Modulation of the host cell proteome by the intracellular apicomplexan parasite Toxoplasma gondii.

To investigate how intracellular parasites manipulate their host cell environment at the molecular level, we undertook a quantitative proteomic study of cells following infection with the apicomplexan parasite Toxoplasma gondii. Using conventional two-dimensional electrophoresis, difference gel electrophoresis (DIGE), and mass spectrometry, we identified host proteins that were consistently modulated in expression following infection. We detected modification of protein expression in key metabolic pathways, including glycolysis, lipid and sterol metabolism, mitosis, apoptosis, and structural-protein expression, suggestive of global reprogramming of cell metabolism by the parasite. Many of the differentially expressed proteins had not been previously implicated in the response to the parasite, while others provide important corroborative protein evidence for previously proposed hypotheses of pathogen-cell interactions. Significantly, over one-third of all modulated proteins were mitochondrial, and this was further investigated by DIGE analysis of a mitochondrion-enriched preparation from infected cells. Comparison of our proteomic data with previous transcriptional studies suggested that a complex relationship exits between transcription and protein expression that may be partly explained by posttranslational modifications of proteins and revealed the importance of investigating protein changes when interpreting transcriptional data. To investigate this further, we used phosphatase treatment and DIGE to demonstrate changes in the phosphorylation states of several key proteins following infection. Overall, our findings indicate that the host cell proteome responds in a dramatic way to T. gondii invasion, in terms of both protein expression changes and protein modifications, and reveal a complex and intimate molecular relationship between host and parasite.

A pilot study of the safety and efficacy of picolinic acid gel in the treatment of acne vulgaris.

BACKGROUND: Cost limitations, adverse effects or lack of efficacy limit the use of current topical therapies in mild to moderate acne vulgaris. OBJECTIVES: To determine the safety and efficacy of picolinic acid, a novel zinc finger therapy, in the treatment of mild to moderate acne vulgaris. METHODS: Twenty subjects with mild to moderate acne vulgaris were treated at our centre during an open-label study with 10% picolinic acid gel (PCL-016) twice daily to the face over 12 weeks. RESULTS: Fifteen patients completed the 12-week open-label study. A reduction of 58.2% (P < 0.001) in mean total lesion count, 55.5% (P < 0.001) in mean inflammatory lesion count and 59.7% (P < 0.005) in noninflammatory lesion count was seen in this population. No serious adverse events or clinically significant changes in laboratory values were noted. CONCLUSIONS: Results from this study suggest that 10% picolinic acid gel applied twice daily may be safe and effective in the treatment of mild to moderate acne vulgaris.

Variation in the fatty acid composition of blubber in Cape fur seals (Arctocephalus pusillus pusillus) and the implications for dietary interpretation.

Analysis of the fatty acid (FA) composition of blubber is a valuable tool in interpreting the diet of marine mammals. This technique is based on the principle that particular FA present in prey can be incorporated largely untransformed into predator adipose tissue stores, thereby providing biochemical signatures with which to identify prey species. Several studies of phocid seals and cetaceans have documented vertical stratification in the FA composition of blubber such that inferences about diet may vary greatly depending on the layer of the blubber that is analysed. It is not known whether blubber in otariid seals (fur seals and sea lions) also displays vertical stratification in FA composition. Furthermore, it is not known whether the FA composition of blubber is uniform in these species. In the present study, the vertical and regional variation in FA composition of blubber was investigated in seven adult female Cape fur seals (Arctocephalus pusillus pusillus). The proportion of monounsaturated fatty acids (MUFA) was greater in the outer (43.6+/-1.3%) than inner portion (40.9+/-1.2%; t(20)=5.59, P<0.001) whereas the proportions were greater in the inner than outer portions for saturated fatty acids (23.6+/-0.5% and 21.9+/-0.6%, respectively, t(20) = 5.31, P<0.001) and polyunsaturated fatty acids (PUFA, 35.5+/-0.7% and 34.5+/-0.7%, respectively, t(20) = 3.81, P < 0.001). There was an inverse relationship between MUFA and PUFA in the blubber, independent of sampling location. In addition, with the exception of the inner portion from non-lactating females, blubber from the mammary area had the highest proportions of 18:1omega9c and total MUFA, followed by blubber from the rump and neck, suggesting that the deposition and mobilisation of blubber lipids may not be uniform around the body in otariid seals. These results support the need for blubber tissue to be sampled from the same site on animals, and to the full depth of the blubber layer, to minimise variation in FA profiles that could occur if different sites and depths were sampled. Such standardisation of sampling will further aid in interpreting diet in otariid seals using the FA Signature Analysis approach.

