Risk factors for pulmonary disease due to culture-positive M. tuberculosis or nontuberculous mycobacteria in South African gold miners

The aim of this study was to determine risk factors for disease due to nontuberculous mycobacteria (NTM) compared to those due to Mycobacterium tuberculosis in South African gold miners with pulmonary mycobacterial disease. A case/control study comparing tuberculosis and NTM cases amongst all patients with a positive sputum mycobacterial culture in 1995 was carried out. The 51 cases of disease due to NTM and 425 tuberculosis cases were similar with regard to age, education, home region, smoking habits and percentage of CD4 cells. After adjustment for confounders, those with NTM were more likely to have had previous tuberculosis treatment (odds ratio (OR) 3.61; 95% confidence interval (CI) 1.9-6.9), have worked longer underground (p-value for trend=0.05) or have evidence of silicosis (OR 12.6; 95% CI 2.2-71) and were less likely to drink regularly (OR 0.12; 95% CI 0.02-0.93) than patients with tuberculosis. In patients with disease due to NTM, 35.3% were human immunodeficiency virus-positive compared with 48.8% of tuberculosis patients (p=0.2) and an estimated 21% overall in the mines at the time of the study. Previous tuberculosis treatment, silicosis and duration of underground work are even more strongly associated with disease due to nontuberculous mycobacteria than with tuberculosis. Attempts to reduce the incidence of all pulmonary mycobacterial disease in this community should address recognized risk factors and ensure that those with tuberculosis are diagnosed, treated and cured.

Phosphatidylinositol-3′ kinase-dependent vesicle formation in macrophages in response to macrophage colony stimulating factor

Treatment of the BAC1.2F5 macrophage cell line with Macrophage Colony Stimulating Factor (M-CSF) resulted in a rapid induction of vesiculation that was reminiscent of macropinocytosis. Time-lapse micrography showed that these vesicles initiated as small vesicles at the cell periphery, but grew in size and migrated with time to a perinuclear localisation after growth factor stimulation. Immunofluorescence showed that the M-CSF receptor (c-fms) associated with the small vesicles and also the larger phase-bright vesicles. Treatment with two distinct inhibitors showed that the rapid initiation of vesicle formation was not dependent on phosphatidylinositol-3′ (PI-3) kinase activity; however, the subsequent maintenance, maturation and translocation of the large, phase-bright, c-fms-containing vesicles was dependent on PI-3 kinase activity. The inhibitors could also reverse the further maturation of preformed vesicles. The inhibition of vesicle trafficking and maturation correlated with ablation of M-CSF-induced PI-3 kinase activity associated with p110(alpha). These data demonstrate a role for PI-3 kinase in vesicle trafficking and maintenance. PI-3 kinase activity was also necessary for the macropinocytotic response in macrophages, a process that is essential for efficient antigen processing and presentation in macrophage-like cells.

Totally synthetic lipid-containing polyoxime peptide constructs are potent immunogens

A synthetic peptide corresponding to a sequence from influenza hemagglutinin was used as a model antigen to study the immunogenicity of polyoxime constructs. In the absence of any adjuvant, tetrameric forms of different polyoxime constructs did not elicit an antibody response. High and long-lasting levels of antibody were induced, however, by polyoxime constructs to which Pam3Cys (tripalmitoyl-S-glyceryl cysteine) was attached. Comparable serum antibody levels were achieved with Tetraoxime-Pam3Cys administered by the intraperitoneal or intranasal routes to those obtained when the monomeric peptide was administered by the intraperitoneal route in complete Freund's adjuvant (CFA). Mice receiving Tetraoxime-Pam3Cys and Pam3Cys-peptide intranasally developed peptide-specific antibody secreting cells (ASCs) in their lungs and mediastinal lymph nodes. At low dose, the Tetraoxime-Pam3Cys induced higher levels of antibody compared to those elicited by the monomeric Pam3Cys-peptide delivered by either route. These results show that lipo-tetraoxime constructs assembled by polyoxime chemistry can be potent inducers of systemic and mucosal immunity.

