Chronic pain in the dental patient

This article reviews the pathophysiology and mediators of pain, and addresses the different subtypes of dental pain. An overview of pharmacotherapy is presented. Contributing factors to chronic pain syndromes are reviewed. Alternative methods of pain management are discussed.

Acute lymphoblastic leukemia with multiple cytogenetic abnormalities secondary to treatment of Ewing's sarcoma

We report the case of a 22-year-old man with Ewing's sarcoma who attained a complete remission (CR) after combination radiotherapy and chemotherapy. Secondary acute lymphoblastic leukemia with multiple cytogenetic abnormalities involving chromosome 5 and 7 developed 16 years later. The patient underwent induction chemotherapy and entered a CR. Peripheral blood stem cell transplantation from a matched sibling was performed successfully and he is in complete remission of both ALL and Ewing's sarcoma.

Time course of word identification and semantic integration in spoken language

The minimum duration signal necessary to identify a set of spoken words was established by the gating technique; most words could be identified before their acoustic offset. Gated words were used as congruous and incongruous sentence completions, and isolation points established in the gating experiment were compared with the time course of semantic integration evident in event-related brain potentials. Differential N400 responses to contextually appropriate and inappropriate words were observed about 200 ms before the isolation point. Semantic processing was evident before the acoustic signal was sufficient to identify the words uniquely. Results indicate that semantic integration can begin to operate with only partial, incomplete information about word identity. Influences of semantic constraint, word frequency, and rate of presentation are described.

Assessment of infant cardiopulmonary resuscitation rescue breathing technique: relationship of infant and caregiver facial measurements

OBJECTIVE

Although a few infants ever require resuscitation, pediatric cardiopulmonary resuscitation (CPR) is performed most commonly under 1 year of age. American Heart Association guidelines for pediatric basic life support recommend that the caregiver place his/her mouth over the infant's mouth and nose to create a seal. The way CPR is currently taught encourages parents to attempt to seal the nose and open the mouth of the infant for rescue breathing. Recent studies suggest some parents may have trouble sealing an infant's nose and open mouth, but their study participant numbers were small. The aim of this report is to estimate, among a large cohort, the ability of caregivers to create a seal to their infants for the provision of rescue breathing according to current guidelines.

METHODS

Infants up to 1 year of age (n = 281) and their caregivers were enrolled from Philadelphia pediatric offices. Facial measurements of the infants were obtained to estimate the length needed to seal the nose and open mouth, and the nose and closed mouth. Mouth widths of the caregivers were compared with their infant's nose and mouth lengths. One-way analysis of variance with Tukey's postmortem analysis and ordinary least squares means regression were used for univariate analysis with analysis of covariance used to control for the effects of multiple variables when necessary. Infant measurements were stratified into 3-month age quadrants to compare against matched adult caregiver measurements.

RESULTS

Most caregivers (n = 270) were female. Females had smaller mouth widths than males (4.9 +/- 0.5 cm vs 5.2 +/- 0.5 cm). Infant nose and mouth length increased during the first year of life, with the largest increase between 0 to 3 months and 3 to 6 months (4.2 +/- 0.4 cm to 4.7 +/- 0.4 cm). As infant age and face length increased, a progressively higher rate of adult females were estimated not to be able to cover their infant's nose and open mouth, with the greatest increase again between 0 to 3 months (9%) and 3 to 6 months (40%). All female caregivers except 1 were predicted to be able to seal their infant's nose and closed mouth by our measurements.

CONCLUSIONS

Infant face length grows rapidly during the first year of life with the most rapid growth occurring during the first 6 months. As early as 3 to 6 months of infant age, many adult caregivers' facial measurements, especially female, predict that they may not be able to form a seal for mouth-to-nose and open-mouth infant rescue breathing. By related measurements, nearly 100% of caregivers should be able to seal their infant's nose and closed mouth. If facial measurement predictions correlate with functional inability to seal an infant's nose and open mouth, infant CPR rescue breathing instruction will need to emphasize head position and creation of a seal over the mouth and nose without teaching that the mouth be open. pediatric basic life support, infant CPR, rescue breathing, sudden infant death syndrome, acute life-threatening episode.

