Differential effects of fat and sucrose on body composition in A/J and C57BL/6 mice

The C57BL/6 (B6) mouse is more sensitive to the effects of a high-fat diet than the A/J strain. The B6 mouse develops severe obesity, hyperglycemia, and hyperinsulinemia when fed this dietary regimen. This study was conducted to determine the effects of dietary fat and sucrose concentrations on body composition and intestinal sucrase (EC 3.2.1.48) and maltase (EC 3.2.1.20) activity in these two mouse strains. High-fat diets, regardless of sucrose content, resulted in significant weight gain, higher body fat, and lower body protein and water content in both strains of mice. The shift toward higher body fat and lower protein and water content was far greater in the B6 strain. Low-fat, high-sucrose diets resulted in lower body weight in both strains, as well as significantly greater body protein content in B6 mice. Analysis of intestinal sucrase showed that the enzyme was less active in B6 mice when the diet was high in sucrose. Both sucrase and maltase had lower activity in the presence of high dietary fat in both mouse strains. The percent reduction of intestinal enzyme activity due to dietary fat was similar in both strains. The B6 mouse exhibits disproportionate weight gain and altered body composition on a high-fat diet. This coupled with the reduced body weight and increased body protein on a low-fat, high-sucrose diet suggests that factors-relative to fat metabolism rather than sucrose metabolism are responsible for obesity.     

Appendicular bone mass in children with a high prevalence of low dietary calcium intakes

We have previously documented evidence of dietary calcium deficiency in black children living in a rural community in the eastern part of South Africa. The present study determined the bone mass of the distal one-third of the radius in a random sample of children living in the same community and compared their bone mass measurements with those of black children living in a similar rural community but without evidence of dietary calcium deficiency. Further, factors (weight, height, serum corrected total calcium, phosphorus, and alkaline phosphatase [ALP]) that might influence appendicular bone mass were assessed and correlated with the bone mass measurements. A random sample of 306 boys and 345 girls between the ages of 1 and 20 years were included in the study. Hypocalcemia was found in 6.5% of the boys and 5% of the girls, while elevated ALP values were recorded in 20 and 26% of the boys and girls, respectively. After adjusting for differences in age, weight, and height, bone mineral density (BMD) and bone mineral apparent density (BMAD) were significantly lower and bone width (BW) greater in study than control children. In a stepwise regression analysis, weight and/or height accounted for the majority of the observed variance in BMC, BW, and BMD; however, a significant effect of serum calcium (positively) and ALP (negatively) on BMC and BMD was also found. In boys, but not girls, serum ALP also had a positive effect on BW.BMAD was negatively correlated to ALP and positively correlated to serum calcium in both boys and girls. Those children with hypocalcemia or elevated ALP levels had significantly lower BMC, BMD, and BMAD and a trend toward greater BW than children with normal biochemistry. The findings suggest that low dietary calcium intake may have a detrimental effect on appendicular bone density in rural black children. Whether or not these effects are disadvantageous in the long-term is not known.     

Cigarette smoking as a determinant of high-grade carotid artery stenosis in Hispanic, black, and white patients with stroke or transient ischemic attack

