[Clinical analysis of the correlation between gallbladder adenomyomatosis and occult pancreaticobiliary reflux]

Objective: To explore the association between gallbladder adenomyomatosis (GA) and occult pancreaticobiliary reflux (OPBR). Methods: A total of 81 patients with GA who underwent cholecystectomy in Shanghai East Hospital from December 2020 to January 2022 were enrolled, including 48 cases of fundal type, 28 cases of segmental type and 5 cases of diffuse type. Patient's intraoperative bile was coltected and tested for amylase. According to gallbladder bile amylase level, patients were divided into OPBR group (bile amylase>110 U/L) and the control group (bile amylase≤110 U/L). Results: Among 81 patients, 32 were male and 49 were female, and aged (49.1±13.2) years; there were 66 cases in control group, including 27 males and 39 females, and aged (50.0±12.9)years; there were 15 patients in the OPBR group, including 5 males and 10 females, and aged (45.1±14.2) years. In terms of the clinical features of the two groups, there was no significant difference (all P>0.05), except for a significant increase in biliary amylase in the OPBR group compared with the control group (P<0.001). However, the incidence of OPBR was significantly different in the three types of GA, with a lower incidence of OPBR in the fundal type (10.4%, 5/48) than in the segmental type (28.6%, 8/28) and diffuse type (2/5) (P=0.038). In addition, segmental GA was more likely to be combined with gallbladder stones (85.7%, 24/28) than fundal GA (58.3%, 28/48) and diffuse GA (3/5) (P=0.031). Univariate and multivariate logistic regression analyses showed OPBR [OR (95%CI)=3.410 (1.010 to 11.513), P=0.048] and combined gallbladder stones [OR (95%CI)=2.974 (1.011 to 8.745), P=0.048] indepenclently correlated with segmental and diffuse GA. Conclusions: The incidence of OPBR is higher in segmental and diffuse GA, and gallstones and OPBR are independently associated with the occurrence of segmental and diffuse GA. These results suggest that OPBR may be the initiating factor for the occurrence and carcinogenesis of segmental and diffuse GA.

Clinical characteristics and disease burden in prurigo nodularis

BACKGROUND

Prurigo nodularis (PN) is a chronic inflammatory skin disease characterized by intense pruritus, but information on patient experience and impact on quality of life (QoL) remains understudied.

AIM

To characterize disease characteristics and QoL in a global sample of patients with PN.

METHODS

An anonymous survey was distributed via patient support groups for PN.

RESULTS

In total, 231 members responded to the survey. The majority of respondents reported itch localized both to nodules and to intervening skin (67.0%). Associated symptoms included prickling, pain, stinging and burning. The extensor lower legs (69% right, 67.3% left) and flexor forearms (66.1% right, 62% left) were the most common sites of itch. Participants reported frequent healthcare utilization, with 36.3% visiting a doctor ≥ 10 times in the past year. Physician-diagnosed anxiety (45.4%), depression (16.4%) and the atopic triad (18.7%) were commonly reported. Patients with PN had mean scores of 16.4, 11.6 and 16.8 on the Dermatology Life Quality Index, Pittsburgh Sleep Quality Index and 5-Dimensions Itch, respectively.

CONCLUSIONS

Severe pruritus with accompanying pain, stinging and burning is characteristic of PN, with the majority of patients experiencing itch in both nodular and interlesional skin. Patients further report decreased QoL scores and impaired sleep. Patient experiences should guide future management of PN.

[Clinicopathologic features of solitary fibrous tumor in urogenital system]

OBJECTIVE

To study the clinicopathologic features and differential diagnosis of solitary fibrous tumor (SFT) in the urogenital system.

METHODS

The clinical data and pathologic characteristics of eight cases of SFT in the urogenital system were analyzed, and the relevant literature was reviewed.

RESULTS

The cohort included six male and two female patients, with age of onset ranging from 25 to 80 years. Five occurred in the kidney (three in the right kidney), one case each occurred in the bladder, the prostate and the spermatic cord. Most patients showed no obvious clinical symptoms or only had low back pain and swelling. The diameter of the tumor was ranged from 2.5 to 11.8 cm (median 5.2 cm). Microscopy showed at low magnification, the tumor cells were spindle-shaped and arranged in bundles or helicoid pattern. The regional mesenchymal fibroblasts showed hyperplasia, with obvious collagenization and formed hemangiopericytoma-like structure. One case showed increased mitotic figures (>5 cells/10 HPF) and focal necrosis. By immunohistochemistry, the tumor cells were positive for CD34 and STAT6 in all eight cases, CD99 and vimentin in six cases, bcl-2 in four cases and SMA in one case. All seven cases with follow-up did not show any tumor recurrence or metastasis.

CONCLUSIONS

SFT is rare in the urogenital system and most patients show good prognosis. SFT expresses CD34 and STAT6 and needs to be distinguished from other spindle cell tumors.

Pretreatment gastric histology is helpful to predict the symptomatic response after H. pylori eradication in patients with nonulcer dyspepsia

This study aimed to test whether pretreatment gastric pathology in H. pylori-infected nonulcer dyspepsia (HpNUD) patients is relevant to and predictive of the symptomatic response after H. pylori eradication. Anti-H. pylori triple therapy was administered to 250 HpNUD patients, enrolled as the therapy group. In addition, 60 patients were enrolled as the control group, in which omeprazole was an alternatives to the triple therapy. Pretreatment gastric histology was evaluated thoroughly by the updated Sydney system. A [13C] urea breath test was also performed to evaluate the H. pylori eradication two months and 12 months later. For each patient, the baseline, month 2, and month 12 symptom scores were assessed for the month 2 or month 12 residual symptom ratio (RSR-2m or RSR-12m), calculated from: 100% x month 2 or month 12 score/baseline score. Based on either RSR-2m or RSR-12m, patients were categorized as good response (RSR < 50%), moderate response (50-70%), and poor response (> 70%) subgroups in both therapy and control groups to define the short-term and long-term symptomatic responses. Patients with successful H. pylori eradication in the therapy group showed a higher incidence of good symptomatic response (RSR < 50%) than those from the control group (month 2: 30.3 vs 12%, P < 0.05; month 12: 34.7 vs 17.1%, P < 0.05). Univariate and multivariate analysis disclosed that patients with a higher acute inflammation score (AIS) and the lowest incidence of lymphoid follicles (LF) at pretreatment gastric histology are predisposed to having a good symptom response after H. pylori eradication (P < 0.05). For HpNUD patients who have an AIS of more than three and an absence of LF at gastric histology, more than 85% had good short-term (month 2) and long-term (month 12) symptomatic relief after H. pylori eradication. In conclusion, nearly 30% of HpNUD patients can obtain symptomatic relief following H. pylori eradication. The pretreatment gastric histology of HpNUD can be helpful to monitor the symptomatic response after H. pylori eradication.

Rapid identification of yeasts in positive blood cultures by a multiplex PCR method

Yeasts are emerging as important etiological agents of nosocomial bloodstream infections. A multiplex PCR method was developed to rapidly identify clinically important yeasts that cause fungemia. The method amplified the internal transcribed spacer 1 (ITS1) region between the 18S and 5.8S rRNA genes and a specific DNA fragment within the ITS2 region of Candida albicans. With this method, C. albicans produced two amplicons, whereas other species produced only one. Through sequence analysis, the precise lengths of the PCR products were found to be as follows: C. glabrata (482 or 483 bp), C. guilliermondii (248 bp), C. parapsilosis (229 bp), C. albicans (218 or 219 and 110 bp), C. tropicalis (218 bp), Cryptococcus neoformans (201 bp), and C. krusei (182 bp). The PCR products could be effectively separated by disk polyacrylamide gel electrophoresis. The method was used to test 249 positive blood cultures (255 isolates), from which the following species (strain number) were isolated: C. albicans (128), C. tropicalis (51), C. glabrata (28), C. parapsilosis (23), C. neoformans (9), C. krusei (5), C. guilliermondii (3), and other, minor species (8). The test sensitivity of the method was 96.9% (247 of 255 isolates). The eight minor species were either misidentified (one strain) or not identified (seven strains). From the time at which a positive bottle was found, the multiplex PCR could be completed within 8 h; the present method is simpler than any previously reported molecular method for the identification of blood yeasts.

