PubMed HealthSearch

Biomedical subjects

M Majd

Publications and source records attributed to M Majd.

At least 19 recordsLinked to original sources

Renal cortical scintigraphy in the diagnosis of acute pyelonephritis.

Comparative clinical studies have shown renal cortical scintigraphy, using technetium-99m (99mTc)-labeled glucoheptonate or dimercaptosuccinic acid (DMSA), to be significantly more sensitive than either intravenous pyelography or renal sonography in the diagnosis of acute pyelonephritis. However, due to uncertainties about the diagnostic accuracy of the clinical and laboratory parameters used in these studies, true sensitivity of renal cortical scintigraphy was unknown. Therefore, we evaluated the accuracy of [99mTc]DMSA scintigraphy in the diagnosis of experimentally induced acute pyelonephritis in piglets using strict histopathologic criteria as the standard of reference. The sensitivity and specificity of the DMSA scan for the diagnosis of acute pyelonephritis were 91% and 99%, respectively, with an overall 97% agreement between the scintigraphic and histopathologic findings. Based on the results of this experimental study, we used the [99mTc]DMSA scan as the standard of reference for the diagnosis of acute pyelonephritis, and conducted a prospective clinical study of 94 children hospitalized with the diagnosis of acute febrile urinary tract infection (UTI). The aims of this study were (1) to determine the relationship among vesicoureteral reflux, P-fimbriated Escherichia coli, acute pyelonephritis, and renal scarring, and (2) to evaluate the diagnostic reliability of the clinical and laboratory parameters commonly used in the diagnosis of acute pyelonephritis. We documented acute pyelonephritis in 62 (66%) of 94 patients. Vesicoureteral reflux was demonstrated in 29 (31%) of the total group and in only 23 (37%) of 62 patients with acute pyelonephritis. The prevalence of P-fimbriae in the E coli isolates was 64% in the patients with acute pyelonephritis and 78% in those with a normal DMSA scan. Even in patients without reflux, P-fimbriae were found in 71% of isolates from the patients with acute pyelonephritis and in 75% of those with a normal renal scan. Follow-up DMSA scans were obtained in 33 patients with acute pyelonephritis in 38 kidneys. We found complete resolution of the acute inflammatory changes in 58% of the involved kidneys and renal scarring in the remaining 42%, including 40% of the kidneys associated with reflux and 43% of those without reflux.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease

Pyelonephritis in male infants: how important is the foreskin?

We investigated the association of the uncircumcised foreskin and pyelonephritis in male infants less than 6 months old. During a 21-month prospective study 94 children (age range 2 weeks to 18.9 years) were hospitalized for febrile urinary tract infection. The male-to-female ratio for 35 patients less than 6 months old was 2.2:1. Of 59 patients older than 6 months the male-to-female ratio was reversed at 0.25:1 (p less than 0.001). In 13 of 24 infants (54%) less than 6 months old and in 8 of 12 boys (67%) older than 6 months a dimercaptosuccinic acid renal scan documented acute parenchymal damage (p = 0.72). Vesicoureteral reflux or other genitourinary abnormalities were found in only 3 of 24 patients (12.5%) less than 6 months old compared with 6 of 12 boys (50%) older than 6 months (p = 0.036). Of 24 infants less than 6 months old 22 (92%) were uncircumcised compared with 6 of 12 boys (50%) older than 6 months (p = 0.009). We then retrospectively compared the circumcision status of the infants who had febrile urinary tract infection with a control group of 63 infants matched for age, race and socioeconomic status hospitalized with febrile upper respiratory infection during a similar period. The frequency of uncircumcised infants in the control group with febrile upper respiratory infection was only 44% (28 of 63) compared with 91% of infants with febrile urinary tract infection (p less than 0.001). Overall the findings of the male predominance among patients less than 6 months old with febrile urinary tract infection, the disproportionately high frequency of infants with febrile urinary tract infection who were not circumcised, and the disproportionately low occurrence of vesicoureteral reflux and other genitourinary abnormalities in infants with febrile urinary tract infection strongly support an association between circumcision status and the risk for febrile urinary tract infection and pyelonephritis in male infants.

Acute Disease

Dimercaptosuccinic acid renal scintigraphy for the evaluation of pyelonephritis and scarring: a review of experimental and clinical studies.

