Blocking the effects of IL-1 in rheumatoid arthritis protects bone and cartilage

Destruction of articular joints occurs progressively in patients with rheumatoid arthritis (RA). Although the exact aetiology of RA has not been fully elucidated, a large body of evidence supports a role for interleukin-1 (IL-1) in cartilage and bone erosion. In vitro studies suggest that IL-1 can cause cartilage destruction by stimulating the release of matrix metalloproteinases and other degradative products, and it can increase bone resorption by stimulating osteoclast differentiation and activation. In animal models of RA, blocking the effects of IL-1 with either IL-1 receptor antagonist (IL-1Ra; endogenous), anti-IL-1 monoclonal antibodies, or soluble IL-1 type II receptors significantly reduced cartilage destruction and bone erosion. Gene therapy with IL-1Ra was also effective in reducing joint destruction in experimental RA and osteoarthritis (OA) models. In clinical studies, anakinra, a human recombinant IL-1 receptor antagonist (IL-1ra; exogenous), significantly slowed radiographic progression of RA relative to placebo and significantly reduced clinical symptoms when used as monotherapy or in addition to existing methotrexate therapy. These results demonstrate that blocking IL-1 protects bone and cartilage from progressive destruction in RA.

Thromboprophylaxis rates in US medical centers: success or failure?

BACKGROUND

As hospitalized medical patients may be at risk of venous thromboembolism (VTE), evidence-based guidelines are available to help physicians assess patients' risk for VTE, and to recommend prophylaxis options. The rate of appropriate thromboprophylaxis use in at-risk medical inpatients was assessed in accordance with the 6th American College of Chest Physicians (ACCP) guidelines.

METHODS

Hospital discharge information from the Premier Perspective(trade mark) inpatient data base from January 2002 to September 2005 was used. Included patients were 40 years old or more, with a length of hospital stay of 6 days or more, and had no contraindications for anticoagulation. The appropriateness of VTE thromboprophylaxis was determined in seven groups with acute medical conditions by comparing the daily thromboprophylaxis usage, including type of thromboprophylaxis, dosage of anticoagulant and duration of thromboprophylaxis, with the ACCP recommendations.

RESULTS

A total of 196 104 discharges from 227 hospitals met the inclusion criteria. The overall VTE thromboprophylaxis rate was 61.8%, although the appropriate thromboprophylaxis rate was only 33.9%. Of the 66.1% discharged patients who did not receive appropriate thromboprophylaxis, 38.4% received no prophylaxis, 4.7% received mechanical prophylaxis only, 6.3% received an inappropriate dosage, and 16.7% received an inappropriate prophylaxis duration based on ACCP recommendations.

CONCLUSIONS

This study highlights the low rates of appropriate thromboprophylaxis in US acute-care hospitals, with two-thirds of discharged patients not receiving prophylaxis in accordance with the 6th ACCP guidelines. More effort is required to improve the use of appropriate thromboprophylaxis in accordance with the ACCP recommendations.

Selection of antibiotic-resistant bacterial mutants: allelic diversity among fluoroquinolone-resistant mutations

To obtain a general framework for understanding selection of antibiotic-resistant mutants, allelic diversity was examined with about 600 fluoroquinolone-resistant mutants of mycobacteria. Selection at low fluoroquinolone concentration produced many low-level resistance mutants. Some of these contained mutations that conferred unselected antibiotic resistance; none contained alterations in the quinolone-resistance-determining region of the GyrA protein, the principal drug target. As selection pressure increased, a variety of GyrA variants became prevalent. High concentrations of antibiotic reduced the variety to a few types, and eventually a concentration was reached at which no mutant was recovered. That concentration defined a threshold for preventing the selection of resistance. The pattern of variants selected, which was also strongly influenced by antibiotic structure, readily explained the variants present in clinical isolates. Thus, resistance arises from selection of mutants whose identity depends on drug concentration and structure, both of which can be manipulated to restrict selection.

