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Biomedical subjects

D W Johnson

Publications and source records attributed to D W Johnson.

At least 217 records · Page 12Linked to original sources
PubMed1984

Temporal bone trauma: high-resolution computed tomographic evaluation.

High-resolution computed tomography (CT) was used to examine 12 patients with temporal bone trauma. The CT findings were correlated with the clinical signs and symptoms (hearing loss, facial nerve dysfunction) and with the operative findings in the 5 patients who underwent surgery. CT was able to demonstrate ossicular chain disruption or fractures causing the clinical findings in the majority of cases. The CT findings affected patient care by alerting the otologist to the abnormalities likely to be encountered during surgery.

Adult↗
PubMed1984

An adjustable breast bridge for use in multiple-plane interstitial breast implants.

A newly designed adjustable breast bridge used for patients requiring multiple-plane interstitial breast implants is described. The bridge offers a simple, rapid, and accurate method for determining interplane separation on the sloping breast surface, and is applicable to breasts of all shapes and sizes. The precise interplane spacing of 192Ir sources made possible by using the breast bridge provides uniformity of dose within the implanted volume. The breast bridge allows the radiotherapist to alter interplane spacing to optimise the dose rate to the implanted volume, based upon the preplanned number and strength of 192Ir seeds to be used for each case.

Brachytherapy↗
PubMed1984

Protein synthesis but not DNA synthesis is required for tumor cell invasion in vitro.

The effects of protein and DNA synthesis inhibitors on in vitro tumor cell invasion was studied in a quantitative invasion system using human amnion. Highly invasive M5076 tumor cells were incubated on the basement membrane (BM) of the amnion in the presence of cycloheximide, aphidicolin or sodium butyrate. Tumor cell penetration through the entire thickness of the amnion was measured after 24 h. Protein synthesis in the M5076 cells was inhibited 95% within 1 h by 10(-6)M cycloheximide while DNA synthesis was unaffected. Treatment with cycloheximide reduced the number of spontaneously invading cells by 82% and by 66% in the presence of the chemoattractant, formylmethyl leucine-phenylalanine (FMLP), known to stimulate invasiveness. DNA synthesis in the M5076 tumor cells was selectively inhibited with aphidicolin (10 micrograms/ml). Although the DNA synthesis was greatly reduced, no significant effect on invasiveness with or without FMLP was observed. A less specific inhibitor of DNA synthesis, sodium butyrate (1 mM), arrested cell proliferation in the G1 phase of the cell cycle. When the butyrate-treated M5076 cells were tested in the invasion assay, a 50% increase in the number of invasive cells was observed. All three inhibitors were used in concentrations that did not affect cell viability or cell attachment to the amnion. These data indicate that protein synthesis but not DNA synthesis and not cell proliferation are required for tumor cells to invade native connective tissue barriers in vitro.

Amnion↗
PubMed1984

Brucellosis control in an infected herd by serological testing, removal of reactors, vaccination with reduced dose of strain 19 and improved hygiene.

Brucellosis was diagnosed in a closed herd of approximately 200 Fresian cattle in February 1982. Diagnosis was based on positive serologic tests and abortions from which B. abortus was isolated. Initial efforts to control the disease were the isolation of all cows which were positive on the standard tube agglutination test. In addition all cows which calved or aborted were isolated. In August 1982 all cows which were negative to the standard tube agglutination test were vaccinated with a reduced dose of strain 19 vaccine (approximately 1 X 10(9) organisms). The herd was retested 60 days after vaccination and all animals which were positive on the rivanol supplemental test at a titer of 1:50 or greater were considered infected and removed from the herd. Subsequent to vaccination there were an additional 22 cows which aborted. These cows were removed from the herd. A calfhood vaccination programme utilizing the standard dose of strain 19 has been initiated in the herd. An increased effort was made to maintain all of the stables at a higher level of sanitation.

Abortion, Veterinary↗
PubMed1984

CT of the postsurgical ear.

High-resolution CT has proved to be a reliable and accurate method for evaluating the postsurgical ear. The presence or absence of cholesteatoma can usually be determined. Because of this, CT is a viable alternative to the "second look" or staging surgical procedure. Methods, techniques, and case examples are discussed.

Cholesteatoma↗
PubMed1983

Hodgkin's disease limited to intrathoracic sites.