Renal cortical scintigraphy has been reported to be useful in children for confirmation of the diagnosis of acute pyelonephritis. Subsequent experimental studies have demonstrated that dimercaptosuccinic acid (DMSA) scintigraphy, when compared directly with histopathology, is highly reliable for the detection and localization of parenchymal inflammatory changes associated with acute pyelonephritis. Recent clinical studies of acute pyelonephritis using DMSA scintigraphy reveal that the majority (50 to 91%) of children with febrile urinary tract infections have abnormal DMSA renal scan findings and that the majority of these children do not have demonstrable vesicoureteral reflux. However, when vesicoureteral reflux is present, renal cortical abnormalities are demonstrated by DMSA scintigraphy in 79 to 86% of the kidneys. In children with febrile urinary tract infections routine clinical and laboratory parameters are not reliable in the differentiation of acute pyelonephritis, documented by DMSA renal scan findings, from urinary tract infections without parenchymal involvement. Furthermore, the presence of P-fimbriated Escherichia coli associated with febrile urinary tract infections does not reliably predict those kidneys that have acute parenchymal inflammation demonstrated by DMSA renal scans. DMSA is also the isotope agent of choice for the detection of renal scarring. Clinical studies report greater sensitivity of DMSA renal scintigraphy for the detection of renal scarring when compared with the excretory urogram, particularly in infants and young children. In a recent prospective study of post-pyelonephritic renal scarring in children we found that acquired renal scarring only occurs in sites corresponding exactly to previous areas of acute pyelonephritis demonstrated by DMSA scintigraphy at the time of infection. Furthermore, once acute pyelonephritis occurs, ultimate renal scarring is independent of the presence or absence of vesicoureteral reflux. These findings provide convincing evidence that renal parenchymal infection, rather than vesicoureteral reflux, is the prerequisite for acquired (postnatal) renal scarring. Vesicoureteral reflux as a risk factor for acquired renal scarring is directly related to its role as a risk factor for acute pyelonephritis. We conclude that DMSA scintigraphy is a valid tool for confirming the diagnosis of acute pyelonephritis in children and for identifying kidneys at risk for subsequent renal scarring.

Acute Disease

Renal scarring following reflux and nonreflux pyelonephritis in children: evaluation with 99mtechnetium-dimercaptosuccinic acid scintigraphy.

99mTechnetium dimercaptosuccinic acid (DMSA) scintigraphy is the imaging modality of choice for the detection of acute pyelonephritis and chronic renal scarring in children. Using the DMSA scan we prospectively evaluated renal scarring after reflux and nonreflux pyelonephritis in children. The study population consisted of 33 patients with acute pyelonephritis documented by a DMSA renal scan at infection. The children were evaluated for renal scarring with a followup DMSA scan 4 to 42 months (mean 10.7 months) after the acute infection. All new scarring on followup DMSA scans occurred at sites corresponding exactly to areas of acute inflammation on the initial DMSA scan. Therefore, only those kidneys with acute changes on the initial scan were subsequently analyzed. Of 38 kidneys new or progressive scarring developed in 16 (42%), including 6 of 15 (40%) with associated vesicoureteral reflux and 10 of 23 (43%) without demonstrable reflux. New renal scarring developed in 6 of the 7 kidneys (86%) associated with a neuropathic bladder or posterior urethral valves. In contrast, new scarring developed in only 10 of 31 kidneys (32%) associated with a normal bladder (p = 0.028). Excluding the kidneys associated with a neuropathic bladder or posterior urethral valves, new renal scarring developed in 3 of 12 (25%) with primary reflux, compared with 7 of 19 (37%) without vesicoureteral reflux. Except for the white blood count and the species of infecting bacteria, no other statistically significant differences could be found between those cases in which scars did or did not develop. We conclude that acquired renal scarring only occurs at sites corresponding to previous areas of acute pyelonephritis, the acute parenchymal inflammatory changes of acute pyelonephritis are reversible and do not lead to new renal scarring in the majority of cases, and once acute pyelonephritis has occurred ultimate renal scarring is independent of the presence or absence of vesicoureteral reflux.

Adolescent

Escherichia coli virulence factors and 99mTc-dimercaptosuccinic acid renal scan in children with febrile urinary tract infection.

Correlation of virulence factors of Escherichia coli with renal inflammation documented by 99mTc-dimercaptosuccinic acid renal scan was undertaken in 59 children with febrile urinary tract infections to identify more accurately the role of bacterial virulence factors in the development of pyelonephritis. P fimbriae were present in 63% of isolates from the positive scan group and 83% of those from the negative scan group (P = 0.126). Multivariate regression analysis showed no significant role for established E. coli virulence factors in the development of pyelonephritis. The pap genome was independently associated with negative scan (P less than 0.007) and with the absence of reflux (P = 0.031). E. coli pyelonephritogenic clone O16:K1:H6 was isolated from negative scan patients and did not produce hemolysin. We conclude that P fimbriae are important in the development of febrile urinary tract infection regardless of the level of infection. Virulent E. coli clones described in prior Scandinavian urinary tract infection studies were not common causes of pyelonephritis in our patient population.

