Changes in Cellular Fatty Acid Composition of Cephalosporium acremonium during Cephalosporin C Production

Cephalosporium acremonium was cultivated in fermentation medium containing sucrose or methyl oleate as a carbon source for cephalosporin C production. The level of antibiotic production was 48 g of cephalosporin C per liter under optimum conditions when methyl oleate was used. The C(18:1) (oleic acid) methyl ester appeared to be utilized faster than the C(18:2) (linoleic acid) methyl ester in fermentation broth. Physiological characteristics of C. acremonium were investigated by determining the fatty acid composition of the total cellular free lipid. Significant changes in cellular fatty acid composition occurred during inoculum cultivation and fermentation. The percentage of C(18:1) increased from 19.1 to 38.5%, but the percentage of C(18:2) decreased from 56.7 to 36.1%, and there was an increase in pH during inoculum cultivation. The cellular fatty acid composition of C. acremonium grown in fermentation medium containing methyl oleate (methyl oleate medium) was significantly different from that in fermentation medium containing sucrose (sucrose medium). The major fatty acids detected were C(16:0) (palmitic acid), C(18:1), and C(18:2). In methyl oleate medium, the ratio of C(18:1) to C(18:2) increased from 0.34 to 1.37, while the cell morphology changed from hyphae to arthrospores and conidia. In contrast, in sucrose medium, the ratio of C(18:1) to C(18:2) decreased from 0.70 to 0.43, and most of the cells remained hyphal at the end of fermentation. We observed that hyphae contained a higher proportion of C(18:2) but arthrospores and conidia contained a higher proportion of C(18:1).

Effect of carbon monoxide intoxication on skin perfusion in anaesthetized rats

Carbon monoxide intoxication decreases systemic blood pressure and peripheral resistance. In order to assess the role of the skin in this process, we measured the perfusion of hind limb shaven skin in anaesthetized rats during acute moderate carbon monoxide intoxication. At a steady blood level of 25% carboxyhaemoglobin, the red blood cell flux was measured as an index of tissue perfusion, using laser Doppler fluxmetry. The mean blood pressure decreased by 30% during carbon monoxide exposure, but there was no change in mean red blood cell flux of the hind limb skin microvessel bed. Thus, rat hind limb skin perfusion was not affected by acute moderate steady state carbon monoxide intoxication.

Suprageneric classification of peptidoglycan group B actinomycetes by nucleotide sequencing of 5S ribosomal RNA

5S ribosomal RNA sequences were determined for thirteen actinomycetes mainly representatives with the rare group B type peptidoglycan. The primary and secondary structure of the resultant sequences were of the type characteristic of Gram-positive bacteria with DNA rich in guanine plus cytosine. The sequencing and associated chemotaxonomic data provide compelling grounds for classifying actinomycetes with a group B type peptidoglycan in a single family. The family Microbacteriaceae fam. nov. is proposed to accommodate actinomycetes classified in the genera Agromyces, Aureobacterium, Clavibacter, Curtobacterium and Microbacterium.

Rapidly-frozen polypeptide samples for characterization of high definition dynamics by solid-state NMR spectroscopy

A method is described for defining anisotropic local dynamics in polypeptides by solid-state NMR. To avoid conformational heterogeneity introduced by large hexagonal ice crystals in low temperature hydrated samples, a fast-freezing technique is used for sample preparation. For a demonstration of this approach, the backbone librational motions of the gramicidin A channel conformation are studied in hydrated DMPC bilayers. The static 15N chemical shift tensor is characterized at 123 K for the Ala3 site. The temperature dependence of this tensor yields a determination of the librational amplitude and anisotropy of the motionally sampled space. This amplitude represents the sum of nanosecond and picosecond time-frame motions, both of which have a significant amplitude.

