Alterations of the levels of glycoproteins Ib-IX and IIb-IIIa in platelets stored at 22°C

Platelets stored in CLX™ blood bags, under normal blood banking conditions, were studied for up to 7 days to determine if changes ocurred in the levels of membrane glycoproteins (GP) Ib-IX and IIb-IIIa. Radiolabeled monoclonal antibodies (MAB) were used to estimate the number of glycoprotein molecules on the surface membrane of intact platelets. GP IX and GP IIb-IIIa levels remained essentially unaltered during storage. In contrast, the content of GP Ib at day 7 decreased by 45% of the total when fresh. The aggregation response to ristocetin, which requires GP Ib, was also diminished after 7 days. Addition of protease inhibitors, leupeptin and/or aprotinin did not appear to influence the degradation of this glycoprotein. We conclude that storage at 22°C has deleterious effects on the GP Ib content of platelets.     

The use of the rat facial nerve model to assess the effect of differing nerve anastomotic agents on the facial nerve

There are relatively few papers which prove that one nerve anastomotic agent for the facial nerve is superior to any other. Previous experiments on the division and anastomosis of the facial nerve have failed to consider the indeterminate variables involved, i.e. operator variability, controls and the reaction of the materials on normal nerve tissue. In this experiment, a variety of anastomotic agents were tested to see if the anastomotic agents themselves affected the extra-temporal facial nerve function. The absorbable suture, non-absorbable suture, glue and tube wrap used had no effect on normal nerve tissue or on the anastomosis of the sectioned facial nerve of the rat compared with simple laying together of the divided ends of the divided nerve.     

Induction of antibody responses to breast carcinoma associated mucins using synthetic peptide constructs as immunogens

A strategy for directing and enhancing B cell immune responses against synthetic peptide determinants has been developed in order to produce antibodies specifically against protein epitopes of clinical relevance. A peptide sequence based upon the MUC-1 mucin protein core was selected for this purpose since anti-MUC-1 antibodies have proven diagnostic application and therapeutic potential in human breast and ovarian cancer. Peptide constructs were synthesised co-linearly linking the immunodominant B cell determinant region, PDTRPAP, in the protein core of the MUC-1 mucin, to sequence 111 – 120 of influenza haemagglutinin A/X-31, a determinant recognised by T helper cells through association with MHC class II molecules. Induction of anti-MUC-1 antibodies to the B cell determinant region by immunisation with peptide was shown to be dependent upon both the presence and the position of the T cell determinant. In addition, haplotype mismatching with respect to the T cell determinant resulted in a significant lowering of the anti-MUC-1 antibody response in peptide construct immunised mice. These findings are relevant to the design of immunogens to produce antibodies against peptide epitopes of tumour associated proteins and glycoproteins.     

Sensitivity of effect variables in rheumatoid arthritis: A meta-analysis of 130 placebo controlled NSAID trials controlled NSAID trials

In a meta-analysis of placebo controlled NSAID trials, the sensitivity of the effect variables was calculated as the correlation coefficient and as the difference between drug and placebo, divided by the placebo group standard deviation. The patient's global evaluation was the most sensitive variable overall. Pain was more sensitive than Ritchie's index. Several variables may be omitted from clinical trials, especially if two active drugs are being compared. For example, the best maximum estimate for the difference in ESR between NSAADs and placebo was 1.0 mm/hr (95% confidence interval −1.5 to 3.4 mm/hr), and for joint size 0.44% (−1.0 to 1.9%), corresponding to a quarter of a millimeter for each of the 10 joints usually measured. It is suggested to record only the patient's global evaluation, pain, and morning stiffness.     

