Disconnecting prefrontal cortical neurons from the ventral midline thalamus: Loss of specificity due to progressive neural toxicity of an AAV-Cre in the rat thalamus

BACKGROUND

The thalamic reuniens (Re) and rhomboid (Rh) nuclei are bidirectionally connected with the medial prefrontal cortex (mPFC) and the hippocampus (Hip). Fiber-sparing N-methyl-D-aspartate lesions of the ReRh disrupt cognitive functions, including persistence of certain memories. Because such lesions irremediably damage neurons interconnecting the ReRh with the mPFC and the Hip, it is impossible to know if one or both pathways contribute to memory persistence. Addressing such an issue requires selective, pathway-restricted and direction-specific disconnections.

NEW METHOD

A recent method associates a retrograde adeno-associated virus (AAV) expressing Cre recombinase with an anterograde AAV expressing a Cre-dependent caspase, making such disconnection feasible by caspase-triggered apoptosis when both constructs meet intracellularly. We injected an AAVrg-Cre-GFP into the ReRh and an AAV5-taCasp into the mPFC. As expected, part of mPFC neurons died, but massive neurotoxicity of the AAVrg-Cre-GFP was found in ReRh, contrasting with normal density of DAPI staining. Other stainings demonstrated increasing density of reactive astrocytes and microglia in the neurodegeneration site.

COMPARISON WITH EXISTING METHODS

Reducing the viral titer (by a 4-fold dilution) and injection volume (to half) attenuated toxicity substantially, still with evidence for partial disconnection between mPFC and ReRh.

CONCLUSIONS

There is an imperative need to verify potential collateral damage inherent in this type of approach, which is likely to distort interpretation of experimental data. Therefore, controls allowing to distinguish collateral phenotypic effects from those linked to the desired disconnection is essential. It is also crucial to know for how long neurons expressing the Cre-GFP protein remain operational post-infection.

Inhibition of the ventral midline thalamus does not alter encoding, short-term holding or retrieval of spatial information in rats performing a water-escape working memory task

Working memory (WM) is a function operating in three successive phases: encoding (sample trial), holding (delay), and retrieval (test trial) of information. Studies point to a possible implication of the thalamic reuniens nucleus (Re) in spatial WM (SWM). In which of the aforementioned 3 phases the Re has a function is largely unknown. Recently, in a delayed SWM water-escape task, we found that performance during the retrieval trial correlated positively with c-Fos expression in the Re nucleus, suggesting participation in retrieval. Here, we used the same task and muscimol (Musc) inhibition or DREADD(hM4Di)-mediated inhibition of the Re during information encoding, right thereafter (thereby affecting the holding phase), or during the retrieval trial. A 6-hour delay separated encoding from retrieval. Concerning SWM, Musc in the Re nucleus did not alter performance, be it during or after encoding, or during evaluation. CNO administered before encoding in DREADD-expressing rats was also ineffective, although CNO-induced inhibition disrupted set shifting performance, as found previously (Quet et al., Brain Struct Function 225, 2020), thereby validating DREADD efficiency. These findings are the first that do not support an implication of the Re nucleus in SWM. As most previous studies used T-maze alternation tasks, which carry high proactive interference risks, an important question to resolve now is whether these nuclei are required in (T-maze alternation) tasks using very short information-holding delays (seconds to minutes), and less so in other short-term spatial memory tasks with longer information holding intervals (hours) and therefore reduced interference risks.

The reuniens and rhomboid nuclei of the thalamus: A crossroads for cognition-relevant information processing?

Over the past twenty years, the reuniens and rhomboid (ReRh) nuclei, which constitute the ventral midline thalamus, have received constantly growing attention. Since our first review article about the functional contributions of ReRh nuclei (Cassel et al., 2013), numerous (>80) important papers have extended anatomical knowledge, including at a developmental level, introduced new and very original electrophysiological insights on ReRh functions, and brought novel results on cognitive and non-cognitive implications of the ReRh. The current review will cover these recent articles, more on Re than on Rh, and their contribution will be approached according to their affiliation with work before 2013. These neuroanatomical, electrophysiological or behavioral findings appear coherent and point to the ReRh nuclei as two major components of a multistructural system supporting numerous cognitive (and non-cognitive) functions. They gate the flow of information, perhaps especially from the medial prefrontal cortex to the hippocampus and back, and coordinate activity and processing across these two (and possibly other) brain regions of major cognitive relevance.

