Identification and characterization of a chymotrypsin-like serine protease from periodontal pathogen, Tannerella forsythia

Tannerella forsythia is a bacteria associated with severe periodontal disease. This study reports identification and characterization of a membrane-associated serine protease from T. forsythia. The protease was isolated from T. forsythia membrane fractions and shown to cleave both gelatin and type I collagen. The protease was able to cleave both substrates over a wide range of pH values, however optimal cleavage occurred at pH 7.5 for gelatin and 8.0 for type I collagen. The protease was also shown to cleave both gelatin and type I collagen at the average reported temperature for the gingival sulcus however it showed a lack of thermal stability with a complete loss of activity by 60 °C. When treated with protease inhibitors the enzyme's activity could only be completely inhibited by serine protease inhibitors antipain and phenylmethanesulfonyl fluoride (PMSF). Further characterization of the protease utilized serine protease synthetic peptides. The protease cleaved N-succinyl-Ala-Ala-Pro-Phe p-nitroanilide but not N_α-benzoyl-dl-arginine p-nitroanilide (BAPNA) or N-methoxysuccinyl-Ala-Ala-Pro-Val p-nitroanilide indicating that the protease is a chymotrypsin-like serine protease. Since type I collagen is a major component in the gingival tissues and periodontal ligament, identification and characterization of this enzyme provides important information regarding the role of T. forsythia in periodontal disease.

Sodium replacement and fluid shifts during prolonged exercise in humans

In the study presented here, we examined the affects of a close to complete replacement of sweat water and Na+ losses on fluid shifts during exercise. Six cyclists performed three 4-h rides at 55% of their peak oxygen uptake in a 20 degrees C environment while consuming 3.85 l of an 8% carbohydrate solution containing 5, 50 or 100 mEq.l-1 of Na+. Increases in Na+ intake reduced renal free water clearance from around 40 ml.h-1 to -8 and -121 ml.h-1 and led to a decrease in urine volume from approximately equal to 1.0 to 0.5 l (P < 0.05). In contrast, the 3.5-3.9 l fluid and 150-190 mEq Na+ losses in sweat were similar in each trial, as were the approximately equal to 80 mEq K+ losses in sweat and urine and the 282-288 mosmol.kg-1 plasma osmolalities. During the low-Na+ trial, plasma osmolality was maintained by a approximately equal to 1.3 l contraction of extracellular fluid (ECF) with the loss of approximately equal to 200 mEq Na+. However, in the other trials, approximately equal to 1.3 l of water was lost from the intracellular fluid. During the medium-Na+ trial, a loss of only approximately equal to 40 mEq Na+ maintained ECF volume, and during the high-Na+ trial, a gain of approximately equal to 160 mEq Na+ expanded the ECF by approximately equal to 0.8 l. However, corresponding changes in plasma volumes from -0.20 to 0.15 l had no effect on cardiovascular drift or thermoregulation. These data suggest that during prolonged exercise of moderate intensity under mild environmental conditions when sweat rates are approximately equal to 0.9 l.h-1, complete Na+ replacement maintains plasma volume and reduces dehydration, but when fluid intake matches sweat rate, has little effect on plasma osmolality.

Hypertonic saline-dextran suppresses burn-related cytokine secretion by cardiomyocytes

Whereas hypertonic saline-dextran (HSD, 7.5% NaCl in 6% D70) improves cardiac contractile function after burn trauma, the mechanisms of HSD-related cardioprotection remain unclear. We recently showed that cardiomyocytes secrete tumor necrosis factor-alpha (TNF-alpha), a response that was enhanced by burn trauma. This study addressed the question: does HSD modulate cardiac contraction/relaxation by altering cardiomyocyte TNF-alpha secretion? Wistar-Furth rats (325 g) were given a burn injury over 40% of the total body surface area and were then randomized to receive a bolus of either isotonic saline or HSD (4 ml/kg, n = 14 rats/group). Sham burn rats were given either isotonic saline or HSD (n = 14 rats/group) to provide appropriate controls for the two burn groups. Hearts were isolated 24 h postburn for either Langendorff perfusion (n = 8 hearts/group) or to prepare cardiomyocytes (n = 6 hearts/group). Myocytes were stimulated with lipopolysaccharide (LPS) (0, 10, 25, or 50 microg for 18 h) to measure cytokine secretion. Burn trauma increased myocyte TNF-alpha and interleukin-1 beta and -6 secretion, exacerbated cytokine response to LPS stimulus, and impaired cardiac contraction. HSD treatment of burns decreased cardiomyocyte cytokine secretion, decreased responsiveness to LPS challenge with regard to cytokine secretion, and improved ventricular function. These data suggest that HSD mediates cardioprotection after burn trauma, in part, by downregulating cardiomyocyte secretion of inflammatory cytokines.