Negligible genetic diversity of mycobacterium tuberculosis host immune system protein targets: evidence of limited selective pressure

A common theme in medical microbiology is that the amount of amino acid sequence variation in proteins that are targets of the host immune system greatly exceeds that found in metabolic enzymes or other housekeeping proteins. Twenty-four Mycobacterium tuberculosis genes coding for targets of the host immune system were sequenced in 16 strains representing the breadth of genomic diversity in the species. Of the 24 genes, 19 were invariant and only six polymorphic nucleotide sites were identified in the 5 genes that did have variation. The results document the highly unusual circumstance that prominent M. tuberculosis antigenic proteins have negligible structural variation worldwide. The data are best explained by a combination of three factors: (i) evolutionarily recent global dissemination in humans, (ii) lengthy intracellular quiescence, and (iii) active replication in relatively few fully immunocompetent hosts. The very low level of amino acid diversity in antigenic proteins may be cause for optimism in the difficult fight to control global tuberculosis.

Increased nitric oxide production accompanied by the up-regulation of inducible nitric oxide synthase in vascular endothelium from patients with systemic lupus erythematosus

OBJECTIVE

To investigate whether systemic lupus erythematosus (SLE) is accompanied by increased serum nitrite levels, whether active compared with inactive disease is associated with greater nitric oxide (NO) production, and whether endothelial cells or keratinocytes serve as cellular sources of NO by virtue of their increased expression of either constitutive nitric oxide synthase (cNOS) or inducible NOS (iNOS).

METHODS

Fifty-one serum samples (46 from patients with SLE) were analyzed for NO production by measuring nitrite levels in a calorimetric assay. Skin biopsy samples from 21 SLE patients and 11 healthy volunteers were evaluated immunohistochemically, using monoclonal antibodies, for endothelial cell and keratinocyte cNOS and iNOS expression.

RESULTS

Serum nitrite levels were significantly elevated in the 46 patients with SLE (mean +/- SEM 37 +/- 6 microM/liter) compared with controls (15 +/- 7 microM/liter; P < 0.01), and were elevated in patients with active SLE compared with those with inactive disease (46 +/- 7 microM/liter versus 30 +/- 7 microM/liter; P < 0.01). Serum nitrite levels correlated with disease activity (r = 0.47, P = 0.04) and with levels of antibodies to double-stranded DNA (r = 0.35, P = 0.02). Endothelial cell expression of iNOS in SLE patients (mean +/- SEM score 1.5 +/- 0.2) was significantly greater compared with controls (0.6 +/- 0.2; P < 0.01), and higher in patients with active disease compared with those with inactive SLE (1.7 +/- 0.2 versus 1.2 +/- 0.2; P < 0.01). Keratinocyte expression of iNOS was also significantly elevated in SLE patients (0.9 +/- 0.1) compared with controls (0.4 +/- 0.1; P < 0.001). With regard to expression of cNOS, there were no differences between patients with active SLE, those with inactive SLE, and normal controls in either the vascular endothelium or the keratinocytes.

CONCLUSION

NO production is increased in patients with SLE, and 2 potential sources of excessive NO are activated endothelial cells and keratinocytes via up-regulated iNOS.

Characterization of Mycobacterium tuberculosis isolates from patients in Houston, Texas, by spoligotyping

Mycobacterium tuberculosis isolates (n = 1,429) from 1,283 patients collected as part of an ongoing population-based tuberculosis epidemiology study in Houston, Texas, were analyzed by spoligotyping and IS6110 profiling. The isolates were also assigned to one of three major genetic groups on the basis of nucleotide polymorphisms located at codons 463 and 95 in the genes (katG and gyrA) encoding catalase-peroxidase and the A subunit of DNA gyrase, respectively. A total of 225 spoligotypes were identified in the 1,429 isolates. There were 54 spoligotypes identified among 713 isolates (n = 623 patients) assigned to 73 IS6110 clusters. In addition, among 716 isolates (n = 660 patients) with unique IS6110 profiles, 200 spoligotypes were identified. No changes were observed either in the IS6110 profile or in the spoligotype for the 281 isolates collected sequentially from 133 patients. Five instances in which isolates with slightly different spoligotypes had the same IS6110 profile were identified, suggesting that in rare cases isolates with different spoligotypes can be clonally related. Spoligotypes correlated extremely well with major genetic group designations. Only three very similar spoligotypes were shared by isolates from genetic groups 2 and 3, and none was shared by group 1 and group 2 organisms or by group 1 and group 3 organisms. All organisms belonging to genetic groups 2 and 3 failed to hybridize with spacer probes 33 to 36. Taken together, the results support the existence of three distinct genetic groups of M. tuberculosis organisms and provide new information about the relationship between IS6110 profiles, spoligotypes, and major genetic groups of M. tuberculosis.

