The incorporation site of Er in nanosized CaF2.

The incorporation site of Er dopants inserted at high and low concentration (respectively 5 and 0.5 mol%) in nanoparticles of CaF2 is studied by x-ray absorption spectroscopy (XAS) at the Er L III edge. The experimental data are compared with the results of structural modeling based on density functional theory (DFT). DFT-based molecular dynamics is also used to simulate complete theoretical EXAFS spectra of the model structures. The result is that Er substitutes for Ca in the structure and in the low concentration case the dopant ions are isolated. At high concentration the rare earth ions cluster together binding Ca vacancies.

Experimental phase-space-based optical amplification of scar modes.

Wave billiards which are chaotic in the geometrical limit are known to support nongeneric spatially localized modes called scar modes. The interaction of the scar modes with gain has been recently investigated in optics in microcavity lasers and vertical-cavity surface-emitting lasers. Exploiting the localization properties of scar modes in their wave-analogous phase-space representation, we report experimental results of scar mode selection by gain in a doped D-shaped optical fiber.

Visible and near infra-red up-conversion in Tm3+/Yb3+ co-doped silica fibers under 980 nm excitation.

The spectroscopic properties of Tm(3+)/Yb(3+) co-doped silica fibers under excitation at 980 nm are reported. Three distinct up-conversion fluorescence bands were observed in the visible to near infra-red regions. The blue and red fluorescence bands at 475 and 650 nm, respectively, were found to originate from the (1)G(4) level of Tm(3+). A three step up-conversion process was established as the populating mechanism for these fluorescence bands. The fluorescence band at 800 nm was found to originate from two possible transitions in Tm(3+); one being the transition from the (3)H(4) to (3)H(6) manifold which was found to dominate at low pump powers; the other being the transition from the (1)G(4) to (3)H(6) level which dominates at higher pump powers. The fluorescence lifetime of the (3)H(4) and (3)F(4) levels of Tm(3+) and (2)F(5/2) level of Yb(3+) were studied as a function of Yb(3+) concentration, with no significant energy back transfer from Tm(3+) to Yb(3+) observed.

Time-trends in necropsy prevalence and birth prevalence of lung hypoplasia.

Congenital lung hypoplasia (LH) has been identified with increasing frequency in perinatal and neonatal necropsy reviews. The available prevalence figures have been derived using various diagnostic criteria in different populations and at various times. We therefore reviewed our experience in 15 years of consecutive early neonatal necropsies using one constant set of diagnostic criteria for LH and looked for a time-trend. We determined the necropsy prevalence (no. of cases of LH/no. of necropsies) and the birth prevalence (no. of cases of LH documented at necropsy per 1000 livebirths for inborn patients, and per 1000 referrals for outborn patients) between 1971 and 1985. We then divided this 15-year period into five consecutive 3-year periods to determine if a time-trend was discernible. Whereas early neonatal mortality for neonatal intensive care unit (NICU) admissions progressively decreased from 11.4% to 4.0% between the first and the last 3-year periods, the number of cases of LH per 3-year period did not vary appreciably. As a result, the prevalence of LH at necropsy showed a slight upward trend with time. The overall prevalence was 18%; it was 13% during the first and 23% during the last 3-year period. We found no time-trend in birth or referral prevalence for this lesion, which averaged 1.1 per 1000 livebirths and 9.8 per 1000 referrals. We conclude that lung hypoplasia appears to be emerging as an increasingly prevalent necropsy finding as a result of a shift in proportionate mortality, with the number of patients dying of other causes (denominator) decreasing, and the number of patients dying with lung hypoplasia remaining constant.

Correlation of clinical, radiographic, and arthroscopic findings in internal derangements of the TMJ.

Arthroscopic, clinical, and imaging observations were compared in 80 temporomandibular joints with suspected internal derangements. Rating scales were developed for assessment of the key arthroscopic findings of "roofing," vascularity, redundancy, articular surface condition, adhesions, and disc function. Clinical and imaging findings were correlated with the rated arthroscopic findings. The degree of roofing was found to have a significant relationship to disc quality and function. Arthroscopy completed the diagnostic picture in these cases and provided detailed information on the joints that was not elicited from clinical findings or imaging studies.

Hemangioma with Kaposi's sarcoma-like features: report of two cases.

