Return to Play Following Achilles Tendon Rupture in NFL Players Based on Position

BACKGROUND

The purpose of this study was to determine the return-to-play (RTP) rate and postinjury performance after Achilles tendon (AT) ruptures in National Football League (NFL) skill position players.

METHODS

The study included NFL skill positions with an AT rupture between the 2009-2010 and 2015-2016 seasons. Performance data were collected and compared against a matched control group. RTP was defined as playing in at least 1 game after repair.

RESULTS

RTP rate was 57% for the study cohort. The tight ends (TEs) had the highest RTP rate at 71% while the wide receivers (WRs) had the lowest RTP rate at 38%. Compared with the control group, WRs with successful RTP had significantly less receptions per game (P = .01). For defensive players with RTP there were significant decreases in postrepair performance in tackles, passes defended, and fumbles forced/recovered compared with the control group.

CONCLUSION

A total of 57% of players achieved RTP with WRs and running backs (RBs) having the lowest RTP rates and TEs and linebackers (LBs) having the highest RTP rates. RBs, defensive backs (DBs), and LBs with successful RTP had decreased performance in all categories. This updated information may be helpful for athletes, physicians, scouts, and coaches in evaluating players with a history of AT rupture.

LEVELS OF EVIDENCE

Analytic, level 3, retrospective cohort study, Epidemiologic study.

Point-of-care Ultrasound to Evaluate Breast Pathology in the Emergency Department

Introduction

As physician-performed point-of-care ultrasound (POCUS) becomes more prevalent in the evaluation of patients presenting with various complaints in the emergency department (ED), one application that is significantly less used is breast ultrasound. This study evaluates the utility of POCUS for the assessment of patients with breast complaints who present to the ED and the impact of POCUS on medical decision-making and patient management in the ED.

Methods

This was a retrospective review of ED patients presenting with breast symptoms who received a POCUS examination. An ED POCUS database was reviewed for breast POCUS examinations. We then reviewed electronic health records for demographic characteristics, history, physical examination findings, ED course, additional imaging studies, and impact of the POCUS study on patient care and disposition.

Results

We included a total of 40 subjects (36 females, 4 males) in the final analysis. Most common presenting symptoms were breast pain (57.5%) and a palpable mass (37.5%). “Cobblestoning,” ie, dense bumpy appearance, was the most common finding on breast POCUS, seen in 50% of the patients. Simple fluid collections were found in 37.5% of patients.

Conclusion

Our study findings illustrate the utility of POCUS in the evaluation of a variety of breast complaints in the ED.

Handheld Ultrasound: Overcoming the Challenge of Difficult Peripheral Intravenous Access in the Emergency Department

OBJECTIVES

The purpose of this study was to evaluate the performance of a handheld ultrasound device for difficult peripheral intravenous (PIV) access performed by nurses and paramedics in the emergency department (ED).

METHODS

This was a retrospective review at an academic medical center. Participants were ED nurses and paramedics with competence in ultrasound-guided PIV placement. Participants were asked to log their use of the handheld device when used on patients deemed to have "difficult" access and complete a questionnaire, which consisted of items related to the effectiveness and ease of use of the device. Data were collected over the course of 1 year. An electronic medical record review was performed to track the success rates and the occurrence of any associated complications throughout the hospital stay.

RESULTS

Nurses and paramedics logged a total of 483 cases in which PIV access was attempted with the handheld ultrasound device. Ninety-two percent (95% confidence interval [CI], 89%-94%) of the ultrasound-guided PIV lines attempted were placed successfully. Eighty-four percent (95% CI, 80%-87%) of the lines were placed successfully on the first attempt. In most cases (396 of 483 [82%]), no complications associated with the PIV occurred. A total of 429 questionnaires were completed over the study period. Most of the operators (84%; 95% CI, 80%-87%) stated that the handheld device was adequate to perform ultrasound-guided PIV access.

