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Biomedical subjects

M Barnes

Publications and source records attributed to M Barnes.

At least 91 records · Page 5Linked to original sources
PubMed1992

Submandibular rhabdomyoma.

A case of recurrent adult rhabdomyoma of the submandibular gland is presented. This is a rare tumor of the skeletal muscle. Approximately 80 cases have been reported. The salient pathologic features are reviewed and a discussion and review of the literature is presented.

Aged↗
PubMed1991

Photodynamic therapy of the canine peritoneum: normal tissue response to intraperitoneal and intravenous photofrin followed by 630 nm light.

A toxicity study was performed in a canine model to explore the feasibility of using intraperitoneal photodynamic therapy for patients with peritoneal carcinomatosis. Dogs received 1.25 mg/kg Photofrin II both intravenously (48 hours) and intraperitoneally (2 hours) before intraperitoneal light treatment. The entire peritoneal surface was illuminated with 0.57-0.74 J/cm2 of red light (630 nm). Thirteen dogs were treated: 4 control and 9 full treatment. Of the fully treated dogs, 5 received a single treatment and 4 received 3 treatments. The dogs were evaluated clinically and pathologically for immediate (4 days) and late (60 days) side effects. All animals tolerated the treatment without significant morbidity. Postoperative blood tests were normal except for low lymphocyte counts and elevated liver transaminases, both of which normalized rapidly. Histopathologically, there was approximately a 50% incidence of mild inflammatory peritoneal response. This study provides the basis for a Phase I human trial.

Animals↗
PubMed1991

Inhibitory effect of ritanserin on the 5-hydroxytryptophan-mediated cortisol, ACTH and prolactin secretion in humans.

Oral administration of the serotonin (5-HT) precursor L-5-hydroxytryptophan (5-HTP), 200 mg, significantly increased plasma cortisol levels in man. L-5-HTP had no significant effect on the plasma prolactin levels. A borderline effect of 5-HTP on plasma ACTH levels was found. Pretreatment with the 5-HT2/5-HT1c antagonist ritanserin (5 mg, PO, b.i.d. for 2 days) significantly inhibited 5-HTP-induced cortisol secretion. Ritanserin had no effect on the basal plasma cortisol or prolactin levels. These data are suggestive that 5-HTP stimulates cortisol secretion in man via 5-HT2/5-HT1c receptor mechanisms.

5-Hydroxytryptophan↗
PubMed1991

Threshold dose for peripheral neuropathy following intraoperative radiotherapy (IORT) in a large animal model.

Radiation injury to peripheral nerve is a dose-limiting toxicity in the clinical application of intraoperative radiotherapy, particularly for pelvic and retroperitoneal tumors. Intraoperative radiotherapy-related peripheral neuropathy in humans receiving doses of 20-25 Gy is manifested as a mixed motor-sensory deficit beginning 6-9 months following treatment. In a previous experimental study of intraoperative radiotherapy-related neuropathy of the lumbro-sacral plexus, an approximate inverse linear relationship was reported between the intraoperative dose (20-75 Gy range) and the time to onset of hind limb paresis (1-12 mos following intraoperative radiotherapy). The principal histological lesion in irradiated nerve was loss of large nerve fibers and perineural fibrosis without significant vascular injury. Similar histological changes in irradiated nerves were found in humans. To assess peripheral nerve injury to lower doses of intraoperative radiotherapy in this same large animal model, groups of four adult American Foxhounds (wt 20-25 kg) received doses of 10, 15, or 20 Gy to the right lumbro-sacral plexus and sciatic nerve using 9 MeV electrons. The left lumbro-sacral plexus and sciatic nerve were excluded from the intraoperative field to allow each animal to serve as its own control. Following treatment, a complete neurological exam, electromyogram, and nerve conduction studies were performed monthly for 1 year. Monthly neurological exams were performed in years 2 and 3 whereas electromyogram and nerve conduction studies were performed every 3 months during this follow-up period. With follow-up of greater than or equal to 42 months, no dog receiving 10 or 15 Gy IORT shows any clinical or laboratory evidence of peripheral nerve injury. However, all four dogs receiving 20 Gy developed right hind limb paresis at 8, 9, 9, and 12 mos following intraoperative radiotherapy. These experimental data suggest that intraoperative doses of less than 20 Gy may not result in clinically significant peripheral nerve injury with follow-up of 3.5 years. Longer (5 yrs) follow-up with planned sacrifice of the remaining dogs is scheduled to assess any late peripheral nerve damage.

