Half-sandwich nickel complexes with ring-expanded NHC ligands - synthesis, structure and catalytic activity in Kumada-Tamao-Corriu coupling.

The general synthesis of [Ni(Cp)(X)(NHC)] complexes from a nickel halide, CpLi, and a carbene solution is reported. This procedure yields unprecedented complexes with ring-expanded NHC ligands (RE-NHC) of six- (1a, 1b), seven- (1c), and eight-membered (1d) heterocycles. The NMR spectra of 1a-1d are consistent with the hindered rotation of Ni-Ccarbene and N-CMes bonds, while X-ray analyses of 1b, 1c, and 1d reveal a pronounced trans influence of the RE-NHC ligands. Complexes 1a-1e are efficient pre-catalysts in Kumada-Tamao-Corriu coupling with the maximum efficiency observed for complexes bearing the six-membered NHC.

A Comparison Of Cervical Smear Adequacy Using Either The Cytobrush Or The Ayre Spatula: A Practice Audit

Background: To obtain an adequate cervical (Papanicolaou) smear; the transformation zone; including the squamo-columnar junction; should be sampled as carcinoma develops preferentially in this transformation zone. The Ayre spatula has been widely used but is not very effective. Other sampling devices have been developed to improve efficiency; including the cytobrush. The purpose of this study was to compare the adequacy of cervical smears taken with the Ayre spatula as opposed to the cytobrush. MethodsThis was a retrospective analytical study. One sampler; an experienced general practitioner; took the smears in the period 1990 to 2004. Initially; the Ayre spatula was used to consecutively sample the cervix and thereafter; a cytobrush alone was used. Two groups were thus formed for comparison. The presence of endocervical cells was accepted as an indicator of an adequate smear. A Cusco speculum was used to visualize the cervix. The sample was smeared onto a slide and fixated with an alcohol aerosol spray. ResultsA total of 4561 smears were taken and 247 had no endocervical cells. A further 34 smears were classified as unsatisfactory due to the presence of degeneration (19); insufficient squamous cells (7); inflammatory exudate (4); excess blood (3) and/or a thick slide (1).The cytobrush group was similar demographically to the Ayre spatula group: 1981 (99) and 2490 (98) respectively were non pregnant; 67 (3) and 110 (4) were nulliparous; 1008 (50) and 1370 (54) were para 1 - 5; and 931 (46) and 1075 (42) were para 6 or more; 0 (0) and 2 (0.1) were aged between 10 - 19 years; 1496 (75) and 2012 (78) between 20 - 49; and 510 (25) and 541 (21) were aged 50 years or more. Of 2006 smears taken with a cytobrush; 1955 (97.5) contained endocervical cells compared with 2325 (91) of 2555 smears taken with an Ayre spatula. The difference was significant with an Odds Ratio of 4.56 (95Confidence Interval 3.42-6.42). ConclusionThe cytobrush is significantly more efficacious than the Ayre spatula in obtaining adequate cervical smears. Use of the cytobrush will ensure less repeat smears with a consequent reduction in workload for samplers and laboratories. Although very few smears lacked sufficient squamous cells (an indicator of adequate ectocervical sampling); current best practice is that the cytobrush be used together with a wooden spatula to ensure adequate sampling of both the endocervical and ectocervical components of the transformation zone

A Comparison of Cervical Smear Adequacy Using either the Cytobrush or the Ayre Spatula: a Practice Audit

Background: The study aimed to i) investigate the smoking habits of students attending tertiary institutions of learning in the Eastern Cape Province (ECP) and ii) determine the knowledge of the students about the health hazards of smoking and their attitude towards current government anti-smoking legislation.Methods: This was a questionnaire-based study involving all seven tertiary institutions of learning in the ECP; viz. the Universities of Transkei; Fort Hare; Port Elizabeth and Rhodes University; and the Border; Eastern Cape and Port Elizabeth technikons. A total of 1 728 students were interviewed out of a student population of 30;080. Stratified random sampling was used to select the students. Two-way tables were used to test the independence of the variables and chi-square tests were applied. A 'p' value of below 5 was used as a test of significance. Results : A total of 1 480 students completed the questionnaires (86). The racial classification of the respondents was 79 Black; 13 White; 7 Coloured and 2 Indian. Twenty-six per cent of the students were smokers; of which 37 were male and 15 were female. Forty-five per cent of the Coloured students smoked; while the figures for Whites and Blacks were 26 and 25 respectively. Seventy per cent of the students smoked less than 10 cigarettes a day. Fifty-two per cent of the smokers said they wanted to stop smoking. Sixty-one per cent had been influenced to start smoking by their friends and only 13 were influenced by advertisements. Ninety-four percent agreed that smoking was dangerous to the smoker's health; while 73 responded that there was a relationship between mothers who smoke and low birth weight. Thirteen per cent thought the legislation was too tough; while 30 said it was good as it was. On measures to reduce smoking; 86 favoured restricting smoking in public places.Conclusion: This study has demonstrated that smoking is prevalent in tertiary institutions of learning in the Eastern Cape Province. The demographic profile of the smokers reflects the national picture. The knowledge of the harmful effects of smoking is generally good

