Diffuse Pulmonary Meningotheliomatosis: A Case Report

Introduction/Objective

Diffuse pulmonary meningotheliomatosis (DPM) is a pulmonary disease characterized by the presence of widespread bilateral minute pulmonary meningothelial-like nodules (MPMNs). It is exceedingly rare and predominantly seen in females. The nodules are typically asymptomatic and detected incidentally on imaging.

Methods/Case Report

We present a case of a 57-year-old woman with a history of chronic cough and CT imaging findings of bilateral multiple ground-glass nodules. Wedge resections from the right upper and right lower lobes were obtained, which revealed gross changes suggestive of interstitial lung disease. Histologic evaluation of the wedges showed similar morphology, consisting of discrete areas with variable interstitial expansion of the stroma with ovoid/spindle cells, collagen, elastosis, and mild chronic inflammatory cells, in a somewhat perivascular pattern. Some areas were also cystic. This appeared in a background of emphysematous change and focal foreign body giant cell reaction to non-polarizable material. Immunohistochemical stains were diffusely positive for vimentin, EMA , and PR, and CD163 highlighted increased cells that were S100 and CD1a negative. Additionally, the ovoid/spindle cells were negative for desmin, SMM, HMB-45, HHV8, pan-CK, chromogranin, and multiplex SOX10-MART1.

Results (if a Case Study enter NA)

NA

Conclusion

Diffuse pulmonary meningotheliomatosis is a rare entity that requires sufficient histological evaluation to identify the ovoid/spindle cell component histologically and immunohistochemically. This disease should be considered in the differential for cases of diffuse interstitial pulmonary infiltrates. Few cases have been reported in the literature, requiring further research to understand the mechanisms of this disease and its clinical significance.

Applications of regional anaesthesia in paediatrics

Advances in the field of paediatric regional anaesthesia have specific applications to both acute and chronic pain management. This review summarizes data regarding the safety of paediatric regional anaesthetic techniques. Current guidelines are provided for performing paediatric regional techniques, with a focus on applications for postoperative pain management. Brief descriptions of relevant anatomy followed by indications for commonly performed blocks are highlighted along with the potential of adverse side-effects.

Mechanisms of response homeostasis during retinocollicular map formation

The mechanisms of Hebbian synaptic plasticity have been widely hypothesized to play a role in the activity-dependent development of neural circuits. However, these mechanisms are inherently unstable and would lead to the runaway excitation or depression of circuits if left unchecked. In the last decade, a number of elegant studies have demonstrated that homeostatic plasticity mechanisms exist to stabilize neural networks and maintain the constancy of neuronal output in response to changes in activity levels. These include synaptic scaling, sliding threshold models of synaptic plasticity, dynamic regulation of the number and strength of synapses, and bidirectional control of intrinsic excitability. Recently, we showed that the total synaptic input onto individual neurons of the mouse superior colliculus is preserved regardless of the size of their visual receptive fields, a phenomenon we term 'response homeostasis'. Here, we argue that regulating the capacity for synaptic plasticity and controlling the number and strength of retinocollicular inputs can preserve collicular neuron output, and we present evidence that changes in intrinsic excitability are not associated with response homeostasis. We also review findings from a number of different mutant mice and discuss whether and how different cellular mechanisms may underlie response homeostasis. Combined with other studies, our work reveals an important role for homeostatic mechanisms in regulating functional connectivity during the construction of receptive fields and the refinement of topographic maps.