The effect of chitin, poly-beta-(1 --> 4)-N-acetyl-glucosamine, and chitosan, a polymer of glucosamine obtained by the deacetylation of chitin, on growth and nutrient digestibility was studied in grass shrimp, Penaeus monodon. Shrimp were fed for 8 wk diets containing no supplement (control) or 2, 5 or 10 g/100 g chitin or chitosan. Each diet was fed to triplicate groups of shrimp with a mean initial body weight of 0.45 +/- 0.05 g. Significantly higher body weight gains were observed in shrimp fed the 5% chitin diet than in those fed the 10% chitin or the control diet. The weight gain of shrimp decreased as dietary chitosan supplementation level increased (r = 0. 87, P < 0.05). Feed efficiencies (FE) and protein efficiency ratios (PER) followed the same pattern. Lower protein and lipid digestibilities and lower body protein and lipid contents were observed in shrimp fed all chitosan-containing diets than in controls (P < 0.05). Carbohydrate digestibility was lower in shrimp fed the 10% chitosan diet than in those fed the control diet. Lower protein and lipid digestibilities, body lipid content and blood cholesterol concentration were observed in shrimp fed the 10% chitin diet compared with controls (P < 0.05). Higher weight gains, body lipid contents and blood cholesterol concentrations were observed in shrimp fed the 2 and 5% chitin diets than in those fed the chitosan diets. Shrimp fed the 5% chitin diet had higher protein and lipid digestibilities and higher body protein content than those fed the 5% chitosan diet (P < 0.05). These data suggest that dietary chitin, supplemented at 5%, enhances P. monodon growth, whereas chitosan depresses shrimp growth, regardless of the supplementation level.     

MIC and time-kill study of antipneumococcal activities of RPR 106972 (a new oral streptogramin), RP 59500 (quinupristin-dalfopristin), pyostacine (RP 7293), penicillin G, cefotaxime, erythromycin, and clarithromycin against 10 penicillin-susceptible and -resistant pneumococci

Broth MICs and time-kill studies were used to test the activity of RP 59500 (quinupristin-dalfopristin), RPR 106972, pyostacine (RP 7293), erythromycin, clarithromycin, and cefotaxime for four penicillin-susceptible (MICs of 0.008 to 0.03 microgram/ml), two penicillin-intermediate (MIC of 0.25 microgram/ml), and four penicillin-resistant (MIC of 2.0 to 4.0 micrograms/ml) strains of pneumococci: 6 of 10 strains were resistant to macrolides (MICs of > or = 0.5 microgram/ml). MICs of RP 59500 (0.5 to 1.0 microgram/ml), RPR 106972 (0.125 to 0.25 microgram/ml), and pyostacine (0.125 to 0.25 microgram/ml) did not alter with the strain's penicillin or macrolide susceptibility status. Three penicillin-susceptible strains and one penicillin-intermediate strain were susceptible to macrolides (MICs of < or = 0.25 microgram/ml); the macrolide MICs for the remaining strains were > or = 4.0 micrograms/ml. Cefotaxime MICs rose with those of penicillin G, but all strains were inhibited at MICs of < or = 2.0 micrograms/ml. RP 59500 was bactericidal for all strains after 24 h at 2 x MIC and yielded 90% killing of all strains at 6 h at 2 x MIC; at 8 x MIC, RP 59500 showed 90% killing of six strains within 10 min (approximately 0.2 h). In comparison, RPR 106972 was bactericidal for 9 of 10 strains at 2 x MIC after 24 h and yielded 90% killing of all strains at 2 x MIC after 6 h; 90% killing of six strains was found at 8 x MIC at 0.2 h. Results for pyostacine were similar to those of RPR 106972. Erythromycin and clarithromycin were bactericidal for three of four macrolide-susceptible strains after 24 h at 4 x MIC. Clarithromycin yielded 90% killing of three strains at 8 x MIC after 12 h. Cefotaxime was bactericidal for all strains after 24 h at 4 x MIC, yielding 90% killing of all strains after 6 h at 4 x MIC. All three streptogramins yielded rapid killing of penicillin- and erythromycin-susceptible and -resistant pneumococci and were the only compounds which killed significant numbers of strains at 0.2 h.     

Experimental coryza in broiler chickens. I. Effects of vaccination with Haemophilus gallinarum bacterin and its components on weight gains and resistance to infection

Effects of a Haemophilus gallinarum bacterin and its components were studied in young broiler chickens. When the bacterin was administered subcutaneously in the dorsal neck region at 2 weeks of age, no significant differences in weight gains of vaccinated and control birds were detected at eight weeks of age. In four groups vaccinated at 1, 2, 3, or 4 weeks of age and challenged with virulent haemophilus organisms 3 weeks later, the incidence of clinical signs was 30% in the vaccinates and 60% in controls. The bacterin was equally protective at the four ages of administration. Caseous plugs were found at the vaccination sites in all birds which had received adjuvant either alone or in the complete bacterin. Signs of depression lasting about 24 hours were observed in the youngest birds injected with the bacterin, but overall weight gains were normal.     