Hepatoprotective effects of Hibiscus, Rosmarinus and Salvia on azathioprine-induced toxicity in rats

As an anti-metabolite, Azathioprine inhibits the de novo and salvage pathways of purine synthesis. Intraperitoneal injection of this drug results in not only lymphocyte suppression but also toxicity to bone marrow, gastrointestinal tract, and liver. This Azathioprine-induced hepatotoxicity was found to be associated with oxidative damage. Plants with antioxidative properties have been traditionally used to prevent diseases associated with free radicals. In this report, we used water extracts of three herbal plants that have been commonly used for treating many illnesses (Hibiscus sabdariffa, Rosmarinus officinalis and Salvia officinalis). Here we show their novel hepatoprotective effects against Azathioprine-induced hepatotoxicity in rats. Typically, administration of Azathioprine induces oxidative stress through depleting the activities of antioxidants and elevating the level of malonialdehyde in liver. This escalates levels of alanine aminotransferase, and aspartate aminotranferase in serum. Pretreatment with any of the three herbal plants used in this investigation proved to have a protective effect against Azathioprine-induced hepatotoxicity. Animals pretreated with water extracts from any of the three herbs under investigation not only failed to show necrosis of the liver after azathioprine administration, but also retained livers that, for the most part, were histologically normal. In addition, these herbs blocked the induced elevated levels of alanine aminotransferase and aspartate aminotranferase in serum. The Azathioprine-induced oxidative stress was relieved to varying degrees by the examined herbal extracts. This effect was evident through reducing malonialdehyde levels and releasing the inhibitory effect of Azathioprine on the activities of glutathione, catalase and superoxide dismutase. To our knowledge, this report is the first that shows hepatoprotective effects of Hibiscus, Rosmarinus and Salvia species against Azathioprine-induced acute liver damage.

Cotinine validation of self-reported smoking in commercially run community surveys

A validation study was carried out on self-reported smoking for 1177 people in Sydney and Melbourne in 1983. Because of its long half life and the fact that smoking is its only source in body fluids, saliva cotinine was chosen as the validation measure. Cotinine levels above 250 nmol/l were used to classify people as smokers. The sensitivity of self-reported smoking was 92.6% and the specificity was 93.4%. There was some evidence that people in the process of changing their smoking status might be slow in updating their self-classification. The smoking prevalence estimate based on cotinine levels was found to be 1.7% lower than that for self-reported smoking status. The small proportion of false negatives and false positives suggests that commercially collected data banks can be valid sources of prevalence data. Correlation between cotinine level and reported cigarette consumption was not affected by sample volume, and was similar to that achieved for carbon monoxide and thiocyanate at a low 0.34. Regression analysis using self-reported cigarette consumption filter/non-filter cigarettes, and time since last cigarette as predictors, explained 13.6% of the variance in cotinine level.

Transplantation of adenovirally transduced allogeneic chondrocytes into articular cartilage defects in vivo

Gene transfer to chondrocytes followed by intra-articular transplantation may allow for functional modulation of chondrocyte biology and enhanced repair of damaged articular cartilage. We chose to examine the loss of chondrocytes transduced with a recombinant adenovirus containing the gene for Escherichia coli beta-galactosidase (Ad.RSVntlacZ), followed by transplantation into deep and shallow articular cartilage defects using New Zealand White rabbits as an animal model. A type I collagen matrix was used as a carrier for the growth of the transduced chondrocytes and to retain the cells within the surgically created articular defects. Histochemical analysis of matrices recovered from the animals 1, 3 and 10 days after implantation showed the continued loss of lacZ positive chondrocytes. The number of cells recovered from the matrices was also compared with the initial innoculum of transduced cells present within the matrices at the time of implantation. The greatest loss of transduced cells was observed in the first 24 h after implantation. The numbers of transduced cells present within the matrices were relatively constant between 1 and 3 days postimplantation, but had progressively declined by 10 days postimplantation. These results suggest that transduction of chondrocytes followed by intra-articular transplantation in this rabbit model may enable us to examine the biological effects of focal transgenic overexpression of proteins involved in cartilage homeostasis and repair.

l-phenylalanine modulates gut hormone release and glucose tolerance, and suppresses food intake through the calcium-sensing receptor in rodents

OBJECTIVE

High-protein diets (HPDs) are associated with greater satiety and weight loss than diets rich in other macronutrients. The exact mechanisms by which HPDs exert their effects are unclear. However, evidence suggests that the sensing of amino acids produced as a result of protein digestion may have a role in appetite regulation and satiety. We investigated the effects of l-phenylalanine (L-Phe) on food intake and glucose homeostasis in rodents.

