PBI-4050 reduces pulmonary hypertension, lung fibrosis, and right ventricular dysfunction in heart failure

AIMS

Heart failure with reduced ejection fraction (HFrEF) causes lung remodelling with myofibroblasts proliferation and fibrosis leading to a restrictive lung syndrome with pulmonary hypertension (PH) and right ventricular (RV) dysfunction. PBI-4050 is a first-in-class anti-fibrotic, anti-inflammatory, and anti-proliferative compound. The present study evaluated the therapeutic impact of PBI-4050 on PH in an HFrEF model.

METHODS AND RESULTS

HFrEF was induced after myocardial infarction (MI) in rats. Two weeks later, sham-operated and MI groups received PBI-4050 (200 mg/kg/day by gavage) or saline for 3 weeks. Animals were analysed according to infarct size as large (≥30% left ventricle) or medium MI (<30%). Large MI caused PH and RV hypertrophy (RVH) with a restrictive lung syndrome. PBI-4050 did not adversely affect left ventricular (LV) function but markedly reduced PH and RVH and improved RV dysfunction. PBI-4050 reduced lung remodelling and improved respiratory compliance with decreased lung fibrosis, alveolar wall cellular proliferation and α-smooth muscle actin expression. The increased expression of endothelin-1 (ET-1), transforming growth factor beta (TGF-β), interleukin-6 (IL-6) and of tissue inhibitor of metalloprotease-1 in the lungs from HFrEF were reduced with PBI-4050 therapy. Activation of isolated human lung fibroblasts (HLFs) to a myofibroblastic pro-fibrogenic phenotype was markedly reduced by PBI-4050. The fatty acid receptor GPR84 was increased in HFrEF lungs and in activated HLFs, and reduced by PBI-4050. GPR84 agonists activated fibrogenesis in HLFs and finally, PBI-4050 reduced ERK1/2 phosphorylation.

CONCLUSIONS

PBI-4050 reduces PH and RVH in HFrEF by decreasing lung fibrosis and remodelling. This novel agent decreases the associated restrictive lung syndrome and recovers RV function. A contributing mechanism involves reducing the activation of lung fibroblasts by IL-6, TGF-β, and ET-1 by antagonism of GPR84 and reduced ERK1/2 phosphorylation. PBI-4050 is a novel promising therapy for targeting lung remodelling in group II PH.

Fatty acid mimetic PBI-4547 restores metabolic homeostasis via GPR84 in mice with non-alcoholic fatty liver disease

Non-alcoholic Fatty Liver Disease (NAFLD) is the most common form of liver disease and is associated with metabolic dysregulation. Although G protein-coupled receptor 84 (GPR84) has been associated with inflammation, its role in metabolic regulation remains elusive. The aim of our study was to evaluate the potential of PBI-4547 for the treatment of NAFLD and to validate the role of its main target receptor, GPR84. We report that PBI-4547 is a fatty acid mimetic, acting concomitantly as a GPR84 antagonist and GPR40/GPR120 agonist. In a mouse model of diet-induced obesity, PBI-4547 treatment improved metabolic dysregulation, reduced hepatic steatosis, ballooning and NAFLD score. PBI-4547 stimulated fatty acid oxidation and induced gene expression of mitochondrial uncoupling proteins in the liver. Liver metabolomics revealed that PBI-4547 improved metabolic dysregulation induced by a high-fat diet regimen. In Gpr84^−/− mice, PBI-4547 treatment failed to improve various key NAFLD-associated parameters, as was observed in wildtype littermates. Taken together, these results highlight a detrimental role for the GPR84 receptor in the context of meta-inflammation and suggest that GPR84 antagonism via PBI-4547 may reflect a novel treatment approach for NAFLD and its related complications.

Phase 2 clinical trial of PBI-4050 in patients with idiopathic pulmonary fibrosis

PBI-4050 is a novel orally active small-molecule compound with demonstrated anti-fibrotic activity in several models of fibrosis, including lung fibrosis. We present results from our first clinical study of PBI-4050 in patients with idiopathic pulmonary fibrosis (IPF).