Brassica rapa has three genes that encode proteins associated with different neutral lipids in plastids of specific tissues

Plastid lipid-associated protein (PAP), a predominant structural protein associated with carotenoids and other non-green neutral lipids in plastids, was shown to be encoded by a single nuclear gene in several species. Here we report three PAP genes in the diploid Brassica rapa; the three PAPs are associated with different lipids in specific tissues. Pap1 and Pap2 are more similar to each other (84% amino acid sequence identity) than to Pap3 (46% and 44%, respectively) in the encoded mature proteins. Pap1 transcript was most abundant in the maturing anthers (tapetum) and in lesser amounts in leaves, fruit coats, seeds, and sepals; Pap2 transcript was abundant only in the petals; and Pap3 transcript had a wide distribution, but at minimal levels in numerous organs. Immunoblotting after sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that most organs had several nanograms of PAP1 or PAP2 per milligram of total protein, the highest amounts being in the anthers (10.9 microg x mg(-1) PAP1) and petals (6.6 microg x mg(-1) PAP2), and that they had much less PAP3 (<0.02 microg x mg(-1)). In these organs PAP was localized in isolated plastid fractions. Plants were subjected to abiotic stresses; drought and ozone reduced the levels of the three Pap transcripts, whereas mechanical wounding and altering the light intensity enhanced their levels. We conclude that the PAP gene family consists of several members whose proteins are associated with different lipids and whose expressions are controlled by distinct mechanisms. Earlier reports of the expression of one Pap gene in various organs in a species need to be re-examined.

A noninvasive H. pylori stool antigen assay to detect H. pylori infection of in vivo BALB/c mice models

BACKGROUND/AIMS

Previous tests for H. pylori infection status of mice have required sacrificing the small host for histological evaluation. We thus aim to determine whether a noninvasive HpSA (H. pylori-specific stool antigen assay) could be applied to detect H. pylori infection in living mice.

METHODOLOGY

A total of 60 BALB/c specific pathogen-free mice were used, 20 per control group and 40 per exposed group, the exposed group being challenged with H. pylori isolates. In both groups, the stool samples of each mouse were collected before, 7 days, and 4 weeks after the challenge with H. pylori isolates in the exposed group. All the stool samples were processed with HpSA to detect the presence of H. pylori infection. Four weeks after the inoculation of the exposed group and no inoculation in the control group, each mouse received gastrectomy for histology to judge the presence of H. pylori.

RESULTS

None of the mice had a positive histology in the control group. Five BALB/c mice expired due to H. pylori inoculation in the exposed group. Four weeks after inoculation, 85.7% (30/35) of the BALB/c mice achieved the H. pylori infection. Applying the stool samples collected on the 7th day and selecting cutoff point as 0.2, the sensitivity and specificity of HpSA to detect the H. pylori colonization achieved as 100% and 88%, respectively. The 4th week stool samples for HpSA achieved a high sensitivity as 96.6% and specificity as 96% to detect H. pylori infection rate, while choosing cutoff point as 0.20.

CONCLUSIONS

HpSA can be an effective tool without subject lethality to detect H. pylori infection in BALB/c mice model.

Evaluation of Etest for direct antifungal susceptibility testing of yeasts in positive blood cultures

The performance of the Etest (AB BIODISK, Solna, Sweden) for direct antifungal susceptibility testing of yeasts in positive blood cultures was compared with that of the macrodilution method for determining the MICs of five antifungal agents. Culture broths with blood from bottles positive for yeasts were inoculated directly onto plates for susceptibility testing with the Etest, and the MICs were read after 24 and 48 h of incubation. A total of 141 positive blood cultures (72 cultures of Candida albicans, 31 of Candida tropicalis, 14 of Candida glabrata, 11 of Candida parapsilosis, 3 of Candida krusei, and 3 of Cryptococcus neoformans, 4 miscellaneous yeast species, and 3 mixed cultures) were tested, and the rates of MIC agreement (+/-1 log(2) dilution) between the direct Etest (at 24 and 48 h, respectively) and macrodilution methods were as follows: amphotericin B, 81.8 and 93.5%; flucytosine, 84.8 and 87.7%; fluconazole, 89.4 and 85.5%; itraconazole, 69.7 and 63.8%; ketoconazole, 87.9 and 79.0%. By a large-sample t test, the difference in log(2) dilution between the direct Etest and the macrodilution method was found to be small (P < 0.05). The lone exceptions were ketoconazole at 48 h of incubation and itraconazole at both 24 and 48 h of incubation (P > 0.05). By Tukey's multiple comparisons, the difference between the direct Etest (48 h) and reference methods among different species was found to be less than 1 log(2) dilution. When the MICs were translated into interpretive susceptibility, the minor errors caused by the direct Etest (at 24 and 48 h, respectively) were as follows: flucytosine, 2.3 and 1.4%; fluconazole, 3.0 and 3.6%; itraconazole, 21.2 and 21.3%. Itraconazole also produced an additional 3.0 and 3.6% major errors as determined by the direct Etest at 24 and 48 h, respectively. It was concluded that, except for itraconazole, the Etest method was feasible for direct susceptibility testing of blood cultures positive for yeasts. The method is simple, and the results could be read between 24 and 48 h after direct inoculation, whenever the inhibition zones were discernible.

Local attenuation of systemically mediated splanchnic vasoconstriction during shock due to cholera

Hypovolemic shock, most often due to hemorrhage, is typically associated with intense splanchnic vasoconstriction. This can be severe enough to impair the functional and structural integrity of the gastrointestinal tract. Paradoxically, with cholera the structure of the gastrointestinal tract is preserved, and the intestine continues to secrete fluid delivered to it in the circulating blood in spite of severe hypovolemic shock. This suggests that splanchnic blood flow is maintained at higher levels in hypovolemic shock due to cholera than in hypovolemic shock due to hemorrhage. Our hypothesis is that cholera toxin in the intestinal lumen activates local mechanisms that attenuate systemically mediated splanchnic vasoconstriction. Blood flow to an isolated ileal segment in situ in the anesthetized rabbit was measured continuously (ultrasound transit-time volume flow probe) for 5 to 6 h after instillation of cholera toxin into the isolated intestinal lumen. Norepinephrine was infused selectively into the mesenteric artery supplying the segment to elicit local responses uncomplicated by compensatory changes secondary to systemic effects of norepinephrine. Baseline vascular conductance increased gradually and became significantly greater in cholera toxin experiments than in vehicle experiments 5 h after treatment (P < 0.035). Animals treated with cholera toxin were less responsive to norepinephrine than vehicle treated animals were (P < 0.05) and became more so over time (P < 0.001). Our conclusion is that cholera toxin activates local mechanisms that attenuate systemically mediated splanchnic vasoconstriction, at least in part by reducing vascular responsiveness to a systemic vasoconstrictor, norepinephrine.

Rapid differentiation of fermentative from nonfermentative gram-negative bacilli in positive blood cultures by an impedance method

Rapid differentiation of fermentative gram-negative bacilli (fermenters) from nonfermentative gram-negative bacilli (nonfermenters) in positive blood cultures may help physicians to narrow the choice of appropriate antibiotics for empiric treatment. An impedance method for direct differentiation of fermenters from nonfermenters was investigated. The bacterial suspensions (or positive culture broths containing gram-negative bacteria) were inoculated into the module wells of a Bactometer (bioMérieux, Inc., Hazelwood, Mo.) containing 1 ml of Muller-Hinton broth. The inoculated modules were incubated at 35 degrees C, and the change in impedance in each well was continuously monitored. The amount of time required to cause a series of significant deviations from baseline impedance values was defined as the detection time (DT). The percent change of impedance was defined as the change of impedance at the time interval from DT to DT plus 1 h. After testing 857 strains of pure cultures (586 strains of fermenters and 271 strains of nonfermenters), a breakpoint (2.98%) of impedance change was obtained by discriminant analysis. Strains displaying impedance changes of greater than 2.98% were classified as fermenters; the others were classified as nonfermenters. By using this breakpoint, 98.6% (340 of 345) of positive blood cultures containing fermenters and 98% (98 of 100) of positive blood cultures containing nonfermenters were correctly classified. The impedance method was simple, and the results were normally available within 2 to 4 h after direct inoculation of positive blood culture broths.

Impact of Helicobacter pylori antimicrobial resistance on the outcome of 1-week lansoprazole-based triple therapy

PURPOSE

To determine the effect of Helicobacter pylori antimicrobial resistance on the efficacy of different proton pump inhibitor (PPI)-based triple therapies.

METHODS

One-hundred and twelve dyspeptic patients with H. pylori infection, as demonstrated by positive histology and culture, were randomized to receive one of the three PPI-based triple therapies. The regimens included lansoprazole (L) plus any two of the following three antibiotics: amoxicillin (A), metronidazole (M), and clarithromycin (C); patients were allocated to ALC, MLC, and ALM subgroups. Six weeks after the start of triple therapy, the 13C-urea breath test (UBT) was performed to evaluate the success of H. pylori eradication. Patients with positive UBT results underwent endoscopy for H. pylori culture. The pre- and post-treatment H. pylori isolates were analyzed for initial and acquired resistance using the E-test.

