OP0251 IMPACT OF INTERSTITIAL LUNG DISEASE ON SEVERE COVID-19 OUTCOMES FOR PATIENTS WITH RHEUMATOID ARTHRITIS: A MULTICENTER STUDY

Background

RA has been associated with poor COVID-19 outcomes, but few studies have investigated outcomes in RA features such as interstitial lung disease.

Objectives

To assess COVID-19 outcomes in patients with RA overall, and those with and without ILD, compared to general population comparators.

Methods

A multicenter, retrospective cohort study was conducted at Mayo Clinic (19 hospitals and affiliated outpatient centers in 4 states) and Mass General Brigham (14 hospitals and affiliated outpatient centers in New England). Consecutive patients with RA meeting ACR/EULAR criteria and a positive COVID-19 test from March 1, 2020 through June 6, 2021 were matched 1:5 on age, sex, race, and COVID-19 test date with general population comparators without RA. RA features assessed included: RA-ILD per Bongartz criteria [1], duration, rheumatoid factor (RF), cyclic citrullinated peptide antibody (CCP), bone erosions, and treatments. The primary outcome was a composite of hospitalization or death following COVID-19 diagnosis. We used multivariable Cox regression to investigate the association of RA, and features such as ILD, with COVID-19 outcomes compared to matched comparators.

Results

We analyzed 582 patients with RA and 2892 comparators without RA, all with COVID-19. Mean age was 62 years, 51% were female, and 79% were White. Mean RA duration was 11 years, 67% were seropositive (52% RF+ and 54% CCP+), 27% had bone erosions, 28% were on steroids, and 79% were on DMARDs. 50/582 (9%) patients with RA had ILD.

The COVID-19 hospitalization or death rate for RA patients was higher than comparators (3.0 per 1,000 days [95% CI 2.5-3.6] vs. 1.9 per 1,000 days [95% CI 1.7-2.1], respectively). Overall, RA patients had a 53% higher risk of hospitalization or death than comparators after adjustment (95% CI 1.20-1.94).

Among those with RA-ILD, the hospitalization or death rate was significantly higher than comparators (10.9 [95% CI 6.7-15.2] vs. 2.5 per 1,000 days [1.8-3.2], respectively). RA-ILD was associated with nearly 3-fold higher risk for hospitalization or death than comparators (multivariable HR 2.84 [95% CI 1.64-4.91], Table 1). There was a significant interaction between RA/comparator status and presence/absence of ILD for risk of severe COVID-19 (p<0.001, Figure 1). The elevated risk for severe COVID-19 was similar for RA subgroups defined by serostatus or bone erosions.

Table 1.

Frequencies, proportions, and hazard ratios for COVID-19 outcomes, comparing all RA patients, and subgroups with or without RA-ILD, to matched comparators.

COVID-19 OutcomesAll RA Patients (n=582)RA-ILD (n=50)RA Patients without ILD (n=532)Comparators (n=2,892)Hospitalization, n (%)121 (21)24 (48)97 (18)402 (14)Unadjusted HR (95% CI)1.58 (1.27, 1.96)2.65 (1.71, 4.09)1.43 (1.12, 1.82)Ref.Adjusted* HR (95% CI)1.45 (1.14, 1.83)2.35 (1.38, 4.00)1.31 (1.00, 1.70)Ref.Death, n (%)26 (4)9 (18)17 (3)63 (2)Unadjusted HR (95% CI)1.72 (0.98, 3.01)5.88 (2.07, 16.71)1.13 (0.56, 2.29)Ref.Adjusted* HR (95% CI)1.24 (0.66, 2.32)13.94 (4.30, 45.18)0.75 (0.35, 1.63)Ref.Hospitalization or death, n (%)126 (22)25 (50)101 (19)419 (14)Unadjusted HR (95% CI)1.66 (1.33, 2.07)3.01 (1.93, 4.70)1.47 (1.14, 1.89)Ref.Adjusted* HR (95% CI)1.53 (1.20, 1.94)2.84 (1.64, 4.91)1.34 (1.02, 1.77)Ref.

*Adjusted for age, sex, race, and smoking

Figure 1.

