Enalapril and low protein reverse chronic puromycin aminonucleoside nephropathy

The effects of dietary protein and converting enzyme inhibition (CEI) on chronic puromycin aminonucleoside nephropathy (PAN) were studied. PAN was induced with seven SQ injections of puromycin aminonucleoside 20 mg/kg over 10 weeks in male Sprague-Dawley rats. The rats were divided into a 22.5% protein diet group (Gr 1), a 6% protein diet group (Gr 2), and an enalapril-treated group on 22.5% protein diet (Gr 3). Group 4 animals served as age-matched controls. Both diets were isocaloric and had the same phosphorus content. Rats from groups 1, 2, and 4 were sacrificed at 12, 18 and 24 weeks. Five rats of group 3 were sacrificed at 12 weeks, and the others were divided in subgroups 3A (diet changed to 6% protein) and 3B (no changes); half of each subgroup was sacrificed at 18 and 24 weeks, respectively. Group 2 had significantly less proteinuria than group 1 at all times. Group 3 had the same proteinuria as group 1 until 12 weeks and then began to decrease. In group 3A proteinuria decreased to group 2 levels, while in group 3B the decrease was slower but still prominent. Early lesions of focal and segmental glomerular sclerosis/hyalinosis (FSH) were present in groups 1, 2, 3 at 12 weeks (16 +/- 1.2%, 15 +/- 1.3%, 7 +/- 1.3%, respectively, versus 1.3 +/- 0.4% in controls), but by 18 weeks a reversal in FSH was seen in groups 2 and 3A/B (3 +/- 1.6%, 2 +/- 0.4%, and 3 +/- 0.9%, respectively, vs. 14 +/- 1.5% in group 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Human immunodeficiency virus (HIV) infection and the kidney

Since the first report on the acquired immunodeficiency syndrome (AIDS) in 1981, organ involvement of AIDS has increased. We discuss the effect of human immunodeficiency virus (HIV) infection, the causative agent of AIDS, on the field of nephrology. Hyponatremia, the commonest fluid and electrolyte abnormality, is caused by various pathophysiologic mechanisms, including adrenal insufficiency. The renal parenchymal complications are diverse, but a new entity, HIV-associated nephropathy, is becoming recognized because of its characteristic clinical and pathologic features, including the fact that it causes irreversible renal failure. HIV infection in patients with end-stage renal failure, both before and after initiation of maintenance dialysis, is a significant problem. The present methods of preventing spread of virus in dialysis units seem successful. Few patients who are infected with HIV or who have AIDS have had renal transplantation, although unsuspected viral infection of cadaveric organs remains a concern.

Glomerular atrial natriuretic factor receptors in primary glomerulopathies: studies on human renal biopsies

Human renal biopsies are currently used to provide information about morphologic changes, chronicity of disease, patterns of inflammation, and immunoglobulin deposition. This practice has provided only limited insight into functional aberrations and has failed to provided information necessary for disease classification based on pathophysiology. To expand the potential of the renal biopsy in this regard and to determine whether differences in glomerular atrial natriuretic factor (ANF) binding exist in different forms of primary renal disease, quantitative autoradiography and 125I-human ANF (1-28) were used to determine the location and pharmacological characteristics of ANF binding sites in the normal human kidney. Specific ANF binding was highest in the glomeruli, but lower levels of specific binding were localized to the inner medulla and the interlobular arteries. ANF binding sites in the human kidney were found to be highly stable and similar in both location and pharmacology to those observed in experimental animals. As determined by saturation experiments, the equilibrium dissociation constants for glomeruli, inner medulla, and interlobular arteries were almost identical at 4.0 x 10(-11) mol/L. Competitive binding inhibition studies with unlabeled human ANF (1-28) demonstrated highly specific binding shared by the glomerulus, inner medulla, and interlobular artery, with apparent half-maximal inhibition concentrations of 9.2 x 10(-10) mol/L, 8.0 x -10 mol/L, and 8.2 x 10(-10) mol/L, respectively. Quantitation of specific binding of ANF to glomeruli in needle biopsy specimens of three primary glomerulopathies, ie, minimal-change disease, membranous nephropathy, and focal glomerulosclerosis, showed no differences among the groups. This study demonstrates the feasibility of studying receptor physiology on biopsy specimens of the human kidney and should allow renal diseases, particularly of glomerular origin, to be characterized according to differences in hormone binding and hormone responsiveness. The absence of significant differences in glomerular ANF binding in the primary glomerulopathies studied is consistent with other studies that have failed to delineate important pathophysiological differences in renal function and volume homeostasis in these disease states.