The nucleus reuniens, a thalamic relay for cortico-hippocampal interaction in recent and remote memory consolidation

The consolidation of declarative memories is believed to occur mostly during sleep and involves a dialogue between two brain regions, the hippocampus and the medial prefrontal cortex. The information encoded during experience by neuronal assemblies is replayed during sleep leading to the progressive strengthening and integration of the memory trace in the prefrontal cortex. The gradual transfer of information from the hippocampus to the medial prefrontal cortex for long-term storage requires the synchronization of cortico-hippocampal networks by different oscillations, like ripples, spindles, and slow oscillations. Recent studies suggest the involvement of a third partner, the nucleus reuniens, in memory consolidation. Its bidirectional connections with the hippocampus and medial prefrontal cortex place the reuniens in a key position to relay information between the two structures. Indeed, many topical works reveal the original role that the nucleus reuniens occupies in different recent and remote memories consolidation. This review aimed to examine these contributions, as well as its functional embedment in this complex memory network, and provide some insights on the possible mechanisms.

A comparison of self and proxy quality of life ratings for people with dementia and their carers: a European prospective cohort study

Objectives: To identify correlates of self-rated and proxy-rated quality of life (QoL) in people with dementia on (i) a dementia-specific and (ii) a capability-wellbeing QoL measure at baseline and 12-month follow-up, and to consider such factors in the context of QoL intervention development.Method: Prospective clinical and demographic data were collected from 451 community-dwelling dyads (mild-moderate dementia) across eight European countries. QoL was measured using the QOL-AD and the ICECAP-O. Multivariate modelling identified correlates of self- and proxy-rated QoL at baseline and at 12-month follow-up.Results: Carer's proxy-ratings of QoL were significantly lower than self-ratings at all time-points for both measures. Proxy-ratings declined over time, but self-ratings remained stable. Baseline predictors of greater self-rated QoL were education, and greater functional ability and relationship quality. Greater proxy-rated QoL was associated with education and greater functional ability, relationship quality, carer social support and carer QoL, lower carer anxiety/depression and less severe neuropsychiatric symptoms in people with dementia. At follow-up, greater self-rated QoL was predicted by greater functional ability, relationship quality, carer social support and having a spousal carer. Greater proxy-rated QoL at follow-up was associated with the same factors as at baseline; however, the dyad living together was an additional predictive factor.Conclusion: Both proxy-ratings and self-ratings of QoL should be interpreted with caution and in the context of each individual caregiving relationship. Different functional, psychosocial, relational and contextual factors influence self- and proxy-ratings, and both sets of factors should be considered in the context of QoL intervention development for the dyad.

Access to community care for people with dementia and their informal carers : Case vignettes for a European comparison of structures and common pathways to formal care

BACKGROUND

People with dementia and their informal carers often do not receive appropriate professional support or it is not received at the right time.

OBJECTIVES

Description and comparison of common pathways to formal community dementia care in eight European countries as a part of the transnational Actifcare project.

MATERIALS AND METHODS

The German team was responsible for creating an individual case scenario as a starting point. The research teams in Ireland, Italy, the Netherlands, Norway, Portugal, Sweden, and the United Kingdom were then asked to describe a common pathway to formal dementia care by writing their own vignette using the provided individual case scenario.

RESULTS

A transnational qualitative content analysis was used to identify the following categories as being the most important: involved professionals, dementia-specific and team-based approaches, proactive roles, and financial aspects. General practitioners (GPs) are described as being the most important profession supporting the access to formal care in all the involved countries. In some countries other professionals take over responsibility for the access procedure. Dementia-specific approaches are rarely part of standard care; team-based approaches have differing significances in each of the countries. Informal carers are mainly proactive in seeking formal care. The Nordic countries demonstrate how financial support enhances access to the professional system.

CONCLUSION

Enhanced cooperation between GPs and other professions might optimize access to formal dementia care. Team-based approaches focusing on dementia care should be developed further. Informal carers should be supported and relieved in their role. Financial barriers remain which should be further investigated and reduced.

Assessment of information needs in diabetes: Development and evaluation of a questionnaire

AIM

To develop a questionnaire suitable for assessing the information needs of individuals with diabetes mellitus types 1 and 2 in diverse healthcare settings (e.g. primary care or long-term care) and at different time points during the course of the disease.

