Search PubMed⌕ Search

Biomedical subjects

D Miller

Publications and source records attributed to D Miller.

At least 523 records · Page 29Linked to original sources

An analysis of induction and adjuvant chemotherapy in the multidisciplinary treatment of squamous-cell carcinoma of the head and neck.

This study examines the role of combination chemotherapy with surgery and/or radiotherapy in the initial treatment of patients with advanced stage III and IV squamous-cell carcinoma of the head and neck (SCCHN). Two courses of initial (induction) cisplatin, bleomycin, and methotrexate with oral calcium leucovorin (PBM) were used with the principal intent of increasing the effectiveness of subsequent surgery and/or radiotherapy. Following induction chemotherapy and local treatment, disease-free patients who had responded to initial chemotherapy were entered into a randomized trial of adjuvant PBM. The response rates to induction PBM chemotherapy were a complete response (CR) rate of 26% and a partial response (PR) rate of 52%, for an overall response rate of 78%. A response to induction PBM was highly correlated with failure-free survival (P less than .0001). A Cox multistep regression analysis of potential prognostic factors was performed. After adjusting for the significant prognostic factors of performance status, initial tumor size, and primary tumor site, a response to induction chemotherapy remained independently associated with improved survival (P = .0002). The randomized trial of adjuvant chemotherapy demonstrated that such treatment significantly improved failure-free survival by decreasing local-regional failures. The benefit of adjuvant chemotherapy was particularly evident in patients who had a PR to induction chemotherapy (P = .01). The toxicity of this multidisciplinary approach was predictable and acceptable. Surgery and radiotherapy were not compromised by induction or adjuvant chemotherapy. Definitive evidence that chemotherapy can favorably influence survival awaits confirmation of these results by a randomized trial using a control arm of patients treated with conventional surgery and/or radiotherapy alone.

Aged↗

Effect of vegetarian diet on serum 1,25-dihydroxyvitamin D concentrations during lactation.

The effect of maternal diet on serum 1,25-dihydroxyvitamin D has not been determined in human lactation. Serum 1,25-dihydroxyvitamin D, other calcitropic hormones, osteocalcin, and minerals were examined in lactating and nonlactating women consuming a vegetarian or nonvegetarian diet. The vegetarian diet was a macrobiotic diet consisting primarily of whole cereal grains and vegetables; dairy products, eggs, and meats were generally avoided. We tested the thesis that the effect of lactation on serum 1,25-dihydroxyvitamin D is more pronounced in women on vegetarian diets than in those on nonvegetarian diets. Serum 1,25-dihydroxyvitamin D concentrations were significantly higher in lactating women compared with nonlactating women and in vegetarian compared with nonvegetarian women. Among vegetarian women, mean serum 1,25-dihydroxyvitamin D concentrations were 37% higher in the lactating group. For all subjects, serum parathyroid hormone was elevated during lactation compared with nonlactation. Thus, a vegetarian diet appears to be associated with increased serum 1,25-dihydroxyvitamin D during lactation.

Adult↗

Screening for colorectal cancer.

Colorectal cancer is a good candidate for secondary prevention strategies. It appears to have a long lead time since most, if not all, of these cancers arise from premalignant adenomas, and several screening methods are available that might detect the cancer in a very early stage. However, there is little evidence at present to show that the available methods of early detection will actually decrease the mortality from colorectal cancer of a screened population as compared to a non-screened population. Studies that might convincingly provide this evidence are still in progress. This paper critically reviews the natural history of colorectal cancer, risk factors, screening trials and treatment.

Colonic Neoplasms↗

Wound necrosis following dacryocystorhinostomy in patients with Wegener's granulomatosis.

