Severe preeclampsia is associated with postpartum diastolic dysfunction and non-dipping blood pressure profile pattern

Background

Left ventricular diastolic dysfunction and non-dipping profile, detected by ambulatory blood pressure monitoring (ABPM), are two features recorded to be associated with sustained hypertension. Both are predictors of an increased cardiovascular morbidity later in life. Complete normalization of blood pressure (BP) in preeclampsia is detected over a variable period of time.

Methods

A prospective cohort study was conducted in a tertiary university hospital including normotensive women with a history of preeclampsia in the current pregnancy enrolled within the first week postpartum. All cases were subjected to 24 h-ABPM and 2D trans-thoracic echocardiography three months post postpartum concomitantly with a clinical evaluation. Chi2-test was used to compare the qualitative data while student t-test was used to compare the quantitative data. Multivariate regression analysis was used for prediction of non-dippers and diastolic dysfunction in our cohort.

Results

Hundred twenty eight women were included in the study. Their mean age was 28.6±5.1 years and the mean basal BP was 123.1±6.4/74.6±5.9 mm Hg. Out of the studied women, 90 (70.3%) women were dippers and 38 (29.7%) women were non-dippers. It was noticed that diastolic dysfunction was presented in 28 (73.7%) of non-dippers while none of dippers had diastolic dysfunction. Women with severe preeclampsia had higher frequency of non-dipper (35.5% vs. 24.2%; P=0.02) and diastolic dysfunction (29% vs. 15%; P=0.01) in comparison to those women with mild preeclampsia. Severe preeclampsia and previous history of preeclampsia were significant predictors for non-dipping status (OR=1.1, 95% CI: 0.05–10.56 and 1.4, 95% CI: 0.30–4.26 respectively, R2 = 0.7; P<0.001). They were also predictors for diastolic dysfunction in our studied population (OR = 1.6, 95% CI: 1.1–2.2 and 1.3, 95% CI: 1.2–2.2 respectively, R2 = 0.6; P<0.05).

Conclusion

Women with a history of preeclampsia have the risk for developing cardiovascular events later in life. The severity and recurrence of preeclampsia were significant predictors for both non-dipping profile and diastolic dysfunction.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): Orman Heart Hospital-Assiut University; Women Health Hospital-Assiut University

Expanded Newborn Screening Program in Saudi Arabia: Incidence of screened disorders

AIM

To address the implementation of the National Newborn Screening Program (NBS) in Saudi Arabia and stratify the incidence of the screened disorders.

METHODS

A retrospective study conducted between 1 August 2005 and 31 December 2012, total of 775 000 newborns were screened from 139 hospitals distributed among all regions of Saudi Arabia. The NBS Program screens for 16 disorders from a selective list of inborn errors of metabolism (IEM) and endocrine disorders. Heel prick dry blood spot samples were obtained from all newborns for biochemical and immunoassay testing. Recall screening testing was performed for Initial positive results and confirmed by specific biochemical assays.

RESULTS

A total of 743 cases were identified giving an overall incidence of 1:1043. Frequently detected disorders nationwide were congenital hypothyroidism and congenital adrenal hyperplasia with an incidence of 1:7175 and 1:7908 correspondingly. The highest incidence among the IEM was propionic acidaemia with an incidence rate of 1:14 000.

CONCLUSION

The article highlights the experience of the NBS Program in Saudi Arabia and providing data on specific regional incidences of all the screened disorders included in the programme; and showed that the incidence of these disorders is one of the highest reported so far world-wide.

Extended right hemicolectomy and left hemicolectomy for colorectal cancers between the distal transverse and proximal descending colon

INTRODUCTION

We report our experience with extended right hemicolectomy (ERH) and left hemicolectomy (LH) for the treatment of cancers located between the distal transverse and the proximal descending colon, and compare postoperative morbidity, mortality, pathological results and survival for the two techniques.

METHODS

A retrospective review was performed of a single institution series over ten years. Patients who underwent different operations, had benign disease or received palliative resections were excluded. Data collected were patient demographics, type and duration of surgery, tumour site, postoperative complications and histology results.

RESULTS

Ninety-eight patients were analysed (64 ERHs, 34 LHs). ERH was conducted using an open approach in 93.8% of cases compared with 73.5% for LH. The anastomotic leak rate was similar for both groups (ERH: 6.3%, LH: 5.9%). This was also the case for other postoperative complications, mortality (ERH: 1.6%, LH: 2.9%) and overall survival (ERH: 50.4 months, LH: 51.8 months). All but one patient in the ERH cohort had clear surgical margins. Nodal evaluation for staging was adequate in 78.1% of ERH cases and 58.8% of LH cases.

CONCLUSIONS

In our experience, both ERH and LH are adequate for tumours located between the distal transverse and the proximal descending colon.

Lymph node retrieval for colorectal cancer: Estimation of the minimum resection length to achieve at least 12 lymph nodes for the pathological analysis

INTRODUCTION

Adequate lymph node retrieval is important in colorectal cancer staging for the selection of patients that necessitate adjuvant treatments. The minimum number of 12 lymph nodes is one of the premises and is dependent, among the other factors, from the length of bowel resected. We have reviewed our specimens to identify the high-risk operations for inadequate nodal sampling and estimate the minimum length of bowel needed to resect to achieve this purpose.