Prolonged fasting in pediatric outpatients does not cause hypoglycemia

Two hundred and thirty healthy children scheduled for receiving elective minor surgery were assigned into 4 different groups. Group I (small infant group) included 27 infants of age from 1 to 3 months (2.0 +/- 0.6 months), Group II (infant group) included 42 infants age from 3 to 12 months (7.4 +/- 2.8 months), Group III (pre-school children group) included 122 patients of age from 1 to 6 years (3.1 +/- 1.4 years). The remained 39 cases of age older than 6-years-old (8.0 +/- 1.5 years) were collected in group IV (old children group). All studied children were starved for at least 4, 6, or 8 hours in infants, pre-school children, and old children group, respectively, pre-operatively. The fasting time and fasting blood glucose levels of the 4 groups were 6.7 +/- 1.4 hours and 109.0 +/- 22.9 mg% in group I, 7.7 +/- 2.3 hours and 98.6 +/- 18.0 mg% in group II, 10.4 +/- 2.9 hours and 96.9 +/- 24.7 mg% in group III, and 12.6 +/- 2.6 hours and 95.7 +/- 20.5 mg% in group IV, respectively. No one in the 230 children had blood glucose less than 40 mg% even in 5 infants who were starved for 12 hours or more. Therefore, we concluded that preoperative starvation is well tolerated than the originally expected in the infants and children. The fasting time before anesthesia can be executed safely even though the operation schedule may not be right on time.

Effects of tannic acid on 12-O-tetradecanoylphorbol-13-acetate-induced protein kinase C activation in NIH 3T3 cells

Tannic acid (TA) is a naturally occurring phenol, which has been found to display an antipromotion effect on mouse skin carcinogenesis. In order to explore the molecular mechanism, we have examined the process of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced protein kinase C (PKC) activation, including phorbol ester binding, enzyme translocation, autophosphorylation and substrate phosphorylation, and finally the TPA-stimulated DNA synthesis. In an initial study, we found that TA slightly inhibited [3H]phorbol dibutyrate (PDBu) binding to intact cells, and only 30% reduction of phorbol ester binding was observed at the highest dose of TA (100 microM). Further analysis by Scatchard plot showed that TA reduced the Bmax of [3H]PDBu from 1.3 pmol/10(6) cells to 1.1 pmol/10(6) cells, but the Kd was increased from 24 to 30 nM. Analysis by western blot indicated that TA did not interfere with the TPA-induced PKC translocation, whereas TA effectively blocked the TPA-evoked phosphorylation of the membrane-bound PKC moiety and its 80 kDa substrate in a dose-dependent manner. We also found that pre- or post-treatment with TA both lead to a similar reduction of 80 kDa protein phosphorylation and that the TPA-stimulated DNA synthesis was also inhibited by TA in a dose-dependent manner, suggesting that the blockage of protein phosphorylation by TA was of biological significance. In conclusion, the work presented here demonstrated that the antitumor promoting effect of TA was not mediated by competing for the binding site with phorbol ester or interrupting the PKC translocation, but rather by effectively blocking phosphorylation by membrane-bound PKC, possibly through altering the biophysical properties of the membrane environment.

Ocular effects of topical administration of the phosphodiesterase III inhibitor milrinone in rabbits and cats

Increases in intracellular cAMP levels have previously been shown to decrease intraocular pressure (IOP) and increase ocular blood flow (OBF). However, the ocular effects of milrinone, which increases intracellular cAMP levels via selective cAMP PDE III inhibition, have not been investigated. The purpose of this study was to investigate the ocular effects of topically administered milrinone at different concentrations in rabbits and cats. When compared to vehicle in conscious rabbits, topical administration of milrinone at 0.03% decreased IOP (-14.1 +/- 2.6% vs. -7.4 +/- 3.7%, max. changes expressed as mean +/- SEM), at 0.1% increased IOP (10.4 +/- 8.5% vs. -1.7 +/- 4.1%), and at 0.01% and 1% did not significantly affect IOP. Neither pupil size nor central corneal thickness were affected by milrinone. Additionally, there were no signs of inflammation and no effects on corneal clarity. In anesthetized cats, topical administration of milrinone at 0.01-0.3% increased OBF (38.9 +/- 6.0% for milrinone vs. -7.4 +/- 4.4% for vehicle), and at 0.03%-0.3% decreased mean arterial pressure (-19.0 +/- 5.6 vs. 3.0 +/- 4.1 mmHg) in a dose-related manner. The durations of OBF enhancement (1.5-2.5 h) and MAP reduction (less than 30 min to 2 h) were also dose-dependent. In conclusion, milrinone induced biphasic IOP effects: IOP was decreased at 0.03% but increased at 0.1%. Milrinone at 0.01% increased OBF, possibly via a local vasodilator effect, and at 0.03-0.3% increased OBF, possibly via local and systemic effects. These data suggest that cAMP PDE III inhibitors such as milrinone may have efficacy as agents which enhance ocular blood flow following topical ocular application.

