IgA nephropathy and polycystic kidney disease

We report a patient with polycystic kidney disease, advanced renal failure, and nephrotic-range proteinuria. Kidney biopsy revealed IgA nephropathy with lesions of focal and segmental glomerular sclerosis. This association had not been previously described and is probably coincidental. This case supports the assumption that the nephrotic-range proteinuria observed in some polycystic patients could be the consequence of another superimposed glomerular disease. This glomerulopathy can worsen the course of azotemia in these patients.     

Metallothionein in human retinal pigment epithelial cells: expression, induction and zinc uptake.

The retinal pigment epithelium (RPE) plays several important roles in the continual support and renewal of photoreceptor outer segments. In the present study, we have demonstrated that RPE cells contain a low molecular weight protein with a high capacity for zinc binding that is dependent on available sulfhydryl groups. This protein is inducible by a 24 hour incubation of cultured RPE in medium supplemented with zinc, cadmium, or dexamethasone. The induction of this protein is correlated with an increased capacity for zinc-65 uptake into cultured RPE. Analysis with a cDNA probe specific for the human metallothionein II gene corroborated the existence and induction of metallothionein gene products in RPE cells. Based on these properties, we have identified this protein as metallothionein. The induction of metallothionein likely has a critical influence on the zinc economy of the RPE.     

Post-antibiotic diarrheas: role of Klebsiella oxytoca]

From May 1989 to January 1991, 20 patients were investigated for antibiotic-associated acute diarrhea. Colonoscopy or rectosigmoidoscopy was performed in each patient. Cultures of colonic mucosal biopsies were carried out using conventional culture grounds (cystine-lactose-electrolyte-deficient). The aim of this study was to investigate the role of a gram negative bacillus: Klebsiella oxytoca. Among the 20 patients with antibiotic-associated acute diarrhea, 11 had bloody and mucus diarrhea and colitis ranging from a right-sided hemorrhagic to diffuse acute ulcerative or erosive colitis, 7 had a grossly normal colonic appearance, while 2 had mucus diarrhea and pseudomembranous colitis. Of colonic biopsies cultures obtained from 36 control patients, 15 had a normal colonic appearance, 15 had ulcerative or crohn's colitis, 6 had well-tolerated amoxicillin therapy. Klebsiella oxytoca was never found in the 36 control patients; Klebsiella oxytoca was noted among 8/11 patients with mucus-discharging and bloody diarrhea. These results suggest that antibiotic-associated, non pseudomembranous colitis is frequently associated with Klebsiella oxytoca infection, which may be the cause of this type of colitis.     

Abnormalities of thirst regulation in patients with chronic renal failure on hemodialysis.

To determine whether thirst mechanisms are altered in nondiabetic patients with chronic renal failure on hemodialysis, 4 patients with an average weight gain between dialysis sessions of more than 5% of dry body weight (group I), 5 patients with less than 3% weight gain (group II), and a group of 6 healthy subjects (group III) were submitted to infusion of hypertonic saline. After infusion the subjects had free access to water. Thirst was evaluated by visual analogue rating scales. Despite similar increments of effective plasma osmolality during saline infusion, patients of group I were thirstier than groups II and III (p less than 0.005 and p less than 0.01, respectively). Changes in thirst ratings were similar in groups II and III. Osmotic thresholds for thirst onset were similar in groups II and III (288.9 +/- 8.5 and 289.8 +/- 3.4 mosm/kg, respectively), but lower in group I (277.6 +/- 7.6 mosm/kg). Nevertheless, great variations were observed in the latter group. Thus, 2 patients showed thresholds for thirst within the normal range, whereas the others had low osmolar thresholds for thirst and baseline plasma osmolalities and high basal thirst scores. During the drinking period, the patients of group I drank more (14.2 +/- 2.8 ml/kg) than those of groups II (5.3 +/- 1.6 ml/kg; p less than 0.02) and III (10.2 +/- 1.6 ml/kg; n.s.) The plasma levels of angiotensin II in uremic patients were higher than in healthy subjects, although there were no differences between groups I and II and no correlation between basal angiotensin II levels and the interdialytic weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intra-operative quick insulin assay to confirm complete resection of insulinomas guided by selective arterial calcium injection (SACI)

