Chlamydia trachomatis pneumonitis in the C57BL/KsJ mouse: pathologic and immunologic features

Pneumonitis occurred in both normal and diabetic C57BL/KsJ mice, inoculated with a Chlamydia trachomatis strain isolated from a human infant . Animals were inoculated intranasally under light ether anesthesia. Control animals receiving carrier medium did not develop pulmonary disease. The pneumonitis was focal and involved interstitial and peribronchial structures. Pathological changes were most pronounced at 10 to 14 days after inoculation, but no animals died of their disease. The early cellular response was polymorphonuclear (4 to 6 days); this was followed by a predominantly mononuclear cell infiltrate. Immunopathological examination revealed immunoglobulin- and complement-bearing cells in a peribronchial distribution, corresponding to the mononuclear infiltrates seen by light microscopy. Infected animals seroconverted to C. trachomatis. Specific antichlamydial IgM antibody was detected at days 6 through 21 and higher titer IgG at days 10 through 28. Splenic lymphocyte stimulation responses to chlamydial antigen were observed at 10 and 21 days. C. trachomatis was cultured only from 6-day lung tissue. The histopathological and immunopathological features of the pneumonitis were similar in normal and diabetic mice. In addition, humoral and cellular immunoresponsiveness to chlamydial infection were not compromised in the diabetics. This animal model resembles human infant chlamydial pneumonitis in its pathological manifestations and may increase our understanding of the human disease.

Correlation between the infrared and visible extinction coefficients of fog

It is demonstrated that measuring extinction coefficients at frequent time intervals enables one to observe fog-evolution processes in which the infrared and visible extinction coefficients are well correlated. Less-frequent measurements can lead to erroneous interpretations.

A management science approach to contingency models of organizational structure

This study demonstrates the applicability of a quantitative modeling approach, specifically goal programming, in operationalizing the relationship between environmental variables and specific organizational structural variables for optimal goal attainment. A goal programming model is developed to analyze and determine the optimal relationships for goal attainment.

The effect of a high fibre diet on diabetic nephropathy in the db/db mouse

Genetically diabetic mice (C57 BLKsJ db/db) aged 5-6 weeks were given a diet containing 20% by weight of non-nutritive bulk and compared with age matched control diabetic mice on a normal diet (fibre content 4.5%) and non-diabetic mice. The duration of study was 12 weeks. No adverse effects were observed in animals given the high fibre diet. Total food consumption was greater in mice receiving the fibre enriched diet, but their absolute caloric intake was 6% less than control diabetic mice. Both groups exhibited similar rates of growth and development. Water intake in the experimental diabetic mice was reduced and similar to that of normal non-diabetic mice. Fasting blood glucose was significantly decreased in the experimental diabetic mice at 12 weeks. Renal pathological lesions in the control diabetic mice showed glomerular mesangial expansion and deposition of immunoglobulins within the mesangium. The experimental diabetic animals exhibited significantly less renal pathology, including light and immunofluorescent lesions. It is concluded that addition of non-absorbable fibre to the diet of genetically diabetic mice improves glycaemic control and retards the development of diabetic nephropathy.

IgA nephropathy: morphologic predictors of progressive renal disease

IgA nephropathy has a variable course and leads to renal failure in a substantial number of cases. In an attempt to identify prognostic indicators in this disease, we evaluated the clinical and pathologic findings of 20 unselected patients with IgA nephropathy, 13 of whom were followed for 1.5 to 5 years (mean 2.8 years). Biopsy specimens were obtained from all patients and were examined by light and electron microscopy and by immunofluorescence. The activity and severity of the lesions were graded according to a modified classification used by Meadow et al. for the nephropathy associated with Henoch-Schönlein purpura. The results reveal a correlation between the histopathologic grading in the initial biopsy and the clinical outcome: Patients with mild (grade II) or moderate (grade III) lesions had a benign course or showed evidence of active disease without deterioration of renal function, whereas all patients with grade IV or V lesions who were followed for more than one year developed end-stage renal failure. These observations suggest that histologic grading at initial renal biopsy may be a useful prognostic indicator of the clinical outcome of IgA nephropathy.