Munchausen syndrome presenting in a patient who has undergone temporomandibular joint surgery

Munchausen syndrome is a rare psychiatric disorder. Patients with Munchausen syndrome insist on and repeatedly undergo unnecessary investigations and operative treatments. No organic pathosis is demonstrated, and treatment consistently fails to alleviate the symptoms. This article presents a case report and a brief discussion to facilitate recognition and management techniques.

Evaluation and treatment of temporomandibular disorders: considerations for the general dentist

Temporomandibular disorders are only one of a host of different conditions that may result in orofacial pain. Hence, due to this multifactorial etiology, it is imperative to adopt a multidisciplinary approach when treating these patients. Listed in Table 3 are some of the conditions that must be considered when a dentist faces the dilemma of orofacial pain of unknown etiology in clinical practice.

Nitric oxide modulation of TNF-alpha-induced cardiac contractile dysfunction is concentration dependent

Whereas previous studies suggest that tumor necrosis factor-alpha (TNF-alpha) induces cardiac contraction-relaxation deficits, the mechanisms remain unclear. Our recent studies have implicated cardiac-derived nitric oxide (NO). This study examined the detrimental and protective effects of NO donors S-nitroso-N-acetyl-penicillamine (SNAP) or (Z)-1- [N-(3-ammonio-propyl)-N-(n-propyl)amino]diazen-1-ium- 1,2diolate (PAPA/NO) on TNF-alpha-related changes in cardiac contractile function (Langendorff), cellular injury, and intracellular myocyte Ca(2+) concentration ([Ca(2+)](i)). Myocytes were incubated in the presence/absence of TNF-alpha (200-500 pg/ml x 10(5) cells) for 3 h; subsets of myocytes were incubated with one of several concentrations of SNAP or PAPA/NO (0.1, 0.3, 0.5, and 1.5 mM) for 15 min before TNF-alpha challenge. Supernatant creatine kinase (CK), cell viability (Trypan blue dye exclusion), and myocyte [Ca(2+)](i) (fura 2-acetoxymethyl ester) were measured. In parallel experiments, cardiac function (Langendorff) was examined after TNF-alpha challenge in the presence or absence of SNAP or PAPA/NO (0.1 and 1.5 mM). TNF-alpha in the absence of an NO donor impaired cardiac contraction and relaxation and produced cardiomyocyte injury. Pretreating perfused hearts or isolated cardiomyocytes with a low concentration of either SNAP or PAPA/NO decreased TNF-alpha-mediated cardiac injury and improved contractile dysfunction, whereas high concentrations of NO donor exacerbated TNF-alpha-mediated cardiac effects. These data provide one explanation for the conflicting reports of beneficial versus detrimental effects of NO in the face of inflammation and suggest that the effects of NO on organ function are concentration dependent; low concentrations of NO are cardioprotective, whereas high concentrations of NO are deleterious.

Detection of endometrial adenocarcinoma in two asymptomatic postmenopausal women receiving tamoxifen. A report of two cases

BACKGROUND

Tamoxifen has been linked to an increased risk for the development of endometrial adenocarcinoma. The majority of these carcinomas present with postmenopausal bleeding. The current standard is to undertake sampling only after the onset of bleeding.

CASES

Two cases illustrate the utility of transvaginal saline infusion sonohysterography (TVS/SIS) in the detection of endometrial carcinoma prior to the onset of bleeding.

CONCLUSION

Annual TVS/SIS may be useful for screening asymptomatic, tamoxifen-exposed patients with a uterus in situ and is likely to be more acceptable to such patients than annual biopsies.