Adolescent

Diagnostic imaging in the evaluation of the first urinary tract infection in infants and young children.

The evaluation of infants and children after the first urinary tract infection has undergone change in recent years. Standard diagnostic imaging studies are being utilized on a more frequent basis, because these procedures can provide information which often has a direct impact on patient care. Selection of the proper tests requires an understanding of how they are performed and the basis for their choice. The rationale for the use of different imaging studies and their application to patient care are discussed.

Child

Relationship among vesicoureteral reflux, P-fimbriated Escherichia coli, and acute pyelonephritis in children with febrile urinary tract infection.

Ninety-four children with febrile urinary tract infection were studied prospectively to determine the relationship between vesicoureteral reflux, P-fimbriated Escherichia coli, and acute pyelonephritis, and to evaluate the diagnostic reliability of commonly used clinical and laboratory observations. By using renal scan with dimercaptosuccinic acid labeled with technetium 99m as the standard of reference, we documented acute pyelonephritis in 62 (66%) of 94 patients. Vesicoureteral reflux was demonstrated in 29 (31%) of the total group and in only 23 (37%) of 62 patients with pyelonephritis. Of the 70 E. coli urinary isolates, 48 (69%) were P-fimbriated, including 30 (64%) of 47 isolates from patients with pyelonephritis and 18 (78%) of 23 isolates from patients with normal renal scans. The prevalence of P-fimbriated E. coli in patients with pyelonephritis and vesicoureteral reflux was 46%, compared with 71% in those with pyelonephritis who had no concurrent vesicoureteral reflux (p = 0.222). Multiple clinical and laboratory variables commonly used in the diagnosis of acute pyelonephritis did not adequately predict the presence or absence of parenchymal involvement. These data show the following: (1) Acute pyelonephritis in the absence of demonstrable vesicoureteral reflux is common. (2) Febrile urinary tract infections in children are commonly associated with P-fimbriated E. coli, both in the presence and absence of vesicoureteral reflux. (3) The presence of P fimbriae alone does not fully explain the pathophysiology of renal parenchymal invasion by bacteria in the absence of vesicoureteral reflux. (4) The diagnosis of acute pyelonephritis in children with febrile urinary tract infections on the basis of clinical and laboratory observations is unreliable.

Acute Disease

Diagnosis of acute pyelonephritis in children: comparison of sonography and 99mTc-DMSA scintigraphy.

Ninety-one children 1 week to 10 years old with culture-documented febrile urinary tract infection were evaluated with renal sonography and renal cortical scintigraphy by using 99mTc-labeled dimercaptosuccinic acid (DMSA). On the basis of previous experimental studies, DMSA scintigraphy was used as the standard of reference for the diagnosis of acute pyelonephritis. The DMSA scans showed changes consistent with acute pyelonephritis in 63% (57/91) of the patients. Sonograms showed changes consistent with acute pyelonephritis in 24% (22/91) of the whole group and in only 39% (22/57) of the patients with scintigraphically documented acute pyelonephritis. Pertinent sonographic findings were areas of increased cortical echogenicity in 14 patients and decreased echogenicity in eight, including three patients with renal abscesses. Dilatation of the renal collecting system was noted in nine patients and renal enlargement was noted in three. We conclude that renal sonography is a relatively insensitive test for the detection of acute inflammatory changes of renal cortex. Therefore, it should not be used as the primary imaging technique for the diagnosis of acute pyelonephritis. However, sonography is a useful technique in evaluating the nature of the defects seen on the DMSA scan and in detecting obstructive uropathies that may be associated with urinary tract infections.

Acute Disease

Renal scarring and vesicoureteral reflux in children with myelodysplasia.

