A homoallelic FECH mutation in a patient with both erythropoietic protoporphyria and palmar keratoderma

Background Erythropoietic protoporphyria (EPP) is a hereditary disorder caused by the deficiency of ferrochelatase (FECH) in the haem biosynthetic pathway. In the majority of families, EPP is transmitted as a pseudodominant trait. Autosomal recessive form of EPP is found in only about 3% of the families. Objectives In this study, we describe a 6‐year‐old boy who suffered from both EPP and palmar keratoderma. Methods and Results A novel homoallelic missense mutation (p.Ser318Tyr) was identified in the FECH gene. In addition, a region of homozygosity of approximately 6.8 Mb was observed in chromosome 18 of the patient by both microsatellite and SNP array. The parents of the patient, both of Palestinian (Jordanian) origin, were heterozygous for the S318Y mutation, although no history of consanguinity was known. Microsatellite genotyping identified a partial haplotype from each parent that corresponds to the region of homozygosity in the patient. Assuming S318Y is a founder mutation, the number of generations separating the two parents from their common ancestor from whom they inherited S318Y was estimated as 21.7 (95% CI 3.42–69.7). Conclusion EPP was therefore inherited as an autosomal recessive trait in the family. This study confirms the association between palmar keratoderma and autosomal recessive EPP.     

The Kallmann syndrome gene product expressed in COS cells is cleaved on the cell surface to yield a diffusible component

Kallmann syndrome is characterized by hypogonadotropic hypogonadism and anosmia and caused by a defect of migration and targeting of gonadotropin-releasing hormone-secreting neurons and olfactory axons during embryonic development. We previously cloned the gene responsible for the X-linked form of the disease encoding a 680 amino acid protein, KAL, which displays the unusual combination of a protease inhibitor domain with fibronectin type III repeats. Previous expression studies by northern blot and RNA in situ hybridization in human and chick indicated that the gene is expressed at very low levels in the olfactory bulb during development. Therefore, low abundance of the protein has hampered a detailed biochemical characterization. By overexpressing both the human and chick KAL cDNAs in eukaryotic cells, we now provide evidence that KAL is a glycosylated peripheral membrane protein with an apparent molecular weight of approximately 100 kDa. We show that this 100 kDa protein is proteolytically processed on the cell membrane to yield a 45 kDa diffusible component, which is detectable with an antisera against the C-terminal part of the protein and binds tightly to cell surfaces. These data provide a first step toward understanding KAL function in neuronal interactions and neurite extension in the olfactory bulb and suggest that KAL might be a diffusible chemoattractant molecule for olfactory axons.      

论高等医学院校普及医院信息系统课程

在我国,医院信息系统已是现代化医院工作的支撑环境。高等医学院校的医院信息系统课程留白,可能削弱医学生临床工作能力和职业适应力。文章阐明了高等医学院校开设医院信息系统专业课的重要性,讨论了教学目标、教学内容;详细介绍了高校与医院合作建立HIS实验室、实地教学和针对专业掌握实际操作技能的教学方法。     

Assesment of polyunsaturated fatty acids in cord blood of infants of diabetic mothers

Objective：To assess whether infants of diabetic mothers [ pre pregnancy diabetics （PPD） and gestational diabetics mellitus （GDM） ] have compromised arachidonic and docosahexaenoic acids in their plasma and the relationship with deficiency of the same compounds in their mothers. Methods： This study was conducted on 30 diabetic mothers （ both PPD and GDM） and their infants. Twenty healthy infants and their mothers with age and sex matched were included as controls. All infant （ of diabetic and non diabetic mothers） were subjected to assessment of APGAR Scoring, thorough history taking and anthropometric measures. Lipid profile components as well as polyunsaturated fatty acids（PUFA） were assessed in diabetic GDM and PPD and non diabetic mothers as well as in their babies. Results ： High-density lipoproteir（HDL） level was found to be significantly lower in diabetic mothers （specially those with PPD） compared to non diabetic ones, whereas no significant difference was found between babies of the two groups. Also, the current study revealed that diabetic mothers （ GDM and PPD） and their babies had significantly higher levels of PUFA precursors linoleic acids （LA） and alpha linoleic acids（ALA）. PUFA arachidonic acid（AA） and docosahexaenoic acids（DHA） were found to be significantly lower in diabetic mothers （GDM and PPD） compared to non diabetic mothers, and same results were found in the babies of the two groups. Conclusion： Neonates with diabetic mothers （both GDM and PPD） have highly compromised plasma levels of AA and DHA PUFA, which affects the child well being by far, and produces hazardous muhi-system complications on the long run.     

