[Pelvic floor dyssynergia: videoproctographic analysis and pathologic associations in defecation obstruction syndrome]

INTRODUCTION

Pelvic floor dyssynergia is included pathophysiologically in the functional dyschezia group. It is characterized by the paradoxical contraction or lack of relaxation of the puborectal muscle and/or external sphincter during defecation, with consequent functional outlet obstruction. The diagnosis is not always easy because there is no really specific test, nor any diagnostic gold standard; also, many pathophysiologic and epidemiologic findings are still unknown. We tried to define the diagnostic criteria of this condition with the statistical analysis of the main defecographic parameters and to assess the radiologic correlation between functional forms and "mixed" forms, that is those associated with other anorectal disorders.

MATERIAL AND METHODS

We reviewed 121 videoproctographic examinations performed January, 1995, to December, 1996, in patients with clinical and instrumental signs suggestive of pelvic floor dyssynergia and compared the findings with those of a control group of 20 patients with no defecation disorders. We also assessed the frequency of the major anorectal disorders associated with pelvic floor dyssynergia relative to the pure form.

RESULTS

Initiation time (11 s versus 1 s; p < .05), evacuation time (47 s versus 10 s; p < .01) and the rate of residual contrast material (57 versus 7) were on average greater in dyssynergia patients. These parameters provide important information on the degree and rapidity of rectal voiding. 81% of our dyssynergia patients had rectal voiding time > 30 s, with final residual contrast material 1/3 to 2/3 of the initial volume. Posterior anorectal angle measurements showed significant differences on strain and evacuation and in anorectal angle excursion at rest/on evacuation (4 +/- 17 degrees; p < .01). Anorectal angle excursion < 15 degrees or its paradoxical reduction was associated with anal diameter < 12 mm during voiding in 85% of cases. We subdivided our population into 4 groups: group A (15 patients: median age: 38 +/- 14 years) with dyssynergia only: group B (22 patients; median age: 54 +/- 23 years) with dyssynergia associated with a functional megarectum); group C (66 patients; median age: 52 +/- 14 years) with mixed pathophysiological patterns such as megarectum, rectocele, intrarectal intussusception, mucosal prolapse and perineal descent; group D (18 patients; median age: 52 +/- 16 years) with the same characteristics as in group C but also with hemorrhoids and anal fissures.

DISCUSSION AND CONCLUSIONS

At first (digital radiography) and second level (videoproctography), the diagnosis of pelvic floor dyssynergia is based manly on dynamic parameters (initiation and evacuation times) correlated with the residual contrast agent volume. At baseline, the diagnosis is based on the reduced/no excursion of the anorectal angle between rest and evacuation, together with a narrowed anal eanal. The rate of pure pelvic floor dyssynergia was lower (12.4%) than that of the pathophysiologically mixed patterns and the median age of this group of patients was 38 +/- 14 years, which is statistically lower than that of the other groups (52 +/- 14). Comparing the frequency of purely functional forms in the age range < 40 years, we observed a statistically significant difference (p < .001), which suggests that this disorder is always the first cause of the outlet obstruction syndrome.

[Paraesophageal hiatal hernia]

Paraesophageal hiatal hernia is an uncommon disease but it frequently presents in aged people, causing chronic vague abdominal symptoms up to surgical emergencies from incarceration, strangulation or obstruction. The authors describe the physiopathology and clinical anatomical features of paraesophageal hiatal hernia. Important diagnostic radiological and instrumental aspects are then illustrated, versus sliding esophageal hiatal hernia. There are followed by a description of possible complications of this lesion and therapeutic implications.