Monocytes and focal glomerulosclerosis

It has been suggested that focal glomerulosclerosis (FGS) is analogous to atherosclerosis. Because monocytes and their derivatives are involved in the latter, these cells may be involved in the development of the former. To investigate this possibility a combined histochemical and ultrastructural study of FGS was done. Sections from 13 biopsies showing FGS were stained for either nonspecific esterase or lysozyme to detect monocytes and their derivatives. These include foam cells (lipid-containing macrophages) in which there was positive cytoplasmic staining for both nonspecific esterase and lysozyme. Twenty-one of 29 glomeruli (72%) with segmental sclerotic lesions contained monocytes and/or foam cells, whereas only 18 of 251 glomeruli (7%) without the lesions demonstrated these cells (p less than 0.0001). The mean number of monocytes and/or foam cells in segmentally sclerotic glomeruli was 2.0 +/- 1.7 compared with 0.2 +/- 0.3 for uninvolved glomeruli (p less than 0.01). In glomeruli with sclerotic lesions foam cells predominated over monocytes. Neutral lipid was observed focally and segmentally in 29 of 35 biopsies with FGS. Electron microscopy in 23 biopsies consistently demonstrated intracapillary cells with monocytic features but few foam cells in very early lesions characterized by epithelial cell changes but no or minor glomerular tuft alterations. With progression, the relative number of monocytes declined but foam cells were observed more frequently. These results suggest that monocytes and their derivatives are involved in the development of FGS.

Evidence for functional regeneration in the adult lamprey spinal cord following transection

We report here that following partial spinal transections in adult lampreys, the fibers of the spinal cords can regenerate and restore some intersegmental coordination to the central pattern generator for locomotion, as tested in the isolated cord preparation. However, the regeneration by this test is not successful in all animals.

Mycobacterium tuberculosis cervical adenitis. Diagnosis and management

Cervical adenopathy as the sole presentation of tuberculosis is seen infrequently in the pediatric age group. Despite modern treatment and public health measures, tuberculous cervical adenitis persists, and its prompt diagnosis and treatment are important from both a clinical and preventive health perspective. The authors report five cases of children with ages ranging from 8 to 17 years, in whom cervical adenitis was the only presentation of infection with Mycobacterium tuberculosis. The clinical presentation and methods of diagnosis and treatment are described, and the difficulty of differentiation between infections with M. tuberculosis and non-tuberculous mycobacterial infections is stressed. Tuberculous cervical adenitis should be considered in cases of an elusive diagnosis of a cervical mass in the pediatric patient.

Idiotypic characteristics of immunoglobulins associated with systemic lupus erythematosus. Studies of antibodies deposited in glomeruli of humans

Indirect immunofluorescence with monoclonal antibodies to 6 different idiotypes was used to characterize immunoglobulins deposited in the glomeruli of renal biopsy samples from 32 patients with systemic lupus erythematosus (SLE) and 19 patients with nonlupus immune glomerulonephritis. IdGN2 was present in 75% of the biopsy specimens from SLE patients and in 6% of those from patients with non-lupus nephritis; IdGN1 occurred in 38% and 6%, respectively. The other idiotypes were not increased in biopsy samples from patients with SLE. Deposition of IdGN2 was associated with a subendothelial location of Ig and proliferative changes in the glomeruli. In studies of glomerular eluates from 4 immunosuppressed SLE patients, an average of 26% of total Ig and 37% of anti-DNA was composed of IdGN2. Compared with IdGN2- immunoglobulin, IdGN2+ immunoglobulin was enriched in IgG1 in all 4 eluates, and was enriched in high-avidity anti-DNA in 2 eluates. IdGN2 is a marker of antibody subsets that are characteristic of SLE and are associated with severe lupus nephritis.

Demonstration of human immunodeficiency virus in renal epithelium in HIV-associated nephropathy

HIV-associated nephropathy (HIVAN) is a renal disease characterized clinically by heavy proteinuria and renal failure and morphologically by severe and rapidly evolving focal and segmental glomerulosclerosis, tubular necrosis, interstitial edema, and ultrastructural cellular inclusions. In an attempt to elucidate its pathogenesis, we evaluated the role of direct viral (HIV) infection of renal epithelium with the use of a cDNA probe for viral nucleic acid and an immunoperoxidase-labeled antibody to p24 core protein. In 10 of 11 kidneys with HIVAN, nucleic acid was localized to glomerular and tubular epithelium, while only 2 of 4 kidneys from HIV-infected patients with immune complex glomerulonephritis were similarly affected, but with considerably less cellular involvement. Kidneys from patients with acquired immune deficiency syndrome but without renal disease had only rare cellular positivity. In all instances, the cDNA probe was more sensitive than anti-p24 immunoperoxidase. These data suggest a role for direct HIV infection of renal epithelial cells in the initiation and/or progression of HIV-associated nephropathy.