This 12-week open-label study explored the safety, efficacy and pharmacokinetics of daily oral doses of 800 mg PBI-4050 alone and in combination with nintedanib or pirfenidone in patients with predominantly mild or moderate IPF. Nine patients received PBI-4050 alone, 16 patients received PBI-4050 with nintedanib and 16 patients received PBI-4050 with pirfenidone.

PBI-4050 alone or in combination with nintedanib or pirfenidone was well tolerated. Pharmacokinetic profiles for PBI-4050 were similar in the PBI-4050 alone and PBI-4050+nintedanib groups but reduced in the PBI-4050+pirfenidone group, suggesting a drug–drug interaction. There were no significant changes in forced vital capacity (FVC), either in % predicted or mL, from baseline to week 12 for PBI-4050 alone or PBI-4050+nintedanib. In contrast, a statistically significant reduction (p<0.024) in FVC % pred was seen for PBI-4050+pirfenidone after 12 weeks.

There were no safety concerns with PBI-4050 alone or in combination with nintedanib or pirfenidone in IPF patients. The stability of FVC between baseline and week 12 looked encouraging for PBI-4050 alone and in combination with nintedanib.

PBI-4050 alone and in combination with nintedanib demonstrated no safety concerns and showed encouraging results for lung function in IPF patientshttp://ow.ly/olQD30myD0E

Design and Synthesis of New 1,3,5-Trisubstituted Triazines for the Treatment of Cancer and Inflammation

Low-molecular-weight synthetic molecules 1 with the general 2-(fluorophenylamino)-4,6-disubstituted 1,3,5-triazine structure and showing anti-inflammatory and anticancer activities were explored. Structure-activity relationship studies demonstrated the importance of the aminopentyl chain, the 3- or 4-fluorophenylaniline component, and the presence of at least one substituent, such as a tyramine moiety, attached directly to the triazine ring as essential for good activity. These compounds, represented by leads 4-{2-[4-(5-Aminopentylamino)-6-(3-fluorophenylamino)-1,3,5-triazin-2-ylamino]ethyl}phenol (6) and 4-{2-[4-(5-Aminopentylamino)-6-(4-fluorophenylamino)-1,3,5-triazin-2-ylamino]ethyl}phenol (10), displayed moderate and significant in vitro and in vivo dual activities, respectively, and address the molecular link between inflammation and cancer. Compound 10 demonstrated significant antitumor efficacy upon administration by the oral and intravenous routes in several animal models. This class of triazine compounds is new, safe, and nontoxic and offers a novel approach to the treatment of inflammation and cancer.

PBI-4050 Reduces Stellate Cell Activation and Liver Fibrosis through Modulation of Intracellular ATP Levels and the Liver Kinase B1/AMP-Activated Protein Kinase/Mammalian Target of Rapamycin Pathway

Hepatic fibrosis is a major cause of morbidity and mortality for which there is currently no effective therapy. We previously showed that 2-(3-pentylphenyl)acetic acid (PBI-4050) is a dual G protein-coupled receptor GPR40 agonist/GPR84 antagonist that exerts antifibrotic, anti-inflammatory, and antiproliferative action. We evaluated PBI-4050 for the treatment of liver fibrosis in vivo and elucidated its mechanism of action on human hepatic stellate cells (HSCs). The antifibrotic effect of PBI-4050 was evaluated in carbon tetrachloride (CCl₄)- and bile duct ligation-induced liver fibrosis rodent models. Treatment with PBI-4050 suppressed CCl₄-induced serum aspartate aminotransferase levels, inflammatory marker nitric oxide synthase, epithelial to mesenchymal transition transcription factor Snail, and multiple profibrotic factors. PBI-4050 also decreased GPR84 mRNA expression in CCl₄-induced injury, while restoring peroxisome proliferator-activated receptor γ (PPARγ) to the control level. Collagen deposition and α-smooth muscle actin (α-SMA) protein levels were also attenuated by PBI-4050 treatment in the bile duct ligation rat model. Transforming growth factor-β-activated primary HSCs were used to examine the effect of PBI-4050 and its mechanism of action in vitro. PBI-4050 inhibited HSC proliferation by arresting cells in the G0/G1 cycle phase. Subsequent analysis demonstrated that PBI-4050 signals through a reduction of intracellular ATP levels, activation of liver kinase B1 (LKB1) and AMP-activated protein kinase (AMPK), and blockade of mammalian target of rapamycin (mTOR), resulting in reduced protein and mRNA levels of α-SMA and connective tissue growth factor and restored PPARγ mRNA expression. Our findings suggest that PBI-4050 may exert antifibrotic activity in the liver through a novel mechanism of action involving modulation of intracellular ATP levels and the LKB1/AMPK/mTOR pathway in stellate cells, and PBI-4050 may be a promising agent for treating liver fibrosis.