Developmental homeostasis of mouse retinocollicular synapses

Spontaneous retinal waves during development are thought to provide an instructive signal for precise retinotopic mapping by correlating the activity of neighboring retinal ganglion cells. In mutant mice (beta2-/-) that lack correlated waves, retinocollicular map refinement is impaired. In vivo recordings reveal that neurons in the superior colliculus of beta2-/- mice have large receptive fields and low peak visual responses, resulting in a conservation of total integrated response. We find that this "response homeostasis" is maintained on a cell-by-cell basis, and argue that it does not depend on regulation from the visual cortex during adulthood. Instead, in vitro recordings show that homeostasis arises from the conservation of total synaptic input from the retina, and that it is maintained via different mechanisms over development. In the absence of correlated retinal waves, beta2-/- neurons sample a larger number of weaker retinal inputs relative to controls after the first postnatal week. Once retinal waves are restored, developmental learning rules and homeostasis drive refinement so that fewer, stronger synapses are retained, as in wild-type mice, but from a larger retinal area. Homeostasis in neurons has been shown previously to regulate the gain of synaptic transmission in response to perturbations of activity. Our results suggest that during the development of sensory maps, a unique consequence of homeostatic mechanisms is the precise shaping of neuronal receptive fields in conjunction with activity-dependent competition.

Estrogen-induced changes in the microtubular system correlate with a decreased susceptibility of aging neurons to beta amyloid neurotoxicity

A growing body of evidence suggests that estrogen has beneficial effects on Alzheimer's disease. However, the mechanisms underlying estrogen's neuroprotective effects are not completely understood. In the present study, we analyzed first whether estrogen protects mature hippocampal neurons against fibrillar Abeta-induced neurotoxicity. 17alpha-Estradiol and 17beta-estradiol partially prevented neuronal death induced by fibrillar Abeta. Estrogen-induced neuroprotection correlated with the formation of a more dynamic microtubular system, including an increase in the pool of unstable microtubules and the expression of juvenile microtubule-associated proteins MAP2c and MAP1b. These results provide further evidence that experimental conditions capable of increasing the pool of unstable microtubules might render mature hippocampal neurons resistant to the degeneration caused by fibrillar Abeta deposits.

Membrane topology of a metabotropic glutamate receptor

The metabotropic glutamate receptors (mGluRs) have been predicted to have a classical seven transmembrane domain structure similar to that seen for members of the G-protein-coupled receptor (GPCR) superfamily. However, the mGluRs (and other members of the family C GPCRs) show no sequence homology to the rhodopsin-like GPCRs, for which this seven transmembrane domain structure has been experimentally confirmed. Furthermore, several transmembrane domain prediction algorithms suggest that the mGluRs have a topology that is distinct from these receptors. In the present study, we set out to test whether mGluR5 has seven true transmembrane domains. Using a variety of approaches in both prokaryotic and eukaryotic systems, our data provide strong support for the proposed seven transmembrane domain model of mGluR5. We propose that this membrane topology can be extended to all members of the family C GPCRs.

Spectroscopic methods for determining enantiomeric purity and absolute configuration in chiral pharmaceutical molecules

Analytical support, such as methods development, along with identification and characterization of intermediates and impurities, are critical in the development of a chemical process. The preparation of a drug substance requires the development of analytical methods for monitoring reactions and identifying impurities. Methods development for a chiral drug molecule is more difficult as the method must be capable of monitoring the overall reaction as well as possible racemization of starting materials and products. Chiral methods are often required to monitor the reaction steps of a synthesis, however, the development of enantiomeric purity methods are time-consuming and expensive. The use of chiroptical detectors, such as circular dichroism (CD), optical rotation (OR) and vibrational circular dichroism (VCD), can help to reduce or eliminate the need to develop chiral monitoring methods and also to predict absolute configuration. Recently, VCD has shown remarkable success with the latter and currently holds the most promise as a general, direct method that can be used as an alternative to X-ray crystallography. Each of the mentioned techniques can help analytical chemists to reduce the time associated with traditional enantiomeric purity methods development and to determine absolute configuration. This review will discuss the scope and limitations of these techniques for the rapid and routine determination of both enantiomeric excess and absolute configuration.

Combined CT venography and pulmonary angiography in suspected thromboembolic disease: diagnostic accuracy for deep venous evaluation

OBJECTIVE

Combined CT venography and pulmonary angiography is a new diagnostic test that evaluates both pulmonary embolism and deep venous thrombosis (DVT) in a single study. Our purpose was to compare the CT venous findings with lower extremity venous sonography.

