Twin pregnancy chorionicity determination in a tertiary care setting.

Ultrasound determination of chorionicity is most reliable before 14 weeks and subsequently reduces in accuracy with advancing gestation. The aim of this study was to evaluate the accuracy of chorionicity determination in a birth cohort of twin pregnancies. Antenatal ultrasound determination of chorionicity in twin pregnancy was undertaken at suboptimal period of gestation in over twothirds of twin pregnancies. Even in the first trimester of pregnancy, the accuracy of chorionicity determination was lower than previously reported.

Evaluation of disinfection of flexible nasendoscopes using Tristel wipes: a prospective single blind study.

INTRODUCTION: The otorhinolaryngology department at Northwick Park Hospital uses the Tristel wipes system for cleaning nasendoscopes in the outpatient clinics. This system uses chlorine dioxide as its only disinfectant. The manufacturer claims the system provides safe sterilisation of nasendoscopes. However, there appear to be no reports in the literature to date that evaluate the efficacy of this system in a clinical setting. The aim of this study was to evaluate the 'in use' efficacy of Tristel wipes in decontaminating nasendoscopes and to identify any significant contamination between cleaning and usage. METHODS: A total of 31 cleaning episodes were performed. Each cleaning episode included two swabs after cleaning the scopes, one from the tip and the other from the handle. Another two swabs from the same areas were also taken before application to the patient. The microbiology unit evaluated all swabs for bacterial, fungal and mycobacterial growth. RESULTS: Overall, 123 swabs from 31 cleaning episodes were tested. None of the swabs taken from the tips (n=31) or handles (n=31) after cleaning with Tristel wipes developed any organism growth. Furthermore, none of the swabs taken from the tip of the scopes before using on patients (n=31) developed any growth. Of the 31 swabs taken from the handle before use, 3 developed significant staphylococcal growth. CONCLUSIONS: In our study, the 'in use' efficacy of Tristel wipes in cleaning the scopes of bacteria, fungi and mycobacteria was 100%. Attention to hand hygiene and the use of gloves should be considered when handling the cleaned scopes to minimise the risk of contamination between cleaning and application to patients.

Detection of micrometastases in lymph nodes using reverse transcription polymerase chain reaction (RT-PCR) for cytokeratin 20 (CK-20)--a pilot study.

OBJECTIVES: The aim of the study was to detect micrometastases in lymph nodes in patients with rectal cancer following neoadjuvant therapy, staged node negative by routine histology. PATIENTS AND SETTING: Mesenteric lymph nodes from patients who have undergone neoadjuvant therapy for rectal cancer were harvested during surgery. Nodes were bisected and one half was sent for haematoxylin and eosin (H&E) staining and evaluated by a single pathologist. The other half was examined for CK20 by RT-PCR. The technique was validated by testing mesenteric lymph nodes with known metastases and nodes from patients without cancer. Twenty one lymph nodes from 6 patients (median age 46 years, range 25-55) which were negative for tumour deposits by H & E stain were assessed for micro-metastases. RESULTS: All 21 nodes which were histologically negative for metastases were positive for micrometastases. Two nodes with known metastases were positive for CK20 and 3 nodes from non cancer patients were negative for CK20. CONCLUSIONS: Detection of CK20 is accurate in identification of rectal cancer micro-metastasing to lymph nodes. Assessment of nodes by H & E histology risks under staging.

Prevalence of childhood atopic diseases in the Western Province of Sri Lanka.

BACKGROUND: Atopic diseases in children are major public health problems around the world and the prevalence is increasing. Our objective was to assess the prevalence of atopic diseases in schoolchildren in the Western Province of Sri Lanka. METHODS: Children attending grade 5 in 17 schools in the Western Province of Sri Lanka were recruited to the study. Data were collected using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, which was filled by the parent/guardian of the selected children. RESULTS: A total of 640 schoolchildren were recruited. Their mean age was 10 years (SD +/- 0.5) and 55.9% of the study population was boys. Prevalence (95% CI) of asthma, rhinitis and eczema was 17% (13.7-20.3), 21.4% (17.8-25.1) and 5% (3.1-7.0) respectively, while 33.7% (29.6-37.9) had one or more diseases. Only the prevalence of allergic rhinitis showed a statistically significant difference between the two sexes, being more common in boys. Less than 30% of affected children's parents recognised that their child had either asthma or rhinitis, whereas a higher number of parents (54.2%) recognised that their child had eczema. Among children with asthma, 44.4% had rhinitis. CONCLUSIONS: The prevalence of atopic diseases in schoolchildren in grade 5 in the Western Province of Sri Lanka is as common as in other countries in the south Asian region. Parental recognition of these conditions was not satisfactory.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL): a patient from Sri Lanka.

