Repetitive negative thinking as a unique transdiagnostic risk factor for suicidal ideation

Repetitive negative thinking (RNT) is a transdiagnostic symptom observed across mood and anxiety disorders and is characterized by frequent, distressing thoughts that are perceived as uncontrollable. Specific forms of RNT have been linked to increased suicide risk. However, most work examining links between RNT and suicide has been conducted within specific disorders and subtypes of RNT (e.g., rumination in individuals with depression). The present study aimed to investigate associations between transdiagnostic RNT and suicidal ideation. We hypothesized RNT would be associated with suicide risk beyond disorder-specific clinical symptoms. Fifty-four participants with mood, anxiety, and/or traumatic stress disorders completed an interview assessing suicidal risk (Columbia-Suicide Severity Rating Scale (C-SSRS)) and self-report questionnaires assessing transdiagnostic RNT, depression, and anxiety. Based on C-SSRS, we divided participants into high or low suicide risk groups. We analyzed the relationship between suicidal risk group and RNT and found that RNT was uniquely associated with suicidal risk group, controlling for depression and anxiety severity. Our results suggest including assessments of RNT may have clinical utility for understanding the degree of suicide risk in individuals and point to the potential utility of including clinical interventions to target this symptom for those at high risk of suicide.

A-31 Examining Interactions between Concussion Population and Biological Sex on Post-Concussive Symptom Reporting in FITBIR

Purpose: The purpose of this study was to examine interactions between population (sport/civilian vs. military) and biological sex (females vs. males) on post-concussive symptom reporting using Federal Interagency Traumatic Brain Injury Research (FITBIR) data. Methods: Data were obtained from the national FITBIR informatics system. Studies released as of 04/07/21 that included both males and females with a history of concussion were included. In total, 6 studies with 9957 participants (8918 sport/civilian, 1039 military; 3209 females, 6748 males) were evaluated. Symptom measures included the Sport Concussion Assessment Tool-3rd Edition, Neurobehavioral Symptom Inventory, and Rivermead Post Concussion Symptoms Questionnaire. These measures were harmonized to generate an overall composite score and three symptom domains (somatic, affective, and cognitive). Data were analyzed using linear mixed-effects models. Symptom scores were regressed onto population, sex, and the population-by-sex interaction. Results: We found significant main effects of population (military>sport/civilian; beta(β) = 0.30, p = 0.003) and sex (females>males; β = 0.06, p < 0.001) on the overall composite, as well as a significant population-by-sex interaction such that female service members/veterans endorsed the highest rates of symptoms (β = 0.27, p < 0.001). Similar patterns of significance and effect sizes were observed for the somatic and affective composites. Cognitive symptom composites showed a similar pattern, but with smaller effect sizes overall. Conclusions: Findings increase our understanding of population and sex-specific experiences following concussion, suggesting a need for individually-tailored treatments and interventions for these groups. Future studies are planned using FITBIR data to further explore the population-by-sex interaction on post-injury outcomes.

Impact of STIMUlant and osmotic LAXatives (STIMULAX trial) on gastrointestinal recovery after colorectal surgery: randomized clinical trial

BACKGROUND

Recovery of gastrointestinal (GI) function is often delayed after colorectal surgery. Enhanced recovery protocols (ERPs) recommend routine laxative use, but evidence of benefit is unclear. This study aimed to investigate whether the addition of multimodal laxatives to an ERP improves return of GI function in patients undergoing colorectal surgery.

METHODS

This was a single-centre, parallel, open-label RCT. All adult patients undergoing elective colorectal resection or having stoma formation or reversal at the Royal Adelaide Hospital between August 2018 and May 2020 were recruited into the study. The STIMULAX group received oral Coloxyl® with senna and macrogol, with a sodium phosphate enema in addition for right-sided operations. The control group received standard ERP postoperative care. The primary outcome was GI-2, a validated composite measure defined as the interval from surgery until first passage of stool and tolerance of solid intake for 24 h in the absence of vomiting. Secondary outcomes were the incidence of prolonged postoperative ileus (POI), duration of hospital stay, and postoperative complications. The analysis was performed on an intention-to-treat basis.

RESULTS

Of a total of 170 participants, 85 were randomized to each group. Median GI-2 was 1 day shorter in the STIMULAX compared with the control group (median 2  (i.q.r. 1.5-4) versus 3 (2-5.5) days; 95 per cent c.i. -1 to 0 days; P = 0.029). The incidence of prolonged POI was lower in the STIMULAX group (22 versus 38 per cent; relative risk reduction 42 per cent; P = 0.030). There was no difference in duration of hospital day or 30-day postoperative complications (including anastomotic leak) between the STIMULAX and control groups.

CONCLUSION

Routine postoperative use of multimodal laxatives after elective colorectal surgery results in earlier recovery of gastrointestinal function and reduces the incidence of prolonged POI. Registration number: ACTRN12618001261202 (www.anzctr.org.au).

Safety and efficacy of laxatives after major abdominal surgery: systematic review and meta-analysis

Background

Recovery of gastrointestinal function is often delayed after major abdominal surgery, leading to postoperative ileus (POI). Enhanced recovery protocols recommend laxatives to reduce the duration of POI, but evidence is unclear. This systematic review aimed to assess the safety and efficacy of laxative use after major abdominal surgery.

Methods

Ovid MEDLINE, Embase, Cochrane Library and PubMed databases were searched from inception to May 2019 to identify eligible RCTs focused on elective open or minimally invasive major abdominal surgery. The primary outcome was time taken to passage of stool. Secondary outcomes were time taken to tolerance of diet, time taken to flatus, length of hospital stay, postoperative complications and readmission to hospital.

