Acetate enhances citric acid production by Yarrowia lipolytica when grown on sunflower oil

It was discovered that the addition of 10 g/l acetate to a medium containing 30 g/l sunflower oil caused a drastic increase in citric acid production by Yarrowia lipolytica UOFS Y-1701 i.e. from 0.5 g/l in the absence of acetate to 18.7 g/l in the presence of acetate. Similarly, the ratio of citric acid:isocitric acid increased significantly from 1.7:1 in the absence of acetate to 3.7:1 in the presence of acetate after 240 h of growth.

Retrospective Analysis of Capecitabine and Radiation Therapy in the Treatment of Pancreatic Cancer

PURPOSE: To report our clinical experience with 25 patients receiving concurrent capecitabine and irradiation in the treatment of locally advanced or resected pancreatic cancer. METHODS AND MATERIALS: We reviewed the medical records of patients with pancreatic cancer who received treatment with capecitabine and irradiation for pancreatic cancer and received capecitabine 1200 to 1600 mg/m(2) orally twice daily Monday through Friday with concurrent radiation (5040-5400 cGy, 180 cGy, 5 days/week), followed by a 4-week rest, then 6 to 8 cycles of capecitabine alone 2000 to 2500 mg/m(2) twice daily for 14 days every 3 weeks (surgically resected), and capecitabine 2000 to 2500 mg/m(2) BID for 14 days every 3 weeks until progressive disease (unresected). RESULTS: The population consisted of 14 females and 11 males, with a median age of 64 years (range 37-80 years). Histology was adenocarcinoma in 23 patients and neuroendocrine tumor in 2 patients. One patient had resected tumor, 3 patients were resected with positive margins, 1 patient was resectable with poor performance status prohibiting resection, and 20 patients had unresected locally advanced disease. Median dose of capecitabine concurrent with radiation was 1500 mg/m(2)/day (600-1600 mg/m(2)/day) given orally in two divided doses, 5 days per week on days of treatment with radiation therapy. Patients received a median total radiation dose of 5040 cGy (4500-5040 cGy) over 6 weeks. Eleven patients were continued on capecitabine cycles after treatment with concurrent capecitabine and irradiation. The median number of cycles completed was 3, with one patient completing 8 cycles. Median survival was 14 months, with 18 patients surviving through the end of the study period. Median overall primary tumor response over the study period was -2% (-100%-100%). Five patients were taken to laparotomy after treatment based on radiographic response and two patients were successfully resected. By the end of the study period, there were 4 complete remissions, 2 partial remissions, 6 stable disease, and 13 progressive disease. Grade 3 or 4 toxicity was observed mainly with gastrointestinal symptoms including nausea, vomiting, diarrhea, and anorexia. Three patients had G3 hand-foot syndrome, 1 patient had G3 peripheral neuropathy, 1 patient had G4 gastrointestinal bleed, and 1 patient had G3 radiation enteritis. There was one death directly related to treatment secondary to uncontrolled GI bleeding. CONCLUSION: In patients with locally advanced pancreatic cancer, concurrent capecitabine and radiation had good survival response in patients and good tumor response. Toxicity of oral capecitabine was well tolerated.

Intracranial pressure monitoring in a resource-constrained environment: a technical note

Most published literature supports the use of ICP monitoring as a standard of care, though the benefit has never been conclusively proved by a prospective, randomized trial. Unfortunately, ICP monitoring is routinely performed in very few centers in India on a systematic basis. This is probably due to the common perception that it requires very sophisticated facilities and is prohibitively expensive for most patients. The author's institution was also faced with a comparable situation, and we have therefore developed a simple and economical system that is presented in practical detail. No custom-made equipment is necessary, and all disposables should be available in any hospital pharmacy. It is our hope that this will enable any center with an ICU for the management of neurosurgical patients to begin monitoring ICP. The system has been in consistent use for 3 years in our institution, and over 100 patients have been monitored successfully.

Interhemispheric subdural hematoma: an uncommon sequel of trauma

Interhemispheric subdural hematomas are relatively uncommon and usually seen in patients with bleeding disorders. They may present with signs of the falx syndrome or seizures. The management options range from craniotomy and evacuation to conservative management. We report such a case in a patient with normal bleeding parameters, which was managed with a twist drill craniostomy and drainage of the hematoma.

Ambient noise strategy: a solution for noise control?

The British Government earlier this year undertook a consultation on its proposal, announced in the Rural White Paper, to develop an Ambient Noise Strategy in England. The proposals envisage a three phase approach: In phase 1 we would aim to establish three key sets of information: information on the ambient noise climate in the country--i.e. the number of people affected by different levels of noise, the source of that noise (road, rail, airports and industry) and the location of the people affected, by producing noise maps of the main sources of noise; methods which the Government might use to assess the effects of noise--particularly regarding people's quality of life and tranquility; the techniques available to take action to improve the situation where bad or preserve it where good. In phase 2 we would aim to evaluate and identify options for prioritising the various alternatives from phase 1 in terms not only of costs and benefits but also time-scales and synergies and conflicts with other Government priorities including economic and social issues. An optimal policy reduces noise at lowest net cost, whilst capturing as many synergistic benefits, and minimising any potentially adverse impacts. Decision makers need to ensure that the impacts of the noise policies do not cost society more than the benefits expected. A recent study undertaken by the Government, looked at how a cost-benefit type framework could be used, with noise maps, to help inform such decisions. Finally, in phase 3, the Government would need to agree on the necessary policies to move towards the desired outcome--i.e. the National Ambient Noise Strategy itself. The results of the consultation are expected to be published later this year.

