Biomedical subjects
Publications and source records attributed to T K Jones.
Limited orthodontic treatment prior to preparing and making prosthodontic restorations will often enhance the final outcome. A technique using grooved acid-etch composite resin buttons bonded to teeth will increase the effectiveness of removable orthodontic devices.
This article describes an easily made and used intraoral surveying device that can aid the dentist in transferring needed preparation information from the diagnostic cast. This device also allows checking of the preparations as they are progressing. The device consists of a Proxabrush handle and a drafting lead.
Encouraging results of several clinical trials utilizing combination chemotherapy and irradiation in unresectable non-small-cell lung cancer have been reported. A recent report from a cooperative group study suggested that preirradiation vinblastine and cisplatin improved survival over irradiation alone. In an attempt to enhance the possible effectiveness of combination chemotherapy and irradiation, the Radiation Therapy Oncology Group embarked on a Phase II trial utilizing preirradiation vinblastine (5 mg/m2 weekly x 5) and cisplatin (100 mg/m2) on days 1 and 29 prior to irradiation and on days 50, 71, and 92 during irradiation. The irradiation began on day 50 and consisted of 6300 cGy in 7 weeks. Between May 20, 1988 and May 1, 1989, 30 patients were entered on study. Seventy-two percent of patients had Karnofsky status greater than 90, and 76% had weight loss less than 5%. Forty-eight percent of the patients were younger than 60 years of age. Forty-five percent of the patients had Stage IIIA disease. Eighty-three percent of the patients received at least four courses of vinblastine, and 59% received at least four courses of cisplatin. Seventy-eight percent of the patients received at least 95% of the prescribed irradiation. The major toxicity was hematologic, and there were two fatal complications in the study group. The preliminary survival figures are encouraging. This combination of chemotherapy and irradiation appears to be tolerable and may merit further investigation.
A technique for the ipsilateral insertion of tandem 8.5-French catheters for subclavian catheters is presented. This technique allows rapid volume administration while minimizing the risk associated with bilateral subclavian insertions.
Exsanguination may be presumed in pale, mottled, unresponsive trauma victims with no palpable pulse nor spontaneous respirations with noncranial penetrating wounds. Under ideal circumstances, those victims initially witnessed to have some signs of life can be successfully revived in 5 to 25% of cases. The chance for a successful outcome influences the decision to initiate resuscitation and depends on the mode of injury, anatomic location of the wound, and elapsed time until presentation as well as the organization of the available facilities and personnel. The resuscitative algorithm for presumed exsanguination is markedly different from the ACLS guidelines for cardiogenic arrest and requires some degree of surgical expertise. After confirming the witnessed cardiopulmonary arrest from presumed exsanguination, the four phases of resuscitation are restoring central oxygenation, controlling internal hemorrhage, re-establishing spontaneous cardiac function, and definitively repairing the injury. Regardless of the type or location of the noncranial penetrating injury, these phases must be accomplished sequentially to minimize the risks of cerebral and cardiac anoxia.
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Prevention is the best therapy for deep venous thrombosis, but when this fails, prompt diagnosis and appropriate treatment can usually avoid lethal pulmonary embolism. Anticoagulation is the preferred treatment for thromboembolic disease because it prevents lethal pulmonary embolism and also arrests the underlying thrombotic process. However, in specific patients with documented pulmonary embolism or deep venous thrombosis, or who are at high risk that either of these will develop, anticoagulation therapy may be contraindicated, may fail to control the thrombotic process, or may offer inadequate protection from lethal pulmonary embolism. In these instances, or when a previous mechanical attempt has failed to prevent pulmonary embolism from a caval source, a Greenfield filter should be considered. The available information on the natural history of patients in these specific categories and subcategories is reviewed, and the indications for and timing of Greenfield filter placement are explained.
Sixty-five children with severe asthma were tested on a bicycle ergometer to determine their cardiopulmonary endurance and to determine whether they could achieve normal levels of endurance after a physical rehabilitation program. Workloads on entry into the study ranged from 12% to 222% (median 70%) of predicted. Abnormalities in cardiopulmonary endurance did not correlate with historical features commonly used to define severe asthma or degree of airways obstruction. Forty (58%) patients required further bicycle ergometry training two to five times per week: 32 had scores less than 2 SD below the mean, and eight had scores between 1 and 2 SD below the mean. No adverse side effects were encountered during either testing or training. Of the children with scores less than 2 SD below the mean, 84% achieved normal workloads within 2 to 17 weeks of hospitalization. Rates of improvement were similar in the 27 children who subsequently passed and the five children who did not pass, suggesting that duration of program participation was the most important variable in determining success. Thus severely asthmatic children with abnormal fitness levels can achieve normal cardiopulmonary fitness after training on the bicycle ergometer.
