OS057. Pathophysiological role of elevated tissue transglutaminase in autoantibody-induced features of preeclampsia in pregnant mice.

INTRODUCTION: Preeclampsia (PE) is highly associated with the presence of autoantibodies that activate the major angiotensin receptor, AT1R. These autoantibodies (termed AT1-AA) cause most features of PE when introduced into pregnant mice and are believed to contribute to disease pathogenesis. Tissue transglutaminase (tTG) is a prominent member of a family of enzymes that crosslink proteins by catalyzing the formation of an isopeptide bond between the amide group of glutamine and the free amino group of lysine and is believed to play a role in AT1R activation. OBJECTIVES: To test the hypothesis that tTG plays a role in autoantibody-mediated AT1R activation and thereby contributes to the pathophyhsiology of PE. METHODS: Western blotting was used to quantify tTG in placentas of normotensive pregnant women and those with PE. Immunohistochemistry was used to determine cellular localization of tTG, AT1R and glutamyl-lysine isopeptides in placenta tissue. Co-immunoprecipitation experiments were used to explore the possible association of tTG and AT1R. Finally, in an effort to determine the role of tTG in AT1-AA-induced features of PE in vivo, we treated autoantibody-injected pregnant mice with cystamine, a potent tTG inhibitor. RESULTS: Western blot analysis showed elevated tTG in placentas of women with PE. Immunohistochemical analysis revealed that increased levels of tTG, glutamyl-lysineisopeptides, AT1R co-localized in the microvillous membrane of PE placentas. Immunoprecipitation of tTG from human trophoblast cell (HTR) lysates resulted in the co-immunoprecipitation of AT1R, thereby providing evidence for an interaction between tTG and AT1R in HTR cells. Finally, we found that cystamine treatment significantly attenuated key features associated with PE including hypertension and proteinuria in the PE-IgG-injected pregnant mice. CONCLUSION: Taken together, we identified a previously unrecognized role of elevated tTG in PE likely by activating or stabilizing AT1Rs. These studies provide novel mechanisms of autoantibody-induced AT1R activation by elevated placental tTG, highlight the role of tTG in the pathogenesis of PE and suggest novel therapeutic strategies for the disease.

OS069. Light, a TNF superfamily member, contributes to pathophysiology in a mouse model of preeclampsia.

INTRODUCTION: Preeclampsia (PE) is associated with alterations in the renin-angiotensin system due to the presence of autoantibodies that activate the major angiotensin receptor, AT1R. The resulting chronic activation of the AT1 receptor is believed to contribute to a pro-inflammatory state that is also characteristic of PE. Microarray analysis revealed a pronounced increase in the abundance of LIGHT, a potent member of the TNF superfamily that has emerged as a key factor mediating strong T-cell inflammatory responses and a contributor to autoimmune disease pathogenesis. OBJECTIVES: The goal of research described here is to determine the contribution of LIGHT to the pathophysiology of PE. METHODS: An ELISA, specific for LIGHT was used to validate the results of the initial microarray analysis. Infusion experiments were used to determine the effects of elevated LIGHT in pregnant and non-pregnant mice. An adoptive transfer model of PE in pregnant mice was used to determine if AT1R agonistic autoantibodies (AT1AA) stimulate LIGHT production. The potential contribution of increased LIGHT to clinical features of PE in pregnant mice was evaluated by the use of neutralizing antibodies directed to the LIGHT receptors, HVEM and LTßR. RESULTS: The use of a LIGHT-specific ELISA showed that the cytokine was significantly increased in the circulation and placentas of women with PE. The infusion of recombinant LIGHT into pregnant mice induced major clinical features of PE, including hypertension and proteinuria. Such changes were not observed when LIGHT was infused into not non-pregnant mice. LIGHT was significantly elevated in a pregnant mouse model of PE based on the introduction of IgG from women with PE. In this autoantibody-injection model of PE, the use of neutralizing antibodies to the LIGHT receptors, HVEM and LTßR, blocked autoantibody-induced hypertension, proteinuria, elevated sFlt-1 production, impaired placental angiogenesis and endothelial dysfunction. CONCLUSION: Overall, our studies show that LIGHT is significantly elevated in women with PE and that elevated LIGHT contributes to pathophysiology of PE in an antibody-injection model of PE in pregnant mice. LIGHT-induced pathophysiology can be abrogated by the use of neutralizing antibodies directed at its receptors, HVEM and LTßR. These results indicate that LIGHT may have a previously unrecognized role in the pathophysiology of PE and that its detrimental effects are pregnancy-dependent. These findings immediately suggest novel therapeutic possibilities.

