Clinical Outcomes and Tau Pathology in Retired Football Players: Associations With Diagnosed and Witnessed Sleep Apnea

Background and Objectives

Obstructive sleep apnea (SA) is common in older men and a contributor to negative cognitive, psychiatric, and brain health outcomes. Little is known about SA in those who played contact sports and are at increased risk of neurodegenerative disease(s) and other neuropathologies associated with repetitive head impacts (RHI). In this study, we investigated the frequency of diagnosed and witnessed SA and its contribution to clinical symptoms and tau pathology using PET imaging among male former college and former professional American football players.

Methods

The sample included 120 former National Football League (NFL) players, 60 former college players, and 60 asymptomatic men without exposure to RHI (i.e., controls). Diagnosed SA was self-reported, and all participants completed the Mayo Sleep Questionnaire (MSQ, informant version), the Epworth Sleepiness Scale (ESS), neuropsychological testing, and tau (flortaucipir) PET imaging. Associations between sleep indices (diagnosed SA, MSQ items, and the ESS) and derived neuropsychological factor scores, self-reported depression (Beck Depression Inventory-II [BDI-II]), informant-reported neurobehavioral dysregulation (Behavior Rating Inventory of Executive Function-Adult Version [BRIEF-A] Behavioral Regulation Index [BRI]), and tau PET uptake, were tested.

Results

Approximately 36.7% of NFL players had diagnosed SA compared with 30% of the former college football players and 16.7% of the controls. Former NFL players and college football players also had higher ESS scores compared with the controls. Years of football play was not associated with any of the sleep metrics. Among the former NFL players, diagnosed SA was associated with worse Executive Function and Psychomotor Speed factor scores, greater BDI-II scores, and higher flortaucipir PET standard uptake value ratios, independent of age, race, body mass index, and APOE ε4 gene carrier status. Higher ESS scores correlated with higher BDI-II and BRIEF-A BRI scores. Continuous positive airway pressure use mitigated all of the abovementioned associations. Among the former college football players, witnessed apnea and higher ESS scores were associated with higher BRIEF-A BRI and BDI-II scores, respectively. No other associations were observed in this subgroup.

Discussion

Former elite American football players are at risk of SA. Our findings suggest that SA might contribute to cognitive, neuropsychiatric, and tau outcomes in this population. Like all neurodegenerative diseases, this study emphasizes the multifactorial contributions to negative brain health outcomes and the importance of sleep for optimal brain health.

Antibiotic prescriptions in the context of suspected bacterial respiratory tract superinfections in the COVID-19 era: a retrospective quantitative analysis of antibiotic consumption and identification of antibiotic prescription drivers

This study aims to quantify antibiotic consumption for suspected respiratory tract superinfections in COVID-19 patients, while investigating the associated drivers of antibiotic prescribing in light of the current signs of antibiotic overuse. Adult patients with a positive COVID-19 diagnosis admitted to a Belgian 721-bed university hospital were analyzed retrospectively (March 11th-May 4th, 2020), excluding short-term admissions (< 24 h). Antibiotic prescriptions were analyzed and quantified, using Defined Daily Doses (DDD) per admission and per 100 bed days. Possible drivers of antibiotic prescribing were identified by means of mixed effects logistic modelling analysis with backwards selection. Of all included admissions (n = 429), 39% (n = 171) were prescribed antibiotics for (presumed) respiratory tract superinfection (3.6 DDD/admission; 31.5 DDD/100 bed days). Consumption of beta-lactamase inhibitor-penicillin combinations was the highest (2.55 DDD/admission; 23.3 DDD/100 bed days). Four drivers were identified: fever on admission (OR 2.97; 95% CI 1.42-6.22), lower SpO₂/FiO₂ ratio on admission (OR 0.96; 95% CI 0.92-0.99), underlying pulmonary disease (OR 3.04; 95% CI 1.12-8.27) and longer hospital stay (OR 1.09; 95% CI 1.03-1.16). We present detailed quantitative antibiotic data for presumed respiratory tract superinfections in hospitalized COVID-19 patients. In addition to knowledge on antibiotic consumption, we hope antimicrobial stewardship programs will be able to use the drivers identified in this study to optimize their interventions in COVID-19 wards.

