FINGERPRINTING OF HLA CLASS I GENES FOR IMPROVED SELECTION OF UNRELATED BONE MARROW DONORS

The degree of matching of HLA genes between the selected donor and recipient is an important aspect of the selection of unrelated donors for allogeneic bone marrow transplantation (UBMT). The most sensitive methods currently used are serological typing of HLA class I genes, mixed lymphocyte culture (MLC), IEF and molecular genotyping of HLA class II genes by direct sequencing of PCR products. Serological typing of class I antigenes (A, B and C) fails to detect minor differences demonstrated by direct sequencing of DNA polymorphic regions. Molecular genotyping of HLA class I genes by DNA analysis is costly and work-intensive. To improve compatibility between donor and recipient, we have set up a new rapid and non-radioisotopic application of the ‘fingerprinting PCR’ technique for the analysis of the polymorphic second exon of the HLA class I A, B and C genes. This technique is based on the formation of specific patterns (PCR fingerprints) of homoduplexes and heterodu-plexes between heterologous amplified DNA sequences. After an electrophoretic run on non-denaturing polyacrylamide gel, different HLA class I types give allele-specific banding patterns. HLA class I matching is performed, after the gel has been soaked in ethidium bromide or silver-stained, by visual comparison of patients’ fingerprints with those of donors. Identity can be confirmed by mixing donor and recipient DNAs in an amplification cross-match. To assess the technique, 10 normal samples, 22 related allogeneic bone marrow transplanted pairs and 10 unrelated HLA-A and HLA-B serologically matched patient-donor pairs were analysed for HLA class I polymorphic regions. In all the related pairs and in 1/10 unrelated pairs, matched donor-recipient patterns were identified. This new application of PCR fingerprinting may confirm the HLA class I serological selection of unrelated marrow donors.     

A dinucleotide mutation in the endothelin-B receptor gene is associated with lethal white foal syndrome (LWFS); a horse variant of Hirschsprung disease

Lethal white foal syndrome (LWFS) is a congenital anomaly of horses characterized by a white coat colour and aganglionosis of the bowel, which is similar to Hirschsprung disease (HSCR). We decided to investigate possible mutations of the endothelin-B receptor gene ( EDNRB ) in LWFS as recent studies in mutant rodents and some patients have demonstrated EDNRB defects. First, we identified a full-length cDNA for horse EDNRB . This cDNA fragment contained a 1329 bp open reading frame which encoded 443 amino acid residues. The predicted amino acid sequence was 89, 91 and 85% identical to human, bovine and mouse as well as rat EDNRB respectively, but only 55% identical to the human, bovine and rat endothelin A receptor (EDNRA). Secondly, sequence analysis, together with allele-specific PCR and the amplification- created restriction site (ACRS) technique, revealed a dinucleotide TC-- >AG mutation, which changed isoleucine to lysine in the predicted first transmembrane domain of the EDNRB protein. This was associated with LWFS when homozygous and with the overo phenotype when heterozygous.      

Relationship between HLA-DRB1 and DQ alleles and the genetic susceptibility to type 1 diabetes

Objective　To study the relationship between human leukocyte antigen (HLA)-DRB1 and DQ alleles and the genetic susceptibility of type 1 diabetes in North Chinese children. Methods　Polymerase chain reaction (PCR) techniques were used to amplify the second exon of DRB1 and DQ alleles, after which sequence specific olignucleotide probe (SSOP) dot blot hybridization techniques were used to analyze the amplified products. Results　DRB1*0301, DQA1*0301, DQB1*0201 alleles and DRB1*0301-DQA1*0501-DQB1*0201 haplotype were significantly increased in patients, while DQA1*0103 and DQB1*0601 alleles were significantly increased in controls. The distribution of DR4 and DR9 haplotypes in patients and controls were not significantly different, but DR3/DR4 and DR4/DR9 heterozygotes were significantly increased in patients. Conclusions　DRB1*0301, DQA1*0301 and DQB1*0201 confer susceptibility while DQA1*0103 and DQB1*0601 confer protection to type 1 diabetes. DRB1*0301-DQA1*0501-DQB1*0201 haplotype offers a predisposition to type 1 diabetes in North Chinese. Although the distribution of DR4 and DR9 in patients and controls had no significant difference, DR3/DR4 and DR3/DR9 heterozygotes were significantly increased in patients, showing that the susceptive effects of DR3 and DR4 or DR4 and DR9 haplotypes could be added up.     