Poor prognosis in end-stage lupus nephritis due to nonautologous vascular access site associated septicemia and lupus flares

A poor prognosis was observed in patients who had end-stage renal disease (ESRD) as a result of systemic lupus erythematosus (SLE). This was true even in patients in whom SLE disease activity was transiently quiescent during the period of hemodialysis. Six of 9 patients with ESRD and SLE died with active SLE and/or sepsis 1-28 months following the onset of dialysis. In 5 of the 6 patients, acute inflammatory activity of SLE flared within 1 month of the patient's death. Four patients died with superimposed sepsis, but only 2 of the 4 were receiving high-dose concomitant immunosuppressives for more than 1 week prior to death. Infected hemodialysis vascular access sites were implicated as the source of septicemia in 3 of 4 infectious deaths. The 3 surviving patients had minimal lupus activity prior to the development of ESRD, a possible marker for stability in SLE patients who require hemodialysis. Our results suggest that hemodialyzed lupus patients with nonautologous vascular access sites may be at continued increased risk for life-threatening inflammatory and septic complications.

Clinical utility of kidney biopsies in the diagnosis and management of renal disease

A prospective study was undertaken to assess the utility of the renal biopsy as a tool in the clinical practice of nephrology. Nephrologists performing this procedure were surveyed concerning prebiopsy diagnosis, plans for therapy and estimation of prognosis, before and after biopsy results were disclosed. On the basis of 108 specimens from both academic centers and community hospitals, clinical and pathological diagnoses differed in 63% and therapeutic approach was altered in 34% of the cases. These results were greatest for nephrotic syndrome and for renal failure of rapid onset. The change in treatment was frequently of major consequence: decisions for the use of corticosteroids, cytotoxic agents and/or plasma exchange were altered based upon biopsy diagnoses. There were no differences either in diagnostic acumen or therapeutic approach between academic and community nephrologists. We conclude that renal biopsies are an important and frequently used part of the nephrologists' approach to patient care.

Plasma exchange for recurrent nephrotic syndrome following renal transplantation

Patients with steroid-resistant nephrotic syndrome and focal segmental glomerulosclerosis (FGS) who develop end-stage renal disease are at risk for recurrence of the disease following renal transplantation. Recurrence of the nephrotic syndrome in renal allografts of two children with primary FGS was successfully controlled by plasma exchange. This report suggests that plasma exchange instituted early in the course of recurrent nephrotic syndrome may be beneficial in some patients with steroid-resistant nephrotic syndrome and FGS.

Light chain cardiomyopathy associated with small-vessel disease

Intramyocardial small-vessel disease associated with systemic light chain deposition is a rare condition that may occur in patients with monoclonal plasma cell proliferation. This article describes a 39-year-old woman who had experienced several episodes of subendocardial myocardial infarction and was found to have plasma cell dyscrasia. Endomyocardial biopsy revealed kappa light chain deposits along the sarcolemmal and vascular basement membranes, the latter of which resulted in vascular occlusion and myocardial infarction. Postmortem examination showed polyvisceral deposition of kappa light chains. This rare complication of plasma cell proliferative process has a poor prognosis.

Alport's syndrome and achalasia

A 7-year-old boy presented with a history of postprandial vomiting, failure to thrive, hematuria, proteinuria and decreased renal function. Electron microscopy of a renal biopsy specimen demonstrated the typical glomerular basement membrane changes associated with Alport's syndrome. Audiometry revealed a moderate bilateral high-tone sensorineural hearing loss. Bilateral anterior lenticonus and a unilateral cataract were also diagnosed. Achalasia diagnosed radiologically and confirmed by biopsy was corrected by surgery. Evaluations of the parents and three siblings were negative. The patient subsequently developed end-stage renal failure. This case report and a review of the literature suggest that achalasia may be part of Alport's syndrome in some patients.

Regenerated fibers of the lamprey spinal cord can coordinate fictive swimming in the presence of curare

Recently evidence was presented that, following transection, spinal cords of larval lampreys could regenerate functional connections. The demonstration in isolated spinal cord-notochord preparations consisted of fictive swimming coordinated across the lesion site. In the study reported here curare was added to the bath to eliminate the possible contribution from reflexes mediated by contractions from any remaining muscle fibers attached to the notochord. Coordination remained in the presence of curare, adding further evidence that indeed the regenerated fibers formed functionally appropriate connections.

HIV-associated nephropathy. A unique combined glomerular, tubular, and interstitial lesion

Although a variety of renal lesions may occur in acquired immune deficiency syndrome (AIDS), a rare but aggressive form of focal and segmental glomerulosclerosis with capillary collapse has been considered a possible component of this disorder. It is manifested by heavy proteinuria and progression to renal failure in a short time. We studied renal biopsies from nine patients with HIV infection and the above clinical features and compared the renal tissues to biopsies from HIV-positive individuals with immune complex glomerulonephritis and to biopsies from patients with heroin abuse nephropathy. The HIV-associated nephropathy was characterized by a combination of lesions: focal and segmental glomerulosclerosis, often in an early stage of evolution and with prominent degenerative changes of visceral epithelium; tubular necrosis without identifiable nephrotoxic or hemodynamic etiology; interstitial edema; large plasma protein-containing tubular casts in all segments of the nephron associated with marked tubular dilatation; and widespread tubuloreticular structures in vascular endothelium. In contrast, neither the sclerosing glomerular changes nor the tubulointerstitial abnormalities were present in HIV-infected patients with immune complex glomerulonephritis. Similarly, the tubular and interstitial changes and widespread tubuloreticular structures were absent in heroin-abuse nephropathy. The lesions of HIV-associated nephropathy occurred in patients with AIDS, AIDS-related complex, and in individuals clinically asymptomatic for HIV infection. Their morphological features in asymptomatic patients are sufficiently specific to allow for accurate diagnosis of HIV infection.

