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Biomedical subjects

P Kennedy

Publications and source records attributed to P Kennedy.

At least 19 recordsLinked to original sources
PubMed1992

Uncoupling of hypomyelination and glial cell death by a mutation in the proteolipid protein gene.

Proteolipid protein (PLP; M(r) 30,000) is a highly conserved major polytopic membrane protein in myelin but its cellular function remains obscure. Neurological mutant mice can often provide model systems for human genetic disorders. Mutations of the X-chromosome-linked PLP gene are lethal, identified first in the jimpy mouse and subsequently in patients with Pelizaeus-Merzbacher disease. The unexplained phenotype of these mutations includes degeneration and premature cell death of oligodendrocytes with associated hypomyelination. Here we show that a new mouse mutant rumpshaker is defined by the amino-acid substitution Ile-to-Thr at residue 186 in a membrane-embedded domain of PLP. Surprisingly, rumpshaker mice, although myelin-deficient, have normal longevity and a full complement of morphologically normal oligodendrocytes. Hypomyelination can thus be genetically separated from the PLP-dependent oligodendrocyte degeneration. We suggest that PLP has a vital function in glial cell development, distinct from its later role in myelin assembly, and that this dichotomy of action may explain the clinical spectrum of Pelizaeus-Merzbacher disease.

Amino Acid Sequence↗
PubMed1992

Testicular feminization syndrome in a mare.

Testicular feminization syndrome was diagnosed in a mare with aggressive, stallion like behavior and a history of infertility. She was found to have a high baseline testosterone concentration suggesting that testicular tissue was present, and ovarian-like structures examined by use of transrectal ultrasonography had the appearance typical of testicular tissue. Although her external female genitalia appeared normal, her vagina ended in a blind sac, and no cervix or uterus were identified. Surgery was performed, and structures removed from the abdominal cavity were determined to be hypoplastic testicles. Removal of the testicular tissue resulted in complete resolution of her aggressive behavior. Chromosomal evaluation revealed that the mare had 64X,Y (normal male) karyotype. Testicular feminization syndrome is a condition characterized by insensitivity of reproductive tissues to androgens during development because of an abnormality in androgen receptors. This androgen insensitivity results in development of normal external female genitalia, with high testosterone concentrations being released from developing testicles. Testicular feminization syndrome has not been commonly diagnosed in horses, but should be considered as a differential diagnosis for overly aggressive mares with a history of infertility.

Aggression↗
PubMed1992

Quality assurance for intraoperative electron radiotherapy clinical trials: ionization chamber and mailable thermoluminescent dosimeter results.

Ionization chamber and thermoluminescent dosimeter measurements were made to verify the dosimetry data provided to the Radiation Therapy Chart Review office of interinstitutional electron intraoperative radiotherapy clinical trials. The ionization measurements included intraoperative radiotherapy applicator output and depth dose measurements made at the stated 80% and 50% depths at 14 different radiotherapy facilities. Mailable thermoluminescent dosimeter measurements, including output and depth dose measurements were made at 16 institutions. The mailable thermoluminescent dosimeter results show similar inter-institutional agreement, both for output and depth dose comparison, with the corresponding ion chamber results for intraoperative radiotherapy applicators. These results are compared to similar measurements made for conventional electron applicators.

Clinical Trials as Topic↗
PubMed1992

Major neurological disease and occupational exposure to organic solvents.

Five patients are described who presented with major organic brain disease affecting one or more of pyramidal and extrapyramidal tracts, cerebellum, and higher cortical functions. All had a history of 10 years or more of regular occupational exposure to solvents in confined spaces, three in painting inside ships and the others in weapons maintenance and printing. All had been regularly exposed to high air vapour peaks as well as to skin contamination. Four showed some evidence of improvement after the exposure ceased. None was initially suspected of having a toxic encephalopathy by the consultant to whom he was referred. The spectrum of neurological disease presented by these men mirrors closely that described in solvent abusers. All were forced by illness to retire from their work, a circumstance which might have in the past have led to such conditions being missed in cross-sectional studies, which in general have not shown evidence of major disease. We suggest that when such disease occurs nowadays, its cause is usually not suspected. Further epidemiological study of the problem is necessary.

