Ultrasound detection of colonic polyps: perspective

Colorectal cancer is often preventable if the precursor adenoma is detected and removed. Although ultrasound is clearly not one of the widely accepted screening techniques, this non-invasive and radiation-free modality is also capable of detecting colonic polyps, both benign and malignant. Such colon lesions may be encountered when not expected, usually during general abdominal sonography. The discovery of large colonic polyps is important and can potentially help reduce the incidence of a common cancer, whereas detection of a malignant polyp at an early stage may result in a curative intervention. This pictorial review highlights our experience of sonographic detection of colonic polyps in 43 adult patients encountered at our institutions over a 2-year period. 4 out of 50 discovered polyps were found to be malignant lesions, 3 polyps were hyperplastic, 1 polyp was a hamartomatous polyp and the rest were benign adenomas. The smallest of the detected polyps was 1.3 cm in diameter, the largest one was 4.0 cm (mean 1.7 cm; median 1.6 cm). In each case, polyps were discovered during a routine abdominal or pelvic examination, particularly when scanning was supplemented by a brief focused sonographic inspection of the colon with a 6-10 MHz linear transducer. In this paper, we illustrate the key sonographic features of different types of commonly encountered colonic polyps in the hope of encouraging more observers to detect these lesions, which may be subtle.

An immunohistochemical method for the diagnosis of melioidosis

In order to assess the usefulness of immunohistochemistry in the diagnosis of melioidosis, an infection by Burkholderia pseudomallei, polyclonal antibodies were applied to tissues from known cases of melioidosis and to other infected tissues. Formalin-fixed, paraffin-embedded tissues were stained by a modified immunoperoxidase technique. In autopsy tissues with inflammatory lesions of melioidosis, the cytoplasm of phagocytes and intact bacilli, both intra- and extracellular, were stained very strongly positive. Relatively more focal positive staining was observed in some but not all surgical biopsies from proven cases of melioidosis. In granulomas staining was mainly found in the central necrotic areas, with little staining of peripheral phagocytes. All control materials stained negative. Immunohistochemistry appears to be a useful diagnostic tool in melioidosis.

Dynamic holography for optical interconnections. II. Routing holograms with predictable location and intensity of each diffraction order

An analysis of dynamic phase-only holograms, described by fractional notation and recorded onto a pixelated spatial light modulator (SLM) in a reconfigurable optical beam-steering switch, is presented. The phase quantization and arrangement of the phase states and the SLM pixelation and dead-space effects are decoupled, expressed analytically, and simulated numerically. The phase analysis with a skip-rotate rule reveals the location and intensity of each diffraction order at the digital replay stage. The optical reconstruction of the holograms recorded onto SLM's with rectangular pixel apertures entails sinc-squared scaling, which further reduces the intensity of each diffraction order. With these two factors taken into account, the highest values of the nonuniform first-order diffraction efficiencies are expected to be 33%, 66%, and 77% for two-, four-, and and eight-level one-dimensional holograms with a 90% linear pixel fill factor. The variation of the first-order diffraction efficiency and the relative replay intensities were verified to within 1 dB by performing the optical reconstruction of binary phase-only holograms recorded onto a ferroelectric liquid crystal on a silicon SLM.

Phototherapy for neonatal jaundice

Exchange transfusion for severe neonatal jaundice is a tedious and expensive procedure with high morbidity and mortality rates, and is followed by a prompt and marked bilirubin rebound. It has largely been replaced by phototherapy, which though more gradual in its effect results in a prolonged reduction of the bilirubin concentration. Its efficacy is influenced by the gestational age, birthweight and postnatal age of the infant, the aetiology of the jaundice, and the spectral emission and intensity (dose) of the light; its dose-response relationship enables it, at the optimal dose, to control very severe jaundice or a rapidly rising bilirubin concentration, including severe haemolysis. Its relative freedom from complications together with its non-invasive nature, ease of usage and convenience has resulted in widespread acceptance in virtually all neonatal units.

Evaluation of a low dose of hepatitis B vaccine given within a childhood immunisation programme in Singapore