Effects of keto acid supplements on renal function and histology in azotemic rats fed high-protein diets

The mechanism by which keto-acid-supplemented diets may retard the progression of renal failure is not known. We examined whether the protective effect of keto acids may be independent of a low nitrogen intake. Azotemic subtotally nephrectomized Sprague-Dawley rats were pair-fed a 30% casein diet supplemented with a 10% keto acid mixture (n = 10) or 10% cornstarch (n = 10) for 18 weeks. No differences were observed between the two groups of rats with regard to survival, weight gain, plasma urea, blood pressure, albuminuria, or, at the termination of the study, PAH and inulin clearances. Creatinine clearances, measured weekly during the study, were transiently higher in the keto acid group. There was no difference in the incidence or severity of segmental glomerulosclerosis or tubular atrophy in the two groups. These results indicate that the keto acid mixture used did not exert a protective effect against glomerular sclerosis and progressive albuminuria in azotemic rats fed high-protein diets.

Characterization of renal injury initiated by immunization of rats with heparan sulfate

To investigate the role of antibody to heparan sulfate (HS) in the development of glomerular injury, male Lewis rats were immunized with HS and compared with unimmunized controls. In HS-immunized rats circulating antibodies that bound to renal basement membranes, an increase in serum creatinine (0.8 mg/dl versus 0.6 in controls P less than 0.01), and a 40% decline in creatinine clearance developed. In no animal did abnormal proteinuria develop. By histologic examination there was glomerular and interstitial capillary engorgement with erythrocytes, modest infiltration by polymorphonuclear leukocytes, and no proliferation of intrinsic glomerular cells. Immunofluorescence microscopy demonstrated deposits of rat IgG along the glomerular basement membrane. Bowman's capsule, and peritubular capillaries. Electron-microscopic examination revealed capillary engorgement with erythrocytes that appeared adherent to each other and contained entrapped areas of rarefied material. These observations demonstrate that binding of antibody to HS in the glomerulus induces a mild inflammatory reaction and a reduction in glomerular filtration rate, but no abnormal proteinuria.

Acquired cystic kidney disease in children undergoing long-term dialysis

Acquired cystic kidney disease (ACKD) occurs in adult patients undergoing long-term dialysis. Early detection is important because clinically significant hematuria and malignancies are associated with ACKD. We evaluated by magnetic resonance imaging (MRI) and ultrasonography (US) the incidence of ACKD in 15 patients aged 7.3-21.6 years (mean 15.9 years) with non-cystic primary renal disease. Nine patients had been treated with peritoneal dialysis only, and 6 with both hemodialysis and peritoneal dialysis for 24-73 months (mean 37 months). Three patients (20%) had no cysts. In 5 patients (33%) with bilateral multiple cysts, the diagnosis of ACKD was made by MRI and US. In another 5 patients, solitary cysts were localized to one kidney by MRI, and in 2 patients solitary cysts were seen in both kidneys. This study documents that ACKD is not limited to older patients with end-stage renal disease. Early detection of these cysts can be accomplished by MRI and is warranted since 1 patient developed neoplastic tubular changes which can precede tumor formation.

Accelerated glomerulosclerosis in diabetic rats with immune complex injury

Immune complex-mediated injury has been postulated to contribute to diabetic microangiopathy. To test this hypothesis, immune complex disease was induced in both insulin-deficient (I-) and insulin-treated (I+) rats with streptozocin-induced diabetes mellitus (DM), and the rats were compared with their respective controls. Heymann nephritis (HN), an animal model of membranous nephropathy, was induced in rats by immunization with proximal renal tubular brush border antigen. In addition to the homogeneous mesangial deposits of IgG that developed in diabetic rats, diabetic rats with immune injury also developed immune deposits of IgG and tubular antigen. Diabetic animals with Heymann nephritis developed more intense granular mesangial and capillary wall immune deposits, detected by immunofluorescence (ranked-sums test, P = .002) and electron microscopy. Mesangial immune deposits were associated with mesangial hypercellularity, determined by counting nuclei per glomerular cross section. Diabetic animals with immune injury had an increased number of nuclei (DM, I-, HN: 70 +/- 4; DM, I+, HN: 65 +/- 3) compared with animals with only Heymann nephritis (55 +/- 4) or only diabetes [DM, I-: 52 +/- 4; DM, I+: 54 +/- 3 (mean +/- SE); P less than .05, ANOVA]. An increase in the accumulation of mesangial matrix in diabetic animals with Heymann nephritis was also apparent by light microscopy and immunofluorescence staining of the mesangium for fibronectin. Insulin treatment and control of hyperglycemia did not prevent the development of these changes. Animals with only Heymann nephritis had lesser amounts of immune deposits, which were limited to the subepithelial space and not associated with structural alterations of the mesangium.(ABSTRACT TRUNCATED AT 250 WORDS)