CONCLUSIONS

The handheld ultrasound device performed well in terms of usability and reliability for PIV access.

The Fundamental Characteristics and Unique Outcomes of Christian Summer Camp Experiences

Very little research is available on the unique characteristics and outcomes of Christian summer camps, in spite of their prevalence in the industry. The Effective Camp Research Project is a mixed-methods study seeking to close the research gap. This article presents the major findings of the study, detailing the emergence of a distinct Christian camp model with five fundamental characteristics: relational, safe space, participatory, unplugged from home, and faith-centered. A multi-test survey of campers provides compelling evidence for outcomes that are immediate, subsequent, and lasting. Some of these outcomes are common to all camp types, though many are unique to the contextual realities of Christian camps that effectively partner with the ministries of churches and homes. Camper outcomes identified in other studies are interpreted theologically in the context of Christian camps, providing particular relevance to faith communities and people of faith.

Abstract P2-02-02: Clinical significance of TP53 mosaic mutations uncovered in constitutional genetic testing

Background: Mosaic findings (mutations outside of the expected 50:50 allele ratio) are often detected in the course of routine constitutional genetic testing due to the high sensitivity of next-generation sequencing (NGS) technologies. The significance of these findings is however often unclear. They can result from constitutional mosaicism secondary to an early embryological event, an acquired somatic mutation in hematopoietic cells, a technical artifact, or (less likely) a reversion event. Studies have shown that clonal hematopoiesis increases with age, seen in up to 10% and 25% of individuals 65 and 90 years of age, respectively. Additional studies have demonstrated expansion of TP53 mutations in peripheral blood cells following chemotherapy administration. We therefore wanted to investigate the potential clinical significance of mosaic mutations found in the peripheral blood in samples submitted for hereditary cancer testing with a focus on TP53.

Methods: We examined high-depth NGS data from blood cell-derived DNA for mutations with pathogenic potential suggestive of mosaicism (5-30% allele frequency) in known hereditary cancer genes. For each gene, we determined the average ages of patients tested and compared these distributions to the distribution of ages of patients found to have mosaic mutations. For the mosaic TP53 mutations, we further characterized the mutations found as well as described the clinical scenarios in which the mosaic findings occurred.

Results: To date, 101 patients were found to have possibly mosaic mutations with pathogenic potential, including 26 cases with TP53 mutations (0.07% of patients tested), 16 with CHEK2 mutations (0.05%), and 16 with ATM mutations (0.05%). Significant bias towards older ages is seen in patients with ATM (p= 0.0026) and CHEK2 (p=4.2x10-6) mosaic findings. Mosaic TP53 and NF1 mutations were also enriched in older patients , although not as significantly as CHEK2 and ATM mosaic patients. 24/25 patients with TP53 mosaic mutations with a known history were cancer affected. In the COSMIC database, 20/20 of the TP53 mosaic mutations are associated with neoplastic conditions and 13/20 are associated with hematolymphoid neoplasms. 15/20 of the pathogenic mosaic TP53 findings were seen previously in our lab at a ratio corresponding to germline, thereby significantly lessening the possibility of technical artifact.

Conclusion: The statistically significant older ages of patients with ATM and CHEK2 mosaic variants suggests that many of these are acquired changes in hematopoietic stem cells rather than constitutional mosaicism per se. Although NF1 is known to be associated with constitutional mosaicism, the bias towards older patients of the NF1 mosaics we saw similarly suggests that most are acquired changes in the hematopoietic stem cells. The less significant age bias in the TP53 events suggests that chemotherapy administration may be leading to enrichment of TP53 mutated clones, although an increased rate of constitutional mosaicism cannot be ruled out.

Citation Format: Deucher A, Lincoln S, Sorenson J. Clinical significance of TP53 mosaic mutations uncovered in constitutional genetic testing [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-02-02.