SUBJECTS AND METHODS

Seventy-one consecutive patients with suspected pulmonary embolism underwent helical CT pulmonary angiography during rapid i.v. infusion of contrast medium. Axial scans at 5-cm intervals from the patient's upper calves to the diaphragm were generated 3.5 min after the beginning of contrast medium injection. CT venous phase images were interpreted prospectively and compared with subsequent bilateral lower extremity venous sonography performed within 12 hr.

RESULTS

DVT was revealed by CT venous phase images in 19 patients, 12 of whom also had pulmonary embolism. CT and sonographic findings correlated exactly in the femoropopliteal deep venous system, where most pulmonary emboli originate. CT venous phase images also revealed pelvic extension of DVT in six patients and isolated vena cava thrombus in one patient.

CONCLUSION

CT venous phase imaging at the time of CT pulmonary angiography is comparable with venous sonography in the evaluation of femoropopliteal DVT. The iliac veins and vena cava, vessels poorly shown on sonography but sometimes the source of significant pulmonary emboli, are also depicted by CT venography.

Potent, orally active GPIIb/IIIa antagonists containing a nipecotic acid subunit. Structure-activity studies leading to the discovery of RWJ-53308

Although intravenously administered antiplatelet fibrinogen receptor (GPIIb/IIIa) antagonists have become established in the acute-care clinical setting for the prevention of thrombosis, orally administered drugs for chronic use are still under development. Herein, we present details from our exploration of structure-activity surrounding the prototype fibrinogen receptor antagonist RWJ-50042 (racemate of 1), which was derived from a unique approach involving the gamma-chain of fibrinogen (Hoekstra et al. J. Med. Chem. 1995, 38, 1582). Our analogue studies culminated in the discovery of RWJ-53308 (2), a potent, orally active GPIIb/IIIa antagonist. To progress from RWJ-50042 to a suitable candidate for clinical development, we conducted a series of optimization cycles that employed solid-phase parallel synthesis for the rapid, efficient preparation of nearly 250 analogues, which were assayed for fibrinogen receptor affinity and inhibition of platelet aggregation induced by four different activators. This strategy produced several promising analogues for advanced study, including 3-(3,4-methylenedioxybenzene)-beta-amino acid analogue 3 (significant improved in vivo potency) and 3-(3-pyridyl)-beta-amino acid 2 (significantly improved potency, oral absorption, and duration of action). In dogs, 2 displayed significant ex vivo antiplatelet activity on oral administration at 1.0 mg/kg, 16% systemic oral bioavailability, minimal metabolic transformation, and an excellent safety profile. Additionally, 2 was found to be efficacious in three in vivo thrombosis models: canine arteriovenous (AV) shunt (0.01-0.1 mg/kg, iv), guinea pig photoactivation-induced injury (0.3-3 mg/kg, iv), and guinea pig ferric chloride-induced injury (0.3-1 mg/kg, iv). On the basis of its noteworthy preclinical data, RWJ-53308 (2) was selected for clinical evaluation.

A prospective, randomized comparison of preoperative and continuous balanced epidural or paravertebral bupivacaine on post-thoracotomy pain, pulmonary function and stress responses

Both epidural and paravertebral blocks are effective in controlling post-thoracotomy pain, but comparison of preoperative and balanced techniques, measuring pulmonary function and stress responses, has not been undertaken previously. We studied 100 adult patients, premedicated with morphine and diclofenac, allocated randomly to receive thoracic epidural bupivacaine or thoracic paravertebral bupivacaine as preoperative bolus doses followed by continuous infusions. All patients also received diclofenac and patient-controlled morphine. Significantly lower visual analogue pain scores at rest and on coughing were found in the paravertebral group and patient-controlled morphine requirements were less. Pulmonary function was significantly better preserved in the paravertebral group who had higher oxygen saturations and less postoperative respiratory morbidity. There was a significant increase in plasma concentrations of cortisol from baseline in both the epidural and paravertebral groups and in plasma glucose concentrations in the epidural group, but no significant change from baseline in plasma glucose in the paravertebral group. Areas under the plasma concentration vs time curves for cortisol and glucose were significantly lower in the paravertebral groups. Side effects, especially nausea, vomiting and hypotension, were troublesome only in the epidural group. We conclude that with these regimens, paravertebral block was superior to epidural bupivacaine.

