An STS-based map of the human genome

A physical map has been constructed of the human genome containing 15,086 sequence-tagged sites (STSs), with an average spacing of 199 kilobases. The project involved assembly of a radiation hybrid map of the human genome containing 6193 loci and incorporated a genetic linkage map of the human genome containing 5264 loci. This information was combined with the results of STS-content screening of 10,850 loci against a yeast artificial chromosome library to produce an integrated map, anchored by the radiation hybrid and genetic maps. The map provides radiation hybrid coverage of 99 percent and physical coverage of 94 percent of the human genome. The map also represents an early step in an international project to generate a transcript map of the human genome, with more than 3235 expressed sequences localized. The STSs in the map provide a scaffold for initiating large-scale sequencing of the human genome.

Isolation of Clostridium difficile from the environment and contacts of patients with antibiotic-associated colitis

Clostridium difficile is the most important cause of antibiotic-associated colitis, but its epidemiology remains unknown. Using a selective medium for the isolation of C. difficile, cultures were obtained from the environment and contacts of hospitalized patients carrying C. difficile in their stools. In areas where carriers had diarrhea, 85 (9.3%) of 910 cultures of floors and other surfaces, especially those subject to fecal contamination, were positive. In areas where there were no known carriers, only 13 (2.6%) of 497 cultures of similar sites were positive (P less than 0.005). C difficile was isolated from hands and stools of asymptomatic hospital personnel, from sewage and soil, and from the home of a patient. Environmental isolates were toxigenic. C. difficile inoculated onto a floor persisted there for five months. Further studies are needed to document how often floor persisted there for five months. Further studies are needed to document how often C. difficile shed by patients with antibiotic-associated colitis is acquired by other persons and whether isolation precautions are capable of limiting the organism's spread.

Clostridium difficile-associated diarrhea and colitis

OBJECTIVES

To review and summarize the status of diagnosis, epidemiology, infection control, and treatment of Clostridium difficile-associated disease (CDAD).

DIAGNOSIS

A case definition of CDAD should include the presence of symptoms (usually diarrhea) and at least one of the following positive tests: endoscopy revealing pseudomembranes, stool cytotoxicity test for toxin B, stool enzyme immunoassay for toxin A or B, or stool culture for C difficile (preferably with confirmation of organism toxicity if a direct stool toxin test is negative or not done). Testing of asymptomatic patients, including those who are asymptomatic after treatment, is not recommended other than for epidemiologic purposes. Lower gastrointestinal endoscopy is the only diagnostic test for pseudomembranous colitis, but it is expensive, invasive, and insensitive (51% to 55%) for the diagnosis of CDAD. Stool culture is the most sensitive laboratory test currently in clinical use, but it is not as specific as the cell cytotoxicity assay.

EPIDEMIOLOGY

C difficile is the most frequently identified cause of nosocomial diarrhea. The majority of C difficile infections are acquired nosocomially, and most patients remain asymptomatic following acquisition. Antimicrobial exposure is the greatest risk factor for patients, especially clindamycin, cephalosporins, and penicillins, although virtually every antimicrobial has been implicated. Cases of CDAD unassociated with prior antimicrobial or antineoplastic use are very rare. Hands of personnel, as well as a variety of environmental sites within institutions, have been found to be contaminated with C difficile, which can persist as spores for many months. Contaminated commodes, bathing tubs, and electronic thermometers have been implicated as sources of C difficile. Symptomatic and asymptomatic infected patients are the major reservoirs and sources for environmental contamination. Both genotypic and phenotypic typing systems for C difficile are available and have enhanced epidemiologic investigation greatly.

INFECTION CONTROL

Successful infection control measures designed to prevent horizontal transmission include the use of gloves in handling body substances and replacement of electronic thermometers with disposable devices. Isolation, cohorting, handwashing, environmental disinfection, and treatment of asymptomatic carriers are recommended practices for which convincing data of efficacy are not available. The most successful control measure directed at reduction in symptomatic disease has been antimicrobial restriction.