METHODS

The initial questionnaire was developed on the basis of literature search and analysis, reviewed by clinical experts, and evaluated in two focus groups. The revised version was pilot-tested on 39 individuals with diabetes type 2, type 1 and gestational diabetes.

RESULTS

The final questionnaire reveals the most important information needs in diabetes. A choice task, a rating task and open-ended questions are combined. First, participants have to choose three topics that interest them out of a list with 12 general topics and specify in their own words their particular information needs for the chosen topics. They are then asked how informed they feel with regard to all topics (4-point Likert-scale), and whether information is currently desired (yes/no). The questionnaire ends with an open-ended question asking for additional topics of interest.

CONCLUSIONS

Careful selection of topics and inclusion of open-ended questions seem to be essential prerequisites for the unbiased assessment of information needs. The questionnaire can be applied in surveys in order to examine patterns of information needs across various groups and changes during the course of the disease. Such knowledge would contribute to more patient-guided information, counselling and support.

Drug-based pain management in people with dementia after hip or pelvic fractures: a systematic review protocol

BACKGROUND

Studies show that people with dementia do not receive the same amount of analgesia after a hip or pelvic fracture compared to those without cognitive impairment. However, there is no systematic review that shows to what extent and how drug-based pain management is performed for people with dementia following a hip or pelvic fracture. The aim of this systematic review is to identify studies addressing drug-based pain management for people with dementia who have had a hip or pelvic fracture for which they had either an operation or conservative treatment. We will analyse to what extent and how the drug-based pain treatment for people with dementia is performed across all settings and how it is assessed in the studies.

METHODS

The development of this systematic review protocol was guided by the PRISMA-P requirements, which will be taken into consideration during the review procedure. MEDLINE, EMBASE, CINAHL, Web of Knowledge and ScienceDirect will be searched, using keywords such as "analgesia", "dementia", "cognitive impairment", "pain treatment", "hip fracture" or "pelvic fracture". Publications published up to January 2016 will be included. The data extraction and a content analysis will be carried out systematically, followed by a critical appraisal.

DISCUSSION

This review will provide a valuable overview on the current evidence on drug-based pain management for PwD in all settings who were conservatively treated after a hip or pelvic fracture. The review may expose a need to enhance pain management for PwD. It may also provide motivation for healthcare providers and policymakers to give this topic their attention and to facilitate further research by considering aspects of care transitions in all settings.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016037309.

Delta opioid receptors expressed in forebrain GABAergic neurons are responsible for SNC80-induced seizures

The delta opioid receptor (DOR) has raised much interest for the development of new therapeutic drugs, particularly to treat patients suffering from mood disorders and chronic pain. Unfortunately, the prototypal DOR agonist SNC80 induces mild epileptic seizures in rodents. Although recently developed agonists do not seem to show convulsant properties, mechanisms and neuronal circuits that support DOR-mediated epileptic seizures remain to be clarified. DORs are expressed throughout the nervous system. In this study we tested the hypothesis that SNC80-evoked seizures stem from DOR activity at the level of forebrain GABAergic transmission, whose inhibition is known to facilitate the development of epileptic seizures. We generated a conditional DOR knockout mouse line, targeting the receptor gene specifically in GABAergic neurons of the forebrain (Dlx-DOR). We measured effects of SNC80 (4.5, 9, 13.5 and 32 mg/kg), ARM390 (10, 30 and 60 mg/kg) or ADL5859 (30, 100 and 300 mg/kg) administration on electroencephalograms (EEGs) recorded in Dlx-DOR mice and their control littermates (Ctrl mice). SNC80 produced dose-dependent seizure events in Ctrl mice, but these effects were not detected in Dlx-DOR mice. As expected, ARM390 and ADL5859 did not trigger any detectable change in mice from both genotypes. These results demonstrate for the first time that SNC80-induced DOR activation induces epileptic seizures via direct inhibition of GABAergic forebrain neurons, and supports the notion of differential activities between first and second-generation DOR agonists.

[Functional outcome of tuberculous arthiritis of the knee in a male Moroccan patient]

PURPOSE

The purpose of this article is to present a case of tuberculous arthritis of the knee and discuss the importance of early diagnosis and rehabilitatin in management outcome.

CASE REPORT

A 57-year-old Moroccan man with no medical history presented with a mass in the left knee associated with pain and fever. Analysis of aspirated fluid demonstrated sterile inflammatory liquid. Presumptive antibiotic therapy was ineffective. Diagnosis of tuberculous arthritis was made based on positive tuberculin skin test and interferon-release assays. Diagnosis was confirmed by arthroscopic biopsy. Physiotherapy allowed improvement in both function and analytical test findings.