Mechanistic insights from targeted molecular profiling of repolarization alternans in the intact human heart

AIMS

Action potential duration (APD) alternans is an established precursor or arrhythmia and sudden cardiac death. Important differences in fundamental electrophysiological properties relevant to arrhythmia exist between experimental models and the diseased in vivo human heart. To investigate mechanisms of APD alternans using a novel approach combining intact heart and cellular cardiac electrophysiology in human in vivo.

METHODS AND RESULTS

We developed a novel approach combining intact heart electrophysiological mapping during cardiac surgery with rapid on-site data analysis to guide myocardial biopsies for laboratory analysis, thereby linking repolarization dynamics observed at the organ level with underlying ion channel expression. Alternans-susceptible and alternans-resistant regions were identified by an incremental pacing protocol. Biopsies from these sites (n = 13) demonstrated greater RNA expression in Calsequestrin (CSQN) and Ryanodine (RyR) and ion channels underlying IK1 and Ito at alternans-susceptible sites. Electrical restitution properties (n = 7) showed no difference between alternans-susceptible and resistant sites, whereas spatial gradients of repolarization were greater in alternans-susceptible than in alternans-resistant sites (P = 0.001). The degree of histological fibrosis between alternans-susceptible and resistant sites was equivalent. Mathematical modelling of these changes indicated that both CSQN and RyR up-regulation are key determinants of APD alternans.

CONCLUSION

Combined intact heart and cellular electrophysiology show that regions of myocardium in the in vivo human heart exhibiting APD alternans are associated with greater expression of CSQN and RyR and show no difference in restitution properties compared to non-alternans regions. In silico modelling identifies up-regulation and interaction of CSQN with RyR as a major mechanism underlying APD alternans.

Re-emergence of rabies virus maintained by canid populations in Paraguay

Paraguay has registered no human cases of rabies since 2004, and the last case in dogs, reported in 2009, was due to a variant maintained in the common vampire bat "Desmodus rotundus". In 2014, a dog was diagnosed as positive for rabies with aggression towards a boy and all required measures of control were successfully adopted. Epidemiological investigation revealed that the dog was not vaccinated and had been attacked by a crab-eating fox, "zorro" (Cerdocyon thous). The sample was diagnosed by the Official Veterinary Service of the Country and sent to the Center on Rabies Research from the University of São Paulo, Brazil, for antigenic and genetic characterization. A second sample from a dog positive for rabies in the same region in 2015 and 11 samples from a rabies outbreak from Asuncion in 1996 were also characterized. The antigenic profile of the samples, AgV2, was compatible with one of the variants maintained by dogs in Latin America. In genetic characterization, the samples segregated in the canine (domestic and wild species)-related group in an independent subgroup that also included samples from Argentina. These results and the epidemiology of the case indicate that even with the control of rabies in domestic animals, the virus can still circulate in wildlife and may be transmitted to domestic animals and humans, demonstrating the importance of continuous and improved surveillance and control of rabies, including in wild species, to prevent outbreaks in controlled areas.

Novel Paramedic Programs Respond to Behavioral Health-related Calls

A number of communities are turning to community paramedicine programs to help manage the crushing demand on EDs and EMS providers by patients with behavioral health (BH) concerns. In Modesto, CA, a pilot program provides extra training to paramedics to respond to BH-related calls, and a program in Atlanta pairs paramedics with mental health social workers to meet the needs of BH patients, many of whom repeatedly call 911 for help. Both programs curb the need for hospital and ED visits while linking patients with appropriate care more expeditiously. However, a shortage of psychiatric treatment facilities remains a barrier. Paramedics in the Modesto, CA, program undergo 140 hours of specialized training in how to handle BH related 911 calls safely and appropriately. Program developers note that most of these patients can be stabilized within 23 hours, nixing the need for a bed in an inpatient psychiatric facility. Developers say that the pilot program has saved more than $1 million and significantly reduced the time to treatment for BH patients. The Upstream Crisis Intervention program in Atlanta teams a paramedic with a mental health social worker to respond to BH related calls through a mental health unit that is dispatched through the 911 system. The mental health unit teams also check on BH patients when they are not in crisis to make sure they have their medicine and are on track with their plan of care; the teams will intervene if patients need assistance.

Abstract T P267: Development of an EMS Interfacility Ground Transport Protocol for Patients During/After IV tPA Administration for Acute Ischemic Stroke

Purpose: To standardize the care of acute stroke patients who receive IV tPA being transported by ground EMS from a treating hospital to a stroke center.