TREATMENT

Treatment of symptomatic (but not asymptomatic) patients with metronidazole or vancomycin for 10 days is effective; metronidazole may be preferred to reduce risk of vancomycin resistance among other organisms in hospitals. Recurrence of symptoms occurs in 7% to 20% of patients and is due to both relapse and reinfection. Over 90% of first recurrences can be treated successfully in the same manner as initial cases. Combination treatment with vancomycin plus rifampin or the addition orally of the yeast Saccharomyces boulardii to vancomycin or metronidazole treatment has been shown to prevent subsequent diarrhea in patients with recurrent disease.

EEG delta activity: an indicator of attention to internal processing during performance of mental tasks

In previous papers we proposed that an increase in delta EEG activity during mental tasks might be related to an increase in subjects' attention to internal processing. In this paper we have made a narrow band analysis to detect those EEG frequencies that change selectively during the performance of a mental task that requires attention to internal processing. Two different experiments were performed: (1) a difficult mental calculation task and a control stimulus with the same physical characteristics as the arithmetical symbols were presented in random order; (2) the Sternberg paradigm for the analysis of short term memory using a memory set of 5 or 3 digits was also presented in random order. Referential recordings to linked ears were obtained in all leads of the 10/20 system. In the first experiment, the increase of power from 1.56 to 5.46 Hz was observed only during the performance of the task and not during the control condition. In the Sternberg paradigm, the increase of power from 1.56 to 3.90 Hz was greater during the difficult than during the easy condition. These results support our hypothesis that an increase in delta activity may be related to attention to internal processing during the performance of a mental task.

Analysis of exosome release and its prognostic value in human colorectal cancer

A significant proportion of extracellular nucleic acids in plasma circulate highly protected in tumor-specific exosomes, but it is unclear how the release of exosomes is modulated in carcinogenesis. We quantified by cytometry exosomes in plasma of 91 colorectal cancer patients to evaluate their potential as a tumor indicator and their repercussions on diagnosis and prognosis. We examined the involvement of TSAP6, a TP53-regulated gene involved in the regulation of vesicular secretion, in levels of circulating exosomes in plasma of colorectal patients and in HCT116 TP53-(wild-type and null) human colorectal cancer cell lines. The fraction of exosomes in cancer patients was statistically higher than in healthy controls (mean rank ¼ 53.93 vs. 24.35). High levels of exosomes in plasma of patients correlated with high levels of carcino-embryonic antigen (P ¼ 0.029) and with poorly differentiated tumors (P ¼ 0.039) and tended to have shorter overall survival than patients with low levels (P ¼ 0.056). Release of exosomes did not correlate with TSAP6 expression; and regulation of TSAP6 by TP53 was not shown either in tumor samples or in HCT116 cell lines. Although it was not suggested that the TP53/TSAP6 pathway regulates the release of exosomes into the plasma of colorectal cancer patients, the level of circulating exosomes may be used as a tumor indicator, because it correlates with poor prognosis parameters and shorter survival.

Clostridium difficile-associated diarrhea and colitis

OBJECTIVES

To review and summarize the status of diagnosis, epidemiology, infection control, and treatment of Clostridium difficile-associated disease (CDAD).

DIAGNOSIS

A case definition of CDAD should include the presence of symptoms (usually diarrhea) and at least one of the following positive tests: endoscopy revealing pseudomembranes, stool cytotoxicity test for toxin B, stool enzyme immunoassay for toxin A or B, or stool culture for C difficile (preferably with confirmation of organism toxicity if a direct stool toxin test is negative or not done). Testing of asymptomatic patients, including those who are asymptomatic after treatment, is not recommended other than for epidemiologic purposes. Lower gastrointestinal endoscopy is the only diagnostic test for pseudomembranous colitis, but it is expensive, invasive, and insensitive (51% to 55%) for the diagnosis of CDAD. Stool culture is the most sensitive laboratory test currently in clinical use, but it is not as specific as the cell cytotoxicity assay.