Results

Five RCTs with a total of 416 patients were included. Laxatives reduced the time to passage of stool (mean difference (MD) −0·83 (95 per cent c.i. −1·39 to −0·26) days; P = 0·004), but there was significant heterogeneity between studies for this outcome measure. There was no difference in time to passage of flatus (MD −0·17 (−0·59 to 0·25) days; P = 0·432), time to tolerance of diet (MD −0·01 (−0·12 to 0·10) days; P = 0·865) or length of hospital stay (MD 0·01(−1·36 to 1·38) days; P = 0·992). There were insufficient data available on postoperative complications for meta‐analysis.

Conclusion

Routine postoperative laxative use after major abdominal surgery may result in earlier passage of stool but does not influence other postoperative recovery parameters. Better data are required for postoperative complications and validated outcome measures.

Deviation from expected cognitive ability is a core cognitive feature of schizophrenia related to neurophysiologic, clinical and psychosocial functioning

Cognitive functioning in schizophrenia is characterized by a generalized impairment in current cognitive ability based on traditional population-based norms. However, these norms assume a normal cognitive trajectory and do not directly account for illness-related declines from expected cognitive potential. Indeed, schizophrenia patients exhibit even greater deviation between their observed and expected cognitive functioning based on expanded norms that leverage premorbid variables resistant to illness-related features. The current study further quantified the extent to which illness-related features account for this deviation from expectation and assessed its relationship to neurophysiologic (mismatch negativity, P3a, theta oscillations), clinical, and psychosocial functioning in schizophrenia patients. Expected cognitive ability (PENN-CNB global cognition) in patients (n = 684) was calculated using healthy comparison subject (n = 660) weighted regression based on premorbid variables resistant to illness-related decline (demographics, single-word reading, parental education). The magnitude of any deviation between current (observed) and regression-predicted (expected) cognitive ability was calculated. Results indicated that 24% (n = 164) of the total patient population exhibited significant (≥-1.96 SD) deviation between observed and expected global cognitive ability. Interestingly, 20% of the total patient population (n = 136) had "normal" range cognitive performance when using traditional population-based norms, but also had significant deviation from expected cognitive ability. The magnitude of this deviation was associated with more severe neurophysiologic abnormalities, longer illness duration, higher levels of negative symptoms, and worse psychosocial functioning. Assessment of cognitive deviation is thus a complementary metric for characterizing the severity of illness-related cognitive declines in patients, while also reflecting the expression and severity of key endophenotypes of schizophrenia.

Decomposing the constituent oscillatory dynamics underlying mismatch negativity generation in schizophrenia: Distinct relationships to clinical and cognitive functioning

Abnormalities in early auditory information processing (EAIP) contribute to higher-order deficits in cognition and psychosocial functioning in schizophrenia. A passive auditory oddball paradigm is commonly used to evoke event-related potential (ERP) measures of EAIP reflecting auditory sensory registration and deviance detection, including mismatch negativity (MMN) and P3a responses. MMN and P3a have been extensively studied in healthy subjects and neuropsychiatric patient populations and are increasingly used as translational biomarkers in the development of novel therapeutics. Despite widespread use, relatively few studies have examined the constituent oscillatory elements and the extent to which sensory registration and deviance detection represent distinct or intercorrelated processes. This study aimed to determine the factor structure and clinical correlates of these oscillatory measures in schizophrenia patients (n = 706) and healthy comparison subjects (n = 615) who underwent clinical, cognitive, and functional characterization and EEG testing via their participation in the Consortium of Genomics in Schizophrenia (COGS-2) study. Results revealed significant deficits in theta-band (4-7 Hz) evoked power and phase locking in patients. Exploratory factor analyses of both ERP and oscillatory measures revealed two dissociable factors reflecting sensory registration and deviance detection. While each factor shared a significant correlation with social cognition, the deviance detection factor had a unique relationship to multiple cognitive and clinical domains. Results support the continued advancement of functionally relevant oscillatory measures underlying EAIP in the development of precognitive therapeutics.

Characterization of Tumor-Associated Antigens on Human Oral Squamous Cell Carcinomas Using Monoclonal Antibody 3F8E3

Tumor associated antigen (TAA) on oral squamous cell carcinoma (SCC) was characterized using the monoclonal antibody (MAb) 3F8E3. Flow cytometric analysis revealed a varying degree of reactivity of MAb 3F8E3 to TAA on oral tumor cells. Pretreatment of SCC cells with pronase and trypsin annulled the reactivity of MAb 3F8E3. Sodium metaperiodate (NaIO4) and neuraminidase marginally enhanced the binding of 3F8E3 on oral SCC cells. The studies indicate that the TAA recognized by MAb 3F8E3 on oral tumors is a protein moiety. On Western blotting MAb 3F8E3 showed reactivity to proteins with a molecular weight of 60-66 kDa on oral tumor lysates. MAb 3F8E3 reacted strongly to recombinant human hsp60 and 70 in ELISA. The results suggest that MAb 3F8E3 may react to an epitope expressed on a family of heat shock proteins.

MIC-1/GDF15 in Barrett's oesophagus and oesophageal adenocarcinoma

Background:

Biomarkers are needed to improve current diagnosis and surveillance strategies for patients with Barrett's oesophagus (BO) and oesophageal adenocarcinoma (OAC). Macrophage inhibitory cytokine 1/growth differentiation factor 15 (MIC-1/GDF15) tissue and plasma levels have been shown to predict disease progression in other cancer types and was therefore evaluated in BO/OAC.

Methods:

One hundred thirty-eight patients were studied: 45 normal oesophagus (NE), 37 BO, 16 BO with low-grade dysplasia (LGD) and 40 OAC.