The records of 1470 patients treated for Hodgkin's disease between 1960 and 1980 were reviewed, and sites of initial involvement were scored. Forty-four patients had disease limited to the chest after clinical and/or pathologic staging. Eighteen asymptomatic patients underwent a staging laparotomy and no occult subdiaphragmatic disease was identified. All 44 patients were treated with irradiation (XRT) to involved (IF), mantle (M), subtotal lymphoid (STLI), or total lymphoid (TLI) fields. Eighteen patients were also treated with chemotherapy, consisting of nitrogen mustard, vincristine, and procarbazine, with or without prednisone (MOP(P)), or procarbazine, melphalan, and vinblastine (PAVe). With a median follow-up of 7.5 years the survival at five and ten years was 93% and 89%, respectively, and the freedom from relapse (FFR) at five and ten years was 81% and 78%, respectively. Ten patients relapsed, all in supradiaphragmatic sites (including six relapses within lung parenchyma). Eight had initially received XRT alone, and two had received combined modality treatment. The risk of relapse in the 26 patients treated with XRT alone varied inversely with the volume irradiated: IF, 100% (3/3); M, 45% (3/7); STLI, 17% (2/12); TLI, 0% (0/4) relapsed. Seven of the eight relapsing patients treated with XRT alone were salvaged with subsequent XRT and/or chemotherapy whereas both of the combined modality patients who relapsed, died with progressive disease despite all salvage therapy.

Antineoplastic Agents↗
PubMed1983

High resolution CT scanning for detection of cholesteatoma and complications in the postoperative ear.

Otologists who prefer intact canal wall surgery for removal of cholesteatoma recognize a 12.25% return rate. Revisions often indicated to correct hearing loss are frequently negative for recurrent cholesteatoma. To determine the reliabiity of a noninvasive method of diagnosing recurrent disease and possible complications, 40 patients previously operated on for cholesteatoma using the intact canal wall technique were scanned with a General Electric 8800 scanner. Second procedures were performed on 24 patients and findings compared with preoperative film interpretations. Scans correctly predicted no significant masses in 6 patients and cholesteatoma recurrence in 11; the remaining 6 with diffuse soft tissue changes were incorrectly diagnosed. Focal areas of bone erosion were detectable in 3 cases, indicating active or potential complications. Scans were reliable in detecting cholesteatoma depending upon the pathology.

Cholesteatoma↗
PubMed1983

The use of para-aortic radiation therapy based on lymphangiogram interpretation in uterine cervical carcinoma.

From January, 1965, to June, 1979, 79 nonrandomized patients with carcinoma of the uterine cervix had a bipedal lymphangiogram (LAG) prior to radiotherapy at the Stanford University Medical Center. In 32 patients the LAGs were interpreted as normal. Of the remaining 47 patients, 28 had LAGs interpreted as positive for metastatic involvement of pelvic nodes alone, 11 as positive for pelvic and para-aortic (PA) metastasis, and 8 as positive in PA nodes alone. Five-year survival and freedom from relapse (FFR) were found to be similar for patients with LAGs interpreted as normal or positive in pelvic nodes only (all stages combined). The addition of elective PA irradiation in those patients with positive pelvic nodes alone (median 5000 rad/5 weeks) did not enhance either survival or FFR in this group. The 19 patients with positive PA nodes had significantly worse survival and FFR when compared with the other groups. Survival was not enhanced by the addition of therapeutic PA irradiation (median 5000 rad/5 weeks) and the 7 patients in this group so treated appeared to have a reduced FFR when compared to the 12 untreated patients. Irrespective of the location of nodal abnormality on LAG and regardless of stage, the majority of relapses (16/23) occurred either centrally or at the pelvic sidewalls. It is concluded that the LAG is a good predictor of subsequent relapse and survival, but that the addition of either elective or therapeutic PA radiotherapy based on LAG interpretation does not affect survival of FFR and should, therefore, be considered for investigational or palliative use only.

Adenocarcinoma↗
PubMed1983

Application of indomethacin as a potentiator of lymphocyte blastogenesis in Brucella abortus exposed cattle.

