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Biomedical subjects

J Christensen

Publications and source records attributed to J Christensen.

At least 235 records · Page 13Linked to original sources
PubMed1981

The familial syndromes of intestinal pseudoobstruction.

Ten reported families with chronic intestinal pseudoobstruction were reviewed. Although clinical manifestations and gastrointestinal contrast roentgenograms are similar in these families, the pathology and inheritance are quite different. Five families have degeneration and fibrosis of the gastrointestinal tract and urinary bladder, three have normal intestinal morphology, and one has degeneration of the myenteric plexus throughout the gastrointestinal tract. Four families are consistent with dominant inheritance, three are consistent with X-linked dominant transmission, and three are compatible with recessive inheritance. Patients in these families have a wide spectrum and degree of chronic and/or intermittent gastrointestinal symptoms. As many as 20% of the family cases discovered are asymptomatic. Operative procedures to drain or resect short dilated intestinal segments may help to relieve symptoms.

Female↗
PubMed1981

A double-blind study of the value of treatment with a single dose tinidazole of partners to females with trichomoniasis.

Tinidazole 2 g single oral dose was given to 137 females with positive trichomonal cultures. On a random basis the same dose of tinidazole was given to half the sexual partners, and matching placebo to the other half. One to two weeks after treatment 5 females had positive cultures, indicating a primary cure rate of 96.4%. At an average of 2 months after treatment and 6 weeks after resuming sexual activity, 118 females were reexamined; 17 had a positive culture, giving an overall relapse rate of 14.4%. The relapse rate with tinidazole-treated partner was 5.1%, and with placebo-treated partner 23.7% (p equals 0.01). The definitive cure rate after a single dose of tinidazole 2 g was in females with treated partner 91.8% and with untreated partner 72.6%. It is concluded that a single dose of tinidazole is an effective treatment for females with trichomoniasis but to avoid relapse it is necessary to treat the sexual partner too.

Adolescent↗
PubMed1981

Recurrent or chronic intestinal pseudo-obstruction.

Recurrent or chronic intestinal pseudo-obstruction is not a rare problem. More cases will be recognized and diagnosed when clinicians are more aware of this problem. Medical treatment is unsatisfactory in most cases unless the patients have such treatable associated systemic diseases as myxoedema, hypoparathyroidism or phaeochromocytoma. Intermittent antibiotic therapy may be needed to alleviate diarrhoea or steatorrhoea due to bacterial overgrowth in the small intestine. Surgery may help to relieve the symptoms in those cases with short segmental dilatation of the bowel. Most patients will have an exploratory laparotomy to rule out an organic obstructing lesion. Either a drainage procedure or resection of a short dilated segment should be carried out. Once the diagnosis of chronic intestinal pseudo-obstruction is made, repeated exploratory operations must be avoided. Preoperative antibiotic therapy to treat bacterial overgrowth in the small bowel will reduce postoperative peritonitis from peritoneal soiling by septic small bowel contents.

Chronic Disease↗
PubMed1980

The effect of maximal mouth opening on dimension discrimination.

The ability of twenty-five young persons to discriminate dimensions was tested. A reference stick of 10 mm was placed between the teeth, alternating with test sticks of different heights. After application of the reference stick the subjects were asked to open the mouth maximally. A test stick was placed on the lower incisors and the subjects closed the mouth slowly, until their upper incisors contacted the test stick. The subjects were then asked to assess whether a test stick felt higher or lower than the reference stick. Using this experimental method, it was found that incorrect assessments were symmetrically distributed around the 10 mm reference stick. A receptor mechanism is proposed, and applied to explain the results of the present and a previous experiment.

Humans↗
PubMed1980

Metabolic dependence of the electromyogram of the cat colon.

