Capillary filling dynamics of polymer melts in a bicontinuous nanoporous scaffold

Polymer infiltrated nanoporous gold is prepared by infiltrating polymer melts into a bicontinuous, nanoporous gold (NPG) scaffold. Polystyrene (PS) films with molecular weights (Mw) from 424 to 1133 kDa are infiltrated into a NPG scaffold (∼120 nm), with a pore radius (Rp) and pore volume fraction of 37.5 nm and 50%, respectively. The confinement ratios (Γ=RgRp) range from 0.47 to 0.77, suggesting that the polymers inside the pores are moderately confined. The time for PS to achieve 80% infiltration (τ80%) is determined using in situ spectroscopic ellipsometry at 150 °C. The kinetics of infiltration scales weaker with Mw, τ80%∝Mw1.30±0.20, than expected from bulk viscosity Mw3.4. Furthermore, the effective viscosity of the PS melt inside NPG, inferred from the Lucas-Washburn model, is reduced by more than one order of magnitude compared to the bulk. Molecular dynamics simulation results are in good agreement with experiments predicting scaling as Mw1.4. The reduced dependence of Mw and the enhanced kinetics of infiltration are attributed to a reduction in chain entanglement density during infiltration and a reduction in polymer-wall friction with increasing polymer molecular weight. Compared to the traditional approach involving adding discrete particles into the polymer matrix, these studies show that nanocomposites with higher loading can be readily prepared, and that kinetics of infiltration are faster due to polymer confinement inside pores. These films have potential as actuators when filled with stimuli-responsive polymers as well as polymer electrolyte and fuel cell membranes.

Investigating Nanoparticle Organization in Polymer Matrices during Reaction-Induced Phase Transitions and Material Processing

Controlling nanoparticle organization in polymer matrices has been and is still a long-standing issue and directly impacts the performance of the materials. In the majority of instances, simply mixing nanoparticles and polymers leads to macroscale aggregation, resulting in deleterious effects. An alternative method to physically blending independent components such as nanoparticle and polymers is to conduct polymerizations in one-phase monomer/nanoparticle mixtures. Here, we report on the mechanism of nanoparticle aggregation in hybrid materials in which gold nanoparticles are initially homogeneously dispersed in a monomer mixture and then undergo a two-step aggregation process during polymerization and material processing. Specifically, oleylamine-functionalized gold nanoparticles (AuNP) are first synthesized in a methyl methacrylate (MMA) solution and then subsequently polymerized by using a free radical polymerization initiated with azobis(isobutyronitrile) (AIBN) to create hybrid AuNP and poly(methyl methacrylate) (PMMA) materials. The resulting products are easily pressed to obtain bulk films with nanoparticle organization defined as either well-dispersed or aggregated. Polymerizations are performed at various temperatures (T) and MMA volume fractions (Φ_MMA) to systematically influence the final nanoparticle dispersion state. During the polymerization of MMA and subsequent material processing, the initially homogeneous AuNP/MMA mixture undergoes macrophase separation between PMMA and oleylamine during the polymerization, yet the AuNP are dispersed in the oleylamine phase. The nanoparticles then aggregate within the oleylamine phase when the materials are processed via vacuum drying and pressing. Nanoparticle organization is tracked throughout the polymerization and processing steps by using a combination of transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). The resulting dispersion state of AuNPs in PMMA bulk films is ultimately dictated by the thermodynamics of mixing between the PMMA and oleylamine phases, but the mechanism of nanoparticle aggregation occurs in two steps that correspond to the polymerization and processing of the materials. Flory-Huggins mixing theory is used to support the PMMA and oleylamine phase separation. The reported results highlight how the integration of nonequilibrium processing and mean-field approximations reveal nanoparticle aggregation in hybrid materials synthesized by using reaction-induced phase transitions.

