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Biomedical subjects

D Rice

Publications and source records attributed to D Rice.

At least 19 recordsLinked to original sources
PubMed1992

High-sensitivity analysis of sialyl-oligosaccharide glycosylation sites in glycoproteins by miniaturized tryptic digestion and microcolumn liquid chromatography.

A highly sensitive analytical procedure was developed to assess the site of glycosylation in a model glycoprotein, bovine fetuin. First, sample cleavage with immobilized trypsin and the peptide map development are accomplished by microcolumn liquid chromatography. Second, the sialic acids content is measured fluorometrically using their precolumn conversion to quinoxaline derivatives. A unique preconcentration system was developed to secure sensitivity of the second measurement.

Amino Acid Sequence↗
PubMed1992

The HsdS polypeptide of the type IC restriction enzyme EcoR124 is a sequence-specific DNA-binding protein.

The HsdS and HsdM polypeptides of the type IC restriction enzyme EcoR124 have been purified independently and used in a set of gel retardation experiments to determine the minimum requirements for sequence-specific recognition of DNA by this enzyme. The HsdS polypeptide alone is able to bind to DNA in a sequence-specific manner. In addition, whilst the presence of the HsdM polypeptide gives rise to a stimulation of DNA binding by the HsdS subunit it is not clear whether, under the conditions of the experiments reported here, the HsdS subunit maintains the same interactions with the HsdM subunits observed in the absence of DNA.

Bacterial Proteins↗
PubMed1990

Octreotide acetate induces fasting small bowel motility in patients with dumping syndrome.

The long acting somatostatin analogue octreotide acetate has been effective in the treatment of early dumping syndrome. We hypothesized that this may be related to its effects on inhibiting gastric emptying and delaying intestinal transit. To study the effect of octreotide acetate on intestinal motility in patients we carried out a randomized, double-blinded study using a subcutaneous injection of either octreotide acetate (100 micrograms) or placebo given 20 min prior to ingestion of a high carbohydrate "dumping" meal in six patients with known severe dumping syndrome. Prior to each study a multilumen polyethylene tube was inserted into the efferent limb to study small intestinal contractions using low compliance pneumo-hydraulic water-perfused manometry. Octreotide acetate prevented dumping symptoms in all six patients and induced the appearance of migrating myoelectric complexes (MMC) characteristic of interdigestive motility. After ingestion of the dumping meal the postprandial "fed" motility pattern lasted for 141 +/- 9 min while after octreotide acetate the fed motility lasted for 29 +/- 5 min (P less than 0.03). The vigor of the fed motility pattern as measured by the motility index (MI = loge (sum of amplitudes X No. of contractions + 1] was lower after octreotide acetate than after placebo (15.1 +/- 0.1 vs 13.4 +/- 0.2, P less than 0.03). The induction of fasting MMC motility pattern and reduction in the duration and vigor of fed motility may explain the symptomatic relief these patients obtained with octreotide acetate. It is not known whether the induction of the MMC is a direct effect of octreotide acetate or secondary to the concomitant inhibition of peptide release (neurotensin, insulin, glucagon, pancreatic polypeptide) that has been demonstrated in earlier studies.

Dumping Syndrome↗
PubMed1990

Abnormal EEG responses to photic stimulation in schizophrenic patients.

Numerous studies have differentiated schizophrenic patients and normal controls in electroencephalography (EEG) spectral patterns recorded at rest. We replicated the resting EEG spectral differences between these groups and observed significant differences in periodic photic stimuli on the EEG spectra. Drug-free schizophrenic male patients (n = 8, mean age = 23.9) and normal male controls (n = 11, mean age = 24.3) were studied. Eighty seconds of EEG were collected from each subject for each of four experimental conditions: one resting and three photic-driving conditions (2.38, 4.54, and 8.33 Hz). Eye movement and other movement artifacts were minimized by use of an automatic amplitude threshold filter. Although large eye movements could be excluded as confounding factors, the filter could not for certain exclude small eye movements. Subjects were instructed to keep their eyes closed throughout. A significant difference was found between the groups both at rest and following photic stimulation in EEG activity. This result was characterized by increased delta activity and decreased alpha activity in schizophrenic patients at rest. The EEG activity following the photic driving also differentiated the groups. Schizophrenic patients had decreased sensitivity to the photic stimulation in the alpha range for spectra derived from both fundamental and harmonic analysis.

Adult↗
PubMed1990

Efficacy of octreotide acetate in treatment of severe postgastrectomy dumping syndrome.