RESULTS

One hundred patients completed the study. The H. pylori eradication rates were 70% (21/30) in the ALM subgroups, 79% (26/33) in the MLC subgroup, and 89% (33/37) in the ALC subgroup. The frequencies of pretreatment H. pylori antimicrobial resistance were 0% for amoxicillin resistance (AR), 32% for metronidazole resistance (MR), and 6% for clarithromycin resistance (CR). For H. pylori isolates with initial MR, the eradication rates in the ALM (40%) and MLC (67%) subgroups were apparently lower than that in the ALC (92%) subgroup. In the ALM and MLC subgroups (i.e., patients who received metronidazole), the eradication failure rate was significantly higher for patients with MR isolates than for patients with metronidazole-susceptible isolates (47% vs 16%, p < 0.05). In the ALC and MLC subgroups (i.e., patients who received clarithromycin), the eradication failure rate was significantly higher for patients with CR isolates than for those with clarithromycin-susceptible isolates (100% vs 11%, p < 0.05).

CONCLUSIONS

The results indicate that H. pylori antimicrobial resistance is relevant to the success of eradication. The high MR but low CR and AR prevalence among H. pylori isolates in this study suggests that PPI-based triple therapy including amoxicillin and clarithromycin may achieve the most favorable eradication rate.

Prevalence of polyclonal mefA-containing isolates among erythromycin-resistant group A streptococci in Southern Taiwan

A total of 204 nonrepetitive isolates of group A streptococci (GAS), including 107 randomly collected between 1992 and 1995 and 66 and 31 consecutively collected in 1997 and 1998, respectively, from a university hospital in southern Taiwan were examined to determine the prevalence and mechanisms of erythromycin resistance among these isolates. Resistance to erythromycin was detected in 129 isolates (63.2%) by the agar dilution test. Of these, 42 isolates (32.6%) were assigned to the constitutive macrolide, lincosamide, and streptogramin B resistance (cMLS) phenotype, and all carried the ermB gene; 4 (3.1%) were assigned to the inducible MLS resistance (iMLS) phenotype, and all harbored the ermTR gene; and 83 (64.3%) were erythromycin resistant but susceptible to clindamycin (M phenotype), and all possessed the mefA gene. Distributed by years, the rates of erythromycin resistance and different phenotypes were 61.7% (53.0% cMLS, 6.1% iMLS, and 40.9% M phenotype) between 1992 and 1995, 62.1% (12.2% cMLS and 87.8% M phenotype) in 1997, and 71. 0% (9.1% cMLS and 90.9% M phenotype) in 1998. Pulsed-field gel electrophoresis showed that all but 2 cMLS isolates were clonal in origin, and 17 clones were detected among the M-phenotype isolates. These results indicate that the high incidence and increasing rate of erythromycin-resistant GAS in southern Taiwan are due to the prevalence of multiple M-phenotype clones and that clindamycin may be the drug of choice for the treatment of infections with GAS in penicillin-hypersensitive patients in this area.

Comparison of the MB/BacT and BACTEC MGIT 960 system for recovery of mycobacteria from clinical specimens

A total of 543 specimens were cultured in parallel with the MB/BacT and BACTEC MGIT 960 systems and on the conventional solid media. Mycobacteria were identified from 95 (17.5%) specimens, including 63 (66.3%) Mycobacterium tuberculosis and 32 (33.7%) nontuberculous mycobacteria. The recovery rates for the MB/BacT, MGIT 960, and solid media were 91.6, 87.4, and 54.7%, respectively, for all mycobacteria; the recovery rates were 93.6, 88.9, and 63.4%, respectively, for M. tuberculosis complex alone, and 87.5, 84.4, and 37.5%, respectively, for all nontuberculous mycobacteria. The mean times to detection of all mycobacteria by individual systems were 13. 9, 8.7, 31.7 days for the MB/BacT, MGIT 960 and solid media, respectively, 13.9, 9.3, 32.9 days for M. tuberculosis alone, and 14. 1, 8.1, 27.2 days for all nontuberculous mycobacteria. The contamination rates of the MB/BacT and MGIT 960 were 10.2 and 5.4%, respectively. With regard to detection times and recovery rates, both automated systems are superior to the conventional media (all p < 0.005). As compared to the MB/BacT, the MGIT 960 detected mycobacterial growth more rapidly (p < 0.001), and had a lower contamination rate (p = 0.003); however, there was no statistically significant difference in recovery rates between these two systems. These results indicate that both MGIT 960 and MB/BacT systems are rapid, sensitive, and efficient methods for the recovery of mycobacteria from clinical specimens.

Rapid dissemination of Staphylococcus aureus with classic oxacillin resistance phenotype at a new university hospital

To determine the prevalence rates of oxacillin-resistant Staphylococcus aureus (ORSA) at a new university hospital since its opening, the results of disk diffusion tests on all clinical isolates, recovered between 1990 and 1998 at the National Cheng Kung University Hospital, were reviewed. In order, to investigate the mechanisms of oxacillin resistance among strains of S. aureus in Taiwan, MICs were determined by an agar dilution method, and polymerase chain reaction and colony hybridization assays were performed on 288 isolates collected during November 1998 to detect the mecA gene. The prevalence rates of ORSA increased rapidly from 14.1% in 1990 to 61.0% in 1998. The increasing rates were most rapid in the first four-year period, ranging from 11.6 to 106.7% per year, and became steady after 1994, ranging from 1.8% to 11.6%. Of 288 clinical isolates collected in November 1998, 206 (71.5%) were resistant to oxacillin (MIC >/= 16 mg/L), and four were borderline resistant (MIC 2-8 mg/L). All 210 strains possessed the mec A gene (classic resistance). The present study demonstrated that ORSA could disseminate in a new hospital with great speed, and indicated that all ORSA strains in Taiwan revealed classic resistance phenotype.

Evaluation of a capacitance method for direct antifungal susceptibility testing of yeasts in positive blood cultures

The feasibility of using a capacitance method (CM) for direct antifungal susceptibility testing of yeasts in positive blood cultures was evaluated. The CM used the same test conditions as those recommended by the National Committee for Clinical Laboratory Standards. After direct inoculation of positive culture broths into module wells (Bactometer; bioMérieux, Inc., Hazelwood, Mo.), the end-point determination was made by monitoring the capacitance change in the culture broths with Bactometer. The MIC of amphotericin B was the lowest concentration at which yeast growth was completely inhibited, while the MICs of ketoconazole, flucytosine, and fluconazole were the concentrations at which a >/=80% reduction in capacitance change was observed. The MICs of the four drugs against each blood isolate obtained on subculture plates were also determined by the macrodilution method. For 51 positive blood cultures tested, the percent agreement (+/-2 log(2) dilutions) between the CM and the macrodilution method were as follows: amphotericin B (98%), ketoconazole (92%), flucytosine (84%), and fluconazole (96%). The CM was further used for breakpoint susceptibility testing of fluconazole (8 and 64 microg/ml) and flucytosine (4 and 32 microg/ml) against yeasts in positive blood cultures. After testing of 74 specimens by the CM, flucytosine and fluconazole produced one (1.4%) major error and two (2.8%) minor errors, respectively. All yeasts that displayed resistance to flucytosine or fluconazole were detected within 24 h after direct inoculation of the positive broths into Bactometer. The CM may be useful for the rapid detection of antifungal resistance in positive blood cultures containing yeasts.

Arcobacter butzleri bacteremia in a patient with liver cirrhosis

Invasive Arcobacter butzleri infection in humans has been rarely described. We report a 60-year-old man with liver cirrhosis who presented with high fever and esophageal variceal bleeding. Two aerobic blood cultures grew Campylobacter-like organisms. The biochemical reactions of the isolate were inconclusive, while sequence analysis of the 16S rRNA gene definitively identified the organism as A. butzleri. The patient's bleeding stopped after endoscopic sclerosing therapy. Although the organism appeared to be resistant to cephalosporins on the basis of the minimum inhibitory concentrations determined with the E test, the fever resolved with parenteral cefuroxime. Whether the clinical improvement was related to cephalosporin therapy or to the self-limited nature of Arcobacter bacteremia is not known.