Glucocorticoid resistance and the immune function in the immunodeficiency syndrome

Glucocorticoids, the final product of HPA axis, and their receptors (GRs) on mononuclear cells are crucial mediators in the endocrine-immune interaction. An alteration in GRs involving a lower receptor affinity (Kd) for glucocorticoids has been found in a group of advanced AIDS patients, who developed Addisonian symptoms (weakness, weight loss, hypotension, hyponatremia, and intense mucocutaneous melanosis) in spite of hypercortisolism and normal or slightly elevated values of ACTH (AIDS-GR). In these patients, data for the suppression test showed decreased cortisol and ACTH suppression in response to exogenous dexamethasone. The inhibitory effect of dexamethasone on radiolabeled-thymidine incorporation in mononuclear cells from these patients was also reduced. Monocytes of AIDS-GR patients had a receptor Kd of 10.5 +/- 4.2 nmol/l that was higher than that of other AIDS patients (AIDS-C) (2.9 +/- 0.8 nmol/l) and normal subjects (2.0 +/- 0.8 nmol/l: p < 0.01). Correlations were found between plasmatic IFN-alpha and receptor Kd on monocytes of AIDS-GR (r = 0.77). Poly (i)-poly (c)-induced IFN-alpha production by monocytes was inhibited by glucocorticoids in the AIDS-C group and controls (approx. 80% in both groups): The effect was reversed by the receptor antagonist RU-486. By contrast, glucocorticoid did not inhibit IFN-alpha production in AIDS-GR group. In conclusion, levels of plasmatic IFN-alpha, a cytokine with antiviral properties, may be increased several times, and dexamethasone fails to inhibit monocytes' IFN-alpha production only in AIDS with cortisol resistance, a disturbance that confirms an important immunoregulatory role of glucocorticoids in HIV disease.

Within-patient variability of hormone and cytokine concentrations in heart failure

Several studies on disease and treatment effects on neurohormones have been conducted with small numbers of patients, using one blood sample as representative of their states. The aim of this study was to assess the within-patient variability of plasma concentrations of several hormones and cytokines of recent interest, in patients with moderate heart failure and controlled stable background therapy over 3 weeks. Blood for neurohormone and cytokine assays was sampled in duplicate from 18 patients with moderate heart failure. After an initial visit, the patients were kept on stable therapy until the second blood sampling 21 +/- 3 days later. The plasma concentrations of several neurohormones (endothelin, renin, angiotensin II, aldosterone, norepinephrine) and cytokines (interleukin-6 (IL-6), interleukin-13 (IL-13), ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF) and soluble receptor type I of tumour necrosis factor-alpha, (sTNF-RI) were measured with immunochemical methods. Some cytokines (IL-13, CNTF and LIF) were not detected. Despite clinically satisfactory ACE inhibition, circulating angiotensin II and aldosterone levels were still elevated in some patients, suggesting aldosterone escape. The between-visit agreement of plasma concentrations measured in duplicate was less than 35% for all circulating factors, except renin which showed a higher variability throughout the 3-week study period.

Prevalence of subclinical neuropathy in diabetic patients: assessment by study of conduction velocity distribution within motor and sensory nerve fibres

Nerve conduction velocity distribution (CVD) study is a newly-developed electrodiagnostic method for detecting alterations in the composition of nerve fibres according to their conduction velocity. The presence of subclinical neuropathy was evaluated in 138 diabetic patients by CVD study of four motor nerves (external popliteal and ulnar nerves bilaterally) and two sensory nerves (median nerve bilaterally), and the data obtained were compared with standard electrophysiological parameters in the same nerve segments. CVD studies revealed an altered distribution pattern in 106 of 129 evaluable patients for motor nerves (82%) and in 67 of 115 evaluable patients for sensory nerves (58%), while standard examination gave abnormal findings in 92 of 137 patients (67%) and in 33 of 118 patients (11%), respectively. Of the patients adequately evaluated by both techniques, 21 of 129 patients (16%) revealed altered CVD data unaccompanied by slowing of maximum nerve conduction velocity, and 37 patients of 101 (37%) showed similar findings for sensory nerves. Subclinical alterations of motor and sensory nerve CVD were not significantly related to age or to metabolic control expressed as glycated haemoglobin levels; a significantly longer duration of disease was found in patients with motor and mixed subclinical neuropathy with respect to non-neuropathic patients. The CVD study allowed us to detect subclinical abnormalities of motor and sensory nerve fibres; often this is a more sensitive method than the standard electrodiagnostic study. This method can be very useful as a diagnostic tool and in research in the study of the progression of diabetic neuropathy.

