[Perivascular epithelioid cell tumor of the lung: a clinicopathological analysis of eight cases]

Objective: To investigate the clinicopathological features of perivascular epithelioid cell tumor (PEComa) of the lung. Methods: Eight PEComa cases of the lung diagnosed at the First Affiliated Hospital of Soochow University, Suzhou, China from July 2008 to December 2021 were collected and subject to immunohistochemical staining, fluorescence in situ hybridization and next generation sequencing. The relevant literature was reviewed and the clinicopathological features were analyzed. Results: There were 5 males and 3 females, aged from 18 to 70 years (mean 39 years). There were 3 cases of the right upper lung, 3 cases of the left lower lung, 1 case of the left upper lung and 1 case of the right middle lung. Seven cases were solitary and 1 case was multifocal (4 lesions). Seven cases were benign while one was malignant. The tumors were all located in the peripheral part of the lung, with a maximum diameter of 0.2-4.0 cm. Grossly, they were oval and well circumscribed. Microscopically, the tumor cells were oval, short spindle-shaped, arranged in solid nests, acinar or hemangiopericytoma-like patterns, with clear or eosinophilic cytoplasm. The stroma was rich in blood vessels with hyalinization. Coagulated necrosis and high-grade nuclei were seen in the malignant case, and calcification was seen in 2 cases. Immunohistochemically, the tumor cells were positive for Melan A (8/8), HMB45 (7/8), CD34 (6/8), TFE3 (4/7), and SMA (3/8). All cases were negative for CKpan and S-100. TFE3 (Xp11.2) gene fusion was examined using the TFE3 break-apart fluorescence in situ hybridization in 5 cases, in which only the malignant case was positive. The next generation sequencing revealed the SFPQ-TFE3 [t(X;1)(p11.2;p34)] fusion. Follow-up of the patients ranged from 12 to 173 months while one patient was lost to the follow-up. The malignant case had tumor metastasis to the brain 4 years after the operation and then received radiotherapy. Other 6 cases had no recurrence and metastasis, and all the 7 patients survived. Conclusions: Most of the PEComas of the lung are benign. When there are malignant morphological features such as necrosis, high-grade nuclei or SFPQ-TFE3 gene fusion, close follow-up seems necessary.

What can the Interventional Endoscopist Offer in the Management of Upper Gastrointestinal Malignancies?

The therapeutic possibilities of endoscopy have rapidly increased in the last decades and now allow organ-sparing treatment of early upper gastrointestinal malignancy as well as an increasing number of options for symptom palliation. This review contains an overview of the interventional endoscopic procedures in upper gastrointestinal malignancies. It describes endoscopic treatment of early oesophageal and gastric cancers, and the palliative options in managing dysphagia and gastric outlet obstruction. It also provides an overview of the therapeutic possibilities of biliary endoscopy, such as retrograde stenting and radiofrequency biliary ablation. Endoscopic ultrasound-guided therapeutic options are discussed, including biliary drainage, gastrojejunostomy and coeliac axis block. To aid in clinical decision making, the procedures are described in the context of their indication, efficacy, risks and limitations.

Prognostic value of integrated cardiopulmonary ultrasound in inpatients with acute heart failure with preserved and reduced ejection fraction and without heart failure

Objective

To assess the prognostic value of B-lines integrated with echocardiography in patients admitted to a Cardiology Department, with and without acute heart failure (AHF).

Background

Lung-ultrasound (LUS) B-lines are sonographic signs of pulmonary congestion and can be used in the differential diagnosis of dyspnea to rule in or rule out AHF. Their prognostic value at admission is less established, as well as the different role in AHF with reduced and preserved ejection fraction (HFrEF and HFpEF), or patients admitted for cardiac conditions but without overt signs and symptoms of AHF.

Methods

A total of 1021 consecutive in-patients (69±12 years) admitted for various cardiac conditions were enrolled. Patients were classified into three groups: 1) acute HFrEF; 2) acute HFpEF; 3) no AHF. All patients underwent on the admission an echocardiogram coupled with LUS, according to standardised protocols.

