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Biomedical subjects

W H Baker

Publications and source records attributed to W H Baker.

At least 19 recordsLinked to original sources

Histopathologic effects of soluble glucan and WR-2721, independently and combined in C3H/HeN mice.

Soluble glucan, an immunomodulator, and Walter Reed (WR)-2721, a radioprotectant, increase postirradiation survival when administered before and after exposure, respectively. Combined, these agents act synergistically through WR-2721's ability to spare hematopoietic stem/progenitor cells from radiation injury and glucan's ability to subsequently stimulate spared cells to proliferate. In this study, the histopathologic effects of WR-2721 (200 mg/kg, ip) and glucan (250 mg/kg, iv), at doses capable of increasing survival in lethally irradiated mice, were evaluated in unirradiated and irradiated female C3H/HeN mice. After treatment, whole body weights and wet organ weights of liver, spleen, and kidney, as well as gross and histologic changes in these and other tissues, were monitored on Days 1, 4, 7, 11, 15, 21, and 28. Morphometric studies of splenic white and red pulps were also performed. Soluble glucan, with or without WR-2721, in unirradiated groups, was associated with splenomegaly, transient morphometrically determined perturbations of white and red pulp areas, and histologic alterations of white pulp. In irradiated mice, splenic weight loss was initially dampened in glucan groups and accompanied by morphologic and histologic changes similar to those seen in unirradiated counterparts. The subsequent rebound of splenic parameters in irradiated mice was limited to WR-2721-treated mice and was associated with hematopoietic reconstitution. Glucan, with or without WR-2721, in unirradiated groups was associated with transient hepatomegaly and associated histologic changes. Similar changes in irradiated animals were seen only in the combined treatment group.

Amifostine

Selection process for surgeons in the Asymptomatic Carotid Atherosclerosis Study.

BACKGROUND AND PURPOSE: The Asymptomatic Carotid Atherosclerosis Study is a prospective, multicenter, randomized clinical trial of carotid endarterectomy for the treatment of asymptomatic hemodynamically significant stenosis. This report describes the selection process for participating surgeons in the trial. METHODS: The Surgical Management Committee established guidelines for minimal annual experience and maximum neurological morbidity and mortality for surgeons to qualify to participate in the study. For approval, a surgeon must perform at least 12 carotid endarterectomies per year. Based on a review of the surgeon's last 50 consecutive endarterectomies, the combined neurological morbidity and mortality rate must be no greater than 5% for all indications and no greater than 3% for endarterectomies performed on asymptomatic patients. RESULTS: One hundred sixty-four surgeons from 48 centers applied for approval: 117 were approved, 17 were rejected, and 30 were not reviewed. The 117 approved surgeons submitted a total of 5,641 endarterectomies with a combined mortality and neurological morbidity rate of 2.3% for the variety of indications for operation. CONCLUSIONS: This overall experience with carotid endarterectomy is one of the largest series reported to date. The data from approved surgeons are well within the range of acceptable neurological morbidity and mortality rates recommended by the Stroke Council of the American Heart Association, which attests to the overall quality of the surgeons participating in the study.

Carotid Artery Diseases

An evaluation of external jugular vein patch angioplasty after carotid endarterectomy.

Seventy-six patients had 91 internal carotid endarterectomies closed with patch angioplasty. There were 36 redo and 55 primary procedures. External jugular vein was used as the patch material in 38, facial vein in nine, Dacron in seven, polytetra flour ethylene (PTFE) in nine, and saphenous vein in 28 operations. There were no perioperative deaths. Five patients required reoperation, but only one required replacement of a defective facial vein. There were five postoperative strokes, but two were related to a contralateral occlusion. Two of the three ipsilateral strokes had a temporary indwelling shunt. Only one patient returned with recurrent neurologic symptoms. Five other restenoses of greater than 75 per cent were noted in three patients. One false aneurysm occurred three months after an external jugular vein patch angioplasty. External jugular vein, although requiring careful handling, is conveniently located in the operative field, does not appear to be associated with increased complications, has excellent long-term results, and allows preservation of the saphenous vein for other bypass surgery.

Adult

Use of sequential B-mode ultrasonography to manage abdominal aortic aneurysms.