Glucocorticoids and the immune function in the human immunodeficiency virus infection: a study in hypercortisolemic and cortisol-resistant patients

Immunological studies in human immunodeficiency virus (HIV)-positive patients suggest that the disease progression is accompanied by a defective production of type 1 cytokines (interleukin-2 (IL-2) and IL-12], an increased production of type 2 cytokines (IL-4, IL-6, and IL-10), and an increased production of IgE. HIV infection is also associated with activation of the hypothalamo-pituitary-adrenal axis function and increased plasma and urinary cortisol concentrations. As cortisol is involved in the physiological regulation of cytokines, a study was conducted to examine cytokine patterns in two groups of hypercortisolemic patients, one with normal sensitivity to glucocorticoids and the other with glucocorticoid resistance. Ten HIV-infected patients with normal receptor affinity to glucocorticoids (AIDS-C), 10 HIV-infected patients with low receptor affinity to glucocorticoids (AIDS-GR), and 20 healthy subjects were studied. Receptor characteristics of peripheral blood mononuclear cells were evaluated by [3H]dexamethasone binding. Serum cortisol and urinary free cortisol were measured by RIA. Serum ACTH and IgE were measured by immunoradiometric assay, and IL-2, IL-4, and IL-10 cytokines and interferon-gamma were measured by enzyme-linked immunosorbent assay. AIDS-C patients showed low IL-2 and high IL-4, IL-10, and IgE concentratios; conversely, AIDS-GR patients showed high IL-2 and low IL-4 and IgE concentrations. Thus, in HIV infection, elevated cortisol levels suppress cell-mediated immunity and stimulate humoral immunity, whereas this response is not detected in cortisol-resistant patients. These findings indicate that cortisol and its receptors are critically involved in the regulation of immune function in HIV infection.

Short-term variations in bone remodeling biochemical markers: cyclical etidronate and alendronate effects compared

Bone-remodeling markers have been proposed to monitor antiosteoporotic therapy, as substantial changes in these markers usually occur in a relatively short time interval. In this study we have evaluated the short term effects of two bisphosphonates on bone-remodeling markers with the aim of 1) defining the shortest reliable time interval after which markers should be measured, and 2) comparing the effects of different bisphophonates. To do so, 74 postmenopausal women with a lumbar spine t score of at least -1 were randomly allocated to 4 different treatments: calcium carbonate (500 mg/day; n = 18), 5 mg/day alendronate (A5; n = 18), 10 mg/day alendronate (A10; n = 20), and cyclical etidronate (CE; n = 18). Serum and 24-h urine samples were collected at baseline and 14, 28, 56, and 84 days after the beginning of therapy. Type I collagen N-terminal (NTx) and C-terminal (CTx) telopeptides and total deoxypyridinoline (tDPD) were measured in urine and normalized for urinary creatinine excretion. Osteocalcin and bone alkaline phosphatase in serum were measured. Alendronate (at both doses) and CE significantly decreased bone-remodeling markers, whereas calcium carbonate did not. Bone resorption markers reduction reached a plateau 14 (A10) or 28 (A5 and CE) days after the beginning of treatment, whereas osteocalcin and bone alkaline phosphatase were significantly reduced at 56 (A10) and 84 (CE) days. The global effects of alendronate and CE on NTx and CTx (calculated as the area under the curve) were significantly different from those of calcium (P < 0.05), but were not significantly different from each other. The percent change from baseline obtained with tDPD, NTx, or CTx during bisphosphonate treatment were significantly different (P < 0.05), but this difference disappeared when the variability in the calcium carbonate group was taken into account. In conclusion, this study shows that 1) etidronate and alendronate induce a significant and rapid reduction in bone-remodeling markers; 2) the changes in NTx, CTx, and tDPD urinary excretions reach a plateau after 2-4 wk of treatment; and 3) short term treatments with CE or alendronate induce similar changes in the urinary excretion of NTx and CTx.

