Walking the talk for dementia: A unique immersive, embodied, and multi-experiential initiative

Coping with dementia requires an integrated approach encompassing personal, health, research, and community domains. Here we describe "Walking the Talk for Dementia," an immersive initiative aimed at empowering people with dementia, enhancing dementia understanding, and inspiring collaborations. This initiative involved 300 participants from 25 nationalities, including people with dementia, care partners, clinicians, policymakers, researchers, and advocates for a 4-day, 40 km walk through the Camino de Santiago de Compostela, Spain. A 2-day symposium after the journey provided novel transdisciplinary and horizontal structures, deconstructing traditional hierarchies. The innovation of this initiative lies in its ability to merge a physical experience with knowledge exchange for diversifying individuals' understanding of dementia. It showcases the transformative potential of an immersive, embodied, and multi-experiential approach to address the complexities of dementia collaboratively. The initiative offers a scalable model to enhance understanding, decrease stigma, and promote more comprehensive and empathetic dementia care and research.

Facial emotion recognition in people with schizophrenia and a history of violence: a mediation analysis

Evidence for an association between impaired facial emotion recognition and violence in people with schizophrenia is inconclusive. In particular, the role of misidentification patterns involving specific emotions such as anger and the influence of clinical characteristics on this association remain unclear. In this study, we compared facial emotion recognition performance in age- and gender-matched schizophrenia spectrum disorders subjects with (N = 52) and without (N = 52) a history of violence. Data on current symptom severity, Cluster B personality status, past victimization, and alcohol and substance misuse were also collected. Compared to those without, subjects with a history of violence showed worse facial emotion recognition performances, involving anger, fear, disgust, sadness, and happiness. When formally testing the reporting of angry faces, evidence of enhanced sensitivity to anger was not supported. Finally, when the impact of current symptoms was assessed, higher severity of activation symptoms, including motor hyperactivity, elevated mood, excitement and distractibility, mediated the relationship between history of violence and poor facial emotion recognition performance. As a whole, our findings seem to support the role of perceptual deficits involving different emotions as well as of a mediation played by activation symptoms. Facial emotion recognition deficits associated with the propensity to violence, as well certain symptoms mediating their relationship, should be targeted by specific treatment approaches.

Enhanced Antithrombotic Mechanisms in Patients with Maturity-Onset Diabetes mellitus without Thromboembolic Complications

Some haemostatic parameters have been evaluated in a group of rigorously selected patients with maturity-onset diabetes mellitus without thromboembolic complications and in apparently normal subjects of the same age before and after the venous occlusion test (VOT).

In basal conditions diabetics had higher levels of AT III as biological activity and higher fibrinolytic and antifibrinolytic activities than controls

After VOT, F VIII R:Ag increased significantly in both groups, more markedly in controls than in diabetics, while F VIII: C showed no modification.

Also AT III R:Ag increased after the test, but such variation was significant only in diabetics; on the contrary, the biological activity of AT III was always significantly decreased after the test.

After VOT there were also in both groups highly significant increases in the fibrinolytic and antifibrinolytic activities.

Finally, HbA1c levels directly correlated with AT III as biological activity before VOT, but with no other parameter either before or after the test.

These data suggest the existence in patients with diabetes mellitus without thromboembolic complications of an activated protective mechanism against intravascular clotting.

Synoviorthesis Versus Synovectomy in the Treatment of Recurrent Haemophilic Haemarthrosis: Long-Term Evaluation

The authors report a long-term evaluation of the effects of chemical and surgical synovectomies performed in two groups of patients which were comparable as regards number of haemarthrosis per year and joint mobility. The results obtained indicated that both synovectomy and synoviorthesis were effective in reducing the bleeding episodes; however, while synovectomy stopped almost completely the recurrence of haemarthrosis, synoviorthesis in 3 patients younger than 12 years did not modify it and in one case it even increased the bleeding tendency.

Moreover, the occurrence of arthritic pain was observed in 6 knees treated by synoviorthesis and only in 3 knees treated by synovectomy. Finally, the joint function was significantly reduced in the synoviorthesis group as compared to the synovectomy group.

In conclusion, synovectomy gave better results than synoviorthesis but the latter treatment has a number of economical and technical advantages and should therefore be considered in patients older than 12 years of age with good joint function and without evident radiological changes, in whom fulldose replacement therapy has had no effect on the recurrence of haemarthrosis.

Cigarette-Smoking Effect on Platelet Function

The immediate effect of cigarette-smoking on ADP-induced platelet aggregation and on platelet adhesiveness was investigated in 12 normal subjects aged 20 to 40, in 10 normal subjects aged 43 to 72 and in 10 patients with cerebrovascular disease aged 45 to 75.

All the subjects were heavy smokers (more than 20 cigarettes a day).

After smoking 2 cigarettes a significant increase in ADP aggregation and platelet adhesiveness was found in the group of young heavy smokers, while in the old subjects with or without cerebrovascular disease the increase in platelet activity was never significant.

These data were discussed and some hypotheses for this higher reactivity of platelets from young people were suggested.

Facial emotion recognition in schizophrenia: An exploratory study on the role of comorbid alcohol and substance use disorders and COMT Val158Met

OBJECTIVES

To explore whether facial emotion recognition (FER), impaired in both schizophrenia and alcohol and substance use disorders (AUDs/SUDs), is additionally compromised among comorbid subjects, also considering the role of catechol-O-methyltransferase (COMT) Val158Met.

METHODS

We conducted a cross-sectional study, randomly recruiting 67 subjects with a DSM-IV-TR diagnosis of schizophrenia, and rigorously assessing AUDs/SUDs and COMT Val158Met polymorphism. FER was assessed using the Ekman 60 Faces Test- EK-60F.

RESULTS

As a whole, the sample scored significantly lower than normative data on EK-60F. However, subjects with comorbid AUDs/SUDs did not perform worse on EK-60F than those without, who had a better performance on EK-60F if they carried the COMT Val/Met variant.