Cross-linking and electron microscopy studies of the structure and functioning of the Escherichia coli ATP synthase

ATP synthase, also called F(1)F(o)-ATPase, catalyzes the synthesis of ATP during oxidative phosphorylation. The enzyme is reversible and is able to use ATP to drive a proton gradient for transport purposes. Our work has focused on the enzyme from Escherichia coli (ECF(1)F(o)). We have used a combination of methods to study this enzyme, including electron microscopy and chemical cross-linking. The utility of these two approaches in particular, and the important insights they give into the structure and mechanism of the ATP synthase, are reviewed.

Factors influencing use of digital prostheses in workers' compensation recipients

The purposes of this study were to retrospectively identify factors associated with decreased use of digital prostheses in workers' compensation recipients 6 months after fitting and to identify characteristics of those individuals who requested and received a second set of prostheses after demonstrating consistent use of the first set. One hundred seventy-eight patients fitted with 281 digital prostheses completed a questionnaire 6 months after fitting. Forty-nine patients (28%) stated they never or occasionally used their prosthesis (low utilization) and 42 (24%) stated they used them more than 4 hours per day (high utilization). One hundred ten patients (62%) reported stump problems; 37 (21%) stated that the problem interfered with the use of the prosthesis. High utilization was associated with nonmanual employment after the injury. Low utilization was associated with male gender, stump problems, and a distal amputation level. Ring finger prostheses were least likely to be used; small finger prostheses, most likely. The country of origin of the patient was not associated with frequency of use. One hundred sixty-one patients had received the prostheses at least 3 years before the end of the study; 45% of these patients had requested and received a second set of prostheses. Women were more likely to request and receive a second set than men. We could not accurately predict future use of digital prostheses. Each case must be evaluated on an individual basis. (J Hand Surg 2000; 25A:80-85.

Approach to the management of complex hepatic injuries

BACKGROUND

Complex hepatic injuries American Association for the Surgery of Trauma Organ Injury Scale grades IV and V incur high mortality rate ranging from 40 to 80%, respectively. The objective of this study is to assess the clinical experience with an aggressive approach to the management of these, the most complex of hepatic injuries.

METHODS

This is a retrospective 6-year study (1992-1997) at an American College of Surgeons urban Level I trauma center of patients sustaining complex hepatic injuries whose interventions included surgery, angiographic embolization, endoscopic retrograde cholangiopancreatography plus biliary stenting and percutaneous computed tomographic-guided drainage. The main outcome measure was survival.

RESULTS

A total of 22 patients sustaining complex hepatic injuries; mean age of 26 years (range, 10-52 years), mean Revised Trauma Scale score of 9.9, mean Injury Severity Score of 32 (range, 16-75), American Association for the Surgery of Trauma - Organ Injury Scale grade IV (13 cases); grade V (9 cases). Mean estimated blood loss was 4,600 mL; mean number of units of blood transfused was 15. The patients underwent the following interventions: surgery (n = 22), re-operated (n = 13), mean number of operations 1.6 (range, 1-4), extensive hepatotomy and hepatorrhaphy (n = 17), nonanatomic resection (n = 7), formal hepatectomy (n = 4), packing (n = 10), direct approach to hepatic veins (n = 3); angiographic embolization (n = 15); endoscopic retrograde cholangiopancreatography and stenting (n = 5); computed tomographic guided drainage (n = 6). Mean length of stay in the intensive care unit was 21 days (range, 2-134 days), mean hospital length of stay was 40 days (range, 2-147 days). Overall mortality rate was 14% (3 of 22 cases), hepatic mortality rate was 9% (2 of 22 cases), mortality rate by injury grade was 8% grade IV (1 of 13 cases) and 22% grade V (2 of 9 cases).

CONCLUSION

In this select patient population, improvements in mortality rates can be achieved with an aggressive approach to the management of complex hepatic injuries, including surgery, early packing, angiographic embolization, endoscopic retrograde cholangiopancreatography and stenting of biliary leaks, and drainage of hepatic abscesses.