Results:

Median tissue expression of MIC-1/GDF15 mRNA was ⩾25-fold higher in BO and LGD compared to NE (P<0.001); two-fold higher in OAC vs BO (P=0.039); and 47-fold higher in OAC vs NE (P<0.001). Relative MIC-1/GDF15 tissue expression >720 discriminated between the presence of either OAC or LGD vs NE with 94% sensitivity and 71% specificity (ROC AUC 0.86, 95% CI 0.73–0.96; P<0.001). Macrophage inhibitory cytokine 1/growth differentiation factor 15 plasma values were also elevated in patients with OAC vs NE (P<0.001) or BO (P=0.015).

High MIC-1/GDF15 plasma levels (⩾1140 pg ml⁻¹) were an independent predictor of poor survival for patients with OAC (HR 3.87, 95% CI 1.01–14.75; P=0.047).

Conclusions:

Plasma and tissue levels of MIC-1/GDF15 are significantly elevated in patients with BO, LGD and OAC. Plasma MIC-1/GDF15 may have value in diagnosis and monitoring of Barrett's disease.

B-cell depletion extends the survival of GTKO.hCD46Tg pig heart xenografts in baboons for up to 8 months

Xenotransplantation of genetically modified pig organs offers great potential to address the shortage of human organs for allotransplantation. Rejection in Gal knockout (GTKO) pigs due to elicited non-Gal antibody response required further genetic modifications of donor pigs and better control of the B-cell response to xenoantigens. We report significant prolongation of heterotopic alpha Galactosyl transferase "knock-out" and human CD46 transgenic (GTKO.hCD46Tg) pig cardiac xenografts survival in specific pathogen free baboons. Peritransplant B-cell depletion using 4 weekly doses of anti-CD20 antibody in the context of an established ATG, anti-CD154 and MMF-based immunosuppressive regimen prolonged GTKO.hCD46Tg graft survival for up to 236 days (n = 9, median survival 71 days and mean survival 94 days). B-cell depletion persisted for over 2 months, and elicited anti-non-Gal antibody production remained suppressed for the duration of graft follow-up. This result identifies a critical role for B cells in the mechanisms of elicited anti-non-Gal antibody and delayed xenograft rejection. Model-related morbidity due to variety of causes was seen in these experiments, suggesting that further therapeutic interventions, including candidate genetic modifications of donor pigs, may be necessary to reduce late morbidity in this model to a clinically manageable level.

Crickets detect the genetic similarity of mating partners via cuticular hydrocarbons

Animals should decipher information about the genetic make-up of conspecifics in order to enhance the fitness benefits associated with mate choice. Although there is increasing evidence to suggest that animals make genetically informed decisions about their mating partners, we understand relatively little about the sensory mechanisms informing these decisions. Here, we investigate whether cuticular hydrocarbons, chemical compounds found on the cuticle of most terrestrial arthropods, provide a means of discerning genetic similarity during mate choice in the cricket, Teleogryllus oceanicus. We found that individuals preferentially mated with partners who share more dissimilar cuticular hydrocarbon profiles and that similarity in cuticular hydrocarbon profiles between mating pairs correlated with their genetic similarity. Our results provide good evidence that cuticular hydrocarbon profiles offer a means of assessing genetic compatibility in T. oceanicus, enabling individuals to choose their most genetically suitable mate.

Surgical and nonsurgical complications of a pig to baboon heterotopic heart transplantation model

A modified immunosuppressive regimen, developed at the National Institutes of Health, has been employed in a large animal model of heterotopic cardiac xenotransplantation. Graft survival has been prolonged, but despite this, our recipients have succumbed to various surgical or nonsurgical complications. Herein, we have described different complications and management strategies. The most common complication was hypercoagulability (HC) after transplantation, causing thrombosis of both small and large vasculature, ultimately leading to graft loss. While managing this complication we discovered that there was a delicate balance between HC and consumptive coagulopathy (CC). CC encountered in some recipient baboons was not able to be reversed by stopping anticoagulation and administering multiple blood transfusions. Some complications had iatrogenic components. To monitor the animals, a solid state left ventricular telemetry probe was placed directly into the transplanted heart via the apex. Induction of hypocoagulable states by continuous heparin infusion led to uncontrollable intra-abdominal bleeding in 1 baboon from this apical site. This occurrence necessitated securing the probe more tightly with multiple purse strings and 4-quadrant pledgeted stay sutures. One instance of cardiac rupture originated from a lateral wall infarction site. Earlier studies have shown infections to be uniformly fatal in this transplant model. However, owing to the telemetry placement, infections were identified early by temperature spikes that were treated promptly with antibiotics. We had several cases of wound dehiscence due to recipients disrupting the suture line. These complications were promptly resolved by either re-approximating the wound or finding distractions for the baboon. A few of the most common problems we faced in our earlier experiments were related to the jacket, tether, and infusion pumps. It was difficult to keep the jackets on some baboons and the tether had to be modified several times before we assured long-term success. Infusion catheter replacement resulted in transplant heart venous obstruction and thrombosis from a right common femoral venous line. Homeostatic perturbations such as HC and CC and baboon-induced wound complications comprised most complications. Major bleeding and death due to telemetry implantation and infarct rupture occurred in 2 baboons. Despite the variety of complications, we achieved significant graft prolongation in this model.

The effect of volume of local anesthetic on the anatomic spread of caudal block in children aged 1-7 years

OBJECTIVES

To examine the anatomic spread of caudal local anesthetic solution in children aged 1-7 years.

AIM

To determine whether incremental increases in the volume of caudal injections of 0.5, 0.75, and 1.0 ml·kg(-1) result in reliable (>90%) and potentially clinically significant increases in the number of vertebral segments reached.

BACKGROUND

Caudal block is one of the most frequently performed pediatric regional analgesic techniques. Traditional formulae suggest that changes in the volume of caudal injectate in the range 0.5-1.0 ml·kg(-1) would have clinically useful effects.