CONCLUSIONS

This study is the first to date examining the impact of AUDs/SUDs and COMT variants on FER in an epidemiologically representative sample of subjects with schizophrenia. Our findings do not suggest an additional impairment from comorbid AUDs/SUDs on FER among subjects with schizophrenia, whilst COMT Val158Met, though based on a limited sample, might have a role just among those without AUDs/SUDs. Based on our results, additional research is needed also exploring differential roles of various substances.

Executive control in schizophrenia: a preliminary study on the moderating role of COMT Val158Met for comorbid alcohol and substance use disorders

BACKGROUND

A functional polymorphism in the catechol-O-methyltransferase (COMT) gene (Val158Met) appears to influence cognition in people with alcohol/substance use disorders (AUD/SUD) and in those with psychosis.

METHODS

To explore the potential moderating effect of these factors, a cross-sectional study was conducted, randomly recruiting subjects with DSM-IV diagnosis of schizophrenia. AUD/SUD was rigorously assessed, as well as COMT Val158Met polymorphism. Executive control functioning was measured using the Intra-Extra Dimensional Set Shift (IED). The effect of a possible interaction between comorbid AUD/SUD and COMT Val158Met polymorphism on IED scores was explored.

RESULTS

Subjects with schizophrenia, comorbid AUD/SUD, and MetMet carriers for SNP rs4680 of the COMT gene showed worse performance on IED completed stages scores, as compared with individuals with ValVal genotype. However, among subjects without AUD/SUD, those with the MetMet variant performed better than people carrying ValVal genotype.

CONCLUSIONS

This study is the first to date examining the impact of COMT on cognition in a highly representative sample of people with schizophrenia and comorbid AUD/SUD. Differential moderating effects of COMT Val/Met genotype variations may similarly influence executive functions in people with schizophrenia and comorbid AUD/SUD.

Effectiveness and safety of calcium dobesilate in treating chronic venous insufficiency: randomized, double-blind, placebo-controlled trial

Objective: To determine whether calcium dobesilate is effective in reducing chronic venous insufficiency-related peripheral oedema.

Methods: Randomized, double-blind, placebo-controlled, multicentre, parallel-group study in 253 consecutive outpatients with chronic venous insufficiency (CEAP C3-C4). The patients were treated for four weeks with either calcium dobesilate (CaD) 500 mg three times a day or matching placebo. The primary outcome measure was the reduction in lower leg volume. The leg volume calculation was based on a truncated cone model

Results: Active drug treatment resulted in a median reduction of the leg volume of 25.5 ± 33.6 ml/l tissue. The difference in the median change of the leg volume between the treatment groups at week 4 was -12.2 ml/l tissue (95 % CI -21.6 to -2.8; P =0.01). In contrast with the placebo, the effects of CaD were independent of the duration of CVI and most pronounced in more severely diseased patients. Safety variables did not differ significantly between groups.

Conclusions: Calcium dobesilate is an effective and well tolerated treatment for chronic venous insufficiency.

Intraoperative intravenous administration of rFVIIa and hematoma volume after early surgery for spontaneous intracerebral hemorrhage: a randomized prospective phase II study

BACKGROUND

Surgery of spontaneous supratentorial intracerebral hemorrhage (ICH), especially if performed early, can be complicated by rebleeding, a condition that can worsen the outcome. We evaluated the effect of recombinant activated factor VII (rFVIIa) on postoperative rebleeding.

METHODS

In this randomized, open-label, single-blinded study, 21 patients with spontaneous supratentorial ICH diagnosed by computed tomography (CT) scan were treated with intravenous rFVIIa (100 mcg/Kg b.w., N=13) or placebo (N=8). Hematoma volume was assessed using CT scan immediately, 18-30 hours, and 5-7 days after hematoma evacuation. The primary endpoint was a hematoma volume at 18-30 hours after surgery. All CT scans were evaluated at one center by the same investigator who was unaware of the treatment. Hematoma volume was measured using dedicated software.

RESULTS

At baseline, the hematoma volume was 59.2±27.4 and 71.5±32.1 mL in the rFVIIa and placebo group, respectively. Hematoma evacuation resulted in significantly smaller ICH volumes that were similar in the rFVIIa and placebo group at 18-30 hours after surgery (15.9±14.2 mL and 18±15.1 mL, respectively; mean difference 2.1 mL, 95% confidence interval -12.1 to 16.2, P=0.76 (0.03 mL after adjustment for baseline value)). The frequencies of deep venous thrombosis, myocardial infarction, troponin I elevation and cerebral ischemia were similar in both groups.

CONCLUSION

In this pilot study, intraoperative, intravenous rFVIIa administration did not modify hematoma volume after early ICH surgery. However, the 95% CI was wide, which indicates considerable uncertainty. Therefore, our results do not disprove the potential benefit of rFVIIa administration, which could be shown in a larger study.

Thrombophilic screening in Turner syndrome

AIM

The aim of this study was to determine, in patients with Turner syndrome (TS), the prevalence of thrombophilic disorders correlating with a higher risk of venous thromboembolism (VTE), to evaluate if thrombophilia is associated with the genetic features of these patients and whether screening before hormone replacement therapy (HRT) is advisable.

PATIENTS AND METHODS

We examined 82 TS patients. In all patients we analyzed activated factor VIII:C, fibrinogen, antithrombin (AT), protein C (PC), protein S (PS), activated PC resistance, and homocysteine. For every patient, an investigation for mutations in prothrombin G20210A, factor V R506Q, methylenetetrahydropholate reductase (MTHFR) C 677T and A1298C was conducted.

RESULTS

Low values of PC in 3 patients (3.70%), low values of PS in 12 (14.81%), and hyperhomocysteinemia in 4 (4.87%) were found; 52 girls (64.2%) presented hyperfibrinogenemia. Three patients were heterozygous for the prothrombin G20210A allele mutation (3.66%) and the factor V mutation was present in 4 patients (4.88%). No TS patient had a homozygous mutation. Mutations in the MTHFR gene were present in 62 girls, in 17 patients (20.7%) they were homozygous and in 45 patients (54.88%) heterozygous.