Biotin uptake by human colonic epithelial NCM460 cells: a carrier-mediated process shared with pantothenic acid

Previous studies showed that the normal microflora of the large intestine synthesizes biotin and that the colon is capable of absorbing intraluminally introduced free biotin. Nothing, however, is known about the mechanism of biotin absorption in the large intestine and its regulation. To address these issues, we used the human-derived, nontransformed colonic epithelial cell line NCM460. The initial rate of biotin uptake was found to be 1) temperature and energy dependent, 2) Na+ dependent (coupling ratio of 1:1), 3) saturable as a function of concentration [apparent Michaelis constant (Km) of 19.7 microM], 4) inhibited by structural analogs with a free carboxyl group at the valeric acid moiety, and 5) competitively inhibited by the vitamin pantothenic acid (inhibition constant of 14.4 microM). Pretreatment with the protein kinase C (PKC) activators phorbol 12-myristate 13-acetate (PMA) and 1, 2-dioctanoyl-sn-glycerol significantly inhibited biotin uptake. In contrast, pretreatment with the PKC inhibitors staurosporine and chelerythrine led to a slight, but significant, increase in biotin uptake. The effect of PMA was mediated via a marked decrease in maximal uptake velocity and a slight increase in apparent Km. Pretreatment of cells with modulators of the protein kinase A-mediated pathway, on the other hand, showed no significant effect on biotin uptake. These results demonstrate, for the first time, the functional existence of a Na+-dependent, specialized carrier-mediated system for biotin uptake in colonic epithelial cells. This system is shared with pantothenic acid and appears to be under the regulation of an intracellular PKC-mediated pathway.

Arterial occlusions as a presenting feature of acute promyelocytic leukemia

Arterial thrombosis as a presentation of acute promyelocytic leukemia is uncommon. The authors report a patient who presented with a clot in the left external iliac artery and pulmonary emboli. The literature is reviewed.

Dysplastic nitrergic neurons in the rectum of a patient with rectal ectasia

We present a histochemical study of resected colon from a 13-year-old boy diagnosed with rectal ectasia. Laminar preparations and sectioned tissue of rectum were assayed histochemically for nitric oxide (NO) synthase activity by reducing nitro blue tetrazolium salt in the presence of the cofactor NADPH. Tissue preparations displayed intensely labelled neurons and fibers throughout the gut wall. Laminar preparations of Meissner's plexus showed a hyperplasia of ganglia and NO-related neurons throughout the length of the resected rectum compared with normal bowel. Sectioned tissue of the Auerbach's plexus demonstrated a normal number of ganglia and NO-related neurons. As well, the ectatic bowel showed a proliferation of nerve fibers in keeping with the degree of circular smooth muscle hypertrophy. This proliferation may represent a reactive phenomenon secondary to the functional obstruction. The NO histochemical technique may form the basis of further investigations in defining the cause of this functional obstruction.

Minimum urine flow rate during water deprivation: importance of the nonurea versus total osmolality in the inner medulla

Antidiuretic hormone leads to an increase in the permeability for water and urea in the inner medullary collecting duct. Hence, urea may not be an "effective" osmole in the inner medulla during maximal renal water conservation. Accordingly, the purpose of this study was to evaluate whether differences in the rate of urea excretion would influence maximum renal water conservation in humans. In water-deprived rats, the concentration of urea and total osmolality were somewhat higher in the urine exiting the inner medullary collecting duct than in interstitial fluid obtained from the entire papillary tip. Nevertheless, the "nonurea" (total osmolality minus urea in millimolar terms) osmolality was virtually identical in both locations. Chronically fasted human subjects that were water-deprived for 16 h had a lower rate of urea excretion (71 +/- 7 versus 225 +/- 14 mumol/min) and a somewhat lower urine osmolality (745 +/- 53 versus 918 +/- 20 mosmol/kg H2O). Nevertheless, they had identical urine flow rates (0.5 +/- 0.01 and 0.5 +/- 0.02 ml/min, respectively), and their nonurea osmolality also was similar (587 +/- 25 and 475 +/- 14 mosmol/kg H2O, respectively) to the water-deprived normal subjects. The composition of their urine differed in that the principal nonurea osmoles became NH4+ and beta-hydroxybutyrate rather than Na and C1. During water deprivation in normal subjects, the ingestion of urea caused a twofold rise in urine flow rate, a fall in the nonurea osmolality, and a rise in the rate of excretion of nonurea osmoles. The nonurea osmolality of the urine, and presumably the medullary interstitial fluid as well, was inversely related to the urea excretion rate. In chronic fasting, the nature, but not the quantity, of nonurea osmoles changed. The similar minimum urine volume was predictable from an analysis based on nonurea osmole considerations.