The effect of chronic alpha-glycosidase inhibition on diabetic nephropathy in the db/db mouse

Acarbose, a complex oligosaccharide, is a potent competitive inhibitor of sucrase and decreases postprandial hyperglycemia when administered with food. To evaluate its potential for metabolic control and prevention of diabetic nephropathy, groups of gentically diabetic mice (C57 BLKsJ db/db) were treated with Acarbose for 10 wk. Control mice received normal chow and experimental groups were given Acarbose prepared as a drug-food mixture in doses of 10, 20, and 40 mg/100 g of food. Acarbose did not influence fasting blood glucose, food intake, or the normal development of obesity in the mice. Urinary glucose excretion and glycosylated hemoglobin was significantly reduced in animals receiving high-dose Acarbose (40 mg/100 g food). Immunopathologic examination of the kidneys showed a dose-dependent decrease in glomerular mesangial immunoglobulin deposition. By light microscopy, glomerular mesangial thickening was significantly reduced in the group receiving high-dose Acarbose (40 mg/100 g food). To the extent that Acarbose improves metabolic control in the db/db mouse, chronic treatment with this agent produces a dose-dependent amelioration of diabetic nephropathy. Alphaglycosidase inhibition may be a useful adjunctive therapy for blood glucose control in diabetes mellitus.

Dexamethasone suppressible hyperaldosteronism in a child with nephrosclerosis

A 9 year old Mexican boy presented with severe hypertension, hypokalaemia and features suggesting acute glomerulonephritis. Nephrosclerosis was present on renal biopsy. Aldosterone levels were unresponsive to variations in dietary salt intake and plasma renin activity was suppressed. Following oral dexamethasone therapy (2 mg/day), plasma aldosterone decreased to undetectable levels, serum potassium normalized and plasma renin activity gradually increased. Dexamethasone also restored the normal responsiveness of the renin-aldosterone system to postural stimuli. The patient exhibited a marked response to a single dose of ACTH with a rise in plasma aldosterone. Long-term blood pressure control and normal potassium levels have been achieved with oral prednisone therapy (5 mg/day) for a period of one year. This case of dexamethasone suppressible hyperaldosteronism (DSH) illustrates that the degree of hypertension in this syndrome may produce severe renal microvascular lesions. DSH should be considered in all children who present with low renin hypertension.

CT determination of renal and hepatic microvascular volumes in experimental acute renal failure

Alterations in renal blood flow are considered to play an important role in the pathogenesis of acute renal failure. Most techniques designed to assess organ blood flow and microcirculatory disturbances are relatively invasive and cumbersome. This study describes a noninvasive method for the determination of an organ's fractional vascular volume (FVV)-the fraction of an organ occupied by blood vessel lumen. It utilizes computed tomographic (CT) scanning and a contrast agent, perfluoroctylbromide (PFOB), which remains intravascular and is not excreted by the kidney. Acute renal failure (ARF) was induced in rats by intraperitoneal injection of glycerol (5 g/kg). CT scans of kidneys, liver, and heart were performed prior to and following intravenous administration of PFOB. FVV of kidney and liver were calculated prior to induction of ARF and at selected time periods following ARF (20-50 minutes and 60-120 minutes). FVV of the kidney decreased significantly 20-50 minutes following ARF and had returned to control values at 60-120 minutes. Renal histologic abnormalities were more severe at the later time period. Thus, early alterations in blood flow precede pathologic abnormalities in the kidney following glycerol-induced ARF. Determination of an organ's fractional vascular volume is a simple noninvasive technique which provides useful information on the microcirculation during the course of experimental disease.

Metabolic control of prevention of nephropathy by 2-tetradecylglycidate in the diabetic mouse (db/db)

The genetically diabetic mouse (db/db) exhibits hyperphagia, progressive weight gain, hyperglycemia, and hyperinsulinemia during the first few months of life during which time characteristic pathologic changes occur in several organ systems including the kidney. The extent to which long chain fatty acid oxidation (LCFAO) contributes to excessive gluconeogenesis and hyperglycemia in these animals in unknown. Therefore, the synthetic fatty acid analogue 2-tetradeclyglycidate (TDHA), a potent inhibitor of LCFAO, was given orally to db/db mice to evaluate its capacity to control the blood glucose and prevent their diabetic nephropathy. Five groups of diabetic mice (N = 6) were assigned to receive TDGA in a dose of 5, 10, and 25 mg/kg/day, vehicle (tragacanth), or nothing (control). TDGA had no observable effects on food intake or growth patterns. Drug-treated animals had significant lowering of fasting glucose at 0 and 4 h after dosing during the midportion of the study (2-6 wk). In the latter part of the study (wk 8-11), blood glucose 4 h after dosing was lowered in mice given 10 and 25 free fatty acids. Animals receiving TDGA 25 mg/kg/day exhibited significant inhibition of immunopathologic changes in the kidney. Heart weight was significantly increased in mice receiving TDGA 25 mg/kg/day, and the total amount of myocardial carnitine content was increased in all three drug-treated groups. Increased tissue deposition of lipid was not apparent on histologic examination of liver in drug-treated animals. Inhibition of long chain fat oxidation in the db/db mouse results in significant lowering of blood glucose, and decreased the renal immunopathologic features of diabetic nephropathy in this animal model.