Multivariable hazard ratios for the composite outcome of hospitalization or death from COVID-19, comparing all RA and subgroups by serostatus, bone erosions, and ILD to matched comparators without RA.

Conclusion

We confirmed that RA was associated with severe COVID-19 outcomes compared to the general population. We found evidence that ILD may be an effect modifier for the relationship between RA and severe COVID-19 outcomes, but RA subgroups defined by serostatus and bone erosions had similarly elevated risk. These findings suggest that ILD or its treatment may be a major contributor to severe COVID-19 outcomes in RA.

References

[1]Bongartz, T, et al, Arthritis Rheum. 2010 Jun;62(6):1583-91.

Disclosure of Interests

None declared

Use of inhaled loxapine in acute psychiatric agitation

Objectives

The aim of this work is to study the efficacy of loxapine inhalation powder on agitated patients in a psychiatric inpatient unit.

Methods

Nineteen patients sample, with an average age of 39.4 years old, diagnosed with schizophrenia, bipolar disorder or schizoaffective disorder. Patients inhaled loxapine 10 mg, using the staccato system, when they suffered a psychomotor agitation. The clinical efficacy was measured as a change from baseline in the Positive and Negative Syndrome Scale-Excited Component (PANSS-EC) and in the Young Mania Rating Scale (YMRS) one hour after the administration of loxapine.

Results

A mean of 9.8 points reduction (22.6 at baseline and 12.7 one hour after the administration) was found on the PANSS-EC (t-test, P < .001) and 68.4% of the patients were considered responders as they obtained a reduction of at least 40% of the basal score. On 10 of the total of the agitated patients showed an improvement of the psychomotor excitement, and this allowed the clinicians to remove the physical restraint; on 6 of the agitated patients the physical restraint could be avoided during the whole treatment; and 3 of the patients experienced a reduction of the excitement. The reduction on PANNS-EC on the latest group was not statistically significant (t-test, P = .121).

Conclusions

Inhaled loxapine was a non-invasive, rapid and effective alternative treatment for acute agitation in a psychiatric inpatient unit. It resulted more effective on mild and moderate cases; not been significantly effective on the severe cases of agitation.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

The US National Cholesterol Education Programme Adult Treatment Panel III (NCEP ATP III): prevalence of the metabolic syndrome in postmenopausal Latin American women

BACKGROUND

Metabolic syndrome (METS) is a strong predictor of cardiovascular risk. Since the prevalence of METS increases after menopause, gynecological routine consultation offers an excellent screening opportunity.

OBJECTIVES

To assess the prevalence of METS in Latin American postmenopausal women and factors modifying its risk; as well as to assess the role of simple routine care measurements in the diagnosis of the METS.

METHODS

A total of 3965 postmenopausal women, aged 45-64 years, seeking health care at 12 gynecological centers in major Latin American cities were included in this cross-sectional study. The US National Cholesterol Education Programme Adult Treatment Panel III (NCEP ATP III) guidelines were applied to assess METS. This was present if three or more of the following conditions were present: waist circumference > or = 88 cm; blood pressure > or = 130/85 mmHg; fasting plasma triglycerides > or = 150 mg/dl; high density lipoprotein (HDL) cholesterol < 50 mg/dl; glucose > or = 110 mg/dl or subjects were receiving treatment for their condition.

RESULTS

The prevalences of having at least two, three, four or five components were 62.5, 35.1, 13.5 and 3.2%, respectively. The prevalence increased from 28.1% in those aged 40-44 years to 42.9% in those aged 60-64 years. The risk of METS detection (multivariate analysis) increased with age (odds ratio (OR) 1.22, 95% confidence interval (CI) 1.03-1.43), time elapsed since menopause (OR 1.18, 95% CI 1.00-1.38), smoking cigarettes (OR 1.40, 95% CI 1.19-1.65), obesity (OR 13.01, 95% CI 10.93-15.49) and hypertension (OR 9.30, 95% CI 7.91-10.94). In contrast, hormone therapy reduces this risk (OR 0.59, 95% CI 0.51-0.70).

CONCLUSION

There is a high prevalence of the metabolic syndrome in postmenopausal Latin American women seeking gynecologic health care. Age, years since menopause, obesity and hypertension are strong predictors of this condition.