Two patients with Wegener's granulomatosis underwent dacryocystorhinostomy (DCR) for nasolacrimal duct obstruction and epiphora. Wound necrosis occurred in each individual with the formation of a nasal-cutaneous fistula. A pedicle flap was the treatment of choice in one case, while direct closure of the necrotic incision site and high-dose steroid therapy was used in the other. Both did well with complete wound healing. The tearing persisted in one and resolved in the other. Dacryocystorhinostomy should be avoided whenever possible in patients with Wegener's granulomatosis, and steroid dosage should be increased if surgery is necessary in the presence of active inflammation.

Adult↗

The egasyn gene affects the processing of oligosaccharides of lysosomal beta-glucuronidase in liver.

The accumulation of the relatively large amounts of beta-glucuronidase in microsomal fractions of normal mice depends on formation of complexes with the protein egasyn. Unexpectedly, it was found that the egasyn gene also affects the processing of beta-glucuronidase, which is segregated to lysosomes. In egasyn-positive mice lysosomal beta-glucuronidase from liver has a mean pI of 5.9 with a minor proportion at pI 5.4, whereas in egasyn-negative mice the proportion of the two lysosomal forms is reversed. Combined experiments measuring susceptibility to neuraminidase and to endoglycosidase H and specific binding to Ricinus communis lectin-agarose columns showed that the alterations in isoelectric point were associated with a decrease in complex oligosaccharides of lysosomal beta-glucuronidase in egasyn-positive mice. Since this alteration occurs not only in a congenic strain carrying the Eg0 gene but also in several other inbred strains that are homozygous for this gene, it is considered to be a genuine effect of the Eg gene rather than other genes that might regulate oligosaccharide processing. Also, the alteration is likely to be a result of direct physical interaction of the egasyn protein and lysosomal beta-glucuronidase, since a second lysosomal enzyme, beta-galactosidase, which does not form complexes with egasyn, is unaffected. The results suggest a model in which egasyn not only causes accumulation of beta-glucuronidase in the microsomal compartment but also acts upon the precursor to lysosomal beta-glucuronidase to alter its interaction with trans-Golgi-apparatus processing enzymes.

Acetylglucosaminidase↗

Stimulation of Escherichia coli adenylate cyclase activity by elongation factor Tu, a GTP-binding protein essential for protein synthesis.

A unique feature of eucaryotic adenylate cyclases is their interaction with GTP-binding proteins that mediate hormonal responses. Until now, there has been no evidence for regulation of Escherichia coli adenylate cyclase by a GTP-binding protein. We describe here that the most abundant protein in E. coli, the GTP-binding protein EF-Tu, which is important as an elongation factor in protein synthesis, also serves as a stimulator of adenylate cyclase activity. Homogeneous EF-Tu specifically increased the activity of purified adenylate cyclase as much as 70%; other E. coli GTP-binding proteins had no effect on enzyme activity. A study of the guanine nucleotide specificity for EF-Tu-mediated stimulation of adenylate cyclase activity suggested that the preferred activator is EF-Tu X GDP. To account for the GTP-specific stimulation of adenylate cyclase activity observed in intact cells, we propose that the nucleotide specificity for EF-Tu-dependent activation of adenylate cyclase is governed by other factors in the cell.

Adenylyl Cyclases↗

Changes in intracellular levels of Ap3A and Ap4A in cysts and larvae of Artemia do not correlate with changes in protein synthesis after heat-shock.

Artemia larvae respond to a brief heat-shock between 28 degrees and 40 degrees C with an increase in the synthesis of two groups of proteins of Mr 68,000 and 89,000. At 40 degrees C synthesis of all other proteins is strongly repressed. Cysts, which are naturally thermotolerant, synthesise both heat-shock proteins at temperatures up to 47 degrees C but maintain normal protein synthesis. During pre-emergence development, Ap3A is present in cysts at a concentration twice that of Ap4A. The maximum level of 7.6 pmol/10(6) cells is reached shortly before hatching of the larvae. After hatching, the levels of both nucleotides decline. A 40 degrees C heat-shock produces a 1.8-fold increase in both nucleotides within 20 min in cysts and larvae. A 2.8-fold increase results from a 47 degrees C heat-shock to cysts. The rates of increase parallel but do not precede the increases in the heat-shock proteins. Since non-heat-shocked cysts possess higher levels of Ap3A and Ap4A than do heat-shocked larvae, the observed heat-induced changes in gene expression cannot be explained simply in terms of the intracellular concentrations of these nucleotides.