Mouse liver glutathione S-transferases. Biochemical and immunological characterization

Three major forms of cytosolic glutathione S-transferase (designated F1, F2, and F3 transferases according to increasing isoelectric points) were purified to homogeneity from liver of DBA/2J mice, primarily by CM-cellulose and hydroxylapatite chromatography. The purified enzymes were shown to have specific activities of 104, 281, and 143 units/mg, respectively, when assayed with 1 mM each of 1-chloro-2,4-dinitrobenzene and reduced glutathione. Antisera against these three forms of mouse transferase were raised separately in rabbits. F1 and F2 transferases showed complete immunological identity either by double immunodiffusion or enzyme immunoinactivation tests. No cross-reactivity was observed between the antisera to F1 (or F2) transferase an F3 transferase or between the antisera to F3 transferase and F1 (or F2) transferase. F1 and F2 transferases were shown to be homodimers with an identical molecular weight of 44,000 +/- 1,000, whereas F3 transferase has a dimeric molecular weight of 51,000 +/- 2,000. The amino acid composition and tryptic peptide map of F1 transferase are similar to those of F2 transferase, but are distinct from those of F3 transferase. In addition to these major forms, a minor form of mouse transferase (F4) with a high isoelectric point (greater than 9.5) was shown to be a mixture of interconvertible isomers of F2 and F3 transferase. Different forms of mouse transferase were studied extensively with respect to their biochemical properties, including Michaelis constants, substrate specificity, thermal stability, and fluorometric ligand binding. The results of this study suggest great species variations regarding the multiple forms as well as the substrate specificity of this family of enzymes.

Clodronate kinetics and dynamics

Clodronate disodium (Cl2MDP) was given intravenously in doses of 3, 6 and 10 mg/kg to six men (aged 23 to 30 yr). Volume of distribution was 0.2720 +/- 0.0255 l/kg (mean +/- SD) after 3 mg/kg dose, 0.3037 +/- 0.0445 l/kg after 6 mg/kg, and 0.2528 +/- 0.417 l/kg after 10 mg/kg. The elimination rate constant was 0.3787 +/- 0.0546 hr(-1), 0.3492 +/- 0.0616 hr(-1), adn 0.3962 +/- 0.0358 hr(-1) after 3, 6, and 10 mg/kg. Corresponding total body clearances were 0.1026 /+- 0.0149, 0.1049 +/- 0.0159, and 0.0998 +/- 0.0172 l/kg/hr. Renal clearance accounted for 73% of total body clearance; 73% of the drug was extracted unchanged in the urine in 24 hr. After Cl2MDP serum phosphate decreased approximately 13%; this was associated at the 10 mg/kg dose with a transient fall in fractional phosphate excretion. There was no significant changes in the serum concentration of fractional excretion of calcium, sodium, or uric acid. Creatinine clearance and renal concentrating ability were not altered by Cl2MDP. After short-term administration Cl2MDP is excreted primarily by the kidney but has no significant effects on renal function.

Adrenal glomerulosa function in patients with dexamethasone-suppressible hyperaldosteronism

The response of the adrenal glomerulosa to renin stimulation was determined in 10 patients with dexamethasone-suppressible hyperaldosteronism. The patients were treated continuously with 2 mg/day dexamethasone (DEX) and were studied on a regular sodium diet (87 meq/m2 . day) and on a 10 meq/day sodium diet. With DEX treatment all patients showed a prompt suppression of adrenal fasciculata function as evidenced by suppression of serum cortisol, corticosterone, desoxycorticosterone, and urinary 18-OH-desoxycorticosterone. The complete suppression of urinary pH 1 aldosterone (aldo) by DEX, unique to this disorder, was paralleled by a prompt suppression of urinary 18-OH-corticosterone. With continued DEX administration, plasma renin activity rose to the normal or supranormal range. Dietary sodium restriction resulted in a further rise in plasma renin activity and a rise in urinary pH 1 aldo and 18-OH-corticosterone. We conclude that in DEX-suppressible hyperpaldosteronism, although ACTH appears to be the primary stimulus for aldo secretion in the untreated state, when ACTH is suppressed, the adrenal glomerulosa responds normally to the stimulation of renin-angiotensin II.