Results

Patients were followed-up for a median of 14.4 months (interquartile range: 4.6–24.3) for death and HF readmission (composite endpoint). During the follow-up, 126 events occurred. Kaplan-Meier survival analyses showed admission B-lines >30 identified patients with worse outcome at follow-up in the overall population and each of the three groups (Figure). At multivariable analysis (Table), admission B-lines >30, EF <50%, tricuspid regurgitation velocity >2.8 m/s and tricuspid annular plane systolic excursion (TAPSE) <17 mm resulted in independent predictors of the composite endpoint. B-lines >30 had a strong predictive value in HFpEF and non-AHF, but not in HFrEF.

Conclusions

Ultrasound B-lines can detect subclinical pulmonary interstitial edema in patients thought to be free of congestion, and provide useful information not only for the diagnosis but also for the prognosis in different cardiac conditions. Their added prognostic value among standard echocardiographic parameters is stronger in patients with HFpEF compared to HFrEF.

Figure 1

Funding Acknowledgement

Type of funding source: None

4329Mega-studies in heart failure, effect dilution in examination of new therapies

Aims

All phase 3 studies in patients with acute heart failure (AHF) and HF with preserved ejection fraction (HFpEF) have failed in the last decades. We explore the likelihood that the negative results are due to chance and/or to study size and dilution of statistical power.

Methods and results

First, using simulations, we examined the probability that a positive finding in phase 2 would result in studying truly effective drugs in phase 3. We simulated phase 2 studies under six scenarios where the range of true relative risk (RR) for an outcome of interest varied from 0.5 (major benefit) to 1.15 (some harm). The proportion of simulated studies where the RR <0.8 (we assumed that a 20% or greater risk reduction reflects an effective drug) ranged from 6% to 42% across the six scenarios studied. To further simulate “real life” clinical research, we simulated a continuous surrogate outcome that was linearly related to the true RR in each simulation of each scenario. Regardless of criteria considered for a positive phase 2 trial, results suggest that even in our worst-case scenario, where overall only 6% of drugs taken into phase 2 are effective, roughly 20% of phase 3 studies, if appropriately powered, should have yielded positive results. Given this, we then explored study size in AHF research, as a potential explanation for the high failure rate in these studies. Comparison of published phase 2 and 3 clinical trials with registries in AHF suggest that populations in both large and small trials differ from “real life”. Meta-regression models suggest that both control event rates, and in the serelaxin program as an example, treatment effects, decline with increasing study size greatly reducing power (figure). This effect dilution might be explained by an increasing proportion of patients enrolled in studies who cannot benefit from the study drug.

Figure 1. Power at two-sided 0.05 significance level to detect an effect size of hazard ratio of 0.65 (left) or 0.8 (right) with a placebo event rate of 10% (top) and 20% (bottom) at N=100 at various treatment effect dilutions with increasing sample size.

Conclusion

These data suggest that it is unlikely that the very high rate of negative AHF phase III trials can be explained by chance alone. Potentially, our tendency to increase sample size does not necessarily increase statistical power, due to more heterogenous populations leading to reduced event rates and treatment effects.

A radiomics model for determining the invasiveness of solitary pulmonary nodules that manifest as part-solid nodules

AIM

A nomogram model was developed to predict the histological subtypes of lung invasive adenocarcinomas (IAs) and minimally invasive adenocarcinomas (MIAs) that manifest as part-solid ground-glass nodules (GGNs).

MATERIALS AND METHODS

This retrospective study enrolled 119 patients with histopathologically confirmed part-solid GGNs assigned to the training (n=83) or testing cohorts (n=36). Radiomic features were extracted based on the unenhanced computed tomography (CT) images. R software was applied to process the qualitative and quantitative data. The CT features model, radiomic signature model, and combined prediction model were constructed and compared.

RESULTS

A total of 396 radiomic features were extracted from the preoperative CT images, four features including MaxIntensity, RMS, ZonePercentage, and LongRunEmphasis_angle0_offset7 were indicated to be the best discriminators to establish the radiomic signature model. The performance of the model was satisfactory in both the training and testing set with areas under the curve (AUCs) of 0.854 (95% confidence interval [CI]: 0.774 to 0.934) and 0.813 (95% CI: 0.670 to 0.955), respectively. The CT morphology of the lesion shape and diameter of the solid component were confirmed to be a significant feature for building the CT features model, which had an AUC of 0.755 (95% CI: 0.648 to 0.843). A nomogram that integrated lesion shape and radiomic signature was constructed, which contributed an AUC of 0.888 (95% CI: 0.82 to 0.955).

