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Biomedical subjects

N M Rich

Publications and source records attributed to N M Rich.

At least 19 recordsLinked to original sources

The valvular anatomy of the iliac venous system and its clinical implications.

Clinical and phlebographic evidence exists that correlates the presence of varices of the vulva, posterior thigh, and the pelvic congestion syndrome with insufficiency of the internal iliac venous system (pelvic dumping syndrome). Information in the modern medical literature regarding the valvular anatomy of the internal iliac veins and its tributaries is limited. We dissected 82 iliac venous system specimens in 42 human cadavers (29 men, 13 women) to gain information on the relationship between the disease described and the anatomy of the region. Each specimen contained common, external, and internal iliac veins, including the tributaries of the latter. We recorded the anatomic variations of the internal iliac vein trunk and the location of valves in the complete iliac venous system, including 485 tributaries of the internal iliac veins. Five specimens of internal iliac vein had calcified thrombosis or were extensively involved with pelvic carcinoma and were not suitable for valve study, which left 79 specimens for analysis. The internal iliac vein drained into the external iliac venous system by means of a single trunk in 73% of the specimens and by two well-formed and separated trunks in 27% of the specimens. In one specimen (1.2%) the internal iliac vein drained directly into the inferior vena cava (parallel internal and external iliac veins). One specimen had a well-developed valve in the common iliac vein (1.2%). The external iliac vein had one valve in 26.2% of the specimens. This vein had three times as many valves on the right side as in the left (39.6% vs 14.6%: p = 0.0106).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Alterations in serum creatine kinase and lactate dehydrogenase. Association with abdominal aortic surgery, myocardial infarction and bowel necrosis.

Experimental studies have shown that peripheral serum creatine kinase and lactate dehydrogenase change with bowel infarction. Some clinical reports have suggested that similar changes occur in patients. This prospective study documents the changes in these enzymes associated with acute myocardial infarction, acute bowel necrosis (MES INF), and uncomplicated abdominal aortic reconstruction. Analysis of 15 patients with AMI, 13 patients undergoing major AAS, and eight patients with MES INF has shown that these conditions may be differentiated by analysis of serum CK and LD isoenzymes. The study suggests that in the absence of electrocardiographic changes, a patient with epigastric distress with elevated levels of serum CK and either CK-MB or CK-BB bands present may well have a mesenteric rather than a myocardial infarction. Acute myocardial infarction can be ruled out further through analysis of serum LD1/LD2 ratios.

Aged

Intermittent claudication caused by atherosclerosis in patients aged forty years and younger.

Intermittent claudication may represent a severe limitation in daily life-style for young, active patients and may result in loss of professional career for members of the armed forces. Our recent experience with young patients with atherosclerotic claudication was reviewed to determine whether more liberal use of angioplasty and surgery is warranted in these patients to salvage their military careers and improve their life-styles. A systemic review was made of patients aged 40 years and younger with atherosclerosis who have undergone arteriography at our institution during the past 67 months. From this study, 22 patients were found with the initial complaint of intermittent claudication. Fifteen of these patients (68%) had occlusive disease confined to the iliac arteries, and six (27%) had single-level occlusive disease in a femoropopliteal distribution. Only one patient had multilevel disease. Symptoms of coronary occlusive disease developed in five patients (23%) within 38 months of the onset of claudication, and two of these patients died of myocardial infarctions. Of 19 patients who underwent interventions to correct symptoms of claudication, 16 (85%) had complete relief of symptoms at the end of follow-up, ranging from 6 months to 7 years. Ten of these patients remained symptom free after a single intervention, but six patients had rapid progression of disease and required secondary procedures. These results indicate that a majority of young patients with claudication caused by atherosclerosis can be returned to full active-duty status in the military after angioplasty or surgery. However, some patients may require secondary procedures to relieve recurrent symptoms caused by rapid progression of disease. We believe that an aggressive interventional approach is warranted in the evaluation and treatment of young patients with work-limiting claudication caused by atherosclerosis. These patients are at significant risk of developing premature coronary occlusive disease and should be monitored closely.

Adult

Abnormalities of lymphatic drainage in lower extremities: a lymphoscintigraphic study.

