Hindbrain Administration of Oxytocin Reduces Food Intake, Weight Gain and Activates Catecholamine Neurons in the Hindbrain Nucleus of the Solitary Tract in Rats

Existing studies show that CNS oxytocin (OT) signaling is important in the control of energy balance, but it is unclear which neurons may contribute to these effects. Our goals were to examine (1) the dose-response effects of acute OT administration into the third (3V; forebrain) and fourth (4V; hindbrain) ventricles to assess sensitivity to OT in forebrain and hindbrain sites, (2) the extent to which chronic 4V administration of OT reduces weight gain associated with the progression of diet-induced obesity, and (3) whether nucleus tractus solitarius (NTS) catecholamine neurons are downstream targets of 4V OT. Initially, we examined the dose-response effects of 3V and 4V OT (0.04, 0.2, 1, or 5 μg). 3V and 4V OT (5 μg) suppressed 0.5-h food intake by 71.7 ± 6.0% and 60 ± 12.9%, respectively. 4V OT (0.04, 0.2, 1 μg) reduced food intake by 30.9 ± 12.9, 42.1 ± 9.4, and 56.4 ± 9.0%, respectively, whereas 3V administration of OT (1 μg) was only effective at reducing 0.5-h food intake by 38.3 ± 10.9%. We subsequently found that chronic 4V OT infusion, as with chronic 3V infusion, reduced body weight gain (specific to fat mass) and tended to reduce plasma leptin in high-fat diet (HFD)-fed rats, in part, through a reduction in energy intake. Lastly, we determined that 4V OT increased the number of hindbrain caudal NTS Fos (+) neurons (156 ± 25) relative to vehicle (12 ± 3). The 4V OT also induced Fos in tyrosine hydroxylase (TH; marker of catecholamine neurons) (+) neurons (25 ± 7%) relative to vehicle (0.8 ± 0.3%). Collectively, these findings support the hypothesis that OT within the hindbrain is effective at reducing food intake, weight gain, and adiposity and that NTS catecholamine neurons in addition to non-catecholaminergic neurons are downstream targets of CNS OT.

Visitation policies at NCI-designated comprehensive cancer centers during the COVID-19 pandemic

Purpose

Family/caregiver visitation provides critical support for patients confronting cancer and is associated with positive outcomes. However, the COVID-19 pandemic brought historic disruptions including widespread visitation restrictions. Here, we characterize in-depth the visitor policies of NCI-designated comprehensive cancer centers (CCCs) and analyze geographic/temporal patterns across CCCs.

Methods

The public-facing CCC websites, including archived webpages, were reviewed to abstract initial visitation policies and revisions, including end-of-life (EoL) exceptions and timing of visitation restrictions relative to regional lockdowns. Chi-squared and Fisher’s exact tests were employed to analyze associations between geographic region, timing, and severity of restrictions.

Results

Most CCCs (n=43, 86%) enacted visitation restrictions between March 15 and April 15, 2020. About half barred all visitors for COVID-negative inpatients (n=24, 48%) or outpatients (n=26, 52%). Most (n=36, 72%) prohibited visitors for patients with confirmed/suspected COVID-19. Most (n=40, 80%) published EoL exceptions but the specifics were highly variable. The median time from initial restrictions to government-mandated lockdowns was 1 day, with a wide range (25 days before to 26 days after). There was no association between timing of initial restrictions and geographic location (p=0.14) or severity of inpatient policies (p=1.0), even among centers in the same city. Outpatient policies published reactively (after lockdown) were more restrictive than those published proactively (p=0.04).

Conclusion

CCCs enacted strict but strikingly variable COVID-19 visitation restrictions, with important implications for patients/families seeking cancer care. A unified, evidence-based approach to visitation policies is needed to balance proven infection control measures with the needs of patients and families.

