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Biomedical subjects

M Martin

Publications and source records attributed to M Martin.

At least 649 records · Page 36Linked to original sources
PubMed1990

The effects of glucocorticoids on the availability of L-tryptophan and tyrosine in the plasma of depressed patients.

There is evidence that a functional deficit of serotonin/noradrenaline and/or of their precursors L-tryptophan (L-TRP)/tyrosine and disorders in the hypothalamic-pituitary-adrenal (HPA) axis are linked to the pathophysiology of severe depressions. Several reports suggest a reciprocal relationship between these neurotransmitters and HPA axis activity. In order to investigate the effect of glucocorticoid excess on the availability of L-TRP and tyrosine to the brain, we measured urinary cortisol (UC) excretion in 24-h urine, and the availability of both amino acids before and after treatment with 1 mg dexamethasone in 26 depressed patients. We found no relationship between UC excretion and the availability of either amino acid. Dexamethasone significantly suppressed the availability of L-TRP (P less than 10(-5] and of tyrosine (P = 0.005). Major depressed patients with melancholia exhibited a significantly lower availability of L-TRP than minor depressives (P = 0.007).

Amino Acids↗
PubMed1990

A revised interpretation of postdexamethasone ACTH and cortisol findings in unipolar depressed females.

Baseline 8 a.m. adrenocorticotropic hormone (ACTH) and cortisol levels and the postdexamethasone ACTH/cortisol values at 8 a.m. and 4 p.m. were determined in 86 depressed females diagnosed using DSM-III criteria. Postdexamethasone ACTH and cortisol values were significantly correlated with their baseline levels. We have shown that regression analysis should be used to assess dexamethasone-induced changes as the residual ACTH and cortisol responses, with the relative effects of the baseline data on the hormone responses being partialed out. The residual ACTH and cortisol values were significantly increased in the most severely depressed females as compared to minor depressives. The residual ACTH responses were markedly correlated with the residual cortisol responses. Cortisol nonsuppression during a depressive episode appeared to be determined by an augmented ACTH escape from dexamethasone suppression. The residual ACTH and cortisol responses could prove to be the most sensitive reflection of the disorder in the negative feedback by dexamethasone on the pituitary. In clinical practice, the ratio ln (postdexamethasone ACTH): ln (basal ACTH) can be used, since this ratio is linearly correlated with the residual ACTH responses.

Adrenocorticotropic Hormone↗
PubMed1990

Clinical subtypes of unipolar depression: Part III. Quantitative differences in various biological markers between the cluster-analytically generated nonvital and vital depression classes.

The hypothalamic-pituitary-adrenal (HPA) axis, the hypothalamic-pituitary-thyroid (HPT) axis, and the availability of L-tryptophan (L-TRP) to the brain were studied in their relationships to (1) 14 depressive symptoms measured by the Structured Clinical Interview for DSM-III-R--Patient Version (SCID) and (2) the cluster-analytically generated vital/nonvital classes. The following biological parameters were measured in 100 depressed females: free thyroxine (FT4), baseline thyroid stimulating hormone (TSH), predexamethasone and postdexamethasone cortisol and adrenocorticotropic hormone (ACTH) values, the circulating levels of total L-TRP, and the L-TRP/sum of competing amino acids ratio. We found that the psychopathological correlates of disorders in the HPA/HPT axis and of a decreased availability of L-TRP were vital symptoms, i.e., distinct quality of mood, nonreactivity, early morning awakening, anorexia-weight loss, and psychomotor disorders. There was no significant relationship between those biological markers and the nonvital symptoms of the SCID inventory for depressive symptoms. However, we did not validate our SCID clustering in vital and nonvital classes by qualitative differences in the biological variables. It was concluded that our nonvital/vital clusters should be regarded as continuous categories with regard to the biological markers studied; these clusters constitute relevant stages in the continuum of progressing biological dysfunction.

