Hypodontia: genotype or environment? A case report of monozygotic twins.

A case report is presented of monozygotic twins with variable expression of hypodontia. DNA fingerprinting was used to confirm monozygosity, and this evidence supports the theory that genetic coding is not the sole controlling factor in tooth agenesis. It is suggested that DNA fingerprinting should be considered the gold standard for determination of monozygosity.

The value of routine computed tomography scanning of the chest in patients presenting with supradiaphragmatic Hodgkin's disease.

Six patients presenting with supradiaphragmatic Hodgkin's disease are presented to demonstrate the potential benefits of chest computed tomography (CT) scanning as a routine staging procedure. These cases show that CT scanning can detect mediastinal and lung involvement not readily detected by other investigations, and that such findings can influence the radiotherapy plan, the need for extended radiotherapy fields or the use of chemotherapy. Following treatment, CT scanning can be useful to assess treatment response and may permit earlier detection of relapse. The use of chest CT scanning as a routine staging procedure in all patients with supradiaphragmatic Hodgkin's disease is advocated.

Primary malignant mediastinal germ cell tumours: improved prognosis with platinum-based chemotherapy and surgery.

A retrospective analysis was performed of 18 patients with primary malignant germ cell tumours of the mediastinum treated with platinum-based chemotherapy between 1977 and 1990. All seven patients with pure seminoma were treated initially with chemotherapy and four of these patients received additional mediastinal radiotherapy. Only one patient relapsed; his initial therapy had included radiotherapy and single-agent carboplatin and he was successfully salvaged with combination chemotherapy. With a follow-up of 11 to 117 months (median 41 months) all seven patients with seminoma remain alive and disease free giving an overall survival of 100%. Eleven patients had malignant non seminoma; following chemotherapy eight of these had elective surgical resection of residual mediastinal masses. Complete remission was achieved in nine (82%) patients, however, one of these patients died from bleomycin pneumonitis. With a follow-up of 12 to 113 months (median 55 months) eight of 11 (73%) patients with malignant mediastinal teratoma remain alive and disease free.

The optimisation of carboplatin dose in carboplatin, etoposide and bleomycin combination chemotherapy for good prognosis metastatic nonseminomatous germ cell tumours of the testis.

An analysis of carboplatin dose response was performed in 121 patients with good prognosis metastatic nonseminomatous germ cell tumours (NSGCT) of the testis, referred to the Royal Marsden Hospital since 1984, who had been given combination carboplatin, etoposide and bleomycin (CEB) chemotherapy. With a median follow-up of 40 months (range: 7 to 85 months) nine patients (7%) have failed CEB. Carboplatin dose was analysed in all patients using body surface area (BSA) to derive a carboplatin dose per metre squared (mg/m2) and by calculation of a predicted serum concentration chi time (AUC: area under the curve) derived from the glomerular filtration rate (GFR), using the formula; Dose = AUC(GFR + 25). At a carboplatin dose of 400 mg/m2 or greater 2 out of 58 patients (3.4%) failed treatment while 7 out of 63 patients (11%) who received a dose less than this failed (p greater than 0.1). At an AUC of 5.0 mg.min/ml or greater, 2 out of 74 patients (2.7%) failed while 7 out of 47 patients (14.9%) who had an AUC less than this failed (p less than 0.05). There was evidence for a dose/response relationship at relatively low doses and the failure rate rose to 26% for doses less than 4.5 mg.min/ml (p less than 0.001) or 15.6% for doses less than 350 mg/m2 (p greater than 0.1). In view of the more precise determination of toxicity and efficacy it is recommended that carboplatin dose be based on the GFR.

The management of metastases to eye and orbit from carcinoma of the breast.

This report describes 11 patients who developed visual symptoms due to choroidal or orbital metastases from carcinoma of the breast. All patients were treated using palliative radiotherapy with regression of metastases in five of six patients (83%) having choroidal involvement and three of five patients (60%) having orbital metastases. There were no complications due to radiotherapy. All these patients had advanced metastatic breast cancer with poor survival following development of orbital or choroidal metastases.

Selective modulation of bacterial attachment to oral epithelial cells by enzyme activities associated with poor oral hygiene.