Strips of colon muscle (1 x 10 cm) were exposed to alterations of temperature, to 2,4-dinitrophenol, and were deprived of O2. Cooling reduced slow-wave frequency in proximal colon from 5.2 at 37 degrees C to 3.9, 2.7, 1.2 and 0.5 cycle/min at 34, 30, 25, and 20 degrees C, respectively; all changes were significant (P < 0.05). Heating also reduced slow-wave frequency in proximal colon from 5.2 at 37 degrees C to 5.1, 4.8 (P < 0.05), and 3.3 (P < 0.05) cycle/min at 39, 41, and 43 degrees C, respectively. Hypoxia reduced slow-wave frequency from 4.6 at 95% O2 to 2.8 cycle/min at 0% O2 (P < 0.05). 2,4-Dinitrophenol (10(-4) M) reduced frequency from 5.3 to 2.7 cycle/min (P < 0.05). The results of studies of distal colon were similar. In distal colon cooling reduced the time occupied by migrating spike bursts from 20.7% at 37 degrees C to 11.1% at 25 degrees C, and 7.9% at 20 degrees C (P < 0.05). Hypoxia also reduced the time occupied by migrating spike bursts from 16.7% at 95% O2 to 5.9% at 0% O2 (P < 0.05).

2,4-Dinitrophenol↗
PubMed1980

Better oral health for children--the Danish model.

Since 1972 a public, fully subsidized municipal school dental service has been established in Denmark. The school dental service comprises general and individual preventive measures, regular dental examinations and all odontological treatment needed to keep the masticatory system in a good functional order. At the same time a recording system for the oral health of children was established. Information from the school dental service and private practitioners on the oral condition of children is passed to the dental division of the National Health Board. The statistics, published once a year, have proved extremely valuable for evaluation and planning purposes. The school dental service on a nationwide scale has been in function for too short a time to allow a final conclusion to be drawn. However, a positive trend in the caries experience of children may already be seen as a possible result. The importance of a regular dental service for children and of regular visits to a dentist for adults is illustrated. The problems arising when children leave school and pass from the school dental service to the National Health Insurance System are discussed.

Adolescent↗
PubMed1979

Effect of age on noradrenaline sensitivity of mesenteric resistance vessels in spontaneously hypertensive and Wistar-Kyoto rats.

1. We have compared the noradrenaline sensitivity of 150 micron arterial resistance vessels taken from a specific place in the mesenteric bed of spontaneously hypertensive (SH) rats and of control Wistar-Kyoto (WK) rats at three ages: 6 weeks, 12 weeks and 24 weeks. 2. The noradrenaline sensitivity of the vessels under normal conditions was the same at all ages in both SH and WK rats (ED50 about 3 mu mol/l). 3. After addition of cocaine (which inhibits the uptake of noradrenaline in the nerve terminals) all vessels became more sensitive to noradrenaline, but at all ages the increase in sensitivity was greater in the vessels of SH rats, suggesting that the smooth muscle cells in these vessels had a greater intrinsic noradrenaline sensitivity than the vessels of WK rats. 4. Since elevation of the blood pressure in the SH rats occurs mainly between the ages of 6 and 12 weeks, the results suggest that the greater intrinsic smooth muscle cell sensitivity of the SH rat vessels is a factor which is amongst the primary factors responsible for the development of hypertension in the SH rat.

Aging↗
PubMed1979

Surgical treatment in familial visceral myopathy.

In a kindred with a familial visceral myopathy, seven patients had operations seeking relief of chronic abdominal pain and other symptoms of intestinal obstruction; one patient had an 80% cystectomy and a Y-V-plasty of the bladder neck for urinary retention. Five patients with megaduodenum had bypass operations; a side-to-side duodenojejunostomy was done in four and a retrocolic gastrojejunostomy in one. Two of these died of postoperative complications, and one developed symptomatic adhesions. Two other patients who had duodenojejunostomy have done well for 6 years and 1 1/2 years respectively. One patient with dilation of the distal jejunum and proximal ileum had relief of intestinal obstructive symptoms from jejunostomy to decompress the destal jejunum. One patient who had a resection of the descending and sigmoid colon for sigmoid volvulus has done well for four years. Three of these seven patients developed peritonitis postoperatively, and two had symptomatic adhesions after operations. Duodenal aspiration from a patient who developed postoperative peritonitis grew E. coli, 10(13) colonies per ml. After review of the results of operations in other families and in our kindred, we favor side-to-side duodenojejunostomy in megaduodenum. Duodenal aspirate must be cultured before operation. Evidence of bacterial overgrowth in the aspirate should prompt appropriate antibiotic treatment to reduce the likelihood of sepsis.