Prevention of diabetic nephropathy by diet control in the db/db mouse

Diabetes in the C57BL/KsJ(db/db) mouse is initially expressed as hyperinsulinemia, followed by hyperphagia, progressive obesity, and widespread pathologic abnormalities. This study was designed to evaluate the effects of metabolic control on the natural history of the diabetic nephropathy. Beginning at 1 mo of age and continuing for 12 wk, diabetic mice were subjected to controlled dietary restriction, such that their weight was maintained similar to that of age-matched, nondiabetic heterozygotes. Diet-restricted diabetics were compared with diabetics fed ad libitum and heterozygote nondiabetics. Significant lowering of fasting blood glucose, water intake, and plasma insulin was achieved by diet restriction. The diet-restricted diabetes demonstrated enhanced metabolic efficiency, consuming approximately half as much food as the nondiabetics, while maintaining a similar weight. Diabetics fed ad libitum evidenced well-defined renal lesions that included 3 + to 4 + immunoglobulin deposition in the glomerular mesangium, and generalized mesangial matrix expansion. These lesions were completely prevented in diet-restricted diabetes whose glomeruli were normal light microscopy, and demonstrated trace to 1 + mesangial immunoglobulin deposition, features identical in all respects to the nondiabetics. These results indicate that diabetic control achieved by preventing of obesity in the db/db mouse prevents the development of diabetic nephropathy.

Renovascular hypertension from segmental renal artery stenosis: importance of segmental renal vein renin sampling

We report a case of severe hypertension in a girl with no evidence of parenchymal renal disease. Arteriography revealed segmental stenosis and a saccular aneurysm affecting a branch of the left renal artery. Segmental renal vein renin sampling demonstrated a markedly increased rate of renin secretion from the ischemic portion of the left kidney. Partial nephrectomy resulted in normalization of the blood pressure. The resected kidney showed striking hyperplasia of the juxtaglomerular apparatus and medial fibromuscular dysplasia as the etiology of the arterial stenosis. This case emphasizes the value of segmental renin vein sampling in the evaluation of pediatric hypertension and illustrates the high cure rate obtained by surgical correction.

Identification and biochemical analysis of mouse mutants deficient in cytoplasmic malic enzyme

During the biochemical screening of mutant enzymes in mice, individuals with an apparent nonfunctional allele at the locus (Mod-l) responsible for cytoplasmic malic enzyme were identified by starch gel electrophoresis and by enzyme activity measurements. A series of matings and genetic analyses were made, and mice homozygous for the nonfunctional or null allele (Mod-ln) were produced. The mutation appeared to occur spontaneously in the C57BL/6J strain. By double-immunodiffusion and enzyme immunoinactivation assays, the null mutants were shown to express no proteins that cross-react with the antiserum to cytoplasmic malic enzyme (CRM-negative). In liver homogenates of homozygous null mutants, lack of protein components that form complexes with IgG from the cytoplasmic malic enzyme specific antiserum was further demonstrated by passage of the original serum through a mutant liver homogenate--Sepharose column, where the postadsorbed serum retained its titer and specificity. The residual malic enzyme activity (< 10% of the normal) observed in various tissue homogenates of the homozygous null mutants was attributed to that of mitochondrial isozyme of malic enzyme. Assays of enzymes from tissues of different genotypes revealed no significant differences in activities of six other enzymes in the related metabolic pathways. However, in liver from mutant mice, a lower NADPH/NADP+ ratio was consistently observed in comparison to that from control mice. Both the mutant and the control mice of the same age were found to have comparable body weight and lipid content.

The use of double-lumen tubes in upper gastrointestinal surgery

The use of a double-lumen tube for simultaneous gastric suction and jejunal feeding is described. This eliminates the need for a separate jejunostomy. Not only is the chance of complication reduced, but also the operating time is shortened and nursing care is simplified. The management of a case of completely transected duodenum, of a pancreatic abscess, and of a case of prolonged gastric retention and atony is presented to illustrate the usefulness of the tube. Each patient received adequate nourishment by jejunal feeding while gastric suction was continued.

In vivo barium microangiography in the mouse

Barium microangiography is an accepted method for study of the microcirculation. Nonetheless, no method has been previously described for use in mouse models of renal microangiopathy. Using a midline abdominal approach on each of seven anesthetized A/J mice, we inserted a No. 27 lymphangiogram needle into the infrarenal aorta. Using a Harvard pump, the animals were perfused first with 20 ml of 1% glutaraldehyde, then 20 ml of 10% barium sulfate suspension, at 150 mmHg constant pressure. Kidney sections were radiographed onto high-resolution glass plates. Photomicrographs of these images were then enlarged to 5 x 7-inch prints, from which we derived our observations. We observed the normal branching pattern of the renal microcirculation. Mean interlobular artery diameter was 31.89 +/- 2.12 micron SD. Afferent arterioles tapered to a mean preglomerular diameter of 13.55 +/- 1.64 micron. Mean glomerular area was measured to be 2945 +/- 233 sq micron. We have developed a method of renal barium microangiography in the mouse. Desirable features of the technique include its performance on living animals and resolution sufficient to permit objective measurements of microvascular structures.