Effect of androgens combined with hormone therapy on quality of life in post-menopausal women with sexual dysfunction

AIM

To evaluate with validated instruments changes in quality of life and sexuality in women receiving hormonal replacement therapy (AHT).

DESIGN

Randomised, double-blind, double-dummy study with two parallel treatment arms.

PATIENTS AND METHODS

Forty-seven healthy post-menopausal women, aged 45-64 years, were evaluated using the Female Sexual Function Index (FSFI) and the menopause-specific quality of life questionnaire (MENQOL). Of them, 40 diagnosed with sexual dysfunction were randomised (1:1) to receive daily 0.625 mg of conjugated estrogens plus 1.25 mg of methyl-testosterone and 100 mg of micronised progesterone or placebo. After 3 months follow-up, FSFI and MENQOL questionnaires were administered for a second time.

RESULTS

Quality of life was unchanged in the placebo group whereas AHT significantly improved scores of vasomotor, psychological, physical and sexual symptoms. As expected, FSFI was not modified in the placebo group while in AHT group the FSFI score improved significantly. In addition, at the end of the study, 68.7% of subjects of the AHT group did not fit did not fit the criteria for sexual dysfunction as per the FSFI (p < 0.0001).

CONCLUSIONS

Adding methyl-testosterone to hormone therapy improves quality of life and sexuality in post-menopausal women with sexual dysfunction.

Pro-inflammatory effects of early non-enzymatic glycated proteins in human mesothelial cells vary with cell donor's age

BACKGROUND AND PURPOSE

Diabetes mellitus is prevalent in the elderly population. It is also a disease causing tissue damage through several different mechanisms. Some of these mechanisms are also activated by ageing and this overlap raises questions about how diabetes induces damage in the elderly. Early products of non-enzymatic glycation of proteins (Amadori adducts), and the ageing process share the capacity to induce oxidative stress and inflammation in human peritoneal mesothelial cells (HPMCs). We have evaluated the interactions between the age of the donor of the HPMCs and the pro-inflammatory effects of Amadori adducts in those cells.

EXPERIMENTAL APPROACH

HPMCs were isolated from 20 individuals (age range 21-81 years) and grown in culture. Using different experimental approaches we determined NF-kappaB dependent transcriptional activity and different NF-kappaB-related pro-inflammatory gene and protein expressions in basal (or non-stimulated) conditions and after stimulation with two Amadori adducts; highly-glycated haemoglobin and glycated bovine serum albumin.

KEY RESULTS

Amadori-induced effects on NF-kappaB dependent-transcription and on the activity of NOS, COX and several NF-kappaB-related pro-inflammatory genes (iNOS, COX-2, TNF-alpha, IL-1beta, and IL6) diminished as the donor's age increased, being practically absent in cells from donors more than 65 years old. Such decreased effects were inversely correlated with an increased basal expression and activity of these pro-inflammatory markers with age.

CONCLUSIONS AND IMPLICATIONS

Pro-inflammatory effects of Amadori-adducts in HPMCs were strongly dependent on cell donor's age. This may have significant implications for the mechanisms underlying diabetes-induced tissue damage in patients of different ages.

Changes in the human peritoneal mesothelial cells during aging

The number of older patients admitted to peritoneal dialysis (PD) programmes is growing. At the same time, there is increasing data about the role of mesothelial cells in determining the functional alteration of the peritoneum during PD. However, little is known about the functional changes accompanying the ageing process in mesothelial cells. We aimed to evaluate whether the aging process is accompanied by changes in some functional characteristic of the human peritoneal mesothelial cells (HPMC), which could account for the poor prognosis observed in old patients with PD. HPMCs were isolated from patients undergoing a nonurgent, nonseptic abdominal surgical procedure, without renal, vascular or inflammatory disease. Cytokine levels (by enzyme-linked immunosorbent assay (ELISA)), nitrates+nitrites, and cyclooxygenase (COX) activity (by a chemiluminescence assay), cytokines, COX, nitric oxide synthase (NOS), and nuclear factor (NF)-kappaB1, two messenger ribonucleic acid (mRNA) gene expressions (by reverse transcriptase (RT)-Multiplex PCR), COX, and NOS promoter gene activities, and NF-kappaB-dependent transcription (by transient transfection assays) were determined. Our data show a significant increase in cytokines, COX, and NOS activities, and mRNA expression of cytokines, COX-2, inducible nitric oxide synthase (iNOS) and precursors of NF-kappaB in HPMCs from old people. This was also the case for COX-2 and iNOS promoter gene activities and NF-kappaB-dependent transcription. There was a positive correlation between the age of the donor's cell and the proinflammatory profile of the HPMCs. Such age-dependent increase (around two-three times) is partially abolished by different antioxidant or free-radical scavengers. Thus, aging is accompanied by the presence of an inflammatory state in HPMCs, which involves the participation of different reactive oxygen species.