Polymer-Infiltrated Nanoparticle Films Using Capillarity-Based Techniques: Toward Multifunctional Coatings and Membranes

Polymer-infiltrated nanoparticle films (PINFs) are a new class of nanocomposites that offer synergistic properties and functionality derived from unusually high fractions of nanomaterials. Recently, two versatile techniques,capillary rise infiltration (CaRI) and solvent-driven infiltration of polymer (SIP), have been introduced that exploit capillary forces in films of densely packed nanoparticles. In CaRI, a highly loaded PINF is produced by thermally induced wicking of polymer melt into the nanoparticle packing pores. In SIP, exposure of a polymer-nanoparticle bilayer to solvent vapor atmosphere induces capillary condensation of solvent in the pores of nanoparticle packing, leading to infiltration of polymer into the solvent-filled pores. CaRI/SIP PINFs show superior properties compared with polymer nanocomposite films made using traditional methods, including superb mechanical properties, thermal stability, heat transfer, and optical properties. This review discusses fundamental aspects of the infiltration process and highlights potential applications in separations, structural coatings, and polymer upcycling-a process to convert polymer wastes into useful chemicals.

Maternal haemorrhage

Maternal haemorrhage is the leading cause of preventable maternal death worldwide and encompasses antepartum, intrapartum, and postpartum bleeding. This review highlights factors that predispose to severe bleeding, its management, and the most recent treatment and guidelines. Advances in obstetric care have provided physicians with the diagnostic tools to detect, anticipate, and prevent severe life-threatening maternal haemorrhage in most patients who have had prenatal care. In an optimal setting, patients at high risk for haemorrhage are referred to tertiary care centres where multidisciplinary teams are prepared to care for and deal with known potential complications. However, even with the best prenatal care, unexpected haemorrhage occurs. The first step in management is stabilization of haemodynamic status, which involves securing large bore i.v. access, invasive monitoring, and aggressive fluid management and transfusion therapy. Care for the patient with maternal bleeding should follow an algorithm that goes through a rapid and successive sequence of medical and surgical approaches to stem bleeding and decrease morbidity and mortality. With the addition of potent uterotonic agents and the advent of minimally invasive interventional radiological techniques such as angiographic embolization and arterial ligation, definitive yet conservative management is now possible in an attempt to avoid hysterectomy in patients with severe peripartum bleeding. If these interventions are inadequate to control the bleeding, the decision to proceed to hysterectomy must be made expeditiously. Recombinant factor VIIa is a relatively new treatment that could prove useful for severe coagulopathy and intractable bleeding.

Age-related toxicity of amyloid-beta associated with increased pERK and pCREB in primary hippocampal neurons: reversal by blueberry extract

Further clarification is needed to address the paradox that memory formation, aging and neurodegeneration all involve calcium influx, oxyradical production (ROS) and activation of certain signaling pathways. In aged rats and in APP/PS-1 mice, cognitive and hippocampal Ca(2+) dysregulation was reversed by food supplementation with a high antioxidant blueberry extract. Here, we studied whether neurons were an important target of blueberry extract and whether the mechanism involved altered ROS signaling through MAP kinase and cyclic-AMP response element binding protein (CREB), pathways known to be activated in response to amyloid-beta (Aβ). Primary hippocampal neurons were isolated and cultured from embryonic, middle-age or old-age (24 months) rats. Blueberry extract was found to be equally neuroprotective against Aβ neurotoxicity at all ages. Increases in Aβ toxicity with age were associated with age-related increases in immunoreactivity of neurons to pERK and an age-independent increase in pCREB. Treatment with blueberry extract strongly inhibited these increases in parallel with neuroprotection. Simultaneous labeling for ROS and for glutathione with dichlorofluorescein and monochlorobimane showed a mechanism of action of blueberry extract to involve transient ROS generation with an increase in the redox buffer glutathione. We conclude that the increased age-related susceptibility of old-age neurons to Aβ toxicity may be due to higher levels of activation of pERK and pCREB pathways that can be protected by blueberry extract through inhibition of both these pathways through an ROS stress response. These results suggest that the beneficial effects of blueberry extract may involve transient stress signaling and ROS protection that may translate into improved cognition in aging rats and APP/PS1 mice given blueberry extract.

Symptoms to pollen and fruits early in life and allergic disease at 4 years of age

BACKGROUND

The predictive value of reported early symptoms to pollen or fruits on later allergic disease is unclear. Our aim is to evaluate if symptoms to pollen and/or to fruits early in life are associated with allergic disease and sensitization to pollen at 4 years.

