Evaluation of monoclonal antibodies for the detection of exfoliative nasopharyngeal carcinoma cells

Exfoliative cells were aspirated from 15 patients suspected of having nasopharyngeal carcinoma (NPC) and showing the presence of lesions or other abnormalities in the nasopharynx. They were tested for binding with a 125I monoclonal antibody (MAb) (MA6) which is selectively reactive against human B lymphocytes and a variety of carcinomas. A positive result was obtained from 6/9 patients with, and from 0/5 patients without, histologically confirmed disease. One patient with eskimoma also gave a negative binding result. Cytology was specific but less sensitive, tumour cells being detected in 3 of the patients with confirmed disease. Immunocytology using MA6 was limited, like cytology, by poor recovery of the tumour cells and the results were in complete concordance with cytology. The other MAbs used were raised against carcinoembryonic antigen (CEA) and a carcinoma cell line (Ca2), respectively. The latter was not reactive against the NPC tumour cells while the CEA antibody was not sufficiently selective to be useful.

A murine monoclonal antibody specific for the outer core oligosaccharide of Salmonella lipopolysaccharide

Immunoglobulin G3 murine monoclonal antibody T6 specific for the lipopolysaccharide of Salmonella O serogroups A to E was established. By using R mutants of Salmonella spp., Escherichia coli, and Shigella spp., the major reactive epitope with T6 was tentatively identified as the terminal disaccharide, N-acetylglucosamine 1.2----alpha glucose, of the core oligosaccharide. T6 was reactive with 10 clinical isolates of each of the Salmonella O serogroups A to E but not with 58 isolates of other gram-negative bacteria. Its selective reactivity against Salmonella spp. renders T6 a potentially more useful reagent than the conventional polyvalent serum for the identification of Salmonella spp. It may also serve as a useful molecular tool for the study of the outer core structure of all Salmonella and related species.

In-vitro ligament tension pattern in the flexed knee in passive loading

Tensions generated in selected bands of the four major ligaments of the flexed knee (40-90 degrees) have been measured in vitro when the tibia is subjected to passive anterior translation and axial rotation with and without a compressive preload. The measurements were made in 30 fresh-frozen specimens using the buckle transducer attached to the anteromedial band of the anterior cruciate ligament [ACL (am)], the posterior fibres of the posterior cruciate ligament [PCL (pf)], the superficial fibres of the medial collateral ligament [MCL (sf)], and in the total lateral collateral ligament (LCL). Particular attention was placed on the evaluation of the performance of the transducer specific to such measurements in order to minimize the errors associated with the use of this transducer. The results indicate that, among the measured ligaments, substantial tension (greater than 20 N) is generated only in the ACL (am) in tibial anterior translation up to 5 mm. The tension pattern generated in response to tibial axial rotation, however, is complex and exhibits considerable variation between specimens. In general, both the MCL (sf) and LCL are tensed at all tested flexion angles, with the tension in external rotation being significantly greater than in internal rotation. At 40 degrees of flexion, the ACL (am) bears tension mainly in internal rotation, while at 90 degrees of flexion the PCL (pf) is tensed in both senses of rotation. The response of the LCL shows marked variation among specimens; very small tension (less than 15 N) is generated in internal rotation in 48% of the specimens, and in either sense of rotation in 20% of the specimens. The tension in the ACL (am) in internal rotation is invariably greater in those specimens in which LCL tension is negligible. This correlation between increased ACL (am) function and inadequate LCL restraint appears significant in terms of ACL injury and repair.

beta 2-Microglobulin and systemic lupus erythematosus

Serum beta 2-microglobulin (beta 2-M) was measured in 115 patients with systemic lupus erythematosus (SLE) on 192 occasions. Raised beta 2-M was found in 16.4% of patients with only extrarenal manifestations of SLE, in 29.2% of patients with renal manifestation but an endogenous creatinine clearance greater than 80 ml/min/1.73 m2 and in 65.7% of patients with decreased creatinine clearance. beta 2-M was higher in SLE than non-SLE glomerulonephritides matched for creatinine clearance. Using an arbitrary scoring system, renal, extrarenal and serological activity correlated with beta 2-M. Changes in clinical activity on repeat studies were reflected by changes in beta 2-M. Serum beta 2-M can serve as a monitor of disease activity in SLE.

