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Biomedical subjects

R B Rutherford

Publications and source records attributed to R B Rutherford.

At least 127 records · Page 7Linked to original sources

Role of intra-arterial streptokinase in treatment of arterial thromboembolism.

We treated 27 cases of arterial thromboembolism, including nine thrombosed grafts, with intra-arterial (IA) streptokinase. Complete lysis without significant residual lesions was achieved in eight (30%) of the cases, and partial lysis with sustained improvement was achieved in an additional six cases (22%). Partial lysis revealing inaccessible residual disease in runoff vessels occurred in four (15%) of the cases, and nine (33%) were primary failures. Surgery was completely avoided in 11 (41%) of the patients, lesser amputations were possible in three (11%), and 18 (67%) avoided major amputation. Grafts lysed faster (35 v 62 hours) and more frequently (seven [78%] of nine v 11 [61%] of 18) than native vessels, but had a higher rethrombosis rate (four [71%] of seven v two [11%] of 11) and a lower late patency rate (two [22%] of nine v nine [50%] of 18). Significant bleeding occurred in one (3.7%) of the patients, and major thromboembolic complications occurred in four (13.8%). None occurred in those treated with concomitant heparin sodium. Better patency and fewer complications were also observed in limbs that were not acutely threatened, when IA streptokinase infusion was completed within 48 hours, and when the occluded segment and runoff vessels were rendered widely patent by IA streptokinase, with the aid of balloon angioplasty when necessary (five [36%] of 14).

Arteries↗

Effects of serum on C3b-stimulated release of prostaglandins and thromboxane B2 from human monocytes.

Previous studies have demonstrated that C3b stimulates the release of prostaglandin E and thromboxane B2 from human monocytes in serum-free cultures. We have examined the influence of serum on this phenomenon, and have found that addition of normal human serum or fetal calf serum to such cultures at concentrations of 0.1-5.0% results in enhanced release of both eicosanoids in C3b-stimulated cultures, while release in control cultures is unaffected or, in many cases, inhibited. Addition of human serum albumin or transferrin to serum-free cultures is not sufficient to mimic the serum effect. Fetal calf and normal human sera increase the efficacy of C3b in stimulating release of both prostaglandin E and thromboxane B2 at all but the lowest doses tested, but fail to significantly alter the kinetics or release or the acquired unresponsiveness of monocytes to C3b that occurs following culture periods of greater than 24 h. By preincubation of purified C3b in normal human serum, it can be shown that such serum degrades C3b stimulatory activity, but at a rate that is slow enough to permit expression of its activity when added at the beginning of the culture period. In contrast, the stimulatory activity of E. coli lipopolysaccharide is unaffected by pretreatment with serum. Thus, in contrast to the inhibitory effect of serum on the activity of C3 fragments in in vitro assays of certain mononuclear cell functions such as lymphocyte transformation and antibody production, serum enhances the ability of C3b to stimulate monocyte prostaglandin release.

Animals↗

The efficacy of dextran 40 in preventing early postoperative thrombosis following difficult lower extremity bypass.

In a randomized, multicenter trial the efficacy of intravenous dextran 40 (D-40; Rheomacrodex) in preventing early postoperative thrombosis was tested in the following difficult lower extremity bypasses: (1) femoropopliteal with poor runoff using autologous vein (AV), (2) femoropopliteal using grafts other than AV, (3) single or sequential bypasses to infrapopliteal arteries, and (4) the above-mentioned bypasses with adjunctive procedures that destroy adjacent endothelial surfaces (e.g., thrombectomy and endarterectomy). Five units of D-40 was administered to the experimental group at 75 to 100 ml/hr, two during and immediately after operation and one each 3 days postoperatively. Antiplatelet drugs were withheld until 1 week after surgery. The overall 1-week occlusion rate was 6.9% (5 of 73) with D-40 and 20.5% (17 of 83) for controls, which is statistically significant. Particularly significant was the difference in group 3: 0% (0 of 28) for D-40 and 27.8% (10 of 36) for controls. In the same time period there were no occlusions in group I and only one occlusion each with AV grafts in both D-40 and control groups, 2.6% (1 of 38). When grafts other than AV were used, the occlusion rate was significantly lower at 1 week for D-40, 11.4% (4 of 35), than controls, 35.6% (16 of 45). By 1 month the protective effect of D-40 was partially lost--15.3% (11 of 72) for D-40 and 20.7% (17 of 82) for controls (no statistical significance). Use of antiplatelet drugs during this period had no discernible effect.

