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Biomedical subjects

B B Dahms

Publications and source records attributed to B B Dahms.

At least 19 recordsLinked to original sources
PubMed1995

Renal histological changes secondary to ureteropelvic junction obstruction.

The treatment of children with apparent ureteropelvic junction obstruction is controversial. In an asymptomatic infant or child the decision to recommend pyeloplasty usually is based on interpretation of the renal scan. We retrospectively analyzed the renal biopsy obtained during pyeloplasty in 55 children. Histological changes were compared to the differential renal function revealed on the preoperative renal scan. Histological changes were graded on a scale of I to V; I--normal, II--mild dilatation of the collecting tubules or Bowman's space and III to V--progressively severe changes of obstructive uropathy, including reduced glomerular number, glomerular hyalinization, cortical cysts and interstitial inflammation. Patient age ranged from 4 days to 19 years (mean 4.8 years). Mean differential function according to histological grade was I--49%, II--43%, III--42%, IV--30% and V--25%. Of 33 patients with a differential function of 40% or greater 26 (79%) had a grade I or II biopsy, while 21% had a more significant alteration in renal histology. In contrast when the differential function was less than 40% 6 of 18 patients (33%) had grade I or II disease on biopsy. In conclusion, in approximately 25% of children with ureteropelvic junction obstruction there is a disparity between preoperative differential renal function computed during diuretic renography and renal biopsy.

Adolescent↗
PubMed1993

Influence of vas deferens mobilization on rat fertility: implications regarding orchiopexy.

Children who undergo bilateral orchiopexy often have oligospermia or azoospermia in adulthood. This subfertility generally has been attributed to histological alterations in the cryptorchid testis. However, the possibility that an iatrogenic factor, such as mobilization of the vas deferens during orchiopexy, may have an adverse effect on fertility has not been studied. Six groups of mature Sprague-Dawley rats underwent right orchiectomy and the following procedures on the left side: group 1--sham operation, group 2--2 cm. of vas mobilized, group 3--4 cm. of vas mobilized, group 4--2 cm. of vas mobilized and deferential artery stripped off of vas, group 5--4 cm. of vas mobilized and deferential artery stripped off of vas and group 6--vasectomy. Each rat was then housed with 2 female rats for 24 days. Mobilization of the vas with disruption of the mesentery resulted in slight but statistically insignificant reduction in fertility. However, when the deferential artery was dissected off the vas, there was a marked reduction in fertility and fecundity. Histologically the vasa were normal without evidence of ischemic necrosis. The testes in groups 2 to 5 showed variable depletion of germ cells with shedding of germinal epithelium, and the testes and epididymides in group 5 were similar to the changes seen in vasectomized rats (group 6). No testes were necrotic. These data suggest that extensive mobilization of the vas causes subfertility in this animal model and may be secondary to a functional obstruction resulting from vas denervation. Whether a similar effect occurs during orchiopexy in humans deserves study.

Animals↗
PubMed1991

Morphometric analysis of the lung in bronchopulmonary dysplasia.

We studied lung development in children with or without bronchopulmonary dysplasia (BPD) using light microscopic morphometry and thick lung sections stained for elastic fibers. One lung was obtained at autopsy from each of eight patients with BPD (ages, 2 to 28 months) and six children (ages, 5 days to 51 months) who died without lung disease. Patients with BPD demonstrated severe somatic growth retardation and had reduced lung volumes with abnormal lobar volume proportions. In the central bronchi mean volume proportion of glands and smooth muscle was increased in BPD. Bronchiolar density was also increased, but it tended to normalize with advancing age. Mean bronchiolar diameter was slightly smaller in BPD, and bronchiolar smooth muscle hypertrophy was a constant histologic feature. The most striking change, however, was noted in alveolar structure and development. Total alveolar number was severely decreased in patients with BPD compared with that in control subjects, and there was little evidence of compensatory alveolar development with increasing age. Lung internal surface area was correspondingly reduced, and mean linear intercept was increased. Sections stained for elastic tissue demonstrated in the patients with BPD a simplified acinar structure with thickened, tortuous, and irregularly distributed alveolar elastic fibers. We conclude that in severe, fatal BPD there is marked impairment of lung development with alveolar hypoplasia and reduced internal surface area. In addition, bronchial and bronchiolar smooth muscle hypertrophy and bronchial gland hyperplasia may be important contributing factors to airflow limitation.

Body Height↗
PubMed1990

Pathology of neonatal necrotizing enterocolitis: a ten-year experience.

