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M Morris

Publications and source records attributed to M Morris.

At least 109 records · Page 6Linked to original sources

Identification of additional rRNA fragments encoded by the Plasmodium falciparum 6 kb element.

Sequences similar to mitochondrial large and small subunit rRNAs are found as small scattered fragments on a tandemly reiterated 6 kb element in the human malaria parasite Plasmodium falciparum. The rDNA sequences previously identified include strongly conserved portions of rRNA, suggesting that fragmented rRNAs derived from them are able to associate into functional ribosomes. However, sequences corresponding to other expected rRNA regions were not found. We here report that 10 of the 13 previously described rDNA regions have abundant small transcripts. An additional 10 transcripts were found from regions not previously known to contain genes. Five of the latter have been identified as rRNA fragments, including those corresponding to the 5'end and 790 loop sequences of small subunit rRNA and the sarcin/ ricin loop of large subunit rRNA. Demonstration that most of the previously described rDNA regions have abundant transcripts and the identification of new transcripts with other portions of conventional rRNAs provide support for the hypothesis that these small transcripts comprise functional rRNAs.

Animals↗

Prognostic significance of residual disease in patients with stage IV epithelial ovarian cancer.

PURPOSE: To evaluate the role of surgical debulking in patients with stage IV ovarian cancer. METHODS: We conducted a retrospective review of patients with advanced epithelial ovarian cancer treated at M. D. Anderson Cancer Center. Eligible patients included women with stage IV disease treated with platinum-based chemotherapy. Surgical debulking was considered optimal if the diameter of the largest residual tumor was 2 cm or less. Survival analysis and comparisons were performed using the Kaplan-Meier method and the log-rank test. RESULTS: One hundred eight women with stage IV ovarian cancer were identified. The extraperitoneal metastatic sites were the liver parenchyma in 16 patients, the pleura in 54 patients, a variety of other organs in 22, and two or more sites in the remaining 16. Median age of the patient population was 58 years (range 35-81 years). Surgery to reduce the primary tumor was performed in 100 patients. The procedures included salpingo-oophorectomy with or without hysterectomy in 94 patients, omentectomy in 90, small bowel resection in 4, large bowel resection in 23, and splenectomy in 2. At the completion of surgery, tumor reduction was considered optimal in 31 patients, suboptimal in 61, and undetermined in 8. The overall median survival for optimally debulked patients was 25 months compared to 15 months for suboptimally debulked patients (P < 0.02). The progression-free survival, on the other hand, was not statistically different between the two groups. CONCLUSION: Residual tumor seems to be an important prognostic factor in patients with stage IV ovarian cancer. Surgical debulking may play a significant role in the treatment of these patients.

Adult↗

Cervical carcinoma metastatic to the brain.

Brain metastases from cervical cancer are uncommon and are usually considered incurable. Characterization of presentation and a consensus on standard effective treatment have not been published. We present a case in which long-term disease-free survival has been achieved by surgical resection of a solitary brain metastasis with postoperative whole brain radiation. The world literature is examined and discussed in relation to this experience.

Aged↗

The effect of dietary fiber on bowel function following radical hysterectomy: a randomized trial.

OBJECTIVE: To assess the effect of high-fiber dietary instruction in relieving chronic constipation, a known and accepted complication of radical hysterectomy (RH). METHODS: Thirty-five women with a diagnosis of cervical cancer who were scheduled for RH were randomized into groups that followed either a high-fiber diet plan or their usual diet. Data were gathered using a validated subjective bowel function questionnaire (SBFQ); a typical day's intake form and food frequency tool; and a diary used to record food, medication, bowel, and exercise information. Patients were evaluated at 1, 4, and 7 months after surgery. RESULTS: Postoperatively, the dietary fiber intake was significantly higher for the treatment (T) group (22.9 g) than the control (C) group (12.4 g) (P = 0.007). With regard to intergroup comparisons, there were few differences at the first follow-up. By the second visit, the T group reported taking medications to achieve regularity less often (P = 0.0269), straining less often (P = 0.0210), having pain with bowel movement (BM) less often (P = 0.0116), and having crampy abdominal pain less often (P = 0.123) than the C group. Four significant positive changes occurred in the T group, whereas only one occurred in the C group. With regard to intragroup comparison, the significant changes in bowel function in the T group were generally positive, whereas all of the C group's significant changes were negative. According to summary questions on the SBFQ, the T group reported a significant change in the frequency of BM (P = 0.0096); however, the C group reported no significant changes. Analysis of bowel function records showed clearer differences. The T group took less time to defecate (P < 0. 001) but had more BMs accompanied by gas (P < 0.001). The C group had significantly more BMs with cramps (P < 0.001), straining (P < 0. 001), and retention (P < 0.001) and significantly more BMs, which were hard (P < 0.001). Two C patients dropped out of the study because of severe bowel dysfunction despite maximum medication. CONCLUSION: Dietary management seems to be an inexpensive effective therapeutic intervention for addressing bowel dysfunction associated with RH.

