Catastrophic antiphospholipid syndrome. Clinical and laboratory features of 50 patients

We analyzed the clinical and laboratory characteristics of 50 patients with catastrophic antiphospholipid syndrome (APS) (5 from our clinics and 45 from a MEDLINE computer-assisted review of the literature from 1992 through 1996). Thirty-three (66%) patients were female and 17 (34%) were male. Twenty-eight (56%) patients had primary APS, 15 (30%) had defined systemic lupus erythematosus (SLE), 6 (12%) had "lupus-like" syndrome, and 1 (2%) had rheumatoid arthritis. Mean age of patients in this series was 38 +/- 14 years (range, 11-74 yr). Three (6%) patients developed the clinical picture of catastrophic APS under the age of 15 years, and 11 (22%) were 50 years old or more. In 11 (22%) patients, precipitating factors contributed to the development of catastrophic APS (infections in 3, drugs in 3, minor surgical procedures in 3, anticoagulation withdrawal in 2, and hysterectomy in 1). The presentation of the acute multi-organ failure was usually complex, involving multiple organs simultaneously or in a very short period of time. The majority of patients manifested microangiopathy--that is, occlusive vascular disease affecting predominantly small vessels of organs, particularly kidney, lungs, brain, heart, and liver--with a minority of patients experiencing only large vessel occlusions. Thrombocytopenia was reported in 34 (68%) patients, hemolytic anemia in 13 (26%), disseminated intravascular coagulation in 14 (28%), and schistocytes in 7 (14%). The following antibodies were detected: lupus anticoagulant (94%), anticardiolipin antibodies (94%), anti-dsDNA (87% of patients with SLE), antinuclear antibodies (58%), anti-Ro/SS-A (8%), anti-RNP (8%), and anti-La/SS-B (2%). Anticoagulation was used in 70% of the patients, steroids in 70%, plasmapheresis in 40%, cyclophosphamide in 34%, intravenous gammaglobulins in 16%, and splenectomy in 4%. Most patients, however, received a combination of nonsurgical therapies. Death occurred in 25 of the 50 (50%) patients. In most, cardiac problems seemed to be the major cause of death. In several of these, respiratory failure was also present, usually due to acute respiratory distress syndrome and diffuse alveolar hemorrhage. Among the 20 patients who received the combination of anticoagulation, steroids, and plasmapheresis or intravenous gammaglobulins, recovery occurred in 14 (70%) patients. The use of ancrod and defibrotide appeared to be effective in the 2 respective patients in whom they were used.

Atomic structure of an alphabeta T cell receptor (TCR) heterodimer in complex with an anti-TCR fab fragment derived from a mitogenic antibody

Each T cell receptor (TCR) recognizes a peptide antigen bound to a major histocompatibility complex (MHC) molecule via a clonotypic alphabeta heterodimeric structure (Ti) non-covalently associated with the monomorphic CD3 signaling components. A crystal structure of an alphabeta TCR-anti-TCR Fab complex shows an Fab fragment derived from the H57 monoclonal antibody (mAb), interacting with the elongated FG loop of the Cbeta domain, situated beneath the Vbeta domain. This loop, along with the partially exposed ABED beta sheet of Cbeta, and glycans attached to both Cbeta and Calpha domains, forms a cavity of sufficient size to accommodate a single non-glycosylated Ig domain such as the CD3epsilon ectodomain. That this asymmetrically localized site is embedded within the rigid constant domain module has implications for the mechanism of signal transduction in both TCR and pre-TCR complexes. Furthermore, quaternary structures of TCRs vary significantly even when they bind the same MHC molecule, as manifested by a unique twisting of the V module relative to the C module.