Calcium antagonists improve cardiac mechanical performance after thermal trauma

Burn trauma initiates a pathophysiologic cascade, which includes cardiac dysfunction and intramyocyte calcium accumulation. This study examined the hypothesis that therapeutic interventions which limit intracellular cardiac Ca(2+) accumulation after burn trauma will improve cardiac function. Guinea pigs were anesthetized (methoxyflurane), burned over 43% of total body surface area, and fluid resuscitated (FR) for 24 h. Burn guinea pigs were randomly divided into three groups: Group 1, FR alone, Group 2, FR plus dantrolene (10 mg/kg body wt, IV, 30 min, 8 and 22 h postburn), a drug which inhibits the Ca(2+) release channel (ryanodine receptor) of the cardiac sarcoplasmic reticulum, and Group 3, FR plus diltiazem (0.20-0.22 mg/kg given IV as a slow infusion over 6 h postburn), a drug which specifically blocks Ca(2+) slow channels; sham burn guinea pigs were given vehicle (Group 4), dantrolene (Group 5), or diltiazem (Group 6) as described above (respective controls). Cardiac dysfunction was impaired in fluid-treated burns (Group 1) compared to sham burns (Group 4) as indicated by reduced developed left ventricular pressure (LVP) (86 +/- 2 vs 52 +/- 3 mm Hg, P < 0.05), rate of LVP rise, (+dP/dt max, 1379 +/- 64 vs 909 +/- 44 mm Hg/s, P < 0.05), and LVP fall (-dP/dt max, 1184 +/- 31 vs 881 +/- 40 mm Hg/s, P < 0.05), and time to peak pressure (110 +/- 2 vs 102 +/- 2 ms, P < 0.05). In addition, [Ca(2+)](i) rose in cardiomyocytes harvested from fluid-treated burns (Group 1, 307 +/- 29 nM) compared to vehicle-treated controls (Group 4, 152 +/- 6 nM, P < 0.05). Neither calcium antagonist altered ventricular function or [Ca(2+)](i) in sham burns (Groups 5 and 6). In contrast, antagonists given after burn injury reduced cardiomyocyte [Ca(2+)](i) (Group 2, dantrolene-treated burns: 196 +/- 8 nM, and Group 3, diltiazem treated burns: 216 +/- 8 nM) and improved cardiac performance compared to that measured in burns given FR alone. Our data suggest that calcium antagonists given after burn trauma restored intracellular Ca(2+) homeostasis, decreased cardiac cell injury, and improved cardiac contractile function.

Water and electrolyte shifts with partial fluid replacement during exercise

In this study, we examined whether athletes, who typically replace only approximately 50% of their fluid losses during moderate-duration endurance exercise, should attempt to replace their Na+ losses to maintain extracellular fluid volume. Six male cyclists performed three 90-min rides at 65% of peak O2 uptake in a 32 degrees C environment and ingested either no fluid (NF), 1.21 of water (W), or saline (S) containing 100 mmol of NaCl x l(-1) to replace their electrolyte losses. Both W and S conditions decreased final heart rates by approximately 10 betas min(-1) (P<0.005) and reduced falls in plasma volume (PV) by approximately 4% (P<0.05). Maintenance of PV after 10 min in the W trial prevented further rises in plasma concentrations of Na+ [Na+], Cl- and protein but in the S and NF trials, plasma [Na+] continued to increase by approximately 4 mEq x l(-1). Differences in plasma [Na+] had little effect on the approximately 2.4 l fluid, approximately 120 mEq Na+ and approximately 50 mEq K+ losses in sweat and urine in the three trials. The main effects of W and S were on body fluid shifts. During the NF trial, PV and interstitial fluid (ISF) and intracellular fluid (ICF) volumes decreased by approximately 0.1, 1.2 and 1.0 l, respectively. In the W trial, the approximately 1.2 l fluid and approximately 120 mEq Na+ losses contracted the ISF volume, and in the S trial, ISF volume was maintained by the movement of water from the ICF. Since the W and S trials were equally effective in maintaining PV, Na+ ingestion may not be of much advantage to athletes who typically replace only approximately 50% of their fluid losses during competitive endurance exercise.

Behaviors that cause clinical instructors to question the clinical competence of physical therapist students

BACKGROUND AND PURPOSE

Clinical instructors (CIs) observe behavior to determine whether students have the skills assumed necessary for safe and effective delivery of physical therapy services. Studies have examined assumptions about necessary skills, but few studies have identified the types of student behaviors that are "red flags" for CIs. This study examined the student behaviors that negatively affect students' clinical performance, which can alert CIs to inadequate performance.

SUBJECTS

Twenty-eight female and 5 male CIs discussed the performance of 23 female and 17 male students who were anonymous.

METHODS

Using questionnaires and semistructured interviews that were taped and transcribed, CIs described demographics and incidents of unsafe and ineffective physical therapy. After reading the transcripts, investigators identified and classified the behaviors into categories and checked their classification for reliability (kappa=.60-.75).

RESULTS

Behaviors in 3 categories emerged as red flags for CIs: 1 cognitive category--inadequate knowledge and psychomotor skill (43% of 134 behaviors)--and 2 noncognitive categories--unprofessional behavior (29.1%) and poor communication (27.6%). The CIs noticed and valued noncognitive behaviors but addressed cognitive behaviors more often with students. Students who did not receive feedback about their performance were unlikely to change their behavior. The CIs used cognitive behaviors often as reasons to recommend negative outcomes.

CONCLUSION AND DISCUSSION

Clinical instructors need to identify unacceptable cognitive and noncognitive behaviors as early as possible in clinical experiences. Evidence suggests that they should discuss their concerns with students and expect students to change.

