Distribution of the tetrodotoxin-resistant sodium channel PN3 in rat sensory neurons in normal and neuropathic conditions

The novel sodium channel PN3/alpha-SNS, which was cloned from a rat dorsal root ganglion (DRG) cDNA library, is expressed predominantly in small sensory neurons and may contribute to the tetrodotoxin-resistant (TTXR) sodium current that is believed to be associated with central sensitization in chronic neuropathic pain states. To assess further the role of PN3, we have used electrophysiological, in situ hybridization and immunohistochemical methods to monitor changes in TTXR sodium current and the distribution of PN3 in normal and peripheral nerve-injured rats. (1) Whole-cell patch-clamp recordings showed that there were no significant changes in the TTXR and TTX-sensitive sodium current densities of small DRG neurons after chronic constriction injury (CCI) of the sciatic nerve. (2) Additionally, in situ hybridization showed that there was no change in the expression of PN3 mRNA in the DRG up to 14 d after CCI. PN3 mRNA was not detected in sections of brain and spinal cord taken from either normal or nerve-injured rats. (3) In contrast, immunohistochemical studies showed that major changes in the subcellular distribution of PN3 protein were caused by either CCI or complete transection of the sciatic nerve. The intensity of PN3 immunolabeling decreased in small DRG neurons and increased in sciatic nerve axons at the site of injury. The alteration in immunolabeling was attributed to translocation of presynthesized, intracellularly located PN3 protein from neuronal somata to peripheral axons, with subsequent accumulation at the site of injury. The specific subcellular redistribution of PN3 after peripheral nerve injury may be an important factor in establishing peripheral nerve hyperexcitability and resultant neuropathic pain.     

Biological characterization of human epithelial ovarian carcinoma cells in primary culture: the insulin-like growth factor system

Current hypotheses for explaining which sex cares for offspring assume a relationship between the mode of fertilization and the sex showing parental care. In general, it is hypothesized that maternal care should be concentrated in taxa with internal fertilization, and paternal care should be concentrated in taxa with external fertilization. Studies have supported this relationship; however, new comparative techniques and new data on parental care and the frequency of internal fertilization in anurans suggest that the relationship should be re-evaluated. I examined the relationship between mode of fertilization and sex providing parental care in 334 taxa of anurans using concentrated changes tests and in 396 taxa of anurans using a method developed by Ridley (1983. The Explanation of Organic Diversity. The Comparative Method and Adaptations of Mating. Oxford: Clarendon). The results of the concentrated changes tests showed that both female and male parental care are randomly distributed among taxa with respect to mode of fertilization. However, using Ridley's method, I found significant relationships between mode of fertilization and sex providing parental care. The observed and expected numbers of transitions from external fertilization and no parental care to external fertilization and male parental care or to internal fertilization and female parental care are not qualitatively different. Therefore, the results of my analyses suggest that current hypotheses for explaining the occurrence of maternal versus paternal care in anurans should be reconsidered. Copyright 1998 The Association for the Study of Animal Behaviour.     

Stress proteins are not induced in mammalian cells exposed to radiofrequency or microwave radiation

We performed 34 antenatal MRI, in utero in 29 foetuses with cerebral malformations depicted by US. For five patients, a second antenatal MRI was performed because of a technical failure or of diagnosis doubt. We considered that MRI is a valuable imaging method. We have observed 2 false negatives (myelomeningocele, gyration abnormality) on MR study (n = 34). MRI is more contributive that US for the etiological diagnosis of ventricular enlargement: 83% versus 46%. MRI depicted corpus callosum agenesis misdiagnosed in 5 patients by US. MR results modified the therapeutic procedure in 37% of our patients. We think that the optimal term to perform MRI study is after 28 weeks gestational age because of the size of the fetus and for the timing of cerebral development. Ventricular dilatation (criteria: occipital horn size more that one centimeter at 25 weeks of term) is the main indication of MR study.     