Failure of angiotensin converting enzyme inhibition to affect the course of chronic puromycin aminonucleoside nephropathy

The effects of the angiotensin converting enzyme (ACE) inhibitor enalapril on the proteinuria and degree of focal glomerular sclerosis hyalinosis (FSH) in chronic puromycin aminonucleoside nephropathy (PAN) were examined. Chronic PAN was induced in male Sprague-Dawley rats by seven subcutaneous injections of puromycin aminonucleoside (20 mg/kg) over 10 weeks (Groups I and II). Group II rats also received enalapril 10 mg/kg/day in the drinking water throughout the study (12 weeks). Group III rats served as age-matched controls. Proteinuria was similar in Groups I and II (35.5 +/- 9.7 versus 29.1 +/- 4.1 mg protein/mg creatinine, mean +/- SEM, P greater than 0.05). Serum creatinine remained unchanged in Group I, but rose from 0.7 +/- 0.04 to 1.2 +/- 0.1 mg/dl (mean +/- SEM, P less than 0.05) in Group II. FSH was 13.8% in Group I, 12.9% in Group II (P greater than 0.05), and 0.6% in Group III. There was no significant difference in glomerular lipid content and in immunofluorescence for rat albumin, fibrinogen, IgM, IgG, and C3 between Groups I and II. ACE activity was inhibited by 94% in serum, 83% in lungs, and 92% in kidneys; and blood pressure response to. Angiotensin I challenge was decreased by 50% in rats similarly treated with enalapril versus controls. In summary, proteinuria and glomerular sclerosis in this model are not affected by ACE inhibition.

Effects of oscillator frequency on phase-locking in the lamprey central pattern generator

The central pattern generator (CPG) for locomotion can be thought of as a chain of segmental oscillators coupled together that produces the basic locomotor pattern. The isolated spinal cord of the lamprey is an excellent preparation in which to formulate general principles for the operation of the CPG. The stability of the preparation and the ease with which surgical lesions can be made in the cord have allowed the study of the coordinating system with a convenience unobtainable in more complex vertebrates. Mathematical models have been developed to help analyze the CPG and other systems of coupled oscillators. The models have pointed to two important parameters for determining the relative timing of a system of coupled oscillators: the nature of the coupling and the difference in frequency among the oscillators. The latter is dealt with here. In lampreys, the frequency differences of the segmental oscillators along the cord can be quite large. This factor is shown to be related to changes in the intersegmental phase lags during serotonin modulation of fictive swimming. An understanding of some effects of the frequency difference is also shown to have been important in helping to formulate a protocol for the demonstration of functional regeneration in the isolated spinal cord preparation.

A comprehensive eye/vision program

As an essential element of the comprehensive rehabilitation efforts at Northport VA Medical Center, and as a service whose demand is projected to increase substantially with the expanding proportion of aging veterans, eye/vision care has become increasingly important. As a result, the administration of the Medical Center decided to heed the suggestions of Congress and the Director of Optometry in VA Central Office and reorganize the delivery of eye/vision services so the ever-increasing demand could be met more rationally, efficiently and effectively. In this paper, the Northport VA Medical Center's Comprehensive Eye/Vision Program, including the residency program in rehabilitative optometry, will be described and the benefits of the reorganization will be discussed.

Recurrent Henoch-Schönlein purpura following renal transplantation

A 20-year-old patient with Henoch-Schönlein purpura leading to end-stage renal failure received a living-related renal transplant. She was treated with conventional immunosuppressive therapy. Following a quiescent period of 18 months pretransplant, at 3 months after engraftment there was recurrence of purpuric lesions with subsequent abdominal pain and glomerulonephritis. Renal and skin biopsies confirmed the immunopathologic changes of Henoch-Schönlein purpura. This case represents the second report of an adult with multiorgan recurrence of Henoch-Schönlein purpura following transplantation.