DISCUSSION

Tuberculous arthritis is rare occurring in only 2 to 5% of people with tuberculosis. It can be very destructive. Diagnosis is often delayed leading to joint pain, tissue damage, and functional disability (e.g. inability to walk). Since prompt treatment (antibiotics then physiotherapy) can limit complications, early diagnosis is necessary and often requires deep biopsy, except endemic zones. In the acute phase, immobilization of the extremity in a functional position is necessary. When inflammatory signs subside, physiotherapy can be undertaken in short but frequent sessions without excessive weight or resistance.

CONCLUSION

The functional outcome of tuberculous arthritis depends on early multidisciplinary care involving the rheumatologist, infectious disease specialist, orthopedic surgeon and attending physician.

[Intracranial extension of cutaneous facial squamous cell carcinoma: involvement of the neurotropic pathway]

BACKGROUND

Squamous cell carcinoma is the most common form of skin cancer after basal cell carcinoma. It comprises locoregional malignant tumours with more rapid and severe spread, and which may metastasise through blood or lymph, and through a less well-known neurotropic pathway. We report a case of late and slowly progressive recurrence of squamous cell carcinoma revealed and characterized by neurological symptoms alone.

OBSERVATION

A 69-year-old woman with a history of cutaneous squamous cell carcinoma on the left nostril edge removed 10 years earlier presented right trigeminal neuralgia in 2003. These symptoms gradually expanded and in 2007 a subcutaneous induration of the two cheeks appeared. Magnetic resonance imaging (MRI) showed subcutaneous infiltration of the 2 nasolabial sulci, as did contrast enhancement of the two trigeminal nerves up to the cavernous sinuses. Deep biopsy allowed a diagnosis of invasive squamous cell carcinoma to be made.

DISCUSSION

Neurotropism is an important feature of squamous cell carcinoma, and reveals the aggressive nature of this condition. This feature makes it hard to diagnose relapse since the neurological symptoms may be isolated for a long period, hence the need for systematic screening for perineural tumour sites on histological analysis of the initial lesion. Treatment for these forms is limited and for the moment consists of radiation, cetuximab and a combination of these two treatments.

Uncalibrated arterial pressure waveform analysis for less-invasive cardiac output determination in obese patients undergoing cardiac surgery

BACKGROUND

Uncalibrated arterial waveform analysis (FloTrac/Vigileo) uses standard arterial access to determine cardiac output (CO). Calculations are based on arterial waveform characteristics in combination with patient characteristic data to estimate individual arterial compliance. It has been shown that obesity is associated with altered arterial compliance independently of other risk factors. We conducted this study to assess the validity of measuring CO by the FloTrac/Vigileo device in obese patients undergoing cardiac surgery in comparison with bolus thermodilution technique.

METHODS

Fifteen obese patients with a BMI of > or = 30 and 23 non-obese patients (BMI 18-25) undergoing coronary artery bypass grafting (CABG) were included. Simultaneous CO measurements by bolus thermodilution and the FloTrac/Vigileo device (software version 1.10) were obtained intraoperatively after induction of anaesthesia, before cardiopulmonary bypass (CPB), after CPB, and after sternal closure. Measurements in the intensive care unit (ICU) were performed upon arrival in the ICU, after 4, 8, and 24 h after surgery. CO was indexed to the body surface area (cardiac index, CI).

RESULTS

The analysis of 262 data pairs revealed a bias and precision of 0.19 and +/-0.66 litre min(-1) m(-2), resulting in a percentage error of 26.6%. Thermodilution CI values ranged from 1.1 to 4.2 litre min(-1) m(-2) [mean 2.4 (0.52) litre min(-1) m(-2)]. Subgroup analysis resulted in a percentage error of 29.8% in obese patients and 24.4% in patients with normal BMI.

CONCLUSIONS

The semi-invasive FloTrac/Vigileo device was found to adequately agree with bolus pulmonary artery thermodilution in both obese and non-obese patients undergoing CABG.