Mapping Molecular Datasets Back to the Brain Regions They are Extracted from: Remembering the Native Countries of Hypothalamic Expatriates and Refugees

This article focuses on approaches to link transcriptomic, proteomic, and peptidomic datasets mined from brain tissue to the original locations within the brain that they are derived from using digital atlas mapping techniques. We use, as an example, the transcriptomic, proteomic and peptidomic analyses conducted in the mammalian hypothalamus. Following a brief historical overview, we highlight studies that have mined biochemical and molecular information from the hypothalamus and then lay out a strategy for how these data can be linked spatially to the mapped locations in a canonical brain atlas where the data come from, thereby allowing researchers to integrate these data with other datasets across multiple scales. A key methodology that enables atlas-based mapping of extracted datasets-laser-capture microdissection-is discussed in detail, with a view of how this technology is a bridge between systems biology and systems neuroscience.

Broadened Allocation of Pancreas Transplants Across Compatible ABO Blood Types

BACKGROUND

Current Organ Procurement and Transplantation Network (OPTN) policy restricts certain blood type-compatible simultaneous pancreas and kidney (SPK) transplants. Using the Kidney Pancreas Simulated Allocation Model, we examined the effects of 5 alternative allocation sequences that allowed all clinically compatible ABO transplants.

METHODS

The study cohort included kidney (KI), SPK, and pancreas alone (PA) candidates waiting for transplant for at least 1 day between January 1, 2010, and December 31, 2010 (full cohort), and kidneys and pancreata recovered for transplant during the same period. Additionally, because the waiting list has shrunk since 2010, the study population was reduced by random sampling to match the volume of the 2015 waiting list (reduced cohort).

RESULTS

Compared with the current allocation sequence, R4 and R5 both showed an increase in SPK transplants, a nearly corresponding decrease in KI transplants, and virtually no change in PA transplants. Life-years from transplant and median years of benefit also increased. The distribution of transplants by blood type changed, with more ABO:A, B, and AB transplants performed, and fewer ABO:O across all transplant types (KI, SPK, PA), with the relative percent changes largest for SPK.

DISCUSSION

Broadened ABO compatibility allowances primarily benefitted SPK ABO:A and AB candidates. ABO:O candidates saw potentially reduced access to transplant. The simulation results suggest that modifying the current allocation sequence to incorporate broadened ABO compatibility can result in an increase in annual SPK transplants.

Chronic CNS oxytocin signaling preferentially induces fat loss in high-fat diet-fed rats by enhancing satiety responses and increasing lipid utilization

Based largely on a number of short-term administration studies, growing evidence suggests that central oxytocin is important in the regulation of energy balance. The goal of the current work is to determine whether long-term third ventricular (3V) infusion of oxytocin into the central nervous system (CNS) is effective for obesity prevention and/or treatment in rat models. We found that chronic 3V oxytocin infusion between 21 and 26 days by osmotic minipumps both reduced weight gain associated with the progression of high-fat diet (HFD)-induced obesity and elicited a sustained reduction of fat mass with no decrease of lean mass in rats with established diet-induced obesity. We further demonstrated that these chronic oxytocin effects result from 1) maintenance of energy expenditure at preintervention levels despite ongoing weight loss, 2) a reduction in respiratory quotient, consistent with increased fat oxidation, and 3) an enhanced satiety response to cholecystokinin-8 and associated decrease of meal size. These weight-reducing effects persisted for approximately 10 days after termination of 3V oxytocin administration and occurred independently of whether sucrose was added to the HFD. We conclude that long-term 3V administration of oxytocin to rats can both prevent and treat diet-induced obesity.

Abnormally elevated serum hCG in a patient with end-stage renal disease seeking abortion: to be expected or a cause for concern? A case report

A patient with end-stage renal disease on hemodialysis was referred to our abortion clinic with a concern for molar pregnancy. By 12 weeks, her human chorionic gonadotropin (hCG) level was over 500,000. A review of the literature demonstrates that elevated hCG should be expected in this population and should not alter care.