We describe two children with vascular neoplasms that resembled Kaposi's sarcoma in places. Both presented with intraabdominal masses and severe thrombocytopenia. At autopsy the tumors extensively infiltrated the peritoneum and retroperitoneum and surrounded or invaded numerous organs including the kidneys, pancreas, adrenal glands, gastrointestinal tract, mesentery, and lymph nodes in both cases, and spleen or bone marrow in one case each. The neoplasms were histologically identical and displayed two patterns: dilated vascular spaces (angiomatous areas) lined by flat endothelial-like cells and areas of spindle cells forming slitlike vascular spaces similar to those described in Kaposi's sarcoma. Tumor cells in both cases expressed markers for endothelial cells. The clinical and histologic character of these neoplasms differentiates them from Kaposi's sarcoma, hemangioendothelioma, and from conventional juvenile hemangioma.

Abnormalities of the coronary circulation in pulmonary atresia and intact ventricular septum.

To identify developmental aspects and establish morphologic criteria useful for clinical recognition of sinusoids and coronary artery abnormalities in pulmonary atresia and intact ventricular septum, we studied 17 autopsy hearts with this lesion. Hearts from age- and weight-matched infants served as controls. There were two stillborn fetuses, 12 full-term neonates, and 3 infants. None of the eight hearts with normal or large-sized right ventricular chambers had sinusoids or coronary artery abnormalities. Five of nine hearts with small right ventricular chambers had sinusoids; all five lacked trabecular and outlet portions of the ventricle. Four of these five contained major coronary artery abnormalities: atrophy of one or both coronaries proximal to a communication between a sinusoid and the coronary artery. We conclude (1) there is a strong association between the presence of sinusoids and coronary anomalies, supporting the developmental concept of abnormal persistence of embryonic right ventricular sinusoid--coronary artery communications in pulmonary atresia and intact ventricular septum; (2) the absence of trabecular and outlet portions of the small right ventricle indicates a strong possibility of coronary artery abnormalities; and (3) this initial report of a fully-developed lesion in a mid-gestation fetus documents that the coronary artery problem may arise early in fetal life.

Prune belly syndrome: 35 years of experience.

Between 1949 and 1984, 50 children with the prune belly syndrome were treated at our institution. The modes of evaluation and treatment, and the long-term results are discussed.

Hemangioma of the umbilical cord.

Tumors of the umbilical cord are extremely rare. Only two types are recognized: hemangioma and teratoma. A case of hemangioma of the cord prompted a review of the world literature that uncovered 17 other cases, bringing the total number of known cases up to 18. Our case is the first to be diagnosed by ultrasonography and was associated with polyhydramnios.

Umbilical cord length in Down's syndrome.

Fetal motor activity is believed to influence umbilical cord growth. As Down's syndrome is associated with hypotonicity and reduced fetal activity, we hypothesized that newborn infants with this syndrome have short umbilical cords. We identified 21 infants with Down's syndrome and compared each individual cord length to mean standard values derived from the same population and matched for sex, race, and gestational age. Infants with Down's syndrome were found to have significantly shorter umbilical cords (mean of 45.1 cm compared with 57.3 cm for matched standards). It is not clear whether their cords are shorter on the basis of decreased fetal activity, genetics, or both. If it is on the basis of decreased fetal activity, it would be interesting to see if those with the shortest cords (presumed to have been the most hypoactive in utero) could be predicted to have worse neurodevelopmental outcomes.

Morphometric analysis of the growth of the normal fetal guinea pig lung.

The structural development of the fetal guinea pig lung is described and quantified morphometrically in this report. At 35 days gestation the lung is in the pseudoglandular phase of growth, by 40 days it is in the canalicular phase, and at 50 days the saccular growth phase has begun. At term (67 days), the fetal guinea pig lung appears mature. From the beginning of the canalicular to the end of the saccular phases, the correlation coefficient between lung volume and gestational age is +.98, between internal surface area and gestational age is +.94 and between total number of saccules and gestational age is +.97. Internal surface area (ISA) correlates closely with lung volume (r = +.99) and the correlation coefficient between total number of saccules and lung volume is +.98. At term, lung volume is 4.22 ml. ISA is 0.5 M2, and total number of saccules is 253 million. Parenchymal growth is achieved by increases in both number and size of airspaces in the canalicular phase, primarily by increases in number during the early saccular phase and largely by increases in airspace size near term. The total length of parenchymal elastic tissue increases from 223 M at 45 days gestation to 5,253 M at term. Elastic tissue fibers first appear in the parenchyma of the fetal guinea pig lung during the canalicular phase, when the rate of saccule formation is high. The quantitative increase in elastic tissue correlates closely with the increase in the total number of saccules from day 45 to day 60 of gestation (r = +.99). The rate of elastic tissue growth increases sharply in the late saccular phase, coinciding with the period of greatest saccular expansion. These data suggest an interdependent relationship between saccular growth, i.e., proliferation and expansion, and the development of lung parenchymal elastic tissue.

