Three underdogs among galenic veins: anatomical analysis and literature review of surgical relevant veins in the quadrigeminal cistern.

Recent studies (Alaou-Ismaili et al. 2020; Kilic et al. Eur J Radiol 56:212-219, 2005) among experienced sub-specialized neurosurgeons described divergent perceptions of surgical risk for venous sacrifice in posterior fossa surgery. Three galenic veins stood out as controversial in venous risk assessment and underexplored in the literature: the internal occipital vein (IOV), the precentral cerebellar vein (PCV), and the superior vermian vein (SVV). We have conducted a narrative review based on a systematic literature search to analyze terminology and anatomic descriptions and to suggest a coherent synthesis of published data on these veins. A systematic PubMed literature search was carried out using the keywords: "posterior fossa," "venous anatomy," and "radiology." Relevant radiological, microsurgical, and anatomical articles were selected if they described the anatomy of the three veins. Anatomical descriptions were analyzed with hermeneutic methodology alongside the articles' radiological and anatomical dissection pictures. New illustrations were created to depict the synthesized image of the venous anatomy. A total of 13 articles described the anatomy and terminology of the relevant veins. The descriptions of the IOV included smaller non-occipital vessels that confused the identification of the vessel. IOV is analyzed to be the vein draining the primary visual cortex, which drains into the vein of Galen (VG). The PCV and SVV enter the VG from below and are fused in almost half of all studied patients, creating a third vessel by the name of the superior cerebellar vein. A conscientious narrative review and hermeneutic analysis produced a synthesized, uniform picture of terminology and anatomy. Consensus on anatomical descriptions and definitions are indispensable for validation of anatomy, research into anatomical variation, for surgical planning and documentation.

Ictal and interictal electric source imaging in pre-surgical evaluation: a prospective study.

BACKGROUND AND PURPOSE: Accurate localization of the epileptic focus is essential for surgical treatment of patients with drug-resistant epilepsy. Electric source imaging (ESI) is increasingly used in pre-surgical evaluation. However, most previous studies have analysed interictal (II) discharges. Prospective studies comparing the feasibility and accuracy of II and ictal (IC) ESI are lacking. METHODS: We prospectively analysed long-term video-electroencephalography recordings (LTM) of patients admitted for pre-surgical evaluation. We performed ESI of II and IC signals using two methods, i.e. equivalent current dipole (ECD) and a distributed source model (DSM). LTM recordings employed the standard 25-electrode array (including inferior temporal electrodes). An age-matched template head model was used for source analysis. Results were compared with intracranial recordings, conventional neuroimaging methods [magnetic resonance imaging (MRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT)] and outcome at 1 year after surgery. RESULTS: A total of 87 consecutive patients were analysed. ECD gave a significantly higher proportion of patients with localized focal abnormalities (94%) compared with MRI (70%), PET (66%) and SPECT (64%). Agreement between the ESI methods and intracranial recording was moderate to substantial (k = 0.56-0.79). A total of 54 patients were operated (47 patients more than 1 year ago) and 62% of them became seizure-free. The localization accuracy of II-ESI was 51% for DSM and 57% for ECD, and that for IC-ESI was 51% for DSM and 62% for ECD. The differences between the ESI methods were not significant. Differences in localization accuracy between ESI and MRI (55%), PET (33%) and SPECT (40%) were not significant. CONCLUSIONS: The II-ESI and IC-ESI of LTM data have high feasibility and their localization accuracy is similar to that of conventional neuroimaging methods.

Organ-specific responses during brain death: increased aerobic metabolism in the liver and anaerobic metabolism with decreased perfusion in the kidneys.

