Microsurgical management of old injuries of the peripheral nerve and brachial plexus

A prospective study was carried out in patients suffering from old peripheral nerve and brachial plexus injuries to attempt to validate that functional improvement was possible after microsurgical management. Fifty patients underwent operative procedures, of whom 35 were peripheral-nerve injury cases, from 1.2 to 50 years after injury, and 15 were brachial-plexus injury cases, from 1.2 to 12 years after injury. The patients were treated by external and interfascicular neurolysis and/or autogenous nerve grafts. In cases of preganglionic nerve injury, neurotization from C3, C4 roots was done for reinnervation of trunks or cords. During external and interfascicular neurolysis in 19 of the 35 peripheral-nerve injuries, significant improvement was found in amplitude (p = 0.0001) and latency (p = 0.01) of compound muscle action potentials (CMAPs) at the end of the surgery, compared to the onset of surgery. Twenty (57 percent) of the 35 showed functional motor improvement up to M4-or M4. Electrophysiologic analysis of amplitude of CMAPs 1 year after surgery showed statistically significant improvement (p = 0.0003). Five (33 percent) of the 15 patients with upper brachial-plexus injuries showed functional motor improvement up to M4-(active movements against gravity and slight resistance) or M4 (active movements against gravity and moderate resistance) after surgery and of these, 11 also had lower brachial-plexus injuries, with four (36 percent) showing antigravity function M3 (active movement against gravity). Statistical analysis of recruitment 1 year after surgery demonstrated the appearance of or significant voluntary muscle activity in 45 percent of the muscles. Intraoperative electrophysiologic findings after external and interfascicular neurolysis confirmed that the viability of nerve tissue is of longer duration than previously considered. This study suggests that the use of microsurgical techniques results in the functional improvement of patients suffering from old injuries of the peripheral nerve and brachial plexus.     

C1q nephropathy presenting as rapidly progressive crescentic glomerulonephritis

C1q nephropathy is an immune complex glomerulonephritis defined by the presence of mesangial immunoglobulins and complement deposits, most notably C1q, and the absence of clinical and laboratory evidence of systemic lupus erythematosus. Histology in C1q nephropathy is characterized by a slight to severe increase in mesangial cellularity and matrix, with or without segmental sclerosis. C1q nephropathy usually presents with nephrotic-range proteinuria in older children and young adults, and has a poor response to steroids. Patients may have decreased creatinine clearance at presentation, but progression to end-stage renal disease (ESRD) is slow. Severe crescentic glomerulonephritis has not been reported in C1q nephropathy. We describe a 3-year-old Hispanic girl who presented with renal insufficiency. Kidney biopsy showed C1q nephropathy with severe crescentic glomerulonephritis. The clinical and serological evaluation ruled out systemic lupus erythematosus or other immunological or infectious etiologies. In spite of immunosuppressive therapy, she progressed to ESRD within 14 weeks and is currently on chronic peritoneal dialysis. The atypical features of C1q nephropathy observed in our patient, which have not been described in earlier reports, are an early age of onset, severe crescentic glomerulonephritis, and rapid progression to ESRD. C1q nephropathy should be added to the differential diagnosis of glomerulonephritis in young children and in the patient with crescentic glomerulonephritis.     

Success and safety of same-day kidney biopsy in children and adolescents

Renal biopsy is crucial for the diagnosis, management, and monitoring of many kidney diseases. Although percutaneous renal biopsy is considered a routine safe procedure in children, the optimal length of in-hospital observation following the procedure is not yet known. We prospectively studied two comparable groups of children to compare the success and safety of performing native renal biopsy as an outpatient procedure versus keeping the children hospitalized post biopsy. Doppler ultrasonography of the biopsied kidney was performed approximately 2 weeks after the procedure. For 40 children the biopsy was performed on a same-day basis (study group) and another 15 children were kept for overnight observation (control group). All biopsies yielded adequate tissue for histopathological diagnosis. There was no difference between the two groups in the amount of reported pain and analgesics used after the procedure. Only 1 child in the study group was readmitted 5 days after the biopsy for 48 h, but no major complications were detected. The incidence of post-biopsy intra- or perirenal hematoma detection by sonography was not statistically different between the two groups (39% study group, 43% control group). Follow-up imaging studies were performed on 10 of the 20 children who had an early post-biopsy hematoma and all were completely normal. Patients and their families appreciated being discharged home the same day. In addition, total charges for hospitalization were significantly less for the study group than the control group. We conclude that in selected patients, same-day discharge after renal biopsy may be performed safely without an increased risk of complications.     

