Brain-region-specific changes in neurons and glia and dysregulation of dopamine signaling in Grin2a mutant mice

A genetically valid animal model could transform our understanding of schizophrenia (SCZ) disease mechanisms. Rare heterozygous loss-of-function (LoF) mutations in GRIN2A, encoding a subunit of the NMDA receptor, greatly increase the risk of SCZ. By transcriptomic, proteomic, and behavioral analyses, we report that heterozygous Grin2a mutant mice show (1) large-scale gene expression changes across multiple brain regions and in neuronal (excitatory and inhibitory) and non-neuronal cells (astrocytes and oligodendrocytes), (2) evidence of hypoactivity in the prefrontal cortex (PFC) and hyperactivity in the hippocampus and striatum, (3) an elevated dopamine signaling in the striatum and hypersensitivity to amphetamine-induced hyperlocomotion (AIH), (4) altered cholesterol biosynthesis in astrocytes, (5) a reduction in glutamatergic receptor signaling proteins in the synapse, and (6) an aberrant locomotor pattern opposite of that induced by antipsychotic drugs. These findings reveal potential pathophysiologic mechanisms, provide support for both the "hypo-glutamate" and "hyper-dopamine" hypotheses of SCZ, and underscore the utility of Grin2a-deficient mice as a genetic model of SCZ.

Predictors for affected stroke territory and outcome of acute stroke treatments are different for posterior versus anterior circulation stroke

Distinct patient characteristics have been proposed for ischaemic stroke in the anterior versus posterior circulation. However, data on functional outcome according to stroke territory in patients with acute stroke treatment are conflicting and information on outcome predictors is scarce. In this retrospective study, we analysed functional outcome in 517 patients with stroke and thrombolysis and/or thrombectomy treated at the University Hospital Zurich. We compared clinical factors and performed multivariate logistic regression analyses investigating the effect of outcome predictors according to stroke territory. Of the 517 patients included, 80 (15.5%) suffered a posterior circulation stroke (PCS). PCS patients were less often female (32.5% vs. 45.5%, p = 0.031), received thrombectomy less often (28.7% vs. 48.3%, p = 0.001), and had lower median admission NIHSS scores (5 vs. 10, p < 0.001) as well as a better median three months functional outcome (mRS 1 vs. 2, p = 0.010). Predictors for functional outcome were admission NIHSS (OR 0.864, 95% CI 0.790–0.944, p = 0.001) in PCS and age (OR 0.952, 95% CI 0.935–0.970, p < 0.001), known symptom onset (OR 1.869, 95% CI 1.111–3.144, p = 0.018) and admission NIHSS (OR 0.840, 95% CI 0.806–0.876, p < 0.001) in ACS. Acutely treated PCS and ACS patients differed in their baseline and treatment characteristics. We identified specific functional outcome predictors of thrombolysis and/or thrombectomy success for each stroke territory.

Comparative effectiveness of antitumour necrosis factor agents, biologics with an alternative mode of action and tofacitinib in an observational cohort of patients with rheumatoid arthritis in Switzerland

Background

Multiple biologic and targeted synthetic disease-modifying rheumatic drugs (b/tsDMARDs) are approved for the management of rheumatoid arthritis (RA), including TNF inhibitors (TNFi), bDMARDs with other modes of action (bDMARD-OMA) and Janus kinase inhibitors (JAKi). Combination of b/tsDMARDs with conventional synthetic DMARDs (csDMARDs) is recommended, yet monotherapy is common in practice.

Objective

To compare drug maintenance and clinical effectiveness of three alternative treatment options for RA management.

Methods

This observational cohort study was nested within the Swiss RA Registry. TNFi, bDMARD-OMA (abatacept or anti-IL6 agents) or the JAKi tofacitinib (Tofa) initiated in adult RA patients were included. The primary outcome was overall drug retention. We further analysed secondary effectiveness outcomes and whether concomitant csDMARDs modified effectiveness, adjusting for potential confounding factors.

Results

4023 treatment courses of 2600 patients were included, 1862 on TNFi, 1355 on bDMARD-OMA and 806 on Tofa. TNFi was more frequently used as a first b/tsDMARDs, at a younger age and with shorter disease duration. Overall drug maintenance was significantly lower with TNFi compared with Tofa [HR 1.29 (95% CI 1.14 to 1.47)], but similar between bDMARD-OMA and Tofa [HR 1.09 (95% CI 0.96 to 1.24)]. TNFi maintenance was decreased when prescribed without concomitant csDMARDs [HR: 1.27 (95% CI 1.08 to 1.49)], while no difference was observed for bDMARD-OMA or Tofa maintenance with respect to concomitant csDMARDs.

Conclusion

Tofa drug maintenance was comparable with bDMARDs-OMA and somewhat higher than TNFi. Concomitant csDMARDs appear to be required for optimal effectiveness of TNFi, but not for bDMARD-OMA or Tofa.

