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Biomedical subjects

D Driscoll

Publications and source records attributed to D Driscoll.

At least 55 records · Page 3Linked to original sources

Staging and grading in the survival of adrenal carcinomas.

In 53 patients with histologically proven adrenal cortical carcinomas the most common metastatic sites, at the time of diagnosis, were the liver, lymph nodes, bone and lungs, and during the course of the disease, the lungs. At the time of diagnosis six (11%) of our patients were in Stage S1, seven (13%) in S2, 11 (21%) in S3 and 29 (55%) in S4. Histologic grading (G) in 43 patients showed G1 grade in 11 (26%), G2 in seven (16%) and G3 in 25 patients (58%). Median survival in months (estimated 5-year survival rate) for the various stages were: S1 46 (33%), S2 84 (57%), S3 eight (18%) and S4 seven (7% at 2 years) (P = 0.01). Median survival in months (estimated 5-year survival rate) for the various grades were: G1 46 (46%), G2 24 (43%), G3 five (4% at 2 years) (P = 0.003). In this series, tumor stage (P = 0.01) and grade (P = 0.003) were predictors of survival and the two were closely correlated (P = 0.02).

Adrenal Cortex Neoplasms↗

Results of salvage mastectomy for local recurrence after breast-conserving surgery without radiation therapy.

BACKGROUND: Between 1975 and 1987, 128 patients with infiltrating breast cancer, categorized as clinical Stage I and II disease, were treated by breast conservation surgery without radiation therapy. MATERIALS: After a median disease-free interval of 20 months (range, 8-64 months), 25 of 128 patients had local recurrence, for which salvage mastectomy was performed. The results of modified radial mastectomy as a salvage procedure were analyzed in these 25 patients. RESULTS: After a median disease-free interval of 52 months (range, 8-75 years) after the salvage procedure, 12 patients had chest wall and distant recurrences, whereas 13 patients remained free of disease. The 5-year actuarial disease-free and overall survival rates after the salvage mastectomy were 51% and 65%, respectively. CONCLUSIONS: Univariate analyses of factors affecting disease-free survival and overall survival showed that the size of the local recurrence (< or = 2 cm) (P = 0.009) and the number of pathologically positive axillary nodes at the time of the salvage procedure (fewer than four nodes) (P = 0.002) were associated with a better prognosis.

Adult↗

Microdeletions of chromosomal region 22q11 in patients with congenital conotruncal cardiac defects.

Congenital conotruncal cardiac defects occur with increased frequency in patients with DiGeorge syndrome (DGS). Previous studies have shown that the majority of patients with DGS or velocardiofacial syndrome (VCFS) have a microdeletion within chromosomal region 22q11. We hypothesised that patients with conotruncal defects who were not diagnosed with DGS or VCFS would also have 22q11 deletions. Seventeen non-syndromic patients with one of three types of conotruncal defects most commonly seen in DGS or VCFS were evaluated for a 22q11 deletion. DNA probes from within the DiGeorge critical region were used. Heterozygosity at a locus was assessed using restriction fragment length polymorphisms. Copy number was determined by dosage analysis using Southern blot analysis of fluorescence in situ hybridisation of metaphase spreads. Five of 17 patients were shown to have a 22q11 deletion when evaluated by dosage analysis. This study shows a genetic contribution to the development of some conotruncal cardiac malformations and alters knowledge regarding the risk of heritability of these defects in certain cases.

Abnormalities, Multiple↗

Factors affecting outcome in locally advanced breast cancer.