METHODS

In a single blind design, 45 children aged 1-7 years undergoing caudal block received one of the three predetermined volumes (0.5, 0.75, and 1 ml·kg(-1) ) of local anesthetic solution containing radio-opaque contrast under controlled conditions. Following X-ray examination, the anatomic spread of the block was reported by a radiologist blinded to the volume of solution received.

RESULTS

There were 15 children in each group, and they were similar in terms of age, height, and weight. Spread was observed between the 5th lumbar (L5) and 12th thoracic (T12) vertebral levels. A volume of 1 ml·kg(-1) results in a small but significantly greater spread of solution than 0.5 ml·kg(-1) (P < 0.05), but there was no difference between 0.5 and 0.75 ml or between 0.75 and 1.0 ml. No volume reliably reached a level higher than the second lumbar vertebra (L2).

CONCLUSIONS

Incrementally increasing the volume of injectate between 0.5 and 1.0 results in a modest increase in the spread of the caudal solution. It is unlikely that volumes of <1 ml will reliably reach a vertebral level that is higher than L2.

Cuticular hydrocarbons are heritable in the cricket Teleogryllus oceanicus

The ability of individuals to respond differentially to conspecifics depending on their genetic relatedness is a widespread phenomenon across the animal kingdom. Despite this, little is known about the selection processes that act on the phenotypic variation of traits used during recognition. Here we use a quantitative genetic approach to examine the patterns of genetic variation in cuticular hydrocarbon (CHC) profiles, a pheromonal system used extensively in insect communication. Using gas chromatography, we found family specificity in the CHC profiles of male crickets, Teleogryllus oceanicus. Across CHC peaks, our mean coefficient of additive genetic variation was 10.8%. Multivariate principal component analysis showed that most axes of variation were weighted by CHC peaks with significant additive genetic variation. Our results provide evidence that variation in CHC profiles can reflect genetic relatedness, supporting the widely held belief that this phenotypic trait is used as a mechanism for chemosensory kin recognition.

Impact of the European Working Time Directive on the training of paediatric anaesthetists

The European Working Time Directive and the New Deal have decreased the number of hours worked by anaesthetic trainees. We implemented the Working Time Directive in May 2004 and evaluated the effect of its implementation on training. During two 6-month periods, one before and one after the change, we determined the number of operating lists undertaken by each Specialist Registrar in Anaesthesia. After implementation of the Working Time Directive, the mean number of lists performed by Specialist Registrars decreased from 24 to 21 lists per registrar per month, a 13% decrease. Exposure to subspecialty lists was the same in both periods, but this was at the expense of general lists and those in remote locations. We conclude that the Working Time Directive has had a measurable impact on the training of paediatric anaesthetists, but that the significance of this change for clinical practice has not yet been measured.

Maternal temperature during labour using low-dose (ambulatory) epidural analgesia with bupivacaine and fentanyl

Maternal temperature is known to increase during labour with conventional epidural analgesia mixtures. To date, the effect of newer low-dose (ambulatory) epidural concentrations on maternal temperature has not been studied. Twenty-six women in established labour received epidural analgesia with 0.1% bupivacaine and 2 microg/ml fentanyl. Tympanic membrane (core) temperature was measured every 30 min during labour. There was no significant overall rise in maternal temperature during labour with the use of an ambulatory epidural mixture. One patient exhibited an increase in temperature of 0.8 degrees C to 38 degrees C after 720 min and another of 1.1 degrees C to 38.1 degrees C after 630 min. We conclude that, whilst overall maternal temperature does not increase following low-dose epidural analgesia, individual increases may still occur after 10 h.

The effect of magnesium deficiency on volatile anaesthetic requirement in the rat: the role of central noradrenergic neuronal activity

Volatile anaesthetic minimum alveolar concentration (MAC, a measure of anaesthetic requirement) increased in a time-dependent manner in rats fed a Mg2+-deficient diet. MAC values in hypomagnesemic rats were 22-30 per cent greater than those in age-matched controls at 12 and 17 days after starting the diet (p < 0.01). Noradrenergic neuronal activity, as assessed from the ratio of the concentration of 3,4-dihydroxyphenylethylene-glycol (DHPG) to that of norepinephrine (NE), decreased in the brain stem and cerebrum-cerebellum in hypomagnesemic rats owing to an increase in NE concentration in both regions of the brain (p < 0.025). We conclude that prolonged hypomagnesemia (> or = 12 days) increases volatile anaesthetic MAC in the rat. The concomitant decrease in the ratio of DHPG/NE suggests that this increase in MAC cannot be attributed to an increase in noradrenergic neuronal activity in brain.

Oesophageal diverticula

BACKGROUND

Oesophageal pulsion diverticula, excluding pharyngeal types, are uncommon sequelae of oesophageal dysmotility. Current opinion favours myotomy as effective therapy, but the role of diverticulectomy, myotomy selection and placement, and the need for fundoplication remain unresolved.

METHODS

A Medline search and review of references identified relevant English language articles. Data on epidemiology, aetiology, oesophageal motility, pathology, symptomatology, investigations, surgical management and outcome were examined.

RESULTS

Data were largely retrospective. Significant morbidity and mortality were associated with pulmonary aspiration and diverticulectomy site leaks. Surgical outcome was similar whether or not a diverticulectomy was added to a myotomy, but a myotomy clearly reduced the risk of leaks. Fundoplication reduced the incidence of postcardiomyotomy reflux symptoms. Results from minimally invasive techniques were similar to those of open surgery.

CONCLUSION

Surgery should be reserved for symptomatic patients; asymptomatic patients may benefit from surveillance. Pulmonary aspiration mandates surgical intervention. Myotomy remains the mainstay of treatment and an adequate subdiverticular extension is crucial in relieving obstruction. A partial fundoplication is preferred in selected patients. Minimally invasive techniques should become the routine approach for oesophageal pulsion diverticula.