Primary repair of isolated ventricular septal defect in infancy guided by echocardiography

Between 1989 and 1995, 96 consecutive infants affected by isolated ventricular septal defect (VSD) were submitted for primary correction at a median age of 4 months. Of the 96, 60 (group I) underwent surgery on the base of a 2-dimensional Doppler echocardiographic (DD echo) test alone. The preoperative DD echo anatomic definition of the type of VSD was confirmed at surgery in all 60 patients without false-positive results in terms of additional cardiac anomalies. There were 2 false-negatives: in 2 patients an associated cardiac anomaly was not detected by DD echo and required a second surgical procedure after postoperative cardiac catheterization. During the same period 36 infants (group II) underwent surgical closure of isolated VSD on the basis of cardiac catheterization and angiocardiography in addition to DD echo. The retrospective comparison between the 2 groups revealed no significant difference in terms of sensitivity and specificity of the diagnostic tools, early and late mortality after surgical correction, postoperative hospital stay, and need for late cardiac catheterization and surgery. We conclude that after an accurate selection, most of the infants with uncomplicated VSD can safely undergo primary repair on the basis of DD echo alone.

Glucocorticoids and Th-1, Th-2 type cytokines in rheumatoid arthritis, osteoarthritis, asthma, atopic dermatitis and AIDS

Endogenous or exogenous glucocorticoids play a key role in the control of the immune and inflammatory network. Regulation of the effects of the glucocorticoids depends on changes in therapeutic levels, but also, as recently discovered, on modifications of the binding characteristics of the glucocorticoid receptors of target cells. In rheumatoid arthritis (RA), chronic bronchial asthma, atopic dermatitis, in chondrocytes from osteoarthritic patients, and in advanced stages of HIV infection, there is a down-regulation of the glucocorticoid receptors. As a consequence, B cell immune proliferation is stimulated in RA, proteolysis is enhanced in osteoarthritis, the glucocorticoids' therapeutic effect is reduced in asthma and atopic dermatitis, and a chronic persistent increase of interferon alpha is seen in HIV. Finally, glucocorticoids are also capable of switching CD4 cells from a Th-1 to a Th-2 pattern. A decreased affinity of lymphocyte glucocorticoid receptors could hinder such a switch, with obvious clinical implications.

[Biliodigestive fistulae. Apropos 2 cases with opposite symptomatology]

Biliodigestive fistulas are the most frequent internal biliary fistulas and occur when a calculus or neoplasia perforates the wall of the biliary tract of intestine at any point. Symptoms vary given that completely asymptomatic cases have been reported in which the findings of a biliodigestive fistula was completely coincidental, but there are also cases in which the severe clinical conditions at onset require immediate surgery. The Authors report two cases with opposing symptoms and underline the importance of diagnostic imaging in the preoperative analysis. They also underline that a correct therapeutic approach is fundamentally important in these cases.

Comparison of the clinical performance of the immunoenzymometric assays for N-terminal and C-terminal type I collagen telopeptides and the HPLC assay for pyridinium cross-links