Hindbrain oxytocin receptors contribute to the effects of circulating oxytocin on food intake in male rats

Oxytocin (OT)-elicited hypophagia has been linked to neural activity in the nucleus of the solitary tract (NTS). Because plasma OT levels increase after a meal, we hypothesized that circulating OT acts at both peripheral and hindbrain OT receptors (OTRs) to limit food intake. To initially determine whether circulating OT inhibits food intake by acting at hindbrain OTRs, we pretreated rats with an OTR antagonist administered into the fourth ventricle (4V) followed by either central or systemic OT administration. Administration of the OTR antagonist into the 4V blocked anorexia induced by either 4V or i.p. injection of OT. However, blockade of peripheral OTRs also weakened the anorectic response to ip OT. Our data suggest a predominant role for hindbrain OTRs in the hypophagic response to peripheral OT administration. To elucidate central mechanisms of OT hypophagia, we tested whether OT activates NTS catecholaminergic neurons. OT (ip) increased the number of NTS cells expressing c-Fos, of which 10%-15% were catecholaminergic. Furthermore, electrophysiological studies in mice revealed that OT stimulated 47% (8 of 17) of NTS catecholamine neurons through a presynaptic mechanism. However, OT-elicited hypophagia did not appear to require activation of α1-adrenoceptors, and blockade of glucagon-like peptide-1 receptors similarly did not attenuate anorexia induced by OT. These findings demonstrate that OT elicits satiety through both central and peripheral OTRs and that although catecholamine neurons are a downstream target of OT signaling in the NTS, the hypophagic effect is mediated independently of α1-adrenoceptor signaling.

Familial aggregation of sarcoidosis. A case-control etiologic study of sarcoidosis (ACCESS)

Despite reports of familial clustering of sarcoidosis, little empirical evidence exists that disease risk in family members of sarcoidosis cases is greater than that in the general population. To address this question, we estimated sarcoidosis familial relative risk using data on disease occurrence in 10,862 first- and 17,047 second-degree relatives of 706 age, sex, race, and geographically matched cases and controls who participated in the multicenter ACCESS (A Case-Control Etiology Study of Sarcoidosis) study from 1996 to 1999. Familial relative risk estimates were calculated using a logistic regression technique that accounted for the dependence between relatives. Sibs had the highest relative risk (odds ratio [OR] = 5.8; 95% confidence interval [CI] = 2.1-15.9), followed by avuncular relationships (OR = 5.7; 95% CI = 1.6-20.7), grandparents (OR = 5.2; 95% CI = 1.5-18.0), and then parents (OR = 3.8; 95% CI = 1.2-11.3). In a multivariate model fit to the parents and sibs data, the familial relative risk adjusted for age, sex, relative class, and shared environment was 4.7 (95% CI = 2.3-9.7). White cases had a markedly higher familial relative risk compared with African-American cases (18.0 versus 2.8; p = 0.098). In summary, a significant elevated risk of sarcoidosis was observed among first- and second-degree relatives of sarcoidosis cases compared with relatives of matched control subjects.

Effectiveness of neomycin/polymyxin bladder irrigation to treat resistant urinary pathogens in those with spinal cord injury

Individuals with spinal cord injury (SCI) will sometimes develop bacterial organisms in the bladder that are resistant to oral antibiotics. This study evaluated the effectiveness of a 5-day course of intermittent neomycin/polymyxin bladder irrigation at eradicating or changing the bacterial sensitivity from parenteral to oral antibiotics. A chart review of individuals with SCI who were treated with neomycin/polymyxin bladder irrigations was performed. Inclusion criteria included the use of an indwelling catheter and the presence of asymptomatic bacteria resistant to oral antibiotics. The most common reason for treatment was eradication of resistant organisms prior to urologic testing. Bladder irrigation consisted of 3 rinses with 30 ml 3 times a day for 5 days. Pre- and post-urine samples were compared for white blood cells (WBCs), colony count and culture, and sensitivity. Chi-square tests were used to determine whether the proportion of changes in resistance or sensitivities was different from zero. The Wilcoxon Signed Rank Test was used to determine differences in bacteria, colony counts, and WBCs. Ten individuals were identified. A total of 12 neomycin/polymyxin irrigation treatments were evaluated because 2 individuals had a second series of irrigations at least 6 months apart. Nine of the 12 (75%) were considered to have successful irrigations because there was a change in culture sensitivity so that oral antibiotics would be effective post irrigation. This was statistically significant. There were no significant changes in colony counts or the number of WBCs. The authors concluded that while neomycin/polymyxin bladder irrigation did not change the type of organism, it was effective in changing resistance of most organisms. Individuals could then be treated with oral rather than intravenous or intramuscular antibiotics. Further work is needed to determine whether other variables, such as increased length of time of irrigation or increased frequency of irrigations, may actually eradicate the organisms.

