Search

Summary Lysosomal storage diseases are rare and coexistence of more than one in a family can present a diagnostic challenge as illustrated by this study. The index case born to consanguineous Asian parents presented with developmental delay. Investigations led to an incidental finding of Fabry disease. After numerous additional investigations over a year, a second diagnosis of aspartylglucosaminuria (AGU) was made. A family history of renal disease and developmental delay was disclosed. The sister and first cousin of the index case were diagnosed as homozygous for AGU, but do not have Fabry disease. The younger brother has since been diagnosed with both Fabry disease and AGU. Another cousin has learning difficulties and fits, but is heterozygous for AGU, and possibly has another uncharacterised autosomal recessive disorder. In a family with consanguinity when the clinical picture in an individual is not fully explained by the presence of one rare metabolic disease, it is essential to investigate further for the presence of others.

The cases of a brother and sister with dentato-olivary dysplasia are described. Both had severe developmental delay, severe epilepsy of early onset, evolving hypertonic quadriplegia, and death in early childhood. Postmortem examination of the brain in one child showed a particular form of dentato-olivary dysplasia. These children show many features in common with previously described cases of this condition, but this is the first report of occurrence in sibs.

Les calculs d'energie d'interaction pour les 3 conformations de PVF 2 montrent que la conformation tout-trans est tres favorisee. L'orientation du polymere pour l'energie globale minimale est telle qu'un petit dipole demeure dans le film epitaxial. La contribution coulombique a l'energie d'interaction totale est elevee (≃40%) pour les 3 conformations

The clinical and radiological features are described in male and female siblings with a unique form of spondyloepimetaphyseal dysplasia. In addition to generalized platyspondyly with epiphyseal and metaphyseal involvement, these children also have thin tapering fingers with accentuated palmar creases and abnormal dentition with oligodontia and pointed incisors. Parental consanguinity suggests that this is an autosomal recessive disorder.

The purpose of these studies were to determine the distribution of a lipophilic antineoplastic agent, annamycin (Ann), and its liposomal counterpart (LAnn) in plasma which had been altered in its lipoprotein concentration and lipid composition.Ann, LAnn, and doxorubicin (a hydrophilic control) were incubated in human plasma for 1 hour at 37 degrees C. Following incubation plasma samples were assayed by fluorimetry for drug in each of the lipoprotein and lipoprotein-deficient plasma (LPDP) fractions. To assess the influence of modified lipoprotein concentrations and lipid composition on plasma distribution of Ann and LAnn, either Ann or LAnn were incubated in human plasma which had been supplemented with very low density lipoproteins (VLDL) or low density lipoproteins (LDL).When unbound Ann or doxorubicin was incubated in plasma for 1 hour at 37 degrees C, the majority of drug was found in the LPDP fraction. However, when Ann was incorporated into liposomes composed of dimyristoylphosphatidylcholine and dimyristoylphosphatidylglycerol (LAnn) the majority of Ann was recovered in the high-density lipoprotein (HDL) fraction. Elevation of plasma LDL-cholesterol or VLDL-triglyceride concentrations increased the amounts of Ann and LAnn associated with these lipoprotein classes. Alterations in HDL composition decreased the amount of Ann, but increased the amount of L-Ann within the HDL fraction. Lipid transfer protein (LTP) activity did not significantly modify the plasma distribution of Ann and LAnn in short-term experiments, but the modified lipoprotein composition that LTP facilitates in long-term incubations reduced the capacity of VLDL and LDL to accept drug.These findings suggest that lipoprotein concentration and composition alter the plasma distribution of Ann and LAnn and may help to explain the discrepancies observed in the pharmacokinetics of Ann and LAnn when they are administered to healthy versus cancer patients.