AT1-receptor blockade enhances ischemic preconditioning in hypertrophied rat myocardium

The purpose of this study was to determine whether ischemic preconditioning protects contractile function in hypertrophied rat myocardium from ischemia-reperfusion (I/R) injury. Male salt-sensitive rats were fed a high-salt diet for 2 wk to induce myocardial hypertrophy. Nonhypertrophied hearts were obtained from age-matched Sprague-Dawley (SD) rats fed a regular diet. Heart weight-to-body weight ratios were higher in salt-sensitive rats than in SD rats (6.9 +/- 0.2 vs. 4.7 +/- 0.2 g/kg, P < 0.01). A second group of salt-sensitive and SD rats was administered losartan (10 mg. kg(-1). day(-1)), an AT(1)-receptor blocker, for 1 wk before the study. Isolated hearts were preconditioned with transient ischemia before global I/R. After I/R, preconditioned hypertrophied hearts exhibited greater recovery of left ventricular developed pressure compared with that of preconditioned normal hearts (73 +/- 8 vs. 18 +/- 8%, P < 0.01). Left ventricular developed pressure was further enhanced by losartan in both hypertrophied and normal myocardium (99 +/- 5 vs. 73 +/- 8%, P < 0.05 and 97 +/- 15 vs. 18 +/- 8%, P < 0.01). Hypertrophied rat myocardium can be protected from I/R-induced contractile dysfunction by ischemic preconditioning. Losartan improves the ischemic tolerance of normal and hypertrophied myocardium.

Increase of intestinal Bifidobacterium and suppression of coliform bacteria with short-term yogurt ingestion

To determine whether ingestion of yogurt would alter human intestinal bacterial composition and whether Bifidobacterium numbers would increase in the intestine, 34 healthy volunteers were studied. The experimental period was 26 d, including an initial 8 d without yogurt, 10 d with three bottles (230 ml each) of AB yogurt per day (President Enterprise Corporation, Tainan, Taiwan), and 8 d without yogurt. Stool samples were taken at 3- to 4-d intervals. The bacteria of each fresh stool sample were promptly analyzed by dilution and culture on blood, MacConkey, Center for Disease Control and NNLP agars, the agar contained nalidixic acid, neomycin sulfate, LiCl, and paromomycin sulfate for aerobes, coliforms, anaerobes, and bifidobacteria, respectively. The number of bacteria was determined as colony-forming units per gram of dried stool. Results indicated that ingestion of AB yogurt increased the counts of anaerobic bacteria, suppressed aerobic bacteria, and significantly elevated the bifidus to coliform ratio. Arbitrarily primed polymerase chain reaction was used to differentiate the identity of bifidobacteria in four volunteers before and after yogurt ingestion and confirmed that B. bifidum ingested from the yogurt survived and proliferated in the stool throughout the experiment. However, the elevated bifidus to coliform ratio gradually diminished and disappeared after yogurt consumption was discontinued. In conclusion, ingestion of yogurt increased the numbers of stool bifidobacteria and suppressed coliform bacteria. The ingested bifidobacteria survived for more than 8 d after yogurt consumption was discontinued.

The predominant protein on the surface of maize pollen is an endoxylanase synthesized by a tapetum mRNA with a long 5' leader

In plants, the pollen coat covers the exine wall of the pollen and is the outermost layer that makes the initial contact with the stigma surface during sexual reproduction. Little is known about the constituents of the pollen coat, especially in wind-pollinated species. The pollen coat was extracted with diethyl ether from the pollen of maize (Zea mays L.), and a predominant protein of 35 kDa was identified. On the basis of the N-terminal sequence of this protein, a cDNA clone of the Xyl gene was obtained by reverse transcriptase-polymerase chain reaction. The deduced amino acid sequence of the 35-kDa protein shared similarities with the sequences of many microbial xylanases and a barley aleurone-layer xylanase. The 35-kDa protein in the pollen-coat extract was purified to homogeneity by fast protein liquid chromatography and determined to be an acidic endoxylanase that was most active on oat spelt xylan. Northern and in situ hybridization showed that Xyl was specifically expressed in the tapetum of the anther after the tetrad microspores had become individual microspores. Southern hybridization and gene-copy reconstruction studies showed only one copy of the Xyl gene per haploid genome. Analyses of the genomic DNA sequence of Xyl and RNase protection studies with the transcript revealed many regulatory motifs at the promoter region and an intron at the 5' leader region of the transcript. The Xyl transcript had a 562-nucleotide (nt) 5' leader, a 54-nt sequence encoding a putative signal peptide, a 933-nt coding sequence, and a 420-nt 3'-untranslated sequence. The unusually long 5' leader had an open reading frame encoding a putative 175-residue protein whose sequence was most similar to that of a microbial arabinosidase. The maize xylanase is the first enzyme documented to be present in the pollen coat. Its possible role in the hydrolysis of the maize type II primary cell wall (having xylose, glucose, and arabinose as the major moieties) of the tapetum cells and the stigma surface is discussed.

Development of Helicobacter pylori infection model in BALB/c mice with domestic cagA-positive and -negative strains in Taiwan

We aimed to develop an H. pylori-infected mouse model using clinically stored strains in Taiwan and to test whether development of H. pylori infection in an in vivo animal model is related to the status of the cagA gene. A total of 100 male BALB/c mice, 6-8 weeks old, including 80 in the experimental group and 20 in the control group, were used. Two clinically stored H. pylori isolates, a cagA-positive and a cagA-negative strain, were selected to induce the H. pylori infection in half (N = 40) of the mice in the experimental group. Bacterial isolates of 0.8 x 10(9) CFU/ml were orally inoculated in each mouse of the experimental group for three consecutive days. Ten mice in the control group were sacrificed to confirm the initial absence of H. pylori. Eight weeks after inoculation of the experimental group and no inoculation of the remaining 10 mice of the control group, each mouse was killed. Gastrectomy was then performed for rapid urease test (CLOtest) and histology. In the control group, none of 20 mice had positive results from the CLOtest or histology. In contrast, excluding eight of 80 mice that died before the eighth week, 90.3% (65/72) of the mice challenged with H. pylori showed persistent presence of H. pylori by histology. The severity of gastritis at the eighth week was more evident in H. pylori-infected mice than in control and noninfected mice (P < 0.05). Although gastritis was more severe in mice inoculated with the cagA-positive strain than with the cagA-negative strain, the rates of H. pylori infection in mice were not different between cagA-positive and -negative strains (91.4% vs 89.2%, P > 0.05). In summary, stored strains of H. pylori can be applied to induce an infection model in BALB/c mice. The less virulent cagA-negative strain can induce H. pylori infection in mice as effectively as the cagA-positive strain. The high prevalence of cagA-positive strains in Taiwanese patients may be related to factors other than only the cagA gene of the bacteria.

Steryl esters in the elaioplasts of the tapetum in developing Brassica anthers and their recovery on the pollen surface

The tapetum cells in the developing anthers of Brassica napus contained abundant elaioplasts, which had few thylakoid membranes but were packed with globuli of neutral esters. Of the neutral esters, the major ester group possessed mainly 24-methylenecholesterol, 31-norcycloartenol, 24-dehydropollinastanol, and pollinastanol esterified to 18:3 and other unsaturated and saturated fatty-acyl moieties. The minor ester group had a dominant component tentatively identified as 12-dehydrolupeol esterified to mostly 18:0, 16:0, and 20:0 fatty-acyl moieties. The elaioplasts also contained a high proportion (16% w/w of total lipids) of monogalactosyldiacylglycerols (MGDG). This is the first report of plastids having steryl esters as the predominant lipids. We propose that the globuli contain steryl esters and are stabilized by surface MGDG and structural proteins. The tapetosomes, the other abundant lipid-containing organelles in the tapetum, possessed triacylglycerols (TAG) as the predominant lipids. At a late stage of anther development, the minor group of neutral esters and MGDG of the elaioplasts, as well as the TAG of the tapetosomes, were degraded. Steryl esters similar to those of the elaioplasts were recovered from the pollen surface and were the major lipids of the pollen coat. The pollen coat steryl esters and proteins could be extracted with moderately polar or nonpolar solvents. These proteins, which were mostly fragments of oleosins derived from the tapetosomes, had a high proportion of lysine (13 mol %). The possible functions of the steryl esters and the proteins on the pollen surface are discussed.