Three-dimensional structure of Schistosoma japonicum glutathione S-transferase fused with a six-amino acid conserved neutralizing epitope of gp41 from HIV

The 3-dimensional crystal structure of glutathione S-transferase (GST) of Schistosoma japonicum (Sj) fused with a conserved neutralizing epitope on gp41 (glycoprotein, 41 kDa) of human immunodeficiency virus type 1 (HIV-1) (Muster T et al., 1993, J Virol 67:6642-6647) was determined at 2.5 A resolution. The structure of the 3-3 isozyme rat GST of the mu gene class (Ji X, Zhang P, Armstrong RN, Gilliland GL, 1992, Biochemistry 31:10169-10184) was used as a molecular replacement model. The structure consists of a 4-stranded beta-sheet and 3 alpha-helices in domain 1 and 5 alpha-helices in domain 2. The space group of the Sj GST crystal is P4(3)2(1)2, with unit cell dimensions of a = b = 94.7 A, and c = 58.1 A. The crystal has 1 GST monomer per asymmetric unit, and 2 monomers that form an active dimer are related by crystallographic 2-fold symmetry. In the binding site, the ordered structure of reduced glutathione is observed. The gp41 peptide (Glu-Leu-Asp-Lys-Trp-Ala) fused to the C-terminus of Sj GST forms a loop stabilized by symmetry-related GSTs. The Sj GST structure is compared with previously determined GST structures of mammalian gene classes mu, alpha, and pi. Conserved amino acid residues among the 4 GSTs that are important for hydrophobic and hydrophilic interactions for dimer association and glutathione binding are discussed.

Patterns of morbidity and rehospitalisation following spinal cord injury

STUDY DESIGN

Longitudinal, descriptive design.

OBJECTIVES

The aim of this study was to investigate the frequency, cause and duration of rehospitalisations in individuals with spinal cord injury (SCI) living in the community.

SETTING

Australian spinal cord injury unit in collaboration with State Health Department.

METHODS

A data set was created by linking records from the NSW Department of Health Inpatient Statistics Collection between 1989-1990 and 1999-2000 with data from the Royal North Shore Hospital (RNSH) Spinal Cord Injuries Database using probabilistic record linkage techniques. Records excluded were nontraumatic injuries, age <16 years, spinal column injury without neurological deficit, full recovery (ASIA Grade E) and index admission not at RNSH. Descriptive statistics and time to readmission using survival analysis, stratified by ASIA impairment grade, were calculated.

RESULTS

Over the 10-year period, 253 persons (58.6%) required one or more spinal-related readmissions, accounting for 977 rehospitalisations and 15,127 bed-days (average length of stay (ALOS) 15.5 days; median 5 days). The most frequent causes for rehospitalisation were genitourinary (24.1% of readmissions), gastrointestinal (11.0%), further rehabilitation (11.0%), skin-related (8.9%), musculoskeletal (8.6%) and psychiatric disorders (6.8%). Pressure sores accounted for only 6.6% of all readmissions, however, contributed a disproportionate number of bed-days (27.9%), with an ALOS of 65.9 (median 49) days and over 50% of readmissions (33 out of 64) occurred in only nine individuals aged under 30 years. Age, level and completeness of neurological impairment, all influenced differential rates of readmission depending on the type of complication. Overall rehospitalisation rates were high in the first 4 years after initial treatment episode, averaging 0.64 readmissions (12.6 bed-days) per person at risk in the first year and fluctuating between 0.52 and 0.61 readmissions (5.1-8.3 bed-days) per person at risk per year between the second to fourth years, before trending downwards to reach 0.35 readmissions (2.0 bed-days) as 10th year approaches. Time to readmission was influenced by degree of impairment, with significantly fewer people readmitted for ASIA D (43.2%) versus ASIA A, B and C (55.2-67.0%) impairments (P<0.0001). The mean duration to first readmission was 46 months overall, however, differed significantly between persons with ASIA A-C impairments (26-36 months) and ASIA D impairment (60 months).

CONCLUSION

Identifying rates, causes and patterns of morbidity is important for future resource allocation and targeting preventative measures. For instance, the late complication of pressure sores in a small subgroup of young males, consuming disproportionately large resources, warrants further research to better understand the complex psychosocial and environmental factors involved and to develop effective countermeasures.