Surfactant treatment for ventilation-induced lung injury in rats: effects on lung compliance and cytokines

The objective of this study was to determine if exogenous surfactant therapy could prevent the harmful effects of ventilation at high tidal volumes without positive end-expiratory pressure (PEEP). Rats were randomized to either a nontreated control group (8 mL/kg 4 cm H2O PEEP), a nontreated injuriously ventilated group (20 mL/kg 0 cm H2O PEEP) or a treatment group of either 50 mg/kg, 50 mg/kg + 5% surfactant-associated protein A, 100 mg/kg exogenous surfactant followed by injurious ventilation. Isolated lungs from animals in all 5 groups were ventilated in a humidified box at 37 degrees C for 2 hours. Pressure-volume curves and light microscopy showed that surfactant treatment reduced the ventilation-induced lung injury (VILI). Inflammatory cytokines (tumor necrosis factor-alpha [TNFalpha], interleukin [IL]-1beta, and IL-6) in the lavage were significantly higher in injuriously ventilated lungs compared to the control group. However the 3 treatment groups had cytokine concentrations that were similar to the injuriously ventilated group. We conclude that surfactant treatment is beneficial in preventing VILI; however, it does not prevent the release of inrflammatory cytokines during mechanical ventilation.

Mechanical ventilation of isolated septic rat lungs: effects on surfactant and inflammatory cytokines

The effects of mechanical ventilation (MV) on the surfactant system and cytokine secretion were studied in isolated septic rat lungs. At 23 h after sham surgery or induction of sepsis by cecal ligation and perforation (CLP), lungs were excised and randomized to one of three groups: 1) a nonventilated group, 2) a group subjected to 1 h of noninjurious MV (tidal volume = 10 ml/kg, positive end-expiratory pressure = 3 cmH(2)O), or 3) a group subjected to 1 h of injurious MV (tidal volume = 20 ml/kg, positive end-expiratory pressure = 0 cmH(2)O). Nonventilated sham and CLP lungs had similar compliance, normal lung morphology, surfactant, and cytokine concentrations. Injurious ventilation decreased compliance, altered surfactant, increased cytokines, and induced morphological changes compared with nonventilation in sham and CLP lungs. In these lungs, the surfactant system was similar in sham and CLP lungs; however, tumor necrosis factor-alpha and interleukin-6 levels were significantly higher in CLP lungs. We conclude that injurious ventilation altered surfactant independent of sepsis and that the CLP lungs were predisposed to the secretion of larger amounts of cytokines because of ventilation.

Effects of mutations at the stambh A locus of Drosophila melanogaster

We report novel findings on the cytogenetic location, functional complexity and maternal and germline roles of the stambh A locus of Drosophila melanogaster. stmA is localized to polytene bands 44D1.2 on 2R. stmA mutations are of two types: temperature-sensitive (ts) adult and larval paralytic or unconditional embryonic or larval lethal. Twelve alleles reported in this study fall into two intragenic complementing groups suggesting that stmA is a complex locus with more than one functional domain. Some unconditional embryonic lethal alleles show a 'neurogenic' phenotype of cuticle loss accompanied by neural hypertrophy. It is shown that embryos of ts paralytic alleles also show mild neural hypertrophy at permissive temperatures while short exposure to heat induces severe cuticle loss in these embryos. stmA exerts a maternal influence over heat-induced cuticle loss. Unconditional embryonic lethal alleles of stmA are also germline lethal.

Comparative evaluation of tensile bond strength of denture base resins to surface pretreated cobalt chromium base metal alloys--an in vitro study

This study was undertaken to evaluate the tensile bond strength of acrylic resins to surface pretreated Cobalt-chromium base metal alloy. A total of 60 tensile bar specimens were prepared. One half of the bar was cast in cobalt-chromium alloy and the other half made of denture base resins attached to the alloy following surface pretreatment. Two denture base resins and five surface pre-treatments were used which included sandblasting, acid etching, use of metal adhesive primers and the combination of the above mentioned modes. Gradual axial loads were applied on the tensile bar specimen mounted on a Hounsfield tensometer till bond failure was evident. Statistical evaluation was done using Mann-Whitney U test. The study results indicate that the bond strength in those specimens wherein a combination of sandblasting, acid etching and priming was done as surface pretreatment, showed the maximum values as compared to the other groups.

Relative contribution of hemopoietic and pulmonary parenchymal cells to lung inducible nitric oxide synthase (inos) activity in murine endotoxemia

Acute lung injury is an important feature of sepsis and increased iNOS expression and NO production contribute to the pathogenesis of this syndrome. We generated bone marrow-transplanted chimeric mice with iNOS expression limited to either inflammatory or pulmonary parenchymal cells, and assessed pulmonary iNOS activity and systemic levels of NO metabolites in an endotoxemic model of sepsis. We found that while both pulmonary parenchymal cells and inflammatory cells contribute to the increased lung iNOS activity in endotoxemia, pulmonary parenchymal cells contribute to a significantly greater degree. Using measurement of plasma NO(-)(x), whole body NO production was assessed in this model. We found that the main source of NO(-)(x) was again, parenchymal cells and not inflammatory cells. This is the first study to demonstrate that most of the increased NO production in this model of endotoxemic sepsis derives from parenchymal cells rather than inflammatory cells.

