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Biomedical subjects

J M Graham

Publications and source records attributed to J M Graham.

At least 271 records · Page 15Linked to original sources
PubMed1980

Extensive arterial aneurysm formation proximal to ligated arteriovenous fistula.

As a result of abnormal flow patterns and hyperdynamic flow in arteries proximal to an arteriovenous fistula a particular susceptibility to atherosclerotic changes and aneurysmal deterioration develops. In the following report two patients are presented in which chronic arteriovenous fistulas existed for 15 and 33 years prior to correction. Each patient developed extensive and progressive aneurysmal dilation of the proximal arterial tree and subsequently required surgical resection and graft replacement.

Adolescent↗
PubMed1980

Management of subclavian vascular injuries.

Greater civilian use of firearms and improved transportation and resuscitation of the injured have provided our institutions with an increasing experience with subclavian vascular injuries. Ninety-three patients with subclavian vascular injuries are presented and two time periods are compared. Principles of management gained from the earlier experience have been utilized with a decline in mortality to 4.7% among the patients admitted with a palpable pulse or blood pressure. Successful treatment as before still lies in the recognition of the severity of the injury, rapidity of preparation for operation, and adequacy of surgical exposure. Recent trends have included an increased reliance on selective arteriography when the patient is stable, extensive use of the 'book' thoracotomy as a primary incision, preoperative and intraoperative autotransfusion, and a more frequent use of interposition grafting for vascular repair. Primary arterial repair was seldom accomplished; most patients required segmental resection with end-to-end anstomosis or interposition grafts.

Adolescent↗
PubMed1980

Mass spectrometry in anesthesia. Problems in using mass spectrometer for monitoring anesthetic gases and vapours.

The use of mass spectrometers for total gas monitoring during anesthesia presents a number of problems which stem from the Cracking Pattern of the gases present, inlet design, viscosity variations, water vapour and machine deterioration. Some of these have been adequately solved, by making mechanical modifications to the inlet system, and by using more complex electronic circuitry to process the signals obtained. Remaining problems, however, still limit accuracy and ease of operation. CO2 measurements are particularly prone to error, especially when sampling halothane-containing gas which leads to significant internal production CO2. A study of the principal sources of error remaining in the machine suggests that the only definitive solution is to develop a microprocessor system which could cope with complex Cracking Patterns and non-linearities, and which would allow complete automation of the calibration procedure.

Anesthetics↗
PubMed1980

Metopic craniostenosis as a consequence of fetal head constraint: two interesting experiments of nature.

Two instances of metopic craniosynostosis provide dramatic experiments of nature which implicate fetal head constraint as one cause of early sutural fusion. The presumed restriction of growth stretch at the metopic suture in one instance was due to a bicornuate uterus in which the fetal head was markedly constrained. The second instance was in one of monozygotic triplets reared in a small mother in which the affected fetal head had been wedged between the hips of the two unaffected siblings.

Adult↗
PubMed1980

Coronal craniostenosis: fetal head constraint as one possible cause.

A retrospective study of 11 instances of idiopathic coronal craniostenosis in otherwise normal children revealed that early lightening, prolonged moderate to severe pelvic discomfort late in pregnancy, and/or an abnormal fetal lie were unusual gestational features indicative of intrauterine constraint for eight of these patients. The impression of unusual constraint in utero was further implied by finding associated positional foot deformities in four of these latter eight children. We hypothesize that prolonged constraint of the fetal head may limit anteroposterior growth stretch at the coronal suture and thereby predispose toward early sutural fusion.

Acrocephalosyndactylia↗
PubMed1979

Tissue-culture cell fractionation. Fractionation of membranes from tissue-culture cells homogenized by glycerol-induced lysis.

1. The disruption of various types of tissue-culture cells by (a) incubation in solutions of 1.2 M-glycerol and (b) transfer of the glycerol-loaded cells to relatively hypo-osmotic solutions of 0.25 M-sucrose was studied. 2. Bivalent cations (2mM-Mg2+) were generally included to preserve the nuclei, but some cells (polyoma-virus-transformed baby-hamster kidney cells) failed to be disrupted adequately under these conditions. 3. Other cells (mouse-embryo fibroblasts) required additional gentle Dounce homogenization to effect complete cell breakage. 4. Purification of the whole homogenate was carried out by a combination of differential centrifugation and sedimentation or flotation through sucrose gradients. 5. Enzyme analysis showed that plasma-membrane, endoplasmic-reticulum and mitochondrial fractions were obtained in good yield and purity.

Animals↗
PubMed1979

Tissue-culture fractionation. Zonal centrifugation of Lettrée cells homogenized by glycerol-induced lysis: subfractionation of membranes in sucrose gradients.