Lower diagnostic accuracy of thallium-201 SPECT myocardial perfusion imaging in women: an effect of smaller chamber size

OBJECTIVES

We attempted to formally compare the diagnostic accuracy of thallium-201 single-photon emission computed tomographic (SPECT) myocardial perfusion imaging in men and women and the effect of chamber size on accuracy.

BACKGROUND

The diagnostic accuracy of conventional exercise testing has been shown to be lower in women. Less is known about the relative accuracy of perfusion imaging. Because of smaller body size, women have a smaller heart size than men, a factor that may reduce accuracy.

METHODS

We identified 323 patients undergoing thallium-201 SPECT myocardial perfusion imaging who either had < 5% probability of coronary artery disease (CAD) by Bayesian analysis or who underwent cardiac catheterization within 60 days of stress testing. Patients with documented history of infarction, coronary artery bypass grafting, pathologic Q waves on the electrocardiogram, left bundle branch block or nonischemic cardiomyopathy were not included. We performed strict quantitative analysis, and receiver operating characteristic (ROC) curves were generated and the area under the curve was calculated for men and women. A size index was generated from the number of short-axis slices and average radius of each slice, and the group was classified as having a large or a small chamber size. The ROC areas of men and women with a large and a small chamber size were then compared.

RESULTS

Diagnostic accuracy was lower in women than in men (ROC are 0.82 vs. 0.93, p < 0.05) despite similar values for peak heart rate and rate-pressure product and similar severity of CAD. There was a greater difference in accuracy between patients with a large versus a small chamber size (ROC area 0.94 vs. 0.73, p < 0.01) despite similar levels of exercise and severity of CAD. When we compared men and women in groups stratified by chamber size, we could not detect a significant difference between ROC area values of men and women (large: 0.94 men, 0.93 women, p = 0.77, power to detect difference in area of 0.15 = 91%; small: 0.79 men, 0.72 women, p = 0.58, power to detect difference in area of 0.15 = 35%).

CONCLUSIONS

The diagnostic accuracy of thallium SPECT myocardial perfusion imaging is lower in women than in men. Most of the difference appears to be due to smaller left ventricular chamber size in women, although a small residual gender effect in smaller heart sizes cannot be entirely excluded. It is proposed that the most likely cause for this difference is the relatively greater effect of imaging blurring on smaller hearts.

The relationship of thoracic lymphadenopathy to pulmonary interstitial disease in diffuse and limited systemic sclerosis: CT findings

OBJECTIVE

Mediastinal lymphadenopathy is frequently associated with interstitial lung disease (ILD) in patients with systemic sclerosis (SSc). This study compared the extent of lymphadenopathy in diffuse and limited SSc with the presence and type of ILD found on CT scans.

SUBJECTS AND METHODS

Seventy-three patients with diffuse and limited SSc underwent thoracic CT. The presence of lymphadenopathy was correlated with the frequency and type of ILD.

RESULTS

Fifty-eight percent (18/31) of patients with diffuse cutaneous SSc and 40% (17/42) of patients with limited cutaneous SSc had lymphadenopathy. A significant relationship was found between lymphadenopathy and the presence of interstitial disease (p = .0002). Seventy-two percent (18/25) of patients with a ground-glass parenchymal pattern of interstitial disease and 74% (14/19) of patients with a honeycomb pattern had lymphadenopathy.

