Genotypic analysis of Escherichia coli recovered from product and equipment at a beef-packing plant

AIMS

To identify sources of Escherichia coli on beef by characterizing strains of the organism on animals, equipment and product at beef-packing plant.

METHODS AND RESULTS

Generic E. coli were recovered from hides, carcasses, beef trimmings, conveyers and ground beef during the summer of 2001 (750 isolates) and winter of 2002 (500 isolates). The isolates were characterized by Random Amplification of Polymorphic DNA (RAPD). The numbers of E. coli recovered from dressed carcasses were less than the numbers recovered from hides. The numbers recovered from chilled carcasses were too few for meaningful analysis of the strains present on them but the numbers recovered from trimmings and ground beef were larger. The RAPD patterns showed that the majority of isolates from hides, carcasses, beef trimmings, conveyers and ground beef were of similar RAPD types, but a few unique RAPD types were recovered from only one of those sources. The E. coli populations present on the hides of incoming animals and in the beef-processing environment were highly diverse. Randomly selected E. coli isolates from each of the five sources were further characterized by pulsed-field gel electrophoresis (PFGE). Most genotypes of E. coli defined by PFGE corresponded to the E. coli types defined by RAPD.

CONCLUSIONS

The hides of the incoming animals appeared to be only one of the sources of the E. coli on trimmings and in ground beef, as additional sources were apparently present in equipment used for carcass breaking.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study indicates that hazardous microbiological contamination of meat may occur after the dressing of carcasses at commercial beef-packing plants, which suggests that attention should be given to the control of the contamination of meat during carcass breaking as well as during the dressing of carcasses.

Lipids and lipoprotein(a) concentrations in Pakistani patients with type 2 diabetes mellitus

AIM

The aim of the present study was to analyze serum lipoprotein(a) [Lp(a)] levels in Pakistani patients with type 2 diabetes mellitus (DM) and to find correlations between clinical characteristics and dyslipidaemias in these patients.

METHODS

Fasting blood samples were analyzed for Lp(a), total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), glucose and glycosylated haemoglobin (HbA1c) in 68 Pakistani patients with type 2 DM and 40 non-diabetic healthy control subjects.

RESULTS

Lp(a) levels were significantly raised in diabetics as compared to the control group. No correlation of Lp(a) was seen with age, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP) and fasting glucose. There was a positive correlation of BMI to SBP and DBP. There was a significant positive correlation between Lp(a) and total cholesterol and LDL-c. No correlation of Lp(a) was observed with HDL-c, triglycerides and glycosylated haemoglobin (HbA1c).

CONCLUSION

The present study led us to conclude that serum Lp(a) levels are significantly raised in type 2 DM and have a positive correlation with serum total and LDL-c levels.

Second allogeneic bone marrow transplantation after myeloablative conditioning analysis of 43 cases from single institution

Between March 1984 and December 1999, a total of 43 second related allogeneic BMT procedures after myeloablative conditioning were carried out in our institution, 37 following allogeneic, and 6 following autologous BMT. Thirty one patients were males (72%). At 1st BMT (BMT1), median age was 11.5 years (range, 0.16-45 years). BMT1 was carried out for the diagnosis of AML in 13 patients (30%), SAA in nine (21%), ALL in six (14%), CML in six (14%), immunodeficiency in three (7%), NHL in two, beta-thal in two, HD in one, Red cell aplasia in one. HLA matching status for allogeneic BMT1 was full match in 33, one antigen mismatch in two and haplo identical in two patients. Median age at the 2nd BMT (BMT2) was 14 years (range, 0.41-46.7 years). Indications for BMT2 were recurrent hematologic neoplasm in 23 patients (53%), primary graft failure in 12 (28%) and late graft failure in 8 (19%). Median time from BMT1 to recurrence of hematologic neoplasm or late graft failure was 10 months (range, 2.5- 88 months). Median BMT1 to BMT2 interval was 13 months (range, 1-107 months). For BMT2, the same donor was used in 29 patients, while 14 patients had alternate related donor (12 full match, 1-one Ag mismatch, 1 haplo identical). A different conditioning regimen was used in the majority of the patients (39, 91%). Radiation containing conditioning regimen were used mostly for patients previously conditioned with chemotherapy only for BMT1 and chemotherapy conditioning +/- ATG for those who received radiation containing conditioning at BMT1. Bone marrow was the stem cell source for all patients at BMT2 and all except three autologous peripheral stem cell transplantation patient at BMT1. Significant organ toxicity leading to procedure related death in 13 patients (30%) was observed after BMT2. At a median follow up of 36 months after BMT2, 22 patients (51%) are alive (20 free of disease, 2 with recurrent disease) with overall median survival of 47.5 (SD +/- 9) months. Univariate analysis of relevant clinical factors identified the following variables as the only statistically significant favorable prognostic factors for overall survival: BMT1-BMT2 interval of > or = 6 months (P=0.0007) and age at BMT2 < or = 10 years (P=0.041). The nature of underlying disease (neoplastic or non-neoplastic) was not statistically significant (P=0.23). There was no statistically significant difference in survival outcome of BMT2 using same donor vs. alternate related donor (P=0.51). Due to the relatively limited sample size, multivariate analysis was not attempted. This single institution study suggests that second allogeneic BMT after myeloblative conditioning has an acceptable treatment related morbidity/mortality and favorable outcome if performed at age < or = 10 years and with an interval of > or = 6 months after the first BMT. Additionally same donor can successfully be used for the second transplant with similar survival outcome to alternate donor.

