Mutational analysis of mucopolysaccharidosis type VI patients undergoing a trial of enzyme replacement therapy

Mucopolysaccharidosis type VI (MPS VI), or Maroteaux-Lamy syndrome, is a lysosomal storage disorder caused by a deficiency of N-acetylgalactosamine-4-sulfatase (ARSB). Seven MPS VI patients were chosen for the initial clinical trial of enzyme replacement therapy. Direct sequencing of genomic DNA from these patients was used to identify ARSB mutations. Each individual exon of the ARSB gene was amplified by PCR and subsequently sequenced. Nine substitutions (c.289C>T [p.Q97X], c.629A>G [p.Y210C], c.707T>C [p.L236P], c.936G>T [p.W312C], c.944G>A [p.R315Q], c.962T>C [p.L321P], c.979C>T [p.R327X], c.1151G>A [p.S384N], and c.1450A>G [p.R484G]), two deletions (c.356_358delTAC [p.Y86del] and c.427delG), and one intronic mutation (c.1336+2T>G) were identified. A total of 7 out of the 12 mutations identified were novel (p.Y86del, p.Q97X, p.W312C, p.R327X, c.427delG, p.R484G, and c.1336+2T>G). Two of these novel mutations (p.Y86del and p.W312C) were expressed in Chinese hamster ovary cells and analyzed for residual ARSB activity and mutant ARSB protein. The two common polymorphisms c.1072G>A [p.V358M] and c.1126G>A [p.V376M] were identified among the patients, along with the silent mutation c.1191A>G. Cultured fibroblast ARSB mutant protein and residual activity were determined for each patient, and, together with genotype information, were used to predict the expected clinical severity of each MPS VI patient.

The development of clinical practice guidelines for the use of aromatherapy in a cancer setting

The need to develop guidelines for the use of aromatherapy was identified to ensure safe and appropriate use in clinical practice. Therapeutic actions and safety data were reviewed along with literature relating to nurses' use of aromatherapy. A policy was developed with the needs of the oncology patient being the foremost consideration. Methods of administration and dosage of essential oils were stipulated to address safety issues.

Long-term outcome of surgery for dogs with cranial cruciate ligament deficiency

Fifty-eight dogs with cranial cruciate ligament deficiency were assessed and treated surgically. At an average of 50 months postoperatively, the functional outcome was assessed by means of an owner-based clinical assessment and a clinical examination. Client-based data were available for 26 dogs and 20 dogs were reassessed after 50 months. The results were compared with the initial values and with data from an assessment 13 months postoperatively. The level of disability at 50 months was judged to be significantly less than initially. However, there were no differences between the initial assessments and those made after 50 months for the perceived 'effect of cold weather' and the dogs' 'ability to jump', despite both measures having improved after 13 months. Age and meniscal injury were identified as poor prognostic indicators for the long-term outcome. The equivalent joint on the contralateral limb deteriorated significantly during the study.

Toxic shock syndrome associated with newly diagnosed type I diabetes

Studies of two post-mortem pancreata of children at the onset of type I diabetes have suggested activation and expansion of islet infiltrating T cells by a superantigen. We present the first reported case of a superantigen mediated disease, toxic shock syndrome (TSS), occurring at the diagnosis of type I diabetes. A 12-year-old girl presented with TSS and newly diagnosed diabetes with ketoacidosis. At presentation she was unconscious, febrile and hypotensive, with a desquamating erythematous rash and Kussmaul breathing. During resuscitation, her renal impairment, diarrhoea, thrombocytopaenia and ketoacidosis resolved. Vaginal discharge and blood cultures grew Staphylococcus aureus. T cell studies at 2 weeks after diagnosis detected a high level of spontaneous and islet antigen-specific proliferation with associated interleukin-10 production compared to human leucocyte antigen DR matched controls.

Islet autoimmunity in infants with a Type I diabetic relative is common but is frequently restricted to one autoantibody

AIMS/HYPOTHESIS

To determine the sequence of development of islet autoantibodies and their relation to HLA genes in infants at risk for Type I diabetes followed from birth.