Sequence and analysis of chromosome 4 of the plant Arabidopsis thaliana

The higher plant Arabidopsis thaliana (Arabidopsis) is an important model for identifying plant genes and determining their function. To assist biological investigations and to define chromosome structure, a coordinated effort to sequence the Arabidopsis genome was initiated in late 1996. Here we report one of the first milestones of this project, the sequence of chromosome 4. Analysis of 17.38 megabases of unique sequence, representing about 17% of the genome, reveals 3,744 protein coding genes, 81 transfer RNAs and numerous repeat elements. Heterochromatic regions surrounding the putative centromere, which has not yet been completely sequenced, are characterized by an increased frequency of a variety of repeats, new repeats, reduced recombination, lowered gene density and lowered gene expression. Roughly 60% of the predicted protein-coding genes have been functionally characterized on the basis of their homology to known genes. Many genes encode predicted proteins that are homologous to human and Caenorhabditis elegans proteins.

The adhesive binding site of cadherins revisited

Cadherins are single-pass transmembrane proteins that, through their homophilic specificity, function in selective cell adhesion and sorting. They have a modular structure that includes an ectodomain composed of tandem 'cadherin domains,' which have a beta-sandwich topology similar to that of immunoglobulin domains. Some early experiments suggest that, for the 'classical' cadherins, the adhesive specificity is encoded in the membrane-distal amino-terminal cadherin domain. Here, we review these data, and present new data that supports this idea.

Imprecision in medical communication: study of a doctor talking to patients with serious illness

Uncertainty is believed to be a central feature in illness experiences. Conversations between a consultant hematologist and 61 seriously ill patients were transcribed, entered on a database and scrutinized for patterns of language uncertainty by linguistic concordancing analysis. Transcripts were then discussed in detail with the hematologist, and techniques of protocol analysis were used to gain insight into his thought processes during consultations. The main findings were that the doctor used many more expressions of uncertainty than did patients: that evaluative terms were widely used to reassure rather than to worry patients; and that patients and doctor together used certain key terms ambiguously, in a manner which allowed the doctor to feel that facts were not misrepresented while perhaps permitting the patient to feel reassured.

Use of miniradiographs to detect silicosis. Comparison of radiological with autopsy findings

Radiological and routine autopsy findings from 241 South African gold miners were compared, using pathology as the "gold standard." Previous annual screening miniradiographs were read independently by two readers, using the International Labor Office (ILO) grading system, without reference to personal identifiers. Individual and consensus silicosis grades were recorded for each subject. When pathological and radiological silicosis were defined as any abnormal grade, the sensitivity and specificity of the radiological diagnosis was 67.5% and 80%, with positive and negative predictive values of 63% and 83%. Most undetected autopsy silicosis was early-grade. Using higher pathological and radiological grades to define silicosis (5 nodules or more and ILO grades 1/1 and above), sensitivity and specificity increased to 71% and 96%, and positive and negative predictive values increased to 76% and 95%, respectively. Use of a consensus grade made little difference to results from individual readers. For each radiological definition, sensitivity was considerably higher than, but specificity was similar to, that found in a previous study of South African gold miners which used the same pathology source and standard sized films. The difference between these two study findings, and unexpected demonstration of higher sensitivity from miniradiographs, suggests that further research is required into factors affecting radiological interpretation before silicosis grading can be considered to be adequately standardized.