Arginine in burn injury improves cardiac performance and prevents bacterial translocation

This study examined the effects of arginine supplement of fluid resuscitation from burn injury on cardiac contractile performance and bacterial translocation after a third-degree burn comprising 43% of the total body surface area in adult rats. Before burn injury, rats were instrumented to measure blood pressure; after burn (or sham injury), paired groups of sham-burned and burned rats were given vehicle (saline), L-arginine, D-arginine, or N-methyl-L-arginine (300 mg/kg in 0.3 ml of saline 30 min, 6 h, and 23 h postburn) plus fluid resuscitation; sham-burned rats received drug only. Twenty-four hours after burn trauma, hemodynamics were measured; the animals were then killed and randomly assigned to Langendorff heart studies or to studies examining translocation of gut bacteria. Burn rats treated with vehicle, D-arginine, or N-methyl-L-arginine had well-defined cardiocirculatory responses that included hypotension, tachycardia, respiratory compensation for metabolic acidosis, hypocalcemia, cardiac contractile depression, and significant bacterial translocation. Compared with values measured in vehicle-treated burn rats, L-arginine given after burn improved blood pressure, prevented tachycardia, reduced serum lactate levels, improved cardiac performance, and significantly reduced bacteria translocation, confirming that L-arginine administration after burn injury provided significant cardiac and gastrointestinal protection. Circulating neutrophil counts fell after burn trauma and serum glucagon levels rose, but these changes were not altered by pharmacological intervention. Our finding of significantly higher coronary perfusate guanosine 3',5'-cyclic monophosphate concentration in L-arginine-treated burn rats suggests that the beneficial effects of L-arginine were mediated by nitric oxide production.

Clinical trial of the uterine thermal balloon for treatment of menorrhagia

STUDY OBJECTIVES

To evaluate the safety and efficacy of thermal balloon endometrial ablation in women with menorrhagia, and to identify factors influencing outcome.

DESIGN

Prospective, observational study (Canadian Task Force classification II-2).

SETTING

Three Canadian university-affiliated teaching hospitals.

PATIENTS

One hundred twenty-one women suffering from menorrhagia serious enough to make them candidates for endometrial ablation or hysterectomy. Patients without obvious structural or (pre)malignant abnormalities were included if their uterine cavities sounded to less than 12 cm, they were in good health, and had undergone hysteroscopy or pelvic ultrasound and endometrial biopsy within 6 months and had a normal Papanicolaou smear within 1 year.

INTERVENTIONS

A balloon catheter was placed through the cervix and after inflation in the endometrial cavity with 5% dextrose in water, was heated to 87 +/- 5 degrees C. Two-thirds of patients avoided general anesthesia and very few required cervical dilatation to admit the 4.5-mm diameter catheter. Balloon pressures were 90 to 140 mm Hg in 13 patients; pressures between 140 and 190 mm Hg were well tolerated by the rest. Nineteen women underwent 12 minutes of therapy, and the rest had 8-minute sessions.

MEASUREMENTS AND MAIN RESULTS

No intraoperative complications occurred, and minor postoperative morbidity occurred in 4% of patients. Preoperative and postoperative bleeding was assessed by pad counts and patient self-reports. The degree of dysmenorrhea was recorded similarly. A paired t test was used to compare pretreatment with posttreatment pad counts. A Wilcoxon signed rank test was employed to evaluate the effect of treatment on dysmenorrhea. The effects on outcome of several independent variables were analyzed by multiple and logistic regression. Success of the procedure was constant over the year (range 86-90%). Treatment led to significant decreases in menstrual flow, duration, and pain (p <0.0001). No significant effects of parity, uterine position or cavity depth, timing, or various endometrial-thinning regimens were found. Increasing age was significantly associated with increased odds of success (p < 0.05). Excluding the 19 women who underwent 12 minutes of therapy did not change statistical results, whereas excluding the 13 treated with balloon pressures less than 140 mm Hg improved the results. Conclusion. The facts that bleeding and dysmenorrhea were significantly reduced by thermal balloon endometrial ablation, that no intraoperative complication occurred, and that postoperative morbidity was minimal, lead us to conclude that this is potentially a safe and effective technique. Larger studies and longer follow-up are required to substantiate this impression.

Cost effectiveness of an allergy consultation in the management of asthma

In a large Denver HMO, a retrospective study of asthma management was reviewed. Seventy moderate to severe asthmatic patients' charts were reviewed through April 1994. All patients admitted to the study had to be followed for at least 1 year by a primary care physician before the allergy evaluation (AE) and for at least one year of followup (F/U) after the AE. All patients had at least two acute care (ER) visits and/or one hospitalization before the AE. All primary care, AE, and F/U were done by staff physicians in the Kaiser Permanente system. The findings included 1) Forty-five percent decrease (308 to 169) in the number of sick care office visits (P = 0.0001); 2) fifty-five percent decrease (266 to 118) in acute care visits (P = 0.0001); 3) sixty-seven percent decrease (34 to 11) in the number of hospitalizations after the AE (P = 0.001); 4) average hospital days before AE were four days and after AE, 2.5 days; 5) estimated cost saving of $145,500, or $2,100 per patient.

