The relationship between gastric mucosal changes and nitrate intake via drinking water in a high-risk population for gastric cancer in Moping county, China

There are conflicting reports on whether nitrate intake is related to gastric carcinogenesis. In this laboratory/field study from a high-risk area for gastric cancer, we analysed 178 samples of drinking water for nitrate and nitrite, and examined the relationship between gastric mucosal lesions (including gastric cancer) and quality of different types of drinking water and nitrate intake via water. The results showed that the nitrate content in the local drinking water was generally very high, with a mean of 109.6 mg/l (range 4.4-497.2 mg/l). There were significant differences in the nitrate content in drinking water from different wells in qualitatively different types of water. The histological changes were closely related to the quality of drinking water and its nitrate content. The results suggest that nitrate in drinking water probably plays an important role in gastric carcinogenesis and that in future aetiological studies of gastric cancer should include more information on well depth, the presence of public or private wells and nitrate content of water.

[Commercial investigation and identification of Chinese drug mabo]

According to a commercial investigation on the Chinese drug mabo being marketed in Gansu Province, there are 17 species belonging to 2 orders, 3 families and 8 genera, of which 6 species including Calvatia candida are discovered on the market for the first time. Morphologic and microscopic characteristics have been studied. A key to the identification is given.

The influence of adaptation on the oscillatory potentials of the human electroretinogram

The influence of adaptation on the oscillatory potentials of the human electroretinogram was studied in the domains of frequency and time. The amplitude of OP1 to OP4, the summed amplitude of OP1 to OP4, as well as the area, decreased from dark adaptation to light adaptation. With increasing intensities of background illumination, they increased slightly and appeared to decrease with the strongest background illumination. The implicit time of oscillatory potentials 3 and 4 increased with stronger background illumination and decreased with the strongest background illumination. The results of the dominant frequency and the total power of the OPs correspond to the results in the time domain. The dominant power decreased from dark adaptation into light adaptation and did not show any systematic changes with increasing intensity of background illumination.

Virological survey of rhesus monkeys in China

A virological survey of rhesus monkeys captured in China for 13 viruses and/or antibodies was performed. Antigens used were SFV, SF40, HSV-1, Sa11, measles, vaccinia, epidemic or simian hemorrhagic fever, Langat, Kunming, poliomyelitis, HIV, SV41 and rubella. Monkeys were from Sichuan, Hunan, Guizhou, Yunnan and Guangxi provinces. Antibody was detected to all the listed viruses except HIV, SV41 and rubella. Both SFV and SV40 were recovered from monkeys, but H. simiae, LCM and coxsackieviruses were not.

Preventive health practices in a teaching hospital: house staff attitudes and performance of gynecological screening

Attitudes toward and the performance of Pap smears by the house staff in nongynecological hospital admissions were evaluated as markers of preventive health practices in a tertiary-care hospital. A major discrepancy between house staff attitudes and behaviors was noted. The residents considered it important to offer a Pap smear to all women on admission. However, a random review of 150 medical and surgical charts revealed a lack of documentation of pelvic examinations in 67 percent of the charts and Pap smears in 33 percent of the charts. Overall, Pap smears were actually performed on only eight of 150 patients. A survey of random hospital floors revealed a lack of equipment and facilities for performing Pap smears. Such factors were thought to be the major contributors to the failure by house staff to perform pelvic exams and Pap smears. Steps to increase the performance of these types of preventive health practices should include the use of a checklist admission form and the maintenance of appropriately equipped facilities on all hospital floors. We suggest a greater emphasis on the development of educational strategies to teach preventive health care principles in residency training programs.

Effect of interstitial fluid (kerosene) on pressure-volume characteristics of rat lung

Although pulmonary interstitial edema has been estimated to decrease pulmonary compliance (CL), it has been experimentally difficult to demonstrate whether the observed changes in CL are directly due to the presence of interstitial fluid or if they result instead from concomitant pulmonary vascular engorgement and/or alveolar edema. Since kerosene-inflated lungs do not leak, we were able to use kerosene to measure the effect on CL of the accumulation of interstitial fluid (kerosene) in the postmortem rat lung. Pressure-volume (PV) studies of the lung were done during the progressive increase in interstitial fluid (kerosene). Analysis of the deflation limbs of the quasistatic PV curves obtained following serial inflations with kerosene indicated that the maximal volume of kerosene [MV35, equal to the maximum tissue plus airway volume at a transpulmonary pressure (Ptp) of 35 cmH2O] was 3.8 +/- 1.2 ml (31.0 +/- 11.8%) greater than TLC35 [air volume at Ptp of 35 cmH2O prior to kerosene inflation]. The increases in interstitial kerosene volume had no effect on kerosene PV characteristics, as was demonstrated by superimposing lung PV curves obtained at various states of interstitial filling. We conclude that the interstitial compartment is large and very compliant and that the presence of even great amounts of fluid limited to this compartment does not restrict lung expansion.

Spectroscopic characterization of alpha-crustacyanin

alpha-Crustacyanin exhibits two CD extrema with negative and positive bands at 690 and 583 nm in phosphate buffer, respectively. The CD spectrum is interpreted in terms of dipoledipole coupling between the transition moments of the two astaxanthin molecules on each subunit. The CD splitting yields an exciton bandwidth of 2800 cm-1, corresponding to an inter-chromophore distance of ca. 13 A in which the two astaxanthin molecules exist in a dimeric array with a mutual orientation angle of ca. 90 degrees. The SDS denaturation completely abolishes the long wavelength CD splitting, while 2 M NaCl reduces the overall CD intensity without destroying the split CD spectrum. It is suggested that the characteristic CD extrema at 583 and 690 nm arise from the intra-subunit astaxanthin-astaxanthin coupling. The binding site for astaxanthin contains one or more tryptophan residues, as the tryptophan fluorescence is quenched by energy transfer from the tryptophan to the prosthetic group in the native form of the carotenoprotein. The strong red shift (lambda max 487 nm) is probably due to interactions between tryptophan residue(s) and the chromophore molecules through dipole-dipole or partial charge transfer forces.