METHODS

The study included 3619 children from the Barn (Children), Allergy, Milieu, Stockholm, Epidemiology project (BAMSE) birth cohort. Reported symptoms of wheeze, sneeze or rash to birch, grass or weed, symptoms (vomiting, diarrhea, rash, facial edema, sneeze, or wheeze) to fruits including tree-nuts at 1 or 2 years of age, and definitions of asthma, rhinitis and eczema at 4 years were derived from questionnaire data. Sensitization to pollen allergens was defined as allergen-specific IgE-antibodies to any pollen (birch/timothy/mugwort) > or =0.35 kU(A)/l.

RESULTS

At 1 or 2 years of age, 6% of the children were reported to have pollen-related symptoms, 6% had symptoms to fruits, and 1.4% to both pollen and fruits. Children with symptoms to both pollen and fruits at 1 or 2 years of age had an increased risk for sensitization to any pollen allergen at age 4 (OR(adj) = 4.4, 95% CI = 2.1-9.2). This group of children also had a substantially elevated risk for developing any allergic disease (asthma, rhinitis, or eczema) at 4 years irrespective of sensitization to pollen (OR(adj) = 8.6, 95% CI = 4.5-16.4).

CONCLUSIONS

The prevalence of reported symptoms to pollen and fruits is very low in early childhood. However, children with early symptoms to both pollen and fruits appear to have a markedly elevated risk for allergic disease.

Dopamine-induced stress signaling in COS-7 cells transfected with selectively vulnerable muscarinic receptor subtypes is partially mediated via the i3 loop and antagonized by blueberry extract

Muscarinic receptors (MAChRs) are intimately involved in various aspects of both neuronal and vascular functioning, and there is selective oxidative stress sensitivity (OSS) among MAChR subtypes, with M1, M2, and M4 showing>OSS. OSS was assessed by determining the loss of ability of the cell to extrude or sequester Ca2+ following oxotremorine-induced depolarization following exposure to dopamine (DA) subtypes in transfected COS-7 cells. This OSS can be prevented by pretreatment with blueberry (BB) extract. Present studies were carried out to determine BB treatment of the cells transfected with wild type, truncated or chimeric [where the i3 loop of one receptor was switched with the i3 loop of the other; i.e., M1(M3i3) and M3(M1i3)] receptors would alter DA-induced changes in calcium buffering and would confer protection through alterations in pMAPK, pCREB or PKC signaling. These findings also suggest that BB may antagonize OS effects by lowering activation of pCREB and possibly PKCgamma induced by DA. In the truncated and chimeric receptors, results indicated that BB reduced OSS in response to DA in M1-transfected cells. However, BBs were also effective in preventing these Ca2+ buffering deficits in cells transfected with M1 receptors in which the i3 loop had been removed, but only partially enhanced the protective effects of the M3 i3 loop in the M1(M3i3) chimerics. A similar partial effect of BBs was seen in the M3(M1i3) chimerics which showed increased OSS in response to DA. It appears that antioxidants found in BBs might be targeting additional sites on these chimerics to decrease OSS.

First trimester screening for congenital heart disease

Most obstetrical practices in the United States offer pregnant women at least one ultrasound during pregnancy. This prenatal ultrasound is usually scheduled at around 18 to 20 weeks gestation. Both the American Institute of Ultrasound in Medicine and the American College of Obstetricians and Gynecologists recommend that the four-chamber view be included to screen for congenital heart disease. Recently, many investigators have attempted to screen for congenital heart disease earlier in pregnancy. Fetal nuchal translucency thickness traditionally used to screen for fetal aneuploidy by transvaginal and abdominal ultrasound has also been shown to identify a large proportion of fetuses with congenital heart disease. Recent studies have also reported congenital heart disease in chromosomally normal fetuses with increased nuchal translucency thickness in the first trimester. Advances in ultrasound technology and training over the last 10 years allow greater visualization rates of the four-chamber view and outflow tracks in the late first trimester (up to 90% visualization at 13 weeks). Fetal echocardiography in the first trimester may be indicated for fetuses at risk for congenital heart disease. In this article we present a review of the most recent and ongoing clinical and basic research to support an earlier first trimester approach to diagnosing congenital heart defects.

