Characterization of a benzyladenine binding-site peptide isolated from a wheat cytokinin-binding protein: sequence analysis and identification of a single affinity-labeled histidine residue by mass spectrometry

A wheat embryo cytokinin-binding protein was covalently modified with the radiolabeled photoaffinity ligand 2-azido-N6-[14C]benzyladenine. A single labeled peptide was obtained after proteolytic digestion and isolation by reversed-phase and anion-exchange HPLC. Sequencing by classical Edman degradation identified 11 of the 12 residues but failed to identify the labeled amino acid. Analysis by laser photodissociation Fourier-transform mass spectrometry of 10 pmol of the peptide independently confirmed the Edman data and also demonstrated that the histidine residue nearest the C terminus (underlined) was modified by the reagent in the sequence Ala-Phe-Leu-Gln-Pro-Ser-His-His-Asp-Ala-Asp-Glu.     

Cytogenetic analysis of tissues from patients with familial paragangliomas of the head and neck

Background. Paragangliomas of the head and neck are slow-growing tumors that originate from neural crest cells. Between 7% and 9% of these tumors have a familial occurrence. The suspected gene for familial paragangliomas (FP) is transmitted with an autosomal dominant mode of inheritance with incomplete penetrance, and appears to exhibit genomic imprinting. It has been demonstrated by family studies that individuals who inherit the gene(s) from their father will develop the disease. Through linkage analysis, the gene(s) for FP has been postulated to be located on the long arm of chromosome 11. The discovery of many different genes has been elucidated through the cytogenetic analysis of affected individuals who carry specific chromosome aberrations. This project was designed to look for chromosome abnormalities in several second-generation family members to further assist in the localization of the gene(s) for FP. Methods. This study involved the cytogenetic evaluation of lymphocytes, fibroblasts, and tumor cells of several second-generation family members from a three-generation family with FP of the head and neck to look for chromosome abnormalities generally, and for abnormalities of chromosome 11 specifically. Standard cytogenetic techniques were used for lymphocyte and fibroblast cultures. Tumor cells were cultured in a collagen matrix with F12 medium supplemented with 3% L-glutamine and 10% fetal calf serum. Results. There were no detectable abnormalities of chromosome 11 in any of the cells. However, nonrandom abnormalities of chromosomes 5 and 7 were seen in some of the tumor cells of one FP patient. To our knowledge, this is the first article which demonstrated the ability to successfully culture FP of the head and neck. © 1995 Jons Wiley & Sons, Inc.     

Acinetobacter skin abscess in a neonate.

Although Acinetobacter is usually a species of low virulence, it is becoming increasingly more important as a cause of hospital outbreaks, particularly on intensive care units. Antibiotic resistance can develop rapidly. This organism has not been reported to cause skin abscesses previously. We describe a case of a neonate who developed an Acinetobacter abscess on our neonatal intensive care unit.     

The contribution of a non-invasive test to clinical care. The impact of echocardiography on diagnosis, management and patient anxiety

We prospectively studied the impact of echocardiography on a cardiologist's diagnosis and management plan and on patient anxiety for 300 consecutive referrals. There was an impact on diagnosis in 90% of patients. Most common was confirmation of diagnosis usually with the addition of information pertinent to management (81%); change of disease category or resolution of diagnostic doubt was uncommon (9%). The consultant cardiologist believed the heart to be normal in 48 patients who did not have any associated disease; none had any echocardiographic abnormality. The cardiologist reported increased diagnostic confidence in 74% of all patients but management changed in only 9%. One-third of all patients reported reduced anxiety when this was an important clinical issue but in less than half of them did the cardiologist consider that echocardiographic information was essential for reassurance. Anxiety was increased in 6%, and in 12% the anxiety response was inconsistent with the test result. The clinical contribution of the test report was most obvious for those patients (30%) in whom this data was required for (a) a decision concerning specific diagnostic or technical intervention (b) a change of management plan which implied obvious or likely health benefit (c) reassurance which was a clinically important issue. The magnitude of this contribution was related to the study indication. The value of echocardiography is obvious when assessing patients for invasive intervention or when proper treatment or adequate reassurance are impeded by diagnostic doubt. However, for many current indications, we need better definition of factors which predict a clinically useful result. In particular, when the aim is to rule-out disease, our results suggest that an expert cardiological opinion would often be more appropriate than an echocardiogram.     

Hepatitis C virus outside the liver

Observational and some experimental data suggest that hepatitis C virus can manifest in a variety of disease processes outside the liver. The links between hepatitis C virus and membranoproliferative glomerulonephropathy, porphyria cutanea tarda, lichen planus, cryoglobulinemia, diabetes mellitus, B-cell non-Hodgkin’s lymphoma, and thyroiditis are critically reviewed. Based on the available evidence, recommendations for the clinical approach to patients with extrahepatic diseases are discussed.