Mesosomes of Staphylococcus aureus ATCC 25923 treated with antibiotics were examined morphologically under the electron microscope. The Transmission Electron Microscope Rapid Method was used to eliminate the artifacts due to sample processing. Mesosomes were seen in all the antibiotic treated bacteria and not in the control group. The main factor that contributes to the formation of mesosomes in the bacteria was the mode of action of the antibiotics. The continuous cytoplasmic membrane with infolding (mesosomes) as in the S. aureus ATCC 25923 is therefore confirmed as a definite pattern of membrane organization in gram positive bacteria assaulted by amikacin, gentamicin, ciprofloxacin, vancomycin and oxacillin antibiotics. Our preliminary results show oxacillin and vancomycin treated bacteria seemed to have deeper and more mesosomes than those treated with amikacin, gentamicin and ciprofloxacin. Further research is needed to ascertain whether the deep invagination and the number of mesosomes formed is associated with the types of antibiotic used.
Antibiotics ; seconds ; Mesosome ; Staphylococcus aureus ; Bacterial

INTRODUCTIONIntravenous thrombolysis has been shown to improve outcome after acute cerebral infarction if given within 3 hours of symptom onset. There are no data in Singapore on the timing of hospital presentation after acute cerebral infarction as well as factors and reasons for delayed presentation.

MATERIALS AND METHODSAs intravenous thrombolysis has recently been licensed for use in acute cerebral infarction in Singapore, we studied 100 consecutive acute cerebral infarction admitted to the Singapore General Hospital for timing of hospital presentation, reasons associated with delay in presentation and hypothetical acceptance of intravenous thrombolysis.

RESULTSOnly 9% of patients presented to hospital within 2 hours of symptom onset. Factors associated with hospital presentation within 2 hours were a large stroke and lack of pre-hospital consultation. Failure to recognise the severity of symptoms and inability to seek medical attention unaided were the 2 most common reasons for delayed presentation. One-third of patients or their relatives hypothetically would accept intravenous thrombolysis, suggesting that a thrombolysis service is feasible at the Singapore General Hospital. However, it would be hindered by the low proportion of patients who present early to hospital after symptom onset.

CONCLUSIONOur results support the need for a public education programme to highlight the identification of stroke symptoms and the need to present to hospital as soon as possible after the onset of stroke symptoms.

Acute Disease ; Aged ; Cerebral Infarction ; drug therapy ; physiopathology ; Emergency Service, Hospital ; Female ; Fibrinolytic Agents ; therapeutic use ; Hospitals, General ; Humans ; Infusions, Intravenous ; Male ; Middle Aged ; Patient Acceptance of Health Care ; statistics & numerical data ; Prospective Studies ; Singapore ; Time Factors ; Treatment Outcome

Humans ; Pharmaceutical Preparations ; Singapore