Kohl (surma): a toxic traditional eye cosmetic study in Saudi Arabia

The use of kohl (surma) as eyeliner is a popular practice in Saudi Arabia and people firmly believe that it is safe to use. A total of 107 kohl samples (branded and unbranded) were collected from different regions of Saudi Arabia, and analysed for the presence of lead. In addition, aluminium and antimony levels were also determined. Lead levels up to 53% were detected in some kohl preparations, and some samples were found to contain camphor and menthol. The blood analyses of regular kohl users revealed a high lead concentration and relatively low haemoglobin levels. Due to the health risk, an official public awareness campaign is suggested to encourage the use of lead-free kohl.

Promoter hypermethylation of MGMT, CDH1, RAR-beta and SYK tumour suppressor genes in granulosa cell tumours (GCTs) of ovarian origin

Ovarian carcinoma (OC) is a leading cause of death among women throughout the world. A number of cancer-associated genes have been shown to be inactivated by hypermethylation of CpG islands during tumorigenesis. We tested the hypothesis that methylation status of MGMT, CDH1, RAR-β and SYK could be important in the ovarian tumorigenic process and can lead to the gene(s) inactivation. Therefore, we assessed the promoter hypermethylation of MGMT, CDH1, RAR-β and SYK in 43 ovarian granulosa cell tumours (GCTs) (adult type) using methylation-specific PCR. These tumours are relatively rare, accounting for approximately 3% of all ovarian cancers. Hypermethylation of MGMT (in 14 tumours), CDH1 (in nine tumours), RAR-β (in eight tumours) and SYK (in seven tumours) have been found. Selective loss of RAR-β and RAR-β2 mRNA has been found in seven patients, while that of MGMT and SYK in three patients who also show aberrant methylation in promoter region of RAR-β in addition to MGMT, SYK and CDH1 genes. Promoter CpG hypermethylation may be an alternative to mutation(s) to inactivate tumour suppressor genes such as MGMT, CDH1, RAR-β and SYK, and this can also be an early event in the pathogenesis of OCs. Moreover, hypermethylation of the MGMT and CDH1, MGMT and RAR-β and CDH1 and RAR-β promoters occurred concordantly (P< 0.001, 0.0421 and 0.0005 respectively; Fischer's exact test). In addition to this, monosomy 22 and trisomy 14 have also been found in 10 tumours. It is clear from the results that hypermethylation of the promoter region of these tumour suppressor genes, monosomy 22 and trisomy 14, may be critical steps in the tumorigenesis, which consequently play a permissive role for tumour aggressiveness. All these events might play an important role in the early clinical diagnosis of the disease. Our results, therefore, suggest a potential role for epigenetic modification of these critical tumour suppressor genes in pathways relevant to the transformation and differentiation of rare type of ovarian cancer (GCTs).

Tumor embolization causing acute ischemia with sometimes fatal results. Case report and review of literature

Peripheral arterial embolism arising from a malignant tumor is an infrequent manifestation of neoplastic disease and also a rare cause of acute arterial occlusion. A diagnosis of lower limb acute ischemia in young adults could be overlooked because the condition is quite uncommon in this age group. A case of lower extremities arterial embolization from metastatic lung cancer of germ cell origin is reported and the literature is reviewed.

