Evaluation of trabecular bone score in patients with a distal radius fracture.

We compared bone mineral density (BMD) and trabecular bone score (TBS) in postmenopausal women with a distal radius fracture older than 50 years with controls. Total hip BMD was significantly different, but TBS was not different between two groups, suggesting TBS does not reflect microarchitectural changes of the distal radius. INTRODUCTION: The purpose of this study was to determine whether trabecular bone score (TBS) has additive value for discriminating distal radius fracture (DRF) independent of BMD. METHODS: We compared BMD and TBS in 258 postmenopausal women with a DRF older than 50 years of age with age- and body mass index (BMI)-matched controls who had no history of osteoporotic fracture. BMD was measured at the lumbar spine and hip using dual energy X-ray absorptiometry scans (GE Lunar Prodigy). TBS was calculated on the same spine image. A multivariate logistic regression analysis was used to analyze the odds ratio (OR) for the occurrence of DRF using age, BMI, lumbar spine BMD, total hip BMD, and TBS. RESULTS: Patients with a DRF had significantly lower BMDs at hip (neck, trochanter and total) than those of controls: 0.752 ± 0.097, 0.622 ± 0.089, and 0.801 ± 0.099 in patients and 0.779 ± 0.092, 0.648 ± 0.089, 0.826 ± 0.101 in controls. However, lumbar spine BMD and TBS were not significantly different between the groups (p = 0.400 and 0.864, respectively). The multivariate analysis indicated that only total hip BMD was significantly associated with the occurrence of DRF (OR, 10.231; 95 % confidence interval, 1.724-60.702; p = 0.010). CONCLUSIONS: TBS was not different between women with a DRF and those without a history of osteoporotic fracture, suggesting that TBS measured at the lumbar spine does not reflect early microarchitectural changes of the distal radius. Only total hip BMD is associated with the risk of DRF in Korean women.

The lipidome of Thoroughbred racehorses before and after supramaximal exercise.

BACKGROUND: A comprehensive study of the effect of supramaximal exercise in lipid homeostasis of Thoroughbreds provides the basis for future research on the role of lipids on energy metabolism in racehorses. OBJECTIVE: To compare the plasma lipidome of Thoroughbreds before and after supramaximal exercise using an untargeted lipidomics approach. STUDY DESIGN: Pilot experimental study. METHODS: Four Thoroughbred horses were used. The maximal oxygen consumption (VO2 max ) was calculated for each horse. Horses then underwent treadmill exercise at the speed for which the oxygen requirements had been calculated to be 115% VO2 max . Plasma samples were obtained before (T0) and immediately (T1), 15 (T2) and 30 (T3) minutes post-exercise, and evaluated using liquid chromatography/mass spectrometry. Data analysis consisted of principal component analysis and one-way repeated measures analysis of variance. RESULTS: A total of 933 plasma lipids were detected. Supramaximal exercise-induced significant changes in the signal intensity of 13 lipids; all ubiquitous in the organism as major components of biological membranes or energy substrates. MAIN LIMITATIONS: A treadmill was used to replicate track conditions. Also, sample size involved only four horses and the statistical analyses failed to achieve the desired power of 80%. CONCLUSIONS: The findings in this pilot study suggest that supramaximal exercise induces changes in specific plasma lipids in Thoroughbred racehorses. While the biological significance of these findings remains to be determined, these results provide baseline information for future studies in lipidomics applied to equine exercise physiology. Further research is warranted to better understand the role of lipids on energy metabolism in Thoroughbred racehorses.

Genetics and biochemistry of secondary metabolites in plants: an evolutionary perspective.

The evolution of new genes to make novel secondary compounds in plants is an ongoing process and might account for most of the differences in gene function among plant genomes. Although there are many substrates and products in plant secondary metabolism, there are only a few types of reactions. Repeated evolution is a special form of convergent evolution in which new enzymes with the same function evolve independently in separate plant lineages from a shared pool of related enzymes with similar but not identical functions. This appears to be common in secondary metabolism and might confound the assignment of gene function based on sequence information alone.

Regulation of penicillin acylase in Escherichia coli by cyclic AMP.

1. Cyclic AMP was found to stimulate penicillin acylase activity. 2. It also overcame the repression of glucose and restored enzyme synthesis to the non-repressed levels. 3. The conversion of inactive enzyme precursor into active enzyme was not stimulated by cyclic AMP in cells in which protein synthesis was inhibited by chloramphenicol. 4. Cyclic AMP failed to stimulate enzyme production in cells in which messenger RNA synthesis was arrested by rifampicin or inducer removal. 5. Cyclic AMP appears to participate in the regulation of this enzyme at the transcriptional level.

Regiochemical control of monolignol radical coupling: a new paradigm for lignin and lignan biosynthesis.

