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Biomedical subjects

J N Blackwell

Publications and source records attributed to J N Blackwell.

At least 19 recordsLinked to original sources
PubMed1993

A comparison of esophageal motility in response to bread swallows and water swallows.

Studies of esophageal manometry during eating have demonstrated abnormal motility in patients with dysphagia in whom standard water-swallow manometry was normal. However, there have been few concurrent motility studies making a direct comparison of food swallows with water swallows. This paper presents the results of such a study in 20 healthy volunteers. A comparison of bread swallows with water swallows revealed that both peristaltic amplitude in the proximal esophagus and peristaltic duration throughout the esophagus were significantly increased (p < 0.05). Peristaltic propagation velocity was significantly decreased in the proximal and mid-esophagus (p < 0.05). Percentages of nonconducted and nonperistaltic contractions were significantly increased (p < 0.05-0.001) during bread-swallow manometry. Therefore, the response of the normal esophagus to food has been shown to be different from its response to water swallows. In particular, the high percentage of nonpropagated swallows in normal subjects when eating indicates that the results of food manometry in patients with dysphagia must include wider limits of normality.

Adult↗
PubMed1987

Esophageal manometry in 95 healthy adult volunteers. Variability of pressures with age and frequency of "abnormal" contractions.

UNLABELLED: Although esophageal manometry is widely used in clinical practice, the normal range of esophageal contraction parameters is poorly defined. Therefore, 95 healthy volunteers (mean age: 43 years; range 22-79 years) were studied with a low-compliance infusion system and 4.5-mm-diameter catheter. All subjects were given 10 wet swallows (5 cc H2O) and 38 subjects also were given 10 dry swallows. RESULTS: Amplitude, but not duration, was greater (P less than 0.05) after wet compared to dry swallows. Both distal mean contractile amplitude and duration of wet swallows significantly increased with age and peaked in the fifties. Double-peaked waves frequently occurred after both wet (11.3%) and dry (18.1%) swallows, but triple-peaked waves were rare (less than 1%). Nonperistaltic contractions were more common (P less than 0.001) after dry compared to wet swallows (18.1% vs 4.1%). This difference resulted from frequent simultaneous contractions after dry swallows (12.6% vs 0.4%). CONCLUSIONS: Distal esophageal contractile amplitude and duration after wet swallows increases with age. Triple-peaked waves and wet-swallow-induced simultaneous contractions should suggest an esophageal motility disorder. Double-peaked waves are a common variant of normal. Dry swallows have little use in the current evaluation of esophageal peristalsis.

Adult↗
PubMed1987

Daytime gastro-oesophageal reflux is important in oesophagitis.

Fifty two patients were studied to investigate the patterns of gastro-oesophageal reflux during ambulatory pH monitoring and the relationship of reflux to presence and severity of oesophagitis. Twenty nine had evidence of oesophagitis which was graded according to severity. Acid exposure (pH less than 4) was calculated in each case for the total study period, the recumbent and upright periods, and the three hour period after the evening meal. Exposure in the upright period correlated closet (r=0.92: p less than 0.001) with that during the total period. Recumbent exposure correlated with both upright and postprandial exposure (p less than 0.001). Acid exposure during all four periods correlated significantly with the severity of oesophagitis, but postprandial acid exposure correlated best and recumbent acid exposure least well. Although acid clearance in the total, recumbent and upright periods correlated with oesophagitis, postprandial clearance showed the closest relationship. Thus the magnitude of daytime reflux, especially postprandial reflux and acid clearance, is more closely related than nocturnal reflux to oesophagitis. The results do not support the contention that night time reflux is inherently more injurious than daytime reflux to the oesophageal mucosa.

Eating↗
PubMed1987

Effects of additional dietary gluten on the small-intestinal mucosa of volunteers and of patients with dermatitis herpetiformis.

In an attempt to confirm the existence of latent coeliac disease--dose-related gluten-sensitive enteropathy--we have increased dietary gluten by 20 g daily for 2 weeks, in 6 healthy adults and 11 patients with dermatitis herpetiformis (DH). Six of the DH patients had entirely normal jejunal morphology on a normal diet. Jejunal biopsy specimens were taken before and at the end of the study. Measurements of crypts, villi, and crypt mitoses were made on microdissected specimens; disaccharidases were assayed, and intraepithelial lymphocyte counts performed. In one of the six adult volunteers, gluten loading produced diarrhoea and jejunal biopsy abnormalities. Five DH patients on a gluten-free diet had deterioration of biopsy pathology after the gluten challenge. Features suggestive of a latent gluten-sensitive enteropathy were found in one of the other six DH patients; he developed disaccharidase deficiencies and villus atrophy when 20 g gluten was added to his usual gluten-containing diet. This study supports previous suggestions that a gluten-sensitive enteropathy may be latent and dose-related.