An assay for the determination of sirolimus levels in the lymphocyte of transplant patients

Both tacrolimus (TAC) and sirolimus (SRL) bind to the same immunophilin FKBP12; however, their mechanisms of action are distinct. SRL inhibits mammalian target of rapamycin (TOR), which is an enzyme critical to the immune function. TOR inhibition blocks the signal that mediates T-cell proliferation by preventing cell-cycle progression from G1 to S phase. Moreover, TOR inhibition results in a decrease in antibody production by blocking B-cell proliferation and maturation into antibody producing cells. The use of SRL has resulted in a decrease in the number of rejection episodes. As with other immunosuppressive agents, SRL can cause dose-related side effects, the most notable of which are hypercholesterolemia, hyperlipidemia, anemia, and thrombocytopenia. Thus, therapeutic drug monitoring to assess efficacy and toxicity has became a necessity. SRL blood levels do not correlate with its bioactivity and are affected by the concomitant use of other immunosuppressive drugs. To determine the bioactivity of SRL we have developed an assay to determine the level of Sirolimus per lymphocyte of transplant patients. The levels were correlated with lymphocyte count.

METHODS

Whole blood samples from patients on SRL were collected in Ethylene Diamine Tetra-acetic acid (EDTA) vacutainer tubes. Immediately the lymphocytes from 2 mL of blood were separated using 1.5 mL of Ficoll gradient, by centrifugation for 30 minutes at 2500 RPM. The lymphocytes were washed three times with phosphate-bufferd saline and the pellet suspended in 150 microL of Middle East research institute (MERI) drug extraction solution (Beirut, Lebanon), which was then added to 300 microL of IMx solublizing reagent. The cytoplasmic SRL concentrations in lymphocytes were measured using kits supplied from Abbott diagnostics or by high-performance liquid tomography. A corresponding whole blood sample from each patient was used to measure blood levels. To determine the level per lymphocyte, the value obtained was divided by the number of lymphocytes and expressed as Pg/cell. A pharmacokinetic profile for both blood and lymphocytes was constructed for each patient using data corresponding to predose C(0), 1 hour (C(1)) and 2 hours (C(2)) after the dose. The lymphocyte enumeration for C(0), C(1), and C(2) was performed using the FACS Calibur Flow Cytometer from Becton Dickinson. The average dose was 2.86 +/- 1.27 mg/d with a C(0) = 8.05 +/- 4.24, C(1) = 21.9 +/- 8.9 ng/mL, and C(2) = 23 +/- 0.03 ng/mL. Although there was a significant correlation (P=.0975) between the dose and C(0), there was no correlation between the dose and C(0) level on the lymphocyte count P=.897. However, there was a strong correlation between SRL lymphocyte levels (pg/cell) and the lymphocyte count (r(2)=.6.06). The higher the concentration of the drug the lower the lymphocyte counts. The assay is sensitive to within 0.45 pg/cell, reproducible with a coefficient of variance (CV) of 6.4% within assay and 7.5% for intraassay.

Switchability of neoral and equoral according to Food and Drug Administration rules and regulations

According to the US Food and Drug Administration (FDA), if a drug product contains a drug substance that is chemically identical and is delivered to the site of action at the same rate and extent as another drug product, then it is equivalent and can be substituted (switchable) for that drug product. Methods used to define bioequivalence as stated by the FDA rules (FDA 21 CFR 320, 24) are (1) pharmacokinetic (PK) studies in healthy volunteers, (2) comparative clinical trials, and (3) pharmacodynamic (PD) studies (bioactivity). We evaluated the switchability of Equoral (IVAX-USA) with Neoral (Novartis Switzerland using all FDA rules. In a single oral dose, we undertook a comparative bioavailability study of Equoral (IVAX, USA) Neoral (Novartis, USA), and Neoral (Novartis UK). The pharmacokinetics of Equoral and Neoral were determined with blood levels at 0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 10, 12, 16, 24, 30, 36, 42, and 48 hours. The area under curve (AUC), AUC extrapolated to infinity (AUC0-inf), rate of absorption (Tmax), extent of absorption (Cmax), half time (t1/2) of Equoral and Neoral were all within the 90% confidence interval of 80% to 125% boundaries. A comparative multinational multicenter clinical trial in stable renal transplant patients included 70 patients (22 women and 48 men) of mean age of 33 years (range, 26 to 43) was performed in Turkey, Lebanon, and Pakistan. In this study the ratios of LSM and the 90% confidence intervals for the Nontransformed/Parameters (AUC0-t, AUCinf, Tmax, and Cmax) of Equoral and Neoral SGC were 98% and 95%, respectively, which are within the 80% to 125% FDA acceptance range. For immunosuppressive drugs, the site of action is the lymphocyte and the measurable response is the decrease in lymphocyte count caused by the relative concentration of the drug in the lymphocyte. In a controlled switch, fixed-dose study, both Equoral and Neoral achieved the same concentration in the lymphocytes and caused the same degree of lymphocyte count reduction. The results of the testing (bioavailability-bioequivalence, clinical studies, and pharmacodynamic-bioactivity) required by FDA for interchangeability ("switchability") of immunosuppressive agents suggests that Neoral and Equoral are switchable.