Protein intake and renal function in children

To evaluate the effects of protein intake on renal tubular functions, seven metabolic studies were performed on five adolescents with mild, chronic renal insufficiency. After equilibration, patients were randomly assigned to two periods of four days each on either a high-protein diet (HPD) or a low-protein diet (LPD), with energy intakes remaining the same during both periods. High protein intake resulted in significantly higher mean (+/- SD) daily creatinine excretion and clearance rates. The HPD was associated with significantly increased excretion rates of potassium, phosphate, sulfate, and calcium. Net acid excretion with the HPD was nearly threefold higher than that observed with the LPD. These differences were unassociated with urinary pH, which remained similar with both diets. We conclude that different protein intakes affect urinary excretion of creatinine, potassium, phosphate, sulfate, calcium, and net acid.     

Post-obstructive urinary concentrating defect. A case study in the role of prostaglandins

A child with post-obstructive urinary concentrating defect was studied for the possible pathophysiological role of prostaglandins and an eventual therapeutic approach. Increased urinary excretion of prostaglandins was corrected by indomethacin, with resultant increased nephrogenous cyclic AMP and partial improvement in the concentrating defect. The addition of a thiazide restored urinary concentration. These results add clinical support to the conception of the important role of prostaglandins in the mechanism of post-obstructive hyposthenuria. This therapeutic regimen is advocated for prolonged post-obstructive concentrating defect.     

Effects of nonischemic hypoxia on jejunal mucosal structure and function: study of an experimental model in dogs

A model of nonischemic hypoxia of the jejunum was designed in dogs, by shunting of blood from the inferior vena cava directly into the regional mesenteric arterial supply, thereby lowering the PaO2 of the blood that reached the jejunal wall from 98.6 +/- 3 to 62 +/- 5 mm Hg. Absorption rates of sodium, glucose, fructose, glycine, and the dibasic aminoacid lysine were studied by in situ luminal perfusion of a 30-cm proximal jejunal segment with a bicarbonate buffer solution containing phenol red as a nonabsorbable marker for determination of water fluxes. During periods of control, hypoxia, and after discontinuation of the venoarterial admixture (recovery), effluent perfusate was collected and mucosal biopsies were obtained for assay of lactase, maltase and sucrase activity, mucosal ATPase activity and ATP content, and for light- and electron microscopic examination. Mesenteric supply with hypoxic blood was associated with a significant inhibition of Na+,K+-ATPase activity (p less than 0.001) and a rise in mucosal ATP content (p less than 0.05). There was a significant reduction in the absorption rates of sodium (p less than 0.001), glucose, and glycine (p less than 0.01), but no change in the transport of fructose and of lysine. Brush border enzymes were unaltered. The histological appearance of the mucosa remained normal throughout the experiment, but on electron microscopy a distinct swelling of the enterocyte mitochondria was noted during the hypoxia period.(ABSTRACT TRUNCATED AT 250 WORDS)     

Muscle involvement in progressive diaphyseal dysplasia

Muscle involvement in progressive diaphyseal dysplasia was evaluated in five children, of whom four were members of one family. Age range was 2 to 10 years 9 months, and mean age was 5.5 years. Evaluation included serum enzymes, electromyography, and muscle biopsy examined by light and electron microscopy. Serum enzymes were usually noncontributory. Electromyography revealed "myopathic pattern" in four of the five patients. Muscle biopsy specimens were taken from three of the five children, including two patients from one family, of whom one had normal electromyography, and one sporadic case. Examination of the biopsy specimens by light microscope was generally not useful, whereas electron microscopic examination revealed myopathic and vascular changes consisting of atrophy of isolated muscle fibers, accumulation of endomysial collagen fibrils, and thickening of the perivascular basement membrane. The main contribution of this study is to describe electron microscopic vascular changes in muscles that appear to be similar in familial and sporadic cases of progressive diaphyseal dysplasia.