Adult↗
PubMed1987

Relationship of radionuclide liquid bolus transport and esophageal manometry.

Using simultaneous esophageal manometry and radionuclide transit studies, we compared liquid bolus transport with the various parameters of esophageal contractions. Study subjects included seven normal individuals, six patients with the "nutcracker esophagus" (mean distal peristaltic amplitude greater than 180 mm Hg), and three patients with spastic motility disorders. Manometric studies were performed when the subjects were in the basal state and after intravenous administration of edrophonium and atropine. Simultaneous radionuclide studies were done with subjects in the supine position by swallows of 250 mu Ci technetium Tc 99m sulfur colloid in 10 ml water. We found that normal liquid bolus transport (less than 15 seconds) is primarily dependent on the presence of a peristaltic wave front throughout the esophagus. Above a threshold pressure of 30 mm Hg, liquid transport was not affected by amplitude (33 to 500 mm Hg) or duration (3 to 15 seconds) of esophageal contractions. Repetitive wave forms also gave normal transit times as long as the wave front was peristaltic in onset. There was a significant inverse correlation (-0.65; P less than 0.001) between liquid transit time and peristaltic velocity. Prolonged radionuclide transport (30 to less than 50 seconds) was observed only with nonperistaltic contractions and very low amplitude (15 to 30 mm Hg) peristaltic waves.

Atropine↗
PubMed1986

Oral pirenzepine does not affect esophageal pressures in man.

Pirenzepine has been proposed to selectively inhibit gastric acid production. In contrast to classical anticholinergics, pirenzepine does not appear to produce systemic side effects or to strongly inhibit contractions in gastrointestinal tract smooth muscle. This study compares the effects of two doses of pirenzepine (25 and 50 mg per os) with a standard anticholinergic, propantheline, 30 mg per os, and with placebo on esophageal contraction pressures in 12 healthy volunteers in a random double-blind study sequence. No significant change in lower esophageal sphincter pressure (LESP) or in peristaltic pressures occurred with placebo or pirenzepine 25 or 50 mg. However, propantheline produced marked reduction in peristaltic contraction pressures and increased velocity (4 of 12 subjects had complete loss of peristalsis). LESP decrease was almost significant. Seven of 12 subjects experienced dry mouth after propantheline, but none after either dose of pirenzepine or placebo. This study indicates that, as opposed to a classical anticholinergic, pirenzepine does not adversely affect esophageal contraction pressures nor does it have anticholinergic side effects with the oral doses studied.

Administration, Oral↗
PubMed1986

Clinical value of radionuclide oesophageal transit measurement.

We have reviewed our experience of 150 patients to assess the clinical value of radionuclide oesophageal transit measurements in relation to established oesophageal motility investigations. Achalasia and conditions characterised by incoordinate oesophageal motor activity were detected with equal frequency by manometry and radionuclide transit measurement. Radionuclide transit measurements identified abnormalities not detected by manometry in 18 patients, and manometry was abnormal in 26 patients with normal radionuclide studies, including all patients with nutcracker oesophagus and most with hypertensive lower oesophageal sphincter. The overall sensitivity of radionuclide transit measurements in detecting oesophageal dysmotility was 75%, the sensitivity of manometry was 83% and that of conventional barium radiology 30%. We conclude that radionuclide transit measurement is a useful test for patients with suspected oesophageal motility disorders. Although it has limitations as a screening test, it provides additional information which complements oesophageal manometry.

Adolescent↗
PubMed1985

The oesophagus as a cause of recurrent chest pain: which patients should be investigated and which tests should be used?

Investigations of the oesophagus were undertaken in 50 consecutive patients who presented with recurrent chest pain thought to be non-cardiac in origin after cardiological assessment. An oesophageal disorder was demonstrated in 60%, gastro-oesophageal reflux and diffuse oesophageal spasm being the two commonest entities. However, routine contrast radiology and upper gastrointestinal endoscopy revealed abnormalities in only a minority of patients. Patients with non-cardiac chest pain of uncertain origin should initially undergo endoscopy. If no major abnormalities are detected radionuclide oesophageal transit studies, oesophageal manometry, and ambulatory monitoring of oesophageal pH should be carried out.

Adolescent↗
PubMed1984

Sequential studies of gliadin antibodies in patients with dermatitis herpetiformis.