Hepatic and renal energy status prior to transplantation correlates with graft survival. However, effects of brain death (BD) on organ-specific energy status are largely unknown. We studied metabolism, perfusion, oxygen consumption, and mitochondrial function in the liver and kidneys following BD. BD was induced in mechanically-ventilated rats, inflating an epidurally-placed Fogarty-catheter, with sham-operated rats as controls. A 9.4T-preclinical MRI system measured hourly oxygen availability (BOLD-related R2*) and perfusion (T1-weighted). After 4 hrs, tissue was collected, mitochondria isolated and assessed with high-resolution respirometry. Quantitative proteomics, qPCR, and biochemistry was performed on stored tissue/plasma. Following BD, the liver increased glycolytic gene expression (Pfk-1) with decreased glycogen stores, while the kidneys increased anaerobic- (Ldha) and decreased gluconeogenic-related gene expression (Pck-1). Hepatic oxygen consumption increased, while renal perfusion decreased. ATP levels dropped in both organs while mitochondrial respiration and complex I/ATP synthase activity were unaffected. In conclusion, the liver responds to increased metabolic demands during BD, enhancing aerobic metabolism with functional mitochondria. The kidneys shift towards anaerobic energy production while renal perfusion decreases. Our findings highlight the need for an organ-specific approach to assess and optimise graft quality prior to transplantation, to optimise hepatic metabolic conditions and improve renal perfusion while supporting cellular detoxification.

Efficacy of the Danish epilepsy surgery programme.

OBJECTIVE: Despite optimal medical treatment, approximately one-third of patients with epilepsy continue to have seizures. Epilepsy surgery is widely accepted as a therapeutic option in the selected subset of patients with drug-resistant focal epilepsy. Here, we report the results of the Danish epilepsy surgery programme from 2009 to 2014. MATERIAL AND METHODS: A total of 169 consecutive patients, operated at Rigshospitalet, were included. Information was gathered from digital patient records. Before 1-year follow-up, two patients were lost to follow-up and three were referred to new surgery. RESULTS: The median years of drug resistance before operation were 11 years. At 1-year follow-up (n = 164), seizure outcomes were as follows: 65% Engel I (free from disabling seizures), 51% Engel IA (completely seizure free) and 9% Engel IV (no worthwhile improvement), and for patients operated in the medial temporal lobe (n = 114): 70% Engel I, 56% Engel IA, 5% Engel IV. The outcomes of the 53 patients needing intracranial EEG recording (ICR) were not significantly different from the patients only evaluated with surface EEG. None of the eight MRI-negative patients operated outside the medial temporal lobe after ICR were free of disabling seizures. 12% of MTLE patients developed de novo depression after epilepsy surgery despite good surgical outcome. Three patients required rehabilitation due to post-operative hemiplegia. CONCLUSION: The outcomes of the Danish epilepsy surgery programme align with international results found in recent meta-analyses. Serious complications to epilepsy surgery are seldom. In accordance with international recommendations, Danish drug-resistant patients should be referred to epilepsy surgery evaluation at an earlier stage of the disease.

Remote Ischemic Conditioning on Recipients of Deceased Renal Transplants Does Not Improve Early Graft Function: A Multicenter Randomized, Controlled Clinical Trial.

Delayed graft function is a frequent complication following deceased donor renal transplantation, and is closely related to ischemia-reperfusion injury. Experimental and clinical studies have shown protection by remote ischemic conditioning (RIC). We hypothesized that recipient RIC before kidney graft reperfusion reduces the time to graft recovery. This multicenter, blinded, randomized, controlled clinical trial included 225 adult recipients of renal transplants from deceased donors at four transplantation centers in Denmark, Sweden, and the Netherlands. Participants were randomized 1:1 to RIC or sham-RIC. RIC consisted of 4 × 5-min thigh occlusion by an inflatable tourniquet each followed by 5-min deflation, performed during surgery prior to graft reperfusion. The tourniquet remained deflated for sham-RIC. The primary endpoint was the estimated time to a 50% decrease in baseline plasma creatinine (tCr50) calculated from plasma creatinine measurements 30 days posttransplant or 30 days after the last, posttransplant dialysis. No significant differences were observed between RIC and sham-RIC-treated patients in the primary outcome median tCr50 (122 h [95% confidence interval [CI] 98-151] vs. 112 h [95% CI 91-139], p = 0.58), or the number of patients receiving dialysis in the first posttransplant week (33% vs. 35%, p = 0.71). Recipient RIC does not reduce the time to graft recovery in kidney transplantation from deceased donors. ClinicalTrials.gov: NCT01395719.