1. Lettrée cells were grown intraperitoneally in MF-1 mice. 2. Cells that were loaded with glycerol were swollen in 0.1 M-sucrose and disrupted by Dounce homogenization. 3. Early-passage Lettrée cells were more easily disrupted than late-passage cells by this method, and the former produced larger fragments of plasma membrane. 4. The membranes were fractionated initially in sucrose gradients (on the basis of sedimentation rate) in a BXIV zonal rotor. 5. Fractions from this gradient were further resolved in isopycnic sucrose gradients. 6. Plasma-membrane and endoplasmic-reticulum fractions were recovered in good yield and high purity.

Animals↗
PubMed1979

Tissue-culture cell fractionation. Fractionation of cellular membranes from 125I/lactoperoxidase-labelled Lettrée cells homogenized by bicarbonate-induced lysis: resolution of membranes by zonal centrifugation and in sucrose and metrizamide gradients.

1. Lettrée cells were grown intraperitoneally in MF-1 mice and labelled extrinsically by the 125I/lactoperoxidase technique. 2. The cells were swollen in 1 mM-NaHCO3 and disrupted in a Dounce homogenizer. 3. Crude fractions of endoplasmic reticulum, plasma membrane and mitochondria were separated from a post-nuclear supernatant by sedimentation-rate gradient centrifugation in a BXIV zonal rotor. 4. Further resolution of these membranes was carried out in isopycnic sucrose gradients. 5. Bands of material from the latter were subfractionated in gradients of metrizamide. Some very pure subfractions of plasma membrane and endoplasmic reticulum were obtained. In addition, one subfraction containing 125I and NADPH-cytochrome c reductase but no Na++K+-stimulated adenosine triphosphatase and another containing these two enzymes but no 125I were resolved.

Animals↗
PubMed1979

Major complications of percutaneous subclavian vein catheters.

New and reportedly safet techniques for subclavian venipuncture with the passage of central venous catheters appear regularly in the surgical literature [55--59]; yet reports of major complications continue to appear as well. We have reported on eight patients with major complications of percutaneous subclavian vein catheters, two of whom died. In our own hospital an improved educational program for junior house staff and nurses has been instituted. Better supervision of junior house staff when performing this potentially lethal technique is necessary. Daily inspection of catheters, early removal of unnecessary catheters, and improved equipment should help to prevent these complications in the future.

Adult↗
PubMed1979

A rapid method for the separation of large and small thymocytes from rats and mice.

Thymocytes from rats and mice have been separated into large and small cell populations in high yield and purity by isopycnic centrifugation in a discontinuous (three-layered) gradient of Percoll. Cells are mixed with the middle layer and during low-speed centrifugation the small, denser cells sediment to the bottom interface whilst the large, less dense cells float to the top interface. Red blood cells, and small debris particles separate into the bottom and top layers respectively. Studies on the uptake of [3H]TdR show that the small cells are non-dividing while more than half of the large cells are capable of division.

Animals↗
PubMed1979

Chronic traumatic aneurysms of the thoracic aorta: an analysis of 50 patients.

The records of 50 patients having thoracic aortic aneurysms and a remote history of severe chest trauma were reviewed. Time intervals between thoracic trauma and operation varied from 3 months to 32 years (average, 11.9 years). In 25 patients (50%) this interval was greater than 10 years and in six (12%) greater than 20 years. Surgical correction was accomplished with low mortality and morbidity. Detection and diagnosis of chronic traumatic thoracic aortic injuries may not become clinically evident in some cases for many years. This diagnosis should be considered in all patients with a history of severe thoracic trauma, no matter how remote.

Aorta, Thoracic↗
PubMed1979

Combined pancreatoduodenal injuries.

Operative management of combined pancreatic and duodenal injuries has been a controversial subject in recent years. Methods advocated include resection, duodenal diversion, and simple repair and drainage. Excellent results have been reported with each of these, but most reported series are small, preventing definitive conclusions concerning the value of any treatment modality. During an 8-year period ending December 1976, 308 pancreatic injuries and 175 duodenal injuries were treated. Sixty-eight of the patients had combined pancreatic and duodenal injuries and constitute the basis for this report. Fifty-five patients sustained penetrating injuries and 13 had blunt injuries. Eighteen underwent repair and drainage. The remaining 50 required more extensive procedures which included duodenal diversion and pyloric exclusion in 32, pancreatoduodenectomy in six, and a variety of procedures in the remainder. The operative mortality rate was 26.4%, including five patients who died intraoperatively. In the entire series only one death was directly attributable to the pancreatoduodenal injury. We conclude that no single procedure is uniformly applicable to these injuries. Surgeons treating trauma of this severity should be familiar with a variety of techniques for repair, and treatment should be individualized. Preservation of tissue should be accomplished when possible.

Adolescent↗