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Biomedical subjects

J M Graham

Publications and source records attributed to J M Graham.

At least 307 records · Page 17Linked to original sources
PubMed1977

Electrical stimulation of the human cochlea using a transtympanic electrode.

Thirteen patients received stimulation of the cochlea using a transtympanic electrode. The purpose was to investigate the effect of alternating current on the normal and the damaged cochlea and also to discover what effect, if any, it has on tinnitus. Measurements were made of the electrical dynamic range and in one case a loudness balance test was performed against an acoustic signal in the contralateral ear. In addition nine patients experienced a variety of somatic sensations and four had vertigo. Tinnitus was temporarily suppressed in two out of nine cases.

Cochlea↗
PubMed1977

Observations on the possible invasiveness of Clostridium botulinum for waterfowl.

Twenty-four ducklings given multiple doses of Clostridium botulinum type C spores and toxin per os and 27 affected waterfowl from four natural outbreaks of the disease were examined bacteriologically. No evidence of invasion of the blood or liver was found in any bird and it is suggested that invasiveness and toxigenesis in internal organs are probably of little, if any, importance in the causation of botulism in waterfowl.

Animals↗
PubMed1977

Myocardial revascularization prior to subsequent major surgery in patients with coronary artery disease.

Of our series of patients undergoing direct myocardial revascularization, we selected 60 patients who had subsequent major surgical and cardiovascular operative procedures. Thirteen of these patients had a second subsequent operative procedure, and four of the original 60 patients had a third subsequent operation. None of the patients died during the subsequent operation and none sustained a myocardial infarction. During the 77 subsequent procedures, there were eight different episodes of cardiac complications: seven patients had supraventricular arrhythmias and one patient had acute pulmonary edema. All patients responded to medical therapy. These results are suggestive that myocardial revascularization should be performed prior to other major indicated operative procedures in patients with documented coronary artery disease.

Adult↗
PubMed1976

The fluidity of normal and virus-transformed cell plasma membrane.

1. The phospholipid composition and cholesterol/phospholipid ratio of plasma membrane is the same in normal as in transformed BHK (baby-hamster kidney) cells; no significant difference in length or degree of unsaturation of the contributing acyl chains is apparent. 2. The turnover of acetate-labelled phosphatidylcholine species in the plasma membrane of normal and transformed BHK cells is the same. 3. Intramembranous particles of normal and transformed 3T3-cell plasma membrane are randomly distributed, whether at 4degreesC or at 37degreesC, in sparse or in dense cultures. There is no correlation between distribution of particles and the movement of concanavalin A receptor sites. 4. It is concluded that transformation of fibroblastic cells by oncogenic viruses does not lead to major changes in the lipid fluidity of the plasma membrane. 5. Details of the phospholipid composition of nuclei, mitochondria and endoplasmic reticulum in normal and transformed BHK cells have been deposited as Supplementary Publication SUP 50061 (5 pages) at the British Library Lending Division, Boston, Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies may be obtained on the terms given in Biochem. J. (1976) 153, 5.

Cell Membrane↗
PubMed1976

Glycolipid glycosyl transferases of a hamster cell line in culture. II. Subcellular distribution and the effect of culture age and density.

The activities of two galactosyl transferases catalysing the formation of di- and tri-glycosyl ceramides in NIL-2 hamster cells have been studied with respect to culture age and density, subcellular distribution, and transformation of cells by virus. The activity of the transferases was found to increase considerably as culture density increased, although maximal activities were found before appreciable cell contact occurred. The highest transferase activities were found in the endoplasmic reticulum. Virus transformation reduces the activity of the transferase catalysing triglycosyl ceramide synthesis, while the transferase catalysing diglycosyl ceramide synthesis is slightly increased. There is no evidence that the transformed cells produce a dialysable soluble inhibitor of transferase activities.

Adenosine Triphosphatases↗
PubMed1976

Audiogenic priming in DBA/2J and C57BL/6J mice: interactions among age, prime-to-test interval and index of seizure.

C57BL/6J mice, not susceptible to audiogenic seizures (AGS) on the 1st exposure to an acoustic stimulus, were exposed to the acoustic stimulus for 1 min and then tested at some later date (acoustic priming). They were first exposed at either 8, 16, 19, 22, or 28 days of age, and then tested for AGS 2-16 days after priming. DBA/2J mice, susceptible to AGS on the 1st exposure to intense noise, were exposed to the acoustic stimulus at 26 days of age, and then again 2-14 days later. Data indicate that the incidence of AGS upon the 2nd exposure to the acoustic stimulus is a function of age at priming, the prime-to-test interval in days, and the index of seizures. In the case of DBA mice, later effects are also dependent on the initial level of seizure.

Acoustic Stimulation↗
PubMed1976

Deep vein thrombosis in ear, nose and throat surgery.