Pedicled rhinotomy for clival chordomas invaginating the brainstem

Object

Clival chordomas are frequently midline lesions whose posterior growth may breach the dura and invaginate the brainstem. This precludes safe delivery of potentially curative high-dose fractionated proton radiotherapy. To avoid this problem, the authors performed pedicled rhinotomy to resect chordomas in 10 patients.

Methods

Pedicled rhinotomy is a midface transnasal route to the intercarotid sella and clivus from the tuberculum sellae to the mid-C-2 level. It involves a lateral rhinotomy incision, osteotomies of nasal bones and cartilage, lateral rotation of the nose, removal of the nasal septum and medial maxillary walls, opening of ethmoid and sphenoid sinuses, and dissection of nasopharynx and oropharynx to expose the clivus and craniovertebral junction. Tumors involving the sella, medial cavernous sinuses, middle and lower clivus, and C-1 arch and dens can be removed even if they traverse the dura. Closure involves dural repair, grafting of fat and split-thickness skin, rotation of a vascularized mucosal pedicle, and reattachment of nasal cartilage.

Ten clival chordomas in adult patients were surgically removed via a pedicled rhinotomy approach. Seven patients had previously undergone a total of nine skull base procedures. In eight of the 10 patients, tumors compressing the brainstem were completely removed using this technique. One patient required an additional subtemporal resection of a suprasellar tumor before definitive radiotherapy could be undertaken. No patient sustained any new neurological deficit; in eight patients headache, diplopia, or hemiparesis improved. One patient developed postoperative cerebrospinal fluid leakage and meningitis that were successfully treated with antibiotic agents and shunt placement.

Conclusions

Pedicled rhinotomy provides excellent shallow-field exposure of midline clival chordomas and permits relief of brainstem compression and the postoperative administration of potentially curative proton beam irradiation.

Effects of mechanical ventilation of isolated mouse lungs on surfactant and inflammatory cytokines

Mechanical ventilation of the lung is an essential but potentially harmful therapeutic intervention for patients with acute respiratory distress syndrome. The objective of the current study was to establish and characterize an isolated mouse lung model to study the harmful effects of mechanical ventilation. Lungs were isolated from BalbC mice and randomized to either a nonventilated group, a conventionally ventilated group (tidal volume 7 mL x kg(-1), 4 cm positive endexpiratory pressure (PEEP)) or an injuriously ventilated group (20 mL x kg(-1), 0 cm PEEP). Lungs were subsequently analysed for lung compliance, morphology, surfactant composition and inflammatory cytokines. Injurious ventilation resulted in significant lung dysfunction, which was associated with a significant increase in pulmonary surfactant, and surfactant small aggregates compared to the other two groups. Injurious ventilation also led to a significantly increased concentration of interleukin-6 and tumour necrosis factor-a in the lavage. It was concluded that the injurious effects of mechanical ventilation can effectively be studied in isolated mouse lung, which offers the potential of studying genetically altered animals. It was also concluded that in this model, the lung injury is, in part, mediated by the surfactant system and the release of inflammatory mediators.

Modulation of high-affinity IgE receptor expression in blood monocytes: opposite effect of IL-4 and glucocorticoids

BACKGROUND

The expression of high-affinity IgE receptor (Fc epsilon RI) is increased in blood monocytes (BMs) from allergic patients compared with those of nonatopic subjects (NASs).

OBJECTIVE

We investigated the in vitro effect of cytokines involved in allergic diseases on the modulation of Fc epsilon RI expression in BMs from allergic asthmatic patients (AAPs) and NASs. The influence of in vitro and in vivo treatments with glucocorticoids (GCs) was also assessed.

METHODS

Fc epsilon RI alpha-chain expression on BMs evaluated by flow cytometry analysis was studied ex vivo in AAPs treated or not with GCs and in NASs. IgE receptor expression was also evaluated in vitro with or without stimulation by IL-4, IL-13, GM-CSF, and/or GCs. Messenger (m)RNA expression was also analyzed with RT-PCR.

RESULTS

The expression of the Fc epsilon RI alpha chain was significantly increased in BMs from untreated patients, with AAPs compared with NASs (P <.05). In steroid-treated AAPs Fc epsilon RI alpha-chain expression returned to the level found in BMs from NASs. In vitro addition of IL-4 induced a dose-dependent increase in Fc epsilon RI alpha-chain expression on BMs from NASs, and this effect was significantly enhanced with BMs from AAPs. Fc epsilon RI alpha-chain mRNA was significantly upregulated by IL-4, whereas the beta chain was always undetectable. The gamma chain was not modulated by IL-4. Similar findings were obtained with IL-13. In contrast with CD23 expression, GM-CSF alone or in coincubation with IL-4 had no effect on Fc epsilon RI alpha-chain expression in BMs. Lastly, GCs significantly inhibited in vitro the IL-4-induced Fc epsilon RI alpha-chain expression (P <.05).

CONCLUSION

Two different pathways by which Fc epsilon RI alpha-chain expression was modulated in BMs were identified: (1) the enhancing effect of IL-4 and IL-13 and (2) the inhibitory effect of GCs. Modulation of Fc epsilon RI alpha-chain expression on BMs may affect their capacity to regulate allergic inflammation.