Adrenocorticotropic Hormone↗
PubMed1990

Rapid antiviral DNA-DNA hybridization assay for human cytomegalovirus.

A rapid DNA-DNA hybridization technique that can be accomplished in 4 to 5 days was compared with plaque reduction assay to determine its reliability in performing antiviral assays for human cytomegalovirus (HCMV). The assay involves lysing infected cells, direct wicking of denatured DNA onto membranes and hybridization using a 125I-labeled HCMV DNA probe. Using ten ganciclovir sensitive clinical HCMV strains for comparison, the DNA hybridization technique correlated well with the plaque assay. Clinical HCMV strains previously identified as resistant to ganciclovir were also readily identified. The DNA-DNA hybridization assay is less tedious and more rapid than plaque reduction assays, and thus, provides an excellent alternative for evaluation of the antiviral activity of drugs against HCMV.

Cells, Cultured↗
PubMed1990

Comparison of curietherapy versus external irradiation combined with curietherapy in stage II squamous cell carcinomas of the mobile tongue.

One hundred and ten patients with Stage II epidermoid carcinomas of the mobile tongue were treated by interstitial irradiation (Group I: 85 patients) or external irradiation to the primary and the regional lymphatics followed by an interstitial boost (Group II: 25 patients). The neck was managed by either an elective neck dissection (43 patients) completed by external irradiation in 13 patients with pathological specimen or close follow-up (40 patients) with therapeutic neck dissection for relapses (7 patients) in Group I. Primary local control was 88% in Group I and 36% in Group II. Regional control was 91% in Group I and 5/6 in Group II for patients whose primary tumor was controlled. Five-year absolute disease-free survival (DFS) was 42% in Group I and 24% in Group II, but there was an imbalance in the distribution of larger tumors favoring Group I. There were 30 radiation-induced complications and four patients required corrective surgery. This retrospective analysis showed better results in patients whose primary was treated by interstitial irradiation alone which has the extra advantage of preserving salivary function.

Adult↗
PubMed1990

Weekly high-dose infusion of 5-fluorouracil in advanced colorectal cancer.

18 patients with advanced colorectal cancer entered a phase I-II study of high-dose 48 h continuous infusion 5-fluorouracil (5-FU) for 6 weeks. 7 patients were included at the first dose level (3 g/m2) and only 1 had serious toxicity (grade 3 diarrhoea and mucositis). 7 patients were included at the second dose level (3.5 g/m2). 6 had a good tolerance to treatment, while the remaining patient had grade 4 leukopenia. 4 patients received 4 g/m2: 3 had severe toxicity (grade 4 diarrhoea, myelosuppression, mucositis, central nervous system), such that the entry of new patients was stopped. Anti-tumour activity was seen in 33% (95% confidence interval 13-59%) of the overall population. Only patients who had not had previous chemotherapy responded to treatment (response rate in this subgroup [43%, 18-71%]). The optimal dose of 5-FU was 3.5 g/m2 weekly for six cycles.

Aged↗
PubMed1990

The decreased availability of L-tryptophan in depressed females: clinical and biological correlates.

1. The plasma levels of L-tryptophan (L-TRP) and the sum of five competing amino acids (CAA) namely tyrosine, phenylalanine, valine, leucine, isoleucine, were determined in 79 depressed females categorized according to the DSM-III. 2. In these patients the authors measured several parameters known to affect the availability of the above amino acids, i.e. triidothyronine (FT3) and thyroxine (FT4), vanilylmandelic acid (VMA), noradrenaline and adrenaline in 24 hr urine, the sex hormonal and nutritional state. 3. The 1 mg dexamethasone suppression test was performed and the pre and postdexamethasone cortisol and adrenocorticotropic hormone (ACTH) levels were determined at 8 a.m. 4. L-TRP and the ratio L-TRP/CAA were significantly lower in severely depressed females (296.X3, 296.X4) as compared with minor (300.40, 309.00) and simple major depressives (296.X2). The ratio L-TRP/CAA performed well as a clinical tool separating melancholic from minor depression. 5. FT3, FT4, VMA and noradrenaline were significantly increased in the severely depressed females, but these data did not correlate with the availability of L-TRP. Neither baseline cortisol nor the sex hormonal, nor the nutritional state related to the L-TRP data. The ratio L-TRP/CAA was significantly and negatively correlated with the postdexamethasone cortisol and ACTH values.