The utility and safety of sequential B-mode ultrasonography to treat male patients with small (less than 6.0 cm in diameter) abdominal aortic aneurysms (AAAs) were studied retrospectively in 149 consecutive patients. Sixty-three of these patients have had operative repair of the AAA. Eight-six remain unoperated on. Mean growth rate was 0.79 cm/y (1.06 cm/y in the operated-on group and 0.36 cm/y in the unoperated-on group). Seven patients sustained rupture of the AAA during follow-up and 4 patients died as a consequence of elective repair, for a combined mortality rate of 7.4% (11/149). Only one AAA that was less than 5.0 cm ruptured. This has proved to be an effective way to manage AAAs in this population.

Aged

Institutionally shared trauma rotations are viable solutions to deficiencies in trauma training.

Numerous national trauma leaders have expressed concern about the lack of uniformity of trauma training in this country. In 1984 we instituted a trauma rotation between the University of Louisville (U.L.), with a large trauma volume, and Loyola University (L.U.) in the planning stages of trauma center development. Third year L.U. residents rotated at U.L. in 3-month blocks with an increased level of responsibility monthly, culminating in major decision-making roles and operative treatment under the chief resident's direction. The L.U. residents functioned as full members of the team and not as passive observers. Fifteen L.U. residents and 12 U.L. residents rotated during this period. Yearly major trauma visits, helicopter flights, and trauma service admissions average 1,908, 700, and 1,520, respectively. U.L. chief residents averaged 136 major operative trauma cases and 115 nonoperative trauma cases each were managed during this time period (RRC records greater than 85th percentile for all U.L. residents). L.U. residents performed an average of 30 major operative cases, nine as teaching assistant, in 3 months. Each managed more than 75 nonoperative cases. Several elements are critical in such a multi-institutional rotation: 1) active communication among the program directors, 2) commitment to one sharing arrangement only, 3) financing and malpractice for off-site residents, 4) housing, and 5) the ability to assimilate off-site residents as true trauma team members. The resident-to-resident interplay is crucial and has succeeded because both residency staffs have had excellent early training.(ABSTRACT TRUNCATED AT 250 WORDS)

Academic Medical Centers

Successful revascularization of an occluded renal artery after prolonged anuria.

Renal atherosclerosis and fibromuscular dysplasia are the most common causes of curable human renovascular hypertension and renal failure. Vascular reconstruction often preserves renal function, but renal failure is rarely reversed, especially after days of anuria. We report a case of a 23-year-old woman who as a child underwent a nephrectomy for congenital hydroureter and renal hypoplasia. She later experienced fibromuscular dysplasia of the remaining renal artery, which ultimately progressed to a complete occlusion and 31 days of total anuria. The patient was revascularized, and within 2 months renal function returned with a blood urea nitrogen and creatinine of 9.0 and 1.0 mg/dl, respectively. After a follow-up of 6 months the patient's blood pressure remained 120/80 to 130/80 mm Hg without administration of hypertension medication. In this report we emphasize that under selected circumstances a kidney can survive prolonged ischemia and that delayed revascularization may reestablish renal function.

Adult

Molecular markers of hemostatic activation in atherosclerosis: a new concept in diagnostic profiling of endogenous pathophysiologic transition.

Molecular markers of hemostatic activation provide a reliable measure of the endogenous pathophysiologic state in atherosclerosis. Measurement of these markers before and after exercise provides a diagnostic probe for cellular-vascular interactions in patients with atherosclerosis. Molecular markers may possibly identify very early stages of atherosclerosis due to their inherent sensitivity. A high-risk cardiovascular population can be easily recognized by profiling molecular markers of hemostatic activation. Newly developed immunoassays can be used to quantitate these markers in routine laboratories. Additional clinical studies are needed to establish the diagnostic role of these molecular markers in patients with atherosclerosis and related disorders.

6-Ketoprostaglandin F1 alpha

Pneumatic compression devices for prophylaxis of deep venous thrombosis (DVT).

A pneumatic compression device was applied to 155 patients with a normal Doppler venous examination who underwent a general surgical procedure of at least 1 hr in duration. One hundred fifty-three patients had neither PE nor DVT clinically or by Doppler studies, one patient had a venographically proven DVT, and one patient had a clinical pulmonary embolism verified by lung scanning. Using clinical and Doppler criteria, the device was effective in the prophylaxis of thromboembolic complications.

Aged

Quality and duration of survival in glioblastoma multiforme. Combined surgical, radiation, and lomustine therapy.

