Biomedical subjects

H Pinar

Publications and source records attributed to H Pinar.

34 records · Page 2Linked to original sources

PubMed1994

Neoplastic hormone-producing cells of the placenta produce and secrete parathyroid hormone-related protein. Studies by immunohistology, immunoassay, and polymerase chain reaction.

BACKGROUND: Parathyroid hormone-related protein (PTHrP) was originally discovered as a product of tumors associated with hypercalcemia. Subsequent studies have demonstrated the widespread production of PTHrP in both fetal and adult tissues, among them the placenta, where it has been identified in amniotic epithelial cells and trophoblasts. However, studies of PTHrP production by the neoplastic placenta have not been reported. EXPERIMENTAL DESIGN: We have studied placental cells and tissues for PTHrP by immunohistology, immunoassay, and the polymerase chain reaction. We studied normal placenta, placenta neoplasia, and placental cell lines grown in culture. RESULTS: Our studies in abnormal placenta demonstrate that PTHrP is produced by chorioangioma, choriocarcinomas, and hydatidiform moles, indicating that PTHrP may be a marker for neoplasia of the placenta. Our studies in normal placenta demonstrate that PTHrP is produced by several placental cell types, including, syncytiotrophoblast, intermediate trophoblasts, cytotrophoblasts, and amniotic epithelium, suggesting an important role for this protein in several aspects of placental function. Cell lines derived from trophoblasts and amniotic epithelium also produced PTHrP and secreted it into culture medium. Polymerase chain reaction with PTHrP coding sequence primers demonstrated the appropriate polymerase chain reaction product in these placental cells. CONCLUSIONS: The production of PTHrP by several normal and abnormal placental cell types is evidence for an important function for PTHrP in normal and neoplastic placenta.

Cell Line↗

PubMed1992

Open traumatic posterior dislocation of the hip. A case report.

A case of open traumatic posterior dislocation of the hip is presented. The femoral head and neck were completely out of the skin and there were accompanying fractures of the acetabular floor, the ischial ramus and the greater trochanter. To our knowledge, such a case has not been reported previously and this, together with its interesting mechanism, has led us to report the case. It was followed for 18 months and roentgenographic and 99mtechnetium sulphur colloid scanning studies showed avascular necrosis and osteoarthritis.

Accidents, Traffic↗

PubMed1992

Indomethacin for prevention of heterotopic ossification after total hip arthroplasty.

Twenty-four patients (29 hips) undergoing total hip arthroplasty were routinely given 75 mg of indomethacin daily for 4 weeks after operation and reviewed radiographically for heterotopic ossification (HO) for a minimum of 6 months. A comparison group of 25 patients (27 hips) without indomethacin treatment was formed and studied in the same manner. This group of patients received the usual postoperative analgesic treatment, which is diclofenac sodium twice daily parenterally for 5-10 days. The indomethacin group also received the same treatment. In the indomethacin group no patient had grade II, III, and grade IV HO and the incidence of grade I HO was 31% (nine patients). In the comparison group one patient (3%) had grade I, three (11%) grade II, and eight (30%) grade III HO. These findings suggested that indomethacin effectively prevented higher grades of HO following total hip arthroplasty. Two patients not included in the study had gastrointestinal bleeding and recovered after withdrawal of the drug.

Adult↗

PubMed1992

Distribution of transforming growth factor beta in a two-week-old human embryo.

Using immunohistochemical methods we have investigated the presence of transforming growth factors beta 1, beta 2 and beta 1 precursor in a two-week-old bilaminar human embryo. TGF-beta 1 precursor was seen in both the epiblast and the hypoblast. In contrast to the widespread localization of TGF-beta 1 precursor in the embryo proper, antibodies to the mature TGF-beta 1 peptide localized preferentially to the hypoblast with only weak staining in the epiblast. Staining with antibodies to TGF-beta 2 was generally weak in both the epiblast and hypoblast layers of the embryo proper. These results show that TGF-beta 1 and beta 2 peptides are detectable as early as the second week of human development.

Embryo, Mammalian↗

PubMed1992

The Alici spinal system in the surgical treatment of scoliosis.

