The accuracy of a high-precision digitizer for CAD/CAM of crowns

An alternative method for manufacturing fixed prostheses that uses machine digitalization and a combination of milling and spark erosion has been developed. The digitizer used has a contact probe with a ball-shaped tip. This study evaluated the accuracy of the device and the transfer of data from the individual die to the computer. The dimensions of a square gauge as read by the machine were compared with the known dimensions of the object with a computer, which allowed determination of the accuracy of the digitalization. Procera machining and the implications for reliable prosthodontic treatment are discussed.

A 25 year longitudinal study of patients treated with removable partial dentures

A 25 year longitudinal study was carried out on a number of patients fitted with removable partial dentures (RPDs) in 1969. Before the prosthetic treatment all patients were given oral hygiene motivation and instructions in order to create a high level of co-operation. The RPDs, most of which were lower bilateral distal extension dentures, were carefully planned and designed. During the first 10 years the patients were examined in our clinic at yearly intervals at which time encouragement and reinstruction regarding oral hygiene were given and various treatment procedures were performed as required. After the initial 10 years the patients were advised, for practical reasons, to continue to have yearly controls on their own initiative. Of the initial 30 patients from 1969, 23 were still alive in 1994, all of whom were examined. In five of those 23 the original RPD situation had changed more or less due mainly to general illness contracted and/or change to other therapies. In the remaining 18 patients wearing in total 20 RPDs, 13 (65%) of the original RPDs were still functioning. Seven RPDs were new with principally the same design as the original ones. Among these 18 patients the number of lost teeth, the number of new DF surfaces and the increased number of endodontically treated teeth were few. No apparent changes took place regarding the periodontal condition during the follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)

Sociodemographic characteristics and criminality in victims of firearm injuries

This study is based on all victims of firearm injuries (n = 820) treated in public hospitals in Stockholm, Sweden, between 1972 and 1992. The aim of the study was to determine the sociodemographic characteristics, criminality, and mortality in victims of firearm injuries. The diagnosis was accident in 56.0%, suicide/attempted suicide in 11.7%, murder/attempted murder in 20.6%, and undetermined in 11.7%. Information was procured from the Swedish National Population Register, the Swedish National Board of Health and Welfare's register on causes of death, and the Swedish National Police Board's register on sentences passed. The average victim of a firearm injury was a young man, single, and often divorced. The proportion of immigrants was larger than expected, involvement in criminality was massive, and the mortality rate was high. The risk of being killed by the gunshot if brought to the hospital alive was relatively low, except in the cases of attempted suicide. The recurrent rate in violent trauma was high. It is suggested that secondary prevention could make an important contribution to the reduction of firearm injuries and fatalities. If the necessary surgical care is supplemented with a psychosocial intervention program to help the patient change his or her current situation, the number of "chronic" victims of violence could be reduced.

Long-term survival in small-cell lung cancer: posttreatment characteristics in patients surviving 5 to 18+ years--an analysis of 1,714 consecutive patients

PURPOSE

To describe in patients with small-cell lung cancer (SCLC) the characteristics of those who survive for > or = 5 years, to identify long-term prognostic factors, to analyze survival data of 5-year survivors, and to study 10-year survival in patients entered before 1981.

PATIENTS AND METHODS

A total of 1,714 unselected patients with SCLC were treated with combination chemotherapy in nine consecutive clinical trials from 1973 to 1991. All medical records were reviewed and follow-up data obtained to analyze and compare pretreatment and posttreatment characteristics.

RESULTS

Sixty patients survived longer than 5 years. Late relapses occurred in 15.0% of 5-year survivors and secondary malignancies in 20.0%. Twenty-six patients are still alive and disease-free 5 to 18 years (median, 9.5 years) from initiation of treatment. Extensive-stage disease, performance status (PS) more than 2, liver and bone marrow metastases, and elevated lactate dehydrogenase (LDH) and alkaline phosphatase levels were all negative prognostic factors. The 5-year survival rate was 3.5% (limited-stage disease, 4.8%; extensive-stage disease, 2.3%), and the 10-year survival rate was 1.8% (limited-stage disease, 2.5%; extensive-stage disease, 1.2%).