The present study evaluates the acute and chronic use of a long-acting somatostatin analog, octreotide acetate, in the treatment of patients with severe postgastrectomy dumping syndrome. In the acute phase, 10 patients with severe dumping were studied over 2 consecutive days before and for 3 hours after the ingestion of a 'dumping breakfast' in a randomized double-blind fashion. On one day octreotide (100 micrograms) was given subcutaneously 30 minutes before the test meal and on the other day an equal volume of vehicle was injected. An additional group of six postgastrectomy patients without dumping were studied in a similar fashion and these acted as controls. During placebo treatment the test meal resulted in an immediate increase (p less than 0.01) in the pulse rate and in plasma levels of glucose, glucagon, pancreatic polypeptide, neurotensin, and insulin. Similar changes were seen in the control group with respect to placebo; however glucagon and neurotensin (p less than 0.05) did not show the same magnitude of increase as seen with placebo. Treatment with octreotide acetate prevented the development of both vasomotor and gastrointestinal symptoms and completely ablated all of the above responses in plasma peptides. These changes were associated with complete ablation of diarrhea (p less than 0.001). Pretreatment with octreotide acetate completely suppressed the rise in plasma insulin response to the meal and this ablated the late hypoglycemia of dumping. Treatment with octreotide acetate resulted in delayed gastric emptying and transit time (578 +/- 244 minutes) versus 76 +/- 23 minutes with placebo and 125 +/- 36 minutes in controls (p less than 0.05). Chronic daily treatment with octreotide acetate resulted in minimal side effects. These patients demonstrated a stable fasting plasma glucose, normal liver function tests, and an average weight gain of 11% during a 12-month period. In addition most patients were able to resume employment. The long-acting somatostatin analog, octreotide acetate, is highly effective in preventing the development of symptoms of severe dumping syndrome, both vasomotor and gastrointestinal.

Adult↗
PubMed1989

Streptozotocin-induced diabetes is not a model for methylmalonic acidaemia.

The streptozotocin-treated diabetic rat was not found to be a suitable animal model for methylmalonic acidaemia as previously described. Urinary methylmalonic acid (MMA) was measured in adult Wistar rats prior to and following injection of streptozotocin (40 mg/kg). Plasma and tissue MMA levels were measured following the induction of diabetes and compared with data from control rats. MMA levels were determined by a gas chromatographic-mass spectrometric method (McMurray et al., 1986). Diabetes was confirmed by the 10 x increase in 24 h urine volume; glycosuria; glycaemia; and weight loss. Urinary MMA excreted did not change during the 11 week diabetic period and there was no difference between the pre- and post-diabetic phases (p less than 0.05). Plasma and tissue MMA concentrations were not elevated in this diabetic animal model. Also in contrast to earlier reports, the vitamin B12 levels of the diabetic rats were not elevated compared to controls (p less than 0.05).

Animals↗
PubMed1989

Investigations of the use of clay minerals and prussian blue in reducing the transfer of dietary radiocaesium to milk.

Two experiments were performed with lactating dairy cattle to assess the efficacy of clay minerals and Prussian Blue (AFCF form) in controlling the transfer of dietary radiocaesium to milk. In Experiment 1, bentonite was included in the diet at 0, 300, 600 and 900 g d-1 and the transfer of radiocaesium from silage to milk was determined. Bentonite inclusion significantly (P less than 0.001) depressed the transfer of radiocaesium to milk with no benefit in increasing the dietary inclusion above 600 g d-1 when a 73% reduction was observed. In Experiment 2, the effectiveness of bentonite (300 g d-1), clinoptilolite (300 g d-1) and Prussian Blue (3 g d-1) as dietary additives was compared. All treatments significantly (P less than 0.001) depressed the transfer of dietary radiocaesium to milk. Clinoptilolite was less effective than bentonite and both treatments were considerably less effective than Prussian Blue, the reductions being 35%, 62% and 85% respectively.

Aluminum Silicates↗
PubMed1989

The effects of prussian blue provided by indwelling rumen boli on the tissue retention of dietary radiocaesium by sheep.

A study was carried out to examine the effects of a form of Prussian Blue, provided by indwelling rumen boli, on the tissue retention of dietary radiocaesium by sheep. A single bolus providing 20-24 mg PB d-1 achieved a 42% reduction in tissue radiocaesium content. Multiple boli were not successful due to their loss from the rumen. The preparation used did not affect the health and well being of the animals.

Animals↗
PubMed1989

Breast cancer and breastfeeding: results from an Australian case-control study.

