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Biomedical subjects

C Langston

Publications and source records attributed to C Langston.

104 records · Page 6Linked to original sources

Intralobar pulmonary sequestration (a nonentity?).

Intralobar pulmonary sequestration has generally been considered a congenital malformation in which an accessory lung bud develops, is enveloped by normal lung, and retains its systemic arterial supply. Also usually included in the "sequestration spectrum" are aberrant arteries to normal lung with either normal or anomalous venous connection. We reviewed all surgical pathology specimens and autopsies performed at Texas Children's Hospital from 1955 through 1984. There were 15 cases with an aberrant systemic artery to normal or abnormal lung. Nine were cases of structurally normal lung with an aberrant systemic artery, and five were cystic adenomatoid malformations with a systemic artery. In one older child some features of intralobar sequestration were present, but a major bronchial connection was retained. We propose that most intralobar sequestrations represent either cystic adenomatoid malformations that clinically are unrecognized until they become secondarily infected or developmentally normal lung supplied by a systemic artery.

Arteries↗

Expression of thyroid transcription factor-1, surfactant proteins, type I cell-associated antigen, and Clara cell secretory protein in pulmonary hypoplasia.

Pulmonary hypoplasia (PH) is a developmental abnormality characterized by diminished distal lung parenchyma. Recent studies have demonstrated that thyroid transcription factor 1 (TTF-1), a member of NKx2 family of homeodomain transcription factors, plays an important role in lung organogenesis and lung epithelial gene expression. In order to evaluate whether abnormal expression of TTF-1 contributes to the pathophysiology of PH, we studied the expression of TTF-1, as well as that of the surfactant proteins (SPs), Clara cell secretory protein (CCSP), and type I cell-associated antigen (T1 cell-Ag), in PH. Immunolocalization patterns of these proteins were evaluated in 15 cases of PH with different associated diseases and compared with those of 14 matched controls. Our study demonstrated that the concentration gradient of TTF-1 along the proximal-distal axis in normal fetal lung is disrupted in PH after 24 weeks gestational age, while the expression of the SPs, CCSP, and T1 cell-Ag seemed to be preserved. We conclude that a normal TTF-1 expression pattern might be crucial in the control of distal lung development. Failure to switch off expression of TTF-1 in PH of more than 24 weeks gestational age may be a final common pathway leading to PH associated with the disease processes investigated in this study.

Epithelial Cells↗

Gastrin-releasing peptide in hypoplastic lungs.

The relative abundance of pulmonary neuroendocrine cells synthesizing gastrin-releasing peptide (GRP) was estimated for normal fetal lungs and hypoplastic lungs. Percentage of bronchiolar epithelial area staining positively with anti-GRP antiserum was computed for each case using a SAMBA 4000 image analyzer. The majority of hypoplastic lungs (10 of 12 cases) showed markedly diminished GRP immunoreactivity, which appeared to vary with etiology. Six cases of pulmonary hypoplasia associated with renal anomalies, three cases associated with hydrops, and one case of diaphragmatic hernia showed an average fivefold reduction in percentage of GRP immunostaining. A case of hypoplasia associated with Werdnig-Hoffmann disease had GRP immunoreactivity similar to that of controls, and GRP expression was markedly elevated (fivefold) in a case of hypoplasia with omphalocele.

Antibodies, Monoclonal↗

Bacillus species infections in neonates.

A case of neonatal meningitis due to Bacillus cereus is presented. Postmortem histopathologic examination revealed an invasive disease involving the brain parenchyma, with a cellular composition consistent with an indolent process indicative of possible perinatally acquired infection. One other neonate from our institution with systemic disease due to a nonanthrax bacillus is described, and a review of the English-language literature since 1900 reveals four additional neonates infected with these unusual pathogens. Such Bacillus species infections are rare but should be suspected when gram-positive bacilli are noted on gram stain, especially in an immunocompromised host.

Bacillus↗

Iatrogenic gastroschisis decreases pulmonary hypoplasia in an ovine congenital diaphragmatic hernia model.