The gammaepsilon-c subunit interface in the ATP synthase of Escherichia coli. cross-linking of the epsilon subunit to the c subunit ring does not impair enzyme function, that of gamma to c subunits leads to uncoupling

Mutants with a cysteine residue in the gamma subunit at position 207 and the epsilon subunit at position 31 were expressed in combination with a c-dimer construct, which contains a single cysteine at position 42 of the second c subunit. These mutants are called gammaY207C/cc'Q42C and epsilonE31C/cc'Q42C, respectively. Cross-linking of epsilon to the c subunit ring was obtained almost to completion without significant effect on any enzyme function, i.e. ATP hydrolysis, ATP synthesis, and ATP hydrolysis-driven proton translocation were all close to that of wild type. The gamma subunit could also be linked to the c subunit ring in more than 90% yield, but this affected coupling. Thus, ATP hydrolysis was increased 2. 5-fold, ATP synthesis was dramatically decreased, and ATP hydrolysis-driven proton translocation was abolished, as measured by the 9-amino-6-chloro-2-methoxyacridinequenching method. These results for epsilonE31C/cc'Q42C indicate that the c subunit ring rotates with the central stalk element. That the gamma-epsilon cross-linked enzyme retains ATPase activity also argues for a gammaepsilon-c subunit rotor. However, the uncoupling induced by cross-linking of gamma to the c subunit ring points to important conformational changes taking place in the gammaepsilon-c subunit interface during this. Blocking these structural changes by cross-linking leads to a proton leak within the F(0).

Remodeling of an acellular collagen graft into a physiologically responsive neovessel

Surgical treatment of vascular disease has become common, creating the need for a readily available, small-diameter vascular graft. However, the use of synthetic materials is limited to grafts larger than 5-6 mm because of the frequency of occlusion observed with smaller-diameter prosthetics. An alternative to synthetic materials would be a biomaterial that could be used in the design of a tissue-engineered graft. We demonstrate that a small-diameter (4 mm) graft constructed from a collagen biomaterial derived from the submucosa of the small intestine and type I bovine collagen has the potential to integrate into the host tissue and provide a scaffold for remodeling into a functional blood vessel. The results obtained using a rabbit arterial bypass model have shown excellent hemostasis and patency. Furthermore, within three months after implantation, the collagen grafts were remodeled into cellularized vessels that exhibited physiological activity in response to vasoactive agents.

Report of the International Equine Gene Mapping Workshop: male linkage map

The goal of the First International Equine Gene Mapping Workshop, held in 1995, was the construction of a low density, male linkage map for the horse. For this purpose, the International Horse Reference Family Panel (IHRFP) was established, consisting of 12 paternal half-sib families with 448 half-sib offspring provided by 10 laboratories. Blood samples were collected and DNA extracted in each laboratory and sent to the Lexington laboratory (KY, USA) for dispatch in aliquots to 14 typing laboratories. In total, 161 markers (144 microsatellites, seven blood groups and 10 proteins) were tested for all families for which the sire was heterozygous. Genealogies and typing data were sent for analysis to the INRA laboratory (Jouy-en-Josas, France) according to a specific format and entered into a database with input verification and output processes. Linkage analysis was performed with the CRIMAP program. Significant linkage was detected for 124 loci, of which 95 were unambiguously ordered using a multipoint analysis with an average spacing of 14.2 CM. These loci were distributed among 29 linkage groups. A more comprehensive analysis including synteny group data and FISH data suggested that 26 autosomes out of 31 are covered. The complete map spans 936 CM.

Helical interactions and membrane disposition of the 16-kDa proteolipid subunit of the vacuolar H(+)-ATPase analyzed by cysteine replacement mutagenesis

Theoretical mechanisms of proton translocation by the vacuolar H(+)-ATPase require that a transmembrane acidic residue of the multicopy 16-kDa proteolipid subunit be exposed at the exterior surface of the membrane sector of the enzyme, contacting the lipid phase. However, structural support for this theoretical mechanism is lacking. To address this, we have used cysteine mutagenesis to produce a molecular model of the 16-kDa proteolipid complex. Transmembrane helical contacts were determined using oxidative cysteine cross-linking, and accessibility of cysteines to the lipid phase was determined by their reactivity to the lipid-soluble probe N-(1-pyrenyl)maleimide. A single model for organization of the four helices of each monomeric proteolipid was the best fit to the experimental data, with helix 1 lining a central pore and helix 2 and helix 3 immediately external to it and forming the principal intermolecular contacts. Helix 4, containing the crucial acidic residue, is peripheral to the complex. The model is consistent not only with theoretical proton transport mechanisms, but has structural similarity to the dodecameric ring complex formed by the related 8-kDa proteolipid of the F(1)F(0)-ATPase. This suggests some commonality between the proton translocating mechanisms of the vacuolar and F(1)F(0)-ATPases.