Post-movement EEG synchronization studied with different high resolution methods

The influence of environmental ethanol on different fitness components and the larval activities of some enzymes were studied in three strains of Drosophila melanogaster. All three strains carried the AdhS-alphaGpdhF allele combination on their second chromosomes while they had unique allele combinations at the Odh and Aldox loci on their third chromosomes (strain 1: OdhS-AldoxF; strain 2: OdhF-AldoxS; strain 3: OdhS-AldoxS). Normal lines and exposure lines, kept on 5% ethanol supplemented medium for at least 20 generations, were established from each strain and the responses of the two lines to different ethanol concentrations were compared. Two survival components were estimated in the juvenile life history stages. In addition, the weights of the emerging adult males were measured at various concentrations of ethanol. The changes in the activities of two enzymes (ADH and alpha GPDH) were also surveyed in the larvae after the different ethanol treatments. Strain-specific differences were observed in the responses of all investigated traits to ethanol. OdhS-AldoxF larvae seemed to be more tolerant to ethanol than the larvae of the other two strains while the utilisation of ethanol as energy source appeared to be the least effective in this strain. Larvae of the exposure lines had significantly higher tolerance to ethanol, and the adult males were heavier, than the ones from the normal lines. The enzymatic responses of the two lines to the ethanol treatments were also different. ADH activity, fresh male weight, and pupa-to-adult survival seemed only to be associated under short-term exposure to ethanol. Ethanol tolerance appeared to be independent of the utilisation of ethanol in the larva-to-pupa stage.     

Hypophysectomy or adrenalectomy of rats with insulin-dependent diabetes mellitus partially restores their responsiveness to growth hormone

The studies reported herein were conducted to confirm that the pituitary gland is involved in maintaining growth hormone (GH) resistance in rats with insulin-dependent diabetes mellitus (IDDM) and to determine whether the adrenocorticotropic hormone (ACTH)-adrenal cortical axis is responsible. The rats were made diabetic by injecting streptozotocin (85 mg/kg body wt) IP once daily on two consecutive days. They were then injected with 15 IU insulin SC twice daily on two consecutive days to enable them to survive hypophysectomy or adrenalectomy. Intact nondiabetic (NonDb), diabetic (Db), hypophysectomized diabetic (HxDb), and adrenalectomized diabetic (AxDb) rats were injected twice daily with 50 micrograms porcine (p) GH or with 0.9% saline for 2 weeks following the surgeries. Serum glucose levels of the saline-injected Db, HxDb, and AxDb rats were significantly greater than those of the NonDb rats by 106%, 65% and 49%, respectively. However, the levels in the HxDb and AxDb animals were significantly lower than those of the Db group by 20% and 28%, respectively. Injections of pGH into NonDb rats increased serum glucose concentrations by 38%, over their saline-treated controls, and by 29% in AxDb rats. This diabetogenic effect of GH was not seen in any other group. Administration of pGH to Db rats failed to increase body weight gain, tall growth, tibial epiphysial plate width, or serum IGF-I concentration over saline-injected controls. By contrast, HxDb and AxDb rats injected with pGH showed significant increases in all four growth parameters. Total serum IGF-I concentrations in AxDb rats injected with pGH equaled those in NonDb controls. To determine whether the lack of corticosterone (B) in the AxDb rats was responsible for the reduced hyperglycemia and restored responsiveness to pGH, AxDb rats were given B in their drinking water at 5 or 25 micrograms/ml. Administration of B reduced the beneficial effects of adrenalectomy by restoring hyperglycemia and growth impairment, and partially restored resistance to the pGH injections. These studies confirm that the pituitary contributes to diabetic growth impairment and show that the ACTH-adrenal cortical axis is primarily responsible for the GH-resistant state that develops in rats with IDDM.     