Staphylococcus capitis bacteremia of very low birth weight premature infants at neonatal intensive care units: clinical significance and antimicrobial susceptibility

Coagulase-negative staphylococci (CNS) are frequently isolated from blood cultures in critically ill neonates. However, Staphylococcus capitis is rarely reported as a pathogen in human beings. From January, 1995 to December, 1997 at a tertiary care neonatal intensive care unit (NICU), a total of 147 (62%) CNS isolates were detected from 236 positive blood cultures, including 27 isolates of S. capitis. Among the S. capitis bacteremia, 17 isolates were judged to be infections as opposed to 10 of the noninfection cultures. The occurrence of S. capitis infection was correlated with long hospital stay (52 +/- 17.6 days vs. 28 +/- 18.5 days, p=0.003) and total parenteral nutrition administration (46 +/- 17.4 days vs. 22 +/- 19.1 days, p=0.006). Apnea, bradycardia, temperature instability and poor activity were the predominant clinical features. Among the 17 episodes of bacteremia, one patient had complicated septic meningitis. There is no statistical significance between S. capitis infection and the duration of a central venous catheter placement (37 +/- 17.5 days vs. 26 +/- 19.5 days, p=0.165). No catheter related infection was proven. Removal of a percutaneous central venous catheter routinely in patients with S. capitis bacteremia is not recommended. All the patients survived after antibiotic treatment. The prevalence rate of multiple resistant S. capitis was 94%. All isolates were resistant to oxacillin, erythromycin and clindamycin but susceptible to ampicillin/sulbactam, vancomycin and teicoplanin. Empiric therapy for S. capitis infection in NICU with ampicillin/sulbactam is therefore recommended. It is important to detect S. capitis which has a high degree of antibiotic resistance in order to treat the patient correctly. S. capitis should be included as etiology and the possibility of nosocomial outbreak in very low birth weight (VLBW) premature infants at NICU.

Constituents of the tapetosomes and elaioplasts in Brassica campestris tapetum and their degradation and retention during microsporogenesis

In Brassica anthers during microsporogenesis, the tapetum cells contain two abundant lipid-rich organelles, the tapetosomes possessing oleosins and triacylglycerols (TAGs), and the elaioplasts having unique polypeptides and neutral esters. B. campestris, for its simplicity of possessing only the AA genome and one predominant oleosin of 45 kDa, was studied. In the developing anthers, the lipids and proteins of the tapetosomes and elaioplasts were concomitantly accumulated but selectively degraded or retained. Upon incubation of isolated tapetosomes in a pH-5 medium, the predominant 45 kDa oleosin underwent selective enzymatic proteolysis to a 37 kDa fragment, which was not further hydrolyzed upon prolonged incubation. The unreacted 45 kDa oleosin was retained in the organelles, whereas the 37 kDa fragment was released to the exterior. The fragment would become the predominant 37 kDa polypeptide in the pollen coat. Isolated tapetosomes did not undergo hydrolysis of the TAGs upon incubation in media of diverse pHs. An alkaline lipase in the soluble fraction of the anther extract was presumed to be the enzyme that would hydrolyze the tapetosome TAGs, which disappeared in the anthers during development. The tapetum elaioplasts contained several unique polypeptides of 31-36 kDa. The gene encoding a 32 kDa polypeptide was cloned, and its deduced amino acid sequence was homologous to those of two proteins known to be present on the surface of fibrils in chromoplasts. Upon incubation of isolated elaioplasts in media of diverse pHs, the organelle polypeptides were degraded completely and most rapidly at pH 5, whereas the neutral esters remained unchanged; these neutral esters would become the major lipid components of the pollen coat. The findings show that the constituents of the two major tapetum organelles underwent very different paths of degradation, or modification, and transfer to the pollen surface.

High rates of antimicrobial resistance among clinical isolates of nontyphoidal Salmonella in Taiwan

To assess trends in antimicrobial-resistant Salmonella infections from 1989 to 1996 in southern Taiwan, the minimum inhibitory concentrations (MICs) of 14 antibiotics or antibiotic combinations were determined by the agar dilution method for 297 clinical isolates of nontyphoidal Salmonella. The rates of resistance to ampicillin, chloramphenicol, and tetracycline were 65, 67, and 78%, respectively. Resistance to trimethoprim-sulfamethoxazole (TMP-SMX) increased from 25% in 1989-1992 to 35% in 1993-1996 (P=0.057). For new quinolones and extended-spectrum cephalosporins, no resistant strains were encountered. Multiple resistance to more than five antimicrobial drugs doubled from 10.6% in 1989-1992 to 19.7% in 1993-1996. Multiply resistant salmonellae were isolated more commonly from blood samples than from feces (30% vs. 14%, P<0.05). In Taiwan, ampicillin, chloramphenicol, and even TMP-SMX are no longer the drugs of choice for treatment of serious nontyphoidal Salmonella infections. Extended-spectrum cephalosporins are now the preferred drugs in Taiwan for treatment of invasive Salmonella infections in children.

Direct antimicrobial susceptibility testing of gram-negative bacilli in blood cultures by an electrochemical method

Nonfastidious aerobic gram-negative bacilli (GNB) are commonly isolated from blood cultures. The feasibility of using an electrochemical method for direct antimicrobial susceptibility testing of GNB in positive blood cultures was evaluated. An aliquot (10 microliter) of 1:10-diluted positive blood cultures containing GNB was inoculated into the Bactometer module well (bioMérieux Vitek, Hazelwood, Mo.) containing 1 ml of Mueller-Hinton broth supplemented with an antibiotic. Susceptibility tests were performed in a breakpoint broth dilution format, with the results being categorized as resistant, intermediate, or susceptible. Seven antibiotics (ampicillin, cephalothin, gentamicin, amikacin, cefamandole, cefotaxime, and ciprofloxacin) were used in this study, with each agent being tested at the two interpretive breakpoint concentrations. The inoculated modules were incubated at 35 degreesC, and the change in impedance in each well was continuously monitored for 24 h by the Bactometer. The MICs of the seven antibiotics for each blood isolate were also determined by the standardized broth microdilution method. Of 146 positive blood cultures (1,022 microorganism-antibiotic combinations) containing GNB tested by the direct method, the rates of very major, major, and minor errors were 0, 1.1, and 2.5%, respectively. The impedance method was simple; no centrifugation, preincubation, or standardization of the inocula was required, and the susceptibility results were normally available within 3 to 6 h after inoculation. The rapid method may allow proper antimicrobial treatment almost 30 to 40 h before the results of the standard methods are available.

Comparison of five days versus seven days of incubation for detection of positive blood cultures by the Bactec 9240 system

The specimen capacity of blood culture systems is determined by the length of time that blood cultures are incubated. Since the patient populations served by hospitals vary, individual laboratories should evaluate the relative cost and benefits of different testing regimens for their particular setting. To be cost-effective, the use of a 5-day rather than a 7-day protocol for the Bactec 9240 system (Becton Dickinson Diagnostic Instrument Systems, USA) has been recommended. To evaluate whether the shorter schedule would be appropriate at the Microbiology Laboratory at the National Cheng Kung University Medical Center in Tainan, Taiwan, the yield from 5 days versus 7 days of incubation was compared using a total of 9653 blood specimens collected from 1 April to 30 September 1997. Of the 1848 positive vials, 1822 (98.6%) were positive in the first 5 testing days; only 26 (1.4%) were positive on day 6 or 7. Only five of the latter vials were judged to contain clinically significant organisms: one Cryptococcus neoformans, one Candida albicans, one Enterobacter cloacae, one Klebsiella pneumoniae, and one Proteus mirabilis. Two vials contained organisms whose clinical significance was categorized as unknown, while 19 contained organisms that were considered contaminants. These data suggest that, for the laboratory studied, the 5-day protocol for the Bactec 9240 system is more cost-effective than the 7-day protocol and is adequate for detection of positive blood cultures.

One-week proton pump inhibitor-based triple therapy eradicates residual Helicobacter pylori after failed dual therapy

The purposes of this study were to assess the efficacy of a 1-week proton pump inhibitor (PPI)-based triple therapy after failure of dual therapy in Helicobacter pylori eradication, and to compare the effectiveness of clarithromycin and metronidazole in this regimen. Between January 1996 and March 1997, 67 patients with persistent H. pylori infection after a 2-week course of dual therapy (amoxicillin plus omeprazole) were enrolled. They were randomly assigned to receive amoxicillin (1000 mg twice daily) and omeprazole (20 mg twice daily) plus either metronidazole (500 mg twice daily) or clarithromycin (250 mg twice daily). Endoscopy was performed in each patient to assess the status of H. pylori using the rapid urease test (CLOtest) and the histologic findings before dual therapy, after dual therapy, and after triple therapy. H. pylori isolates were tested for antibiotic resistance when triple therapy failed. The 1-week triple therapy was well tolerated in both groups with no adverse effects severe enough to cause withdrawal from the trial. Residual H. pylori was eradicated in 94% (33/35) of patients in the clarithromycin group and 84% (27/32) in the metronidazole group; the difference was not statistically significant. All seven patients in whom triple therapy failed were infected with metronidazole-resistant isolates and two also had clarithromycin-resistant isolates. This 1-week triple therapy is safe and effective in eradicating residual H. pylori after dual therapy failure. Failure of the rescue regimen is related to antimicrobial agent resistance. Because of the high metronidazole resistance rate in Taiwan, clarithromycin appears to be more promising than metronidazole for the control of H. pylori.