The feasibility of introducing low dose (5 micrograms) hepatitis B (HB) virus vaccination at birth and again 1 and 2 months later as part of an existing primary immunisation programme of childhood, was assessed in 662 healthy newborn Singapore children. The vaccine (B-Hepavac, Menck, Sharp and Dohme) was given to three neonatal groups: those born to HB surface antigen (sAg)-negative mothers, HBsAg-positive/HBeAg-positive mothers and HBsAg-positive/HBeAg-negative mothers. A dose of 5 micrograms was compared in a randomised study with the more usual 10 micrograms dose given at the same intervals. Neonates born to HBsAg-positive/HBeAg-positive mothers were also given hepatitis B immunoglobulin (HBIg) at birth. The 5 microgram dose of vaccine was as immunogenic as the 10 microgram dose in all three groups of children studied. At 1 year, anti-HBsAg seroconversion among infants of antigen-negative mothers was 95.8% for the 5 microgram dose and 91.9% for the 10 microgram dose. Suppression of anti-HBsAg formation was not seen even when maternal anti-HBsAg was present or HBIg given. Among infants born to HBsAg-positive/HBeAg-positive mothers, passive plus active immunisation was 100% protective at doses of 5 micrograms and 10 micrograms vaccine in the newborns who were HBsAg-negative at 24 h. Seroconversion after both the 5 and 10 microgram doses of vaccine was reduced, however, to 88% in each group of infants who were already HBsAg-positive at 24 h of age. Overall, passive plus active immunisation as well as HB vaccine alone (5 micrograms dose), given within the existing but expanded primary immunisation programme of childhood, was effective in preventing infection and the chronic carrier state in newborns exposed to risk of HB virus infection during infancy.

A comparative study on schizophrenia diagnosed by ICD-9 and DSM-III: course, family history and stability of diagnosis

Data from the Taipei Center of the International Pilot Study of Schizophrenia were reanalyzed using the ICD-9 and DSM-III diagnoses at 7-year follow-up. Patients diagnosed as schizophrenic according to DSM-III were shown to be a more homogeneous group in terms of their clinical manifestations, social functions and family psychiatric history than those defined as schizophrenic by ICD-9. The discordant cases of ICD-9 schizophrenia and DSM-III affective disorders were found to be different from the concordant schizophrenic group, but similar to the concordant group of affective disorders diagnosed by ICD-9 and DSM-III. Thirty-five per cent of mood-incongruent psychotic major depressive disorders defined by DSM-III at initial evaluation were diagnosed as schizophrenia at 7-year follow-up.

Trends in the practice of arterial surgery in Western Australia

An overview of arterial surgery in Western Australia and the Department of Vascular Surgery at Royal Perth Hospital was undertaken for the ten year period from 1983 to 1992. The annual number of arterial procedures increased 116% from 937 to 2027 and lower limb amputations increased 44% from 335 to 483. Five arterial procedures were examined in detail. There was a marked increase in carotid endarterectomy and angioplasty, a moderate increase in aortic aneurysm repair and a small increase in aortofemoral and femoropopliteal bypass surgery. The major amputation rate was not influenced by bypass surgery. It rose from 113 per million population in 1983 to a peak of 148 in 1986, and then fell to 113 per million population in 1992. From June 1982 to June 1992 the population of Western Australia rose 24%, from 1.34 to 1.66 million (and for persons 60 years and over, rose 38% from 0.16 to 0.23 million). At Royal Perth Hospital similar trends were observed. Mean duration of operation for all vascular procedures and for the individual procedures of carotid endarterectomy, angioplasty, aortic aneurysm repair and aortofemoral and femoropopliteal bypass remained unchanged. Average length of stay decreased for carotid endarterectomy (29%) and angioplasty (74%), but remained unchanged for aortic aneurysm repair and aortofemoral and femoropopliteal bypass.

Alpha-thalassaemia in association with beta-thalassaemia patients in Malaysia: a study on the co-inheritance of both disorders

BACKGROUND/AIMS

Individuals with double heterozygosity for alpha- and beta-thalassaemia and heterozygous beta-thalassaemia show a similar haematological picture. Co-inheritance of alpha- and beta-thalassaemia in both partners may result in pregnancies with either Hb Bart's hydrops foetalis or beta-thalassaemia major, or pregnancies with both disorders.

METHODS

The co-inheritance of alpha-thalassaemia in 322 beta-thalassaemia carriers in Malaysia was studied.

RESULTS

The frequency of alpha-thalassaemia in the beta-thalassaemia carriers was 12.7% (41/322), with a carrier frequency of 7.8% for the SEA deletion, 3.7% for the -alpha(3.7) deletion, 0.9% for Hb Constant Spring and 0.3% for the -alpha(4.2) deletion.

CONCLUSION

Double heterozygosity for alpha- and beta-thalassaemia was confirmed in 5 out of the 41 couples and the risk of the fatal condition Hb Bart's hydrops foetalis was confirmed in two of these couples. Detection of the Southeast Asian (SEA) deletion in the Malaysian Malays in this study confirms that Hb Bart's hydrops foetalis can occur in this ethnic group. Results of this study have provided new information on the frequency and different types of alpha-thalassaemia (--(SEA), -alpha(3.7) and -alpha(4.2) deletions, Hb Constant Spring) in Malaysian beta-thalassaemia carriers.