Fatty acid receptor modulator PBI-4050 inhibits kidney fibrosis and improves glycemic control

Extensive kidney fibrosis occurs in several types of chronic kidney diseases. PBI-4050, a potentially novel first-in-class orally active low-molecular weight compound, has antifibrotic and antiinflammatory properties. We examined whether PBI-4050 affected the progression of diabetic nephropathy (DN) in a mouse model of accelerated type 2 diabetes and in a model of selective tubulointerstitial fibrosis. eNOS-/- db/db mice were treated with PBI-4050 from 8-20 weeks of age (early treatment) or from 16-24 weeks of age (late treatment). PBI-4050 treatment ameliorated the fasting hyperglycemia and abnormal glucose tolerance tests seen in vehicle-treated mice. In addition, PBI-4050 preserved (early treatment) or restored (late treatment) blood insulin levels and increased autophagy in islets. PBI-4050 treatment led to significant improvements in lifespan in the diabetic mice. Both early and late PBI-4050 treatment protected against progression of DN, as indicated by reduced histological glomerular injury and albuminuria, slow decline of glomerular filtration rate, and loss of podocytes. PBI-4050 inhibited kidney macrophage infiltration, oxidative stress, and TGF-β-mediated fibrotic signaling pathways, and it also protected against the development of tubulointerstitial fibrosis. To confirm a direct antiinflammatory/antifibrotic effect in the kidney, further studies with a nondiabetic model of EGFR-mediated proximal tubule activation confirmed that PBI-4050 dramatically decreased the development of the associated tubulointerstitial injury and macrophage infiltration. These studies suggest that PBI-4050 attenuates development of DN in type 2 diabetes through improvement of glycemic control and inhibition of renal TGF-β-mediated fibrotic pathways, in association with decreases in macrophage infiltration and oxidative stress.

Abstract 672: PBI-1402, a first-in-class erythropoiesis regulating agent, inhibits tumor growth and metastasis of murine mastocytoma and does not overshoot hemoglobin: Comparison with erythropoietin

BACKGROUND: PBI-1402 reduces the need for transfusion and increases hemoglobin (Hb) level and red blood cell count (RBC) in chemotherapy-induced anemia (CIA) by a mechanism of action distinct from erythropoietin (EPO).

AIM: The objective was to compare the effect of PBI-1402 and EPO on modulation of tumor growth.

METHODS: The effect of PBI-1402 (200 mg/kg, oral, once a day) or EPO (200 or 2000 U/kg, s.c. injection, twice a week) was studied in a subcutaneous P815 mastocytoma model. P815 cells express both PBI-1402 and EPO receptors. Tumor growth, metastasis, serum nitric oxide (NO) and hematocrit (Ht) were assessed.

RESULTS: P815 tumor growth is rapid and metastasizes to the liver. Inflammation is also associated with P815 tumor growth. PBI-1402 significantly reduced tumor growth (T/C=37%) and invasion as demonstrated by a 33% reduction of mice with liver metastasis. In comparison, EPO had no effect (200 U/kg, equivalent dose used in CKD treatment). However, high dose EPO (2000 U/kg, equivalent dose used in human cancer treatment) exacerbated tumor growth (T/C: 135%). Both doses of EPO induced a significant increase in the percentage of mice with liver metastasis (2X, 200 U/kg, and 3X, 2000 U/kg) compared to control. PBI-1402 treatment had no effect on NO and did not overshoot normal hematocrit. However, treatment with high dose EPO significantly increased NO and Ht levels (Table 1).

CONCLUSION: These results suggest that oral treatment with PBI-1402 may inhibit growth and metastasis of cancer cells. As an important safety feature, PBI-1402 does not induce overshoot of hemoglobin. In contrast to EPO, PBI-1402 may offer the advantage of reducing tumor growth and metastasis while preventing anemia induced by chemotherapy. In conclusion, PBI-1402 has the potential to be a safe erythropoiesis-regulating agent useful in treating anemia in cancer patients.

