Animal and translational models of SARS-CoV-2 infection and COVID-19

COVID-19 is causing a major once-in-a-century global pandemic. The scientific and clinical community is in a race to define and develop effective preventions and treatments. The major features of disease are described but clinical trials have been hampered by competing interests, small scale, lack of defined patient cohorts and defined readouts. What is needed now is head-to-head comparison of existing drugs, testing of safety including in the background of predisposing chronic diseases, and the development of new and targeted preventions and treatments. This is most efficiently achieved using representative animal models of primary infection including in the background of chronic disease with validation of findings in primary human cells and tissues. We explore and discuss the diverse animal, cell and tissue models that are being used and developed and collectively recapitulate many critical aspects of disease manifestation in humans to develop and test new preventions and treatments.

Clinical assessment of acellular dermal matrix (AlloDerm©) as an option in the replacement of the temporomandibular joint disc: A pilot study

BACKGROUND

There is limited data available in the literature describing the utility of acellular dermal matrix (AlloDerm©) in the replacement of the temporomandibular joint disc. Few reports of clinicians using implantable AlloDerm to replace the disc do exist, however, this has been described for reconstruction after surgical resection of the entire temporomandibular joint complex to treat pathology, as opposed to isolated articular disc disorders. Moreover, there is a lack of description in the literature regarding associated perioperative outcomes after such a procedure. We sought to assess the immediate perioperative outcomes in the form of a pilot study, to determine whether this technique warrants further investigation in the form of prospective clinical studies.

METHODS

The study team conducted a retrospective review of medical records for patients who underwent temporomandibular joint discectomy and replacement with AlloDerm© at a single tertiary care center, from 2011 to 2016. Perioperative outcomes of interest including pain levels and range of motion were recorded and descriptive statistics were utilized for statistical analysis.

RESULTS

15 patients met the inclusion criteria, of which 87% were females and 13% males. The mean age was 47.27±15.93 years. Preoperatively, 74% of the patients reported severe pain (VAS scores of 7-10); in contrast, 73% of the patients reported only mild pain (VAS scores of 1-3) during the postoperative visits, suggesting an overall reduction in pain intensity. Range of motion also improved from an average of 27.73±13.04mm, to an average of 38.60±6.08mm (P<0.01).

CONCLUSIONS

Based on our preliminary data, patients with advanced TMJ articular disc disorders showed clinical improvement from discectomy and replacement with acellular dermal matrix (AlloDerm©). Further longitudinal studies evaluating long-term outcomes need to be conducted to validate this technique, in the form of larger sample sizes with a control group, as well as radiographic assessment of long-term clinical outcomes.

Effective therapeutic strategy for massive retroperitoneal hematoma after conization: arterial embolization and pigtail catheter insertion

The loop electrosurgical excision procedure (LEEP) is commonly used to remove cervical intraepithelial neoplasia (CIN) because of its safety profile and likelihood of fewer complications. The authors report a rare case of massive retroperitoneal bleeding combined with hypovolemic shock after LEEP conization. Vessel injury was detected by angiographic computed tomography (CT) and embolization of the uterine artery was successfully performed to achieve hemostasis by an intervention radiologist. A pigtail catheter was subsequently inserted for the drainage of the large retroperitoneal hematoma. The patient did not show any further hemorrhage and recovered safely from hypovolemic shock. Th present case demonstrates a successful multidisciplinary and minimal invasive approach to manage retroperitoneal bleeding with uterine artery embolization. Thus, it should be considered a potential treatment option for hemostasis.