The electrocardiogram predicts one-year outcome of patients with unstable angina and non-Q wave myocardial infarction: results of the TIMI III Registry ECG Ancillary Study. Thrombolysis in Myocardial Ischemia

OBJECTIVES

We sought to determine the prognostic value of the admission electrocardiogram (ECG) in patients with unstable angina and non-Q wave myocardial infarction (MI).

BACKGROUND

Although the ECG is the most widely used test for evaluating patients with unstable angina and non-Q wave MI, little prospective information is available on its value in predicting outcome in the current era of aggressive medical and interventional therapy.

METHODS

ECGs with the qualifying episode of pain were analyzed in patients enrolled in the Thrombolysis in Myocardial Ischemia (TIMI) III Registry, a prospective study of patients admitted to the hospital with unstable angina or non-Q wave MI.

RESULTS

New ST segment deviation > or = 1 mm was present in 14.3% of 1,416 enrolled patients, isolated T wave inversion in 21.9% and left bundle branch block (LBBB) in 9.0%. By 1-year follow-up, death or MI occurred in 11% of patients with > or = 1 mm ST segment deviation compared with 6.8% of patients with new, isolated T wave inversion and 8.2% of those with no ECG changes (p < 0.001 when comparing ST with no ST segment deviation). Two other high risk groups were identified: those with only 0.5-mm ST segment deviation and those with LBBB, whose rates of death or MI by 1 year were 16.3% and 22.9%, respectively. On multivariate analysis, ST segment deviation of either > or = 1 mm or > or = 0.5 mm remained independent predictors of death or MI by 1 year.

CONCLUSIONS

The admission ECG is very useful in risk stratifying patients with non-Q wave MI. The new criteria of not only > or = 1-mm ST segment deviation but also > or = 0.5-mm ST segment deviation or LBBB identify high risk patients, whereas T wave inversion does not add to the clinical history in predicting outcome.

Hemorrhagic events during therapy with recombinant tissue plasminogen activator, heparin, and aspirin for unstable angina (Thrombolysis in Myocardial Ischemia, phase IIIB trial)

This study assesses the effects of invasive procedures, hemostatic and clinical variables, and doses of recombinant tissue plasminogen activator (t-PA) on hemorrhagic events in the thrombolysis in myocardial ischemia (TIMI), phase 1B clinical trial (n = 1,425). Patients seen within 24 hours of the onset of ischemic chest pain at rest were randomized using a 2 x 2 factorial design for comparison of: (1) t-PA versus placebo as initial therapy, and (2) an early invasive (coronary arteriography with percutaneous angioplasty, if feasible) versus an early conservative strategy (coronary arteriography followed by revascularization if initial medical therapy failed). All patients received conventional medication for acute ischemic syndromes, including heparin, aspirin, beta blockers, nitrates, and calcium antagonists. The total dose of t-PA or placebo was 0.8 mg/kg, up to a maximum dose of 80 mg. In patients treated with t-PA, major and minor hemorrhagic events were more common than among those assigned to placebo (p < 0.001). Patients assigned to the invasive strategy arm had a higher hemorrhagic event rate than the noninvasive strategy, although the difference was not significant (p = 0.026). Patients > 75 years of age had higher intracranial hemorrhage rates than those < 75 years of age (6.7% vs 0.2%, respectively, p = 0.01). Major hemorrhagic events were more common in patients with higher heparin levels (p < 0.001), higher peak D-dimer levels (p = 0.007), and lower nadir fibrinogen levels (p = 0.005). Thus, increased morbidity due to hemorrhagic complications is associated with the use of t-PA, increased age, and selected hemostatic measures. Comparison to TIMI II demonstrates a significant association between the dose of t-PA and hemorrhagic complications.

