Biomedical subjects

Katrine Hansen

Publications and source records attributed to Katrine Hansen.

7 recordsLinked to original sources

PubMed2004

Reference values for valve circumferences and ventricular wall thicknesses of fetal and neonatal hearts.

To evaluate valvular stenosis, cardiac dilation, and/or cardiac hypertrophy, measurements of valve circumference and ventricular wall thickness are of importance. To establish reference values in fetuses and neonates, we reviewed pathology reports at Women and Infants Hospital from 1978 through 2002 and found measurements in 776 cases that were suitable for analysis. Gestational ages (GA) ranged from 15 to 42 wk. The tabulated data include the mean, standard deviation, and 10th and 90th percentile values for foot length, body weight, body length, heart weight, valve measurements, and ventricular wall thicknesses for each week of GA. In cases in which clinical dating is not reliable, we estimated the GA by the mean value nearest that of the observed foot length. All linear measurements increased in a linear fashion throughout the second and third trimesters of development. The circumferences of cardiac valves at all ages, in descending order of magnitude, are: tricuspid, mitral, pulmonary, and aortic. Mean left ventricular (LV) wall thickness is greater than mean right ventricular (RV) wall thickness throughout gestation. The tables offer a means of determining valvular stenosis, or cardiac dilation and/or hypertrophy, based on various gestational ages.

Fetal Heart↗

PubMed2004

Placental findings after laser ablation of communicating vessels in twin-to-twin transfusion syndrome.

As laser ablation of placental vascular communications gains acceptance as treatment option for severe twin-to-twin transfusion syndrome (TTTS), pathologists are increasingly confronted with the interpretation of laser-treated placentas. We present our preliminary institutional experience with the gross and microscopic analysis of these specimens. Patients underwent selective ablation for severe TTTS (Quintero stages II to V) between 16 and 25 wk gestation and the placentas were examined between < 24 h and 19 wk postoperatively. The placental vasculature was injected with gelatin-dye mixtures. The type and number of vascular anastomoses were recorded, followed by routine histopathological analysis of the placenta. Foci of laser impact were identified in all placentas examined within 1 month after laser coagulation. Located along the recipient side of the dividing membrane, the laser-treated vessels appeared hemorrhagic and showed a characteristic abrupt interruption of dye filling after vascular injection. In placentas examined more than 1 month after intervention, the most frequent gross finding was the absence or relative paucity of intertwin anastomoses, associated with subchorionic fibrin deposition. Microscopically, laser-treated vessels showed varying degrees of necrosis, associated with focal hemorrhage, avascular villi, and fibrin deposition in the underlying parenchyma. In some cases of intrauterine fetal demise or placental disruption, no definite laser scars were identified. As expected, the number of residual anastomoses (all types) was significantly smaller in laser-treated placentas than in control monochorionic placentas (2.4 +/- 2.2 [ n = 10] vs. 6.2 +/- 3.2 [ n = 70], P < 0.01). Velamentous cord insertion was noted in 50% of cases; markedly uneven placental sharing in 60%. Detailed analysis of laser-treated placentas and clinicopathological correlation may lead to a better understanding of the pathophysiology of TTTS and continued refinement of therapeutic approaches for this often lethal condition.

Female↗

PubMed2004

Core excision of the foramen cecum for recurrent thyroglossal duct cyst after Sistrunk operation.

The recurrence rate for thyroglossal duct cysts after a Sistrunk operation is 5% compared with 20% if the hyoid cartilage is not removed. However, few guidelines exist when a lesion recurs after an adequate Sistrunk operation. A 2-year-old boy was referred for recurrent thyroglossal duct cyst after complete and adequate resection. Reexploration of the wound and wider excision of the midline cervical tissues failed to treat the problem. Using a combined transoral/cervical approach, a core of tongue around the foramen cecum was removed. A cystic structure was found at pathologic examination. The child remains asymptomatic 24 months later. If thyroglossal duct cysts recur despite an adequate Sistrunk operation, an intralingual remnant should be suspected. Transoral excision of tongue tissue around the foramen cecum may offer a cure.

Abscess↗

PubMed2003

Renal tubular apoptosis in twin-to-twin transfusion syndrome.