Blood Vessel Prosthesis↗

Immunoregulation of the mixed lymphocyte reaction by macrophage-derived factors: functional and biochemical separation of enhancing and inhibitory factors.

Positive and negative immunoregulation of the mixed lymphocyte reaction (MLR) occurred through release of macrophage(MO)-derived, soluble enhancing and inhibitory factors. Macrophages, sonicated or cultured in low concentrations, produced nondialyzable, soluble factor(s) capable of enhancing the MLR; but the culture supernatant had no biologically detectable levels of Interleukin 1, Interleukin 2, or interferon. Production of enhancing supernatants was not affected by pretreatment of MO with trypsin or anti-Thy 1 antibody plus complement. In contrast, MO cultured in high concentrations yielded an inhibitory supernatant factor(s) which suppressed MLR reactivity even when MO were cultured in the presence of indomethacin. Culturing MO with proteolytic enzyme inhibitors increased the yields of the inhibitory and enhancing factors. Both factors were precipitable with ammonium sulfate and could be separated into several biologically active fractions using anion exchange chromatography.

Animals↗

Diagnosis of brain death by common carotid artery velocity waveform analysis.

In addition to neurologic criteria, some test of cessation of brain blood flow is recommended before diagnosing "brain death." Cerebral arteriography, radionuclide scintigraphy, and contrast computed axial tomography, though reliable, possess significant practical limitations. Analysis of the dimensions and contours of common carotid Doppler velocity tracings of brain-dead patients has identified qualitative and quantitative differences not only from normal subjects, but also from patients with complete atheromatous carotid occlusion and from those unconscious after brain injury. Though accurate separation was initially made using computer-assisted classification function analysis, a simplified algorithmic approach using only three velocity waveform variables has been developed without loss of accuracy. The speed, simplicity, portability, and inexpensiveness of this approach commend its use.

Adult↗

Thymectomy for myasthenia gravis: a changing perspective.

A review of 28 patients with nonthymomatous myasthenia gravis who underwent thymectomy at the University of Colorado Health Sciences Center, Denver, from 1967 to 1979 shows significant stepwise changes in management and results. Comparison among three periods--period 1 (1967 to 1971), when thymectomy competed with prednisone,which were not given in the perioperative period (seven patients); period 2 (1974 to 1976), when thymectomy was followed by six months of prednisone therapy (ten patients); and period 3 (1977 to 1979), when prednisone was also given to prepare the patients for thymectomy (11 patients)--demonstrated a decreasing need for tracheostomy and respiratory support (86% v 10% v 0%), shorter stay in the intensive care unit (21 v 3 v 1 day), and shorter hospitalization (36 v 13 v 4 days). Remission or marked amelioration of symptoms occurred in 56% of group 1 and 100% of both groups 2 and 3. Earlier application of thymectomy and its performance through a short upper transverse sternotomy incision also contributed to the improved results.

Adult↗

Traumatic thrombosis of the inferior vena cava.

A case of a 21-year-old male with blunt abdominal trauma and subsequent acute thrombosis of the inferior vena cava, presenting as abdominal pain, is reported. The apparent mechanism of proximal inferior vena cava thrombosis with distal extension into the iliac veins differs from that suggested in earlier reports. Resolution of symptoms was achieved by heparinization and bedrest alone, in spite of thrombus in the suprarenal vena cava.

Abdominal Injuries↗

Combining segmental systolic pressures and plethysmography to diagnose arterial occlusive disease of the legs.

Computer-assisted analysis of the data from SLP and PVR study of the legs with angiographically documented arterial occlusive disease, projected against a background of normal limbs, was used to assess the diagnostic value of each study, including its individual variables, as well as their varied combinations. The accuracy of both SLP and PVR interpretation was significantly improved by standarization against brachial values, but even with the aid of superimposed physician interpretation, each only reached 86 per cent when cases with multilevel occlusive disease were included. The combination of these two studies, which compensate for each other's limitations in several respects, achieved an overall accuracy of 97 per cent, with no errors observed in diagnosing either normal limbs or those with isolated occlusive disease. Objective diagnostic criteria for both SLP and PVR interpreatation are presented in algorithmic form.