Focal glomerular sclerosis and sarcoidosis

Idiopathic nephrotic syndrome occurred in a patient with sarcoidosis. Typical features of focal segmental glomerulosclerosis were present on kidney biopsy. A unique finding was the occurrence of IgA in blood vessels of the skin and lymph node. Whereas the sarcoid hilar adenopathy responded to steroid therapy, the nephrotic syndrome was resistant to steroids and immunosuppression. Evaluation of humoral and cellular immune responsiveness showed no abnormalities except cutaneous anergy. Glomerulonephritis is uncommon in sarcoidosis, and a brief outline of this association is included. This patient is of importance in view of the unexplained relationship between idiopathic nephrotic syndrome and T lymphocyte abnormalities.

Prune-belly syndrome in a 54-year-old man

A 54-year-old man was diagnosed as having prune-belly syndrome, a deficiency of abdominal musculature, cryptorchidism, abnormalities of the urinary tract, and chronic renal failure. The patient was asymptomatic until the diagnosis was made at the age of 54 years; he is one of the oldest living patients to be reported in detail. Recognition of the syndrome in adults with chronic renal failure is important.

Renal acidification in sickle-cell disease

Renal acidification was evaluated in patients with sickle-cell disease (HvSS) with both oral NH4CI and NaHC03 and the results were compared to those of subjects with sickle-cell trait (HbAS) and controls. The pH of arterial blood was normal in HbSS subjects but their PC02 and [HC03] were lower than those of controls. In response to NH4CI, six of 20 HbSS subjects had an abnormal minimal urine pH (greater than 5.3) and the entire HbSS group had a higher mean value than did either controls or HbAS subjects. Since none of the six HbSS subjects had evidence of proximal tubular abnormalities, it was concluded that they exhibited the syndrome of incomplete distal renal tubular acidosis. Only one of the six HbSS volunteers with an abnormal response to NH4CI and two of seven with a normal response increased their urinary PC02 normally after bicarbonate loading. PAH clearance was significantly higher and inulin clearance tended to be higher in HbSS subjects than in either controls or HbAS subjects. Maximal concentrating ability was decreased in both sickle-cell groups but more so in HbSS. No adverse effects occurred and no appearance or increase in per cent of sickled cells resulted from short-duration NH4CI acid-loading. No differences were found either in the clinical characterstics or in hematological, renal, and acid-base variables between the HbSS subjects with and without a normal response to acid-loading. The mechanism for the observed renal acidification abnormality remains unknown.

Renal acidification in sickle cell trait

Nine sickle cell trait and nine control subjects underwent six-hour ammonium chloride acid loading. Maximal urine osmolality and renal hemodynamics were studied separately. Base line arterial pH, carbon dioxide pressure (Pco2), and [HCO3] were normal and comparable in the two groups. After ammonium chloride loading, urine pH decreased to 5.3 or less in all, and maximal excretion of ammonium and titratable and net acid was comparable as was urine minus blood Pco2 after bicarbonate loading. The ammonium chloride acidosis caused a small decrease in red blood cell 2,3-diphosphoglycerate levels but no alteration in oxygen pressure at 50% saturation at pH 7.4, sickling, or adverse effects. Control and sickle cell trait subjects had comparable renal hemodynamics but maximal urine osmolality was lower in sickle-cell trait subjects. Adults with sickle cell trait have diminished renal concentrating ability and normal renal acidification and hemodynamics.

Analysis of acetoin and diacetyl in bacterial culture supernatants by gas-liquid chromatography

The acetoin and diacetyl contents of culture supernatants of Voges-Proskauer-positive "viridans" streptotocci, Klebsiella pneumoniae and Staphylococcus aureus, were determined by a gas liquid chromatographic procedure, in which supernatants were extracted with diethyl ether and diacetyl was measured on columns of 10% (wt/wt) polyethylene glycol 400 (PEG 400) at 73 C. Acetoin was converted to diacetyl, before analysis, by a simple oxidation procedure with ferric chloride and without a distillation step. Streptococcal culture supernatants were shown by this method to contain only acetoin; supernatants of K. pneumoniae and S. aureus contained both acetoin and diacetyl.