iPath - a Telemedicine Platform to Support Health Providers in Low Resource Settings.

In many developing countries there is an acute shortage of medical specialists. The specialists and services that are available are usually concentrated in cities and health workers in rural health care, who serve most of the population, are isolated from specialist support [1]. Besides, the few remaining specialist are often isolated from colleagues. With the recent development in information and communication technologies, new option for telemedicine and generally for sharing knowledge at a distance are becoming increasingly accessible to health workers also in developing countries. Since 2001 the Department of Pathology in Basel, Switzerland is operating an Internet based telemedicine platform to assist health workers in developing countries. Over 1800 consultation have been performed since. This paper will give an introduction to iPath - the telemedicine platform developed for this project - and analyse two case studies: a teledermatology project from South Africa and a telepathology project from Solomon Islands.

Concomitant sarcoidosis in a patient with tuberculosis: first report of association in Africa.

Sarcoidosis occasionally develops in patients previously treated for tuberculosis. Less commonly, tuberculosis develops as an opportunistic infection in patients following corticosteroid treatment for sarcoidosis. Rarely do you find sarcoidosis and tuberculosis coexisting in the same patient. This report in an African, documents the co-existence of both diseases in a patient, highlighting this relationship and reviews the literature on the possible aetiologic relationship between tuberculosis and sarcoidosis.

Expression of endogenous lectins (galectins, receptors for ABH-epitopes) and the MIB-1 antigen in esophageal carcinomas and their syntactic structure analysis in relation to post-surgical tumor stage and lymph node involvement.

Squamous cell carcinomas of the esophagus, a disease with poor prognosis, are especially frequent in China and South Africa. To initiate the study of endogenous lectins in this tumor class we employed synthetic neoglycoconjugates and focused on galectins as markers. Histological sections of 43 cases of esophageal carcinomas were analyzed with labeled galectins-1 and -3 and their specific antibodies, neoglycoconjugates exposing chemically prepared histo-blood group A-, B- and H-trisaccharides and the antibody MIB-1 (Ki-67). Features of structural and numerical staining intensities determined quantitatively were correlated to clinical data sets of pTN stages, sex and age of patients. Low tumor stages (pT1/T2) were seen in 10/43 cases (23%) and 65% of the carcinomas surgically treated lacked notable lymph node involvement (pN0). The women were younger than the men (47 years versus 54 years). The proliferation activity of the tumor cells was high and amounted to 75% at average. The presence of galectin-1 and the structural entropy of distribution of staining with carrier-immobilized A-trisaccharide were associated with pN stages. These initial data indicate that distinct glycohistochemical features appear to have prognostic significance in this tumor class, adding to the emerging significance of this marker class in lung cancer.

Nephroblastoma (Wilms' tumour) diagnosed in the Department of Anatomical Pathology Medunsa/Ga-Rankuwa Hospital for the period 1980 to 1997.

OBJECTIVE: The aim of the analysis was to describe the clinicopathological features of Wilms' Tumour (WT) diagnosed in our Department and compare results to other WT Registers. DESIGN: All cases of WT for the period 1980 to 1997 were retrieved from the Register of Renal Tumours of Childhood. SETTING: The Medical University of Southern Africa, Department of Anatomical Pathology and Department of Paediatrics, Ga-Rankuwa Hospital. SUBJECTS: A total of 171 cases of WT (97% of all renal tumours) were the subject of the analysis. RESULTS: The age of the patients ranged from four to 216 months. The two sexes were represented equally. Tumours were solid in 73.9%, cystic in 20% and mixed in 6.1%. There were as many tumours involving the right kidney as those involving the left kidney. In nine cases WT was bilateral. Only 2.4% of tumours were in stage I and II. The mass of the kidney with tumour ranged from 50 g to 5,400 g and in diameter from three to 28 cm. Histopathologically classic, blastemal and stromal type were nearly equally represented. Follow up was very inadequate and in 66% of cases the fate of the patient remains unknown. CONCLUSION: Occurrence of WT is similar to that reported from other regions of the world. Cases are in a more advanced stage than reported by SIOP and NWTS. Follow up is highly inadequate.