Mycophenolic acid plasma trough level: correlation with clinical outcome

OBJECTIVES

Assess the relationship between clinical diagnosis, state of immunosuppression, mycophenolic acid (MPA) plasma trough levels (MPACmin), and mycophenolate mofetil (MMF) dosage in renal transplant recipients.

MATERIALS AND METHODS

MPACmin were determined in 30 kidney transplant patients, of whom 7 exhibited biopsy-proven acute rejection. The remaining 23 had normal graft function. Graft outcome, defined by clinical diagnosis and serum creatinine level, was compared according to MPACmin, MMF dosage, and total lymphocyte count (LC).

RESULTS

Patients with acute rejection had similar MPACmin (2.4 +/- 1.7 microg/mL), MMF dosages (1.7 +/- 0.5 g), and LCs (0.001165 +/- 0.0040 x 10(9)/L) when compared with normal patients (2.2 +/- 0.7 microg/mL, 1.7 +/- 0.4 g and 0.001160 +/- 0.00527 x 10(9)/L) respectively. Rejection rates were comparable irrespective of MPACmin)ranges and higher in those receiving the 1-g dose (30%) when compared with those receiving 1.5-g and 2-g doses (12.5% and 11.7%). No relationship was observed between MPACmin and MMF doses, and neither parameter correlated with LC.

CONCLUSIONS

These results suggest that MPACmin is a poor correlate of clinical outcome and state of immunosuppression. Although the usually recommended dosage of MMF (2 g) may be associated with acute rejection, low-dose MMF (1 g) seems to constitute a higher risk.

A transplanted kidney surviving total vessel occlusion and anuria

We report a case of a 46-year-old white male with renal graft artery stenosis who developed acute renal shutdown with total anuria while on the ACE inhibitor lisinopril, one week following the discontinuation of aspirin. The serum creatinine was 8.5 mg/dl. Doppler ultrasound and MAG3 scintigraphy of the grafted kidney were highly suggestive of a viable but nonfunctioning kidney. A femoro-femoral bypass for total thrombosis of the right common iliac artery was performed distal to the occlusion. Immediate diuresis was obtained after establishing the bypass. Serum creatinine dropped to 1.35 mg/dl three days later. In this case we believe that the collateral circulation played a significant role in immediate recovery of kidney function by maintaining renal perfusion pressure and preventing acute tubular necrosis (ATN). We also believe that the ACE inhibitor might have contributed to salvaging the kidney by improving medullary oxygen balance and maintaining adequate medullary blood flow.

The pharmacokinetics of equoral versus neoral in stable renal transplant patients: a multinational multicenter study

We studied the pharmacokinetics (PKs) of the new generic cyclosporine formulation, Equoral capsules, after the switch from original formulation Neoral capsules in stable renal transplant patients. The study was carried out in accordance with the basic principles defined in the US 21 CFR Part 312.20 and the principles of the Declaration of Helsinki. The study included clinically stable first renal transplant patients maintained on cyclosporine with no rejection episode during the past 6 months. Hematology, biochemistry, and urine chemistry were determined on day 7, and day 21. The patients were all switched to Neoral (lot number 416MFD0601) on day 0 when the first sparse sampling PK was performed. On day 14 a 12-hour PK profile included predose, 30 minutes; 1 hour; 1 hour 30 minutes; 2 hours; 3 hours; 4 hours; 5 hours; 6 hours; 8 hours; 10-hours and 12-hour samples. Cyclosporine levels were determined using a CYA kit (Abbott TDx). On day 15 the patients were switched from Neoral capsules to Equoral capsules (lot 5T111014) at an equivalent dosage (mg/mg). The second sparse sampling PK was performed on day 21 and a 12-hour PK was performed on day 28. On the morning of day 29 patients were switched from Equoral capsules to Neoral capsules at an equivalent dosage (mg/mg). Additional concentrations were measured on days -7, 18, and 35. Safety parameters were monitored at each visit. The pharmacokinetics of both formulations were equivalent. The mean AUC for Neoral and Equoral was 2856 and 2892, respectively. The ratios of LSM and the 90% confidence intervals for the in-transformed parameters (AUC o-t, AUC inf, and Cmax) of Equoral and Neoral SGC were 98% and 95%, respectively, suggesting that Equoral and Neoral SGC are bioequivalent.