The records of 180 myelodysplasia patients followed from 3 to 18 years were reviewed. Studies included cystography to evaluate vesicoureteral reflux and dimercapto-succinic acid renal scintigraphy to identify acute inflammation and renal scarring. Scarring was noted in 28 of 180 patients (15.5%), of whom 68% were girls. Of the patients with renal scarring 75% had associated reflux and 40% over-all were identified as having reflux. Management of patients with vesicoureteral reflux included clean intermittent catheterization, antibiotic prophylaxis and anticholinergics when indicated. Only 17 of 72 patients (24%) had ureteral reimplantation. Surgical indications included persistent high grade reflux and/or progressive upper tract damage. Reflux resolved in 62% of those on medical management. Resolution was not dependent on grade of reflux (as compared to primary reflux). Twenty-one patients are stable and being followed with persistent reflux. In 7 patients new renal scars developed during aggressive medical management, 5 of whom underwent subsequent surgical correction.

Child

Feeding disorders and gastroesophageal reflux in infants with chronic renal failure.

Twenty-two infants (mean age 7.5 months) with chronic renal failure (CRF) were studied for their nutrition, growth, and upper gastrointestinal function. Most infants had a history of poor caloric intake and 7 had received supplemental feeding (SF) prior to the investigation. All infants were undergrown, underweight, and malnourished. The infants were characterized as having only a fair interest in food, refusing feedings, and vomiting excessively. Sixteen of 22 infants (73%) had significant gastroesophageal (GE) reflux demonstrated by 24-h esophageal pH monitoring. Gastroesophageal scintiscans were less sensitive and specific in detecting the reflux. Infants with GE reflux were significantly younger and more often required SF than those without GE reflux. There were no significant differences in the degree of renal failure, growth failure, caloric intake, protein intake, or nutritional status between the infants with and without GE reflux. From these studies we conclude that GE reflux should be considered as one of the factors contributing to the feeding problems of infants with CRF.

Energy Intake

Renovascular hypertension in children: current concepts in evaluation and treatment.

Since 1981, we have evaluated and treated 22 children with renovascular hypertension (RVH). Seventeen patients had stenosis of their native renal arteries, and five had stenosis of the artery in a transplanted kidney. RVH was caused by fibromuscular dysplasia in 13 patients, by trauma in 2 patients, and by arteritis in 2 patients. Among the patients who had transplanted kidneys, three had technical causes for stenosis and two had stenosis due to rejection. The disease was unilateral in 10 patients, bilateral in 5, and present in a solitary kidney in 7, including the five renal transplants. Diagnostic studies that strongly suggested the presence of renovascular disease were an initial diastolic blood pressure greater than 100 mm Hg, an elevated peripheral vein renin activity level, and an abnormal renal scan if the patient's hypertension was being controlled with an angiotensin-converting enzyme inhibitor (ACEI). Only the renal arteriogram was 100% accurate in confirming the presence of RVH. Percutaneous angiographic correction was attempted in 13 patients and resulted in lasting improvement of the hypertension in five (38%). Surgical revascularization was attempted in 17 children, including the 8 with failed angioplasty, with improvement or cure of the hypertension in 15 patients (88%). Combining percutaneous transluminal angioplasty (PTA) and surgical results gave 20 of 22 patients (91%) with cure or improvement of their hypertension. Four of 27 affected kidneys (15%) could not be revascularized and were removed. We conclude from this series of patients that despite improvements in noninvasive studies, renal arteriogram remains the only study that is 100% accurate in evaluating children for RVH.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Reflex sympathetic dystrophy syndrome in children and adolescents. Report of 18 cases and review of the literature.

Reflex sympathetic dystrophy syndrome is a well-recognized disorder in adults, but it is rarely diagnosed in the pediatric age group. This report summarizes our experience with this condition from 1975 to 1985. We diagnosed, treated, and followed up this condition in 18 children and adolescents. The condition usually followed trauma. The most prominent feature in all patients was a constant limb pain with episodes of paroxysmal exacerbation. The pain was associated with two or more of the following: edema, hyperhidrosis or anhidrosis, cyanosis or erythema, and, in severe cases, dystrophic skin changes and muscle atrophy. Roentgenograms were normal. Bone scans were helpful to exclude other possible causes of bone and joint pain. Reflex sympathetic dystrophy syndrome in children probably often goes unrecognized, sometimes being confused with psychiatric conditions such as conversion reaction and malingering. Reflex sympathetic dystrophy syndrome should always be considered in the differential diagnosis of unexplained persistent limb pain in children: early recognition and proper management may result in the prevention of potentially crippling sequelae.

Adolescent

Evaluation of 99mtechnetium-dimercapto-succinic acid renal scans in experimental acute pyelonephritis in piglets.