Patients presenting with locally advanced breast cancer (LABC) constitute a diverse group for which a variety of treatment modalities have been instituted. To assess which factors have a direct impact on outcome, we reviewed the medical records of 104 patients diagnosed with stage IIIA, stage IIIB and T3N0M0 breast carcinoma. When considered individually (univariate analysis), clinical stage, pathological stage, oestrogen receptor status and type of therapy were significant predictors for disease-free survival (DFS) and overall survival (OS). However, in a multivariate analysis, only clinical stage was a significant predictor for both DFS and OS, while ER status was a significant predictor for OS. There was a high degree of correlation between clinical and pathological staging. Nearly two-thirds of the patients developed a recurrence by 5 years. Loco-regional recurrence was the site of first recurrence in one-third of the patients by 5 years. The prognosis for patients presenting with LABC is poor, and they should be treated aggressively with loco-regional and systemic multimodality therapy. Although groups of patients with improved outcome could be identified by clinical or pathological staging, no group demonstrated an outcome good enough to be spared from multimodality therapy.

Adult↗

Mandibular osteotomies for tumor extirpation: the advantages of rigid fixation.

Adequate exposure of intraoral tumors occupying the posterior oral cavity, base of tongue, tonsil, and superior hypopharynx for wide-field primary surgical resection is critical to precise tumor ablation. The exposure resulting from a mandibular osteotomy has greatly assisted the tumor ablation of these areas. This procedure has also been beneficial in providing exposure to the anterior skull base, pterygomaxillary, and infratemporal space, clivus, and nasopharynx. In evaluating various osteotomy sites and methods of fixation, we reviewed 26 patients treated for benign or malignant neoplasia of the head and neck requiring mandibulotomy. The osteotomy complication rate was 2 (29%) of 7 for wire osteosynthesis and 1 (5.3%) of 19 for plate osteosynthesis. All patients with osteotomy complications had received preoperative radiation therapy. The one complication in the plated group was associated with a lateral stairstep osteotomy and two screws on either side of the osteotomy. This study suggests advantages of absolute rigid internal fixation of mandibular osteotomies used for tumor ablation. It is also concluded that a midline osteotomy reapproximated with rigid internal fixation has the benefits of 1. primary bone healing by means of plating counteracting the balanced forces acting on the symphysis; 2. improved reapproximation with minimal bony loss, improving occlusion; 3. decreased incidence of osteoradionecrosis as the symphysis lies outside the usual radiation ports; 4. preservation of the neurovascular bundle; and 5. maintenance of osteotomy-site immobility in an infected field. This review helped identify surgical techniques that decrease the complications that are commonly associated with mandibular osteotomies for precise tumor ablation.

Adult↗

Hydrogen peroxide is involved in hamster sperm capacitation in vitro.

We have investigated the possibility that the generation of hydrogen peroxide (H2O2) by spermatozoa plays a physiological role during capacitation. Capacitation is defined as the incubation period required for fertilization in mammals. Capacitation culminates in an exocytotic event, the acrosome reaction (AR). Mammalian sperm generate H2O2 during aerobic incubation and do not contain catalase, the enzyme that promotes scavenging of H2O2. In the present work we show that added catalase inhibited the AR, while glucose oxidase (GO), an enzyme that generates H2O2, accelerated the onset of the AR. Direct addition of H2O2 also stimulated the AR; catalase inhibited both the stimulation by GO and by H2O2. The onset of the AR was always preceded by the appearance of hyperactivated motility. The stimulation of the AR by H2O2 was manifest 1-2 h after the addition of H2O2. Catalase added at 3 h of incubation was less effective in inhibiting the AR than catalase added at the beginning. Incubation of sperm with catalase prevented the induction of the AR by the membrane-perturbing lipid, lysophosphatidyl choline. Taken together, these results suggest that H2O2 produced by hamster sperm plays a significant role during capacitation, possibly in membrane reorganization to facilitate the fusion that takes place during exocytosis of the acrosomal contents.

Animals↗

Overproduction of the regulatory subunit of the cAMP-dependent protein kinase blocks the differentiation of Dictyostelium discoideum.