CONCLUSION

Long-term survival can be achieved for both stages of SCLC, but without any change in survival rates over the last decade. Long-term survivors continuously seem to have considerable mortality due to late relapses and secondary malignancies, especially tobacco-related cancers and other tobacco-related diseases.

Quality-of-life and cost-effectiveness assessment in lung cancer

This paper reviews recent advances in the methods for assessing the quality of life of patients with lung cancer and recent applications of quality-of-life measures in lung cancer clinical trials. In terms of methodology, there exist today a number of self-report quality-of-life questionnaires that are valid, reliable, and sufficiently brief to be of practical use in clinical research settings. Application of these measures in lung cancer clinical trials has contributed to the evaluation of: 1) long-versus short-duration chemotherapy, four- versus two-drug combinations, intensive versus standard chemotherapy, and continuous versus bolus injection chemotherapy in the treatment of small cell lung cancer; 2) high versus low radiation doses in the treatment of non-small cell lung cancer; 3) megestrol acetate and hydrazine sulfate as supportive treatment for small cell lung cancer and non-small cell lung cancer patients receiving chemotherapy; 4) granulocyte colony-stimulating factor in small cell lung cancer patients receiving dose-intensified chemotherapy; and 5) the rehabilitation needs of lung cancer survivors. Future efforts should be directed toward achieving higher levels of compliance with clinical trial-based quality-of-life studies, and the development of techniques for integrating quality of life and clinical outcomes for purposes of cost-effectiveness evaluations.

Effect of the carbon dioxide laser on viability of ear cartilage in a rabbit model

The carbon dioxide (CO2) laser can be used for rapid, detailed sculpting of cartilage for creation of an ear framework for reconstruction of microtia. Clinical and animal studies of the effect of the CO2 laser have noted good healing with little evidence of a zone of tissue injury adjacent to the laser incisions. The current study has investigated the longer term effect of CO2 on chondrocyte viability in a rabbit ear model in which the laser has been used to incise autogenous cartilage segments for implantation into subcutaneous pockets. Over a 3-month period, the conformational integrity of the segments, when compared to segments incised with a scalpel, was no different. However, radioactive sulfur uptake studies to assess the viability of chondrocytes indicated a decrease in chondrocyte density in those specimens that have been subjected to laser incisions. Although other studies of acute cellular injury indicate that the CO2 laser may be beneficial for cartilage incision and sculpting, the current study indicates that resorption over longer periods of time might be encountered as a consequence of decreased chondrocyte viability in the vicinity of the laser incisions.

Corrosion of titanium and amalgam couples: effect of fluoride, area size, surface preparation and fabrication procedures

OBJECTIVES

The aim of this investigation was to study the effect of surface treatments and electrode area size on the corrosion of cast and machined titanium in contact with conventional and high-copper amalgams in saline solutions with and without added fluoride ions.

METHODS

The potentials and the charges transferred between amalgam and titanium couples were registered using standard electrochemical methods.

RESULTS

Conventional amalgam corroded more than high-copper amalgams in contact with titanium in saline solutions. Adding fluoride to the solution made the titanium potential more active and enhanced the corrosion of titanium in combination with high-copper amalgams. The amalgam corrosion increased with a five-fold enlargement of the titanium area. The increase was significant for one titanium-amalgam combination. Surface preparations affected the electrochemical behavior, and surface alterations were occasionally observed on wet-ground titanium specimens. No significant differences were found in comparisons of cast and lathe-cut titanium.

SIGNIFICANCE

Surface preparations and fluoride affect the electrochemical activity of titanium.