Hydroxy-alkyl bisphosphonic acid partial esters (HABPA-PE): Structures of two symmetrical and non-symmetrical members of a new class of prodrugs in bone disease treatments

Two new hydroxy alkyl bisphosphonate partial esters (HABPA-PE) have been crystallised. The first compound C6H15NaO7P2C2H5O, crystallises as an ethanol solvate and forms rigid infinite β-sheet-like ribbons. The second, C6H16O7P2, displays self-association in dimers. In these new structures, packing analyses confirm the enhanced hydrophobic character due to partial esterification compared to naked hydroxybisphosphonic acids and the simplification of their H bonding patterns.

Silver-sulfadiazine eschar pigmentation mimics invasive wound infection: a case report

A 3-year-old girl with 52% TBSA scalds, mostly partial thickness, was treated topically with 5% mafenide acetate solution and 1% silver sulfadiazine cream. All blood cultures and wound swabs were negative for the first 5 days. On day 6 gram-negative bacteria and yeast forms were isolated from her wounds. High fever and leukocytosis were present and the child was treated with intravenous ampicillin and gentamicin according to sensitivity bacteriogram. The bacteria were identified as Pseudomonas aeruginosa and the yeast was Candida tropicalis. On day 7, Escherichia coli was identified in blood cultures and intravenous cefixime was added. Amphotericin B was added on day 9 when blood cultures grew Candida tropicalis and Burkholderia cepacia. On day 13 dark pigmentation foci developed on some areas of partial-thickness burns in the back, resembling invasive wound infection. White blood cell count was 14,300 cells/mm3, and her body temperature reached 39.7 degrees C. Cultures from the pigmented areas were negative, and biopsies revealed deposits of silver. Most of the areas healed uneventfully, and only about 8% TBSA needed grafting, including some of the pigmented areas. No residual pigmentation remained on discharge.

Destabilizing effect of a fluorouracil extra base in a hybrid RNA duplex compared with bromo and chloro analogues

In the presence of cobalt, rhodium or iridium hexammine salts, the RNA/DNA hybrid r-GCUUCGGC-d(X)U (with X = F, Cl or Br) crystallizes as a double-stranded helix with four consecutive G-U and C-U mismatches. The deoxy chloro- and bromouracil derivatives are isomorphous, space group C2, unit-cell parameters a = 53.80, b = 19.40, c = 50.31 A, beta = 109.9 degrees, with the same infinite helix arrangement in the packing along the c axis with one extra DNA halogenouracil base included in the stacking. However, the fluorouracil derivative, with unit-cell parameters a = 53.75, b = 19.40, c = 45.84 A, beta = 105.7 degrees, is not isomorphous. The corresponding extra DNA base d(F)U of the second strand is ejected out of the helical stack, leading to a shortening of the c axis. The specific destabilization of the fluorouracil for the duplex building is analyzed in terms of the polarization effect of the halogen atom attached to the 3'-terminal base that modulates its interactions.

A pilot study of whole body hyperthermia and carboplatin in platinum-resistant ovarian cancer

The aim of this study was to determine whether the addition of whole body hyperthermia (WBH) to carboplatin (CBDCA) can induce responses in patients with platinum-resistant ovarian cancer. 16 pretreated patients with platinum-resistant ovarian cancer were entered on a Systemic Hyperthermia Oncological Working Group (SHOWG) study; (14 patients were eligible with 14 evaluable for toxicity and 12 for response). The patients were treated with WBH (Aquatherm) 41.8 degrees C x 60 min in combination with carboplatin (CBDCA) (area under the curve (AUC) of 8) every 4 weeks. Disease status was evaluated every two cycles. Patients were treated for a maximum of six cycles. One patient had a complete response (CR) and 4 had a partial response (PR). 4 patients had stable disease (SD). 3 patients had progressive disease (PD). 2 patients were unevaluable: 1 had a bowel obstruction shortly after her first treatment; the second patient achieved a CR, but only had one treatment secondary to an idiosyncratic reaction to sedative drugs. 2 patients entered on study were ineligible, as they did not meet criteria for platinum resistance; 1 entered a CR and 1 had SD. Dose-limiting toxicity, which required CBDCA dose reductions, was grade 4 thrombocytopenia. Other toxicities included neutropenia (grade 3/4), and nausea and/or vomiting. Consistent with preclinical modelling, these results suggests that 41.8 degrees C WBH can overcome platinum resistance in ovarian cancer. These observations suggest further investigation of the therapeutic potential of WBH in a group of patients who historically fail to respond to salvage therapies is warranted.

