A straightforward method for determination of the sevoflurane metabolite hexafluoroisopropanol in urinary occupational medical samples by headspace-gas chromatography mass spectrometry.

Biological monitoring of the unmodified sevoflurane and its metabolite hexafluoroisopropanol (HFIP) in urine samples was proposed to determine the individual exposure levels of the medical staff. In this study, a method for simultaneous determination of both compounds in urine using static headspace-gas chromatography-mass spectrometry (HS-GC-MS) was developed. The method is linear over a broad concentration range from 1 to 1000 µg/L (r2 > 0.999) and shows high precision. Limits of quantification (LOQ) are 0.6 µg/L for sevoflurane and 3 µg/L for HFIP, representing an excellent sensitivity without the necessity of analyte enrichment. The method was successfully applied in a German pilot-study to monitor both compounds in samples from medical personnel working in operating theatres. Urinary concentrations of HFIP ranged between < LOQ and 145 µg/L, while sevoflurane was below the LOD in all samples.

A world-wide survey and field study in clinical haemostasis laboratories to evaluate FVIII:C activity assay variability of ADYNOVATE and OBIZUR in comparison with ADVATE.

INTRODUCTION: Discrepancies have been previously reported for one-stage clotting and chromogenic assays for FVIII activity analysis. Inter-laboratory variations in instruments, method of clot detection, assay set-up, reference standard calibration, reagent source and reagent composition all contribute to assay variability. AIM: To characterise multilaboratory assay variability in measuring ADYNOVATE, OBIZUR and ADVATE FVIII activity in human plasma and survey multinational FVIII activity assay preferences. METHODS: As samples from patients treated with either of the FVIII products are not available in the quantities required for a systematic collaborative study, haemophilia A plasma was spiked in vitro with either ADYNOVATE (PEGylated rFVIII), OBIZUR [Porcine Sequence Antihaemophilic Factor (Recombinant)] or ADVATE at high (0.80 IU or U mL-1 ), medium (0.20 IU or U mL-1 ) and low (0.05 IU or U mL-1 ) FVIII concentrations, based on labelled potencies. Clinical laboratories used their routine FVIII activity assay to determine FVIII activity of each product. Thirty-five data sets using one-stage clotting assay and 11 sets using chromogenic assay were obtained. RESULTS: A vast majority of laboratories (98%) prefer and rely on the one-stage clotting assay. Mean recoveries across all concentrations were 113%, 120% and 127% for ADYNOVATE, OBIZUR and ADVATE respectively. Assay variation was comparable between ADVATE, ADYNOVATE and OBIZUR with inter-laboratory percent coefficients of variation (%CV) ranging from 11 to 22%. Mean chromogenic assay results were 116%, 51% and 113% for ADYNOVATE, OBIZUR and ADVATE respectively. Inter-laboratory CV's were similar for ADYNOVATE, OBIZUR and ADVATE. CONCLUSIONS: One-stage clotting assays can and will be used with sufficient accuracy and precision for the measurement of ADYNOVATE, OBIZUR and ADVATE in plasma samples from subjects with haemophilia A. Chromogenic assay underestimates OBIZUR potency, particularly at lower concentrations.

Novel insight into the inflammatory and cellular responses following experimental glaucoma surgery: a roadmap for inhibiting fibrosis.

Failure after glaucoma filtration surgery is attributed to fibrosis at the operated site. To understand the wound healing process after glaucoma filtration surgery, we have developed a mouse model for glaucoma filtration surgery which closely mimics the clinical response. In this study, we describe a systematic analysis of the wound healing response in vivo. Our data revealed that the post-surgical tissue response was separable into two distinguishable phases. The early "acute inflammatory" phase was characterized by significantly increased transcript expression of Vegfa, Cxcl1, Cxcl5, Ccl2, Ccl3, Ccl4, Gmcsf and specific Mmps as well as greater infiltration of monocytes/macrophages and T cells. The late "fibrotic" phase was characterized by an increased expression of Tgfb2 and extracellular matrix genes as well as a notable reduction of infiltrating inflammatory cells. Significantly, more mitotic cells were observed at both time points post-surgery. Subconjunctival fibroblasts may be involved in both phases since they have the capacity to reiterate the in vivo gene expression profiles upon either pro-inflammatory or pro-fibrotic cytokine stimulation. Given that the cellular and molecular targets that govern the early and late phases of wound healing are distinct and time sensitive, a multi-targeted therapeutic approach to sequentially inhibit inflammation and fibrogenesis at the critical time point may lead to improved surgical outcomes in glaucoma filtration surgery.

