SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
The hereditary hemolytic anemias include a heterogeneous class of disorders caused by defects in the proteins that constitute the membrane skeleton of the red blood cell. The combination of classical and molecular genetics together with clinical findings is rapidly improving our understanding of the basis of these defects.
Nocardia rubra cell wall skeleton (N-CWS) was shown to augment interleukin 1 (IL-1) production from peritoneal resident and exudate macrophages in C3H/HeN mice. The mol. wt of the N-CWS-induced IL-1 product was about 17,000 daltons, which is a similar weight to that obtained by lipopolysaccharide stimulation. The stimulation of IL-1 production by N-CWS was seen as early as 8 h after the start of incubation and peak production was observed at 48 h. Profound effects were seen with 10 micrograms/ml or more of N-CWS. Experiments on the regulation of the N-CWS-augmented IL-1 production showed that prostaglandin E2 inhibited the augmentation, and indomethacin (cyclo-oxygenase inhibitor) further augmented it. Leukotriene B4 and AA861 (lipoxygenase inhibitor) had no effect. Our findings suggest that the previously reported adjuvant effect of N-CWS may, in part, be mediated via its ability to stimulate IL-1 production; and that such a stimulation may be blocked by prostaglandins.
A retrospective analysis of 104 patients with maxillofacial skeleton injuries, treated at the University College Hospital, Ibadan was undertaken. 84.62% of the patients were male, 75.0% of the fractures were mandibular. 80.77% were due to road traffic accidents and 4.81% to armed robbery attacks. The aetiology, pattern and incidence of fractures, age, sex, presence of infection, time lag between injury and treatment and the results are discussed.
A retrospective look at the incidence and aetiology of fractures of the facio-maxillary skeleton over a 2 year period was carried out in the department of Oral and Maxillofacial Surgery, Dental College, Trivandrum, India.
A retrospective study was undertaken of 311 patients with injuries to the maxillofacial skeleton treated at Harare Central Hospital, Harare. Two hundred and fifty two (80.7%) of the patients were males, 74.6% of all the fractures involved the mandible and assault was the most common causative agent (81.6%). The aetiology, incidence, pattern of fractures, presence of infection, choice of treatment and the results of treatment are discussed.
Fractures of the facial skeleton are infrequent in children. A series of 147 fractures in 116 children aged from 10 days to 13 years old was retrospectively reviewed. The male to female ratio was 1.4:1 and the highest incidence occurred in the age group 8 to 10 years. The main aetiological factor was road traffic accidents. The mandible was predominantly involved (83.7%). The incidence of fractures of the middle third of the face was very low (4.0%). Closed reduction was undertaken most frequently. Complications were found to be minimal.
Professor A. K. Henry coined the term 'extensile exposure'. Three incisions are described to expose the facial skeleton. The incisions are placed to best cosmetic advantage and provide extensile exposure to fit many of the routine procedures undertaken by the oral and maxillofacial surgeon.
Multiple cutaneous approaches to both the superior and inferior orbit have been reviewed. Incisional choices are optimally based on both facial esthetics and orbital function, which are achieved by an understanding of the unique anatomy of this region. The superior orbit is best approached by a blepharoplasty (lid crease) incision in conjunction with a lateral extension if additional exposure is necessary. Almost all aspects of the bony orbit can be reached with the exception of the frontal bone superior to the supraorbital rim. When wide exposure of the orbital skeleton is necessary, a bicoronal scalp flap is most effective in a nonalopecic patient. The inferior orbit can be approached by a ciliary, blepharoplasty, or conjunctival incision with a lateral canthotomy. None has proven esthetic advantages over the others, with the exception of the conjunctival incision when used alone. The lid incisions must be used with the understanding that orbital function must be assessed both pre- and postoperatively and meticulous attention paid to protection and care of the anterior globe. In addition, because of the thinness of the tissues being manipulated, edema, bruising, and final settling of lid form may require more postoperative time than is typical of more peripheral approaches.
This paper develops the concept that the dramatic appearance of calcareous skeletons in the Lower Cambrian is directly related to the origin of refined mechanisms of intracellular modulation of calcium ion concentration. An homologous family of calcium modulated proteins has recently been discovered. These proteins contain "EF hands", involved in the maintenance of low concentrations of intracellular calcium and the informational use of calcium ion flow (Kretsinger, 1977). The evolution of this specialized calcium physiology, especially in muscle systems, coupled with natural selection by predators are identified as some of the preadaptations for the impressive Tommotian diversification of calcified metazoans. The distribution of calcium biominerals in the phyla of the five kingdoms and the time of first appearance of calcareous mineralization in the fossil record are tabulated. Macroscopic calcified hard parts apparently required the prior evolution of certain cell, tissue and organ system physiologies which are briefly discussed here.
