The relation of cerebrospinal fluid and plasma glycine levels in propionic acidaemia, a 'ketotic hyperglycinaemia'.

The characteristic elevation of plasma glycine concentrations observed in propionic acidaemia (PA) and other 'ketotic hyperglycinaemias' has been attributed to secondary inhibition of the hepatic glycine cleavage system (GCS) by accumulating CoA derivatives of branched-chain amino acid metabolites. In nonketotic hyperglycinaemia (NKH), cerebrospinal fluid (CSF) and plasma glycine levels and their ratio are increased due to primary deficiency of central nervous system (CNS) as well as hepatic GCS. Whether the GCS in the CNS is also inhibited in PA is unclear, as there are scant data available on CSF glycine levels in this disorder. We studied the relation of CSF and plasma glycine levels in 6 paired samples from 4 PA patients, including one PA patient with bacterial meningitis who underwent ventriculoperitoneal shunting and multiple CSF analyses (n = 26). In contrast to the CSF glycine levels which were generally elevated in all four PA patients, the CSF/plasma glycine concentration ratios in paired samples were normal (0.016-0.029), with the exception of a single sample (0.132) with extremely high CSF protein concentration (2010 mg/L) during the course of meningitis indicating a disturbed blood-brain barrier. This finding of normal CSF/plasma glycine ratio in PA suggests that the observed elevations of CSF glycine levels are a reflection of the concurrent hyperglycinaemia resulting from secondary inhibition of hepatic GCS, but that brain GCS is not affected, in contrast to the situation in NKH. The neurological sequelae in PA are therefore unlikely to be related to disturbed glycine metabolism.

Newborn screening for MCAD deficiency: experience of the first three years in British Columbia, Canada.

BACKGROUND: Medium Chain Acyl-CoA Dehydrogenase (MCAD) Deficiency is an autosomal recessive disorder of fatty acid oxidation, with potential fatal outcome. MCAD deficiency is diagnosed by acylcarnitine analysis on newborn screening blood spot cards by tandem mass spectrometry. Early diagnosis of MCAD and presymptomatic treatment can potentially reduce morbidity and mortality. OBJECTIVES: To evaluate incidence, clinical outcome, biochemical and molecular phenotype of MCAD cases detected in the first three years of newborn screening in British Columbia (BC). METHODS AND RESULTS: Medium chain length acylcarnitines, octanoylcarnitine (C8) and decanoylcarnitine (C10), were measured on newborn screening blood spot cards. Out of 121,000 live births, 17 newborns had C8 values above the screening cut-off of 0.38 umol/L. Ten newborns had elevated C8 on repeat cards and were investigated further. Both C8 and C8/C10 ratios remained abnormal in all confirmed MCAD cases. Positive predictive value of screening was 58% with no false negative results. Seven patients were homozygous for the common c.985A > G MCAD mutation and three others were compound heterozygous for the c.985A > G and a second mutation. Two novel mutations were identified (c.260T > C and c.382T > A). The estimated incidence of MCAD was approximately 1:12,000 live births. Upon frequent feeding and carnitine supplementation, none of the patients had metabolic crises or adverse outcomes. CONCLUSION: Frequency of MCAD in BC is comparable to reports from other newborn screening programs. Persistence of elevated C8 levels and C8/C10 ratios in confirmed MCAD cases suggest that these are sensitive markers for newborn screening. Early detection and treatment have successfully prevented adverse health outcomes in patients with MCAD.

Altered retinoblastoma protein expression and prognosis in early-stage non-small-cell lung carcinoma.