Adrenocorticotropic Hormone↗
PubMed1990

Randomized study of 5 fluorouracil and cis platin as neoadjuvant therapy in head and neck cancer: a preliminary report.

A randomized prospective study of 5 fluorouracil (5-FU) and Cis platin preceding definitive local treatment for squamous cell carcinoma of the head and neck region was initiated in September 1986. Seventy-five patients were stratified by site (oral cavity-12, oropharynx-28, larynx-16, hypopharynx-19), and by Stage (Stage II-20, Stage III-43, Stage IV-12) and randomized to receive definitive local treatment (surgery and post-operative radiation or radiation alone) or chemotherapy followed by definitive local treatment. Chemotherapy consisted of three cycles of 120 hr 5-FU infusion 1 g/m2/day plus Cis platin 100 mg/m2 on day 1 on each cycle. Response to chemotherapy was complete in 17 patients (46%) for an overall response rate of 68%. All the patients have completed therapy with a median follow-up of more than 12 months. After local treatment, the complete response rate is 84% for the control group and 86% in the chemotherapy group. Actuarial disease-free survival at 1 year is 61% in the control group and 73% in the chemotherapy group (p = 0.25). These preliminary results show that in spite of initial tumor response, neoadjuvant chemotherapy does not improve long-term control and survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Alternating radiotherapy and chemotherapy in 173 consecutive patients with limited small cell lung carcinoma. GROP and the French Cancer Center's Lung Group.

One-hundred seventy-three patients with limited small cell lung cancer were included in three consecutive protocols alternating radiotherapy and chemotherapy. The alternating schedule consisted of six courses of chemotherapy (doxorubicin, VP16213, cyclophosphamide, and methotrexate in the first protocol; methotrexate being replaced by cisplatinum in the other two protocols) and three series of thoracic radiotherapy delivering a total dose of 45, 55, and 65 Gy in each consecutive protocol. Radiotherapy was started after the second course of chemotherapy. A 1-week gap was respected between each course of chemotherapy and each series of radiotherapy. Seventy percent of patients were in complete remission at the end of the induction treatment. The actuarial 5-year local control was 60% and the 5-year overall survival was 18%. Sixty percent of patients developed distant metastases. The death rate unrelated to cancer was 10%. These results show that alternating radiotherapy and chemotherapy schedules are reproducible, and provide a consistent long-term local control and a long-term survival rate exceeding 15% in limited disease.

Adult↗
PubMed1990

Iridium-192 curietherapy for T1 and T2 epidermoid carcinomas of the floor of mouth.

From 1970 to 1986, 117 patients with T1 (47) or T2 (70) epidermoid carcinomas of the floor of the mouth (SCC) were treated by iridium-192 implantation (192 Ir). The dose was prescribed according to the Paris System and varied over those years. Follow-up information was available on 116 patients. There were 46 T1N0, 47 T2N0, and 23 T2N1-3. Neck management varied for the 93 N0 patients consisting of surveillance (24 T1, 17 T2) or elective neck dissection (22 T1:all pN-, 30 T2: 20 pN-, 10 pN+). Cause specific survival rates were 94% for T1N0, 61.5% for T2N0, and 28% for T2N1-3 at 5 years. Primary local control was 93.5%, 74.5%, and 65%, respectively, and 98%, 79%, and 65% after salvage. Patients with gingival extension or a tumor size over 3 cm (T2b) had a local control of 50% (9/18) and 58% (15/26), respectively. Nodal control was 93.5% for Stage I, 85% for Stage II, and 48% for T2N1-3 patients. There was no difference in nodal control with regard to treatment policy for Stage I-II patients. There were few complications including three deaths: two from surgery and one from 192 Ir. Nodal status, tumor size defined as T1, T2a (less than or equal to 3 cm), T2b (greater than 3 cm), and gingival extension were the only independent prognostic factors. The management of T1N0 and T2N0 SCC by 192 Ir to a dose of 65 or 70 Gy, using the Paris System, is recommended for lesions 3 cm or less and without gingival extension.