Development of intestinal intraepithelial lymphocytes, NK cells, and NK 1.1+ T cells in CD45-deficient mice

The transmembrane protein tyrosine phosphatase CD45 is differentially required for the development and function of B, T, and NK cells, with mice partially deficient for CD45 having a significant inhibition of T cell, but not NK or B cell, development. CD45-mediated signaling has also been implicated in the development of intrathymic, but not extrathymic, intestinal intraepithelial T lymphocytes (iIELs) in the CD45ex6(-/-) mouse. As NK1.1(+) CD3(+) (NK-T) cells can also develop through extrathymic pathways, we have investigated the role of CD45 in NK-T cell development. In mice with a complete absence of CD45 expression (CD45ex9(-/-)) the NK-T cell population was maintained in the iIEL compartment, but not in the spleen. Functionally, CD45-deficient NK-T cells were unable to secrete IL-4 in response to TCR-mediated signals, a phenotype similar to that of CD45-deficient iIELs, in which in vitro cytokine production was dramatically reduced. Using the CD45ex9(-/-) mouse strain, we have also demonstrated that only one distinct population of NK-T cells (CD8(+)) appears to develop normally in the absence of CD45. Interestingly, although an increase in cytotoxic NK cells is seen in the absence of CD45, these NK calls are functionally unable to secrete IFN-gamma. In the absence of CD45, a significant population of extrathymically derived CD8alphaalpha(+) iIELs is also maintained. These results demonstrate that in contrast to conventional T cells, CD45 is not required during the development of CD8(+) NK-T cells, NK cells, or CD8alphaalpha(+) iIELs, but is essential for TCR-mediated function and cytokine production.

Evaluation of a transdermal fentanyl system in yucatan miniature pigs

Of 18 pigs used on a coronary stent experimental protocol, 6 each received a transdermal fentanyl patch to document the patterns of transdermal fentanyl absorption in swine. This approach was taken to reduce animal use and potentially refine the surgical regimen. The objective of the fentanyl portion of the study was to demonstrate that transdermal fentanyl may be useful in the management of postoperative analgesia in swine. This study sought to document that demonstrable levels of fentanyl are achievable in swine plasma via a transdermal system and to compare the magnitude of these levels to data in other species. This study does not directly correlate plasma fentanyl levels with analgesic efficacy. Plasma fentanyl concentration peaked within 42 h in five pigs and within 48 h in the remaining pig. All pigs had similar absorption patterns; the only difference was in magnitude. One pig reached 0.99 ng/ml at 42 h; the next highest concentration was 0.77 ng/ml at 48 h in a different animal. The peak concentration in the others ranged from 0.38 to 0.71 ng/ml.

Molecular cloning of MIS, a myeloid inhibitory siglec, that binds protein-tyrosine phosphatases SHP-1 and SHP-2

We describe the molecular cloning and characterization of a novel myeloid inhibitory siglec, MIS, that belongs to the family of sialic acid-binding immunoglobulin-like lectins. A full-length MIS cDNA was obtained from murine bone marrow cells. MIS is predicted to contain an extracellular region comprising three immunoglobulin-like domains (V-set amino-terminal domain followed by two C-set domains), a transmembrane domain and a cytoplasmic tail with two immunoreceptor tyrosine-based inhibitory motif (ITIM)-like sequences. The closest relative of MIS in the siglec family is human siglec 8. Extracellular regions of these two siglecs share 47% identity at the amino acid level. Southern blot analysis suggests the presence of one MIS gene. MIS is expressed in the spleen, liver, heart, kidney, lung and testis tissues. Several isoforms of MIS protein exist due to the alternative splicing. In a human promonocyte cell line, MIS was able to bind Src homology 2-containing protein-tyrosine phosphatases, SHP-1 and SHP-2. This binding was mediated by the membrane-proximal ITIM of MIS. Moreover, MIS exerted an inhibitory effect on FcgammaRI receptor-induced calcium mobilization. These data suggest that MIS can play an inhibitory role through its ITIM sequences.

Thoracoscopy as a nonpharmacotherapeutic research modification for limiting postoperative chest pain

Diminished tissue injury and shortened clinical recovery are benefits of using an endoscopic approach for patients needing operative procedure. In the course of developing an experimental model requiring procurement of topographically precise lung biopsy specimens, we sought to apply thoracoscopy as a research alternative to thoracotomy. In addition, we investigated the influence of thoracoscopy on postprocedure recovery practices using rabbits divided into four treatment groups. Rabbit groups 1 and 2 underwent thoracoscopy and lung biopsy while maintained by one-lung anesthesia. Additionally, group 2 had ketoprofen and bupivacaine HCl analgesics injected for treatment during postprocedure recovery. These two groups were compared to control rabbits in groups 3 and 4, which underwent inhalant anesthesia without thoracoscopy. Control group 3 also received the injection analgesic combination. During recovery, rabbit behavior was systematically assessed for evidence of pain. No behavior considered indicative of pain needing intervention was observed regardless of treatment group. Limited changes in plasma corticosterone, catecholamines, and prostaglandin E2 levels measured during recovery were difficult to associate with any treatment. Unexpectedly, significantly different mean corticosterone and catecholamines levels were detected in rabbits given the injection analgesic combination in the absence of thoracoscopic procedure, as compared to other treatment groups. The results highlight the importance of awareness that analgesic drug administration has the potential to alter homeostasis and affect interpretation of some study findings by its own guise. Correlation of the mean pain study results with plasma biochemical data supports preferential use of thoracoscopy as a refinement for limiting postprocedural pain in research models.

True aneurysm of the thyrocervical trunk: case report and literature review

The third reported case of aneurysm of the thyrocervical trunk is presented. The patient developed embolization to the fingers of the right hand. Diagnosis was confirmed by arteriogram. Treatment was by surgical resection and arterial reconstruction.