Animals↗
PubMed1990

Tumor induction following intraoperative radiotherapy: late results of the National Cancer Institute canine trials.

Intraoperative radiotherapy has been employed in human cancer research for over a decade. Since 1979, trials to assess the acute and late toxicity of IORT have been carried out at the National Cancer Institute in an adult dog model in an attempt to establish dose tolerance guidelines for a variety of organs. Of the 170 animals entered on 12 studies with a minimum follow-up of 2 years, 148 dogs received IORT; 22 control animals received only surgery. Animals were sacrificed at designated intervals following IORT, usually at 1, 6, 12, 24, and 60 month intervals. 102 of 148 irradiated dogs were sacrificed less than 24 months; 46 dogs were followed greater than or equal to 24 months after IORT. To date, 34 of the 46 animals have been sacrificed; the 12 remaining animals are to be followed to 5 years. These 12 animals have minimum follow-up of 30 months. In the irradiated group followed for greater than or equal to 24 months, 10 tumors have arisen in 9 animals. One animal developed an incidental spontaneous breast carcinoma outside the IORT port, discovered only at scheduled post-mortem exam. The remaining nine tumors arose within IORT ports. Two tumors were benign neural tumors--a neuroma and a neurofibroma. One animal had a "collision" tumor comprised of grade I chondrosarcoma adjacent to grade III osteosarcoma arising in lumbar vertebrae. Two other grade III osteosarcomas, one grade III fibrosarcoma, and one grade III malignant fibrous histiocytoma arose in retroperitoneal/paravertebral sites. An embryonal rhabdomyosarcoma (sarcoma botryoides) arose within the irradiated urinary bladder of one animal. No sham irradiated controls nor IORT animals sacrificed less than 24 months have developed any spontaneous or radiation-induced tumors. The time range of diagnoses of tumors was 24-58 months (median 40 months). The IORT dose range associated with tumor development was 20-35 Gy (median 30 Gy). The carcinogenesis capability of single fraction, high dose radiation in animals is discussed, as are the implications of these data for continued research and clinical usage of IORT in the treatment of humans.

Animals↗
PubMed1990

Delay in thrombolytic treatment in acute myocardial infarction: the role of the accident and emergency department.

During a 6-week period, 248 patients presenting with chest pain presumed to be cardiac in origin, were recruited in a time and motion study in the Accident and Emergency Department of the Leicester Royal Infirmary. The study considered the ambulance-response and transfer times from the scene to the hospital, as well as the duration of the patients stay in the Department. While Ambulance Time from the scene of the incident to the hospital averaged 28 min, the time spent in the Accident and Emergency Department prior to admission averaged 76.5 min. This study was conducted in the light of growing concern expressed at the delay in administering thrombolytic agents to those patients with acute myocardial infarction (AMI). The authors propose possible ways of reducing such delays.

Adult↗
PubMed1990

Protection by indomethacin against acute radiation esophagitis.

The mechanism of radiation induced damage to the mucosal lining of the gastrointestinal tract, as well as mucositis, is not fully characterized. Prostaglandins may partially mediate the inflammatory response to radiation damage. The effect of the prostaglandin synthetase inhibitor indomethacin on radiation induced esophagitis, pneumonitis, and tumor response was evaluated in the C3H mouse. The effects of indomethacin on radiation induced damage to the esophagus was determined by evaluation of weigh lost, survival, and histologic findings at doses of 28-34 Gy. Although there is a clear difference that supports the use of indomethacin for the prevention of esophagitis, the radiation dose response for esophagitis is steep and likewise, the therapeutic index for the indomethacin amelioration of radiation esophagitis is narrow. Since the tumor response to radiation is unchanged and since indomethacin clearly lessens radiation induced esophagitis in the mouse, this study suggests that indomethacin should be studied in humans for lessening radiation mucositis without jeopardizing the therapy of tumors.

Acute Disease↗
PubMed1990

Treatment of radiation- and chemotherapy-induced stomatitis.