Response of viral hepatitis B and C to interferon alpha treatment: Possible role of MGP-Positive lymphoid cells

Fifty-six needle liver biopsies from 28 patients with viral hepatitis B (15 cases) and hepatitis C (13 cases) treated with Interferon alpha for a minimum of six months were studied with the aim of determining the role of MGP-positive lymphoid cell infiltrates in the response to treatment with interferon. Besides assessing the MGP-positive cells, the following parameters were assessed and graded: (i) Inflammation in and around the portal tracts, (ii) fibrosis, nodularity and cirrhosis, (iii) piece-meal necrosis (inter-face hepatitis), (iv) lobular activity, (v) stainable iron. Sec-tions were stained with H&E, PAS, PASD, Perl, Masson Trichrome and MGP (Methyl Green Pyronin). All the parameters were graded 1 to 3 except stainable iron which was noted as present or absent.

Fourteen patients (50%) demonstrated histological evidence of a response to treatment. Seven of these showed a very pronounced response with the post treatment liver bi-opsies returning almost to normal. Five of the seven, 27.8% of all MGP stained cases and 71% of all brisk responses, contained ten or more MGP-positive lymphoid cells in the portal tracts.

In contrast, the non-responsive and worsened cases con-tained less than five MGP-positive cells as well as a pre-dominantly small mature lymphocytic infiltrate in the por-tal tracts.

Severity of piece-meal necrosis, lobular activity, portal tract inflammation, the presence or absence of stainable iron, were not of predictive value in the response of viral hepatitis to treatment with interferon alpha.

It appears that MGP-positive lymphoid cells, most prob-ably immune competent activated lymphoid cells, have a positive influence on, and are of predictive value for, the response to treatment of viral hepatitis B and C with inter-feron alpha.

Onychomycosis caused by trichosporon beigelii

Onychomycosis is caused primarily by dermatophytes, candida sp and nondermatophytic moulds. Trichosporon beigelii is an inhabitant of soil and occasionally is part of the normal flora of human skin. A 38- year- old male presented with brown discolouration of both big toes since one year. Repeated KOH preparation and culture of nail scrapings and clippings yielded Trichosporon beigelii, which was identified by standard techniques.

Haematopoietic tissue presenting as a sphenoid sinus mass: case report

We report an incidentally discovered mass in the sphenoid sinus in a patient with beta thalassaemia and sickle-cell disease which proved to be an isolated site of extramedullary haematopoiesis in the skull.

[Study of the behavior of the vegetative meristem of alfa (Stipa tenacissima L.). Cytological and histological approaches]

The biological and cytological studies of the vegetative meristem of Stipa tenacissima L. gave clear indication about its structure. It was similar to what was previously described in several species. This meristem showed an axial apical zone constituted by sommital cells of both tunica and corpus, a sub-apical lateral zone, very chromophilous, representing the initial ring and a medullar meristem. The cytofluorimetric determination of DNA in interphasic nuclei of these three zones revealed that the nuclei of the apical and lateral zones were in S phase, announcing the beginning of mitosis and meaning that these zones were the centers of the foliar initiation. The medullar meristem was in dormancy: all the nuclei were in G1 phase.

Stress variations in recast Ni-Cr alloy--a finite element analysis

A finite element analysis was carried out to analyse the stress variations in a mandibular posterior fixed partial denture (FPD), made of recast nickel-chromium alloy. A two dimensional finite element model was developed and then analysed with STAAD III/ISDS program with an occlusal load of 1 kg applied to the casting surface. The analysis revealed that the connectors experienced maximum stresses and the generated stress values decreased within the fixed partial denture made of recast Ni-Cr alloy. It seemed unlikely that FPD inspite of being made of recast alloy might fail before the other tissue components show signs of degeneration thus establishing the potential for recycling the Ni-Cr alloy in actual dental practice.

Comparison of IgE and IgG antibody-dependent cytotoxicity in vitro and in a SCID mouse xenograft model of ovarian carcinoma

Allergic reactions are mediated by IgE antibodies bound to high-affinity receptors on mast cells in peripheral tissues and are characterized by their immediacy and hypersensitivity. These properties could also be advantageous in immunotherapy against cancer growth in peripheral tissues. We have constructed chimeric IgE and IgG1 antibodies with murine V regions and human C regions corresponding to the MOv18 monoclonal antibody against the human ovarian tumor-associated antigen, folate binding protein. The antibodies exhibited the expected binding affinities for antigen and Fc receptors, and effector activities with human basophils and platelets in vitro. The protective activities of MOv18-IgE and MOv18-IgG1 were compared in a SCID mouse xenograft model of ovarian carcinoma. The beneficial effects of MOv18-IgE were greater and of longer duration than those of MOv18-IgG1. Our results suggest that the allergic reaction could be harnessed for the suppression of ovarian tumors.

Comparative evaluation of the effect of simulated porcelain firing cycle on the mechanical properties and microstructure of base metal ceramic alloys

A comparison of mechanical properties and microstructure of four metal ceramic alloys in as-cast and heat-treated conditions resulted in significant differences. The alloys that were tested included two nickel-based and two cobalt-based metal ceramic alloys. Mechanical properties tested included strength, percent elongation and hardness. Ten tensile bars were cast for each alloy. Five of the ten bars for each alloy were randomly selected for heat treatment with the simulated porcelain firing cycle. Results indicated that the nickel-based alloys were weakened by the heat treatment and showed a decreased hardness and an increased elongation. The effects of heat treatment on the strength of cobalt-based alloys were variable, showing an increase in hardness and a decrease in elongation. Differences in mechanical properties exhibited by the alloys were related to compositional and microstructural changes.