Abstract 3534: PBI-1402, a first-in-class erythropoiesis regulating agent, possesses differentiation properties and demonstrates synergistic anticancer activity in combination with chemotherapy

Background: PBI-1402 reduces the need for transfusion and increases hemoglobin (Hb) level and red blood cell count (RBC) in chemotherapy-induced anemia (CIA) patients by a mechanism of action which is distinct from erythropoietin (EPO). The PBI-1402 receptor is also expressed on certain cancer cells such as leukemia (K562), lung (LL-2), prostate (PC-3) and pancreas (Panc-02).

Aim: The objective of this study was to determine the role of the PBI-1402 receptor on tumor growth.

Methods: Cell proliferation and differentiation of K562 (human erythroleukemia) was studied in presence of PBI-1402 or EPO using 2,7-diaminofluorene for hemoglobin quantification. The effect of oral administration of PBI-1402 in combination with chemotherapy agents (gemcitabine or cyclophosphamide) was studied in subcutaneous syngeneic Panc02, LL-2 and xenogeneic PC-3 models.

Results: PBI-1402 inhibits proliferation of K562 cells and promotes differentiation of the remaining cells. K562 cells express both EPO and PBI-1402 receptors. EPO increases phosphorylation of ERK1/2 and Stat3 (linked to cell proliferation) while PBI-1402 decreases it in a dose dependent manner. The antitumor efficacy of oral administration of PBI-1402 was studied in combination with gemcitabine in subcutaneous LL2 and Panc02 as well as in orthotopic Panc02 cancers. In subcutaneous Panc02, gemcitabine induced a significant inhibition (p&lt;0.05) of tumor growth from day 27 to 34 with T/C from 55% to 78%. PBI-1402 induced a significant inhibition (p&lt;0.05) of tumor growth from day 23 to 44 with T/C from 26% to 58%. The combination therapy induced a significant (p&lt;0.05) inhibition of tumor growth and T/C&lt;40% from day 23 to 37 when compared to control and at day 23, 25 and 30 to 39 when compared to gemcitabine alone. In orthotopic Panc02, mice treated with gemcitabine or a combination of gemcitabine and PBI-1402 displayed prolonged survival (71 and 88 days, respectively) compared to control (48 days). In LL-2 cancer, at day 25, mice treated with PBI-1402 or gemcitabine alone had a T/C of 94% and 72%, respectively. Mice treated with a combination of gemcitabine plus PBI-1402 displayed a significant (synergistic) reduction of tumor growth (T/C: 33%). The effect of PBI-1402 alone or in combination with cyclophosphamide was also studied in a xenograft prostate PC-3 tumor. Mice treated with PBI-1402 or cyclophosphamide alone have a significant T/C&lt;40% from day 21 to 56 and day 35 to 56, respectively. Mice treated with a combination of cyclophosphamide plus PBI-1402 displayed tumor regression from day 21 to 56.

Conclusion: These results suggest that PBI-1402 has the potential to inhibit the growth of lung, prostate and pancreatic cancer by induction of cell differentiation. PBI-1402-differentiated cancer cells appear to be more susceptible to chemotherapeutic agents.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3534. doi:10.1158/1538-7445.AM2011-3534

IgA endomysium antibodies--an early predictor for celiac disease in children without villous atrophy

AIM

To evaluate possible differences between children with anti-endomysium antibodies (EMA) positivity and normal small bowel mucosa and children with positive EMA and an enteropathy diagnosed as celiac disease (CD).

METHODS

Children with suspected CD and positive EMA (>or=1/10) undergoing small bowel biopsy during 1996 to 2002, were investigated (n=133). Data registered were: year and month of birth, timing of the first biopsy, sex, heredity for CD, dermatitis herpetiformis and diabetes mellitus and outcome of the anti-gliadin antibody test (AGA). The case group, with EMA positivity and normal histology (n=39; 59% female, mean age at the first biopsy 7.3 years, range 1.4-16), was compared with the disease control group, with positive EMA and a biopsy suggestive and further on diagnosed as CD (n=94; 56% female; mean age 7.6 years at the first biopsy, range 0.70-17).