One hundred twenty-four patients with tetralogy of Fallot have undergone either primary total repair (61), shunt and later repair (30), or an initial shunt (33). The mean ratio of pulmonary anulus to descending thoracic aorta increased from 0.80 +/- 0.25 before the shunt to 1.22 +/- 0.26 before the repair (p less than 0.0001). The mean ratio in the primary repair group was 1.23 +/- 0.25. A transannular patch was necessary in only six of 91 patients (6.6%). Postrepair right ventricular/left ventricular pressure ratio averaged 0.50 +/- 0.11 in the shunt plus repair group and 0.43 +/- 0.12 in the primary repair group. Only four patients had a right ventricular/left ventricular pressure ratio less than 0.65. A significant inverse linear relationship existed between this ratio and the pulmonary anulus size measured at operation and normalized for the patient's height (p less than 0.01). Postoperative complications occurred in 21% of patients after a shunt and 20% of patients after open heart repair. The early mortality was 0.8% (1/124). An initial shunt in patients with a small pulmonary anulus can result in an increased anulus size and better hemodynamic result with frequent avoidance of a transannular patch. Staged repair may result in improved overall mortality rates.
Previous studies at the University of Minnesota suggest that overall survival rates after treatment for adenocarcinoma of the endometrium are related to increased surgical applicability, that vaginal recurrence is frequently related to cervical involvement, and that virtually all women can safely undergo abdominal hysterectomy and radical irradiation therapy. In this program a simple abdominal hysterectomy was applied to as many women with this disease as possible. High-risk patients also received preoprative or postoperative irradiation. This program increased the survival rate for all stages from 58% to 69.7%. The survival rate among women with Stage I high-risk disease treated with supplementary irradiation was significantly lower when compared to that among women with low-risk disease who were treated by surgery alone. No vaginal recurrences were observed in either group and 98.4% were operated upon. The survival rate of women with Stage II disease treated with irradiation and surgery improved significantly. The rate of vaginal recurrence was 2.2%.
Diagnosis, treatment and follow-up of 8 patients from 1955 to 1975 with extratesticular seminoma are presented. In 5 patients, the neoplasm developed in the mediastinum and in 3 in the retroperitoneum. All the patients were treated by radiation therapy after resection or biopsy. In the entire group, no tumor was diagnosed in the testes. Two patients expired with disease, one after 2 months due to pneumonia, and the other 5 years after diagnosis (10 months after treatment) due to cerebral metastases. Two patients died 12 and 16 years after diagnosis and treatment. At death, they were free of seminoma and the cause of death was a second malignancy. Four patients are alive and healthy, free of disease, 5, 10, 13, and 17 years after diagnosis and treatment. In essence, of the 8 patients, only one actually died of disease, and he was not adequately treated. We feel that this is an entity with an excellent prognosis if adequately and appropriately treated with radiation. We recommend not to perform an orchiectomy when the testes are clinically normal, and to follow the patient closely after treatment.
From 1970 through 1977, 92 patients with ovarian cancer received 20 Gy (2,000 rad) to the abdomen, followed by 30 Gy (3,000 rad) to the pelvis. Small-bowel obstruction developed in 7 (7.6%). The number of previous laparotomies, thin physique, and hypertension were significantly associated with complications. Two patients receiving isoniazid and 2 receiving Premarin had enteric complications. Pre-existing vascular damage may potentiate radiation damage to the small bowel.
Confronted with the hazards of a patient unable to cooperate predictably with a 3-day radium implantation procedure as a part of cancer therapy, the authors describe in a case report their solution to an unusual clinical dilemma. The patient displayed adverse responses to psychotropics and nursing care was markedly restricted by radiation exposure limits. Behavioral management of the patient through the interval of radium therapy was successfully effected by the use of closed-circuit television monitoring combined with brief nursing interventions. This novel psychiatric adjunct to cancer therapy averted the threat posed by displacement of the radium implants.
The protection of the upper thoracic spine achieved by a tube-tilt technique was found to be comparable to that obtained from direct shielding during cross-fire therapy of the intrathoracic esophagus. An isocentric technique was utilized which included one anterior and two posterior-oblique fields. Significant underdosages to the esophagus at levels superior to the isocenter are caused by tube-tilt, whereas direct shielding resulted in a uniformity of esophageal doses to within 5%. The need for a tissue compensator for the anterior field must be assessed on an individual basis from off-axis treatment planning.
The authors describe an independent minicomputer consisting of a CRT and a cassette unit which was designed to store patient data and interact with the main computer at a convenient time. This system permits the computer to handle data entry and treatment planning functions simultaneously. The layout of the overall system, the function of the program and a time analysis of the system are discussed.
The authors suggest that closed-circuit television be used to monitor patients who cannot understand or cooperate with hazardous medical treatment.
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