BACKGROUND: Although the lignins and lignans, both monolignol-derived coupling products, account for nearly 30% of the organic carbon circulating in the biosphere, the biosynthetic mechanism of their formation has been poorly understood. The prevailing view has been that lignins and lignans are produced by random free-radical polymerization and coupling, respectively. This view is challenged, mechanistically, by the recent discovery of dirigent proteins that precisely determine both the regiochemical and stereoselective outcome of monolignol radical coupling. RESULTS: To understand further the regulation and control of monolignol coupling, leading to both lignan and lignin formation, we sought to clone the first genes encoding dirigent proteins from several species. The encoding genes, described here, have no sequence homology with any other protein of known function. When expressed in a heterologous system, the recombinant protein was able to confer strict regiochemical and stereochemical control on monolignol free-radical coupling. The expression in plants of dirigent proteins and proposed dirigent protein arrays in developing xylem and in other lignified tissues indicates roles for these proteins in both lignan formation and lignification. CONCLUSIONS: The first understanding of regiochemical and stereochemical control of monolignol coupling in lignan biosynthesis has been established via the participation of a new class of dirigent proteins. Immunological studies have also implicated the involvement of potential corresponding arrays of dirigent protein sites in controlling lignin biopolymer assembly.

Dysmaturation in infants of mothers with myotonic dystrophy.

We examined the pathologic findings in four infants of mothers with myotonic dystrophy. Four of the anomalies present in these infants (nesidioblastosis, renal blastema, cryptorchidism, and patent ductus arteriosus) represent persistence of fetal organ structures or configurations. We suggest that a maturational defect may be present not only in muscle, but also in other tissues.

Immunocytochemical diagnosis of alpha-1-antitrypsin deficiency.

Eight cases of liver disease associated with alpha-1-antitrypsin deficiency are described. Six of the cases, including the only childhood case, showed no evidence of lung disease. An occult but variable clinical course is defined in this disorder. A spectrum in the severity of tissue change was noted, and in some instances, extensive liver disease was correlated with relatively minor derangement in liver function. While this form of liver disease is uncommon, it should be included in the differential diagnosis of adult liver disease. Screening for alpha-1-antitrypsin globules in periodic acid-Schiff stained liver tissue sections should be considered in certain cases of cryptogenic liver disease in adults, particularly when advanced disease presents suddenly, where micronodular (portal) cirrhosis is unrelated to excessive alcohol use, or where tissue changes exceed those anticipated from serum biochemical abnormalities. In most of these cases, tissue findings from liver biopsy or autopsy, rather than clinical suspicion, led to the diagnosis. The availability of a simple and reliable immunoperoxidase technique, applicable to routinely processed tissue samples, allowed for rapid and specific diagnosis in all cases. This immunocytochemical method has proven its usefulness in the prospective and retrospective tissue diagnosis of alpha-1-antitrypsin deficiency and associated liver disease.

Preparation of genomic DNA for RAPD analysis from thick-walled dormant teliospores of Tilletia species.

We describe a method for isolating genomic DNA from teliospores of Tilletia caries (DC) Tul., T. controversa Kuhn and T. foetida (T. laevis) (Wallr.) Liro. for random-amplified polymorphic DNA (RAPD) analysis. DNA analysis of teliospores of covered smut or bunt has been difficult because of the thick wall and the high lipid content of the spores. This method overcomes these problems and yields sufficient quantities of DNA from the three species' teliospores for RAPDs. DNA quality appears to be good with very little degradation. RAPD amplifications of the extracted DNAs are reproducible and produce numerous large molecular weight bands from each individual. This procedure should permit the use of DNA analysis techniques to study species and races of Tilletia as well as fungi with similar spore structure.

Brief clinical report: an X-linked mental retardation syndrome with craniofacial abnormalities, microcephaly and club foot.

A male infant, who died of renal insufficiency at 6 months, had 2 similarly affected maternal uncles who died at 16 and 6 months respectively. Their manifestations include microcephaly, a large anterior fontanel, short nose with anteverted nostrils, club foot deformity, retarded psychomotor development and, in the index case only, kidney hypoplasia and dysplasia. The 2 obligatory carriers of this evidently X-linked recessive syndrome had no physical abnormalities.

Anomalies in an infant with Nager acrofacial dysostosis.

We report on an infant with Nager acrofacial dysostosis, laryngeal and epiglottic hypoplasia, abnormal septation of the right middle lobe of the lung, hypoplastic right first rib, and dislocation of the right hip. These findings suggest the possibility that patients with the Nager syndrome may have other developmental defects in addition to the facial and acral anomalies associated with this syndrome.

Postmortem manifestations of echovirus 11 sepsis in five newborn infants.

Five cases of fatal neonatal echovirus type 11 infection were observed in the Boston area during the summer and fall of 1979. Four of the mothers experienced gastroenteritis with fever and abdominal cramps late in the third trimester of pregnancy. The clinical course of each case was characterized by jaundice, hepatosplenomegaly, and progressive hepatic failure; all five infants were severely hypotonic. At autopsy massive hepatic and adrenal hemorrhage and necrosis, with evidence of consumption coagulopathy, were found. Echovirus type 11 was isolated from various sites before and after death. The histopathologic features and epidemiologic aspects of these cases are briefly discussed.