Suberoylanilide hydroxamic acid: a potential epigenetic therapeutic agent for lung fibrosis?

Pulmonary fibrosis represents a fatal stage of interstitial lung diseases of known and idiopathic aetiology. No effective therapy is currently available. Based on an indication-discovery approach we present novel in vitro evidence that the histone deacetylases inhibitor suberoylanilide hydroxamic acid (SAHA), an FDA approved anti-cancer drug, has antifibrotic and anti-inflammatory potential. Human lung fibroblasts (fetal, adult and idiopathic adult pulmonary fibrosis) were treated with transforming growth factor (TGF)-beta 1 with or without SAHA. Collagen deposition, alpha-smooth muscle actin (alpha-SMA) expression, matrix metalloproteinase (MMP)1 activity, tissue inhibitor of MMP (TIMP)1 production, apoptosis and cell proliferation were assessed. Pro-inflammatory cytokines relevant to pulmonary fibrosis were assayed in SAHA-treated human peripheral blood mononuclear cells (PBMC) and its subpopulations. SAHA abrogated TGF-beta 1 effects on all the fibroblast lines by preventing their transdifferentiation into alpha-SMA positive myofibroblasts and increased collagen deposition without inducing apoptosis. However, MMP1 activity and TIMP1 production was modulated without a clear fibrolytic effect. SAHA also inhibited serum-induced proliferation of the fibroblast lines and caused hyperacetylation of alpha-tubulin and histone. Cytokine secretion was inhibited from PBMC and lymphocytes at nonapoptotic concentrations. Taken together, these data demonstrate combined antifibrotic and anti-inflammatory properties of SAHA, suggesting its therapeutic potential for pulmonary fibrosis.

DNA-level diversity and relatedness of Helicobacter pylori strains in shantytown families in Peru and transmission in a developing-country setting.

The efficiency of transmission of a pathogen within families compared with that between unrelated persons can affect both the strategies needed to control or eradicate infection and how the pathogen evolves. In industrialized countries, most cases of transmission of the gastric pathogen Helicobacter pylori seems to be from mother to child. An alternative model, potentially applicable among the very poor in developing countries, where infection is more common and the sanitary infrastructure is often deficient, invokes frequent transmission among unrelated persons, often via environmental sources. In the present study, we compared the genotypes of H. pylori from members of shantytown households in Peru to better understand the transmission of H. pylori in developing-country settings. H. pylori cultures and/or DNAs were obtained with informed consent by the string test (a minimally invasive alternative to endoscopy) from at least one child and one parent from each of 62 families. The random amplified polymorphic DNA fingerprints of 57 of 81 (70%) child-mother strain pairs did not match, nor did the diagnostic gene sequences (>1% DNA sequence difference), independent of the child's age (range, 1 to 39 years). Most strains from siblings or other paired family members were also unrelated. These results suggest that H. pylori infections are often community acquired in the society studied. Transmission between unrelated persons should facilitate the formation of novel recombinant genotypes by interstrain DNA transfer and selection for genotypes that are well suited for individual hosts. It also implies that the effective prevention of H. pylori infection and associated gastroduodenal disease will require anti-H. pylori measures to be applied communitywide.

[The South-American eel. Two early letters on animal electricity from the Dutch colonies]. / De Zuid-Amerikaanse aal. Twee vroege brieven uit de Nederlandse koloniën over dierlijke elektriciteit.

Speculations about the nature of nerve action, including animal spirits, date back to antiquity. Only during the 18th century, when it became possible to store electricity in Leyden jars, did natural philosophers begin to realise that the sensations caused by electric fish are like those produced by these primitive capacitors. The important roles played by amateur observers in the Dutch colonies of South-America, and how they communicated with more established Dutch scientists in The Netherlands, are often relatively overlooked in histories of how the nerves became electrical. In this article we examine two mid-18th-century letters from South-America to the Netherlands. Both dealt with what would soon be called the electric eel, and were published in the proceedings of the first Dutch Society of Science (in Haarlem). The discovery of the electric nature of the shocks produced by these fish in particular proved to be a crucial step in understanding animal electricity and the true nature of neurophysiology.

Effectiveness of enterobacterial repetitive intergenic consensus PCR and random amplified polymorphic DNA fingerprinting for Helicobacter pylori strain differentiation.

