mismatch. Recipients' diagnoses were sarcoidosis (3), alfa-1 antitrypsin deficiency (3), and idiopathic emphysema (1). Mean recipient age was 48 +/- 2.4 years (range 45-52). Donor age was 29.7 +/- 5.6 years (range 16-49). The immunosuppressive regimen included cyclosporin A, azathioprine, steroids and rabbit antithymocyte globulin. Excellent graft function was achieved. Six patients survived the postoperative period and are alive 4-18 months posttransplant. One patient died after the operation due to pneumonia with respiratory distress syndrome. Graft function was also monitored by transbronchial biopsy, and 57 biopsy procedures were performed without fatal complications. Acute cellular rejection was seen in 16 biopsy specimens from 5 recipients (grade 1 and 2 rejection in 14, grade 3 rejection in 2). Neither severe rejection with septal necrosis (grade 4) nor obliterative bronchiolitis was seen. The rejection rate was 0.03 episodes per patient/month. In contrast to other reports, episodes of cellular rejection occurred throughout the observation period, and were not mainly limited to the first 4 months posttransplant. Graft vascular occlusive disease or chronic vascular rejection was found in 6 biopsy specimens from one recipient. Five patients experienced 7 episodes of cytomegalovirus infection. The cytomegalovirus infection rate was 0.01 episodes per patient/month. The incidence of infection was significantly lower compared to previous studies of rejection in other lung graft combinations. Both infections and rejection episodes may contribute to the development of obliterative bronchiolitis. Almost one third of the specimens (30%) showed lymphocytic bronchitis without perivascular inflammation. The absence of perivascular infiltrates and exclusion of infectious agents leaves in question the aetiology of this inflammation. The lymphocytic bronchitis could be ischaemic, related to aspiration, or represent recurrent sarcoidosis, or, in fact, express bronchial rejection. All biopsy specimens regarded as rejection with cellular infiltrates in the lung parenchyma also showed a lymphocytic bronchitis. The impact of HLA mismatch on cellular and vascular rejection is unclear. Transbronchial biopsy is a reasonably safe and reliable method in the diagnosis of rejection and infection in single lung transplantation.

Daily home spirometry facilitates early detection of rejection in single lung transplant recipients with emphysema

Eight single lung transplant recipients with emphysema, aged 40-58 yrs, have been followed up for 90 patient months. Starting 2-4 weeks postoperatively, they recorded their forced vital capacity (FVC), and forced expiratory volume in one second (FEV1), at a fixed time every morning using a Micro Spirometer. They were instructed to contact the hospital if the FVC or FEV1 displayed a persistent (two days or more) decrease of 10%, compared with the average values during the last seven days. Transbronchial biopsies (TBB) were performed regularly in the follow-up, and whenever the patients had respiratory symptoms, or the FVC or FEV1 displayed a persistent decline of more than 10%. We performed 59 TBBs, and 23 biopsy specimens showed rejection. The FVC and FEV1 values on the TBB day were compared with the mean values of the 7 previous days. FVC and FEV1, associated with negative TBBs (16 events), showed no significant changes. However, FVC and FEV1 decreased significantly (p < 0.001, paired t-test) during rejections (mean percentage change 14 and 21% respectively, range +8% to -53%). In 16 of the 23 rejections, the FEV1 decreased by > 10%. We recommend the use of daily home spirometry when monitoring single lung recipients with emphysema, and suggest that a persistent 10% decrease in FEV1 or FVC for at least two days is an indication for hospital admission and possible TBB.

Daily home spirometry facilitates early detection of rejection in single lung transplant recipients with emphysema

Eight single lung transplant recipients with emphysema, aged 40-58 yrs, have been followed up for 90 patient months. Starting 2-4 weeks postoperatively, they recorded their forced vital capacity (FVC), and forced expiratory volume in one second (FEV1), at a fixed time every morning using a Micro Spirometer. They were instructed to contact the hospital if the FVC or FEV1 displayed a persistent (two days or more) decrease of 10%, compared with the average values during the last seven days. Transbronchial biopsies (TBB) were performed regularly in the follow-up, and whenever the patients had respiratory symptoms, or the FVC or FEV1 displayed a persistent decline of more than 10%. We performed 59 TBBs, and 23 biopsy specimens showed rejection. The FVC and FEV1 values on the TBB day were compared with the mean values of the 7 previous days. FVC and FEV1, associated with negative TBBs (16 events), showed no significant changes. However, FVC and FEV1 decreased significantly (p < 0.001, paired t-test) during rejections (mean percentage change 14 and 21% respectively, range +8% to -53%). In 16 of the 23 rejections, the FEV1 decreased by > 10%. We recommend the use of daily home spirometry when monitoring single lung recipients with emphysema, and suggest that a persistent 10% decrease in FEV1 or FVC for at least two days is an indication for hospital admission and possible TBB.

Quantitative assessment of sudomotor activity by capacitance hygrometry

A commercial capacitive hygrometer device manufactured for use in technical or chemical laboratory environments has been used for quantitative and dynamic assessment of sweat gland activity in selected skin areas. For this purpose the hygrometer device was supplemented by a chamber attached to the skin for collecting evaporated water and a supply of dry nitrogen gas providing a gas flow through the chamber and through the hygrometer capsule. The accuracy of the technique was proven in pilot experiments in which fixed amounts of water were evaporated. A positive correlation was found between the weight of the water and the water evaporation computed from the hygrometer readings (r = 0.997). The time constant of the device was in the range of 10 s. This time constant appears to be fast enough for recording physiological changes in the sweating rate of human subjects. In experiments on healthy subjects sudomotor reflexes were assessed and compared to vasoconstrictor responses and to thermographically measured temperature changes of the skin during the Valsalva manoeuvre and a painful mechanical stimulus. Direct measurement of water evaporation such as by this technique may provide information on sympathetic reactions which could be utilized in both physiological and pathophysiological states.

Life events and psychosis. Initial results from the Camberwell Collaborative Psychosis Study

Data from the Camberwell Collaborative Psychosis Study were used to examine the proposition that there is an excess of life events preceding the onset of psychoses of all types. Of 97 patients from the study who had episodes within the past year that were datable, 51 had developed psychotic symptoms from an essentially symptom-free state, 29 had been suffering only from neurotic symptoms, and 17 had experienced a marked exacerbation of psychotic symptoms. DSM-III diagnoses were collapsed into three major groups: 51 cases of schizophrenia; 31 cases of mania; and 14 cases of depressive psychosis. Life-event histories were taken for the six months before onset, and when these were compared with equivalent histories from a psychiatrically healthy sample from the local general population, there was a significant excess of life events, particularly in the three months before onset of psychosis. This was apparent in all groups, and remained even when events were restricted to the independent category. The excess of events began rather earlier than has been found in previous studies. In our view, this study provides some of the strongest evidence for a link between life events and the emergence of psychotic symptoms.