We report the first patient from Sri Lanka (the third patient from the Indian subcontinent) with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). The patient experienced a young onset familial stroke with an 856T>G missense mutation in exon 5 of the NOTCH3 gene resulting in a C260G mutation in the sixth epidermal growth factor-like repeat. We believe this is the first reported Sri Lankan patient. CADASIL is probably underdiagnosed in the region.

Distinct yet complementary mechanisms of heparin and glycoprotein IIb/IIIa inhibitors on platelet activation and aggregation: implications for restenosis during percutaneous coronary intervention.

OBJECTIVE: To study the effect of unfractionated heparin (UFH) versus low molecular weight heparin (LMWH) in combination with glycoprotein (Gp) IIb/IIIa blockers on platelet activation and aggregation. METHODS: Washed platelets were stimulated with thrombin in the presence or absence of UFH (monoparin), LMWH (enoxaparin), and a Gp IIb/IIIa blocker (abciximab, eptifibatide, or tirofiban). RESULTS: Although Gp IIb/IIIa antagonists blocked the final common pathway of thrombin induced platelet aggregation, UFH and LMWH were better at blocking upstream platelet activation. UFH was significantly more effective than LMWH at inhibiting P selectin expression (p = 0.001) and platelet derived growth factor release from thrombin activated platelets (p = 0.012). CONCLUSIONS: UFH and LMWH exert complementary effects to Gp IIb/IIIa blockers by inhibiting afferent pathways of platelet activation. Coadministration of heparin with Gp IIb/IIIa blockers provides improved protection against persistent platelet activation, thereby improving outcome after percutaneous coronary intervention. Judging from these data, UFH may be more effective in this regard than LMWH, at least in vitro. The use of LMWH in preference to UFH during percutaneous coronary intervention, although initially attractive, may inadequately protect against platelet activation despite the presence of Gp IIb/IIIa blockers.

Resistance to malarial infection is achieved by the cooperation of NK1.1(+) and NK1.1(-) subsets of intermediate TCR cells which are constituents of innate immunity.

We previously reported that the major expanding lymphocytes were intermediate TCR (TCR(int)) cells (mainly NK1.1(-)) during malarial infection in mice. Cell transfer experiments of TCR(int) cells indicated that these T cells mediated resistance to malaria. However, TCR(int) cells always contain NK1.1(+)TCR(int) cells (i.e., NKT cells) and controversial results (NKT cells were effective or not for resistance to malaria) have been reported by different investigators. In this study, we used CD1d((-/-)) mice, which almost completely lack NKT cells in the liver and other immune organs. Parasitemia was prolonged in the blood of CD1d((-/-)) mice and the expansion of lymphocytes in the liver of these mice was more prominent after an injection of Plasmodium yoelii-infected erythrocytes. However, these mice finally recovered from malaria. In contrast to B6 mice, CD4(-)8(-) NKT cells as well as NK1.1(-)CD3(int) cells expanded in CD1d((-/-)) mice after malarial infection, instead of CD4(+) (and CD8(+)) NKT cells. These newly generated CD4(-)8(-)NKT cells in CD1d((-/-)) mice did not use an invariant chain of Valpha14Jalpha281 for TCRalpha. Other evidence was that severe thymic atrophy and autoantibody production were accompanied by malarial infection, irrespective of the mice used. These results suggest that both NK1.1(-) and NK1.1(+) subsets of TCR(int) cells (i.e., constituents of innate immunity) are associated with resistance to malaria and that an autoimmune-like state is induced during malarial infection.

A comparative study of induction and recovery characteristics of propofol and midazolam.