Variation of volatile compounds among wheat varieties and landraces.

Analysis of volatile compounds was performed on 81 wheat varieties and landraces, grown under controlled greenhouse conditions, in order to investigate the possibility of differentiating wheat varieties according to their volatile compound profiles. Volatile compounds from wheat samples were extracted by dynamic headspace extraction and analysed by gas chromatography-mass spectrometry. Seventy-two volatile compounds were identified in the wheat samples. Multivariate analysis of the data showed a large diversity in volatile profiles between samples. Differences occurred between samples from Austria compared to British, French and Danish varieties. Landraces were distinguishable from modern varieties and they were characterised by higher averaged peak areas for esters, alcohols, and some furans. Modern varieties were characterised by higher averaged peak areas for terpenes, pyrazines and straight-chained aldehydes. Differences in volatile profiles are demonstrated between wheat samples for the first time, based on variety. These results are significant to plant breeders and commercial users of wheat.

Kidney disease and risk of venous thromboembolism: a nationwide population-based case-control study.

BACKGROUND: Chronic kidney disease is associated with hemostatic derangements, including both procoagulant activity and platelet dysfunction, which may influence the risk of venous thromboembolism. However, data associating kidney disease with risk of venous thromboembolism are sparse. OBJECTIVES: We examined whether kidney disease is associated with increased risk of venous thromboembolism. METHODS: We conducted this nationwide case-control study using data from medical databases. We included 128,096 patients with a hospital diagnosis of VTE in Denmark between 1980 and 2010 (54,473 had pulmonary embolism and 73,623 had deep venous thrombosis only) and 642,426 age- and gender-matched population controls based on risk-set sampling. We identified all previous hospital diagnoses of kidney disease, including nephrotic syndrome, glomerulonephritis without nephrotic syndrome, hypertensive nephropathy, chronic pyelonephritis/interstitial nephritis, polycystic kidney disease, diabetic nephropathy, or other kidney diseases. We used conditional logistic regression models to compute odds ratios (ORs) for venous thromboembolism with adjustment for potential confounders. RESULTS: Kidney disease was associated with an adjusted OR for venous thromboembolism ranging from 1.41 (95% CI, 1.22-1.63) for hypertensive nephropathy to 2.89 (95% CI, 2.26-3.69) for patients with nephrotic syndrome. The association was strongest within the first 3 months after a diagnosis of chronic kidney disease (adjusted OR for nephrotic syndrome = 23.23; 95% CI, 8.58-62.89), gradually declining thereafter. The risk, however, remained elevated for more than 5 years, especially in patients with nephrotic syndrome and glomerulonephritis. CONCLUSIONS: Kidney diseases, in particular nephrotic syndrome and glomerulonephritis, were associated with an increased risk of venous thromboembolism.

CLIPPERS among patients diagnosed with non-specific CNS neuroinflammatory diseases.