Dopamine D5 receptors in nucleus accumbens contribute to the detection of cocaine in rats

Dopamine D(1)/D(5) receptor antagonism has been shown to block the euphoric and stimulatory effects of cocaine in humans and rats. In the present study, rats trained to discriminate the presence of cocaine (10 mg/kg) from its absence were used to analyze the functional contribution of D(1) (D(1)R) versus D(5) (D(5)R) receptors in the nucleus accumbens, an important neural site for the actions of cocaine. Bilateral microinfusion into the nucleus accumbens of an antisense oligonucleotide directed at the D(5)R (0. 75 nmol/0.3 microl per side, two times per day for 3 d) elicited a downward shift in the dose-effect curve for cocaine with a suppression of peak efficacy; the dose of cocaine estimated to elicit 50% drug-lever responding (ED(50)) was 6.71 mg/kg when assessed 12 hr after the D(5)R antisense oligonucleotide compared to the control ED(50) of 1.83 mg/kg and to the ED(50) of 1.75 mg/kg established 7 d after the last D(5)R antisense oligonucleotide infusion. The D(1)R antisense and scrambled oligonucleotide (0.75 nmol/0.3 microl per side, two times per day for 3 d) were both ineffective. Thus, using drug discrimination techniques that model the subjective effects of cocaine, we show that responsiveness to cocaine is dramatically attenuated after interference with the process of translation of the D(5)R mRNA to its protein product. These findings suggest that D(5)R is a functionally important target site for the indirect actions of cocaine and that rigorous investigations of the function of D(5)R may help guide the discovery of strategies for pharmacotherapy in cocaine dependence.

A supramolecular basis for CD45 tyrosine phosphatase regulation in sustained T cell activation

Transmembrane protein tyrosine phosphatases, such as CD45, can act as both positive and negative regulators of cellular signaling. CD45 positively modulates T cell receptor (TCR) signaling by constitutively priming p56lck through the dephosphorylation of the C-terminal negative regulatory phosphotyrosine site. However, CD45 can also exert negative effects on cellular processes, including events triggered by integrin-mediated adhesion. To better understand these opposing actions of tyrosine phosphatases, the subcellular compartmentalization of CD45 was imaged by using laser scanning confocal microscopy during functional TCR signaling of live T lymphocytes. On antigen engagement, CD45 was first excluded from the central region of the interface between the T cell and the antigen-presenting surface where CD45 would inhibit integrin activation. Subsequently, CD45 was recruited back to the center of the contact to an area adjacent to the site of sustained TCR engagement. Thus, CD45 is well positioned within a supramolecular assembly in the vicinity of the engaged TCR, where CD45 would be able to maintain src-kinase activity for the duration of TCR engagement.

Influence of ovarian hormones and estrous cycle on the behavioral response to cocaine in female rats

Both humans and experimental animals demonstrate gender differences in response to cocaine. However, the mechanisms underlying these differences remain unclear. The purpose of the present study was to determine whether ovarian steroid hormones play a role in the locomotor response to cocaine in rats. Initial assessments of locomotor activity measured using photobeam monitors verified the robust gender difference in response to cocaine in our experimental paradigm. Subsequently, cocaine (5.0, 7.5, and 10.0 mg/kg) was shown to increase total horizontal activity in a dose-dependent manner in independent groups of intact females; the 5.0 mg/kg dose was selected for use in additional studies to determine the effect of estrogen (E) and progesterone (P) on the response to cocaine. Mature female rats were ovariectomized (OVX) or OVX and implanted with hormone-filled (E or P) Silastic capsules. Three to 4 weeks later, automated and observational measures of behavior were recorded after the administration of 5 mg/kg cocaine. Hormone replacement with E or E + P (but not P alone) resulted in greater cocaine-evoked hyperactivity than was observed in OVX animals. On measurement in normally cycling rats, hyperactivity induced by 5 mg/kg cocaine was greater during proestrus and estrus than during diestrus 2. The results of this series of experiments demonstrate that E significantly influences the responsiveness of female rats to cocaine. The enhanced response to cocaine was demonstrated in the presence of pharmacologically administered E as well as correlated with the normal estrous cycle.

Mutations in the tyrosine phosphatase CD45 gene in a child with severe combined immunodeficiency disease

The hematopoietic-specific transmembrane protein tyrosine phosphatase CD45 functions to regulate Src kinases required for T- and B-cell antigen receptor signal transduction. So far, there have been no reports to our knowledge of a human deficiency in a tyrosine-specific phosphatase. Here, we identified a male patient with a deficiency in CD45 due to a large deletion at one allele and a point mutation at the other. The point mutation resulted in the alteration of intervening sequence 13 donor splice site. The patient presented at 2 months of age with severe combined immunodeficiency disease. The population of peripheral blood T lymphocytes was greatly diminished and unresponsive to mitogen stimulation. Despite normal B-lymphocyte numbers, serum immunoglobulin levels decreased with age. Thus, CD45 deficiency in humans results in T- and B-lymphocyte dysfunction.

gammadelta T cells lyse autologous and allogenic oesophageal tumours: involvement of heat-shock proteins in the tumour cell lysis

T cells expressing gammadelta receptors were isolated from the peripheral blood of oesophageal cancer patients and analysed for their potential to lyse tumour targets. Immunophenotyping by flow cytometry showed that the dominant population of gammadelta T cells expressed the Vgamma9 and the Vdelta2 T cell receptor, and a minor population expressed the Vdelta1 receptor. Cytotoxicity assays revealed that activated gammadelta T cells lysed Daudi Burkitt's lymphoma and K562 cells. Lysis of autologous oesophageal tumours was higher than of allogenic tumours. Anti-hsp60 and anti-hsp70 mAb significantly inhibited the cytotoxicity of gammadelta T cells to both autologous and allogenic oesophageal tumours. Surface expression of hsp60 and hsp70 on oesophageal tumours and Daudi cells was demonstrated by flow cytometry. In conclusion, gammadelta T cells isolated from the peripheral blood of oesophageal cancer patients have the ability of kill oesophageal tumour cells. The lysis of tumour targets by the gammadelta T cells is brought about via recognition of heat-shock proteins expressed on the surface of tumour cells. gammadelta T cells isolated from the peripheral blood may have applications in adoptive immunotherapy of oesophageal cancer.