Biochemical indicators of implantation success of tissue-engineered oral mucosa

Real-time (RT) determination of the health of in vitro tissue-engineered constructs prior to grafting is essential for prediction of success of the implanted tissue-engineered graft. In addition, the US Food and Drug Administration requires specific release criteria in RT prior to the release of tissue-engineered devices for human use. In principle, assessing the viability and functionality of the cellular component can be achieved by quantifying the secretion of growth factors and chemokines of tissue-engineered constructs. Ex vivo-produced oral mucosa equivalents (EVPOMEs) were fabricated under thermally stressed conditions at 43 °C for 24 h to create a functionally compromised EVPOME. We used microchannel enzyme-linked immunosorbent assay to evaluate the functionality of the cellular component, oral keratinocytes, of stressed and unstressed EVPOMEs by measuring the release of vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), human β-defensin 1 (hBD-1), and tissue inhibitor of metalloproteinase 1 and 2 (TIMP-1 and -2) into the spent medium, which was collected on the same day prior to graft implantation into severe combined immunodeficiency mice. Implanted EVPOMEs' histology on the seventh postimplantation day was used to correlate outcomes of grafting to secreted amounts of IL-8, hBD-1, VEGF, TIMP-1, and TIMP-2 from corresponding EVPOMEs. Our findings showed that significantly higher levels of IL-8, hBD-1, and TIMP-2 were secreted from controls than from thermally stressed EVPOMEs. We also found a direct correlation between secreted VEGF and IL-8 and blood vessel counts of implanted EVPOMEs. We concluded that measuring the constitutive release of these factors can be used as noninvasive predictors of healthy tissue-engineered EVPOMEs in RT, prior to their implantation.

Evaluation of a large-scale donation of Lifebox pulse oximeters to non-physician anaesthetists in Uganda

Pulse oximetry is widely accepted as essential monitoring for safe anaesthesia, yet is frequently unavailable in resource-limited settings. The Lifebox pulse oximeter, and associated management training programme, was delivered to 79 non-physician anaesthetists attending the 2011 Uganda Society of Anaesthesia Annual Conference. Using a standardised assessment, recipients were tested for their knowledge of oximetry use and hypoxia management before, immediately following and 3–5 months after the training. Before the course, the median (IQR [range]) test score for the anaesthetists was 36 (34–39 [26–44]) out of a maximum of 50 points. Immediately following the course, the test score increased to 41 (38–43 [25–47]); p < 0.0001 and at the follow-up visit at 3–5 months it was 41 (39–44 [33–49]); p = 0.001 compared with immediate post-training test scores, and 75/79 (95%) oximeters were in routine clinical use. This method of introduction resulted in a high rate of uptake of oximeters into clinical practice and a demonstrable retention of knowledge in a resource-limited setting.

Tumor necrosis factor-related apoptosis-inducing ligand translates neonatal respiratory infection into chronic lung disease

Respiratory infections in early life can lead to chronic respiratory disease. Chlamydia infections are common causes of respiratory disease, particularly pneumonia in neonates, and are linked to permanent reductions in pulmonary function and the induction of asthma. However, the immune responses that protect against early-life infection and the mechanisms that lead to chronic lung disease are incompletely understood. Here we identify novel roles for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in promoting Chlamydia respiratory infection-induced pathology in early life, and subsequent chronic lung disease. By infecting TRAIL-deficient neonatal mice and using neutralizing antibodies against this factor and its receptors in wild-type mice, we demonstrate that TRAIL is critical in promoting infection-induced histopathology, inflammation, and mucus hypersecretion, as well as subsequent alveolar enlargement and impaired lung function. This suggests that therapeutic agents that target TRAIL or its receptors may be effective treatments for early-life respiratory infections and associated chronic lung disease.

Neonatal respiratory infection and adult re-infection: effect on glucocorticoid and mineralocorticoid receptors in the hippocampus in BALB/c mice

Stressful events during the perinatal period in both humans and animals have long-term consequences for the development and function of physiological systems and susceptibility to disease in adulthood. One form of stress commonly experienced in the neonatal period is exposure to bacterial and viral infections. The current study investigated the effects of live Chlamydia muridarum bacterial infection at birth followed by re-infection in adulthood on hippocampal glucocorticoid receptors (GR) and mineralocorticoid receptors (MR) and stress response outcomes. Within 24 h of birth, neonatal mice were infected intranasally with C. muridarum (400 inclusion-forming units [ifu]) or vehicle. At 42 days, mice were re-infected (100 ifu) and euthanized 10 days later. In males, infection in adulthood alone had the most impact on the parameters measured with significant increases in GR protein compared to adult infection alone; and significant increases MR protein and circulating corticosterone compared to other treatment groups. Neonatal infection alone induced the largest alterations in the females with results showing reciprocal patterns for GR protein and TH protein. Perinatal infection resulted in a blunted response following adult infection for both males and females across all parameters. The present study demonstrates for the first time that males and females respond differently to infection based on the timing of the initial insult and that there is considerable sex differences in the hippocampal phenotypes that emerge in adulthood after neonatal infection.