Interannual variations in the lipids of the Antarctic pteropods Clione limacina and Clio pyramidata.

Antarctic pteropods, Clione limacina (Order Gymnosomata) and Clio pyramidata (order Thecosomata), were collected near Elephant Island, South Shetland Islands, during 1997 and 1998. Total lipid was high in C. limacina (29--36 mg g(-1) wet mass) and included 46% of diacy1glyceryl ether (DAGE, as % of total lipid) for both 1997 and 1998. DAGE was not detected in C. pyramidata, which had mainly polar lipid and triacy1glycerol. 1-O-Alkyl glyceryl ethers (GE) derived from the DAGE consisted primarily of 15:0 and 16:0, with lower 17:0 and a17:0. The principal sterols of both pteropods included trans-dehydrocholesterol, brassicasterol, 24-methylenecholesterol, cholesterol and desmosterol. Levels of 24-methylenecholesterol and desmosterol were lower in both pteropods in 1997 compared to 1998. C. limacina had high levels of the odd-chain fatty acids 17:1(n--8)c and 15:0 in contrast to C. pyramidata. The previously proposed source of elevated odd-chain fatty acids in C. limacina is via propionate derived from phytoplankton DMPT; another possible source may be from thraustochytrids, which are common marine microheterotrophs. C. pyramidata had twice as much PUFA as C. limacina, largely due to higher 20:5(n--3). The PUFA 18:5(n--3) and very long chain fatty acids (C(24), C(26) and C(28) VLC-PUFA) were only detected in 1998 pteropods. In comparison, 1996 samples of C. limacina contained lower DAGE levels, which also may reflect differences in diet and oceanographic conditions. Interannual variations in specific lipid biomarkers are discussed with respect to possible different phytoplankton food sources available in the AMLR survey area.

Lipids of gelatinous Antarctic zooplankton: Cnidaria and Ctenophora.

Cnidaria (Calycopsis borchgrevinki, Diphyes antarctica, Stygiomedusa gigantea, Atolla wyvillei, Dimophyes arctica) and Ctenophora (Beroe cucumis, B. forskalii, Pleurobrachia pileus, Bolinopsis infundibulum) were collected near Elephant Island, South Shetland Islands, during January and February 1997 and 1998. Total lipid was low in all zooplankton (0.1-5 mg g wet mass) and included primarily polar lipids (59-96% of total lipid). Triacylglycerols were 0-26% of total lipids, and wax esters were 0-11% in all species. Cholesterol was the major sterol in all Cnidaria (50-63% of total sterols) whereas in most ctenophores it was lower at 26-45%. These cholesterol levels are consistent with a combined carnivorous and phytoplanktivorous diet in the ctenophores, with the carnivorous diet more dominant in the Cnidaria. Other sterols included primarily trans-dehydrocholesterol, desmosterol, 24-methylcholest-5,22E-dien-3beta-ol, 24-nordehydrocholesterol, and 24-methylenecholesterol. Total stanols were 0-6% in all zooplankton. Eicosapentaenoic acid and docosahexaenoic acid were the major polyunsaturated fatty acids (PUFA) in all samples (7-25% of total fatty acids) except for A. wyvillei in which docosapentaenoic acid was 10% of total fatty acids. The PUFA 18:5n-3 was not detected in 1997 samples, but constituted 0.2-0.8% in most 1998 samples. Monounsaturated fatty acids included primarily 18:1n-9c, 16:1n-7c, and 18:1n-7c. The principal saturated fatty acids in all samples were 16:0, 18:0, and 14:0. These data are the first for many of these zooplankton species and the first sterol data for most species. The use of the signature lipid approach has enabled examination of aspects of trophodynamics not obtainable by conventional techniques.

The occurrence and possible significance of diacylglyceryl ether lipids in abalone.

