Acute respiratory failure after deep cervical plexus block for carotid endarterectomy as a result of bilateral recurrent laryngeal nerve paralysis

We report about a case of acute respiratory distress (73-year-old female), which occurred minutes after a deep cervical plexus block (40 ml ropivacaine 0.5%) for carotid endarterectomy (CEA) and required immediate endotracheal intubation of the patient's trachea and consecutive mechanical ventilation. Subsequently, CEA was performed under general anaesthesia (TIVA) with continuous monitoring by somatosensory-evoked potentials. After a period of 14 hours, the endotracheal tube could be removed, the patient being in fair respiratory, cardiocirculatory and neurological conditions. Retrospectively, acute respiratory distress was caused by a combination of ipsilateral plexus blockade-induced and pre-existing asymptomatic contralateral recurrent laryngeal nerve (RLN) paralysis confirmed by a postoperative ENT-check and related to previous thyroid surgery more than 50 years ago. RLN paralysis, often being asymptomatic, represents a typical complication of thyroid and other neck surgery with reported incidences of 0.5-3%. Therefore, a thorough preoperative airway check is advisable in all patients scheduled for a cervical plexus block. Particularly in cases with a history of respiratory disorders or previous neck surgery a vocal cord examination is recommended, and the use of a superficial cervical plexus block may lower the risk of respiratory complications. This may prevent a possibly life-threatening coincidence of ipsilateral plexus blockade-induced and pre-existing asymptomatic contralateral RLN paralysis.

The cardiolipin-binding domain of Bid affects mitochondrial respiration and enhances cytochrome c release

Bid is cleaved by caspase 8 during apoptosis and the truncated Bid (tBid) translocates to mitochondria by targeting cardiolipin. Amino acids 103-162 of Bid were reported as the cardiolipin-binding domain (CBD). The EGFP-CBD fusion protein targets to mitochondria and induces apoptosis. Using [(3)H]cardiolipin, we proved that recombinant CBD binds cardiolipin similar to tBid and tBid(G94E), a mutant with a defective BH3 domain. CBD could induce cytochrome c release from isolated mitochondria, but much less potent than tBid. Free cardiolipin inhibited the CBD-induced cytochrome c release, suggesting that it may be mediated by interfering with mitochondrial cardiolipin, especially with the interaction between cytochrome c and cardiolipin. This is consistent with the findings that CBD induced cytochrome c release in Bax-deficient cells, and that CBD suppressed mitochondrial respiration through directly interfering with cardiolipin, a critical lipid involved in oxidative phosphorylation. These results indicate the functional importance of CBD in tBid-induced apoptosis.

Orthostatic hypotension in the elderly: are the diagnostic criteria adequate?

Orthostatic hypotension (OH) is a common finding in the elderly. OH is defined as a fall of at least 20 mmHg in systolic blood pressure (BP) and/or 10 mmHg in diastolic BP upon assuming an upright posture. Some patients exhibit a fall in BP of less than the defined OH upon standing. The aim of this study was to estimate the prevalence of BP changes not defined as OH among elderly in-patients and to assess the relationship between these changes in the morning and the occurrence of OH during the day. Postural BP measurements were performed in 502 in-patients; in the morning, early afternoon, and in the evening. We defined intermediate postural drop (ID) in BP as a decrease of 10-19 mmHg in systolic BP and/or of 5-9 mmHg in diastolic BP. We observed that OH and ID occurred in 39.2 and 18.5% of the measurements in the morning, respectively. The prevalence of OH and ID was lower in the evening than in the morning (P<0.05) and afternoon (P<0.005). Postural BP changes in the morning correlated with those occurring later in the day. Patients who had ID in the morning had a 57% probability of having OH later during the day. In conclusions, ID is prevalent in elderly in-patients. ID in the morning predicts OH later in the day. Thus, postural BP drops below the OH range may be an important finding in the geriatric population.