Constipation↗

A new mutation, 3905insT, accounts for 4.8% of 1173 CF chromosomes in Switzerland and causes a severe phenotype.

We have analysed 1173 cystic fibrosis (CF) chromosomes from Switzerland for eight mutations in the CF transmembrane conductance regulator (CFTR) gene. This permitted the identification of 88.5% of all mutations present. A novel insertion mutation in exon 20 of the CFTR gene, 3905insT, was discovered. This mutation accounted for 4.8% of CFTR gene mutations in Switzerland and has since been identified in other populations of probable Swiss descent. It is associated with a highly variable clinical phenotype but always with pancreatic insufficiency. Haplotype analysis with three intragenic microsatellites in the CFTR gene showed that the mutation is associated with a haplotype rarely identified on other CFTR alleles and, therefore, that the frequency of the mutation in Switzerland is explained by a founder effect of a relatively recent mutation event.

Cystic Fibrosis↗

A large family with subtelomeric translocation t(18;21)(q23;q22.1) and molecular breakpoint in the Down syndrome critical region.

We describe a 17-month-old infant with clinical features of Down syndrome and a normal karyotype by standard chromosomal analysis, her two uncles aged 28 and 30 years, respectively, with reduced intelligence and unusual appearance but not apparent Down syndrome, and a severely retarded 6-year-old girl with dysmorphy and epilepsy from the same family. Cytogenetic studies of patients and normal intervening relatives had been carried out at different institutions with normal results. Fluorescence in situ hybridization using whole chromosome painting and unique-copy probes (cosmids) and high-resolution banding revealed a familial subtelomeric translocation of chromosomes 18 and 21, resulting in partial trisomy 21 in the infant and her two uncles, and partial monosomy 21 in the 6-year-old girl. Cytogenetic breakpoints were located in bands 18q23 and 21q22.1, respectively. The molecular breakpoint on chromosome 21 was located between D21S211 (proximal) and D21S1283 (distal) and thus maps within the Down syndrome critical region.

Adult↗

An outcomes management program in gynecologic oncology.

OBJECTIVE: To evaluate the effectiveness of an outcomes-management program designed to provide high-quality patient care, generate data for outcomes research, and decrease costs in a managed-care environment. METHODS: An outcomes-management program was launched in June 1994, based on the elimination of wasteful or ineffective therapies through the systematic development of practice guidelines and collaborative care paths, with concomitant definition of desired outcomes. Over 3 months, care paths were developed for our most common surgical procedures. A matched control outcomes study was undertaken for the most commonly performed gynecologic oncology procedure: total abdominal hysterectomy and oophorectomy with pelvic and para-aortic node sampling for endometrial cancer. Thirty consecutive women treated on the care path were compared with 29 matched controls accrued during the period of care-path planning and with 73 controls from the period preceding care-path planning. Patient satisfaction with care-path treatment was assessed by a survey sent 2 weeks after discharge. RESULTS: Median length of hospital stay decreased significantly, from 6 days before care-path planning to 4 days after care-path implementation (P < .001). Median laboratory costs decreased by 74% (P < .001), medication costs by 35% (P < .001), room costs by 29% (P < .001), and total hospital costs by 20% (P < .002). Incremental improvements were observed during care-path planning. There were no readmissions for complications in the care-path group. According to the survey results, patient satisfaction with care was very high among care-path patients. CONCLUSIONS: A physician-driven outcomes-management program in an academic setting permits the delivery of high-quality care and supports outcomes research while decreasing costs.