In 1986 all 90 children aged 4-19 years with Down's syndrome attending school in the area served by the Southern Derbyshire Health Authority underwent radiography to identify atlantoaxial instability (AAI). This study details repeat observations five years later. Full results were available on 67 (74%), information on health status was available on the remaining 19 (21%); four (4%) were untraced. There was an overall significant reduction in the atlanto-axial gap over five years. No one developed AAI on repeat testing who had not had it earlier. One child who had previously had normal neck radiography developed acute symptomatic AAI after ear, nose, and throat surgery. Radiographs were done on three occasions on the same day in 49 individuals, ensuring full flexion of the upper neck. There were no significant differences between the radiographs, even in five subjects with AAI. Management of AAI in Down's syndrome is discussed in the light of these findings. Radiography can reliably detect children with chronic AAI who may be at risk of gradually developing symptoms; this may justify a screening programme. This must be distinguished from those who develop symptoms after acute trauma or anaesthesia, for which specific precautions are needed, and previous screening radiographs are unhelpful.

Previously, we have shown that liposomal amphotericin B (L-AmpB) composed of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylglycerol (DMPG) was less nephrotoxic but equally as effective as Fungizone, which consists of amphotericin (AmpB) and deoxycholate. We have also observed that AmpB predominantly associates with high-density lipoproteins (HDL) in human serum and that the amount of AmpB associated with HDL increases when AmpB is incorporated into negatively charged liposomes. Furthermore, we observe that AmpB was less toxic in vitro to pig kidney cells when associated with HDL, but still toxic when associated with LDL. To further understand why HDL-associated AmpB causes reduced renal toxicity, we first examined LLC PK1 cells for the presence of LDL and HDL receptors and then the cytotoxic effects of HDL- and LDL-associated AmpB following trypsin treatment of LLC PK1 renal cells, which removed only the high-affinity LDL receptors. We found that LLC PK1 renal cells expressed high- and low-affinity LDL receptors but only low-affinity HDL receptors. Furthermore, when LLC PK1 cells were treated with trypsin, HDL- and LDL-associated AmpB were less toxic to the cells than was AmpB. The reduced renal cell toxicity of HDL-associated AmpB may be due to its lack of interaction with renal cells because of the absence of HDL receptors. Since AmpB interacts with cholesteryl esters (CE) whose transfer among lipoproteins is regulated by lipid transfer protein (LTP), the role of LTP on the distribution of AmpB to HDL and LDL was next investigated. We observed that LTP facilitated the transfer of AmpB, but not L-AmpB, from HDL to LDL.(ABSTRACT TRUNCATED AT 250 WORDS)

We have previously shown that lecithin:cholesterol acyltransferase (LCAT) can transform ultracentrifugally isolated HepG2 lipoproteins (d1.235 g/ml) into particles that differ substantially from their nascent precursors. Transformed high density lipoprotein (HDL) subpopulations, as judged by nondenaturing gradient gel electrophoresis (GGE), resemble plasma HDL, i.e., HDL2a- and HDL3a-sized particles predominate. In HepG2 conditioned medium (CM), 60-70% of apoA-I is in the d1.235 g/ml fraction (lipid-poor apoA-I); hence we investigated whether inclusion of d1.235 g/ml fraction in LCAT incubations altered HDL subpopulations. After 18 h incubation of CM (containing lipoproteins and d1.235 g/ml fraction) with purified LCAT, the major transformation product on GGE was a large 9.7-nm particle (HDL2b pattern); a minor component appeared at 7.4 nm (HDL3c). Differences in particle size distribution between CM and isolated lipoprotein incubations were not the result of differences in LCAT activity; mass ratios of unesterified cholesterol:cholesteryl ester and phospholipid:cholesteryl ester were similar. Removal of apoA-I from the d1.235 g/ml fraction by immunoaffinity chromatography prior to incubation with the d1.235 g/ml fraction produced the same products (i.e., HDL2b pattern) as incubations performed with the unaltered d1.235 g/ml fraction; therefore, lipid-poor apoA-I does not influence nascent HDL transformation. Cholesteryl ester was transferred from HepG2 HDL to LDL in CM incubations; however, cholesteryl ester transfer protein was not immunochemically identified. Removal of HepG2 LDL from CM prior to incubation with LCAT still resulted in the HDL2b pattern. We conclude that HepG2 cells secrete a factor(s) that modifies nascent HDL transformation products into a predominantly HDL2b subpopulation.