CONCLUSIONS

Considering the increased risks with the association between VTE and the higher prevalence of PC and PS deficiencies, TT genotype mutations and high level of fibrinogen, it is advisable to perform a complete thrombophilia screening in TS patients before starting HRT.

Homocysteine, vitamin B12 and folic acid levels in psoriatic patients and correlation with disease severity

Hyperhomocysteinaemia represents an independent risk factor for atherosclerotic cardiovascular disease, stroke, peripheral arterial occlusive disease and venous thrombosis. Psoriasis is a chronic inflammatory skin disease associated with increased atherothrombosis and cardiovascular risk profile. The aim of this study is to investigate homocysteine, folic acid and vitamin B12 levels in a cohort of psoriatic patients and its relationship with the severity of the disease. A retrospective observational study in 98 patients with chronic plaque psoriasis and 98 healthy controls was performed. Total plasma homocysteine level, folic acid, vitamin B12 and PASI index were assessed in every patient. Patients with psoriasis had plasma homocysteine levels higher than controls (57% of cases and 25% of controls; p<0.0001). Folic acid and vitamin B12 plasma levels were lower in psoriatic patients than in controls (p = NS), lower levels of vitamin B12 were found in patients with hyperhomocysteinaemia compared to patients with a normal value of homocysteine (p = 0.0009). The severity of psoriasis assessed according to PASI (19.51+/-16.26) did not directly correlate either with higher levels of homocysteine or with vitamin B12 and folic acid plasma levels. In conclusion, a significantly higher prevalence of hyperhomocysteinaemia was found in psoriatic patients compared to healthy controls. A significant correlation between hyperhomocysteinaemia and lower vitamin B12 levels, but not folic acid, was evidenced. On the contrary, our data do not correlate the high level of homocysteine with higher PASI scores or psoriasis type, suggesting that homocysteine level can be considered an independent risk factor in psoriatic patients.

Mitral valve prolapse and abnormalities of haemostasis in children and adolescents with migraine with aura and other idiopathic headaches: a pilot study

OBJECTIVE

To investigate the prevalence of mitral valve prolapse (MVP) and abnormalities of haemostasis in children and adolescents with migraine with aura (MA) compared with peers affected by other idiopathic headaches.

MATERIALS AND METHODS

We recruited 20 MA patients (10 men and 10 women; age range 8-17 years) and 20 sex- and age-matched subjects with other idiopathic headaches. Both groups underwent colour Doppler transthoracic echocardiography to detect MVP and the following laboratory work-up: plasma prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, protein C, protein S, homocysteine, lupus anticoagulant, von Willebrand factor (vWF) ristocetin cofactor activity, immunoglobulins (Ig) G and M anticardiolipin antibodies (aCL). Factor V Leiden, factor II and methylenetetrahydrofolate reductase were investigated (we did not test the entire genes, but screened for specific point mutations).

RESULTS

The prevalence of MVP was significantly higher in the MA subjects than in the patients affected by other idiopathic headaches (40% vs 10%; P < 0.05). Moreover, the MA patients showed a higher rate of above-normal IgM aCL titres (45% vs 10%; P < 0.05). Finally, in the group of patients with MVP we found a higher prevalence of aCL in those with MA compared with those affected by other idiopathic headaches.

CONCLUSIONS

A proportion, at least, of the MA patients showed a more complex phenotype characterized by MVP and/or positive aCL titres. The pathogenetic role of these associations is obscure and larger studies are needed to confirm the usefulness of echocardiographic and laboratory investigations in this area and to identify possible new treatment approaches that might be explored in this group of MA patients.

Platelet-Independent defect in hemostasis associated with sirolimus use

Sirolimus is currently used to prevent rejection of solid organ transplant, and sirolimus-eluting stents have shown promise for the prevention of coronary artery restenosis. Thrombocytopenia is a well-known adverse effect of sirolimus limiting its use. Herein we report on a patient in whom sirolimus caused a platelet-independent hemostasis defect. The patient was a 52-year-old woman who underwent renal transplant with consequent normal kidney function. The immunosuppressive regimen included basiliximab, steroids, and cyclosporine induction later shifted to sirolimus and mycophenolate due to biopsy findings of tubular necrosis on day 6 posttransplantation. At discharge the serum creatinine was 0.7 mg/dL. Four months after transplantation the patient was admitted to our hospital because of fever (37.5 degrees C to 38 degrees C), anorexia, and asthenia. Blood analysis showed: creatinine 1.7 mg/dL, Hb 9.6 g/dL, WBC 6 x 10(3)/microL, PLT 123 x 10(3)/microL, liver function tests normal, LDH 720 mU/mL, fibrinogen 628 mg/dL, d-dimer 0.42 ng/mL, FDP > 40 ng/mL, INR 1.10, PT 87%, aPTT 40 seconds. Cultures and tests for infection were negative. Serum sirolimus level was 25.9 ng/mL. The following day the serum creatinine rose to 2.3 mg/dL and diuresis fell to 20 mL/h. Multiple bleeding times (Ivy test) performed before the renal biopsy were repeatedly over 30 minutes (normal 3 to 5 minutes), despite normal platelet count and platelet function studies. There was no spontaneous aggregation and in vitro aggregation was normal (collagen, ADP, adrenalin, and ristocetin induced). Coagulation studies showed a defect in fibrin formation and a reduction of fibrinolysis. Suspension of sirolimus treatment was followed by remission of fever, improvement of renal function (serum creatinine 1.2 mg/dL), and normalization of bleeding time.