Socioeconomic status and lifestyle behaviours in cancer survivors: smoking and physical activity

PURPOSE

Smoking cessation and increased physical activity (pa) have been linked to better outcomes in cancer survivors. We assessed whether socioeconomic factors influence changes in those behaviours after a cancer diagnosis.

METHODS

As part of a cross-sectional study, a diverse group of cancer survivors at the Princess Margaret Cancer Centre (Toronto, ON), completed a questionnaire about past and current lifestyle behaviours and perceptions about the importance of those behaviours with respect to their health. The influence of socioeconomic indicators on smoking status and physical inactivity at 1 year before and after diagnosis were assessed using multivariable logistic regression with adjustment for clinico-demographic factors.

RESULTS

Of 1222 participants, 1192 completed the smoking component. Of those respondents, 15% smoked before diagnosis, and 43% of those smokers continued to smoke after. The proportion of survivors who continued to smoke increased with lower education level (p = 0.03). Of the 1106 participants answering pa questions, 39% reported being physically inactive before diagnosis, of whom 82% remained inactive afterward. Survivors with a lower education level were most likely to remain inactive after diagnosis (p = 0.003). Lower education level, household income, and occupation were associated with the perception that pa had no effect or could worsen fatigue and quality of life (p ≤ 0.0001).

CONCLUSIONS

In cancer survivors, education level was a major modifier of smoking and pa behaviours. Lower socioeconomic status was associated with incorrect perceptions about pa. Targeting at-risk survivors by education level should be evaluated as a strategy in cancer survivorship programs.

Open Reduction and Palmar Plate-Osteosynthesis in Combination with a Nanocrystalline Hydroxyapatite Spacer in the Treatment of Comminuted Fractures of the Distal Radius

In a prospective study, we used the nanocrystalline hydroxyapatite paste Ostim (Osartis, Obernburg, Germany) in combination with a palmar plate to treat comminuted radius fractures with a metaphyseal and articular component in order to examine the clinical use of Ostim as a bone substitute. Twenty-one patients with 22 radius fractures of AO types C2 and C3 were included in the study. The measurements, taken 10.2±1.3 months after the initial treatment, revealed a dorsopalmar tilt of 8.8±3.7°, a radioulnar inclination of 18.8±2.8° and an ulnar variance of 0.8±1.8 mm. According to the Gartland and Werley evaluation, eight of the treated fractures attained an excellent, 11 a good and the remaining three a fair result. The study demonstrates that Ostim, in combination with angularly stable osteosynthesis, can be used as an acceptable bone substitute for the treatment of type C2 and C3 radial fractures.

Identification of predictive CT angiographic factors in the development of high-risk type 2 endoleaks after endovascular aneurysm repair in patients with infrarenal aortic aneurysms

PURPOSE

An extensive analysis of the value of computed tomography (CT) parameters as potential predictors of the clinical outcome of type 2 endoleaks after endovascular aortic aneurysm repair (EVAR).

MATERIALS AND METHODS

Initial CT scans of 130 patients with abdominal aortic aneurysms (AAAs) were retrospectively reviewed. On the basis of postoperative CT scans and angiographies, patients were stratified into a low-risk group (LRG; without or transient type 2 endoleak; n = 80) and a high-risk group (HRG, persistent type 2 endoleak or need for reintervention; n = 50). Statistical analysis comprised a univariate and multivariate analysis.

RESULTS

Anatomical, thrombus-specific, as well as aortic side branch parameters were assessed on the initial CT scan. Of all anatomical parameters, the diameter of the immediate infrarenal aorta was significantly different in the univariate analysis (LRG 22.4 ± 3.8 mm; HRG 23.6 ± 2.5 mm; p = 0.03). The investigation of the thrombus-specific parameters showed a trend towards statistical significance for the relative thrombus load (LRG 31.7 ± 18.0%; HRG 25.3 ± 17.5%; p = 0.09). Assessment of aortic side branches revealed only for the univariate analysis significant differences in the patency of the inferior mesenteric artery (LRG 71.3%; HRG 92.0%; p = 0.003) and their diameter (LRG 3.3 ± 0.7 mm; HRG 3.8 ± 0.9 mm; p = 0.004). In contrast, the number of lumbar arteries (LAs; LRG 2.7 ± 1.4; HRG 3.6 ± 1.2; univariate: p = 0.01; multivariate: p = 0.006) as well as their diameter (LRG 2.1 ± 0.4 mm; HRG 2.4 ± 0.4 mm; univariate: p < 0.001; multivariate: p = 0.006) were highly significantly associated with the development of type 2 endoleaks of the HRG.

CONCLUSION

The most important predictive factors for the development of high-risk type 2 endoleaks were mainly the number and the diameter of the LAs which perfused the AAA.