Acylshikonin analogues: synthesis and inhibition of DNA topoisomerase-I

Compounds bearing an acyl group of a various size at 1'-OH of shikonin were synthesized as acyl analogues of shikonin, which was isolated from the root of Lithospermum erythrorhizon, and evaluated for inhibitory effect on topoisomerase-I activity. A selective acylation at 1'-OH of shikonin in the presence of dicyclohexylcarbodiimide and 4-(dimethylamino)pyridine gave rise to a good yield of corresponding acylshikonin derivatives. In general, analogues with an acyl group of shorter chain lengths (C2-C6) exerted a stronger inhibitory action than those with longer chain lengths (C7-C20). While the halogen substitution at C-2 of the acetyl moiety failed to increase the inhibitory potency, the placement of double bonds in the acyl group (C5-C7) augmented the potency remarkably. Of the 32 derivatives evaluated, 15 compounds exhibited a higher inhibitory effect than shikonin. Noteworthy, the inhibitory potency of acetylshikonin, propanoylshikonin, and 4-pentenoylshikonin was approximately 4-fold greater than that of camptothecin. All these data suggest that the size of acyl moiety is important for the enhancement of potency, and the presence of olefinic double bonds is also beneficial.

Effects of red-pepper diet on the energy metabolism in men

We investigated the effects of dietary red pepper on the energy metabolism in male subjects. In the first experiment, after having a standardized dinner on the previous evening, the subjects consumed a breakfast (650 kcal) either with or without 10 g of red pepper. For 150 min after the meal, they took a rest and their expired gas was collected. During the initial 30 min after the meal, the energy expenditure tended to be higher in the red-pepper diet period than in the control diet period. For the remaining 120 min, no difference in the energy expenditure was found between the red-pepper diet period and the control diet period. However the carbohydrate oxidation was significantly higher in the red-pepper diet period than in the control diet period while the lipid oxidation was lower in the red-pepper diet period than in the control diet period for 150 min after the meal. In the second experiment, the subjects consumed a breakfast with 10 g of red pepper after an oral administration of propranolol or a placebo. The propranolol abolished the increase in energy expenditure during the initial 30 min due to the meal containing red pepper. For the remaining 120 min, no difference in energy expenditure was found between the propranolol period and the placebo period. These results suggest than an increase in the energy expenditure after the meal containing red pepper appeared only immediately after the meal ingestion and a red-pepper diet increases the carbohydrate oxidation without increasing total energy expenditure for 150 min after the meal. And an increase in the energy expenditure immediately after the meal containing red pepper is considered to be caused by beta-adrenergic stimulation.

SIRT2 regulates tumour hypoxia response by promoting HIF-1α hydroxylation

Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor that has a central role in the regulation of tumour metabolism under hypoxic conditions. HIF-1α stimulates glycolytic energy production and promotes tumour growth. Sirtuins are NAD(+)-dependent protein deacetylases that regulate cellular metabolism in response to stress; however, their involvement in the hypoxic response remains unclear. In this study, it is shown that SIRT2-mediated deacetylation of HIF-1α regulates its stability in tumour cells. SIRT2 overexpression destabilized HIF-1α under hypoxic conditions, whereas HIF-1α protein levels were high in SIRT2-deficient cells. SIRT2 directly interacted with HIF-1α and deacetylated Lys709 of HIF-1α. Deacetylation of HIF-1α by SIRT2 resulted in increased binding affinity for prolyl hydroxylase 2, a key regulator of HIF-1α stability, and increased HIF-1α hydroxylation and ubiquitination. Moreover, a pharmacological agent that increased the intracellular NAD(+)/NADH ratio led to the degradation of HIF-1α by increasing SIRT2-mediated deacetylation and subsequent hydroxylation. These findings suggest that SIRT2-mediated HIF-1α deacetylation is critical for the destablization of HIF-1α and the hypoxic response of tumour cells.

SEPT5_v2 is a parkin-binding protein

Mutations in parkin are associated with various inherited forms of Parkinson's disease (PD). Parkin is a ubiquitin ligase enzyme that catalyzes the covalent attachment of ubiquitin moieties onto substrate proteins destined for proteasomal degradation. The substrates of parkin-mediated ubiquitination have yet to be completely identified. Using a yeast two-hybrid screen, we isolated the septin, human SEPT5_v2 (also known as cell division control-related protein 2), as a putative parkin-binding protein. SEPT5_v2 is highly homologous to another septin, SEPT5, which was recently identified as a target for parkin-mediated ubiquitination. SEPT5_v2 binds to parkin at the amino terminus and in the ring finger domains. Several lines of evidence have validated the putative link between parkin and SEPT5_v2. Parkin co-precipitates with SEPT5_v2 from human substantia nigra lysates. Parkin ubiquitinates SEPT5_v2 in vitro, and both SEPT5_v1 and SEPT5_v2 accumulate in brains of patients with ARJP, suggesting that parkin is essential for the normal metabolism of these proteins. These findings suggest that an important relationship exists between parkin and septins.