CONCLUSIONS

The radiomic signature could provide an important reference for differentiating IAs from MIAs, and could be significantly enhanced by the addition of CT morphology. The nomogram may be highly informative for making clinical decisions.

Epidemiology of Inflammatory Bowel Disease in Southern Peninsular Malaysia

AIM

To record the incidence and prevalence of inflammatory bowel disease (IBD), its social demographics, clinical characteristics and treatment, in the state of Johor, Malaysia.

METHODS

Hospital Sultanah Aminah, Johor Bahru, is the only public hospital in Johor with a Gastroenterology service. Data on all existing and new IBD patients managed by the Gastroenterology Unit in 2016 were collected. Incidence and prevalence of IBD in 2016 were then calculated based on the estimated population of Johor and Johor Bahru.

RESULTS

Twenty-five new cases of IBD were diagnosed in 2016. Among the 25 cases, 13 cases were Crohn's disease (CD), 10 were ulcerative colitis (UC) and two were IBD Unclassified (IBDU). The crude incidence of IBD, CD, UC and IBDU were 0.68, 0.36, 0.27, and 0.05 per 100,000 population respectively. Ethnic Indians had the highest incidence of IBD at 4.21 followed by Malays and Chinese at 0.56 and 0.18 per 100,000 population respectively. A total of 156 IBD cases were captured. Amongst them, 85 cases were UC, 68 cases were CD and three cases were IBDU, hence the prevalence of IBD, UC, CD and IBDU were 4.27, 2.33, 1.86 and 0.08 per 100,000 population respectively. Similarly, Indians had the highest prevalence at 16.84, followed by Chinese at 4.06 and Malays at 3.44 per 100,000 population.

CONCLUSIONS

The incidence of IBD in Johor is comparable to that of a previous study in northern Peninsular Malaysia. The ethnicity preponderance is similar to the previous studies conducted in Malaysia.

How Evidence-Based is our Practice in a Hong Kong Emergency Department?

Objective

To evaluate how evidence-based our daily practice was.

Design

Retrospective study.

Setting

Emergency department of a public district hospital.

Patients and Methods

Between 1st August 2000 to 7th August 2000, 91 patients' records were chosen at random. A chief diagnosis was assigned for each patient. Corresponding treatments were reviewed by searching relevant randomised controlled trials (RCTs), systematic reviews and meta-analyses. Each patient had only one chief diagnosis but could have multiple interventions for that diagnosis.

Results

Out of 91 records, 14 were discarded. All of them had not been given any intervention and 11 required admission. For the remaining 77 records, there were 38 subjects in medical, paediatric, or gynaecological specialties and 39 in surgical or orthopaedic specialties. Intervention(s) given for each subject were then searched electronically through our hospital Knowledge Gateway and the results were expressed as either EBM-positive or EBM-negative. “EBM-positive” interventions denoted a support by RCTs. “EBM-negative” interventions denoted an absence of any supportive RCTs. Each patient might have EBM-positive and/or EBM-negative interventions together if that patient received more than one treatment. There were 52 patients (52/77 = 68%) who had one of their interventions being RCT-supported. The majority were patients with (1) antipyretic use of paracetamol in upper respiratory tract infection, or (2) control of pain by nonsteroidal anti-inflammatory drug, dologesic and paracetamol. There were 25 patients (25/77 = 32%) who did not receive any RCT-supported interventions. Concurrently 53 patients out of 77 (69%) received EBM-negative interventions. The majority were patients with (1) the use of antibiotics, antitussives and antihistamines in upper respiratory tract infection, (2) antispasmodics in gastroenteritis or patients with nonspecific abdominal pain, and (3) the use of analgesic balm in minor orthopaedic complaints.