The role of circulating antigen in the formation of immune deposits in experimental membranous nephropathy

To investigate the role of circulating antigen in the formation of subepithelial immune deposits in the Heymann rat model of membranous nephropathy, the renal uptake and site of renal deposition of intravenously injected renal tubular antigen (F X 1A) was studied. F X 1A, (15, 30, 60, and 600 micrograms) radiolabeled with 125I, and bovine serum albumin (BSA; 15 micrograms) labeled with 131I were intravenously injected into naive rats. Plasma clearance and organ uptake of brush border antigens were determined. Of the injected F X 1A, 75% was cleared from the circulation by 1 hr as compared to 10% of the BSA. Uptake of F X 1A by heart, lung, and spleen was less than 1% at all doses studied. Renal uptake of F X 1A (29.8 micrograms/g tissue) was greater than that for liver (4.75 micrograms/g), spleen, heart, and lung (each less than 1 microgram/g tissue). Evaluation of washed renal homogenate and isolated glomeruli confirmed specific tissue-associated F X 1A antigen. Direct immunofluorescence demonstrated deposits of F X 1A antigen along the glomerular capillary wall in animals injected with F X 1A. Small scattered electron dense deposits were demonstrated in the subepithelial space. Similar binding could be reproduced in vitro by incubating cryostat sections of normal rat kidney or isolated glomeruli with solubilized F X 1A antigens. Direct binding of a tubular antigen to a constituent of the glomerulus could initiate in situ immune complex formation, and may explain the variably demonstrable "cross-reactivity" of the Heymann antibody with the glomerular capillary wall.

Nephronophthisis. A primary tubular basement membrane defect

In order to characterize abnormalities in nephronophthisis, renal tissues from four patients were studied by light and electron microscopies and immunofluorescence using antibodies to laminin, type IV collagen, and tubular basement membranes (TBM). There were constant morphological alterations affecting TBM of all segments of the nephron, with or without cysts. These included extreme thinning and attenuation, layering, and thickening of these structures which ranged in size from 36 nm to 2000 nm. A combination of these features often affected the same TBM simultaneously, with abrupt transitions between different lesions. Although the ultrastructural TBM aberrations were observed in a wide variety of other chronic and acute renal disorders, they rarely occurred to the extent as in nephronophthisis or with abrupt transitions, both suggesting diagnostic significance. Laminin and type IV collagen were present in normal intensity and distribution, however, anti-TBM antibody staining was inconstantly reduced, perhaps signifying lack of a normal antigenic component in the TBM. These findings may well indicate the fundamental defect in nephronophthisis to be production of abnormal TBM, similar to the glomerular basement membrane lesions and consequences in Alport's syndrome.

Splenic immune deposits in bacterial endocarditis

Splenic and renal tissues from a 61-year-old man with subacute bacterial endocarditis and acute renal failure were studied. Immune complex deposits were found both within glomeruli and splenic venous sinus basement membranes, substantiating the systemic nature of the immune injury in this disorder. The splenic deposits may, in part, be responsible for the splenomegaly often present in endocarditis.

Yield of endomyocardial biopsy in patients with biventricular failure. Comparison of patients with normal vs reduced left ventricular ejection fraction

Twenty five patients with biventricular failure underwent endomyocardial biopsy procedures. Twelve of these 25 patients had normal left ventricular ejection fraction. Endomyocardial biopsy sampling was useful in eight of 12 patients (67 percent) with biventricular failure and normal left ventricular ejection fraction. Biopsy specimens in five of these 12 patients demonstrated endocardial or infiltrative heart disease and excluded these diseases in three other patients with constrictive pericarditis. This study suggests that the clinical presentation of biventricular failure, combined with the noninvasive determination of a normal left ventricular ejection fraction, is helpful in selecting patients for endomyocardial biopsy study. Patients with biventricular failure and normal left ventricular ejection fractions have a high probability of having pericardial or infiltrative heart disease, conditions that often can be differentiated only by analysis of myocardial tissue. Hemodynamic assessment of patients without infiltrative processes further allows one to eliminate those patients with a high likelihood of having constrictive pericardial disease.

Pharmacokinetics and pharmacodynamics of subcutaneous naltrexone pellets in the rat

Subcutaneous implantation of naltrexone pellets is a standard method of producing chronic blockade of opioid receptors. In the present experiments, rats were treated with two, 30-mg naltrexone pellets and the pharmacokinetics and pharmacodynamics examined. This dosing method produced high plasma naltrexone levels (350 ng/ml) by 1 hr which declined over an implant period of 192 hr (24 ng/ml). Approximately 40% of the systemically available naltrexone (15.6 mg) was released in the first 24 hr. A total of 39.8 mg was released over the 192-hr implantation period. At 192 hr after implantation, naltrexone produced a greater than 50-fold shift to the right in the dose-response curve for morphine analgesia relative to placebo-implanted controls. When naltrexone pellets were removed at 192 hr after implantation, morphine analgesia (10 mg/kg) returned with a time course that was inversely related to the elimination of naltrexone. Pharmacokinetic analysis indicated that naltrexone has a terminal elimination half-life of 4.6 hr. Probit analysis revealed a linear plasma level-response relationship for naltrexone antagonism of morphine analgesia with a plasma ED50 of 2.1 ng/ml when plasma morphine levels average 1126 ng/ml. In the rat, s.c. naltrexone pellets are a dosage form that provides a rapid release of systemic drug. The systemic availability of naltrexone continues for at least 192 hr after implantation. The high potency of naltrexone permits continued antagonism of morphine even when the systemic availability of naltrexone from the pellets has greatly diminished.