Oligohydramnios-induced lung hypoplasia: the influence of timing and duration in gestation.

We drained amniotic fluid for periods of 5 and 10 days at various times in gestation between days 40 and 55 in the guinea pig (term is 67 days). We analyzed the impact of this procedure on fetal lung growth and used untouched littermate fetuses as controls. During the canalicular stage of lung development, total lung DNA per gram of fetal weight was significantly reduced after only 5 days of oligohydramnios and the percent change did not vary between the two consecutive 5-day periods studied (period A, days 40 to 45, delta of -0.047 mg, p = 0.004; period B, days 45 to 50, delta of -0.042 mg, p = 0.002). The impact of the same duration of oligohydramnios on lung growth later in gestation, during the terminal sac stage of lung development, was less (period C, days 50 to 55, delta of -0.027 mg, p = 0.097). This reduction in effect between period A or B and C was significant at the 0.05 level using a one-way analysis of variance. Two overlapping 10-day periods were also studied. In both experiments, the percent changes in lung DNA per gram of fetal weight between experimental and littermate controls were significant (period D, days 40 to 50, delta of -0.072 mg, p = 0.001; period E, days 45 to 55, delta of -0.047 mg, p = 0.001). The inhibitory effect of oligohydramnios on lung growth was more marked in period D than E (significant at the 0.05 level).(ABSTRACT TRUNCATED AT 250 WORDS)

Morphometry of hypoplastic fetal guinea pig lungs following amniotic fluid leak.

Deficient quantity of amniotic fluid causes fetal guinea pig lung hypoplasia. Oligohydramnios that lasts only 5 days in early gestation is sufficient to reduce fetal lung growth significantly. We quantitated lung structural alterations at 50 days gestation (term is 67 days) of fetal guinea pigs whose amniotic fluid was drained on day 45 gestation. The study period spans the late canalicular-early saccular phases of guinea pig lung growth. Compared to littermate controls (n = 4), experimental fetuses (n = 5) have reduced lung:body weight ratio (2.81 +/- 0.16 versus 3.21 +/- 0.20 X 10(-2), p less than 0.01), indicating lung hypoplasia. Lung volume is significantly decreased in the experimental fetuses (1.17 +/- 0.15 versus 1.34 +/- 0.07 ml, p less than 0.05). The proportion of lung containing parenchyma (i.e. developing alveoli and alveolar ducts) is reduced following oligohydramnios (0.83 +/- 0.04 versus 0.90 +/- 0.02, p less than 0.025). The hypoplastic lungs contain fewer saccules (fetal "alveoli") (46 +/- 20 versus 69 +/- 23 X 10(6), p less than 0.1) and the surface area that would be available for gas exchange is decreased (698 +/- 234 versus 974 +/- 80 cm2, p less than 0.05). Lung volume and volume proportion of parenchyma are reduced in the experimental lung and therefore diminished parenchymal elastic tissue is anticipated. However, the total length of parenchymal elastic tissue in the experimental lungs is decreased to a surprising degree and is little more than half the length in control lungs (504 +/- 222 versus 974 +/- 70 m, p less than 0.0025). Such marked reduction in total length suggests that factors other than smaller lung size have contributed to the decrease of elastic tissue in the experimental group. In fact, elastic tissue length per unit volume is significantly reduced (509 +/- 189 versus 809 +/- 115 m/cm3, p less than 0.025) indicating an absolute decrease in parenchymal elastic tissue in the hypoplastic lungs.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of maternal cigarette smoking on placental morphology, histomorphometry, and biochemistry.