2H NMR determination of the global correlation time of the gramicidin channel in a lipid bilayer

A detailed experimental description of molecular dynamics requires an accurate description of the global correlation time. For the gramicidin cation-selective channel the local dynamics of the polypeptide backbone are thought to play a very significant role in the functional process of this channel which occurs on the 10-100-ns time scale. By solid-state NMR spectroscopy an experimental description of the local dynamics including a description of the axis about which the motions occur, the amplitude of the motions, whether they are diffusional or discontinuous and the frequency of the motions is possible. Initial interpretations of the NMR data for this polypeptide backbone in fully hydrated lipid bilayers suggests that the time scale for the local motions is the same as the kinetic time scale (North and Cross, 1993). Here the global correlation time is found from d4-Ala3 and d4-Ala5-gramicidin A powder pattern spectra to be 36 microseconds at 309 K. This surprisingly long correlation time may reflect the high viscosity of the peptide environment or possibly the higher molecular weight of a peptide-lipid aggregate. Furthermore, this reassessment of the global correlation time supports the initial interpretation of relaxation data for the local motions.

Tryptophans in membrane proteins: indole ring orientations and functional implications in the gramicidin channel

Orientational constraints generated from solid-state NMR of uniformly aligned gramicidin A in hydrated lipid bilayers have been used to determine the indole ring orientations for the four tryptophans of the gramicidin A monomer with respect to the bilayer normal and the channel axis. 15N epsilon 1 labeled tryptophan has been incorporated into gramicidin at positions 9, 11, 13, and 15. The chemical shift tensor orientation has been oriented with respect to the N-H bond via doubly labeled sample in which the 15N epsilon 1-1H has been exchanged for 2H. By observation of the dipolar coupled 15N chemical shift powder pattern of the amino acid, sigma cc has been shown to be perpendicular to the plane of the ring and that sigma aa makes an angle of 25 degrees with respect to the N-H bond. The indole ring orientations were obtained from a consideration of both the chemical shift and the 15N-1H dipolar interaction. These four rings have very similar orientations with respect to the bilayer normal as given by the range of angles between the bilayer and ring normals (64-67 degrees). Furthermore, the N-H bond orientations with respect to the bilayer normal varies by only 10 degrees among the four sites. This orientational analysis has been based on an assumption that large amplitude librational motions in the hydrated bilayer samples are not averaging the nuclear spin interactions. This assumption was verified by analyzing the 2H quadrupole spectra of d5-Trp11-labeled gramicidin A in oriented preparations. The orientations predicted for the five C-H bonds in the indole ring from the 15N data agreed (root-mean-square deviation of 3.7 degrees) with the observed orientations from quadrupole splittings of the C-D bonds in the ring. From the orientation of the indole rings with respect to the bilayer normal and a polypeptide backbone conformation, the four typtophans of the gramicidin monomer are oriented with respect to the backbone of the channel conformation. The similarity among the indole orientations with respect to the bilayer normal is therefore consistent with the electrophysiological results that the individual replacement of the indole rings with phenyl rings results in a incremental decrease in the conductance of the channels formed. The indole orientations with respect to the backbone as defined by the side-chain torsion angles is not uniquely determined but yields a discrete set of possible values.(ABSTRACT TRUNCATED AT 400 WORDS)

Comparison of a conscious versus anesthetized canine model in response to milrinone, hydralazine and nitroprusside