MATERIALS AND METHODS

A retrospective review of colorectal specimens over 10 years of activity looking at data including location of the tumor, type of operation performed, length of bowel resected and number of lymph nodes retrieved.

RESULTS

Abdominoperineal and Hartmann's resections produced significant lower adequate retrievals compared to other colorectal operations, corresponding to 45.4% and 59.1% of cases respectively. The measured average length of bowel was 30 cm and 25 cm respectively, increasing the length to 36 cm and 42 cm would increase the adequacy rate to 90%.

CONCLUSIONS

Abdominoperineal and Hartmann's resections are, in our series, high-risk operations that frequently do not produce the minimum number of lymph nodes necessary. These operations may require additional maneuvers such as mobilization of the splenic flexure to achieve the minimum length of bowel to resect.

Intraprostatic injection of botulinum toxin-A in patients with refractory chronic pelvic pain syndrome: The transurethral vs. transrectal approach

OBJECTIVE

To evaluate the outcome of an intraprostatic injection of botulinum toxin-A (BTX-A) in men with refractory chronic prostatitis-associated chronic pelvic-pain syndrome (CP/CPPS) and to compare the efficacy of the transurethral and transrectal routes.

PATIENTS AND METHODS

In an uncontrolled randomised clinical trial conducted in men with refractory CP/CPPS, the patients were classified into two groups according to the route of BTX-A injection; transurethral (group 1, 28 patients) and transrectal ultrasonography-guided (group 2, 35 patients). The chronic prostatitis symptom index (CPSI), maximum urinary flow rate (Q max) and white blood cell (WBC) count in expressed prostatic secretion (EPS) were measured before and at 3, 6 and 12 months after the injection. A significant clinical improvement (SCI, defined as a reduction of 4 points or a 25% decrease in total CPSI score) was correlated with patient age, prostate volume and symptom duration.

RESULTS

In group 1, the pain and quality-of-life domain scores improved, but statistically significantly only at 6 months. The voiding score improved at all follow-up visits. In group 2 there was a significant improvement in all the CPSI domain scores at all follow-up visits, except for pain, which was insignificantly improved by 12 months. The SCI ratings in groups 1 and 2 were 36%, 79% and 57%, and 49%, 89% and 74% in group 2 at the three follow-up visits, respectively. The Q max was significantly improved in both groups during the follow-up (except at 12 months in group 1). There was a significant reduction in the mean WBC count in the EPS in patients with inflammatory prostatitis. Both prostate volume and symptom duration were significantly associated with a lower SCI rating.

CONCLUSION

BTX-A is an available treatment option for patients with refractory CP/CPPS. It is more effective in patients with a small prostate and short symptom duration. The transrectal route provided better results than the transurethral route. More prospective longer term studies are needed.

Clinical, neuroimaging, and genetic features of L-2-hydroxyglutaric aciduria in Arab kindreds

BACKGROUND AND OBJECTIVES

L-2-hydroxyglutaric aciduria is a neurometabolic disorder with autosomal recessive mode of inheritance in which patients exhibit elevated L-2-hydroxyglutaric acid in body fluids, central nervous system manifestations, and increased risk of brain tumor formation. Mutations in L2HGDH gene have been described in L-2-hydroxyglutaric aciduria patients of different ethnicities. The present study was conducted to perform a detailed clinical, imaging and genetic analysis.

DESIGN AND SETTINGS

A cross-sectional clinical genetic study of 16 L-2-hydroxyglutaric aciduria patients from 4 Arab consanguineous families examined at the metabolic clinic of the hospital.

PATIENTS AND METHODS

Genomic DNA was isolated from the blood of 12 patients and 10 unaffected family members, and the L2HGDH gene was sequenced. DNA sequences were compared to the L2HGDH reference sequence from GenBank.

RESULTS

All patients exhibit characteristic clinical, biochemical, and imaging features of L-2-hydroxyglutaric aciduria, and 4 patients exhibited increased incidence of brain tumors. The sequencing of the L2HGDH gene revealed the c.1015delA, c.1319C > A, and c.169G > A mutations in these patients. These mutations encode for the p.Arg339AspfsX351, p.Ser440Tyr, and p.Gly57Arg changes in the L2HGDH protein, respectively. The c.169G > A mutation, which was shown to have a common origin in Italian and Portuguese patients, was also discovered in Arab patients. Finding of the homozygous c.159T SNP associated with the c.169G > A mutation in Arab patients points to an independent origin of this mutation in Arab population.

CONCLUSION

The detailed description of clinical manifestations and L2HGDH mutation in this study is useful for diagnosis of L-2-hydroxyglutaric aciduria in Arab patients. While reoccurrence of an L2HGDH mutation in L-2-hydroxyglutaric aciduria patients of different ethnicity is extremely rare, the c.169G mutation has an independent origin in Arab patients. It is likely that this mutation may also be present in patients of other ethnicities.

Smith-Lemli-Opitz syndrome among Arabs

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder of variable presentation caused by the deficiency of the 3β- hydroxycholesterol Δ(7) - reductase. Over the past 10 years, our biochemical laboratory has screened 191 plasma samples for possible SLOS, measuring the plasma cholesterol and 7-dehydrocholesterol using gas chromatography-mass spectrometry (GC-MS). The SLOS was confirmed in only five Arab patients with growth retardation, global developmental delay, dysmorphic features, and 2-3 toe syndactyly, among other findings. All cases represented moderate to severe form of SLOS. One patient had a unique cardiovascular malformation (cor triatriatum with significant obstruction of the right pulmonary veins). Two previously reported N287K (861 C>A) and R352Q (1055 G>A) and a novel R352L (1055 G>T) mutations were identified in the DHCR7 gene in these patients. The paper sheds light on this rare disease among Arabs and reviews all reported SLOS cases in the Arab population.