Chronic lower-leg edema in patients with venous disorders was studied by means of lymphoscintigraphy. Lymphatic patterns of flow were evaluated prospectively in 26 patients with technetium 99m antimony trisulfide colloid injected subcutaneously in the interdigital web spaces on the feet. Most patients in this study had postphlebitic syndrome, and all of these patients had abnormal lymphoscintigraphic flow patterns. Nine had evidence of lymphatic obstruction, and one had an enhanced flow pattern. Three patients had veins used for distal arterial bypass, and all these veins showed decreased lymphatic flow. Two patients with Klippel-Trenaunay syndrome (congenital varicose veins associated with limb elongation, a capillary nevus, and an abnormal deep venous system) had obstruction to lymphatic flow, and two others had normal and enhanced patterns. Normal studies were seen in four of five patients who had veins used for coronary artery bypass grafting. The finding of decreased lymphatic flow in patients appears to be the result of the length of time from an episode of deep venous thrombosis, the occurrence and number of episodes of cellulitis and lymphangitis, and mobilization of the vein for use in distal arterial bypass surgery. This study shows that the edema attributed previously to primary venous disorders may have a significant lymphatic component. The degree of lymphatic obstruction can be determined by lymphoscintigraphy with technetium-labeled antimony trisulfide colloid.

Adult

Management of venous trauma.

There has been considerable interest in the management of injured extremity veins since the American experience during the Vietnam War. Fortunately, there are an increasing number of reports from civilian experience in the United States that add valuable information. Although the controversy continues, it appears that there is merit in repair of many injured lower-extremity veins, particularly the popliteal vein when it is a single return conduit, assuming that the patient's general condition will permit, in an attempt to prevent acute venous hypertension initially and chronic venous hypertension subsequently. Figure 1 identifies the recovery potential that exists even if the initial venous repair fails. In contrast to thrombosis in the arterial system, recanalization is the rule in venous thrombosis. Patent valves can exist above and below the rather localized area of thrombosis. It appears that recanalization will prevent the problems of chronic venous insufficiency. It is obvious that many patients do well for years; however, the sequelae of acute venous hypertension may be more demonstrable after 10 or 15 years. There has not been similar evidence supporting a more aggressive approach in general in upper-extremity veins. However, it should be appreciated that a return pathway must remain patent, as noted in replantation of extremities. Obviously, there are differences in military and civilian wounds, with the former usually having more extensive soft-tissue destruction and obliteration of collateral veins and lymphatic channels. Unfortunately, many civilian gunshot wounds are being seen in the United States that are similar to the military type. We must not forget the lessons of the past, and we must continue to analyze our experience in the management of injured veins under a variety of conditions.

Blood Vessel Prosthesis

Three-dimensional computer graphic modeling of ballistic injuries.

Multiple variables affect the tissue destruction caused by missiles, and the interaction of these variables is incompletely understood. The recently developed technology of computerized solid modeling now makes it possible to analyze these parameters in three dimensions. A technique for creating solid models of organic structures is described. The tissues within the boundaries thus defined are ascribed physical attributes by means of finite element analysis with data derived from empirical studies. An interactive user-friendly program is being developed combining this modeling with a probabilistic scheme (Monte Carlo simulation) to describe a variety of wounding scenarios. The data from these predictions will be compared with information from wound registries and the model refined until it can project consistently accurate patterns of injury.

Computer Graphics

Intra-abdominal vascular injury secondary to penetrating trauma.

There were 85 patients in this series. The overall mortality was 17.6%. Gunshot wounds were responsible for 51 injuries, with a 21% mortality. There were three stabbings and three shotgun blasts, with a mortality of 10% and 33%, respectively. There were 127 intra-abdominal vascular injuries. The majority were to the SMA and its branches: 34. The highest mortality occurred with protal vein and combined aortic and vena caval injuries (80%). Fatalities averaged twice as many vascular injuries as survivors. There were 194 organ injuries. A liver injury predicted the highest mortality as did injuries to the spleen, lung, and pancreas. The presence of shock and the ability to rapidly control the source were the major predictors of survival. Fatalities averaged a Trauma Score of 7.5; survivors averaged a score of 14.0. There were 12 deaths which occurred intra-operatively and three postoperatively, for a total of 15 deaths. Once the patients made their way from surgery, their survival was 96% assured. Early suspicion of an intra-abdominal vascular injury followed by rapid exposure and control of hemorrhage are the keys to successful management.

Abdominal Injuries

Long-term followup of penetrating abdominal aortic injuries after 15 years.

Eleven of 14 survivors who sustained trauma to the abdominal aorta have been evaluated 16 to 18 years after injury through personal interview, physical examination, and abdominal contrast computerized tomography (CCT). The average age of survivors was 39 years (range, 37-47). All patients had minimal debridement of the aortic injury with lateral arteriorrhaphy. No patients had symptoms of arterial insufficiency. However, five patients had abnormal ankle/brachial indices (ABI). In four patients, ABI was less than 1.00 at rest and a fifth patient's ABI decreased significantly: 0.60 left and 0.65 right from an average of 1.00 bilaterally after standardized exercise treadmill. CCT evaluation revealed aortic calcification in five patients in the area of aortic injury. Aortic calcification occurred only in the patients with abnormal ABI's. This long-term followup identifies no evidence for late compromise in the aorta; however, there is a suggestion that injury and repair may contribute to the accelerated development of atherosclerosis.