Functional regeneration following spinal transection demonstrated in the isolated spinal cord of the larval sea lamprey

Axons in the larval sea lamprey can regenerate across the site of a spinal cord transection and form functioning synapses with some of their normal target neurons. The animals recover normal-appearing locomotion, but whether the regenerating axons and their synaptic connections are capable of playing a functional role during this behavior is unknown. To test this, "fictive" swimming was induced in the isolated spinal cord by the addition of D-glutamate to the bathing solution. Ventral root discharges of segments above and below a healed transection showed a high degree of phase-locking. This strongly suggests that the behavioral recovery is mediated by regenerated functional synaptic connections subserving intersegmental coordination of the central pattern generator for locomotion.

Integrating ophthalmological and optometric services in a VA hospital program

Basic eye care has been available at the Veterans Administration Medical Center (VAMC), Northport, NY, for the past 20 years. The demand for these services increased as the mission of this medical center was broadened to include major medical and surgery services. Increased migration of veterans to Long Island and their subsequent aging further increased the demand for eye-vision care. Originally, primary eye-vision care was provided independently by optometry and ophthalmology services. There was unnecessary duplication of equipment and inappropriate utilization of providers. Consequently, the services provided were quite limited in scope and sophistication. Both patients and providers became disenchanted with this practice mode. In December 1983, the administration of the Northport VAMC approved the establishment of a coordinated eye-vision care program that integrates ophthalmological and optometric services in a matrix structure. Since the program became operational in April 1984, patient satisfaction has increased, the working relationships between optometrists and ophthalmologists have improved, the ophthalmology residency program has been upgraded, and the combined staff productivity has increased.

Postpartum renal failure in a patient with membranoproliferative glomerulonephritis type II

The previously reported detrimental effects of pregnancy on the course of membranoproliferative glomerulonephritis type II (MPGN type II) are limited and are usually considered to be mild. Based on these reports, a 19-year-old female with the diagnosis of MPGN type II who had stable renal function (creatinine 0.9 mg/dl) and a mild nephrotic syndrome with hypertension for 5 years of close follow-up was advised to complete her pregnancy. After a full-term pregnancy, complicated only by moderate nephrotic syndrome, a healthy female infant was born. Two weeks after delivery, the patient presented with acute renal failure and malignant hypertension, without evidence of hemolysis of hepatic failure. Immunologic parameters, including, C3, C4, antinuclear antibodies, circulating immune complexes as well as antibodies to glomerular basement membrane antigen and tubular basement membrane antigen were negative. Peritoneal dialysis was initiated and a renal biopsy was performed which showed MPGN type II with 50% crescents. Despite pulse therapy with methylprednisolone, renal function did not improve, resulting in the need for chronic dialysis. Although no specific nephritogenic mechanism was shown, the course of this patient should be considered when counseling female patients with MPGN type II, regarding the possibility of pregnancy exacerbating their disease, or resulting in rapidly progressive renal failure.

Adherence of Candida to cultured vascular endothelial cells: mechanisms of attachment and endothelial cell penetration

To elucidate the pathogenesis of hematogenous Candida infections, we developed an in vitro model of Candida adherence to and penetration of human endothelial cells. We enhanced or inhibited adherence in order to probe mechanisms of attachment. Adherence of Candida albicans showed a linear relation to Candida inoculum (range, 10(2)-10(5) cfu, r = .99, P less than .01) and exceeded that of less virulent Candida species and that of Saccharomyces cerevisiae (P less than .01). Candida immune serum blocked attachment (greater than 95% inhibition; P less than .001), however, this activity was abolished by immunoprecipitation of immune serum with C. albicans mannan (P less than .001) and was unaffected by immunoprecipitation with S. cerevisiae mannan or by adsorption with particulate chitin. Adherence was diminished by exposing C. albicans to heat (greater than 99% inhibition; P less than .01), UV light (98% inhibition; P less than .01), or sodium periodate (greater than 72% inhibition; P less than .01). An extract from heat-exposed C. albicans blocked adherence (greater than 51% inhibition; P less than .001). Transmission electron microscopy demonstrated that viable or killed Candida organisms were attached to endothelial cells, were enveloped by membrane processes from the endothelial cell surface, and were incorporated into the endothelial cells within phagosomes. Cytochalasin B blocked incorporation without blocking surface attachment.

Renal cholesterol granulomas: identification and morphological pattern of development

Cholesterol granulomas are infrequent and rarely described renal lesions occurring usually in the interstitium, characterized by clusters of foreign body giant cells containing ingested cholesterol crystals. Over a seven-year period, we observed them in 5 of 789 (0.6%) renal biopsies from patients with nephrotic syndrome of varying glomerulopathies. Four patients had renal insufficiency at the time of biopsy, while the fifth developed it within three months. To define the lesions we studied the morphogenesis of cholesterol granulomas by light and electron microscopy. Initially small cholesterol crystals formed in tubular epithelium; the crystals enlarged and were released into tubular lumina where they elongated or were passed in the urine. Further luminal growth caused the crystals to become lodged at some point in the nephron, distort and destroy tubule cells, and pierce through basement membranes with subsequent exposure to interstitial monocytes and formation of granulomas. It is likely these morphological abnormalities evolve from lipid disturbances in the nephrotic syndrome.