Chronic Lymphocytic Inflammation with Pontine Perivascular Enhancement Responsive to Steroids (CLIPPERS) is an inflammatory CNS disorder characterized by 1) subacute onset of cerebellar and brainstem symptoms, 2) peripontine contrast-enhancing perivascular lesions with a "salt-and-pepper" appearance on MRI, and 3) angiocentric, predominantly T-lymphocytic infiltration as revealed by brain biopsy. Inflammatory diseases including neuroinfections, CNS lymphoma and neurosarcoidosis must be excluded. Since CLIPPERS was described in 2010, many patients might have been misdiagnosed in the past. We therefore searched medical records from a large tertiary neurological center, the Department of Neurology at Rigshospitalet, Copenhagen University Hospital, for patients discharged between 1999 and 2013 with a diagnosis of "sarcoidosis with other localization", "other acute disseminating demyelination", "other demyelinating disease in the CNS" or "encephalitis, myelitis or encephalomyelitis". Of 206 identified patients, 24 had been examined by brain biopsy and were included for further evaluation. Following clinical, neuroradiological and neuropathological review, 3 patients (12.5%) were reclassified as having CLIPPERS. Median long-term follow-up was 75 months. The present results suggest that clinical re-evaluation of patients previously diagnosed with unspecified inflammatory demyelinating CNS disease or atypical neurosarcoidosis may increase the detection rate of CLIPPERS. Further, potentially severe neurological deficits and progressive parenchymal atrophy on MRI may suggest neurodegenerative features, which emphasizes the need for early immunomodulatory treatment.

Genetics of steroid-resistant nephrotic syndrome: a review of mutation spectrum and suggested approach for genetic testing.

UNLABELLED: Identification of genes, associated mutations and genotype-phenotype correlations in steroid-resistant nephrotic syndrome (SRNS) is being translated to clinical practice through genetic testing. This review provides an update on the genes and mutations associated with SRNS along with a suggested approach for genetic testing in patients with SRNS. CONCLUSION: The number of indentified genes associated with SRNS is increasing along with our understanding of their impact on treatment response and risk of recurrence. A systematic approach to genetic testing in patients with SRNS might aid the physician in selecting appropriate treatment.

Messengers of renal graft quality during warm and cold ischemia: a porcine microdialysis study.

INTRODUCTION: Little is known about local graft metabolism during warm and cold ischemia before renal transplantation. We sought to characterize local metabolic changes in renal grafts during storage to understand acceptable ischemia time. METHODS: Kidneys from 60- or 15-kg pigs were randomized to cold (4°C) or warm (37°C) storage. Local renal graft metabolism was monitored for 24 hours by use of microdialysis and measurements of glycerol, glutamate glucose and lactate. RESULTS: For all metabolites, there was a significant interaction between time, storage temperature, and kidney size (all P < .0001). For local glycerol and glutamate, a significant increase was observed initially during warm storage, reaching a high steady state level. Glycerol remained low in cold kidneys for 80 minutes, but after 100 minutes there was an ongoing increase (P = .003) with no steady-state maximum level reached during the first 24 hours. The curves in the 2 size groups were parallel (P = .384) with 74% higher glycerol content in large kidneys (P = .005). Glutamate increased in cold kidneys in a similar manner in the 2 size groups (P = .924). Warm storage caused a rapid glucose decline within 60-100 minutes. In cold storage, glucose remained at a steady level until 480 minutes. CONCLUSIONS: Reducing cold ischemia time is of great importance, because concentrations of ischemic metabolites continuously increase in renal grafts. Furthermore, small kidney grafts from growing individuals are more resistant to cold ischemia but more susceptible to warm ischemia. In the setting of donation after circulatory death with prolonged warm ischemia, ongoing catabolism in the potential renal graft may be measured by microdialysis to achieve optimal timing of transplantation.

Improved renal function after early conversion from a calcineurin inhibitor to everolimus: a randomized trial in kidney transplantation.