[D-2-hydroxyglutaric aciduria. Report of two cases]

D-2-hydroxyglutaric aciduria (D-2-HGA) is a cerebral organic aciduria characterized by the accumulation of abnormal amounts of D-2-hydroxyglutaric acid in cerebrospinal fluid, blood, and urine. The clinical phenotype varies widely from neonatal severe epileptic encephalopathy to asymptomatic. Magnetic resonance imaging of affected patients typically show signs of delayed cerebral maturation, ventricular abnormalities and the presence of sub-ependymal cysts in the first months of life. We present clinical, biochemical and brain magnetic resonance imaging data of two pediatric patients with D-2-hydroxyglutaric aciduria. One patient presented with severe early infantile-onset epileptic encephalopathy, marked hypotonia, visual deficit, developmental delay and abnormal neuroradiological findings; while the other had hypotonia and development delay. Our findings reinforce the described phenotype of this rare neurometabolic inherited disorder. The diagnostic approach is based on clinical findings and the neuroimaging pattern and is established by the detection of D-2-hydroxyglutaric acid in body fluids. We suggest considering D-2-hydroxyglutaric aciduria in the differential diagnosis of any neonate or infant with epileptic encephalopathy and CNS dysfunction of unknown origin.

Preimplantation genetic diagnosis for Zellweger syndrome

OBJECTIVE

To report on the first live birth of a normal child after performance of preimplantation genetic diagnosis (PGD) for Zellweger syndrome (ZS).

DESIGN

Case report.

SETTING

Tertiary-care hospital.

PATIENT(S)

A family with four children diagnosed with ZS, who were all born at term and who expired around 4 months of age.

INTERVENTION(S)

In vitro fertilization and preimplantation genetic diagnosis.

MAIN OUTCOME MEASURE(S)

Preimplantation genetic diagnosis of ZS in embryos, and live birth from the transferred normal embryos.

RESULT(S)

After PGD, two genotypically normal embryos were transferred back to the mother. Pregnancy ensued, and a healthy baby girl was delivered in week 40 of pregnancy. The baby was confirmed as genotypically wild-type, and free of any sign of ZS.

CONCLUSION(S)

To the best of our knowledge, this is the first successful PGD for ZS caused by mutation in PEX26 gene, with the subsequent delivery of a homozygous normal baby.

Comparison of BMI-for-age in adolescent girls in 3 countries of the Eastern Mediterranean Region

International comparisons of adolescent overweight and obesity are hampered by the lack of a single agreed measurement reference. We compared 3 BMI-for-age references on samples of adolescent girls from Egypt, Kuwait and Lebanon. Overweight and obesity was highest in Kuwait and lowest in Lebanon. Performance of the 3 standards differed only slightly although one was particularly applicable in country-to-country comparisons.

L-carnitine supplementation in hemodialysis patients

L-Carnitine supplementation has shown beneficial effects in patients on hemodialysis. We studied 36 ESRD adult patients with a mean age of 47.5 +/- 15 years to evaluate the effect of L-Carnitine supplementation on hemoglobin, lipid levels and physical performance in patients on hemodialysis. The study group consisted of 18 randomly selected patients who received L-Carnitine 15 mg/kg and the control group consisted of 18 randomly selected patients who received equal volume of normal saline as a placebo three times a week for six months. Laboratory tests were performed at baseline, then monthly until the end of the study. A significant increase in the hemoglobin (Hb) and hematocrit (HCT) in the presence of unchanged doses of erythropoietin hormonal supplementation was observed (pre 79 +/- 7.5 gm/l, post 103 +/- 10.6 gm/l) P< 0.001 (pre 24+/- 2 %, post 33 +/- 4%) P< 0.001 respectively) in the L-Carnitine treated group. Similarly total serum cholesterol (TCL) and serum triglyceride (TG) levels showed a statistically significant decrease in the study group, TCL (pre 4.6 +/- 1.2, post 3.7 +/- 1.1 mmol/L), P < 0.03 and TG (pre 3.1 +/- 1.7, post 1.8 +/- 0.6 mmol/L) P < 0.004. The physical performance as assessed by mild and moderate exercise showed a trend towards improvement. There was a significant increase in free carnitine and total carnitine levels in the L-Carnitine treated group. In conclusion, these results demostrate positive effect of L-Carnitine supplementation in the hemodialysis patients marked by an increase in Hb, HCT, a decrease in TCL and TG and improved physical performance in comparison to the control group.