Efficacy of "high-intensity" blue-light and "standard" daylight phototherapy for non-haemolytic hyperbilirubinaemia

We report our clinical experience with phototherapy in 3802 infants; 3629 were exposed to "standard" daylight phototherapy and 173 to "high-intensity" blue-light phototherapy. High-intensity blue-light phototherapy was twice as effective as standard daylight phototherapy in decreasing bilirubin concentrations. No failures occurred with high-intensity phototherapy compared with an overall failure rate of 1.84/1000 with daylight lamps; these cases were transferred to high-intensity phototherapy with prompt response. Rebound after cessation of phototherapy was greater in those exposed to high-intensity blue light with a significantly greater number requiring a second exposure. However, the incidence was still low. No third exposure was required in any infant. Nursing of infants under high-intensity blue light was more difficult and inconvenient as was clinical monitoring. The light also caused more stress on the nursing and medical personnel. However, the infants tolerated both types of phototherapy equally well. High-intensity blue-light phototherapy would seem to be the treatment of choice for infants with rapidly increasing or very high bilirubin levels, as well as in those not responding adequately to daylight phototherapy.     

Short term neurophysiological monitoring in multiple sclerosis bouts. Evaluation of steroid treatment

Visual (VEP) and brainstem auditory (BAEP) evoked potentials (EP) were recorded in 21 multiple sclerosis (MS) patients in acute relapse before and after steroid treatment. VEPs were abnormal in 14/21 patients and BAEPs in 10/21 patients before treatment. In 4 patients with acute optic neuritis (ON), an improvement of VEPs paralleled clinical evolution in 3 cases. Substantial and contrasting changes in VEPs or BAEPs, with no clinical counterpart, were related to a spontaneous fluctuation of EPs in acute relapses of MS. These changes suggest frequent subclinical (multifocal and, possibly, sequential) central nervous system involvement in MS bouts. Group analysis showed nonsignificant changes in EP parameters before and after treatment. Our results indicate that evoked potentials (EPs) are of limited value for monitoring the short-term effect of steroid treatment in MS in bouts.

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Sommario I potenziali evocati visivi (VEP) ed acustici troncoencefalici (BAEP) sono stati eseguiti in 21 pazienti affentti da sclerosi multipla (SM) in fase di poussée, prima e dopo un ciclo di trattamento con steroidi. Prima del trattamento i VEP edi BAEP sono risultati alterati in 14 e 10 pazienti rispettivamente. 4 pazienti presentavano una neurite ottica (ON) in fase acuta; in 3, dopo il trattamento, è stato rilevato un significativo miglioramento dei VEP e dell'acuità visiva. Significative, ma contrastanti, modificazioni dei VEP e BAEP, riscontrate in altri 5 pazienti, non correlate all'evoluzione clinica, sono suggestive di un interessamento subclinico, multifocale e possibilmente sequenziale, durante una poussée della SM. L'analisi per gruppi non evidenzia differenze statistiche significative tra prima e dopo il trattamento. I nostri risultati indicano che i potenziali evocati sono di limitata utilità ai fini di un monitoraggio a breve termine della SM in poussée.

     

Informed consent, parental awareness, and reasons for participating in a randomised controlled study

BACKGROUND: The informed consent procedure plays a central role in randomised controlled trials but has only been explored in a few studies on children. AIM: To assess the quality of the informed consent process in a paediatric setting. METHODS: A questionnaire was sent to parents who volunteered their child (230 children) for a randomised, double blind, placebo controlled trial of ibuprofen syrup to prevent recurrent febrile seizures. RESULTS: 181 (79%) parents responded. On average, 73% of parents were aware of the major study characteristics. A few had difficulty understanding the information provided. Major factors in parents granting approval were the contribution to clinical science (51%) and benefit to the child (32%). Sociodemographic status did not influence initial participation but west European origin of the father was associated with willingness to participate in future trials. 89% of participants felt positive about the informed consent procedure; however, 25% stated that they felt obliged to participate. Although their reasons for granting approval and their evaluation of the informed consent procedure did not differ, relatively more were hesitant about participating in future. Parents appreciated the investigator being on call 24 hours a day (38%) and the extra medical care and information provided (37%) as advantages of participation. Disadvantages were mainly the time consuming aspects and the work involved (23%). CONCLUSIONS: Parents' understanding of trial characteristics might be improved by designing less difficult informed consent forms and by the investigator giving extra attention and information to non-west European parents. Adequate measures should be taken to avoid parents feeling obliged to participate, rather than giving true informed consent.     