Model for outcomes assessment of antihistamine use for seasonal allergic rhinitis

BACKGROUND

Drug selection for optimal treatment of common medical conditions may be difficult and involve many diverse factors.

OBJECTIVE

The efficacy, safety, quality of life, and cost of treatment of seasonal allergic rhinitis with cetirizine, chlorpheniramine, or terfenadine were compared in a prospective, two-phase, randomized, single-blind clinical trial conducted in a managed care setting.

METHODS

In phase I, which lasted 2 weeks, patients were randomized to receive one of the study drugs. In phase II, which lasted 4 weeks, the initial treatment was continued unless patients were dissatisfied, in which case they could be randomly assigned to receive another study drug. In both phases pseudoephedrine could be taken as needed. Patients kept daily diaries of symptoms and costs, and study drugs were evaluated at the end of each phase for efficacy, safety, and effect on quality of life by means of a validated questionnaire. A multiattribute outcomes assessment model for formulary decision making was used to rank the antihistamines.

RESULTS

Physicians' and patients' assessments in phases I and II indicated that cetirizine and chlorpheniramine were significantly more effective than terfenadine (p < 0.05). Incidence of sedation in phase I and phase II was 40.5% and 16.7% for chlorpheniramine, 11.6% and 9.8% for cetirizine, and 6.7% and 5.1% for terfenadine, respectively. At the end of phase I, 28.9% of the patients treated with chlorpheniramine, 50% of the patients treated with terfenadine, and 69.4% of the patients treated with cetirizine were satisfied with their therapy and chose not to switch their medication. Quality of life scores improved most after treatment with cetirizine and least after treatment with terfenadine.

CONCLUSION

The result of this trial indicate that antihistamine selection is best made with the use of a multiattribute evaluation that includes quality of life. In this study cetirizine was favored by patients and physicians most often, followed by chlorpheniramine and then terfenadine.

Preparticipation physical examinations

Preparticipation physical examinations are a prerequisite for competition at most levels of sports. This article discusses the unique opportunity that the health care team has to participate in the provision of sports assessment and screening services to a wide variety of individuals. In addition, this article reviews the purpose of the examination, organizational consideration, components of the examination, and special considerations that should be included.

Management of internal derangements of the temporomandibular joint

This article discusses the orthodontist's involvement in treating patients with complex temporomandibular joint (TMJ) disorders. It includes a review of the literature and information regarding classification, epidemiology, incidence, and diagnosis of TMJ internal derangements. Controversies in management discussed include the importance of disc position, the consequences of not repositioning the disc, and the predictability of progression of disease. Considerations regarding home care, medical care, and surgical care are also presented.

Mediation of abusive childhood experiences: depression, dissociation, and negative life outcomes

A study of 301 college undergraduates is employed to test a causal model which proposes that dissociation and depression act as mediator variables that develop from child abuse and lead to various negative outcomes. As predicted, child maltreatment was found to be related to negative life experiences, with depression and dissociation differentially mediating the various outcomes.

High-yield selection criteria for cranial computed tomography after acute trauma

OBJECTIVE

To develop and prospectively evaluate criteria for selecting head-injured patients requiring cranial CT.

METHODS

A two-phased prospective observational study design was implemented at a university ED. Physicians completed a form with 51 variables for 540 patients in Phase I. Ten high-yield variables were identified and prospectively tested on 273 patients in Phase II. Prediction rule performance for identification of patients with abnormal CT scans was determined.

RESULTS

The combined criteria had a sensitivity of 97% for CT-scan abnormalities in Phase I; sensitivity was 96% in Phase II. Negative predictive values were 97% and 94%, respectively. Prevalence of disease in Phase I was 17%; prevalence in Phase II was 16%. Had the Phase I criteria been implemented during Phase II, 43 of 273 patients (16%) would not have been scanned, including two patients with positive results who did not require operative intervention.

CONCLUSIONS

Fifty-one clinical variables from head-injured patients were narrowed to ten of statistical significance and consistent interpretation for prospective evaluation. Patients with none of these criteria were found to be at low risk of having sustained significant head injury.