Chronic (-)-hydroxycitrate administration spares carbohydrate utilization and promotes lipid oxidation during exercise in mice

(-)-Hydroxycitrate (HCA) is an active ingredient that is extracted from the rind of the Indian fruit, Garcinia cambogia, which is available as an herbal supplement and is used to lose weight. In this study, the acute and chronic effects of HCA on energy metabolism were examined in male Std ddY mice. Mice were placed into metabolic chambers and administered 10 mg HCA or water (control) orally. Serum free fatty acid levels were significantly higher 100 min after administration in the HCA group, but the respiratory exchange ratio was not different from that in the control group. The concentration of glycogen in the gastrocnemius muscle was higher in the HCA group 16 h after administration, and in a separate study, the maximum swimming time until fatigue was slightly longer (P: = 0. 21) than that in the control group on d 1. The difference was significant on d 3 after 3 d of HCA or water administration. Other mice were administered 10 mg HCA or water orally twice a day for 25 d. On d 26, they were placed into metabolic chambers after administration and allowed to rest for 1 h, followed by 1 h of running at 15 m/min. Respiratory gas was monitored. The respiratory exchange ratio was significantly lower in the HCA group during both resting and exercising conditions. These results suggest that chronic administration of HCA promotes lipid oxidation and spares carbohydrate utilization in mice at rest and during running.

Effect of O-glycosylated mucin on invasion and metastasis of HM7 human colon cancer cells

Mucinous colorectal cancers have a poorer prognosis than colorectal cancers which produce a low amount of mucin, but the exact mechanism is not well understood. The present study was undertaken to elucidate the possible mechanisms of invasion and metastasis of colon cancer cells producing high levels of mucin using mucin glycosylation inhibitor, benzyl-alpha-N-acetylgalactosamine. The binding activity of treated HM7 cells to endothelial leukocyte adhesion molecule (ELAM-1) was significantly decreased and fixed cell binding of MoAb SNH-3 and 19-9 (specific for sialyl Le(x) and sialyl Le(a), respectively) was also significantly decreased. Metalloproteinase activity in conditioned medium and invasion of matrigel-coated porous filters by treated HM7 cells were decreased. However, there was no difference between control and treated HM7 cells in terms of matrix protein binding. These results suggest that O-glycosylated mucin is important in the invasive and metastatic properties of HM7 human colon cancer cells.

Opportunistic screening for oral cancer and precancer in general dental practice: results of a demonstration study

OBJECTIVES

To demonstrate the feasibility of opportunistic oral cancer and precancer screening in general dental practice and to determine the prevalence of relevant lesions and risk habits in a population of general dental practice attenders.

DESIGN

A prospective demonstration study, recruiting patients opportunistically.

SETTING

General dental practices.

METHODS

Eighteen general dental practitioners took part in this study. Each attended training sessions to be advised of the study protocol and the criteria of a positive and negative screen. Patients over the age of 35 years were prospectively and opportunistically recruited. Each patient was asked to complete a health questionnaire concerning age, gender, ethnicity, smoking and drinking habits. The dentist then examined the soft tissues and recorded the presence or absence of lesions independently on a second form. The forms were collated and data were analysed to determine prevalence of lesions and associations with risk habits.

RESULTS

Data on 2,265 patients were available for analysis. Oral lesions were detected in 319 patients (14.1%). Ninety-four patients (4.2%) had lesions considered to be either malignant or potentially malignant. There was a significant association between positive lesions and male gender(IRR 1.86, 95% CI 1.22-2.82), heavy smoking (males: IRR 3.68, 95% Cl2.10-6.43: female; IRR 3.58, 954b CI 1.35-9.50) and heavy alcohol use in males (IRR 2.98, 95%q CI 1.06-3.47).

CONCLUSIONS

The results suggest that patients attending general dental practices are representative of the general population both in terms of lesion prevalence and high risk habits such as smoking and drinking. This supports the view that opportunistic screening in a general dental practice setting may be a realistic alternative to population screening. Further research is needed to determine the cost effectiveness of this approach and to investigate the value of targeting high risk groups within this population. General dental practice is ideal for the evaluation of such systems prior to extending these studies to other healthcare settings.