Severe stomatitis is a common problem encountered during either radiation therapy or chemotherapy. Most therapeutic regimens are empirical, with no scientific basis. The purpose of this study is to determine the efficacy of various topical solutions in the treatment of radiation- or chemotherapy-induced stomatitis. Eighteen patients were entered into a prospective double-blinded study to test several topical solutions: (1) viscous lidocaine with 1% cocaine; (2) dyclonine hydrochloride 1.0% (Dyclone); (3) kaolin-pectin solution, diphenhydramine plus saline (KBS); and (4) a placebo solution. Degree of pain relief, duration of relief, side effects, and palatability were evaluated. The results showed that Dyclone provided the most pain relief. Dyclone and viscous lidocaine with 1% cocaine provided the longest pain relief, which averaged 50 minutes This study provides objective data and defines useful guidelines for treatment of stomatitis.

Administration, Topical↗
PubMed1990

Common peroneal nerve dysfunction after high tibial osteotomy.

We assessed 16 patients before and after high tibial osteotomy by electrophysiological recordings, creatine phosphokinase levels, radiographs and intracompartmental pressure monitoring. We found mild electrophysiological abnormalities pre-operatively in 12 of the 16 patients, but postoperatively these had deteriorated in 11 of the 14 patients studied. Creatine phosphokinase levels, compartment pressure and radiological deformity were not predictive of the development of postoperative common peroneal nerve palsy. Patients who also had a proximal fibular osteotomy had greater electrical abnormalities postoperatively and two of them developed common peroneal palsies. Proximal fibular osteotomy appears to be a causative factor in the development of common peroneal nerve palsy; more work is needed on the blood supply of the nerve.

Adult↗
PubMed1989

Recommendations for control and prevention of human immunodeficiency virus (HIV) infection in intravenous drug users.

Considerable evidence indicates that intravenous drug users are emerging as the group at greatest risk for both acquiring and spreading human immunodeficiency virus (HIV) infection. Thus, all possible methods to control the spread of HIV infection in intravenous drug users should be explored. Key recommendations are that HIV antibody testing of intravenous drug users should be voluntary, because mandatory testing is counterproductive; free distribution of needles and syringes to intravenous drug users should occur only in carefully controlled circumstances to determine its effectiveness in decreasing infection rates; and drug-free and methadone maintenance treatment programs should be available on demand to all intravenous drug users as a means of reducing the spread of HIV infection. At present, the primary strategy for prevention must be education resulting in behavioral change. Education is currently the only definitive means for controlling the spread of HIV infection among intravenous drug users, their sex contacts, and to fetuses.

AIDS Serodiagnosis↗
PubMed1989

A comparison of chromosomal aberrations induced by in vivo radiotherapy in human sperm and lymphocytes.

Chromosomal aberrations in human sperm and lymphocytes were compared before and after in vivo radiation treatment of 13 cancer patients. The times of analyses after radiotherapy (RT) were 1, 3, 12, 24, 36, 48 and 60 months. The median total radiation dose was 30 Gy and the testicular dose varied from 0.4 to 5.0 Gy. Human sperm chromosome complements were analysed after fusion with golden hamster eggs. There were no abnormalities in sperm or lymphocytes before RT. Following RT there was an increase in the frequency of numerical and structural chromosomal abnormalities in both lymphocytes and sperm. For structural abnormalities there were more rejoined lesions (dicentrics, rings) in lymphocytes and more unrejoined lesions (chromosome breaks, fragments) in sperm. After RT there was a dramatic increase in the frequency of chromosomal abnormalities in lymphocytes: at 1 mo. the frequency was 42%, at 3 mo. 25%, at 12 mo. 14%, at 24 mo. 11%, at 36 mo. 9%, at 48 mo. 7% and at 6 mo. 4%. Since the majority of men were azoospermic after RT, there is little data on sperm chromosome complements before the analyses performed at 24 mo. post-RT. At 24 mo. the frequency of abnormalities was 13%, followed by 21% at 36 mo., 12% at 48 mo. and 22% at 60 mo. Thus it appears that the frequency of lymphocyte chromosomal abnormalities had an initial marked increase after RT followed by a gradual decrease with time whereas the frequency of sperm chromosomal abnormalities was elevated when sperm production recovered and remained elevated from 24 to 60 mo. post-RT. This difference in the effect of time makes it very difficult to compare abnormality rates in lymphocytes and sperm and to use analysis of induced damage in somatic cells as surrogates for germ cells since the ratio between sperm and lymphocytes varied from 1:1 (at 24 mo. post-RT) to 5:1 (at 60 mo. post-RT).

Adult↗