Characteristics of violent alcoholics

This study is based on interviews with 53 male alcoholics. Its purpose was to study the relationship between childhood conditions, history of alcohol and drug misuse and assaultive and suicidal behaviour. Fifty-seven per cent of the alcoholics reported a history of violent behaviour. Hidden violence, often towards women, was common. One-third of the violent patients had a history of attempted suicide compared to 17% in the non-violent group. The assaultive alcoholics also had a more violent childhood, a higher proportion of fathers with alcohol problems and had started drinking earlier in life. Drug addiction was much more common in this group too. We find support for our hypothesis that there is a positive correlation between violence in the parental home and assaultive and suicidal behaviour and drug misuse later in life. When violent and non-violent alcoholics are compared many of the same characteristics appear as when suicidal and non-suicidal and type 2 and type 1 alcoholics are compared. This study raises the question of adding attempted suicide as a characteristic of the type 2 alcoholic.

Characteristics of imprisoned wife-beaters

The aim of this study is to present the authors' recent findings concerning the wife-beater and to discuss the existing state of knowledge as well as practical implications concerning the treatment of these men. The study presents interview and register data as well as some endocrinological findings in 18 wife-beaters sentenced to prison. These men generally lived under unfavourable socio-economic conditions, half of them were immigrants and most of them had been maltreated as children. Drug and alcohol abuse was common. The men showed an overconsumption of both somatic in-patient and out-patient care but had virtually no previous psychiatric history. Depressive symptoms were common, however, as were anti-social personality traits, reflected in a marked involvement in both violent and non-violent offences. The levels of testosterone were generally high. It is argued that the most efficient therapeutic approach would be to treat alcohol and drug addiction, an aspect of rehabilitation that has often been underestimated or overlooked in previous treatment programmes. The period of imprisonment could be utilized for these purposes, as an alcoholic who becomes sober is probably less prone to abuse his wife.

Hormone levels and personality traits in abusive and suicidal male alcoholics

This study presents personality and biochemical correlates to abusive and suicidal behavior in 49 male alcoholics. Our hypothesis was that neuroendocrine and personality characteristics reflect a postulated regulatory mechanism that determines the direction of aggression either outward (abusive) or inward (suicidal). Eleven patients (22%) had physically abused someone on one occasion and 15 (31%) constituted a more violent subgroup with repeated instances of abuse. Thirteen (27%) had attempted suicide at least once. There was a significant positive correlation between the number of abusive and suicidal events (r = 0.33). The violent subgroup with repeated episodes of physical abuse had elevated levels of serum testosterone and low levels of cortisol when compared with the rest of the sample. Aggressive, antisocial, and impulsive personality traits were common. Suicidal alcoholics did not differ from the rest regarding hormone levels, but exhibited high impulsivity and muscular tension on the personality test. It is suggested that the high impulsivity without aggressive traits makes them exhibit autoagressive rather than abusive behavior. Both the abusive and suicidal alcoholics partly had a history typical of the type 2 alcoholic. We propose that these two categories constitute subgroups of the type 2 alcoholic determined by a combination of genetic predisposition to alcoholism, certain personality traits, and, with regard to the violent group, also hormone disturbances. We find it highly justified to identify and treat these subgroups because of their harmful acting-out behavior.

Does digital chest radiography assess regional ventilation?

Digital radiography of the chest was evaluated for estimation of regional ventilation disturbances. Thirty-three patients with suspected bronchial carcinomas were examined. Objective measurements of regional density changes during breathing correlated significantly with standardized regional lung function tests (133Xe ventilation scintigraphy), but did not permit reliable individual estimations of regional ventilation. About 35% of the density variations could be explained by regional ventilation. Thus, factors other than ventilation, e.g. changes in the geometry of the thorax, have a major impact on the density variation at digital radiography.

Titanium copings veneered with Procera ceramics: a longitudinal clinical study

In 1989, 47 titanium copings veneered with a low-fusing ceramic were fabricated for 24 patients. Forty-four crowns could be examined after a period varying between 26 and 30 months. It was found that the bulk ceramic of two crowns had fractured. California Dental Association ratings for "Surface and Color" had changed markedly from the "Excellent" to the "Acceptable" level, and for "Anatomic Form" there was a small shift from the "Excellent" to the "Acceptable" level. The factor of "Margin Integrity" was recorded as "satisfactory" for all crowns and a large majority were rated "Excellent."