Mucopolysaccharidosis VII in a Cat Caused by 2 Adjacent Missense Mutations in the GUSB Gene

BACKGROUND

Mucopolysaccharidoses (MPS) are common lysosomal storage disorders causing typically progressive skeletal and ocular abnormalities.

OBJECTIVES

To describe the clinic features, metabolic profile and a unique mutation in a domestic shorthair (DSH) kitten with MPS VII.

ANIMALS

Affected kitten and 80 healthy cats.

METHODS

Serum lysosomal enzyme activities and urinary glycosaminoglycan (GAG) accumulation were assessed. Exons of the β-glucuronidase gene (GUSB) were sequenced from genomic DNA and genotyping was conducted.

RESULTS

A 3-month-old DSH cat was presented for stunted growth, paresis, facial dysmorphia, multiple skeletal deformities, and corneal opacities. Evaluation of blood smears disclosed metachromatic granules in leukocytes and a urinary mucopolysaccharide spot test was positive. The proband had no GUSB activity but normal or increased activities for other lysosomal enzymes. Sequencing of the GUSB gene from the proband and comparison to the sequence of 2 healthy cats and the published feline genome sequence demonstrated 2 unique single base transitions (c.1421T>G and c.1424C>T) in exon 9, altering 2 adjacent codons (p.Ser475Ala and p.Arg476Trp). These amino acid changes are in a highly conserved domain of the GUSB protein and nontolerable to maintain function. Moreover, the p.Arg476Trp mutation previously has been identified in human patients. None of the other clinically healthy cats had these mutations.

CONCLUSIONS AND CLINIC IMPORTANCE

The diagnostic approach to MPS disorders is delineated. This is only the second mutation known to cause MPS VII in cats. Similarly, 2 different mutations have been described in MPS VII dogs, thereby showing the molecular heterogeneity of MPS VII in companion animals.

Opportunities for public health genetics trainees: results of an employer/workplace survey

OBJECTIVE

To conduct the first employer/workplace survey identifying employment opportunities for graduates of programs with training in public health genetics in the USA, and to determine whether employment opportunities will increase in coming years.

METHODS

Six public health genetics training competencies were developed. A survey about workplace and employment opportunities was then conducted with mailings to (1) departments in schools of public health and departments of preventive medicine, (2) local and regional public health officials, (3) insurance companies and health management organizations (HMOs), and (4) biotechnology and pharmaceutical companies.

RESULTS

A total of 196 surveys were returned among 1,464 that were mailed. Response rates varied from 5.8 to 46.5% among the target groups. The percent of responding organizations currently employing individuals with skills in genetics ranged from 20 to 62%. The percent currently employing individuals with skills in public health ranged from 39 to 96%. Training opportunities such as internships or practicum experiences are reported for one-third of respondents. For all of the competencies, approximately half of survey respondents who rated the competency important or very important already employ individuals with public health genetics skills. Similarly, at least a quarter of survey respondents who rated the competency important or very important plan to hire individuals with that skill in the next 5 years. Overall, approximately 40% of those surveyed are planning to hire individuals with competencies in public health genetics in the next 5 years.

CONCLUSION

Employment opportunities already exist and new positions are becoming available in schools of public health and departments of preventive medicine, departments of public health, insurance companies and HMOs for professionals with public health genetics training. Based on our survey findings, skills and training in public health genetics are important in the workplace.

Retinal angiomatous proliferation in age-related macular degeneration

BACKGROUND

It is known that choroidal neovascularization (CNV) in age-related macular degeneration (ARMD) may erode through the retinal pigment epithelium, infiltrate the neurosensory retina, and communicate with the retinal circulation in what has been referred to as a retinal-choroidal anastomosis (RCA). This is extremely common in the end stage of disciform disease. In recent years, the reverse also seems to be possible, as angiomatous proliferation originates from the retina and extends posteriorly into the subretinal space, eventually communicating in some cases with choroidal new vessels. This form of neovascular ARMD, termed retinal angiomatous proliferation (RAP) in this article, can be confused with CNV.

