By: Alatise O.I., Obiajunwa E.I, Lawal O.O, Adesunkanmi A.R.
Gallstone disease is a major health problem in many parts of the world. In Nigeria, however, only a few cases of gallstone disease are reported. Minor/trace elements are reported to play a significant role in the formation of gallstones. This study was conducted to assess the minor elements in gallstone of Nigerian patients who had cholecystectomy in our institution using particle-induced X-ray emission (PIXE) technique. We also compare the findings with previous reports from outside Nigeria. Fourteen patients who had cholecystectomy for calculous cholecystitis at Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife, Nigeria, between March 2006 and July 2008, had the stone retrieved. The stones were analyzed for trace elements at the Center for Energy Research and Developments of the University using PIXE experiments. Certified standard reference material, NIST 1577a (bovine liver), was equally analyzed to confirm the accuracy of the experimental procedure. Computer code GUPIXWIN was used to analyze the data. Fourteen elements, phosphorus, sulfur, chlorine, potassium, calcium, manganese, iron, copper, zinc, bromide, lead, titanium, rubidium, and strontium, were detected in most of the samples. The concentrations of the elements varied in the different samples, ranging from a few parts per million to a few percent. Ca was the major constituent of all samples. The black sand-like samples had very high levels of P, S, K, and Pb, which were different from a previous report. The distribution of trace elements in stones in Nigeria patients is different from previous report outside Nigeria, and this may have some role in the occurrence of gallstones in the black African.
Introduction
Stone disease is a major health problem in many parts of the world. In Nigeria a good number of people suffer from various forms of stone disease. The stones are commonly found in the gallbladder, kidney, urinary tract, etc. Gallstones are formed when liquid stored in the gallbladder harden into pieces of stone-like materials. Gallstones can be as small as a grain of sand or as large as a golf ball. The gallbladder can develop just one large stone, hundreds of tinny stones, or a combination of the two. Gallstones can block the normal flow of bile if it move from the gallbladder and lodges in any of the ducts that carry bile from the liver to the small intestine1.
We report here the results of the analysis of human gallstones extracted from eight patients at O.A.U.T.H.C, Ile-Ife. The gallstones were of various types as shown in figure 1.
Fig. 1: Pictures of the different gallstones extracted from patient
PIXE a powerful technique for elemental analysis, particularly in the investigation of concentrations of trace elements was used in the analysis of these samples.
Experimental
Samples preparation and Methods
Gallstones removed from different patients were collected at the O.A.U.T.H.C, Ile-Ife. They were washed with double distilled water to remove possible blood constituents and dried in desiccators at room temperature. The dried samples were ground in agate mortar and mixed with 10% by weight of ultra pure graphite powder and prepared into thick pellets of 11 mm diameter without binder
The PIXE experiments were performed using a 3.0 MeV proton beam obtained from CERD ion beam analysis (IBA) facility. This facility is centered on a NEC 5SDH 1.7 MV Pelletron Accelerator, equipped with a RF charge exchange ion source. The ion source is equipped to provide proton and helium ions. The end-station consists of an Aluminum chamber of about 150cm diameter and 180cm height. It has four ports and a window. Port 1 at 165° is for the RBS detector, Port 2 at 135° is for the PIXE detector, Port 3 at 30° is for the ERDA detector, the window at 0° is for observing the beam position and size, while Port 4 at 225° is for PIGE. The chamber has a sample stick that can carry 11 (eleven) (13mm Ø) samples. The End-station has a turbo pump and a variable beam collimator to regulate beam size, and an isolation value. Bovine liver standard (NIST 1577a) was used for the determination of the H-value which was subsequently used for analyzing the gallstone samples.
Fig 2: Typical Spectrum of the black sand-like gallstones
Fig 3: Typical Spectrum of the dark brown pebble-like gallstones
Fig 4: Typical Spectrum of the yellow powdery gallstones
Results
The concentrations of various elements present in the gallstones samples are provided in Table 1. The PIXE data analysis showed the presence of P, S, K, Ca, Ti, Mn, Fe, Cu, Zn, Br, Rb, Sr, and Pb. The spectra of the gallstones are shown in Figs. 2, 3, and 4.
Table 1: PIXE results (μg/g) of the gallstones samples
**This work has been published in Biol. Trace Elem. Res (2010) 134:13-24.
Biol Trace Elem Res. 2010 Apr;134(1):13-24. doi: 10.1007/s12011-009-8453-3. Epub 2009 Jul 17.