Lymphocytes from Brucella abortus field strain infected, strain 19 vaccinated, non-exposed and field strain infected, but immunologically unresponsive cattle were incubated with B. abortus antigen and indomethacin. There were significant increases (P less than 0.005) in the blastogenic responses, as measured by [3H] thymidine uptake, in cultures with indomethacin as compared to cultures without indomethacin. Lymphocyte blastogenic responses to B. abortus antigen were potentiated by indomethacin in both B. abortus exposed and non-exposed cultures. However, potentiation of sensitized lymphocyte blastogenic responses by indomethacin was significantly greater (P less than 0.005) than that in non-exposed lymphocytes. Additionally, indomethacin significantly potentiated Brucella-induced lymphocyte blastogenic responses in lymphocytes from anergic cattle.

Adjuvants, Immunologic↗
PubMed1983

Special uses of a gas chromatograph-mass spectrometer in endocrinology.

Based on the isotope dilution principle, and using deuterium-labelled steroids as tracers combined with GC-MS analysis, clinically acceptable procedures for the measurement of daily urinary production rates (UPR's) and metabolic clearance rates (MCR's), of hormonal steroids, have been developed. In clinical tests, using progesterone and androstenedione as models the UPR's and MCR's obtained compared favourably with values obtained using radioisotope-labelled tracers. The heavy isotope procedure proved, however, to be superior to the radioisotope methods in accuracy, speed and patient safety.

Androstenedione↗
PubMed1983

Survival, prognostic factors, and relapse patterns in uterine cervical carcinoma.

Between 1965 and 1979, 295 evaluable patients were treated with radiotherapy and/or surgery for invasive cervical carcinoma at the Stanford University Medical Center. The records of these patients were analyzed retrospectively with regard to survival, possible prognostic factors of freedom-from-relapse, and relapse patterns. Survival for the entire population at 5 years was 67%, with a median follow-up of 5 years. Five-year freedom-from-relapse (FFR) rates for stages I-IV were 88%, 61%, 33%, and 11%, respectively. Eighty-eight percent of all relapses occurred within 5 years. Several possible prognostic factors of FFR--including stage, histology, tumor differentiation, lymphangiogram status, treatment modality, age, presence of cervical stump, and initial serum hemoglobin value--were evaluated with a multivariate analysis. Stage was the best predictor of FFR, and lymphangiogram (LAG) status was the next most important covariate: 13 of 19 patients who showed involvement of paraaortic nodes on LAG relapsed within 1 year. There was no difference in survival or FFR between adenocarcinoma or squamous cell histologies. FFR in stage IB patients was independent of treatment modality; i.e., radiotherapy alone, surgery alone, or combined therapy. Initial serum hemoglobin (less than 12 vs. greater than 12) was not predictive of FFR or survival. Stage for stage, patients over 57 years of age tended to have better FFR than younger patients. The majority of relapses occurred centrally or at the pelvic sidewalls (58%), and future attempts to improve local control rates will rely more heavily on the individualized use of interstitial template applicators.

Adenocarcinoma↗
PubMed1983

Cholesteatomas of the temporal bone: role of computed tomography.

Computed tomography (CT) of the temporal bone was performed in 64 patients thought to have a cholesteatoma of the middle ear. Twenty had not had surgery before, while 44 had been operated on; special consideration was given to 21 patients who were scanned immediately before a second operation and had confirmation of the CT findings. Inflammatory disease without cholesteatoma was characterized by absence of erosion of the otic capsule or ossicular chain. Sharply circumscribed cholesteatomas were easily diagnosed by CT. When they were combined with scarring, granulation tissue, or postsurgical changes, the resulting soft-tissue masses were indistinguishable, although cholesteatoma may be suspected if there is evidence of progressive bone erosion about the middle ear. CT can play a major role in postoperative follow-up by confirming that the ear is normal and demonstrating displacement of ossicular grafts or prostheses.

Cholesteatoma↗
PubMed1983

Tympanic membrane perforations from water sports: treatment and outcome.

A study of 15 patients with 17 tympanic membrane perforations resulting from water sports was carried out. Most small perforations healed spontaneously. Perforations that persisted after 8 weeks were treated surgically, usually with the office paper patch procedure. A frequent history of middle ear problems in these patients suggests that middle ear dysfunction may play a role in the occurrence and delayed healing of traumatic perforations.

Adolescent↗