Alternative splicing and diversity of renal transporters

The growing molecular identification of renal transporter genes is revealing that alternative splicing is common among transporters. In this paper, I review the physiological consequences of alternative splicing in some genes encoding renal transporters in which spliced isoforms have recently been identified. In some cases, the spliced isoforms resulted in nonfunctional proteins, which, however, possess a dominant negative effect on the cotransporter function, suggesting that the presence of such isoforms can be important in the functional regulation of the transporter. In most transporter genes, however, the spliced isoforms have been shown to be functional, resulting in a variety of physiological consequences, including, for example, changes in the polarization of isoforms to the apical or basolateral membrane, changes in pharmacological or kinetic properties, and changes in tissue distribution or intrarenal localization. In some cases, although the spliced isoform is functional, the consequence of splicing is still unknown. Different regulation among isoforms is an interesting possibility. Thus the diversity of several renal transporters is enhanced by alternative splicing mechanisms.

Renal potassium-chloride cotransporters

The electroneutral cotransport of potassium and chloride is mediated by potassium-chloride transporters, which are encoded by members of the gene family of cation-chloride cotransporters. A significant body of evidence argues for swelling-activated, basolateral potassium-chloride transport in the proximal tubule and thick ascending limb, with a potential role in transepithelial salt transport. However, the lack of specific inhibitors has impeded progress in this area. The cloning of the four potassium-chloride cotransporter genes has sparked new interest in this transport pathway, and promises to yield novel insights into their roles in cellular and renal physiology.

Functional and molecular characterization of the K-Cl cotransporter of Xenopus laevis oocytes

The K-Cl cotransporters (KCCs) have a broad range of physiological roles, in a number of cells and species. We report here that Xenopus laevis oocytes express a K-Cl cotransporter with significant functional and molecular similarity to mammalian KCCs. Under isotonic conditions, defolliculated oocytes exhibit a Cl(-)-dependent (86)Rb(+) uptake mechanism after activation by the cysteine-reactive compounds N-ethylmaleimide (NEM) and mercuric chloride (HgCl(2)). The activation of this K-Cl cotransporter by cell swelling is prevented by inhibition of protein phosphatase-1 with calyculin A; NEM activation of the transporter was not blocked by phosphatase inhibition. Kinetic characterization reveals apparent values for the Michaelis-Menten constant of 27.7 +/- 3.0 and 15.4 +/- 4.7 mM for Rb(+) and Cl(-), respectively, with an anion selectivity for K(+) transport of Cl(-) = PO(4)(3-) = Br(-) > I(-) > SCN(-) > gluconate. The oocyte K-Cl cotransporter was sensitive to several inhibitors, including loop diuretics, with apparent half-maximal inhibition values of 200 and 500 microM for furosemide and bumetanide, respectively. A partial cDNA encoding the Xenopus K-Cl cotransporter was cloned from oocyte RNA; the corresponding transcript is widely expressed in Xenopus tissues. The predicted COOH-terminal protein fragment exhibited particular homology to the KCC1/KCC3 subgroup of the mammalian KCCs, and the functional characteristics are the most similar to those of KCC1 (Mercado A, Song L, Vazquez N, Mount DB, and Gamba G. J Biol Chem 275: 30326--30334, 2000).

Safety and efficacy of thalidomide in patients with myelofibrosis with myeloid metaplasia

We administered the anti-angiogenic drug thalidomide to 21 patients (12 men) with myelofibrosis with myeloid metaplasia (MMM), who were not responsive to standard treatment. Patients received thalidomide at an escalating dose from 100 to 400 mg/d. Administration of the drug was discontinued before the planned 6 months of treatment in 19 patients (90.5%), mainly because of somnolence and/or fatigue, neurological symptoms or neutropenia. Of the 13 evaluable patients (who received more than 30 d of therapy), anaemia improved in three out of seven (43%) who were treated because of anaemia; thrombocytopenia improved in two out of three (66.6%) who were treated because of thrombocytopenia; splenomegaly was reduced in four (30.8%). Undesired increases in white blood cell and platelet counts were observed in three (23.1%) and five (38.5%) patients respectively. A severity score, indexed on haematological and clinical parameters, improved in two patients (15.4%), but worsened in five (38.5%). In conclusion, standard-dose thalidomide in MMM patients is burdened with a high rate of side-effects, which prevent prolonged treatment. Because the drug is effective in improving anaemia and thrombocytopenia and in reducing splenomegaly, low-dose therapy warrants evaluation. The unexpected observation of leucocytosis and thrombocytosis suggests biological studies and better criteria for selection of patients for treatment.

Thiazide-sensitive cotransporter mRNA expression is not altered in three models of hypertension

BACKGROUND/AIMS

Several lines of evidence support that the kidney is involved in the increase of arterial blood pressure, and some genetic studies suggest that the thiazide-sensitive Na+:Cl- cotransporter could be implicated in the development of hypertension. In the present study, we analyzed the Na+:Cl- cotransporter mRNA levels in the kidney during the development of hypertension in three experimental models.

METHODS

The first model included 18 spontaneously hypertensive rats studied at 4, 10, and 16 weeks of age. The second model included 28 Wistar rats with two-kidney, one-clip Goldblatt hypertension studied at 7, 14, 21, and 28 days. The third model included 6 Wistar rats treated with N(G)-nitro-L-arginine methyl ester during 10 days. Respective controls were studied for all models. At the end of each experimental period, the systolic blood pressure was measured in the tail by plethysmography. Individual renal cortex total RNA was extracted, and the mRNA levels of the thiazide-sensitive Na+:Cl- cotransporter were assessed following a semiquantitative RT-PCR strategy.

RESULTS

All experimental models developed systemic hypertension. However, the level of mRNA expression of the Na+:Cl- cotransporter did not change in any of the models studied as compared with their respective controls.

CONCLUSION

Our results suggest that a change in mRNA levels of the thiazide-sensitive Na+:Cl- cotransporter is not associated with the development of hypertension in spontaneously hypertensive rats, in rats with renovascular hypertension, nor in rats with hypertension induced by nitric oxide synthesis inhibition.