During the aggregation of Dictyostelium discoideum extracellular cAMP is known to act as a chemotractant and as an inducer of cellular differentiation. However, its intracellular role as a second messenger remains obscure. We have constructed a fusion gene consisting of the cDNA encoding the regulatory subunit (R) of the cAMP-dependent protein kinase fused to the promoter and N-terminal-proximal sequences of a Dictyostelium actin gene. Stable transformants, containing multiple copies of this gene, overproduce the R subunit which accumulates prematurely relative to the endogenous protein. These transformants fail to aggregate. Detailed analysis has shown that they are blocked at interphase, the period prior to aggregation, and that they are severely defective in most responses to cAMP including the induction of gene expression. Our observations suggest that intracellular cAMP acts, presumably by activation of the catalytic subunit of the cAMP-dependent protein kinase, to facilitate early development.

Blotting, Western↗

Coarctation of the aorta. Long-term follow-up and prediction of outcome after surgical correction.

The long-term clinical course was studied in 646 patients, who underwent isolated operative repair of coarctation of the aorta at the Mayo Clinic from 1946 to 1981. There were 17 perioperative deaths, and 58 patients were lost to follow-up. Of the 571 patients with long-term follow-up, 11% required subsequent cardiovascular surgery, and 25% developed hypertension. There were 87 late deaths. The mean age at death was 38 years (range, 0-67 years). Estimated survival analysis revealed 91% of patients alive at 10, 84% at 20, and 72% at 30 years after operative repair. The most common cause of late death was coronary artery disease in 32 patients, followed by sudden death, heart failure, cerebrovascular accidents, and ruptured aortic aneurysm. Age, sex, and postoperative systolic blood pressure were found to be independently predictive of survival. For patients less than 14 years of age at the time of initial coarctectomy, survival to 20 years was 91%, and for patients 14 years or older at the time of operation, survival was 79%. The best survivorship was observed in patients operated on at 9 years of age or less. The higher the postoperative systolic pressure, the higher the probability of death. This study has the largest population undergoing repair of coarctation of the aorta with a median follow-up of as long as 20 years. Four main points emerged. 1) Age at the time of initial repair is the most important predictor of long-term survival. Surgery should be offered to patients after age 1 year or sooner if hypertension is severe. 2) Coronary artery disease is the most common cause of late death.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Septic arthritis of the shoulder in adults.

Septic arthritis of the shoulder is uncommon in adults. We reviewed the cases of eighteen patients who were followed for a minimum of one year. The patients ranged in age from forty-two to eighty-nine years. All but one patient had at least one serious associated disease. Eight patients had had an injection or aspiration of the shoulder before development of the infection. All but one patient had had a delay in diagnosis. At the time of admission to the hospital, the erythrocyte sedimentation rate was always elevated, but the body temperature and white blood-cell count were not. After treatment, the functional result was usually poor: only five patients regained forward flexion to 90 degrees or more, eight patients had no active motion of the glenohumeral joint, and two patients died. Arthrotomy appeared to afford a better result than did repeated aspiration.

Adult↗

High-resolution 13C NMR study of pressure effects on the main phase transition in L-alpha-dipalmitoyl phosphatidylcholine vesicles.

The effects of pressure on the liquid-crystalline to gel transition in vesicles of L-alpha-dipalmitoyl phosphatidylcholine were investigated by high-resolution proton-decoupled natural-abundance 13C NMR spectroscopy. The linewidths of several 13C resonances, including the choline methyl groups, carbonyl carbons, and choline methylene groups and the palmitoyl methyl groups are reported as a function of pressure at 52.7 degrees C. These preliminary NMR experiments clearly demonstrate that high-pressure, high-resolution proton-decoupled natural-abundance 13C NMR spectra are a promising tool to study the phase-transition behavior and the dynamics of model membrane systems.

1,2-Dipalmitoylphosphatidylcholine↗

A field study of the fertility of transported equine semen.