Efficacy and rectal toxicity of hypofractionated radiation therapy with daily image guidance

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Background: To assess the biochemical control rates and long-term rectal side effect profile of hypofractionated image guided radiation therapy for prostate cancer. We hypothesize that daily CT-based image guidance will allow a higher dose per fraction to be safely administered, shortening the overall treatment time from 8 weeks to 4-5.5 weeks.

Methods: 160 patients were treated with image guided radiation therapy with or without adjuvant hormonal ablation between 2005 and 2009 for patients <= T3a N0 M0. Patients were classified into risk groups with 51 patients defined as low risk, 67 as intermediate risk, and 43 as high risk. Mean age was 70.2 years. All patients were treated with 60/67.6/70/70.2 Gy to the prostate divided into 20/26/28/27 fractions. 57% of patients received hormone therapy. Daily CT or fiducial-based image guidance was performed prior to each fraction. The median follow up was 34 months. Biochemical control was defined by the Phoenix definition. Rectal toxicity was graded by the CTCAE 4.0 scale. In general patients with rectal bleeding more than once per week were started on rectal steroids.

Results: 12/160 (7.5%) of patients had late grade 2 or worse rectal toxicity after radiation treatment. The Kaplan-Meier estimate for grade 2 rectal toxicity at 2 years was 6.9%. The crude rate of biochemical no evidence of disease was 96.3%. Kaplan Meier estimates for biochemical no evidence of disease at 3 and 5 years are 0.98/0.84, 0.97/0.97, and 1.0/0.67 for low, medium, and high-risk patients respectively. Log-rank analysis showed no statistically significant difference among the dosing regimens for toxicity-free survival (p=0.24).

Conclusions: With daily image guidance hypofractionated radiation therapy is clinically safe with moderate late rectal toxicity. Early follow-up suggests high efficacy. Ongoing and future randomized trials such as RTOG 0415 will be required to confirm these findings.

No significant financial relationships to disclose.

Which MR imaging sequences are necessary in determining the need for radiation therapy for cord compression? A prospective study

BACKGROUND AND PURPOSE

To determine which MR imaging sequences are necessary to assess for spinal metastases.

METHODS

Hypothetical MR imaging interpretations and management plans were made prospectively for consecutive adult cases acquired retrospectively. Standardized MR imaging protocols were independently interpreted by 2 neuroradiologists. MR imaging protocol types varied: 1) T1-weighted images only; 2) T1-weighted and T2-weighted images; 3) T1-weighted and postcontrast T1-weighted images; and 4) T1- and T2-weighted images and postcontrast T1-weighted images. Hypothetical management plans were created by 2 radiation oncologists. Logit model was used to investigate the effect of MR imaging protocol type on the probability of recommending radiation therapy (RT). Mixed effect models were used to investigate whether median spinal level or total number of spinal levels of planned RT was associated with MR imaging protocol type.

RESULTS

Thirty-one subjects were evaluated, each with multiple scan interpretations. Logit model showed that neither MR imaging protocol type nor neuroradiologist reader affected the probability that the oncologist would recommend RT (all P > .50). Mixed models showed that neither ML nor NL was affected by MR imaging protocol type or by neuroradiologist reader (all P > .12).

CONCLUSION

Although MR imaging is known to be the most useful diagnostic test in suspected spinal cord compression, which particular MR images are necessary remain unclear. Compared with T1-weighted images alone, the additional use of T2-weighted and/or postcontrast T1-weighted sequences did not significantly affect the probability that RT would be recommended or the levels that would be chosen for RT in our study. Our data suggest that unenhanced T1-weighted images may be sufficient for evaluation of possible cord compression.

Surgical removal of subfoveal choroidal neovascularization without removal of posterior hyaloid: a consecutive series in younger patients

PURPOSE

Subfoveal choroidal neovascularization (CNV) remains a common and important cause of visual loss. Previous studies have suggested that submacular surgery may improve or maintain visual acuity, particularly in younger patients. The majority of reported cases included removal of the posterior hyaloid during vitrectomy. The authors present a consecutive series of patients age 55 or younger with subfoveal CNV removal without posterior hyaloid removal.