Adenine Nucleotides↗

Performance of primary and derived M-mode echocardiographic measurements for detection of left ventricular hypertrophy in necropsied subjects and in patients with systemic hypertension, mitral regurgitation and dilated cardiomyopathy.

To determine which M-mode echocardiographic (echo) measurement best detects left ventricular (LV) hypertrophy, the sensitivity and specificity of upper normal limits of echo LV anatomic measurements (previously shown to have 97% specificity in living normal subjects) were tested in 60 necropsied patients with anatomic hypertrophy and in 28 necropsied patients with normal left ventricles. The prevalence of hypertrophy by each echo criterion was determined in 165 living patients with systemic hypertension, mitral regurgitation or dilated cardiomyopathy. The best separation between patients with normal vs increased necropsy LV mass was obtained using sex-specific echo LV mass index criteria (overall accuracy = 73 of 88 patients, 83%). Lower overall accuracies for separation of patients with and without hypertrophy were observed for echo cross-sectional area (59 of 88 patients, 67%; p less than 0.05 vs LV mass index) and indexes of LV wall thickness (39 to 51%, p less than 0.001). Among 113 living patients with moderate or severe hypertension, mitral regurgitation or dilated cardiomyopathy, LV mass index was increased in 73%, cross-sectional area index in 58% (p less than 0.02 vs LV mass index), and posterior wall thickness, septal thickness and relative wall thickness in only 11 to 32% (all p less than 0.001 vs LV mass index). Thus, an M-mode echo LV mass index of more than 134 g/m2 in men and more than 110 g/m2 in women detects concentric and eccentric LV hypertrophy accurately by comparison with necropsy and clinical reference standards; cross-sectional area is slightly less useful; and other M-mode echo criteria of LV hypertrophy perform too poorly to be clinically applicable.

Adult↗

Type II renal tubular acidosis in a mare.

Persistent, severe metabolic acidosis complicated the operative and postoperative period in a 4-year-old mare with colic. On the basis of clinical and laboratory findings, a renal tubular disorder was diagnosed. Renal tubular acidosis is rare in horses. In the only report found on the subject, type I renal tubular acidosis was described in 2 horses. Bicarbonate titration studies in our case helped document type II renal tubular acidosis in this mare.

Acidosis, Renal Tubular↗

The syndrome of inappropriate antidiuretic hormone secretion associated with induction chemotherapy for squamous cell carcinoma of the head and neck.

Two patients with squamous cell carcinoma of the head and neck are reported in whom the syndrome of inappropriate antidiuretic hormone (SIADH) secretion occurred transiently during the rapid cytolytic phase of tumor destruction after chemotherapy with cis-platinum diamminedichloride and bleomycin. Immunoperoxidase staining for ADH of the original biopsy specimens from both patients was negative. Possible mechanisms for and the implications of the production of SIADH in this setting are discussed.

Antineoplastic Agents↗

Analysis of prognostic factors in acute lymphoblastic leukemia.

Children with ALL who have a high probability of excellent response, long-term survival, and cure when treated with widely available standard therapy can be identified at the time of diagnosis. Others can be identified who are at high risk of failure to respond, early relapse, and death. The importance of such prognostic characteristics is so great that they should be considered in the selection of appropriate treatment for each patient. Prognostic factors also must be considered in the design and analysis of clinical trials. All prognostic factors are not equally significant and many of them are closely associated. It is possible to rank them in importance and usefulness by appropriate statistical methods. As additional prognostic factors are identified, and as more effective and more specific therapies are developed, the relative importance of prognostic factors will change.

Adolescent↗