Adult

Inhibition of acid secretion in guinea pigs by tricyclic antidepressants: comparison with ranitidine and omeprazole.

The antisecretory properties of imipramine on gastric secretion in guinea pig in comparison with other antisecretory agents was determined. In awake guinea pigs s.c. infusion of histamine (30 micrograms/kg/hr) increased acid and fluid secretion by 3- to 4-fold. When acid output peaked, a bolus administration of the tricyclic anti-depressant imipramine inhibited acid and fluid secretion. Imipramine and other agents, such as ranitidine and omeprazole, inhibited gastric secretion in a dose-dependent fashion. The most potent was the H2-antagonist ranitidine (IC50, 0.2-0.3 mumol/kg), followed by the gastric H-K-adenosine triphosphatase inhibitor, omeprazole (IC50, 0.5-0.6 mumol/kg). Imipramine (IC50 1-2 mumol/kg) was the least potent of the inhibitors. Both ranitidine and omeprazole could abolish acid secretion, but maximal inhibition with imipramine was 60% of initial. Promethazine (25 mumol/kg), an H1 antagonist, and atropine (12 mumol/kg), a muscarinic antagonist, inhibited gastric secretion by 40 to 50%. Imipramine and atropine also inhibited basal acid secretion. In dispersed gastric cells comparison between imipramine and omeprazole showed that imipramine was about 5-fold more potent than omeprazole in blocking histamine or dibutyryl cyclic AMP stimulation of aminopyrine accumulation. Imipramine probably acts as a protonophore by increasing the rate of proton-gradient dissipation rather than by interfering with the hydrogen-pump system because, in gastric membranes, imipramine was 20-fold less potent than omeprazole in inhibiting the gastric H-K-adenosine triphosphatase activity. These results suggest that imipramine administered s.c. in guinea pigs is a potent antisecretory drug. Its action may be due to a combination of anticholinergic and antihistamine H2 activities.

Adenosine Triphosphatases

A new in vivo method for repeatedly studying gastric acid secretion and other secretory parameters in awake guinea pig.

A new model for measuring gastric secretory parameters in awake guinea pigs is described. A chronic cannula was surgically implanted in the stomach of each guinea pig. The rates of gastric secretion and changes in intragastric volume were measured using a dye dilution technique. In contrast to previous techniques in small laboratory animals, there was no collection of gastric juice via drainage, no oral intubation for aspiration was involved, no special or sophisticated equipment was used, no anesthesia was employed, and there was no stress associated with acute surgery. This method offers a valuable advantage by combining the chronic gastric cannula with a dye dilution technique in that the same animal can be used several times and finally, several gastric secretory parameters can be measured simultaneously. The animals were used from 3 weeks to 10 months after surgery and as many as 15 studies were performed on the same guinea pig. Samples were collected at 10-min intervals and analyzed for acid and dye concentration from which the onset and kinetics of gastric secretion were followed. Basal gastric secretion (11.8 +/- 1.6 mueq/kg/min; all mean +/- 1 SEM) was increased within 20 min after subcutaneous infusion of histamine (30 micrograms/kg/hr) and peaked by 40-60 min at a mean acid output rate of 41 +/- 3 mueq/kg/min. Histamine also increased the intragastric volume from 6.3 to 13.4 ml as it increased fluid output from 1.6 +/- 0.1 ml/10 min to 3.4 +/- 0.2 ml/10 min. The increase in acid output caused by histamine was inhibited by the H2-antagonists cimetidine (3 mumole/kg) and ranitidine at 0.5 mumole/kg. Omeprazole (1.2 mumole/kg), an H-K-ATPase inhibitor, almost abolished acid output under both basal and histamine-stimulated conditions. Thus, the present method is simple and suitable to study the physiology and pharmacology of gastric secretion in the guinea pig with a particular emphasis on the action of histamine. Furthermore, because of the species involved, there is also a significant economical advantage and the guinea pig can also be used as a potential model for studying experimental ulcer.

Animals

Intraoperative local anesthetic injection of the carotid sinus nerve. A prospective, randomized study.