KEY POINTS

• This study is a very detailed and comprehensive analysis of the value of various CT parameters as potential predictors of the clinical outcome of type 2 endoleaks after EVAR. • Anatomical as well as thrombus-specific parameters were unsuitable as predictors. • The most important predictive factors were mainly the number and the diameter of the LAs which perfused the AAA.

Can early computed tomography angiography after endovascular aortic aneurysm repair predict the need for reintervention in patients with type II endoleak?

PURPOSE

This study was designed to identify parameters on CT angiography (CTA) of type II endoleaks following endovascular aortic aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA), which can be used to predict the subsequent need for reinterventions.

METHODS

We retrospectively identified 62 patients with type II endoleak who underwent early CTA in mean 3.7 ± 1.9 days after EVAR. On the basis of follow-up examinations (mean follow-up period 911 days; range, 373-1,987 days), patients were stratified into two groups: those who did (n = 18) and those who did not (n = 44) require reintervention. CTA characteristics, such as AAA, endoleak, as well as nidus dimensions, patency of the inferior mesenteric artery, number of aortic branch vessels, and the pattern of endoleak appearance, were recorded and correlated with the clinical outcome.

RESULTS

Univariate and receiver operating characteristic curve regression analyses revealed significant differences between the two groups for the endoleak volume (surveillance group: 1391.6 ± 1427.9 mm(3); reintervention group: 3227.7 ± 2693.8 mm(3); cutoff value of 2,386 mm(3); p = 0.002), the endoleak diameter (13.6 ± 4.3 mm compared with 25.9 ± 9.6 mm; cutoff value of 19 mm; p < 0.0001), the number of aortic branch vessels (2.9 ± 1.2 compared with 4.2 ± 1.4 vessels; p = 0.001), as well as a "complex type" endoleak pattern (13.6 %, n = 6 compared with 44.4 %, n = 8; p = 0.02).

CONCLUSIONS

Early CTA can predict the future need for reintervention in patients with type II endoleak. Therefore, treatment decision should be based not only on aneurysm enlargement alone but also on other imaging characteristics.

Prestimulus frontal-parietal coherence predicts auditory detection performance in rats

Electrophysiology in primates has implicated long-range neural coherence as a potential mechanism for enhancing sensory detection. To test whether local synchronization and long-range neural coherence support detection performance in rats, we recorded local field potentials (LFPs) in frontal and parietal cortex while rats performed an auditory detection task. We observed significantly elevated power at multiple low frequencies (<15 Hz) preceding the target beep when the animal failed to respond to the signal (misses), in both frontal and parietal cortex. In terms of long-range coherence, we observed significantly more frontal-parietal coherence in the beta band (15-30 Hz) before the signal on misses compared with hits. This effect persisted after regressing away linear trends in the coherence values during a session, showing that the excess frontal-parietal beta coherence prior to misses cannot be explained by slow motivational changes during a session. In addition, a trend toward higher low-frequency (<15 Hz) coherence prior to miss trials compared with hits became highly significant when we rereferenced the LFPs to the mean voltage on each recording array, suggesting that the results are specific to our frontal and parietal areas. These results do not support a role for long-range frontal-parietal coherence or local synchronization in facilitating the detection of external stimuli. Rather, they extend to long-range frontal-parietal coherence previous findings that correlate local synchronization of low-frequency (<15 Hz) oscillations with inattention to external stimuli and synchronization of beta rhythms (15-30 Hz) with voluntary or involuntary prolongation of the current cognitive or motor state.

Detection of high-energy phosphates in cortical bone as an indicator of bone healing and remodelling: use of a rabbit model

PURPOSE; To study high-energy phosphates in cortical bone through experiments on inbred white New Zealand rabbits.

METHODS

Tibial fractures were induced in 80 rabbits and then stabilised by screw osteosynthesis. After 3 (group A; n=40) or 7 days (groups B; n=40), the defective tissue was covered by local muscle flaps. At increasing intervals (from 1 to 16 weeks), the screws were removed and the animals were euthanised (n=8 per group). The bone was removed and analysed histomorphologically; adenosine triphosphate (ATP) levels were determined by high-performance liquid chromatography.

RESULTS

The mean ATP concentration in healthy cortical bone at 16 weeks was 0.092 (standard error, 0.009) nmol/mg dry mass, which was significantly higher than that in the group with delayed healing: 0.081 (0.011) nmol/mg in group A and 0.005 (0.001) nmol/mg in group B (paired t test, p<0.05). Earlier healing led to lower rates of necrosis (0 vs 38; groups A vs B) and osteomyelitis.

CONCLUSION

Early muscle-flap coverage can revascularise the cortical bone, which is reflected in the higher ATP content in the cortical bone measured by high-performance liquid chromatography. Measuring changes of ATP levels can help investigate the metabolism of the pathological bone.