Perimembrane localization of the estrogen receptor alpha protein in neuronal processes of cultured hippocampal neurons

There is clear evidence of rapid, nongenomic responses to estrogen in a variety of neuronal model systems. To address the question of whether some of these rapid estrogen signals might be transduced by the classical estrogen receptor (ER) alpha or a closely related protein in nontransformed neurons, we undertook the present study using isolated fetal rat hippocampal neurons. Several antibodies developed to detect ERalpha were tested in this system and showed positive membrane staining in nonpermeabilized neurons. MC-20, an affinity purified anti-ERalpha, rabbit polyclonal IgG antibody which does not recognize ERbeta was selected to carry out the majority of the experiments. When permeabilized, the hippocampal neurons exhibited low levels of nuclear staining for ERalpha, but abundant labeling for ERalpha throughout the entire cell including the neurites. In addition to traditional immunocytochemistry controls, incubation of neurons for 24 h in the presence of 10 microM antisense oligonucleotide directed against the translation start site of ERalpha reduced ERalpha immunoreactivity throughout the neurons providing further evidence that the immunostaining was specific for ERalpha. Confocal and conventional microscopy demonstrated that the antigen was predominately extranuclear and localization of ERalpha in the neurites suggests that the receptor is in close proximity to the plasma membrane. This localization is consistent with a role for ERalpha as a transducer of rapid, nongenomic estrogen responses in hippocampal neurons.

Induction of a germinal center phenotype in B cells in vitro by a Th2 cell line

We have investigated the contribution of various stimuli for generating in vitro the changes in surface phenotype characteristic of B cells responding to a T-dependent antigen in a germinal center (GC). We show that, unlike many other stimuli such as B cell mitogens, cytokines, and surrogate antigen, alone or in combination, an alloreactive Th2 clonal line induces splenic B cells to become cell surface peanut agglutinin (PNA)(hi), Ig(lo), CD62L(lo), and CD44(hi) to produce mRNA for M17 and to express a GC-specific transgene even without B cell receptor ligation. Neither proliferation nor prior activation of responding B cells is needed, but B cells from CD45-null mice show reduced efficiency of this induction. These findings open up possibilities for separation and dissection of the various components of the GC response.

CD45-associated protein is not essential for the regulation of antigen receptor-mediated signal transduction

CD45 is a transmembrane protein tyrosine phosphatase required for signaling through the T-and B-cell antigen receptors. In lymphocytes, CD45 interacts with CD45-associated protein (CD45AP), a 32 000 Mr phosphoprotein, through their respective transmembrane domains. To determine whether CD45AP affects the ability of CD45 to regulate antigen receptor signaling, CD45AP-deficient mice were generated. Thymocyte development was grossly normal. Moreover, the cellularity of the thymus and spleens were normal. CD45 expression on thymocytes and splenocytes, ascertained by flow cytometry, was comparable between CD45AP-deficient mice and littermate controls. In contrast to a previous report (Matsuda et al., J. Exp. Med. 1998 187: 1863 - 1870). CD45AP-deficient and normal thymocytes and splenocytes proliferated similarly in response to various mitogens or antigen receptor cross-linking. Furthermore, thymocyte CD45-associated p56(lck) kinase activity was similar between CD45AP-deficient and normal cells. We conclude that CD45AP is not essential for the regulation of Src-family kinase activity by CD45.

Modulation of TCR signaling by beta1 integrins: role of the tyrosine phosphatase SHP-1

When cross-linked, beta1 integrins co-activate T cells together with a TCR-CD3 signal. Soluble anti-beta1 monoclonal antibodies, however, inhibit T cell activation. We report inhibition of early tyrosine kinases, including ZAP-70, p59(fyn), CD4-associated p56(lck) and TCR components under this condition. The tyrosine phosphatase SHP-1 is activated by engagement of beta1 integrins and is implicated in this negative regulation since no inhibition occurs in SHP-1 dominant-negative T cells. As shown by the use of Lck-deficient cells, the activation of the protein tyrosine phosphatase depends on a pool of p56(lck) that is not associated with CD4. These cross-talk events were also observed with the alpha4beta1 integrin ligand, VCAM-1. We propose that these results may be important in terms of lymphocyte circulation; while T cells migrate through the vascular endothelium, they are primed for an amplified response; as inflammation develops, a local accumulation of soluble integrin ligands may help to turn it off.

The sialoadhesin CD33 is a myeloid-specific inhibitory receptor

Activating and inhibitory receptors act in concert to regulate cellular activation. Inhibitory receptors are characterized by the presence of a characteristic sequence known as an immunoreceptor tyrosine-based inhibitory motif (ITIM) in their cytoplasmic tail. Phosphorylated ITIM serve as docking sites for the SH2-containing phosphatases which then inhibit signal transduction. CD33 is a member of the immunoglobulin superfamily and contains two immunoglobulin-like domains, a transmembrane region and a cytoplasmic tail that has two potential ITIM sequences. CD33 expression is restricted to cells of myelomonocytic lineage. The precise function of CD33 is unknown although it is a lectin that binds sialic acid residues in N- and O-glycans on cell surfaces. Co-immunoprecipitation studies demonstrate that CD33 associates with the SH2-containing tyrosine phosphatase SHP-1 in monocytes. The proximal ITIM is necessary and sufficient for SHP-1 binding which is mediated by the aminoterminal SH2 domain. Treatment of SHP-1 with a phosphopeptide representing the proximal CD33 ITIM results in increased SHP-1 enzymatic activity. CD33 exerts an inhibitory effect on tyrosine phosphorylation and Ca(2+) mobilization when co-engaged with the activating FcgammaRI receptor. This data indicates that CD33 is an inhibitory receptor that may regulate FcgammaRI signal transduction.