PURPOSE

The purpose of this article is 1) to review the clinical and angiographic characteristics of a series of patients with RAP and 2) to propose a theoretical sequence of events that accounts for the neovascularized process.

METHODS

In this retrospective clinical and angiographic analysis, 143 eyes with RAP (108 patients) were reviewed and classified based on their vasogenic nature and course. Clinical biomicroscopic examination, fluorescein angiography, and indocyanine green angiography were used to evaluate patients.

RESULTS

The results of this series suggest that angiomatous proliferation within the retina is the first manifestation of the vasogenic process in this form of neovascular ARMD. Dilated retinal vessels and pre-, intra-, and subretinal hemorrhages and exudate evolve, surrounding the angiomatous proliferation as the process extends into the deep retina and subretinal space. One or more dilated compensatory retinal vessels perfuse and drain the neovascularization, sometimes forming a retinal-retinal anastomosis. Fluorescein angiography in these patients usually revealed indistinct staining simulating occult CNV. Indocyanine green angiography was useful to make an accurate diagnosis in most cases. It revealed a focal area of intense hyperfluorescence corresponding to the neovascularization ("hot spot") and other characteristic findings. Based on understanding of the nature and progression of the neovascularized process, patients with RAP were classified into three vasogenic stages. Stage I involved proliferation of intraretinal capillaries originating from the deep retinal complex (intraretinal neovascularization [IRN]). Stage II was determined by growth of the retinal vessels into the subretinal space (subretinal neovascularization [SRN]). Stage III occurred when CNV could clearly be determined clinically or angiographically. A vascularized pigment epithelial detachment and RCA were inconsistent features of this stage.

CONCLUSIONS

Retinal angiomatous proliferation appears to be a distinct subgroup of neovascular ARMD. It may present in one of three vasogenic stages: IRN, SRN, or CNV. Whereas ICG angiography is helpful in diagnosing RAP and in documenting the stage of the neovascularized process, it is frequently difficult to determine the precise nature and location of the new vessel formation. It is important for clinicians to recognize the vasogenic potential and the associated manifestations of this peculiar form of neovascular ARMD so that a proper diagnosis can be made, and when possible, an appropriate management administered.

Multiple tactile maps in the human cerebellum

Functional imaging studies of the cerebellum have mostly investigated motor performance or have been limited to the anterior lobe and therefore the somatosensory representations in the human cerebellum have not been fully demonstrated. We used fMRI of the entire cerebellum during tactile stimulation of the hand and foot in six normal subjects. Our results demonstrate that the tactile projections to the cerebellum in humans are represented in both the anterior and posterior lobes. in agreement with previous functional imaging studies, our results show a large-scale, between-limb somatotopy comparable to that shown in early animal studies.

Low neutral endopeptidase levels in bronchoalveolar lavage fluid of lung cancer patients

Neutral endopeptidase (NEP) is a cell surface enzyme found in normal human lung and which hydrolyzes small bioactive peptides, some of which act as growth factors for normal and malignant airway epithelial cells. Expression of NEP varies widely in human lung tissue from different individuals. NEP is often expressed at low or undetectable levels in both small-cell and non-small-cell lung cancer, and inhibits the growth of lung cancer cell lines. Variation in the expression of NEP could be a factor in susceptibility to lung cancer. We hypothesized that NEP could be measured in bronchoalveolar lavage fluid (BALF) and that airway levels of NEP would be low in lung cancer patients as compared with normal controls. We measured NEP and total protein in cell-free BALF supernatant, and expressed the respective concentrations as a ratio. NEP levels showed wide variation in BALF of healthy volunteers. Most patients with lung cancer had no NEP detectable in BALF. The mean NEP/total protein ratio was significantly lower in patients with lung cancer (0.87 +/- 0.7 ng NEP/mg protein) than in normal healthy subjects (14.0 +/- 4.3, p < 0.0003). We conclude that NEP levels are highly variable in BALF of normal volunteers, and are low or undetectable in most BALF specimens from patients with lung cancer. Low NEP levels in the airways may be a factor in the pathogenesis of carcinoma of the lung.