Thermodiffusion for the quantification of tissue perfusion in skeletal muscle--clinical evaluation in standardized traumatological procedures with tourniquet and potential application in the diagnosis of compartment syndrome

The quantification of tissue perfusion in different parenchymal organs like liver, kidney, and brain by means of thermodiffusion has recently been validated experimentally and was introduced into clinical practice. Traumatology and plastic surgery deal as well with issues of microcirculation. Therefore, it was the aim of this study to validate thermodiffusion for use in skeletal muscle. Eighteen patients were studied during knee arthroscopic procedures that utilized a tourniquet. A thermodiffusion probe was inserted in the tibialis anterior muscle of the side under treatment. Measurement started before the initiation of limb ischemia (by tourniquet) and continued throughout the procedure until tissue perfusion returned to normal values postoperatively. Furthermore, an example of clinical applicability of this technique is given by monitoring muscle tissue perfusion in 3 patients with imminent compartment syndrome. Preoperative values of muscle tissue perfusion in the patients undergoing arthroscopic procedures were 17.74 +/- 4.27 ml/min 100 g. After initiation of tourniquet perfusion quickly decreased to 3.59 +/- 3.53 ml/min 100 g. Upon reperfusion tissue perfusion increased to values above normal for a few minutes and then returned to preischemic values of 20.86 +/- 7.01 ml/min 100 g. There was no significant difference between pre- and postoperative values (P=0.154) but tissue perfusion during tourniquet was significantly reduced (P=0.0001). In 3 patients presenting with the clinical signs of imminent compartment syndrome, thermodiffusion measurement was applied and showed microcirculatory impairment of different degrees. Fasciotomy was followed by a prompt increase of muscle microcirculation to levels slightly above normal. In summary, valid and stable measurements of tissue perfusion in skeletal muscle by means of thermodiffusion are possible under clinical circumstances. Thermodiffusion allows for on-line monitoring of muscle microcirculation, e.g., in compartment syndrome. The clinical potential of thermodiffusion measurements in trauma surgery needs further prospective evaluation.

Laser doppler flow imaging of open lower leg fractures in an animal experimental model

PURPOSE

Open lower leg fractures are frequently associated with severe soft tissue damage, followed by osteomyelitis. Using an animal experimental model, we investigated the effect of timing of coverage of a tibial fracture with a local muscle flap.

METHODS

80 rabbits had a tibial fracture induced in a standardised fashion, which was stabilised by screw osteosynthesis. After 3 (group A; n=40) and 7 days (group B; n=40), respectively, the tissue defect was covered by a local gastrocnemius flap. In increasing intervals from 1 to 2, 4, 8, and 16 weeks, the rabbits from each group were killed and the bone fracture was analysed histomorphologically. Cortical microcirculation was measured by 2-channel laser doppler flowmetry.

RESULTS

Muscle flaps after 3 days improved perfusion significantly as compared with 7 days (24 Flux [standard error, 5 Flux] versus 10 Flux [3 Flux]; baseline, 1.4 Flux). Group A animals also displayed a lower rate of necrosis (0 versus 38). The incidence of osteomyelitis was higher in group B than in group A (24% versus 0%).

CONCLUSION

Laser doppler flowmetry was proven to be a reliable, minimally invasive means for identifying avital tissue, leading to reduction in the loss of vital bone tissue in experimental settings.

Glutathione depletion with L-buthionine-(S,R)-sulfoximine demonstrates deleterious effects in acute pancreatitis of the rat

A common pathway in the pathogenesis of acute pancreatitis is the generation of free oxygen radicals. The most important defense mechanisms are free radical scavengers, especially glutathione. This study evaluates the influence of the inhibition of glutathione synthesis with L-buthionine-(S,R)-sulfoximine (BSO) on the course of experimentally induced acute pancreatitis in rats and the effects on isolated pancreatic acini and their secretion pattern. Thus acute necrotizing pancreatitis was induced with intraductal infusion of low-dose glycodeoxycholic acid and subsequent hyperstimulation with cerulein with and without pretreatment with BSO. In vitro pancreatic acini were isolated and stimulated with different concentrations of cerulein with and without BSO. The BSO-treated group showed a significantly reduced survival, more necrosis, and a decreased secretion of amylase in vivo. No effect on secretion pattern in either groups was seen in vitro and BSO did not exert toxic effects. Based on the data presented, this study demonstrates deleterious effects of scavenger depletion on the course of experimental pancreatitis. This is due to the systemic effects of free oxygen radicals rather than to local effects.

[Angle- and rotation-stable internal fixation of proximal humerus fractures with the humerus fixator plate. Early clinical experience with a newly developed implant]

INTRODUCTION

The Humerus Fixator Plate is presented as a new implant for angle- and rotation-stable internal fixation for the operative treatment of proximal humerus fractures at the surgical neck.