METHODS

We investigated the effects of the aromatic amino-acid and calcium-sensing receptor (CaSR) agonist l-phenylalanine (L-Phe) on food intake and the release of the gastrointestinal (GI) hormones peptide YY (PYY), glucagon-like peptide-1 (GLP-1) and ghrelin in rodents, and the role of the CaSR in mediating these effects in vitro and in vivo. We also examined the effect of oral l-Phe administration on glucose tolerance in rats.

RESULTS

Oral administration of l-Phe acutely reduced food intake in rats and mice, and chronically reduced food intake and body weight in diet-induced obese mice. Ileal l-Phe also reduced food intake in rats. l-Phe stimulated GLP-1 and PYY release, and reduced plasma ghrelin, and also stimulated insulin release and improved glucose tolerance in rats. Pharmacological blockade of the CaSR attenuated the anorectic effect of intra-ileal l-Phe in rats, and l-Phe-induced GLP-1 release from STC-1 and primary L cells was attenuated by CaSR blockade.

CONCLUSIONS

l-Phe reduced food intake, stimulated GLP-1 and PYY release, and reduced plasma ghrelin in rodents. Our data provide evidence that the anorectic effects of l-Phe are mediated via the CaSR, and suggest that l-Phe and the CaSR system in the GI tract may have therapeutic utility in the treatment of obesity and diabetes. Further work is required to determine the physiological role of the CaSR in protein sensing in the gut, and the role of this system in humans.

Role of the ATP-binding domain of the human papillomavirus type 11 E1 helicase in E2-dependent binding to the origin

Replication of the genome of human papillomaviruses (HPV) is initiated by the recruitment of the viral E1 helicase to the origin of DNA replication by the viral E2 protein, which binds specifically to the origin. We determined, for HPV type 11 (HPV-11), that the C-terminal 296 amino acids of E1 are sufficient for interaction with the transactivation domain of E2 in the yeast two-hybrid system and in vitro. This region of E1 encompasses the ATP-binding domain. Here we have examined the role of this ATP-binding domain, and of ATP, on E2-dependent binding of E1 to the origin. Several amino acid substitutions in the phosphate-binding loop (P loop), which is implicated in binding the triphosphate moiety of ATP, abolished E2 binding, indicating that the structural integrity of this domain is essential for the interaction. The structural constraints imposed on the E1 P loop may differ between HPV-11 and bovine papillomavirus type 1 (BPV-1), since the P479S substitution that inactivates BPV-1 E1 is tolerated in the HPV-11 enzyme. Other substitutions in the E1 P loop, or in two other conserved motifs of the ATP-binding domain, were tolerated, indicating that ATP binding is not essential for interaction with E2. Nevertheless, ATP-Mg stimulated the E2-dependent binding of E1 to the origin in vitro. This stimulation was maximal at the physiological temperature (37 degrees C) and did not require ATP hydrolysis. In contrast, ATP-Mg did not stimulate the E2-dependent binding to the origin of an E1 protein containing only the C-terminal domain (353 to 649) or that of mutant E1 proteins with alterations in the DNA-binding domain. These results are discussed in light of a model in which the E1 ATP-binding domain is required for formation of the E2-binding surface and can, upon the binding of ATP, facilitate and/or stabilize the interaction of E1 with the origin.

Activation of stress-activated protein kinase in osteoarthritic cartilage: evidence for nitric oxide dependence

OBJECTIVE

We have demonstrated in bovine chondrocytes that nitric oxide (NO) mediates IL1 dependent apoptosis under conditions of oxidant stress. This process is accompanied by activation of c-Jun NH2-terminal kinase (JNK; also called stress-activated protein kinase). In these studies we examined activation of JNK in explant cultures of human osteoarthritic cartilage obtained at joint replacement surgery and we characterized the role of peroxynitrite to act as an upstream trigger.

DESIGN

A novel technique to isolate chondrocyte proteins (<10% of total cartilage protein) from cartilage specimens was developed. It was used to analyse JNK activation by a western blot technique. To examine the hypothesis that chondrocyte JNK activation is a result of increased peroxynitrite, in vitro experiments were performed in which cultured chondrocytes were incubated with this oxidant.