Background: National consensus guidelines exist for the hospital management of patients receiving IV tPA for acute ischemic stroke. Such patients require close monitoring and management to minimize risk of clinical deterioration. Although patients are often emergently transported from local hospitals to a stroke center, there are no treatment specific national guidelines for managing such patients enroute. As a result, there is a need to develop and implement a standardized approach to guide EMS personnel, particularly in states like Georgia where the public health burden of stroke is high.

Methods: In 2012, the “Georgia EMS Interfacility Ground Transport Protocol for Patients during/after IV tPA Administration for Acute Ischemic Stroke” was developed in conjunction with the Georgia Coverdell Acute Stroke Registry, the Georgia State Office of EMS, a representative group of Georgia hospitals and EMS providers. Stakeholders were brought together with the goal of creating a unified statewide protocol. The intent was to create a streamlined protocol which could be readily implemented by pre-hospital care providers.

Results: Stakeholders discussed challenges and opportunities to change the process of pre-hospital care. Challenges included recognition of the broad diversity of EMS providers representing over 250 agencies in the state. Opportunities included establishing the framework for greater collaboration across organizations and providers. The final protocol was endorsed by both the Georgia Coverdell Acute Stroke Registry and the State Office of EMS, and distributed to all EMS regions in Georgia. EMS agencies are currently implementing the protocol.

Conclusion: Engaging a diverse group of statewide stakeholders to develop a new treatment protocol enhances success in implementation and serves to further the public health mission of improving care of acute stroke patients.

How well do General EMS 911 dispatch protocols predict ED resource utilization for pediatric patients?

INTRODUCTION

The use of Emergency Medical Services (EMS) for low-acuity pediatric problems is well documented. Attempts have been made to curb potentially unnecessary transports, including using EMS dispatch protocols, shown to predict acuity and needs of adults. However, there are limited data about this in children. The primary objective of this study is to determine the pediatric emergency department (PED) resource utilization (surrogate of acuity level) for pediatric patients categorized as "low-acuity" by initial EMS protocols.

METHODS

Records of all pediatric patients classified as "low acuity" and transported to a PED in winter and summer of 2010 were reviewed. Details of the PED visit were recorded. Patients were categorized and compared based on chief complaint group. Resource utilization was defined as requiring any prescription medications, labs, procedures, consults, admission or transfer. "Under-triage" was defined as a "low-acuity" EMS transport subsequently requiring emergent interventions.

RESULTS

Of the 876 eligible cases, 801 were included; 392/801 had no resource utilization while 409 of 801 had resource utilization. Most (737/801) were discharged to home; however, 64/801 were admitted, including 1 of 801 requiring emergent intervention (under-triage rate 0.12%). Gastroenterology and trauma groups had a significant increase in resource utilization, while infectious disease and ear-nose-throat groups had decreased resource utilization.

DISCUSSION

While this EMS system did not well predict overall resource utilization, it safely identified most low-acuity patients, with a low under-triage rate. This study identifies subgroups of patients that could be managed without emergent transport and can be used to further refine current protocols or establish secondary triage systems.

Double isolated limb infusion with cytotoxic agents for recurrent and metastatic limb melanoma

Metastatic melanoma confined to a limb can be treated effectively by isolated limb infusion (ILI) with cytotoxic drugs. The present study was undertaken to determine whether electively performing a second ILI procedure after 4 weeks increases the frequency and/or duration of response, and also to assess the value of a second ILI when disease recurrence or progression in a limb occurs after a first ILI. In 47 patients, a planned double ILI protocol achieved an overall response (OR) rate of 88% (complete response (CR) 41%, partial response (PR) 47%, median duration of response 18 months). Response rates after double ILI were similar to those in 81 patients treated with a single ILI over the same time period (CR 41%, PR 41%), without significant differences in response duration. After double ILI more patients experienced Wieberdink Grade III or IV limb toxicity. Following a second ILI for progression after an initial ILI (n=14), the OR rate was 71%, with a 5 month median duration of response. Since elective double ILI increases toxicity without increasing efficacy, performance of a single ILI is the preferred treatment option for melanoma confined to a limb. However, a second ILI can be of value if limb disease recurs or progresses following a previous ILI.