Digital subtraction indocyanine green angiography of occult choroidal neovascularization

OBJECTIVE

This study aimed to use a new technique for ocular imaging, digital subtraction indocyanine green angiography (DS-ICGA), to evaluate patients with occult choroidal neovascularization (CNV).

DESIGN

The design was a cross-sectional study of patients with occult CNV.

PARTICIPANTS

A total of 31 eyes of 31 patients were studied.

INTERVENTION

Digital subtraction of sequentially acquired indocyanine green angiographic frames was used to image the progression of the dye front in eyes with occult CNV. A method of pseudocolor imaging of the choroid was developed that allows differentiation and identification of underlying choroidal arteries and veins.

RESULTS

The DS-ICGA of occult CNV showed consistent findings. Occult CNV was imaged with greater detail and in a shorter period of time than with conventional indocyanine green angiography. The fundus landmarks were retained with DS-ICGA much better than with conventional indocyanine green angiography.

CONCLUSIONS

The DS-ICGA uses time to dissect the choroidal circulation. With DS-ICGA, occult CNV could be imaged more quickly and in greater detail than with conventional imaging techniques. The DS-ICGA may improve the authors ability to image, and subsequently treat, occult CNV.

Peptide amidating activity in human bronchoalveolar lavage fluid

Monitoring respiratory epithelial biology may reveal individuals with incipient lung cancer. The expression of neuroendocrine (NE) markers in pulmonary epithelium is thought to be central to lung development, repair of injury and may contribute to carcinogenesis. In this study, we evaluate several candidate NE markers to determine the feasibility of prospective analysis of clinical specimens. The potential NE markers include the enzyme L-DOPA decarboxylase (DDC), the neuropeptide gastrin releasing peptide (GRP), and peptidyl-glycine alpha-amidating monooxygenase (PAM), the bifunctional enzyme responsible for the final bioactivation step of many neuropeptides. A comparison of PAM activity and DDC levels in 30 lung cancer cell lines indicated that peptide amidating activity may be an indicator of NE status. Bronchoalveolar lavage (BAL) fluid from subjects at risk of developing second primary lung cancer and from volunteers was obtained. The activity of the first PAM enzyme, peptidylglycine alpha-hydroxylating monooxygenase (PHM), ranged from not detectable to 507 pmol/h/mg protein in 57 specimens. The second PAM enzyme, peptidylamidoglycolate lyase (PAL), ranged from not detectable to 414 pmol/h/mg protein in 56 specimens. Using cluster analysis by the average linkage method, a group of enzyme values with PHM greater than 230 pmol/h/mg protein was determined. Long-term follow-up of these patients for new second primary lung cancers may help to determine the potential predictive value of PAM detected in the BAL fluid.

National assessment of physicians' breast-feeding knowledge, attitudes, training, and experience

OBJECTIVE

Previous reports have demonstrated that physician counseling can improve rates of breast-feeding initiation and duration but suggest that physicians are ill-prepared for this role. It is unclear whether residency training for pediatricians, obstetrician/gynecologists, and family physicians provides the knowledge and skills necessary for effective breast-feeding promotion.

DESIGN

Survey.

PARTICIPANTS

A national random sample of 3115 residents and 1920 practicing physicians in pediatrics, obstetrics/gynecology, and family medicine.

OUTCOMES

Assessment of breast-feeding knowledge, attitudes, training, and experience.