BACKGROUND: Altered retinoblastoma (RB [also known as RB1]) gene expression was initially found in a small cohort study to occur in five (22%) of 23 patients with primary stage I and II non-small-cell lung carcinomas (NSCLCs). Putative mutation of the p53 gene (also known as TP53) has also been found to occur frequently in stage I and II NSCLCs and to be associated with more aggressive disease and a poorer prognosis. PURPOSE: Our purpose was to determine the Rb protein status in the same cohort that had been previously studied for their p53 protein status and to document whether loss of Rb protein expression was also an important factor in overall survival. METHODS: One hundred one stage I or II NSCLC specimens were analyzed by immunohistochemical staining. These paraffin-embedded tumor sections were obtained from individual paraffin blocks prepared for each patient in the previous study. Patient survival status was obtained from hospital and tumor registry records. RESULTS: Altered Rb protein expression was found in 24 of 101 stage I and II NSCLCs. The median survival was 32 months for patients with Rb-positive (Rb+) tumors and 18 months for individuals in whom expression of Rb protein was absent or altered (Rb-) in tumor cells. Log-rank analysis of the differences in overall survival was statistically significant (P = .007). When these results were combined with the p53 status in the same tumor, the median survival was 12 months for those individuals who had theoretically the worst pattern (Rb-/p53+) and 46 months for those patients with theoretically the best pattern (Rb+/p53-) (P < .001). The Rb+ and Rb- groups in this cohort were well balanced with respect to the distribution of age, disease stage, histologic types, p53 status, and sex. Using a multivariate proportional hazards regression model, both altered Rb and p53 status were found to be significantly associated with poor prognosis (P = .005 and .012, respectively) in the overall cohort. CONCLUSION: Altered Rb protein expression is an independent prognostic marker for overall decreased survival in early-stage NSCLC as detected by absence of nuclear Rb protein staining. There appears to be a poorer prognosis when loss of Rb protein function and mutated p53 protein occur in the same tumor. IMPLICATIONS: If these findings can be confirmed in larger prospective studies, the results would suggest that both the Rb and p53 status should be utilized as independent prognostic factors in early-stage NSCLC.

Accumulation of p53 protein correlates with a poor prognosis in human lung cancer.

Mutations in the gene coding for the p53 tumor suppressor protein are common in a variety of human cancers. To assess the role of a putative mutated p53 protein in human lung cancer, a monoclonal antibody recognizing it was used in an immunoperoxidase detection system. A total of 114 cases of Stage I and II adenocarcinomas and squamous cell carcinomas were studied. The staining pattern was always intranuclear and heterogeneous. When the median or mean survival time was compared between cases, p53 accumulation had a statistically significant negative prognostic value. This was supported by a Kaplan-Meier survival plot of p53 producers and nonproducers. In 7 of 24 Stage II cases that were negative for p53 in the primary tumor, metastatic regional lymph nodes were p53-positive. These latter cases had greatly reduced survival times. Thus, p53 accumulation in primary tumors (and regional lymph nodes) may identify a subgroup of lung cancer patients with a prognosis of more aggressive disease.

Cardiomyopathy associated with nonendemic selenium deficiency in a Caucasian adolescent.

We describe a girl aged 17 y who died after a cardiac arrest secondary to septic shock. At autopsy, the enlarged, soft, and flabby heart showed microscopic evidence of acute myocardial infarction, myocardial edema, myocardiocyte loss, replacement fibrosis in the interventricular septum, and right and left ventricular hypertrophic nucleomegaly. The pathological diagnosis was that of cardiomyopathy due to prolonged selenium deficiency. The patient had been on total parenteral nutrition for 17 mo, following extensive bowel resection for intractable pain, nausea, and vomiting caused by chronic idiopathic intestinal pseudoobstruction. Seven months before death, when severe biochemical selenium deficiency was diagnosed, supplemental selenium was added to the infusion, and plasma selenium concentrations increased. In long-standing selenium deficiency, sepsis may contribute the final insult to a damaged myocardium, triggering symptomatic cardiac failure and sudden death.

Guanosine triphosphate cyclohydrolase I deficiency: early diagnosis by routine urine pteridine screening.