The SAPHO syndrome in children: a rare cause of hyperostosis and osteitis

The SAPHO syndrome is a rare constellation of signs and symptoms characterized by synovitis, acne, pustulosis, hyperostosis, and osteitis. The most common musculoskeletal complaints are hyperostosis, causing pain, tenderness, and swelling of the anterior chest wall, although any part of the axial and appendicular skeleton may be affected. There is a great degree of variability in the dermatologic involvement of this syndrome. A combination of clinical, radiographic, and pathological investigation is required to establish the correct diagnosis. No single treatment has been found to be effective, although nonsteroidal antiinflammatory drugs have been the most frequently used. Because there is no mention of SAPHO syndrome in the English orthopaedic literature, and pediatric orthopaedic surgeons may be the first caregivers to treat these children, we thought it appropriate to share our experience with a 5-year-old boy with SAPHO syndrome recently under our care.

Production of chemokines and proinflammatory and antiinflammatory cytokines by human alveolar macrophages activated by IgE receptors

BACKGROUND

The alveolar macrophage (AM) expresses the low affinity IgE receptor and has the ability to produce not only several proinflammatory cytokines (TNF-alpha, IL-1, IL-6) but also antiinflammatory cytokines (IL-1 receptor antagonist [IL-lra], IL-10), chemokines (IL-8, monocyte chemotactic protein-1 [MCP-1]), and macrophage inflammatory protein-1alpha (MIP-1alpha).

OBJECTIVE

The aim of this study was to evaluate the capacity of the AM from patients with allergic asthma and control subjects to produce chemokines and antiinflammatory versus proinflammatory cytokines after activation by IgE receptors and to define the role of CD23 in this activation.

METHODS

AMs were collected by bronchoalveolar lavage from 13 patients with allergic asthma and 14 healthy subjects. Adherent AMs were activated either by the successive addition of IgE and anti-IgE or by monoclonal mouse IgG anti-CD23 or by a control monoclonal mouse antibody. TNF, IL-1beta, IL-1ra, IL-10, IL-8, MCP-1, and MIP-1alpha levels were evaluated in supernatants of AMs incubated for 18 hours and in some cases after 4 hours of incubation.

RESULTS

Activation by IgE and anti-IgE antibodies significantly increased the production of TNF, IL-1beta, IL-8, MCP-1, MIP-lalpha, and IL-10 in both control subjects and patients with asthma, whereas the increase for IL-1ra was only significant for the control subjects. Whereas F(ab) fragments of anti-CD23 antibodies inhibited IgE plus anti-IgE-induced cytokine production, activation by monoclonal IgG anti-CD23 antibodies reproduced the effect of IgE immune complexes. At 4 hours, the secretion of proinflammatory cytokines was increased by activation by IgE receptors, in contrast to antiinflammatory cytokines. In addition, analysis of the balance between proinflammatory and antiinflammatory cytokines showed that IgE-dependent activation largely favored the proinflammatory cytokines, particularly in patients with asthma.

CONCLUSION

IgE-dependent activation by the FcepsilonRII receptor upregulates the synthesis of both chemokines and antiinflammatory cytokines in addition to proinflammatory cytokines. However, AMs from patients with allergic asthma may promote airway inflammation after activation by IgE receptors through its preferential effect on proinflammatory cytokines.

Pathologic-spontaneous-rupture of the spleen as a presenting sign of splenic T-cell lymphoma--case report with review

A 39 year-old man presented for surgery with epigastric pain, tachycardia, hypotension and a progressive decrease of hemoglobin due to blood loss. Immediate abdominal ultrasonography followed by prompt paracentesis revealed massive intraperitoneal hemorrhage. During emergency laparotomy, a linear, actively bleeding rupture of an enlarged spleen was found and splenectomy was performed. The patient survived and the post-operative course was uneventful. Histopathology of the spleen as well as bone marrow biopsy confirmed the diagnosis of T-Cell lymphoma. Chemotherapy was initiated 3 weeks after surgery. To the best of our knowledge, this is the first reported case of previously undiagnosed T-Cell lymphoma presenting as pathologic rupture of the spleen.

Comparative evaluation of effect of auxiliary retentive features on retention of complete cast crowns in teeth with adequate and inadequate crown height. An invitro study

This study was done to evaluate the retention of complete cast crowns in teeth with adequate and inadequate crown height and to evaluate the effects of auxiliary retentive features on retention from of complete cast crowns. Thirty-six extracted human maxillary first premolars were obtained. In one group teeth were prepared to a constant height of 3.5 mm and in the second group teeth were prepared to a constant height of 2.5 mm. Each group was further subgrouped into three. In the first subgroup teeth were prepared conventionally, second subgroup proximal grooves were incorporated and in the third subgroup proximal boxes were incorporated. Tensional forces required to dislodge each cemented casting from its preparation was used for comparison of retention quality. These results were then subjected to an analysis of variance (ANOVA). The retention of crown in tooth with adequate crown height were statistically highly significant (P < 0001), compared to inadequate crown height and in boxes compared to grooves and conventional preparation.