The functional role of the renin-angiotensin system in pregnancy and preeclampsia.

During normal pregnancy, the renin-angiotensin system (RAS) plays a vitally important role in salt balance and subsequent well-being of mother and fetus. In this balance, one must consider not only the classical renal RAS but also that of the uteroplacental unit, where both maternal and fetal tissues contribute to the signaling cascade. Many studies have shown that in normal pregnancy there is an increase in almost all of the components of the RAS. In derangements of pregnancy this delicate equilibrium can become unbalanced. Preeclampsia is one such case. It is a disorder of pregnancy characterized by hypertension, proteinuria and placental abnormalities associated with shallow trophoblast invasion and impaired spiral artery remodeling. Despite being a leading cause of maternal death and a major contributor to maternal and perinatal morbidity, the mechanisms responsible for the pathogenesis of preeclampsia are poorly understood. Immunological mechanisms and the RAS have been long considered to be involved in the development of preeclampsia. Numerous recent studies demonstrate the presence of the angiotensin II type I receptor agonistic autoantibody (AT1-AA). This autoantibody can induce many key features of the disorder and upregulate molecules involved in the pathogenesis of preeclampsia. Here we review the functional role of the RAS during pregnancy and the impact of AT1-AA on preeclampsia.

Applications of optical resonance to biological imaging and label-free protein microarrays.

We present biological imaging and sensing methods based on optical resonance and interference. In fluorescence microscopy, our nanoscale imaging capability sheds light onto conformational changes of DNA, DNA-protein complexes and polymer coatings on a solid surface. Interference measurements on a layered substrate yield a label-free sensing platform for protein binding in a high-throughput micro-array format.

Cu/Zn superoxide dismutase mutants associated with amyotrophic lateral sclerosis show enhanced formation of aggregates in vitro.

Mutations in Cu/Zn superoxide dismutase (SOD) are associated with the fatal neurodegenerative disorder amyotrophic lateral sclerosis (ALS). There is considerable evidence that mutant SOD has a gain of toxic function; however, the mechanism of this toxicity is not known. We report here that purified SOD forms aggregates in vitro under destabilizing solution conditions by a process involving a transition from small amorphous species to fibrils. The assembly process and the tinctorial and structural properties of the in vitro aggregates resemble those for aggregates observed in vivo. Furthermore, the familial ALS SOD mutations A4V, G93A, G93R, and E100G decrease protein stability, which correlates with an increase in the propensity of the mutants to form aggregates. These mutations also increase the rate of protein unfolding. Our results suggest three possible mechanisms for the increase in aggregation: (i) an increase in the equilibrium population of unfolded or of partially unfolded states, (ii) an increase in the rate of unfolding, and (iii) a decrease in the rate of folding. Our data support the hypothesis that the gain of toxic function for many different familial ALS-associated mutant SODs is a consequence of protein destabilization, which leads to an increase in the formation of cytotoxic protein aggregates.

Corneal topography of photorefractive keratectomy versus laser in situ keratomileusis. Summit PRK-LASIK Study Group.