Fusaproliferin production by Fusarium subglutinans and its toxicity to Artemia salina, SF-9 insect cells, and IARC/LCL 171 human B lymphocytes

Fusarium subglutinans is an important pathogen of maize and other commodities worldwide. We examined MRC-115 and 71 other F. subglutinans strains from various geographic areas for their ability to synthesize fusaproliferin, a novel toxic sesterterpene recently isolated from F. proliferatum. Fusaproliferin production ranged from 30 to 1,500 micrograms/g of dried ground substrate, with 33 strains producing more than 500 micrograms/g. In particular, strain MRC-115 produced as much as 1,100 to 1,300 micrograms/g. In toxicity studies of two invertebrate models, fusaproliferin was toxic to Artemia salina (50% lethal dose, 53.4 microM) and to the lepidopteran cell line SF-9 (50% cytotoxic concentration, approximately 70 microM, after a 48-h exposure). Fusaproliferin was also toxic to the human nonneoplastic B-lymphocyte cell line IARC/LCL 171 (50% cytotoxic concentration, approximately 55 microM in culture in stationary phase after a 48-h exposure). Experiments performed will cells exposed at seeding suggested a possible cytostatic effect at subtoxic concentrations.     

Regulatory mechanism of non-shivering thermogenesis in cold acclimation--with special reference to in vitro thermogenic activity and lipolysis of brown adipose tissue

In vitro brown adipose tissue (BAT) thermogenesis from cold-acclimated (CA) rats has been shown to exhibit the decreased responses to noradrenaline (NA) and glucagon (G), although an enhanced biochemical machinery for thermogenesis develops in the tissue. The present study was undertaken to clarify the inhibitory mechanism of in vitro thermogenic responses of BAT in CA rats. NA-treated rats were injected NA (40 micrograms/100g BW) twice a day for 2 or 4 weeks. The other rats were kept at 25 +/- 1 degree C (warm controls: WC), 5 +/- 1 degree C (CA), or 5 +/- 1 degree C/6h/day (intermittent cold exposure: ICE) for 5-6 weeks. The oxygen consumption, and glycerol as well as free fatty acids (FFA) release were measured on finely minced tissue blocks in Krebs-Ringer phosphate buffer at 37 degrees C. In vitro BAT thermogenic responses to NA and G in NA-treated rats did not differ from those in vehicle-injected controls. NA as well as G increased-oxygen consumption was greatest in WC, followed by ICE and CA. NA as well as G increased glycerol and FFA releases in WC and ICE, but the degree of increment was greater in WC than that in ICE, while NA or G did not increase glycerol and FFA releases in CA. FFA/glycerol ratio in WC was decreased by NA as well as G, but it was not changed in ICE, and increased in CA. Mitochondrial GDP binding as an index of BAT thermogenic capacity did not differ between CA and WC under resting state (CA rats were transferred in warm condition before 18h at the beginning of the experiment), but it was significantly greater in ICE. GDP binding was significantly greater in CA sacrificed at 5 degrees C compared with WC and CA resting. Acute cold exposure (5 degrees C/1h) enhanced GDP binding in WC, resting CA and ICE resting, but the degree of increment was greater in CA and ICE than in WC. These findings suggest that cold exposure inhibits BAT thermogenic responses according to the duration NA action during cold exposure, by means of suppressing fatty acid utilization and/or masking uncoupling protein.     