EPIDEMIOLOGY

C difficile is the most frequently identified cause of nosocomial diarrhea. The majority of C difficile infections are acquired nosocomially, and most patients remain asymptomatic following acquisition. Antimicrobial exposure is the greatest risk factor for patients, especially clindamycin, cephalosporins, and penicillins, although virtually every antimicrobial has been implicated. Cases of CDAD unassociated with prior antimicrobial or antineoplastic use are very rare. Hands of personnel, as well as a variety of environmental sites within institutions, have been found to be contaminated with C difficile, which can persist as spores for many months. Contaminated commodes, bathing tubs, and electronic thermometers have been implicated as sources of C difficile. Symptomatic and asymptomatic infected patients are the major reservoirs and sources for environmental contamination. Both genotypic and phenotypic typing systems for C difficile are available and have enhanced epidemiologic investigation greatly.

INFECTION CONTROL

Successful infection control measures designed to prevent horizontal transmission include the use of gloves in handling body substances and replacement of electronic thermometers with disposable devices. Isolation, cohorting, handwashing, environmental disinfection, and treatment of asymptomatic carriers are recommended practices for which convincing data of efficacy are not available. The most successful control measure directed at reduction in symptomatic disease has been antimicrobial restriction.

TREATMENT

Treatment of symptomatic (but not asymptomatic) patients with metronidazole or vancomycin for 10 days is effective; metronidazole may be preferred to reduce risk of vancomycin resistance among other organisms in hospitals. Recurrence of symptoms occurs in 7% to 20% of patients and is due to both relapse and reinfection. Over 90% of first recurrences can be treated successfully in the same manner as initial cases. Combination treatment with vancomycin plus rifampin or the addition orally of the yeast Saccharomyces boulardii to vancomycin or metronidazole treatment has been shown to prevent subsequent diarrhea in patients with recurrent disease.

Impaired lymphocyte function in depressive illness

Mood states and immunity may be related. To investigate the immune status of patients with primary depressive illness, we compared in-vitro lymphocytic responses to three different mitogens in 26 drug-free depressed patients and 20 normal controls of comparable age and sex. We observed a generalized and marked decrease in the lymphocyte mitogenic activity among the depressive group. This defect in lymphocyte function may be indicative of an impairment in cell-mediated immunity in patients with primary depressive illness.

Vesicle-related microRNAs in plasma of nonsmall cell lung cancer patients and correlation with survival

The identification of tumour biomarkers that detect the presence of disease using noninvasive diagnostic procedures is a key part of cancer research. We determined in plasma the vesicle-related microRNA (miRNA) expression profile of nonsmall cell lung cancer (NSCLC) and evaluate whether plasma miRNAs can be both discriminating (between patients and healthy controls) and prognostic markers. 365 human miRNAs were analysed by Taqman® low-density arrays (Applied Biosystems, Foster City, CA, USA) in the plasma from 28 NSCLC patients and 20 controls. Five selected miRNAs (let-7f, miR-20b, miR-30e-3p, miR-223 and miR-301) were validated independently by real-time PCR in plasma from 78 NSCLC and 48 controls and correlated with pathologic parameters and survival. Levels of let-7f, miR-20b and miR-30e-3p were decreased in plasma vesicles of NSCLC patients. Moreover, levels of let-7f and miR-30e-3p distinguished between two groups of patients for stage of disease and therefore possibility of surgery. Plasma levels of miR-30e-3p and let-7f were associated with short disease-free survival and overall survival, respectively. NSCLC patients and healthy controls differ in vesicle-related miRNAs in plasma. Levels of let-7f and miR-30e-3p in NSCLC patients are associated with poor outcome. Thus, plasma vesicle-related miRNAs obtained by noninvasive methods could serve as circulating tumour biomarkers of discriminating and prognostic value.