The measurement of psychological maltreatment: early data on the Child Abuse and Trauma Scale

This paper describes a self-report measure, the Child Abuse and Trauma Scale, which yields a quantitative index of the frequency and extent of various types of negative experiences in childhood and adolescence. Data on this measure are presented for two large samples of college students and for a small clinical sample of subjects with a diagnosis of Multiple Personality Disorder. The strong internal consistency and test-retest reliability of the scale in the college population is documented, and its validity is attested to by demonstrating that it correlates significantly with outcomes such as dissociation, depression, difficulties in interpersonal relationships, and victimization, all of which have previously been associated with childhood trauma or abuse. The extremely high scores of the Multiple Personality subjects confer additional validity to the measure. The authors suggest that the construct of psychological maltreatment underlies the destructive elements of numerous forms of abuse and neglect, and that the scale they have developed may provide a useful index of this construct.

Custom CAD/CAM total temporomandibular joint reconstruction system: preliminary multicenter report

PURPOSE

The purpose was to test the outcome of a custom computer assisted design/computer assisted manufactured (CAD/CAM) total temporomandibular joint (TMJ) reconstruction system.

PATIENTS AND METHODS

There were 215 patients (13 males and 202 females); the average age at reconstruction was 40.9 +/- 10.3 years (range, 15 to 77 years). There were 363 joints placed, 296 bilateral and 67 unilateral. The patients had TMJ problems for an average of 10.3 +/- 7.0 years (range, 1 to 44 years), and had undergone a mean of 5.4 +/- 4.8 (range, 0 to 28) prior unsuccessful surgeries. Preoperative and postoperative data were collected for up to 48 months using a standardized data collection format. Subjective data related to pain, function of the lower jaw, and diet, were obtained using a visual analogue scale. Objective measures of mandibular range of motion were made directly on the patient preoperatively and postoperatively.

RESULTS

Preliminary analysis of these data reveals a statistically significant decrease in pain, an increase in function, and improvement in diet (P < .0001) from the preoperative measurements to 1 and 2 years postoperatively. There was also improvement in mandibular vertical range of motion. The number of previous surgeries was a strong predictor of postoperative pain, function, and diet scores, as well as of maximal interincisal opening. A life table analysis of failures indicates good durability of the prosthesis over time.

CONCLUSION

These preliminary data indicate that this custom CAD/CAM total TMJ reconstruction system seems to be useful in the treatment of the multiply operated, and/or anatomically mutilated TMJ.

Forced single-nostril breathing and cognition

This experiment investigated whether forced single-nostril breathing differentially affects cognitive abilities presumed to be mediated by the left and right cerebral hemispheres. Phase I was an attempted replication of a reported sex difference in the effects of unilateral breathing on verbal versus spatial performance and Phase II was a study of breathing effects on different verbal and spatial tests. No differences associated with breathing condition were found in the replication study. In Phase II, men breathing through the right nostril scored significantly lower than men in the control condition on a letter-matching test although they did not differ significantly from men in the left-nostril condition on that test. There were no significant breathing-related differences on two spatial tests, and no differences associated with breathing condition for the women. Assessment of nostril dominance before and after cognitive testing showed that the forced-breathing exercise did not significantly alter subjects' nostril dominance. A significant left-nostril bias was found in this sample.

Superior fatigue resistance of elite black South African distance runners

Black athletes currently dominate long-distance running events in South Africa. In an attempt to explain an apparently superior running ability of black South African athletes at distances > 3 km, we compared physiological measurements in the fastest 9 white and 11 black South African middle-to long-distance runners. Whereas both groups ran at a similar percentage of maximal O2 uptake (%VO2max) over 1.65-5 km, the %VO2max sustained by black athletes was greater than that of white athletes at distances > 5 km (P < 0.001). Although both groups had similar training volumes, black athletes reported that they completed more exercise at > 80% VO2max (36 +/- 18 vs. 14 +/- 7%: P < 0.005). When corrections were made for the black athletes' smaller body mass, their superior ability to sustain a high %VO2max could not be explained by any differences in VO2max, maximal ventilation, or submaximal running economy. Superior distance running performance of the black athletes was not due to a greater (+/- 50%) percentage of type I fibers but was associated with lower blood lactate concentrations during exercise. Time to fatigue during repetitive isometric muscle contractions was also longer in black runners (169 +/- 65 vs. 97 +/- 69 s; P < 0.05), but whether this observation explains the superior endurance or was due to the lower peak muscle strength (46.3 +/- 10.3 vs. 67.5 +/- 18.0 Nm/l lean thigh volume; P < 0.01) remains to be established.

Is the gender difference in mental rotation disappearing?