Potentiation of mitogenic response by extracts of the swiftlet's (Collocalia) nest

The edible bird's nest extract from Collocalia spp. was found to contain a glycoprotein which could potentiate mitogenic response of human peripheral blood monocytes to stimulation with Concanavalin A or Phytohemagglutinin A. The potentiating effect of the extract was most marked at suboptimal mitogenic concentrations of these lectins, decreasing the 50% optimal concentration of Con A and PHA by 6- and 2.5- folds respectively. The potentiating effect was exerted early during the first 10 hours following stimulation with Con A. This potentiation activity was not dialysable, but it was stable to limited digestion with trypsin, alkaline pH and extraction with ether.

Efficacy and safety of recombinant hepatitis B vaccine in infants born to HBsAg-positive mothers

Infants born to HBsAg-positive women were randomly assigned to receive either the plasma-derived hepatitis B vaccine or the yeast-derived recombinant hepatitis B vaccine within 12 h of birth, simultaneously with HBIg. The second and third doses of both vaccines were given at 1 and 6 months of age respectively. Two hundred and twenty-two infants received two doses, and 80 infants received three doses of either vaccine. Five infants were found to be HBsAg-positive at 6 months of age. Four of these infants had received the plasma vaccine and the remaining infant the recombinant vaccine. Anti-HBs was present in all the HBsAg-negative infants at 6 months of age. The titres of anti-HBs were similar in both groups of infants who had received either the plasma or the recombinant hepatitis B vaccine. No major adverse reactions were reported with either vaccine. The preliminary results from this study suggest that the yeast-derived recombinant hepatitis B vaccine is safe, immunogenic and at least as effective as the plasma-derived hepatitis B vaccine in preventing the HBsAg carrier state in infants born to HBsAg-positive women.

Skull fractures in children: their assessment in relation to developmental skull changes and acute intracranial hematomas

Retrospective analysis of 12,072 pediatric head injury cases revealed 1,297 skull fractures. Patients with skull fractures were divided into four age groups according to the fusion of skull sutures and other developmental radiological skull changes. Results revealed that the patients with open skull sutures (aged less than 2 years) and with linear skull fractures alone had a negligible chance of developing intracranial hematomas. With the fusion of metopic and mendosal sutures associated with other skull changes (greater than 2 years), the children became progressively more susceptible to developing intracranial hematomas if they had a skull fracture. The risk of developing intracranial hematomas was the highest among those patients (much greater than 11-15 years) whose paranasal sinuses had reached adult size and spheno-occipital synchondrosis had begun to fuse.

Serotype c Streptococcus mutans mutatable to lactate dehydrogenase deficiency

Three lactate-dehydrogenase-deficient mutants of serotype c S. mutans were made by using, as parents, two serotype c strains that produced unusually large amounts of ethanol, acetic acid, and acetoin, and very little lactic acid, when grown in broth containing a limiting amount of glucose. The mutants, obtained with N-methyl-N'-nitro-N-nitrosoguanidine, were stable during 12 weeks of daily subculture in broth. Crude cell-free extracts of the mutants had less than 1% of the LDH-specific activity of their parent strains. The serotype c mutants resembled serotype g mutants in having molar growth yields at least as high as those of their parents. However, in contrast to the g mutants, the c mutants produced cell crops (cell mass per ml medium) that were as high as those of their parent strains.

Lactate dehydrogenase-deficient mutants of serotype g Streptococcus mutans

Three LDH-deficient mutants of a serotype g strain of Streptococcus mutans were produced essentially as described by Hillman (1978): They were produced using ethylmethane sulfonate, and isolated using triphenyltetrazolium-glucose agar. Similar attempts to obtain mutants from a serotype c strain were unsuccessful. The g mutant did not revert during 12 weeks of daily transfer in broth, and, when grown in glucose-containing broth, they reached pH values of 4.9 to 5.0, compared with 4.4 for the parent strain. The efficiency of conversion of glucose to cell mass (Yg) was at least as great with the mutants as with the parent strain. The LDH activities of the mutants were less than 1% of that of the parent strain. Like Hillman's (1978) mutants, ethanol, acetic acid, and acetoin were the major products resulting from the metabolism of glucose. Although at pH 7.0 the mutants grew more slowly than did the parent, at pH 5 and pH 6 one of the mutants grew as rapidly as did the parent. The stability, serotype, and ability of these mutants to grow at low pH suggest their potential usefulness for replacement therapy.