We related cigarette smoking during pregnancy to the macroscopic and microscopic morphology, histomorphometry, and biochemistry of the placenta among participants in The Prenatal Project, a randomized, controlled trial of nutritional supplementation during pregnancy. The aim was to ascertain if the harmful effects of cigarette smoking on the fetus were reflected, and possibly mediated, by changes in the placenta, and whether such changes might be modified by the nutritional supplements, parallel to the nutritional reversal of birthweight depression among heavy smokers. Maternal smoking was associated with increased alkaline ribonuclease (RNase) levels, possibly resulting in disturbed protein synthesis. More smokers had placentas with villous hyperplasia on histologic examination. This was accompanied by biochemical evidence of significantly increased cellularity (increased DNA/gm of placental mass and decreased protein/DNA ratios) and (nonsignificant) trends to reduced syncytial villous cell size on histomorphometry. There were joint effects of cigarette smoking and use of either form of nutritional supplementation on the fibrin and stoma components of the villi, but such changes are not necessarily pathologic. The significant reduction in pathology of the stem villi among smokers was confined to those who were nutritionally supplemented, particularly heavy smokers. This change may thus have reflected the protective effects of supplementation on the birthweight of the offspring of these heavy smokers.

Morphology of early fetal deaths and their chromosomal characteristics.

The morphologic features of a consecutive series of 3,472 singleton spontaneous abortions are described. Of the total, 21% consisted of well-formed fetuses (over 30 mm long), 27.9% had no identifiable fetal tissues, 34.2% consisted of fetal membranes only, and the remainder, 16.8%, consisted of a variety of embryonic types. The rate of focal malformations among embryos over 10 mm in length and among fetuses was 16.4%. The overall rate of chromosome anomalies in the 1,356 karyotyped specimens was 39.8%. The vast majority, 94%, occurred in embryos less than 30 mm, and in specimens whose development had not proceeded beyond differentiation of fetal membranes. The rate of chromosome anomalies among nonmalformed fetuses (greater than 30 mm) was only 1.7%. However, the presence of limited embryonic development was not a good predictor of the presence of a chromosome anomaly. Slightly over half (56%) of all specimens less than 30 mm long had chromosome anomalies; for individual classes of such specimens the rate ranged from 45% to 81%. The morphologic category with the highest rate of karyotypic anomalies had an excess of monosomy X abortuses. A gradient of developmental level could be associated with the degree of intrauterine mortality of each chromosome anomaly; i.e., conceptuses with karyotypes that occur at term had a greater degree of embryonic development than karyotypes that are never seen among term births. Thus, trisomies 13, 18, and 21 were more often associated with fetuses, and less often with tissue fragments than other trisomies. Focal malformations were multiple and severe in abortuses with triploidy, trisomies 13 and 18, and monosomy X and mild in trisomy 21. With the exception of monosomy X the malformations were similar to, and not more severe than those reported from, term births with the same anomaly. The high rate of intrauterine mortality in conceptuses with chromosome anomalies could be ascribed to their failure to develop past the embryonic stages. However, the presence of an equally large fraction of chromosomally normal abortions with the same degree of rudimentary development suggests the existence of early and profound developmental problems that are not associated with anomalies of the chromosome complement.

Healing of ischemic colonic anastomoses in the rat: role of antibiotic preparation.

In this study we evaluated the relative effects of ischemia with and without antibiotic bowel preparation on colonic wound healing. Thirty-two Sprague-Dawley rats (185 to 300 gm) were divided into five study groups: Groups I and II (n = 14) had no colonic ischemia, half receiving antibiotic bowel preparation before colocolostomy. Groups III, IV, and V (n = 18) had colonic ischemia induced by division of the marginal artery and ligation of the arteries to the splenic flexure and pelvic colon, assuring that all blood supply to the left side of the colon was intramural. Enteral (neomycin and erythromycin) antibiotic preparation was given in group III, no antibiotics were given in group IV, and parenteral (clindamycin and gentamicin) preparation was given in group V. The mid-left side of the colon was transected and an everting anastomosis was constructed with continuous 6.0 silk sutures. All animals were killed on the seventh postoperative day. Anastomotic healing in unprepared, ischemic rat colon was severely impaired, with an 83% dehiscence rate. In the colon prepared with enteral antibiotics, no adverse effect of ischemia was found. No animal had dehiscence, proximal dilation of the colon, or intra-abdominal abscess. This study may have clinical relevance in patients with ischemic intestinal disorders.