Immunophenotyping of childhood acute lymphoblastic leukemia in Saudi Arabia: Second look

Geographical variations in the incidence of disease are of considerable theoretical and practical importance. It has been claimed that the distribution of acute lymphoblastic leukemia (ALL) phenotypes in Saudi Arabia is different from that recorded in the Western literature. One hundred and twelve (112) patients under 15 years of age, diagnosed as ALL between January 1992 and May 1994 had immunophenotypes performed on their blast cells. Common ALL (cALL) together with pre-B-ALL, formed 86.5% of the total; B-cell 3%, T-cell 6% and null cell 4.5%. These figures are not significantly different from the Western literature. A previous claim from this institution in 1990, that both null and B-cell ALL were significantly increased compared with elsewhere, is not supported by the present figures. Age and sex distribution, and FAB classification, L1 77%, L2 20% and L3 3%, were also of the same order as described elsewhere and, in particular, there was no increase in the frequency of L3 subtype.     

Interrelationship between secretion, protein phosphorylation and intracellular Ca2+ concentration in platelets stimulated by thrombin or thromboxane A2 analogue

The interrelationship between ATP-secretion, protein phosphorylation and intracellular Ca²⁺ concentration ([Ca²⁺]i) was studied in both ³²P and quin 2 loaded human platelets stimulated by thrombin or thromboxane A₂ analogue (STA₂). In platelets stimulated by thrombin, the degree of 47,000 dalton polypeptides (P47) phosphorylation was observed in completely dose-related manner, regardless of the amount of [Ca²⁺]i. In the same condition, the degree of myosin light chain (P20) phosphorylation, however, was well correlated with ATP secretion and [Ca²⁺]i, when platelets were stimulated by lower dose of thrombin. The similar results were obtained in platelets stimulated by STA₂. These findings suggested that P20, but not P47, phosphorylation in activated platelets is mediated by a rise of [Ca²⁺]i and is well correlated with the secretory reaction. It was unlikely that P47 phosphorylation plays any role in promoting platelet activation.     

Throat pain and pharyngeal packing: a controlled randomized double-blind comparison between gauze and tampons

In order to determine whether patients having pharyngeal packing experience more or less post-operative throat pain when tampons were used, 80 patients were randomized into two groups to receive either gauze or tampon pharyngeal packing. A third control group of 40 patients were intubated but did not have any throat packs. Post-operative throat pain was subjectively rated at both 6 hours and at 24 hours by an independent observer. Thirty-eight per cent of patients had moderate or severe throat pain in the gauze group, whilst in the tampon and control groups these amounted to only 15% and 1% respectively. A significantly higher proportion of patients also had a moderate or severe sore throat at 24 hours in the former group. Intubation alone resulted in a sore throat post-operatively in 50% of patients, but 85% of those had a mild sore throat only. No differences in pain ratings in any group could be shown between men or women or between age groupings. Endotracheal intubation often causes post-operative throat pain which is exacerbated by the use of pharyngeal packing. The results presented suggest that tampons are a safe, effective alternative to gauze and result in less severe post-operative throat pain.     

Attitudes toward psychiatry among Irish final year medical students

This study investigated the attitudes of medical students towards psychiatry, both as a subject on the medical curriculum and as a career choice. Three separate questionnaires previously validated on medical student populations were administered prior to and immediately following an 8-week clinical training programme. The results indicate that the perception of psychiatry was positive prior to clerkship and became even more so on completion of training. On completion of the clerkship, there was a rise in the proportion of students who indicated that they might choose a career in psychiatry. Attitudes toward psychiatry correlated positively with the psychiatry examination results. Those that intended to specialise in psychiatry achieved significantly higher examination scores in the psychiatry examination.     

Gynandroblastoma of ovary with juvenile granulosa cell component and heterologous intestinal type glands

An ovarian gynandroblastoma in a 15-year-old girl is described. The predominant component was juvenile granulosa cell tumour. Areas of adult granulosa cell tumour and Sertoli cell elements were also present. Stromal theca and luteinised cells were identified. An additional histological finding was the presence of heterologous intestinal type glands. There was positive immunohistochemical staining of juvenile and adult granulosa cell areas with inhibin and MIC2 antibodies. Electronmicroscopy showed a close ultrastructural resemblance between tumour cells in granulosa and Sertoli cell areas, in spite of differences in architectural pattern, suggesting that both morphological components may derive from a single cell of origin. The tumour demonstrates a unique combination of elements which has not previously been described.