METHODS

In an ongoing two-centre study, 47 patients were treated with the new implant. To date, 31 patients had clinical and radiological postoperative follow-up examinations with a mean interval of 10 months (range: 6-14 months).

RESULTS

In 46 patients (97.9%), complete angle and rotational stability was achieved without limiting the range of motion or requiring immobilization. Good pain relief was obtained in 43 patients (91.5 %), and 3 patients (6.4%) showed moderate pain relief following surgery. There was one implant failure. Utilizing the Constant-Raw score (without any correction factors), a mean result of 82.8 points (range: 46-100 points) was ascertained. The majority of the patients (87.1%) achieved "excellent" or "good" clinical results. X-ray analysis revealed no non-union nor humerus head necrosis. In 4 cases (12.9%), protrusion of a humerus head screw was observed which mandated removal of the implant.

CONCLUSION

The first clinical investigations of the novel Humerus Fixator Plate are encouraging and provide essential advances in the treatment of unstable proximal humerus fractures.

[Psychotropic substances in the area of preclinical intensive care medicine]

The aim of preclinical intensive care is to prevent severe consequences by providing immediate therapeutic aid to emergency patients in a life-threatening condition. We investigated how the abuse of drugs and alcohol influences the frequency and the category of emergency cases as well as the patient outcome. 250 emergency cases were analysed in a prospective study in the area of Heidelberg, Germany, from the summer of 1995 to the spring of 1999. The analysis is based on patient data obtained from the German standardised Emergency Record and on the clinical outcome and influence of drugs and alcohol. A serious level of drugs or alcohol was detected in 17% of the patients (the average level of alcohol was 1.97 promille). 81% of these intoxicated patients were given a NACA (National Advisory Committee for Aeronautics) score of less than 4 (not life-threatening) and therefore were not in need of the a presence of a physician.

[Prevention and treatment of procedural pain in pediatric wards: collected guidelines]

Present knowledge and available pharmacological agents allow for adequate prevention and treatment of pain in children. We present guidelines we prepared for the prevention and treatment of procedural pain in children in our general pediatric ward. This followed extensive review of the literature, participation in scientific meetings, discussions with experts and consultation with interested clinicians. Successful implementation of the guidelines requires increased appreciation of the importance of pain prevention, participation of the nursing, as well as medical staff, and ability to evaluate pain in children of various ages.

[Oral rehydration in acute gastroenteritis in infants and children--advantages of a standardized protocol]

Oral rehydration (OR) for acute gastroenteritis in infants and children has been shown to be as effective as IV therapy, with less discomfort and lower costs. In this retrospective study we compared 2 pediatric wards, in 1 of which only a standardized, simplified, bedside protocol, based on American Academy of Pediatrics guidelines, was used. There were no significant clinical characteristics in the 208 patients. In the ward which used the above protocol, OR utilization was significantly more frequent than in the other ward (48% versus 15%), thus saving equipment costs of nearly $1,000/3 months. There were no significant differences in outcome between the wards. We conclude that introducing a standardized management protocol may increase OR utilization in hospitalized children with acute diarrhea.

Congenital insensitivity to pain with anhidrosis (CIPA) in Israeli-Bedouins: genetic heterogeneity, novel mutations in the TRKA/NGF receptor gene, clinical findings, and results of nerve conduction studies

Congenital insensitivity to pain with anhidrosis (CIPA), a rare and severe disorder, comprises absence of sensation to noxious stimuli, inability to sweat, and recurrent episodes of hyperthermia. It has a relatively high prevalence in the consanguineous Israeli-Bedouins. Clinical studies of 28 patients are reported here. Using the linkage analysis approach, we linked the disease in 9 of 10 unrelated Israeli-Bedouin families with CIPA to the TrkA gene, which encodes the receptor for nerve growth factor. In one family, linkage was excluded, implying that another gene, yet unidentified, is involved. Two new mutations in the tyrosine kinase domain of the TrkA gene were identified in our CIPA patients: a 1926-ins-T in most of the southern Israeli-Negev CIPA patients, and a Pro- 689-Leu mutation in a different isolate of Bedouins in northern Israel. Eight prenatal diagnoses were made in the southern Israeli-Negev Bedouins, two by linkage analysis and six by checking directly for the 1926-ins-T mutation. Three polymorphisms in the TrkA protein kinase encoding domain were also observed.

Vascular structure and microcirculation of experimental pancreatic carcinoma in rats

OBJECTIVE

To study angiogenesis and microcirculation in experimental pancreatic carcinoma.

DESIGN

Open experimental study.

SETTING

2 University hospitals, Germany and USA.

ANIMALS

16 male Lewis rats.

INTERVENTIONS

Induction of a duct-like pancreatic cancer in the pancreas and peritoneum by interposition of fragments of tumour between 2 inert transparent polymethylmethacrylate plates.