Propofol and midazolam were compared in 40 adult patients in A.S.A. 1 or 2 presenting for short surgical procedures (< 70 minutes) with respect to induction time, pain on injection, apnoea, heart rates, blood pressure, oxygen saturation, time to eye opening on command. The first group was induced with midazolam (0.15-0.20 mg/kg) while the second was induced with propofol (2-2.5 mg/kg) intravenously. In all other respects except for the surgery that patients had the same treatment. The mean induction time was 55.25 + 26.66 and 69.75 + 24.72 for propofol and midazolam groups respectively. In the midazolam group apnoea occurred in 10% of patients compared to 80% of patients in the propofol group. Local reaction (phlebitis) was absent in the midazolam compared with 20% incident rate observed in the midazolam group. Propofol lowered blood pressure more than midazolam after three minutes of induction at a statistically significant level (P < 0.05). Recovery was significantly more rapid following propofol (P < 0.05).

Coronary artery bypass grafting in non-dialysis-dependent mild-to-moderate renal dysfunction.

OBJECTIVES: The effect of mild-to-moderate elevation of preoperative serum creatinine levels on morbidity and mortality from coronary artery bypass grafting has not been investigated in a large multivariable model incorporating preoperative and intraoperative variables. Our first objective was to ascertain the effect of a mild-to-moderate elevation in the preoperative serum creatinine level on the need for mechanical renal support; the duration of special care and total postoperative stay; the occurrence of infective, respiratory, and neurologic complications; and hospital mortality. Our second objective was to ascertain which patient variables contributed to an increase in the serum creatinine level in association with coronary artery bypass grafting. METHODS: A total of 1427 patients who had no known pre-existing renal disease and who were undergoing first-time coronary artery bypass grafting with cardiopulmonary bypass were recruited for the study. Patients were divided, on the basis of preoperative serum creatinine level, into 3 groups as follows: creatinine level of less than 130 micromol. L(-1); creatinine level of 130 to 149 micromol. L(-1); and creatinine level of 150 micromol. L(-1) or greater. A multivariable stepwise logistic regression analysis was used, and variables significant at the 5% level were included when developing the final multivariable models. RESULTS: Multivariable analysis showed that elevation of the preoperative serum creatinine level to 130 micromol. L(-1) or greater increased the likelihood of needing mechanical renal support postoperatively (P <.001), as well as the need for postoperative special care (P <.001) and total hospital stay (P <.001). In-hospital mortality was also significantly elevated as the preoperative creatinine level rose to 130 to 149 micromol. L(-1) (P =.045) and to 150 micromol. L(-1) or greater (P <.001). It was further observed that patients with preoperative serum creatinine levels of 130 to 149 micromol. L(-1) (P =.02), patients with preoperative serum creatinine levels of 150 micromol. L(-1) or greater (P =.001), hypertensive patients (P =.007), patients with angina of New York Heart Association class III or greater (P =.001), patients having a nonelective operation (P =.002), and patients having a prolonged cardiopulmonary bypass time (P =.008) had a significantly greater increase in the serum creatinine level as a result of coronary artery bypass grafting. Of particular note was the finding that the method of myocardial protection (cardioplegia or crossclamp fibrillation) did not significantly influence in-hospital mortality, need for mechanical renal support, or special care or total postoperative hospital stay. CONCLUSIONS: A mild elevation (130-149 micromol. L(-1)) in the preoperative serum creatinine level significantly increases the need for mechanical renal support, the duration of special care and total postoperative stay, and the in-hospital mortality. As the preoperative serum creatinine level increases further (> or =150 micromol. L(-1)), this effect is more pronounced. No significant difference in outcome was observed between the use of cardioplegia or crossclamp fibrillation for myocardial protection.

Mechanisms involved in enteropathy induced by administration of nonsteroidal antiinflammatory drugs (NSAIDS).