Functional properties of a truncated recombinant GIRK5 potassium channel

Xenopus laevis oocytes codify a G-protein-activated inward rectifier potassium channel (GIRK5 or Kir3.5). Coinjection of other GIRKs, the muscarinic m2 receptor, or Gbetagamma protein cRNAs is required to observe functional GIRKx-GIRK5 heteromultimers in oocytes. Studies with GIRK2 isoforms have shown that the size of the amino or carboxyl terminus plays a crucial role on giving functional K(+) channels. In this work we studied the properties of a GIRK5 with 25 amino acids deleted toward its amino-terminal domain. Injection of GIRK5-Delta25 cRNA alone displayed large basal and transient inward rectifying currents in oocytes. The instantaneous currents reached a stationary level after a long duration voltage pulse (10 s). For this relaxation, fast (tau(1)) and slow (tau(2)) time constants were estimated at different voltages. Recovery from inactivation followed a monoexponential function (tau=0.95+/-0.07 s). By contrast with other inward rectifier channels, blockade of GIRK5-Delta25 by extracellular Ba(2+) was voltage-independent (K(d)=102+/-2 microM), suggesting the presence of a Ba(2+) site at the external channel vestibule. To confirm this hypothesis, the Ba(2+) sensitivity of two charged mutants GIRK5-Delta25(N129E) and GIRK5-Delta25(K157E) at each of the external loops was determined. GIRK5-Delta25(N129E) and GIRK5-Delta25(K157E) showed a 100-fold and 2-fold higher affinity to Ba(2+), respectively, supporting the existence of this Ba(2+) binding site.

Effect of aminoguanidine, a nitric oxide synthase inhibitor, on ocular infection with herpes simplex virus in Balb/c mice

PURPOSE

To study the effect of aminoguanidine (AMG), an inhibitor of nitric oxide production, on the ocular infection of Balb/c mice with herpes simplex virus (HSV) type 1 strain F and HSV-2 strain G.

METHODS

Animals were treated with different amounts of AMG (0.5, 0.1, and 0.05 mg/mouse) by topical application in the eye from postinfection (PI) days -2 through +5, considering 0 the day of infection. At different PI days, development of herpetic keratitis was evaluated in treated and control mice.

RESULTS

Treated animals showed a dose-dependent increase in ocular disease after viral infection, compared with control animals. Viral titers in ocular washings were higher in AMG-treated mice (PI day 2, HSV-1: AMG 0.5 mg, 1.3 x 10(3) plaque-forming units (PFU)/ml; control, 0. 22 x 10(2) PFU/ml, P < 0.025). At PI day 3, control corneas had only scattered inflammatory cells, whereas those from treated animals showed a conspicuous infiltrate consisting primarily of neutrophils. Viral titers were also higher in brains of treated mice. These animals died earlier and in a greater proportion than control animals (percentage of mortality, PI day 12, HSV-1: AMG 0.5 mg, 40% +/- 4%; control, 18% +/- 3%, P < 0.05).

CONCLUSIONS

These data indicate an inhibitory effect of nitric oxide on HSV ocular infection.

Peritoneal protein loss in patients with high peritoneal permeability: comparison between continuous ambulatory peritoneal dialysis and daytime intermittent peritoneal dialysis

BACKGROUND

Dialysate protein loss is involved in the etiology of hypoalbuminemia and malnutrition on continuous ambulatory peritoneal dialysis (CAPD). Patients with high peritoneal membrane permeability had the lowest serum albumin (Alb) and highest dialysate protein concentrations and achieved higher small solute dialysis/plasma equilibration in a shorter time than patients with low peritoneal transport. The aim of this prospective crossover study was to evaluate whether protein loss might be decreased in patients with high peritoneal permeability on short dwell-time (DT) peritoneal dialysis.

METHODS

Five high and nine high-average peritoneal transport patients were subjected to the following sequential dialysis schemes (four exchanges/day, glucose 1.5%): scheme A, three daytime exchanges (4-6 h DT) and one nightly (8-12 h DT) for 2-3 days, scheme B, 3-h DT each and dry peritoneum at night during 5 days, a wash-out period similar to scheme A, and scheme C, 2-h DT each and dry peritoneum the remainder of day and night during 5 days. Dialysate Alb, IgG, IgA, and IgM losses and adequacy of dialysis were evaluated at the end of each scheme.

RESULTS

Dialysate IgM was not detected. All protein losses were reduced with the short DT dialysis schemes; however, dialysis CCl and KT/V(urea) were also decreased. In patients with high peritoneal transport type, the 3-h DT dialysis scheme achieved a reduction in Alb loss without significant reduction of adequacy of dialysis.

CONCLUSIONS

Peritoneal Alb, IgG, and IgA losses are significantly reduced in patients with high peritoneal permeability on short dwell-time dialysis and extended dry periods. However, a reduction of dialysis contribution to small solute clearances was also observed, Three-hour dwell-time dialysis may be particularly useful in patients with high peritoneal transport type, as it tends to reduce peritoneal protein loss without notably reducing adequacy of dialysis.

Alternatively spliced isoform of apical Na(+)-K(+)-Cl(-) cotransporter gene encodes a furosemide-sensitive Na(+)-Cl(-)cotransporter

