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Biomedical subjects

D Miller

Publications and source records attributed to D Miller.

At least 487 records · Page 27Linked to original sources

Oxidation of gamma-hydroxybutyrate to succinic semialdehyde by a mitochondrial pyridine nucleotide-independent enzyme.

An antibody that inhibits over 95% of the cytosolic NADP+-dependent gamma-hydroxybutyrate (GHB) dehydrogenase activity of either rat brain or kidney was found to inhibit only approximately 50% of the conversion of [1-14C]GHB to 14CO2 by rat kidney homogenate. A similar result was obtained with sodium valproate, a potent inhibitor of GHB dehydrogenase. The mitochondrial fraction from rat brain and kidney was found to catalyze the conversion of [1-14C]GHB to 14CO2. The dialyzed mitochondrial fraction also catalyzed the oxidation of GHB to succinic semialdehyde (SSA) in a reaction that did not require added NAD+ or NADP+ and which was not inhibited by sodium valproate. The enzyme from the mitochondrial fraction which converts GHB to SSA appears to be distinct from the NADP+-dependent cytosolic oxidoreductase which catalyzes this reaction.

Animals↗

Two cases of hypomania in AIDS.

HIV disease often leads to neuropsychiatric disturbance, either through direct infection of the brain by the virus or through CNS disease secondary to immunodeficiency. Neuropsychiatric complications of AIDS and AIDS-related disorders may present clinically as acute or chronic organic mental syndromes, or may mimic functional psychiatric illness, in particular depression, anxiety, or psychotic states. Two cases of hypomanic states in homosexual men suffering from AIDS are reported. Neither of the two men had a personal or family history of affective disorder. In one man, hypomanic symptoms were caused by early HIV encephalopathy; he rapidly developed typical HIV dementia with a marked downhill course. In the second case, a clear connection between the hypomanic symptoms and direct HIV brain involvement was not established.

Acquired Immunodeficiency Syndrome↗

The effects on auditory function of damage to the pontine olivo-cochlear bundle in man.

A patient with multiple sclerosis (MS) in whom a lesion developed in the pons between successive nuclear magnetic resonance image scans (MRI) is described. The patient developed intolerance of loud sounds, with distorted perception of speech and music, and abnormalities of stapedius reflex threshold, masked speech audiometry, and masking level difference assessment in the presence of an unchanged pure tone threshold. These abnormalities partially resolved over a number of months. It is postulated that the efferent olivo-cochlear bundle was involved on one side of the pons and the abnormalities are interpreted in terms of bilateral removal of inhibition from the hair cells of the cochlea.

Adult↗

The site of the lesion causing deafness in multiple sclerosis.

A patient with multiple sclerosis who developed sequential hearing loss, first on the right, with recovery is discussed. Magnetic resonance imaging demonstrated lesions in the VIII nerve root entry zones which were thought to be responsible for the hearing loss.

Deafness↗

The expression of viral and cellular genes in papillomas of the choroid plexus induced in transgenic mice.

A line of transgenic mice that carry the SV40 gene for the large Tumor antigen express this protein during the first two weeks of life in brain tissue. By 30-40 days after birth, independently derived multiple foci of abnormal cells appear throughout the choroid plexus. After 90 days, higher levels of T antigen and rapid tumor growth are detected and all these animals die in a narrow time span, between 100-120 days. In situ hybridization with tissue sections and Northern blot analysis have been employed to follow the steady state levels of SV40 RNA and the p53 oncogene RNA levels in normal and tumor tissues. The level of SV40 RNA is quite variable between tumor cells in a section. This heterogeneity of T antigen mRNA levels could permit the selection of cells (from the multiple foci) expressing higher levels of T antigen and growing more rapidly. The increased levels of p53 RNA observed in tumor cells could then result from the active growth state of these cells or a more direct transcriptional activation. Two cellular genes, transthyretin and the 5-HT1C serotonin receptor, both of which are preferentially expressed in normal choroid plexus cells, were also examined for RNA production in these tumors of the choroid plexus. Both of these genes produced high levels of RNA in tumor tissue indicating the retention of well differentiated gene expression in these tumor tissues. This reflects, at the level of gene expression, the well differentiated morphology of these papillomas of the choroid plexus. Interestingly, as cell lines have been derived from these tumors, both the choroid plexus specific RNA species (for 5-HT1C receptor) and characteristic morphology were lost and an increase in T antigen levels was observed.

Animals↗

Comparative tolerability of two formulations of Rhinalar (flunisolide) nasal spray in patients with seasonal allergic rhinitis.