Villous adenoma of the urinary bladder: a morphologic or biologic entity?

Villous adenomas in the urinary bladder are rare neoplasms whose malignant potential is unclear. A case of a morphologically benign non-invasive mucin producing papillary neoplasm of the urinary bladder associated with cystitis glandularis is presented. Absence of A tissue isoantigen from the neoplastic and metaplastic cells and the presence of H tissue isoantigen in both neoplastic and metaplastic cells is observed in a patient whose blood type is A, indicating incomplete maturation of surface coat constituents. The histologically benign appearance of this lesion may belie a malignant potential.

Unusual sacrococcygeal embryologic malformations with cutaneous manifestations.

Two unusual sacrococcygeal neuroepithelial heterotopias manifested as masses associated with cutaneous signs. In a 13-month-old infant, a cystic coccygeal medullary vestige was associated with a midline epidermal nevus. In another patient, a lipomeningocele with neuroepithelial heterotopia manifested as a skin tag and mass in the right buttock. In both cases, the malformations probably resulted from abnormal canalization and retrograde differentiation of the distal neural tube. Cystic coccygeal medullary vestige results from dilation of a persistent ependymal cyst present commonly in neonates at the distal part of the coccyx. The lipomeningocele appears to have arisen from an aberrantly formed ependymal canal. The embryologic events that gave rise to the lesions, the differential diagnosis of postrectal masses, and the common association of midline lesions of skin and soft tissue with neural defects are stressed.

Infantile polycystic disease of the liver and kidneys.

Kidney and liver tissue from eleven patients with recessively inherited infantile polycystic disease (IPCD) were examined to document the extent of renal tubular cyst formation and hepatic fibrosis, to assess survival, and to examine the usefulness of current classifications. Four infants with 90% or more cystic renal change did not survive beyond twenty days. In contrast five of the seven less severely diseased patients with a 20-75% range of cystic change are still alive at six to twenty-one years of age. Liver samples showed hamartomatous bile duct proliferation in all patients studied with the most prominent portal fibrosis in the oldest patient. In both families with two affected siblings, the clinical course and pathological expression of renal disease were dissimilar. Tissue analysis from these cases is consistent with the idea that IPCD has a spectrum of phenotypic expression with prognostic implications from tissue diagnosis in the individual patient, but not necessarily as four genetically determined rigidly defined subgroups. It is concluded that each affected child with IPCD must be evaluated separately.

Wilms' tumor of the endocervix.

We report a case of primary Wilms' tumor of the endocervix in a 13-year-old girl. The tumor was polypoid, filled the vagina, and was attached to the endocervix by a stalk. Microscopic examination disclosed blastematous, epithelial, and stromal elements characteristic of Wilms' tumor. The patient's kidneys were normal on intravenous pyelographic examination and on palpation at laparotomy, and she has remained free of disease for 9.6 years after hysterectomy.

Fatal pulmonary embolism following removal of a central venous catheter.

A 1-year-old child developed fatal septic pulmonary embolism upon removal of a central intravenous catheter. Histologically identical material was found in the pulmonary arteries and in the inferior vena cava at the catheter tip site. The pathophysiology of pulmonary embolism occurring during childhood is reviewed.

Fatal postoperative acute appendicitis in a neonate with congenital heart disease.

Acute appendicitis with perforation is almost unknown in the first week of life. We present a 7-day-old male infant with the hypoplastic right heart syndrome and clinically unsuspected acute appendicitis who died 7 days after the successful creation of a Waterston shunt.

Cryotherapy of subglottic hemangioma.

The natural history of the hemangioma is spontaneous regression; therefore, most lesions require no treatment. The large occlusive subglottic hemangioma which presents before the age of 6 months, however, may be life-threatening. Two infants with subglottic hemangiomas with complete upper airway obstruction were treated successfully with cryotherapy, after tracheostomy. In each case the cryoprobe was placed transbronchoscopically on the subglottic hemangioma at -80 degrees C. for 30 to 45 seconds, the freezing interval varying with the age of the patient. One infant is asymptomatic and has had the tracheostomy tube removed. The other infant, after successful cryosurgical treatment, died from an unrelated illness. The histopathology of the larynx 3 1/2 months after cryotherapy of the hemangioma showed tracheal reepithelialization, active regeneration of cartilage with maintenance of luminal diameter, minimal submucosal fibrosis, and minimal residual hemangioma. Cryotherapy for subglottic hemangiomas offers many advantages including hemostasis, controlled local surgical injury, subsequent rapid healing of tissues with minimal fibrosis, and preservation of lumen without stricture. Previous forms of therapy which have been supplanted include radiotherapy, injection of sclerosing substances, systemic steroids, and surgical excision. Carbon dioxide laser is an effective therapeutic modality that we reserve for selected smaller hemangiomatis lesions of the subglottic area.