In the absence of vasopressin, medullary thick ascending limb cells express a K(+)-independent, furosemide-sensitive Na(+)-Cl(-) cotransporter that is inhibited by hypertonicity. The murine renal specific Na(+)-K(+)-2 Cl(-) cotransporter gene (SLC12A1) gives rise to six alternatively spliced isoforms. Three feature a long COOH-terminal domain that encodes the butmetanide-sensitive Na(+)-K(+)-2 Cl(-) cotransporter (BSC1-9/NKCC2), and three with a short COOH-terminal domain, known as mBSC1-A4, B4, or F4 (19). Here we have determined the functional characteristics of mBSC1-A4, as expressed in Xenopus laevis oocytes. When incubated at normal oocyte osmolarity (approximately 200 mosmol/kgH(2)O), mBSC1-4-injected oocytes do not express significant Na(+) uptake over H(2)O-injected controls, and immunohistochemical analysis shows that the majority of mBSC1-4 protein is in the oocyte cytoplasm and not at the plasma membrane. In contrast, when mBSC1-4 oocytes are exposed to hypotonicity (approximately 100 mosmol/kgH(2)O), a significant increase in Na(+) uptake but not in (86)Rb(+) uptake is observed. The increased Na(+) uptake is Cl(-) dependent, furosemide sensitive, and cAMP sensitive but K(+) independent. Sodium uptake increases with decreasing osmolarity between 120 and 70 mosmol/kgH(2)O (r = 0.95, P < 0.01). Immunohistochemical analysis shows that in hypotonic conditions mBSC1-A4 protein is expressed in the plasma membrane. These studies indicate that the mBSC1-A4 isoform of the SLC12A1 gene encodes a hypotonically activated, cAMP- and furosemide-sensitive Na(+)-Cl(-) cotransporter. Thus it is possible that alternative splicing of the BSC1 gene could provide the molecular mechanism enabling the Na(+)-Cl(-)-to-Na(+)-K(+)-2Cl(-) switching in thick ascending limb cells.

The reliability of leg circumference assessment: a comparison of spring tape measurements and optoelectronic volumetry

The purpose of this study was to compare the reliability of repeated spring tape measurements with optoelectronic volumeter measurements for the assessment of lower leg circumferences. The limb circumferences at mid-calf and ankle level of both legs were measured three times using a spring tape measure as well as an optoelectronic volumeter. In all, 30 healthy volunteers participated in the study. Test reliability and repeatability were described through the process-related and between-subject variances and variance-derived parameters such as the reliability coefficient (intraclass correlation coefficient, RC), the relative precision (RP), and the coefficient of repeatability (CR). A higher value for the RC and a lower value for the RP indicate that the test variability is predominantly due to between-subject variance and not to test process-related variance. RCs for both methods, independent of whether measurements were taken at calf or at ankle level, always exceeded 0.95. RPs were in the same order of magnitude for both methods but lower for measurements at calf than at ankle level (range: RPcalf 6.36-8.74%; range: RPankle 12.49-18.56%). CRs for both methods were low and of comparable magnitude (CR range: 4.8-7.7), although slightly smaller for the spring tape. When measurement results from the spring tape and the volumeter were compared, results achieved with the volumeter were significantly longer than those from the spring tape (p<0.05). Results from both methods were linearly in good agreement and there was no proportional bias; differences shown were due to a significant constant bias regarding the volumeter. Circumference measurements taken by spring tape and by optoelectronic volumetry are both characterized by a comparably high reliability. However, these methods cannot be used in an interchangeable way because a constant bias exists for volumetry, resulting in significantly larger circumferences compared with those measured using the spring tape.

[Viral hepatitis C in patients with terminal chronic renal insufficiency. III. Viral quantification]

BACKGROUND

We have previously shown that the prevalence of hepatitis associated with the hepatitis C virus (HCV) in patients with end stage renal disease in our institution is 10.2%. However, quantification of viral RNA in plasma and its relation with clinical variables has never been studied in our patients. Thus, the aim of the present work was to quantify the HCV viral load in patients with ESRD in dialysis, and to correlate these values with the dialysis modality and the viral genotype.

METHODS

We performed a transverse, prospective and comparative study in patients with HCV infection in hemodialysis, continuous ambulatory peritoneal dialysis and patients in peritoneal dialysis, but with history of hemodialysis. Viral load was quantified with RT-PCR by using a commercial kit known as Amplicor HCV 2.0. Clinical variables studied were: age, gender, end stage renal disease etiology, modality and time in dialysis, transfusions, serum albumin, aminotransferases, blood urea nitrogen, and serum creatinine.

RESULTS

Twenty four patients in dialysis with HCV infection entered into the study. Of these patients, 25% were on peritoneal dialysis, 29% on peritoneal dialysis with history of hemodialysis, and 46% were in hemodialysis. The average viral load (copies x 10(6)/mL) was 1.41 +/- 3.01. Viral load was lower in patients on peritoneal dialysis than in patients treated, or with history of hemodialysis (0.20 +/- 0.12 vs 2.04 +/- 0.88; p < 0.05). We observed no differences in viral load among patients with different viral genotypes.

DISCUSSION

The average viral load of our patients in dialysis is lower than the levels usually observed in hepatitis C infected patients without end stage renal disease. The lower viral load in patients treated with peritoneal dialysis, and no history of hemodialysis, probably denotes lower risk of chronic liver disease in these subpopulation.

Improvement of the ocular surface using hypotonic 0.4% hyaluronic acid drops in keratoconjunctivitis sicca

BACKGROUND

The ocular surface changes of keratoconjunctivitis sicca (KCS) could be the result of the effect of an altered tear film on the epithelial environment.

PURPOSE

To evaluate the possibility of improving the environmental conditions of the ocular surface by lowering tear osmolarity, increasing tear film volume and stabilising the tear film. Also, to study the effect of such an improvement on the epithelial cells of the ocular surface.

METHODS

One hundred and thirty-five patients with a diagnosis of KCS were treated on a randomised basis with either unpreserved hypotonic 0.4% hyaluronic acid (HHA) eye drops or 0.3% hydroxypropylmethylcellulose plus 0.1% Dextran 70 (HPMC) eye drops 6 times a day for 60 or 90 days. In all patients a Schirmer I test, break-up time (BUT), ocular surface staining with 1% Bengal Rose, or 2% fluorescein, as well as subjective symptoms, were recorded before and 15, 30 and 60 days after the beginning of the study. Patients were divided into three subgroups and the effect of the treatment was studied using three different techniques: the tear ferning test, conjunctival impression cytology and tear osmolarity measurement.