Sequential studies of circulating gliadin antibodies (IgG, IgA, IgM, IgD) were performed in 24 patients with dermatitis herpetiformis (DH) by an ELISA. Three groups of patients were studied: (a) 14 patients who responded to a gluten-free diet and were able to stop their drug therapy, (b) 5 patients who did not respond to a gluten-free diet, (c) 5 patients with normal jejunal biopsies, who did not receive a gluten-free diet. Most of the serum gliadin antibodies detected were of IgG class, but in several patients IgA gliadin antibodies were found in addition. When the patients were on a normal diet, 63% had elevated IgG gliadin antibody titres (titres which exceeded the maximum titre of the controls by one dilution) and there were no significant differences between the three groups. When the patients were followed up, there was a significant fall in the gliadin antibody titres in those who responded to a gluten-free diet compared to the two other groups of patients. Thus assays of IgG gliadin antibodies might be helpful in some patients in judging the compliance of patients on a gluten-free diet.

Adolescent↗
PubMed1984

Oesophageal motility: recent advances and implications.

Oesophageal motility studies have greatly enhanced our knowledge of the physiology of the oesophagus. The abnormalities, particularly of the LOS, that occur in gastro-oesophageal reflux disease have been extensively studied. Although motility studies have relatively little impact on the clinical management of the majority of patients with oesophagitis, they are indicated when there is diagnostic doubt and most especially when surgical treatment is being considered. In numerical terms oesophageal motility studies are required most often for the investigation of obscure dysphagia or non-cardiac chest pain. Research is continuing to expand our knowledge of the oesophageal dysmotility syndromes.

Esophageal Diseases↗
PubMed1984

Dermatitis herpetiformis: diagnosis, diet and demography.

We describe a long term study of 76 patients with dermatitis herpetiformis. Unlike patients with coeliac disease, where the peak incidence was during the first and fourth decades, no dermatitis herpetiformis patients presented in the first decade; also, there was a male preponderance in dermatitis herpetiformis which contrasts with the excess of females in coeliac disease. The apparent prevalence of dermatitis herpetiformis was 11 per 100 000 in our population; approximately one fifth of that of coeliac disease. Jejunal villous atrophy was present in 78% of our dermatitis herpetiformis patients, and a single jejunal biopsy was as effective at detecting this as the multiple biopsy technique. A majority of patients were able to stop, or radically reduce their dapsone or sulphapyridine treatment after the institution of a gluten free diet. Spontaneous remission of the skin lesion occurred in only two patients not receiving a gluten free diet. Gastric parietal or thyroid antibodies were detected in 38% of patients, and three cases of thyroid disease and two cases of pernicious anaemia were detected. Lymphoma developed in two patients, one being intestinal in origin. We conclude that a gluten free diet is of therapeutic benefit in dermatitis herpetiformis and that spontaneous remission is uncommon in those not on a diet. Despite patchiness of the enteropathy, a single jejunal biopsy is quite adequate to diagnose the presence of upper intestinal villous atrophy.

Adolescent↗
PubMed1984

Clinical applications of oesophageal motility studies?

Technological advances in the investigation of oesophageal motility have resulted in progressive awareness of gastro-oesophageal reflux disease and motor disorders of the oesophagus as causes of obscure "noncardiac" chest pain, as well as for unexplained swallowing difficulties. Oesophageal motility studies should also be undertaken before surgery for reflux oesophagitis.

Deglutition Disorders↗
PubMed1983

Radionuclide transit studies in the detection of oesophageal dysmotility.

A scintigraphic method is described to measure the transit of a fluid bolus through the oesophagus. Transit times in 16 normal subjects ranged from five to 15 seconds and were highly reproducible. Prolonged transit times were observed in 16 of 19 patients with known oesophageal motility disorders, and in these patients inspection of the time activity curves frequently permitted an adynamic oesophagus to be distinguished from one showing excessive incoordinate contractions. The technique was then applied prospectively to 50 patients referred for oesophageal motility studies and a comparison made between the oesophageal transit measurements and the findings on conventional oesophageal manometry. There was agreement between these tests in 42 (84%) of the 50 patients. The measurement of oesophageal transit may be made quickly and safely, without causing discomfort to the patient, and it appears to be at least as sensitive as manometry in the detection of oesophageal motility disorders.

Adult↗
PubMed1981

Laparoscopy and radioisotope imaging in the investigation of suspected liver disease.

We have reviewed the clinical and investigative details of 141 patients who underwent laparoscopy in order to determine how best this technique can be used. The clinical history and biochemical investigations usually only indicated some form of hepatobiliary disease, but all patients with spider telangiectasia, splenomegaly, or esophagogastric varices had diffuse parenchymal liver disease, and further investigation was only required to detect its cause. Laparoscopy succeeded in 129 patients (91%), and serious complications occurred in six (4%). The appearance of the liver did not accurately reflect the underlying pathology, indicating the need for biopsy in all cases. Laparoscopy and 99mTc-sulfur colloid liver imaging each failed to detect a few hepatic malignancies, but none were missed by both investigations combined, and similar results were obtained for parenchymal liver disease. Scanning and laparoscopy proved a highly accurate diagnostic combination.

Humans↗