RESULTS

Activated JNK was detected in the cytoplasm of osteoarthritis (OA) affected chondrocytes but not in that of controls. In vitro, chondrocytes produce NO and superoxide anion. IL-1 (48 h), which induces nitric oxide synthase, resulted in an activation of JNK; this effect was reversed by N-monomethylarginine (NMA). TNFalpha treated chondrocytes at 48 h produce superoxide anion (EPR method). Exposure of cells to peroxynitrite led to an accumulation of intracellular oxidants, in association with JNK activation and cell death by apoptosis.

CONCLUSION

We suggest that JNK activation is among the IL-1 elicited responses that injure articular chondrocytes and this activation of JNK is dependent on intracellular oxidant formation (including NO peroxynitrite). In addition, the extraction technique here described is a novel method that permits the quantitation and study of proteins such as JNK involved in the signaling pathways of chondrocytes within osteoarthritic cartilage.

Laser in situ keratomileusis for correction of myopia and astigmatism after penetrating keratoplasty

PURPOSE

To determine the safety and effectiveness of laser in situ keratomileusis (LASIK) for visual rehabilitation of residual myopia and astigmatism after penetrating keratoplasty.

DESIGN

Prospective, noncomparative case series.

PARTICIPANTS

LASIK was performed on 23 eyes of 22 patients unable to wear glasses or contact lenses after penetrating keratoplasty due to anisometropia, high astigmatism, and/or contact lens-intolerance.

METHODS

All patients underwent LASIK for visual rehabilitation after penetrating keratoplasty. Uncorrected visual acuity and best spectacle-corrected visual acuity, degree of anisometropia, and corneal transplant integrity were recorded before surgery, as well as at 1 month, 3 months, 6 months, and 12 months after LASIK surgery.

RESULTS

The mean spherical equivalent before surgery was -7.58+/-4.42 diopters (D), which was reduced to -1.09+/-2.01 D, -0.79+/-1.84 D, -0.77+/-1.25 D, and -1.57+/-1.20 D, respectively, at 1, 3, 6, and 12 months after LASIK. The mean cylinder before surgery was 3.64+/-1.72 D, which was reduced to 1.98+/-1.15 D, 1.64+/-1.14 D, 1.48+/-0.92 D, and 1.29+/-1.04 D, respectively, at 1, 3, 6, and 12 months after LASIK. Spherical equivalent anisometropia was reduced from a mean of 6.88+/-4.4 D to 1.42+/-1.05 D at the final examination. Best-corrected visual acuity remained the same or improved in 21 of 23 eyes and decreased by 1 and 3 lines in 2 patients. There were no surgical flap or corneal transplant complications.

CONCLUSIONS

LASIK is a viable treatment alternative for myopia and astigmatism after penetrating keratoplasty in patients who are contact lens-intolerant. LASIK is more effective in treating myopia than astigmatism after penetrating keratoplasty.

Nitric oxide stimulates ADP ribosylation of actin in association with the inhibition of actin polymerization in human neutrophils

In these studies we provide conclusive evidence that (beta/gamma) actin present in human neutrophils is a substrate for nitric oxide (NO)-dependent ADP ribosylation and that this modification is associated with the inhibition of actin polymerization. A 43-kDa substrate for NO-dependent ADP ribosylation was identified as actin by four methods: (1) comigration with the botulinum C2 toxin substrate by two-dimensional gel electrophoresis (pI 5.2), (2) identity between the peptide map generated by V8 protease digestion of the NO and botulinum C2 substrates, (3) immunoprecipitation with antiactin antibodies, and (4) the ability of NO to ADP ribosylate purified neutrophil G-actin in the presence of plasma membrane cofactors. Because the ADP ribosylation of actin by the botulinum C2 toxin is known to inhibit F-actin polymerization, we examined the effect of NO on actin assembly. Flow cytometry revealed that NO inhibited formyl-methionine-leucine-phenylalanine (fMLP)-dependent (30 s at 37 degrees C) F-actin formation (108 +/- 8 vs. 89 +/- 6 relative fluorescence units, P < .02). These results were confirmed by quantification of F-actin formation by gel scanning (10% sodium dodecyl sulfate gel, Coomassie, and densitometry): pretreatment of polymorphonuclear leukocytes with NO resulted in a reduction of fMLP-induced, cytoskeletal-associated F-actin, which was accompanied by an increase of Triton-soluble G-actin. NO also inhibited F-actin formation, as observed by means of rhodamine phalloidin staining of neutrophils adherent to a fibronectin-coated surface. This effect was accompanied by a dose-dependent inhibition of neutrophil adherence in NO-treated cells. The data indicate that NO inhibits cytoskeletal assembly and adherence in human neutrophils in association with the ADP ribosylation of actin.