Characterizing alterations in the pulmonary surfactant system in a rat model of Pseudomonas aeruginosa pneumonia

Bacterial pneumonia remains a significant cause of patient morbidity and mortality worldwide. Pulmonary surfactant serves to maintain homeostasis in the lung through the maintenance of alveolar stability and the regulation of the alveolar immune response. The purpose of this study was to characterize the lung injury and associated surfactant alterations in a rat model of acute Pseudomonas aeruginosa pneumonia. Pneumonia was induced in male Sprague-Dawley rats via intratracheal injection of 0.2 ml, phosphate-buffered saline (PBS) containing P. aeruginosa (6x10(8) colony-forming units x mL(-1)). Control animals received 0.2 mL sterile PBS. Twenty-four hours after inoculation, the pneumonia group (PN) exhibited clinical signs of pneumonia including deficits in gas exchange, leukopenia and elevated arterial lactate levels. Morphological assessment confirmed the presence of pneumonia with airspaces filled with polymorphonuclear cells. Lung homogenate analysis demonstrated evidence of bacterial colonization of pneumonic lung tissue. Lung compliance was also significantly lower in the PN group. Lung lavage analysis of PN rats revealed the pooled surfactant levels to be lower and the surfactant function reduced compared to control rats. Surfactant composition was also found to be altered in PN rats. These results demonstrate that in Pseudomonas aeruginosa pneumonia, the pulmonary surfactant system is both poorly functioning and reduced in quantity. These alterations may contribute to the lung dysfunction characteristic of this disorder.

p300/MDM2 complexes participate in MDM2-mediated p53 degradation

Control of p53 turnover is critical to p53 function. E1A binding to p300/CBP translates into enhanced p53 stability, implying that these coactivator proteins normally operate in p53 turnover control. In this regard, the p300 C/H1 region serves as a specific in vivo binding site for both p53 and MDM2, a naturally occurring p53 destabilizer. Moreover, most of the endogenous MDM2 is bound to p300, and genetic analysis implies that specific interactions of p53 and MDM2 with p300 C/H1 are important steps in the MDM2-directed turnover of p53. A specific role for p300 in endogenous p53 degradation is underscored by the p53-stabilizing effect of overproducing the p300 C/H1 domain. Taken together, the data indicate that specific interactions between p300/CBP C/H1, p53, and MDM2 are intimately involved in the MDM2-mediated control of p53 abundance.

Insight into the environment of tryptophan in a hydrophobic model peptide upon aggregation and interaction with lipid vesicles: a steady state and time resolved fluorescence study

Fluorescence spectroscopy is extensively used to monitor binding of peptides to lipid vesicles as well as orientation in the lipid bilayer. In steady-state fluorescence, the emission characteristics of intrinsic and extrinsic fluorophores, which are sensitive to environment are monitored. Life time measurements should yield useful information about the location and flexibility of fluorophores, as these factors have a significant effect on the life times. However, studies on protein structure and dynamics indicate that interpretation of life-time data is complicated (Beechem. J.M. and Brand, L. (1985) Annu. Rev. Biochem. 54, 43-71). Hence, simple well-defined systems should help in interpretation of life time data, especially in lipid-peptide interactions. In order to examine how fluorescence characteristics of tryptophan and anthroyl group would reflect molecular details of peptide aggregation and lipid-peptide interaction, studies have been carried out on a model hydrophobic peptide and its fatty acylated derivative. Steady-state fluorescence measurements suggest that: (1) the fatty acyl chain attached to an amino acid associates with the peptide chain in aqueous environment. (2) In the lipid bilayer, the acyl chain is oriented perpendicular to the lipid bilayer surface with the peptide chain at an angle to it. Analysis of the fluorescence decay of tryptophan indicates the predominance of a very short life-time component (<1ns) in aqueous environment and lipid-vesicles. Since the preexponentials were not negative, it is unlikely that this is due to extensive deactivation process. We attribute the observation of the low life time component to predominance of one rotamer around (C alpha-C beta)bond of tryptophan in aqueous and lipid environments. Our investigations suggest that fluorescence life time data need to be complemented with steady state measurements to get an insight into details of lipid-peptide interaction.

Expression and functions of the high-affinity IgE receptor on human platelets and megakaryocyte precursors

Platelets can be activated by IgE and are therefore involved in IgE-mediated effector mechanisms against parasites and in allergic disorders. Here we show that, besides the low-affinity IgE receptor (Fc epsilon RII/CD23), platelets express the high-affinity receptor for IgE (Fc epsilon RI). Flow cytometry analysis revealed the existence of surface Fc epsilon RI on platelets with a large heterogeneity among individual donors, and a low proportion of platelets co-expressing Fc epsilon RI and FC epsilon RII/CD23. Northern hybridization and reverse transcription polymerase chain reaction confirmed the presence of mRNA encoding the alpha, beta and gamma chains of Fc epsilon RI in platelets and in their megakaryocytic precursors. Cross-linking of Fc epsilon RI with monoclonal antibody (mAb) to alpha chain using either the whole molecule or F(ab')2 triggered platelet cytotoxicity for Schistosoma mansoni larvae. Anti-Fc epsilon RII/CD23 mAb significantly inhibited IgE- or Fc epsilon RI-mediated cytotoxicity, indicating down-regulatory effects of Fc epsilon RII/CD23 on Fc epsilon RI-dependent functions. These results demonstrate functional properties for Fc epsilon RI on platelets and indicate unsuspected interactions between the low- and the high-affinity IgE receptors.