The purpose of this study was to demonstrate, based on previous and new data, that the differences between a conscious and anesthetized canine model in the cardiovascular responses to cardiovasoactive agents were beyond their difference in the sensitivity of the compensatory mechanisms. In both conscious and anesthetized canine models, mean arterial pressure (MAP) was decreased by hydralazine (at 1-3 mg/kg and 0.3-3 mg/kg; by -26.5 +/- 4.5 and -18.8 +/- 11.7% [max. changes expressed as mean +/- SEM], respectively). MAP was also decreased by nitroprusside (both at 0.01-0.1 mg/kg, by 54.6 +/- 2.8 and -60.5 +/- 3.0%, respectively) in the conscious and anesthetized models. However, the differential MAP responses to hydralazine and nitroprusside between the two models are inconsistent with a difference in the sensitivity of the two models. Hydralazine at 1 mg/kg decreased MAP greater in the conscious than anesthetized model, whereas nitroprusside decreased MAP similarly in the two models. In conclusion, not all differential responses to hydralazine and nitroprusside between conscious and anesthetized canine models can be explained by a difference in the sensitivity of their compensatory mechanisms.

High frequency of thyroid tumor induction by N-methyl-N'-nitro-N-nitrosoguanidine in the hermaphroditic fish Rivulus marmoratus

In the self-fertilizing hermaphroditic fish, Rivulus marmoratus, the susceptibility to tumor induction by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was evaluated. Seven-day-old fish larvae were exposed for 2 h to MNNG at concentrations ranging from 5 to 25 ppm in a static water bath. The exposed fish were observed at 2 and 4 months after carcinogen treatment to assess tumor development. Within 4 months after 25 ppm MNNG exposure, nearly all fish developed thyroid tumors. The tumor incidences were dose- and time-dependent, and the latent period of tumor induction was less than 2 months. Most induced neoplasms were papillary carcinomas similar histologically to those of rodents and humans, and the tumors were serially transplantable to other fish of the same species. These results demonstrate that rivulus could be useful as a model of thyroid carcinogenesis.

Rodent model of renal ischemia and reperfusion injury: influence of body temperature, seasonal variation, tumor necrosis factor, endogenous and exogenous antioxidants

The influences of body temperature (T), seasonal variation, antiserum of tumor necrosis factor (TNF), exogenous and endogenous antioxidants on the extent of renal injury in a rodent model were examined. Renal injury was induced by 15-45 min of renal vascular (arterial and venous) occlusion followed by 1-3 days of reperfusion in right-nephrectomized male rats. Plasma creatinine concentration (PC, a reflection of renal injury) was independent of T when T was within 35-40 degrees C (n = 8), but directly related to T when T was within 31-35 degrees C (n = 10). PCs in rats with renal insults performed during October, November and December were similar (600 mcM, n = 10-24), but were higher than that during April (380 mcM, n = 16). Neither TNF antiserum nor exogenous antioxidants (Trolox, ascorbic acid, phytic acid, U-78517F) reduce PC (n = 5-7). However, PC was lower in normal rats than vitamin E deficient rats when subjected to 45 min (329.1 +/- 93.6 mcM vs. 695.9 +/- 37.7 mcM, n = 5-6), but not to 15-30 min of ischemia. In conclusion, renal injury induced by ischemia/reperfusion was T- and season-dependent. An excess of exogenous antioxidants did not reduce, whereas a reduction in endogenous antioxidant vitamin E level enhanced, renal injury.