Carcinoma of the uterine cervix: results of Ka-Ngwane screening programme and comparison between the results obtained from urban and other unscreened rural communities.

OBJECTIVE: The Ka-Ngwane screening programme was initiated by the Department of Anatomical Pathology and the Department of Community Health at Medunsa to establish the incidence of cervical intraepithelial neoplasia (CIN) and cervical carcinoma (CaCx) in previously unscreened rural population in our catchment area. STUDY DESIGN: Ten thousand consecutive PAP smears from Ka-Ngwane (Mpumalanga) area are the subject of the analysis. The incidence of CIN I-CIN III and CaCx is calculated in the screened material. The changes are related to age, age of first pregnancy and parity of the patients. The incidence of cervical abnormalities is compared with 20,000 consecutive cases from Pretoria and 18,000 consecutive cases from previously unscreened rural population of Transkei. RESULTS: Positive cases consisted of three per cent in Ka-Ngwane, five per cent in Greater Pretoria area and of more than six per cent in Transkei. CaCx constituted 12.35% of all positive cases for Ka-Ngwane, 4.8% for urban population and 26% of Transkei positive cases. More than 75% of positive cases in Ka-Ngwane were below 40 years of age and five cases of CaCx were found in the 21-30 year age group. In Pretoria more than 80% of positive cases were younger than 41 years. In the material from Transkei similarly 80% of the positive cases were younger than 41 years. CONCLUSION: The screening programme confirmed the high incidence of CIN and CaCx in previously unscreened population and an urgent need to develop educational programme which will facilitate early detection, proper treatment and follow up of the cases with cervical pathology. CaCx was found at a younger age than in the developed countries which indicated that screening programmes in our environment should involve all adult females from the age of 25 years.

Proliferative activity of normal and neoplastic colonic mucosa in population groups with high and low risk for colorectal carcinoma.

Europeans have a high incidence of colorectal cancer in comparison to Africans. Lack of detectable sequence adenoma-colorectal carcinoma in Africans may suggest the development of adenocarcinoma is de novo. The aim of this study is to assess colonic mucosal proliferative activity in various pathological conditions of diverse population groups. Materials included routinely processed tissue specimens from consecutively resected well- and moderately differentiated colorectal adenocarcinomas from 32 rural Africans (South Africa) and 27 urban Europeans (Poland) and from apparently normal rectal mucous membrane from the age and sex matched each population group (28 and 25 samples respectively). In addition, 32 resected adenomatous polyps were examined in Europeans as well. The MIB 1 monoclonal antibody was used to assay the expression of Ki67 antigen in routinely processed tissue specimens. Proliferative activity in colonic carcinomas was scored by the percentage of positively stained cells. Labelling indices were estimated in 5 crypt compartments in apparently normal colonic mucosa adjacent and distant to the tumour, in mucosal samples of controls from both population groups and in adenomatous polyps from Europeans. The mean age of African patients with adenocarcinoma was markedly lower than in European counterparts (48.6 yrs vs. 66.4 yrs). The overall proliferative activity in cancerous tumours of Africans was higher than in Europeans. The labelling indices were lower in all compartments in normal colonic mucosa in Africans. Overall increase of the labelling indices in adjacent and distant to the tumour mucosa noted when compared to the mucosa of healthy individuals. No such differences were detected between indices in the mucosa adjacent and the mucosa distant to the tumour. Proliferative activity in the mucosa adjacent to adenoma was also higher than in normal mucosa from healthy individuals. Adenomas with marked dysplasia showed higher and diffuse proliferative activity, when regular adenomas shown superficial labelling only. Relatively young age, lack of detectable evidence of adenoma-carcinoma sequence and low proliferative activity in all compartments of mucosa from healthy individuals indicate different etiopathogenesis of colorectal carcinoma in rural Africans.

Hepatic siderosis, fibrosis and cirrhosis: the association with hepatocellular carcinoma in high-risk population.