Abdomen↗
PubMed1979

Effects of some autonomic drugs on duodenal smooth muscle.

Longitudinal muscle strips (LMS) and circular muscle strips (CMS), 2 mm wide and 1.5--2 cm long, from opossum duodenum were exposed to some autonomic agonists. The cholinergic agonists, acetylcholine, carbachol, methacholine, and bethanechol stimulated only tonic contractions in LMS and tonic followed by phasic contractions in CMS. These effects were abolished by atropine 10(-6) M. The ED50S of all cholinergic agonists for LMS were significantly lower than for CMS. Norepinephrine caused initial contraction (abolished by phenoxybenzamine, 10(-4) M), followed by relaxation (abolished by propranolol, 10(-5) M), and isopropylnorepinephrine caused relaxation (abolished by propranolol, 10(-5) M) in both layers. There were no differences in relative potencies for adrenergic agonists between the layers. Tetrodotoxin did not affect the response to adrenergic agonists. Thus, the potency of cholinergic agonists is greater in longitudinal than in circular muscle, and the layers respond differently to cholinergic agonists. The alpha-adrenergic receptors mediate contraction and beta-adrenergic receptors mediate relaxation on the duodenal smooth muscle.

Acetylcholine↗
PubMed1979

Some determinants of latency of off-response to electrical field stimulation in circular layer of smooth muscle of opossum esophagus.

Transverse strips from smooth muscle of opossum esophagus were subjected to electrical field stimulation of intramural nerves to study the latency of the off-response. Latency is the time from the end of the stimulus train to the beginning of the off-response. Latency increased from one end of the smooth muscle segment to the other; it was shortest proximally and longest distally. Variables altering this latency gradient were sought. Strip width and tension had no effect (P greater than 0.02). Longer stimulation trains shortened latency (P less than 0.02). Krebs solution was modified by changing potassium concentration and by the addition of: hexamethonium, 1 x 10(-4) M; D-tubocurarine, 1 x 10(-4) M; bethanechol, 5 x 10(-7) M; carbachol, 5 x 10(-7 M; physostigmine, 1 x 10(-7) M; propranolol, 1 x 10(-6) M; tolazoline, 5 x 10(6) M; norepinephrine, 1 x 10(-5) M; isoproterenol, 1 x 10(-6) M; and dopamine, 1 x 10(4) M. Increased potassium concentrations shortened latency, and decreased potassium concentrations lengthened it (P less than 0.02). Carbachol, bethanechol, physostigmine, and isoproterenol shortened latency (P less than 0.02). Hexamethonium, D-tubocurarine, tolazoline, propranolol, norepinephrine, and dopamine had no effect (P greater than 0.02).

Animals↗
PubMed1978

Carcinoma of the papilla of Vater. A review of fifty-seven cases.

Fifty-seven cases of carcinoma of the papilla of Vater are reviewed. Clinical and pathologic features as well as results of various surgical treatments are summarized. The Whipple operation may be the operation of choice for cancer of the papilla of Vater, offering a chance for cure and obviating further surgery.

Adult↗
PubMed1978

Influence of intrinsic nerves on electromyogram of cat colon in vitro.

The electromyogram of the circular muscle layer of the cat colon was studied in vitro in superfused strips of muscle. Records exhibited electrical slow waves and migrating spike bursts, as described previously. Both the neurotoxin, tetrodotoxin, and the local anesthetic lidocaine, (P less than 0.05) prolonged the duration of migrating spike bursts, but migrating spike bursts were not affected by the adrenergic alpha-antagonist, phenoxybenzamine, nor by the adrenergic beta-antagonist, propranolol. Also, physostigmine and atropine did not affect them. Large concentrations of catecholamines did abolish them. This suggests that the migrating spike burst represents periodic release of the muscle from the tonic influence of nonadrenergic inhibitory nerves in the intramural plexuses. Slow-wave frequency and the congruence of slow waves were not affected (P greater than 0.05) by the antagonists listed above, nor by cholinergic and adrenergic agonists. This suggests that the slow waves are not importantly controlled by intrinsic nerves.

Action Potentials↗