RESULTS

Improvements in BUT, vital staining, Schirmer I and symptoms were recorded in both groups of treatment, with significant differences for patients treated with 0.4% HHA. On day 60, 30 min after installation: tear ferning patterns changed from 100% pathological (types III-IV) to 93% physiological (types I-II) in the 0.4% HHA group and from 100% pathological to 78% physiological in the 0.3% HPMC group (p < 0.01 between groups). Tear osmolarity shifted from 353 +/- 23 to 305 +/- 6 mosmol/l in the 0.4% HHA group and from 346 +/- 15 to 336 +/- 8 mosmol/l in the 0.3% HPMC group (p < 0.001 between groups). On day 90, the impression cytology score improved from 1.2 to 1.9 in the 0.4% HHA group while it did not change in the 0.3% HPMC group (p < 0.05 between groups).

CONCLUSION

In KCS appropriate treatment with a hypotonic 0.4% HHA tear substitute can change the tear environment and results in improvement of the epithelial conditions of the ocular surface.

Quantification and characterization of protein loss in continuous ambulatory peritoneal dialysis

BACKGROUND/AIMS

Dialysate protein loss is involved in the etiology of hypoalbuminemia and malnutrition on CAPD. There is no information regarding the peritoneal transport of proteins in neither Mexican nor LatinAmerican CAPD patients. Therefore, the aim of this study was to quantify and characterize the peritoneal membrane transport of albumin (Alb), IgG, IgA, and IgM in CAPD patients. In addition, factors associated to protein losses were investigated.

METHODS

Thirty-seven CAPD patients were randomly selected and subjected to a standard peritoneal equilibration test (PET). Alb, IgG, IgA, and IgM were measured during the PET in both serum and dialysate.

RESULTS

Dialysate IgM was not detected with the employed nephelometry method. A significant continuous and gradual increasing pattern in Alb, IgG and IgA losses was observed throughout the PET. During the PET, patients with the fastest transport type displayed the lowest serum concentration of Alb (but not Igs) and the greatest dialysate loss of all the assayed proteins. The strongest predictor for Alb, IgG, and IgA losses was peritoneal transport rate in both the univariate and multivariate analyses.

CONCLUSIONS

Peritoneal Alb, IgG, and IgA losses in Mexican CAPD patients are mainly dependent on peritoneal transport rate and dialysate dwell-time.

Nifedipine prevents changes in nitric oxide synthase mRNA levels induced by cyclosporine

Cyclosporine toxicity mainly affects kidney and liver function. We have previously shown that cyclosporine nephrotoxicity alters kidney nitric oxide synthase mRNA pattern of expression. To determine if nitric oxide synthase expression changes are mediated directly by cyclosporine or by secondary hemodynamic alterations induced by cyclosporine, we evaluated if these effects are tissue specific and if nifedipine-induced vasodilation prevents these alterations. Uninephrectomized Wistar rats treated for 7 days with olive oil, cyclosporine (30 mg/kg), nifedipine (3 mg/kg), and nifedipine+cyclosporine were studied. In vehicle and cyclosporine groups, the gene expression of the neuronal, inducible, and endothelial nitric oxide synthases in cerebellum, heart, intestine, liver, renal cortex, and medulla was evaluated. The administration of cyclosporine was associated with nephrotoxicity and hepatotoxicity, increased endothelial nitric oxide synthase mRNA levels in renal cortex and liver, and a decrease in inducible nitric oxide synthase and neuronal nitric oxide synthase in renal medulla. The mRNA levels of the 3 nitric oxide synthase isoforms were not affected in any other tissue. Nifedipine did not alter nitric oxide synthase expression in the control group but prevented changes associated with cyclosporine. These results suggest that cyclosporine-induced changes in the pattern of expression of the nitric oxide synthases may be secondary to its hemodynamic effects.

Functional comparison of the K+-Cl- cotransporters KCC1 and KCC4

The K(+)-Cl(-) cotransporters (KCCs) are members of the cation-chloride cotransporter gene family and fall into two phylogenetic subgroups: KCC2 paired with KCC4 and KCC1 paired with KCC3. We report a functional comparison in Xenopus oocytes of KCC1 and KCC4, widely expressed representatives of these two subgroups. KCC1 and KCC4 exhibit differential sensitivity to transport inhibitors, such that KCC4 is much less sensitive to bumetanide and furosemide. The efficacy of these anion inhibitors is critically dependent on the concentration of extracellular K(+), with much higher inhibition in 50 mm K(+) versus 2 mm K(+). KCC4 is also uniquely sensitive to 10 mm barium and to 2 mm trichlormethiazide. Kinetic characterization reveals divergent affinities for K(+) (K(m) values of approximately 25.5 and 17.5 mm for KCC1 and KCC4, respectively), probably due to variation within the second transmembrane segment. Although the two isoforms have equivalent affinities for Cl(-), they differ in the anion selectivity of K(+) transport (Cl(-) > SCN(-) = Br(-) > PO(4)(-3) > I(-) for KCC1 and Cl(-) > Br(-) > PO(4)(-3) = I(-) > SCN(-) for KCC4). Both KCCs express minimal K(+)-Cl(-) cotransport under isotonic conditions, with significant activation by cell swelling under hypotonic conditions. The cysteine-alkylating agent N-ethylmaleimide activates K(+)-Cl(-) cotransport in isotonic conditions but abrogates hypotonic activation, an unexpected dissociation of N-ethylmaleimide sensitivity and volume sensitivity. Although KCC4 is consistently more volume-sensitive, the hypotonic activation of both isoforms is critically dependent on protein phosphatase 1. Overall, the functional comparison of these cloned K(+)-Cl(-) cotransporters reveals important functional, pharmacological, and kinetic differences with both physiological and mechanistic implications.