A case-control study of breast cancer, diet, and lactational history was carried out in Brisbane, Australia, between 1981 and 1985. Cases were recruited from both the private and the public health care sectors. The breastfeeding histories of 459 cases and 1,091 controls selected from the electoral roll were analyzed. An odds ratio of 0.85 (95% confidence interval 0.55-1.30) for any lactation versus no lactation was observed, with no suggestion of a monotonic trend with increasing duration. This estimate was only slightly altered by multiple logistic regression analysis. A statistically significant nonlinear association was noted for breastfeeding of the first liveborn child (chi 2 = 14.8, df = 6; p less than 0.05), with a slightly elevated odds ratio for lactations of less than one month, a lowered odds ratio for lactations of one month to three months, and a weakly elevated odds ratio in women breastfeeding for more than nine months. Results for premenopausal women were very similar to those for postmenopausal women. Taken together with other recent studies, these results suggest that lactation may play a modest direct or indirect part in reducing the risk of breast cancer.

Breast Feeding↗
PubMed1989

Tinted lenses and dyslexics--a controlled study. SPELD (S.A.) Tinted Lenses Study Group.

We have carried out a randomised prospective controlled trial of the effect of tinted lenses on the reading ability of 24 non-asthmatic dyslexic children aged between nine and twelve years. Reading ability was assessed using the Neale Analysis of Reading. After one school term, there was no significant difference in the change in reading age between treatment and control groups. After two school terms (approximately six months), only 11 children (44%) were still wearing the glasses. Of 381 suitable subjects for entry into the study, 208 were excluded because of a diagnosis of asthma (to avoid effects of medication on cerebral function). As a result, we may have excluded subjects who would have responded favourably to tinted lenses.

Child↗
PubMed1988

Effects of cholesterol on (Na+,K+)-ATPase ATP hydrolyzing activity in bovine kidney.

The (Na+,K+)-ATPase ATP hydrolyzing activity from rabbit kidney medulla basolateral membrane vesicles was studied as a function of the cholesterol content of the basolateral membranes. The cholesterol content of the membranes was modified by incubation with phospholipid vesicles. When the cholesterol content was increased above that found in the native membrane, the (Na+,K+)-ATPase ATP hydrolyzing activity was inhibited. When the cholesterol content was decreased from that found in the native membranes, the (Na+,K+)-ATPase ATP hydrolyzing activity was inhibited. Analogous effects were found with the K+-activated phosphatase activity of the same membrane vesicles. Therefore, at low cholesterol contents, cholesterol was stimulatory, and at high cholesterol contents, cholesterol was inhibitory. The structural specificity of this effect was tested by introducing lanosterol and ergosterol as 50% of the membrane sterol. Ergosterol was the least effective at supporting (Na+,K+)-ATPase ATP hydrolyzing activity, while lanosterol was more effective, but still not as effective as cholesterol.

Adenosine Triphosphate↗
PubMed1988

Treatment of carcinoma of the skin with bone and/or cartilage involvement.

From 1956 to 1978, 23 patients with stage T4 carcinoma of the skin of the head and neck were treated with radiotherapy (RT). There were nine patients with cancer of the skin of the nose, eight with tumors of the pinna, and six with lesions of the eyelids. Basal cell carcinoma (BCC) was seen in 61%, squamous cell carcinoma (SCC) in 26%, and 13% of patients had tumors with BCC and SCC features. The majority of patients had large tumors. Less than one-third of patients had smaller lesions, whereas three patients had intermediate-size tumors (greater than 2 cm to less than or equal to 5 cm). Of the 23 patients treated, nine had prior surgical therapy and recurrent or persistent tumor. The remaining 14 patients had no prior therapy. RT was given up to an average total dose of 55 Gy. The 5-year actuarial tumor control rate was 80%. Of the 23 patients treated, four had recurrent tumors. There were no recurrences among the 14 BCC patients, whereas there were four recurrences among the nine SCC and mixed histology patients. Of the four patients who had tumor recurrence, one was salvaged by subsequent radical surgery and three died of their tumor. No serious complications were observed in this group of 23 patients. There was no cartilage, bone, or soft-tissue necrosis noted. RT is a good treatment option and it may be treatment of choice in patients with BCC and SCC of the skin with cartilage or bone involvement. It provides an excellent chance of tumor control, good cosmesis, preservation of function, and a low incidence of complications.

Adult↗
PubMed1988

Methylation deficiency causes vitamin B12-associated neuropathy in the pig.