Dietary red pepper ingestion increases carbohydrate oxidation at rest and during exercise in runners

The effects of dietary hot red pepper on energy metabolism at rest and during exercise were examined in long distance male runners 18-23 yr of age. A standardized meal was given on the evening prior to the experiment. The subjects had a meal (2720 kJ) with or without 10 g of hot red pepper for breakfast. During rest (2.5 h after meal) and exercise (pedaling for 1 h at 150 W, about 60% VO2max, using cycling ergometry), expired gasses and venous blood were collected. The meal with hot red pepper significantly elevated respiratory quotient and blood lactate levels at rest and during exercise. Oxygen consumption at rest was slightly but nonsignificantly higher in the hot red pepper meal at 30 min after the meal. Plasma epinephrine and norepinephrine levels were significantly higher in those who had only hot red pepper at 30 min after the meal. These results suggest that hot red pepper ingestion stimulates carbohydrate oxidation at rest and during exercise.

Selective antagonism of dopamine D1 and D2 receptors does not block the development of behavioral sensitization to cocaine

The objective of this study was to determine whether the development of behavioral sensitization to cocaine could be prevented by either D1 or D2 selective dopamine receptor antagonists. Male Wistar rats were treated daily for 7 days with either cocaine (15 mg/kg, IP) or vehicle in combination with the D1 dopamine antagonist SCH 23390 (0.3 mg/kg, SC), the D2 dopamine antagonist sulpiride (100 mg/kg, IP), or vehicle. After the daily injections, the rats were tested for locomotor activity in photocell arenas. Twenty-four hours after the last pre-exposure test session, all rats were given a challenge injection of cocaine (15 mg/kg, IP) and tested for activity. Cocaine treatments produced a greater relative increase in locomotor activity with repeated exposure (i.e. sensitization). Moreover, this increase in cocaine-induced locomotor activity was attenuated by both SCH 23390 and sulpiride. In contrast, neither sulpiride nor SCH 23390 blocked the development of behavioral sensitization to cocaine. That is, rats pretreated with sulpiride or SCH 23390 and cocaine did not differ from rats pre-exposed only to cocaine when given a cocaine challenge injection. These results suggest that behavioral sensitization to cocaine may develop through either D1 or D2 dopamine receptor stimulation or possibly through stimulation of some non-dopaminergic receptor.

Crystal structure and thermodynamic analysis of human brain fatty acid-binding protein

Expression of brain fatty acid-binding protein (B-FABP) is spatially and temporally correlated with neuronal differentiation during brain development. Isothermal titration calorimetry demonstrates that recombinant human B-FABP clearly exhibits high affinity for the polyunsaturated n-3 fatty acids alpha-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, and for monounsaturated n-9 oleic acid (K(d) from 28 to 53 nm) over polyunsaturated n-6 fatty acids, linoleic acid, and arachidonic acid (K(d) from 115 to 206 nm). B-FABP has low binding affinity for saturated long chain fatty acids. The three-dimensional structure of recombinant human B-FABP in complex with oleic acid shows that the oleic acid hydrocarbon tail assumes a "U-shaped" conformation, whereas in the complex with docosahexaenoic acid the hydrocarbon tail adopts a helical conformation. A comparison of the three-dimensional structures and binding properties of human B-FABP with other homologous FABPs, indicates that the binding specificity is in part the result of nonconserved amino acid Phe(104), which interacts with double bonds present in the lipid hydrocarbon tail. In this context, analysis of the primary and tertiary structures of human B-FABP provides a rationale for its high affinity and specificity for polyunsaturated fatty acids. The expression of B-FABP in glial cells and its high affinity for docosahexaenoic acid, which is known to be an important component of neuronal membranes, points toward a role for B-FABP in supplying brain abundant fatty acids to the developing neuron.