Identification of 6 new mutations in the iduronate sulfatase gene. Mutation in brief no. 233. Online

Mucopolysaccharidosis type II (Hunter syndrome) is an X-linked lysosomal storage disorder caused by a deficiency of the enzyme iduronate-2-sulfatase. We sequenced genomic DNA and RT-PCR products in the iduronate sulfatase (IDS) gene in 6 unrelated patients with Hunter syndrome to assess genotype/phenotype relationships and offer carrier testing where required. Six novel mutations were identified: four missense mutations, one four-base pair deletion (596-599delAACA) and a cryptic splice site mutation. Three of the missense mutations were significant amino acid substitutions (S143F, S491F, E341K) of which the latter two involve amino acids conserved amongst sulfatase enzymes. The patients identified with these mutations all had a severe clinical phenotype. One missense mutation with a minimal amino acid substitution (H342Y), in a non-conserved region of the gene, was associated with a mild clinical phenotype. We identified a novel cryptic splice site (IVS5+934G>A) with some normal (wild type) mRNA processing. We predict that the normal mRNA product confered some residual functional enzyme, resulting in a mild phenotype associated with the absence of overt central nervous system disease.

Clinical, fluorine-18 labeled 2-fluoro-2-deoxyglucose positron emission tomography of the brain, MR spectroscopy, and therapeutic attempts in methylenetetrahydrofolate reductase deficiency

The cases of three infants, two Saudi and one Bahraini, with methylenetetrahydrofolate reductase (MTHFR) deficiency are reported. They presented in the neonatal period with lethargy, poor feeding, hypotonia, and frequent apneas. Tandem mass spectrometry (MS/MS) of a blood spot indicated very low methionine level and of urine revealed high homocysteine. The diagnosis was confirmed by demonstrating severe deficiency of MTHFR in the cultured skin fibroblast. All patients were treated with folinic acid, vitamin B12, betaine, and methionine, with good initial response to the therapy. In two patients, the diagnosis was late and their disease was severe, resulting in neurological crippling. However, in the third patient, who was diagnosed and treated early, the current neurological status is normal. In her case, at 1 month of age, the brain FDG PET scan documented very faint cerebral and cerebellar cortical activities. After 5 months of intensive therapy, that included 200-600 mg/kg per day methionine, she had a dramatic clinical and biochemical recovery as well as a parallel improvement in FDG PET. Brain MR spectroscopy indicated normal neuronal glial and myelin markers for her age. We conclude that the functional changes confirmed by the FDG PET study were better correlated with the clinical course of the patient and adequately monitored the response to therapy. This disease warrants early detection through neonatal screening program, since the beneficial effect of early administration of adequate therapy with combined use of betaine and a high dose of methionine is rewarding and may be the treatment of choice for MTHFR deficiency.

Molecular phylogeny of the live-bearing fish genus Poecilia (Cyprinodontiformes: Poeciliidae)

Members of the genus Poecilia exhibit extensive morphological, behavioral, and life history variation within and between species. This natural variation, coupled with short generation times and the ease with which members of this genus can be cultured in the lab, have made several species model systems for studying the effects of sexual and natural selection on the evolution of natural populations. Given that there is no clear understanding of the phylogenetic relationships within the genus, these studies have not been put into a historical context, and between-species comparisons have been limited. We sequenced the complete NADH Dehydrogenase Subunit 2 (ND2) mitochondrial gene (1047 bp) in representatives of the major divisions of the genus in order to examine these relationships. The subgeneric groups of Rosen and Bailey (1963) are, for the most part, supported, with some adjustment within the subgenera Poecilia and Pamphorichthys. The morphological distinctness of the groups within Poecilia suggest that the original generic designations be reinstated, but this awaits a more thorough analysis. Two implications from the phylogeny are particularly relevant to sexual selection studies: within the North and Central American mollies, the three species of sailfin mollies form a monophyletic group, and within the subgenus Lebistes, the sister taxon to the guppy, P. reticulata, is most likely the group of species previously designated as Micropoecilia.

Zellweger syndrome in Saudi Arabia and its distinct features

Clinical and laboratory findings of Zellweger syndrome (ZS) patients diagnosed at King Faisal Specialist Hospital and Research Center (KFSH & RC), Riyadh, Saudi Arabia over a period of 10 years are presented in this report. Eleven patients (nine females and two males) from 2 to 4 months old were referred to KFSH & RC for evaluation of hypotonia, seizures, and dysmorphic features. The common clinical findings included high forehead, large fontanelle, shallow orbit ridges, micrognathia, upslanting palebral fissures, epicanthal folds, severe hypotonia, hyporeflexia, pigmentary retinopathy, optic nerve atrophy, complete or partial agenesis of corpus callusum, and failure to thrive. We did not observe any Brushfield spots, any renal and brain cysts, or adrenal insufficiency. Some unique clinical findings were the presence of gallstones, club feet, or bilateral knee or hip dislocation in some patients. All patients had markedly elevated plasma levels of very long chain fatty acids (VLCFA). Electron microscopy performed on liver biopsies of two patients revealed absence of peroxisomes. Biochemical studies of dermal fibroblasts from three patients showed deficient beta-oxidation of lignoceric acid and dihydroxyacetone phosphate acyltransferase (DHAPATase) activity. The tribal living in Saudi Arabia and our observation that 10 of the 11 parents in this study were first-degree relatives and, except for families 1 and 3, each family had at least another baby who died of the same disease. This suggests that the incidence of ZS in Saudi Arabia may actually be higher than our experience at KFSH & RC.

Saudi experience with classic homocystinuria

BACKGROUND

Classic homocystinuria is an autosomal recessive disorder due to cystathionine ss-synthase deficiency. The clinical, radiological and neurophysiological findings of classic homocystinuria diagnosed at King Faisal Specialist Hospital and Research Centre (KFSH&RC) are presented in this report.