One hundred patients undergoing carotid endarterectomy under general anesthesia were prospectively randomized to receive either a local anesthetic injection of their carotid sinus nerve with bupivacaine (Marcaine) or no injection. Systolic blood pressure and pulse rate were recorded before injection and at 5 and 30 minutes after injection. The need for intraoperative and postoperative use of systemic vasopressor and vasodilator medications was recorded for each group as was the incidence of arrhythmias, neurologic complications, and myocardial infarctions. Intraoperative local anesthetic injection of the carotid sinus nerve did not significantly influence the intraoperative pulse rate or incidence of hypotension. It did, however, significantly increase the incidence of intraoperative hypertension and the need for systemic vasodilator medications intraoperatively. The incidence of postoperative hypotension (6 percent of patients), hypertension (34 percent), arrhythmias (6 percent), cerebrovascular accidents (1 percent), transient ischemic attacks (3.1 percent), and myocardial infarctions (2 percent) were not significantly influenced by intraoperative local anesthetic injection of the carotid sinus nerve. Intraoperative and postoperative hypotension did not cause morbidity in this series, however, local anesthetic injection was associated with a significant incidence of perioperative hypertension. Routine prophylactic local anesthetic injection of the carotid sinus nerve cannot be recommended in view of its detrimental effects in relation to the development of hypertension.

Anesthesia, Local

The cytotoxic effect of surgical glove powder particles on adult human vascular endothelial cell cultures: implications for clinical uses of tissue culture techniques.

Clinical use of autogenous endothelial cell (EC) seeding of vascular prostheses (VP) would require reliable methods for EC harvest for immediate seeding or primary culture in a hospital or operating room setting. Observation of glove powder particles (GPP) in failed primary adult human saphenous vein EC (AHSVEC) cultures led us to study the effect of surgical GPP on cultured AHSVEC. Addition of GPP to the culture medium of growing ASHVEC cultures reduced the cell counts in a dose-dependent fashion; the mean concentration of GPP required to produce a greater than 50% decrease in cell number was 1.5 +/- 0.8 (SD) X 10(4) GPP/ml (N = 10 experiments), equivalent to a mean dose of 36 micrograms glove powder per milliliter. The effect was seen within 24 hr of addition of GPP and was not due to interference with EC attachment and spreading or to changes in medium osmolality, pH, glucose, electrolyte, Ca2+, or Mg2+ content. Instead, the effect appeared to be due to a filterable toxin added during the final rubber-vulcanizing stage of glove manufacture, since pure cornstarch particles and epichlorhydrin-treated pure cornstarch did not prevent culture growth, whereas 0.2 micron filtrates of medium incubated with GPP taken directly from gloves were lethal. We conclude that filterable cytotoxic substances from GPP may be an avoidable cause of failure in EC seeding of VP, and may affect surgical wound healing as well.

Cell Adhesion

The noninvasive diagnosis of vasculogenic impotence.

One hundred eleven impotent men and 25 potent men were prospectively evaluated with a standardized exercise treadmill test (SETT) used to noninvasively define their pelvic hemodynamics. Fifty-six men had vasculogenic impotence, whereas the remaining 55 had erectile dysfunction resulting from undetermined causes (31), psychogenic factors (10), or other identifiable reasons (14). Arteriography was performed on 40 (71%) of the patients with vasculogenic impotence without false positive results, as well as in 11 (44%) of the potent control patients and in six (11%) of the patients with nonvasculogenic impotence without false negative results, confirming the validity of the SETT. The distinction between vasculogenic and nonvasculogenic impotence can be accurately made with the SETT. Patients with vasculogenic impotence had a resting penile-brachial index (PBI) equal to 0.60 +/- 0.022 (mean +/- SEM) and a PBI after exercise equal to 0.45 +/- 0.019 with a fall in the mean PBI of -0.15 (p less than 0.001). Patients with nonvasculogenic impotence had a resting PBI equal to 0.80 +/- 0.024 and a PBI after exercise equal to 0.88 +/- 0.019 with a rise in mean PBI of 0.08 (p less than 0.001). This response was not significantly different between the control group and the nonvasculogenic impotence patients. The addition of PBI determinations after treadmill exercise revealed that 18% of the patients with vasculogenic impotence would have been incorrectly diagnosed, because their resting PBI was greater than the traditional standard of 0.70. Furthermore, 18% of the patients with nonvasculogenic impotence would have been incorrectly diagnosed as having vasculogenic impotence because their resting PBI was less than 0.70.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography

Effect of 1% sodium hyaluronate (Healon) on a nonregenerating (feline) corneal endothelium.