Epidemiology of antibiotic-associated colitis; isolation of Clostridium difficile from the hospital environment

Clostridium difficile is the most important cause of antibiotic-associated colitis. Using selective media, it was found that contamination with this organism was common in the environment of patients in the hospital with the disease. It was often found on floors, hoppers, toilets, bedding, mops, scales and furniture. This organism was also present on these items, but less often, in areas in which patients known to carry this hardy spore-forming organism had not been detected. Air, food and walls were negative. The organism was isolated from the hands and stools of asymptomatic hospital personnel. It was also found on surfaces in a patient's home. The importance of the various sources of the organism in its spread in the hospital is not known, and further studies are needed. It is suggested that enteric isolation precautions, and careful handwashing and cleansing of potentially contaminated surfaces and objects may be worthwhile when cases of antibiotic-associated colitis are identified.

Cytosolic-free calcium elevation in Trypanosoma cruzi is required for cell invasion

To replicate, the trypomastigote form of Trypanosoma cruzi must invade host cells. Since a role for Ca2+ in the process of cell invasion by several intracellular parasites has been postulated, changes in the intracellular Ca2+ concentration in T. cruzi trypomastigotes and in tissue culture L6E9 myoblasts during their interaction were studied at the single cell level using digital imaging fluorescence microscopy or in cell suspensions by fluorescence spectrophotometry. An increase in cytosolic Ca2+ in T. cruzi trypomastigotes was detected at the single cell level after association of the parasites with the myoblasts. Ca2+ mobilization in the host cells was also detected upon contact with trypomastigotes either at the single cell level or in cells grown in coverslips and exposed to suspensions of trypomastigotes. Pretreatment of the parasites with the Ca2+ chelators quin 2 (50 microM) or bis-(o-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (BAPTA, 50 microM) decreased the trypomastigotes' association to myoblasts by approximately 40 and 63%, respectively, thus indicating that an increase in intracellular Ca2+ concentration in the parasites is required for cell invasion in addition to Ca2+ mobilization in the host cells.

Treatment of antibiotic-associated Clostridium difficile colitis with oral vancomycin: comparison of two dosage regimens

PURPOSE

High-dose (500 mg orally four times daily) vancomycin is considered by many investigators to be the most effective treatment for antibiotic-associated Clostridium difficile colitis. However, a lower dosage of 125 or 150 mg given three or four times a day has become popular, has been shown to be effective, and is less expensive than the high-dose regimen. We therefore decided to compare two vancomycin dosage regimens in a randomized trial.

PATIENTS AND METHODS

The study involved 46 hospitalized patients with serious underlying diseases complicated by C. difficile diarrhea or colitis. Patients were assigned (according to a table of random numbers) to treatment with either 125 or 500 mg of vancomycin orally four times daily for an average of 10 days.

RESULTS

No significant differences in measurable responses to the two regimens were noted. There were no treatment failures. The mean duration of diarrhea after initiation of therapy was about four days, and almost all patients had no diarrhea after one week. The organism continued to be demonstrated in the stools of about 50 percent of patients for the first few weeks after completion of therapy, and nine (20 percent) patients developed a recurrence of their diarrheal illness. Vancomycin was well tolerated by all patients.

CONCLUSION

Since the dose of 125 mg appeared to be as effective as the 500-mg dose, which is more expensive, the 125-mg dose is preferred when vancomycin is used in treatment of this disease, unless the patient is critically ill.

Retrospective review of congenital heart disease in 976 dogs

BACKGROUND

Knowledge of epidemiology is important for recognition of cardiovascular malformations.

OBJECTIVE

Review the incidence of congenital heart defects in dogs in Italy and assess breed and sex predispositions.

ANIMALS

Nine hundred and seventy-six dogs diagnosed with congenital heart disease (CHD) of 4,480 dogs presented to Clinica Veterinaria Gran Sasso for cardiovascular examination from 1997 to 2010.

METHODS

A retrospective analysis of medical records regarding signalment, history, clinical examination, radiography, electrocardiography, echocardiography, angiography, and postmortem examination was performed. Breed and sex predisposition were assessed with the odds ratio test.