Mice received oral indomethacin (1 mg/mouse) daily for five days. It was found that severe gastroenteropathy (ie, paralytic stomach and necrotic intestine) was induced on the sixth day. Ulcer formation was also seen at many sites in the digestive tract, especially in the colon. In parallel with the increase in the number of leukocytes in the digestive tract, the proportion of granulocytes increased at various sites, for example, in the intraepithelium and lamina propria of the colon and the lamina propria of the appendix. The number of extrathymic T cells at these sites in the digestive tract, especially gammadelta T cells in the colon, increased. A functional assay revealed that granulocytes isolated from mice injected with indomethacin were activated in terms of their superoxide production upon stimulation. In conjunction with the data on the simultaneous activation of granulocytes in the liver and blood, the present results suggest that nonsteroidal antiinflammatory drugs (NSAIDs) have the potential to induce severe granulocytosis in specific sites of the body, possibly via their stimulatory effect on the sympathetic nervous system (ie, granulocytes bear adrenergic receptors on their surface).

Association of intermediate T cell receptor cells, mainly their NK1.1(-) subset, with protection from malaria.

Mice were infected with Plasmodium (P.) yoelii blood-stage parasites. Both the liver and spleen were the sites of inflammation during malarial infection at the beginning of day 7. The major expanding cells were found to be NK1.1(-) intermediate alphabetaTCR (alphabetaTCR(int)) in the liver and spleen, although the population of NK1.1(+) alphabetaTCR(int) cells remained constant or slightly increased. These TCR(int) cells are of extrathymic origin or are generated by an alternative intrathymic pathway and are distinguished from conventional T cells of thymic origin. During malarial infection, the population of conventional T cells did not increase at all. TCR(int) cells purified from the liver of mice which had recovered from P. yoelii infection protected mice from malaria when they were transferred into 6.5-Gy-irradiated mice. Interestingly, the immunity against malaria seemed to disappear as a function of time after recovery, namely, mice which had recovered from malaria 1 year previously again became susceptible to malarial infection. The present results suggest that TCR(int) cells are intimately associated with protection against malarial infection and, therefore, that mice which had recovered from malaria 1 year previously lost such immunity.

Elevation of plasma high-density lipoprotein concentration reduces interleukin-1-induced expression of E-selectin in an in vivo model of acute inflammation.

BACKGROUND: Although there is strong evidence that plasma HDL levels correlate inversely with the incidence of coronary artery disease, the precise mechanism(s) for the protective effect of HDLs remains unclear. We recently showed that HDLs inhibit endothelial cell expression of cytokine-induced leukocyte adhesion molecules in vitro. Our study therefore sought to test the hypothesis that elevating the level of circulating HDLs would inhibit endothelial cell activation in vivo. METHODS AND RESULTS: We used a porcine model of inflammation previously established in our laboratory, in which the level of vascular endothelial cell expression of E-selectin in interleukin (IL)-1alpha-induced skin lesions was measured by the uptake of a radiolabeled anti-E-selectin antibody (1.2B6). Porcine plasma HDL levels were elevated by use of a bolus injection of reconstituted discoidal HDL (recHDL). These particles resemble nascent HDL particles in shape and contain apolipoprotein A-I as the sole protein and soybean phosphatidylcholine as the sole phospholipid. We found that recHDLs inhibited the expression of IL-1alpha-induced E-selectin by porcine aortic endothelial cells in vitro, confirming that the inhibitory effect is conserved with synthetic HDLs and demonstrating that the phenomenon is not restricted to human endothelial cells. In vivo, elevating the circulating level of HDLs approximately 2-fold led to significant inhibition of basal and IL-1alpha-induced E-selectin expression by porcine microvascular endothelial cells. CONCLUSIONS: These observations demonstrate the potential anti-inflammatory action of HDLs and provide support for the further investigation of the mechanisms underlying the inhibitory effects of HDLs on endothelial cell activation.

A study of co-induction of anaesthesia U.B.T.H. experience.

Co-induction is the concurrent administration of two or more drugs that facilitate induction of anaesthesia. Some combinations have been shown to have pharmacological advantages. In addition to the safety and comfort of the patient, it is also important to find a cost effective combination in view of the rather stringent economy of the times. This project was undertaken to study the response of Nigerian patients to co-induction (midazolam and propofol) by comparison with the traditional thiopentone or propofol alone, and to study the cost implications. 45 patients who came in for various surgical procedures were randomly assigned to three different groups. The first group was induced with thiopentone alone. The second group had a combination of midazolam and propofol and the third group had propofol alone. In all other respects except for the surgery the patients had the same treatment. The induction was satisfactory in all groups. The cardiovascular and respiratory changes were within clinically acceptable limits but the emergence was best with propofol, followed by midazolam/propofol and thiopentone in that order. Although thiopentone was the cheapest in terms of absolute cost, the combination of midazolam and propofol was most cost-effective.