The clinical and radiological features are described in male and female siblings with a unique form of spondyloepimetaphyseal dysplasia. In addition to generalized platyspondyly with epiphyseal and metaphyseal involvement, these children also have thin tapering fingers with accentuated palmar creases and abnormal dentition with oligodontia and pointed incisors. Parental consanguinity suggests that this is an autosomal recessive disorder.

Suprapubic aspiration (SPA) was compared with midstream urine collection (MSU) in the diagnosis of urinary tract infection (UTI) in a busy paediatric out-patient department in Northern Nigeria, where usually only one specimen can be taken before starting antimicrobial therapy. SPA in 287 children was compared with 175 MSU collections. Urine was obtained at the first attempt in 260 (91%) SPA's which were easy to perform and safe. MSU collections were more difficult, particularly in the younger child. In 51 cases MSUs were compared with SPAs taken immediately before, and gave an accurate indication of urine infection with no false negative or positive cultures. It is concluded that when only one urine specimen can be collected before starting antimicrobial therapy, a single MSU specimen gives an adequate result if correctly collected and plated out. When accuracy of diagnosis is essential or if a MSU cannot be obtained, SPA is indicated. A white cell count on unspun urine proved to be the most successful sideroom test for urinary tract. Counts in excess of ten cells per mm3 were found in 62% of patients with positive cultures.

Plasma-derived lipid transfer protein (LTP) facilitates the transfer of cholesteryl ester and triglyceride between all lipoproteins. Kinetic models of the transfer event have suggested that transfer is facilitated through the physical interaction (binding) of LTP with its lipoprotein substrate. Such binding has been observed previously between LTP and high density lipoprotein (HDL), but not between LTP and low (LDL) or very low (VLDL) density lipoproteins. In the present study, the interaction of LTP with plasma lipoproteins has been re-evaluated. These experiments have employed Sepharose-bound lipoproteins in order to facilitate the rapid separation of unbound and lipoprotein-associated LTP. The validity of this approach in assessing LTP-lipoprotein interactions was evidenced by the fact that free (unbound) lipoproteins could competitively inhibit or disrupt the binding of LTP to the Sepharose-bound lipoproteins. LTP was observed to bind to VLDL, LDL, and HDL. Whereas VLDL- and LDL-LTP complexes were labile and almost completely dissociated in 90 min, HDL-LTP complexes remained intact during this time. Under equilibrium conditions, LTP binding to all lipoproteins was characterized by high affinity, saturable kinetics; the apparent affinities (Kd) of VLDL, LDL, and HDL for LTP were nearly the same (congruent to 25 nM). The results of two studies correlated lipid transfer activity with LTP binding to lipoproteins: 1) LTP binding and transfer activity increased in parallel as the amount of LTP in the assay was increased and 2) the inhibition of transfer activity caused by differing amounts of an inhibitory protein correlated with similar decrements in LTP binding. The latter data also suggest that the inhibitor protein suppresses lipid transfer activity by disrupting LTP-lipoprotein interactions. It is concluded that LTP avidly binds to VLDL, LDL, and HDL via a reversible, saturable mechanism and that the binding of LTP to the lipoprotein surface is an integral component of the lipid transfer reaction.

A survey of urinary tract infections (UTI) was conducted in a paediatric out-patient department in Northern Nigeria over six months. The most common presenting complaints of UTI were pyrexia of unknown origin (PUO) and mild diarrhoea. The frequency of symptomatic UTI in out-patients was estimated at 0.4%. Asymptomatic UTI was common in children with nephrotic syndrome (16%) and severe malnutrition (23%). Abnormalities of the urinary tract were found on I.V.P. in four out of twelve boys and one out of nine girls with symptomatic infection. Micturating cystograms (MCUG) were of less value because even if severe ureteric reflux was found, long term follow-up was not practical. Follow-up could be maintained with greater success from local clinics.