A field trial of artificial insemination in horses with transproted, chilled semen was conducted using a specially designed container which permitted a controlled, slow initial rate of cooling (-0.3 degrees C/min) and maintenance of a final temperature of 4 degrees -6 degrees C for more than 36 hrs. Forty-six mares in 23 states were inseminated with semen from three German Warmblood stallions standing at stud in Hamilton, Massachusetts. A third-cycle conception rate of 91% was obtained.

Journal Article↗

The influence of neonatal orchiopexy upon the testis in persistent Müllerian duct syndrome.

We report on a patient with persistent müllerian duct syndrome and normal external genitalia who had embryonal cancer of the testis 16 years after neonatal bilateral orchiopexy. In previous cases the testes of these patients have not been considered predisposed to form tumors. However, the occurrence of a testis tumor has been reported in 8 patients with this syndrome. The specific factors resulting in tumor formation in such patients are uncertain. Until they are clarified we suggest that these patients should be observed carefully for the possible development of testis tumor.

Adolescent↗

The comparative electrophysiologic and hemodynamic effects of verapamil in puppies and adult dogs.

Verapamil has been studied extensively in adult animals. However, there is limited data about the effects of this antiarrhythmic agent in young animals. We studied the electrophysiologic and hemodynamic effects of verapamil in 5 awake, chronically instrumented puppies and in 6 anesthetized, acutely instrumented puppies. We compared the responses in puppies to those in 7 awake, chronically instrumented adult dogs and in 6 anesthetized, acutely instrumented adult dogs. In the awake, chronically instrumented animals, we measured heart rate and the effective refractory period of the atrio-ventricular specialized conduction system (ERP-AVSCS). In the anesthetized, acutely instrumented preparation, we measured heart rate, ERP-AVSCS, mean right atrial and systemic arterial blood pressure, and velocity of blood flow in the aorta, carotid and femoral arteries. We infused verapamil intravenously at doses of 50, 100, 200 and 400 microgram/kg. Verapamil (400 micrograms/kg) increased the ERP-AVSCS by 64% in awake, chronically instrumented puppies; 62% in awake, chronically instrumented adult dogs; 125% in anesthetized, acutely instrumented puppies, and 120% in anesthetized, acutely instrumented adult dogs. The effect of verapamil upon heart rate and ERP-AVSCS was more pronounced in anesthetized animals than in awake animals. Mean systemic arterial blood pressure was reduced by verapamil in anesthetized, acutely instrumented puppies and adult dogs. Verapamil reduced the velocity of aortic, femoral and carotid artery blood flow in anesthetized, acutely instrumented puppies.

Aging↗

Patterns of use of Madang Hospital.

The patterns of inpatient use of Madang Hospital were examined. A highly disproportionate use of the hospital by the neighbouring population was demonstrated. The implications of this for health care planning are discussed and some methods of alleviating the inequalities in health care provision to urban as opposed to rural communities are suggested.

Bed Occupancy↗

Anaplastic carcinoma of the thyroid: a 24-year experience.

BACKGROUND: Anaplastic carcinoma of the thyroid gland is a lethal entity; few patients live more than 12 months following diagnosis. We retrospectively reviewed the experience with this entity at our cancer institute and identified a subgroup of patients with complete resection who have a 60% 5-year survival. METHODS: Twenty-one cases of anaplastic carcinoma of the thyroid gland were analyzed retrospectively with respect to prognostic factors influencing survival. This represents 2.7% of 771 cases of thyroid cancer seen at our institution from 1968 to 1992. The median age at presentation was 65.1 years; male/female ratio was 1:1.1; and the most common symptom was a rapidly enlarging neck mass (76%). RESULTS: Estimated 5-year survival was 10% (median: 4.5 months). Tumor size less than 6.0 cm (p = .004) and female gender (p = .02) were significant prognostic factors. Five patients who underwent complete resection had an estimated 5-year survival of 60% (median: 131 months). Four of these patients had postoperative radiotherapy with or without sequential chemotherapy. Two of these patients survived more than 10 years, and a third remains alive without disease at 26 months.

Adult↗