A shared antigenic determinant between human B lymphocytes and carcinomas (BLCa)

We have raised a murine IgM monoclonal antibody (MA6) against immunoprecipitate obtained by reacting the serum of an NPC patient with extract of the Burkitt lymphoma cell line, Raji. It reacts against an antigen (BLCa) which is broadly represented on human B lymphoid tissues and cell lines but is different from the functional B-cell markers such as surface immunoglobulins, Ia products, Fc and complement receptors. BLCa was found to occur on lymphoid cell lines representing all stages of B-cell differentiation. These included the pre-B and null-cell lines, Nalm 6 and Reh, the EBV-transformed lymphoid cell lines and the myeloma cell line. MA6 was reactive against all the Burkitt lymphoma cell lines, whether or not these harbored the EBV genomes, with the exception of P3HR-I. The antibody was found to be selectively reactive against a proportion of peripheral blood B lymphocytes and to stain the B-cell-rich primary follicles and mantle zones of secondary follicles in the lymph node. However, MA6 was not reactive against cell lines of T-lymphocyte, myeloid, monocyte fibroblast or epithelial origin. It did, nevertheless selectively stain tumor cells from a variety of carcinoma tissues originating from different anatomical sites, including the nasopharynx.

Evidence that respiratory tract is major reservoir for Epstein-Barr virus

Exfoliated cells harvested from bronchial washings of 53 patients with suspected bronchogenic carcinoma were tested by means of DNA dot hybridisation using the cloned large internal repeat (IR) sequence of Epstein-Barr virus (EBV) genome as a probe. 25 of these patients gave positive results. Since the patients had diseases that were not related to the virus, this finding suggests that the lower respiratory tract is a major reservoir for EBV. Attempts at cellular localisation of the virus revealed only an occasional cell which harboured the viral genome or expressed viral capsid antigens. These cells could not account for the quantity of the viral DNA detected in bronchial washings. Moreover, patients had similar profiles of serum EBV antibodies whether they were positive or negative for EBV DNA by dot hybridisation. These findings are compatible with a state of viral latency in which cells harbour a low copy number of the viral genome. Viral expression rarely occurs in these cells, which seem to elicit a minimum host immune response. If it is assumed that each latently infected cell harbours a maximum of approximately 30 EBV genomes (which is the lower limit of detection by the in-situ hybridisation method used in this study), the findings suggest that a considerable proportion of the exfoliative cells from the lower respiratory tract, of the order of 0.1-16%, harbour latent EBV.

Centrode patterns and segmental instability in degenerative disc disease

Moiré fringes were used to determine centrode patterns in cadaveric spines with degenerative disc disease. The normal centrodes were compared with those with minor, mild, moderate, and severe degenerative disc disease. The most complex loci noted were those discs that showed minimal radiographic evidence of degeneration, that is, the minor and mild groups. The loci lengthened significantly (P less than 0.001) when compared with normal controls. The position of the centrode shifted downward into the body of L5 in the moderate group.

Moiré patterns: an accurate technique for determination of the locus of the centres of rotation

This study describes an accurate technique for the determination of the centre of rotation of small angles. The moiré fringe method localizes the centre of rotation by defining two primary fringes, each of which is found by the intersection of three lines. The primary fringes intersect at the centre of rotation at 90 degrees to each other, the angle least likely to produce an error in measurement. By utilizing joints with known centres of rotation, we have found that the method is extremely accurate and reproducible to within 2 mm of the real centre for angular changes as small as 3 degrees. This technique is useful in evaluating whether a joint is a simple hinge, i.e. rotating about a single axis of rotation or whether the joint moves about a changing axis of rotation referred to as a locus or centrode.

Pontine ataxic hemiparesis, a lateral penetrator syndrome?

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Acute haemodynamic and myocardial metabolic effects of intravenous urapidil in severe heart failure

The acute haemodynamic and myocardial metabolic effects of intravenous urapidil were evaluated in 12 patients with severe congestive heart failure due to coronary heart disease. Urapidil was given intravenously (0.5 mg kg-1 min-1 as a bolus) followed by infusion at a rate of 4 micrograms kg-1 min-1 for 120 min. Following urapidil administration, cardiac index increased by 29%, mean pulmonary artery wedge pressure fell by 35% and systemic vascular resistance by 33%. The fall in mean arterial pressure was moderate. No significant alterations in coronary sinus blood flow, myocardial oxygen consumption and myocardial lactate extraction occurred. No untoward effect was observed. This study shows that intravenous urapidil produces beneficial haemodynamic effects without a deleterious effect on myocardial metabolism in patients with heart failure due to coronary heart disease.