We evaluated the clinical performances of the immunoenzymometric assays for type I collagen N-terminal and C-terminal telopeptides and the HPLC assay for total deoxypyridinoline, in distinguishing between subjects with a moderately increased bone resorption rate (women in postmenopause) and subjects with normal bone resorption rate (women in premenopause). The postmenopausal group consisted of 61 women who had been in menopause for no more than 10 years, while the premenopausal group consisted of 52 healthy women with normal menstrual cycles. The biochemical markers were measured in a 24 hour urine sample and the results expressed as the molar ratio with urinary creatinine. The clinical performances were estimated by calculating the accuracy (as the area under a Receiver Operated Characteristic (ROC) curve: mean +/- SEM) and the discriminating power (as score) of each assay in distinguishing postmenopausal subjects from premenopausal subjects. Type I collagen C-terminal telopeptide, type I collagen N-terminal telopeptide and total deoxypyridinoline were significantly higher in the postmenopausal than in the premenopausal group (p < 0.01). Accuracies of these three markers ranged from 66.8 +/- 5.1% to 76.8 +/- 4.3%, while Z scores ranged from 3.54 to 5.67. Type I collagen C-terminal telopeptide, type I collagen N-terminal telopeptide and total deoxypyridinoline were not significantly different in their accuracy or discriminating power. All markers were highly correlated with coefficients of correlation ranging from 0.61 to 0.77. In summary, this study shows that 1) the immunoenzymometric assays for type I collagen N-terminal telopeptide and type I collagen C-terminal telopeptide show a high accuracy and discriminating power in distinguishing subjects with different bone resorption rate; 2) the results obtained with these immunoenzymometric assays are comparable to those obtained with the HPLC assay for total deoxypyridinoline. In conclusion our data support the use of the immunoenzymometric assays for type I collagen N-terminal telopeptide and type I collagen C-terminal telopeptide for estimating bone resorption.

Glucocorticoids and the immune system in AIDS

An interesting aspect of HIV disease is the immunoendocrine dialogue, via the hypothalamo-pituitary-adrenal axis, between glucocorticoids and cytokines and its potential role in HIV disease progression. This study reports recent data on the interaction between glucocorticoids and the immune system in AIDS patients with an acquired form of glucocorticoid resistance. Clinically, glucocorticoid-resistant AIDS patients (AIDS-GR; about 12% in our series of patients) present Addisonian symptoms (weakness, weight loss, hypotension, hyponatremia and intense mucocutaneous melanosis) in spite of elevated values of plasma cortisol and urinary free cortisol. Monocytes from these patients have a significantly lower receptor affinity (higher Kd) for glucocorticoids and a higher receptor density than other patients and controls. Such receptor alteration is associated with higher values of plasma interferon alpha (IFN alpha). In AIDS-GR there is a significant correlation between the values of receptor Kd and of plasma IFN alpha (r = 0.77). After poly(I):poly(C) stimulation, monocytes from AIDS-GR produce much more IFN alpha than other AIDS patients. While in patients with no resistance and in control patients, monocyte production of IFN alpha is inhibited by dexamethasone (the effect being reversed by RU-486), a very slight inhibition of dexamethasone on IFN alpha production is observed in monocytes from AIDS-GR. In conclusion, these data demonstrate that the immunosuppressive mechanisms acting in AIDS may be reversed, as shown by the increased stimulus on IFN alpha production found in cortisol-resistant patients. These data also suggest that antiglucocorticoid drugs may be helpful in HIV disease as they antagonize the excessive immunosuppression induced by the increased production of glucocorticoids found at every stage of HIV disease.

Effect of fluvastatin on lipids and fibrinolysis in coronary artery disease

This randomized, double-blind, placebo-controlled study shows that 20-week fluvastatin treatment induces beneficial changes in the lipid panel and a shift in the fibrinolytic pathway toward activation through a decrease in tissue plasminogen activator antigen. Fluvastatin treatment causes no variation in lipoprotein(a) circulating levels.