Adult↗
PubMed1990

Iridium 192 implantation of T1 and T2 carcinomas of the mobile tongue.

Between 1970 and 1986, 166 patients with T1 or T2 epidermoid carcinomas of the mobile tongue were treated by iridium 192 implantation (70 T1N0, 83 T2N0, 13 T1-2 N1-3). Five-year actuarial survival was 52% for T1N0, 44% for T2aN0, and 8% for or T1-2 N1-3. Cause specific survivals were 90%, 71%, and 46%, respectively. Local control was 87% for both T1N0 and T2N0, and 69% for T1-2 N1-3. Seven of 23 failures were salvaged by surgery, increasing local control to 96% for T1 and 90% for T2. Thirty-six patients developed a minor or moderate necrosis (16% T1, 28% T2). Half of these involved bone but only five required surgical intervention. Both local control (LC) and necrosis (nec) increased with increasing dose but improvement beyond 65 Gy is minimal (less than or equal to 60 Gy: LC = 78% nec = 13%; 65 Gy: LC = 90% nec = 29%; greater than or equal to 70 Gy: LC = 94% nec = 23%). For N0 patients, neck management consisted of surveillance (n = 78), elective neck dissection followed with external irradiation for pathologically positive nodes (n = 72), or irradiation (n = 3). Clinically positive nodes (13 patients) were managed by either neck dissection followed by external irradiation if pathologically positive (n = 10) or irradiation alone (n = 3). Regional control was 79% for N0 patients, improving to 88% after surgical salvage, and was 9/13 for N1-3 patients. We recommend that T1 and T2 carcinomas of the mobile tongue be treated by iridium 192 implantation to deliver 65 Gy. Mandibular necrosis should be reduced by using an intra-oral lead-lined dental mold.

Adult↗
PubMed1990

Vision and hearing during deferoxamine therapy.

To determine the frequency of eye and auditory complications and their relationship to drug dosage and iron stores in patients receiving deferoxamine, we studied 52 regularly transfused patients who received deferoxamine by subcutaneous or intravenous infusion in doses from 26 to 136 mg/kg/day, and whose serum ferritin levels of 185 to 17,775 micrograms/L reflected a wide range of iron stores. Forty-nine patients (94%) had no evidence of drug-induced visual or auditory abnormalities. Symptomatic loss of vision and hearing developed in one patient; both problems improved when chelation therapy was stopped. Of the 51 symptom-free patients, one had a mild degree of macular stippling and one had a mild, bilateral, high-frequency sensorineural hearing loss. Eye and ear abnormalities in the symptom-free patients did not progress despite continuation or resumption of chelation therapy at the same dosage. Patients with ophthalmologic and audiologic abnormalities did not receive higher doses of deferoxamine and did not have lower serum ferritin levels than patients without such abnormalities. These findings demonstrate that eye and ear abnormalities during chelation therapy with deferoxamine may not occur uniformly at as high a frequency as previously reported, even in patients who receive large doses of the chelating agent or who have only modest amounts of excessive iron.

Adolescent↗
PubMed1990

Positive relationship between the catecholaminergic turnover and the DST results in depression.