The pattern of hypogammaglobulinaemia in Sri Lankan children.

OBJECTIVE: To evaluate the prevalence of hypogammaglobulinaemia in Sri Lankan children who present with recurrent or severe bacterial infections. DESIGN: A descriptive study. SETTING: Medical Research Institute (MRI), Colombo. SUBJECTS: 100 children between the ages of four months to twelve years referred to the Department of Immunology, MRI, for evaluation of immune status during four years from 1993 to 1997. MEASUREMENTS: Immunoglobulin G, A and M levels were measured using radial immunodiffusion technique. RESULTS: 22 out of 100 children had an underlying antibody deficiency, of whom IgA deficiency was the commonest (18 patients). Two patients had low IgG and A and elevated IgM levels, and they were diagnosed as having X linked-hyper-IgM syndrome. One patient had deficient IgA and IgM, and all three immunoglobulins were deficient in another. CONCLUSIONS: Results indicate that IgA deficiency is the commonest immunodeficiency in Sri Lanka, which is comparable with studies done in the West. This study also shows the need to improve the standard of care in patients with immunodeficiency.

Resistance of extrathymic T cells to stress and the role of endogenous glucocorticoids in stress associated immunosuppression.

When mice were exposed to restraint stress for 12 or 24 h, severe lymphopenia was induced in all immune system organs, including the liver and the thymus. However, in adrenalectomized mice, this response was completely absent. Phenotypic characterization revealed that interleukin (IL)-2Rbeta+CD3int cells (i.e. extrathymic T cells) with CD4+ phenotype and the NK1.1+ subset of CD3int cells (i.e. NKT cells) in the liver as well as the mature conventional T cells in the thymus were resistant to such stress. In adrenalectomized mice, there was no significant change in the distribution of lymphocyte subsets in all tested organs before stress. Interestingly, the number of lymphocytes in the liver and spleen and the proportion of NKT cells in the liver rather increased after stress in these adrenalectomized mice. Therefore, endogenous steroid hormones were indicated to be important in the induction of immunosuppressive states after stress. Among stress associated cytokines, the secretion of tumour necrosis factor (TNF)-alpha was completely suppressed while that of IL-6 was partially suppressed in adrenalectomized mice. These results suggest that endogenous steroid hormones are important for the induction of the stress associated immunosuppression and that NKT cells are resistant to stress, namely, resistant to exposure to endogenous steroid hormones.

Administration of glucocorticoids markedly increases the numbers of granulocytes and extrathymic T cells in the bone marrow.

Glucocorticoids, steroid hormones, are widely used as an anti-inflammatory drug. However, clinicians have sometimes encountered adverse drug reactions such as ulcers and tissue damage. In this study, we investigated how such adverse reactions of glucocorticoids are evoked, using an experimental mice model. When hydrocortisone (0.5 or 1.0 mg/day/mouse) was administered daily for 2 weeks, severe leukocytopenia was induced in all immune system organs. However, granulocytes (Gr-1(+)Mac-1(+)) were increased in number in the bone marrow and peripheral blood. This seemed to be due to an elevated level of myelopoiesis in the bone marrow. As well as increasing in number, granulocytes were functionally activated as estimated by the Ca2+ influx and superoxide production. The proportion of primordial T cells (CD3(int)IL-2Rbeta+) in the thymus and the number of primordial T cells in the bone marrow also increased. Mice administered hydrocortisone became susceptible to stress. Thus, these mice showed gastric ulcers when they were exposed to restraint stress for 12 h. These results suggest that activated granulocytes and primordial T cells might provide a mechanism involved in steroid ulcers and tissue damage, possibly through the superoxide production of granulocytes and the autoreactivity of primordial T cells.

Mechanisms involved in graft-versus-host disease induced by the disparity of minor histocompatibility M1s antigens.