I. One hundred and three patients undergoing head and neck or ear operations were screened for deep vein thrombosis using I125 labelled fibrinogen. 2. No thrombosis was detected in thirty-five patients undergoing ear operations. 3. Nine (16%) of fifty-six patients who underwent head and neck operations subsequently developed deep vein thrombosis. In a further twelve patients undergoing head and neck operations the ankle was used as a drip site and seven of these patients developed thrombosis in that leg.

Adult↗
PubMed1976

Chronic mesenteric arterial insufficiency: results of revascularization in 33 cases.

The symptoms of mesenteric arterial insufficiency and the advantages of surgical revascularization have become widely recognized in recent years. Follow-up data are accumulating on patients who have had surgery for revascularization. In this study we report on 33 patients who had mesenteric revascularization for intestinal angina. Twenty-nine patients presented with postprandial pain; most had weight loss. Abdominal bruits were heard preoperatively in 26 patients. Aortogram demonstrated involvement of one mesenteric vessel in 13 (39%) patients and two or more vessels in 20 (61%). Revascularization was accomplished with the use of a Dacron graft or an autogenous vein bypass graft to 48 vessels. Endarterectomy and patch angioplasty were done once. One patient died in the early postoperative period. Of the other 32 patients, 30 (94%) had relief of symptoms. Eight patients died from 8 to 135 months after operation, but only one died from mesenteric vascular occlusion and bowel infarction. Five years after operation, 83% of the patients were alive; in ten years, 62%.

Adult↗
PubMed1976

The clinical syndrome of triploidy.

The clinical syndrome associated with triploidy is quite typical but is rarely reported in near-term stillborns and newborns. The occurrence of a large placenta with areas of hydatidiform changes in combination with an edematous fetus with macroglossia, facial clefts, eye defects, dysplastic cranial bones, omphalocele, meningomyelocele, syndactyly, and, in males, genital maldevelopment is suggestive of a triploid chromosomal constitution.

Abnormalities, Multiple↗
PubMed1975

Exercise stress testing in patients with chest pain and normal coronary arteriography: with review of the literature.

Eighty of 654 patients studied because of chest pain were found to have normal coronary arteriography. Fifty of these completed submaximal treadmill exercise studies. The purpose of this study was to determine whether treadmill electrocardiography could obviate the need for coronary arteriography in the evaluation of patients with undiagnosed chest pain. Of patients studied, 22% had typical angina pectoris, while 78% had atypical chest pain. The resting electrocardiogram was normal in 58% of patients, while 42% showed repolarization abnormalities. Submaximal treadmill testing was normal in 64%, incomplete in 12%, and demonstrated classic ischemic S-T depression in 24%. Our findings of 24% positive studies in patients with normal vessels and 12% incomplete tests suggest that stress electrocardiography may be of limited value in predicting the morphologic state of the coronary arteries in patients with undiagnosed chest pain.

Adult↗
PubMed1975

The location of proteins labeled by the 125I-lactoperoxidase system in the NIL 8 hamster fibroblast.

NIL 8 hamster fibroblast cells were labeled by lactoperoxidase-catalyzed iodination. Their membranes were fractionated by sedimentation-rate and isopycnic zonal centrifugation. All the iodinated proteins except the very prominently labeled high molecular weight protein (greater than 200,000 daltons) were located in a fraction identified enzymically and compositionally as plasma membrane. The high molecular weight protein that was previously shown to be sensitive to virus transformation (Hynes, 1973) is concentrated in a very high density particle (rho equals 1.253-1.259) which contains mainly carbohydrate and protein and very low levels of lipid. 5'-nucleotidase was the only enzyme reproducibly demonstrated in this fraction, and electron micrographs revealed a predominantly amorphous morphology together with a few membraneous structures. The iodine label in this fraction was very sensitive to trypsinization prior to homogenization. All the available evidence indicates that this fraction is derived from the surface coat. Mitochondria, nuclei, and soluble protein were labeled to an insignificant extent. The presence of the iodinated surface proteins associated with the endoplasmic reticulum fraction is discussed in the light of these results.

Acid Phosphatase↗
PubMed1975

Responses of inner and outer muscle of the sheep carotid artery to injury.

1. Direct injury to the smooth muscle of the sheep carotid artery in vivo caused large, persistent and sharply limited annular contraction, even with tetrodotoxin 10(-5)M present to block nerves. 2. Surcose gap records from artery strips showed that mechanical injury caused slow, prolonged depolarization of the smooth muscle that spread for a few millimetres in a circular direction in relation to the intact artery wall with an apparent space constant of 1-26--3.49 mm. In the longitudinal direction, no depolarization was recorded 1 mm from the site of injury. No spikes were recorded more than 1 mm in either direction from the site of injury except when procaine, which facilitates electrical activity in the smooth muscle, was present. 3. When responses of inner and outer muscle were recorded separately, injury caused comparable contraction of both parts. 4. Clotted blood caused large contractions of intact artery strips; it contracted inner much more than outer muscle. 5. The main factors in the intact vessel's response to injury therefore seem to be inner and outer muscles' direct response to injury, reinforced by spread of depolarization round the vessel wall, and inner muscle's response to vasoconstrictor agents released by clotting blood.

Animals↗