Early and intermediate Amadori glycosylation adducts, oxidative stress, and endothelial dysfunction in the streptozotocin-induced diabetic rats vasculature

AIMS/HYPOTHESIS

In a model of streptozotocin-induced Type 1 diabetes mellitus in rats of 9 weeks duration, we analysed time associations between the development of hyperglycaemia, early and intermediate glycosylation Amadori adducts, or AGE compared with enhancement of oxidative stress and endothelial dysfunction.

METHODS

Endothelial function was tested at several stages of streptozotocin-induced diabetes and after treatment with insulin, resulting in different concentrations of blood glucose, glycosylated haemoglobin (an Amadori adduct), and AGE. Other animals were studied antagonising the formation of AGE with aminoguanidine.

RESULTS

Relaxation in response to acetylcholine (1 nmol/l to 10 micro mol/l) was tested in isolated segments from aorta or mesenteric microvessels. Impairment of endothelium-dependent relaxations occurred after 2 weeks of untreated diabetes. Preincubation of vessels affected with 100 U/ml superoxide dismutase improved the relaxations to acetylcholine, along the time-course of the endothelial impairment. This indicates the participation of reactive oxygen species on diabetic endothelial dysfunction. The impairment of endothelium-dependent relaxations was recovered after 3 more weeks of insulin treatment. Aminoguanidine treatment did not modify this pattern of development. The time course of the rise and disappearance of endothelial dysfunction showed a higher correlation with glycosylated haemoglobin concentrations than with blood glucose or serum AGE.

CONCLUSION/INTERPRETATION

Enhancement of early and intermediate Amadori adducts of protein glycosylation was the factor showing a better relation with the development of endothelium impairment. These results are consistent with a role for these products in the development of diabetic vasculopathy.

High glucose induces cell death of cultured human aortic smooth muscle cells through the formation of hydrogen peroxide

Alterations of the vessel structure, which is mainly determined by smooth muscle cells through cell growth and/or cell death mechanisms, are characteristic of diabetes complications. We analysed the influence of high glucose (22 mM) on cultured human aortic smooth muscle cell growth and death, as hyperglycaemia is considered one of the main factors involved in diabetic vasculopathy. Growth curves were performed over 96 h in medium containing 0.5% foetal calf serum. Cell number increased by 2 - 4 fold over the culture period in the presence of 5.5 mM (low) glucose, while a 20% reduction in final cell number was observed with high glucose. Under serum-free conditions, cell number remained constant in low glucose cultures, but a 40% decrease was observed in high glucose cultures, suggesting that high glucose may induce increased cell death rather than reduced proliferation. Reduced final cell number induced by high glucose was also observed after stimulation with 5 or 10% foetal calf serum. The possible participation of oxidative stress was investigated by co-incubating high glucose with different reactive oxygen species scavengers. Only catalase reversed the effect of high glucose. Intracellular H(2)O(2) content, visualized with 2',7'-dichlorofluorescein and quantified by flow cytometry, was increased after high glucose treatment. To investigate the cell death mechanism induced by high glucose, apoptosis and necrosis were quantified. No differences were observed regarding the apoptotic index between low and high glucose cultures, but lactate dehydrogenase activity was increased in high glucose cultures. In conclusion, high glucose promotes necrotic cell death through H(2)O(2) formation, which may participate in the development of diabetic vasculopathy.