A modified rotating cryostat and its use for in situ infrared studies are described. An improvement in sensitivity over present low temperature infrared cells and much shorter deposition times have been obtained.

This study investigates the effect of altered lipoprotein free cholesterol (FC) content on the transfer of cholesteryl ester (CE) and triglyceride (TG) from very low- (VLDL), low- (LDL), and high-(HDL) density lipoproteins by the plasma-derived lipid transfer protein (LTP). The FC content of VLDL and HDL was selectively altered by incubating these lipoproteins with FC/phospholipid dispersions of varying composition. FC-modified lipoproteins were then equilibrated with [3H] TG, [14C]CE-labeled lipoproteins of another class to facilitate the subsequent modification of the radiolabeled donor lipoproteins. LTP was added and the extent of radiolabeled TG and CE transfer determined after 1 h. With either LDL or VLDL as lipid donor, an increase in the FC content of these lipoproteins caused a concentration-dependent inhibition (up to 50%) of CE transfer from these particles, without any significant effect on TG transfer. In contrast, with HDL as donor, increasing the HDL FC content had little effect on CE transfer from HDL, but markedly stimulated (up to 2.5-fold) the transfer of TG. This differential effect of FC on the unidirectional transfer of radiolabeled lipids from VLDL and HDL led to marked effects on LTP-facilitated net mass transfer of lipids. During long-term incubation of a constant amount of LTP with FC-modified VLDL and HDL, the extent of net mass transfer was linearly related to lipoprotein FC content; a 4-fold increase in FC content resulted in a 3-fold stimulation of the CE mass transferred to VLDL, which was coupled to an equimolar, reciprocal transfer of TG mass to HDL. Since lipid transfer between lipoproteins is integral to the process of reverse cholesterol transport, we conclude that lipoprotein FC levels are a potent, positive regulator of the pathways involved in sterol clearance. FC may modulate lipid transfer by altering the availability of CE and TG to LTP at the lipoprotein surface.

Radiography of the lateral neck was performed on all children with Down's syndrome aged 4-15 in the Southern Derbyshire health district (n = 67) and a random selection of adults (n = 94). Atlantoaxial instability, defined as a gap of over 4 mm, was present in seven (10%) children and two (2%) adults. Odontoid hypoplasia, defined as an odontoid peg two standard deviations below the mean in an age matched population, was present in 15 (22%) children and 14 (15%) adults, with accessory odontoid ossicles present in two (2%) and two (3%) respectively. No one was found to have symptoms or clinical signs of spinal cord compression. Atlantoaxial instability was therefore found to be commoner in children than adults. Different programmes of management are suggested, in terms of regular clinical examination for signs and symptoms and by radiographic screening. Particular care should be taken with those who have both atlantoaxial instability and odontoid hypoplasia or accessory ossicles as they are at particular risk of spinal cord damage.

