[Comparison of bacteriostatic ability of oleum of Perilla frutescens (L.) Britt., Cinnamomum cassia Presl and Nipagin A]

A comparison of bacteriostatic ability has been carried out among oleum of Perilla frutescens and Cinnamomum cassia, benzoic acid and nipagin A. The result shows that the inhibiting effect of Perilla frutescens and Cinnamomum cassia on microorganisms inoculated and spontaneously contaminated is similar to or obviously superior to nipagin A and benzoic acid.

Gaussian beam spread in biological tissues

Flux density distributions were measured in large tissue sections illuminated with 633- and 1064-nm laser radiation delivered by an optical fiber. The results were modeled by solving the 2-D diffusion approximation for an incident Gaussian beam and fitting the data with nonlinear regression. It is shown that the radial average flux density is exponentially attenuated for an arbitrary incident irradiance profile.

The Cerium(IV)-Induced Decomposition of Peroxymonosulfate: Acid Dependence and Peroxydisulfate Formation

An improved rate law for the CeIV-induced decomposition of HOOSO3- in aqueous H2SO4 has been established by study of the rate as a function of acidity. In aqueous HClO4 the rate is much faster but a rate law could not be obtained. Peroxydisulfate, by a variant of the AsIII and FeII analysis of the redox system, has been shown to be formed in the amount of half of the CeIV lost. A free-radical chain mechanism is postulated.

Pancreaticoduodenectomy (Whipple resection) in the treatment of chronic pancreatitis

The armamentarium of the pancreatic surgeon must include multiple operative techniques, to be adapted to the clinical and anatomical findings in the patient with chronic pancreatitis. Pancreaticoduodenectomy is an essential component of this armamentarium. Its indications and limitations require continued refinement. Pancreaticoduodenectomy (Whipple operation) provides excellent results in the relief of the pain of chronic pancreatitis. The incidence of reoperation for control of pain after this procedure is less than after drainage procedures. The postoperative mortality rate in recent report is less than 2%. Whereas resection of pancreatic tissue diminishes pancreatic function, the metabolic deficits are partially compensated by the better nutritional status resulting from pain relief and discontinuation of narcotics. In experienced hands, pancreaticoduodenectomy would appear to be the procedure of choice in patients with small pancreatic ducts. In selected patients, it appears to be a good procedure and, possibly, the operation of choice when the disease is predominantly present in the head of the pancreas and/or the uncinate process, especially when strictures involve the common bile duct and duodenum. The authors prefer the procedure when a hard, chronically-inflamed mass is present in the head of the pancreas. In our experience, if the suspicion of malignancy of the head of the pancreas persists at operation, pancreaticoduodenectomy is the procedure of choice. Before undertaking resection, the individual surgeon must assess his/her own experience; a low risk is essential. The continuing alcoholic is not a candidate for pancreaticoduodenectomy. Those who will not stop drinking should seldom be accepted for resection. The same limitation exists for the narcotic addict, but few such patients are encountered today. In the authors' experience, the operation is excellent for the relief of pain. It is the lifestyle of the continuing alcoholic that poses the more significant problem.

A dual-frequency electrical impedance tomography system

An electrical impedance tomography (EIT) system has been constructed, operating at two frequencies, 40.96 and 81.92 kHz, for investigating the practicability of the dual-frequency imaging method discussed theoretically in a previous paper. For testing the system, a phantom with a frequency-dependent electrical conductivity was designed. The properties of the phantom can be adjusted to match the frequency dependence observed in a given type of tissue. Dual-frequency images were obtained from a phantom simulating liver and also from 200 g of porcine liver in a saline tank. Prior to image reconstruction, it was necessary to apply a correction to the data to cancel the effects of stray capacitance within the electronics.

Technetium-99m labeled p-aminohippuric acid analogues: renal function agents

A number of p-aminohippuric acid analogues were synthesized in order to develop clinically useful 99mTc-labeled radiopharmaceuticals for evaluation of renal function measurements. Stable 99mTc-labeled complexes were formed at pH 5.7 using a Sn(II) reduction method with all derivatives. The newly synthesized complexes were screened utilizing biodistribution studies in small animals. All complexes were excreted via the GU tract within 60 min post iv administration, with no significant activity in GI tract and liver. The [99mTc]methyl-PAHIDA complex showed optimal biodistribution among these analogues. Further investigation is needed to determine if these derivatives may be used to replace [131I]o-iodohippuric acid for the evaluation of renal function.

Applications of the 1-D diffusion approximation to the optics of tissues and tissue phantoms

Optical constants of animal and plant tissues were measured over a wide spectral range using an integrating sphere spectrophotometer. The data were analyzed with two formulations of the 1-D diffusion approximation differing in the phase function. The accuracy of the similarity transformation was examined with tissue phantoms incorporating known chromophores in light scattering media.

Clinical manifestations and diagnosis of acute pyrethroid poisoning

This article reviews 573 cases of acute pyrethroid poisoning reported in the Chinese medical literatures during 1983-1988. There were 325 cases of acute deltamethrin poisoning (occupational 158, accidental 167), 196 patients of acute fenvalerate poisoning (occupational 63, accidental 133, including 2 cases of ingestive fenvalerate-organophosphate mixture poisoning), 45 cases of acute cypermethrin poisoning (occupational 6, accidental 39) and 7 cases of other pyrethroid poisoning (occupational 2, accidental 5). The clinical manifestations have been reviewed and analysed. The diagnosis, gradation and differential diagnosis of occupational acute pyrethroid poisoning have been discussed.

Observation of high-order degenerate wave mixing in BaTiO(3)

We report for the first time to our knowledge some phenomena of high-order degenerate wave mixing observed in a BaTiO(3) crystal when self-pumped phase conjugation occurs. Applications of these phenomena are discussed.

Selective control of rat granulosa cell inhibin production by FSH and LH in vitro

We studied the role of luteinising hormone (LH) and human chorionic gonadotropin (hCG) in regulation of rat granulosa cell inhibin production. Whereas pregnant mare serum gonadotropin (PMSG) or purified rat follicle-stimulating hormone (FSH) stimulated inhibin accumulation in culture media up to 6-fold in a dose-dependent manner, hCG or LH alone were without significant effect. Concomitant addition of hCG or LH to cultures containing half maximal or maximal stimulating concentrations of PMSG did, however, result in a dose-dependent inhibition of PMSG/FSH-induced inhibin production. However, in the 2-step culture system a biphasic effect of hCG treatment on FSH-primed granulosa cell inhibin and progesterone production was evident. hCG was only inhibitory when the cells in the 2-step system were primed with PMSG. These data indicate that granulosa cell inhibin production is under direct control of both FSH and LH, and provide a possible explanation for alterations in inhibin activity around the time of ovulation in vivo.