BANANAS

Today the Internet offers a single path between end-systems even though it intrinsically has a large multiplicity of paths. This paper proposes an evolutionary architectural framework "BANANAS" aimed at simplifying the introduction of multipath routing in the Internet. The framework starts with the observation that a path can be encoded as a short hash ("PathID") of a sequence of globally known identifiers. The PathID therefore has global significance (unlike MPLS or ATM labels). This property allows multipath capable nodes to autonomously compute PathIDs in a partially upgraded network without requiring an explicit signaling protocol for path setup. We show that this framework allows the introduction of sophisticated explicit routing and multipath capabilities within the context of widely deployed connectionless routing protocols (e.g. OSPF, IS-IS, BGP) or overlay networks. We establish these characteristics through the development of PathID encoding and route-computation schemes. The BANANAS framework also allows considerable flexibility in terms of architectural function placement and complexity management. To illustrate this feature, we develop an efficient variable-length hashing scheme that moves control-plane complexity and state over-heads to network edges, allowing a very simple interior node design. All the schemes have been evaluated using both sizable SSFNet simulations and Linux/Zebra implementation evaluated on Utah's Emulab testbed facility.

Differential activity of the gelatinases (matrix metalloproteinases 2 and 9) in the fetal membranes and decidua, associated with labour

Degradation of the extracellular matrix in fetal membranes has been implicated in the rupture of fetal membranes, the process of parturition and placental detachment from the decidua after parturition. In this study we assessed labour-associated changes in gelatinase activity in cultured human amnion, chorion and decidua, as well as in amniotic fluid. We found that in media conditioned by decidua, following the establishment of uterine contractions, matrix metalloproteinase-2 (MMP-2) activity is increased while the protein tissue inhibitors of matrix metalloproteinase-1 (TIMP-1) level is decreased. The formation of a 130 kDa gelatinase band was also significantly increased after contractions began. In media conditioned by chorion, the initiation of uterine contractions did not change MMP activity or TIMP-1 levels. However, an increase in MMP-9 activity and a decrease in TIMP-1 protein levels were observed following the establishment of uterine contractions in media conditioned by amnion. We suggest that this differential spatial regulation provides a form for modulatory hieratical activity of the MMPs in the onset of labour allowing rupture of the membranes while avoiding premature placental separation.

A comparison of total intravenous with balanced anaesthesia for middle ear surgery: effects on postoperative nausea and vomiting, pain, and conditions of surgery

We compared postoperative nausea and vomiting (PONV), pain and conditions for surgery in patients scheduled for middle ear surgery. In a double-blind study, 100 patients were randomly allocated to receive either balanced anaesthesia (group A) using fentanyl, propofol and isoflurane, or total intravenous anaesthesia (group B) using propofol and remifentanil infusions. Pain scores, nausea/vomiting scores, conditions for surgery and analgesic requirements were recorded for 18 h post operatively. In the recovery ward, patients in group B suffered significantly less PONV (p = 0.026) with a reduced requirement for anti-emetic medication (p = 0.023); however, this difference was not maintained on the ward. The overall incidence of PONV was 34% and 17% in groups A and B, respectively. Initial pain scores were higher in group B in the recovery ward (p = 0.003) and patients required more morphine administration (p = 0.002); however, pain scores were similar on the ward. Conditions for surgery were found to be better in group B.

Pseudomembranous tracheobronchial aspergillosis: a rare manifestation of invasive aspergillosis in a non-neutropenic patient with Hodgkin's disease

Pseudomembranous tracheobronchial aspergillosis coincident with systemic pulmonary aspergillosis represents a rare manifestation of fungal infection in immunocompromized hosts. We report on a patient with recurrent Hodgkin's disease, showing this infectious pattern after treatment with corticosteroids within the antineoplastic schedule, whereas neutropenia--the main risk factor for mold infections--had not occurred. An impaired number of helper T lymphocytes was merely detected as an additional, but hypothetical risk factor, when investigating the status of immunosuppression. Treated systemically with amphotericin B, the patient recovered quickly, although reported mortality rates are disastrous. What is crucial for the clinical management is an early diagnosis by bronchoscopy and cultural proof of the pathogen followed by an adequate antifungal treatment.

[Echocardiographic detection of tricuspid valve endocarditis and right atrial and ventricular masses in a patient with acute myeloid leukaemia]

In a patient with acute leukaemia, tricuspid valve vegetations and both right atrial and ventricular masses formed within a few weeks were detected by echocardiography. In addition to endocarditis which is a very rare condition in patients with acute leukaemia, the diagnostic efforts including cardiac surgery resulted in the unusual finding of right-sided cardiac thrombi which had formed autochthonously. The most likely cause was thought to be a very severe systemic infection with staphylococci characterised by repeated episodes of bacteraemia during profound and prolonged neutropenia as well as a paraneoplastic coagulopathy. Surgery performed on the grounds of the echocardiography findings and differential-diagnostic considerations resulted in the relapse-free removal of the infectious focus. The maintenance therapy for leukaemia could thus be continued and led to a distinctly improved outcome. This case report confirms the great importance of sonography in the management of fever of unknown origin in immunocompromised patients.