RESULTS

AGA positivity and heredity for CD were found to predict the outcome of a pathological jejunal mucosa. Nineteen of the 39 children in the case group were rebiopsied of whom 11 had developed an enteropathy during a follow-up period of 2-7 years (median 4.5 years).

CONCLUSIONS

EMA positivity in the absence of small bowel enteropathy could be a very early predictor for later overt CD, and necessitates further follow-up, especially if the child is AGA positive and there is a family history of CD.

Increasing prevalence of coeliac disease in Swedish children: influence of feeding recommendations, serological screening and small intestinal biopsy activity

BACKGROUND

The prevalence of coeliac disease (CD) in Swedish children has attracted considerable interest over the past few decades, and especially the influence of feeding habits on the increased incidence. A national study has reported a trend towards a decrease in incidence after a change in infant feeding recommendations was introduced in 1996. The aim of this study was to evaluate, in a geographically defined area, the change in incidence with time and the influence of the introduction of antibody analysis.

METHODS

Cases of suspected paediatric CD between 1980 and 2003 were studied for prevalence, biopsy findings and antibody analyses.

RESULTS

A total of 2029 children were investigated by small intestinal biopsy, yielding 554 CD cases. The area initially showed the same trend as the national study, but the annual incidence rate is now increasing again. Median age at diagnosis has increased significantly since 1997 from less than 2 years of age to above 5 years. Cumulative incidence at 2 years of age is much higher for the birth cohorts 1983-96 than 1980-82 or 1997-2001. Diagnostic accuracy was significantly higher after the introduction of antigliadin (AGA) analysis, and especially after antiendomysium (EMA) analysis.

CONCLUSIONS

The incidence rate of CD in small children in our region has varied widely over the 24-year period observed. Feeding practice and methods of investigation have changed during this period. The annual incidence rate for the total child population in 2003 was almost equal to the peak value observed in 1994. There were no conclusive results on whether antibody analysis had an influence on diagnostic activity, but this seems to have increased diagnostic accuracy.

Oats to children with newly diagnosed coeliac disease: a randomised double blind study

BACKGROUND

Treatment of coeliac disease (CD) requires lifelong adherence to a strict gluten free diet (GFD) which hitherto has consisted of a diet free of wheat, rye, barley, and oats. Recent studies, mainly in adults, have shown that oats are non-toxic to CD patients. In children, only open studies comprising a small number of patients have been performed.

AIM

To determine if children with CD tolerate oats in their GFD.

PATIENTS AND METHODS

In this double blind multicentre study involving eight paediatric clinics, 116 children with newly diagnosed CD were randomised to one of two groups: one group was given a standard GFD (GFD-std) and one group was given a GFD with additional wheat free oat products (GFD-oats). The study period was one year. Small bowel biopsy was performed at the beginning and end of the study. Serum IgA antigliadin, antiendomysium, and antitissue transglutaminase antibodies were monitored at 0, 3, 6, and 12 months.

RESULTS

Ninety three patients completed the study. Median (range) daily oat intake in the GFD-oats group (n = 42) was 15 (5-40) g at the six month control and 15 (0-43) g at the end of the study. All patients were in clinical remission after the study period. The GFD-oats and GFD-std groups did not differ significantly at the end of the study regarding coeliac serology markers or small bowel mucosal architecture, including numbers of intraepithelial lymphocytes. Significantly more children in the youngest age group withdrew.

CONCLUSIONS

This is the first randomised double blind study showing that the addition of moderate amounts of oats to a GFD does not prevent clinical or small bowel mucosal healing, or humoral immunological downregulation in coeliac children. This is in accordance with the findings of studies in adult coeliacs and indicates that oats, added to the otherwise GFD, can be accepted and tolerated by the majority of children with CD.

Increase in nitric oxide urinary products during gluten challenge in children with coeliac disease

BACKGROUND

Coeliac disease is a gluten-sensitive enteropathy where pro-inflammatory cytokines and excess nitric oxide (NO) production can contribute to mucosal damage. NO urinary products are elevated in coeliac children on a gluten diet, but it is not known how rapidly this increase develops after gluten exposure.