METHODS

Seventeen patients without age-related macular degeneration (ARMD), with subfoveal CNV from choroiditis, presumed ocular histoplasmosis syndrome, myopia, or idiopathic causes, underwent a small retinotomy technique to extract the membranes after vitrectomy without posterior hyaloid removal.

RESULTS

Median improvement in visual acuity was from 20/320 to 20/50. Eleven patients (65%) experienced an improvement of three or more lines of Snellen acuity (average 7.5), 4 (23%) were within two lines of preoperative acuity, and 2 (12%) had decreased acuity, with an average follow-up of 12 months (range 3-31). Choroidal neovascularization recurred in six patients (35%). Postoperative retinal detachment, epiretinal proliferation, or macular hole did not occur.

CONCLUSIONS

In this series of younger patients with subfoveal CNV not from ARMD, visual acuity was improved in the majority after submacular membrane removal. Omission of removal of the posterior hyaloid did not adversely affect outcome.

Long-term follow-up of RTOG 92-10: cervical cancer with positive para-aortic lymph nodes

PURPOSE

The purpose of this study was to evaluate the late toxicity and efficacy of twice-daily external irradiation to the pelvis and lumbar para-aortic region with brachytherapy and concurrent chemotherapy for carcinoma of the cervix with positive para-aortic lymph nodes.

PATIENTS AND METHODS

This study was designed to administer twice-daily radiation doses of 1.2 Gy to the pelvis and lumbar para-aortic lymph nodes (simultaneously) at 4-6-h intervals, 5 days per week. The total external radiation doses were 24-48 Gy to the whole pelvis, 12-36 Gy parametrial boost, and 48 Gy to the lumbar para-aortic region with an additional boost to a total dose 54-58 Gy to the positive para-aortic lymph node(s). One or two intracavitary implants were performed to deliver a minimum total dose of 85 Gy to point A. Cisplatin (75 mg/m(2); Days 1, 22, and 43) and 5-fluorouracil (1,000 mg/m(2)/24 h x 4 consecutive days, beginning on Days 1, 22, and 43) were given for two or three cycles.

RESULTS

Thirty patients with clinical Stages I-IV carcinoma of the cervix with biopsy-proven para-aortic lymph node metastases were enrolled in this study. Hyperfractionated external irradiation was completed in 87% (26 of 30). Brachytherapy was given in two implants to 47% (14 of 30) and in one implant to 33% (10 of 30); 13% (4 of 30) did not receive brachytherapy, 1 patient had three implants, and 1 had five high-dose-rate implants. Radiotherapy was completed per protocol in 70%. Three cycles of chemotherapy were given to 23% (7 of 30); 73% (22 of 30) received two cycles, and 1 patient did not receive chemotherapy. The acute toxicity from chemotherapy was Grade 1 in 3%, Grade 2 in 17%, Grade 3 in 48%, and Grade 4 in 28%. Acute toxicity from radiotherapy was Grade 1 in 7%, Grade 2 in 34%, Grade 3 in 21%, and Grade 4 in 28%. Late toxicity was Grade 1 in 10%, Grade 2 in 17%, Grade 3 in 7%, and Grade 4 in 17%. Grade 5 toxicity occurred in 1 patient during the course of therapy, but none had a late Grade 5 toxicity. The median follow-up time for the 7 patients alive at the time of last follow-up was 57 months. The overall survival estimates were 46% at 2 years and 29% at 4 years. The probability of local-regional failure was 40% at 1 year and 50% at 2 and 3 years. The probability of disease failure at any site was 46% at 1 year, 60% at 2 years, and 63% at 3 years.

CONCLUSION

The results suggest that twice-daily external irradiation to the pelvis and lumbar para-aortic region with brachytherapy and concurrent chemotherapy resulted in an unacceptably high rate (17%, 5 of 29) of Grade 4 late toxicity. One patient died of acute complications of therapy. The survival estimates seem no better than standard fractionation irradiation without chemotherapy.