Iron overload has been shown to impair the immune response of the liver, and induce hepatic fibrosis and cirrhosis. Opinions differ concerning the relative risk of developing hepatocellular carcinoma (HCC) in siderotic patients as compared with patients with hepatic fibrosis and cirrhosis and the possible mechanism of liver carcinogenesis in genetic hemochromatosis is still unknown. The purpose of this study is to assess hepatic iron overload, fibrosis and cirrhosis in liver tissue adjacent to hepatocellular carcinoma and in liver tissue of controls in population at risk for hepatocellular carcinoma. Liver tissue was available for examination in 147 biopsies with HCC collected in South Africa. As controls we used liver samples from 211 age and sex matched Africans who died in accidents. Tissue samples were processed routinely, stained with H and E, Sweet's reticulin, Masson's trichrome for fibrous tissue, Prussian blue for iron stain and immunohistochemically for HBsAg. Iron content was assessed with the method described by Brissot. Iron overload was detected in 42.1% of cancerous livers and in 43.7% of livers from controls. The presence of siderosis and iron content gradually increased with the age of studied similarly in cases and in controls. Cirrhosis was present in 32% of cancerous livers and was associated with iron overload in 13%. No cirrhosis and 6% of mild periportal fibrosis not related with siderosis was observed in controls. HBsAg was stainable in 80% of cancerous livers of patients below 25 years of age and in 40% of patients over 35 years. HBsAg in controls was positive in 9%. No relationship of HBsAg and amount of stainable iron in cancerous and livers of controls was found. In conclusion, African siderosis can not play important role in the etiopathogenesis of HCC.

Hepatocellular carcinoma in young patients.

The study was based on the biopsy material collected in Eastern coastal region of South Africa with high incidence of primary hepatocellular carcinoma (HCC). Forty-one patients were between 9 and 25 years old of the total number of 474 cases of HCC available for examination. Liver biopsies were fixed in 10% of neutralised formalin, processed to paraffin blocks, cut and stained with hematoxylin and eosin, silver reticulin, Masson trichrome and Prussian blue stains. Representative biopsies of 21 patients younger than 25 years and 56 older than 35 years were in addition examined immunohistochemically with HBsAg antibody, endothelial marker (F VIII-related antigen) and for oncoproteins c-myc and c-erbB-2 using peroxidase-antiperoxidase method. Cirrhotic liver was evident in 41.5% of all patients and in 28% of younger than 25 years. Hemosiderosis of the liver of patients over 35 years was nearly twice as common as in younger than 25 years and showed the opposite relationship to the presence of HBsAg in liver tissue. Oncoprotein expression was also higher in tumor tissue of younger patients. These results indicate the etiological association of HCC with HBV infection, cirrhosis and possibly siderosis of the liver with HCC. Simultaneous expression of oncoproteins and HBsAg indicate the primary importance of viral infection in etiopathogenesis of HCC.

Hepatocellular carcinoma in young patients: histology, cellular differentiation, HBV infection and oncoprotein p53.

The study of 226 cases of hepatocellular carcinoma (HCC) in a homogenous rural Southern African population is based on the assessment of histology, HBV infection, p53 oncoprotein and transforming growth factor alpha (TGFa) expression. Epidemiological and morphological observations were compared to HCC observed in 89 cases from pathological files in Poland and published information from Japan and Italy. Comparatively high number of young patients with HCC in Africa presented high rates of HBV infection, p53 oncoprotein overexpression and high HBsAg/p53 correlation rates. In all patients histological grading of HCC was inversely related to p53 and TGFa expression. No significant differences in histological grading of HCC and patients' mean age were noted between various population groups. The association of hepatic cirrhosis was at least twice as common in non-African patients, whereas iron overload was noted almost exclusively in African patients livers. Signs of HBV infection were lowest in Japanese female patients. The mechanism by which early HBV infection contributes to hepatocarcinogenesis at an early stage of life is confirmed by epidemiological observations in Poland and by the clear association of p53 gene with HBsAg and the age of patients.

Toxic hepatic injury is associated with proliferation of portal nerve fibers.

Hepatic innervation is thought to play an important role in the regulation of metabolism. Regenerating liver nodules in cirrhosis have a paucity of nerve fibers. The situation in chronic necroinflammatory and cholestatic liver diseases is unclear. We have therefore evaluated hepatic innervation in toxic hepatitis and non-specific reactive hepatitis. Liver biopsies from 42 patients considered to have chronic toxic liver injury, 25 patients with chronic reactive inflammatory infiltrates and variable degree of hepatic fibrosis and the control group comprising of 23 individuals who had undergone laparotomy for non-hepatic reasons (trauma etc.) and who had entirely normal hepatic histology were studied histologically and immunohistochemically for the presence of nerve fibres. Semiquantitative analysis showed significant proliferation of portal nerve fibers in biopsies confirmatory of toxic liver injury. Assessment of hepatic neural elements may be useful in the differential diagnosis of unspecified liver injury where toxic injury may be implicated.