Bi-modality (chemo-radiation) versus tri-modality (chemo-radiation followed by surgery) treatment for carcinoma of the esophagus

The purpose of the study was to investigate the difference in overall survival in patients with localized carcinoma of esophagus treated using chemo-radiation (bi-modality, BM) or chemo-radiation followed by surgery (tri-modality, TM). From 1981 to 1999, 65 patients were identified who had localized carcinoma of the esophagus treated with either concurrent chemo-radiation (BM, n=22) or concurrent chemo-radiation followed by surgery (TM, n=43) at the University of Texas Medical Branch at Galveston. All 65 patients received concurrent chemotherapy and external beam radiation. Radiation was delivered by linear accelerators (greater-than-or-equal 6 MV), except in one patient who had part of his treatment given by a Co-60 machine. Chemotherapy consisted of 5-fluorouracil and cisplatin plus minus vinblastine under different regimens. Median follow-up time was 10 months (range=1-195 months) for all patients. Of the 14 patients still alive, the median follow-up time was 32 months (range=2-192 months). No difference in overall survival was detected between the two treatment groups, BM vs. TM (P=0.394) despite a selection bias favoring the TM group. Five-year survival rates of the BM and TM groups were 17% and 18%, respectively; 10-year survival rates were 17% and 12%, respectively. The presence of significant past medical history (P=0.017) and a complete pathologic response in the TM group (P < 0.001) were significant independent predictors of survival. We did not find any difference in survival between chemo-radiation or chemo-radiation followed by surgery in patients with localized carcinoma of the esophagus. Use of biologic markers and functional imaging should be explored in order to segregate patients with different tumor biology for treatment using different treatment strategies.

Mucolipidosis type IV is caused by mutations in a gene encoding a novel transient receptor potential channel

Mucolipidosis type IV (MLIV) is a developmental neurodegenerative disorder characterized by severe neurologic and ophthalmologic abnormalities. The MLIV gene, ML4 (MCOLN1), has recently been localized to chromosome 19p13.2-13.3 by genetic linkage. Here we report the cloning of a novel transient receptor potential cation channel gene and show that this gene is mutated in patients with the disorder. ML4 encodes a protein, which we propose to call mucolipin, which has six predicted transmembrane domains and is a member of the polycystin II subfamily of the Drosophila transient receptor potential gene family. The role of a potential receptor-stimulated cation channel defect in the pathogenesis of mucolipidosis IV is discussed.

Lack of differential G2 chromosomal radiosensitivity between non-tumorigenic and tumorigenic human hybrid cells (HeLa x skin fibroblasts)

Previous studies have shown, that for log phase cultures, tumorigenic segregants of HeLa x skin fibroblast human hybrid cells are slightly more radiosensitive in terms of cell killing than their nontumorigenic parents (Redpath et al. 1985, Colman et al. 1988). Other studies have shown that these same tumorigenic segregants exhibit a markedly enhanced G2 chromosomal radiosensitivity (Sanford et al. 1986) thus offering a possible explanation for the cell killing data. The present study set out to examine the G2-phase radiosensitivity of these cells in terms of cell killing with the expectation that an enhanced sensitivity in the tumorigenic cells would be seen. No enhanced sensitivity was observed. The G2 chromosomal radiosensitivity was then examined and no differential was seen between the non-tumorigenic and tumorigenic cells. This lack of confirmation of previously reported studies may be due to some technical differences in the experimental protocols.

Whole-abdominal radiotherapy for patients with minimal residual epithelial ovarian cancer

Sixteen patients with advanced epithelial ovarian cancer who were treated with cytoreductive surgery followed by multiagent chemotherapy were found to have residual tumor masses less than 2 cm in greatest diameter at reexploration and were treated with whole-abdominal radiation (19-31 Gy). Thirteen patients also received pelvic boosts to a total pelvic dose of 41-53.7 Gy. Radiotherapy was completed in all but 2 patients after treatment delays in 7 patients. Early treatment complications included myelosuppression in 11 patients, diarrhea in 3, and a self-limited small bowel obstruction in one. Delayed complications were severe and included 9 patients with radiation enterocolitis, 8 of whom required intestinal resection or diversion. One additional patient with radiation cystitis required instillation of formalin to control bleeding. Two patients are without evidence of disease 28 and 30 months following radiotherapy, while the remaining 14 patients have recurred after a median progression-free interval of 9 months (range 1-30 months). All patients who recurred failed within the treatment field and died of cancer after a median interval of 19 months following radiotherapy and 9 months after documentation of progression. These data suggest that few patients with persistent ovarian cancer following surgery and chemotherapy will be salvaged with radiotherapy.