Atmospheric perfluorocarbons

Collectively, man-made emissions of a few greenhouse gases may cause about the same amount of global warming as increasing carbon dioxide. Among the most potent of these non-CO2 greenhouse gases are the perfluorocarbons that have extraordinarily long atmospheric lifetimes of 10,000 to more than 50,000 yr. We report atmospheric concentrations over two decades, between 1978 and 1997, of the three most abundant perfluorocarbons--CF4, C2F6, and C3F8--and delineate the sources that account for the present abundances and trends. We show that C2F6 and C3F8 are present at only 2.9 and 0.2 pptv, respectively. CF4 is the most abundant perfluorocarbon at 74 pptv (in 1997) of which about 40 pptv are from natural emissions, 33 pptv from aluminum manufacturing, and 1 pptv from the semiconductor industry. The increasing trend of CF4 has slowed in recent years due to the major reductions in the emission rate per ton of aluminum produced. The effect of the falling emission factor is partially offset by increased production and increasing use by the semiconductor industry.

Hypoxia and pulmonary acclimatisation at 4578 m altitude: the role of acetazolamide and dexamethasone

OBJECTIVES

To quantify the changes in ventilatory response and arterial blood gases in healthy male volunteers on acute ascent to 4578 meters altitude along with evaluating the role of acetazolamide and dexamethasone prophylaxis in acclimatisation.

METHODS

Forty four lowlander male subjects participated as two groups in the study. Twenty four lowlander healthy male adults (age mean +/- SE 27.8 +/- 1.24 years) comprised the non-acclimatised group. They were sub grouped in a double blind fashion into four. Each subgroup (n=6) received placebo (multivitamin) or acetazolamide (250 mg) or dexamethasone (4 mg) or combined regimen of the two drugs twice daily for 5 days commencing 24 hours before ascent. The volunteers reached the altitude of 4578 meters within a span of one day. The second group (acclimatised) comprised of age and height matched twenty volunteers who had arrived 4 and 8 weeks earlier at the same altitude. Arterial PO2, PCO2, SO2 and minute respiratory rate pH were measured. The pulmonary functions (FVC, %FEV1 PEF, FEF(25-75%) and MVV) were recorded by Compact Spirometer (Vitalograph). Pre and post ascent measurements were carried out in non-acclimatised group whereas one measurement of the same parameters were made in acclimatised group.

RESULTS

The study revealed a significant increase in respiratory rate min-1 after 24 hours of ascent along with reduction in PaO2 and SaO2. The gradual increase in PaO2 and SaO2 and reduction in PaCO2 was observed after 4 weeks at the same altitude. The reduction in FVC, %FEV1, PEF, FEF(25-75%) and MW were recorded in our subjects after 24 hours of acute ascent. Nevertheless, all pulmonary parameters in volunteers having 8 weeks of stay at 4578 m altitude, were found equivalent to the non-acclimatised group. The greater increase in minute respiratory rate, PaO2, SaO2 and pulmonary functions was found in volunteers taking acetazolamide.

CONCLUSION

It is concluded that hyperventilation and increase in lung volumes are the adaptive pulmonary responses which help in improving levels of PaO2 and SaO2. The acetazolamide-dexamethasone prophylaxis appears beneficial in promoting pulmonary acclimatisation during hypobaric hypoxia.

Modulation of oesophago-UOS contractile reflex: effect of proximal and distal esophageal distention and swallowing

Upper oesophageal sphincter (UOS) tone is influenced by intraoesophageal pressure events. Our aim was to test the hypothesis that UOS tone is responsive to simultaneous inhibitory and stimulatory signals originating from the oesophagus and compare effect of proximal and distal oesophageal air distention on oesophageal balloon-stimulated UOS contraction. We studied 16 healthy volunteers, ages 19-80 years in two stages. We induced UOS contraction by distending various size balloons intraoesophageally and studied response of contracted UOS to oesophageal air distentions and swallowing. Intraoesophageal injections of 60-ml room air resulted in UOS pressure augmentation (31%), relaxation (64%) and no effect in the remaining 5% of instances. The majority of air injections into the oesophageal segment proximal to the distended balloon were followed by relaxation of the contracted UOS, whereas, the majority of oesophageal air distentions distal to the balloon resulted in augmentation of UOS contraction (P < 0.01). Swallowing resulted in complete relaxation of the UOS. In conclusion, UOS contractile response to oesophageal balloon distention is overridden by further augmentation or relaxation as a result of oesophageal air distention and swallowing. Contractile and inhibitory responses of the contracted UOS to generalized oesophageal distention is region-specific.