Impaired binocular depth inversion in patients with alcohol withdrawal

Binocular depth inversion represents an illusion of visual perception. Such inversion does not occur in all cases, especially when objects with a higher degree of familiarity (e.g. photographs of faces) are displayed. Cognitive factors are assumed to override the binocular disparity cues of stereopsis. We tested the hypothesis that during alcohol withdrawal the human CNS is unable to correct the implausible perceptual hypothesis. Measurements of binocular depth inversion in perception of 3D objects were performed in 10 patients with mild alcohol withdrawal and in 11 healthy volunteers. The binocular depth inversion scores were highly elevated in the patients group in comparison to the healthy volunteers. The data demonstrates a strong impairment of binocular depth inversion in alcohol withdrawal and support the view that alcohol withdrawal may be accompanied by a disorganization of the interaction between sensory input and generation of perceptual hypotheses.

Atrial natriuretic peptide in multiple system atrophy

Central nervous system feedback loops centered on hypothalamic neurons control atrial natriuretic peptide (ANP). We evaluated the ANP response to arterial hypotension, isotonic blood volume expansion, and increase in plasma osmolality in 14 patients with multiple system atrophy (MSA). Seven of the patients were characterized by a lack of vasopressin response to hypotension (MSA type B), suggesting chronic sinoaortic denervation, and seven by a preserved response (MSA type A). Orthostatic hypotension decreased ANP in controls and type A patients, whereas ANP in type B was not affected. Isotonic saline infusion increased ANP and diuresis in controls and type A patients, whereas it did not affect ANP in type B. Osmotic load increased plasma osmolality and vasopressin in controls and MSA patients and ANP in controls and type A but not in type B patients. In MSA patients with altered afferent control of vasopressin, ANP secretion is not stimulated by blood volume expansion, osmotic load, or blood pressure, suggesting that afferent excitatory control plays a role in the release of ANP.

Affinity of angiotensin I-converting enzyme (ACE) inhibitors for N- and C-binding sites of human ACE is different in heart, lung, arteries, and veins

Angiotensin-converting enzyme (ACE) has two enzymatically active domains: a C-domain in the carboxy terminal region and an N-domain in the amino terminal region. We based the pharmacologic characterization of these sites on the rat testis-lung model. In testis, only a truncate form of ACE is present (C-site), whereas both N- and C-sites are present in lung. In this model, captopril was shown to be N-selective and delaprilat to be C-selective. Ro 31-8472, a cilazapril derivative, and enalaprilat proved to be not site selective. We used these drugs to evaluate the affinity of C and N sites in various human tissues involved in the cardiovascular actions of ACE and used [125I]Ro31-8472 as ligand. The number and affinity of ACE binding sites were 17,680 +/- 2,345 fmol/mg protein (Kd = 0.32 +/- 0.04 nM) in lung, 560 +/- 65 (Kd = 0.36 +/- 0.05 nM) in heart, 237 +/- 51 (Kd = 0.37 +/- 0.06 nM) in coronary artery, 236 +/- 63 (Kd = 0.14 +/- 0.05 nM) in saphenous vein, and 603 +/- 121 (Kd = 0.50 +/- 0.06 nM) in mammary artery. The affinity (pKi) of captopril for the N sites ranged from 9.40 +/- 0.14 (lung) to 8.41 +/- 0.10 (coronary artery). The affinity for the C-site by delaprilat ranged from 9.97 +/- 0.15 (coronary artery) to 9.10 +/- 0.14 (mammary artery). Therefore, the affinity of C- and N-sites of ACE for ACE inhibitor (ACEI) drugs is different according to the organ involved. Because ACE is a glycosylated enzyme and glycosylation is organ dependent, we suggest that organ-specific glycosylation affects the binding characteristics of ACE inhibitors to N- or C-site of human tissular ACE.