Alterations of the endogenous surfactant system in septic adult rats

Sepsis is the most common factor leading to the acute respiratory distress syndrome (ARDS) and is associated with the highest mortality rate. It has been suggested that the pulmonary surfactant system is altered and contributes to the lung dysfunction associated with ARDS. The objective of this study was to characterize the lung injury, specifically the endogenous surfactant system in septic adult rats. Sepsis was induced in male Sprague-Dawley rats by cecal ligation and perforation and resulted in significant increases in heart rates, respiratory rates, and lactate levels along with positive blood cultures in septic animals compared with a sham control group. Two distinct septic groups were developed, a septic group and a sepsis with lung injury (septic+LI) group. The septic group had no significant differences in oxygenation compared with the sham group, whereas the septic+LI group had significantly lower PaO2 and higher A-a gradient values compared to both the sham and septic groups. The total surfactant pool size was significantly lower in the septic+LI group compared with the sham group. The small surfactant aggregate to large surfactant aggregate ratio was significantly lower in the septic group and was further reduced in the septic+LI group. There were also significantly higher levels of surfactant protein A (SP-A) in both septic and septic+LI groups compared to the sham group. These results demonstrated that the endogenous surfactant system was altered in systemic sepsis without lung dysfunction and is further altered when a lung injury is present.

A new X linked recessive syndrome of mental retardation and mild dysmorphism maps to Xq28

Efforts to understand the genetic basis of mental retardation are greatly assisted by the identification of families with multiple relatives with mental retardation that clinical geneticists encounter in the routine practice of their profession. Here we describe a linkage study of a four generation family in which X linked recessive mental retardation (XLMR) is associated with minor dysmorphism and premature death of the affected males. Microsatellite based polymorphic loci evenly spaced over the entire X chromosome were used initially to detect linkage to Xq28. Further analysis identified a haplotype of Xq28 markers bounded proximally by locus DXS1113 and distally by DXS1108 that cosegregated with XLMR in this family. Two point lod scores > 3.0 provided strong evidence that the gene locus responsible for XLMR in this family is within this 7 Mb region of Xq28. The minor anomalies noted in some affected males were not distinctive enough to suggest a unique syndrome. None of our patients had features of the Waisman-Laxova syndrome or the PPM-X syndrome. The possibility of allelism with any of the five other non-specific XLMR syndromes (MRX3, MRX16, MRX25, MRX28, and MRX41) mapped to Xq28 could not be excluded. While the recognition of a gene responsible for this disorder needs much additional work, multiple female relatives at risk in this family benefit immediately from knowing their genotype and heterozygotes will have the opportunity to undergo prenatal diagnosis.

Is the role of fatty acids only to provide membrane-anchor in fatty acylated proteins?

A large number of proteins on the eukaryotic cell surface that play an important role in cellular metabolism are covalently modified with fatty acids like palmitic and myristic acids. While some of these proteins have transmembrane spanning segments, many others do not. Early hypothesis was that this co or posttranslational modification helped in membrane-association and the fatty acyl chain provided a stable membrane anchor. We have investigated the structure of peptides with these modifications and also their interaction with membranes. Our results indicate that the fatty acylated peptides, especially when the peptide segment is not hydrophobic, do not have strong affinity for membranes. The recent observations about the dynamic nature of fatty acid acylation as well as the importance of protein-protein interactions for function in fatty-acylated proteins suggest that membrane-association may involve factors other than only the fatty acid, either myristic or palmitic. Revised models depicting the possible role of fatty acids in modulating protein-protein interaction and their dynamics is presented.

Xp pseudoautosomal gene haploinsufficiency and linear growth deficiency in three girls with chromosome Xp22;Yq11 translocation

Colony stimulating factor-2 receptor alpha (CSF2RA) and interleukin-3 receptor alpha (IL3RA), two genes from the chromosome Xp and Yp pseudoautosomal region (PAR), have been suggested as candidate genes for short stature in Turner syndrome. We report three girls with X;Y translocation (46,X,der(X)t(X;Y)(p22;q11) initially detected by amniocentesis. The terminal portion of the X chromosome distal to the translocation breakpoint at Xp22 was deleted on the derivative X chromosome in all three patients. Each had normal stature at birth, with greater than expected deceleration of growth velocity by the second year. Using fluorescence in situ hybridisation (FISH), we have shown deletion of the CSF2RA and IL3RA loci on the derivative X chromosomes of all three patients. The role of CSF2RA and IL3RA haploinsufficiency in linear growth and final adult stature is discussed. Additional studies, particularly of molecular deletions within the PAR, are needed to improve our understanding of the role of these and other PAR loci in the genetic control of adult stature.

Interactions between endothelial cells and effector cells in allergic inflammation

The local inflammatory response that occurs after repeated exposure to allergens or during the late-phase reaction results from a complex network of interactions between inflammatory cells (mast cells, eosinophils, macrophages) and resident cells belonging to the lung structure itself like EC, fibroblasts, or bronchial epithelial cells. Among structural cells, EC represent critical elements: they control leukocyte traffic through the expression of adhesion molecules; they are also able to amplify leukocyte activation through the production of proinflammatory cytokines like IL-1, IL-6, or of chemokines like IL-8. Three cell models have been successively considered. When supernatants of alveolar macrophages, recovered from patients exhibiting a late asthmatic response after allergen exposure, were tested on HUVEC cultures, a TNF alpha-dependent ICAM-1 and E-selectin overexpression was observed. Among mast-cell mediators, histamine was already known to induce a rapid and transient expression of P-selectin; we demonstrated that histamine also induced an IL-6 and IL-8 secretion by HUVEC, which was concentration-dependent and inhibited by H1 or H2 receptor antagonists. Finally purified eosinophils obtained from donors with hypereosinophilia similarly increased adhesion molecule expression and chemokine production. The precise nature of the eosinophil product(s) involved in this process is currently under investigation.