Tocopherols, retinol, beta-carotene and fatty acids in fat globule membrane and fat globule core in cows'' milk

To develop and characterize a murine model for investigating the long-term effects of prenatal cocaine exposure, the present study established the route of drug administration and the doses to be used for pregnant C57BL/6 mice. Comparison of the effects of a high dose of cocaine (60 mg/kg) when gavaged or injected subcutaneously (SC) established patterns of pathology characteristic of administration route but no dominating logic for selecting one over the other route for prenatal studies; however, because of the fourfold greater brain levels, with no evidence of greater pathology, the SC route was selected. When injected daily during gestation days 12-18, the period of prenatal development of dopamine systems, cocaine at doses producing plasma concentrations consistent with its stimulatory effects reduced food ingestion and weight gains during pregnancy and fetal body and brain weights at term. The extent of these reductions was comparable to reports on babies exposed to cocaine prenatally. Furthermore, the present study suggests that maternal undernutrition is not a likely mediator of these perinatal effects and that differences in the amount of cocaine exposure may cause the contrasting effects of maternal cocaine noted in the human literature.     

Fungicidal properties of defensin NP-1 and activity against Cryptococcus neoformans in vitro

Defensin NP-1, derived from the neutrophils of rabbits, was tested for its fungistatic and fungicidal activity against strains of Cryptococcus neoformans. The MICs for the encapsulated strains tested ranged from 3.75 to 15.0 micrograms of NP-1 per ml. The minimum fungicidal concentrations for these strains were similar to the MICs. An acapsular strain, however, had a lower MIC of 0.93 and minimum fungicidal concentration of 1.88 micrograms/ml. NP-1 demonstrated time-dependent and concentration-dependent killing of C. neoformans. Killing occurred rapidly in the first 20 min of exposure to NP-1 and was maximum at 90 to 120 min. Killing of C. neoformans by NP-1 was concentration dependent with 31% +/- 9% survival at 25 micrograms/ml, 13% +/- 4% survival at 50 micrograms/ml, 9% +/- 5% survival at 75 micrograms/ml, and 5% +/- 3% survival at 100 micrograms/ml. NP-1's fungicidal effect on C. neoformans was also inoculum dependent, with increased activity observed at 10(4) versus 10(5) or 10(6) cells per ml. In addition, stationary-phase C. neoformans was less susceptible to NP-1 killing than yeast cells in the logarithmic phase. Subinhibitory concentrations of both NP-1 (0.25 x MIC) and fluconazole (0.25 x MIC) acted synergistically in inhibiting growth of C. neoformans. Similar combinations of NP-1 and amphotericin B, however, did not yield synergy.     

Clinical study on azithromycin in 10% fine granules and 100mg capsules in the field of pediatrics