Background and aims Insulinomas are rare endocrine disorders. Pre-operatively, conventional imaging techniques often fail to localise the tumor. In addition, due to the lack of quick insulin assays, intra-operative confirmation of complete resection was impossible until recently. Materials and methods Six patients with biochemical evidence of an insulinoma underwent pre-operative localisation studies and selective arterial calcium injection (SACI). In addition, insulin was measured before surgery and every 10–15 min after resection of the tumor using a quick insulin assay. Results Pre-operative localisation studies identified the tumor correctly as follows: endosonography: three of four, magnetic resonance imaging: two of four and SACI: six of six. Tumors in the head and body were enucleated while those in the tail were resected (n = 2, each). Those three patients, in whom magnetic resonance imaging and/or endosonography could localise the tumors pre-operatively, underwent laparoscopic surgery while the remaining three patients underwent open surgery. Intra-operatively, insulin dropped to normal levels within 20 min in all cases. After a follow-up of 0.8–3 years, all patients remained biochemically cured. Conclusions Pre-operatively, SACI appears to be a very sensitive localisation technique and may be most helpful in guiding the surgeon if conventional imaging techniques fail to localise the tumor. Complete removal of an insulinoma can be reliably predicted using a quick insulin assay. This paper was presented at the 2nd Biennial Meeting of the European Society of Endocrine Surgeons (ESES), May 18–20, 2006, Krakow, Poland.     

A randomized trial of low-protein diet in type 1 and in type 2 diabetes mellitus patients with incipient and overt nephropathy.

OBJECTIVE: The efficacy of a low-protein diet in the secondary prevention of diabetic nephropathy is not established in patients with type 1 or type 2 diabetes mellitus. To determine whether a low-protein diet slows the decrease in glomerular filtration rate (GFR) and decreases the albumin excretion rate (AER) in diabetic patients with incipient and overt nephropathy, we performed a 2-year prospective, randomized controlled trial comparing the effects of a low-protein diet (0.8 g/kg/day) with a usual-protein diet. SETTING AND PATIENTS: The study was conducted in a University hospital and included 63 type 1 and type 2 diabetic patients with either incipient or overt nephropathy and mild renal failure (prestudy GFR, 80 +/- 20 mL/min). The primary outcome measures were decreased in GFR and 24-hour AER. RESULTS: In the low-protein-diet group, patients were younger (52 +/- 12 versus 63 +/- 9 years old) and more often were type 2 diabetic. During the follow-up period, according to dietary records the low-protein-diet group consumed 16% +/- 3% of total caloric intakes as compared with 19% +/- 4% in the usual-protein-diet group (P < .02), but 24-hour urinary urea excretions did not differ between the two groups. The 2-year GFR decrease was 7 +/- 11 mL/min in the low-protein-diet group and 5 +/- 15 mL/min in the usual-protein-diet group (P = not significant). AER did not increase significantly in the two diet groups during the follow-up period. Blood pressure and glycemic control were similar in the two groups all along the study. The decrease in GFR and AER were also similar in 6 compliant patients according to dietary records and to 24-hour urinary urea excretions from the low-protein-diet group and in 12 patients from the usual-protein-diet group. CONCLUSIONS: A 2-year low-protein diet did not alter the course of GFR or of AER in diabetic patients with incipient or overt nephropathy receiving renin-angiotensin blockers with strict blood pressure control.     

The 'Functional Muscle-Bone Unit': probing the relevance of mechanical signals for bone development in children and adolescents.

The present text deals with the relationship of muscle force and mass to bone mass and geometry in the developing skeleton of children and adolescents. Recent results of the last ten years are discussed with reflection on Harold Frost's 'mechanostat hypothesis'. Bone mass and geometry follow the development of body size and muscle force in children and adolescents. Thereby, bone is adapted to the tissue strain due to biomechanical forces. This process is modified by hormonal signals (i.e., estrogens and androgens). Therefore, the quantified relationship of muscle force to bone stability is a reasonable approach to distinguish between primary and secondary bone diseases. Primary bone diseases are characterized by a disturbed adaptation of bone to biomechanical forces. In contrast, secondary bone diseases show a correct adaptation of bone to loaded forces in combination with a decline of muscle force. Therefore, the 'Functional Muscle-Bone Unit' was introduced into the diagnostics of pediatric bone diseases. The ratio of two parameters--referred to bone strength on the one and to biomechanical forces on the other side--is a reasonable diagnostic approach to distinguish between primary and secondary bone diseases.     

Laser treatment of eye disorders in children.

The increasing range of indications for laser treatment and the development of new modalities of lasering have led to a growing tendency to extend this type of treatment to the pediatric population. Problems of compliance in this age group often necessitate the use of general anesthesia. This report describes the operative technique used in 11 children (13 eyes) under the age of 13 years, all of whom underwent laser treatment under general anesthesia for a variety of ocular conditions. Argon or krypton laser photocoagulation was performed in eight children (10 eyes), seven of whom were treated for various retinal pathologies and one for an iris cyst. The other three children underwent Nd:YAG posterior capsulotomy for secondary cataract.