In an open-label, multicenter trial, de novo kidney transplant recipients at low to medium immunological risk were randomized at week 7 posttransplant to remain on CsA (n = 100, controls) or convert to everolimus (n = 102), both with enteric-coated mycophenolate sodium and corticosteroids. The primary endpoint, change in measured GFR (mGFR) from week 7 to month 12, was significantly greater with everolimus than controls: 4.9 (11.8) mL/min versus 0.0 (12.9) mL/min (p = 0.012; analysis of covariance [ANCOVA]). Per protocol analysis demonstrated a more marked difference: an increase of 8.7 (11.2) mL/min with everolimus versus a decrease of 0.4 (12.0) mL/min in controls (p < 0.001; ANCOVA). There were no differences in graft or patient survival. The 12-month incidence of biopsy-proven acute rejection (BPAR) was 27.5% (n = 28) with everolimus and 11.0% (n = 11) in controls (p = 0.004). All but two episodes of BPAR in each group were mild. Adverse events occurred in 95.1% of everolimus patients and 90.0% controls (p = 0.19), with serious adverse events in 53.9% and 38.0%, respectively (p = 0.025). Discontinuation because of adverse events was more frequent with everolimus (25.5%) than controls (3.0%; p = 0.030). In conclusion, conversion from CsA to everolimus at week 7 after kidney transplantation was associated with a greater improvement in mGFR at month 12 versus CNI-treated controls but discontinuations and BPAR were more frequent.

Effect of remote ischemic conditioning on dendritic cell number in blood after renal transplantation--flow cytometry in a porcine model.

Delayed graft function after transplantation increases the risk of rejection. Remote ischemic conditioning (rIC) consists of repetitive, brief, non-damaging periods of ischemia in a limb. For reasons not fully understood, rIC protects the target organ against subsequent ischemia-reperfusion injury. Because ischemic endothelium attracts dendritic cells (DCs), we hypothesised that rIC protects the organ by "trapping" circulating DCs in the limb exposed to rIC. With fewer DCs thus available to infiltrate the graft, a strong T-cell mediated immune response toward the graft is less likely. To test this hypothesis, we measured the number of circulating DCs in a porcine model of renal transplantation with and without rIC. Brain death was induced in eight 65-kg donor pigs. After 22 h of cold ischemia, the kidneys were transplanted into sixteen 15-kg recipient pigs. The recipients were randomised to either non-rIC or rIC before reperfusion of the graft and observed 10 h after reperfusion. The number of DCs was determined by flow cytometry. DCs were identified on the basis of forward- and side-scatter characteristics of CD14-negative mononuclear cells with expression of CD172a. Dendritic cells were subclassified as either plasmacytoid (pDCs) (CD172a(dim), CD4(+), CD14(-)) or conventional (cDCs) (CD172a(high), CD4(-), CD14(-)). Remote ischemic conditioning did not affect the number of circulating cDCs or pDCs within the 10h after transplantation studied. Regardless of rIC, the number of pDCs decreased after graft reperfusion and then returned to baseline levels. In contrast, the number of circulating cDCs increased after reperfusion and later returned to baseline levels.

Early high-dose immunosuppression in Henoch-Schönlein nephrotic syndrome may improve outcome.

OBJECTIVE: Renal involvement in Henoch-Schönlein purpura (HSP) constitutes a risk of end-stage renal disease (ESRD), especially in patients presenting with nephrotic syndrome. PATIENTS AND METHODS: The clinical courses of six patients (mean age 13.2 years; four boys and two girls) admitted from 2000 to 2007 with HSP and nephrotic syndrome were reviewed. Average follow-up was 44 months (28-59). Treatment protocols included oral prednisolone and in non-responders cyclosporin A, cyclophosphamide, mycophenolate mofetil or tacrolimus. Five patients were treated immediately after presentation of nephrotic syndrome/nephrotic range proteinuria (median 277 mg/m(2)/h). The last patient was treated locally with low-dose prednisolone (0.2-0.9 mg/kg/day) and 3 months of low-dose cyclophosphamide (1 mg/kg/day). RESULTS: All five patients treated promptly with high-dose immunosuppressant had normal estimated glomerular filtration rate (eGFR) (median 159 ml/min/1.73 m(2)) at follow-up. One obtained complete remission, two had positive dipstick proteinuria and two needed angiotensin-converting enzyme inhibitors to stay normotensive. The patient receiving low-dose immunosuppression at onset progressed to ESRD 44 months later. At initial presentation eGFR, blood pressure, renal biopsy grading, proteinuric range and plasma albumin were similar in all patients. CONCLUSION: Follow-up data from the patients suggest that an early aggressive immunosuppressive approach improves long-term renal outcome in HSP patients with nephrotic syndrome.