Formyl peptide receptors are coupled to multiple mitogen-activated protein kinase cascades by distinct signal transduction pathways: role in activation of reduced nicotinamide adenine dinucleotide oxidase

Formyl peptide receptor activation of three mitogen-activated protein kinase (MAPK) cascades, extracellular signal-regulated kinases (ERKs), N-terminal kinases (JNKs), and p38 MAPK was examined in differentiated HL-60 granulocytes. FMLP stimulated a concentration- and time-dependent increase in ERK, JNK, and p38 MAPK activities, all of which were dependent on a pertussis toxin-sensitive G protein. Pharmacologic inhibitors were used to examine the roles of tyrosine kinases, phosphatidylinositol 3-kinase, protein kinase C, and phospholipase C. FMLP-stimulated ERK activity was dependent on tyrosine kinases, phosphatidylinositol 3-kinase, protein kinase C, and phospholipase C; p38 MAPK activation was dependent on phosphatidylinositol 3-kinase and phospholipase C; while JNK activation was independent of all of these signaling components. The mitogen-activated protein kinase/ERK kinase inhibitor PD098059 reduced ERK activation by 90%, while an inhibitor of p38 MAPK, SB203580, inhibited p38 MAPK activation by 80%. Both PD098059 and SB203580 inhibited FMLP-stimulated superoxide release, as did inhibitors directed against protein kinase C, tyrosine kinases, and phosphatidylinositol 3-kinase. We conclude that formyl peptide receptors are coupled to three MAPK cascades by Gi proteins. ERKs, p38 MAPK, and JNKs are each activated by distinct proximal signal transduction pathways. Activation of p38 MAPK is necessary for FMLP stimulation of respiratory burst activity; however, a second signal that may involve ERK is also required for this activity.     

Conservatively managed tibial shaft fractures in Nottingham, UK: are pain, osteoarthritis, and disability long-term complications?

OBJECTIVES: To investigate longterm pain and disability subsequent to a tibial shaft fracture treated conservatively. DESIGN AND SETTING: Subjects who had sustained a tibial shaft fracture more than 27 years ago were compared with those who had not. SUBJECTS: 572 fracture patients (identified from the records of the plaster room) aged over 16 at the time of injury were contracted and were compared with 2285 randomly selected subjects matched for age, sex, and general practice. MAIN OUTCOME MEASURES: Self reported knee pain; self reported GP's diagnosis of osteoarthritis; ability to climb stairs, walk 100 yards, to bend, kneel, or stoop; and SF-36 physical functioning score. RESULTS: Subjects were reviewed between 27 and 41 years after tibial shaft fracture (mean 35 years). Fracture patients were more likely to suffer chronic knee pain (odds ratio 1.23; 95% confidence interval (CI) 1.00, 1.51) and report being given a diagnosis of osteoarthritis by their GP (odds ratio 1.46; 95% CI 1.08, 1.97). The ability to climb stairs, walk 100 yards, and bend, kneel, or stoop was less in the fracture group than the other subjects. The SF-36 physical function score was significantly lower in the fracture group. CONCLUSIONS: More than 27 years after a tibial shaft fracture, subjects have more knee pain than the rest of the population. They also have greater difficulty performing everyday physical activities. The excess morbidity may be due to injury factors or treatment factors, and further research is needed to investigate this important association further.     

Transgenic dairy cattle: genetic engineering on a large scale

Amid the explosion of fundamental knowledge generated from transgenic animal models, a small group of scientists has been producing transgenic livestock with goals of improving animal production efficiency and generating new products. The ability to modify mammary-specific genes provides an opportunity to pursue several distinctly different avenues of research. The objective of the emerging gene "pharming" industry is to produce pharmaceuticals for treating human diseases. It is argued that mammary glands are an ideal site for producing complex bioactive proteins that can be cost effectively harvested and purified. Consequently, during the past decade, approximately a dozen companies have been created to capture the US market for pharmaceuticals produced from transgenic bioreactors estimated at $3 billion annually. Several products produced in this way are now in human clinical trials. Another research direction, which has been widely discussed but has received less attention in the laboratory, is genetic engineering of the bovine mammary gland to alter the composition of milk destined for human consumption. Proposals include increasing or altering endogenous proteins, decreasing fat, and altering milk composition to resemble that of human milk. Initial studies using transgenic mice to investigate the feasibility of enhancing manufacturing properties of milk have been encouraging. The potential profitability of gene "pharming" seems clear, as do the benefits of transgenic cows producing milk that has been optimized for food products. To take full advantage of enhanced milk, it may be desirable to restructure the method by which dairy producers are compensated. However, the cost of producing functional transgenic cattle will remain a severe limitation to realizing the potential of transgenic cattle until inefficiencies of transgenic technology are overcome. These inefficiencies include low rates of gene integration, poor embryo survival, and unpredictable transgene behavior.     