Humans↗
PubMed1991

OKT-3/cyclophosphamide up-regulation of peripheral blood killer-lymphocyte subsets in human cancer patients.

We have initiated a clinical trial in 7 patients using low-dose OKT-3 monoclonal antibody, 50 mcg, followed 24 hours later by low-dose cyclophosphamide, 300 mg/m2. Complete data in 5 patients indicate a significant up-regulation of the number of peripheral blood lymphocytes. Before treatment, the mean (+/- standard deviation) total lymphocyte count was 524 (+/- 364)/mm3. After 4 weeks the value rose 64% to 860 (+/- 243)/mm3, (P less than .025, Student's t test). Similar changes were observed for the CD3+, CD4+, CD8+, and CD16+ (NK) lymphocyte subsets. The mean CD3+ population rose from 372 (+/- 325)/mm3 to 593 (+/- 300)/mm3 (P less than .025), the mean CD4+ group rose from 209 (+/- 142)/mm3 to 321 (+/- 104)/mm3 (P less than .05), the CD8+ cells rose from 218 (+/- 205)/mm3 to 341 (+/- 197)/mm3 (P less than .05), and the CD16+ (NK cells) rose from 80 (+/- 37)/mm3 to 157 (+/- 63)/mm3 (P less than .025). Statistically significant up-regulation occurred for all patients. The fraction of each lymphocyte subset and the T4/T8 ratio did not change. OKT-3/cyclophosphamide appears to modulate the number of circulating lymphocytes in human cancer patients.

Adult↗
PubMed1990

Preliminary report: imaging of Kaposi sarcoma and lymphoma in AIDS with indium-111-labelled liposomes.

Kaposi sarcoma and malignant lymphoma were successfully imaged with high purity liposomes containing indium-111 in two patients with AIDS. Gamma camera images of the patient with Kaposi sarcoma showed four discrete lesions along the left foot and calf with no foci along the right foot, and no uptake into clinically enlarged but non-neoplastic lymph nodes. The spread of the Kaposi sarcoma was proximal along the leg. The neoplastic cervical lymph nodes in the second patient who had large-cell diffuse intermediate grade lymphoma were also imaged successfully. Since Kaposi sarcoma and lymphoma frequently involve occult sites, liposome imaging may prove useful in the diagnosis and management of these diseases.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Recombinant human erythropoietin for patients with AIDS treated with zidovudine.

Bone marrow suppression and anemia are frequent side effects of treatment of the acquired immunodeficiency syndrome (AIDS) with zidovudine (formerly azidothymidine [AZT]). We conducted a randomized, double-blind, placebo-controlled clinical trial of recombinant human erythropoietin (100 U per kilogram of body weight thrice weekly by intravenous bolus) in 63 patients with AIDS treated with zidovudine (29 in the erythropoietin group and 34 in the placebo group). Reductions in the number of units of red cells transfused and the number of patients given transfusions per month became apparent in the second and third months of the trial. The reductions were observed in patients with endogenous erythropoietin levels less than or equal to 500 IU per liter at base line, but not in patients whose levels were greater than 500 IU per liter at the beginning of the study. Although the hematocrit and hemoglobin level were not used as the primary criteria of efficacy because the patients received transfusions when their physicians decided that they needed them, a significantly higher rate of increase in the hematocrit was observed in the patients treated with recombinant human erythropoietin whose levels of endogenous erythropoietin were less than or equal to 500 IU per liter (0.00353 points per week) than in the patients given placebo (0.00116 points per week). This effect was not seen in patients with higher levels of endogenous erythropoietin. Serious side effects did not occur more often in the group treated with erythropoietin than in the placebo group. We conclude that recombinant human erythropoietin may be useful in patients with AIDS treated with zidovudine, although the indicators for its use remain to be clarified.

Acquired Immunodeficiency Syndrome↗
PubMed1990

The intergroup Hodgkin's disease in children. A study of stages I and II.