In the past some workers have reported positive relationships between indices of noradrenaline activity and measures of hypothalamic-pituitary-adrenal (HPA)-axis function. In order to investigate these relations, the authors measured noradrenaline, adrenaline and vanillylmandelic acid (VMA) in 24 h urine samples of 72 depressed females. Serum adrenocorticotrophic hormone (ACTH) and cortisol concentrations were determined before and after administration of 1 mg of dexamethasone. Cortisol non-suppressors exhibited a significantly higher noradrenaline, adrenaline and VMA excretion as compared to cortisol suppressors. We determined significantly positive correlations between the postdexamethasone cortisol values and the excretion rates of noradrenaline and VMA. These indices of noradrenaline activity correlated neither with the baseline cortisol and ACTH nor with the postdexamethasone ACTH values.

Adrenocorticotropic Hormone↗
PubMed1990

International collaborative study to compare assays for antibodies that neutralize human immunodeficiency virus.

A variety of techniques are currently in use to measure antibodies that neutralize human immunodeficiency virus (HIV), and standardization of these assays is needed. Eleven laboratories participated in this comparison study of 14 methods for detection of HIV neutralizing antibodies (NA). A panel of 10 coded sera and a positive and a negative control serum were tested in each assay. The 10 coded samples included aliquots of the same sera that were distributed as positive and negative control sera, an aliquot of the WHO reference human anti-HIV-1 serum, and seven other sera from people with HIV-1 infection. Each laboratory reported features of its test methods and results. The results demonstrated excellent within laboratory and between laboratory consistency. The most important variable appeared to be the virus strain used. Cell line, conditions of neutralization or culture, method of endpoint determination, or use of VSV pseudotypes did not appear to be important variables. The results indicate that standardization of HIV-1 NA assays should be readily achievable.

Blotting, Western↗
PubMed1990

Estimation of Carbon and Nitrogen Allocation during Stalk Elongation by C and N Tracing in Zea mays L.

Zea mays L. (cv Dea) plants grown to the stage of stalk elongation, were allowed to assimilate (13)CO(2) and (15)N-nitrates from 45 to 53 days after sowing. Isotopic abundances in labeled nutrients were slightly enriched compared to natural abundances. The new C in plant was acropetally distributed and the new N was preferentially accumulated in the sheath and stalk in the medium region. C input was 25-fold higher than N input. The new C in total plant C was 20%, whereas it was 10% for N. The stalk acted as a major sink because it accumulated, respectively, 27.5 and 47.5% of the C and N inputs. The new C in soluble carbohydrates was 76% in growing organs (upper stalk) and only 39% in source leaves, whereas it was 43% and 13% in starch, respectively. New N in nitrates+amino-acids spanned in the range from 20% (leaf) to 50% (stalk). New C and N in soluble proteins were, respectively, 13.4 and 3.8% in leaves, 8.8 and 9.6% in stalk, and 8.7 and 14.3% in roots. In the middle stalk and leaves, the proteins and carbohydrates represent an equivalent C and N source for remobilization.

Journal Article↗
PubMed1990

Treatment of periodontal furcation defects. Coronally positioned flaps versus dura mater membranes in class II defects.

Mandibular class II furcation defects in 19 subjects were treated using 2 different methods of wound closure. In 16 of the defects, the wound was closed with a coronally positioned surgical flap secured by crown-attached sutures. In 15 of the defects, a collagenous membrane (freeze-dried dura mater) was placed to cover the exposed defect, followed by suturing of the surgical flap at the level of the alveolar crest. After use of a coronally positioned flap, an average of 70% of the defect volume became filled with bone, with complete closure by bone fill for 9 of the 16 treated defects. After use of dura mater membrane, 38% of the defect volume was filled with bone, with complete bony closure for 3 of the 15 treated defects. The results following use of coronally positioned flaps support our previous findings and the potentials of this technique. The results following use of dura mater membranes, together with recently reported risk for spread of virus with dura implants, do not justify the use of dura mater for these regenerative purposes.

Adult↗