Simulated microgravity enhances cerebral artery vasoconstriction and vascular resistance through endothelial nitric oxide mechanism

Elevations in arterial pressure associated with hypertension, microgravity, and prolonged bed rest alter cerebrovascular autoregulation in humans. Using head-down tail suspension (HDT) in rats to induce cephalic fluid shifts and elevate arterial pressure, this study tested the hypothesis that 2-wk HDT enhances cerebral artery vasoconstriction and that an enhanced vasoconstriction described in vitro will alter regional cerebral blood flow (CBF) and vascular resistance (CVR) during standing and head-up tilt. To test this hypothesis, basal tone and vasoconstrictor responses to increases in transmural pressure, shear stress, and K+ were determined in vitro in middle cerebral arteries (MCAs) from HDT and control rats. All in vitro measurements were done in the presence and absence of the nitric oxide synthase (NOS) inhibitor NG-nitro-l-arginine methyl ester (l-NAME; 10−5 M) and with endothelium removal. Endothelial NOS (eNOS) mRNA and protein expression levels were measured by RT-PCR and immunoblot, respectively. Regional CBF and CVR were determined with a radiolabeled tracer technique and quantitative autoradiography. Basal tone and all vasoconstrictor responses were greater in MCAs from HDT rats. l-NAME and endothelium removal abolished these differences between groups, and HDT was associated with lower levels of MCA eNOS protein. CBF in select regions was lower and CVR higher during standing and head-up tilt in HDT rats. These results indicate that chronic cephalic fluid shifts enhanced basal tone and vasoconstriction through alterations in the eNOS signaling mechanism. The functional consequence of these vascular alterations with HDT is regional elevations in CVR and corresponding reductions in cerebral perfusion.

Immune checkpoint inhibitors in MITF family translocation renal cell carcinomas and genetic correlates of exceptional responders

Background

Microphthalmia Transcription Factor (MITF)family translocation renal cell carcinoma (tRCC) is a rare RCC subtype harboring TFE3/TFEB translocations. The prognosis in the metastatic (m) setting is poor. Programmed death ligand-1 expression was reported in 90% of cases, prompting us to analyze the benefit of immune checkpoint inhibitors (ICI) in this population.

Patients and methods

This multicenter retrospective study identified patients with MITF family mtRCC who had received an ICI in any of 12 referral centers in France or the USA. Response rate according to RECIST criteria, progression-free survival (PFS), and overall survival (OS) were analyzed. Genomic alterations associated with response were determined for 8 patients.

Results

Overall, 24 patients with metastatic disease who received an ICI as second or later line of treatment were identified. Nineteen (82.6%) of these patients had received a VEGFR inhibitor as first-line treatment, with a median PFS of 3 months (range, 1–22 months). The median PFS for patients during first ICI treatment was 2.5 months (range, 1–40 months); 4 patients experienced partial response (16,7%) and 3 (12,5%) had stable disease. Of the patients whose genomic alterations were analyzed, two patients with mutations in bromodomain-containing genes (PBRM1 and BRD8) had a clinical benefit. Resistant clones in a patient with exceptional response to ipilimumab showed loss of BRD8 mutations and increased mutational load driven by parallel evolution affecting 17 genes (median mutations per gene, 3), which were enriched mainly for O-glycan processing (29.4%, FDR = 9.7 × 10^− 6).

Conclusions

MITF family tRCC is an aggressive disease with similar responses to ICIs as clear-cell RCC. Mutations in bromodomain-containing genes might be associated with clinical benefit. The unexpected observation about parallel evolution of genes involved in O-glycosylation as a mechanism of resistance to ICI warrants exploration.

