Growth, Germination and Toxigenic Activity of Bacillus cereus in Milk Products

Growth, germination and toxigenic activity of Bacillus cereus in pasteurized milk, fruit-flavored reconstituted milk and fermented milk at 30°C were studied. Vegetative cells of B. cereus rapidly increased to 10⁸ CFU/ml in 8 h and 10⁶ CFU/ml in 12 h in pasteurized milk and fruit-flavored reconstituted milk respectively. In fermented milk, vegetative cells of B. cereus were killed or inactivated in 40 min; while about 31% of spores survived the 7 d test period. Spore germination of B. cereus was inhibited by fruit-flavored reconstituted milk and fermented milk. Chinese hamster ovary cells were transformed and/or lysed by pasteurized milk and sterilized milk with B. cereus cultured for 8 h and also by laboratory-prepared fermented milk with B. cereus introduced at the beginning of fermentation an incubated for 12 or 72 h.

Effects of Lactic Acid Bacteria and Organic Acids on Growth and Germination of Bacillus cereus

Growth and germination of vegetative cells and endospores of Bacillus cereus were affected by Streptococcus lactis, Streptococcus thermophilus, Lactobacillus acidophilus , and Lactobacillus bulgaricus in nonfat milk medium and by salts of organic acids in broth medium. Growth of the lactic acid bacteria was not affected by B. cereus. B. cereus increased rapidly to about 10 8 CFU/ml when cells were added at the beginning of growth of lactic acid bacteria; it was inactivated slowly when added after 24 h and rapidly when added after 72 h of lactic acid bacterial growth. Streptococci were more inhibitory to the growth of B. cereus than lactobacilli were at 24 h. Spore germination was not affected after 24 h, but it was inhibited after 48 and 72 h of lactic acid bacterial growth. Acetate was more inhibitory to the growth of vegetative cells, while formate was more inhibitory to spore germination. Acetate, formate, and lactate (all at 0.1 M) completely inactivated multiplication of B. cereus at pH 6.1, 6.0, and 5.6, respectively. Spores of B. cereus were more resistant to these organic acids compared with the resistance of vegetative cells. Formate, lactate, and acetate (all at 0.1 M) caused 50% inhibition of spore germination at pH 4.4, 4.3, and 4.2, respectively.

Study on erythrocyte membrane fluidity by laser Raman spectroscopy

Differences between patients with cirrhosis of liver, nephrotic syndrome, coronary heart disease and normal subjects in laser Raman spectra of erythrocyte membranes have been found. In regions of 1000-1140 cm-1 and 2840-3000 cm-1, the ratios I1130/I1080 and I2890/I2850 in patient membranes are higher than those in normal ones respectively. These results mean that erythrocyte membrane fluidity of these patients is reduced. This reduction may be attributed to the possibility that erythrocyte membrane of patients get more cholesterol from their plasma and resulted in the modification of the ratio of cholesterol/phospholipids in the membranes.

Chlamydial infection in a Chinese gynecologic outpatient clinic

In an attempt to detect the presence, if any, of cervical chlamydial infection, we obtained endocervical smears from 1000 female patients attending the outpatient gynecologic and family planning clinics at Women's Hospital, Zheijiang Medical University, Hangzhou, People's Republic of China. Using direct immunofluorescent monoclonal antibody staining technique, we identified elementary bodies typical of the Chlamydia trachomatis organism in ten of the 1000 slides (1%). The only characteristic of statistical significance in this small group of infected women was the complaint of infertility for more than two years' duration, noted in six of the ten cases.