Traumatic injury to the superior mesenteric artery

BACKGROUND

Superior mesenteric artery (SMA) injuries are rare and devastating injuries incurring very high mortality rates. It is the purpose of this study to review our experience with these injuries, to analyze Fullen's classification based on anatomical zone and injury grade for its predictive value, and to correlate the American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS) for abdominal vascular injury with mortality.

METHODS

Retrospective study was made over a 65-month period of all patients sustaining SMA injuries in an urban level I trauma center.

RESULTS

Thirty-five patients, mean age 31, had a mean Revised Trauma Score of 5.86 and a mean Injurity Severity Score of 23. Mechanisms of injury were penetrating 27 (77%) and blunt 8 (23%). Mean admission systolic blood pressure was 85 mm Hg. Mean estimated blood loss was 8,500 mL and mean total fluid replacement 17,000 mL. Operating room findings were retroperitoneal hematoma in 34 (97%) and "black bowel" in 2 (6%). Number of associated injuries was nonvascular, mean 4.2, and vascular, mean 1.5. Surgical management consisted of ligation in 18 (51%), primary repair in 14 (40%), and interposition graft in 2 (6%). Overall mortality was 19 of 35 (54%). Mortality versus Fullen's zones was zone I, 100%, zone II, 43%, and zones III and IV, 25%. Mortality versus Fullen's ischemia grade was grade 1, 89%, grade 2, 58%, grade 3, 100%, and grade 4, 19%. Mortality versus AAST-OIS: was grade 1, 0%, grade II, 20%, grade III, 0%, grade IV, 59%, and grade V, 88%.

CONCLUSIONS

SMA injuries are highly lethal. Most deaths are due to exsanguination. A higher number of associated vascular injuries increases mortality. "Black bowel" is an uncommon finding. Both Fullen's anatomical zones and the AAST-OIS for abdominal vascular injuries correlate with mortality. Fullen's ischemia grade does not.

Clonal immunoglobulin light chain variable region germline gene use in AL amyloidosis: association with dominant amyloid-related organ involvement and survival after stem cell transplantation

AL (primary or immunoglobulin light chain) amyloidosis (AL) differs from myeloma per se in that tissue deposits of amyloid are found, typically in association with small numbers of clonal plasma cells producing lambda light chains, and also in that AL patients typically present with a predominantly dysfunctional organ-system. This constellation of features - fibrillar deposits comprised of light chains, lambda light chain predominance, and organ-system tropism and dysfunction - remains unexplained. Select patients with AL respond to haemopoietic stem cell transplantation (SCT) with clinical improvement and extended survival, particularly those who do not have cardiac involvement. In order to ascertain whether the organ-system tropism of AL was associated with immunoglublin light chain variable region (Ig VL) germline gene utilization, we attempted to clone, sequence and assign germline donors to the clonal Ig VL genes of 62 AL patients, all of whom were treated with SCT. We succeeded in 39 cases, identifying clonal AL genes derived from donors of the lambdaI (n = 10), lambdaII (n = 5), lambdaIII (n = 6), lambdaVI (n = 11) and KI (n = 7) subtypes. The majority of the donors (IGLV6S1, DPL5, DPL2, DPL23 and LFVK431) were genes that appear in the expressed repertoire <5% of the time, suggesting an intrinsic propensity to form amyloid under certain conditions. Patients whose clones derived from the lambdaVI IGLV6S1 donor uniformly presented with dominant renal involvement while those with other Vlambda or unknown donors often had dominant cardiac or other organ involvement, particularly patients whose clones derived from the lambdaI DPL2 donor. In addition, both early (<3 months) and overall post-SCT survival were significantly better in lambdaVI IGLV6S1 patients compared to patients with other Vlambda donors. These findings indicate that there are important associations in AL amyloidosis among Ig VL gene utilization, organ-system tropism and post-SCT survival.