Potentiation of the pressor response to stress by tolbutamide in dogs

Tolbutamide has previously been shown to amplify the pressor effects of "exogenous" catecholamines in conscious dogs, possibly due to sensitization of the alpha 1-adrenoreceptor-mediated vasoconstriction. The objective of this study was to examine if tolbutamide also amplifies the pressor effects of "endogenous" catecholamines released during psychological stress (classical Pavlovian aversive conditioning). Experiments were conducted in beta-adrenoreceptor-blocked (propranolol, 1 mg/kg, i.v.) conscious dogs (n = 4) trained in classical aversive conditioning. Conditioning was accomplished by following a tone (CS+) with a 1/2 second shock; another tone (CS-) was not followed by any shock and served as control. With saline pretreatment, aversive conditioning (i.e., CS+) increased mean arterial pressure (MAP) only by approximately 4.7% when compared to CS-, whereas with tolbutamide (45 mg/kg, i.v.) pretreatment, the increase in MAP induced by CS+ beyond what was induced by the CS- (approximately 6.2%) was significantly (p < 0.05) larger than that with saline pretreatment. In isolated canine femoral arterial segments (n = 4), the vasoconstrictor effect of phenylephrine (an alpha 1-agonist) at 5 x 10(-6) M (which was the EC50 value) was amplified by 2 x 10(-2) M of tolbutamide from 54.0 +/- 2.0% to 66.9 +/- 2.1%. In conclusion, tolbutamide amplifies the pressor effects of "endogenous" catecholamines in conscious dogs, possibly by sensitization of the alpha 1-adrenoreceptor-mediated vasoconstriction. This mechanism of action is novel and has not been reported with other agents.

Surgical glove perforations in otolaryngology: prevention with cut-resistant gloves

This study examines the role of cut-resistant, "orthopedic-type" gloves in prevention of exposure of surgical personnel to infectious body fluids through surgical glove perforation. The incidence of glove perforations in 12 consecutive cases of intermaxillary fixation (IMF) was studied. Surgeons were double-gloved with standard latex gloves and wore cut-resistant gloves between the outer and inner gloves. As controls, six cadaver heads were wired into IMF with surgeons double-gloving without the cut-resistant glove. The rates of latex glove perforation were then compared between the two groups. Fifty-three percent (32 of 60) of outer latex gloves, but no inner latex gloves (0 of 50) were perforated when surgeons wore cut-resistant gloves. In the control group, 45% of outer gloves (9 of 20) and 15% of inner gloves (3 of 20) were perforated. The difference of inner glove perforations--hence cutaneous exposure--between these two groups was statistically significant (p < 0.01). The use of cut-resistant gloves in addition to double-gloving with latex surgical gloves is recommended for facial plastic and reconstructive procedures with metal implants and major head and neck surgery, because these operations have a high rate of glove perforation. Because some loss of dexterity is noted when cut-resistant gloves are worn, the risk of glove perforation must be weighted against the need for optimal dexterity.

Extension of surgical indications for hepatocellular carcinoma by portal vein embolization

We studied, clinically and experimentally, hypertrophy of the part of the liver not embolized after portal vein embolization (PVE). The subjects of the clinical study were 29 patients with hepatocellular carcinoma (HCC) who underwent embolization of the right first portal branch; 19 patients had cirrhosis, and 10 did not. The volume of the liver was calculated from computed tomograms obtained before PVE and 2 weeks after. In all patients, the volume of the nonembolized (left) lobe increased significantly. For the experimental study, we used male Wistar rats. Normal rats were untreated, and in the other rats cirrhosis was induced with carbon tetrachloride. The portal branch that supplies 70% of the total volume of the liver was embolized. The rats underwent one of four procedures: 70% PVE, 70% portal vein ligation, 70% hepatectomy, or laparotomy only. Rats wre killed at different times after surgery, and the livers were removed and weighed. The mitotic index and DNA synthesis were measured in the nonembolized lobe (PVE group), in the lobe not supplied by the ligated branch (ligation group), or in the remaining liver (hepatectomy group). The liver weight, mitotic index, and DNA synthesis were high in the PVE, ligation, and hepatectomy groups for both normal rats and rats with cirrhosis. PVE caused cell proliferation and hypertrophy in the nonembolized part of the liver in the normal rats and even in those with cirrhosis. We concluded that PVE can extend the surgical indications for patients with HCC and underlying cirrhosis.

Biliary tract invasion and obstruction by hepatocellular carcinoma: report of five cases

Major biliary tract obstruction caused by tumour invasion is a rare manifestation of hepatocellular carcinoma. The authors had the opportunity to diagnose and treat five such cases, three of whom had features of acute cholangitis. The prevalence of both hepatocellular carcinoma and recurrent pyogenic cholangitis is high in patients from the Far East. The former may first present under the guise of the latter. Gastroenterologists and surgeons should be aware of hepatocellular carcinoma when managing these patients who present with obstructive jaundice, gross hepatomegaly and cholangitis.