RESULTS

CHD was observed in 21.7% of cases. A total of 1,132 defects were observed with single defects in 832 cases (85%), 2 concurrent defects in 132 cases (14%), and 3 concurrent defects in 12 cases (1%). The most common defects were pulmonic stenosis (PS; 32.1%), subaortic stenosis (SAS; 21.3%), and patent ductus arteriosus (20.9%), followed by ventricular septal defect (VSD; 7.5%), valvular aortic stenosis (AS; 5.7%), and tricuspid dysplasia (3.1%). SAS, PS, and VSD frequently were associated with other defects. Several breed and sex predispositions were identified.

CONCLUSIONS AND CLINICAL RELEVANCE

The results of this study are in accordance with previous studies, with slight differences. The breed and sex predilections identified may be of value for the diagnosis and screening of CHD in dogs. Additionally, the relatively high percentage of concurrent heart defects emphasizes the importance of accurate and complete examinations for identification. Because these data are from a cardiology referral center, a bias may exist.

Bacteroides fragilis enterotoxin gene sequences in patients with inflammatory bowel disease

We identified enterotoxigenic Bacteroides fragilis in stool specimens of patients with inflammatory bowel disease and other gastrointestinal disorders. The organism was detected in 11 (13.2%) of 83 patients with inflammatory bowel disease. Of 57 patients with active disease, 19.3% were toxin positive; none of those with inactive disease had specimens positive for enterotoxigenic Bacteroides fragilis gene sequences.

Antibiotic-induced colitis implication of a toxin neutralised by Clostridium sordellii antitoxin

A toxin(s) has been demonstrated in the stools of two patients with antibiotic-associated colitis. This toxin(s) was heat-labile, was rapidly lethal for hamsters, increased vascular permeability in rabbit skin, and was cytotoxic for cells in tissue-culture. It was neutralised by Clostridium sordellii antitoxin but not by antitoxins prepared against other clostridia; Escherichia coli, and Vibrio cholerae toxins. These characteristics were identical to those of a toxin implicated in the aetiology of antibiotic-induced colitis in the hamster. One patient improved rapidly after treatment with oral vancomycin, and at the same time the toxin disappeared from the stool.

Total parenteral nutrition catheter sepsis: impact of the team approach

For a period of 32 months from the inception of the Parenteral and Enteral Nutrition (PEN) Team at the University of Michigan, the infection rate (IR) related to central venous catheters (CVCs) for total parenteral nutrition (TPN) was prospectively evaluated. Six hundred twenty-two catheters were placed in 377 patients for a total of 9,200 patient days. The length of CVC stay ranged from 2 to 108 days with a mean of 14.5. CVC longevity was longer on units where certification of nurses by the PEN team was mandatory (mean 20.4 days, IR 3.5%) vs comparable units which utilized informal instruction (mean 14.4 days, IR 3.5%). Twenty-two catheters led to patient sepsis for a rate of 3.5%, or 2.39 CVC-related infections per 1000 patient days. The preteam infection rate was 24.0%, as determined by a 6-month prospective study. Infection rates for CVCs used for TPN only and those used for parenteral nutrition (PN) plus blood products, antibiotics, and CVP measurements were identical, 3.5%. The team approach can effectively increase PN catheter longevity and reduce infection rates. Conservative cost accounting of best and worst case scenarios determined a range of $3,700 to $8,900 per episode of catheter sepsis.

EEG activation patterns during the performance of tasks involving different components of mental calculation

In this study we demonstrate the existence of different patterns of EEG activation during the performance of 4 different tasks involving different components of mental calculation in normal subjects. The EEG was recorded in all monopolar leads of the 10/20 system using linked ear lobes as reference. Absolute and relative power were calculated in the delta (1.5-3.5 Hz), theta (3.5-7.5 Hz), alpha (7.5-12.5 Hz) and beta (12.5-19 Hz) bands. The tasks were presented randomly and the EEG segments preceding presentation of the stimulus were considered as the rest corresponding to the task requested by the stimulus. Tasks were of 4 different types, involving number comprehension, recognition of mathematical symbols, the calculation process and the spatial component. ANOVAs between the rest periods showed no differences in any band. Neither did ANOVAs between tasks. However, other variables (task minus rest), which were calculated as the differences in power between task and rest respectively, showed significant differences between tasks in the delta and beta bands in the frontal lobes. In addition, new variables were calculated as the difference between tasks, since many factors were common across several tasks. These variables correspond to the EEG change due to a specific component of mental calculation. Significant differences were obtained in delta and theta bands in right posterior areas and in the beta band in frontal areas. We concluded that the EEG differences observed during different components of mental calculation suggest the participation of different networks.