EUROCARE: a cross-national study of co-resident spouse carers for people with Alzheimer's disease: I--Factors associated with carer burden

BACKGROUND

The challenges presented by the increasing public health and social impact of caring for people with dementia have become clear in recent years. Previous research has identified that, while there are positive as well as negative elements to the caring role, carers are at high risk of mental health problems and that the comprehensive burden of caring has social, economic and health based elements. Co-resident carers, especially spouses, are of primary importance in maintaining people with dementia in their own homes in the community rather than in institutional settings which may be both more costly and have greater environmental poverty. There have, however, been few studies which have sought to investigate factors associated with carer burden and differences and similarities between countries. In this study we aimed to produce a cross-national profile of co-resident spouse carers across the European Community, with particular attention to: living arrangements; formal and informal support; service satisfaction; perceived burden; and psychological well-being.

METHOD

Twenty co-resident spouse carers of people with NINCDS-ADRDA probable dementia, who had been diagnosed as such within the past 12-36 months, were recruited from service contacts in each of 14 out of the 15 countries of the EU. All completed a semi-structured interview which included: sociodemographic data; data on health and social service use; the Carer Burden Inventory (CBI); the General Health Questionnaire-12 (GHQ-12); and open-ended qualitative questions about the experience of caring.

RESULTS

Two hundred and eighty couples were recruited. There was marked variation in all variables of interest between countries, but there were consistently high ratings of carer burden (mean CBI scores between 28 and 52) and psychological distress (between 40% and 75% scoring 4 or more on the GHQ-12). Using multivariate analyses (generalized linear modelling) to estimate the individual associations of variables of interest with carer burden, controlling for the effects of all other variables in the model, the following results were obtained: 11.4% (p = 0.003) of the variance was accounted for by between-country variation; 4.9% (p < 0.001) by expressed financial dissatisfaction; 4.5% (p = 0.001) by lower carer age; 3.2% (p = 0.004) by difficulties with spouse behavioural deficits; and 2.0% (p = 0.024) by perceived negative social reactions. There was a low level of contact with support groups and Alzheimer's disease societies despite the samples having been of service contacts.

CONCLUSIONS

This study confirms the high level of burden and mental distress in spouse carers for people with Alzheimer's disease in the European Community. It suggests that there are elements of burden which may vary by country but also elements which have a common effect in all. These data suggest avenues for the primary and secondary prevention of burden by addressing clinical issues (e.g. behavioural disturbance); public attitudes and education (e.g. negative social reactions); economic support for carers (e.g. financial dissatisfaction); and higher risk groups (e.g. younger spouse carers).

Role of neutrophil apoptosis in the resolution of pulmonary inflammation

Neutrophil-mediated lung injury may result from one or more of the following possible causes: 1) loss of the normal mechanisms that regulate and switch off neutrophil influx, 2) inappropriate or uncontrolled neutrophil activation within the lung, 3) inhibition of neutrophil apoptosis, and 4) impairment or saturation of the normal macrophage-dependent process for the removal of apoptotic neutrophils. Current in vitro data indicate that many factors operating at the inflamed site (e.g. cytokines, growth factors, chemotactic peptides, hypoxia, acidosis, etc.) serve a dual function in both priming and activating these cells, and delay apoptosis. The observation that the rate of eosinophil apoptosis can be accelerated by corticosteroid therapy in vivo suggests a novel mode of action for this drug and indicates that targeting this process in other granulocyte-dependent inflammatory conditions may offer a novel therapeutic approach in inflammatory lung disease.

EUROCARE: a cross-national study of co-resident spouse carers for people with Alzheimer's disease: II--A qualitative analysis of the experience of caregiving

BACKGROUND

Spouses caring for a partner with dementia are subject to physical, psychological and social stresses. In view of the part played by spouse carers in preventing admission to institutional care, a fuller understanding of the subjective experience of caring is an important area of enquiry. Qualitative analysis of their accounts of the difficulties and rewards in looking after their partners may indicate strategies to support them and to alleviate the stresses that they experience.