This double-blind, randomized, crossover study compared the incidence of nasal burning and stinging, as well as overall tolerability of the currently marketed formulation of Rhinalar (original formulation) to a new formulation of Rhinalar containing less propylene glycol. In addition, patient and investigator subjective evaluations were used to compare the effectiveness of the test medications in controlling the nasal symptoms of seasonal allergic rhinitis. A total of 122 patients were enrolled in this 4-week trial. Each patient received one formulation of Rhinalar for 2 weeks and then crossed over to receive the alternate formulation for an additional 2 weeks. Eighteen patients withdrew from the trial prematurely. Ten patients were lost to follow-up and eight withdrew due to side effects and/or inadequate therapeutic response. Statistical comparisons of patient evaluations of nasal burning and stinging with the two formulations of Rhinalar showed a very significant difference in terms of severity (P less than .001), duration (P less than .001), and tolerability (P = .006) in favour of the new formulation. A reduction in severity of throat irritation with the new formulation was also shown to be statistically significant (P = .006). Nausea, headache, and other side effects including watery eyes, taste perversion, and runny nose were seldom reported with either test medication. Both formulations were shown to be equally effective in relieving the nasal symptoms of seasonal allergic rhinitis. The considerable reduction in nasal burning and stinging and throat irritation with the new formulation of Rhinalar was shown to enhance patient acceptability and may lead to better compliance.

Administration, Inhalation↗

Abdominal rescue after incomplete delivery secondary to large fetal sacrococcygeal teratoma.

Two cases are presented of incomplete vaginal delivery because of fetal sacrococcygeal teratomas. Prompt recognition and aggressive therapy resulted in favorable outcomes with minimal morbidity. The combined vaginal and abdominal manipulations involved repositioning the arms, shoulders, and vertex in the vagina, as the breech was extracted abdominally in a direction opposite to that ordinarily used. While this procedure seemed to work well, it is only applicable when the diagnosis of fetal tumor is made too late to prevent an obstructed delivery. Optimally, obstructed delivery is prevented by early ultrasonographic diagnosis and cesarean delivery before advanced labor.

Adult↗

Chemotherapeutic strategies in the multidisciplinary treatment of head and neck cancer.

A role for chemotherapy in the multidisciplinary treatment of patients with advanced squamous cell carcinoma of the head and neck (SCCHN) is yet to be defined. Results of uncontrolled studies indicate high response rates to induction chemotherapy and an association between a response to chemotherapy and either local-regional control or survival. Unfortunately, results of randomized, controlled trials have not confirmed an overall survival advantage with such treatment. From 1979 to the present, the Dana-Farber Cancer Institute has registered more than 224 patients on two trials of induction and adjuvant chemotherapy for patients with stage III to IV SCCHN. Protocol 80-016 (1979 to 1983) evaluated two cycles of induction cisplatin, bleomycin, and methotrexate/leucovorin (PBM) before local regional treatment in 114 patients. Eighty-nine (78%) patients responded to PBM, with 30 (28%) patients achieving a complete response (CR). After surgery and/or radiotherapy (RT), 46 responders to induction PBM entered a trial of the randomly assigned additional adjuvant PBM. Protocol 83-084 (1983 to present) randomly assigned patients to receive up to four cycles of either induction PBM or cisplatin and infusion 5-fluorouracil before local treatment. Adjuvant chemotherapy was not used in the latter study. Updated results from both trials will be presented, with their implications for future phase II and III multidisciplinary studies. Optimal approaches to the treatment of patients with advanced SCCHN can include planned reductions in the extent of surgery or RT offered to selected patients with a good response to induction chemotherapy but may require adjuvant chemotherapy for patients at high risk for recurrent disease. Until the rate of CR to induction chemotherapy is reproducibly over 50%, documentation of an improved overall survival with multidisciplinary treatment may be difficult.

Antineoplastic Combined Chemotherapy Protocols↗

Cyclophosphamide, doxorubicin, and cisplatin combination chemotherapy for advanced carcinomas of salivary gland origin.