A deficiency of hepatic guanosine triphosphate cyclohydrolase I is reported in a 4-month-old infant in whom positive results on a Guthrie phenylketonuria test in the neonatal period were found. Because of the significantly elevated serum phenylalanine levels a diagnosis of classical phenylketonuria was made, and dietary therapy was started. Urinary pteridine screening for cofactor variants, however, revealed extremely low levels of both neopterin and biopterin. This suggested the possibility of guanosine triphosphate cyclohydrolase I deficiency and led to additional confirmatory assays. Repeat urine, serum, and CSF pteridine profiles, combined with tetrahydrobiopterin-loading studies and the assay of guanosine triphosphate cyclohydrolase I activity in a liver biopsy, confirmed the defect. It is significant to note that the diagnosis was made before the onset of major clinical symptoms. This case illustrates the need for routine cofactor variant screening of all infants in whom hyperphenylalaninemia is diagnosed in the neonatal period.

Oral zinc therapy in the treatment of alpha-mannosidosis.

Human alpha-mannosidosis is a lysosomal storage disorder characterized by mental retardation, dysostosis multiplex, and hepatosplenomegaly. Deficiency of the enzyme leads to accumulation of mannose-rich glycoconjugates in tissues. Zinc sulphate has been shown to stimulate alpha-mannosidase activity in vitro. Oral zinc therapy was attempted on a 4-year-old boy with alpha-mannosidosis for 3 years. After almost 10 years of follow-up on and off zinc therapy, we must conclude that oral zinc does not substantially affect the clinical course of alpha-mannosidosis.

Bone marrow transplantation in Gaucher's disease: effect of mixed chimeric state.

The effective dose and schedule of enzyme replacement therapy for Gaucher's disease have not been definitely established. We report a case of mixed chimeric state in an allogeneic BMT patient and followed her clinical and laboratory progress. The result shows that a low but sustained glucocerebrosidase level may provide symptomatic relief for this lysosomal disorder.

Selective media for isolation of Burkholderia (Pseudomonas) cepacia from the respiratory secretions of patients with cystic fibrosis.

One hundred and six specimens from 90 patients with cystic fibrosis were evaluated for the presence of Burkholderia cepacia using a current routine diagnostic protocol as well as a research protocol involving polymyxin B-MacConkey agar without crystal violet, PC agar, OFPVL agar, and a selective brain-heart infusion broth. Ten specimens from eight patients (8.9%) were positive by any method. The selective enrichment broth was the only medium that yielded B cepacia from all 10 positive samples, although the routine protocol was successful for eight of these. Transient carriage was identified in one patient. Epidemiological studies may be better served by the use of selective enrichment rather than selective solid media alone. Carrier status for B cepacia requires more strict definition if positive carrier status is to be accepted as having medical importance.

Pneumatic calf compression, fibrinolysis, and the prevention of deep venous thrombosis.

In a previous pilot study that did not reach statistical significance, intermittent single-leg pneumatic compression appeared effective in reducing the incidence of calf vein thrombosis not only in the pumped calf but also in the unpumped leg in 37 patients, using the 125I-fibrinogen (Abbott Laboratories) technique. The present study was undertaken to investigate mechanical induction of local and systemic fibrinolysis. The euglobulin lysis time in the arm venous effluent was determined in five volunteers before and after unilateral arm compression for 1/2 hour. Shortening averaged 19% (not significant). The experiment was repeated using bilateral calf-length boots with femoral vein sampling. Euglobulin lysis decreased 22% (P < 0.001). To uncover possible systemic effects, the protocol was altered using calf boots with sampling from the arm. The euglobulin lysis diminished 6% in 57 volunteers (P < 0.001). In 27 others the effects of thigh-length and calf-length boots were compared. In half, pumping with a short boot was undertaken first, and in the remainder, the long boot was applied initially. One-half hour of pumping was followed by 1/2 hour of rest. Immediately afterward the second period of pumping took place and continued for 1/2 hour. A total of four arm vein samples were obtained, one before and after each pumping period. Although, in retrospect, the 1/2-hour rest period was inadequate to permit the subjects to return to basal conditions, statistically significant decreases in euglobin lysis time (P = 0.05) occurred with the long boots. This study shows intermittent calf compression increases fibrinolytic potential locally and this effect can be demonstrated systemically. The greater the volume of tissue compressed, the greater the response. The efficacy of intermittent venous compression in reducing the incidence of deep venous thrombosis may be due, in part, to localized induction of fibrinolysis.