Stage III Hodgkin's disease--long-term results following chemotherapy, radiotherapy and combined modality therapy

215 patients with stage III Hodgkin's disease (HD) were treated at the Royal Marsden Hospital between 1963 and 1985 (median follow-up 9 years). The actuarial 5- and 10-year survival was 77 and 65%, respectively with 55 and 48% 5 and 10 year disease-free survival. Of 13 variables tested, age was the only independent prognostic indicator for survival on multivariate analysis. Patients aged under 40, 40-59 and over 60 years had a 10-year survival of 76, 41 and 8%, respectively (p much less than 0.001). Ninety-one patients were initially treated with combined chemotherapy and radiotherapy (combined modality therapy, CMT), 73 patients with radiotherapy (RT) and 51 patients with chemotherapy (CT) alone. Patients under 40 years treated with CMT achieved the best disease-free survival (10 year disease-free survival: CMT 68%; RT 38%; CT 45%). The observed survival advantage for CMT was not statistically significant. In patients aged greater than 40 there was no survival or disease-free survival advantage following CMT. Analysis of recurrence pattern confirmed that CMT improves initial disease control both at previously involved and uninvolved sites. Recurrences at previously uninvolved sites continued up to 6 years following CT, up to 8 years following CMT and up to 14 years after RT alone. These results indicate that only long-term follow-up gives the true picture of stage III HD.

Suppression of the radiation-induced expression of a tumor-associated antigen in human cell hybrids by the protease inhibitor antipain

The effect of the protease inhibitor antipain (1.25 micrograms/ml) on the radiation-induced expression of a tumor-associated antigen in human cell hybrids has been investigated. A variety of treatment protocols have been studied where antipain was present before, during and at various times post-irradiation. It was found that antipain suppressed the radiation-induced expression of the tumor-associated antigen in all treatment protocols. The most effective suppression was obtained in those protocols where the protease inhibitor was present for the first 4 h post-irradiation. A possible explanation for this observation is that antipain may inhibit an error-prone DNA repair process. However, it is clear that this is not the only mechanism whereby the inhibitor can exert its effect since suppression was obtained even when antipain was added 10 days post-irradiation, a time when any DNA repair processes would be expected to be over.

Treatment of advanced and recurrent squamous carcinoma of the uterine cervix with constant intraarterial infusion of cisplatin

Twelve patients with primary or locally recurrent squamous carcinoma of the cervix were treated with constant internal iliac artery infusion of cisplatin (CDDP) via a totally implantable chemotherapy pump. Seven previously untreated patients received standard external and interstitial radiotherapy (RT) in conjunction with CDDP infusion. Five patients with isolated pelvic recurrences received CDDP therapy only. The chemotherapy pump was refilled weekly on an outpatient basis. All nine evaluable patients developed unilateral or bilateral lower extremity pain which responded to dosage reduction. No renal or marrow toxicity was seen. Both of the evaluable patients treated for recurrent tumor died 32 and 60 weeks after initiation of treatment. The seven patients treated primarily with RT + CDDP infusion include one who expired with persistent tumor and one with no evidence of disease (NED) after exenteration for a pelvic recurrence at 48 and 85 weeks respectively. The five remaining patients are NED at 12 to 60 weeks. Constant internal iliac artery infusion of CDDP via an implantable chemotherapy pump can be performed with acceptable toxicity. The preliminary results suggest that further study in previously untreated undergoing concurrent radiotherapy is warranted.

A comparison of the radiation sensitivities of non-tumorigenic and tumorigenic human hybrid cell lines

The radiation sensitivities of two related non-tumorigenic and two related tumorigenic human hybrid cell lines (HeLa x skin fibroblast) have been studied. The data show that the transformation from the non-tumorigenic to the tumorigenic state, which is accompanied by the loss of skin fibroblast chromosomes 11 and 14, is not associated with any major changes in radiation sensitivity. The data do indicate, however, a trend toward a steeper and longer initial slope to the cell survival curve for the tumorigenic cell lines, along with a subsequent reduced ability to accumulate sublethal radiation injury at low doses. Both nontumorigenic and tumorigenic cell lines have the capability of repairing sublethal injury.

