Autism: Is there a folate connection?

Autism is increasing-but why? Birth defect prevention trials were based on the teleological assumption that folic acid could prevent neural tube defects without consideration of long-term effects, some of which could be beneficial, some of which might be harmful. We therefore ask-Is it impossible to look again at these cohorts?

The occurrence of folic acid (pteroyl-L-monoglutamic acid) in human blood serum after small oral doses.

Human serum folates analysed by bioautography after oral doses of 0.5 mg folic acid (pteroyl-L-monoglutamic acid) show folic acid to be present.

Biopterin derivatives in human body fluids and tissues.

Levels of biopterin derivatives in urine, serum, milk, cerebrospinal fluid, brain, and liver have been measured with the Crithidia fasciculata assay. Normal levels in serum and urine have been given and compared with those in a number of benign and malignant proliferative disorders, phenylketonuria, kidney disease, Parkinson's disease, schizophrenia, controlled epilepsy, rheumatoid arthritis, and pernicious anaemia. The active component of Crithidia factor in serum was 7,8-dihydrobiopterin. Tissue, urine, and some serum samples contained two active materials, the principal one being 7,8-dihydrobiopterin; a minor constituent was probably tetrahydrobiopterin. Serum biopterin levels following methotrexate administration were raised and subsequent administration of folic acid and 5-formyltetrahydrofolic acid further increased serum levels of biopterin derivatives; this was in contrast to the total absence of response to oral folates without prior methotrexate and to 5-methyltetrahydrofolic acid either with or without methotrexate being given.

Folates in human serum.

Constituent serum folates have been shown to be altered and in some cases raised in diseases in which total folate levels are known to be frequently decreased. Absorption experiments showed that orally administered folate analogues affect the folate pool in different ways. The stability of the 10-formyltetrahydrofolate level in normal subjects is demonstrated.

Radioimmunoassay that measures serum vitamin B12.

AIMS: To develop a specific radioimmunoassay for the routine determination of serum vitamin B12. METHODS: Antisera were raised in rabbits by immunisation with the monocarboxylic acid derivative of cyanocobalamin coupled to human serum albumin. Antibody titres and affinities were determined and the antiserum giving the highest binding affinity constant, Ka, was used to develop the assay protocol. Donkey-anti-rabbit gamma globulin-coated magnetisable particles were used to separate the bound from free vitamin B12. The considerable cobalamin binding capacity of human serum was destroyed by autoclaving in acetate-cyanide buffer. Sixty samples were assayed by the radioimmunoassay (RIA) and the Lactobacillus leichmannii assay. Recovery and cross-reactivity experiments were performed. RESULTS: Final rabbit antibody titres varied from 1/20,000 to 1/188,000. Scatchard plots did not correlate with the antibody titres. The Ka values varied from 2.6 to 6.7 x 10(10) litres/mol. For maximum sensitivity the highest Ka (titre 1/66,000) was chosen. A tracer concentration of 22 pmol/l, an antiserum dilution of 1/100,000, and a sample volume of 0.1 ml were used. At an antiserum dilution of 1 in 100,000 the cyanocobalamin binding of the rabbit serum was diluted out. The assay showed excellent correlation with the microbiological assay, with 100% recovery of added vitamin B12. Levels of cross-reactivity for dicyanide cobinamide and hydroxocobalamin were 9.8 and 8.1%, respectively. CONCLUSIONS: The development of this immunoassay permits the measurement of serum vitamin B12 without important interference from cobalamin analogues, related corrinoids, and non-specific binders.

Serum folates in man.

In an aseptic microbiological assay of folate compounds and their breakdown compounds, using Lactobacillus casei, Streptococcus faecalis, and Pediococcus cerevisiae, 4a-hydroxy-5methyl-4,5,6,7-tetrahydrofolate and 5-methyl-5,8-dihydrofolate were inactive under all conditions to all three organisms and 5-methyl-5,6-dihydrofolate was inactive unless ascorbate was present in the incubation medium, and then only to L. casei. 5-Methyltetrahydrofolate was active only for L. casei, and activity in purified samples to S. faecalis was due to trace amounts of folic acid. Analysis of S. faecalis values in the serum in normal subjects and in patients with various disorders showed that levels of 10-formyltetrahydrofolate are raised in coeliac disease, leukaemia, rheumatoid arthritis, and schizophrenia. 5-Methyltetrahydrofolate is readily absorbed by normal human subjects and by patients with pernicious anaemia but poorly absorbed by patients with coeliac disease or leukaemia. 5-Methyl-5,6-dihydrofolate was quickly absorbed by normal human subjects, being reflected by a considerably raised level of 5-methyltetrahydrofolate in serum when sodium bicarbonate was given by mouth before the 5-methyl-5,6-dihydrofolate. These higher levels were comparable to those in patients with pernicious anaemia after oral administration of 5-methyl-5,6-dihydrofolate. Oral 5-methyl-5,8-dihydrofolate and 4a-hydroxy-5-methyl-tetrahydrofolate did not appear as microbiologically active folates in the serum. The findings of this study suggest that the availability for biological utilisation of the major dietary folate compounds will depend on the amount of gastric acidity and of ascorbate in the intestinal chyme. Many may be unavailable for metabolic utilization in the body.