Conclusion

Sixty-eight percent of patients had EBM-positive interventions. Thirty-two percent of patients did not receive any EBM-positive intervention. It was quite encouraging as compared to studies in other specialties with similar design. Concurrently 69% of patients had also been given EBM-negative interventions. There were areas for improvement if we were to implement EBM practice in the emergency department.

A Case of Malathion Poisoning with Prolonged Cholinergic Toxicity

A case of severe organophosphate poisoning in a woman who ingested malathion is presented. Pralidoxime was given for more than two weeks but the lady had a poor response and developed recurrent episodes of cholinergic symptoms. Further studies are required to validate the World Health Organization regimen of pralidoxime in organophosphate poisoning.

Germocyte lesions caused by porcine circovirus type 2b in Kunming mice

Porcine circovirus type 2 (PCV2) has been known as a causative agent of reproductive failure in the sow. In the present study mouse model was used to investigate PCV2 infection. In order to investigate whether PCV2 can induce lesions of spermatocytes and oocytes, 6 male and 6 female mice were each inoculated intraperitoneally with PCV2b, and 3 male and 3 female mice mock-infected with cell culture supernatant served as controls. Samples of testes and ovaries from PCV2b-inoculated and mock-infected mice were investigated using PCR, histopathological, ultrastructural and immunofluorescent histochemical methods at 14 and 21 day post infection (dpi). The study revealed that in the virus-inoculated mice leydig cells in testes and granulosa cells in ovaries were degenerated, and a small number of spermatocytes and oocytes showed apoptosis. Positive PCV2b antigen signals were also observed in these apoptotic cells. It can be suggested that PCV2 can cause lesions of spermatocyte and oocyte prior to zygotes formation in its host.

[Predictive value of sonographic features in preoperative evaluation of medullary thyroid carcinoma]

OBJECTIVE

To summarize ultrasound features associated with medullary thyroid carcinoma (MTC) and investigate the predictive value of ultrasonography in preoperative diagnosis of MTC.

METHODS

The sonographic and clinical data were studied in a series of nodules histologically proven as MTC collected from January 1993 to January 2013.

RESULTS

A total of 86 patients (92 nodules proven as MTC) were enrolled in the study with an average age of (47±12) years.Among the MTCs, 21.7%(20/92) were excluded because of missing data and the remained 78.3%(72/92) had complete data with the average diameter of (2.1±1.3) cm.The common US findings for MTC were solid, hypoechogenicity, regular sharp, well-defined margin, AP/ TR<1 and calcification (mostly microcalcification). Calcification and vascularization were more common in MTC nodules(48.6% vs 5.6%, P=0.001). Nodules with enlargement of cervical lymph node tended to be undergone FNAB(76.0% vs 55.3%, P=0.084), and ill-defined margin was more common in MTC nodules with cervical lymph node metastasis(36.4% vs 12.8%, P=0.009).

CONCLUSION

Despite having a few US features closely linked to the malignant nodules such as solid, hypoechogenicity and with microcalcification, the MTC nodules also have specific US imaging characteristics as regular sharp, well-defined margin and AP/ TR<1.

Electronic sensitivity of a single-walled carbon nanotube to internal electrolyte composition

Carbon nanotubes (CNTs) are well known as materials for nanoelectronics and show great potential to be used as the sensing elements in chemical and biological sensors. Recently, CNTs have been shown to be effective nanofluidic channels and the transport of substances through small diameter CNTs is intrinsically fast, selective, and operates at the single molecule level. It has been shown that the transport characteristics of semiconducting single-walled CNT (SWCNT) field effect transistors (FETs) are sensitive to internal water wetting. We report here that the characteristics of semiconducting SWCNT FETs are also sensitive to the concentration, pH and ion type of the ionic solution when the electrolyte is inside the CNT. Such sensitivity is not observed at the outside surface of a semiconducting SWCNT. This opens a new avenue for building new types of CNT sensor devices in which the SWCNT concurrently functions as a nanochannel and an electronic detector.