Glucocorticoids and interferon-alpha in the acquired immunodeficiency syndrome

Some patients with acquired immunodeficiency syndrome (AIDS) develop glucocorticoid resistance characterized by low receptor affinity (Kd) for glucocorticoids in mononuclear, cells and high values of ACTH and cortisol. As glucocorticoids regulate interferon-alpha (IFN alpha) production, we hypothesized that IFN alpha, a cytokine produced predominantly by monocytes in AIDS, should be increased in cortisol-resistant AIDS, attributing the lack of cortisol inhibition to IFN alpha production. Therefore, we examined glucocorticoid receptor characteristics on monocytes by [3H]dexamethasone binding and measured IFN alpha, cortisol, and ACTH in AIDS patients with (AIDS-GR) or without glucocorticoid resistance (AIDS-C) and controls (C). Monocytes of AIDS-GR patients had a receptor Kd of 10.5 +/- 4.2 nmol/L that was higher than that in the AIDS-C group (2.9 +/- 0.8 nmol/L) and normal subjects (2.0 +/- 0.8 nmol/L; P < 0.01). IFN alpha levels were increased in the AIDS-GR group (17 +/- 6 vs. 4 +/- 1 U/mL in the AIDS-C group and 2 +/- 0.5 U/mL in the C group; P < 0.01). Correlations were found between plasma IFN alpha and receptor Kd on monocytes of AIDS-GR (r = 0.77) and between IFN alpha and plasma cortisol in the same group (r = 0.74). The poly(I)-poly(C)-induced IFN alpha production by monocytes was inhibited by glucocorticoids in the C and AIDS-C groups (approximately 80% inhibition in both groups); the effect was reversed by the receptor antagonist RU-38486. By contrast, glucocorticoids failed to inhibit IFNalpha production from AIDS-GR monocytes (approximately 20% inhibition). In conclusion, elevated IFN alpha levels in AIDS-GR may be due to the lack of inhibitory effect of cortisol on IFN alpha production due to cortisol resistance in monocytes.

Gastric Peristalsis Control by Mono Situ Electrical Stimulation: a Preliminary Study

BACKGROUND: This study was initiated 3 years ago when antral gastric stimulation was first used successfully to reduce free feeding in swine. METHODS: Three swine weighing 45 kg each were implanted with one subserosal bipolar electrode, positioned in the antrum, close to the pylorus, at the anterior side of the lesser gastric curvature. RESULTS: During 4 hours of kethamine anesthesia we paced the stomach by various patterns of electrical stimulation and obtained both forward and backward peristalsis, as well as gastric peresis. CONCLUSION: Variations in antral electrical stimulation produce characteristic patterns of forward and reverse peristalsis.

Effect of nimesulide action time dependence on selectivity towards prostaglandin G/H synthase/cyclooxygenase activity

PGHS (cyclooxygenase, prostaglandin endoperoxide synthase, 8.11,14-icosatrienoate hydrogen donor oxygen oxidoreductase, EC 1.14.99.1) is a bifunctional, membrane-bound hemoprotein that catalyzes both the bisoxygenation of arachidonic acid to form PGG2 and the peroxidative reduction of PGG2 to form PGH2. Recently two forms of cyclooxygenase have been isolated, one (COX-1) being "constitutive", the other (COX-2) being mitogen-inducible. Nimesulide (CAS 51803-78-2) has been shown to inhibit with high selectivity COX-2 without affecting COX-1 activity, so explaining the previous observations about the selectivity of the anti-prostaglandin effect of the drug. The potency of the effect, however, seems to be different according to these works. The time dependence of COX-2 inhibitors might afford some clues to a better understanding of the mechanism of COX-2 selective inhibition, on the discrepancy between some authors about the potency of the drug and on the relationship between COX-2 inhibition and inhibition of superoxide anion production, an event also characterized by a time dependence. So we evaluated the time dependency of the effect of nimesulide on COX-1 and COX-2. COX-1 was isolated from ram seminal vesicles, and COX-2 was from sheep placenta. Nimesulide inhibited COX-2 activity in a concentration-dependent manner. The inhibition of COX-2 was characterized by the time dependence, so the IC50 varied according to the time of pre-incubation (from 70 +/- 35 mumol/l to 0.07 +/- 0.05 mumol/l). Nimesulide did not affect COX-1 activity until 1 mumol/l and with an IC50 > 100 mumol/l. In conclusion nimesulide's selective inhibitory effect on COX-2 is time-dependent whereas its weak effect on COX-1 is not time-dependent. This observation agrees with the time dependence effect of COX-2 reported by other workers with NS-398 (N-(2-cyclohexyl-oxy-4-nitrophenyl)methane sulphonamide) and with flosulide and explains the different values of IC50 reported by other workers. Nimesulide shares with other sulfanilide-like drugs the time dependence of its selective effect on COX-2.