Thapsigargin induces apoptosis in cultured human aortic smooth muscle cells

Vascular remodeling is a key feature of many pathologic states, including atherosclerosis, or hypertension. Vascular smooth muscle cells participate in determining the vessel structure by several mechanisms such as cell migration, cell growth, or cell death (necrosis or apoptosis). Here we report that thapsigargin, an inhibitor of endoplasmic reticulum Ca2+ -adenosine triphosphatase (ATPase), is able to induce apoptosis in human vascular smooth muscle cells (HVSMCs). Apoptosis was assessed by three different methods: differential chromatin binding dye staining. cytoplasmic histone-associated DNA fragments detection by enzyme-linked immunosorbent assay (ELISA) and terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). When HVSMCs were treated for 1 h with thapsigargin (100 nM-10 microM), there was a concentration-dependent increase in both parameters 24 h after the thapsigargin pulse. When a time-course experiment was performed, both parameters were significantly enhanced from 3 to 6 h after the exposure to thapsigargin. We conclude that thapsigargin promotes apoptosis in HVSMCs, providing a useful tool for the study of programmed cell death in human vascular smooth muscle.

Treatment with acarbose may improve endothelial dysfunction in streptozotocin-induced diabetic rats

We sought to determine whether a single reduction of hyperglycemia and those derivatives from nonenzymatic protein glycosylation may be effective in reducing the development of diabetic endothelial dysfunction. Therefore, we investigated how acarbose, an inhibitor of intestinal alpha-glucosidase that reduce hyperglycemia by lowering glucose absorption, may prevent the impairment of acetylcholine (ACh)-induced endothelium-dependent relaxations observed in isolated vascular segments from untreated streptozotocin-induced diabetic rats. When administered after diabetes induction, 10 mg/kg acarbose decreased modestly the enhancement of blood glucose and glycosylated hemoglobin (HbA1c) levels, but not those of advanced glycosylation end products (AGEs). This effect was linked to a partial improvement of ACh-induced responses both in conductance vessels, such as aortic segments, and resistance vasculature, like mesenteric microvessels. When acarbose was introduced after 6 weeks of untreated diabetes, blood glucose, HbA1c, and AGE levels were not affected and endothelial dysfunction remained unchanged in mesenteric microvessels, whereas a small improvement was observed in aortic segments. The addition of 100 U/ml superoxide dismutase enhanced the impaired relaxations to values similar to vessels from nondiabetic rats, indicating a main role for superoxide anions in diabetes-induced endothelial dysfunction. We conclude that hyperglycemia itself or elevated HbA1c, but not plasma AGEs, are related to enhanced oxidative stress and to the impairment of endothelium function associated to diabetes. This process can be partially prevented by reducing glucose absorption with acarbose.

Correction of glycosylated oxyhemoglobin-induced impairment of endothelium-dependent vasodilatation by gliclazide

We have investigated whether gliclazide, a second-generation sulfonylurea hypoglycemic agent, interferes with the impairment of endothelium-dependent nitric-oxide-mediated relaxation produced by 14%-glycosylated human oxyhemoglobin (GHHb). For comparative purposes, other agents, like glibenclamide, aminoguanidine, ascorbic acid or superoxide dismutase (SOD), were also tested. GHHb (10 nM) caused a reduction in endothelium-dependent relaxation induced by acetylcholine (1 nM to 10 microM) in both isolated aortic segments and mesenteric microvessels from normoglycemic nondiabetic rats. Preincubation of the vessels with gliclazide (100 nM to 10 microM) prevented the impairment of endothelial relaxation, the threshold concentration of gliclazide being 300 nM. In addition, 10 microM gliclazide also prevented the reduction by 10 nM GHHb of the relaxation induced by exogenous nitric oxide (NO, 10 nM to 100 microM). Determination of superoxide anion release measured by the reduction in ferricytochrome c indicated that GHHb produced significant amounts of these free radicals that were concentration-dependently inhibited by gliclazide. The impairment of endothelium-mediated responses was also prevented by 100 U/ml SOD or 10 microM ascorbic acid, but not by 10 microM glibenclamide or 100 microM aminoguanidine. We conclude that gliclazide can reduce the impairment of nitric-oxide-mediated endothelium-dependent relaxation produced by GHHb. This reduction is likely related to the antioxidant properties of the drug, a mechanism suggested by these studies which demonstrate the inactivation of superoxide anions produced by the glycosylated protein by gliclazide.