OBJECTIVE: This study aimed to compare qualitative patterns of corneal topography early in the postoperative course after excimer laser photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) when used for the treatment of myopia of 6.0 to 15.0 diopters. DESIGN: The study design was a prospective, multicenter, randomized clinical trial. PARTICIPANTS: A total of 64 eyes were treated with PRK and 54 eyes were treated with LASIK. INTERVENTION: Using the Summit Apex excimer laser, patients received either PRK or LASIK using a single pass, multizone excimer laser ablation. Computer-assisted videokeratography was performed at designated postoperative examinations. MAIN OUTCOME MEASURES: Videokeratography maps at 1 and 3 months after surgery were classified using a standard classification scheme. The association of topography patterns to loss of spectacle-corrected visual acuity was tested. RESULTS: At 1 month, for the PRK (n = 60) and LASIK (n = 51) groups, respectively, 63.3% and 19.6% of eyes fell into one of the four optically irregular groups (central island, keyhole, semicircular, or irregularly irregular; P < 0.001). At 3 months, for the PRK (n = 49) and LASIK (n = 39) groups, respectively, 36.7% and 10.3% of eyes fell into one of the optically irregular groups (P = 0.004). Comparing the 1- and 3-month examination results in the PRK and LASIK groups, respectively, 19 (42%) of 45 eyes and 11 (31%) of 36 eyes had a change in topography, generally to an optically smoother pattern. The irregular groups, taken together, were associated with a greater tendency toward loss of spectacle-corrected visual acuity of two or more Snellen lines (P = 0.01). There also was greater tendency toward loss of spectacle-corrected visual acuity in the PRK group that diminished with time (P < 0.01 at 1 month, P = 0.05 at 3 months). CONCLUSIONS: After treatment for moderate-to-high myopia, LASIK topography patterns generally are more regular than are PRK patterns. This may be a result either of masking of underlying topography perturbations by the lamellar corneal flap, thus mitigating induced topography changes, or differences in surface wound healing. This study suggests that more rapid return of spectacle-corrected visual acuity found in patients treated with LASIK may be a result of more regular topography patterns early in the postoperative course.

Physiologic bowing in children: an analysis of the pendulum mechanism.

Prompted by common observations, we investigated why physiologic bowing occurs in infants and what purpose is served by its characteristic varus to valgus to neutral movement of the mechanical axis of the knee which we term "pendulum-like swing" in the frontal plane. Anthropomorphic data were readily available on age-related increase in weight, femoral and tibial lengths, and changes in lower extremity to allow construction of an "average" leg representing "normal" limb alignment of a growing infant male aged 1-8 years. This enabled us to calculate the bending moments on five anatomic levels of the limb about the knee; more important, during some growth periods the bending moments are minimal and may be used to diagnose pathologies of the lower limb. This form of analysis may prove useful in pathologies in which mechanisms serve to "mask" problems diagnosed on the basis of knee angle alone. When the child begins to stand, the pendulum mechanism is needed to equalize physeal growth about the knee.

Quantificaçäo do aspartame por cromatografia líquida de alta resoluçäo(CLAR) em pós para o preparo de sobremesas / Determination of aspartame in dry mix to prepare desserts

Foram analisadas para a determinaçäo do aspartame 72 amostras de mistura em pó para o preparo de sobremesas dietéticas, gelatinas, pudins e flans, de vários sabores e marcas, comercializadas pelas indústrias nacionais, utilizando-se o método da cromatografia líquida de alta resoluçäo(CLAR), com grau de recuperaçäo do aspartame entre 96-97 por cento . Todas as amostras analisadas apresentaram teores de aspartame dentro do limite estabelecido pela legislaçäo em vigor, isto é, 75mg por 100g do produto a ser consumido

Regional variations in oral submucous fibrosis in India.