Detection of epithelial tumour RNA in the plasma of colon cancer patients is associated with advanced stages and circulating tumour cells

BACKGROUND

Although circulating tumour DNA has been detected in patients with different types of cancer, little is known of free RNA in cancer patients.

AIMS

We investigated the presence of RNA from epithelial tumours in plasma from patients with colorectal carcinomas, and its correlation with tumour characteristics and circulating tumour cells.

METHODS

beta-actin mRNA was analysed to assess the viability of plasma RNA in samples from 53 patients with colonic cancer and 25 controls. Subsequently, nested primers were used to detect the presence of cytokeratin 19 (CK19) and carcinoembryonic antigen (CEA) RNA in the same samples. Nine clinicopathological parameters were studied to correlate the molecular and clinical parameters. Additionally, we investigated for micrometastases in blood in 18 of these patients and in 10 of the controls samples.

RESULTS

All samples had detectable quantities of beta-actin RNA. In the controls, one case (4%) was positive for CEA and five (20%) for CK19 RNA; of the 53 patients, 17 cases (32%) were positive for CEA and 39 (73.6%) for CK19 RNA. This was statistically significant (p=0.000001). Advanced stages (p=0.03) and soluble CEA status (p=0.03) were associated with the presence of CEA, CK19, or both RNAs in plasma. Lymph node metastases (p=0.06) and vascular invasion (p=0.07) were almost significant. On the basis of these results, we examined the possible presence of micrometastases in blood in several of these patients. The presence of plasma tumour RNA was found to be associated with circulating tumour cells in blood (p=0.04).

CONCLUSIONS

Epithelial tumour RNA is detectable in plasma from colon cancer patients. This molecular event is associated with advanced stages and circulating tumour cells. Our results could offer new approaches in the diagnosis and monitoring of colon cancer.

Inhibitors of monocyte responses to chemotaxins are present in human cancerous effusions and react with monoclonal antibodies to the P15(E) structural protein of retroviruses

Individuals with cancer have previously been shown to have abnormal chemotactic responsiveness. Surgical removal of the tumor often resulted in normalization of monocyte function, which suggests that human neoplasms might inhibit monocyte chemotaxis by release of soluble mediators. We therefore examined the effects of cancerous effusions on monocyte polarization, i.e., the rapid change in monocyte morphology from round to a triangular "motile" configuration in response to chemoattractants. All 17 malignant effusions, representing 15 tumor types, inhibited monocyte polarization induced by the chemoattractant N-formyl-methionyl-leucyl-phenylalanine by 45-89% (mean 55.9 +/- 12.7%, P less than 0.01) in blinded assays. None of 17 benign effusions signigicantly inhibited polarization (0-15%, mean 6.2 +/- 4.2%). Dilutions of cancerous effusions as low as 1:200 produced inhibition that was time, temperature, and dose dependent . Monocyte polarization induced by activated serum or by chemotactic lymphokine was also blocked by cancerous effusions. The inhibitory activity affected the monocyte directly, and did not destroy the chemoattractant or block the polarization of granulocytes to chemotactic factors. High pressure liquid chromatography of five cancerous fluids revealed three peaks of inhibitory activity: greater than or equal to 200,000, 46,000 +/- 13,000, and 21,000 +/- 3,000 daltons. Fractionation of noncancerous effusions revealed only small amounts of the highest molecular weight inhibitory activity. The inhibitory activity in cancerous effusion was heat stable (56 degrees C, 30 min), trypsin sensitive, and could be absorbed by three different monoclonal antibodies reactive to P15(E), a structural component of type C retroviruses. In contrast, six monoclonal antibodies with other specificities had no effect on the inhibitors of polarization. This study demonstrates that human cancerous effusions contain novel proteins that are potent inhibitors of monocyte function and that are recognized by antibodies reactive to the P15(E) component of retroviruses. By producing such factors, tumor cells may subvert monocyte-mediated surveillance.