Welfare reform and "ineligibles": issue of constitutionality and recent court rulings

In 1996 welfare legislation made lawful immigrants, with a few exemptions, categorically ineligible for most forms of public assistance. This legislation has led affected immigrants and their advocacy groups to file lawsuits to challenge the constitutionality of the Personal Responsibility and Work Opportunity Reconciliation Act. This article reviews recent court rulings that have upheld the act and examines court decisions in light of two constitutional principles (the Equal Protection and Supremacy clauses), which traditionally have been applied to the issue of aliens' eligibility for welfare benefits. The author finds inconsistent outcomes between federal and state legislation in the judicial review process. To resolve this inconsistency, the author suggests several policy changes in the distribution of welfare benefits concerning eligibility of lawful immigrants. The implications for social work practice are discussed.

Bmp6 and Bmp7 are required for cushion formation and septation in the developing mouse heart

The mature heart valves and septa are derived from the cardiac cushions which initially form as local outgrowths of mesenchymal cells within the outflow tract and atrioventricular regions. Endocardial cells respond to signals from the overlying myocardium and undergo an epithelial-to-mesenchymal transformation to invade the intervening extracellular matrix. The molecules that can induce and maintain these cell populations are not known, but many candidates, including several TGFbetas and BMPs, have been proposed based on their expression patterns and activities in other systems. In the present study, we describe the expression of Bmp6 and Bmp7 in overlapping and adjacent sites, including the cardiac cushions during mouse embryonic development. Previous analyses demonstrate that neither of these BMPs is required during cardiogenesis, but analysis of Bmp6;Bmp7 double mutants uncovers a marked delay in the formation of the outflow tract endocardial cushions. A proportion of Bmp6;Bmp7 mutants also display defects in valve morphogenesis and chamber septation, and the embryos die between 10.5 and 15.5 dpc due to cardiac insufficiency. These data provide the first genetic evidence that BMPs are involved in the formation of the cardiac cushions.

Tumor shrinkage before intracavitary brachytherapy for cancer of the cervix: radiotherapy alone versus concurrent chemoradiotherapy

PURPOSE

The purpose of this study was to compare the tumor shrinkage between radiotherapy alone and concurrent chemoradiotherapy before intracavitary brachytherapy (ICBT).

MATERIALS AND METHODS

Nineteen consecutive patients (three stage IB2, nine stage IIB, seven stage IIIB) were selected for measurement of tumor regression. Ten patients underwent radiotherapy alone, and nine patients underwent concurrent cisplatin-based chemoradiotherapy. The average dose of pelvic radiation was given at 45 Gy over a 5-week period in both groups. Computed tomography-based tumor measurement before treatment was compared with measurement after treatment but before intracavitary brachytherapy. The largest width and thickness of the cervical mass were measured from the axial computed tomographic images.

RESULTS

Tumor regression before intracavitary brachytherapy varied widely, ranging from 15% to 65%. However, the tumor regression in patients who underwent chemoradiotherapy was higher, ranging from 41% to 65% (mean, 55%), compared with radiotherapy alone, which ranged from 15% to 52% (mean, 38%).

CONCLUSION

Our results show that significant tumor shrinkage occurs with concurrent chemoradiotherapy compared with radiotherapy alone. This finding supports the results of recent clinical trials demonstrating improvement of pelvic control and survival with concurrent chemoradiotherapy for advanced cancer of the cervix.

Recent developments in chemoradiotherapy for locally advanced cancer of the cervix

Patients with locally advanced cervical cancer comprise a significant proportion of the total population with cervical cancer, particularly in developing countries. The inability to control pelvic tumors is still a significant concern. Although neoadjuvant chemotherapy is associated with a high response rate, data from randomized trials clearly do not support the use of neoadjuvant chemotherapy prior to definitive irradiation. However, the results of concurrent cisplatin (Platinol)-based chemotherapy and radiotherapy are highly promising for locally advanced cancer of the cervix and should be considered as a treatment option. To decrease the risk of distant metastasis and improve survival, more effective drugs or drug combinations need to be developed.