CONCLUSION

Lymphadenopathy is prevalent in patients with SSc and ILD regardless of clinical subtype or interstitial pattern. Lymphadenopathy appears to increase as a function of the profusion rather than the morphology of ILD.

Evaluating a change in practice: femoral sheath removal by registered nurses

A descriptive study was conducted to assess whether there was a difference in patient outcomes when femoral venous and arterial sheaths were removed post percutaneous transluminal coronary angioplasty (PTCA) by MDs as compared to RNs. In addition, the impact on nursing practice of nurses assuming this new task was examined. A chart review revealed a greater occurrence of bleeding in patients whose sheaths had been removed by MDs rather than by RNs (chi square; p < 0.01). Patients received analgesics and anxiolytics pre-sheath removal more frequently when nurses removed femoral sheaths (p < 0.01). Forty-two percent of RNs were not satisfied with the change in practice, and 46% were satisfied. Further research is needed to evaluate patient satisfaction with pain and anxiety management at the time of sheath removal.

Randomized trial of interferon maintenance in multiple myeloma: a study of the National Cancer Institute of Canada Clinical Trials Group

PURPOSE

To determine whether interferon maintenance therapy improves overall survival and response duration in patients with multiple myeloma who have responded to induction therapy with melphalan and prednisone.

PATIENTS AND METHODS

In a multicenter trial, patients with symptomatic clinical stage I and stage II and III multiple myeloma were registered at diagnosis and those who responded to melphalan-prednisone (MP) were randomized either to receive interferon (2 mU/m2) subcutaneously three times per week or no maintenance. MP was discontinued in both groups once a stable response plateau of the monoclonal protein was reached. Interferon was continued until relapse, and then was restarted on subsequent response to MP. Interferon toxicity was recorded using a self-report diary. Survival and response duration were calculated using life-table methods, and were adjusted in the analysis for imbalances in baseline prognostic factors.

RESULTS

Four hundred two patients were registered and 176 responders were randomized (85 to interferon and 91 to control). At a median follow-up time of 43 months, the median survival duration was 43 months for interferon and 35 months for control (P = .16), but when adjusted for chance imbalances in baseline prognostic factors (mainly performance status), the median survival duration was 44 months and 33 months for interferon and control, respectively (P = .049). Progression-free survival from randomization to first relapse also favored interferon (unadjusted P < .002; adjusted P < .003). Interferon toxicity caused 58% of patients to reduce their dose, of which 84% were able to return to the initial dose; 14% had to discontinue interferon treatment.

CONCLUSION

Interferon maintenance therapy improves progression-free and overall survival of patients with multiple myeloma who respond to melphalan and prednisone. Toxicity is substantial and must be weighed by patients against the potential benefits in response duration and survival.

Testicular fate after incarcerated hernia repair and/or orchiopexy performed in patients under 6 months of age

This study assessed testicular viability after 476 inguinal procedures performed in 338 infants under 6 months of age, between 1974 and 1993. One hundred twenty-one elective hernia repairs (contralateral explorations) were compared with 355 hernia repairs complicated by incarceration and/or orchiopexy. Clinical examination of 323 testes in the early postoperative period showed 20 atrophic testes. Since January 1994, 71 of the 338 patients have had testicular measurements obtained through ultrasonography (US). An additional 13 atrophic testes were found during US examination. Of these, nine were believed to be normal during early postoperative examination. Assuming that US examination will confirm atrophy in the 20 atrophic testes noted early in the postoperative clinical evaluation, and that all other testes not yet scanned are found to be normal, the minimal atrophy rate (MAR) would be 9.3% (33 of 355). Neither operative nor early postoperative testicular assessment correlates with ultimate testicular survival. Testicular pathology may become more evident after puberty, and the real incidence of atrophy may increase.

Lids, lacrimals, and lashes

The eyelids and lashes serve to protect the globe from foreign bodies and injuries, and the lacrimal system protects the eyes through lubrication of the corneal and conjunctival surfaces. This article discusses trauma, infection, inflammation, anatomic abnormalities, and tumors that may result in serious complications interfering with normal eye function.