PATIENTS AND METHODS

Twenty-four patients (15 females and 9 males) were referred to KFSH&RC for work-up of mental retardation, seizures, thrombo-embolic episodes and dislocation of the ocular lenses.

RESULTS

The common clinical findings included ectopia lentis (20 patients), skeletal system involvement (18 patients), vascular system involvement (9 patients), and mental retardation (all patients to varying degrees). Unusual findings consisted of a patient who developed severe lower gastrointestinal bleeding, a patient with insulin-dependent diabetes mellitus, probably due to vasculopathy, and another having severe bronchiectasis, which may have been due to fibrillin disruption, and required the resection of a lobe of the lung. The parents of 21 patients were first-degree relatives, and 19 patients had one or more family members affected by the same disease. All patients had markedly elevated plasma levels of methionine. Cystathionine synthase activity in the fibroblast was measured in 25% of the patients and was deficient. Only four patients responded to pyridoxine and their methionine level decreased to almost normal range.

CONCLUSION

The aim of this study was to increase the awareness of this disease in the scientific and medical community, in particular in the general pediatrician working in Saudi Arabia who first encounters the clinical manifestations of the disease. Early detection through tandem mass spectrometry of blood spot screening and treatment are important, and may prevent the major complications of this disease.

Exploring the basis of peptide-carbohydrate crossreactivity: evidence for discrimination by peptides between closely related anti-carbohydrate antibodies

To investigate the molecular basis of antigenic mimicry by peptides, we studied a panel of closely related mAbs directed against the cell-wall polysaccharide of group A Streptococcus. These antibodies have restricted V-gene usage, indicating a shared mechanism of binding to a single epitope. Epitope mapping studies using synthetic fragments of the cell-wall polysaccharide supported this conclusion. All of the mAbs isolated crossreactive peptides from a panel of phage-displayed libraries, and competition studies indicated that many of the peptides bind at or near the carbohydrate binding site. Surprisingly, the peptides isolated by each mAb fell into distinct consensus-sequence groups that discriminated between the mAbs, and in general, the peptides bound only to the mAbs used for their isolation. Similar results were obtained with polyclonal antibodies directed against synthetic oligosaccharide fragments of the streptococcal cell-wall polysaccharide. Thus, the peptides appear to be specific for their isolating antibodies and are not recognized by the same mechanism as their carbohydrate counterparts.

Pharmacokinetics and metabolism of the novel anticonvulsant agent N-(2,6-dimethylphenyl)-5-methyl-3-isoxazolecarboxamide (D2624) in rats and humans

N-(2,6-dimethylphenyl)-5-methyl-3-isoxazolecarboxamide (D2624) belongs to a new series of experimental anticonvulsants related to lidocaine. This study was undertaken to understand the pharmacokinetics and metabolism of D2624 in rats and humans, with emphasis on the possible formation of 2,6-dimethylaniline (2,6-DMA). After oral administration of stable isotope-labeled parent drug to rats and GC/MS analysis of plasma samples, two metabolites were identified: D3017, which is the primary alcohol, and 2,6-DMA, formed by amide bond hydrolysis of either D2624 or D3017. In urine, three metabolites of D2624 were identified: namely D3017,2,6-DMA, and D3270 (which is the carboxylic acid derivative of D3017). Based on plasma AUC analysis, D3017 and 2,6-DMA accounted for > 90% of the dose of D2624. After oral administration, D2624 was found to be well absorbed (93%), but underwent extensive first-pass metabolism in the rat, thus resulting in 5.3% bioavailability. Rat and human liver microsomal preparations were capable of metabolizing D2624 to D3017 and 2,6-DMA. The formation of D3017 was NADPH-dependent, whereas 2,6-DMA formation was NADPH-independent and probably was catalyzed by amidase(s) enzymes. In a single-dose (25-225 mg) human volunteer study, the parent drug (D2624) was not detected in plasma at any dose, whereas 2,6-DMA was detected only at the two highest doses (150 and 225 mg). D3017 was detected after all doses of parent drug, with approximate dose proportionality in AUC and a half-life of 1.3-2.2 hr. The metabolic behavior observed in humans suggests there is a marked species difference in the oxidative and hydrolytic pathways of D2624.

Probing the basis of antibody reactivity with a panel of constrained peptide libraries displayed by filamentous phage

The structural requirements for peptide binding to an antibody may be elucidated by probing it with a variety of peptides having different constraints. To this end, we have constructed and screened a panel of peptide libraries displayed by filamentous bacteriophage. The peptides in most of the libraries have the potential for constraint by fixed Cys residues, which have been placed at different sites within a randomized amino acid sequence of varying length. When taken together, the binding data obtained from screening the panel with a given antibody allow one to determine the types of constraints that promote binding, as well as the residues that are critical for binding. We describe the construction of 11, pVIII-displayed, peptide libraries, whose sizes range from 150 million to 10 billion clones. The libraries were screened with a number of polyclonal and monoclonal antibodies against peptides, proteins and carbohydrates. Cross-reactivity with peptides was always found for antibodies produced against peptides, linear epitopes on folded proteins and, surprisingly, carbohydrates, whereas antibodies against discontinuous epitopes on proteins were found less frequently. The implications of these results are discussed in terms of the structural basis for cross-reactivity with peptides.