Bacteria etiological agents causing respiratory tract infections in children and their resistance patterns to a panel of ten antibiotics

ObjectiveTo study the bacteria etiological agents of respiratory tract infection among 280 school children in South East Nigeria, and to determine their antimicrobial resistance patterns to a panel of ten antibiotics.MethodsThroat swabs (280) were collected from students in four boarding schools located in Enugu and Onitsha metropolis. Standard microbiological procedures were used to screen these swabs to determine the prevalence of respiratory pathogens while the disc diffusion test was used to determine the antimicrobial resistance patterns of the recovered isolates.ResultsOf the 280 samples screened, 57.1% were positive. Haemophilus influenzae was the most prevalent (16.1%), followed by Streptococcus pyogenes (13.9%), Klebsiella pneumoniae (12.5%), Streptococcus pneumoniae (6.8%), Staphylococcus aureus (5.4%) and Corynebacterium diphtheriae (2.5%). More isolates were recovered in the two male schools investigated. However, there was no significant difference in the overall prevalence of isolates according to sex or school location of the subjects. Greater number of isolates (56%) was recovered from those aged 11–14 years. This was statistically significant (P<0.05), compared to the other two age groups (15–18 years and 19–23 years). The pattern of resistance varied according to the bacteria species. There were multi-resistant isolates. Since these students stand the risk of contracting respiratory tract infection particularly from reservoirs among them, there is need to increase surveillance and develop better strategies to curb the increasing prevalence of respiratory tract infection in this and other similar regions of Africa.ConclusionsThe spectrum of bacteria causing respiratory tract infection is still wide in Nigeria. Many isolates showed appreciable levels of antibiotic resistance apparently due to antibiotic abuse. Development of new strategies to curb this increasing prevalence of respiratory tract infection is warranted.     

Alzheimer's disease associated with mutations in presenilin 2 is rare and variably penetrant

Missense mutations in the presenilin 2 (PS-2) gene on chromosome 1 were sought by direct nucleotide sequence analysis of the open reading frame of 60 pedigrees with familial Alzheimer's disease (FAD). In the majority of these pedigrees, PS-1 and beta-amyloid precursor protein (beta APP) gene mutations had been excluded. While no additional PS-2 pathogenic mutations were detected, four silent nucleotide substitutions and alternative splicing of nucleotides 1338-1340 (Glu325) were observed. Analysis of additional members of a pedigree known to segregate a Met239Val mutation in PS-2 revealed that the age of onset of symptoms is highly variable (range 45-88 years). This variability is not attributable to differences in ApoE genotypes. These results suggest (i) that, in contrast to mutations in PS-1, mutations in PS-2 are a relatively rare cause of FAD; (ii) that other genetic or environmental factor modify the AD phenotype associated with PS-2 mutations; and (iii) that still other FAD susceptibility genes remain to be identified.      