Second neoplasms in patients with Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) has been associated with a high incidence of other skin tumors and hematological malignancies. The purpose of this study was to analyze data from the Israel Cancer Registry regarding the incidence of second neoplasms in patients with MCC and their impact on survival.

METHODS

Sixty-seven patients in whom MCC was diagnosed between 1983 and 1999 were included. Data were collected on age, gender and ethnic origin, dates of diagnosis of MCC and any other neoplasm, and date and cause of death, if applicable. Comparison of MCC-specific survival, estimated by the Kaplan-Meier product limit method, between patients with no other neoplasm and those with second primary tumors was performed by log rank test. Age-specific standardized incidence ratio (SIR) was calculated using 5751 age- and ethnic-matched malignant melanoma patients as a control group.

RESULTS

Seventeen patients (25%) had a second neoplasm before, concomitant with, or after the diagnosis of MCC; 2 of them also had a third primary tumor. The SIR was 2.8 (95% CI; range, 1.38-4.22), significantly higher than the control group. Almost half the tumors were squamous cell carcinomas, either skin or head and neck, and most of the remainder were hematological malignancies or breast and ovarian adenocarcinomas. On univariate analysis, the presence of another neoplasm, regardless of its chronology, was associated with higher MCC-specific mortality (65% vs. 40% for patients with MCC only; P = 0.022). Analysis of only those patients in whom a second neoplasm developed during follow-up after treatment for MCC yielded an estimated actuarial risk of developing a second primary of 2.1% for each year of observation.

CONCLUSIONS

There is a high incidence of second neoplasms, including noncutaneous solid tumors, in patients with MCC. The presence of these neoplasms, whether they appear before, after, or simultaneously with MCC, is associated with a higher MCC-specific mortality.

Warfarin skin necrosis: local and systemic factors

Warfarin induced skin necrosis occurs in 0.01-0.1% of warfarin treated patients. The usual presentation is that of painful lesions developing in obese women after the initiation of warfarin treatment. The lesions usually evolve into full thickness skin necrosis within a few days. Although the exact mechanism is not totally clear, low levels of Protein C or S, either functional or inherited, are associated with many of the cases. We report the case of a 17-year-old patient treated with warfarin because of iliofemoral deep vein thrombosis post abortion. The patient developed several huge haemorrhagic blisters on the affected leg. The condition rapidly developed into full thickness skin and fat necrosis. The necrotic lesions were excised and eventually covered with skin graft. The combination of the patient tendency towards hyper-coagulation and the local factors is discussed.

[Plagiocephaly in children: etiology, differential diagnosis and helmet treatment]

Plagiocephaly in a head-and-neck irradiated rat model or rhomboid-shaped head, occurs in at least 1 in 300 live births. In most cases such asymmetry is not caused by synostosis of the unilateral coronal or lambdoid sutures, but is rather a deformity produced by intrauterine and/or postnatal deformational forces. Categorization and diagnosis of plagiocephaly as synostotic or deformational is reliably made by physical examination and computerized tomography. Its differential diagnosis is extremely important because prompt surgical correction is usually indicated for the synostotic type. In contrast, infants with deformational frontal or occipital plagiocephaly generally respond to helmet treatment. 10 infants with significant deformational plagiocephaly were treated with individual plastic helmets during the past 2 years and 4 other infants with plagiocephaly are currently being treated. In each instance, cranial asymmetry dramatically improved as the brain grew and the head filled out the helmet. There were no significant complications. Awareness of deformational plagiocephaly allows more accurate diagnosis and appropriate treatment, avoiding unnecessary surgical intervention in patients with positional molding.