Na(+):K(+):ATPase mRNA expression in the kidney during adaptation to sodium intake and furosemide treatment

Nephron tubular epithelium possesses the capacity of adaptation to any salt ingestion condition. The mechanism of adaptation is due in part to an increase in the activity of Na(+):K(+):ATPase at the basolateral membrane. The goal of the present study was to analyze the long-term regulation of the Na(+):K(+):ATPase alpha(1)-subunit mRNA expression during changes in NaCl metabolism. Male Wistar rats given a normal, high, or low NaCl diet, and intraperitoneal administration of the loop diuretic furosemide from 12 h to 7 days were studied. Rats were kept in metabolic cages 4 days before and throughout the study to determine daily urinary electrolyte excretion and osmolarity. At the end of each experimental period, creatinine clearance and serum electrolytes were also measured. Total RNA was extracted from each individual cortex or outer medulla and from pooled inner medullas using the guanidine/cesium chloride method. Na(+):K(+):ATPase alpha(1)-subunit mRNA expression was assessed by nonradioactive dot-blot analysis. Experimental maneuvers were well tolerated and all groups developed the appropriate renal response to each experimental condition. Urinary sodium excretion was significantly higher in rats administered a high sodium diet or furosemide and lower in rats treated with a low sodium diet after 7 days of treatment. Glomerular filtration rate was similar among all groups. However, the level of expression of the Na(+):K(+):ATPase alpha(1)-subunit did not change in any model. Nephron adaptation to the modification in NaCl intake or furosemide administration over 7 days did not include changes in Na(+):K(+):ATPase alpha(1)-subunit mRNA levels.

Electroneutral chloride-coupled co-transporters

The family of electroneutral chloride-coupled co-transporters has been expanded in the past year by the identification of new genes or new alternatively spliced isoforms of already known genes. In this review, we discuss the molecular cloning of new members of the family, the knowledge revealed by the production of transgenic animals and some new aspects of the functional characteristics of co-transporters.

[Viral C hepatitis in patients with end stage renal disease. II. Viral genotypes]

BACKGROUND

The hepatitis C virus infection is highly prevalent in patients on chronic dialysis. There are more than 10 variants of the hepatitis C virus, with 55 to 72% of identity among them at the amino acid level. However, we do not know the specific genotype in dialysis patients in Mexico. Thus, the aim of the present study was to know the specific genotypes of the C virus in infected dialysis patients, to know the distribution of genotypes in the different dialysis techniques and to know the relation between genotype and hepatic disease stage.

METHODS

We performed a prospective, transversal and comparative study in patients in dialysis in three hospital centers in the south of Mexico City. The presence of C-type hepatitis infection was assessed by ELISA II and qualitative RT-PCR in blood samples. The genotype of the hepatitis C virus was determined by analysis of the restriction pattern of the RT-PCR product using Mva I, Hinf I, BstU I and ScrF I restriction enzymes. Variables analyzed were: age, gender, etiology of renal failure, kind and time in substitutive therapy, transfusion and hepatitis history, liver function test, blood urea, serum creatinine and blood cell count.

RESULTS

We studied 235 dialysis patients that were divided following their dialysis modality into: 132 in continue ambulatory peritoneal dialysis (CAPD), 17 in CAPD, but with history of hemodialysis (PD/HD) of at least one month and 86 on hemodialysis (HD). The hepatitis infection was detected in 24 of the 235 patients (CAPD = 4.5%, PD/HD = 41.1% and HD = 12.7%; p < 0.001). The most common genotype was 1B (12/24), followed by 1A and 2A (4/24 each one), and finally by 2B and 2C (2/24 each one). We detected no patients with genotypes 3 to 6. The patients with 2A genotype were older than those infected with 1A (p < 0.05). History of surgery, transfusions, and hepatitis was similar in all genotypes. Finally the time in dialysis was longer in patients with 2A genotype than others (2A = 60.5 +/- 71.5 months, vs. 1A = 11.5 +/- 11.3, 1B = 26 +/- 26.4 y 2B/C = 17.5 +/- 13.4), but the difference did not reach statistical significance. The genotype distribution between dialysis techniques showed that 1B genotype was the most frequent in all modalities. The 1A genotype was present in similar proportions in patients of the three dialysis groups, the 2C genotype was present only in patients with CAPD. Finally, the 2B was only found in hemodialysis patients.

DISCUSSION

The assessment of viral genotype revealed that 1B is the most common genotype in patients on chronic dialysis in Mexico City. The fact that the 1B and 1A genotypes were the most common types in our dialysis population suggest that transmission was similar to the general population, that is, probably by blood transfusions.

Deranged transcriptional regulation of cell-volume-sensitive kinase hSGK in diabetic nephropathy

Transforming growth factor beta (TGF-beta) has been shown to participate in the pathophysiology of diabetic complications. As shown most recently, TGF-beta stimulates the expression of a distinct serine/threonine kinase (hSGK) which had previously been cloned as an early gene transcriptionally regulated by cell volume alterations. The present study was performed to elucidate transcription and function of hSGK in diabetic nephropathy. As shown by Northern blotting, an increase of extracellular glucose concentration increased hSGK mRNA levels in cultured cells, an effect qualitatively mimicked by osmotic cell shrinkage or treatment with TGF-beta (2 microgram/liter), phorbol 12,13-didecanoate (1 microM), or the Ca(2+) ionophore ionomycin (1 microM) and blunted by high concentrations of nifedipine (10 and 100 microM). In situ hybridization revealed that hSGK transcription was markedly enhanced in diabetic nephropathy, with particularly high expression in mesangial cells, interstitial cells, and cells in thick ascending limbs of Henle's loop and distal tubules. According to voltage clamp and tracer flux studies in Xenopus oocytes expressing the renal epithelial Na(+) channel ENaC or the mouse thick ascending limb Na(+),K(+),2Cl(-) cotransporter BSC-1, coexpression with hSGK stimulated ENaC and BSC-1 11-fold and 6-fold, respectively, effects reversed by kinase inhibitors staurosporine (1 microM) and chelerythrine (1 microM) and not elicited by inactive hSGK. In conclusion, excessive extracellular glucose concentrations enhance hSGK transcription, which in turn stimulates renal tubular Na(+) transport. These observations disclose an additional element in the pathophysiology of diabetic nephropathy.