The present investigation explored the hypothesis that elevated levels of certain enzymes in the gingival crevicular environment of individuals with poor oral hygiene and/or gingival inflammation may modify the surfaces of epithelial cells and thereby modulate the types of bacteria which attach and colonize. Buccal epithelial cells treated with neuraminidase and certain proteases were used as a model for study. Bacteria studied included Streptococcus sanguis and Streptococcus mitis which have been associated with gingival health, Actinomyces species which are increased in plaque associated with developing gingivitis, and Bacteroides gingivalis, Bacteroides intermedius, and Actinobacillus actinomycetemcomitans which are associated with destructive periodontal diseases. Treatment of epithelial cells with the enzymes studied produced selective effects on their receptivity for bacteria. Neuraminidase treatment of epithelial cells greatly reduced the attachment of all strains of S. sanguis and S. mitis studied. In contrast, the number of Actinomyces viscosus, A. naeslundii and A. israelii cells which attached was significantly increased. Neuraminidase treatment also appeared to enhance attachment of B. intermedius and B. gingivalis. Treatment of buccal cells with trypsin, chymotrypsin or papain also selectively affected bacterial attachment. Such protease treatment greatly reduced the numbers of streptococci and A. viscosus cells which attached, while the numbers of B. gingivalis and B. intermedius were significantly increased. Treatment of epithelial cells with preparations of lysosomal enzymes derived from human PMNs produced similar selective effects. The changes in bacterial adhesion observed by the enzyme treatments studied are consistent with the shifts in the composition of the gingival crevice flora which occur when oral hygiene is terminated and gingivitis develops.

Role of cryptic receptors (cryptitopes) in bacterial adhesion to oral surfaces.

Progress in characterizing the receptors that promote bacterial attachment to teeth and oral epithelial cells has suggested that hidden molecular segments may frequently be involved. Such cryptic receptors, referred to as 'cryptitopes', may become exposed by several mechanisms. Hidden segments of salivary acidic proline-rich proteins evidently become exposed when the molecules undergo a conformational change as they adsorb to apatitic mineral. Adhesins of Actinomyces viscosus and certain other prominent dental plaque bacteria are able to bind to these cryptitopes, and this enables these organisms to bind to proline-rich proteins on apatitic surfaces while avoiding interactions with these proteins in solution. Cryptitopes may also become exposed as a result of enzymatic action. Thus, several bacteria, including Fusobacterium nucleatum, Eikenella corrodens, A. viscosus, A. naeslundii and Bacteroides intermedius, have adhesins that bind to galactosyl receptors which become exposed after treatment with neuraminidase. Similarly, the adhesion of some Gram-negative bacteria, such as Bact. gingivalis, is enhanced when tissue surfaces are treated with certain proteases, or lysosomal enzymes derived from human polymorphonuclear leucocytes. It seems likely that elevated levels of enzymes present in gingival fluid as sequelae of poor oral hygiene and gingivitis may generate cryptitopes for potentially periodontopathic bacteria, and thereby contribute to modulation of the gingival flora.

Kaposi's sarcoma in AIDS: the role of radiation therapy.

Radiotherapy can provide good palliation for AIDS patients with symptomatic Kaposi's sarcoma. We have retrospectively reviewed the treatment of 13 lesions in 5 patients. All treated tumours demonstrated significant regression with moderate doses of radiation. Side effects were acceptable and treatment provided good pain relief, functional improvement, and restoration of cosmesis. Our experience confirms that radiotherapy has a meaningful role in the management of AIDS-related Kaposi's sarcoma.

The predominant cultivable microbiota of crevicular epithelial cells.

The purpose of the present investigation was to compare the composition of the predominant cultivable microbiota associated with gingival crevicular epithelial cells with that of the unattached microbiota recovered from the same site. Samples were taken from 2 diseased sites from 8 periodontal patients, by scraping the epithelial lining of the pocket with a curette. The epithelial cells were separated from the unattached subgingival bacteria by centrifugation in a reduced 50% Percoll density gradient. Epithelial cells formed a band at the top of the gradient and were removed separately from the unattached bacteria located at the base. Each layer was dispersed, diluted and plated on Trypticase soy agar with 5% sheep blood and 50 isolates were characterized from each sample. The microorganisms associated with the epithelial layer harbored 5- to 20-fold higher mean percentages of Bacteroides gingivalis, Bacteroides intermedius and Peptostreptococcus micros. The layer of unattached organisms exhibited 4- to 10-fold higher mean percentages of Streptococcus uberis, Capnocytophaga ochracea, Eikenella corrodens and Veillonella parvula.

Use of Percoll density gradients for studying the attachment of bacteria to oral epithelial cells.