Twin-to-twin transfusion syndrome (TTTS) is caused by uneven shunting of blood between monochorionic twins, resulting in polycythemia in the recipient twin and growth restriction, anemia, and oliguria in the donor twin. Recent reports have described loss of proximal convoluted tubules in the kidneys of TTTS donor twins. In order to elucidate the pathogenesis of tubular deficiency in TTTS, we have reviewed the renal pathology in 25 twin pairs with autopsy-proven TTTS. Loss of differentiated proximal tubules, associated with atrophy of medullary tubules, was identified in 12/25 donor twins. In seven of these cases (all > 23-wk gestational age), the kidneys showed diffuse or partial tubular atrophy without evidence of cell death, similar to previously reported patterns. In five cases (all between 18- and 22-wk gestation), proximal and medullary tubules showed active injury characterized by markedly increased apoptosis, cell detachment, and intraluminal cell debris associated with calcifications. Tubular apoptosis tended to be more prevalent in donor fetuses with greater inter-twin body weight discordance, consistent with a more severe degree of TTTS. These results extend the spectrum of tubular alterations in TTTS to include an early stage of active apoptotic injury. The temporal distribution of injury patterns suggests that apoptotic injury of proximal and medullary tubules may be a precursor to partial or diffuse tubular atrophy. We speculate that the risk for development of tubular apoptosis in TTTS depends on the severity and timing of the hemodynamic imbalance, whereby early mid-trimester fetuses may be more vulnerable.

Adult↗

PubMed2003

Reference values for second trimester fetal and neonatal organ weights and measurements.

To establish accurate reference ranges for the entire second trimester, we documented organ weights, body weight, and linear measurements for 597 fetuses and neonates with gestational ages ranging from 12 to 26 wk. We determined the mean and standard deviation for weights and measurements at each week of gestation using the StatView trade mark SE + Graphics statistical program. The analyses revealed a linear correlation between the gestational age and, respectively, the toe-heel length, crown-rump length, and crown-heel length. Body and organ weights increase at varying rates throughout the second trimester. The data correlate well with weights and measurements previously published for the latter half of the second trimester, and extend these reference ranges to encompass the entire second trimester.

Crown-Rump Length↗

PubMed2003

Testing for hematologic disorders and complications.

This review summarizes state-of-the-art and emerging techniques in the antenatal diagnosis of fetal anemia and hemoglobinopathies. Fetal anemia may result from hemolytic disease, hemorrhage, suppression of erythropoiesis, infection (eg, parvovirus B19), or trauma. The clinical laboratory plays an essential role in the evaluation of these disorders by way of the use of various hematologic, biochemical, serologic, cytometric, and molecular genetics methods. Hemoglobinopathies are the most common class of single gene disorders worldwide. The authors have used the example of homozygous alpha-thalassemia major (Hb Barts disease) as a paradigmatic case for antenatal hemoglobinopathy screening. Perhaps the most familiar indication for hematologic screening in pregnancy is HDFN, most commonly in pregnancies previously sensitized to the RhD antigen. All pregnant women, regardless of their past medical or obstetric history or previous antibody screens, should have ABO/Rh blood typing and a red cell antibody screen performed at the first prenatal visit. Long-established methods for assaying FMH (KB method), microcytosis (hemogram with red cell indices), and blood group incompatibility (direct antigen test, serologies) remain critical for rapid, sensitive diagnosis. Analysis of fetal free DNA in maternal plasma holds the promise for rapid, ultrasensitive, and noninvasive detection of many fetal hematologic disorders.

Adult↗

PubMed2002

Postmortem RNA and protein stability in perinatal human lungs.

The availability of fetal and neonatal lung tissue is an invaluable resource to elucidate the molecular regulation of human lung development. In this study, we have investigated the mRNA and protein stability of perinatal lung tissues treated with RNA (Ambion Inc., Austin, TX) or snap frozen in liquid nitrogen (LN ). Lung samples were obtained from 25 consecutive perinatal autopsies of live-born and stillborn infants (median gestational age, 23 weeks) with various clinical presentations. Treatment of lung tissue with RNA yielded more total RNA and protein than LN freezing. The integrity of RNA, assessed by spectrophotometry and gel electrophoresis, was equivalent between both tissue preservation methods, and both methods produced RNA suitable for reverse transcriptase-polymerase chain reaction analysis of representative genes (beta-actin and surfactant protein-B [SP-B]). Similarly, the protein integrity of RNA -treated tissues was equivalent to that of LN -frozen tissues, as judged by Western blot analysis of SP-B/actin protein expression. Although the total yield was similar in live-born, nonmacerated stillborn and macerated stillborn infants, only RNA and protein from live-born or nonmacerated stillborn infants was suitable for subsequent molecular analyses. Within the 41-hour range studied, the duration of the postmortem interval did not affect the yield or integrity of RNA and protein with either tissue preservation method. In summary, high-quality RNA and protein, suitable for routine molecular analyses, can be obtained from postmortem lung tissue from live-born and nonmacerated stillborn infants, even with prolonged postmortem intervals. RNA is equivalent, if not superior, to LN for preservation of postmortem RNA and protein in developing human lungs.

Autolysis↗