Mice with an aspartylglucosaminuria mutation similar to humans replicate the pathophysiology in patients

Aspartyglucosaminuria (AGU) is a lysosomal storage disease with autosomal recessive inheritance that is caused by deficient activity of aspartylglucosaminidase (AGA), a lysosomal enzyme belonging to the newly described enzyme family of N-terminal hydrolases. An AGU mouse model was generated by targeted disruption of the AGA gene designed to mimic closely one human disease mutation. These homozygous mutant mice have no detectable AGA activity and excrete aspartylglucosamine in their urine. Analogously to the human disease, the affected homozygous animals showed storage in lysosomes in all analyzed tissues, including the brain, liver, kidney and skin, and lysosomal storage was already detected in fetuses at 19 days gestation. Electron microscopic studies of brain tissue samples demonstrated lysosomal storage vacuoles in the neurons and glia of the neocortical and cortical regions. Magnetic resonance images (MRI) facilitating monitoring of the brains of living animals indicated cerebral atrophy and hypointensity of the deep gray matter structures of brain-findings similar to those observed in human patients. AGU mice are fertile, and up to 11 months of age their movement and behavior do not differ from their age-matched littermates. However, in the Morris water maze test, a slow worsening of performance could be seen with age. The phenotype mimics well AGU in humans, the patients characteristically showing only slowly progressive mental retardation and relatively mild skeletal abnormalities.      

Serum luteinizing hormone,follicle-stimulating hormone and oestradiol pattern in women undergoing pituitary suppression with different gonadotrophin-releasing hormone analogue protocols for assisted reproduction

Gonadotrophin-releasing hormone analogues (GnRH-a) are used widely in controlled ovarian stimulation (COS) cycles for assisted reproduction. At present, there is great debate about the influence of exogenous hormone activity on the hypothalamus–pituitary axis following pituitary desensitization. The objective of this comparative study was to investigate the pattern of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and oestradiol in women undergoing ovarian stimulation with different GnRH-a preparations. We retrospectively analysed 201 women, aged between 27 and 43 years, who were referred consecutively to our infertility clinic between January 2002 and January 2003. All women had no endocrinopathies or occult ovarian failure as assessed by day-3 hormone profile. Women were enrolled in one of the following COS protocols: depot triptorelin long protocol (n?=?38), buserelin long protocol (n?=?101) or buserelin short protocol (n?=?62). Recombinant FSH was used to induce ovulation. Treatment was monitored by transvaginal ultrasound scan and serum measurement of FSH, LH and oestradiol. Among the women initially included, 30 had cancelled cycles due to poor ovarian response. Serum LH levels were significantly higher in the short-protocol group compared with the long-protocol groups (p?<?0.001). The number of follicles, oocyte yield, number of grade-I embryos and fertilization rate were significantly lower in the short-protocol group than in the long-protocol groups. These findings showed that LH concentrations are significantly higher in women undergoing reversible medical hypophysectomy with a GnRH-a short protocol than in women treated with a long protocol. The hypothesis of an LH ceiling is confirmed.     

Histomorphometric analysis of aplastic bone disease in chronic renal failure at initiation of haemodialysis: Relation to aluminum and parathormone

SUMMARY: We studied bone histology of 134 uraemic patients without a history of vitamin D administration at the start of haemodialysis. Patients were categorized according to bone histology as follows: aplastic bone disease (ABD), ostitis fibrosa, mixed type, mild hyperparathyroidism and osteomalacia. On initiation of haemodialysis, ABD was observed in 48.5% of patients. the average age of the ABD group (50.8 ± 12.5 years) was significantly higher than that of patients with other histologies ( P <0.01). Serum parathyroid hormone (PTH) and alkaline phosphatase (ALP) concentrations were lower ( P <0.01) in the ABD group, especially in patients with diabetes mellitus. Patients with diabetes mellitus and ABD had lower serum concentrations of PTH and ALP than non-diabetic patients, suggesting that depressed PTH may be related to ABD. Eleven (55%) of the 20 patients who were receiving A1(OH)₃ also had ABD. A direct relationship was observed between serum aluminum concentration and aluminum-positive bone surface ( r =0.60; P <0.01). Aluminum staining was more frequently observed in the ABD group than in the non-ABD group ( P <0.01). Because serum intact-PTH concentrations correlate with osteoid surface area, fibrosis volume and bone formation rate, it may be a useful marker of bone histology in renal osteodystrophy. These results suggest that, in addition to conservative treatment with A1(OH)₃, other factors may be involved in the formation of ABD which is often present at the start of haemodialysis.