Rapid typing of the human Fc gamma receptor IIA polymorphism by polymerase chain reaction amplification with allele-specific primers

BACKGROUND: The human Fc gamma receptor IIa (Fc gamma RIIa) is expressed in two polymorphic forms, Fc gamma RIIa-H131 and Fc gamma RIIa-R131, that differ by the replacement of histidine by arginine at position 131. This replacement is caused by a single-nucleotide exchange of A–>G. The resulting receptor forms differ in their binding to human IgG2 and mouse IgG1, which may lead to a different immunologic defense to bacterial polysaccharides and encapsulated bacteria. STUDY DESIGN AND METHODS: A rapid and easy polymerase chain reaction(PCR) method of genotyping the Fc gamma RIIa was developed. Allele-specific primers discriminate between the Fc gamma RIIa-H131 and the Fc gamma RIIa-R131 forms of the receptor. The results were compared with those obtained by another DNA-based genotyping method, in which PCR-amplified DNA was hybridized with allele-specific oligonucleotides, and with a functional phagocytosis assay using mouse IgG1-coated red cells as target antigens. RESULTS: The genotypes deduced from the PCR with allele-specific primers were in complete accordance with those obtained by the data from the hybridization of PCR-amplified DNA with allele- specific oligonucleotides. Furthermore, the Fc gamma RIIa genotypes of 28 individuals in all cases corresponded to the functional phenotypes. CONCLUSION: The use of PCR with allele-specific primers provides a rapid and easily performed method for the determination the Fc gamma RIIa polymorphism.     

Diagnostic error due to vicarious excretion of rectal iodinated contrast

Introduction of iodinated contrast into the intact colon is not expected to result in imaging‐visible renal excretion of this contrast and is a phenomenon that has only rarely been described. We present a case in which such vicarious renal excretion was misinterpreted as a recto‐vesical fistula which resulted in unnecessary delay in the patient’s management.     

Precision of genotyping of Epstein-Barr virus by polymerase chain reaction using three gene loci (EBNA-2, EBNA-3C, and EBER): predominance of type A virus associated with Hodgkin's disease [published erratum appears in Blood 1993 Oct 1;82(7):2268]

To precisely determine the genotype of Epstein-Barr virus (EBV) in Hodgkin's disease (HD), we simultaneously analyzed three divergent gene loci (EBNA-2, EBNA-3C, and EBER) that distinguish type A and B viruses. The primers designed to amplify these three gene loci encompass either type-specific deletion sequences (EBNA-2 and EBNA-3C) or type-specific point mutations (EBER) that identify the virus strain based on the sizes of the polymerase chain reaction (PCR)-amplified products or the mobility shifts in single-strand conformation polymorphism analysis. The locations of point mutations were identified by direct sequencing of the PCR-amplified DNA. We analyzed 15 EBV-infected cell lines and found a good correlation between EBNA-2 and EBNA-3C typing results. In contrast, approximately 33% of the cell lines analyzed maintained type A sequences in EBNA-2 and EBNA-3C genes while carrying type B sequences in the EBER region. Data obtained from analysis of cell lines served as a reference for studying HD samples. EBV DNA was detected in about 70% of HD. Among the EBV-positive samples, 56% were associated with type A virus, 13% with type B, and 31% with dual viral sequences. Thus, type A virus is predominant in HD. Based on the histology, the frequencies of EBV positivity were 83%, 71%, and 33% for mixed cellularity, nodular sclerosis, and lymphocyte predominance, respectively. The detection of high frequency of both type A and B sequences in HD may provide a lead in investigating the role of dual viral infection in EBV pathogenesis.     

Production and characterization of a bispecific IgG capable of inducing T-cell-mediated lysis of malignant B cells

Bispecific monoclonal antibodies (bsabs) recognizing both CD3 and a tumor antigen can redirect T-cell-mediated cytotoxicity toward cells bearing that antigen. Such bsabs have been shown to be more effective than monospecific monoclonal antibodies (MoAbs) at preventing tumor growth in animal models of B-cell malignancy. The current studies describe the production and preliminary evaluation of a bsab designed to induce the lysis of malignant human B cells by human T cells. The bsab was obtained from a hybrid-hybridoma cell line produced by fusing OKT3-secreting hybridoma cells with hybridoma cells that secrete 1D10. 1D10 is an MoAb that recognizes an antigen found on a majority of malignant human B cells that has not been detected to a significant degree on normal resting or activated lymphocytes. High performance liquid chromatography (HPLC) was used to separate bsab from monospecific antibodies that were also present in the hybrid-hybridoma antibody product. The bsab was then evaluated in vitro for its ability to induce lysis of malignant B cells by activated T cells. The bsab consistently induced extensive lysis in vitro of 1D10 (+) cells, including both cell lines and cells obtained from patients with a variety of B-cell malignancies. No such effect was seen with activated T cells alone or activated T cells with monospecific antibody. No increased lysis was seen with 1D10 (-) cell lines. The bsab also mediated lysis of malignant B cells by autologous T cells. We conclude bsab containing an OKT3 arm and a 1D10 arm can induce T-cell-mediated lysis in a manner that is both potent and specific. This supports further evaluation of this bsab as a potential immunotherapy of B-cell malignancy.     

Profile of Live-born Infants of In-vitro Fertilisation

Introduction

The Army Hospital (R&R) is the only service hospital providing in-vitro fertilisation (IVF) facility. Neonatal characteristics of live-born infants at this centre over a two-year period are analyzed in this study.