The Alici spinal system is an instrumentation used for correction and fixation of various deformities of the spine. Idiopathic scoliosis is the most important indication. Scoliosis is a complex deformity in the frontal, sagittal and axial planes, and this system provides perfect correction in all three planes. Furthermore, it permits stable fixation and can be used for both anterior and posterior spinal fusions. The indications for the anterior Alici spinal system are: mature thoracolumbar or lumbar curves of more than 40 degrees, progressive immature thoracolumbar or lumbar curves of more than 35 degrees, painful mature lumbar curves, paralytic or congenital lumbar or thoracolumbar curves, and mature lumbar curves of more than 40 degrees in thoracolumbar double curves. The indications for the posterior Alici spinal system are: immature thoracic curves of more than 40 degrees, progressive thoracic or thoracolumbar curves of more than 35 degrees, and paralytic and congenital curves. During the last two years, 92 scoliosis patients underwent spinal fusion with Alici spinal instrumentation. Scoliosis was idiopathic in 58, congenital in 20, paralytic in 12, and 2 cases were caused by neurofibromatosis. Twenty-four of the patients underwent 2-stage anterior and posterior fusions. In the remaining 68 patients only posterior fusion was performed. The mean follow-up was 14 months (range, 6-24 months). Preoperatively, the mean curves of the idiopathic, congenital, and paralytic groups were 54.7 degrees, 57.8 degrees, and 83 degrees, respectively. In the idiopathic group the mean correction was 93% with anterior instrumentation, and 74.4% with posterior instrumentation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

Dacron augmentation of a free patellar tendon graft: a biomechanical study.

The mechanical characteristics of a knitted 8-mm Dacron tube used as augmentation for patellar tendon strips was analyzed and compared with ligament augmentation device (LAD) tendon strips. The failure load was found to be the same (approximately 320 N) for both types of ligament augmentations. The typical failure mode in the Dacron augmentations was rupture of the Dacron tube proximal to the proximal bone fragment. The LAD augmentations failed at the suture line. The Dacron composite was stiffer than the LAD composite at low loads, but both composites became stiffer after two load cycles to 40 N with stress relaxation. At the end of the second stress relaxation cycle, the remaining load was significantly higher for the Dacron composite. During the second 2-min stress relaxation period, the Dacron composite lost 23% and the LAD composite lost 28% of the applied load. The stiffness and the elongation to failure was the same for both composites. The study showed that the Dacron tube may have possibilities similar to the LAD for use as an augmentation device.

Humans↗

PubMed1980

Papillary elastofibroma of the left ventricular septum.

Papillary elastofibromas of the heart are usually incidental findings at autopsy. They occur more commonly on the surfaces of the valves than on the mural endothelium and are characterized by a papillary configuration with fronds composed of a collagenous and elastic tissue core lined by hyperplastic endothelial cells. Echocardiography and cardiac catherization demonstrated the lesion preoperatively in this case.

Adult↗

PubMedDate not supplied

Beta-cell hyperplasia in macrosomic infants and fetuses of nondiabetic mothers.

The objective of this study was to test the hypothesis that macrosomic infants of nondiabetic mothers have beta-cell hyperplasia in their pancreases. Pancreatic tissues were examined from 10 macrosomic fetuses and liveborn infants and from 10 comparison cases matched for gestational age and gender. None of the mothers had a history of diabetes and all had normal glucose screening during pregnancy. Tissues were stained with hematoxylin and eosin and a monoclonal antibody against beta cells and were analyzed using an image analysis program to evaluate the size and surface area of beta-cell clusters. Brain/liver weight ratios were calculated and compared. The total surface area and cluster size of beta cells in the pancreases of macrosomic subjects were significantly larger than in the comparison pancreases. The study subjects lacked macroscopic and histopathologic findings expected in infants of diabetic mothers. We conclude that some macrosomic fetuses and infants of nondiabetic mothers manifest beta-cell hyperplasia. This corresponds to the higher insulin levels in macrosomic infants of nondiabetic mothers described in previous clinical studies. In macrosomic fetuses the stimulus for beta-cell hyperplasia may not involve aberrant maternal glucose levels.

Autopsy↗

PubMedDate not supplied

Central nervous system malformations in a perinatal/neonatal autopsy series.