Pleural bupivacaine placement for optimal postthoracotomy pulmonary function: a prospective, randomized study

OBJECTIVE

To determine dependent chest tube losses of bupivacaine with paravertebral versus interpleural administration, thereby helping to explain the significant differences in pulmonary function that exist between these two techniques.

DESIGN

A prospective, randomized study.

SETTING

A single hospital.

PARTICIPANTS

Twelve adult patients undergoing posterolateral thoracotomies.

INTERVENTIONS

Paravertebral or interpleural administration of bupivacaine.

MEASUREMENTS AND MAIN RESULTS

Analgesia, as assessed by visual analog pain scores and patient-controlled morphine requirements, was similar in both groups. Postoperative spirometric values were significantly better at most times with the paravertebral route of administration. Dependent chest tube bupivacaine losses were approximately four times higher in the interpleural group.

CONCLUSION

Local anesthetic on the diaphragm might actively impair respiratory function through diaphragmatic and abdominal muscle weakness, while failing to contribute to pain relief.

Extrusion/spheronization--effect of moisture content and spheronization time on pellet characteristics

As part of a larger effort aimed at optimizing the properties of pellets produced by spheronization of extruded masses, the effect of the moisture content of wet masses on extrusion force and torque was studied. The wet masses were composed of either microcrystalline cellulose (MCC) or mixtures of MCC with lactose or dicalcium phosphate. Based on the force and torque data, a moisture content "window" was defined for consistent extrusion. Moisture exerts a lubricant effect, and a moisture level of 100-120% w/w dry solid seemed necessary for the extrusion of MCC into rod-shaped, discrete pieces. Screen force clearly depended on the moisture content but was relatively insensitive to extruder speed, especially at 80% and 100% moisture content. The physical properties of pellets as a function of spheronization time were studied by sampling the material at known intervals. The percent yield, tapped density, and a two-dimensional sphericity index of an 18/20 mesh fraction of pellets were measured. Maximum yield, tapped density, and sphericity were achieved within 60 sec in the spheronizer. With increasing residence time, the shape and density were unchanged while the yield was severely reduced. Among the formulations studied, pellets with equal amounts of lactose and MCC were superior to those of pure MCC in yield, density, and sphericity. Based on these results, an outline to optimize the endpoint of the spheronization process for formulations containing MCC is suggested.

A prospective, randomized comparison of interpleural and paravertebral analgesia in thoracic surgery

We have undertaken a prospective, randomized comparison of the superficially similar techniques of interpleural and paravertebral (extrapleural) analgesia in 53 patients undergoing posterolateral thoracotomy. Local anaesthetic placed anterior to the superior costotransverse ligament and posterior to the parietal pleura produces a paravertebral block and instilled between the parietal and visceral pleurae produces an interpleural block. Patients received preoperative and postoperative continuous bupivacaine paravertebral blocks in group 1 and interpleural blocks in group 2. Premedication comprised diclofenac and morphine, and after operation all patients had regular diclofenac and patient-controlled morphine (PCM). Analgesia was assessed by visual analogue pain scores (VAS), PCM requirements, ratio of preoperative to postoperative spirometric values (PFT), rates of postoperative respiratory morbidity (PORM) and hospital stay, all recorded by blinded observers. Eight patients were withdrawn and data from 45 patients were analysed. Patient characteristics, surgery, VAS scores and PCM use were similar in both groups. PFT were significantly better (P = 0.03-0.0001) in group 1, and PORM was lower and hospital stay approximately 1 day less in this group. Five patients in group 2 became temporarily confused, probably because of bupivacaine toxicity (P = 0.02). We conclude that bupivacaine deposited paravertebrally produced greater preservation of lung function and fewer side effects than bupivacaine administered interpleurally.