Gonadal and foot tissues of the green abalone, Haliotis fulgens, farm-raised on macroalgal [corrected] diets, were analyzed for lipids using thin-layer chromatography/flame-ionization detection and gas chromatography-mass spectrometry (GC-MS). Diacylglyceryl ether (DAGE) was 0.7% of total lipids in the gonad. The major alkyl constituents of the glyceryl ether diols in the gonad (as % of total diols) were 16:0 (38%) and 18:1 (36%). While levels of DAGE in the abalone foot were below flame-ionization detection limits, glyceryl ether diols from them were detected using the more sensitive GC-MS procedure. The major diol components in the foot were 18:0 (39%) and 18:1 (32%). To our knowledge, this is the first report of DAGE in abalone tissues. Although the precise role of DAGE in abalone remains to be determined, a possible structural role may exist.

Assessment of skeletal muscle damage in successive biopsies from strength-trained and untrained men and women.

The effects of repeated biopsy sampling on muscle morphology was qualitatively and quantitatively assessed in strength-trained and untrained men and women. College-age men (13) and women (8) resistance trained twice a week for 8 weeks. A progressive resistance-training program was performed consisting of squats, leg presses, and leg extensions. Nontraining men (7) and women (5) served as controls. Muscle biopsy specimens and fasting bloods were obtained at the beginning and every 2 weeks and histochemical, biochemical, and ultrastructural methods were employed to assess the type and amount of damage. Except for a few scattered atrophic fibers in 2 of the 33 biopsy samples, all initial specimens were normal. In contrast, many of the subsequent biopsy samples from both untrained and resistance-trained men and women contained evidence of damage. Ultrastructural analysis confirmed that degenerative-regenerative processes were occurring in both groups. However, training subjects had a four-fold greater number of damaged fibers than nontraining subjects (8.53% vs 2.08%). In addition, only biopsy samples from training individuals contained fibers with internal disorganization (e.g., Z-line streaming, myofibrillar disruption). Calpain II levels in the biopsy samples and serum creatine kinase activity were not significantly affected supporting the light and electron microscopic observations that most of the damaged fibers were normal in appearance except for their small diameter. In summary, focal damage induced by the biopsy procedure is not completely repaired after 2 weeks and could affect the results, particularly cross-sectional area measurements. Moreover, resistance training appears to cause additional damage to the muscle and may delay repair of the biopsied region.

Causes of mental handicap in Cape Town.

A cross-cultural study of the cause of the mental handicap of greater than 1,000 children born in the Cape Town area between 1974 and 1986 was carried out. Acquired causes were noted to be more prevalent among the black ethnic group. This study showed that at least 80-100 additional cases of moderate-severe mental handicap can be expected in the Cape Town area each year. Attention is drawn to the expanded facilities that will be required to provide for the ongoing special needs of these children. Possible areas for prevention of mental handicap are discussed.

Stickler's syndrome. A report of a family.

Stickler's syndrome is an autosomal dominant condition characterised by degenerative eye and joint diseases. The eye disorders frequently lead to blindness from retinal detachments and there is often associated hearing loss. The condition has not previously been reported in the RSA. Five patients in a family spanning two generations are described.

Proteus syndrome in southern Africa: natural history and clinical manifestations in six individuals.

Six individuals with Proteus syndrome have been investigated; 2 were adults and the others ranged in age from 2 to 11 years. They had a wide spectrum of manifestations and severity together with the hitherto unreported anomalies of penile hypertrophy, macro-orchidism, goiter, and failure of breast development. These findings were associated with normal endocrine function. Bizarre digital overgrowth, hemihypertrophy, thickened palms and soles, exostoses of the skull, and multiple hamartomata were common anomalies. Early overgrowth of limbs and digits occurred in several instances but the ultimate stature of 2 adults was normal. Surgical intervention offers cosmetic and orthopedic benefits, but these must be assessed in the light of potential post-operative complications.

Body composition of Peruvian children with short stature and high weight-for-height. I. Total body-water measurements and their prediction from anthropometric values.

Total body water (TBW) was measured by 18O dilution in 139 undernourished, preschool Peruvian children with high weight-for-height. Values for TBW as a percent of body weight were relatively high, averaging 67.4 +/- 6.4%. Depending upon the method of calculation, mean values for the sample population for percent fat ranged from 9.4-18.5%. Regression of TBW on lean body mass suggested that hydration of the fat-free body was higher than for normally nourished children of comparable age. Thus, the increased weight-for-height in these children did not result from increased fat tissue, but from increased hydration of the fat-free body. TBW was most highly correlated with height and weight, both with r = 0.95. Equations predicting TBW from either height or weight were significantly different from those developed by other investigators to predict TBW for normal, well-nourished American children.