Consanguinity-associated kidney diseases in Lebanon: an epidemiological study

Consanguineous marriages are common in many countries of the Middle East including Lebanon. Their impact on the repartition of kidney diseases and on the risk for familial nephritis is not known. We surveyed all of the dialysis centers in Lebanon. Nine hundred and twenty-five (925) patients and their private physicians were asked to answer a questionnaire. More than half of the hemodialysis (HD) patients had an unknown etiology of their kidney disease. Diabetes, polycystic kidney disease (PKD), chronic pyelonephritis and nephrosclerosis (NS) were the most commonly documented diagnoses. Consanguinity was present in 26% of the total HD population. More consanguineous patients with unknown renal etiology were diagnosed with their kidney diseases and initiated on dialysis before the age of 30 when compared with their non-consanguineous counter-parts (45% versus 33%, P<0.02 and 42% versus 27%, P<0.01), respectively. Similarly, consanguineous polycystic patients were diagnosed and started earlier on dialysis when compared with the non-consanguineous population (34% versus 12%, P<0.05 and 28% versus 8%, P<0.05), respectively suggesting a different disease pattern. Furthermore, the risk for family history of kidney disease was noticeable in the non-consanguineous population and significantly higher among the consanguineous patients (12% versus 18%, P<0.04). Consanguinity-associated kidney diseases affected all religious communities, in particular the Muslim and the Druze (36 and 39%), respectively versus 17% of the Christian community. Certain geographical areas were more involved than others such as the North, South and the Bekaa with the highest percentage (40%) in the latter. Socio-economical level was not a contributing factor. We conclude that the documentation of the underlying etiology in end-stage renal diseases (ESRD) seems to be deficient. Furthermore, consanguinity is prevalent in the Lebanese dialysis patients population, in particular the Muslim and the Druze communities. Consanguinity-associated kidney diseases pattern seems to differ from that of the general HD population by disease diagnosis and initiation at a younger age and a significantly higher risk for familial renal disease. It is a cultural phenomenon prevalent predominantly in the rural areas. We recommend a multi-approach including educational, informative and probably legislative strategy in order to limit and hopefully discourage consanguineous marriages.

Nocturnal accumulation of cyclic 3',5'-guanosine monophosphate (cGMP) in the chick pineal organ is dependent on activation of guanylyl cyclase-B

The role of cGMP in the avian pineal is not well understood. Although the light-sensitive secretion of melatonin is a well-known output of the circadian oscillator, pharmacologically elevated cGMP levels do not result in altered melatonin secretory amplitude or phase. This suggests that pineal cGMP signalling does not couple the endogenous circadian oscillator to the expression of melatonin rhythms. Nonetheless, the free-running rhythm of cGMP signalling implies a link to the circadian oscillator in chick pinealocytes. As the circadian rhythm of cGMP levels in vitro is not altered by pharmacological inhibition of phosphodiesterase activity, we infer that the synthesis, rather than the degradation of cGMP, is under circadian control. In vitro experiments with the nitric oxide synthase (NOS) inhibitor NG-nitro-L-arginine as well as with an inhibitor of the NO-sensitive soluble guanylyl cyclase (sGC), showed that the NOS-sGC pathway does not play a major role in the circadian control of cGMP generation. In organ culture experiments, we demonstrated that C-type natriuretic peptide (CNP), but not atrial natriuretic peptide (ANP), elevated daytime levels of cGMP. As CNP acts on the membrane guanylyl cyclase isoform B (GC-B), which is expressed at very high levels in mammalian pineals, we investigated the effect of the membrane GC-specific inhibitor HS-142 on chick pineal cGMP levels. CNP-induced daytime cGMP levels were reduced by HS-142. More importantly, 'spontaneously' high nocturnal levels of cGMP in vitro were reduced to daytime levels by acute addition of HS-142. These data implicate endogenous nocturnal CNP release and subsequent activation of GC-B as the major input driving cGMP synthesis in the chick pineal organ.