We compared the robustness and discriminatory power of the enterobacterial repetitive intergenic consensus (ERIC) and random amplified polymorphic DNA (RAPD) fingerprinting methods for detecting cases of mixed Helicobacter pylori infection in Peruvian shantytown residents. H. pylori isolates from 63 participants were cultured, and five single colonies and a pool of additional colonies from each participant were analyzed by ERIC-PCR and by RAPD tests with four 10-nucleotide primers (one primer per reaction). There was 94% agreement between the ERIC and RAPD profiles in classifying sets of isolates as uniform versus closely related but not identical versus probably unrelated, indicating a high kappa statistic of 0.8942. Subtle differences in related ERIC or RAPD patterns likely reflect gene transfer between strains, recombination, and/or mutation, whereas markedly different patterns reflect infection by unrelated strains. At least half of infected shantytown residents seemed to carry more than one H. pylori strain, although in 19 of 31 persons, the strains were closely related. Three RAPD tests, each with a different primer, were needed to achieve the sensitivity of one ERIC test. ERIC-PCR constitutes a resource- and time-efficient method for H. pylori strain differentiation.

Validation of string test for diagnosis of Helicobacter pylori infections.

The method of recovering Helicobacter pylori DNA or viable cells absorbed on a string that a person has swallowed and that is retrieved an hour later (string test) should be a useful alternative to traditional analysis of cells or DNA obtained by endoscopy, which is invasive, uncomfortable, relatively costly, and ill-suited for community-based and pediatric studies. Here we assayed the sensitivity and validity of the string test versus conventional endoscopic biopsy for detecting and analyzing H. pylori infection. Forty-four people with gastric complaints were studied using both H. pylori culture and urease gene (ureB) PCR. H. pylori organisms cultured from strings and biopsy specimens from the same patients were fingerprinted by the randomly amplified polymorphic DNA (RAPD) method. Biopsy sections were also hematoxylin and eosin and silver stained for H. pylori detection. H. pylori was cultured from 80% of strings and detected by PCR from 91% of strings from participants whose biopsies had been H. pylori positive by culture, PCR, and/or histology. Strains recovered from strings and biopsy specimens yielded identical or closely related RAPD profiles in each of the 24 cases tested. We conclude that the string test is a useful method for H. pylori recovery and analysis when relatively noninvasive procedures are needed.

The eye as an optical instrument: from camera obscura to Helmholtz's perspective.

The era of modern vision research can be thought of as beginning in the seventeenth century with Johannes Kepler's understanding of the optics of the camera obscura with a lens and its relation to the eye. During the nineteenth century, Helmholtz used "The eye as an optical instrument" as the title for one of his Popular Lectures, and such a conception of the eye is now accepted as a fundamental feature of visual science. In analysing the optics of the eye, Helmholtz constructed some novel optical instruments for studying the eye. The development of optometers, ophthalmometers, and ophthalmoscopes is presented historically, with emphasis on how these instruments and camera analogies helped scientists to understand the functions of the eye, especially the enigma of accommodation. "The laws of optics are so well understood, and the knowledge of the eye, when considered as an optical instrument, has been rendered so perfect, that I do not consider myself capable of making any addition to it; but still there is a power in the eye by which it can adapt itself to different distances far too extensive for the simple mechanism of the parts to effect." (John Hunter in a letter to Joseph Banks in 1793, published by Home 1794, page 24).

Edward Albert Schäfer (Sharpey-Schafer) and his contributions to neuroscience: commemorating of the 150th anniversary of his birth.

The year 2000 marks the 150th anniversary of the birth of Edward Albert Schäfer (Sir Edward Albert Sharpey-Schafer). Affiliated first with University College, London, and then with Edinburgh University, Schäfer made monumental contributions to the fields of histology, physiology, endocrinology, and practical medicine. This paper traces his professional life and emphasizes his seminal contributions to the neurosciences, which include his findings in support of neuron doctrine, his research on cortical localization in monkeys, his discovery of adrenaline and its place in the history of neural transmission, and his studies on recovery after nerve damage. Author of many histology and physiology books, founder of the "Quarterly Journal of Experimental Physiology," and mentor to many students who achieved great fame themselves, Schäfer was an active teacher and researcher, a man who remained committed to his vision of medicine based on laboratory science until he died in 1935.

Victor Horsley on "trephining in pre-historic times".