In this study we investigated which type of T cells: high T-cell receptor (TCRhigh, cells of thymic origin) or intermediate TCR (TCRint, cells of extrathymic origin), expanded in the liver and other organs, resulting in the induction of graft-versus-host disease (GVHD) with minor lymphocyte stimulating (M1s) disparity. When 6.5 Gy-irradiated BALB/c (H-2d M1s-1b2a) mice were injected with interleukin-2 receptor beta-chain(-) (IL-2Rbeta(-)) CD3high cells purified from the spleen of B10.D2 (H-2d M1s-1b2b) mice, IL-2Rbeta(+)CD3high cells expanded in the liver and other organs of recipient mice. The majority of these cells were found to be IL-2Ralpha(-)Mel-14(-)CD4(+)Vbeta3(+) in GVHD mice. The CDR3 region in their TCR-alphabeta (i.e. N-Dbeta-N) was polyclonal, although there were skewed usages of Vbeta3 and Jbeta2.4. The majority of cells were confirmed to be of donor origin by the individual discrimination method, namely, they originated from isolated IL-2Rbeta(-)CD3high cells. Interestingly, these T cells lacked cytotoxicity against both a natural killer (NK)-sensitive target and thymocytes with M1s disparity and nondisparity. Another important finding was that activated granulocytes expanded at generalized sites in GVHD mice. The present results raise the possibility that M1s disparity is mainly recognized by TCRhigh cells with unique properties but that direct effector cells that induce GVHD might not be such T cells but rather accompanied granulocytes.

First redo heart valve replacement: a 10-year analysis.

BACKGROUND: The United Kingdom Heart Valve Registry (UKHVR) has recently completed collecting information on 52 659 heart valve replacements (in 47 718 patients) performed during the period 1986 to 1995 in the whole of the United Kingdom. Information stored in the UKHVR's computer database was used for this study. Factors affecting the time from first prosthesis to first redo prosthesis were analyzed and provided useful predictive information. The association between prosthesis-induced local pathological processes and redo valve size was investigated. METHODS AND RESULTS: This is a retrospective study of 43 301 patients (from among 47 718 in the database) undergoing single-site replacement of a diseased native mitral or aortic valve over a 10-year period from January 1986 to December 1995 in the United Kingdom. Of these patients, 1051 (2.43%) went on to have a first redo heart valve replacement. Valve survival analysis (Cox regression and Kaplan-Meier curves) was used to study the natural progression to the first redo heart valve replacement. Female sex and having a replacement at the aortic rather than the mitral position were both associated with a longer interval to the first redo operation. Regression analysis showed the size of the redo valve to be influenced by the interoperative time. This effect was more pronounced at the mitral position. CONCLUSIONS: Females and patients having an aortic valve replacement exhibit a longer interval to the first redo operation than do males and patients having mitral valve replacements, respectively. The time from the first replacement to the first redo operation significantly affects the size of the first redo valve.

Characterization of NK cells and extrathymic T cells generated in the liver of irradiated mice with a liver shield.

We previously reported that c-kit+ stem cells which give rise to extrathymic T cells are present in the liver of adult mice. Further characterization of extrathymic T cells in the liver of adult mice is conducted here. When mice with a liver shield were lethally (9.5 Gy) irradiated, all mice survived. All tested organs showed a distribution pattern of hepatic lymphocytes on day 7. The distribution pattern in the liver was characterized by an abundance of NK (CD3- IL-2Rbeta+) and extrathymic T cells (CD3int IL-2Rbeta+) before and after irradiation. To determine their function, post-irradiation allogeneic bone marrow transplantation (BMT) was performed in mice with or without a liver shield. Allogeneic BM cells were rejected in mice with a liver shield and specific activation of CD8+ CD3int IL-2Rbeta+ cells was induced. At that time, potent cytotoxicity of liver mononuclear cells (MNC) against allogeneic thymocytes was induced. Both NK1.1+ and NK1.1- subsets of CD3int cells expanded in these mice. An in vivo elimination experiment of the subsets indicated that the NK1.1+ subset of CD3int cells (i.e. NK T cells) was much more associated with the rejection of allogeneic BM cells. However, even after the elimination of NK T cells, allogeneic BM cells were rejected. In this case, granulocytes expanded in parallel with NK1.1- subsets. Granulocytes may also be associated with the rejection of allogeneic BM cells. These results suggest that the liver is an important haematopoietic organ even in adult life.