Reliability of colposcopy and directed punch biopsy

A group of 118 women underwent laser cone biopsy. Data were collected routinely on proforma case notes and entered into a computerized database. The histology of the cone biopsies was compared with that of previous, colposcopically directed punch biopsies, with the cytology of smears taken in the clinic and with the colposcopic diagnosis. The punch biopsy had a 54% false negative rate and neither of the two microinvasive carcinomas biopsied in this way were detected by the biopsy. Ten of 24 women with negative punch biopsies had CIN III in the cone. When the punch biopsy showed CIN II or worse, the cone biopsy confirmed the presence of CIN in 86%. There was some evidence of false negative cone biopsies. The data suggest that management should not be based solely upon the punch biopsy result but should include consideration of the cytology and colposcopy findings. Excisional methods of treatment are more likely to reveal early invasion and adenocarcinoma-in-situ.

Clinical and molecular characterization of a novel PLIN1 frameshift mutation identified in patients with familial partial lipodystrophy

Perilipin 1 is a lipid droplet coat protein predominantly expressed in adipocytes, where it inhibits basal and facilitates stimulated lipolysis. Loss-of-function mutations in the PLIN1 gene were recently reported in patients with a novel subtype of familial partial lipodystrophy, designated as FPLD4. We now report the identification and characterization of a novel heterozygous frameshift mutation affecting the carboxy-terminus (439fs) of perilipin 1 in two unrelated families. The mutation cosegregated with a similar phenotype including partial lipodystrophy, severe insulin resistance and type 2 diabetes, extreme hypertriglyceridemia, and nonalcoholic fatty liver disease in both families. Poor metabolic control despite maximal medical therapy prompted two patients to undergo bariatric surgery, with remarkably beneficial consequences. Functional studies indicated that expression levels of the mutant protein were lower than wild-type protein, and in stably transfected preadipocytes the mutant protein was associated with smaller lipid droplets. Interestingly, unlike the previously reported 398 and 404 frameshift mutants, this variant binds and stabilizes ABHD5 expression but still fails to inhibit basal lipolysis as effectively as wild-type perilipin 1. Collectively, these findings highlight the physiological need for exquisite regulation of neutral lipid storage within adipocyte lipid droplets, as well as the possible metabolic benefits of bariatric surgery in this serious disease.

Multicentre prospective cohort study of body mass index and postoperative complications following gastrointestinal surgery

BACKGROUND

There is currently conflicting evidence surrounding the effects of obesity on postoperative outcomes. Previous studies have found obesity to be associated with adverse events, but others have found no association. The aim of this study was to determine whether increasing body mass index (BMI) is an independent risk factor for development of major postoperative complications.

METHODS

This was a multicentre prospective cohort study across the UK and Republic of Ireland. Consecutive patients undergoing elective or emergency gastrointestinal surgery over a 4-month interval (October-December 2014) were eligible for inclusion. The primary outcome was the 30-day major complication rate (Clavien-Dindo grade III-V). BMI was grouped according to the World Health Organization classification. Multilevel logistic regression models were used to adjust for patient, operative and hospital-level effects, creating odds ratios (ORs) and 95 per cent confidence intervals (c.i.).

RESULTS

Of 7965 patients, 2545 (32·0 per cent) were of normal weight, 2673 (33·6 per cent) were overweight and 2747 (34·5 per cent) were obese. Overall, 4925 (61·8 per cent) underwent elective and 3038 (38·1 per cent) emergency operations. The 30-day major complication rate was 11·4 per cent (908 of 7965). In adjusted models, a significant interaction was found between BMI and diagnosis, with an association seen between BMI and major complications for patients with malignancy (overweight: OR 1·59, 95 per cent c.i. 1·12 to 2·29, P = 0·008; obese: OR 1·91, 1·31 to 2·83, P = 0·002; compared with normal weight) but not benign disease (overweight: OR 0·89, 0·71 to 1·12, P = 0·329; obese: OR 0·84, 0·66 to 1·06, P = 0·147).

CONCLUSION

Overweight and obese patients undergoing surgery for gastrointestinal malignancy are at increased risk of major postoperative complications compared with those of normal weight.