METHODS

Oral gluten challenge was performed in 25 children whose families kept a daily record of gluten intake and symptoms. Blood was analysed monthly for antigliadin (AGA) and endomysium antibodies (EMA). Urine was analysed every second week for NO products, i.e. the sum of nitrite and nitrate was measured with a colorimetric method. We performed a third biopsy when clinical symptoms indicated a relapse. Median age at the post-challenge biopsy was 3.8 (2.7-8.8) years.

RESULTS

Signs of morphological or serological relapse were seen in all children. Mean daily gluten intake was 0.10 (range 0.02-0.26) g/kg bodyweight. Median NO level was doubled and significantly higher after 4 weeks of challenge but not after 2 weeks. EMA, but not AGA levels, correlated positively with NO. Intraepithelial lymphocyte count was significantly higher in the post-challenge biopsy, but did not correlate with the NO levels.

CONCLUSIONS

NO products in urine increased during gluten challenge. EMA levels reflected severity of mucosal damage, and NO products reflected the inflammatory response, which was doubled after 4 weeks of challenge. The NO analysis is simple and non-traumatic for the child. It can be performed repeatedly during investigation of children with suspected coeliac disease.

Improved antibacterial activities of coumarin antibiotics bearing 5',5'-dialkylnoviose: biological activity of RU79115

A new series of coumarin inhibitors of DNA gyrase B bearing a N-propargyloxycarbamate at C-3' of various 5',5'-dialkylnoviose, including RU79115, were synthesised and their antibacterial activities have been delineated. Introduction of dialkyl substituents at 5'5'-position of noviose leads to coumarin analogues with improved in vitro and in vivo antibacterial activity.

Coumarin inhibitors of gyrase B with N-propargyloxy-carbamate as an effective pyrrole bioisostere

The synthesis and biological profile in vitro of a series of coumarin inhibitors of gyrase B bearing a N-propargyloxycarbamate at C-3' of noviose is presented. Replacement of the 5-methylpyrrole-2-carboxylate of coumarin drugs with an N-propargyloxycarbamate bioisostere leads to analogues with improved antibacterial activity. Analysis of crystal structures of coumarin antibiotics with the 24 kDa N-terminal domain of the gyrase B protein provides a rational for the excellent inhibitory potency of C-3' N-alkoxycarbamates.

Synthesis and antibacterial activity of HMR 3647 a new ketolide highly potent against erythromycin-resistant and susceptible pathogens

In the search for new ketolides with improved activities against erythromycin-resistant S. pneumoniae and H. influenzae we synthesized a new 11,12 carbamate ketolide substituted by an imidazo-pyridyl side chain: HMR 3647. This compound demonstrated a potent activity against erythromycin susceptible and resistant pathogens, including penicillin G/erythromycin A-resistant S. pneumoniae and H. influenzae. In vivo, HMR 3647 displayed good pharmacokinetic parameters (Cmax = 2.9 microg/ml, bioavailability=49%, AUC0.8 = 17.2 microg.h/l, t1/2=1h) and was shown to have a high therapeutic efficacy in mice infected by various respiratory pathogens, including multi-resistant S. pneumoniae and Gram negative bacteria such as H. influenzae. HMR 3647 appears to be a very promising agent for the treatment of respiratory infections and is currently in clinical trials.

Structure-activity relationship in two series of aminoalkyl substituted coumarin inhibitors of gyrase B

Two series of aminosubstituted coumarins were synthesised and evaluated in vitro as inhibitors of DNA gyrase and as potential antibacterials. Novel novobiocin-like coumarins, 4-(dialkylamino)methylcoumarins and 4-((2-alkylamino)ethoxy)coumarins, were discovered as gyrase B inhibitors with promising antibacterial activity in vitro.

Synthesis and in vitro evaluation of novel highly potent coumarin inhibitors of gyrase B

The design, synthesis, and in vitro biological activity of a series of novel coumarin inhibitors of gyrase B is presented. Replacement of the 3-acylamino residue (3-NHCOR) of coumarin drugs with reversed isosteres C(=O)R, C(=N-OR)R', COOR, CONHR and CONHOR leads to highly potent analogues which displayed excellent inhibition of the negative supercoiling of the relaxed DNA and antibacterial activity.