Incorporating active learning into a traditional curriculum

During the past three academic years, "self-learning exercises" (SLEs) have been incorporated into the Medical Physiology course for first-year students at the Morehouse School of Medicine. Roughly 20-30% of the material covered in the course is presented to the students in the form of these exercises, instead of in lectures. The exercises are intended to help the students develop skills in active learning and problem solving. Formal analysis of student performances on multiple-choice exam questions showed that the SLEs did not significantly impair learning evaluated by this traditional means. Student feedback was strongly negative the first year and prompted a number of revisions in the format of the SLEs, which seem to have made them more palatable, without negating their emphasis on active learning and application of material.

Isolation and characterization of neutral-lipid-containing organelles and globuli-filled plastids from Brassica napus tapetum

The monolayer tapetum cells of the maturing flowers of Brassica napus contain abundant subcellular globuli-filled plastids and special lipid particles, both enriched with lipids that are supposed to be discharged and deposited onto the surface of adjacent maturing pollen. We separated the two organelles by flotation density gradient centrifugation and identified them by electron microscopy. The globuli-filled plastids had a morphology similar to those described in other plant species and tissues. They had an equilibrium density of 1.02 g/cm(3) and contained neutral esters and unique polypeptides. The lipid particles contained patches of osmiophilic materials situated among densely packed vesicles and did not have an enclosing membrane. They exhibited osmotic properties, presumably exerted by the individual vesicles. They had an equilibrium density of 1.05 g/cm(3) and possessed triacylglycerols and unique polypeptides. Several of these polypeptides were identified, by their N-terminal sequences or antibody cross-reactivity, as oleosins, proteins known to be associated with seed storage oil bodies. The morphological and biochemical characteristics of the lipid particles indicate that they are novel organelles in eukaryotes that have not been previously isolated and studied. After lysis of the tapetum cells at a late stage of floral development, only the major plastid neutral ester was recovered, whereas the other abundant lipids and proteins of the two tapetum organelles were present in fragmented forms or absent on the pollen surface.

Rapid detection of oxacillin-resistant Staphylococcus aureus in blood cultures by an impedance method

The feasibility of using an impedance method for direct detection of oxacillin-resistant Staphylococcus aureus (ORSA) in blood cultures was evaluated. An aliquot (0.1 ml) of the positive blood culture, which showed growth of gram-positive cocci and demonstrated thermonuclease activity, was inoculated into the module well of a Bactometer incubator (bioMerieux Vitek, Hazelwood, Mo.) containing 0.6 ml of Mueller-Hinton agar supplemented with oxacillin (2 microg/ml). The modules were incubated at 37 degrees C, and the change in impedance in each well was continuously monitored by the instrument at 6-min intervals for 24 h. ORSA strains from blood cultures could multiply in the oxacillin-containing medium, and a time point (detection time [DT]) at which an accelerating change of impedance occurred in the medium was obtained, with an average of 5.5 h. The growth of oxacillin-sensitive S. aureus (OSSA) strains was largely inhibited, and no DT was obtained for these strains within an incubation period of 24 h. For 96 positive blood cultures (38 ORSA and 58 OSSA) tested, 36 and 57 were found to be oxacillin resistant and oxacillin sensitive, respectively, by the impedance method. The impedance method had a sensitivity and specificity of 94.7 and 98.3%, respectively, for the detection of ORSA and had an agreement of 96.9% with the disc diffusion method. Comparable results were obtained by the testing of 235 clinical stock cultures of S. aureus (149 ORSA and 86 OSSA). The impedance test is simple for detecting ORSA in blood cultures and may allow proper antimicrobial treatment almost 36 h before the results of the conventional culture methods are available.

Identification, subcellular localization, and developmental studies of oleosins in the anther of Brassica napus

mRNAs encoding putative oleosins have been detected in the tapetum of developing anthers in Brassica and Arabidopsis, but the authentic proteins have not been previously documented. Antibodies against a synthetic 15-residue polypeptide that represents a portion of the putative tapetum oleosins encoded by two cloned Brassica napus genes were raised. Using these antibodies for immunoblotting after SDS-PAGE of the sporophytic extracts of B. napus developing anthers, two oleosins of approximately 48 and 45 kDa were detected. These two oleosins were judged to be the putative oleosins encoded by cloned Brassica genes because of their identical N-terminal sequences. The two oleosins were present in the anthers only during the developmental stage when the tapetum cells were packed with organelles. A fraction of lowdensity organelles was isolated from the developing anthers by flotation centrifugation. The fraction contained plastoglobule-filled plastids and lipid-containing particles. The structures of these two isolated organelles were similar to those in situ in the tapetum cells. Of subcellular fractions of the anther homogenate, the two oleosins were present exclusively in the low-density organelle fraction. They were absent in the surface fractions of the developing microspores and the mature pollen, although fragmented oleosin molecules were earlier reported to be present on the pollen. By immunocytochemistry, immunogold particles were found largely on the periphery of the plastoglobuli inside the plastids in the tapetum cells. The antibodies also detected oleosins on the surface of storage oil bodies inside the maturing microspores. Apparently, the gametophytic microspore oil-body oleosins share common epitopes at the generally non-conserved C-terminal domain with the sporophytic tapetum oleosins.

Oleosin of plant seed oil bodies is correctly targeted to the lipid bodies in transformed yeast

Yeast (Saccharomyces cerevisiae) has been used extensively as a heterologous eukaryotic system to study the intracellular targeting of proteins to different organelles. The lipid bodies in yeast have not been previously subjected to such studies. These organelles are functionally equivalent to the subcellular storage oil bodies in plant seeds. A plant oil body has a matrix of oils (triacylglycerols) surrounded by a layer of phospholipids embedded with abundant structural proteins called oleosins. We tested whether plant oleosin could be correctly targeted to the lipid bodies in transformed yeast. The coding region of a maize (Zea mays L.) oleosin gene was incorporated into yeast high copy and low copy number plasmids in which its expression was under the control of GAL1 promoter. Yeast strains transformed with these plasmids produced oleosin when grown in a medium containing galactose but not glucose. The oleosin produced in yeast had a molecular mass slightly higher than that of the native protein in maize. Oleosin accumulated concomitantly with the storage lipids during growth of the transformed yeast, and it was not secreted. Subcellular fractionation of the cell extracts obtained by two different cell breakage procedures revealed that the oleosin was largely restricted to the lipid bodies. Oleosin apparently did not affect the lipid contents and composition of the transformed yeast lipid bodies but replaced some of the native proteins associated with the organelles. Immunocytochemistry of the transformed yeast cells showed that the oleosin was present mostly on the periphery of the lipid bodies. Oleosin isolated from maize or transformed yeast strain, alone or in the presence of phospholipids or SDS, did not bind to the yeast lipid bodies in vitro. We conclude that plant oleosin is correctly targeted to the lipid bodies in transformed yeast and that yeast may be used as a heterologous system to dissect the intracellular targeting signals in the oleosin.

Bile medium for rapid presumptive identification of group B streptococci

A bile medium was developed for rapid presumptive identification of beta hemolytic group B streptococci. Of 131 clinical isolates of group B streptococci, 125 (95.4%) yielded positive reaction within 6 h incubation. No false positive reaction was found in 134 clinical isolates of groups A, C, F, and G beta-hemolytic streptococci. The sensitivities of the bile medium, rapid hippurate hydrolysis and modified LAL-1 medium were 95.4, 98.5 and 93.1%, respectively. All three media showed 100% specificity. Therefore, the bile medium provides as an additional medium for rapid presumptive identification of group B streptococci.

Oleosin genes in maize kernels having diverse oil contents are constitutively expressed independent of oil contents. Size and shape of intracellular oil bodies are determined by the oleosins/oils ratio

In seeds, the subcellular storage oil bodies have a matrix of oils (triacylglycerols) surrounded by a layer of phospholipids embedded with abundant structural proteins called oleosins. We used two maize (Zea mays L.) strains having diverse kernel (seed) oil contents to study the effects of varying the oil and oleosin contents on the structure of the oil bodies. Illinois High Oils (IHO, 15% w/w oils) and Illinois Low Oils (ILO, 0.5%) maize kernels were the products of breeding for diverse oil contents for about 100 generations. In both maize strains, although the genes for oil synthesis had apparently been modified drastically, the genes encoding oleosins appeared to be unaltered, as revealed by Southern blot analyses of the three oleosin genes and sodium dodecyl sulfate-polyacrylamide gel electrophoresis with immunoblotting of the oleosins. In addition, both strains contained the same three oleosin isoforms of a defined proportion, and both accumulated oils and oleosins coordinately. Oleosins in both strains were restricted to the oil bodies, as shown by analyses of the various subcellular fractions separated by sucrose-density-gradient centrifugation. Electron microscopy of the embryos and the isolated organelles revealed that the oil bodies in IHO were larger and had a spherical shape, whereas those in ILO were smaller and had irregular shapes. We conclude that in seeds, oleosin genes are expressed independent of the oil contents, and the size and shape of the oil bodies are dictated by the ratio of oils to oleosins synthesized during seed maturation. The extensive breeding for diverse oil contents has not altered the apparent mechanism of oil-body synthesis and the occurrence of hetero-dimer or -multimer of oleosin isoforms on the oil bodies.