RESULTS

Overall response rate was 68%. All groups demonstrated significant deficits in knowledge of breast-feeding benefits and clinical management; for example, less than 50% of residents chose appropriate clinical management for a breast-fed jaundiced infant or a breast abscess. Practicing physicians performed slightly better, but still more than 30% chose incorrect advice for mothers with low milk supply. Residents reported that their breast-feeding instruction consisted mainly of didactic lecture, not patient experience. Only 55% of senior residents recalled even one instance of precepting related to breast-feeding, and less than 20% had demonstrated breast-feeding techniques at least five times during residency. Regarding preparation for breast-feeding counseling, more than 50% of all practicing physicians rated their residency training as inadequate. Overall, physician involvement in breast-feeding promotion was endorsed by 90% of respondents, yet only half rated themselves as effective in counseling breast-feeding patients. The greatest predictor of physician self-confidence was previous personal or spousal breast-feeding experience.

CONCLUSIONS

In this national sample of residents and practicing physicians in three specialties, physicians were ill-prepared to counsel breast-feeding mothers. Deliberate efforts must be made to incorporate clinically based breast-feeding training into residency programs and continuing education workshops to better prepare physicians for their role in breast-feeding promotion.

Indocyanine green videoangiography of idiopathic polypoidal choroidal vasculopathy

PURPOSE

To identify the precise choroidal abnormalities associated with idiopathic polypoidal choroidal vasculopathy (IPCV), patients with IPCV were examined with indocyanine green (ICG) videoangiography.

METHODS

Twelve patients with IPCV were examined using standard clinical, fluorescein, and ICG videoangiographic techniques.

RESULTS

Indocyanine green videoangiography showed two basic choroidal vascular changes: a branching network of vessels in the inner choroid, and vascular dilations at the border of the network of vessels. The vascular dilations appeared to be associated with the exudative and hemorrhagic manifestations of IPCV.

CONCLUSION

The choroidal vasculopathy seen in IPCV is distinct from the changes seen in other choroidal abnormalities. Recognition of these changes aids in diagnosis and patient management, since the clinical implications of IPCV differ from those of other similar entities.

The effects of carbamazepine on stuttering

No pharmacological treatment protocol has proven generally useful for all patients who stutter. Various medications, behavior therapy, relaxation, suggestion, and social-based therapies have been used. For this drug treatment study, two groups of adult stutterers were followed in an 8-week open label protocol. All subjects had in the past received speech therapy; none had been treated previously with medication for stuttering. The first group (N = 12) received a maximum dose of 800 mg of carbamazepine; the second group (N = 8) received a maximum dose of 400 mg of carbamazepine. Each patient served as his or her own control. A series of systematic speech tests was given weekly to determine the variability of fluency for each subject. A statistically significant change occurred for a number of "expectancy to stutter" characteristics. Subjects felt that they stuttered less often while taking carbamazepine. Subjective effects began before medication and continued after patients discontinued the medication. Struggle characteristics also subjectively decreased. However, no objective improvement was found. No change was found in percentage of words stuttered, reading improvement, or improvement in spontaneous speech rate. Interrater reliability showed a correlation of .996. Three carbamazepine serum level therapeutic windows were inspected with negative results. Interestingly, naive listener ratings did show a statistically significant improvement on carbamazepine versus placebo. Future anecdotal reports of pharmacological improvement of stuttering should be subjected to rigorous objective testing before general acceptance.

Glioblastoma multiforme: MR imaging at 1.5 and 9.4 T after injection of polylysine-DTPA-Gd in rats