In a previous study we demonstrated that highly purified lipid-transfer protein facilitated the transfer of triglyceride, cholesteryl ester, and phosphatidylcholine between plasma lipoproteins. It remained unclear, however, whether these lipids were transferred by independent sites on the lipid-transfer protein. To address this point, we have studied the protein-mediated transfer of triglyceride, cholesteryl ester, and phosphatidylcholine as a function of the concentration and lipid composition of donor and acceptor lipoproteins. Lipoproteins labeled in vitro, reconstituted lipoproteins of defined lipid composition, and phosphatidylcholine liposomes with or without triglyceride and/or cholesteryl ester have been used to investigate the inter-relationships of lipids transferred by the lipid-transfer protein. In studies of initial (less than or equal to 10-13%) transfer, we found that, although absolute transfer rates were affected, the ratio of cholesteryl ester to triglyceride transferred was independent of donor and acceptor lipoprotein concentrations and acceptor lipoprotein lipid composition. With reconstituted lipoproteins as donor, we demonstrated that this ratio was linearly related to the ratio of cholesteryl ester to triglyceride in the donor particle; the sum of triglyceride and cholesteryl ester transferred remained constant and independent of the lipid composition of the donor. Experiments with intact lipoproteins labeled in vitro and with small unilamellar vesicles in the presence and absence of p-chloromercuriphenylsulfonate, confirmed the interdependence of triglyceride and cholesteryl ester transfer. In contrast, under all assay conditions, no correlation was found between the amount of phosphatidylcholine transferred and the transfer of triglyceride and/or cholesteryl ester. We conclude that triglyceride and cholesteryl ester compete for transfer and that the extent of transfer for each lipid is determined by its relative concentration in the donor particle, whereas phosphatidylcholine transfer is independent of triglyceride and cholesteryl ester transfer. The data also strongly support the conclusion that lipid transfer protein promotes both the exchange and net transfer of triglyceride and cholesteryl ester and that the net transfer process proceeds by a reciprocal exchange of triglyceride and cholesteryl ester without net transfer of core lipid between lipoproteins.

Six cystic fibrosis patients with pulmonary exacerbations were studied to determine the effect of antibiotic treatment on protein nutritional status. Indirect calorimetry, nitrogen balance, protein turnover, urinary 3-methylhistidine, plasma albumin, prealbumin transferrin, and cortisol were measured before and after treatment. N loss averaged 16 and 17% on each balance. N in the sputum was up to 4.5% of absorbed N intake. At the peak of infection, protein synthesis, degradation, and urinary 3-methylhistidine were significantly higher than during recovery (31%, 28%, and 60%, respectively). On recovery a significant fall in blood sugar, albumin, morning cortisol and sputum N and a rise in prealbumin was found. Basal metabolic rate and N balance did not change. For patients in the fed state, active infection is associated with higher rates of protein synthesis and degradation. Antimicrobial treatment alters protein dynamics but does not alter measured N balance or the difference between measured protein synthesis and breakdown.

The capacity of the plasma-derived lipid transfer protein to facilitate the transfer of various cholesteryl ester species has been investigated. Four different molecular species of cholesteryl ester were incorporated into either reconstituted high density lipoproteins or phosphatidylcholine liposomes, and the resulting particles were used as donors in standardized lipid transfer assays. With reconstituted high density lipoproteins as substrate, the rate of transfer of cholesteryl esters was cholesteryl oleate greater than cholesteryl linoleate greater than cholesteryl arachidonate greater than cholesteryl palmitate. The transfer rate for cholesteryl oleate was 154% of that for cholesteryl palmitate. Liposome substrates gave similar results. It is concluded that lipid transfer protein transfers all major species of cholesteryl ester found in plasma; however, the relative rates of transfer were significantly affected by acyl chain composition. The transfer rates appeared to reflect substrate specificity rather than substrate availability within the donor particle.

Pancreatic ascites is usually considered to be a sequela of chronic alcoholic pancreatitis. Our patient had pancreatic pseudocyst formation and pancreatic ascites after acute pancreatitis, the latter secondary to hypercalcemic pancreatitis and documented hyperparathyroidism.

An inhibitor of triglyceride and cholesteryl ester transfer activities has been identified in the plasmas of several animal species. The inhibitor in human plasma has been separated from lipid transfer protein by chromatography on phenyl-Sepharose and CM-cellulose. The inhibitor is characterized as a protein with Mr approximately 35,000 and an isoelectric point of 4 or less. The inhibitor protein decreased the transfer of both triglyceride and cholesteryl ester between all pairs of very low, low, and high density lipoproteins. Although under most conditions the inhibition of triglyceride and cholesteryl ester transfer was similar, the degree of inhibition of lipid transfer was dependent on the lipoprotein pair studied.