The application of tetrazolium bioautography to the identification of folic acid derivatives.

Tetrazolium bioautography has been applied to the identification of folates in solutions of known concentration, and satisfactory resolution has been obtained between pteroyl-L-monoglutamic acid, calcium leucovorin, and N-5-methyltetrahydrofolic acid. The technique is suitable for the identification of folates in biological solutions, and is more specific than differential microbiological assay.

Measurement of 5-methyltetrahydrofolic acid in man by high-performance liquid chromatography.

5-Methyl-5,6,7,8-tetrahydrofolic (5-methylTHF) acid can be measured in human serum and whole blood by fluorescence after deproteinization with perchloric acid and separation by high-performance liquid chromatography (HPLC). The technique is sensitive, rapid, and correlates with existing methods for total folates.

Adenoid cystic carcinoma of the breast.

Adenoid cystic carcinoma of the breast is a rare neoplasm, with only 140 cases having been reported to date. Data on 123 of these cases are reviewed herein and another case is presented in detail. Several features distinguish this type of breast cancer from more typical histologic types and suggest that it may have a unique tumor behavior. The prognosis appears to be favorable and the incidence of axillary lymph node involvement is lower. Distant metastases are uncommon, but they tend to occur without prior lymph node involvement. This lack of prognostic significance for negative axillary lymph nodes underscores the need for other prognostic markers in this disease and suggests that axillary dissection can be eliminated in most cases. Similarities to typical breast cancer include the incidence of local recurrence and the lack of effect of surgical treatment on distant metastases and overall survival. These data suggest that breast-conserving treatment may be applicable to adenoid cystic carcinoma.

The effects of pathological and normal physiological processes on biopterin derivative levels in man.

Mean serum biopterin derivative levels in adult males and females were 1.75 microgram/l and 1.53 microgram/l respectively, increased with age and followed a cyclic pattern during menstruation. Foetal brain and liver levels at 16 weeks approximated adult concentrations. Wide distribution in adult tissues and variation in concentration independent of serum levels demonstrated local synthesis. Serum levels were significantly decreased in senile dementia, lead poisoning, coeliac disease and malignant carcinoid disease. Abnormal metabolism of phenylalanine in senile dementia suggest lowered levels of tetrahydrobiopterin in tissue. Methotrexate increased serum biopterin levels by inhibition of dihydropteridine reductase; a saturation effect was noted.

The effect of folic acid and 5-formyltetrahydrofolic acid on folate-deficient HEp 2 cells in culture.

Folic acid has less effect than 5-formyltetrahydofolic acid (folinic acid) in the alleviation of folate deficiency in cultured HEp 2 cells as measured by the deoxyuridine suppression test. Folic acid inhibits the metabolism of 5-formyltetrahydrofolic acid in vitro, is contraindicated in some cases of clinical folate deficiency and may be inappropriate in others.

Depression and tetrahydrobiopterin: the folate connection.

Total biopterin, neopterin and creatinine were measured in spot urine samples from affective disorder patients on lithium therapy and control subjects. Folic acid was also measured in plasma in a sample of the patients. The mean neopterin: biopterin ratio was significantly higher in the 76 patients (3.2 +/- 0.5) than in the 61 controls (1.8 +/- 0.1). In female patients biopterin levels were significantly lower than in controls. In the control groups there was a significant correlation between the molar concentration of neopterin and biopterin. No such correlation was found in the patients. These data indicate that tetrahydrobiopterin (BH4) biosynthesis is reduced in this group. A significant positive correlation was found between plasma folate and urinary biopterin. It is suggested that folate deficiency may impair the synthesis of BH4, a cofactor essential for the synthesis of 5-HT and other monoamines that are involved in the pathogenesis of affective disorders.

5-Methyltetrahydrofolate level in the serum of depressed subjects and its relationship to the outcome of ECT.