Avian leukosis virus p27 inhibits tumor necrosis factor alpha expression in RAW264.7 macrophages after stimulation with lipopolysaccharide

Avian leukosis is a widely distributed disease caused by Avian leukosis virus (ALV). ALV p27 is a capsid protein and group specific antigen, whose role in host immune response is poorly understood. To explore ALV p27, we developed a RAW264.7 macrophage cell line stably expressing p27-GFP fusion protein. The cells of this line and control cell line expressing GFP protein only were compared in production of tumor necrosis factor alpha (TNF-alpha), interleukins IL-1beta, IL-6, IL-12, and in proliferative activity stimulated by the lipopolysaccharide (LPS). It was found that the ALV p27 expression markedly reduced the production of TNF-alpha, but did not affect the production of IL-1beta, IL-6, and 12, and cell proliferative activity. These results demonstrate that ALV p27 specifically inhibits TNF-alpha expression in the macrophages stimulated by LPS, suggesting a possible contribution of ALV p27 to immunosuppression detected in ALV-infected hosts.

KEYWORDS

Avian leukosis virus; p27; tumor necrosis factor alpha; interleukins; macrophages; lipopolysaccharide.

DNA fusion vaccines incorporating IL-23 or RANTES for use in immunization against influenza

The incorporation of RANTES or IL-23 into DNA vaccines may improve their immunogenicity by the recruitment and activation of dendritic cells. This may also select for a TH1 response counteracting the TH2 response which can predominate when a DNA vaccine is delivered by gene gun. We have immunized mice with various DNA constructs encoding APR/8/34 influenza virus hemagglutinin (HA), either fused to or separate from, IL-23 or RANTES using a gene gun. Those immunized with IL-23/HA fusion constructs and challenged with influenza 27 weeks post-vaccination, tended to have cleared more virus than those vaccinated with HA DNA. Mice immunized with the RANTES/HA fusion construct produced a mixed TH1/TH2 response whereas in HA-vaccinated mice, a TH2 response predominated. Immunization with a plasmid in which HA and RANTES were under the control of separate promoters, failed to generate a mixed TH1/TH2 response suggesting that enhanced antigen uptake via RANTES receptors may contribute to the mixed immune response generated to the fusion construct. Overall these findings provide further evidence that Type 1 cytokines or chemokines, fused to antigen in a DNA vaccine, can influence the nature and the longevity of the immune response and ultimately, its protective capacity.

Is neck ultrasound necessary for early stage oral tongue carcinoma with clinically N0 neck?

OBJECTIVES

To define the necessity of neck ultrasound for investigation of T1 and T2 oral tongue carcinoma with N0 neck.

METHODS

The medical records of all patients with early stage (T1-2 N0) oral tongue cancer treated surgically between January 1985 and December 2000 were reviewed. Patients with 30 neck dissections were identified for analysis. The result of neck ultrasound examination was correlated with the histological examination.

RESULTS

The sensitivity, specificity and overall accuracy of ultrasound examination were found to be 47%, 93% and 70%, respectively. The implication of ultrasound examination with respect to elective neck treatment was discussed in the management of the N0 neck.

CONCLUSIONS

It is concluded that ultrasound alone is inadequate for making decisions regarding neck management of patients with T1 and T2 N0 carcinoma of the tongue and cannot replace a policy of elective neck dissection.

The diagnosis of Clostridium difficile-associated diarrhea: comparison of Triage C. difficile panel, EIA for Tox A/B and cytotoxin assays

This study prospectively compared; Triage(R) C. difficile test (TCT), TechLab C. difficile toxin A-B enzyme immuno-assay (EIA), and cell-culture cytotoxin test (CT). Of the 400 stools tested, 99 were positive by any test with 92, 41 and 58 detected by TCT, EIA and CT, respectively. Culture of discordant samples indicated that 52 contained C. difficile (42 toxigenic, 10 non-toxigenic), 10 contained Clostridium species and 2 had no detectable clostridium isolates. There were 21/42 toxigenic C. difficile isolates from 17 patients whose stools were negative when originally tested by CT. Review of available patient charts indicated that 12/14 did not previously or currently have C. difficile associated diarrhea, whereas 2 patients developed disease within a few days. Compared to CT as the gold standard, the sensitivity and specificity were; 93%, 89% and 66%, 99% for TCT and EIA respectively. The 8 stool samples with Toxin A(-) Toxin B(+) isolates were detected in 8, 4, and 6 samples by TCT, EIA and CT, respectively. In summary, TCT as a screening test allowed reliable reporting for 85% of stools on the day of receipt. For the 15% of stools requiring further testing we recommend the use of CT.