A lipoprotein particle designated A-LDL, which contains apolipoprotein B (apoB) and which is the size of plasma low density lipoproteins (LDL), was isolated from homogenates of human aortic athersclerotic plaques by a combination of affinity chromatography and gel-filtration. Compared to plasma LDL, A-LDL was more electronegative, its hydrated density was lower and more heterogeneous, and its protein-to-lipid ratio was lower. In addition, apoB in A-LDL was highly degraded, and A-LDL was recognized by mouse peritoneal macrophages (MPM) as indicated by its ability to stimulate cholesterol esterification. Cholesterol esterification was saturable with an apparent Km of 100 micrograms of A-LDL cholesterol/ml. Stimulation of cholesterol esterification was linear with time, leading to extensive accumulation of cholesteryl ester in MPM over a 48-hr time interval. The uptake or degradation of acetyl-LDL (radiolabeled either in the protein with 125I or hydrophobic core with [3H]cholesteryl ether) was markedly decreased by excess unlabeled acetyl-LDL but not by A-LDL, and excess acetyl-LDL did not inhibit the uptake or degradation of labeled A-LDL. However, a 10-fold excess of A-LDL also failed to inhibit the uptake of labeled A-LDL. This finding was consistent with the observation that, unlike the saturable stimulation of cholesterol esterification in MPM induced by A-LDL, the uptake of cholesteryl ether-labeled A-LDL was almost linear over a 0-400 micrograms cholesterol/ml range. This discrepancy between dose response curves for A-LDL, which did not occur for acetyl-LDL, could be eliminated by a 24-hr postincubation period in the absence of lipoprotein, suggesting that A-LDL is catabolized less efficiently than acetyl-LDL following internalization. In summary, we conclude that A-LDL uptake by MPM occurs via a low affinity-high capacity process. Although the uptake of A-LDL is not readily saturated, it is of sufficient affinity to lead to lipid loading of macrophages even when A-LDL is present at relatively low concentrations. If these mechanisms are operative in vivo, they could explain how foam cells in human fatty streak lesions develop.

This paper presents fatty acyl compositions of phospholipids derived from mitochondria and microsomes isolated from two Morris hepatomas, one with slow (9618A) and another with intermediate (7794A) growth rate, and from corresponding host livers. These were compared with previous data from our laboratory for the fast-growing Morris hepatoma 7777. In this group of three hepatomas of widely differing growth rate and differentiation, the faster the growth rate of the tumor, the larger the sum of the contents of 16:1, 18:1, and 18:2 and the smaller the sum of the contents of all polyunsaturated fatty acids with four or more double bonds per molecule. The former sum was generally higher and the polyunsaturate content lower in hepatoma organelles than in corresponding host liver organelles. The 18:0/18:1 ratio observed in hepatoma organelles was always significantly less than that in host or control liver organelles.

A case of SLE with the unique association of gastric polyps and vasculitis is reported. Gastrointestinal symptoms, surgical indications, and complications of SLE with gastrointestinal involvement are reviewed. The unusual patterns of ileus or lupus peritonitis secondary to mesenteric vasculitis must be differentiated from a true surgical emergency. Corticosteroids may be expected to produce rapid clinical improvement in the two former instances. Surgical exploration is reserved for those cases with clinical or radiologic evidence of uncontrollable hemorrhage, bowel perforation, or mesenteric infarction.

SUMMARY Data from several sources are used to quantify the expected direct medical costs of a recently healed duodenal ulcer patient prescribed an H2-antagonist (famotidine) for a 6-month period. These costs are compared to the expected direct medical costs associated with not using maintenance therapy. Our results indicate that the estimated direct cost of patients prescribed a 6-month regimen of an H2-antagonist (famotidine) is 30.3% lower than patients who receive no H2-antagonist therapy. Most of the savings result from a reduced risk of hospitalization and surgery. The results of the sensitivity analysis of four varying scenarios indicate that H2-antagonist maintenance therapy remains less costly even when the assumptions underlying the model are varied enormously. We conclude that the decision to withhold maintenance therapy with H2-antagonists should not be based on economics.