Transcriptome analysis of the binucleate ciliate Tetrahymena thermophila with asynchronous nuclear cell cycles

Tetrahymena thermophila harbors two functionally and physically distinct nuclei within a shared cytoplasm. During vegetative growth, the "cell cycles" of the diploid micronucleus and polyploid macronucleus are offset. Micronuclear S phase initiates just before cytokinesis and is completed in daughter cells before onset of macronuclear DNA replication. Mitotic micronuclear division occurs mid-cell cycle, while macronuclear amitosis is coupled to cell division. Here we report the first RNA-seq cell cycle analysis of a binucleated ciliated protozoan. RNA was isolated across 1.5 vegetative cell cycles, starting with a macronuclear G1 population synchronized by centrifugal elutriation. Using MetaCycle, 3244 of the 26,000+ predicted genes were shown to be cell cycle regulated. Proteins present in both nuclei exhibit a single mRNA peak that always precedes their macronuclear function. Nucleus-limited genes, including nucleoporins and importins, are expressed before their respective nucleus-specific role. Cyclin D and A/B gene family members exhibit different expression patterns that suggest nucleus-restricted roles. Periodically expressed genes cluster into seven cyclic patterns. Four clusters have known PANTHER gene ontology terms associated with G1/S and G2/M phase. We propose that these clusters encode known and novel factors that coordinate micro- and macronuclear-specific events such as mitosis, amitosis, DNA replication, and cell division.

Relative Effectiveness of Selenite Cystine Broth, Tetrathionate Broth, and Rappaport-Vassiliadis Medium for Recovery of Salmonella spp. from Raw Flesh, Highly Contaminated Foods, and Poultry Feed: Collaborative Study

A collaborative study was performed in 18 laboratories to validate use of Rappaport-Vassiliadis (RV) medium in the standard culture method for recovery of Salmonella spp. from raw, highly contaminated foods and poultry feed. RV medium made from its individual ingredients and incubated at 42�C was compared with selenite cystine (SC) broth incubated at 35�C and tetrathionate (TT) broth incubated at 35� and 43�C for effectiveness in recovery of Salmonella spp. Four artificially contaminated foods (oysters, frog legs, mushrooms, and shrimp) and poultry feed and one naturally contaminated food (chicken) were analyzed. The artificially contaminated foods were inoculated with single serovars of Salmonella at target levels of 0.04 colony-forming units (CFU)/g for the low level and 0.4 CFU/g for the high level. For analysis of 1125 test portions, RV medium (42�C) recovered Salmonellairom 409 test portions; TT (43�C), from 368 test portions; TT (35�C), from 310 test portions; and SC (35�C), from 334 test portions. Overall, RV medium was comparable with or better than other selective enrichments for recovery of Salmonella from the foods in this study, except mushrooms. From mushrooms, SC broth (35�C) recovered more positive test portions than did RV medium (42�C) and TT broth (43�C). The method for detection of Salmonella in raw, highly contaminated foods and

Enoxaparin-associated severe retroperitoneal bleeding and abdominal compartment syndrome: a report of two cases

OBJECTIVE

To describe a complication of low-molecular-weight heparin (enoxaparin) in the setting of critically ill patients.

DESIGN

Case report.

SETTING

The medical and surgical intensive care units of a tertiary care university teaching hospital.

PATIENTS

Two adult patients receiving enoxaparin developed retroperitoneal hematoma and abdominal compartment syndrome. Both patients became anuric and required high-dose intravenous fluids and vasopressors to maintain blood pressure.

INTERVENTION

Discontinuation of enoxaparin, followed by exploratory laparotomy and evacuation of the hematoma.

MEASUREMENTS AND RESULTS

Immediate clinical improvement following evacuation of hematoma.

CONCLUSIONS

High-risk patients receiving low-molecular-weight heparin should be identified and closely monitored to prevent serious bleeding complications.

Internist Judgments of Chronic Low Back Pain

OBJECTIVE

To examine the consistency of internist judgments about low back pain; to examine the influence of different clinical factors on those judgments.

DESIGN

2 x 4 mixed between- and within-subjects analog experiment.

SETTING

Academic health sciences center, school of medicine; department of internal medicine.

PARTICIPANTS

Forty-eight internal medicine physicians.

INTERVENTIONS

Vignettes describing hypothetical chronic low back pain patient varied by patient pain level (low versus high) and clinical information type (history versus physical examination versus functional disability versus medical diagnostics).

OUTCOME MEASURES

Clinical judgments regarding patient medical, psychological, and disability status; referral, treatment, and test ordering options.

RESULTS

Within-physician consistency was very high, while between-physician consistency was very low. Medical diagnostics had the only consistent influence on judgments. Patient pain level had no effect. Physical examination and functional information had little or no effect.

CONCLUSIONS

While there is little agreement among internists regarding judgments of low back pain, individual physicians hold consistently to their opinions. These findings suggest that management of low back pain may be idiosyncratic, potentially compromising patient care.