Modulation of L-type Ca2+ channels in UMR 106 cells by parathyroid hormone-related protein

The effects of rat parathyroid hormone-related protein (rPTHrP) and bovine and rat parathyroid hormone (bPTH and rPTH) on L-type Ca2+ channels in UMR 106 cells were investigated using the patch clamp technique. rPTHrP increased the whole cell L-type Ca2+ channel currents and the increase was concentration dependent. rPTHrP, at a concentration of 62.5 nM, increased the L-type Ca2+ channel current by 122+/-25%. bPTH was less potent. A concentration of 7.5 microM bPTH increased the current by 99+/-24%. Results obtained with rPTH were similar to those obtained using bPTH. Single channel measurements, using the cell-attached version of the patch clamp technique, showed an increase in both the number of channel openings and the mean open time when the cells were exposed to rPTHrP. This suggested that rPTHrP affected the gating of L-type Ca2+ channels in UMR 106 cells. This study demonstrates that the actions of bPTH and rPTHrP in UMR cells are mediated in part by extracellular Ca2+ entry. PTHrP, a paracrine agent important in development, is more potent in regulating Ca2+ entry than PTH.

Immunomodulating activity of CVT-E002, a proprietary extract from North American ginseng (Panax quinquefolium)

The activity of CVT-E002, an aqueous extract containing mainly oligosaccharides and polysaccharides from North American ginseng (Panax quinquefolium), as an immunobooster on murine spleen cells and peritoneal macrophages, was studied in-vitro. CVT-E002 stimulated the proliferation of normal mouse spleen cells, of which the major responding subpopulation was identified as B lymphocytes. CVT-E002 also activated peritoneal exudate macrophages leading to enhanced interleukin-1 (IL-1), interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) production. In addition, CVT-E002 stimulated in-vivo immunoglobulin G (IgG) production in treated mice. These results identify some of the immunomodulating activities of CVT-E002 and suggest its use clinically for the modulation of immune responses.

Effect of the herbal extract combination Panax quinquefolium and Ginkgo biloba on attention-deficit hyperactivity disorder: a pilot study

OBJECTIVE

A combination herbal product containing American ginseng extract, Panax quinquefolium, (200 mg) and Ginkgo biloba extract (50 mg) (AD-FX; CV Technologies, Edmonton, Alta.) was tested for its ability to improve the symptoms of attention-deficit hyperactivity disorder (ADHD).

DESIGN

Open study.

PATIENTS

36 children ranging in age from 3 to 17 years who fit the diagnostic criteria for ADHD.

INTERVENTIONS

AD-FX capsules were taken twice a day on an empty stomach for 4 weeks. Patients were instructed not to change any other medications during the study.

OUTCOME MEASURES

At the beginning of the study, after 2 weeks, and then at the end of the 4-week trial, parents completed the Conners' Parent Rating Scale--revised, long version, a questionnaire that assesses a broad range of problem behaviours (and was used as an indication of ADHD symptom severity).

RESULTS

After 2 weeks of treatment, the proportion of the subjects exhibiting improvement (i.e., decrease in T-score of at least 5 points) ranged from 31% for the anxious-shy attribute to 67% for the psychosomatic attribute. After 4 weeks of treatment, the proportion of subjects exhibiting improvement ranged from 44% for the social problems attribute to 74% for the Conners' ADHD index and the DSM-IV hyperactive-impulsive attribute. Five (14%) of 36 subjects reported adverse events, only 2 of which were considered related to the study medication.

CONCLUSIONS

These preliminary results suggest AD-FX treatment may improve symptoms of ADHD and should encourage further research on the use of ginseng and Ginkgo biloba extracts to treat ADHD symptoms.