Acylation of proteins: recent advances

The biochemistry and cell biology of covalent attachment of the fatty acids palmitic and myristic to proteins has been the subject of extensive investigations during the past fifteen years. While the site of attachment of fatty acids and the primary structure of proteins around the acylation site have been extensively documented, the exact role of the fatty acids have only been speculated upon. Since fatty acids would prefer to be associated with the lipid bilayer of membranes, it has been assumed that the role of the fatty acid is to provide a stable membrane anchor. This review discusses recent reports in the area of fatty acylation which suggests roles for the fatty acid other than that of a stable membrane anchor.

Venom immunotherapy modulates interleukin-4 and interferon-gamma messenger RNA expression of peripheral T lymphocytes

The mechanism by which specific immunotherapy exerts its beneficial effect remains unclear. In order to evaluate the influence of venom immunotherapy on the T-cell cytokine pattern of allergic reactions, we studied interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) mRNA expression of peripheral T lymphocytes from 12 patients undergoing rush venom desensitization, before treatment at Day 0 (D0), at Day 15 (D15) and Day 90 (D90) after treatment, and from seven controls. Antigen-specific T-cell proliferation was also determined. Cytokine mRNA expression was evaluated using in situ hybridization, 24 hr after culture of peripheral T cells with medium, venom, or an unrelated allergen. Allergen-induced T-cell proliferation decreased at D15 and D90 of rush immunotherapy (P < or = 0.02). In venom-stimulated cultures of the patient group, there was a decrease in IL-4 mRNA-positive cells at D15 and D90 (P < or = 0.001). Before desensitization, IFN-gamma mRNA expression was lower in patients than in controls and did not increase after in vitro allergen stimulation. In contrast, after immunotherapy, spontaneous IFN-gamma mRNA expression increased, but only at D90 (P < or = 0.001). The cytokine pattern observed at D90 after immunotherapy was similar to that observed in control subjects. In conclusion, venom immunotherapy induced an altered cytokine mRNA pattern in allergen-stimulated T cells which was dissociated from the early changes of allergen-induced T-cell responsiveness.

Timing of exogenous surfactant administration in a rabbit model of acute lung injury

The purpose of this study was to evaluate early vs. late administration of exogenous surfactant in an adult rabbit model of acute lung injury. Lung injury was induced by repetitive whole lung saline lavage and subsequent mechanical ventilation. Bovine lipid extract surfactant was instilled either 1 (Early) or 4 h (Late) after the last lavage. Animals were monitored for 7 h after the last lavage. Although arterial PO2 values increased significantly immediately after treatment in both the Early and Late groups, this improvement was not sustained in the Late group. There was also a higher incidence of pneumothoraxes in the Late group vs. both the Early group and a nontreated control group. The ratio of poorly functioning small surfactant aggregates to superior functioning large aggregates was higher in the Late group compared with the Early group. Morphological analysis revealed that early surfactant treatment prevented the progression of lung injury over time. We conclude that administration of exogenous surfactant at an early time point in lung injury resulted in superior responses compared with later treatments.

Risk of human immunodeficiency virus type 1-related neurologic disease in a cohort of intravenous drug users

BACKGROUND

Although the proportion of cases of acquired immunodeficiency syndrome related to intravenous drug use has increased dramatically over the past decade, there has been no longitudinal examination of primary neurologic disease in this group.

OBJECTIVE

To study the development of neurologic disease in human immunodeficiency virus (HIV)-negative and HIV-positive men and women who were intravenous drug users over a 3.5-year period.

DESIGN

Prospective observational cohort study.

SETTING

Subjects were recruited from an infectious disease clinic at a New York City Hospital or from a methadone maintenance program.

PARTICIPANTS

Ninety-nine HIV-negative (62 men and 37 women) and 124 HIV-positive (85 men and 39 women) intravenous drug users volunteered.

MAIN OUTCOME MEASURE

The development of clinically significant manifestations in six neurologic domains.

RESULTS

With multivariate adjustment for current and past substance abuse, age, education, and head injury, we examined the odds of developing HIV-related neurologic disease. Extrapyramidal signs and reduced motor ability became increasingly apparent over time in HIV-infected men as their CD4 cell count declined and as the subjects developed the acquired immunodeficiency syndrome. Fewer neurologic signs were seen in the women.

CONCLUSIONS

The impact of HIV infection among intravenous drug users parallels that in homosexual men and is independent of alcohol and other drug use.

X-linked myotubular myopathy: clinical observations in ten additional cases

X-linked myotubular myopathy (XLMTM) is a recessively inherited disorder, lethal to males in the first months of life. Since the first report in 1969, at least 90 cases have been described in the literature. Diagnosis is confirmed by muscle biopsy. Linkage studies have localized the disorder to the Xq28 region, close to the loci for X-linked hydrocephalus and MASA syndrome. We report on 10 additional cases of XLMTM from six different families. In addition to classic clinical features of XLMTM, our patients showed interesting associated findings which included birth length > 90th centile and large head circumference with or without hydrocephalus in 70%, narrow, elongated face in 80%, and slender, long digits in 60% of cases. There was concordance in the occurrence and severity of hydrocephalus in most sib pairs. These features in a "floppy" male infant serve as clues for early clinical diagnosis of XLMTM, which can then be confirmed by muscle biopsy. Development of polyhydramnios was observed in the third trimester of an at-risk dizygotic twin gestation monitored by serial sonography with confirmation of XLMTM at birth.