A monokine regulates colony-stimulating activity production by vascular endothelial cells

Human umbilical vein endothelial cells were cultured in supernatants of peripheral blood monocytes that had been cultured for 3 days with and without lactoferrin. Colony-stimulating activity (CSA) was measured in supernatants of the endothelial cell cultures and appropriate control cultures using normal, T-lymphocyte-depleted, phagocyte-depleted, low- density bone marrow cells in colony growth (CFU-GM) assays. Monocyte- conditioned medium contained a nondialyzable, heat labile factor that enhanced 4-15--fold the production of CSA by endothelial cells. The addition of lactoferrin to monocyte cultures reduced the activity of this monokine by 69%. Lactoferrin did not inhibit CSA production by monokine-stimulated endothelial cells. Therefore, vascular endothelial cells are potent sources of CSA, the production of CSA by these cells is regulated by a stimulatory monokine, and the production and/or release of the monokine is inhibited by lactoferrin, a neutrophil- derived putative feedback inhibitor of granulopoiesis. Inasmuch as a similar monokine is known to stimulate CSA production by fibroblasts and T lymphocytes, we suggest that mononuclear phagocytes play a pivotal role in the regulation of granulopoiesis by recruiting a variety of cell types to produce CSA.     

Conservative management of unilateral condylar hyperplasia

Objective

The purpose of this study was to eliminate orthodontic treatment in mild to moderate cases of condylar hyperplasia in its early stages by condylectomy.

Patients and methods

A total of five patients (two females and three males) aged between 17 and 40 years were treated with unilateral condylectomy of the involved side without orthodontic treatment. All patients underwent standardized clinical and radiological examination at initial consultation, before surgery, immediately after surgery, and follow-up. Objective and subjective evaluation of temporomandibular joint (TMJ) included maximal incisal opening, lateral excursions, correction of facial asymmetry, occlusal harmony, TMJ pain, and jaw function. Results were recorded at 5-year follow-up.

Results

In all our cases, we achieved good mouth opening and near to normal occlusion. Good facial aesthetics was obtained after 3 months postoperative follow-up without secondary orthodontic treatment.

Conclusion

Thus, we conclude that treatment of mild to moderate cases of unilateral condylar hyperplasia during the inactive phase can be treated with condylectomy without orthodontic treatment, and it significantly improves long-term surgical outcomes.     

Role of Oestrogen Receptors on the Modulation of NADPH‐Diaphorase‐Positive Cell Number in Supraoptic and Paraventricular Nuclei of Ovariectomised Female Rats

Modulation of the nitric oxide producing system (demonstrated via the NADPH‐diaphorase histochemical reaction) by oestradiol has been established in several structures of the rat brain. The present study aimed to explore the possible regulation of NADPH‐diaphorase activity by oestradiol in neurones of the supraoptic (SON) and paraventricular (PVN) nuclei and the role of oestrogen receptors (ERα and ERβ) in this regulation. Adult ovariectomised rats were divided into six groups and injected either with vehicle or a single dose of oestradiol, a selective ERα agonist‐PPT [4,4′,4″‐(4‐propyl‐[1H]‐pyrazole‐1,3,5‐triyl)trisphenol], a selective ERβ agonist‐DPN [2,3‐bis(4‐hydroxyphenyl)‐propionitrile], a selective ERα antagonist‐MPP [1,3‐bis(4‐hydroxyphenyl)‐4‐methyl‐5‐[4‐(2‐piperidinylethoxy)phenol]‐1H‐pyrazole dihydrochloride] or a selective ERβ antagonist‐PHTPP (4‐[2‐phenyl‐5,7‐bis(trifluoromethyl)pyrazolo[1,5‐a]pyrimidin‐3‐yl]phenol). The number of NADPH‐diaphorase positive elements in the SON and the PVN was modulated by both ERs but, depending on the nucleus, ERα and ERβ ligands induced different effects. These results suggest that the regulation of nitrergic system by ERs may play a role in the control of oestrogen‐dependent physiological mechanisms regulated by the SON and the PVN.