Safety and clinical activity of vascular endothelial growth factor receptor (VEGFR)-tyrosine kinase inhibitors after programmed cell death 1 inhibitor treatment in patients with metastatic clear cell renal cell carcinoma

BACKGROUND

Emerging agents blocking the programmed cell death 1 (PD-1) pathway show activity in metastatic clear cell renal cell carcinoma (mRCC). The aim of this study was to evaluate the efficacy and safety of vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR)-tyrosine kinase inhibitor (TKI) therapy after PD-1 inhibition.

PATIENTS AND METHODS

Patients with mRCC treated with anti-PD-1 antibody (aPD-1) monotherapy or in combination (with VEGFR-TKI or ipilimumab) that subsequently received VEGFR-TKI were retrospectively reviewed. The efficacy end points were objective response rate (ORR) and progression-free survival (PFS) stratified by the type of prior PD-1 regimen. Safety by the type and PD-1 exposure was also evaluated.

RESULTS

Seventy patients were included. Forty-nine patients received prior therapy with immune checkpoint inhibitors (CPIs) alone and 21 had combination therapy of aPD-1 and VEGFR-TKI. Overall, ORR to VEGFR-TKI after PD-1 inhibition was 28% (19/68) and the median PFS was 6.4 months (mo) (4.3-9.5). ORR to VEGFR-TKI after aPD-1 in combination with VEGFR-TKI was lower than that in patients treated with VEGFR-TKI after CPI alone (ORR 10% versus 36%, P = 0.039). In the multivariable analysis, patients treated with prior CPI alone were more likely to achieve an objective response than those treated with aPD-1 in combination with VEGFR-TKI (OR = 5.38; 95% CI 1.12-26.0, P = 0.03). There was a trend toward numerically longer median PFS in the VEGFR-TKI after the CPI alone group, 8.4 mo (3.2-12.4) compared with 5.5 mo (2.9-8.3) for those who had VEGFR-TKI after aPD-1 in combination with VEGFR-TKI (P = 0.15). The most common adverse events (AEs) were asthenia, hypertension, and diarrhea.

CONCLUSIONS

The efficacy and safety of VEGFR-TKIs after PD-1 inhibition were demonstrated in this retrospective study. The response rate was lower and the median progression-free survival was shorter in those patients who received prior PD-1 in combination with VEGFR-TKI. PD-1 exposure does not seem to significantly influence the safety of subsequent VEGFR-TKI treatment.

Hepcidin levels in diabetes mellitus and polycystic ovary syndrome

AIM

Increased body iron is associated with insulin resistance. Hepcidin is the key hormone that negatively regulates iron homeostasis. We hypothesized that individuals with insulin resistance have inadequate hepcidin levels for their iron load.

METHODS

Serum concentrations of the active form of hepcidin (hepcidin-25) and hepcidin:ferritin ratio were evaluated in participants with Type 2 diabetes (n = 33, control subjects matched for age, gender and BMI, n = 33) and participants with polycystic ovary syndrome (n = 27, control subjects matched for age and BMI, n = 16). To investigate whether any changes observed were associated with insulin resistance rather than insulin deficiency or hyperglycaemia per se, the same measurements were made in participants with Type 1 diabetes (n = 28, control subjects matched for age, gender and BMI, n = 30). Finally, the relationship between homeostasis model assessment of insulin resistance and serum hepcidin:ferritin ratio was explored in overweight or obese participants without diabetes (n = 16).

RESULTS

Participants with Type 2 diabetes had significantly lower hepcidin and hepcidin:ferritin ratio than control subjects (P < 0.05 and P < 0.01, respectively). Participants with polycystic ovary syndrome had a significantly lower hepcidin:ferritin ratio than control subjects (P < 0.05). There was no significant difference in hepcidin or hepcidin:ferritin ratio between participants with Type 1 diabetes and control subjects (P = 0.88 and P = 0.94). Serum hepcidin:ferritin ratio inversely correlated with homeostasis model assessment of insulin resistance (r = -0.59, P < 0.05).

CONCLUSION

Insulin resistance, but not insulin deficiency or hyperglycaemia per se, is associated with inadequate hepcidin levels. Reduced hepcidin concentrations may cause increased body iron stores in insulin-resistant states.