Azithromycin (AZM), a new oral macrolide antibiotic, in 10% fine granules or 100 mg capsules was given to pediatric patients to treat various infections. The following results were obtained in our studies of AZM for its antibacterial activities against clinical isolates, its pharmacokinetics, its efficacy, and its safety. 1. MICs of AZM, erythromycin (EM) and clarithromycin (CAM) were determined against a total of 57 strains all at 10(6) cfu/ml. Among Gram-positive cocci, MICs of AZM ranged from 0.78 to > 100 micrograms/ml against Staphylococcus aureus (20 strains), from 0.05 to 0.1 microgram/ml against Streptococcus pyogenes (11 strains), and from 0.0125 to 3.13 micrograms/ml against Streptococcus pneumoniae (10 strains). These MICs were similar to those of the other macrolides. Among Gram-negative bacilli, MICs of AZM were 0.05 micrograms/ml against Moraxella subgenus Branhamella catarrhalis (1 strain), from 0.78 to 3.13 micrograms/ml against Haemophilus influenzae (9 strains), 0.78 micrograms/ml against Haemophilus parainfluenzae (1 strain) and 6.25 micrograms/ml against salmonella sp. (1 strain). These values were similar to or lower than those of the other macrolides. Against Mycoplasma pneumoniae, MICs of AZM were < or = 0.0008 micrograms/ml in three strains. One strain of M. pneumoniae showed tolerance to AZM at MIC 25 micrograms/ml. The other agents exhibited higher MIC than AZM against this organism. 2. Plasma samples were collected from five patients receiving fine granules and four patients receiving capsules for drug level determination. The patients received AZM at 10.0 approximately 16.3 mg/kg body weight once daily for 3 days. Drug concentrations in plasma at two hours after Day 3 dosing were in a range between 0.02 and 0.19 micrograms/ml for fine granules and were in a range between 0.11 and 0.42 micrograms/ml for capsules. 3. Urine samples were collected from four patients receiving fine granules and four patients receiving capsules. Drug levels were determined to be 3 micrograms/ml at post-treatment 48 hours for fine granules and post-treatment 72 hours for capsules. Urinary excretion rates of AZM in three patients on capsules lied in a range between 4.69 and 10.17%. 4. Effectiveness of AZM in fine granules was evaluated in 128 patients having a total of 19 different infections. AZM was rated "excellent" in 51 patients, "good" in 63, "fair" in 8, "poor" in 6, resulting in an efficacy rate of 89.1%. Effectiveness of AZM in capsular form was evaluated in 23 patients with five different infections. AZM was found "excellent" in 13 patients and "good" in 10, resulting in an efficacy rate of 100%. 5. AZM in fine granules eradicated 45 strains of 54 in 8 different bacteria. AZM in capsules eradicated 9 strains of 10 strains in 6 different bacteria. 6. As for adverse reactions, one patient complained of eruption, one vomiting, one loose stool, five diarrhea, when administered with fine granular form of AZM. One patient on AZM capsules experienced urticaria and vomiting. 7. As for abnormal laboratory changes, three patients were found with decreased WBC, seven with increased eosinophil, two with increased GOT and GPT, one with increased GPT. They were all on fine granular form of AZM. As far as abnormalities found in patients administered with AZM in capsular form, two showed decreased WBC, one decreased WBC along with increased eosinophil, and three increased eosinophil.     

Investigation and evaluation of zinc protoporphyrin as a diagnostic indicator in lead intoxication

To evaluate the utility of zinc protoporphyrin (ZPP) as an indicator of lead exposure, we examined 128 workers employed at a battery storage plant and two smelters, 343 persons who lived within 200 m of the plants, and 217 controls. Based on Chinese criteria, the "normal" ZPP value among inhabitants of Shaanxi Province was determined to be 85 micrograms/100 ml. ZPP proved to be a more sensitive and specific indicator of lead exposure, at both high and lower levels, than PbB or PbU. Among 115 patients who underwent chelation therapy for lead poisoning, ZPP also proved to be a valid index of recovery.     

Effects of dietary protein and strain on the growth of broiler breeder pullets from zero to five weeks of age

In a series of four experiments, the effects of differences in dietary protein intake on BW, skeletal growth and the weight of the Pectoralis major muscle was studied in Hubbard Standard and Hubbard Hi-Y broiler breeder pullets. In Experiment 1, pullets were fed diets with either 15, 17, or 19% CP from 1 to 21 d. There was a linear increase in BW gain and feed consumption with each increase in CP and Hubbard Standard pullets consumed significantly more feed than Hubbard Hi-Y pullets. From 21 to 34 d, pullets were subjected to feed restriction every day (ED) or every-other-day (EOD). On Day 35, pullets were given ad libitum access to feed and ED-restricted pullets consumed significantly more feed than EOD-restricted pullets through 3.5 h postfeeding. In Experiment (Exp.) 2, pullets were fed the 19% CP diet for approximately 14 d (300 g) or 20 d (600 g) before being switched to the 15% CP diet. In Experiment 3, the 19% CP diet was fed for exactly 7 or 21 d before switching to the 15% CP diet. In all experiments, Hubbard Standard pullets weighed significantly more than Hubbard Hi-Y pullets and had increased overall skeletal growth. When the pullets from both strains were restricted to only 380 g BW at 28 d, (Exp. 3) the longer period of protein intake significantly enhanced breast muscle weight but there were no significant strain differences. When BW at 28 d was increased to 480 g, (Exp. 2), dietary protein and strain differences were observed.     