Possible modes of action of nimesulide in controlling neutrophilic inflammation

Even in recent years the development of new non-steroidal anti-inflammatory drugs (NSAIDs) appears to be essentially driven by the archaic idea to protect humans from pain and other symptoms of inflammation. Very few attempts have been made to understand if any of these drugs can limit the tissue injury during one or several forms of inflammatory reaction. In studying the events underlying the development of the tissue injury during neutrophilic inflammation, it was found that at least a NSAID, i.e. nimesulide (CAS 51803-78-2), has high potential to interfere efficiently with the major pathway responsible for neutrophil-dependent histotoxicity. Other chemically related drugs, not classified as NSAIDs but used in disease conditions characterized by neutrophilic inflammation, i.e. dapsone and sulfapyridine, have similar activities. Therefore, it is suggested that derivates from sulfanilamide (nimesulide, dapsone and sulfapyridine) are the major candidates for developing rational therapeutic anti-inflammatory strategies for controlling the development of tissue injury during neutrophilic inflammation. Also, these molecules might serve to drive the synthesis of new histoprotective antiinflammatory drugs.

Pharmacologic data reveal the heterogeneity of angiotensin-converting enzyme according to its source (lung versus heart)

Angiotensin-converting enzyme (ACE) has 2 different active sites: a C-site (in the carboxy terminal region) and an N-site (in the amino terminal part). Some ACE inhibitors have a relatively greater affinity for the C-sites, whereas others bind to the 2 sites with equal affinity. The different ontogenesis of lung and heart endothelial cells can be related to binding differences to the C- and N-sites. We labeled Ro31-8472, a clizapril derivative, which has the same affinity for the 2 ACE sites. Binding of 125I-Ro31-8472 to human left ventricle and lung plasma membranes was saturable, inhibited by ethylene diaminetetraacetic acid and displayed affinities of 360 +/- 41 pM in heart and 320 +/- 51 pM in lung. For captopril the Hill slope was 0.57 +/- 0.03 for heart and 0.48 +/- 0.05 for lung; for delaprilat, a nonsulfhydryl analogue of captopril, the slope was 0.43 +/- 0.05 for heart and 0.55 +/- 0.05 for lung. These drugs were characterized by biphasic competition isotherms. The Hill slope of enalaprilat was 1.01 +/- 0.06 for heart and 0.93 +/- 0.06 for lung, and Ro31-8472 had a slope of 0.97 +/- 0.04 for heart and 0.93 +/- 0.03 for lung. The affinity of ACE inhibitors with Hill slope different from unity varied according to the source of ACE; in fact, delaprilat had greater affinity for the high-affinity sites of heart than lung (pKi, 9.89 and 9.47, respectively), whereas captopril had greater affinity for the high-affinity sites of lung than heart (9.40 and 8.85, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

[Echographic and sonographic study of ovaries in girls with precocious puberty]

The aim of this study is the biometrical and morphological evaluation of the ovaries by sonography and the study of the haemodynamics of the ovarian artery flow by doppler ultrasound in 14 girls with precocious puberty and in 33 control subjects. All people ranged in age from 5 to 7 years. The gonadian mean volume and the mean pulsatility index have been evaluated. A significant difference in the ovarian volume has been found between patients and controls. No index between the two groups. We conclude that the doppler ultrasound needs a larger number of cases to evaluate its validity in girls with precocious puberty.