Regional variations in the characteristics of submucous fibrosis were studied in two districts in India. In Pune district this condition involved soft palate, uvula and retromolar areas significantly more often than in Ernakulam district. The tongue, floor of the mouth and the hard palate were not involved in Pune. The age of the patients in Pune district was lower than in Ernakulam district. Associated oral cancer, leukoplakia and petechiae were observed solely among patients in Ernakulam. The most important etiologic factor for submucous fibrosis is the chewing of areca nut, and in both areas studied all patients chewed areca nut. In Pune, cured areca nut without other ingredients was chewed by 66% and in Ernakulam, raw areca nut was chewed as an ingredient of pan with tobacco by 100%. Thus in Ernakulam, the juice and the quid were mostly spat out, whereas in Pune they were swallowed. The regional variations in the characteristics of submucous fibrosis could be related to the differences in the areca nut chewing habit between the two areas.

[Efficacy of captopril in the treatment of patients with severe forms of chronic heart failure]. / Effektivnost' kaptoprila pri lechenii bol'nykh s tiazhelymi formami khronicheskoi serdechnoi nedostatochnosti.

A study was made of the efficacy of captopril used alone and in combination with cardiac glycosides in 20 patients with stage IIB congestive heart failure. The patients' clinical status and changes in some indices of hemodynamics and external respiratory function were taken into account. A single use of the drug improved the clinical status and indices of hemodynamics and external respiratory function in the patients. The most noticeable clinical effect was achieved with the combined use of cardiac glycosides, diuretics and captopril.

Epiphysiodesis in slipped capital femoral epiphysis: a comparison of various surgical modalities.

This retrospective study surveys patients treated between 1960 and 1978 for slipped capital femoral epiphyses. The parameters reported are fusion time, blood replacement, hospitalization time, aseptic necrosis, cartilage necrosis, and complications. Twenty-eight hips (24 patients) were treated by pinning, and three hips (three patients) were treated by Smith-Petersen nails. The Heyman or Howorth bone pegging procedures were performed in 48 hips in 41 patients. The average fusion time was 9.4 months for hips treated with Knowles pins, 3.7 months for Hagie or Tachdjian pins, and 4.8 months for bone pegging procedures. Blood loss, hospitalization time, surgical scars, and duration of anesthesia were greater for the bone pegging procedures.

Osteogenesis imperfecta with unusual skeletal lesions: report of three families.

Thirteen individuals with osteogenesis imperfecta (OI) from three families were evaluated. All examined persons with OI had multilocular radiolucent, radiopaque, or radiolucent-radiopaque lesions of the maxilla and mandible. In most patients, the lesions involved the tooth bearing areas, but in two, the rami also were involved. Teeth were normal. Radiologic findings in the extragnathic skeleton included marked coarseness of trabeculae and diffuse osteopenia. It is proposed that these patients represent yet another dominantly inherited OI syndrome.

A possible explanation of the pathogenesis of osteochondritis dissecans.

We present a case in which osteochondritis dissecans of the lateral femoral condyle was associated with a torn discoid lateral meniscus. To our knowledge, this is the first reported case of this association in the radiographic and orthopedic literature. Previous trauma is suggested to play an important role in the development of both lesions.

Long-term results in the treatment of femoral-shaft fractures in young children by immediate spica immobilization.

Manual traction reduction without anesthesia and immediate immobilization in a spica cast were used to treat eighty-five children ranging in age from birth to ten years old who had closed femoral-shaft fractures and no associated injuries. Up to two centimeters of overriding, 30 degrees of anterior angulation, and 15 degrees of medial angulation were accepted. Any angulation in excess of these amounts, or lateral or posterior angulation, was corrected by wedging the cast at the fracture site. Further telescoping of the fracture fragments in the case was attributed to the child pressing the foot against the bottom of the cast and was prevented by removing the sole of the cast. Of the seventy-five children examined two to eighteen years after fracture, none had any residual skeletal deformity or joint stiffness. The length discrepancies of the fractured limbs ranged from 1.7 centimeters of shortening to 0.9 centimeter of overgrowth.