Fluoride and dental age

The dental ages of 1286 (674 males and 612 females) Egyptian children born and grown up in a community with naturally occurring overfluoride ions in the drinking water (more than the optimal level) in Matrouh Governorate, were compared with the Egyptian standards of the fluoride deficient area of the same socioeconomic level. The age ranged from 8 years to 14 years and 6 months. The results of the present study revealed that the communal water supply with a fluoride ions concentration more than optimal level has no long term effect on the dental age, as judged from the tooth emergence of the growing children.

Ethylmalonic aciduria: an organic acidemia with CNS involvement and vasculopathy

Five infants from 3 families, one Egyptian, two Yemeni, are described with a progressive encephalopathy, four of whom have been studied in detail. All patients showed vascular lesions of the skin, characterized by waxing and waning petechiae and ecchymoses. Acrocyanosis was present in three patients. All patients showed retinal lesions characterized by tortuous veins. Protracted diarrhea was not a consistent finding, although they had metabolic crisis in association with diarrhea. They did not show failure to thrive. The neurologic symptoms were indicative of a progressive pyramidal tract disease. Three patients died following sudden emergence of severe basal ganglia, putaminal and head of caudate lesions. In one patient the CT changes in brain were suggestive of infarction. The patients who died manifested pulmonary congestion, or wet lung, and respiratory difficulties during the terminal stage of the disease. In all patients before and during the terminal event, mild-to-moderate hematuria, and in two RBC in CSF, was observed. In one patient there was mild hemoperitoneum at the terminal event. The urine organic acids indicated increased excretion of ethylmalonic, methylsuccinic, glutaric, and adipic acids. The patients invariably showed lactic acidosis, but no ketosis, during and in between the acidotic attacks of the disease. The acylcarnitine profile in blood of two patients showed a pronounced increase in C4 and C5 carnitine esters. In three patients, biopsies from petechiae indicated absence of an immune event, showing only fresh hemorrhage. An immunologic study in one patient was normal for the suppressor:cytotoxic lymphocyte ratio and concentration of interleukin-2 receptor during and in between hemorrhagic attacks. The cytochrome c oxidase activity in fibroblasts was normal. The rate of oxidation of glucose, leucine, isoleucine, valine, propionate and butyrate by fibroblasts was normal. The disease is not responsive to treatment with riboflavin, ascorbic acid, vitamin E, glycine, or carnitine. One patient remained stable on prolonged large doses of methylprednisolone. The biochemical defect leading to ethylmalonic aciduria in this disease remains unknown.

Unusual presentations of propionic acidemia

The files of 25 patients with propionic acidemia (PA), followed by the Inborn Errors of Metabolism Service (IEMS) at King Faisal Specialist Hospital and Research Centre (KFSH & RC) from 1990 to 1993, were studied retrospectively. In 14 patients PA presented acutely with acidosis, hyperammonemia and thrombocytopenia, while in 11 patients the presentation of the disease was unusual. In the latter group, two neonates with PA initially appeared as a primarily hyperammonemic metabolic disease. In two other neonates the vomiting was so severe that they were diagnosed as intestinal obstruction in referral hospitals. The presentation in three infants was primarily as an immune disorder. In four infants, PA appeared as an acute or chronic encephalopathy, i.e. as a silent organic acidemia, with few other findings of the disease. The clinical picture of PA includes facial and nipple dysmorphia, severe hypotonia and vomiting. Severe thrombocytopenia is the hallmark of the metabolic crisis. In one patient it was noticed late and caused intracranial hemorrhage, while in three others intracranial bleeding caused death. The prognosis in PA remained grave despite rigorous treatment. Only seven of the 25 PA patients remained to have a normal life-style, while eight patients expired. The diagnosis is readily achieved by urine gas chromatography/mass spectrometry (GC/MS), by tandem mass spectrometry (MS/MS), or by enzyme analysis of fibroblasts. While there may be both examiner- and patient-related reasons for the variations in the presentation of PA, one other reason may be the heterogeneity of the molecular defect in propionyl-CoA carboxylase.

Experience of King Faisal Specialist Hospital and Research Center with Saudi organic acid disorders

The Inborn Errors of Metabolism and Neurology Services of the King Faisal Specialist Hospital and Research Centre (KFSH&RC) and Armed Forces Hospital have received more than 1,500 patients suspected of having an organic acid disorder (OAD) during a period of four years. Of these, 307 patients suspected of having an organic acid disorder (OAD) during a period of four years. Of these, 307 patients, approximately 20%, had a clearly identifiable disorder. Identified OAD's constituted one-quarter of all patients diagnosed as having various types of inborn errors of metabolism during this period, in these clinical services. Prolonged follow-up was available in the majority of cases, allowing detailed clinical, neuroradiologic and neurophysiologic descriptions. Fifty patients (16%) had rare disorders by standards in the West. Approximately 25% were 'neurologic organic acidurias.' This is a new term we are introducing for OAD's manifesting primarily with neurologic signs, but without appreciable acidosis, hypoglycemia or hyperammonemia. In this special issue, we present the KFSH&RC experience with the rare disorders as individual articles. We estimate the frequency of OAD's in Saudi Arabia as 1/740 births. The increased frequency of OAD's in Saudi Arabia is probably due to increased consanguinity, since most OAD's occurred in excess in certain tribes; and due to increased surveillance and testing by our group. Saudi Arabia provides a unique opportunity for research in this area of pediatrics.