Lipoprotein (a) and glycaemic control in Pakistani subjects with diabetes mellitus

AIMS

To measure lipoprotein (Lp)(a) levels in people with diabetes mellitus (DM) and to see if there is any difference in Lp(a) levels between diabetics with good glycaemic control and those with poor glycaemic control.

METHODS

Sixty subjects with DM and thirty healthy individuals were studied. Fasting blood samples were analyzed for glucose, glycosylated hemoglobin, Serum total cholesterol, triglycerides, low density lipoproteins, high density lipoproteins and Lp(a).

RESULTS

A non significant difference was found between the lipid profile of normal individuals and subjects with DM with a good glycemic control. Lp(a) levels were significantly raised in diabetics. The difference in Lp(a) levels between well controlled and poorly controlled diabetics was non significant. In the control group 23.4% of individuals had high risk levels of Lp(a) while it was 46.7 % for people with DM.

CONCLUSION

Glycaemic control improves lipid profile positively in diabetics and may even lead to near normalization of lipoprotein concentrations. Diabetics have elevated levels of Lp(a) and the difference in Lp(a) levels between well controlled and poorly controlled diabeticsts is non-significant.

Reliability of pre-operative biopsies in the histological grading of colorectal adenocarcinomas

BACKGROUND

Management of colorectal cancer depends on many patient and tumour variables. Decisions are sometimes based on the histological grade of tumour as assessed by initial biopsy. This retrospective study looked at the reliability of grading colorectal cancer from pre-operative biopsies.

METHODS

118 patients with a diagnosis of colorectal cancer, who had adequate pre-operative biopsies, were included in the study. A single consultant histopathologist re-examined all the preoperative biopsy slides, but was blinded to the final grading of the resection specimen.

RESULTS

Of the 118 resection specimens, 41 were graded well-differentiated, 52 moderately differentiated and 25 poorly differentiated. When compared with postoperative grading, 37 (31%) initial biopsies were undergraded, 49 (43%) were correctly graded and 32 (26%) were overgraded.

CONCLUSIONS

These results suggest that the histological grading of pre-operative specimens is inaccurate and should be used with caution to determine treatment. The difficulty with grading pre-operative biopsies in colorectal cancer may be owing to a lack of specific criteria such as is used in, for example, breast cancer.

Solution structures of complement components by X-ray and neutron scattering and analytical ultracentrifugation

The short consensus/complement repeat (SCR) domain (also known as the complement control protein domain) is the most abundant domain type in the complement system. Crystal and NMR structures for proteins that contain single and multiple SCR domains have now been published. These contain inter-SCR linkers of between three and eight residues, and the structures show much variability in inter-SCR orientations. X-ray and neutron scattering, combined with analytical ultracentrifugation and constrained modelling based on known subunit structures will yield a medium-resolution structure for the protein of interest. The fewer parameters that are associated with the structure of interest, the more defined the structure of interest becomes. These solution studies have been applied to several SCR-containing proteins in the complement system, most notably Factor H with 20 SCR domains, a complement receptor type 2 fragment with two SCR domains, and rat complement receptor-related protein (Crry) which contains five SCR domains. The results show great conformational variability in the inter-SCR orientation, and these will be reviewed. Even though the rotational orientation cannot be modelled, it is nonetheless possible to measure the degree of extension of the multi-SCR proteins and, from this, to obtain functionally useful results.

Pictorial review: MRI of the sternum and sternoclavicular joints

The sternum and sternoclavicular joints are difficult to evaluate with plain radiographs. The value of CT in assessing lesions of the sternum and sternoclavicular joints has been well documented, but the potential role of MRI has not been emphasized. We present the MRI techniques, normal appearances and a spectrum of abnormalities, and emphasize the role of MRI as a useful radiological investigation for the sternum and sternoclavicular joints.

An unusual complication of penile prosthesis following urethroplasty

We report a case of an adult who had undergone transpubic urethroplasty for a 5-cm long posterior urethral stricture. A malleable penile prosthesis (AMS 600R) was implanted 19 months later for the trauma-related impotence. The patient was discovered to develop a complete obliteration of the urethra after removal of infected penile prosthesis 18 months later. Perineal urethroplasty cured his restricture. Suggestions are made to prevent urethral restricture if penile prosthesis is required after urethroplasty.