Oleosin genes in maize kernels having diverse oil contents are constitutively expressed independent of oil contents. Size and shape of intracellular oil bodies are determined by the oleosins/oils ratio

In seeds, the subcellular storage oil bodies have a matrix of oils (triacylglycerols) surrounded by a layer of phospholipids embedded with abundant structural proteins called oleosins. We used two maize (Zea mays L.) strains having diverse kernel (seed) oil contents to study the effects of varying the oil and oleosin contents on the structure of the oil bodies. Illinois High Oils (IHO, 15% w/w oils) and Illinois Low Oils (ILO, 0.5%) maize kernels were the products of breeding for diverse oil contents for about 100 generations. In both maize strains, although the genes for oil synthesis had apparently been modified drastically, the genes encoding oleosins appeared to be unaltered, as revealed by Southern blot analyses of the three oleosin genes and sodium dodecyl sulfate-polyacrylamide gel electrophoresis with immunoblotting of the oleosins. In addition, both strains contained the same three oleosin isoforms of a defined proportion, and both accumulated oils and oleosins coordinately. Oleosins in both strains were restricted to the oil bodies, as shown by analyses of the various subcellular fractions separated by sucrose-density-gradient centrifugation. Electron microscopy of the embryos and the isolated organelles revealed that the oil bodies in IHO were larger and had a spherical shape, whereas those in ILO were smaller and had irregular shapes. We conclude that in seeds, oleosin genes are expressed independent of the oil contents, and the size and shape of the oil bodies are dictated by the ratio of oils to oleosins synthesized during seed maturation. The extensive breeding for diverse oil contents has not altered the apparent mechanism of oil-body synthesis and the occurrence of hetero-dimer or -multimer of oleosin isoforms on the oil bodies.

Decreased activity of erythromycin against Streptococcus pyogenes in Taiwan

A total of 78 clinical isolates of Streptococcus pyogenes were collected from January 1992 through December 1993 from patients in southern Taiwan. The in vitro activities of 10 antimicrobial agents were determined by the agar dilution method. Penicillin, cephalothin, cefotaxime, vancomycin, and ofloxacin were shown to be active against S. pyogenes isolates, with MICs at which 90% of isolates are inhibited (MIC90s) being < or = 0.03, < or = 0.13, < or = 0.13, < or = 0.13, and < or = 0.25 microgram/ml, respectively. Erythromycin and azithromycin both had poor activities (MIC50s, 16 and >128 micrograms/ml, respectively; MIC90s, >128 and >128 micrograms/ml, respectively). The activities of tetracycline, clindamycin, and chloramphenicol against a significant number of these isolates were also limited. As the MICs of clindamycin and chloramphenicol for the isolates increased, the MICs of the two macrolides also increased. Clindamycin, chloramphenicol, and the two macrolides were less potent against isolates recovered form throat swab samples than against those from blood or other sources. Isolates of the T12 and T1 serotypes accounted for 53.8% of all isolates. The majority (87.5%) of the isolates recovered from throat swab samples were of the T12 serotype, whereas 19.2% of the isolates recovered from blood were of the T12 serotype. In contrast, 66.7% of the isolates of the T1 serotype were derived from blood but none were derived from throat swab samples. Of the 33 T12 serotype isolates, erythromycin MICs for 78.8% of the isolates were >128 micrograms/ml. Because of the poor activities of erythromycin and azithromycin against S. pyogenes isolates from patients in southern Taiwan, these drugs should no longer be considered the drugs of choice for the management of group A streptococcal infections among patients who live in this area.

Genetic dissection of the co-expression of genes encoding the two isoforms of oleosins in the oil bodies of maize kernel

Oleosins are abundant structural proteins on the surface of intracellular oil bodies in seeds. In many maize (Zea mays L.) inbreds, there are three oleosins, OLE18, OLE17, and OLE16, termed according to their apparent molecular weight, which are present in the proportional amounts of about 1:1:2 in isolated oil bodies. In some inbreds, OLE18 and OLE17 occur as molecular weight variants with a molecular weight difference of 1000 or less. In inbreds CM555 and FR2, OLE18 and OLE17, respectively, are absent; the respective genes ole18 and ole17 in the inbreds are present, but are transcriptionally inactive. The F1 of CM555 x FR2 possesses both OLE18 and OLE17, as expected from the inheritance of ole18 and ole17 genes. In all inbreds examined, including CM555, FR2, and their F1 hybrids, and in both the diploidic embryos and triploidic aleurone layers, the quantity of OLE18 and/or OLE17 equals that of OLE16. Since OLE18 and OLE17 are close members of the high-molecular weight (H) oleosin isoform whereas OLE16 belongs to the low-molecular weight (L) oleosin isoform, the results indicate the presence of equal amounts of the H and L isoforms in the oil bodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Genes encoding oleosins in maize kernel of inbreds Mo17 and B73

We have investigated all three oleosin genes which are expressed in the kernel of maize (Zea mays L., Mo17). Oleosin genes, ole16, ole17, and ole18, encode OLE16, OLE17, and OLE18, respectively, in proportional amounts of approximately 2:1:1 in isolated oil bodies. None of the three genes has an intron or a sequence encoding an N-terminal signal peptide. The three genes are expressed coordinately during seed maturation, and their encoded oleosins are present in similar proportional amounts in oil bodies isolated from the embryonic axis, scutellum, and aleurone layer. OLE16 represents one oleosin isoform, whereas OLE17 and OLE18 are close members of another oleosin isoform. ole16 and ole18 have been mapped to single loci on chromosomes 2 (near b1 gene) and 5S (near phya2), respectively. We predict that ole17 is located on chromosome 1 (near phya1), in a chromosomal segment duplicated on chromosome 5.

Coronary sinus pressure and arterial venting do not affect retrograde cardioplegia distribution

Retrograde techniques for the administration of cardioplegia solutions are of interest because of their relative practical convenience, and because of the possibility that they provide better delivery to myocardial regions jeopardized by coronary stenosis than can be achieved with traditional antegrade techniques. This study was designed to test the following three hypotheses about how the distribution of cardioplegia by retrograde techniques might be optimized: (1) venting an occluded coronary artery improves the distribution of cardioplegia to the myocardial region originally supplied by it; (2) increasing the coronary sinus perfusion pressure makes the distribution of cardioplegia through the myocardium more uniform; and (3) increasing the driving pressure, as achieved by increasing the coronary sinus perfusion pressure or occluding a left coronary artery, improves the distribution of flow to the right ventricular free wall and interventricular septum. Tracer microspheres infused retrogradely with cardioplegia solution into canine hearts in vitro showed that the distribution of flow through the coronary sinus is consistently and significantly nonuniform, and is not significantly altered by coronary arterial occlusion and venting, or by increases in coronary sinus perfusion pressure.

Aerobic blood cardioplegia for revascularization of acute infarct: effects of delivery temperature

The effects of different cardioplegia temperatures on myocardial protection with continuous aerobic blood cardioplegia were studied in a canine model of acute regional injury after left anterior descending coronary artery occlusion and subsequent revascularization. Twenty-five animals underwent 90 minutes of occlusion followed by revascularization during 60 minutes of electromechanical arrest with continuous retrograde blood cardioplegia delivered at one of three temperatures: 18 degrees C (n = 8), 28 degrees C (n = 8), and 37 degrees C (n = 9). Left ventricular protection was assessed in a right heart bypass model in terms of the left ventricular pressure-volume relationships, myocardial oxygen consumption, regional myocardial blood flow, adenosine trisphosphate concentration, and water content. The preload recruitable stroke work relationship at 90 minutes after reperfusion was better in the 18 degrees C and 28 degrees C groups than that in the 37 degrees C group (18 degrees C, 85 +/- 14 erg x 10(3)/mL; 28 degrees C, 77 +/- 17 erg x 10(3)/mL; 37 degrees C, 58 +/- 13 erg x 10(3)/mL; p < 0.05). The maximum elastance and stress-strain relationships showed there were no significant differences between the groups at 90 minutes. The myocardial oxygen consumption was greatest in the 37 degrees C group during the first hour after reperfusion (18 degrees C, 5.4 +/- 1.4 mL O2.min-1.100 g-1; 28 degrees C, 4.7 +/- 1.1 mL O2.min-1.100 g-1; 37 degrees C, 6.3 +/- 1.6 mL O2.min-1.100 g-1; p < 0.05). The regional myocardial blood flow, adenosine triphosphate concentration, and myocardial water content were similar in the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyperthermia induces doxorubicin release from long-circulating liposomes and enhances their anti-tumor efficacy

PURPOSE

To examine the possibility that hyperthermia would accelerate drug release from long-circulating liposomes, and enhance their antitumor activity.