Mechanisms of signaling by the hematopoietic-specific adaptor proteins, SLP-76 and LAT and their B cell counterpart, BLNK/SLP-65

Adaptor proteins lack catalytic activity and contain only protein-protein interaction domains. They have been shown to interact with an ever-growing number of signaling proteins and to play essential roles in many signaling pathways. SLP-76 and LAT are cell-type-specific adaptor proteins expressed in T cells, NK cells, platelets, and mast cells. In these cell types, SLP-76 and LAT are required for signaling by immunoreceptor tyrosine-based activation motif(ITAM)-containing receptors, including the T cell receptor (TCR), the pre-TCR, the high-affinity Fc epsilon receptor, and the platelet GPVI collagen receptor. In B cells, an analogous adaptor, BLNK/SLP-65, is required for signaling by the ITAM-containing B cell receptor. This review summarizes recent research on SLP-76, LAT, and BLNK. A major challenge in understanding adaptor protein function has been to sort out the many interactions mediated by adaptor proteins and to define the mechanisms by which adaptors mediate critical signaling events. In the case of LAT, SLP-76, and BLNK, the availability of tractable genetic systems, deficient in expression of each of these adaptor proteins, has facilitated in-depth investigation of their signaling functions and mechanisms of action. The picture that has emerged is one in which multiple adaptor proteins cooperate to bring about the formation of a large signaling complex, localized to specialized lipid microdomains within the cell membrane and known as GEMs. Adaptors not only recruit signaling proteins, but also play an active role in regulating the conformation and activation of many of the proteins recruited to the complex. In particular, recent research has shed light on the mechanisms by which multiple adaptor proteins cooperate to bring about the recruitment and activation of phospholipase C gamma in response to the activation of ITAM-containing receptors.

The immunological synapse and CD28-CD80 interactions

According to the two-signal model of T cell activation, costimulatory molecules augment T cell receptor (TCR) signaling, whereas adhesion molecules enhance TCR-MHC-peptide recognition. The structure and binding properties of CD28 imply that it may perform both functions, blurring the distinction between adhesion and costimulatory molecules. Our results show that CD28 on naïve T cells does not support adhesion and has little or no capacity for directly enhancing TCR-MHC-peptide interactions. Instead of being dependent on costimulatory signaling, we propose that a key function of the immunological synapse is to generate a cellular microenvironment that favors the interactions of potent secondary signaling molecules, such as CD28.

Laparoscopic subtotal hysterectomy and bilateral adnexectomy in a child with congenital adrenal hyperplasia

OBJECTIVE

To report the results of a subtotal hysterectomy and bilateral adnexectomy in a child with congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

DESIGN

Case report.

SETTING

Gynecology department, Afula, Israel.

PATIENT(S)

An 11-year-old child with a female genotype and saltwasting type congenital adrenal hyperplasia who was being raised as a boy.

INTERVENTION(S)

Laparoscopic subtotal hysterectomy and bilateral salpingo-oophorectomy were performed.

MAIN OUTCOME MEASURE(S)

Surgical efficiency, operating time, recovery, and aesthetic result.

RESULT(S)

The procedure was performed without complications in 26 minutes, and the child was dismissed the following day. Three 5-mL abdominal incisions were required.

CONCLUSION(S)

Laparoscopic subtotal hysterectomy and bilateral adnexectomy can be safely performed in children and is the procedure of choice in the rare cases in which it is indicated.