Physico-mechanical characterization of the extrusion-spheronization process. Part II: Rheological determinants for successful extrusion and spheronization

Spheres are widely used as the basis for the design of multiparticulate drug delivery systems. Although the extrusion and spheronization processes are frequently used to produce such spheres, there is a lack of basic understanding of these processes and of the requisite properties of excipients and formulations. It is hypothesized that the rheological or mechanical properties of the wet mass may address the requirements of both extrusion and spheronization. The fact that certain formulations can be extruded, yet not be successfully spheronized, suggests that the two processes depend on different formulation attributes, and that there are different rheological criteria that must be met for each process to be successful. As a preliminary test of these hypotheses, methods were developed to measure the rheological behavior and mechanical properties (plastic yield value, tensile strength, yield loci) of the wet mass and/or extrudate for a model formulation system (microcrystalline cellulose, lactose, hydroxypropylmethylcellulose). The finished spheres were characterized in terms of particle size, bulk density, individual bead crushing strength, and sphericity. A Box-Behnken experimental design was employed by which the independent formulation variables could be related to the dependent rheological/mechanical properties and finished pellet characteristics. It was observed that there was a critical range of rheological/mechanical variables within which pellets having desirable criteria such as yield of 18/25 mesh cut > 60%, a shape factor > 0.85, etc., can be prepared. Screen pressure was shown to be the most critical variable affecting the yield of 18/25 mesh cut, while the yield value and tensile strength markedly influenced the shape factor. Thus, for the formulations studied, it was possible to define a "window" of rheological/mechanical properties within which both extrusion and spheronization can be successfully carried out.

Physicomechanical characterization of the extrusion-spheronization process. I. Instrumentation of the extruder

Extrusion-spheronization is a popular means of producing spheres which can be coated to form a controlled-release system. In the extrusion process, stress is necessary to force a wet mass through small orifices, and as a result, frictional heat builds up at the screen. Therefore, the quantitative measurement of the screen pressure and screen temperature is described and shown to provide objective measures of extrudability. A strain gauge load cell was mounted tangentially to the screen of a Luwa EXDS-60 extruder with a specifically fabricated holder. The load cell output was calibrated in terms of pressure inside the screen with a special rubber plug system. A fast-response thermocouple was used to measure the screen temperature. Experiments with 50/50 lactose/Avicel PH101 revealed that a linear relationship exists between the amount of water used in the granulation and the screen pressure, that the percentage open area of the screen determines the rank order of the screen pressure, and that the maximal yield of 18/25-mesh cut pellets was uniquely related to the screen pressure. Also, a high degree of correlation was observed between the screen pressure and the screen temperature.

Choledochal cyst (a case report)

A case of choledochal cyst is presented. The cyst was found in an infant aged 40 days and was treated surgically by resection followed by Roux en-Y hepaticojejunostomy.

Gas-Liquid Chromatographic Method for the Analysis of Microencapsulated Diazinon Insecticide: Collaborative Study

The determination of diazinon insecticide in Knox Out 2FM formulation was studied collaboratively by 18 laboratories. Knox Out 2FM is a flowable microencapsulated insecticide formulation containing 23 wt% active ingredient. Analytical samples are first treated by grinding in a tissue grinder and then extracted in situ with acetonitrile. This preparative step breaks the capsules and allows the active ingredient to dissolve in the solvent. Single determinations on each of 2 closely matched samples were made by flame ionization gas-liquid chromatography. The standard deviation by analysts was 0.18 wt% and the coefficient of variation was 0.76%. The combined laboratory and analyst variation gave a standard deviation of 0.59 wt% and a coefficient of variation of 2.49%. The method has been adopted official first action.