Polylysine-DTPA-Gd, a new MR contrast agent, was injected into the aorta of rats 7 days after C6 glioblastoma was implanted in their brains; MR imaging was performed 3 days later. The imaging was done at two field strengths: (1) 1.5 T with a 3-mm slice thickness and in-plane resolutions of 600 microns and (2) 9.4 T with a 125- or 500-microns slice thickness and in-plane resolutions of 95 microns. In animals injected with polylysine-DTPA-Gd (1 microgram or more per rat), the T1-weighted images and mixed T1, T2 images of the C6 glioblastoma revealed a higher signal intensity at the marginal region between tumor and normal brain than that seen in surrounding normal brain. The central tumor region had a low signal intensity. The concentration of Gd in the C6 glioblastoma, after injection of 1 microgram polylysine-DTPA-Gd per rat, was calculated to be 0.14 mumol/l. The central tumor region also had a low signal intensity in animals that were not injected with the contrast agent, but the margin between tumor and normal brain was resolved poorly, if at all. The polylysine-DTPA-Gd revealed the microvasculature of the C6 glioblastoma in the 125-micron-thick slices obtained at 9.4 T. This is the first study to reveal the utility of the 9.4-T MR imager for examination of glioblastomas in situ and to demonstrate the utility of polylysine-DTPA-Gd as a contrast agent for the definition of the margin between glioblastoma and normal brain tissue.

Comparison of speed of sound and ultrasound attenuation in the os calcis to bone density of the radius, femur and lumbar spine

Broadband ultrasonic attenuation (BUA) between 0.1 and 0.6 MHz and speed of sound (SOS) were measured on the os calcis in normal women (n = 40), and women who had mild osteoporosis (n = 36). Comparisons were made between the ultrasonic properties and bone mineral densities (BMD) obtained using photon absorptiometry on the lumbar spine, proximal femur and radius shaft. In the osteoporotic women, whose spine BMD was significantly reduced, BUA and SOS were lower, to about the same degree of significance as radius BMD; ROC analysis demonstrated that for discrimination of spinal osteopenia, the area under the ROC curve was similar for radius BMD, SOS, and BUA. There was a modest correlation (r about 0.65) between either SOS or BUA on the os calcis and BMDs of the spine and radius. Correlations of the SOS and BUA with femoral neck BMD were lower (r about 0.4 to 0.5). The standard error of estimate for both spine and femoral neck BMD was too high (about 0.14 g cm-2) for os calcis measurements to be substituted clinically for densitometry at these fracture sites.

Chromosome changes in a patient achieving complete remission in the acute phase of chronic myelogenous leukemia

A patient with chronic myelogenous leukemia (CML) had a Philadelphia chromosome (Ph') [t(9q+;22q-)] in all cells and trisomy C in 13% of cells (later determined to be trisomy 8) at the time of diagnosis. After 21 months of intermittent treatment with busulfan, the acute phase developed with the appearance of an additional abnormality (trisomy ? 19). During a complete remission and reconversion to the chronic phase, trisomies 8 and ? 19 DISAPPEARed, although the Ph' remained. Following a period of marked thrombocytosis, a second relapse occurred with the reappearance of both marker chromosomes.

Cell loss from three established lines of the C3H mouse mammary tumor: a comparison of the 125I-UdR and the 3H-TdR-autoradiographic methods

The 125I-UdR method for measuring cell loss from solid tumors has been reevaluated. The rate of tumor cell loss from three established lines (S 102F, S102S and Slow) of the C3H mouse mammary tumor was determined by the 125I-UdR method and the results were compared to the estimates for cell loss as determined by the combined approach of cellular 3H-TdR autoradiography and volumetric growth-rate determinations. This detailed comparison shows that the two methods complement each other but cannot substitute for one another because they give different quantitative information. The combined approach measures the flow of viable cells, as determined morphologically, from the proliferating compartment to the quiescent comparment, the quiescent compartment out of the tumor, etc., but does not evaluate the flow of degenerate cells or acellular (necrotic) debris. In contrast, the 125I-UdR method indicates the net flow of intact cells and/or dead cells as well as debris from the tumor as the 125I-labeled material is lost from the tumor, but gives limited internal information. thus, depending on the specific experiment, an investigator could choose one or the other of the methods to answer the question. Perhaps both would be desirable at times; however, in most cases, one could not substitute one method for the other. The data from the Slow tumors also indicate that in certain tumors, the quantitative information from the 125I-UdR method may be quite limited, i.e. the confidence limits within an experiment as well as the replication error between experiments may be high.