Reserpic acid as an inhibitor of norepinephrine transport into chromaffin vesicle ghosts

Reserpic acid, a derivative of the antihypertensive drug reserpine, inhibits catecholamine transport into adrenal medullary chromaffin vesicles. Since it does not affect the membrane potential generated by the H+-translocating adenosine triphosphatase but inhibits ATP-dependent norepinephrine uptake with a Ki of about 10 microM, reserpic acid must block the H+/monoamine translocator. Because reserpic acid is much more polar than reserpine, it does not permeate the chromaffin vesicle membrane, nor is it transported into chromaffin vesicle ghosts in the presence of Mg2+-ATP. Although it inhibits norepinephrine transport when added externally, reserpic acid does not inhibit when trapped inside chromaffin vesicle ghosts. Therefore, reserpic acid must bind to the external face of the monoamine translocator and should be a good probe of the translocator's structural asymmetry.

Increased analgesic potency of morphine and increased brain opioid binding sites in the rat following chronic naltrexone treatment

Implantation of rats with prolonged-release naltrexone pellets increased both morphine's analgesic potency in the tailflick assay and radiolabeled opioid binding in the brain. The increases in both radiolabeled opioid binding and morphine potency were time-dependent. Implantation for 24 hours did not increase binding, whereas increases of approximately 45% were seen following 8 days of implantation. Similarly, morphine's analgesic potency, measured as ED50 values, was increased by 50% following 8 days of exposure to naltrexone while a 24 hour exposure had no significant effect.

Serotonin modulates the central pattern generator for locomotion in the isolated lamprey spinal cord

The central pattern generator for locomotion in the spinal cord of the lamprey can be activated in vitro by the addition of D-glutamate to the bathing saline. Serotonin has no effects when bath-applied alone, but it modulates the D-glutamate-activated swimming pattern. Three major effects are observed: a dose-dependent reduction in the frequency of rhythmic ventral root burst discharge; enhancement of the intensity of burst discharge, due in part to the recruitment of previously inactive motoneurones; prolongation of the intersegmental phase lag. Motoneurone activation appears to result from enhanced synaptic drive from the central pattern generator; no direct effects of serotonin on the motoneurones themselves (resting potential, input resistance or threshold for action potential generation) were observed. Theoretical and experimental studies suggest that the prolongation of the intersegmental phase lag results at least in part from differential effects of serotonin on segmental oscillators in different parts of the spinal cord. Isolated caudal pieces of the cord were more strongly affected by serotonin than isolated rostral pieces. We propose that serotonin may be an endogenous modulator of the central pattern generator for locomotion in the lamprey. It may have a role in the generation of a family of related undulatory movements (swimming, crawling, burrowing) by a single central pattern generator.

Validation study of the New York State Optometric Association (NYSOA) Vision Screening Battery

The New York State Optometric Association (NYSOA) Vision Screening Battery was administered to 1983 grade school children. Complete visual examinations were performed on 125 children. A consensus method for determining a diagnosis was developed and a double-blind paradigm was used to validate the screening battery. The sensitivity was found to be 71.7% and the specificity to be 65%. When compared to the Snellen test, the NYSOA battery is far more sensitive. The Snellen test is 100% specific but misses 75.5% of the children found to have vision problems when given a complete visual examination.

Glomerular capillary aneurysms in light-chain nephropathy. An ultrastructural proposal of pathogenesis

The occurrence of glomerular capillary aneurysms in light-chain nephropathy and a morphologic pattern of development as determined by electron microscopy are described. Renal biopsies from 4 patients with nodular glomerulopathy were evaluated. Light-chain deposition in mesangium and capillary walls was associated with monocyte accumulation in capillaries. Loss of endothelial cell lining and disruption of mesangial anchoring points of basement membranes ensued, resulting in aneurysmal dilatation of the capillaries. The walls collapsed, and the aneurysms healed as a result of mesangial interposition, a process which, in combination with enlarging nodules, led to thickening and collapse of the walls and narrowing of the lumens. This study, in conjunction with review of photographs from previously published reports, indicates that glomerular aneurysms are a common feature of nodular light-chain glomerulopathy. It also emphasizes additional light-microscopic similarities between this glomerulopathy and nodular diabetic glomerulosclerosis.

Effectiveness of visual therapy for convergence insufficiencies for an adult population

Visual therapy has long been considered an appropriate treatment for children with functional problems. The authors have expanded the parameters of effectiveness to include adults with convergence insufficiency.