MAIN OUTCOME MEASURES

Microcirculation in the tumour and interaction between leucocytes, tumour, and endothelium investigated by intravital microscopy.

RESULTS

The density of vessels in the carcinoma was significantly less than in normal pancreatic tissue (p = 0.0004). The vasculature of the tumour was characterised by a lack of differentiation in architecture of vessels, formation of sinusoidal and lacunar vessels and sudden changes in diameter of vessels. Red blood cell velocity differed among tumour vessels, but mean values were similar to those of normal exocrine pancreas. The mixed lymphocyte culture test indicated that the cell line DSL6A was immunogenic. However, high-affinity leucocyte-endothelium-interaction was significantly reduced in the tumour's microcirculation after both orthotopic and heterotopic implantation (p = 0.002). Rates of apoptosis were suppressed in heterotopic tumours compared with orthotopic ones. Tumour growth was faster in heterotopic tumours.

CONCLUSIONS

Experimental duct-like pancreatic carcinoma can be differentiated from normal pancreas by: chaotic arrangement of vessels with loss of differentiation of architecture and heterogeneous distribution; the formation of sinusoidal or lacunar vessels; lower vascular density with similar erythrocyte velocity; increase in mean diameter of vessels; reduced leucocyte-endothelium interaction despite confirmed immunogeneity independent of wall shear rates. The site of implantation influences apoptosis and growth rates.

[Rectovaginal fistulas in patients with Crohn disease--therapy and prognosis]

Perianal and especially rectovaginal fistulas in Crohn's disease represent a great therapeutic dilemma. Surgical intervention is mandatory in the impending destruction of the anal sphincter mechanism, weighed against the efficacy of the methods available. We report on the surgical approach in 25 women with rectovaginal fistula, concluding that either levator plasty or mucosal flap is the procedure of choice.

Caspase-mediated fragmentation of calpain inhibitor protein calpastatin during apoptosis

Two cysteine protease families (caspase and calpain) participate in apoptosis. Here we report that the endogenous calpain inhibitor calpastatin is fragmented by caspase(s) to various extents during early apoptosis in two cell types. In anti-fas or staurosporine-treated Jurkat T-cells, the high-molecular-weight form (HMW) of calpastatin (apparent Mr 110 K) was extensively degraded to immunoreactive fragments of Mr 75 K and 30 K In apoptotic SH-SY5Y human neuroblastoma cells, HMW calpastatin was degraded to a major immunoreactive fragment of 75 K. In both cell types, fragmentation of HMW calpastatin was blocked by a caspase-specific inhibitor carbobenzoxy-Asp-CH2OC(O)-2,6-dichlorobenzene. In vitro translated HMW calpastatin was sensitive to proteolysis by recombinant caspase-1, -3, and -7. By contrast, in vitro translated LMW calpastatin (which lacks domains L and I) was cleaved into multiple fragments only by caspase-1 and was relatively resistant to caspase-3, -7, and other caspases tested. Consistently with that, purified erythroid LMW calpastatin was also highly susceptible to caspase-1 digestion. Recombinant human calpastatin spanning domain I through III (CAST(DI-III)) was found cleaved by caspase-1 at at least three sites, located in either the A or the C helix of domains I and III (ALDD137*L, LSSD203*F and ALAD404*S), while only a single site (ALDD137*L) was cleaved by caspase-3. These findings suggest that both HMW and LMW calpastatins are more vulnerable to caspase-1 than to caspase-3. Surprisingly, both erythroid LMW calpastatin and recombinant CAST(DI-III) fragmented by caspase-1 suffered only a less than twofold reduction of inhibitory activity toward calpain. We propose that the proteolysis of calpastatin in early apoptosis might have yet unidentified effects on the cross-talk between the two protease systems.

Effects of unsaturated fatty acids on interleukin-1beta production by human monocytes

Dihomogammalinolenic acid is derived from gammalinolenic acid, administration of which suppresses joint inflammation. It is reported here that interleukin 1beta (IL-1beta) production by human monocytes is enhanced markedly when cells are incubated 18-24 h with the polyunsaturated fatty acids dihomogammalinolenic acid (DGLA) and arachidonic acid (AA), then stimulated with lipopolysaccharide. Effects of eicosapentaenoic acid (EPA) on IL-1beta production are minimal, and palmitic acid (PA) does not influence IL-1beta production.