Synthesis and antibacterial activity of ketolides (6-O-methyl-3-oxoerythromycin derivatives): a new class of antibacterials highly potent against macrolide-resistant and -susceptible respiratory pathogens

In the search for new antibiotics active against macrolide-resistant pneumococci and Haemophilus influenzae, we synthesized a new class of 3-oxo-6-O-methylerythromycin derivatives, so-called "ketolides". A keto function was introduced in position 3 after removal of L-cladinose, a sugar which has long been thought essential. Further modifications of the macrolactone backbone allowed us to obtain three different series of 9-oxime, 11,12-carbamate, and 11, 12-hydrazonocarbamate ketolides. These compounds were found to be very active against penicillin/erythromycin-resistant pneumococci and noninducers of MLSB resistance. The 11,12-substituted ketolide 61 (HMR 3004) demonstrated a potent activity against multiresistant pneumococci associated with a well-balanced activity against all bacteria involved in respiratory infections including H. influenzae, Mycoplasma catarrhalis, group A streptococci, and atypical bacteria. In addition HMR 3004 displayed high therapeutic activity in animals infected by all major strains, irrespective of their resistance phenotype.

Significantly increased levels of nitric oxide products in urine of children with celiac disease

BACKGROUND

Celiac disease is characterized by morphologic and functional aberrations of the small intestinal mucosa, i.e., crypt hyperplasia, villous atrophy, infiltration of intraepithelial lymphocytes, and alteration of permeability. Nitric oxide has been shown to affect mucosal permeability after ischemia-reperfusion, but little is known about the regulatory role of nitric oxide in celiac disease. The purpose of this study was to assess nitric oxide production in children with celiac disease and in control subjects.

METHODS

The sum of nitrite and nitrate in the urine was measured with a colorimetric method in 137 children with a median age of 3 years, 84 patients and 53 reference children, all of whom underwent a small intestinal biopsy to confirm or overrule suspicion of celiac disease.

RESULTS

Median urinary nitrite-nitrate concentration in celiac children was 3323 microM (4147 +/- 1102; mean +/- SEM) at first clinical examination and 2501 microM (2939 +/- 386) after gluten challenge, which was significantly higher than concentrations in reference children (1029 microM; 1174 +/- 116) and in children with celiac disease on a gluten-free diet (882 microM; 1369 +/- 360) (p < 0.0001).

CONCLUSIONS

A gluten-containing diet is associated with an increased nitrite-nitrate secretion in the urine in children with celiac disease, presumably as a result of nitric oxide synthase activation and nitric oxide production in the diseased small intestinal mucosa.

Infant feeding history shows distinct differences between Swedish celiac and reference children

Infant feeding history was investigated in 72 celiac and 288 age-matched reference children in a retrospective questionnaire study. The reply rate was 100% in celiac and 91.6% in reference children. The celiac children were breast-fed for a significantly shorter time than reference children, and they were less often breast-fed at the introduction of gluten. The age of the children at gluten introduction was similar, but the celiac children were significantly more often introduced by a gluten-containing follow-up formula, while the reference children more often started on a gluten-containing porridge. The results can be interpreted in two ways. First, it could be argued that breast milk per se protects against symptoms of celiac disease in childhood. It could, however, also be claimed that breast-feeding merely modulates the gluten introduction, causing a less abrupt introduction of gluten in the baby diet and thereby fewer overt symptoms of the disease.

Further studies on the relationship of adrenal and gonadal steroids in pubertal development in female rats

Surgical adrenalectomy or the administration of aminoglutethimide, corticosterone (B), and androstenedione (delta 4) to the immature female rat had no effect on the timing of vaginal membrane opening. Dehydroepiandrosterone (DHA) and estrone (E1) significantly hastened vaginal patency. Aminoglutethimide increased pituitary LH content while FSH content was decreased. An anti-17 beta-E2 antibody increased pituitary LH content and plasma concentration suggesting enhanced synthesis and release of LH. Pituitary FSH content was unaltered while plasma FSH decreased. Aminoglutethimide increased adrenal and ovarian but not pituitary weight while the antibody had no effect. Since little DHA is present in rat plasma and adrenal and since only estrogens have any effect on the onset of puberty, it is likely that the adrenal is not directly involved in pubertal development in the female rat.