ABSTRACT
The rhizosphere of two turf cover sorts; Bermuda grass and American grass contained high numbers, 8.1 to 16.8 x 10(6) g(-1) of cultivable oil-utilizing and diazotrophic bacteria belonging predominantly to the genera Agrobacterium, Arthrobacter, Pseudomonas, Gordonia, and Rhodococcus. Those bacteria also grew on a nitrogen-free medium and demonstrated the ability to reduce acetylene to ethylene. These isolates grew on a wide range of n-alkanes (C9 to C40) and aromatic hydrocarbons, as sole sources of carbon. Quantitative determinations revealed that predominant bacteria consumed crude oil and representative aliphatic (n-octadecane) and aromatic (phenanthrene) hydrocarbons efficiently. The fact that those organisms had the combined activities of hydrocarbon-utilization and nitrogen-fixation makes them suitable tools for bioremediating oily desert areas that are normally poor in nitrogenous compounds. Phytoremediation experiments showed that spreading turf cover on oily desert soil inhibited oil volatilization and enhanced oil loss in soil by about 15%. Oil loss was also enhanced in turf free soil samples fertilized with NH4NO3. In conclusion, covering this oil-polluted soil with turf cover minimized atmospheric pollution, increased the numbers of the oil-utilizing/nitrogen-fixing bacteria by about 20 to 46% thus, encouraging oil attenuation.
Subject(s)
Actinobacteria/metabolism , Poaceae/metabolism , Poaceae/microbiology , Proteobacteria/metabolism , Rhizosphere , Soil Pollutants/metabolism , Actinobacteria/classification , Actinobacteria/isolation & purification , Air Pollution/prevention & control , Alkanes/metabolism , Base Sequence , Biodegradation, Environmental , Cynodon/metabolism , Cynodon/microbiology , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Hydrocarbons, Aromatic/metabolism , Kuwait , Molecular Sequence Data , Nitrogen Fixation , Petroleum/metabolism , Petroleum/microbiology , Phenanthrenes/metabolism , Proteobacteria/classification , Proteobacteria/isolation & purification , RNA, Ribosomal, 16S , Sequence Analysis, DNA , Soil/analysis , Soil Pollutants/analysisSubject(s)
Anti-Bacterial Agents/therapeutic use , Drug Prescriptions/statistics & numerical data , Drug Utilization Review/statistics & numerical data , Practice Patterns, Physicians'/statistics & numerical data , Attitude of Health Personnel , Clinical Competence/standards , Drug Resistance, Microbial , Family Practice/education , Family Practice/statistics & numerical data , Guideline Adherence/statistics & numerical data , Health Knowledge, Attitudes, Practice , Humans , Physicians, Family/education , Physicians, Family/psychology , Practice Guidelines as Topic , Saudi Arabia , Surveys and QuestionnairesABSTRACT
BACKGROUND: Gastrointestinal (GI) smooth muscle tumors are a group of intramural GI tumors formerly known as leiomyoma and leiomyosarcoma. This retrospective study was made to review our experience in surgical management of GI smooth muscle tumors. METHODS: The clinical records for patients with GI smooth muscle tumors during 1993-1999 were reviewed. RESULTS: Ten tumors were located in stomach. Abdominal pain was the main presenting symptom followed by GI bleeding. The preoperative diagnosis was made by enhanced computerized tomography (CT) on eleven patients out of thirteen, while upper GI endoscopy with biopsy identified six tumors out of thirteen patients had the test. Tumors were treated by conservative excision in four and radical excision in fourteen. Histology was leiomyoma in six patients (with mitotic figures < 4 per 10 high power field) and leiomyosarcoma was found in twelve patients (with mitotic figures> 4 per 10 high power field). Median follow-up was 4 years. There was one recurrence for leiomyoma (size: 6 cm). All patients with leiomyosarcoma presented later with metastasis and died. CONCLUSION: Size and mitotic activity of tumors are the main determinant factors. Enhanced CT remains the proper diagnostic tool.