Decline of chlorinated hydrocarbon insecticides residues in the tea-garden soils of Taiwan

Residues of chlorinated hydrocarbon insectidies and some of their metabolites, including p,p'-DDT, p,p'-DDD, p,p'-DDE, gamma-BHC, aldrin, dieldrin, heptachlor and heptachlor epoxide, were examined in the soils collected from 21 tea-gardens distributed in 15 countries of 6 prefectures in 1977, and from 100 locations distributed in 46 counties of 10 prefectures in 1984 in Taiwan. Although the use of these chlorinated hydrocarbon insecticides has been banned for many years, minor amounts of residues in the soils have still been detected. From 1977 to 1984, average residues of the chlorinated hydrocarbon insecticides and their metabolites in the soils of tea-gardens decreased from 5.64 to 0.06 ppb for gamma-BHC, 97 54 to 1.10 ppb for aldrin, 35.91 to 1.00 ppb for p,p'-DDE, 17.41 to 0.28 ppb for dieldrin, and 30.17 to 3.42 ppb for p,p'-DDT. But the number of positive cases increased for all chlorinated hydrocarbon insecticides tested, the residual levels were not significantly different among soils with different physiochemical properties or among soil layers. No significant amount of these insecticides was found in the processed tea.

Structure-activity relationships of 6-(heterocyclyl)-methylene penam sulfones; a new class of beta-lactamase inhibitors

6-(Heterocyclyl)methylene penam sulfones (1) are effective beta-lactamase inhibitors and potent ampicillin and cefazolin potentiators against both Gram-positive and Gram-negative beta-lactamase producing bacteria. Several of these analogs having a pi-deficient 2-heteroaryl substituent attached to the C6-methylene position showed better inhibitory activity than clavulanic acid, Ro 15-1903, 6 beta-bromopenicillanic acid, and sulbactam against a variety of beta-lactamases. The compounds were devoid of any antibacterial activity, but in combination with ampicillin or cefazolin, exhibited synergistic activity at least equal to clavulanic acid, Ro 15-1903, 6 beta-bromopenicillanic acid or sulbactam against beta-lactamase producing strains. Structure-activity relationships for a number of compounds are described. The structure-activity relationships can be rationalized by an enzyme inhibition mechanism which we have previously proposed on the basis of methanolysis of 6-(2-pyridyl)methylene penam sulfone (1a). Two synthetic routes to prepare compounds of structural type 1 via either a Wittig reaction or an aldol condensation are reported. beta-Lactamase inhibition and MIC data are presented.

The diagnosis of colorectal cancer with cytologic brushings under direct vision at fiberoptic colonoscopy. A report of 59 cases

Fifty nine cases of colorectal cancer confirmed postoperatively by histologic examination were correlated with the findings of biopsy specimens and cell brushings. Fifty one cases were positive for malignancy on biopsy (86.4 percent). Brush cytology was positive in 51 cases (86.4 percent). The total preoperative confirmed diagnostic rate of the series was 91.5 percent. Brushing cytology under direct vision at fiberoptic colonoscopy, is a safe, reliable, and quite accurate method for the diagnosis of colorectal cancer. The results from brush cytology did not relate to the configuration and appearance of the tumor. For cell brushing, the fluid in the colonic lumen should be aspirated off as thoroughly as possible. Cell brushings are often positive when colonic stricture and obstruction prevent the colonoscope from reaching the lesion; biopsy, obviously, cannot be done in such a case.

Reconstruction of rectal sphincter by transposition of gluteus muscle for fetal incontinence

Many remedial operations have been described for fecal incontinence. We describe a bilateral gluteus muscle transposition to encircle the rectum with striated muscle. This procedure positions a voluntary muscle around the rectum to produce volitional rectal closure, the opposite direction pulling produces a kinking closure of the rectum, and the newly accentuated anorectal angle also facilitates continence. In 6 incontinent patients, 3 were normalized by this procedure, 1 was improved, and 2 had delayed improvement secondary to the development of a fecaloma. Gluteus muscle transposition may be a useful secondary procedure in that patient with muscle dysfunction deficiency fecal incontinence.