Prevention of endothelial dysfunction in streptozotocin-induced diabetic rats by gliclazide treatment

The aim of the present work was to analyze whether the oral hypoglycemic drug gliclazide affects diabetic endothelial dysfunction in streptozotocin-induced diabetic rats. Gliclazide was compared with glibenclamide, ascorbic acid, and aminoguanidine. An insulin-dependent model of diabetes was selected to exclude insulin-releasing effects of the drugs. Both in isolated aortic segments and mesenteric microvessels, endothelium-dependent relaxation evoked by acetylcholine (ACh, 1 nM to 10 microM) was significantly reduced in vessels from diabetic animals. This impairment was reversed when the segments were previously incubated with 100 U/ml superoxide dismutase. When streptozotocin-induced diabetic rats were orally treated from the time of diabetes induction with gliclazide (10 mg/kg) or ascorbic acid (250 mg/kg), ACh-induced endothelium-dependent relaxation was well preserved both in aortic segments and mesenteric microvessels. In addition, the impaired vasodilatation to exogenous nitric oxide (NO) in aortic segments was also improved in gliclazide-treated diabetic rats. On the other hand, oral treatment with glibenclamide (1 and 10 mg/kg) or aminoguanidine (250 mg/kg) did not produce significant improvements in diabetic endothelial dysfunction. We conclude that gliclazide reverses the endothelial dysfunction associated with diabetes. This effect appears to be due not to the metabolic actions of the drug but rather to its antioxidant properties, as it can be mimicked by other antioxidants. We propose that the mechanism involved is the inactivation of reactive oxygen species, which are increased in diabetes probably as a result of increased early protein glycosylation products, such as glycosylated hemoglobin (HbA(1c)). These effects of gliclazide are not shared by other oral hypoglycemic agent such as glibenclamide, or by blockade of advanced glycosylation end product (AGE) generation with aminoguanidine.

Highly glycated oxyhaemoglobin impairs nitric oxide relaxations in human mesenteric microvessels

AIMS/HYPOTHESIS

It has been recently shown that glycated human haemoglobin induces endothelial dysfunction in rat vessels by generating superoxide anions that interfere with nitric oxide mediated responses. Our study analysed the effect of glycated human haemoglobin on the endothelium-dependent relaxations of human vessels.

METHODS

Omental microvessels were obtained from patients (without diabetes, hypertension or vascular disease) during surgery and mounted in a small vessel myograph to study their vasoactive responses (vessels from 3-7 patients for each set of experiments).

RESULTS

Cumulative vasodilatory responses to bradykinin (10 nmol/l to 3 mumol/l) were induced in vessels precontracted with 35-50 mmol/l potassium chloride. Addition of 100 mumol/l NG-nitro-L-arginine methyl ester reduced the relaxation evoked by bradykinin, but preincubation with both NG-nitro-L-arginine methyl ester and 10 mumol/l indomethacin was needed to abolish it. Bradykinin-induced responses were inhibited by 1 mumol/l non-glycated oxyhaemoglobin whereas no effect was obtained with 10 nmol/l oxyhaemoglobin. At these low concentrations (10 nmol/l), glycated human oxyhaemoglobin caused an impairment of bradykinin-induced relaxation when the percentage of glycation was 10% or higher. This effect was prevented by preincubating the vessels with ascorbic acid (10 mumol/l), superoxide dismutase (100 U/ml) and gliclazide (1 and 10 mumol/l), but not with indomethacin (10 mumol/l), catalase (400-600 U/ml), dimethylthiourea (1 mmol/l) or glibenclamide (10 mumol/l). In vessels preincubated with NG-nitro-L-arginine methyl ester (100 mumol/l), glycohaemoglobin did not add any additional effect.

CONCLUSION/INTERPRETATION

Highly glycated human oxyhaemoglobin, at physiological plasmatic concentrations, impairs nitric oxide-mediated responses by a mechanism involving superoxide anions but not cyclooxygenase derivatives.