Thirteen patients with carcinomas of major and minor salivary gland origin (nine adenoid cystic carcinomas and four adenocarcinomas) were treated with cyclophosphamide (500 mg/m2), doxorubicin (50 mg/m2), and cisplatin (50 mg/m2) (CAP) by intravenous injections on the first day of a 28-day regimen. Sixty-one cycles of CAP were administered (mean, 4.7 cycles per patient). Eleven patients were treated for palliation of recurrent disease (locoregional, ten; lung, ten; liver, three; and bone, three). Two patients untreated previously, one with extensive local disease involving the base of the skull and one with a solitary lung metastasis (resected with a positive margin) and an initially unappreciated base of tongue primary, received two cycles of CAP followed by local treatment and adjuvant CAP. Previous therapy for the 11 patients with recurrent disease included surgery (ten), radiotherapy [RT(11)], chemotherapy (three), or hormonal therapy (two). Three complete and three partial responses to chemotherapy were noted for an overall response rate of 46%. The median duration of response in palliative patients was 5 months (range, 2 to 9). Of the two patients receiving induction CAP, one relapsed with distant disease 26 months after treatment, and the other remains disease-free after 60 months of follow-up examination. Chemotherapy was well tolerated generally, and no chemotherapy-related deaths occurred. One hypertensive patient suffered a stroke after 3 cycles of therapy. CAP is an active regimen against salivary gland carcinomas and deserves further study. Also, it may be of value as induction or adjuvant treatment for patients with advanced disease untreated previously.

Adenocarcinoma↗

Interaction of permanently charged analogs of dopamine with the D-2 dopaminergic receptor.

Dopamine can exist in both charged and uncharged forms at physiological pH. At present it is unclear which of these forms is responsible for dopaminergic agonist activity. The purpose of this study was to determine whether permanently charged structural analogs of dopamine containing either a nitrogen, sulfur, or selenium atom in the side chain can bind to and activate the D-2 dopamine receptor. Binding to and activation of the D-2 dopamine receptor were measured by determining the abilities of the permanently charged dopamine analogs to inhibit [3H]spiperone binding to striatal homogenates and to inhibit K+-stimulated [3H]acetylcholine release from striatal slices respectively. The quaternary ammonium, dimethylsulfonium and dimethylselenonium analogs of dopamine were all found to inhibit [3H]spiperone binding to the same extent and in a manner qualitatively similar to the parent amines, dopamine and dimethyldopamine. Thus, [3H]spiperone inhibition curves for dopamine, dimethyldopamine and the permanently charged dopamine analogs were generally shallow and fit best to a two-site binding model as indicated by computer-assisted analyses. The addition of 125 mM NaCl to the incubation medium resulted in a significant decrease in the proportion of high affinity binding sites for both the permanently charged analogs and the parent amines. Similarly, the permanently charged dopamine analogs were found to maximally inhibit the K+-stimulated release of [3H]acetylcholine to the same extent as dopamine and dimethyldopamine. However, the permanently charged analogs were less potent in inhibiting both [3H]spiperone binding and K+-stimulated [3H]acetylcholine release than dopamine and dimethyldopamine. These results show that dopamine analogs possessing a permanent positive charge in the side chain can bind to and activate the D-2 dopamine receptor. The lower potencies of the permanently charged analogs in binding to and activation of the D-2 dopamine receptor suggest that, while the ability of a compound to exist in an uncharged form is not a requirement, both charged and uncharged forms of the agonist molecule appear to play a role in D-2 dopamine agonist activity.

Acetylcholine↗

Patient response to sigmoidoscopy. A randomized, controlled trial of rigid and flexible sigmoidoscopy.

Sigmoidoscopy could aid in the control of large bowel cancer by early detection of the 55% of colorectal cancers that develop in the rectosigmoid and by the identification and eradication of significant rectosigmoid adenomas. Rigid sigmoidoscopy has had poor patient acceptance and therefore has not been successful. The present study is a prospective randomized trial to evaluate patient response to flexible as compared with rigid sigmoidoscopy. Patients reported significantly less discomfort (10.1% versus 29.7%), anxiety (9.8% versus 27.6%) and embarrassment (5.2% versus 12.8%) during flexible as compared with rigid sigmoidoscopy. Flexible sigmoidoscopy appears to have better patient acceptance than rigid sigmoidoscopy (P less than 0.01). This could enhance its value as a cancer-control instrument. This article addresses the feasibility of sigmoidoscopy. Its validity also needs to be addressed within the framework of a long-term trial, evaluating mortality for rectosigmoid cancer.

Clinical Trials as Topic↗

HIV infection: increase in public awareness and anxiety.

Between the end of September and mid-November 1986 the number of patients who requested antibody testing for human immunodeficiency virus (HIV) at this department increased by over 300%. This increase followed a media campaign that emphasised the potential heterosexual spread of HIV. After pretest counselling roughly one quarter of the women and of the heterosexual men decided not to be tested. The reason given most often by women for testing was previous sexual intercourse with bisexual or possibly bisexual men. Heterosexual men were most often concerned about previous casual encounters or contact with prostitutes. Of the 641 tests for HIV antibody performed during the last three months of 1986, 37 (5-8%) were positive. Because an increasing number of patients are attending sexually transmitted diseases clinics for HIV antibody testing staffing levels in these clinics need to be reappraised now.

Acquired Immunodeficiency Syndrome↗