Study of the complex between the contrast agent Iobitridol (Xenetix) and Elastase (PPE): a model for hydrophobic site protection in drug-protein interactions

PURPOSE

The concept of Hydrophilic Sphere Stabilization, or Hydrophobic Shielding, has been postulated in the synthesis of biocompatible contrast agents in vascular imaging. To improve the safety of these polyiodinated agents, interactions with protein hydrophobic sites in biomacromolecules should be kept as low as possible. In order to evaluate the level of interactions with proteins, we have selected the serine proteinase Elastase, in presence of Iobitridol (Xenetix), as a model.

METHODS

The complex between Iobitridol and Pancreatic Porcine Elastase was investigated by X-ray diffraction techniques, on saturated monocrystals, using the synchrotron radiation at 0.98A.

RESULTS

In contrast to Iohexol, which displays several interactions including one in the active site, Iobitridol is unable to interact directly with elastase. Only one partially occupied site is found in between two molecules of the crystal packing.

CONCLUSIONS

The validation of the "hydrophobic shielding" concept, which was at the origin of the design of the Iobitridol molecule, has been proven to be an essential feature in minimizing in vivo protein interactions.

Cryopreserved cadaveric allografts for treatment of unexcised partial thickness flame burns: clinical experience with 12 patients

Partial thickness burns (PTB) usually heal within 3 weeks. Prevention of infection and desiccation of the wounds are crucial for optimal healing. Early tangential excision of the burn eschar and allografting prevent deepening of the burns, and are therefore advocated for treatment with the best functional and aesthetic results. For superficial partial thickness burns (SPTB) conservative use of topical antimicrobial agents with frequent dressing changes are implemented. We compared the conservative treatment for PTBs and SPTBs to grafting cryopreserved cadaveric allografts with no prior excision. Twelve patients with flame PTB areas were allografted after mechanical debridement without excision of the burn wounds. The allografts were cadaveric skin cryopreserved by programmed freezing and stored at -180 degrees C for 30-48 months. Matching burns for depth and area were treated with silver sulfadiazine (SSD) one to two times daily until healing or debridement and grafting were required. It was found that 80 per cent of the cryopreserved allografts adhered well and 76 per cent of the treated areas healed within 21 days, whereas only 40 per cent of the SSD-treated burns healed within 21 days. Partial thickness burns can be treated successfully with viable human allografts (cryopreserved cadaveric skin) with no prior surgical excision. The burn wounds heal well within 3 weeks. For deep partial thickness burns (DPTB) treatment with allografts has no advantage if they have not been previously excised.

Salivary gland transplantation: a canine model

Impaired salivary function with resultant severe dryness of the mouth, or xerostomia, may occur in association with a variety of systemic disorders or therapies. No adequate treatment exists for this debilitating condition, which impedes normal oral function, in particular alimentation and phonation. This study explores the feasibility of salivary gland autotransplantation, using a canine model. A salivary gland with its duct and surrounding blood vessels still attached was excised and reimplanted in the dog's thigh by anastomosing the graft's blood vessels to the femoral artery and vein. The duct was sutured to an artificial orifice cut in the thigh's skin, from which the saliva was collected. Salivary secretion was induced by a single intravenous bolus of pilocarpine (5 mg). Preoperative (normal) salivation was measured by collecting saliva from the gland in situ. Periodic functional studies showed normal saliva production during the first month after grafting, after which the salivary flow was reduced by 35% over the next 2 months. This reduction was interpreted as a sign of disuse atrophy resulting from the lack of autonomic innervation. To overcome this impediment, oral pilocarpine (5 mg/day) was administered to the recipient dog, after which normal levels of saliva were excreted through the graft during the 3-month follow-up period. The quality of the graft saliva was assessed by its protein and electrolyte levels, which showed close to normal values.

Report of the Eriksholm Workshop on auditory deprivation and acclimatization

The terminology used in studies documenting changes in auditory performance following fitting of hearing aids has been diverse. Definitions for the auditory deprivation effect and auditory acclimatization are offered as a first step in rationalization. Two statements summarize current knowledge concerning auditory deprivation effects and auditory acclimatization, as well as considering the potential implications for research, field trial and clinical practice applications. Potential areas for future research are identified.