Kidney transplantation activity and outcome in Denmark 1990-1999.

1. During the period 1990-1999, 1,715 renal transplants were performed in Denmark, corresponding to 31.8 per million population per year. Seventy-five per cent were cadaver donor transplants; in 25%, a living donor kidney was used. 2. Living donors of 437 kidneys were mainly parents (54%) and siblings (36%). In 20 transplants, a kidney from a living-unrelated donor was used. 3. The overall actuarial patient survival rates at one and 5 years were 91.0% and 78.2%, respectively. The major causes of recipient death were cardiovascular disease and infection. 4. The overall actuarial graft survival rates at one and 5 years were 81.4% and 62.0%, respectively. The major single causes of graft loss were rejection (41%) and recipient death (32%). Graft survival has improved during the decade.

Development of technology for the early post mortem prediction of water holding capacity and drip loss in fresh pork.

Two different technologies were tested on the slaughterline for their ability to predict drip loss at 24 h, namely near infrared reflectance (NIR) and impedance measurements using a tetra polar measuring geometry at a frequency of 1000 Hz. The results demonstrate that NIR measurements (900-1800 nm) acquired during a 6 min period starting only 30 min post exsanguination through a fibre optic probe in combination with multivariate data analysis can be used for predicting drip loss 24 h after slaughter. A correlation higher than 0.8 was observed for a trial on 99 carcasses measured at a commercial slaughterhouse. The tetrapolar impedance measurements did not perform as well as NIR yielding a correlation of 0.5 with 24 h drip loss.

Hyperextension injury to the PIP joint or to the MP joint of the thumb--a clinical study.

We present a prospective study of the diagnosis and clinical course of 60 patients with 57 pure hyperextension injuries to the proximal interphalangeal (PIP) joint of the long fingers (fingers 2-5) and seven injuries to the metacarpophalangeal (MP) joint of the thumb. Thirty four of the injuries (57%) were related to ball sports, and the ulnar fingers of the non-dominant hand were usually affected. There were 24 avulsion fractures at the site of the insertion of the volar plate on to the middle phalanx. Twelve (20%) initially presented with hyperextension instability, and this was usually associated with an avulsion fracture. Thirty four of the patients (57%) had symptoms for less than one month, while 10 (17%) complained of symptoms six months after the injury. Severe complications such as daily pain and stiffness were encountered in three cases. The triad sign (pain on extreme flexion and extension) was of no use as a diagnostic or prognostic factor, nor did the radiographic stress-view help to identify acute instability of the joint.

Acute cardiovascular effect of 1,25-dihydroxycholecalciferol in essential hypertension.

A role for vitamin D in the pathophysiology of essential hypertension has frequently been suggested, but acute direct effects on blood pressure, cardiac output, renal hemodynamics, or hormones have not previously been demonstrated. The rapid effects of 1,25-dihydroxycholecalciferol (1,25-D) were assessed over 120 min after a bolus injection (0.02 microg/kg body weight) in eight men with essential hypertension and in nine healthy men. A placebo group of 10 healthy men was also included. Ionized calcium was monitored closely during the study, and was kept constant with a clamping technique. In the hypertensive patients, a transient increase in blood pressure and a reciprocal fall in cardiac output measured by a CO2 rebreathing technique (-15%, P < .05) were observed after 1,25-D injection. In the control group, both blood pressure and cardiac output remained unchanged. The glomerular filtration rate, effective renal plasma flow, and urinary sodium and water excretions were unchanged in both groups. Plasma levels of atrial natriuretic peptide at baseline were higher in the hypertensive patients than in the control subjects (P < .02); plasma levels of renin, aldosterone, norepinephrine, endothelin, and parathyroid hormone(1-84) were similar in the two groups. None of these hormones was affected during the observation time after the injection of 1,25-D. In conclusion, acute administration of 1,25-D caused a fast and likely nongenomic-mediated decrease in cardiac output in patients with essential hypertension, which together with a transient BP increase implies a 1,25-D-induced increase in total peripheral resistance. These data suggest an enhanced cardiovascular responsiveness to 1,25-D in hypertensive compared to healthy normotensive subjects.