METHODS

We followed 357 (189 male, 168 female) infants, with a first degree relative with Type I diabetes for a mean of 3 years from birth. Human leukocyte antigen typing and assays for insulin autoantibodies (IAA), glutamic acid decarboxylase antibodies (GADAb) and tyrosine phosphatase IA2 (IA2Ab) antibodies were done on cord blood, and venous blood was sampled every 6 months for IAA, GADAb and IA2Ab.

RESULTS

We did not find any antibodies in 263 (73%) infants; 50 (14%) were positive for a single antibody once, 19 (5%) for a single antibody more than once and 25 (7%) for two or more antibodies. Of the latter, 10 (2.8% overall) were persistently positive; they had higher frequencies of HLA DR4 (p < 0.01) and HLA DR3, 4 (p < 0.05). Of the group persistently positive for two or more antibodies four infants developed diabetes. Insulin autoantibodies were the first ones to develop in 64% of infants with two or more antibodies.

CONCLUSION/INTERPRETATION

Infants with high risk HLA-DR alleles and multiple antibodies at high risk for diabetes were identified. A much larger group of infants had transient low level increases usually of a single antibody. Whereas transient low level positivity could be attributed to difficulties with assay technique and cut off levels for normality, the results overall support the phenomenon of transient 'self limited' islet autoimmunity in at risk infants.

Lack of association between duration of breast-feeding or introduction of cow's milk and development of islet autoimmunity

The hypothesis that early exposure to cow's milk or lack of breast-feeding predisposes to type 1 diabetes remains controversial. We aimed to determine prospectively the relationship of, first, duration of exclusive breast-feeding and total duration of breast-feeding, and second, introduction of cow's milk protein as infant formula, cow's milk, or dairy products, to the development of islet antibodies in early life. Some 317 children with a first-degree relative with type 1 diabetes were followed prospectively from birth for 29 months (4-73). Mothers kept a home diary and answered infant feeding questionnaires at 6-month intervals. No systematic feeding advice was given. Insulin autoantibodies (normal range <5.5%), anti-GAD antibodies (<5.0 U), and anti-IA2 antibodies (<3.0 U) were measured at 6-month intervals. Cox proportional hazards model of survival analysis detected no significant difference between children who did not develop islet antibodies (225 of 317 [71%]), children with one islet antibody raised once (52 of 317 [16.4%]), children with one antibody raised repeatedly (18 of 317 [5.7%]), or children with two or more antibodies raised (22 of 317 [6.9%]), in terms of duration of exclusive breast-feeding, total duration of breast-feeding, or introduction of cow's milk-based infant formulas, cow's milk, or dairy products (relative risk: 0.91-1.09). Four of the children with two or more islet antibodies developed type 1 diabetes. We conclude that there is no prospective association between duration of breast-feeding or introduction of cow's milk and the development of islet autoimmunity in high-risk children.

Clinical associations of anti-lamin autoantibodies

BACKGROUND

The clinical associations of anti-lamin autoantibodies were first described in 1973. Since then a number of individual case reports and two small series have been published. These have suggested an association with connective tissue disorders and autoimmune liver disease.

AIMS

To identify the clinical and laboratory associations of anti-lamin autoantibodies in an Australian population.

METHODS

Retrospective review of routine antinuclear antibody testing between 1990-1994 for characteristics linear staining of nuclear envelope on indirect immunofluorescence on HEp-2 cells with clinical status defined by retrospective review of case records.

RESULTS

Twenty-eight patients were identified and the clinical status of 27 patients defined. Eleven patients had associated IgG anti-cardiolipin antibodies; anti-phospholipid syndrome was present in nine. Seven further patients had liver disease; five had autoimmune liver disease, with associated autoantibodies. The remaining nine patients had a diverse group of diseases. There was no correlation between the titre of the autoantibody and clinical status. An association with anti-cardiolipin antibodies was found although the cause remains obscure.

CONCLUSION

Anti-lamin autoantibodies, as identified by indirect immunofluorescence, are associated with a diverse group of diseases but particularly with anti-phospholipid syndrome and liver disease. Testing for anti-phospholipid antibodies and more specific markers of systemic lupus erythematosus and autoimmune disease, for example anti-dsDNA antibodies, anti-smooth muscle antibodies and anti-mitochondrial antibodies should be pursued when anti-lamin autoantibodies are detected.