We reviewed pathology specimens from 84 patients seen during a 10-year period with neonatal necrotizing enterocolitis, and these findings were correlated with clinical features. Coagulation (ischemic) necrosis, inflammation, and bacterial overgrowth were all present in the intestine of nearly all patients but with individual variability in the severity of these findings. Overall, coagulation necrosis was more severe than any other finding in most infants, indicating the importance of ischemia in the pathophysiology of necrotizing enterocolitis. Reparative tissue changes such as epithelial regeneration, granulation tissue formation, and fibrosis, found in two thirds of cases, suggested ongoing tissue injury of at least several days' duration. Birth weight, Apgar score, age, feeding status, and the presence of respiratory distress syndrome were not correlated with any particular histologic feature. The pathologic changes of necrotizing enterocolitis suggest that its cause is multifactorial, with ischemia, inflammation, bacterial overgrowth, and reparative tissue changes all playing important roles.

Apgar Score↗
PubMed1989

Enlarged gastric folds in association with Campylobacter pylori gastritis.

Enlarged gastric folds in pediatric patients are uncommon. Fifteen patients with upper gastrointestinal (GI) tract symptoms of chronic epigastric abdominal pain, vomiting, or hematemesis underwent radiologic upper GI barium studies and were found to have Campylobacter pylori gastritis at endoscopic biopsy. Seven patients (47%) with C pylori gastric disease had radiologic evidence of enlarged folds. There was no clinical or pathologic evidence of Ménétrier disease. Therefore, C pylori gastritis should be considered in the differential diagnosis of children with upper GI tract symptoms and radiologic evidence of enlarged folds.

Adolescent↗
PubMed1988

Campylobacter pylori--associated gastritis and peptic ulcer disease in children.

Specimens obtained at gastric biopsies performed for suspected acid peptic disease in patients 5 through 17 years of age were retrospectively reviewed for the presence of Campylobacter pylori (CP), a gram-negative bacillus associated with chronic gastritis and peptic ulcer disease in adults. Of 98 patients who underwent antral biopsy (the most reliably colonized site in the stomach), 40 had chronic gastritis histologically. Of those 40 patients, 22 (55%) had CP present on the gastric surface. None of the 58 patients without gastritis present in biopsy specimens had CP. The gastritis in children with CP was more severe than in those without the organism: 86% of those with moderate gastritis and 92% of those with severe gastritis had CP. Eight patients with duodenal ulcers and one patient with a gastric ulcer had CP on biopsy. Among those patients without CP, only one had a duodenal ulcer and eight had gastric ulcers. An additional nine patients found to have CP on gastric fundic biopsy were identified, for a total of 31 patients with CP identified by either antral (22) or fundic (nine) biopsy. Initial resolution of symptoms with standard acid-antagonist therapy was noted in the 25 of 31 CP(+) patients so treated, but a high relapse rate was noted within one to two years in the patients who also had gastritis and duodenal ulcer. These findings support a strong association between CP colonization of the stomach and the presence of chronic gastritis and duodenal ulcer disease in children.

Adolescent↗
PubMed1987

Barrett's esophagus in three children after antileukemia chemotherapy.

Barrett's esophagus, a columnar metaplasia of the lower esophagus that is usually associated with gastroesophageal reflux (GER), was found in three children on long-term antileukemia chemotherapy. Two of the children had been on a standard acute lymphoblastic leukemia (ALL) maintenance protocol with 2 to 3 years of methotrexate and 6-mercaptopurine administration. The third child received daunorubicin, cytosine arabinoside, and 6-thioguanine for treatment of acute myelogenous leukemia (AML). None of the patients had clinical or pathologic evidence of GER disease. We propose that the Barrett's esophagus in these patients did not result from the usual peptic esophagitis, but rather from chemotherapy-induced esophageal mucosal injury.

Antineoplastic Agents↗
PubMed1987

Three conditions in neonatal asphyxiating thoracic dysplasia (Jeune) and short rib-polydactyly syndrome spectrum: a clinicopathologic study.

Clinicopathologic examination of eight patients with asphyxiating thoracic dysplasia (Jeune; ATD) disclosed two different types, which were designated as type 1 and type 2. Type 1 ATD was characterized by the presence of radiologically irregular metaphyseal ends and histopathologically irregular cartilage bone junction with patchy distribution of physeal zone of hypertrophy. Type 2 ATD showed radiologically smooth metaphyseal ends and histopathologically diffusely retarded and disorganized physes with smooth cartilage bone junctions. Examination of four patients with the "Verma-Naumoff" short rib-polydactyly syndrome showed many radiologic and pathologic features similar to those of type 1 ATD. Differential diagnosis of these three osteochondrodysplasias is discussed along with chondroectodermal dysplasia (Ellis-van Creveld), short rib-polydactyly syndrome type 1 (Saldino-Noonan), short rib-polydactyly syndrome type 2 (Majewski), and the new short rib syndrome reported by Beemer et al [1983].

