Parallel evolution of Pseudomonas aeruginosa phage resistance and virulence loss in response to phage treatment in vivo and in vitro

With rising antibiotic resistance, there has been increasing interest in treating pathogenic bacteria with bacteriophages (phage therapy). One limitation of phage therapy is the ease at which bacteria can evolve resistance. Negative effects of resistance may be mitigated when resistance results in reduced bacterial growth and virulence, or when phage coevolves to overcome resistance. Resistance evolution and its consequences are contingent on the bacteria-phage combination and their environmental context, making therapeutic outcomes hard to predict. One solution might be to conduct ‘in vitro evolutionary simulations’ using bacteria-phage combinations from the therapeutic context. Overall, our aim was to investigate parallels between in vitro experiments and in vivo dynamics in a human participant. Evolutionary dynamics were similar, with high levels of resistance evolving quickly with limited evidence of phage evolution. Resistant bacteria—evolved in vitro and in vivo—had lower virulence. In vivo, this was linked to lower growth rates of resistant isolates, whereas in vitro phage resistant isolates evolved greater biofilm production. Population sequencing suggests resistance resulted from selection on de novo mutations rather than sorting of existing variants. These results highlight the speed at which phage resistance can evolve in vivo, and how in vitro experiments may give useful insights for clinical evolutionary outcomes.

Functional Profiling of FSH and Estradiol in Ovarian Granulosa Cell Tumors

Adult-type granulosa cell tumors (AGCTs) are sex-cord derived neoplasms with a propensity for late relapse. Hormonal modulators have been used empirically in the treatment of recurrent AGCT, albeit with limited success. To provide a more rigorous foundation for hormonal therapy in AGCT, we used a multimodal approach to characterize the expressions of key hormone biomarkers in 175 tumor specimens and 51 serum samples using RNA sequencing, immunohistochemistry, RNA in situ hybridization, quantitative PCR, and circulating biomarker analysis, and correlated these results with clinical data. We show that FSH receptor and estrogen receptor beta (ERβ) are highly expressed in the majority of AGCTs, whereas the expressions of estrogen receptor alpha (ERα) and G-protein coupled estrogen receptor 1 are less prominent. ERβ protein expression is further increased in recurrent tumors. Aromatase expression levels show high variability between tumors. None of the markers examined served as prognostic biomarkers for progression-free or overall survival. In functional experiments, we assessed the effects of FSH, estradiol (E2), and the aromatase inhibitor letrozole on AGCT cell viability using 2 in vitro models: KGN cells and primary cultures of AGCT cells. FSH increased cell viability in a subset of primary AGCT cells, whereas E2 had no effect on cell viability at physiological concentrations. Letrozole suppressed E2 production in AGCTs; however, it did not impact cell viability. We did not find preclinical evidence to support the clinical use of aromatase inhibitors in AGCT treatment, and thus randomized, prospective clinical studies are needed to clarify the role of hormonal treatments in AGCTs.

Chronic compartment syndrome of the quadriceps femoris muscle in athletes. Diagnosis, imaging and treatment with fasciotomy

BACKGROUND AND AIMS

Chronic quadriceps femoris muscle compartment syndrome is described.

MATERIAL AND METHODS

Over a 13 year period nine patients were diagnosed, treated surgically by fasciotomy and followed up at a referral center specialized in sports traumatology. There were four power lifters, three body builders, one endurance walker and one cyclist in the series. The use of anabolic steroids was admitted by four of the nine patients. The patients complained of gradually worsening pain on the anterolateral side of the thigh during training. Initially the pain appeared only at the end of the training session. As the syndrome became more severe, the pain began earlier during exercise and gradually became worse preventing maximal training. Skeletal radiographs and ultrasound examinations were normal, except in two patients, who had a positive echography finding with local atrophy. MRI examination confirmed the US diagnosis.

RESULTS AND CONCLUSIONS

As conservative treatment did not provide relief of symptoms, a fasciotomy anterior to the iliotibial tract was performed bilaterally to seven patients and unilaterally to two patients. Biopsies from the atrophied sites showed muscle cell necrosis. All the patients recovered well after the surgery and were able return to their original level of sport. The only complication of surgery was a postoperative hematoma in one patient, which delayed the beginning of the training, but did not result in any persistent complaints.

Long-term cardiac sequelae after treatment of malignant tumors with radiotherapy or cytostatics in childhood

A series of 41 individuals were restudied after childhood cancer with a median follow-up time of 17 years after chest irradiation or treatment with cyclophosphamide or Adriamycin (doxorubicin). Radiotherapy of the chest had been used in 21 patients, and in 13 of these irradiation was also directed at the heart. Thirty-five patients received cyclophosphamide and five received Adriamycin therapy. All patients were investigated by a pediatric cardiologist. Investigations included an electrocardiogram (ECG), a chest radiographic film, an echocardiogram, an exercise test, and a 24-hour ECG. Altogether 20 patients (49%) showed some abnormality in cardiac tests. Each additional year of follow-up was associated with a 1.3-fold (95% confidence limits, 1.04-1.66; P less than 0.05) increase in the risk for pathologic cardiac findings. The risk for an abnormal cardiac test result in the 13 patients who had received cardiac irradiation was 12.8-fold (95% confidence limits, 1.8-90.8; P less than 0.02) that of the other patients. However, abnormalities in cardiac function were mild.

Iatrogenic, unexpected and other vascular rings in children

Between May 1955 and July 1987, 33 children with a vascular ring compression syndrome were treated at this institution. There were 4 iatrogenic, 2 unexpectedly found and 27 symptomatic congenital vascular rings. Accurate diagnosis is based on a water soluble iodine contrast dye oesophagogram, bronchoscopy and angiography which are complementary examinations. All symptomatic congenital vascular rings were treated successfully without mortality, but the mortality was 50% if the lesion was iatrogenic in origin or unexpectedly found during palliative or corrective cardiac surgery.