Cancer Care Facilities↗

Single and repeated environmental stress: effect on plasma oxytocin, corticosterone, catecholamines, and behavior.

Rat studies were done to further characterize an environmental model of stress designated shaker stress (SS). Plasma oxytocin (OT), corticosterone (CS), norepinephrine (NE), and epinephrine (E) were measured before and after 5 or 30 min of SS applied one time or applied 10 times over a 2-week period. The major findings were partial adaptation of plasma E within 30 min of acute SS, adaptation of plasma CS baselines but not responses to chronic SS, and complete adaptation of plasma OT responses to chronic SS. Poststress behavior during chronic SS was affected in the following ways: freezing time habituated, defecation and rearings increased, and grooming and teeth chattering remained relatively constant. The results show that SS produces consistent patterns of hormonal and behavioral responses; some aspects of the patterns are similar to those elicited by other environmental stresses, whereas some aspects are unique to SS. We conclude that rats do not adapt to repeated SS but rather that most hormonal and behavioral defense mechanisms are renewable on a daily basis.

Animals↗

Acanthoxin, a toxic phospholipase A2 from the venom of the common death adder (Acanthophis antarcticus).

This is the first report of a phospholipase A2 (PLA2) from the venom of the common death adder, Acanthophis antarcticus. Acanthoxin is a basic, monomeric PLA2 of mol. wt 13,000, consistent with the weight of neurotoxic PLA2s from other Australian elapids. However, preliminary ultracentrifugation experimentation has shown that it is able to undergo concentration-dependent aggregation to form dimers. It has a relatively high degree of enzymatic activity (23.93 +/- 1.18 mumoles of phospholipid hydrolysed/min/mg protein), but a low level of toxicity (3.2 mg/kg, s.c.). Acanthoxin is known to exist as two isoforms (A1 and A2), both of which show a high degree of homology with numerous elapid PLA2 neurotoxins, in particular pseudexin A from the red-bellied black snake (Pseudechis porphyriacus).

Amino Acid Sequence↗

Sclerosing encapsulating peritonitis associated with continuous ambulatory peritoneal dialysis: surgical management.

Sclerosis of the peritoneum with encapsulation of the small intestine is one of the most serious complications of continuous ambulatory peritoneal dialysis (CAPD) and is associated with a high mortality rate. Its presence should be suspected in patients treated by CAPD who develop small bowel dysfunction with associated abdominal pain and progressive loss of ultrafiltration. In its severest form, it leads to complete high small intestinal obstruction and requirement for total parenteral nutrition. We report the successful surgical management of two young, severely emaciated patients who had this complication of CAPD. Each had entrapment of their bowel by a thick, fibrosed, and calcified membrane. Both were treated by surgically peeling the membrane away from the intestines.

Adolescent↗

Baroreceptor regulation of salt intake.

Baroreceptor input plays a critical role in body fluid balance and the endocrine response to NaCl consumption [25]. Experiments were performed to characterize the alterations in salt intake that are seen after baroreceptor denervation. Using chronically baroreceptor denervated (SAD) or control (CON) male Sprague-Dawley rats, we determined: 1) concentration-dependent consumption of NaCl, 2) time course of saline intake, 3) effect of food access on saline intake, 4) intake of sucrose vs. saline, and 5) water vs. saline intake using a choice paradigm. In protocols 1-4 the rats were given a single bottle containing saline or sucrose for a 2-h period during the early dark period. A comparison of the intake of varying concentrations of NaCl (0.3 to 2.0% NaCl, six concentrations) demonstrated that the SAD consumed significantly less NaCl than the CON (from 0.9 to 2% NaCl), Saline Intake in SAD was 14-56% of the CON (significant group, salt concentration and interaction effects). Regression analysis demonstrated that in the SAD there was an inverse relationship between concentration and the amount of NaCl consumed (p < 0.02), an effect not seen in the CON. There were also differences in the pattern of saline intake with the CON showing the highest consumption in the early dark period with a gradual decrease as compared to the SAD, which demonstrated a uniformly lower pattern of consumption. The reduction in intake in the SAD appeared to be specific for NaCl because there was no difference in water or sucrose intake. The deficit could not be attributed to alterations in food intake, nor was there any difference in the amount of water consumed after the saline challenge.