A total of 228 previously untreated and eligible children with pathologic Stage I or II Hodgkin's disease were registered in the Intergroup Study of Hodgkin's Disease in Children between February 1977 and April 1981. Patients were randomized in the Southwest Oncology Group (later the Pediatric Oncology Group [POG] to involved-field (IF) radiotherapy alone or IF radiotherapy followed by six courses of mechlorethamine, vincristine, prednisone, and procarbazine (MOPP) chemotherapy; patients in the Children's Cancer Study Group (CCSG) and Cancer and Leukemia Group B (CALGB) were randomized to receive extended-field (EF) radiotherapy or IF radiotherapy followed by six courses of MOPP. An estimated 97% of patients receiving IF + MOPP were relapse-free and surviving (RFS) at 5 years, which was significantly better than 41% for patients receiving IF alone; however there was essentially no overall difference in survival experience between groups. Patients in CCSG and CALGB receiving IF + MOPP had significantly superior RFS at 5 years than patients receiving EF. Survival rate was not different between these two groups, an estimated 93% of patients surviving 5 years or longer. Although patients were not randomized between IF or EF radiotherapy, they were similar with respect to patient characteristics. There was some statistical evidence that RFS was superior at 5 years for patients receiving EF than for IF; however, there was no evidence of a difference in survival experience. The percentages of patients with late effects of therapy were not significantly different by treatment. The most common types of late effects were endocrine dysfunction and impaired resistance to infection. Overall, the response rate to therapy for relapse patients was good, being 83% among all patients who relapsed. Patient characteristics related to poor prognosis were the presence of constitutional (B) symptoms (fever, night sweats, and weight loss) and poor performance status.

Adolescent↗
PubMed1990

Use of the timeout procedure in a child psychiatry inpatient milieu: combining dynamic and behavioral approaches.

An observational study of naturally-occurring timeouts was conducted in a child psychiatry inpatient milieu over a three-month period. Data from nine children were assessed. Child negative behavior was generally low in the timeout, processing, and return to activity phases. Results from individuals were discussed in terms of their diagnosis and events taking place on the unit. Staff behavior during timeouts were also described. The crucial role of processing after the timeout was discussed.

Behavior Therapy↗
PubMed1990

RPC technical report #18: information that should be included in every patient's radiotherapy treatment record (external beam).

The Radiological Physics Center (RPC) has frequently been asked to develop a model daily treatment record. It became obvious that there was some minimum information that must be in patient records. However, equally obvious was the fact that practices at institutions could be very different, so organization of information in records was different. We have compiled a list of data that must be in a patient's treatment record to assure that the radiation treatment can be reconstructed at a later date. The ordering of this information in forms and records is left to the discretion of the institution.

Forms and Records Control↗
PubMed1990

Stiffman syndrome: a rare paraneoplastic disorder?

An unusual case of the stiffman syndrome, associated with an oat cell carcinoma of the bronchus, is reported. Pathological examination showed that it was due to an encephalomyelitis similar to that seen in paraneoplastic disorders. This suggests that atypical cases of the stiffman syndrome may occasionally be paraneoplastic.

Aged↗
PubMed1989

Focal retrograde amnesia: a long term clinical and neuropsychological follow-up.

A patient (E.D.) who had displayed a selective retrograde amnesia in association with transient amnesic episodes (Kapur et al., 1986) was reexamined five years after initial assessment. At the clinical level, his transient amnesic attacks continued, but some of these had clear epileptic features. In addition, EEG investigation indicated temporal lobe abnormality, more prominent in the left temporal region, and supported a clinical diagnosis of temporal lobe epilepsy. Both CT scanning and magnetic resonance imaging were unable to detect the presence of any structural lesion. At the neuropsychological level, there was no evidence of dementia in the form of generalized cognitive dysfunction nor significant deterioration in cognitive functioning since the earlier assessment. Our patient continued to show marked memory loss for public events over the past 20-30 years, in the context of normal or near normal performance on most tests of anterograde memory functioning. While memory for famous scenes and famous faces was markedly impaired, our patient's memory for famous cars was within normal limits and his memory for autobiographical events showed only patchy impairment. Although E.D. performed at an average or above average level on most standard tests of anterograde memory functioning, our patient did show evidence of significant memory loss for public events which had occurred over the past ten years (i.e. since the onset of his illness). The possibility is raised that E.D.'s memory disorder may represent a form of disconnection syndrome.

Aged↗