Further studies on the radiation-induced expression of a tumor-specific antigen in human cell hybrids

The neoplastic transformation of human cell hybrids (HeLa x skin fibroblasts) is accompanied by the expression of a cell surface protein for which monoclonal antibodies have been raised. The gamma-radiation-induced neoplastic transformation of these cells has been studied where the expression of this cell surface protein, as detected by immunoperoxidase staining, has been used as an end point. The yield of foci of positively staining cells has been shown to increase with increasing time postirradiation at which the assay is done and decrease with increasing density of viable cells plated postirradiation. The time of plating postirradiation is also an important parameter with transformation frequencies increasing over the first 6 h of postirradiation holding at confluence, followed by a gradual decrease.

Second malignancies and Hodgkin's disease--the Royal Marsden Hospital experience

The frequency of secondary malignant neoplasms occurring in patients treated for Hodgkin's disease at the Royal Marsden Hospital between 1963 and 1978 is reported and the literature is reviewed. 730 patients were reviewed and 583 patients permanently resident in the United Kingdom were included in the analysis. The frequency of leukaemia and solid tumors was determined from age- and sex-corrected data from the South Thames Cancer Registry. Thirty-seven malignancies were recorded in 36 patients including 9 leukaemias, 10 lung cancers, 6 skin cancers and 2 non-Hodgkin's lymphoma, all of which were observed in significant excess. When all remaining sites are combined, there was a slight excess but no one site is individually significant.

Neoplastic transformation of human hybrid cells by gamma radiation: a quantitative assay

Human skin fibroblasts are extremely refractory to neoplastic transformation by ionizing radiation [C. Borek, Nature 283, 776-778 (1980); M. Namba, H. Nishitani, and T. Kimoto, J. Exp. Med. 48, 303-311 (1978)] and are therefore unsuitable for quantitative studies of dose-effect relationships. We show here that a nontumorigenic human hybrid cell line (HeLa X skin fibroblast) can be neoplastically transformed by treatment with gamma radiation. Furthermore, a dose-response relationship has been established. We propose that this human hybrid cell line may be a useful system for mechanistic studies of transformation from the preneoplastic to the neoplastic state by ionizing radiation and other agents.

An analysis of prognostic factors in early stage Hodgkin's disease

An analysis of prognostic factors has been carried out in 398 patients presenting with clinical Stage I and II Hodgkin's disease treated between 1963 and 1979. By life table analysis older age, lymphocyte depletion histology, systemic symptoms, mediastinal node bulk, and erythrocyte sedimentation rate (ESR) greater than 40 mm/h were associated with a significantly worse survival probability. On multiple factor regression analysis only age and stage were independent prognostic variables for survival, with systemic symptoms having borderline significance. Using this information, together with other analyses of prognosis in early Hodgkin's disease three groups of patients are defined. The first with a predicted 5-year survival of 78% would include patients possessing at least one of the following features; age greater than 60, lymphocyte depletion, greater than 3 sites involved, systemic symptoms, mediastinal/thoracic ratio of greater than 1/3. The second groups present with at least two of the following factors; ESR greater than 40 mm/h, male sex, 3 involved sites, or mixed cellularity histology, and the 5 year survival probability is 84%. The remaining Stage I and II patients would constitute a good prognosis group with a predicted 5-year survival of 92%.

Repair of potentially lethal radiation damage in confluent and non-confluent cultures of human hybrid cells

The repair of potentially lethal damage (PLDR) in a gamma-irradiated human hybrid cell line (skin fibroblast X HeLa) and its tumourigenic segregant has been studied as a function of cell density at the time of irradiation and during the postirradiation repair period. The data show that PLDR occurs in both non-confluent and confluent cultures of both cell lines. Furthermore, there is evidence that the extent of PLDR is dependent on cell density and that cell-cell contact may be an important factor in this regard.

Radiobiological studies of human hybrid cells (skin fibroblasts X HeLa) and their tumourigenic segregants

Data are presented on the survival characteristics following gamma-irradiation of a human hybrid cell line (skin fibroblasts X HeLa), and its tumourigenic segregant, which indicate that transition from the non-tumourigenic to the tumourigenic state is associated with a decrease in the ability to accumulate and repair sublethal damage. Previous studies have demonstrated that this transition to the tumourigenic state is also associated with loss of specific chromosomes (one copy each of chromosomes 11 and 14). It is suggested that this loss of chromosomes may account for the change in radiosensitivity.