Several investigators have used meta-analysis to compare the results of studies of gender differences on various spatial tests and have concluded that the magnitude of the gender difference in spatial ability is decreasing over time. The present study used meta-analytic techniques to compare the effect size (d) of the gender difference in 14 studies published from 1975 to 1992 which administered the Mental Rotations test to adolescents and young adults. Males scored significantly higher than females in all the studies. Analyses of the d's computed for the studies revealed that the magnitude of the gender difference on the Mental Rotations test has remained stable over time. Neither the Pearson correlation relating the d's to the publication dates of the studies nor the Z test of the linear contrast relating the publication dates of the studies to the effect sizes showed a linear change in the size of the gender difference over time. The finding of a stable gender difference on the Mental Rotations test argues against the general conclusion that the gender difference in spatial ability is decreasing.

Temporomandibular joint arthroscopy: a 6-year multicenter retrospective study of 4,831 joints

Four health outcomes (range of motion, pain, diet, and disability) were measured in six diagnostic categories (internal derangement with closed lock, internal derangement with painful click, osteoarthritis, hypermobility, fibrous ankylosis, and arthralgia) in a 6-year retrospective multicenter study of 4,831 temporomandibular joints having undergone arthroscopic surgery. After arthroscopic surgery, 91.6% of all patients had good or excellent motion; 91.3% had good or excellent pain reduction; 90.6% had good or excellent ability to maintain a normal diet; and 92% had a good or excellent reduction in disability. These health outcomes compare favorably with all other known treatments for these conditions. Also, the surgical technique was relatively free of complications (4.4%).

Sex differences in performance and hemispheric organization for a nonverbal auditory task

Musically experienced and inexperienced men and women discriminated among fundamental-frequency contours presented either binaurally (i.e., same contour to both ears) or dichotically (i.e., different contours to each ear). On two separate occasions, males made significantly fewer errors than did females in the binaural condition, but not in the dichotic condition. Subjects with prior musical experience were superior to musically naive subjects in both conditions. The dichotic pitch task produced a left-ear advantage, which was unrelated to gender or musical experience. The results suggest that the male advantage on the binaural task reflects a sex difference in the coordination of the two hemispheres during conjoint processing of the same stimuli rather than a difference in the direction or degree of hemispheric specialization for these stimuli.

Arthroscopic treatment of temporomandibular joint locking resulting from disc derangement: two-year results

This article reports 2-year postarthroscopic surgical treatment data for 18 subjects (17 female and 1 male) who had a diagnosis of restricted mandibular movement due to an internal derangement of the temporomandibular joint (TMJ). These subjects had been treated by an average of 2.1 +/- 1.1 doctors for their TMJ problem before seeing the surgeon for arthroscopic treatment. The subjects' mean pain score at the final time point (21 to 30 months after surgery) was decreased by 57% in usual pain intensity. Jaw function showed an average improvement of 67%. These subjects also showed a 13-mm mean increase in their maximum active opening ability at the 2-year postsurgical time point. Slight to definite clicking noises were present presurgically in 11 of 18 patients, and similar joint noises were reported in 14 of 18 patients postsurgically. The mean overall improvement was rated as 8.18 +/- 2.4, with 10 the highest possible rating. One subject rated her improvement as 0, two subjects rated their improvement as 6 out of 10. No significant morbidity was reported by the subjects as a result of their surgery.

Dissociation and childhood trauma in psychologically disturbed adolescents

OBJECTIVE

To test the hypothesis that dissociation in adolescence is positively correlated with stress or abuse experienced earlier, the authors assessed dissociation in a heterogeneous group of disturbed adolescents and examined the relationship between the degree of dissociation and the degree of reported childhood stress, abuse, or trauma.

METHOD

The subjects were 47 adolescents, 13-17 years old, who were institutionalized for periods of 1-13 weeks in a private mental hospital; 35 were girls and 12 were boys. Participants completed the Dissociative Experiences Scale and a child abuse and trauma questionnaire. The hospital records of 40 of the 47 adolescents were also available.

RESULTS

Scores on the Dissociative Experiences Scale correlated significantly with self-reported physical abuse or punishment, sexual abuse, psychological abuse, neglect, and negative home atmosphere but not with abuse ratings made from hospital records.

CONCLUSIONS

Together with the authors' previous work showing a relation between childhood stress and later dissociation in normal college students, these findings support the view that dissociation represents a reaction to early negative experience and places multiple personality disorder at the extreme end of a continuum of dissociative sequelae of childhood trauma. Researchers should continue to try to identify psychiatric patients with prominent dissociative characteristics or symptoms and attempt to correlate this phenomenology with negative earlier experiences.

Silicone rubber fossa implant removal via partial arthrotomy followed by arthroscopic examination of the internal surface of the fibrous capsule

Thirteen temporomandibular joints were examined arthroscopically for evaluation for fibrous encapsulation of silicone elastomer disk replacement implants. Partial arthrotomies were performed with removal of silicone rubber implants, followed by arthroscopic examination of the internal surfaces of the fibrous capsule as a pseudodisk and to verify the continuity of the fibrous barrier between the condyle and the fossa.