Methods

Data on 504 consecutive live-born IVF infants over a two-year period (01 Feb 2007 to 31 Jan 2009) were analysed.

Result

Of the 504 neonates, 190 (37.7%) were born by vaginal delivery, 156 (30.9%) by elective lower segment cesarean section (LSCS) and 127 (25.19%) following emergency LSCS. Maternal illness posing specific risk to the neonate was present in 165 out of 504 (32.7%). There were 239 (47.4%) preterm neonates. Males formed 51.8% of the cohort. Singletons accounted for 51.2%, while the rest (48.8%) were products of twin pregnancies. Small for gestational age neonates formed 22.6% (n = 114). A total of 20 (3.9%) infants had congenital malformations. There were 242 (48.1%) low birth weight neonates. A total of 128 (25.4%) neonates needed neonatal intensive care. Of the 504, there were 474 (94.1%) survivors while 30 (5.9%) did not survive. Twenty-nine (6.1%) neonates required readmission during the neonatal period.

Conclusion

In our setting, neonates born following IVF appeared to be at increased risk of prematurity, multiple births and low birth weight. Proper obstetric and neonatal management can result in good neonatal outcomes.Key Words: In-vitro fertilisation, Live-births, Low birth weight     

Polymorphisms in genes encoding the serotonin and dopamine pathways in two sisters with metachromatic leukodystrophy

Metachromatic leukodystrophy (MLD) is a metabolic disease that has recently been investigated as a model for the study of psychosis. We report on two sisters with adult-type MLD who developed psychiatric symptomatology, but differed in their expression of psychotic and depressive symptoms. Association studies have indicated that polymorphisms in genes encoding the serotonin and dopamine transporters and receptors are related to the symptomatology of schizophrenia and/or depression; hence both sisters were genotyped for some of these candidate genes. The sisters shared dopamine receptor D(2) (DRD(2)) c.1047GG (p.311Ser/Ser) and c.-141Cins/ins polymorphisms, which are significantly associated with schizophrenia, but differed in the serotonin transporter gene-linked polymorphic region and serotonin receptor 1A (5-HT(1A)) c.-1019C to G polymorphisms, which may have increased the elder sister's susceptibility to depressive symptoms. Much bigger samples would be needed to gain enough statistical power to develop any hypotheses. This is the first report on genotyping MLD patients for candidate genes for psychiatric disorders, although MLD has been proposed as a model for schizophrenia.     

Results of definitive radiotherapy in T1 and T2 glottic carcinoma: Institute of Rotary Cancer Hospital experience

Early glottic carcinomas (T₁ and T₂) constitute only 2% of all laryngeal cancers in our data. Seventy patients were seen between 1985 and 1992. All patients were treated by cobalt-60 small field radiotherapy using a beam directed shell. The total dose delivered was 60–65 Gy in 31 patients and 66–70 Gy in 39 patients. The follow-up period ranged from 5 to 126 months, with a mean follow up of 37 months overall and 55 months in the surgical salvage group. Radiation therapy controlled disease in 71% (50 of 70) of patients overall; 75% with T₁ and 67% with T₂ lesions. Total laryngectomy as salvage surgery was performed in 70% (14 of 20) of patients whose disease recurred. Ultimate control including surgical salvage occurred in 64 (91%) of 70 patients in the present study. The actuarial 5 year survival was 83 and 80% in T₁ and T₂ tumours, respectively (statistically insignificant). This report supports the policy of definitive irradiation, reserving surgical salvage for radiation failures in early laryngeal cancers.     

Breast metastases from cutaneous melanoma: a report of three cases

In this report we describe three female patients with breast metastases from cutaneous melanoma (CM) who were treated in Slovenia in the period from 1988 to 1991. We found that in 476 Slovenian patents with this disease diagnosed in the given period CM disseminated to the breast less frequently than in other series. In one pregnant and one perimenopausal patient breast involvement by CM was confirmed at the time of widespread dissemination of the disease. Treatment was not effective and the survival of these patients was four months and two weeks and six months, respectively. A slightly better outcome was observed in a normally menstruating patient referred from another country with an isolated solitary breast metastasis from CM. In this patient quadrantectomy seemed to have been sufficient to achieve a disease-free interval of more than eight months. Special attention should therefore be given to a small subset of patients with isolated solitary breast metastases from CM, since their prognosis may be less dismal than in patients with massively infiltrated breasts and disseminated disease.     

MID-TRIMESTER MTP USING ENDOCERVICAL PGE2 GEL AND SERIAL INTRAMUSCULAR CARBOPROST

60 cases of mid-trimester pregnancy were terminated using endocervical PGE₂ gel (for achieving cervical priming) followed by serial intramuscular injections of carboprost. In this prospective study, 56 cases were multiparae with gestational age varying between 15-22 weeks. The induction-abortion-interval was 8.4h ± 0.8h with a success rate of 100%. The incidence of incomplete abortion was 5% and check curettage was performed in 16.6% cases. Gastrointestinal side effects were common. Vomiting occurred in 42% cases and diarrhoea in 50%. Febrile morbidity was seen in 8.3% cases. There were no complications of the procedure. The method was highly acceptable to the patients being non-invasive and allowing ambulation throughout. This method of elective mid-trimester abortion is an effective alternative to the other commonly used methods like extra-amniotic ethacridine lactate or intra-amniotic hypertonic saline instillation.KEY WORDS: Carboprost, Mid-trimester abortion, PGE₂