Comparative trials were undertaken using 16 types of guide-tubes of different caliber and external diamter: small caliber (1.35mm) and large cliber (1.80mm) tubes of eight types of external diameter (i. e, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5 and 6.0mm). 540 tappings was performed with a hard needle (length: 58.0mm, diameter: 0.16mm, head diameter: 1.25mm).
The result can be summarized as follows:
1. Among the six small guide-tubes with 2.5-5.0mm external diameter, the larger external diameter was, the less sticking pain was experienced.
2. The four small caliber guide-tubes with 4.5-6.0mm external diameter caused significantly less sticking pain compared with the four small caliber guide-tubes of 2.5-4.0mm and the four large guide-tubes of 4.5-6.0mm.

BACKGROUND: In health examinations for local inhabitants in cadmium-polluted areas, only healthy people are investigated, suggesting that patients with severe cadmium nephropathy or itai-itai disease may be overlooked. Therefore, we performed hospital-based screening to detect patients with cadmium nephropathy in two core medical institutes in cadmium-polluted areas in Akita prefecture, Japan. METHODS: Subjects for this screening were selected from patients aged 60 years or older with elevated serum creatinine levels and no definite renal diseases. We enrolled 35 subjects from a hospital in Odate city and 22 from a clinic in Kosaka town. Urinary ß-microglobulin and blood and urinary cadmium levels were measured. RESULTS: The criteria for renal tubular dysfunction and the over-accumulation of cadmium were set as a urinary ß-microglobulin level higher than 10,000 μg/g cr. and a blood cadmium level higher than 6 μg/L or urinary cadmium level higher than 10 μg/g cr., respectively. Subjects who fulfilled both criteria were diagnosed with cadmium nephropathy. Six out of 57 patients (10.5% of all subjects) had cadmium nephropathy. CONCLUSIONS: This hospital-based screening is a very effective strategy for detecting patients with cadmium nephropathy in cadmium-polluted areas, playing a complementary role in health examinations for local inhabitants. REGISTRATION NUMBER No. 6, date of registration: 6 June, 2010 (Akita Rosai Hospital), and No. 1117, date of registration: 26 December, 2013 (Akita University).
Aged ; Aged, 80 and over ; Cadmium ; adverse effects ; urine ; Cadmium Poisoning ; blood ; complications ; urine ; Creatinine ; urine ; Environmental Exposure ; adverse effects ; Environmental Monitoring ; Environmental Pollutants ; adverse effects ; urine ; Female ; Hospitals ; Humans ; Japan ; Kidney Diseases ; chemically induced ; urine ; Male ; Middle Aged ; Sex Distribution