Analgesic activity and respiratory effects of butorphanol in sheep

The analgesic drug butorphanol tartrate has proved useful clinically in horses and dogs but its analgesic profile had not yet been investigated in sheep. This study was initiated to determine the thermal and mechanical antinociceptive activity of butorphanol (at the dose rates 0.05, 0.1 and 0.2 mg kg-1) in sheep. The drug produced significant analgesia in the thermal test system, the duration of which was dose related but no significant elevation in mechanical pressure thresholds could be detected. In a further set of experiments the dose rate was increased to 0.4 mg kg-1 and mechanical testing was repeated. There was still no clinically significant elevation in pressure thresholds. At a dose rate of 0.2 mg kg-1 the drug had no detectable effect on respiratory blood gas tensions. Behavioural changes were severe if a dose rate of 0.2 mg kg-1 was exceeded.

The protective effect of a purified extract of Withania somnifera against doxorubicin-induced cardiac toxicity in rats

The therapeutic value of doxorubicin as an effective antineoplastic agent is limited by its cardiotoxic side-effects. The administration of doxorubicin (10 mg/kg) to male Wistar rats induced necrosis and apoptosis in heart tissues. It also caused oxidative stress damage as evidenced by the elevation of malondialdehyde and protein carbonyl levels and catalase activity, accompanied by the concurrent depletion of total antioxidant capacity and of superoxide dismutase level in cardiac tissues. The doxorubicin-induced cardiotoxicity and oxidative stress damage were also accompanied by increases of myeloperoxidase activity, total calcium content, and the expression of Bcl-2 protein in heart tissues. Most of these doxorubicin-induced biochemical and histological alterations were effectively attenuated by prior administration of purified standardized extract (1.5% withanolides; manufactured by Idea Sphere Inc., American Fork, UT, USA) of Withania somnifera (300 mg/kg). Thus, Withania may play a role in the protection against cardiotoxicity and thus might be a useful adjuvant therapy where doxorubicin is the cancer-treating drug.

Adipose tissue at entheses: the rheumatological implications of its distribution. A potential site of pain and stress dissipation?

OBJECTIVES

To describe the distribution of adipose tissue within and adjacent to entheses in order to assess its functional significance at attachment sites.

METHODS

Entheses were removed from 29 different sites in the limbs of formalin fixed, elderly, dissecting room cadavers and the samples prepared for paraffin and/or methylmethacrylate histology. Entheses from four young volunteers with no history of significant musculoskeletal injury were examined by magnetic resonance imaging using T(1) weighted sequences.

RESULTS

Adipose tissue was present at several different sites at numerous entheses. Many tendons/ligaments lay on a bed of well vascularised, highly innervated, "insertional angle fat". Endotenon fat was striking between fascicles, where entheses flared out at their attachments. It was also characteristic of the epitenon, where it occurred in conjunction with lamellated and Pacinian corpuscles. Fat filled, meniscoid folds often protruded into joint cavities, immediately adjacent to attachment sites.

CONCLUSION

Adipose tissue is a common feature of normal entheses and should not be regarded as a sign of degeneration. It contributes to the increase in surface area of attachment sites, promotes movement between tendon/ligament and bone, and forms part of an enthesis organ that dissipates stress. The presence of numerous nerve endings in fat at attachment sites suggests that it has a mechanosensory role and this could account for the rich innervation of many entheses. Because damage to fat is known to lead to considerable joint pain, our findings may be important for understanding the site of pain in enthesopathies.

Group B streptococcal serotype distribution of isolates from colonized pregnant women at the time of delivery in United Arab Emirates

OBJECTIVE

To determine the maternal colonization rate with group B streptococcus (GBS) and to identify the most frequent GBS serotypes occurring in UAE women during labour.

STUDY DESIGN

From February 1998 to January 1999, five hundred and sixty three pregnant women from a similar socio-economic and ethnic population were enrolled for the study. High vaginal swab cultures for GBS were obtained at the time of admission for delivery. Isolates were classified according to their capsular polysaccharide types (Ia, Ib, Ic, II-V) and c protein antigen compound.

RESULTS

Fifty-seven (10.1%) of 563 mothers were found to be carriers of GBS. Among the isolates, serotype IV (26.3%) predominated followed by type Ia (21.0%), type III (17.6%), type V (12.3%) and nontypeable, which accounted for 15.8%.

CONCLUSIONS

In view of the unknown status for GBS carrier rates in our community, this study suggests that about 10% of UAE women are colonized with group B streptococcus at delivery. The serotype distribution of the isolates in this population is different than those reported elsewhere with type IV predominating followed by type Ia and III.