Intrathyroidal lymphoepithelial (branchial) cyst: sonographic features of a rare lesion

Intrathyroidal lymphoepithelial cysts are rare, and only 15 such cases have been reported. Although sonography has been performed in some cases, the findings have not been discussed previously. Despite its rarity, the sonographic appearances of this lesion are similar to those of other commonly encountered congenital cystic lesions in the head and neck, such as thyroglossal duct cysts and second branchial cleft cysts, and this may provide a clue to its diagnosis. We describe the sonographic appearances of intrathyroidal lymphoepithelial cysts.

Morphine and methadone have different effects on calcium channel currents in neuroblastoma cells

Using patch-clamp technique, cellular calcium channel currents were studied on nine mouse neuroblastoma N1E115 cells. Both morphine and methadone decreased the T-type calcium currents in dose-dependent fashion. These effects were partially blocked by naloxane. On L-type calcium currents, morphine showed no effect. However, methadone inhibited the L-calcium currents in dose-dependent fashion. This effect was not antagonised by naloxone. Hence, the action of methadone on L-calcium channel is probably not associated with mu receptors.

brakeless is required for photoreceptor growth-cone targeting in Drosophila

The R1-R6 subclass of photoreceptor neurons (R cells) in the Drosophila compound eye form specific connections with targets in the optic ganglia. In this paper, we report the identification of a gene, brakeless (bks), that is essential for R1-R6 growth cone targeting. In brakeless mutants, R1-R6 growth cones frequently fail to terminate migration in their normal target, the lamina, and instead project through it and terminate in the second optic ganglion, the medulla. Genetic mosaic analysis and transgene rescue experiments indicate that bks functions in R cells and not within the lamina target region. bks encodes a nuclear protein. We propose that it participates in a gene expression pathway regulating one or more growth cone components controlling R1-R6 targeting.

The SH2/SH3 adaptor protein dock interacts with the Ste20-like kinase misshapen in controlling growth cone motility

Recent studies suggest that the SH2/SH3 adaptor Dock/Nck transduces tyrosine phosphorylation signals to the actin cytoskeleton in regulating growth cone motility. The signaling cascade linking the action of Dock/Nck to the reorganization of cytoskeleton is poorly understood. We now demonstrate that Dock interacts with the Ste20-like kinase Misshapen (Msn) in the Drosophila photoreceptor (R cell) growth cones. Loss of msn causes a failure of growth cones to stop at the target, a phenotype similar to loss of dock, whereas overexpression of msn induces pretarget growth cone termination. Physical and genetic interactions between Msn and Dock indicate a role for Msn in the Dock signaling pathway. We propose that Msn functions as a key controller of growth cone cytoskeleton in response to Dock-mediated signals.

Substrate specificities of recombinant murine Golgi alpha1, 2-mannosidases IA and IB and comparison with endoplasmic reticulum and Golgi processing alpha1,2-mannosidases

The catalytic domains of murine Golgi alpha1,2-mannosidases IA and IB that are involved in N-glycan processing were expressed as secreted proteins in P.pastoris . Recombinant mannosidases IA and IB both required divalent cations for activity, were inhibited by deoxymannojirimycin and kifunensine, and exhibited similar catalytic constants using Manalpha1,2Manalpha-O-CH3as substrate. Mannosidase IA was purified as a 50 kDa catalytically active soluble fragment and shown to be an inverting glycosidase. Recombinant mannosidases IA and IB were used to cleave Man9GlcNAc and the isomers produced were identified by high performance liquid chromatography and proton-nuclear magnetic resonance spectroscopy. Man9GlcNAc was rapidly cleaved by both enzymes to Man6GlcNAc, followed by a much slower conversion to Man5GlcNAc. The same isomers of Man7GlcNAc and Man6GlcNAc were produced by both enzymes but different isomers of Man8GlcNAc were formed. When Man8GlcNAc (Man8B isomer) was used as substrate, rapid conversion to Man5GlcNAc was observed, and the same oligosaccharide isomer intermediates were formed by both enzymes. These results combined with proton-nuclear magnetic resonance spectroscopy data demonstrate that it is the terminal alpha1, 2-mannose residue missing in the Man8B isomer that is cleaved from Man9GlcNAc at a much slower rate. When rat liver endoplasmic reticulum membrane extracts were incubated with Man9GlcNAc2, Man8GlcNAc2was the major product and Man8B was the major isomer. In contrast, rat liver Golgi membranes rapidly cleaved Man9GlcNAc2to Man6GlcNAc2and more slowly to Man5GlcNAc2. In this case all three isomers of Man8GlcNAc2were formed as intermediates, but a distinctive isomer, Man8A, was predominant. Antiserum to recombinant mannosidase IA immunoprecipitated an enzyme from Golgi extracts with the same specificity as recombinant mannosidase IA. These immunodepleted membranes were enriched in a Man9GlcNAc2to Man8GlcNAc2-cleaving activity forming predominantly the Man8B isomer. These results suggest that mannosidases IA and IB in Golgi membranes prefer the Man8B isomer generated by a complementary mannosidase that removes a single mannose from Man9GlcNAc2.