Bacteriocin production by spray-dried lactic acid bacteria

AIMS

Cell survival and antagonistic activity against Listeria innocua, Listeria monocytogenes and Staphylococcus aureus were investigated after spray-drying three bacteriocin-producing strains of lactic acid bacteria: Carnobacterium divergens, Lactobacillus salivarius and Lactobacillus sakei.

METHODS AND RESULTS

Bacterial cell concentrates were spray-dried and stored at 4 degrees C and 18 degrees C and 0.3% ERH (equilibrium relative humidity). Enumeration and antagonistic activity were evaluated before and after spray-drying and at regular intervals during storage.

CONCLUSIONS

A higher survival rate was obtained when survival was performed at 4 degrees C. With the exception of Carnobacterium divergens which lost the inhibitory activity against Staph. aureus after drying, antagonistic production was not affected by the process nor by the storage. Of the three species studied, Lact. salivarius showed the highest resistance to the spray-drying and storage processes.

SIGNIFICANCE AND IMPACT OF THE STUDY

Spray-drying is a potentially useful process for large scale production of dried powders containing viable organisms with antagonistic activity against pathogens.

Therapy of relapsing Clostridium difficile-associated diarrhea and colitis with the combination of vancomycin and rifampin

Seven patients with multiple bacteriologic and symptomatic relapses of Clostridium difficile-associated diarrhea and/or colitis were treated with vancomycin and rifampin in combination. Diarrhea and abdominal pain promptly resolved in all, and neither C. difficile nor its toxin could be recovered from their stools shortly after therapy. However, stools of all patients subsequently became culture-positive for C. difficile and occasionally had demonstrable cytotoxin. Except in one instance following oral antibiotic use, all patients remained free of symptoms. Resistance to either vancomycin or rifampin was not encountered. Biotyping of isolates with clostridial bacteriophages and bacteriocins suggested true relapse with the same organism in all patients studied, rather than reinfection with another strain. Vancomycin and rifampin in combination appear to be useful in the therapy of relapsing antibiotic-associated diarrhea due to C. difficile.

NF-kappa B inhibition markedly enhances sensitivity of resistant breast cancer tumor cells to tamoxifen

Studies show that high Akt activity in breast carcinoma is associated with endocrine therapy resistance. Breast cancer cell lines expressing a constitutively active Akt are able to proliferate under reduced estrogen conditions, and are resistant to the growth inhibitory effects of tamoxifen. Understanding the targets of Akt signaling mediating tamoxifen resistance is of clinical significance. One possible target is nuclear factor kappa B (NF-kappa B), a transcription factor that plays a critical role in resistance to apoptosis and the induction of angiogenesis and invasion. In the present study, we found that Akt activity correlated with phosphorylation of I kappa B (the negative regulator of NF-kappa B), NF-kappa B DNA binding and tamoxifen resistance in vivo. Importantly, we found that co-treatment with the NF-kappa B inhibitor, parthenolide, or overexpression of I kappa B superrepressor restored tamoxifen sensitivity to our refractory Akt MCF-7 cells. These data suggest that activation of NF-kappa B via the PI3K/Akt signaling pathway may be a significant mechanism for development of endocrine therapy resistance in breast cancer, and that inhibition of NF-kappa B may be an effective treatment strategy to limit the progression of this disease.