Animals↗

Concurrent partnerships and the spread of HIV.

OBJECTIVE: To examine how concurrent partnerships amplify the rate of HIV spread, using methods that can be supported by feasible data collection. METHODS: A fully stochastic simulation is used to represent a population of individuals, the sexual partnerships that they form and dissolve over time, and the spread of an infectious disease. Sequential monogamy is compared with various levels of concurrency, holding all other features of the infection process constant. Effective summary measures of concurrency are developed that can be estimated on the basis of simple local network data. RESULTS: Concurrent partnerships exponentially increase the number of infected individuals and the growth rate of the epidemic during its initial phase. For example, when one-half of the partnerships in a population are concurrent, the size of the epidemic after 5 years is 10 times as large as under sequential monogamy. The primary cause of this amplification is the growth in the number of people connected in the network at any point in time: the size of the largest "component'. Concurrency increases the size of this component, and the result is that the infectious agent is no longer trapped in a monogamous partnership after transmission occurs, but can spread immediately beyond this partnership to infect others. The summary measure of concurrency developed here does a good job in predicting the size of the amplification effect, and may therefore be a useful and practical tool for evaluation and intervention at the beginning of an epidemic. CONCLUSION: Concurrent partnerships may be as important as multiple partners or cofactor infections in amplifying the spread of HIV. The public health implications are that data must be collected properly to measure the levels of concurrency in a population, and that messages promoting one partner at a time are as important as messages promoting fewer partners.

Computer Simulation↗

Prevalence study of the randomized controlled trials in the Journal of Intellectual Disability Research: 1957-1994.

Systematic reviews of care are increasingly potent guides to clinical practice, and it is important that all relevant randomized controlled trials (RCTs) are identified by those within the speciality of learning disability who produce such works. All RCTs in the Journal of Intellectual Disability Research and its predecessor were identified by hand-searching (1957-1994), and the frequency, origin, intervention and quality of reporting of randomization were described. Electronic searches for the trials were undertaken for the years 1974-1994, and the quality of indexing was inspected and tested. These electronic searches were then compared to a 'gold standard' search. Fifty-six RCTs were identified. None contained the world 'randomized' in the title and only nine mentioned it in the abstract. Out of the 37 RCTs published between 1974 and 1994, 36 are in PsycLIT and 37 in MEDLINE. One MEDLINE record contained the wrong abstract. The methodological phrases used in the electronic records were poor, and thus, the precision of electronic searches, using both databases, was low. This international journal contains many relevant RCTs from around the world, involving several types of interventions. Unfortunately, these trials cannot be readily accessed electronically using methodological phrases designed to find RCTs. Improved quality of indexing would facilitate identification of RCTs and their dissemination.

Cross-Sectional Studies↗

Effects of antisense oligodeoxynucleotides on peptide release from hypothalamoneurohypophysial explants.

Rapid effects of antisense oligodeoxynucleotides (AODNs) on the function of the neurohypophysial system have been reported previously. The present studies were designed to determine the effects of vasopressin (VP) and oxytocin (OT) AODNs on osmotically or potassium-stimulated VP and OT release from perifused hypothalamoneurohypophysial (HNS) explants. The AODNs were 18-mer phosphorothioate forms targeted toward the translation initiation sites of either VP or OT mRNA, or a mixed base sequence (4 microM). The explants were exposed to a ramp increase in NaCl (either 20 or 30 mosmol/6 h) or to 25 mM KCl. VP and OT release was measured by radioimmunoassay in sequential 20-min fractions of the perifusate. There was a peptide-specific inhibition by the AODNs of osmotically stimulated VP and OT release. VP AODN inhibited VP, but not OT release, and vice vorsa. However, the AODNs had no effect on potassium-stimulated peptide release, demonstrating that depolarization-secretion coupling was still intact. Furthermore, there were no significant differences in VP and OT mRNA and peptide content after antisense treatment. Thus these observations indicate that acute exposure to peptide AODNs interrupts osmotically stimulated VP and OT release in a peptide-specific manner.

Animals↗