Bacterial indicators of pollution of the Douala lagoon, Cameroon: Public health implications

Background

Indiscriminate disposal of untreated wastes which are often heavily laden with sewage microorganisms some of which are pathogenic to humans into aquatic environments near cities could serve as potential dangers to human health.

Objective

A prospective study was undertaken to investigate the scope of potential bacterial pathogens and to assess the extent of pollution of the Douala lagoon.

Methods

A total of eighty water samples were collected fortnightly from the lagoon at five stations from March to October 2005 and analysed for heterotrophic bacterial densities, coliform counts, faecal coliform and faecal streptococcal counts. Bacteria were isolated and identified using standard microbiology and biochemical techniques.

Results

High heterotrophic bacterial counts (33 × 10⁵ − 161 × 10⁵ CFU/ mL), total coliform counts (1.8 × 10² − 2.4 × 10² CFU/100 mL), faecal coliform counts (2.2 × 10² − 2.4 × 10² CFU/ 100 mL) and faecal streptococcal counts (2.1 × 102 − 2.3 x 10² CFU/100mL were observed in all sampling stations. Eleven species of bacteria: Bacteroides fragilis, Proteus vulgaris, Klebsiella pneumoniae, E. coli, Enterococcus faecalis, Enterobacter aerogenes, Citrobacter freundii, Aeromonas hydrophila, Pseudomonas aeruginosa, Bacillus mycoides and Serratia marcesens, were frequently isolated.

Conclusion

The presence of potential bacterial agents such as Bacteroides fragilis, Pseudomonas aeruginosa, Aeromonas hydrophila, Klebsiella pneumoniae and E. coli in the lagoon may pose a serious threat to the health and well being of users of the Lagoon and calls for urgent intervention.     

Posterior Superior Mesenteric Artery (SMA) First Approach vs. Standard Pancreaticoduodenectomy in Patients with Resectable Periampullary Cancers: a Prospective Comparison Focusing on Circumferential Resection Margins

Background

The ‘SMA-first’ (P-SMA) pancreatoduodenectomy (PD) allows dissection directly on the right lateral aspect of superior mesenteric artery (SMA) which may decrease circumferential resection margin (CRM) positivity. This comparative study between standard PD (sPD) and P-SMA approach was planned focusing on CRM involvement.

Methods

This was a prospective study comparing consecutive patients with resectable periampullary cancers (PACA) undergoing PD using the standard or P-SMA approach. The perioperative outcomes and the CRM positivity rates (specimens analysed according to the standardized Leeds pathology protocol (LEEPP)) were compared.

Results

Overall, 39 patients (28 men; mean age 54 years; sPD 21, P-SMA 18) were included. Both groups were comparable with regard to demographic/tumour characteristics and perioperative outcomes. The P-SMA technique was significantly faster (321.1 ± 54.0 vs. 357.6 ± 55.8 min; p = 0.05). Though the mean tumour size (2.2 vs. 2.1 cm; p = 0.84) and T stage (T2 and T3) distribution were similar in both groups, lymph node yield was significantly higher in the P-SMA group (10.7 vs. 5.95; p = 0.001; mean 8 (2–21)). Though CRM positivity (margin <1 mm) occurred in 8 (21.1%), we did not find the P-SMA PD to yield significantly lower CRM positivity rates compared to the sPD (3/17 (17.6%) vs. 5/21(23.8%); p = 0.71). At a median follow-up of 28 months, fewer patients in the P-SMA PD group developed recurrence (2/15 vs. 5/19; p = 0.3) or died (3/15 vs. 7/19; p = 0.19), though this difference was not significant.

Conclusions

In patients with resectable PACA, P-SMA PD was significantly faster and yielded higher lymph node counts in the specimen but did not lower the rate of CRM positivity as determined by the LEEPP.

     

Risk factors for coronary artery disease in Indians

Background: A case control study was carried out to study the emerging risk factors for coronary artery disease in Indians.     

In vitro chemosensitivity of head and neck cancer cell lines

Background

Systemic treatment of head and neck squamous cell carcinoma (HNSCC) includes a variety of antineoplastic drugs. However, drug-resistance interferes with the effectiveness of chemotherapy. Preclinical testing models are needed in order to develop approaches to overcome chemoresistance.

Methods

Ten human cell lines were obtained from HNSCC, including one with experimentally-induced cisplatin resistance. Inhibition of cell growth by seven chemotherapeutic agents (cisplatin, carboplatin, 5- fluorouracil, methotrexate, bleomycin, vincristin, and paclitaxel) was measured using metabolic MTT-uptake assay and correlated to clinically-achievable plasma concentrations.

Results

All drugs inhibited cell growth in a concentration-dependent manner with an IC50 comparable to that achievable in vivo. However, response curves for methotrexate were unsatisfactory and for paclitaxel, the solubilizer cremophor EL was toxic. Cross-resistance was observed between cisplatin and carboplatin.

Conclusion

Chemosensitivity of HNSCC cell lines can be determined using the MTT-uptake assay. For DNA-interfering cytostatics and vinca alkaloids this is a simple and reproducible procedure. Determined in vitro chemosensitivity serves as a baseline for further experimental approaches aiming to modulate chemoresistance in HNSCC with potential clinical significance.