A new patient with alpha-ketoglutaric aciduria and progressive extrapyramidal tract disease

A 4.5-year-old boy with chronic progressive encephalopathy is described. The clinical presentation initially included seizures and hypotonia which later evolved into severe extrapyramidal disease and dementia. The gas chromatography/mass spectrometry (GC/MS) analysis of urine indicated that alpha-ketoglutarate was increased 210 times and aconitic acid 80 times. No disturbance of acid/base balance, lactic acid or ammonia metabolism accompanied this clinical picture. The fibroblasts contained 29% of normal alpha-ketoglutarate dehydrogenase activity, while the activity of another mitochondrial marker enzyme, glutamate dehydrogenase, was normal. The neuroimaging studies revealed bilateral striatal necrosis. The clinical and biochemical findings were almost identical to two previously reported patients. Experience with this patient emphasizes the need for detailed organic acid biochemical investigation in any progressive encephalopathy and that extrapyramidal tract signs should evoke the possibility of alpha-ketoglutaric aciduria, among other 'neurologic organic acidemias'.

Comparative frequency and severity of hypoglycemia in selected organic acidemias, branched chain amino acidemia, and disorders of fructose metabolism

The Institution's experience with hypoglycemia in different types of organic acidemias, branched chain amino acidemia (MSUD), and disorders of fructose metabolism was reviewed retrospectively. The charts of 144 patients who were followed for 1-5 years were studied for the severity and frequency of hypoglycemia. The patients were mainly Saudi; however, 10-25% were from neighboring countries. Therefore, the observations pertain to the genetic groups in the Arabian peninsula. Organic acidemias which primarily manifest with neurologic signs, such as 4-hydroxybutyric aciduria, infantile onset 3-methylglutaconic aciduria, and glutaric aciduria type 1 never showed hypoglycemia. Patients with beta-ketothiolase deficiency, biotinidase deficiency, or intermittent or intermediate MSUD, also did not have hypoglycemia during metabolic crisis. Hypoglycemia was rare and mild among neonates with classic MSUD, ethylmalonic aciduria, and isovaleric acidemia. Less than 50% of the patients with MSUD older than 8 months, pyruvate carboxylase deficiency, methylmalonic acidemia, or propionic acidemia had hypoglycemia during metabolic crisis. On the other hand, patients with 3-hydroxy-3-methyl glutaryl-CoA lyase deficiency, holocarboxylase synthetase deficiency, medium or long-chain acyl-CoA dehydrogenase deficiency, neonatal onset 3-methylglutaconic aciduria, glutaric aciduria type 2, and disorders of fructose metabolism invariably had moderate-to-severe hypoglycemia associated with metabolic crisis. The purpose of this report is to provide the pediatrician, particularly in the Middle East, with a diagnostic guideline to the identification and management of different types of organic acidemias, based on co-existing hypoglycemia.

4-Hydroxybutyric aciduria

The clinical findings in six patients from three families with 4-hydroxybutyric aciduria are described. The onset of disease was in early infancy in all cases. All infants presented with severe global delay and severe hypotonia, and all patients had seizure disorder. Eye findings included optic atrophy in two patients, and retinitis pigmentosa in one. Three patients had choreoathetosis, two had myoclonus and one had severe dystonia. The urine 4-hydroxybutyric acid was 300-1000 times that of normal, and other organic acids related to its further metabolism or to its inhibitory effect on beta-oxidation were also increased. The administration of vigabatrine rapidly reduced the excretion of 4-hydroxybutyric acid promptly, and in the long-term its excretion could be kept at 80-200 times that of normal. However, the clinical course of the disease improved in only two, remained the same in two, and worsened in the remaining two patients.

3-Methylglutaconic aciduria: ten new cases with a possible new phenotype

3-Methylglutaconic aciduria is an organic aciduria with diverse phenotypic presentations. In more than half of the cases it is a 'neurologic or silent organic aciduria', and, except for one subtype, the biochemical defect is unknown. This report describes 10 new patients. Four of them presented with early global neurologic involvement and arrested development. They rapidly became demented, developed myoclonus or tonic-clonic seizures, spastic quadriplegia, deafness and blindness, and died. Three had acidosis and hypoglycemia neonatally; later, myoclonus and deafness, and eventually severe mental retardation and spastic quadriplegia developed. One patient died. In three children who presented with sudden onset of extrapyramidal tract symptoms, with or without optic atrophy, the clinical presentation was significantly different from that described either for 'unspecified' type or for Costeff syndrome. All three patients showed clinical improvement soon after treatment with coenzyme Q.

3-Ketothiolase deficiency: a review and four new patients with neurologic symptoms

3-Ketothiolase deficiency (3KTD) manifests with intermittent acidosis and is due to deficiency of mitochondrial 2-methylacetoacetate thiolase. Only 22 patients have been previously reported. Although its variable clinical presentation is recognized, the associated neurological findings have not been detailed. We report four new patients all with significant neurological symptoms. Three patients were examined with MRI of the brain which showed increased T2 intensity within the posterior lateral part of the putamen bilaterally. In two the MRI was otherwise normal; in one delayed myelination was also seen. These MRI putaminal findings may be typical enough to suggest the diagnosis of 3KTD. Two of the three had abnormal EEGs; one had an abnormal VEP. 3KTD can thus occur as an organic acidemia associated with encephalopathy.