Islet-specific T-cell clones from the NOD mouse respond to beta-granule antigen

Islet-reactive T-cell clones from NOD mice provide an important approach to the investigation of antigens with relevance to type I diabetes. To identify a source of beta-cell antigen suitable for biochemical studies, we have used two islet-specific, diabetogenic T-cell clones to test beta-tumor cells. beta-tumor cell lines, maintained in continuous culture, were found to lose antigenicity rapidly. However, cells harvested directly from beta-tumors arising spontaneously in the transgenic NOD/Lt-Tg(RIPTag)1Lt mouse proved to be a potent source of beta-cell antigen for the T-cell clones. Subcellular fractionation of beta-tumor cells showed that the T-cell antigen was highly enriched in the beta-granule fraction and that this activity was associated with the granule membrane.

The EORTC QLQ-LC13: a modular supplement to the EORTC Core Quality of Life Questionnaire (QLQ-C30) for use in lung cancer clinical trials. EORTC Study Group on Quality of Life

The EORTC Study Group on Quality of Life has developed a modular system for assessing the quality of life of cancer patients in clinical trials composed of two basic elements: (1) a core quality of life questionnaire, the EORTC QLQ-C30, covering general aspects of health-related quality of life, and (2) additional disease- or treatment-specific questionnaire modules. Two international field studies were carried out to evaluate the practicality, reliability and validity of the core questionnaire, supplemented by a 13-item lung cancer-specific questionnaire module, the EORTC QLQ-LC13. In this paper, the results of an evaluation of the QLQ-LC13 are reported. The lung cancer questionnaire module comprises both multi-item and single-item measures of lung cancer-associated symptoms (i.e. coughing, haemoptysis, dyspnoea and pain) and side-effects from conventional chemo- and radiotherapy (i.e. hair loss, neuropathy, sore mouth and dysphagia). It was administered to patients with non-resectable lung cancer recruited from 17 countries. In total, 883 and 735 patients, respectively, completed the questionnaire prior to and once during treatment. The symptom measures discriminated clearly between patients differing in performance status. All item scores changed significantly in the expected direction (i.e. lung cancer symptoms decreased and treatment toxicities increased) during treatment. With one exception (problems with a sore mouth), the change of toxicity measures over time was related specifically to either chemo- or radiotherapy. However, the single item on neuropathy did not measure adequately the full range of symptoms. The hypothesised scale structure of the questionnaire was partially supported by the data. The multi-item dyspnoea scale met the minimal standards for reliability (Cronbach alpha coefficient > 0.70), while the pain items did not form a scale with reliability estimates acceptable for group comparisons. In conclusion, the results form international field testing lend support to the EORTC QLQ-LC13 as a clinically valid and useful tool for assessing disease- and treatment-specific symptoms in lung cancer patients participating in clinical trials, when combined with the EORTC core quality of life questionnaire. In a few areas, however, the questionnaire module could benefit from further refinements. In addition, its performance over a longer period of time still needs to be investigated.

Septic arthritis of the knee: a 10-year review and long-term follow-up using a new scoring system

The case records of 64 patients with 65 episodes of infectious gonarthritis during 1979-88 were reviewed regarding epidemiological, clinical and laboratory data of possible relevance to the course and outcome of the disease. Long-term healing results were evaluated by means of a new scoring system 2-11 years after the acute disease in 46 patients. The infection was acquired by inoculation in 37% and by the hematogenous route in 55%. The major risk factors were trauma to the joint and arthrosis. Staphylococcus aureus was the causative agent in 58% and Streptococci in 15%. Treatment consisted of suction irrigation (86%) or intermittent aspiration (5%) combined with systemic antibiotic treatment. At follow-up, the pain and ache scores of the arthritic joint had decreased by 21% and 16% respectively, compared with the scores of the contralateral control joints. Anatomy and motility were reduced by 9% and 8% respectively. Age < 45 was associated with a greater score loss than in older patients. Treatment delayed by > 5 days was associated with increased loss of motility. We estimate that 79% of the patients had excellent or good long-term results following treatment of infectious arthritis of the knee. Evaluation of healing after infectious gonarthritis by use of a scoring system is quite feasible and allows comparison of different treatment regimes with improved accuracy.