Structural studies on rhodilunancins A and B

Antitumor antibiotics rhodilunancins A and B were isolated from a culture of Streptomyces violaceus var. lunanensis var. n. No. 1289 by acidic acetone extraction of mycelia and purified by silica gel chromatography. Rhodilunancin A is identical to cosmomycin A. Rhodilunancin B is identical to cosmomycin B (= rhodomycin Y). Both antibiotics exhibited activities against Gram-positive bacteria and inhibition on DNA synthesis of P388 leukemia cell in vitro.

Microsurgical anatomy of the lateral skin flap of the leg

The blood supply, venous drainage, and innervation of the lateral skin flap of the leg were studied in 52 fresh specimens by dissection, angiography, and selected injection of cutaneous arteries with india ink. This flap has a long vascular pedicle that contains the peroneal artery and vein and their branches. The diameter of the peroneal artery is about 3.7 mm. There are 4 to 7 cutaneous branches that penetrate the posterior intermuscular septum and widely anastomose with each other in the subcutaneous tissue. The skin area supplied by the peroneal artery measures approximately 32 X 15 cm. There are 2 sets of veins in the flap: (1) 2 deep veins, the peroneal veins, are about 4 mm in diameter, and (2) a superficial vein, the small saphenous vein, is about 3.3 mm in diameter. The cutaneous nerve is the lateral sural cutaneous nerve. This new lateral skin flap of the leg may be used either as a free flap or as a cutaneous flap and has been proven successful clinically.

A study of dynamic development in radiolesion and cell death of eukaryotes after exposure to ionizing radiation--the visualization of the dynamic reaction by means of cytochemical method with lactate dehydrogenase (LDH) as a nuclear marker and radiation-induced nuclear anomalization by an ultramicrostructural manifestation: a dynamic explanation

The present work deals with the radiation effect on adult rats suffering from acute, whole-body irradiation with cobalt-60 gamma rays of dosages 100R and 300R respectively. The morphological alteration of the lymphocytic nucleus and exhibition of cytochemical reaction of LDH in intra- or extra-nuclear region has been observed at the end of predetermined time intervals after irradiation. A close relationship between the percentage of damage of the lymphocytic nucleus and that of positivity of LDH reaction is seen from their variations with time parallel. From technical color microphotographs which exhibit cytochemical reactions, the existence of enzyme LDH in the nucleus so far obscure has been visually recognized. The events happening in enzymic reaction and the leakage of enzyme across the nuclear envelope reflect the dynamic nature. The ultrastructural alteration of nuclear anomalization confirms the dynamic development of inducing radiolesion. The experimental facts inspire us to attempt an explanation of cellular radiolesion and cell death owing to ionization radiation in light of the dynamic concept.

Effect of higenamine on action potential of ventricular myocardial cells

Action potentials of isolated ventricular myocardial fibers of pigs and the electrophysiological actions of dl-demethylcoclaurine (DMC) or higenamine on the porcine myocardial cells were studied by glass microelectrodes. The action potentials of porcine ventricular myocardial fibers were similar to those of other mammalian hearts. Amplitude of the action potential was 115 +/- 9 mV, duration of action potential 242 +/- 30 ms, resting membrane potential -85 +/- 5 mV and the maximum rise of depolarization of action potential 151 +/- 27 V/s. After perfusion with normal Tyrode's solution containing DMC 5 micrograms/ml, the amplitude of action potential was increased and the duration of action potential was prolonged, the amplitude and duration of the plateau of action potential were increased and the slope of phase 2 of action potential was reduced (p less than 0.05). The resting potential, the slope of phase 3 and the maximum depolarization rate of phase 0 of action potential did not change. In Tyrode's solution containing Mn++ 3 mM, these electrophysiological actions of DMC disappeared. DMC may abolish the conduction block induced by K+-rich solution. In Tyrode's solution containing K+ 32 mM, the upstroke of action potential showed 2 phases under influence of DMC. The second phase disappeared when Mn++ was added. All findings indicate that DMC can be considered as an activator of the slow channel. The electrophysiological mechanism and clinical significance of DMC were discussed.