Hematopoietic progenitor kinase 1 associates physically and functionally with the adaptor proteins B cell linker protein and SLP-76 in lymphocytes

B cell linker protein (BLNK) is a SLP-76-related adaptor protein essential for signal transduction from the BCR. To identify components of BLNK-associated signaling pathways, we performed a phosphorylation-dependent yeast two-hybrid analysis using BLNK probes. Here we report that the serine/threonine kinase hematopoietic progenitor kinase 1 (HPK1), which is activated upon antigen-receptor stimulation and which has been implicated in the regulation of MAP kinase pathways, interacts physically and functionally with BLNK in B cells and with SLP-76 in T cells. This interaction requires Tyr(379) of HPK1 and the Src homology 2 (SH2) domain of BLNK/SLP-76. Via homology modeling, we defined a consensus binding site within ligands for SLP family SH2 domains. We further demonstrate that the SH2 domain of SLP-76 participates in the regulation of AP-1 and NFAT activation in response to T cell receptor (TCR) stimulation and that HPK1 inhibits AP-1 activation in a manner partially dependent on its interaction with SLP-76. Our data are consistent with a model in which full activation of HPK1 requires its own phosphorylation on tyrosine and subsequent interaction with adaptors of the SLP family, providing a mechanistic basis for the integration of this kinase into antigen receptor signaling cascades.

Chemokine gene expression and clonal analysis of B cells in tissues involved by lymphoid interstitial pneumonitis from HIV-infected pediatric patients

Lymphoid interstitial pneumonitis (LIP), a frequent pulmonary complication in HIV-infected pediatric patients, is characterized histologically by marked infiltration of lymphoid cells. We sought to evaluate the nature and pathogenesis of the lymphoid infiltrates and to examine the relationship of LIP to pulmonary MALT lymphoma that has been described in pediatric HIV positive patients. To examine the potential contribution of chemokines and cytokines to the inflammatory cell recruitment in tissues involved by lymphoid interstitial pneumonitis from HIV-infected pediatric patients, RNA was extracted from paraffin-embedded tissues from five lung biopsies in four pediatric HIV-positive patients and from five control, normal lung biopsies in five HIV-negative patients and was analyzed by semiquantitative RT-PCR for the expression of cytokines (TNF-alpha, GM-CSF, IFN-gamma, IL-4, IL-6, IL-10, and IL-18) and chemokines (IP-10, Mig, regulated upon activation, normal T expressed and secreted [RANTES], and MIP1-alpha and beta) after normalization for G3PDH. Expression of IL-18 was increased, as well as expression of IFN-gamma-inducible chemokines IP-10 and Mig in LIP tissues compared with controls. RANTES and MIP1-alpha and -beta were also increased in pediatric LIP lesions compared with controls. In contrast, expression of TNF-alpha, GM-CSF, IL-10, and IL-6 was variable in LIP tissues and controls. In addition, clonality of the B-cell population was evaluated by VDJ-PCR. A polyclonal B-cell population was shown in all five biopsies from five patients with LIP; and in one patient with concurrent LIP and MALT lymphoma, a band of increased intensity was observed in the LIP biopsy that was identical in size to the monoclonal band in the concurrent MALT lymphoma biopsy. These results provide evidence of high-level expression of certain chemokines in lymphoid interstitial pneumonitis tissues and suggest that chemokines and cytokines may play an important role in the recruitment of inflammatory cell infiltrates into these tissues. In addition, LIP may represent an early stage of MALT lymphoma or an immunologic response to a chronic antigenic stimulus that may provide a milieu or microenvironment for the evolution of a monoclonal B-cell population.

PTPRC (CD45) is not associated with the development of multiple sclerosis in U.S. patients

A C-->G nucleotide transition in exon 4 of PTPRC (encoding protein-tyrosine phosphatase receptor-type C, also known as CD45) was recently reported to be genetically associated with the development of multiple sclerosis (MS). We performed an extensive evaluation of this polymorphism using large family-based and case-control comparisons. Overall, we observed no evidence of genetic association between the PTPRC polymorphism and MS susceptibility or disease course.

The Src-like adaptor protein downregulates the T cell receptor on CD4+CD8+ thymocytes and regulates positive selection

In this report, we show that the Src-like adaptor protein (SLAP) plays an important role in thymocyte development. SLAP expression is developmentally regulated; it is low in CD4-CD8- thymocytes, it peaks in the CD4+CD8+ subset, and it decreases to low levels in more mature cells. Disruption of the SLAP gene leads to a marked upregulation of TCR and CD5 expression at the CD4+CD8+ stage. The absence of SLAP was also developmentally significant because it enhanced positive selection in mice expressing the DO11.10 transgenic T cell receptor. Moreover, SLAP deletion at least partially rescued the development of ZAP-70-deficient thymocytes. These results demonstrate that SLAP participates in a novel mechanism of TCR downregulation at the CD4+CD8+ stage and regulates positive selection.