Pharmacological interference of vascular smooth muscle cell hypertrophy induced by glycosylated human oxyhaemoglobin

Nonenzymatically glycosylated human oxyhaemoglobin induces vascular smooth muscle cell hypertrophy by releasing reactive oxygen species. We analysed the ability of drugs with antihypertrophic properties for the vascular wall and/or antioxidant activity, such as captopril, losartan, and nifedipine, or gliclazide, carvedilol, and ascorbic acid, to interfere with 10 nM glycosylated human oxyhaemoglobin-induced increase in vascular smooth muscle cell size (118+/-0.5% of basal). Vascular smooth muscle cell hypertrophy was abolished concentration-dependently, with pD(2) values over a 100-fold interval: 6.4+/-0.3, 7.7+/-0.4, 7.3+/-0.4, 7.4+/-0.6, 8. 8+/-0.2, and 9.0+/-0.2 for captopril, losartan, nifedipine, ascorbic acid, carvedilol and gliclazide, respectively. Drugs with powerful antioxidant properties, especially carvedilol and gliclazide, are particularly effective in preventing glycosylated human oxyhaemoglobin-induced vascular smooth muscle cell hypertrophy.

Impairment of endothelial relaxations by glycosylated human oxyhemoglobin depends on the oxidative state of the heme group

While nanomolar met- or cyanomethemoglobin, either non-glycosylated or glycosylated, did not alter endothelial function, glycosylated oxyhemoglobin induced contractile responses and caused an impairment of endothelium-dependent relaxations in rat aortic segments. The vascular effects induced by glycosylated oxyhemoglobin were prevented by superoxide dismutase. Furthermore, glycosylated oxyhemoglobin produced higher amounts of superoxide anions than other hemoglobin derivatives. These results suggest that glycosylated hemoglobin requires the existence of a functional heme group containing iron in ferrous state to interfere with the endothelial function at nanomolar concentrations. This effect is mediated by generation of superoxide anions.

Vascular smooth muscle cell hypertrophy induced by glycosylated human oxyhaemoglobin

1. Nonenzymatic protein glycosylation is a possible mechanism contributing to oxidative stress and vascular disease in diabetes. In this work, the influence of 14%-glycosylated human oxyhaemoglobin (GHHb), compared to the non-glycosylated protein (HHb), was studied on several growth parameters of rat cultured vascular smooth muscle cells (VSMC). A role for reactive oxygen species was also analysed. 2. Treatment of VSMC for 48 h with GHHb, but not with HHb, increased planar cell surface area in a concentration dependent manner. The threshold concentration was 10 nM, which increased cell size from 7965+/-176 to 9411+/-392 microm2. Similarly, only GHHb enhanced protein content per well in VSMC cultures. 3. The planar surface area increase induced by 10 nM GHHb was abolished by superoxide dismutase (SOD; 50 200 u ml(-1)), deferoxamine (100 nM-100 microM), or dimethylthiourea (1 mM), while catalase (50 200 u ml(-1)) or mannitol (1 mM) resulted in a partial inhibition of cell size enhancement. 4. When a known source of oxygen free radicals was administered to VSMC, the xanthine/xanthine oxidase system, the results were analogous to those produced by GHHb. Indeed, enhancements of cell size were observed, which were inhibited by SOD, deferoxamine, or catalase. 5. These results indicate that, at low concentrations, GHHb induces hypertrophy in VSMC, this effect being mediated by superoxide anions, hydrogen peroxide, and/or hydroxyl radicals. Therefore, glycosylated proteins can have a role in the development of the structural vascular alterations associated to diabetes by enhancing oxidative stress.

[Our experience in endourology]

Exposition of the experience accrued over 8 years in endo-urological procedures performed to 303 patients divided in 2 groups: Lithiasic (Group I) and Non-lithiasic (Group II) patients. Ninety-two (92) percutaneous nephrostomies in 69 patients and 235 ureteroscopies in 234 patients were accomplished, removing 324 calculi and resolving other obstructive conditions. The rate of success was 85% and 98% for the percutaneous nephrostomies and ureteroscopies, respectively. Complications were reported in 7 patients after percutaneous nephrostomy and in 14 patients during ureteroscopy. Most of these complications resolved with the use of endoscopic techniques except in two patients who required open surgery. There were no deaths in the present series. The advantages of applying this technique over the conventional one are discussed.