Victor Horsley was intrigued by newly discovered, ancient trepanned skulls, especially those that revealed that the operation was performed on living patients. He examined the man-made openings as an expert on the locus of the primate motor cortex and as a surgeon who had successfully removed parts of the motor cortex to treat Jacksonian epilepsy. He postulated that trepanation originated as a way to treat pain and epilepsy caused by depressed cranial fractures over the motor cortex. Like Broca before him, Horsley helped create the exciting Zeitgeist that led others in the late-1 800s to explore, ponder, and write about ancient trepanned skulls.

Discovering trepanation: the contribution of Paul Broca.

PAUL BROCA WAS an icon of neuroscience and neurosurgery who also happened to be intrigued by trepanned skulls. His anthropological work established that, thousands of years ago, individuals not only trepanned skulls but also successfully performed these operations on living persons. After first commenting on a pre-Columbian Peruvian skull in 1867 (the first case of trepanning on a living person widely recognized as such), he turned to even older trepanned skulls found on French soil. In the 1870s, he theorized that the procedure originated as a means to treat convulsions in infants. As he saw it, Neolithic man attributed such convulsions to evil spirits, for which trepanation provided a ready means of escape. Because simple infantile convulsions resolve on their own, the practice would have seemed successful, and therefore it would have been propagated and expanded by later generations. Broca's theory skillfully integrated his anthropological and medical knowledge and helped to create the exciting environment in which scientists pondered what Neolithic and primitive people really knew regarding the brain and surgery.

Dr. Otto Soltmann (1876) on development of the motor cortex and recovery after its removal in infancy.

In 1870, Fritsch and Hitzig demonstrated that dogs have a motor cortex. In a chapter published 6 years later, Otto Soltmann studied the functional development of the motor cortex, which he believed functioned in willed movement. He was the first to show that the dog's motor cortex becomes electrically excitable at about 10 days of age, with the contralateral forepaw area appearing first. He also studied the effects of ablating the cortical motor regions unilaterally and bilaterally, and encountered a remarkable degree of sparing of function in his animals operated on as newborns, but not in older-operated dogs. Soltmann turned to the theory of functional take-over (vicariation) to account for the absence of deficits in his young animals. He was especially intrigued by the fact that electrical stimulation of a healthy motor cortex could produce bilateral matched movements, but only in dogs that sustained opposite motor cortex lesions very early in life.

Outcome of total hip arthroplasty in small-proportioned patients.

In a prospective, consecutive series, 41 total hip arthroplasties were performed in 27 small-proportioned patients with small femoral dimensions. The 17 female and 10 male patients averaged 23.6 years (range, 14-47 years), and the mean height and weight were 157 cm (range, 132-183 cm) and 53.5 kg (range, 36-84 kg). The most common preoperative diagnosis was juvenile rheumatoid arthritis in 18 patients (28 hips). Most patients were severely disabled in their daily activity, and 68% of the patients were classified as Charnley functional class C. The femoral implants consisted primarily of the proximally porous-coated miniature Anatomic Medullary Locking femoral component (AML/CDH, Depuy, Warsaw, IN) in 33 hips in 22 patients (average stem diameter, 9.5 mm; range, 8-12.0 mm). A porous ingrowth acetabular cup fixed with screws was used in all procedures. At an average follow-up of 51 months, Harris Hip Scores improved significantly from 34 points (range, 0-65 points) preoperatively to 85 points (range, 33-100 points) after arthroplasty. There were no intraoperative complications. There was 1 revision because of femoral implant loosening. Three cementless femoral components showed evidence of nonprogressive subsidence. One patient had significant bilateral acetabular component polyethylene wear and underwent revision. All other femoral and acetabular components were radiographically stable. The relief of pain and improvement of function were dramatic. The miniature AML/CDH femoral component, combined with an uncemented acetabular cup, provides a promising, off-the-shelf alternative in small-proportioned patients.

The power of a musical instrument: Franklin, the Mozarts, Mesmer, and the glass armonica.

In 1761 Benjamin Franklin invented the armonica (often referred to as the glass harmonica), an instrument designed to simplify the playing of the musical glasses. The instrument immediately became popular and inspired compositions by Wolfgang Mozart, who had the opportunity to hear and play one at the house of Franz Anton Mesmer. Armonica music was used by Mesmer in his séances, because he felt it could promote healing by propagating a mystical fluid that he called animal magnetism through the body. After Mesmer's theories were debunked by a highly respected panel of scientists, the armonica fell out of vogue. Because Franklin was on the panel that examined the discredited mesmerism, he indirectly contributed to his own invention's demise.