A retrospective evaluation of the quality and length of survival of 74 patients nonrandomly receiving lomustine, 100 to 110 mg/sq m, following craniotomy and irradiation for glioblastoma multiforme was performed. After surgery all patients were capable of at least partial self-care. Patients receiving postoperative irradiation and lomustine had a median survival of 11.5 months. While receiving chemotherapy, 40% of these patients were capable of at least partial employment; 75% were able to care for themselves. These levels of function were stable for 70% of the average postoperative course (8.0 months), following which a decline ensued.

Activities of Daily Living

Comparison of hemodynamic, pulmonary, and renal effects of use of three types of fluids after major surgical procedures on the abdominal aorta.

Hemodynamic, pulmonary, and renal variables were measured in 24 patients scheduled for major abdominal aortic operations. Control values were obtained before preoperative medications were given. All patients received 5% dextrose in Lactated Ringer's solution intraoperatively. Postoperatively, group 1 patients received 5% dextrose in water plus albumin, group 2 received 5% dextrose in 0.45 sodium chloride solution, and group 3 received 5% dextrose in lactated Ringer's solution. There were significant increases in Qs/Qt and AaDO2, 48 hours after operation in group 3. Oxygen consumption and cardiac output increased in all groups 24 hours after operation. Twenty-four hours later, these two variables returned to control values in group 1 but continued to rise in the other two groups. Significant diuresis occurred in group 1, 48 hours postoperatively, whereas the other two groups continued to retain water. Use of albumin and 5% dextrose in water in the postoperative period seemed to produce less deviations from control values of most measured variables, than the other two groups.

Albumins

Diagnosis of peripheral occlusive disease: comparison of clinical evaluation and noninvasive laboratory.

One hundred and two patients with peripheral vascular disease were evaluated by the attending surgeon, residents and students, and the vascular laboratory prior to arteriography to test their ability to make a correct anatomic diagnosis. The attending surgeons made a correct anatomic diagnosis in 98 patients and were at least partially correct in the other four. Surgical housestaff and students were 62% totally correct, 35% partially correct, and 3% totally wrong. The vascular laboratory results were almost identical with the attending surgeon, but two patients could not be evaluated because of calcified arteries. The operation that was eventually performed was suggested initially by the laboratory and the attending surgeon in 98% of the patients.

Arterial Occlusive Diseases

Value of concomitant sympathectomy in aortoiliac reconstruction. Results of a prospective, randomized study.

The efficacy of concomitant lumbar sympathectomy in improving results of aortoiliac reconstruction was assessed by a prospective, randomized study of 51 patients undergoing operation for occlusive or aneurysmal disease. Sympathectomy was performed on 50 limbs, while 52 extremities served as controls. Sympathectomy resulted in a significant reduction in foot vascular resistance determined by plethysmography. However, the procedure had no effect on leg circulation, assessed by ankle/arm pressure indices determined by Doppler ultrasound. In the sympathectomy group, there were three early postoperative amputations for ischemia, despite patent grafts. In the control group, there was one late graft occlusion, caused by progressive atherosclerotic disease. Although sympathectomy may improve pedal circulation, the procedure does not appear to improve the results of aortoiliac reconstruction.

Adult

Staged intracranial and extracranial revascularization.

Twenty patients with a combination of intracranial and extracranial cerebrovascular lesions were identified in a series comprised of 118 candidates for superficial temporal artery to middle cerebral artery (STA-MCA) bypass. Ten patients had internal carotid (ICA) occlusion and contralateral ICA stenosis, seven patients had combinations of ipsilateral lesions, usually ICA occlusion and external carotid (ECA) stenosis, and three patients had multiple lesions. Eighteen patients had a STA-MCA bypass performed; 11 of these had contralateral reconstruction for ICA stenosis, and seven had ECA stenosis corrected. Two additional patients became asymptomatic after ECA endarterectomy only and their proposed STA-MCA bypass has been postponed. There were two deaths, one early and one late. Eleven patients are asymptomatic, five are improved, one is unchanged, and one is neurologically worse.

Adult

The healing of below-knee amputations: a comparison of soft and plaster dressing.

To evaluate the effect of wound dressing upon wound healing, fifty-one patients undergoing below-knee amputation using a long posterior myocutaneous flap technic were randomly allocated into a soft or plaster dressing group. Neither wound dressing technic proved superior, as wounds healed in 85.2 per cent of the plaster dressing group and 83.3 per cent of the soft dressing group.

Adult