The effect of energy deprivation (treatment with rotenone in glucose-free medium) and hyperthermia (44 degrees C) on interphase death of EL-4 thymoma, Ehrlich and HeLa carcinomas was studied in vitro. Irreversible damage accompanied by intensive blebbing with subsequent cell death (necrosis) was observed only when elevation of actin in triton-insoluble fraction occurred although some proteins became insoluble before actin. Actin-specific drugs cytochalasin B and phalloidin accelerated both actin insolubilization and cell necrosis in rotenone-treated EL-4 cells; after conditioning treatment with recovery the actin insolubilization during hyperthermia was suppressed. Ehlrich and HeLa carcinomas were much more resistant to energy deprivation and hyperthermia; this correlated with the resistance of their actin to aggregation. It is concluded that stability of actin skeleton may be determinative of tumor cell resistance to energy deprivation, hyperthermia and possibly to some other treatments.
The origin and metabolism of the carbon skeletons of the amino acids ornithine and arginine have been investigated in selected animals--an earthworm, an edible mollusc, a starfish, a sea-squirt, a freshwater crustacean and a rat. Only in the rat and microorganisms of sea water was any evidence obtained for the conversion of glutamate (or N-acetylglutamate) to ornithine. Apart from the crustacean, the other animals were able to synthesise the amidine moiety of arginine. All animals were able to hydrolyse (arginase) the amidine moiety from arginine and had the enzymic capacity to convert ornithine to proline. All the animals had some enzymic ability to oxidise proline to pyrroline-5-carboxylic acid. The crustacean (Cherax destructor) was able to conserve the high concentrations of arginine in its tail muscles during fasting. The hypothesis is put forward that, as arginine appears to be an essential amino acid in the diet of this animal, its demonstrated cannibalism is, among other things, a way of supplementing dietary arginine. The results are discussed in relation to the evolution of different phosphagens derived from arginine.
Genetic diseases of the skeletal system are difficult to accurately diagnose. Changes in the chemical structure of collagen significantly modify the structure of collagen in bone. The ratio of collagen hydration to hydroxylation reflects specific features of the collagen structure. The hypothesis proposes to use this ratio in the diagnosis of diseases of the skeleton.
A 28-year-old male methamphetamine abuser, who had been buried for 5 years after being killed by strangulation, was found skeletonized. Methamphetamine and amphetamine in the significantly denatured fatty material of the bone marrow were analyzed by gas chromatography and gas chromatography-mass spectrometry. The confirmation of the chemicals was carried out by chemical ionization (CI) mass chromatography, CI mass spectrometry and CI mass fragmentography. The concentrations of methamphetamine and amphetamine determined by CI mass fragmentography were 1.0 mumol/100 g and 0.1 mumol/100 g, respectively. The method used would seem to be very useful for determination of methamphetamine and amphetamine in marked putrefied biological materials.
The aim of this study was to assess the potential speed of post mortem alteration to skeletal microstructure by examining human material drawn from differing environmental contexts and time periods. The material was taken from terrestrial, intertidal and lacustrine contexts and extended over a range of 3 months to 83 years post mortem. The examination was conducted using backscattered electron imaging which provided information on microstructure and relative density. The results from this study have significantly brought forward the time of known onset for post mortem alteration for 3 morphological types of microstructural change, the earliest of which was 3 months post mortem. The contribution of the depositing environment was also shown to influence significantly the microstructural/ morphological type of post mortem alteration. It is hypothesized that microstructural changes to bone could occur within days of death as a result of endogenous bacterial migration to the skeleton. Further studies are required to establish definitively the earliest moment that such change can occur prior to skeletonisation.