Arterial Occlusive Diseases↗

Control of vasospasm following trauma and microvascular surgery.

Vasospasm may result in marked reduction of blood flow through injured or revascularized tissues. Neurogenic vasoconstriction is mediated through sympathetic pathways which may be blocked by long-acting local anesthetics resulting in optimal intravascular pressures and elevated flow. An experimental study performed on normal human volunteers has shown that distal sympathetic blockade using Bupivacaine protects the digital circulation against vasospasm elicited by a strong stimulus for a minimum of 7 to 8 hours. A catheter, placed adjacent to the median or ulnar nerve at the wrist level after digital microvascular reconstruction, facilitates continuous Bupivacaine sympathetic blockade. This technique has been used clinically and appears to improve the circulation of replanted or revascularized tissues and protects against vasospasm caused by a variety of stimuli.

Blood Pressure↗

Delayed-onset pulmonary insufficiency in primates resuscitated from hemorrhagic shock.

Forty-one unanesthetized cynomolgus monkeys were subjected to 2 hours of hemorrhagic hypotension at various mean arterial pressures (MAP) between 40 and 60 mm Hg. Resuscitation and maintenance of MAP were provided by lactated Ringer's solution and homologous blood. Thirty-eight per cent (57% of those surviving greater than 24 hours) developed a delayed-onset (18 to 24 hours) pulmonary insufficiency in spite of good urinary output, and which did not respond to furosemide. The group in which this caused death (24%) showed significantly decreased PaO2, PaCO2, dynamic compliance, and FECO2, and increased minute volume, Qs/Qt, pulmonary artery pressure, and VD/VT before death. Their lungs were heavier, with abnormal pressure/volume curves and increased minimum surface tension. During the entire post-resuscitation phase, this group remained in a high-output, low-resistance hemodynamic state in contract to survivors and those dying of shock. The implications regarding current practices of monitoring and resuscitating patients with traumatic shock are discussed.

Animals↗

Function of color in learning an assembly task by learning disabled adolescents.

This study examined the effect of color on responses by 20 14- to 17-yr-old learning disabled students in a probation facility to a puzzle assembly task. Prior to the task, one of two randomly constituted groups of 10 viewed a black and white film illustrating a puzzle assembly, the other group viewed an identical film of the puzzle being assembled in color. Analysis indicated that color does not enhance performance in some cases and may inhibit performance.

Adolescent↗

[Intravascular persistence, tissue storage and excretion of hydroxyethyl starch (HAS)].

Hydroxyethyl starch is a derivative of amylopectin, the branched glycogen-like alpha-1,4-glucose polymer, the amylase hydrolysis of which is retarded by hydroxyethylation. If 70 to 90 per cent of the glucose polymer units contain hydroxyethyl groups, the intravascular persistence and urinary excretion of hydroxyethyl starch of a molecular weight of 435,000 is similar to that of Dextran 70. Hydroxyethyl starch and Dextran 70 are stored briefly in reticuloendothelial and hepatic cells, and cause swelling and vacuolation of renal tubules with little alteration of renal function. Elimination of hydroxyethyl starch from sites of tissue storage is much faster than elimination of the non-metabolized polymers acacia and polyvinylpyrrolidone. The distribution and excretion kinetics of hydroxyethyl starch are thus appropriate for a plasma substitute.

Animals↗

Verbal and nonverbal interaction of mothers with their down's syndrome and nonretarded infants.

While it appears probable that parental expectancies due to early knowledge of the condition of Down's syndrome in infants affects parent-child interactions, little data are available showing how interactions are affected. In an observational, laboratory-based study, we compared verbal and nonverbal interactions between 10 mothers and their Down's syndrome infants and 10 mothers and their nonretarded infants. Although there was no difference between the groups in mothers' language complexity, mothers of Down's syndrome children spoke at a significantly faster rate. Observational measures of infants showed that Down's syndrome babies smiled and vocalized less, but mothers in the two groups failed to differ significantly on the nonverbal interactional behavior observed. The results were discussed in relation to the conclusions of other investigators who have speculated that language delays in Down's syndrome children may be due in part to differences in the environment provided by caregivers.

Adult↗