The effectiveness of processed grapefruit-seed extract as an antibacterial agent: I. An in vitro agar assay

OBJECTIVES: Grapefruit-seed extract (GSE) Citricidal has, in recent reports, been reported to be successful in combating a variety of common infectious agents. In our study, drops of concentrated grapefruit-seed extract were tested for antibacterial properties against a number of gram-positive and gram-negative organisms. DESIGN: Sixty-seven (67) distinct biotypes were tested for their susceptibilities to the GSE as well as to 5 other topical antibacterials (Silvadene, Sulfamylon, Bactroban, Nitrofurazone, and Silvadene, Nystatin). Wells were punched into Mueller-Hinton agar plates, which were then inoculated with the organism to be tested; each well was then inoculated with one of the antibacterial agents. After an overnight incubation period, the plates were checked for zones of bacterial susceptibility around the individual wells, with a measured susceptibility zone diameter of 10 mm or more considered a positive result. RESULTS: The GSE was consistently antibacterial against all of the biotypes tested, with susceptibility zone diameters equal to or greater than 15 mm in each case. CONCLUSIONS: Our preliminary data thus suggest an antibacterial characteristic to GSE that is comparable to that of proven topical antibacterials. Although the GSE appeared to have a somewhat greater inhibitory effect on gram-positive organisms than on gram-negative organisms, its comparative effectiveness against a wide range of bacterial biotypes is significant.     

The effectiveness of processed grapefruit-seed extract as an antibacterial agent: II. Mechanism of action and in vitro toxicity

OBJECTIVES: Recent testimonials report grapefruit-seed extract, or GSE (Citricidal) to be effective against more than 800 bacterial and viral strains, 100 strains of fungus, and a large number of single and multicelled parasites. This study investigated GSE for antibacterial activity at varying time intervals and concentration levels and tissue toxicity at varying concentrations in an effort to determine if a concentration existed that was both microbicidal and nontoxic and in what period of time. DESIGN: Gram-negative and gram-positive isolates were introduced into graduated dilutions of GSE (twofold concentrations ranging from 1:1, through 1:512) for determination of bacterial activity. In vitro assays with human skin fibroblast cells were also performed at the same dilutions to determine toxicity. RESULTS: These tests indicated that from the 1:1 through the 1:128 concentrations, GSE remained toxic as well as bactericidal. However, test results indicated that at the 1:512 dilution, GSE remained bactericidal, but completely nontoxic. CONCLUSIONS: The initial data shows GSE to have antimicrobial properties against a wide range of gram-negative and gram-positive organisms at dilutions found to be safe. With the aid of scanning transmission electron microscopy (STEM), the mechanism of GSE's antibacterial activity was revealed. It was evident that GSE disrupts the bacterial membrane and liberates the cytoplasmic contents within 15 minutes after contact even at more dilute concentrations.     

Predicting the distribution of under-five deaths by cause in countries without adequate vital registration systems

BACKGROUND: The absence of complete vital registration and atypical nature of the locations where epidemiological studies of cause of death in children are conducted make it difficult to know the true distribution of child deaths by cause in developing countries. A credible method is needed for generating valid estimates of this distribution for countries without adequate vital registration systems. METHODS: A systematic review was undertaken of all studies published since 1980 reporting under-5 mortality by cause. Causes of death were standardized across studies, and information was collected on the characteristics of each study and its population. A meta-regression model was used to relate these characteristics to the various proportional mortality outcomes, and predict the distribution in national populations of known characteristics. In all, 46 studies met the inclusion criteria. RESULTS: Proportional mortality outcomes were significantly associated with region, mortality level, and exposure to malaria; coverage of measles vaccination, safe delivery care, and safe water; study year, age of children under surveillance, and method used to establish definitive cause of death. In sub-Saharan Africa and in South Asia, the predicted distribution of deaths by cause was: pneumonia (23% and 23%), malaria (24% and <1%), diarrhoea (22% and 23%), 'neonatal and other' (29% and 52%), measles (2% and 1%). CONCLUSIONS: For countries without adequate vital registration, it is possible to estimate the proportional distribution of child deaths by cause by exploiting systematic associations between this distribution and the characteristics of the populations in which it has been studied, controlling for design features of the studies themselves.     

Management of nonpalpable ultrasound-indeterminate breast lesions

BACKGROUND: A series of such lesions was studied to determine the validity of applying criteria routinely used to manage palpable breast cysts to the management of mammographically detected, nonpalpable breast lesions characterized as indeterminate on ultrasound (US). METHODS: The clinicopathologic data from a series of 134 patients who underwent US-guided fine needle aspiration biopsy for nonpalpable, mammographically detected breast lesions, categorized as indeterminate on US, were reviewed. RESULTS: Of 139 indeterminate lesions, 78 were consistent with complex cysts, whereas in 61, the cystic-versus-solid nature was indistinguishable. All 71 complex cyst lesions that contained nonbloody fluid and resolved completely were benign. Two of 7 complex cyst lesions that had incomplete resolution, bloody aspirate, or both were malignant. Of 61 cystic-versus-solid lesions, 29 and 32 were primarily solid and cystic, respectively. Three of the 29 solid lesions were malignant. Of the 32 cystic lesions, all 26 that contained nonbloody fluid and resolved completely were benign, whereas 1 of 6 lesions that had incomplete resolution, bloody aspirate, or both was malignant. CONCLUSION: Criteria such as complete resolution and nonbloody aspirate are an effective adjunct to the management of nonpalpable, mammographically detected breast lesions categorized as indeterminate by US.     

Depression as a risk factor for mortality after acute myocardial infarction

The ENRICHD clinical trial, which compared an intervention for depression and social isolation to usual care, failed to decrease the rate of mortality and recurrent acute myocardial infarction (AMI) in post-AMI patients. One explanation for this is that depression was not associated with increased mortality in these patients. The purpose of this study was to determine if depression was associated with an increased risk of mortality in a subsample of the ENRICHD trial's depressed patients compared with a group of nondepressed patients recruited for an ancillary study. Three hundred fifty-eight depressed patients with an acute AMI from the ENRICHD clinical trial and 408 nondepressed patients who met the ENRICHD medical inclusion criteria were followed for up to 30 months. There were 47 deaths (6.1%) and 57 nonfatal AMIs (7.4%). After adjusting for other risk factors, depressed patients were at higher risk for all-cause mortality (hazard ratio 2.4, 95% confidence interval 1.2 to 4.7) but not for nonfatal recurrent infarction (hazard ratio 1.2, 95% confidence interval 0.7 to 2.0) compared with nondepressed patients. In conclusion, depression was an independent risk factor for death after AMI, but it did not have a significant effect on mortality until nearly 12 months after the acute event, nor did it predict nonfatal recurrent infarction.