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Biomedical subjects

R Middleton

Publications and source records attributed to R Middleton.

34 records · Page 2Linked to original sources
PubMed1991

Accelerator mass spectrometry: application to study of aluminum kinetics in the rat.

The advent of accelerator mass spectrometry (AMS) now permits the ultrasensitive detection of extremely long-lived isotopes, including 14C, 26Al, and 41Ca. Until now, tracer studies of aluminum kinetics have not been possible because aluminum has only two isotopes, with half-lives of 6.5 min (29Al) and 7 x 10(5) yr (26Al), neither of which is suitable for conventional studies. In a novel experiment we have employed AMS to study aluminum kinetics in a normal rat and a 5/6-nephrectomized rat over a 3-wk period of intravenous injection of a tracer dose of 26Al. Kinetics were similar in the two animals; approximately 75% of intravenously injected tracer 26Al was excreted in the urine in the first 24 h as was approximately 80% after 3 wk. Renal clearance of 26Al was approximately 0.75 ml.min-1.kg body wt-1 in both rats. The results clearly demonstrate the potential of this technique for isotope tracer studies in animals as well as in humans.

Aluminum↗
PubMed1991

Tuberculous pleural effusion. Twenty-year experience.

We reviewed the records of 1,738 cases of tuberculosis seen during the period from 1968 to 1988 in Mobile, Alabama. Seventy cases of tuberculous pleural effusion were identified and constituted 4.9 percent of all disease due to Mycobacterium tuberculosis during this period. Tuberculous pleural effusion was diagnosed if the patient had M tuberculosis cultured from sputum, pleura, or pleural fluid and had a roentgenographic pleural effusion without an alternative explanation for the presence of the effusion. The diagnosis of tuberculous pleural effusion was made in the absence of a positive culture if the patient had an undiagnosed lymphocytic exudative pleural effusion and all clinical and roentgenographic abnormalities resolved on antimycobacterial chemotherapy. The mean age of all patients was 47 +/- 18.4 years. The 70 cases were evenly divided between 35 that were accompanied by roentgenographic pulmonary parenchymal infiltrates and 35 that occurred in the absence of parenchymal infiltrates. We conclude that cultures of all potentially diagnostic specimens (sputum, pleural fluid, and pleura) and an intermediate-strength skin test, are sensitive tests for the diagnosis of tuberculous pleural effusion. In addition, the age of patients with tuberculous pleural effusion appears to be increasing.

Adult↗
PubMed1985

Familial osteochondritis dissecans: a dysplasia of articular cartilage?

Two cases of osteochondritis dissecans in a boy and his mother are described. In the son only the knee and elbow joints and the epiphysis of the right second metacarpal were involved, whereas the mother showed early generalised degenerative joint disease associated with many large loose bodies in one knee. The authors speculate that familial osteochondritis dissecans is a dysplasia of articular cartilage caused by abnormal chondrocyte metabolism.

Adult↗
PubMed1985

Advanced carcinoma of the nasopharynx. 2. Pattern of failure in 256 patients.

Of 256 patients with advanced carcinoma of the nasopharynx, 82% presented with Stage IV disease. The 5-year survival was 15% with 83% failing within 2 years. Prognosis was related to stage (p less than 0.03), neck status (p less than 0.03), initial performance status (p less than 0.001) and radiation dose (p less than 0.003). With no pathological neck glands (N0), less than 5% failed radiotherapy. Overall, 36% had distant metastases, correlating with the N Stage (p less than 0.001) but not with the T Stage. The most frequent site of metastasis was lung, then bone and liver. Radical neck dissection failed to increase tumor control, contributing to three fatal complications. New radiotherapeutic regimens have so far failed to substantially improve the results.

Adult↗
PubMed1983

Cis-platinum induction chemotherapy in the multi-modality initial treatment of advanced stage IV carcinoma of the head and neck.

Twenty-eight previously untreated patients with unresectable and radical radiotherapy incurable advanced stage IV squamous cell carcinoma of the head and neck underwent cis-diamminedichloroplatinum (DDP) induction chemotherapy followed by radiation with 6500 rad to the primary and 5000 rad to the supraclavicular area given over six weeks. Of the 26 patients completing this regimen, none had a complete remission after DDP alone. Following radiation therapy, 39% of the patients had a total regression of all disease. This modality converted 16 patients to operable candidates. After surgery, 68% of the patients were in complete remission. Survival was significantly correlated (P less than or equal to 0.001) with complete disappearance of disease, and surgical intervention was additive to chemotherapy and radiation. Histopathologic staging demonstrated that clinical assessment of residual disease in the neck determined after chemotherapy and radiation of the neck was unreliable. Therefore, radical neck dissection appears indicated in lesions initially staged as N2 and N3 irrespective of the postradiation clinical status of the neck region. Finally, a serious limitation of improved survival duration was the occurrence of disseminated disease in patients whose primary and regional lesions were well controlled.

Carcinoma, Squamous Cell↗
PubMed1982

Advanced carcinoma of the nasopharynx. A clinical study of 274 patients.

A total of 274 patients with a diagnosis of nasopharyngeal carcinoma was treated in eight Veterans Administration Hospitals over a period of 22 years. Of the 274 patients, 256 (93%) had squamous-cell carcinoma, while 18 (7%) had other tumors. Most of the squamous-cell carcinoma patients (82%) had Stage IV disease; cervical lymph node metastases were found in 193 (75%), and distant metastases were present in 22 (9%). The actuarial 5-, 10-, and 15-year survival rates for the 256 squamous-cell carcinoma patients were 15%, 10%, and 7%, while they were 49%, 42%, and 35% for the 18 patients with other tumors (p = 0.006). There was a progressive decrease in 5-year survival with the increase in the stage of tumor. The survival of the 63 patients without metastases was better than the survival of the 193 patients with cervical metastases (24% vs. 12% at 5 years, p = 0.03). The presence of T4 disease or Initial Performance Status of less than 80 on the Karnofsky Scale indicated a poor prognosis (p = 0.0001). Treatment failure occurred in 83% of the patients by 2 years after therapy and was due to the lack of tumor control at the primary site. Advanced (N3) cervical lymph node metastases indicated that systemic tumor dissemination of the nasopharynx is an uncommon malignancy.

Adult↗
PubMed1981

Mandibular and para-mandibular tumors in children. Report of 16 cases.

Sixteen cases of mandibular tumors or paramandibular soft tissue tumors with mandibular involvement are reported. These include such rare mandibular tumors or tumor-like conditions as melanotic progonoma, intraosseous haematoma secondary to von Willebrand's disease, post-irradiation osteosarcoma, monostotic eosinophilic granuloma, aneurysmal bone cyst and osseous hemangiopericytoma. Three cases of cherubism, one of fibrous dysplasia or aggressive fibromatosis and one of central giant cell reparative granuloma are also reported. The soft tissue tumors comprise round cell sarcoma, parotid adeno-carcinoma with generalised metastases, embryonal rhabdo-myo-sarcoma, neuro-fibro-sarcoma and congenital cystic hygroma. In all the cases the disease was well advanced when the patient presented for X-ray examination. The specific X-ray diagnosis of mandibular and paramandibular tumors in childhood is more difficult than that of similar tumors in other parts of the body.

Adolescent↗
PubMedDate not supplied

Partial growth plate closure: apex view on bone scan.

A new technique of using 99mTc bone scan to assess partial closure of the growth plate is described. The site and degree of osseous fusion can be obtained by using the apex view. The technique has the potential of assessing serially the growth of a plate before and after surgery.

Bone Diseases↗