Chest wall deformity following maximal tissue expansion for breast reconstruction

Forty-three women, in a series of 150, participated in a prospective study that examined their chest walls for deformities 3 months after maximal tissue expansion for single-breast reconstruction. Computed tomography imaging was used for this purpose. Twenty-one patients underwent immediate breast reconstruction and the other 22 patients underwent delayed reconstruction. Fifty-three percent had some chest wall abnormality. In the delayed group, chest wall deformities were more statistically significant (p < 0.001). Our findings suggest that chest wall deformity is a common occurrence after maximal tissue expansion for breast reconstruction.

Efficacy of the topical anesthetic cream, EMLA, in alleviating both needle insertion and injection pain

To assess the efficacy of the topical anesthetic cream, EMLA, in alleviating the pain produced by infiltration of local anesthetic prior to surgical skin biopsies, a randomized, double-blind, placebo-controlled study was performed on 54 patients undergoing 162 excisional biopsies. Both pain induced by needle insertion and pain induced by local injection were significantly diminished after topical application of EMLA cream. However, part of the effect was placebo, because the placebo ointment (Vaseline) also produced significant pain alleviation.

Melanoma of the scalp: the invisible killer

A series of 20 patients (15 men and 5 women) suffering from malignant melanoma of the scalp is reported. Their epidemiologic data and outcome are described. The ages ranged from 48 to 78 years (mean 63 years). Analysis of the cases demonstrated that lesions occurring posterior to the tragal line (in hair-bearing area) have the worst prognosis. The 5-year survival rate was poor; 12 patients died within this period. Two representative cases are described, and the preventable aspects of the disease are emphasized.

Cardiac tamponade as the initial manifestation of primary pericardial mesothelioma

Although cardiac tamponade is a known complication of malignancy, it is rarely the initial manifestation. We report a 46-year-old male who presented with malignant cardiac tamponade 6 months prior to the definitive diagnosis of primary pericardial mesothelioma. A thorough literature search has not revealed a similar care.

Rare sites of melanoma: melanoma of the external ear

A small series of melanomas of the external ear is presented. The presentation in general was late and they varied from 2.6 mm to 4.8 mm in thickness. The outcome in most of the patients (9 patients) was bad and within 3 years only 4 survived. The fact that 9 patients remembered having a nevus that suddenly changed to melanoma emphasizes the need for early removal of such nevi.

Angiography contrast agents interact with serine proteinases. The molecular structure of the model system elastase/iohexol

Pancreatic elastase was co-crystallised with iohexol, a tri-iodo benzenic contrast agent used in angiography analyses. The X-ray analysis of the complex reveals the presence of three molecules of iohexol associated with the proteinase with low occupancy factors. Two iohexol molecules are located in and near the active site of the enzyme and provide a model for explaining the inhibition of the hemostatic system, one of the major and inconvenient side effect associated with these chemicals.

Lipomatosis of the scalp and macrocephaly

In summary, a case of macrocephaly and lipomatosis of the scalp and forehead has been presented. The phenotypic and clinical features found in our patient are in accordance with previous reports. The differential diagnosis with other hamartoneoplastic syndromes has been evaluated and discarded, concluding that the present report is in accordance with Bannayan-Zonana syndrome. However, as in other inherited traits, finding a genetic test to diagnose this entity remains a challenge.

Cyclosporin A treatment failed to extend skin allograft survival in two burn patients

Prolongation of skin allograft survival by immunosuppression of burn casualties has been reported sporadically during the past two decades. Recently cyclosporin A (CycA) has been used effectively for such an indication. We report here two paediatric patients with extensive burns (85-95 per cent BSA) treated with fresh, family-related skin allografts that were rejected during CycA treatment after 14-18 days. One of these children survived while the other died with candida sepsis.

Terrorist bombing with a 'Molotov cocktail' inside travelling cars: an old weapon for a new burn syndrome?

The 'Molotov cocktail' terrorist weapon which is thrown into a travelling car has given a new type of injury to people who sustain massive smoke inhalation together with disfiguring burns of face, thighs, hands and chest, and post-traumatic psychological disorder. The combination of petrol ignition with the synthetic fumes inside the care is a unique occurrence with a high morbidity and mortality which is difficult to treat and to manage. We propose to show that the combination of all the above components can be defined as the 'Molotov cocktail' burn syndrome.