Regulation of renal sodium and water excretion in the nephrotic syndrome and cirrhosis of the liver.

Atrial natriuretic peptide (ANP) produced in the heart and prostaglandin E2 (PGE2) synthesised in the kidneys facilitate renal excretion of sodium and water, and thus oppose the actions of angiotensin II, aldosterone, arginine vasopressin (AVP), endothelin, and the renal sympathetic nerves. In the present work we studied the contributions and interactions of these substances in the regulation of blood volume (BV), renal haemodynamics, renal sodium and water handling and blood pressure (BP) in patients with glomerulonephritis and cirrhosis. The aim was through a better understanding of the pathophysiology to improve the treatment of fluid retention in these patients, which occurs as development of the nephrotic syndrome and accumulation of ascites, respectively. Normotensive patients with glomerulonephritis but without the nephrotic syndrome had normal baseline BV values measured as the sum of plasma volume and red cell volume; they responded to BV expansion after infusion of albumin and BV depletion after administration of furosemide with appropriate counterregulatory hormonal changes. However, they tended to hold more fluid within the intravascular phase after both manipulations than did the healthy subjects. The acutely induced increase in BV did not affect the BP, which was likely attributable to the changes in plasma values of angiotensin II and ANP shown. ANP could be expected to be a tool in the management of fluid accumulation in patients with the nephrotic syndrome and cirrhosis. The non-renal effects of high-dose ANP were studied for the first time in dialysis patients without excretory kidney function. A reversible shift of fluid away from the intravascular phase was demonstrated. The BV was maximally reduced 30 min after ANP had been given. The BP was reduced before fluid displacement occurred and to the same extent in patients and healthy subjects. The reduction in the BV was negatively correlated to the reduction in BP. From that study it is inferred that the BP reducing effect of ANP is not mediated by its diuretic effect or ability to displace fluid from the intravascular to the interstitial fluid compartment. As a pharmacological dose of ANP was given, it can only be suggested that endogenous ANP, by altering transcapillary Starling mechanisms, assists in buffering intravascular fluid expansion until renal excretion or dialysis can take place. The same dose of ANP was given to patients with the nephrotic syndrome and cirrhosis. The ability of ANP to increase sodium excretion through inhibition of sodium reabsorption in the distal tubules and to increase the glomerular filtration rate (GFR) was blunted in both patient groups, but the BP was reduced to the same extent as in the healthy controls. Patients with the nephrotic syndrome tended to have a slightly elevated BP. We only studied patients with normal or slightly reduced GFR. They had a normal BV, reduced renal filtration fraction, suppressed aldosterone, increased ANP, but normal plasma values of angiotensin II, endothelin, and AVP, and normal urinary excretion of PGE2. Thus, neither haemodynamic nor hormonal factors can easily explain the spontaneous sodium retention or the resistance to the effects of ANP and furosemide. An interesting finding, not previously reported in nephrotic humans, was the low cyclic guanosine 3'5'-monophosphate (cGMP) in plasma and urine in relation to ANP, both before and after administration of ANP. It is hypothesised that renal resistance to ANP, exaggerated renal cGMP degradation, or preponderance of clearance receptors in nephrotic kidneys may contribute to sodium retention and the low filtration fraction. Elevation of ANP in these patients is connected with increased albuminuria, and probably an increase in intraglomerular capillary pressure. The resistance to furosemide could not be attributed to delayed passage of fluid from the interstitial to the intravascular fluid phase, but is most likely due to renal tubular resistan