Fetal lung hypoplasia associated with maternal smoking: a morphometric analysis.

Our recently reported animal (rat) model of maternal cigarette smoke exposure during pregnancy is characterized by fetal growth retardation and lung hypoplasia. We have further defined the fetal lungs using quantitative histologic techniques. Compared to controls, lung volume at term is reduced in the experimental animals (0.28 versus 0.33 ml, p less than 0.005). Saccules (fetal "alveoli") are reduced in number (3 X 10(6) versus 5.5 X 10(6), p less than 0.005) and increased in size (average saccular volume: 35 X 10(-9) versus 21 X 10(-9) ml, p less than 0.025). These changes in size and number are consequences of reduced formation of saccule partitions (septal crests) in the experimental lungs (volume density: 0.013 versus 0.018, p less than 0.025). Internal surface area is decreased in the hypoplastic lungs (161 versus 198 cm2, p less than 0.001). The total length of parenchymal elastic tissue is diminished (224 versus 354 M, p less than 0.05). In short the hypoplastic lungs contain fewer, larger saccules and the surface potentially available for gas exchange is reduced. These results show that maternal smoking in rats adversely modifies fetal lung growth. If these observations are applicable to humans, then reduced lung growth in children of smoking mothers may begin antenatally.

Malformations and chromosome anomalies in spontaneously aborted fetuses with single umbilical artery.

Presence of a single umbilical artery was noted 13 times among a series of 879 consecutively collected, spontaneously aborted embryos and fetuses. This rate of 1.5% is approximately twice that reported from the largest series of term births. Eight of the 13 fetuses had additional serious malformations. Of nine successfully karyotyped fetuses, six had chromosome anomalies. All six occurred in fetuses with severe malformations in addition to the single umbilical artery. The presence of single umbilical artery with other major anatomic defects may be a significant predictor of the presence of chromosome anomalies in live births. Early recognition of offspring with chromosome anomalies will be useful in counseling the family and in managing the care of the infant.

Immunocytochemical localization of lysozyme and alpha-1-antichymotrypsin in the term human placenta: an attempt to characterize the Hofbauer cell.

The intracellular localization of lysozyme (LSZ) and alpha-1-antichymotrypsin (A1Ac), glycoproteins associated with macrophages, was used to confirm the monocytic lineage of the Hofbauer cell and to assess the maturity of its macrophage function. The peroxidase-labeled antigen method was used to localize these proteins, as well as immunoglobulins, light chains, and albumin, in Bouin-fixed, paraffin-embedded sections of 24 normal term placentas. The demonstration of the latter substances was used as an indication of passive diffusion or phagocytosis of serum proteins resulting in intracellular localization unrelated to synthesis. In all the placentas examined a strong cytoplasmic reaction for A1Ac was seen in the Hofbauer cells. The same cells on adjacent sections did not stain for LSZ, while the occasional maternal macrophage and numerous polymorphonuclear leukocytes in the intervillous spaces gave a positive reaction. The detection of A1Ac supports the contention that these cells are macrophages, previously suggested by their phagocytic capability and the demonstration of Fc receptors and nonspecific esterases. Since they do not appear to contain LSZ, a bactericidal enzyme, we propose that these cells are not fully differentiated macrophages, and the lack of this enzyme may have some relevance to the pathogenesis of certain placental infections.

Chemotherapy and its effect on testicular morphology in children.

Bilateral testicular biopsies were performed on 25 boys between 4 and 16 years old with the diagnosis of acute lymphocytic leukemia after the induction of regression with vincristine and prednisone, followed by cyclic maintenance therapy with a combination of 6-mercaptopurine, methotrexate, L-asparaginase, cyclophosphamide and doxorubicin for 2 years. These drugs were given in accordance with children's cancer study group protocols. Only 3 boys had positive biopsies (12 per cent), although post-treatment testicular morphology was abnormal in the overwhelming majority. Interstitial fibrosis was present in 16 children (70 per cent), basement membrane thickening in 12 (50 per cent) and, most importantly, a reduction in the tubular fertility index of greater than 50 per cent in 20 (80 per cent). There was no relationship between the abnormal morphology encountered and the age of the patient when treated. Most of these changes may be reversible with time but only a biopsy at a later date can establish the long-term effects of treatment on testicular morphology and, perhaps, help to predict future fertility potential.