A component of the chloroplast protein import apparatus functions in bacteria

Toc36 is a family of 44-kDa envelope polypeptides previously identified as components of the chloroplast protein import apparatus by virtue of their close physical proximity to translocating proteins. An indication of their function thus remains at large. A heterologous in vivo approach for studying the function of Toc36 was developed in this study by introducing a member of Toc36 into E. coli to assess its effect on bacterial protein translocation. The presence of Toc36 enhances the translocation of two bacterial periplasmic proteins in a manner resembling the chloroplast system. Translocation of the two bacterial periplasmic proteins was less sensitive to sodium azide, resembling more the azide-insensitive nature of the chloroplast protein import process. Mutated Toc36 proteins were not capable of causing the same effect as that observed for unaltered Toc36. Toc36 was also capable of complementing bacterial strains with temperature-sensitive secA mutations that affected protein translocation. The combined results provide evidence that Toc36 plays a central role in the chloroplast protein translocation process.

Calcitonin gene-related peptide relaxed rat tail artery helical strips in vitro in an intracellular calcium-dependent manner

The vasoactive properties of calcitonin gene-related peptide (CGRP) were examined using the helical strip of the rat tail artery as a model. CGRP was found to inhibit norepinephrine-induced contraction but not KCl- or vasopressin-induced contraction. No significant inhibition occurred in either KCl- or norepinephrine-stimulated strips when Ca2+ was added incrementally to otherwise Ca2+-free bathing solution. However, a dose-related inhibition to norepinephrine-stimulated contraction in Ca2+-free bathing solution was observed. This strongly suggests that CGRP exerts its effect by inhibiting the mobilization of intracellular Ca2+.

Ophthalmologic oncology: sebaceous carcinomas of the eyelids

Sebaceous carcinomas are rare, and deadly, adnexal tumors with a distinct predilection for eyelid skin. A chronic blepharoconjunctivitis and/or a recurrent chalazion are the most common clinical presentations that should alert the clinician to the diagnosis. Great care and skill are needed in interpreting these lesions histopathologically as they can be easily confused with basal- and squamous-cell carcinomas.

Small lymphangiomas of the eyelids

Three patients are described with focal lymphangiomatous lesions of their eyelids. A child with a partially regressed, congenital lesion presented with evidence of recent hemorrhage, while, of two adults with acquired tumors, one had a blue lesion suggesting a malignant melanoma, and the other had a more obviously cystic lesion, suggesting an epidermal or adnexal cyst. In one case, the lesion was situated entirely within the marginal orbicularis striated muscle, and in the other two cases the lesion was restricted to the dermis of the lid. Abrupt change in the coloration of a lesion in the lid should suggest hemorrhage into a preexistent tumor. Hemorrhage into lymphangiomas is extremely common, and therefore this vascular tumor should be included in the differential diagnosis of previously nondiscolored lesions. Other vascular tumors, such as capillary, cavernous or venous angiomas would be expected to have a longstanding reddish-blue hue.

Comparison of procedures used to induce offensive attack in mice

Three groups of male mice ( n = 6 per group) were tested in a study of the effects of repeated exposure to an intruder, dangled opponents, and isolation on territorial aggression (offense). Daily home-cage tests with intruders produced significantly more offensive behavior than either of the other procedures commonly used to induce this type of attack in mice.