Potential application of p53 as an intermediate biomarker in Barrett's esophagus.

Diagnosis of the neoplastic progression in Barrett's esophagus using the histologic classification of dysplasia is frequently difficult. The tumor suppressor protein p53, when mutated, confers a promoter effect on cell growth. The purpose of this study was to evaluate the applicability of p53 as an intermediate biomarker of malignancy in Barrett's esophagus. Archival analysis of 100 biopsy specimens of Barrett's esophagus and 10 esophageal adenocarcinomas were compared with 35 chronic esophagitis biopsy specimens. Immunocytochemistry using an anti-p53 monoclonal antibody was performed and elevated immunoreactivity quantitated microscopically. Data were analyzed using a logistic regression model. Significant p53 immunoreactivity occurred as follows: chronic esophagitis (0%), Barrett's esophagus without dysplasia (10%), with low-grade dysplasia (60%), with high-grade dysplasia (100%), and adenocarcinoma (70%). All cases of Barrett's esophagus were significantly immunoreactive when compared with the chronic esophagitis cases (p = 0.001). There was an increase in p53 immunoreactivity as the histologic classification progressed toward adenocarcinoma (p = 0.001). Progression to high-grade dysplasia may be predicted based on p53 immunoreactivity. These findings suggest a role for p53 as an intermediate biomarker in Barrett's esophagus.

Review of Metabolic Screening Program of Children's Hospital, Vancouver, British Columbia. 1971--1977.

1. Between 1971 to 1977, 74,521 urines, collected on filter paper and mailed in, were screened by the Metabolic Screening Program of the Children's Hospital. These represented 45.9% of live births in B.C. hospitals were the program has been available. The mean age of the infants was 4.4 weeks. Urines were examined by chromatography with ethyl acetate-pyridine-water for sugars. 1423 (2.13%) had an abnormal pattern necessitating a repeat urine card. A persistent abnormality was noted in 167 (0.22%) and from these a liquid urine sample was obtained for two dimensional amino acid chromatography and/or a repeat sugar chromatography. 2. In 47 (0.06%) of these a definite metabolic abnormality was confirmed. These included cases of Iminoglycinuria (8), Hartnup trait (4), Nonketotic hyperglycinemia (2), Histidinemia (1), Cystathioninuria (5), Argininosuccinic aciduria (1), Maple Syrup Urine Disease (1), Diabetes Mellitus (1), Renal glycosuria (1) and Persistent galactosuria (3). 201 infants had a slight increase of cystine and/or lysine, and 19 of these were documented to be heterozygous for cystinuria.

Biochemical investigation of a child with molybdenum cofactor deficiency.

A girl aged eight months, who presented with developmental delay and dislocated optic lenses, was diagnosed as having combined sulfite oxidase and xanthine dehydrogenase deficiencies consistent with molybdenum cofactor deficiency. The diagnosis was confirmed by demonstrating the absence in urine of urothione, a molybdenum cofactor metabolite. Prenatal diagnosis excluded the disease in the mother's second pregnancy. A summary of an in vitro study of molybdenum cofactor synthesis in the patient is given.

Argininosuccinic aciduria. A developmental and biochemical case study.

An infant with argininosuccinic aciduria was detected through the routine newborn screening program for inborn metabolic diseases and has been followed for over 7 years. Treatment consisting of restricted protein intake and arginine base supplementation was initiated at the age of 8 months and was continued intermittently. She maintained normal psychomotor development to the age of 3 years and currently at the age of 7.3 years, she has measured intelligence in the borderline range. She has had mild symptoms of cerebellar ataxia. Her physical growth has been below normal. Biochemical abnormalities are described. Special metabolic investigations and the effects of treatment are discussed.

In vitro assessment of the intra luminal phase of gliadin digestion in coeliac disease: gamma-glutamyl transpeptidase-like activity in saliva.

gamma-Glutamyl transpeptidase (GGTP) is an enzyme of potential relevance to the digestion of dietary gliadin, and hence of possible importance in the development of coeliac disease (CD). We have confirmed that human saliva has GGTP-like activity. Comparison of this activity between treated CD patients in long-term remission, age- and sex-matched normal control subjects, and unaffected relatives of CD patients did not show statistically significant differences. Although our results have not demonstrated a primary abnormality of this particular enzyme activity in CD, the intraluminal phase of gliadin processing is potentially important in the aetiology and pathogenesis of CD and thus deserves further study.