Congenital malformations of the central nervous system (CNS) are among the most common anomalies, but data on the incidence of CNS malformations in autopsy populations are scant. We examined 4122 autopsies between the years 1958 and 1995. There were 363 cases (8.8%) with CNS malformations; 235 were neonates and 128 stillborns. The overall gender ratio was 1:1, although more male neonates and more female stillborns had malformations. The body weights ranged from 24 to 6440 g. Neural tube defects were the most common types of malformations (45.5%) and included anencephaly, meningoencephalocele, meningocele/meningomyelocele, craniospinal rachischisis, and spina bifida occulta. The incidences of other malformations were: congenital hydrocephalus (12.4%), neuronal/glial proliferation disorders such as micro- and macrocephaly (8.8%), neuronal migration disorders (8.8%), prosencephalon growth disorders such as holoprosencephaly and arhinencephaly (8.5%), abnormalities of the midline structures such as agenesis of corpus callosum (4.1%), developmental cysts (3.3%), cerebellar malformations (3%), and vascular malformations (2%). Miscellaneous malformations (3%) consisted of acephalia in four cases with twin reversed arterial perfusion (TRAP), two cases of hydranencephaly, and four cases of rare degenerative and metabolic encephalopathies.

Autopsy↗

PubMedDate not supplied

Hepatic subcapsular hematomas in fetuses and neonatal infants.

In fetuses and neonates hepatic subcapsular hematomas are relatively common lesions and may be life-threatening. Conditions previously associated with these hematomas include trauma, coagulopathies, hypoxia, sepsis, pneumothorax, maternal diseases, and placental lesions. In this study of 755 perinatal autopsies, hepatic subcapsular hematomas were found in 52 (6.9%) cases, including 31 stillborn fetuses and 21 liveborn infants. The average body weight was 690 g. A comparison group consisted of 52 temporally proximal autopsies of fetuses and neonates without hematomas. Body weights, gender, maternal age, and stillbirth or postnatal survival were matched as closely as possible while evaluating the presence or absence of sepsis, pneumothorax, cerebral germinal matrix hemorrhage, trauma, coagulopathy, placental lesions, and maternal diseases. Sepsis was associated with 62% of the cases with hepatic subcapsular hematomas and with 25% of the comparison group (P =.0001). Group B streptococcus infection was the most common cause of sepsis, but many different organisms were isolated. Cerebral germinal matrix hemorrhages were present in 35% of the cases with hematomas and in 14% of the comparison group (P =.0001). No other lesions or conditions were statistically different in the study group versus the comparison group. The delicacy of the hepatic capsule and its connections to the collagen along the sinusoids provide insight for the pathogenesis of hematomas in premature fetuses and neonates. We conclude that sepsis is present in most perinatal cases of hepatic subcapsular hematomas and that such patients also frequently have cerebral germinal matrix hemorrhages. Each of these lesions is a greater hazard among very small premature fetuses or neonates than among older fetuses and neonates.

Adult↗

PubMedDate not supplied

Bilateral discoid medial menisci.

SUMMARY: This article adds 2 more cases of bilateral discoid medial menisci to the previously reported 9 cases. The radiographs of the first case revealed bilateral cupping of the medial tibial plateaus and a small lytic lesion of the left distal medial femoral metaphysis. Beside the posteriorly unstable incomplete type discoid medial meniscus, the left knee had several associated arthroscopic findings: depression of the medial tibial plateau with exposed subchondral bone, anomalous insertion of the anterior horn of the discoid meniscus to the anterior cruciate ligament, a pathological medial plica, and longitudinal deep fissures in the trochlea. The second case was a complete type with peripheral horizontal cleavage tears. Following arthroscopic surgery, magnetic resonance imaging (MRI) scans of the contralateral knees were obtained in both cases to search for bilaterality. MRI revealed discoid medial menisci in the unoperated knees as well. The short-term results of arthroscopic meniscectomy may not be as satisfactory as those reported for normal menisci.

Adolescent↗

PubMedDate not supplied

Reference values for singleton and twin placental weights.

The largest series of normal singleton placental weights was collected in the Collaborative Perinatal Study between the years 1959 and 1966 but values for normal twin placental weights were not published. In our study we examined 787 singleton and 514 twin normal placentas. Placentas with associated conditions known to affect the weights of placentas were excluded. After establishing the normal values for singleton and twin placental weights, we concluded that weight gain of twin placentas appears to accelerate between 24 and 36 weeks but reaches a plateau after 37 weeks, whereas singleton placentas appear to gain weight more uniformly throughout gestation. The mean values of twin placental weights for each gestational age are less than double those of singleton placental weights for the same duration of gestation. Our singleton and twin placentas are heavier than those from previously published data and may reflect a generational or nutritional change over the 30 years since the original numbers were compiled.

Humans↗

PubMedDate not supplied

Renal dysplasia, situs inversus totalis, and multisystem fibrosis: a new syndrome.