A prospective evaluation of the timing of postoperative radiotherapy for preventing heterotopic ossification following traumatic acetabular fractures

PURPOSE

Preoperative and immediate postoperative irradiation of traumatic acetabular fractures (TAF), although known to reduce heterotopic ossification (HO), can cause significant organizational and logistic difficulties. We sought to determine an acceptable time interval between surgery and radiation without compromising control, as well as to update our large experience and to further validate our treatment philosophy.

METHODS AND MATERIALS

Beginning in June 1995, we began a prospective study, irradiating 152 patients on postoperative days 1, 2, or 3. There were also 17 patients delayed further secondary to medical difficulties.

RESULTS

All patients treated since June 1995 received 700 cGy/1 fx. Fifty-eight patients received radiation within 24 hours of surgery, 41 within 2 days, 53 within 3 days, 13 within 4 days, and 4 were delayed further. Delaying irradiation for up to 4 days postoperatively caused no statistical increase in HO (p = 0.625). Of 263 patients in our retrospective cohort, HO occurred in 5.3% of patients who received irradiation versus 60% of patients who did not.

CONCLUSION

In our prospective study, we noted no perceptible increase in HO with up to a 3-day interval between surgery and radiotherapy. This allows a more structured treatment schedule and allows the patient more time to heal and recover. Updated results from our overall series continue to demonstrate that adjuvant radiation decreases the incidence and severity of HO after TAF.

Effects of pelvic rotation and needle angle on pubic arch interference during transperineal prostate implants

PURPOSE

Pubic arch interference due to an enlarged prostate gland or a narrow pubic arch is often a limiting factor in adequate prostate coverage during transperineal brachytherapy. The purpose of this study was to evaluate the effects of both pelvic rotation and needle angles on pubic arch interference using CT-based 3-D information.

METHODS AND MATERIALS

Seven patients had CT imaging in both supine and lithotomy positions and 3-D treatment planning was performed with three needle angles (20 downward, 0, 20 upward). The pubic arch interference was then measured and comparisons were made for each needle trajectory and pelvic position.

RESULTS

Increasing pelvic rotation from supine to lithotomy position shows less pubic arch interference. Directing the needle tip upward shows less pubic arch interference in both supine and lithotomy positions when compared to needle tips directed downward.

CONCLUSIONS

Both pelvic position and needle angles are important factors influencing pubic arch interference. Preplanning CT-based 3-D information may assist for individualized treatment planning in patients with a significant bony interference, thus avoiding pubic arch interference during implantation.

Radiation response of Rosai-Dorfman disease presenting with involvement of the orbits

The purpose of this study was to review an interesting case of recurrent orbital sinus histiocytosis. The patient initially failed surgery, chemotherapy, and steroid therapy, only to have a durable response to low-dose radiation therapy of the orbits, lasting 6 and 11 years, respectively. Because there are few documented responses to radiotherapy, we present a case report in conjunction with the clinical, radiographic, and histopathologic information as well as a literature review of similar cases.

Tuberculous neuroretinitis

OBJECTIVES

To describe a patient with tuberculous neuroretinitis.

MATERIALS AND METHODS

Retrospective case report.

RESULTS

We describe a 43-year-old otherwise asymptomatic woman with a known exposure to tuberculosis who had unilateral optic disc edema and a partial macular star (neuroretinitis). This was followed approximately 1 year later by the development of an exudative retinal detachment in the setting of bilateral multifocal choroiditis. Laboratory testing revealed a marked positive cutaneous reaction to purified protein derivative (PPD). Treatment with antituberculosis medicine alone resulted in prompt resolution of the choroidal infiltrates and complete flattening of the exudative detachment.

CONCLUSIONS

Tuberculosis should be considered in the differential diagnosis for patients with neuroretinitis.

Primary lymphoma of the breast: breast mass as an initial symptom

Seven patients with lymphoma presenting as a breast mass are described. Four of them fulfilled the criteria for primary lymphoma of the breast, and three had evidence of secondary lymphoma of the breast. Two patients were diagnosed with stage IAE disease, and both did well with local treatment with or without chemotherapy. Two patients were diagnosed with stage IIAE disease; both had distant failure without systemic chemotherapy. Although local treatment is curative in a subset of stage IAE disease, combination chemotherapy followed by local radiation is a safer approach. For stage IIAE disease, combination chemotherapy and local radiation therapy should be considered.