Pulmonary hypoplasia is a major problem in infants with congenital diaphragmatic hernia. Intrauterine reparative procedures are associated with a high complication rate. The development of less complex operations to reduce the degree of fetal lung hypoplasia may improve neonatal survival. Our objective was to investigate the effectiveness of an iatrogenic gastroschisis in reducing fetal pulmonary hypoplasia in a sheep model with an artificially created diaphragmatic hernia. A left-sided diaphragmatic hernia (Bochdalek type) was created at 75 days' gestation in an ovine fetal model during the pseudoglandular phase of lung development. At 110 days' gestational age, a left-sided gastroschisis was created by excising part of the lower abdominal wall and buttressing the opening with a rubber ring. The fetus remained in utero until 135 days' gestation, at which time it was sacrificed for autopsy. Histopathologic and morphometric studies were performed on the lungs. Ten animals had creation of a diaphragmatic hernia. Four underwent the second surgery to create a gastroschisis. One animal completed the entire protocol, 3 fetuses aborted after the second surgery. Autopsy confirmed effective decompression of the herniated abdominal contents from the chest into the amniotic cavity in all 4 cases. The lungs of the animal that completed the protocol were appropriately developed, while those fetuses that died soon after gastroschisis creation had severe pulmonary hypoplasia, mainly involving the left lung. Artificially induced diaphragmatic hernia, in the ovine fetus, causes severe pulmonary hypoplasia.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Muscles↗

Supplemental alanylglutamine, organ growth, and nitrogen metabolism in neonatal pigs fed by total parenteral nutrition.

The objective of this study was to determine whether supplemental glutamine (alanylglutamine dipeptide) is effective in preventing small intestinal mucosal atrophy associated with total parenteral nutrition and whether it affects the growth of other organs in neonatal pigs. We compared organ growth, intestinal enzyme activity, and plasma nitrogen metabolites in 4-day-old pigs randomly selected to receive total parenteral nutrition supplemented with 0 g, 2.0 g, or 4.5 g of glutamine per deciliter for a total amino acid intake of either 11 or 25 g.kg-1.d-1 for 7 days. Glutamine supplementation increased (60% to 100%) plasma concentrations of glutamine, urea nitrogen, ammonia, and both jejunal villus height and surface area, but it did not significantly affect jejunal mucosal protein and DNA masses or the relative growth of liver, kidneys, and brain. No histologic evidence of tissue toxicity was found. Supplementing large amounts of glutamine (alanylglutamine dipeptide) did not completely prevent total parenteral nutrition-associated intestinal mucosal atrophy but did improve villus morphology without affecting vital organ growth or histology.

Amino Acids↗

Malignant melanoma of soft parts involving the head and neck region: review of literature and case report.

Malignant melanoma of soft parts (MMSP) was originally described as a distinct entity by Enzinger in 1965 and was termed "clear cell sarcoma of tendons and aponeuroses" because of its association with tenosynovial structures. It has been shown immunophenotypically and ultrastructurally that this tumor is derived from neuroectoderm and shares a number of features with cutaneous melanoma. Over 95% of MMSPs present in the extremities, with the head and neck region (1.9%) being an unusual site. This study presents an additional case of MMSP of the head and neck region involving the posterior cervical region in a 15-year-old Hispanic male and reviews the literature on MMSP. Ultrastructural examination showed rudimentary cell attachments, smooth cell membranes, discontinuous basal lamina, scanty glycogen, and occasional premelanosomes in some tumor cells. Cytogenetic analysis showed a reciprocal translocation between the long arms of chromosomes 12 and 22 [t(12:22)(q13;q12.2)], characteristic for MMSP and not seen in cutaneous melanoma. Survival in MMSP has been correlated with tumor size, tumor necrosis, and ploidy status. Overall reported clinical outcome for this tumor is as follows: died of disease, 45%; alive with disease, 23%; no evidence of disease, 30%; and died of other causes, 2%. MMSP represents a distinct entity with a characteristic ultrastructural appearance and a tumor defining cytogenetic translocation.

Adolescent↗

Patterns of measles pneumonitis.