Renal dysplasia was associated with situs inversus totalis and multisystem fibrosis in a severely hydropic stillborn female fetus. The ureters were duplicated and showed fibrous obliteration. The pancreas, thyroid, and uterus were fibrotic, and the lungs had small and large irregular pulmonary lobules bounded by fibrotic septa. An extensive fibrous pericarditis was considered the etiology of hydrops. A similar spectrum of anomalies including bilateral renal dysplasia, situs inversus totalis, and pancreatic and hepatic fibrosis has been described in three separate reports. Our case is similar with additional findings of fibrosis of the thyroid, uterus, pulmonary septa, and pericardial tissues. We believe the presence of situs inversus totalis, renal dysplasia, and multisystem fibrosis constitutes a new syndrome.

Abnormalities, Multiple↗

PubMedDate not supplied

Pathology of the lung in surfactant-treated neonates.

Respiratory distress syndrome (RDS) is associated with prematurity-related deficiency of surfactant. Surfactant replacement therapy has been used in premature infants to prevent RDS or reduce its severity. In this study we describe the pathology of the lungs after surfactant replacement therapy. All the neonatal autopsies during the years 1989 and 1990 (n = 235) were examined. Infants > or = 31 weeks gestation, with congenital anomalies or who lived more than 2 weeks were excluded from the study. Infants who had received intratracheal Survanta, a modified surfactant extracted from cow lung (n = 14), were compared with infants who did not receive exogenous surfactant (n = 20). The two groups were statistically comparable in terms of weight, gestational and postnatal age, gender, and clinical management. H&E-stained lung sections were examined independently by two pathologists without knowledge of surfactant treatment status; any discrepancies in histological evaluation were resolved by joint review. Nine histological features were evaluated including hyaline membranes, necrosis of the epithelium, hemorrhage, edema, inflammation, metaplasia, arteriolar muscular hyperplasia, interstitial fibrosis, and pulmonary interstitial emphysema (PIE). Histological changes were graded from 0 to 3+. When it was present, cerebral periventricular-intraventricular hemorrhage (PVH-IVH) was graded 1-4. The presence or absence of sepsis and necrotizing enterocolitis (NEC) were also determined. Comparisons between patient groups were performed using the Mann-Whitney U, Student's t and chi 2 tests. The severity of hyaline membrane disease, PIE, and epithelial necrosis was less severe in the surfactant-treated group than in the untreated group. There were no differences between the two groups in the degree of pulmonary hemorrhage or in the incidence of PVH-IVH, sepsis, or NEC.

Biological Products↗

PubMedDate not supplied

Fryns syndrome: a new definition.

Fryns syndrome is a lethal, autosomal recessive syndrome of multiple congenital anomalies described by Fitch et al. in 1978 and Fryns et al. in 1979. As originally described, the major diagnostic criteria included abnormal facies; small thorax with widely spaced, hypoplastic nipples; distal limb and nail hypoplasia; and diaphragmatic hernia with pulmonary hypoplasia. Malformations involving other systems occurred irregularly in published reports. We reviewed 41 published cases of Fryns syndrome and added 4 cases of our own. The major diagnostic criteria described by Fryns were consistent in all cases with the exception of two criteria. Narrow thorax with hypoplastic nipples and gastrointestinal anomalies were present in less than 50% of the cases. Although for 16 of the 41 published cases there was no information on central nervous system findings, 21 of the 29 remaining cases (72%) had CNS malformations. These lesions were absence of corpus callosum, arhinencephaly, and heterotopia of cerebral and cerebellar tissue. Similarly, for 12 of the 41 published cases there was no information on cardiovascular findings but 29 of the 33 remaining cases (88%) had congenital heart disease. These lesions were ventricular septal defects, arterial septal defects, and persistent left superior vena cava. We conclude that central nervous system anomalies and congenital heart disease should be added to the major diagnostic criteria of Fryns syndrome.

Abnormalities, Multiple↗

PubMedDate not supplied

Complete subtalar release in clubfeet.

Complete subtalar release was performed in 18 children with 22 clubfeet between 1987 and 1989. The ages of the patients ranged from 3.5 months to 8.5 years. The patients were evaluated at 9 to 30 months (average 19 months). Twenty procedures were performed through the Cincinnati incision, and the remaining two through two separate posteromedial and posterolateral incisions. At 6 weeks, the pins were removed and cast immobilization was discontinued at 3 to 3.5 months. Complications were superficial necrosis in three feet, and extensive posteromedial skin necrosis in one foot. No recurrences were encountered. Overall results were very good in 18, and good in four feet.

Child↗