Plasma arginine esterase activity in cystic fibrosis of the pancreas.

Using a micro-method for the determination of plasma arginine esterase activity, we have investigated the values for soybean trypsin inhibitor (STI)-inhibited arginine esterase activity in patients with cystic fibrosis, obligate heterozygotes and age matched control individuals. The mean of STI-inhibited activity is lowest for cystic fibrosis patients while the mean for normal controls is the highest. The mean of STI-inhibited activity for the heterozygotes is midway between the values of the patients and the normal individuals. The deficiency of arginine esterase activity was statistically significant for both cystic fibrosis patients and heterozygotes.

Protease binding by alpha 2 macroglobulin in cystic fibrosis.

The interaction of alpha 2 macroglobulin (alpha 2M) with exogenous proteases has been reported by others to be abnormal in cystic fibrosis (CF). We have re-examined these claims. Four parameters were considered:(1) the molar protease binding of alpha 2M; (2) the interaction of bovine cationic trypsin (BCT), complexed to alpha 2M, with low molecular mass substrate, benzoyl arginine ethyl ester (BAEE); (3) the stability of formed alpha 2 M-BCT complexes; and (4) the subunit structure of alpha 2M. We have found CF alpha 2M to be similar to control alpha 2M in every respect studied.

Cystic fibrosis: the effect of medium from cultured cystic fibrosis fibroblasts on ATPase activity.

Culture medium from fibroblasts of cystic fibrosis patients and controls was examined for the ability to inhibit (calcium plus magnesium)-activated ATPase and (sodium plus potassium)-activated ATPase. The ATPase systems used were both a solubilised preparation from dog-fish and a membrane associated preparation from human erythrocyes. Contrary to other reports the medium from cystic fibrosis fibroblasts did not inhibit ATPase activity.

Role of exercise and nutrition status on bone mineral density in cystic fibrosis.

BACKGROUND: Exercise has been shown to maintain or increase bone mineral density (BMD) in non-CF populations. OBJECTIVES: The purpose of our study was to elucidate the relationship between exercise, body composition and dietary intake with BMD in an adult CF population with heterogeneous disease severity. DESIGN: We measured spinal (L1-4) and femoral (femoral neck) BMD by dual energy X-ray absorptiometry (DEXA) in 68 CF adults (24 female, 44 male) with a mean age 30.8(1.7) and 27.4(1.3) (range 18-55) years. We used the average BMD Z score for spine and femoral neck for analyses. Differences in disease severity, exercise capacity, physical activity level, dietary intake, body composition, body mass index (BMI), glucocorticoid use were correlated with BMD scores. Exercise capacity was defined as the maximal amount of oxygen consumed by muscles during maximal exercise (Vo2max). Vertebral and non-vertebral fracture rate were also recorded. RESULTS: Fifty-seven patients were identified with low BMD (Z score < -1). Multiple linear regression identified exercise capacity and BMI as significant predictors of BMD. Later diagnosis of CF was also associated with low adult BMD. CONCLUSIONS: Low BMD is common in adult CF patients. Exercise capacity and BMI are predictors of low BMD.

Treatment of recurrent hemoptysis in a child with cystic fibrosis by repeated bronchial artery embolizations and long-term tranexamic acid.

The course of a 12-year-old girl with cystic fibrosis (CF) and with recurrent hemoptysis since age 8 years is described. Conservative measures failed to control her bleeding. Hemoptysis was only partially controlled by repeated bronchial arterial embolizations. However, the addition of tranexamic acid (TXA) resulted in complete cessation of bleeding. Attempts to withdraw TXA therapy resulted in recurrence of hemoptysis; this patient has, therefore, been continuously maintained on this therapy for the past 4 years. No side effects of long-term TXA treatment have been noted.