Christiana Drake

Anatomic disorders of the temporomandibular joint disc in asymptomatic subjects

PURPOSE This study determined the prevalence and specific anatomic types of disc displacement in asymptomatic versus symptomatic subjects using magnetic resonance imaging (MRI). PATIENTS AND METHODS A detailed MRI assessment was performed on both temporomandibular joints (TMJ) in 76 volunteers and 102 successive patients. Attention was placed on the functional aspects of disc displacement with and without reduction and on the anatomic aspects of disc displacement in the anterior, lateral, medial, anterolateral, and anteromedial directions. These assessments were made by radiologists blinded to the clinical information. RESULTS Disc displacement was found in at least one joint in 25 of 76 (33%) of asymptomatic subjects and 79 of 102 (77%) of symptomatic subjects. The anatomic types of disc displacement between groups was not statistically significant (P = .55). However, there was a significant difference between asymptomatic and symptomatic subjects, with an odds ratio of 3.91 for disc displacement with reduction and 42.71 for disc displacement without reduction (P < .001). CONCLUSION Although there was a 33% prevalence of disc displacement in asymptomatic volunteers, there was a highly significant difference in the prevalence of internal derangement in symptomatic subjects. Bruxing was statistically linked to TMJ disc displacement and could explain the anatomic variation in abnormal disc position.

Effects of misspecification of the propensity score on estimators of treatment effect

A comparison was carried out between the propensity score and prognostic models in estimating treatment effects from observational studies. One issue investigated was the effect of estimating the propensity score on estimators of treatment effect. A second question addressed comparisons of the propensity score and prognostic approach when a confounder is omitted. Third, misspecifications of the propensity score were compared to messpecified response models. In all cases there were two types of models, one involving a continuous and one a binary response.

Mortality among Recent Purchasers of Handguns

BACKGROUND There continues to be considerable controversy over whether ownership of a handgun increases or decreases the risk of violent death. METHODS We conducted a population-based cohort study to compare mortality among 238,292 persons who purchased a handgun in California in 1991 with that in the general adult population of the state. The observation period began with the date of handgun purchase (15 days after the purchase application) and ended on December 31, 1996. The standardized mortality ratio (the ratio of the number of deaths among handgun purchasers to the number expected on the basis of age- and sex-specific rates among adults in California) was the principal outcome measure. RESULTS In the first year after the purchase of a handgun, suicide was the leading cause of death among handgun purchasers, accounting for 24.5 percent of all deaths and 51.9 percent of deaths among women 21 to 44 years old. The increased risk of suicide by any method among handgun purchasers (standardized mortality ratio, 4.31) was attributable entirely to an excess risk of suicide with a firearm (standardized mortality ratio, 7.12). In the first week after the purchase of a handgun, the rate of suicide by means of firearms among purchasers (644 per 100,000 person-years) was 57 times as high as the adjusted rate in the general population. Mortality from all causes during the first year after the purchase of a handgun was greater than expected for women (standardized mortality ratio, 1.09), and the entire increase was attributable to the excess number of suicides by means of a firearm. As compared with the general population, handgun purchasers remained at increased risk for suicide by firearm over the study period of up to six years, and the excess risk among women in this cohort (standardized mortality ratio, 15.50) remained greater than that among men (standardized mortality ratio, 3.23). The risk of death by homicide with a firearm was elevated among women (standardized mortality ratio at one year, 2.20; at six years, 2.01) but low among men (standardized mortality ratio at one year, 0.84; at six years, 0.79). CONCLUSIONS The purchase of a handgun is associated with a substantial increase in the risk of suicide by firearm and by any method; the increase in the risk of suicide by firearm is apparent within a week after the purchase of a handgun. The magnitude of the increase and the relation between handgun purchase and the risk of death by homicide differ between men and women.

Orthodontics and temporomandibular joint internal derangement

The purpose of this investigation is to compare the prevalence of internal derangement of the temporomandibular joints (TMJ) in asymptomatic volunteers versus symptomatic subjects using magnetic resonance imaging (MRI), with a detailed comparison to clinical signs and symptoms and with attention to a prior history of orthodontic treatment. Bilateral MRI scans were obtained of the TMJs in 76 asymptomatic volunteers and 102 symptomatic patients. A comparison was made to the clinical signs and symptoms, a history of orthodontic treatment, and to the MR findings. The MRI scans were reviewed using established criteria for disk displacement and the reviewers were blinded as to the clinical information. Our results show a prevalence of disk displacement in 25 of 76 (33%) volunteers and 79 of 102 (77%) patients with a statistically significant difference (p < 0.001). No statistical link was noted between a history of prior orthodontic treatment and internal derangement of the TMJ.

Risk Factors for First‐Time Homelessness in Low‐Income Women

Determinants of first-time homelessness were evaluated in Sacramento, California and Lehigh Valley, Pennsylvania. First-time homeless women had more cumulative risks for homelessness than low-income never-homeless women, even with the putative advantage of higher levels of education. Solutions to homelessness should address more than one dimension of risk.