Serum 5-MeTHF levels are reported in 26 subjects, before and after completing a course of ECT, and compared to 21 healthy volunteers. 5-MeTHF levels of depressed subjects were significantly lower than controls before and after ECT. There was no difference in 5-MeTHF levels between ECT responders and non-responders but folate deficiency was related to severity of depression before ECT. Serum 5-MeTHF was not related to treatment response and values remained markedly low even after a good response to treatment.

Tetrahydrobiopterin metabolism in the Rett disease.

Tetrahydrobiopterin metabolism was studied in nine Swedish patients with the Rett disease. Normal values were found for the serum biopterin level, urine biopterins level and dihydropterine reductase activity. These findings suggest that a primary disturbance of tetrahydrobiopterin metabolism is unlikely.

From the common cold to cancer: how evolution and the modern lifestyle appear to have contributed to such eventualities.

This hypothesis suggests that psychosocial stress is the pivotal determinator of many modern day disorders in consequence to consuming today's nutritional intakes of ascorbic acid and sodium. For it seems, as a result of our tropical African evolution, present day intakes of these essential nutrients are incompatible with the maintenance of bodily homeostasis when the body is subjected to any form of stress. In addition, the climatic conditions under which most of us live are seemingly ill-suited to experiencing stress, since it appears that a constituent part of the bodily stress response remains exclusively designed to be effective in a hot tropical environment, where the stress can be expected to be accompanied by thermoregulation sweating and an overheated body. For without such an occurrence coinciding with stress, the stress response itself appears to have been transposed into a reaction that inhibits the body's ability to resist infection and disease.

The potentiality and practicality of a 'salt-free' diet for the prevention and amelioration of human disorders.

The potential of a salt-free diet, which restricts sodium intake to 10 mmol/day, for the prevention and amelioration of human diseases and conditions, may be considerable. Several human disorders may be the result of dietary-salt-generated high-bodily-sodium motility and fluid retention, this being incompatible with the maintenance of bodily homeostasis whenever the body is subjected to stress. Equally importantly, the present-day impracticalities of adopting a 'salt-free' diet appear man-made, and therefore soluble once a sufficiency of purpose exists.

A microtitre plate method for measuring biopterin with cryopreserved Crithidia fasciculata.

The assay of biopterin derivatives in dried blood spots is used by us in initial screening for inherited defects in tetrahydrobiopterin synthesis. The previously described method (1) required aseptic technique and microbiological facilities. The modification detailed here has the advantages of antibiotic cover, which overcomes these needs and microtitre plate technology allowing the incubation time to be halved with precision and accuracy retained. Data reduction facilities may be applied.

Inguinal dermoid cyst presenting as an incarcerated inguinal hernia.

A case of an inguinal dermoid cyst presenting as an incarcerated inguinal hernia in a 18-year-old boy is reported. A differential diagnosis of masses in the inguinal region is discussed and includes not only hernias but also gynecologic and vascular lesions. Dermoid cysts must be included in the differential diagnosis. Histologically, these cysts are characterized by an external lining composed of squamous epithelium with an underlying fibroconnective tissue containing hair follicles, sebaceous, eccrine, and apocrine glands. The presence of all the skin appendages in these cysts distinguishes them from epidermoid and sebaceous cysts. The lack of structures foreign to skin differentiates them from dermoids (benign cystic teratomas) in the ovarian, testicular, retroperitoneal, and sacrococcygeal region.

Varicella-zoster virus and facial palsy.

Two cases of Ramsey-Hunt Syndrome are reported, one of which presented features of the Guillain-Barré Syndrome. It is suggested that the varicella-zoster virus is an aetiological factor in the Guillain-Barré Syndrome.

Assessing the health implications of turbidity and suspended particles in protected catchments.

The supply of unfiltered disinfected drinking water from Melbourne's fully protected catchments means that the water-quality managers must ensure that the source water poses no public health risk. High turbidity is currently used as a surrogate of pathogens, and harvesting of water is based on its measurement. The work presented here summarises suspended particle and associated pathogen, microbial indicator and faecal biomarker concentrations collected to (a) quantify turbidity in an Australian water supply system and (b) assess the possibility of increasing water harvesting from selected tributaries. Pathogens and microbial indicators were present in low numbers in these source waters; increased turbidity during storm events was not associated with an increase in pathogen concentration. The results confirmed that protected catchments, along with good management, were effective barriers to pathogen contamination. Aesthetic issues still need to be addressed, but no measurable increase in microbiological risk was associated with storm-generated particles.