Solubilization of thiazolobenzimidazole using a combination of pH adjustment and complexation with 2-hydroxypropyl-beta-cyclodextrin

The thiazolobenzimidazole 1-(2,6-difluorophenyl)-1H,3H-thiazolo[3,4-a] benzimidazole, TBI, is an experimental drug for the treatment of AIDS which exhibits a low water solubility (11 micrograms/mL) and is therefore difficult to administer in an injectable solution dosage form at a target solution concentration of 10 mg/mL. The compound has a single ionizable functional group and exhibits an increase in solubility with decreasing pH consistent with a pKa of 3.55, but the maximum solubility attainable by pH adjustment has been shown to be only 0.4 mg/mL (at pH 2). TBI has been found to form inclusion complexes in either its neutral or its protonated form with 2-hydroxypropyl-beta-cyclodextrin (HPCD). The equilibrium constants for 1:1 complex formation were found to be 81 and 1033 M-1 for the protonated and neutral species, respectively. Although the formation of protonated complex is less favored in comparison to the neutral complex, the contribution of this species to the overall solubility of TBI predominates at low pH. Thus, using a combined approach of pH adjustment and complexation with HPCD, a solubility enhancement of 3 orders of magnitude is possible. NMR proton spectroscopy and molecular modeling studies, conducted to understand the orientation of TBI in the complex and the effect of protonation, are described.

Presence of a bi-directional S phase-specific transcription regulatory element in the promoter shared by testis-specific TH2A and TH2B histone genes

During mammalian spermatogenesis, somatic histones are replaced by testis-specific variants. The synthesis of the variants occurs primarily in the germ cells undergoing meiosis in the absence of DNA replication. We have cloned the genes encoding rat somatic and testis-specific H2A (TH2A) histones. The two genes share 300 bp of 5' upstream region with respective H2B genes: somatic H2A with somatic H2B and testis-specific TH2A with testis-specific TH2B gene. The deduced amino acid sequences show that H2A and TH2A histones have eight amino acid differences in the first half of the molecules and three consecutive changes in the C-terminal region. TH2A gene is expressed only in testis. Although synthesis of TH2A and TH2B histones is independent of DNA replication and insensitive to inhibitors of DNA synthesis in testis, the regulatory region shared by the two genes contain a bi-directional S phase-specific transcription regulatory element. In addition, TH2A gene, like TH2B gene, contains the consensus sequence element in the 3' non-coding region which is involved in the S phase-specific stabilization of histone mRNA.

p38 MAPK Participates in Muscle-Specific RING Finger 1-Mediated Atrophy in Cast-Immobilized Rat Gastrocnemius Muscle

Skeletal muscle atrophy is a common phenomenon during the prolonged muscle disuse caused by cast immobilization, extended aging states, bed rest, space flight, or other factors. However, the cellular mechanisms of the atrophic process are poorly understood. In this study, we investigated the involvement of mitogen-activated protein kinase (MAPK) in the expression of muscle-specific RING finger 1 (MuRF1) during atrophy of the rat gastrocnemius muscle. Histological analysis revealed that cast immobilization induced the atrophy of the gastrocnemius muscle, with diminution of muscle weight and cross-sectional area after 14 days. Cast immobilization significantly elevated the expression of MuRF1 and the phosphorylation of p38 MAPK. The starvation of L6 rat skeletal myoblasts under serum-free conditions induced the phosphorylation of p38 MAPK and the characteristics typical of cast-immobilized gastrocnemius muscle. The expression of MuRF1 was also elevated in serum-starved L6 myoblasts, but was significantly attenuated by SB203580, an inhibitor of p38 MAPK. Changes in the sizes of L6 myoblasts in response to starvation were also reversed by their transfection with MuRF1 small interfering RNA or treatment with SB203580. From these results, we suggest that the expression of MuRF1 in cast-immobilized atrophy is regulated by p38 MAPK in rat gastrocnemius muscles.

Superiority of anti-reflux stent compared with conventional stents in the palliative management of patients with cancer of the lower esophagus and esophago-gastric junction: results of a randomized clinical trial