An assay for studying the attachment of bacteria to oral epithelial cells has been developed which utilizes Percoll density gradient centrifugation to separate bacteria and epithelial cells. 3H-thymidine-labeled bacteria were incubated with suspensions of buccal epithelial cells in microtitration plates for 2.5 hr at 35 degrees C. The mixtures were then subjected to density gradient centrifugation in 50% Percoll. Epithelial cells with attached bacteria formed a band near the top of the tube, while unattached bacteria formed a band near the bottom. The epithelial cells were collected on membrane filters, and the number of attached bacteria was determined by scintillation counting. Binding of S. mitis C5 was found to increase with time, and equilibrium was attained within two hr. Saturation of available binding sites occurred when 10(7) S. mitis cells were incubated with 1.5 x 10(4) buccal epithelial cells. The numbers of streptococci which attached as determined with this assay were in good agreement with values obtained by direct microscopic counts. Adsorption of S. mitis C5 cells was adequately described by a Langmuir isotherm (correlation coefficient 0.998). This permitted calculation of estimates of the number of binding sites and the affinity of the organism. The assay proved reliable even when as few as 1000 epithelial cells were used. Treating the epithelial cells with neuraminidase or trypsin significantly decreased the number of S. mitis C5 cells which attached. In contrast, binding of A. naeslundii 12104 to neuraminidase-treated cells was increased, and attachment of B. gingivalis 381 was also enhanced, especially to epithelial cells which had been treated with trypsin.

The acquired immunodeficiency syndrome in Auckland in 1985.

We reviewed the notes of the first 11 patients with AIDS managed by the infectious disease unit, Auckland Hospital, who all presented during 1985. All were homosexual males: none had other recognised risk factors: ten had travelled beyond New Zealand. Five were diagnosed at Auckland Hospital, six overseas. Median age was 31 (range 28-43) years. Five had Kaposi's sarcoma and three Pneumocystis carinii pneumonia. Five are alive. They have spent a median 13 (range 0-41) days in Auckland Hospital. Treatment options for the more common problems are discussed. We have tended towards conservative treatment of tumour but more aggressive treatment of opportunistic infection. Medical, nursing and ancillary hospital staff and lay people involved have rapidly adapted to caring for these patients without excessive anxiety.

Biosynthesis of D-alanyl-lipoteichoic acid by Lactobacillus casei: interchain transacylation of D-alanyl ester residues.

Lipoteichoic acid (LTA) from Lactobacillus casei contains poly(glycerophosphate) substituted with D-alanyl ester residues. The distribution of these residues in the in vitro-synthesized polymer is uniform. Esterification of LTA with D-alanine may occur in one of two modes: (i) addition at random or (ii) addition at a defined locus in the poly(glycerophosphate) chain followed by redistribution of the ester residues. A time-dependent transacylation of these residues from D-[14C]alanyl-lipophilic LTA to hydrophilic acceptor was observed. The hydrophilic acceptor was characterized as D-alanyl-hydrophilic LTA. This transacylation requires neither ATP nor the D-alanine incorporation system, i.e., the D-alanine activating enzyme and D-alanine:membrane acceptor ligase. No evidence for an enzyme-catalyzed transacylation reaction was observed. We propose that this process of transacylation may be responsible for the redistribution of D-alanyl residues after esterification to the poly(glycerophosphate). As a result, it is difficult to distinguish between these proposed modes of addition.

Evaluation of blood flow velocity in the ascending aorta and main pulmonary artery of normal subjects by Doppler echocardiography.

Blood flow velocity measurements were made in the ascending aorta and proximal main pulmonary artery of 20 adult normal subjects (12 men and eight women, age range 21 to 46 years) with the use of a commercial prototype ultrasound instrument combining a spectrum analyzer-based, pulsed Doppler velocimeter with a two-dimensional sector scanner. The sector scanner was used to produce two-dimensional images of the main pulmonary artery so that the Doppler sample volume could be placed parallel to the flow stream. A 2.25 MHz right-angle M-mode ultrasound transducer was positioned in the suprasternal notch and was used to measure blood flow velocity in the ascending aorta. There were significant differences (p less than 0.001) between the ascending aorta and main pulmonary artery (PA) in the following blood flow parameters: peak flow velocity (aorta = 92 cm/sec, PA = 63 cm/sec), average acceleration (aorta = 940 cm/sec2, PA = 396 cm/sec2), acceleration time (aorta = 98 msec, PA = 159 msec), deceleration time (aorta = 197 msec, PA = 172 msec), average deceleration (aorta = 473 cm/sec2, PA = 356 cm/sec2), and ejection time (aorta = 294 msec, PA = 331 msec). These data indicate that despite a four to five times higher arterial resistance in the systemic circuit compared to the pulmonary circuit, blood is accelerated two to three times more rapidly in the ascending aorta than in the main pulmonary artery. Also, the peak flow velocity is higher in the aorta and is achieved earlier in systole than in the pulmonary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Validation of a computerized edge detection algorithm for quantitative two-dimensional echocardiography.