Relationship between streptomycin susceptibility and rpsL mutations of Mycobacterium tuberculosis strains

The relationship between streptomycin (SM) susceptibility and rpsL mutations of Mycobacterium tuberculosis strains was studied. Of 18 clinically isolated SM-resistant M.tuberculosis strains, mutation was suspected in 9 strains (50%) with SM MICs of > or = 256 micrograms/ml by PCR-single strand conformation polymorphism targeting rpsL gene. On the other hand, using PCR-direct sequence method, amino acid substitution caused by single nucleotide point mutation in rpsL gene was demonstrated in 11 out of 18 strains (61%). The same amino acid substitution at codon 43 (Lys-->Arg) was observed in all 11 strains with SM MICs of > or = 256 micrograms/ml. In addition, PCR products obtained from these 11 strains could not be cut by a restriction enzyme, Mbo II, while H37Rv strain and the other 32 strains with SM MICs of < 256 micrograms/ml were cut into 2 fragments. In conclusion, our results suggest that highly SM-resistant M.tuberculosis strains with MICs of > or = 256 micrograms/ml could be rapidly and easily detected by the restriction enzymatic method.     

Bovine placental lactogen is a potent stimulator of growth and displays strong binding to hepatic receptor sites of coho salmon

Juvenile coho salmon were treated with bovine placental lactogen (bPL) and bovine growth hormone (bGH) to examine the growth promoting activities of these proteins in a lower vertebrate. Fish were intraperitoneally injected either with 0.5 or 5.0 micrograms/g bPL or with 5.0 micrograms/g bGH once a week for 5 weeks. After only a single injection and 1 week of growth, the high dose of bPL stimulated a significant increase in weight and length relative to untreated fish or fish treated with a control protein, bovine serum albumin. At the end of the experiment, all hormone-treated groups were significantly larger than controls. Fish treated with 5 micrograms/g bPL gained more than three times as much weight as controls. The 5.0 micrograms/g bGH group grew at the same rate as fish treated with one-tenth this dose of bPL, indicating that bPL is a potent stimulator of growth in this species. Radioreceptor assays performed on coho salmon liver membrane preparations indicate that bPL binds with approximately 430-fold higher affinity than bGH, and some 8000-fold higher affinity than bovine prolactin. The action of bPL relative to the structure and function of salmonid pituitary hormones is discussed.     

Isolation of penicillin-resistant Streptococcus pneumoniae in Saga Medical School Hospital

A recent nationwide increase in beta-lactams-resistant Streptococcus pneumoniae has attracted a great deal of attention. We studied the drug sensitivity of S. pneumoniae isolated from various clinical specimens in Saga Medical School Hospital between April 1988 and December 1991. To determine the drug sensitivity of the strains, we used a micro-dilution method and determined the MIC. Drug resistance was evaluated using MIC of ampicillin (ABPC) as a reference MIC, and the results were roughly classified into the following three groups: sensitive (< or = 0.1 microgram/ml), moderately resistant (0.2-3.13 micrograms/ml) and highly resistant (> or = 6.25 micrograms/ml). The isolation frequency was calculated on the basis of one strain from one patient. No strain of S. pneumoniae with high resistance against ABPC was found in 1988 (94 strains of S. pneumoniae were isolated) and 1990 (115 strains isolated), but one such strain (0.8%) was found among 129 strains isolated in 1989, and 2 such strains (2.4%) among 84 strains isolated in 1991. Moderately resistant strains were isolated at the frequencies of 12.8%, 15.5%, 22.6%, and 21.4% respectively, in 1988, 1989, 1990, and 1991. A sum of the frequencies of "moderately resistant" and "highly resistant" (2.4%) strains was 23.8% in 1991. The frequency of resistant strains is increasing and the intensity of resistance is also being elevated.     