Assailants and victims: a comparative study of male wife-beaters and battered males

Eighteen male wife-beaters were compared with 19 battered males concerning their background, history of addiction and present social situation, as well as present violence. The two groups of males had a very similar background including violence in their parental home. Alcohol and drug problems were common, the males generally belonged to the lower social classes and the number of divorcees was large. Many of the battered males had abused someone and the male batterers had been victimized themselves. It is concluded that the roles as victims and assailants vary among these men. The same background and precipitating factors will predestine the male to be a batterer or to be battered, but most probably both.

Nasal mucosal congestion after treatment with bromocriptine

Nine women were given bromocriptine a few days after delivery in order to inhibit lactation. Nasal airway resistance to airflow (NAR) was recorded and blood samples were taken before treatment with bromocriptine, 2 to 3 hours after the first dose of this drug, and after 3 to 5 days on this treatment. All the women had increased nasal congestion after bromocriptine and NAR rose significantly. The prolactin, estradiol, and progesterone hormone levels decreased significantly, but no significant difference was found in the levels of thyroid-stimulating hormone (TSH) and vasoactive intestinal polypeptide (VIP). The bromocriptine effect may be caused by different mechanisms.

Cytochrome Oxidase: Subcellular Distribution and Relationship to Nitrogenase Expression in the Nonheterocystous Marine Cyanobacterium Trichodesmium thiebautii

Immunochemical labeling was used to study the subcellular distribution of cytochrome oxidase, a respiratory protein, in Trichodesmium thiebautii . The protein was found associated with both cytoplasmic and thylakoid membranes. About a sixfold variation in the protein content (gold particle count) was found among Trichodesmium cells within a single colony. Double labeling was performed with cytochrome oxidase and nitrogenase antisera. Regression analysis of gold particle counts per unit of cell area of cytochrome oxidase and nitrogenase showed a positive correlation ( r 2 = 0.911); cells with higher nitrogenase levels also had higher levels of cytochrome oxidase. The parallel expression of two proteins suggests that respiratory oxygen uptake may be involved in nitrogenase protection (respiratory protection) in Trichodesmium spp.

Rubisco but not Rubisco activase is clustered in the carboxysomes of the cyanobacterium Synechococcus sp. PCC 7942: Mud-induced carboxysomeless mutants

The Mud technology of Groisman and Casadaban was adapted to the cyanobacterium Synechococcus sp. PCC 7942. A new high-CO2-requiring (hcr) mutant, hcr Mu28 was isolated following the integration of the Mud element 89 bp upstream of ORFI, at the 5'-flanking region of the rbc operon, which encodes RuBP carboxylase/oxygenase (Rubisco). The integration involved a 7 bp duplication that formed a direct repeat at the integration site, as previously shown in Escherichia coli. The mutant was devoid of apparent carboxysome bodies, which are considered to be important for the availability of CO2 for Rubisco. Immunolabelling studies demonstrated that Rubisco was distributed throughout hcr Mu28 cells, while in the wild type (WT) and in the carboxysome aberrant mutant hcr O221, Rubisco was markedly associated with the carboxysomes. Rubisco activase, however, was evenly distributed throughout the cytosol of the hcr and WT cells, without any preferential association with the apparent carboxysomes.

A clinical evaluation of conical crown retained dentures

In an uncontrolled retrospective recall study of 57 patients treated with conical crown retained dentures, 60 restorations (37 in the maxillae and 23 in the mandible jaw) with a mean wearing time of 30.1 months (range 4 to 76) were evaluated. Of the 248 abutments, eight (3.2%) had been lost. Clinically healthy mucosa was seen in 35 jaws. The marginal fit of the copings was judged to be good. No caries or new restorations were observed in 44 patients. Thirteen patients had 19 surfaces with new restorations and 20 surfaces with caries lesions. Of these 39 surfaces, 38 were located subgingivally.