Metabolic chiral inversion of stiripentol in the rat. I. Mechanistic studies

To study enantioselective aspects of the disposition of stiripentol (STP), a chiral allylic alcohol undergoing development as an antiepileptic drug, a stereoselective synthesis was developed and the configuration of the two enantiomers determined to be (R)-(+) and (S)-(-). Following a single oral dose (300 mg kg-1) of the individual enantiomers to adult male Sprague-Dawley rats, it was found that (R)-STP was transformed extensively to its antipode, whereas little inversion was detected when (S)-STP was administered. Studies on the mechanism of this apparently unidirectional chiral inversion revealed that the phenomenon was dependent on the presence of the side-chain C==C double bond, because the enantiomers of the corresponding saturated alcohol (D2602) did not interconvert in vivo. Experiments with analogs of STP labeled with deuterium or oxygen-18 at the chiral center showed that, whereas the deuterium was retained in vivo, partial loss of the 18O occurred from both enantiomers of the drug. Pretreatment of rats with pentachlorophenol (40 mumol kg-1 i.p.), an inhibitor of sulfation (and possibly other conjugation reactions), led to a marked decrease in the rate of conversion of (R)-STP to its antipode, suggesting that the chiral inversion phenomenon may be mediated, at least in part, by an enantioselective conjugation process.

Glutaric aciduria yype 1: First reported cases in three Saudi patients

The clinical and biochemical findings in three patients with glutaric aciduri Type 1 (GAT1) are presented. They had a normal postnatal period of three to 14 months. They developed sudden and severe encephalopathy following an infection or trauma (patient 3) that gradually progressed to severe dystonia, choreathetosis, spastic quadriplegia and mental retardation. Neuroradiologic studies of the brain revealed while matter disease and frontotemporal lobe hypoplasia. The urine findings by gas chromatography/mass spectrometry (GC)/(MS) were characteristic of GAT1. Since GAT1 is an organic acidemia without intermittent acidotic attacks, but primarily manifests with progressive encephalopathy, it is important to recognize the potential of its existence among handicapped children in chronic care facilities. The good clinical response in two of the patients urges early diagnosis in subsequent newborn siblings of the families with the disease. The diagnosis of three patients in less than two years indicate the need for neonatal screening for the recognition of this disease, among other treatable metabolic diseases, in Saudi Arabia.

Detection and characterization of the eae gene of Shiga-like toxin-producing Escherichia coli using polymerase chain reaction

In this study, the polymerase chain reaction (PCR) was used in the detection of the attaching and effacing (eae) gene of Shiga-like toxin-producing Escherichia coli (SLT-EC). Oligonucleotide primers, complementary to the 5' portion of the eae gene of the enteropathogenic E. coli E2348/69 (O127:H6) and of SLT-EC CL8 and EDL933 (O157:H7), generated PCR products of the predicted sizes with DNA from the majority of human clinical SLT-EC strains tested from O serogroups 5, 26, 103, 111, 121, 128, 145, and 157; all SLT-EC strains of O serogroups 5, 26, and 111 from cattle; and a minority of porcine SLT-EC strains (one strain each from O serogroups 107 and 130 and one rough strain). Five HaeIII digestion profiles were obtained for PCR products generated by amplification of a 2.3-kb DNA fragment from the 5' end of eae. The HaeIII profiles for SLT-EC O serogroups, such as 26, 103, and 157, differed from each other but were consistent among strains within these O serogroups. Oligonucleotide primer pairs complementary to the 3' end of either the O127:H6 E. coli or the O157:H7 eae nucleotide sequence only amplified DNA from E. coli strains from a few of the SLT-EC O serogroups examined. One primer pair with homology to the 3' nucleotide sequence of eae from E. coli O157:H7 appeared to be relatively specific for this O serogroup by PCR. No PCR products were obtained in amplification experiments with the eae primers using DNA from human SLT-EC of O serogroups 38 (1 0f 1) and 91 (3 or 3), 15 of 15 SLT-EC strains from edema disease, or 29 of 29 non-SLT-EC strains from pigs and calves with diarrhea.

Toxoplasma gondii stimulates the release of 13- and 9-hydroxyoctadecadienoic acids by human platelets

We have recently demonstrated a novel cytotoxic effect of human platelets against Toxoplasma gondii and a role for thromboxane (TX) in this process (Yong et al., 1991). We now report on the spectrum of lipid mediators released by human platelets after interaction with T. gondii. In addition to TXB2, human platelets after incubation with T. gondii for 90 min released 12-hydroxyheptadecatrienoic acid (12-HHT), 12-hydroxyeicosatetraenoic acid (12-HETE), and an unidentified peak (UVmax 234 nm) as determined by reverse-phase high-performance liquid chromatography. Thermospray-liquid chromatography/mass spectrometry analysis and straight-phase HPLC identified the unknown peak as a mixture of 13-hydroxyoctadecadienoic acid (HODE) and 9-HODE. Radiolabeling studies with [14C]linoleic acid indicated that the platelets were the cellular source of the octadecanoids with 13-HODE (87.7%) greater than 9-HODE (12.3%). Inhibitor studies with indomethacin indicated that 13-HODE was a lipoxygenase product and 9-HODE was a cyclooxygenase product of linoleic acid. Thus, Toxoplasma-stimulated platelets release oxygenated products of both arachidonic acid and linoleic acid which may be important in the host response to T. gondii infection.