Calculate gastric ulcer severity and pharmacological protection efficacy.
Test Group Observations (Cumulative)
Count of rats/lesions with red coloration.
Count of rats/lesions with spot ulcers.
Count of hemorrhagic streaks.
Count of ulcers involving muscularis mucosa.
Count of frank perforations.
Control Group Data (Optional)
Required to calculate % Inhibition/Protection.
Total Severity Score:0.0
Mean Ulcer Index (UI):0.00
Percent Inhibition (%):—
Understanding Ulcer Index Calculation in Rats
In pharmacological research, the evaluation of anti-ulcer activity for potential drug candidates is frequently conducted using rat models. The Ulcer Index (UI) is a quantitative metric used to assess the severity of gastric lesions induced by necrotizing agents (such as ethanol, aspirin, or indomethacin) or physiological stress (pyloric ligation).
Scoring Methodology
To calculate the Ulcer Index, the stomach is removed, opened along the greater curvature, and washed with saline. The mucosal surface is then examined under a magnifying lens. A weighted scoring system is typically applied to quantify the damage:
Score 0: Normal stomach.
Score 0.5: Red coloration or shedding of epithelium.
Score 1.0: Spot ulcers.
Score 1.5: Hemorrhagic streaks.
Score 2.0: Deep ulcers (involving the muscularis mucosa).
Score 3.0: Perforation.
Calculation Formulas
This calculator determines the Mean Ulcer Index for a test group using the arithmetic mean of the cumulative severity scores divided by the number of animals in the group:
Mean UI = (Sum of all individual severity scores) / (Total number of rats)
Percentage Inhibition (Protection)
To evaluate the efficacy of a test drug, the Ulcer Index of the treated group is compared to a control group (which received only the ulcerogenic agent/vehicle). The percentage protection is calculated as:
A higher percentage inhibition indicates stronger gastroprotective activity of the substance being tested.
function calculateUlcerData() {
// 1. Get input values
var redness = parseFloat(document.getElementById('countRedness').value) || 0;
var spot = parseFloat(document.getElementById('countSpot').value) || 0;
var streak = parseFloat(document.getElementById('countStreak').value) || 0;
var deep = parseFloat(document.getElementById('countDeep').value) || 0;
var perf = parseFloat(document.getElementById('countPerforation').value) || 0;
var n = parseFloat(document.getElementById('totalRats').value);
var controlUI = parseFloat(document.getElementById('controlIndex').value);
// 2. Validate N
if (!n || n 0).");
return;
}
// 3. Calculate Weighted Total Score
// Weighting: 0.5, 1.0, 1.5, 2.0, 3.0 based on standard Kulkarni/Ganguly methods
var totalScore = (redness * 0.5) + (spot * 1.0) + (streak * 1.5) + (deep * 2.0) + (perf * 3.0);
// 4. Calculate Mean Ulcer Index
var meanUI = totalScore / n;
// 5. Calculate Inhibition if Control UI is provided
var inhibitionText = "–";
if (!isNaN(controlUI) && controlUI > 0) {
var inhibition = ((controlUI – meanUI) / controlUI) * 100;
// Handle negative inhibition (worsening) or cap at 100? usually just raw math
inhibitionText = inhibition.toFixed(2) + "%";
} else if (controlUI === 0) {
inhibitionText = "N/A (Control is 0)";
}
// 6. Update DOM
document.getElementById('resTotalScore').innerHTML = totalScore.toFixed(1);
document.getElementById('resMeanIndex').innerHTML = meanUI.toFixed(2);
var inhibElem = document.getElementById('resInhibition');
inhibElem.innerHTML = inhibitionText;
// Color coding for inhibition
if(inhibitionText !== "–" && inhibitionText.indexOf("%") > -1) {
var val = parseFloat(inhibitionText);
if(val > 50) {
inhibElem.style.color = "#27ae60"; // Green for good protection
} else if (val < 0) {
inhibElem.style.color = "#c0392b"; // Red for worsening
} else {
inhibElem.style.color = "#2c3e50";
}
}
document.getElementById('resultDisplay').style.display = "block";
}