Abdominal operations after lung transplantation. Indications and outcome

OBJECTIVE: To assess the outcomes of abdominal operations in patients with lung transplants and identify adverse risk factors. DESIGN: Matched cohort study. SETTING: University referral center. PARTICIPANTS: Twelve lung transplant recipients who required abdominal operations (hereafter referred to as case patients) and 12 age-, sex-, and pulmonary diagnosis-matched lung transplant recipients who had not undergone an abdominal procedure (hereafter referred to as control patients). INTERVENTIONS: Elective abdominal operations including laparoscopic cholecystectomies (n = 5), laparoscopic repair of a colovaginal fistula (n = 1), and open colectomy for a benign colovesical fistula (n = 1) and urgent operations including bowel resections (n = 3), subtotal pancreatectomy (n = 1), and hepatorrhaphy for an iatrogenic liver injury (n = 1). MAIN OUTCOME MEASURES: Morbidity and mortality. RESULTS: Abdominal operations were performed in 12 (11%) of the patients undergoing lung transplantation at the university referral center since 1987, with an associated mortality rate of 25%. Morbidity and mortality rates of electively performed procedures were 28% and 14%, respectively. An urgent indication for abdominal procedure was associated with 100% morbidity and 40% mortality. Compared with a matched group of 12 control patients, the long-term survival of the case patients was reduced (18% vs 64% at 4 years). Case patients undergoing an abdominal procedure in the posttransplantation period tended to have a higher prevalence of previous rejection (67% vs 25%), a higher perioperative steroid dosage (53 mg/d vs 36 mg/d), and a significantly lower posttransplantational forced expiratory volume in 1 second (FEV1, 1.23 L vs 1.91 L; P < .05). CONCLUSIONS: Elective abdominal operations are relatively safe in properly prepared lung transplant recipients. However, laparotomy for urgent surgical conditions is associated with increased morbidity and mortality rates caused in part by the magnitude of the abdominal operation and influenced by the status of the lung transplant as manifested by previous rejection episodes, perioperative steroid dosages, and FEV1 values.     

Four new cytotoxic germacranolides from Carpesium divaricatum

In a bioassay-guided search for cytotoxic compounds from higher plants of South Korea, four new sesquiterpenes of the germacranolide type, named cardivins A (1), B (2), C (3), and D (4), have been isolated from the aerial parts of Carpesium divaricatum. Structures of these compounds were elucidated on the basis of spectroscopic techniques. Compounds 1, 2, 3, and 4 showed cytotoxicity to the human tumor cells, A-549 (nonsmall cell lung), SK-OV-3 (ovary), SK-MEL-2 (skin), XF-498 (central nervous system), and HCT-15 (colon).     

Identification and structural influence of a differentially modified N-terminal methionine in human S100b

The calcium-binding protein S100b is a homodimer comprised of two identical 91-residue beta-subunits. Recombinant S100b is a heterogeneous protein, although the basis of this heterogeneity has not been established. We have used mass spectrometry and NMR spectroscopy to determine that heterogeneity in S100b arises from a mixture of formyl-S100b and desformyl-S100b when expressed in Escherichia coli. Reversed-phase HPLC purification of these two forms of S100b has allowed the differences in N-terminal composition to be used as a probe for tertiary contacts in the protein. The presence or absence of the N-terminal formyl group affected the chemical shifts of sequence neighboring residues and those in the linker of the protein (residues 40-43), indicating that these two regions are close in space.     

Randomised, prospective study comparing cemented and cementless total knee replacement: results of press-fit condylar total knee replacement at five years

OBJECTIVE: The objective of this study was to examine the effect of family and neighborhood income on health care use of young children born prematurely and of low birth weight (N = 619). DESIGN: A birth cohort was enrolled in a clinical randomized trial of early childhood educational and family services. SETTINGS/PARTICIPANTS: Infant Health and Development Program provided a sample of low birth weight premature infants stratified by clinical site, birth weight, and treatment group. Maternal reports of health care use, family income, and heath insurance were obtained at 12, 24, and 36 months of corrected age. Neighborhood income was based on census tract residence at birth. MAIN OUTCOME MEASURES: Maternal reports of hospitalizations, doctor visits, and emergency department visits were used; data were averaged over the child's first 3 years of life. RESULTS: Children from poorer families were more likely to be hospitalized and to have more emergency department visits than were children from more affluent families. Residence in poor and middle-income neighborhoods was associated with more emergency department visits than residence in affluent neighborhoods. Families in middle-income neighborhoods reported more doctor visits than families in poor or affluent neighborhoods. CONCLUSION: Neighborhood residence influences health care use by poor and nonpoor families and by insured and uninsured families. The use of the emergency department for low birth weight premature children in middle-income and poor neighborhoods is discussed.