Mice from two series of experiments (S1, S2) involving intraperitoneal (ip) injection of dams with 300 (High or H), 60 (Low or L), or 0 (VEH) mg 5'-bromodeoxyuridine (BUDR) per kilogram body weight (mg/kg) in water (15 mL/kg) on day seven (D7), day eight (D8), or in S2 only, day nine (D9) of gestation (9DPC), and untreated (UNTD) controls, were examined between 60 and 65 days postnatal (DPN) for 88 variations of the skeleton. In S1, 65 variants occurred, and in S2 there were 58 variants that occurred. Substantial numbers of significant differences (P less than 0.01) in frequency of occurrence (%) were seen in High dose only. The number of variants that differed from UNTD were 13, 13, 12, 15, and 11 in S1-D7H, S2-D7H, S1-D8H, S2-D8H, and S2-D9H, respectively; the average absolute difference in frequency among significantly affected variants was 16% to 20%. In the same order as above, 13, 12, 8, 10, and 9 variants differed significantly from VEH, and 9, 8, 7, 8, and 8 variants differed significantly from both UNTD and VEH. In contrast, 0, 0, 1, 1, and 0 variants differed from both UNTD and VEH in S1-D7L, S2-D7L, S1-D8L, S2-D8L, and S2-D9L, respectively. Agreement between the two series was good; 11 traits were affected in High dose litters in both series in at least 3 or 4 comparisons (compared with UNTD, VEH, in S1, S2).(ABSTRACT TRUNCATED AT 250 WORDS)
Results are presented of measurements of skeletal blood flow made in 80 patients with painful benign or malignant diseases of the skeleton, excluding patients with Paget's disease. In crush fracture osteoporosis, total bone blood flow was slightly lower than normal although skeletal perfusion was normal. High values of bone blood flow were seen in 14/20 patients with osteomalacia and 3/12 patients with primary hyperparathyroidism. Very high values, comparable to those seen in the most severely affected patients with Paget's disease, were seen in polyostotic fibrous dysplasia, 2 out of 4 cases of Engelmann's disease and 1 out of 3 cases of renal osteodystrophy. Results were less elevated in myositis ossificans, secondary skeletal involvement with breast and prostatic carcinomata, myelomatosis and sympathetic osteodystrophy.
The effects of prostaglandin E2 (PGE2) were histomorphometrically evaluated in cancellous bone of the axial skeleton of ovariectomized, osteopenic rats. Four months following bilateral ovariectomy (OVX) and sham-ovariectomy (SHAM) at 3 months of age, rats received daily subcutaneous injections of PGE2 at 0, 0.3, 1.0, 3.0 and 6.0 mg/kg/day for 30 days. The undecalcified fourth lumbar vertebral bodies (LVB) were processed for static and dynamic bone histomorphometry. The OVX rats possessed a slightly osteopenic LVB (17% vs. 24% cancellous bone mass). In rats given PGE2 at 3 and 6 mg/kg/day for 30 days, bone turnover, lamellar bone mass, and formation of new woven bone trabeculae were increased. Observations supported the conclusion that PGE2 activates bone modeling and remodeling, and shifts bone balance in favor of formation. In OVX rats given 6 mg PGE2/kg/day, cancellous bone mass and trabecular numbers were restored to levels found in untreated SHAM rats. Cancellous bone mass in the LVB of SHAM rats given 3 and 6 mg PGE2/kg/day increased by 16% and 30% over that of control rats. In addition, PGE2 stimulated longitudinal bone growth in both OVX and SHAM rats, a response that differed from male rats.
In this study we tested the hypothesis that exercise induces an adaptive response in the developing skeleton which may be monitored in vivo by measuring biochemical markers of bone metabolism. The effects of exercise on two biochemical markers of bone formation were determined; the carboxy-terminal propeptide of type I procollagen (PICP), and the bone-specific isoenzyme of alkaline phosphatase (BAP), and one putative marker of resorption, the pyridinoline crosslinked telopeptide domain of type I collagen (ICTP). All three markers were measured for a year in 2-year-old thoroughbred horses exercised three times a week on a treadmill, and values compared to a control group of age-matched animals. Levels of all three markers fell in both exercised and control groups over the 12-month period reflecting normal age changes. However, there were differences between groups in the pattern of this decrease. When expressed as a percentage of baseline values, BAP was higher (p < 0.05) at 2 months and both BAP and the PICP were higher at 4 months (p < 0.01 and p < 0.05, respectively) in the exercised group, reflecting an increase in bone turnover in this group in the early stages of training. PICP levels were also elevated in the exercised group at 10 months and this result indicates an increase in bone turnover at this time. The changes in ICTP were different; at 2 months, levels were higher in exercised animals than in controls, but there was no significant difference between the two groups at 4 and 6 months. After 8 months, ICTP levels in the exercised group increased returning to near baseline values at 10 months.(ABSTRACT TRUNCATED AT 250 WORDS)