Macrodactyly simplex congenita. A case series and considerations of differential diagnosis and aetiology.

Macrodactyly simplex congenita (MSC) is a rare congenital anomaly comprising some 10% of cases of isolated congenital macrodactyly. The essential elements in MSC are mentioned and a differential diagnosis from other forms of enlarged digits is given, in the light of the natural history of the condition. The distinction is shown to have practical therapeutic implications. The causation is discussed and a hypothesis advanced of a possible somatic mutation in an inhibitory chalone receptor allowing the switch-on of unimpeded local growth.

Cyclopia as a result of an unbalanced familial translocation, rcp(7;18)(q34;q21)

One fetus is described with cyclopia and associated abnormalities as a result of an unbalanced translocation involving chromosomes 7 and 18 [46XX,del 7, rcp(7;18)(q34;21)]. The parents had had a previous infant described as having possible holoprosencephaly, but no medical records were available to substantiate this description.

Ataxia-telangiectasia. X,14 translocation, progressive deterioration of lymphocyte numbers and function, and abnormal in vitro immunoglobulin production.

Three children with ataxia-telangiectasia have been followed up since their early childhood. Sequential immunological, biochemical and chromosome studies have been performed over the last 7 years. All the children showed progressive cerebellar ataxia and inexorable neurological deterioration. Further evidence for the progressive nature of this condition is the fall in lymphocyte counts, deterioration of lymphocyte transformation responses to mitogens, and an increase in chromosomal translocations and breakage. Elevated serum alpha-fetoprotein levels are a highly characteristic and useful diagnostic finding in this condition. Two of the patients had an X,14 translocation. In vitro studies of immunoglobulin synthesis suggest an intrinsic defect in B-cell synthesis as well as decreased helper T-cell activity. In spite of moderately severe and progressive abnormalities in the immune system, sinopulmonary infections have not been prominent in our patients.

An association of caudal malformations arising from a defect in the "axial mesoderm" developmental field.

We have studied two newborn infants with a remarkable genital malformation, failure of urethral development with enormous bladder distension, atresia of the distal hindgut, vertebral abnormalities, and compression deformities. This is a pattern of anomalies similar to, and probably an extension of, the association of female pseudohermaphroditism and other anomalies (FPA) described by Lubinsky [Am J Med Genet 6:123-136, 1980]. We propose that its pathogenesis involves a defect expressed in mesoderm, especially caudal mesoderm. We offer some speculation on what might be its nature, with particular reference to the theory of cell surface molecules having a role in morphogenesis. We apply the concept of the developmental field to provide a clarifying perspective.

The campomelic syndrome--prenatal ultrasound investigations. A case report.

The campomelic syndrome is a skeletal dysplasia of unknown aetiology which is apparent at birth and is characterized by bilateral bowing of the tibiae, clubfoot and other multiple congenital abnormalities. Up to 50% of cases are either stillborn or die within 24 hours of birth in respiratory distress. With a few exceptions, the remainder die within 10 months. The patient in this report demonstrated characteristic features of the syndrome which were detected antenatally by ultrasound and confirmed after delivery. The apparently female infant died 2 hours postpartum in respiratory distress, but was subsequently found to have a 46,XY chromosome constitution. Autopsy and postmortem radiographs revealed multiple congenital abnormalities consistent with the campomelic syndrome. The findings in this case are discussed and the possibility of antenatal diagnosis is raised.

Ultrasound examination before amniocentesis and success of culture in genetic referrals. Six years' experience in Cape Town.

Our experience in Cape Town shows that ultrasound examination is of great benefit when amniocentesis is performed to obtain amniotic fluid cells for metaphase plates from patients at risk of carrying a fetus with a genetic disorder. Data taken over a period of 6 years show that the number of blood-contaminated fluid specimens decreases significantly when patients are scanned before amniocentesis is performed. The presence of blood in the fluid increases the possibility that cells will not grow in culture. There was no evidence to suggest that ultrasound examination inhibited amniotic fluid cell growth in culture.