Asphyxia Neonatorum↗
PubMed1986

Dual origin of the left coronary artery with vestigial branch arising from the aorta and main trunk arising from the pulmonary artery.

A 3-month-old infant presented with cardiomegaly, mitral insufficiency, myocardial ischemia, and congestive heart failure suggestive of anomalous left coronary artery. A vestigial left coronary artery was demonstrated on angiography and was thought to represent the only abnormality. At autopsy, the infant had a vestigial left coronary artery arising from the aorta but in addition had a normal caliber anomalous left coronary artery arising from the pulmonary artery.

Aorta↗
PubMed1986

Islets of Langerhans in adolescents and adults with cystic fibrosis. A quantitative study.

The incidence of fasting hyperglycemia and diabetes mellitus (DM) in older patients with cystic fibrosis (CF) is reported to be 8%, but few quantitative studies of the islets of Langerhans in this disease have been done. Three groups of patients were studied in this morphometric autopsy analysis: patients with CF and insulin-dependent DM (n = 7), normoglycemic patients with CF (n = 4), and age-matched adolescents and young-adult controls (n = 11). The islets of Langerhans were stained with immunoperoxidase for insulin, glucagon, and somatostatin. The percentage of the total islet surface area occupied by each immunoperoxidase positive cell type was determined by a point-counting method. The mean percent surface area occupied by insulin-producing cells (28.3%) in diabetics with CF was significantly less than normoglycemics with CF (46.7%) and controls (53.4%). The mean percent surface area occupied by glucagon-producing cells was similar in all three groups: 21.9% in CF diabetics, 25.4% in normoglycemics with CF, and 22.4% in controls. The mean percent surface area occupied by somatostatin was increased in both CF groups compared with controls: diabetics with CF, 29.3%; normoglycemics with CF, 26.2%; and controls, 15.5%. These findings correlate with published clinical endocrine studies of hyperglycemia in CF. Endocrine cell quantitation in diabetics with CF differs from that in both juvenile (type 1) and adult-onset (type 2) DM.

Adolescent↗
PubMed1985

Malignant rhabdoid tumor of the heart in an infant.

A 6-month-old infant presenting with pericardial effusion was found to have a malignant rhabdoid tumor of the heart. As visualized by two-dimensional echocardiography and subsequently by contrast-enhanced computerized axial tomographic scanning, the tumor arose from the left ventricular free wall and grew into the pericardial space. Despite two courses of single-agent chemotherapy with doxorubicin, the child died 3 months later. This is the first reported case of malignant rhabdoid tumor of the heart, and the fifth case of a primary cardiac malignancy in an infant.

Cardiac Catheterization↗
PubMed1985

Acute continuous argon-laser induced tissue effects in the isolated canine heart.

Fresh isolated myocardial, elastic-arterial, and valvular tissues from seven canine hearts were irradiated by argon laser. Irradiation was transmitted through 300 and 400 micron flexible quartz fiberoptic elements. Minimal power densities for vaporization of the myocardial, arterial, and valvular tissues were 80, 90, and 110 W/cm2, respectively, with maximal vaporization distances (fiberoptic tip to tissue) of 4 mm, 1 mm, and 1 mm, respectively. Irradiation of the valves at power densities approaching perforation caused contraction of the tissue. When tissue vaporization occurred, histologic examination of irradiated tissues showed a central crater surrounded by sequential layers of char, vaporization, and coagulation necrosis. These findings were common to all cardiac tissues. Additional findings unique to myocardium were a normal-appearing myocardial layer (skip-area), circumferential halo, and tissue clefts. Elastic arteries showed concentration of necrosis around the collagen and elastic fibers. Valvular damage was the most extensive and also included contraction of adjacent valvular tissue and endocardial sloughing.

Animals↗
PubMed1985

Systemic Malassezia furfur infections in patients receiving intralipid therapy.

Systemic infection with Malassezia furfur was first reported in 1981 as a specific complication of Intralipid therapy in a neonate. Six additional patients, including three older than 16 years of age, were identified subsequently. All had received prolonged Intralipid infusion through central venous catheters. Pulmonary infection was documented in tissue in three cases, the clinical presentation was characterized by pulmonary infiltrates, fever, and, in the infants, thrombocytopenia. Two subgroups of patients appear to be at the greatest risk for Malassezia infection: neonates with cardiopulmonary disease and adults with severe gastrointestinal disease and immunosuppression. The documentation of pulmonary arterial lipid deposits in vessels that had been infiltrated by Malassezia organisms and the observation of organisms in small pulmonary thromboemboli suggest that these lipophilic and lipid-dependent organisms are introduced into the bloodstream from venous catheters and require high lipid concentrations to proliferate in tissue.

Adolescent↗