125I-RIA kit cannot distinguish vitamin D deficiency as well as a more specific assay for 25-hydroxyvitamin D

OBJECTIVES

To compare a new radioimmunoassay (RIA), measuring vitamin D metabolites, against an established, competitive-protein binding assay (CPBA) that uses rat vitamin D binding protein.

METHODS

For the CPBA, we first isolated 25-hydroxyvitamin D (25(OH)D) by eluting sample through silica cartridges. For the RIA, serum was added to acetonitrile and centrifuged, followed by RIA using 125I-25(OH)D3.

RESULTS

The within-run CV was 1.5% to 4.1% by RIA, compared to 8.1% to 15.0% by CPBA. For both methods, analytical recovery was not significantly different from 100%, and both methods were appropriately linear with sample dilution. We compared RIA values (y axis) from 90 subjects with 25(OH)D ranging from 11 to 232 nmol/L by CPBA (x axis). The slope was 0.9992 (not significantly different from 1). However, the RIA exhibited a bias of 11.15 nmol/L (p < 0.05 vs 0), and a correlation coefficient of r = 0.923. When the comparison was confined to the 37 samples in the lower half of our reference range, the RIA did not compare well: slope, 0.764 (p < 0.05 vs 1.0); intercept 18.7 nmol/L (p < 0.05 vs 0); r = 0.517. For the samples below 36 nmol/L by CPBA, there was no discrimination by RIA between the 11 values below, and the 11 above the decision level (25 nmol/L by CPBA) for vitamin D deficiency.

CONCLUSIONS

We conclude that the RIA is not optimized to detect vitamin D deficiency, and for this purpose it is not a valid substitute for conventional 25(OH)D methods.

Near-infrared spectroscopic determination of serum total proteins, albumin, globulins, and urea

We have determined total protein, albumin, globulins, and urea in unmodified human serum using near-infrared (NIR) spectroscopy. The distinctive NIR spectrum of the individual protein fractions allowed unique spectroscopic models to be derived for each fraction using multiple linear least-squares regression (MLR). A more sophisticated partial least-squares (PLS) regression analysis was necessary to fully extract the relevant spectral information for urea. The serum protein data sets consisted of 235 calibration samples and 85 prediction samples. The total protein calibration yielded a multiple correlation coefficient (R) of 0.986 and a standard error of calibration (SEC) of 1.7 g/L. For the validation data set, a correlation coefficient (r) of 0.985 and standard error of prediction (SEP) of 1.7 g/L were obtained. For albumin, the values were R = 0.982 and SEC = 1.2 g/L for calibration and r = 0.984 and SEP = 1.1 g/L for prediction. Calibration results for globulins were R = 0.916 and SEC = 2.1 g/L; validation results were r = 0.885 and SEP = 2.2 g/L. The sum of the separately estimated albumin and globulin fractions agreed well with the total protein estimate. For urea, the calibration model (n = 422) provided an R = 0.994 and SEC = 0.7 mmol/L and the validation results (n = 208) were r = 0.993 and SEP = 0.8 mmol/L. The within-day and between-day precision values (CVs) were respectively, 1.2 and 1.3% for total protein, 1.7 and 1.1% for albumin, 1.5 and 1.3% for globulins, and 8.3 and 5.5% for urea.

Carpal arch alteration and related clinical status after endoscopic carpal tunnel release

One hundred eight endoscopic carpal tunnel releases were performed by a modification of the technique described by Chow. Eighty-seven of the 108 cases were evaluated for quantitative postoperative widening of the transverse carpal arch. The average postoperative widening of the transverse carpal arch was 0.17 cm (7%), with a range of 0 to 0.5 cm. Seventy percent of the patients showed 0% to 10% widening, 26% showed 10% to 20% widening, and 4% showed more than 20% widening of the transverse carpal arch. Preliminary findings show that 3 weeks after endoscopic carpal tunnel release, pinch strength was at 102% and grip strength at 86% of preoperative values. Six weeks after surgery, pinch strength was 106% and grip strength was 121% of preoperative values. The complication rate in this series was 3%. The transverse dimension of the carpal arch generally widens after endoscopic carpal tunnel release but to a lesser degree than has been reported for open carpal tunnel release. The rate of improvement of pinch and grip strength after endoscopic release is faster than that reported in the literature after open release.