Indirect computed tomography lymphography using iodinated nanoparticles to detect cancerous lymph nodes in a cutaneous melanoma model

RATIONALE AND OBJECTIVES To evaluate differences in contrast uptake in normal and cancerous lymph nodes on indirect computed tomography (CT) in swine, we conducted lymphographic examinations after subcutaneous injection of a lymphotropic iodinated nanoparticle suspension. METHODS Perilesional subcutaneous contrast injections (2 ml per lesion) of a 15% wt/vol iodinated nanoparticle suspension were made in immature Sinclair miniature swine (n = 5) with cutaneous melanomas. Average attenuation, iodine concentration, node volume, and total iodine uptake were estimated on the CT scans for each opacified lymph node 24 hr after injection. Nodes were classified as normal or cancerous microscopically, and the percentage of tumor replacement was estimated in cancerous nodes. RESULTS Average attenuation and iodine concentration were higher in normal nodes, and total iodine uptake was higher in cancerous nodes with greater than 25% replacement (p < .05). Architectural alterations in opacified cancerous nodes included medullary filling defects, expansile cortical lesions, and disruption of corticomedullary junctions. CONCLUSION Quantitative and qualitative differences in iodinated nanoparticle enhancement characteristics are useful in distinguishing between normal and cancerous lymph nodes on indirect CT lymphography examinations.

Evaluation of meniscal tears: Fast spin-echo versus conventional spin-echo magnetic resonance imaging

RATIONALE AND OBJECTIVES We compared the performance of fast spin-echo (FSE) with conventional spin-echo (CSE) magnetic resonance (MR) imaging sequences in the detection of meniscal tears. METHODS Seventy-three patients underwent MR examination of the knee for suspected internal derangement. Each patient was scanned with a CSE sequence and one of two FSE sequences. The primary difference between the two FSE sequences consisted of the echo train length (ETL). Thirty-seven patients (group 1) were scanned with the FSE I sequence (ETL = 8), and 36 patients (group 2) were scanned with the FSE II sequence (ETL = 4). Menisci were graded as torn or not torn on the basis of their MR appearance. The sequences were compared with each other and with the surgical findings in 31 patients who underwent arthroscopy. RESULTS In group 1, there was a significant discrepancy between the CSE and FSE I techniques (p = .006). The FSE I sequence detected only 11 of 19 surgically proven torn menisci as opposed to 18 of 19 detected with the CSE sequence. The FSE II sequence performed significantly better in group 2, with an accuracy equal to that of the CSE sequence. CONCLUSION FSE sequences are extremely technique dependent with regard to detecting meniscal tears and should not replace CSE sequences in this setting until further studies are performed to optimize the technique.

Iodinated nanoparticles for indirect computed tomography lymphography of the craniocervical and thoracic lymph nodes in normal dogs.

RATIONALE AND OBJECTIVES We evaluated the imaging characteristics of an interstitially or intraperitoneally delivered iodinated particulate contrast agent for computed tomography (CT) lymphography of the craniocervical and thoracic lymph nodes. METHODS We injected 2-4 ml of 15% wt/vol iodinated nanoparticle suspension subcutaneously, submucosally, or intraperitoneally in eight normal dogs. CT and plain radiographic images were obtained prior to contrast administration and 4 hr, 24 hr, and 7 days after injection. Correlation was made to detailed postmortem assessment. RESULTS CT images showed enhancement of regional nodes draining injection sites. Mean attenuation of opacified nodes was 313 +/- 297 (mean +/- standard deviation), 536 +/- 453, and 492 +/- 372 Hounsfield units at 4 hr, 24 hr, and 7 days postinjection, respectively. Lymph node opacification on CT images correlated well with node location found at postmortem. CONCLUSION Craniocervical and thoracic lymph nodes can be effectively opacified from interstitial or intraperitoneal delivery of this iodinated nanoparticulate contrast agent.

Quality-of-life and surgical treatments for rectal cancer—a longitudinal analysis using the California Cancer Registry

Background: Heterogeneous results for research investigating health‐related quality of life (HRQL) in patients undergoing sphincter‐ablating procedures for rectal cancer are likely due to single institution experiences and measurement of HRQL. To address this heterogeneity, we evaluated HRQL in patients with rectal cancer by type of surgery, location of tumor, and receipt of adjuvant therapy using an HRQL instrument that has not been used to address rectal cancer patients in a population‐based sample over time.

Intakes and breast-milk concentrations of essential fatty acids are low among Bangladeshi women with 24–48-month-old children

Maternal fat intake and adipose reserves are major sources of PUFA during lactation. The present study examined the cross-sectional relationship between prolonged breast-feeding and maternal BMI, assessed adequacy of fat intake among lactating and non-lactating mothers of children 24-48 months of age and determined breast-milk fatty acid composition. Multi-stage sampling was used to select a representative sample of mothers from two rural districts in Bangladesh (n 474). Dietary data were collected during two non-consecutive 24 h periods via 12 h in-home daytime observations and recall. The National Cancer Institute method for episodically consumed foods was used to estimate usual intake distributions. Breast milk samples were collected from ninety-eight women, and breast-milk fatty acid methyl esters were quantified using GC. Approximately 42 % of lactating v. 26 % of non-lactating mothers were underweight (BMI < 18·5 kg/m2; P = 0·0003). The maternal diet was low in total fat (approximately 8 % of mean total energy) and food sources of PUFA, including oil and animal source foods, resulting in a low estimated mean total consumption of PUFA (5·1 g/d). Almost all women were estimated to consume less than the recommended intake levels for total fat, total PUFA, α-linolenic acid (ALA) and DHA. Median breast-milk linoleic acid (8·5 % weight) and ALA (0·2 %) concentrations were among the lowest reported in the literature, in contrast with arachidonic acid (0·5 %) and DHA (0·3 %) concentrations, which were mid-range. Bangladeshi women in general, and especially those who practise prolonged breast-feeding, may benefit from increased consumption of food sources of PUFA.