Computed tomography in medial maxilla-orbital fractures

The frontal process of the maxilla together with the anterior wall of the antrum constitute a major support of the midface. If this is fractured and goes unrecognized, serious facial deformities result. Fractures through this process occurred in 13 of 50 patients who received computed tomographic examination for facial trauma. The fracture had been missed on plain film examination in all but three of the 13 patients. The frontal process is usually displaced directly posteriorly in the more complex midface fractures. It may rotate about its long axis when associated with trimalar fractures and in some of the isolated injuries of the medial maxilla. Computed tomography is the ideal technique for demonstrating these fractures because of ease of examination, optimal anatomical display for demonstrating rotational and posterior displacements, and superior contrast in the severely traumatized facial skeleton.

Verrucous carcinoma of the frontal sinus: a case report and review of the literature

Carcinoma of the frontal sinus is rare. Treatment is controversial, and prognosis is poor, The etiology is unknown, although some risk factors for other paranasal sinus carcinomas have been identified. A 70-year-old male presented with proptosis and x-ray findings consistent with a mucocele of the frontal sinus. At operation the patient was felt to have a cholesteatoma. Pathologic diagnosis was verrucous carcinoma of the frontal sinus. The case is discussed and the literature is reviewed.

Modification of the radiation response of mouse lung by actinomycin D: dependence on interval between radiation and drug treatments

Actinomycin D (0.6 mg/kg, i.p.) enhances the radiation response of mouse lung. The degree of enhancement varies inversely with the interval between radiation and drug treatments. The kinetics of the loss of interaction of the drug with radiation damage is similar to that observed for "slow repair" of radiation injury to the lung.

Repair of subglottic stenosis with a free perichondrial graft

Previous work with dogs has shown that a free perichondrial graft will predictably produce new cartilage when placed in the trachea. In the absence of a wound infection, the production of cartilage was predictable although the amount of cartilage varied. The present study sought to determine if enough cartilage could be produced to correct an acquired subglottic stenosis. In all dogs in whom a wound infection did not occur, enough cartilage was produced to support and maintain the subglottic lumen.

Angiolymphoid hyperplasia with eosinophilia of the external ear canal

Angioblastic lymphoid hyperplasia with eosinophilia, or Kimura's disease, is a clinically and histopathologically recognized entity that is characterized by cutaneous nodules, proliferating blood vessels with atypical histiocyte-like endothelial cells, and numerous eosinophils. It has been treated with steroids and by surgical excision, irradiation, cryotherapy, and electrodesiccation. Persistent residual disease and local recurrence are frequent. We review the literature and report two cases that involve the ear. We present the histopathologic and clinical results of laser removal of a conchal and external canal lesion.

The effect of adriamycin on repair of sublethal damage and slow repair in irradiated mouse lung

The interaction of Adriamycin with radiation damage in the mouse lung has been shown to disappear with the same kinetics as those for the 'slow repair' of such radiation damage. Split-dose experiments have demonstrated that Adriamycin inhibits this 'slow-repair' process whereas the drug has no effect on the repair of sublethal damage in irradiated mouse lung.

A comparative study of the effect of adriamycin on the sensitivity of mice to whole-body irradiation with 6-MVp photons or fast neutrons (67 MeV p--Be)

The effect of Adriamycin (doxorubicin hydrochloride) (10 mg/kg intraperitoneally) on the response of mouse gut to irradiation with 6-MVp photons or fast neutrons (67 MeV p--Be), was assessed with the six-day death endpoint. The drug reduced the LD50/6 by the same factor (approximately 1.25) for both types of radiation. Thus, the radiobiological effectiveness (RBE) (photons/neutrons) for gut damage is unaltered by the addition of Adriamycin. The data indicated no significant effect of drug scheduling if given within 16 hours before or after irradiation.

Stomal recurrence following laryngectomy: a critical evaluation

Recurrent tumor in or around the tracheal stoma following laryngectomy almost always terminates in a fatal outcome. Several investigators have attempted to determine the factors that predispose a patient to stomal recurrence, but their conclusions are not entirely in agreement. The records of 251 consecutive laryngectomy patients treated at the UCLA Hospital between 1955 and 1977 were reviewed. The variables evaluated included type of operation, preoperative tracheostomy, interval from operation to recurrence, presence of neck metastases, performance of thyroidectomy, site of lesion, and control of tumor margins. While certain events, such as preoperative tracheostomy, appeared more frequently than others in the stomal recurrence patients, no single factor or group of factors could explain all the recurrences. It appears that stomal recurrences arise from heterogeneous causes. Good planning and utilization of the principles outlined should reduce the incidence of this dreaded complication.