Antibiotic-associated colitis: effects of antibiotics on Clostridium difficile and the disease in hamsters

Fifteen isolates of Clostridium difficile from hamsters and human patients were inhibited or killed by low concentrations of metronidazole, vancomycin, penicillin, and ampicillin; the isolates were often reesistant to tetracycline, cephalosporins, trimethoprim-sulfamethoxazole, clindamycin, erythromycin, and aminoglycosides. Antibiotics to which C. difficile was susceptible were able to prevent or postpone the colitis caused by clindamycin in hamsters. Colitis could be produced by treatment of hamsters with any one of these antibiotics. Production of colitis not only involved selection of resistant variants, but in some instances seemed to result from the acquisition of organisms after treatment, their persistence despite treatment, or from subinhibitory cecal concentrations of antibiotic (explainable by either pharmacologic factors or enzymatic inactivation). As in humans, no organisms other than C. difficile have been implicated conclusively as etiologic agents of colitis in hamsters. Our results suggest it may be wise to use isolation precautions for patients with colitis caused by C. difficile.

Predictive value of testicular histology in secretory azoospermic subgroups and clinical outcome after microinjection of fresh and frozen-thawed sperm and spermatids

BACKGROUND

A retrospective study was carried out on 159 treatment cycles in 148 secretory azoospermic patients to determine whether histopathological secretory azoospermic subgroups were predictive for gamete retrieval, and to evaluate outcome of microinjection using fresh or frozen-thawed testicular sperm and spermatids.

METHODS

Sperm and spermatids were recovered by open testicular biopsy and microinjected into oocytes. Fertilization and pregnancy rates were assessed.

RESULTS

In hypoplasia, 97.7% of the 44 patients had late spermatids/sperm recovered. In maturation-arrest (MA; 47 patients), 31.9% had complete MA, and 68.1% incomplete MA due to a focus of early (36.2%) or late (31.9%) spermiogenesis. Gamete retrieval was achieved in 53.3, 41.2 and 93.3% of the cases respectively. In Sertoli cell-only syndrome (SCOS; 57 patients), 61.4% were complete SCOS, whereas incomplete SCOS cases showed one focus of MA (5.3%), or of early (29.8%) and late (3.5%) spermiogenesis. Only 29.8% of the patients had a successful gamete retrieval, 2.9% in complete and 77.3% in incomplete SCOS cases. In total, there were 87 ICSI, 39 elongated spermatid injection (ELSI) and 33 round spermatid injection (ROSI) treatment cycles, with mean values of fertilization rate of 71.4, 53.6 and 17%, and clinical pregnancy rates of 31.7, 26.3 and 0% respectively.

CONCLUSIONS

Histopathological subgroups were positively correlated with successful gamete retrieval. No major outcome differences were observed between testicular sperm and elongated spermatids, either fresh or frozen-thawed. However, injection of intact round-spermatids showed very low rates of fertilization and no pregnancies.

Depression, urinary free cortisol excretion and lymphocyte function

An impairment in lymphocyte response to mitogen stimulation, a correlate of cell-mediated immunity, has been reported in patients with depressive illness. To investigate whether such impairment in lymphocyte function is related to excessive secretion of cortisol, an immunosuppressive hormone, we compared mitogen-induced lymphocyte proliferation in three groups of subjects: depressed patients with elevated 24-hour urinary free cortisol (UFC) excretion; depressed patients with normal UFC excretion; and normal controls. Depressed patients in both groups showed significant reductions in lymphocyte mitogenic activity, in comparison with the normal controls, but the two depressive groups did not significantly differ from each other in their lymphocytic responses to any of the mitogens used. Furthermore, no significant correlations were found, within depressed patients, between UFC excretion and lymphocyte mitogenic responses. Depression is therefore associated with an impairment in lymphocyte function that cannot be explained solely on the basis of increased cortisol secretion.

Suppression of Clostridium difficile by normal hamster cecal flora and prevention of antibiotic-associated cecitis

Administration of normal cecal homogenates decreased numbers of viable Clostridium difficile and prevented cecitis in antibiotic-challenged hamsters. Cecal anaerobes appeared to suppress C. difficile.