Otoacoustic emissions from normal-hearing and hearing-impaired subjects: distortion product responses

Distortion product otoacoustic emissions (DPOAE) were measured in normal-hearing and hearing-impaired human subjects. Analyses based on decision theory were used to evaluate DPOAE test performance. Specifically, relative operating characteristic (ROC) curves were constructed and the areas under these curves were used to estimate the extent to which normal and impaired ears could be correctly identified by these measures. DPOAE amplitude and DPOAE/noise measurements were able to distinguish between normal and impaired subjects at 4000, 8000, and, to a lesser extent, at 2000 Hz. The ability of these measures to distinguish between groups decreased, however, as frequency and audiometric criterion used to separate normal and hearing-impaired ears decreased. At 500 Hz, performance was no better than chance, regardless of the audiometric criterion for normal hearing. Cumulative distributions of misses (hearing-impaired ears incorrectly identified as normal hearing) and false alarms (normal-hearing ears identified as hearing impaired) were constructed and used to evaluate test performance for a range of hit rates (i.e., the percentage of correctly identified hearing-impaired ears). Depending on the desired hit rate, criterion values of -5 to -12 dB SPL for DPOAE amplitudes and 8 to 15 dB for DPOAE/noise accurately distinguished normal-hearing ears from those with thresholds greater than 20 dB HL for the two frequencies at which performance was best (4000 and 8000 Hz). It would appear that DPOAE measurements can be used to accurately identify the presence of high-frequency hearing loss, but are not accurate predictors of hearing status at lower frequencies, at least for the conditions of the present measurements.

The European Organization for Research and Treatment of Cancer QLQ-C30: a quality-of-life instrument for use in international clinical trials in oncology

BACKGROUND

In 1986, the European Organization for Research and Treatment of Cancer (EORTC) initiated a research program to develop an integrated, modular approach for evaluating the quality of life of patients participating in international clinical trials.

PURPOSE

We report here the results of an international field study of the practicality, reliability, and validity of the EORTC QLQ-C30, the current core questionnaire. The QLQ-C30 incorporates nine multi-item scales: five functional scales (physical, role, cognitive, emotional, and social); three symptom scales (fatigue, pain, and nausea and vomiting); and a global health and quality-of-life scale. Several single-item symptom measures are also included.

METHODS

The questionnaire was administered before treatment and once during treatment to 305 patients with nonresectable lung cancer from centers in 13 countries. Clinical variables assessed included disease stage, weight loss, performance status, and treatment toxicity.

RESULTS

The average time required to complete the questionnaire was approximately 11 minutes, and most patients required no assistance. The data supported the hypothesized scale structure of the questionnaire with the exception of role functioning (work and household activities), which was also the only multi-item scale that failed to meet the minimal standards for reliability (Cronbach's alpha coefficient > or = .70) either before or during treatment. Validity was shown by three findings. First, while all interscale correlations were statistically significant, the correlation was moderate, indicating that the scales were assessing distinct components of the quality-of-life construct. Second, most of the functional and symptom measures discriminated clearly between patients differing in clinical status as defined by the Eastern Cooperative Oncology Group performance status scale, weight loss, and treatment toxicity. Third, there were statistically significant changes, in the expected direction, in physical and role functioning, global quality of life, fatigue, and nausea and vomiting, for patients whose performance status had improved or worsened during treatment. The reliability and validity of the questionnaire were highly consistent across the three language-cultural groups studied: patients from English-speaking countries, Northern Europe, and Southern Europe.

CONCLUSIONS

These results support the EORTC QLQ-C30 as a reliable and valid measure of the quality of life of cancer patients in multicultural clinical research settings. Work is ongoing to examine the performance of the questionnaire among more heterogenous patient samples and in phase II and phase III clinical trials.