Migraine: a comprehensive review of new treatment options

Headaches are among the most common complaints reported to health care professionals and are classified by the International Headache Society as migraine, tension-type, or cluster, with additional subtypes. Classification and etiology of headache should be determined after thorough review of the patient's history. Once diagnosed, migraine can be treated by preventive or abortive measures. Recent developments add new options, including availability of drugs for intranasal administration (sumatriptan, dihydroergotamine) and 5-HT1B/1D agonists (rizatriptan, zolmitriptan, naratriptan, eletriptan). Although placebo-controlled trials are available, few comparative clinical trials of these agents have been conducted; however, important pharmacologic, pharmacokinetic, and clinical differences exist among the drugs.

Estrogen receptor-alpha detected on the plasma membrane of aldehyde-fixed GH3/B6/F10 rat pituitary tumor cells by enzyme-linked immunocytochemistry

A population of estrogen receptor-alpha (ER alpha) proteins, located at the plasma membrane, is postulated to mediate the rapid, nongenomic responses of GH3/B6/F10 pituitary cells to estrogen. To demonstrate the presence of ER alpha at the plasma membrane and to distinguish this receptor population from that in the nucleus, GH3/B6/F10 cells were first prepared in 2% paraformaldehyde/0.1% glutaraldehyde in PBS (P/G) without detergent, then exposed to one of several antibodies (Abs) raised against nuclear ER alpha. Ab binding was visualized as a fluorescent/chromagenic reaction product catalyzed by avidin-biotin-complexed alkaline phosphatase. With P/G fixation, Abs could only access antigens at the cell surface, as evidenced by the inability of 70K mol wt dextrans to permeate cells and the absence of intracellular staining by Abs to cytoplasmic or nuclear antigens. ER alpha Abs generated membrane, but not nuclear, staining in P/G-fixed cells; nuclear receptor labeling could only be detected in detergent-treated cells. Specificity of staining for ER alpha was confirmed by three approaches: first, treatment with an antisense oligodeoxynucleotide to nuclear ER alpha mRNA reduced immunolabeling of both membrane and nuclear ER alpha; second, labeling by two Abs raised against different ER alpha oligopeptides was neutralized by competing peptide; third, six Abs (ER21, H226, R4, H222, MC20, and C542) that recognize unique epitopes on rodent ER alpha produced immunolabeling, but neither primate-specific ER alpha Ab nor Ab to ER beta caused staining. In addition to demonstrating the plasma membrane ER alpha in GH3/B6/F10 cells, this method should be applicable to other cell types that exhibit nongenomic responses to estrogen or other steroid hormones.

Radar and optical observations of asteroid 1998 KY26

Observations of near-Earth asteroid 1998 KY26 shortly after its discovery reveal a slightly elongated spheroid with a diameter of about 30 meters, a composition analogous to carbonaceous chondritic meteorites, and a rotation period of 10.7 minutes, which is an order of magnitude shorter than that measured for any other solar system object. The rotation is too rapid for 1998 KY26 to consist of multiple components bound together just by their mutual gravitational attraction. This monolithic object probably is a fragment derived from cratering or collisional destruction of a much larger asteroid.

Regulation of integrin-mediated T cell adhesion by the transmembrane protein tyrosine phosphatase CD45

The transmembrane protein tyrosine phosphatase CD45 is required for Ag receptor signal transduction in lymphocytes. Recently, a role for CD45 in the regulation of macrophage adhesion has been demonstrated as well. To investigate further the role of CD45 in the regulation of adhesion, we examined integrin-mediated adhesion to fibronectin of two T cell lines and their CD45-deficient variants. The absence of CD45 correlated with enhanced adhesion to fibronectin via integrin alpha5beta1 (VLA-5), but not alpha4beta1 (VLA-4) in both cell lines. Adhesion returned to normal levels upon transfection of wild-type CD45 into the CD45-deficient lines. Transfection of chimeric or mutant molecules expressing some, but not all, CD45 domains and activities demonstrated that both the transmembrane domain and the tyrosine phosphatase activity of CD45 were required for regulation of integrin-dependent adhesion, but the highly glycosylated extracellular domain was dispensable. In contrast, only a catalytically active CD45 cytoplasmic domain was required for TCR signaling. Transfectants that restored normal levels of adhesion to fibronectin coimmunoprecipitated with the transmembrane protein known as CD45-associated protein. These studies demonstrate a novel role for CD45 in adhesion regulation and suggest a possible function for its association with CD45-associated protein.

Expression of the p56(Lck) Y505F mutation in CD45-deficient mice rescues thymocyte development

Mice deficient in the transmembrane protein tyrosine phosphatase CD45 exhibit a block in thymocyte development. To determine whether the block in thymocyte development was due to the inability to dephosphorylate the inhibitory phosphorylation site (Y505) in p56(lck) (Lck), we generated CD45-deficient mice that express transgenes for the Lck Y505F mutation and the DO11.10 T-cell antigen receptor (TCR). CD4 single-positive T cells developed and accumulated in the periphery. Treatment with antigen resulted in thymocyte apoptosis and the loss of transgenic-TCR-bearing cells. Peripheral CD45-deficient T cells from the mice expressing both transgenes responded to antigen by increasing CD69 expression, interleukin-2 production, and proliferation. These results indicate that thymocyte development requires the dephosphorylation of the inhibitory site in Lck by CD45.