METHOD

Twenty co-resident spouses of people with NINCDS-ADRDA probable dementia of the Alzheimer's type, who had been diagnosed as such within the past 12-36 months, were recruited from service contacts in each of 14 out of the 15 countries of the EU. All completed a semi-structured interview that included open-ended questions about the experience of caring.

RESULTS

Overall, the most commonly expressed difficulties reflected: loss of companionship through diminished quality of communication; loss of reciprocity as carers experienced their partners' growing dependency; and deterioration in their partners' social behaviour. Satisfaction from caring stemmed from: a feeling of job satisfaction; continued reciprocity and mutual affection; companionship; and the fulfillment of a sense of duty.

CONCLUSION

Spouse carers in the 14 countries described the difficulties and rewards of caring in similar terms. This suggests commonality of experience, in spite of diversity in informal and statutory provision of care for older people between different countries.

Involvement of mitogen-activated protein kinase homologues in the regulation of lipopolysaccharide-mediated induction of cyclo-oxygenase-2 but not nitric oxide synthase in RAW 264.7 macrophages

In RAW 264.7 macrophages lipopolysaccharide (LPS) stimulated the activation of p42 and p44 MAP kinases and their upstream activator mitogen-activated protein (MAP) kinase kinase (MAPKK), and induced the 69-kDa isoform of cyclo-oxygenase-2 (COX-2) and the 130-kDa isoform of nitric oxide synthase (iNOS). PD 098059, a specific inhibitor of the activation of MAPKK, prevented LPS-mediated activation of MAPKK (IC50 = 3.0 +/- 0.1 microM, n = 3) and p42/44 MAP kinases and substantially reduced the induction of COX-2 by approximately 40%-70%, but was without effect upon the induction of iNOS. In parallel, LPS also stimulated the activation of p38 MAP kinase and the MAPKAP kinase-2, a downstream target of p38 MAP kinase. SB 203580, a specific inhibitor of p38 MAP kinase prevented the activation of p38 MAP kinase (IC50 = 3.3 +/- 1.4 microM, n = 3) and MAPKAP kinase-2 by LPS and reduced the induction of COX-2 by approximately 50-90%, with no significant effect upon iNOS expression. These studies indicate the involvement of both the classical p42/44 MAP kinases and p38 MAP kinase in the regulation of COX-2 but not iNOS induction following exposure to LPS.

Identification of a novel substitution in the constant region of a gene coding for an amyloidogenic kappa1 light chain

Current concepts regarding the association between immunoglobulin (Ig) light chain structure and AL amyloidosis (AL) emphasize Ig variable region amino acid substitutions because the majority of light chain amyloid fibrils that have been sequenced contain amino termini of the variable region with only small amounts of the constant region. In this report, we describe a patient with rapidly progressive AL whose amyloid deposits contained primarily monoclonal kappa light chain constant region fragments. We sequenced and analyzed this AL protein, determining that it was an O18-O8 kappa1 variant and that the constant region possessed an unusual Ser-->Asn substitution at position 177. Using pre-mortem bone marrow cells, we cloned and sequenced the cDNA for this AL protein (HCAK1) and, using DNA from post-mortem somatic tissue, we cloned and sequenced the patient's kappa germline O18-O8 donor and kappa constant region (Ckappa) gene segments. The cDNA that coded for HCAK1 contained a variable region that was derived from O18-O8, showing 96.1% homology to germline, and a Ckappa that had a nucleotide substitution (AGC to AAC), resulting in the 177Ser-->Asn replacement. Two Ckappa genes were cloned from somatic tissue DNA, one identical to a known Ckappa sequence and another containing this substitution which likely is a new Ckappa allotype. Our findings indicate that further investigation is warranted into the contributions genetic polymorphisms and light chain constant regions may make to amyloidogenesis.