An edge detection algorithm used in conjunction with digitized two-dimensional echocardiograms was applied to validate computerized two-dimensional echocardiographic (2DE) quantitation of cross-sectional areas of canine left ventricular chambers. Images were enhanced by space-time smoothing and dynamic range expansion, after which automatic edge detection was performed by convolving a Laplacian operator with the enhanced image. In an in vitro study of 29 myocardial slabs, computer-derived 2DE measurements of short-axis sections of the left ventricle were compared with manually derived 2DE data and validated against direct measurements of intraluminal areas of myocardial slabs. Correlations of both manually and computer-derived 2D echocardiograms vs direct measurements were equally satisfactory (r = .95 for both). Computer-derived measurements of perimeters tended to underestimate actual perimeters of the endocardial outlines of left ventricular sections. In 13 closed-chest anesthetized dogs, manually and computer-derived left ventricular short-axis areas measured by 2DE techniques showed a good correlation at both end-diastole (r = .91) and end-systole (r = .92). Left ventricular volumes reconstructed from 2DE images were compared with angiographically determined volumes. The computer-enhanced 2DE method correlated against angiography, with r = .93 for end-diastolic and r = .93 for end-systolic volumes. Left ventricular volume correlations between manually and computer-derived 2D echocardiograms were satisfactory, with r = .87 for end-diastole and r = .87 for end systole. We conclude that computerized enhancement and edge detection of 2D echocardiograms obtained in dogs provided accurate analysis of actual left ventricular cross-sectional areas and left ventricular volumes.

Evaluation of dilated cardiomyopathy by pulsed Doppler echocardiography.

The ability of pulsed Doppler echocardiography to identify patients with left ventricular systolic dysfunction was evaluated in 12 patients with dilated (congestive) cardiomyopathy. A range-gated, spectrum analyzer-based Doppler velocimeter was used to record blood flow velocity in the ascending aorta and main pulmonary artery. The following blood flow velocity parameters were measured or derived: peak flow velocity, acceleration time, average acceleration, deceleration time, average deceleration, ejection time, and aortic flow velocity integral. Doppler blood flow velocity data in the cardiomyopathy patients were compared to data from 20 normal subjects. Measurements from the ascending aorta revealed that peak aortic flow velocity discriminated between cardiomyopathy patients (mean 47 cm/sec, range 35 to 62) and normal subjects (mean 92 cm/sec, range 72 to 120) with no overlap in data (p less than 0.001). Aortic flow velocity integral was also able to separate the patients with dilated cardiomyopathy (mean 6.7 cm, range 3.5 to 9.1) from normal subjects (mean 15.7 cm, range 12.6 to 22.5) with no overlap in data (p less than 0.001). Although mean values for average aortic acceleration and aortic ejection time were also significantly different (both p less than 0.005), there was some overlap between the two groups. Pulmonary artery blood flow studies demonstrated significantly increased average acceleration, as well as decreased ejection time (both p less than 0.05), but no difference in average deceleration or peak flow velocity in cardiomyopathy patients compared to normals. Compared to pulmonary flow measurements, aortic Doppler flow velocity measurements allowed better separation of cardiomyopathy and normal groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Biosynthesis of D-alanyl-lipoteichoic acid: role of diglyceride kinase in the synthesis of phosphatidylglycerol for chain elongation.

Lipophilic and hydrophilic D-alanyl-lipoteichoic acids are elongated in Lactobacillus casei by the transfer of sn-glycerol 1-phosphate units from phosphatidylglycerol to the poly(glycerophosphate) moiety of the polymer. These sn-glycerol 1-phosphate units are added to the end of the poly(glycerophosphate) which is distal to the glycolipid anchor; 1,2-diglyceride results from this addition. The presence of a diglyceride kinase was suggested by the ATP-dependent phosphorylation of 1,2-diglyceride to phosphatidic acid. Inorganic phosphate was used to initiate the synthesis of lipophilic lipoteichoic acid (LTA) and the elongation of both lipophilic and hydrophilic LTA. Three observations suggest that phosphate and other anions play a role in the in vitro synthesis of LTA and its precursors. First, the conversion of 1,2-diglyceride to phosphatidic acid by diglyceride kinase was stimulated. Second, the synthesis of phosphatidylglycerol was increased. Third, the elongation of lipophilic and hydrophilic LTA was enhanced. These observations indicated that one effect of phosphate might be to enhance the utilization of 1,2-diglyceride for the synthesis of phosphatidic acid. This phospholipid is a precursor of phosphatidylglycerol, the donor of sn-glycerol 1-phosphate for elongation of LTA.