Palliation of inoperable esophageal cancer with covered stents aims to relieve progressive dysphagia and improve health-related quality of life (HRQoL). Introducing a stent across the esophagogastric junction in lower third tumors may predispose to unchecked gastro-esophageal reflux (GER). Esophageal stents incorporating an anti-reflux valve have been introduced to address this problem. We prospectively compared an anti-reflux stent with a standard stent in the palliation of inoperable lower third esophageal tumors. Forty-nine consecutive patients with malignant dysphagia were randomized to receive a standard (n = 25, group 1) or an anti-reflux stent (n = 24, group 2). HRQoL was assessed before stenting, at 1 week and at 2 months, utilizing European Organization for Research and Treatment of Cancer questionnaires QLQ-C30, QLQ-OES24 and reflux questionnaires. Esophageal pH testing was performed within 1 week of the stent insertion. Detailed statistical analysis was employed to assess general QoL, symptoms and pH scores in both groups. Both groups reported significantly improved QoL, health and dysphagia scores at 1 week and 2 months after stenting. Group 2 patients reported significantly (P < 0.05) better DeMeester symptom, general reflux scores, and normal pH profile at 1 week. At 2 months DeMeester symptom scores were significantly (P < 0.05) better in group 2 compared with group 1. Standard and anti-reflux stents afford comparable relief from dysphagia and improved quality of life in patients with inoperable lower third esophageal cancer. Anti-reflux stents, however, controlled symptomatic and physiologically relevant reflux and should therefore be considered as optimal palliation in this cohort.

Caffeine as a lipolytic food component increases endurance performance in rats and athletes

Caffeine is one of the famous ergogenic aids in the athletic field. Caffeine has been known to stimulate lipolysis that spares stored glycogen utilization during moderate intensity exercise. Therefore, we investigated the effects of caffeine ingestion on exercise performance in rats and athletes. Rats were administered the caffeine (6 mg/kg) 1 h prior to the exercise then were run on a treadmill at a speed of 20 m/min. They were decapitated at 0 min, 30 min, 60 min of exercise, and exhausted time point. Human subjects ingested the caffeine (5 mg/kg) 1 h prior to the exercise. They exercised on a cycle ergometer at 60% of their VO2max for 45 min, and then the exercise intensity was increased to 80% of their VO2max until exhaustion. Blood and breathing gas samples were collected and calculated every 10 min during exercise. Respiratory exchange ratio of the caffeine trial was significantly lower than that of the placebo trial in the athletes' study (p<0.05). Blood free fatty acid (FFA) levels in studies of both rats and athletes were increased by caffeine ingestion during exercise (p<0.05). Blood lactate levels were also increased during exercise in both rats and athletes (p<0.05). Increased FFA and glycerol concentrations reduced glycogen utilization during exercise compared with placebo group in rats. In addition, endurance time to exhaustion was significantly increased by the caffeine ingestion in both rats and athletes (p<0.05). These results suggest that the caffeine ingestion enhanced endurance performance resulting from spare stored glycogen with increasing lipolysis from adipose tissues and fat oxidation during exercise both in rats and in athletes.

On defining the rules for interactions between the T cell receptor and its ligand: a critical role for a specific amino acid residue of the T cell receptor beta chain

The specificity of T cell-mediated immune responses is primarily determined by the interaction between the T cell receptor (TCR) and the antigenic peptide presented by the major histocompatibility complex (MHC) molecules. To refine our understanding of interactions between the TCR and the antigenic peptide of vesicular stomatitis virus (VSV) presented by the class I MHC molecule H-2Kb, we constructed a TCR alpha chain transgenic mouse in a TCR alpha-deficient background to define specific structural features in the TCR beta chain that are important for the recognition of the VSV/H-2Kb complex. We found that for a given peptide, a peptide-specific, highly conserved amino acid could always be identified at position 98 of the complementarity-determining region 3 (CDR3) loop of TCR beta chains. Further, we demonstrated that substitutions at position 6, but not position 1, of the VSV peptide induced compensatory changes in the TCR in both the amino acid residue at position 98 and the length of the CDR3beta loop. We conclude that the amino acid residue at position 98 of the CDR3beta loop is a key residue that plays a critical role in determining the specificity of TCR-VSV/H-2Kb interactions and that a specific length of the CDR3beta loop is required to facilitate such interactions. Further, these findings suggest that the alpha and beta chains of TCRs interact with amino acid residue(s) toward the N and C termini of the VSV peptide, respectively, providing functional evidence for the orientation of a TCR with its peptide/MHC ligand as observed in the crystal structures of TCR/peptide/MHC complexes.

Acute inflammatory polyarthritis in association with tamoxifen

The antioestrogen drug tamoxifen is widely used to treat breast carcinoma. We report three cases in which its use was temporally related to the development of an acute inflammatory polyarthritis resembling RA; a side-effect not previously reported. Possible mechanisms for such an effect are discussed.