Caspase-1 processes IFN-gamma-inducing factor and regulates LPS-induced IFN-gamma production

Interferon-gamma-inducing factor (IGIF, interleukin-18) is a recently described cytokine that shares structural features with the interleukin-1 (IL-1) family of proteins and functional properties with IL-12. Like IL-12, IGIF is a potent inducer of interferon (IFN)-gamma from T cells and natural killer cells. IGIF is synthesized as a biologically inactive precursor molecule (proIGIF). The cellular production of IL-1beta, a cytokine implicated in a variety of inflammatory diseases, requires cleavage of its precursor (proIL-1beta) at an Asp-X site by interleukin-1beta-converting enzyme (ICE, recently termed caspase-1). The Asp-X sequence at the putative processing site in proIGIF suggests that a protease such as caspase-1 might be involved in the maturation of IGIF. Here we demonstrate that caspase-1 processes proIGIF and proIL-1beta with equivalent efficiencies in vitro. A selective caspase-1 inhibitor blocks both lipopolysaccharide-induced IL-1beta and IFN-gamma production from human mononuclear cells. Furthermore, caspase-1-deficient mice are defective in lipopolysaccharide-induced IFN-gamma production. Our results thus implicate caspase-1 in the physiological production of IGIF and demonstrate that it plays a critical role in the regulation of multiple proinflammatory cytokines. Specific caspase-1 inhibitors would provide a new class of anti-inflammatory drugs with multipotent action.

Possible role of atrial natriuretic hormone in pituitary-adrenocortical unresponsiveness in lactate-induced panic

OBJECTIVE

This study investigated whether lactate-induced panic attacks in patients with panic disorder would activate atrial natriuretic hormone, which could explain the missing ACTH and cortisol response found in this kind of experimentally induced panic.

METHOD

Sodium lactate and placebo infusions were administered to 10 patients with panic disorder and to 10 healthy comparison subjects, and the atrial natriuretic hormone responses of the two groups were compared.

RESULTS

During lactate infusion both the seven patients who had panic attacks and the eight comparison subjects who did not responded with increased plasma concentrations of atrial natriuretic hormone, but the patients had more pronounced surges of the hormone.

CONCLUSIONS

Because atrial natriuretic hormone suppresses both pituitary ACTH and adrenal cortisol release, the authors suggest that the immediate rise of atrial natriuretic hormone explains the reported lack of pituitary-adrenocortical activation during lactate-induced panic.

Survival rate and 2 year outcome in very low birthweight infants

The purpose of this study was to determine the mortality rate of 282 infants with a birthweight (BW) of < 1,500 g during a 5 year period (1987-92), and to evaluate 2 year neurodevelopmental outcome in 114 infants (born 1987-90) and its correlation with intracranial pathologies diagnosed by ultrasonography. Overall survival rate was 76.6% (216/282). With the introduction of exogenous surfactant therapy in 1991 a significant increase in survival was noted in the 751-1,000 g BW infants (from 20/36 to 20/22, P < 0.002). Two year evaluation was performed in 114 of 119 infants (95.7%) who survived this age. Twenty-two children (22/114, 19.3%) were functionally disabled, of whom 15 (13%) had a major disability. Of these 15 infants, 5/28 weighed < 1,000 g and 10/86 weighed 1,001-1,500 g (P = 0.6). Severe intraventricular hemorrhage (IVH) and cystic periventricular leukomalacia (PVL) were significantly associated with adverse outcome at 2 year (5/11 and 10/10 respectively were handicapped, P < 0.001). We therefore conclude that every effort should be made to save the extremely premature infants (< 1,000 g BW). Since adverse outcome was significantly associated with severe brain pathologies (large IVH and cystic PVL) rather than with lower BW, brain ultrasonography as a diagnostic mode should be taken into clinical consideration.

Mice deficient in IL-1 beta-converting enzyme are defective in production of mature IL-1 beta and resistant to endotoxic shock

IL-1 beta-converting enzyme (ICE) cleaves pro-IL-1 beta to generate mature IL-1 beta. ICE is homologous to other proteins that have been implicated in apoptosis, including CED-3 and Nedd-2/lch-1. We generated ICE-deficient mice and observed that they are overtly normal but have a major defect in the production of mature IL-1 beta after stimulation with lipopolysaccharide. IL-1 alpha production is also impaired. ICE-deficient mice are resistant to endotoxic shock. Thymocytes and macrophages from the ICE-deficient animals undergo apoptosis normally. ICE therefore plays a dominant role in the generation of mature IL-1 beta, a previously unsuspected role in production of IL-1 alpha, but has no autonomous function in apoptosis.

Atrial natriuretic hormone inhibits corticotropin-releasing hormone-induced prolactin release in man