Inner-city women at risk for cervical cancer: behavioral and utilization factors related to inadequate screening

This study investigated the relationships between health care utilization, knowledge, attitudes, sociodemographic characteristics, and adequacy of cervical cancer screening among a random sample of women from inner-city neighborhoods with high rates of cervical cancer mortality. Of 416 women interviewed, 30.3% reported hysterectomies; women with intact uteri (N = 290) are the subjects of this analysis. Over two-fifths (44.1%) reported not receiving adequate Pap testing during the previous 4 years. Compared with adequately screened women, they were more likely to be 45 years or older, have no medical insurance, report never having been to an obstetrician-gynecologist, recall never having been told by a medical provider how often to get a Pap test, rely on providers for adequate screening, report not seeking care as often as they think they should, have less knowledge of risk factors for cervical cancer, and believe that women should get Pap tests less than yearly. Separate models for younger and older women showed that these factors vary by age, demonstrating the need for interventions to be sensitive to age subgroups. These findings suggest that cancer control activities should place more emphasis on motivating women as well as influencing the health care delivery system to maximize reductions in cervical cancer.

Arthroscopic surgery for treatment of temporomandibular joint hypomobility after mandibular sagittal osteotomy

Arthroscopic surgery is an effective method for treating painful hypomobility of the temporomandibular joint. Decreased range of motion after sagittal ramus osteotomies of the mandible has been reported. Causes may include intra-articular factors. These cases may be effectively treated with arthroscopic lysis and lavage after failure of nonsurgical modalities. A series of 15 patients is presented.

Oral complications in a patient with acute lymphocytic leukemia: a report of case

Herpes viruses and Candida albicans are among the most common opportunistic pathogens infecting patients with neoplastic disease, especially those patients receiving cancer chemotherapy. Herpes virus infections have increased as treatment of oncological disease has become more aggressive and immunosuppression disorders have become more prevalent. Herpes simplex virus on the lips and mouth of a patient receiving chemotherapy can progress to multiple lesions in the mouth, larynx, and in rare instances can lead to pneumonitis and widely disseminated infection. The management and dental findings of a 13-year-old patient with acute lymphocytic leukemia are described.

Arthroscopic surgery of the temporomandibular joint: treatment of internal derangement with persistent closed lock

Arthroscopic surgery to correct symptoms of persistent closed locking of the temporomandibular joint appears, in the short term, to be an alternative to arthrotomy. Obviously, long-term follow-up will be necessary.

Nicotine-produced antinociception in minimally deprived smokers and ex-smokers

The antinociceptive effects of two different modes of nicotine administration were investigated using a within-subject design. Ten minimally-deprived, habitual smokers and fifteen ex-smokers were studied in separate experiments. Nicotine was delivered in research cigarettes and tobacco snuff. Pain was induced using the cold pressor test. Subjects in both experiments exhibited pain reduction after nicotine administration without changes in nicotine withdrawal. The results suggest that nicotine can produce physiological and psychological changes that are relevant to the reinforcement of smoking but are independent of the state of nicotine withdrawal.

Bilateral coronoid hyperplasia resulting in severe limitation of mandibular movement. Report of a case

A case of bilateral coronoid hyperplasia with limitation of mandibular motion in a female patient has been presented. Her symptoms began to develop around the age of 44. We believe that this is the first case to be reported in a female. Also, in all other reported cases symptoms began to develop around the onset of puberty. The literature has been reviewed with specific reference to the etiology of bilateral coronoid hyperplasia. This case brings the total number of reported cases to twenty-two. We hope that if similar cases are identified in female patients the practitioners will report them promptly. Only in this way will we be in a better position to understand the etiology of bilateral coronoid hyperplasia with special reference to heredity.

Effects of outpatient treatment for problem drinkers

This study was designed to investigate the effects of treatment length restriction and follow-up interview style on the outcomes of male alcohol abusers in out-patient treatment. Subjects (N = 48) were randomly assigned to one of four independent groups based on the factorial combination of the two independent variables. Extensive pretreatment data were collected about subjects' drinking and related behaviors, and subjects were then scheduled for monthly interviews. Subjects were interviewed for 18 months postadmission concerning these same factors. Subjects' self-reports were compared with collateral reports, official records, and breath tests. Outcome results showed no effects of follow-up interview style or treatment length restriction on drinking behavior and employment outcomes. However, subjects' drinking behavior postadmission was considerably improved compared to their pretreatment ethanol consumption. Temporal analyses of the drinking behavior data showed that it was possible to predict drinking behavior, especially of the same type, within pretreatment and postadmission intervals. However, it was not possible to predict postadmission drinking from pretreatment drinking. Treatment implications of the findings are discussed.