A series of experiments were performed to investigate the effect of 1% sodium hyaluronate (Healon) on the nonregenerating corneal endothelium of the cat. Aqueous humor replacement with 1% sodium hyaluronate resulted in mild, transient elevations of intraocular pressure compared to eyes that were injected with balanced salt solution. Sodium hyaluronate 1% protected the feline endothelium against cell loss incurred by contact with hyaluronate-coated intraocular lenses compared to endothelial contact with lenses that were not coated with sodium hyaluronate. The use of intraoperative 1% sodium hyaluronate, however, did not protect against endothelial cell loss incurred by penetrating keratoplasty or prevent subsequent skin graft-induced corneal homograft rejections. Homograft rejections were milder, however, in some eyes that received grafts coated with 1% sodium hyaluronate. Image analysis of photographs of trypan blue- and alizarin red-stained corneal buttons after trephining, stretching of Descemet's membrane, rubbing against iris-lens preparations, or immediately after penetrating keratoplasty demonstrated that the stretching of the posterior cornea is an important cause of endothelial damage that would not be protected against by a viscoelastic coating.

Animals

Postnatal development of corneal endothelium.

Comparison specular micrographs of infant and adult corneas from cats, cows, dogs, rabbits, and humans demonstrate that a large decrease in central endothelial cell density occurs during maturation of the cornea. Central endothelial cell counts of developing cat, dog, and rabbit corneas decrease rapidly during the first months of life. This rapid decline in endothelial cell density correlates with growth of the cornea to the adult size. Central endothelial cell counts of adult cat, cow, deer, dog, pig, rabbit, and human corneas are similar (2500 cells/mm2) despite a wide variation in corneal size. Comparison of observed endothelial cell counts with two hypothetical situations, one of unrestricted endothelial mitosis and the other of only endothelial hypertrophy, indicates that hypertrophy of individual cells is primarily responsible for achieving the adult cell density of 2500 cells/mm2 for these species. This observation is true for species that have a high adult endothelial mitotic capacity (rabbit) as well as those that do not (cat). The human cornea is a special case because the decline in central endothelial cell density indicates that a large apparent corneal endothelial cell loss (approximately 45%) occurs early in postnatal development.

Adult

Management of patients with symptomatic extracranial carotid artery disease and incidental intracranial berry aneurysm.

Perioperative fluctuation of blood pressure and the use of anticoagulants during carotid endarterectomy may potentiate lethal aneurysm rupture in patients who have symptomatic extracranial carotid artery occlusive disease with incidental, asymptomatic, intracranial berry aneurysms. Ten patients having this combination are described in the present study. Of five men and five women whose mean age was 63 years, nine had symptomatic carotid bifurcation atherosclerosis, one had internal carotid fibromuscular dysplasia, and all had intracranial berry aneurysms ranging from 2 to 13 mm in diameter (mean diameter 6.6 mm). In seven patients, aneurysms were greater than or equal to 6 mm in diameter. Hypertension was present in seven patients and moderately severe in five. Three of the aneurysms were located in the intracranial internal carotid artery, five in the middle cerebral artery, three in the posterior communicating artery, one in the anterior cerebral artery, and one in the superior cerebellar artery. Twelve carotid reconstructive procedures were performed without morbidity related to aneurysm rupture. These included 10 carotid endarterectomies, one of which was combined with Dacron patch angioplasty and one of which was combined with a simultaneous coronary artery bypass; one carotid artery dilatation for fibromuscular disease; and one reoperative carotid endarterectomy with patch angioplasty. Three patients had correction of hemodynamically significant lesions, two of which were proximal to ipsilateral anterior circulation aneurysms. An intraluminal shunt and heparin anticoagulation therapy were used in all patients. Despite a concerted effort to control blood pressure, the patients' perioperative blood pressures ranged from 60/30 to 240/110 mm Hg. Three patients had subsequent elective clipping of intracranial aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid Arteries

Long-term patency of venous repairs demonstrated by venography.

Indications for venous reconstruction after traumatic injury are controversial, partly because of uncertainty of continued patency. We found no reports in the literature of truly long-term results after venous reconstruction. For clarification of this issue, we reviewed femoral venous injuries in a civilian metropolital population over a 20-year period. There were 31 patients with penetrating femoral venous injuries. Twenty-four patients underwent reconstruction. A search for these patients years after reconstruction located only five patients with six reconstructions. Followup venography at 6 to 20 years demonstrated venous patency and functional valves with asymptomatic patients and no clinical evidence of venous insufficiency in all cases excluding a single 1962 repair with a Teflon graft. This study then supports reconstruction rather than ligation after venous trauma. Although small, this series appears to be the only known report of truly long-term results following venous reconstruction.

Adult