Genotoxicities of nitropyrenes and their modulation by apigenin, tannic acid, ellagic acid and indole-3-carbinol in the Salmonella and CHO systems

Four naturally occurring compounds, indole-3-carbinol (I3C), apigenin (Api), ellagic acid (EA) and tannic acid (TA), were tested for their inhibitory effects against 1-nitropyrene- (1-NP) or 1,6-dinitropyrene (1,6-DNP)-induced genotoxicity in Salmonella tester strains and Chinese hamster ovary (CHO) cells. Api and TA strongly inhibited the bacterial mutagenesis induced by nitropyrenes, while I3C and EA had little or no effect. For example, in TA98, 0.2 mumole Api resulted in 48% and 56% inhibition of the mutagenicity induced by 4 nmole 1-NP and 0.035 nmole 1,6-DNP, respectively. With an equal dose, TA caused 46% and 50% reduction of the mutagenicity induced by 1-NP and 1,6-DNP, respectively. As expected, a good correlation was observed between the antimutagenicity of nitropyrenes and their inhibitory effect on nitroreductase activity. This indicated that one of the possible antimutagenic mechanisms of Api or TA was to inactivate the metabolism of nitropyrenes. Two biological end-points, cytotoxicity and sister-chromatid exchange (SCEs), were used to screen the antigenotoxic effects of these compounds in CHO cells. At the sub-cytotoxic dose, I3C, Api and TA all protected against the cytotoxicity induced by 1-NP and 1,6-DNP, but only TA and Api gave a significant reduction of the frequency of SCEs. Moreover, this reduction was found to be highly dose-dependent.

Aggressive angiomyxoma. A report of four cases occurring in men

Aggressive angiomyxoma is a distinctive, locally aggressive but nonmetastasizing soft tissue tumor of the pelvic soft tissues and perineum. This rare tumor occurs almost exclusively in adult women. We report four cases occurring in adult men, one each located in the scrotum, inguinal region, spermatic cord, and pelvis. The tumors were infiltrative, and were composed of fibromyxoid matrix sparsely populated by bland-looking spindled and stellate cells with delicate cytoplasmic processes. There were haphazardly scattered small and large blood vessels, some of which exhibited hypertrophy or hyalinization of the wall. Immunohistochemically, the stromal cells stained consistently for vimentin and variably for muscle-specific actin, but not alpha-smooth muscle actin, desmin, and S-100 protein. None of the four tumors recurred in follow-up times from 11 months to 6 years, although two previously reported cases in men recurred. This uncommon tumor occurring around the genital region in men merits wider recognition because of its potential for recurrence. It should be distinguished from benign tumors with low risk of recurrence on one hand, and from malignant myxoid tumors with metastatic potential on the other.

[Preoperative percutaneous transhepatic portal vein embolization to extend the indications for hepatectomy and to increase the safety of extended hepatectomy for hepatocellular carcinoma]

The usefulness of preoperative percutaneous transhepatic portal vein embolization (PTPE) in extending the indications for hepatectomy and increasing the safety of extended hepatectomy for hepatocellular carcinoma was studied in 21 patients who underwent right hepatic lobectomy with PTPE of the right first portal branch (group E), in 15 such patients but without PTPE (group N), and in seven such patients who underwent PTPE at this location but could not undergo surgery (group U). The mean volume of the left lobe increased but the results of a 15-minute indocyanine green retention test were worsened 2 weeks after PTPE and again 4 weeks after hepatectomy, but these changes after hepatectomy were almost the same in groups E and N. The worsening of liver function and coagulation test results was less in group E than in group N. The mean prognosis score was better in group E two weeks after PTPE than before, but not in group U. The four patients in group E with high portal vein pressure (> or = 30 cmH2O) or a high prognosis score (> or = 50 points) after PTPE developed hepatic failure after surgery. Preoperative PTPE was useful in extending the indications for hepatectomy and increasing the safety of extended hepatectomy. Evaluation of the clinical course after PTPE was also useful when decisions about the operative method to be used were being made.