METHODS AND MATERIALS

Liposomes were prepared by thin film hydration technique. Hyperthermia was induced by ultrasound apparatus and a water bath heating system. The antitumor efficacy of treatment against RIF-1 tumor in C3H mice was evaluated by the tumor growth delay assay.

RESULTS

In vitro drug release experiments demonstrated that increase in temperature from 37 degrees C to 41 degrees C resulted in about a sixfold increase in doxorubicin (DOX) release in a 1-h period. Increasing the temperature to 43 degrees C, resulted in only a modest additional drug release. Drug uptake studies showed that local hyperthermic treatment immediately following the drug administration dramatically enhanced Stealth liposome-encapsulated doxorubicin (S-DOX) uptake by tumors, but did not do so for free DOX. At 42 degrees C and at a dose of 10 mg/kg, the accumulation of S-DOX was about 10-fold and 2.5-fold higher than that with free drug and S-DOX at 37 degrees C, respectively. The antitumor efficacy study confirmed our hypothesis that the addition of hyperthermia to the treatment of RIF-1 tumors with doxorubicin encapsulated in long-circulating liposomes would enhance antitumor effects. Two hyperthermia treatments given at 24-h intervals appeared to be the most promising method of combining heat and long-circulating liposomes. The increased antitumor activity was not accompanied by increased toxicity, as determined by the body weight of the mice.

CONCLUSION

Local hyperthermic treatment is able to accelerate DOX release from long-circulating liposomes, increase tumor uptake, and enhance their antitumor efficacy. The combination of local hyperthermia and long-circulating liposomes appears to show considerable promise in the treatment of localized diseases.

Renal angiomyolipoma with a prominent angiomatous component and extramedullary hematopoiesis: a case report

Renal angiomyolipoma is a benign tumor of hamartomatous nature. A case of asymptomatic renal angiomyolipoma in a 57-year-old female is reported. Her right renal mass was incidentally discovered during the evaluation of acute hepatitis by abdominal sonography. She received right simple nephrectomy. The renal pelvic tumor was found to be an angiomyolipoma with a prominent angiomatous component containing hematopoietic elements. Unfortunately, the patient died of peritoneal carcinomatosis because of adenocarcinoma of the transverse colon five years later.

Hemodynamic significance of the coronary vein valves

The incidence and morphology of one-way coronary vein valves were studied, together with their influence on the administration of retrograde cardioplegia. Calf, juvenile pig, and adult mongrel canine hearts (12 each) and human cadaver hearts (five adult and seven pediatric) were dissected. The pressure gradients between the coronary sinus and the posterior vein of the left ventricle were measured in 21 hearts during the retrograde administration of fluid. Species differences were noted, with apparently competent valves seen more frequently in calf hearts (mean, 1.33 valves +/- 0.22 [SEM] per heart) than in pig hearts (mean, 0.83 +/- 0.17 [SEM] per heart). In humans, more valves were seen in pediatric hearts (five valves in seven hearts) than in adult hearts (one valve in five hearts). No competent valves were found in dog hearts (chi 2 analysis; p < 0.0001). In calf hearts, a pressure gradient of 5 to 35.5 mm Hg was required before the valve opened. In pig hearts, these opening pressure gradients ranged from 0 to 19.5 mm Hg. The distribution of retrograde cardioplegia may be impaired in the presence of competent valves, particularly when low coronary sinus pressures are used.

Oleosins in the gametophytes of Pinus and Brassica and their phylogenetic relationship with those in the sporophytes of various species

Oleosins, which are structural proteins on the surface of intracellular oil bodies, have been found in the sporophytic seeds of angiosperms. Here, we report an oleosin from the female gametophyte of gymnosperm Pinus ponderosa Laws. seed and another oleosin from the male gametophyte of Brassica napus L. With the pine seed gametophyte, we identified two putative oleosins of 15 and 10 kDa, which are similar to the oleosins in angiosperm seeds in terms of their presence in the oil bodies in massive quantity. The complete sequence of the cDNA encoding the gametophytic 15-kDa oleosin was obtained, and it has a predicted amino-acid sequence similar to those of oleosins in angiosperm sporophytic seeds. A Brassica napus pollen cDNA sequence, which was reported earlier, would encode an amino-acid sequence somewhat similar to those of seed oleosins. We tested if the dissimilarity signifies a substantially different oleosin in the Brassica male gametophyte or an analytic error. By direct sequencing of a polymerase chain reaction (PCR)-amplified fragment of genomic DNA, we obtained evidence showing that this reported dissimilarity is likely to have arisen from a sequencing error. Our predicted sequence of the Brassica pollen oleosin has all the structural characteristics of seed oleosins. A phylogenic tree of 20 oleosins, including those from sporophytic and gametophytic tissues of angiosperm and gymnosperm, was constructed based on their amino-acid sequences. We discuss the evolution of oleosins, and conclude that oleosins are ancient proteins with multiple lineages whose root cannot be determined at this time.

Revascularization for acute regional infarct: superior protection with warm blood cardioplegia

Continuous retrograde warm blood cardioplegia was compared with two widely used hypothermic myocardial protection techniques in a canine model of acute regional myocardial ischemia with subsequent revascularization. Animals (n = 30) underwent 45 minutes of left anterior descending coronary artery occlusion then cardioplegic arrest (60 minutes), followed by separation from cardiopulmonary bypass and data collection. The cold oxygenated crystalloid cardioplegia group (CC; n = 8) and the cold blood cardioplegia group (CC; n = 10) had cardiopulmonary bypass at 28 degrees C, antegrade arrest, and intermittent retrograde delivery. The warm blood cardioplegia group (WB; n = 12) had normothermic cardiopulmonary bypass, antegrade arrest, and continuous retrograde delivery. Overall ventricular function (preload recruitable stroke work relationship; ergs x 10(3)/mL) was significantly (p < 0.001) better for WB (WB, 80 +/- 11; CB, 67 +/- 13; CC, 57 +/- 12). Systolic function (maximum elastance relationship; mm Hg/mL) was also significantly (p < 0.001) better for WB (WB, 11.6 +/- 3.6; CB, 8.6 +/- 2.7; CC, 6.2 +/- 1.3). Diastolic function (stress-strain relationship; dynes x 10(3)/cm2) revealed significantly (p < 0.001) decreased compliance for CC (WB, 20 +/- 6; CB, 19 +/- 7; CC, 27 +/- 11). Left anterior descending coronary artery regional adenosine triphosphate/adenosine diphosphate ratios were significantly (p = 0.02) worse for CC (WB, 10.2 +/- 2.3; CB, 9.4 +/- 2.6; CC, 5.6 +/- 1.5). Myocardial edema significantly (p = 0.03) increased over time only in the CC animals (WB, 0.4% +/- 2.3%; CB, -0.3% +/- 3.6%; CC, 5.5% +/- 2.3%). In this model of acute regional myocardial ischemia and revascularization, continuous retrograde warm aerobic blood cardioplegia provided superior myocardial protection compared with cold oxygenated crystalloid cardioplegia with intermediate results for cold blood cardioplegia.

Brown bowel syndrome: report of two cases

Brown bowel syndrome is a rare intestinal disorder associated with the deposition of lipofuscin pigment in the smooth muscle cells. We report two such cases presenting with intestinal pseudo-obstruction, abdominal pain, and body weight loss. Both cases had malabsorption and fatty liver. Exploratory laparotomy revealed brownish discoloration of the small bowel wall and enlargement of mesenteric lymph nodes. Light microscopy, autofluorescence and ultrastructure studies confirmed the deposition of lipofuscin pigments in the intestinal muscle cells and reticuloendothelial cells of mesenteric lymph nodes. In addition, the calf muscle biopsy of case 1 displayed myopathy and fatty replacement. Skeletal muscle strength of both patients was partially restored after parenteral and oral vitamin E supplement and other conservative treatment, but gastrointestinal symptoms of both patients continued to deteriorate. Thus, brown bowel syndrome associated with prolonged and severe malnutrition and possibly vitamin E deficiency appears only partially responsive to vitamin E supplementation.