Ultrastructural changes of posterior lingual glands after hypoglossal denervation in hamsters

Posterior lingual glands consist of two sets of minor salivary glands that serve important functions in oral physiology. To investigate the hypothesis that the hypoglossal nerve provides sympathetic innervation to the posterior lingual glands, we examined ultrastructural changes in the glands following hypoglossal denervation. In the posterior deep lingual glands (of von Ebner), the serous acinar cells showed a decrease in the number of secretory granules and an increase in lipofuscin accumulation. The ratios of cells containing lipofuscin granules were 11.39, 36.49 and 50.46%, respectively, of the control, 3- and 7-day post-axotomy glands (P < 0.001). Intraepithelial phagocytotic activity was increased. The mucous acinar cells in the posterior superficial lingual glands (of Weber) also showed degenerative changes after hypoglossal denervation. One week after nerve transection, marked cytoplasmic vacuolation and fragmentation of organelles were frequently observed. Degenerative changes were also found in unmyelinated axons associated with the glands. We provide the first evidence of the structural and functional connections between the sympathetic component of the hypoglossal nerve and posterior lingual glands.

Hyponatremia in hospitalized children

To determine the frequency, causes, and clinical significance of hyponatremia in hospitalized children, we reviewed the clinical and laboratory data of all hyponatremic children in Texas Children's Hospital over a 12-month period. One hundred sixty-one patients from among 11,702 hospital admissions were found to have hyponatremia, defined as serum sodium value of less than 130 mEq/L, an overall frequency of 1.38%. Sixty-nine patients (43%) had hyponatremia on admission, and 92 patients (57%) had hospital-acquired hyponatremia. Thirty-seven (23%) were previously healthy children, and 124 (77%) had chronic illnesses. Acute gastroenteritis was the leading cause of hyponatremia present on admission, and diuretic therapy was the leading cause of hospital-acquired hyponatremia. Only four patients (2.5%) had a serum sodium concentration of less than 120 mEq/L. Six patients (3.7%) had neurologic impairment on discharge, and 19 patients (12%) ultimately died long after their hyponatremia was corrected. Each patient who had neurologic sequelae and each patient who died had underlying medical conditions which could explain their morbidity and/or mortality. The prognosis appears to be more clearly related to the underlying medical disorder rather than to the hyponatremic state or its correction.

Glomerular hypertrophy in minimal change disease predicts subsequent progression to focal glomerular sclerosis

The study sought a diagnostic clue to identify the group of pediatric patients with apparent minimal change disease who subsequently develop focal glomerular sclerosis (FGS). Review of all renal biopsy material at our institutions identified 42 pediatric patients who met the standard criteria for minimal change disease (MCD) on initial biopsies. Of those, 10 deteriorated clinically and on rebiopsy showed focal glomerular sclerosis (FGS). The initial renal biopsies of these 10 patients were analyzed morphometrically to determine the mean glomerular tuft area (GA). The results were compared to those of the remaining 32 patients whose subsequent benign clinical course was consistent with MCD, and to randomly selected, age-matched autopsy controls without renal disease (CONT, N = 10). The mean age was comparable among the three groups studied. Separate groups of adult (N = 12) and pediatric (N = 18) patients with initial biopsies with FGS were also studied. The initial biopsy of pediatric patients who subsequently showed FGS (rebiopsy performed on average 3.3 years later) had an average GA of 13.5 x 10(-3) mm2, 76% larger than glomeruli from children with MCD (7.7 x 10(-3) mm2, P less than 0.0005) and 62% larger than CONT (8.4 x 10(-3) mm2, P less than 0.005). Patients with FGS on initial biopsy, whether adult or pediatric, also had significantly larger GA than the age-matched MCD or CONT groups. Evaluation of GA in all the 42 pediatric biopsies with initial MCD further showed that in 23 patients GA was equal to or smaller than the CONT average.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic and prognostic significance of glomerular epithelial cell vacuolization and podocyte effacement in children with minimal lesion nephrotic syndrome and focal segmental glomerulosclerosis: an ultrastructural study

Children with minimal lesion nephrotic syndrome (MLNS) may later develop focal segmental glomerulosclerosis (FSGS). It has been suggested that a low percentage of epithelial podocyte effacement (EPE) and a high degree of epithelial cell vacuolization (ECV) in nonsclerotic glomeruli presage FSGS, and that extensive epithelial cell vacuolization in biopsies clearly showing FSGS predicts a poor clinical outcome. To investigate these contentions, we examined by electron microscopy three glomeruli from each of the first biopsies of 30 patients. Ten patients (group 1) had MLNS, 10 (group 2) had FSGS, and 10 (group 3) had MLNS which progressed to FSGS. Clinical data was obtained by retrospective review of medical records. The percent of epithelial podocyte effacement was calculated by computerized linear tracing and epithelial cell vacuolization was scored semiquantitatively from 0-3. (formula; see text) The percent podocyte effacement in each group was the same and does not distinguish MLNS from FSGS. Group 2 had more extensive epithelial cell vacuolization than group 1 (p less than 0.04) and the same as group 3 (p = 0.16). The combined ECV score for groups 2 and 3, however, was significantly greater than for group 1 (p less than 0.025) suggesting that epithelial cell vacuolization may indeed be a marker of FSGS. The extent of epithelial cell vacuolization did not correlate with creatinine clearance at latest follow-up, and thus does not predict clinical outcome.