Atrial natriuretic hormone (ANH) is found in heart myocytes, and also in the CNS. The inhibitory action of ANH on the hypothalamic-pituitary-adrenocortical (HPA) system has been established by in vivo and in vitro experiments, and could be of considerable importance: whereas several synergists to corticotropin-releasing hormone (CRH), the key hormone of the HPA system, are characterized in the past, until now ANH seems to be the only peptide which counterbalances the effects of CRH at the pituitary. As well as at the corticotroph, CRH has a stimulatory influence upon the lactotroph in vivo, and like ACTH and corticosteroids prolactin (PRL) is released in response to physical and cognitive challenges. To test the hypothesis of whether ANH also inhibits the CRH-mediated prolactin release a randomized, placebo-controlled, double-blind study in 12 males aged from 25 to 30 years was conducted. With regard to the diurnal variation of the HPA system activity we compared the prolactin release by 100 micrograms hCRH during a 30 min infusion of placebo, 150 micrograms ANH or 3 IU arginine vasopressin in the morning (08:00 h) and evening (19:00 h). Evaluation of morning and evening effects revealed that administration of hCRH led to a prompt rise of plasma PRL concentration. Infusion of ANH resulted in a significantly reduced maximum increment of PRL compared to placebo (0.83 +/- 0.87 vs 2.85 +/- 1.57 ng/ml, mean +/- SD, n = 12, p < .001). In addition, the AUC values were significantly lower under ANH than in the placebo condition. Infusion of AVP did not significantly change the PRL response to CRH vs placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Circadian changes in the sensitivity of the corticotropin-releasing hormone-stimulated HPA system after arginine vasopressin and atrial natriuretic hormone in human male controls

In order to investigate whether modulation of the effects of corticotropin-releasing hormone (CRH) by arginine vasopressin (AVP) and atrial natriuretic hormone (ANH) is sensitive to circadian fluctuations, 12 healthy male volunteers were administered 100 micrograms hCRH during 30 min infusion of placebo, 3 IU AVP, or 150 micrograms ANH, the experiment being carried out in the morning (0800h) or in the evening (1900h). Compared with placebo, AVP significantly amplified the CRH-induced adrenocorticotropin hormone (ACTH) surge both in the morning and in the evening, whereas it enhanced cortisol secretion only in the evening. In contrast, ANH significantly reduced the ACTH surge, but only in the evening, and it reduced the cortisol surge in the morning compared to the evening. During ANH infusion plasma AVP levels were suppressed both in the morning and in the evening, pointing to a hypothalamic site of action in addition to the pituitary and adrenocortical effects. The ACTH secretion profiles were indistinguishable between morning and evening in all three experimental conditions, whereas cortisol profiles differed significantly depending on the time of day in the AVP and ANH condition, but not for placebo.

Learning by teaching. A resident-taught oral therapy program for acute diarrhea

An educational program on oral rehydration therapy (ORT) for diarrhea was instituted in our residents' continuity clinics to evaluate the impact that residents teaching parents would have on the knowledge and practices of both groups. Sixty-one residents and 287 parents answered the initial written questionnaire before the teaching program began, and 48 residents and 147 parents completed a second questionnaire at the end of the program. Nineteen residents in two clinics were told to participate frequently in teaching the parents, while 29 residents in three other clinics were given no such instructions. The parents were divided into three groups: 58 received teaching and an instructional handout on the management of diarrhea; 73 received only the instructional handout; and 16 received neither intervention. The 19 "teaching" residents had a significantly improved overall score compared with the "nonteaching" residents (p < .03). No improvement was found in the scores of the 58 parents who received teaching compared with those of the 89 parents who received either a handout or no educational intervention. We conclude that active teaching of ORT may improve the knowledge and practices of residents, but that single teaching encounters, whether or not accompanied by written instructions, may have little impact on parents.

Safety and immunogenicity of hydrogen peroxide-inactivated pertussis toxoid in 18-month-old children

The immunogenicity and adverse effects of an acellular pertussis vaccine consisting of a purified pertussis toxin inactivated with hydrogen peroxide (PTxd) was evaluated. Children aged 15 to 30 months were injected with 10 (n = 33) or 50 micrograms (n = 34) of PTxd or with diphtheria and tetanus toxoids and whole cell pertussis vaccine (DTP) (n = 34). All children had previously received three doses of DTP during infancy. Both dosages of PTxd induced higher IgG antibody (p less than 0.05 for 10 micrograms dose and p less than 0.01 for 50 micrograms dose) and pertussis antitoxin responses (p less than 0.01 for 50 micrograms dose) than DTP. The 50 micrograms dose gave slightly higher (though not significantly) antibody responses than the 10 micrograms dose of PTxd. None of the vaccines induced detectable IgM or IgA antibody responses to pertussis toxin. At 24 h, local reactions occurred in none of the children injected with 10 micrograms PTxd, 12% with 50 micrograms PTxd and 78% with DTP. Fever at 24 h occurred in 13% after 10 micrograms PTxd, in none after 50 micrograms PTxd and in 53% after DTP. Recipients of DTP, but not of PTxd, had significant increases in neutrophils and decreases in lymphocytes and haematocrit at 24 h (all p less than 0.05). None of the groups showed changes in blood glucose at 24 h. PTxd induced pertussis toxin antibody levels similar to those observed in patients convalescing from natural pertussis. This acellular pertussis vaccine deserves further evaluation for safety and immunogenicity in infants and for efficacy in preventing pertussis.