Pigs were treated with N2O which is known to impair vitamin B12 function in vivo. Such pigs demonstrated an inability to gain weight, progressive ataxia, and spinal neuropathy. The ataxia was totally and the neuropathy partially preventable by dietary methionine supplementation. Methionine synthase activity was inhibited in both the liver and brain. There was a marked elevation of S-adenosylhomocysteine in the neural tissues and a concomitant failure of S-adenosylmethionine to rise and thus maintain the methylation ratio, except when supplementary dietary methionine was added. In contrast, the methylation ratio in the rat was affected to a lesser extent. The neuropathy, it is suggested, is caused by raised S-adenosylhomocysteine levels in neural tissue; as a result, the methylation ratio is inverted and S-adenosylmethionine-dependent methylation reactions are inhibited.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1987

Treatment results and patterns of failure in 646 patients with carcinoma of the eyelids, pinna, and nose.

From 1956 to 1978, 646 patients were treated with radiotherapy for carcinoma of the nose (350 patients, 54 percent), eyelids (159 patients, 25 percent), pinna (93 patients, 14 percent), and skin adjacent to the lip (44 patients, 7 percent). The histologic distribution was 72 percent basal cell carcinoma, 18 percent squamous cell carcinoma, and 10 percent mixed basal and squamous cell features. Tumors less than 2 cm in diameter were found in 602 patients (93 percent), whereas 44 patients (7 percent) had larger tumors. Tumor involvement of cartilage and bone was seen in 23 patients at the time of diagnosis. The 5, 10, and 20 year control rates were 99 percent, 98 percent, and 98 percent, respectively, for 502 tumors less than 2 cm in diameter. This compared favorably with control rates of 92 percent at 5 years and 79 percent at 10 years for tumors from 2 to 5 cm in diameter and 60 percent at 5 years and 53 percent at 8 years for 12 patients with massive tumors (p less than 0.0001). The histologic characteristics of the lesion had a strong influence on tumor control (p less than 0.02). Of the patients with cartilage or bone invasion, tumor was controlled in 19 (83 percent). Of these 19 patients, 11 had no evidence of disease for 3 years or more. Of all 646 patients treated, failure was seen in 60 (9 percent). It correlated well with the size of the lesion, being 7 percent for tumors of less than 2 cm and 50 percent for tumors of greater than 5 cm. Of the 60 patients in whom treatment failed, 48 (80 percent) had prior definitive therapy. Radiotherapy was an efficient modality to control operative failures; however, it was not as efficient at control in patients in whom previous radiotherapy failed. Operation was the treatment of choice to salvage patients in whom radiotherapy failed. Of the patients in whom retreatment failed, 10 were known to have died from skin cancer, and an additional 6 patients were presumed to have died from the cancer. This study has demonstrated a good control rate and good cosmetic results for small tumors of the eyelids, pinna, and nose. In addition, a good control rate was obtained in patients with cartilage and bone involvement. Treatment of massive tumors should involve planned operative resection with adjuvant radiotherapy.

Adult↗
PubMed1987

A 6-month, double-blind study comparing nabumetone to naproxen in the treatment of osteoarthritis.

A 6-month, double-blind, controlled, randomized, parallel study was performed to compare the efficacy and tolerance of nabumetone (1000 mg at bedtime) with naproxen (250 mg twice daily) in the treatment of osteoarthritis. Five efficacy parameters were evaluated: patient's assessment of overall osteoarthritis activity and pain, physician's assessment of overall osteoarthritis activity and pain, and physician's assessment of pain with respect to a defined activity. All 40 patients entered (20 in each group) were available for evaluation of tolerance and 36 patients for efficacy analysis (18 in each group). The efficacy results revealed significant improvement in all five parameters for each medication except measurement of pain with respect to a defined activity for naproxen (p less than 0.07). The frequency of possible or probable drug-related adverse experiences was high for both drugs. However, only 1 patient left the study because of a probable drug-related adverse experience (abdominal pain in a nabumetone patient). Six nabumetone and 4 naproxen patients dropped out of the study because of lack of efficacy. The results indicate that nabumetone and naproxen have comparable efficacy and tolerance at the dosage used, and suggest that a single night-time dosage of nabumetone may be a convenient and useful treatment for osteoarthritis.

Adult↗
PubMed1986

Snoring.

Snoring is more than a social annoyance. It is associated with significant physiologic changes that are detrimental to the patient. The palatopharyngoplasty has provided effective treatment with minimum morbidity.

Adult↗