Tear concentrations of topically applied ciprofloxacin

An open-label study of 20 normal, healthy volunteers was conducted to determine the tear concentrations after topical ocular application of ciprofloxacin 0.3% ophthalmic solution (Ciloxan). Tear samples were collected on Schirmer tear strips at 30 min, 2, 3, and 4 h, and were analyzed for ciprofloxacin using reverse-phase high-performance liquid chromatography. The results of this study showed the mean concentration, 4 h after dosing of ciprofloxacin, to be 16.0 micrograms/ml with 95% confidence limits of 8.15 and 23.79. It is concluded that concentrations of ciprofloxacin in tears were significantly greater than the minimum inhibitory concentrations for 90% of strains tested commonly reported for a majority of potential pathogens (i.e., < or = 2 micrograms/ml) 4 h after a single application of ciprofloxacin ophthalmic solution 0.3%.     

In vitro reconstitution of an intermediate assembly stage of vaccinia virus

The effects of chronic exogenous testosterone treatment on the synthesis and/or secretion of two sturgeon gonadotropins (stGTH I and stGTH II) were assessed in 2-year-old juvenile white sturgeon (Acipenser transmontanus) surgically implanted with silastic capsules filled with 75 mg of testosterone and in previtellogenic female white sturgeon females implanted with 150 mg of testosterone. In groups of juvenile white sturgeon sacrificed 30, 60, 90, or 442 days postimplantation, pituitary concentrations of stGTH I were significantly greater in testosterone-treated fish (P < 0.01) when compared to those of controls. Pituitary concentrations of stGTH II were significantly higher (P < 0.01) in juvenile fish treated 60, 90, or 442 days with testosterone when compared to those of controls. Exogenous testosterone had no effect on plasma concentrations of either stGTH. Additional testosterone-treated juvenile sturgeon which were injected intraperitoneally 90 or 442 days postimplantation with 10 microg/kg of the gonadotropin releasing hormone analog d-Ala6-des-Gly10-GnRH ethylamide (GnRHa) also showed no change in plasma concentrations of stGTHs. Similar results were obtained for previtellogenic white sturgeon, as pituitary concentrations of stGTH I and stGTH II were significantly greater (P < 0.01) after 60 days of testosterone treatment compared to those of controls. A second group of 60-day testosterone-treated previtellogenic females also failed to exhibit increases of plasma stGTHs when administered 10 microg/kg of GnRHa. These results indicate that long-term testosterone treatment stimulates the accumulation of pituitary stGTHs in both juvenile and previtellogenic white sturgeon but does not affect basal or GnRHa-induced stGTH secretion.     

Cuticle surface proteins of wild type and mutant Caenorhabditis elegans

The molecular components of the surface of the free-living nematode Caenorhabditis elegans have been identified by surface-specific radioiodination. Four compartments were defined by fractionation of labeled wild type (N2 strain) adult hermaphrodites. Organic solvents extracted cuticular lipids. Homogenization in detergents released a single, non-collagenous, hydrophobic protein. This is not glycosylated and is a heterodimer of 6.5- and 12-kDa subunits. The third compartment, proteins solubilized by reducing agents, included both the cuticular collagens and the heterodimer. Residual material corresponds to the cuticlin fraction. Larval stages showed a similar pattern, except that the dauer larva had an additional 37-kDa detergent-soluble protein. Other species of rhabditid nematodes displayed similar profiles, and comparison with parasitic species suggests that this simple pattern may be primitive in the Nematoda. A C. elegans strain mutant in cuticular collagen (rol-6) had a pattern identical to that of wild type, but another morphological mutant (dpy-3) [corrected] and several mutants that differ in surface reactivity to antibody and lectins (srf mutants) also had striking differences in surface labeling patterns.