We evaluated the sensitivity and specificity of 99mtechnetium-dimercapto-succinic acid renal scans in the detection and localization of experimental acute pyelonephritis in piglets. To create pyelonephritis vesicoureteral reflux of infected urine was surgically induced in 22 piglets. Nine animals were evaluated with a dimercapto-succinic acid renal scan at 1 week and 13 at 2 weeks. Autopsy and histopathological examination of the kidneys were performed subsequently. The location and extent of the inflammatory response found on histopathological examination were compared to dimercapto-succinic acid renal scan findings in a blinded fashion. Of the 22 kidneys subjected to vesicoureteral reflux 15 had positive histopathological findings of acute pyelonephritis, including 13 detected by the dimercapto-succinic acid renal scan findings. The 2 kidneys in which inflammation was not detected had only minimal grade I lesions and were grossly normal. There were no false positive scans in any of these kidneys. The sensitivity of the scan for detection of acute pyelonephritis in the kidneys subjected to reflux was 87 per cent and the specificity was 100 per cent. Furthermore, in these same kidneys the dimercapto-succinic acid renal scan findings correctly predicted the presence or absence of individual pyelonephritic lesions in 62 of 66 poles for an over-all agreement rate of 94 per cent. Thus, dimercapto-succinic acid renal cortical imaging is a highly sensitive and reliable imaging modality to detect and localize experimental acute pyelonephritis in piglets.

Acute Disease

A nonsurgical approach to the management of primary vesicoureteral reflux.

We performed a retrospective review to evaluate the results of a nonsurgical approach to the management of primary vesicoureteral reflux during a 10-year period (1976 to 1986). During that interval patients with reflux were studied initially with a standard voiding cystourethrogram and either an excretory urogram or a renal scan with glomerular filtration rate and/or differential renal function determination. Height, weight, blood pressure, urine cultures and serum creatinine measurements also were obtained. Isotope cystography was used for followup examinations. A single, negative isotope cystogram was the radiological criterion for cessation of reflux. The charts of 545 children (55 per cent had bilateral reflux) with 844 refluxing ureters were reviewed. Based upon the international classification vesicoureteral reflux was grade I in 6.6 per cent of the cases, grade II in 54.2 per cent, grade III in 31.6 per cent, grade IV in 5.7 per cent and grade V in 1.9 per cent. All children were kept on long-term continuous prophylactic antibiotics and they were re-evaluated annually with isotope cystography. The followup rate for the entire group was 88 per cent. During the observation period spontaneous resolution of reflux was noted in 36 per cent of the patients and 39 per cent of the total refluxing ureters. Only 13 per cent of the entire group underwent surgical correction of reflux. Presently, 39 per cent (215) of the patients continue to be followed with reflux. Of the total group 66 patients (12 per cent) were lost to followup. In the 194 patients with spontaneous resolution of reflux the mean duration of reflux was 1.69 years, with 30 to 35 per cent resolving each year. Based on Student's t test there was a significant difference in duration of reflux in patients with grade II compared to grade III reflux (1.56 versus 1.97 years, p less than 0.04). When age at presentation was compared with duration of reflux there was a significantly shorter duration of reflux only in those patients presenting from age 0 to 12 months, compared to those 13 months and older (1.44 versus 1.85 years, p less than 0.02). Renal function was evaluated by serum creatinine, calculated glomerular filtration rate or differential diethylenetriaminepentaacetic acid scan results.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors

Bone scintigraphy in the evaluation of children with obscure skeletal pain.

A retrospective analysis of bone scans of 381 children with unexplained skeletal pain was made. Of these, findings are reported on 358 for whom there were sufficient clinical data. The bone scan results suggested trauma as the cause of pain in 43 patients, inflammatory disease in 73 patients, and neoplasia in ten patients. There was only one false-positive bone scan. Normal findings were obtained from 227 patients, in whom no significant skeletal disease was detected on follow-up, except for juvenile rheumatoid arthritis in 23 patients. Bone scintigraphy is, therefore, an important, noninvasive diagnostic test for evaluating children with obscure bone or joint pain. We recommend that this test be performed early in the evaluation of these children to arrive at the diagnosis expeditiously and with minimal patient discomfort and morbidity.

Adolescent

Multiple duplications of the small intestine.

A case of coexistent cystic and tubular duplications of the small intestine is presented. Staged resection resulted in maximal preservation of small intestinal length. Intraoperative radionuclide scanning is suggested as a technique to assure complete removal of ectopic gastric mucosa. The literature regarding multiple duplications is reviewed and the management of duplications involving long segments of the small intestine is discussed.

Choristoma