As a result of the enlarging pool of unvaccinated children and young adults, there has been an increase in serious measles pneumonitis in our areas. We recently examined autopsy and/or lung biopsy material from five children with fatal measles pneumonitis. Two patients were immunocompromised because of either prematurity or acute leukemia and died 13-16 days following onset of symptoms. Both had classic giant cell pneumonitis, with readily demonstrable intranuclear inclusions. Three other children without known immunocompromise had a more prolonged course. The lungs of these patients lacked the classic pattern and displayed instead a spectrum of less specific findings ranging from organizing diffuse alveolar damage to interstitial pneumonia with giant cells, but without viral inclusions. An accompanying necrotizing bronchiolitis was also present. Electron microscopy and/or detection of elevated measles-specific immunoglobulin M was necessary to confirm the diagnosis in these apparently immunocompetent patients. We conclude that the histologic features of fatal or serious measles pneumonitis are variable and depend to some extent on the immunocompetence of the host as well as the duration and tempo of the disease. Ancillary studies may be necessary to establish the diagnosis in cases lacking classic histopathologic features.

Adult↗

Successful prenatal therapy of thoracic lesions.

Improvements in prenatal imaging techniques now permit in utero treatment of potentially serious lesions. We describe three cases in which decompression of significant space-occupying thoracic lesions resulted in an excellent clinical outcome. The pregnancies were all carried to term after second or early third trimester intervention and resulted in infants with minimal respiratory distress. Cytologic and chemical analysis of the thoracic fluid aspirated in utero provided diagnostic and physiologic information.

Adult↗

Characteristics of infants who undergo neonatal autopsy.

To identify factors associated with the performance of a neonatal autopsy, we surveyed autopsy practice patterns in a tertiary care neonatal intensive care unit for 1 year. After 56 neonatal deaths, 33 (59%) autopsies were performed. We used multivariable analysis to compare the clinical and demographic characteristics of infants who had an autopsy with those who did not. We found two variables to be negatively correlated with having an autopsy performed: birth asphyxia (p < 0.05) and Medicaid coverage (p < 0.05). Early neonatal death (< or = 2 days of age) was not correlated with lack of an autopsy. Pulmonary hypoplasia occurred more often in the group having autopsy. However, only birth asphyxia was significantly correlated with lack of an autopsy after adjusting for other variables in the analysis. The primary cause of death was not associated with performance of an autopsy. We found no significant association between consent for autopsy and the characteristics of the physician requesting it. These data suggest that the infant's socioeconomic status and diagnosis may influence parental consent for autopsy. There may be other characteristics of physicians who request it, parents who consent, or other socioeconomic factors influencing consent for the neonatal autopsy.

Adult↗

Growth fraction determination in pulmonary hypoplasia using Ki-67 (MIB-1) antibody.

Pulmonary hypoplasia (PH) is a developmental abnormality that is typically assessed using lung/body weight ratios, radial alveolar counts, or lung volume measurements. Although it is often assumed that PH results from failure of growth and development, analysis of the proliferative index in PH has not been extensively described. We examined the lungs of 12 fetuses and newborn infants with pulmonary hypoplasia and those of 8 gestational age-matched controls using Ki-67 immunohistochemistry. Formalin-fixed, paraffin-embedded tissues were utilized. Growth fractions (GFs) were determined for peripheral lung parenchyma and bronchioles. The ratio of GFs for parenchyma and bronchioles was compared. There was no significant difference in the GF ratios obtained between control and hypoplastic lungs when gestational age was < 24 weeks. However, for gestational age > 24 weeks the GF ratio of mean values for controls was approximately four times the ratio of the mean values for the hypoplastic lungs. GF did not vary according to the presumed cause of PH, and at gestational ages < 24 weeks rates were the same as or greater than those of controls. These findings suggest that proliferative potential exists at < 24 weeks and that the growth of the lung parenchyma in relation to the conducting airways is significantly reduced or ceases after this point in gestation. Clinical interventions at or before 24 weeks of gestation might result in improved survival of infants with a propensity for pulmonary hypoplasia.

Abortion, Spontaneous↗