Colour duplex ultrasound: a screening modality for femoropopliteal disease in patients with intermittent claudication

In patients presenting with intermittent claudication, Colour Duplex Ultrasound (CDU) examination of the femoro-popliteal segment has been proposed as a screening modality. Those patients with atheromatous lesions suitable for percutaneous transluminal angioplasty (PTA) could proceed to diagnostic angiography. Patients with long segment occlusive disease demonstrated by CDU, who were not considered suitable candidates for surgery, would not require angiographic examination. This prospective study was performed on 46 limbs in 25 consecutive patients who presented for investigation of claudication. There was close correlation between the two methods in the demonstration of high-grade stenoses and occluded segments. Using angiography as the 'gold standard' this study indicated a diagnostic accuracy for CDU of 93% with a sensitivity of 89% and a specificity of 95%. Angiography tended to show longer occluded segments than CDU. Colour Duplex Ultrasound shows promise as a screening investigation in patients with intermittent claudication to detect lesions that may be suitable for PTA.

Carotid-subclavian bypass: a twenty-two-year experience

PURPOSE

A retrospective review of 124 patients who underwent carotid-subclavian bypass from 1968 to 1990 was done to assess primary patency and symptom resolution.

METHODS

Preoperative data included age, atherosclerosis risk factors, and indications for surgery. Perioperative data included mortality and morbidity rates and graft conduit. Postoperative follow-up assessed graft patency, resolution of symptoms, and late survival.

RESULTS

Age ranged from 42 to 78 years (mean 57.9). Indications for surgery were vertebrobasilar insufficiency in 24 (19%), extremity ischemia (EI) in 33 (27%), transient ischemic attacks (TIAs) in 13 (11%), both vertebrobasilar insufficiency and EI in 31 (25%), and both TIAs and EI in 23 (18%) patients. Graft conduits were polytetrafluoroethylene in 44 (35%) and Dacron in 80 (65%) cases. Concomitant ipsilateral carotid endarterectomy was done in 32 (26%) patients. During operation, death occurred in one patient (0.8%), and complications occurred in 10 (8%) patients. Thirty-day primary patency and symptom-free survival rates were 100%. Long-term follow-up ranging from 5 to 164 months was available for the 60 cases done between 1975 and 1990. Three grafts occluded at 30, 36, and 51 months after surgery for a primary patency rate of 95% at 5 and 10 years. Twenty-two patients died, yielding survival rates of 83% at 5 years and 59% at 10 years. Symptom recurrence occurred in six (10%) patients from 9 to 66 months after surgery. The symptom-free survival rate was 98% at 1 year, 90% at 5 years, and 87% at 10 years. Symptoms recurred in three patients with occluded grafts and three with patent grafts. The preoperative symptoms of drop attacks and TIAs did not recur. EI recurred in 5% and was noted only in the presence of graft occlusion. Dizziness recurred in 17% of patients admitted with this symptom and was observed despite graft patency.

CONCLUSION

Carotid-subclavian bypass was a safe and durable procedure for relief of symptomatic occlusive disease of the subclavian artery. Long-term symptomatic relief appeared particularly likely in patients with drop attacks or upper extremity ischemia.

Wound healing in forefoot amputations: the predictive value of toe pressure

A retrospective study of 136 men undergoing forefoot amputation was done to test the hypothesis that preoperative toe pressure (TP) could predict the likelihood of wound healing. Demographic data included age, smoking history, diabetes mellitus (DM), hypertension, hyperlipidemia, and coronary artery disease. Clinical data included infection, preoperative arterial Doppler data, TP, wound disposition, concomitant revascularization (REV), and healing outcome. Among diabetics, no primary amputation healed with a preoperative TP < 38 mm Hg. Among REV diabetics, no healing occurred with a TP < 40 mm Hg after bypass, but no failures occurred either with a TP > 68 mm Hg or an increase in TP > or = 30 mm Hg after bypass. Nondiabetic patients exhibited no threshold TP values. Univariate analysis revealed that DM and REV were significantly different in the healed (N = 83) vs. nonhealed (N = 53) populations (p = 0.027 and 0.034). In healed patients mean TP (71.8 +/- 3.5 mm Hg SEM) was significantly higher than in nonhealed patients (45.1 +/- 4.3 mm Hg SEM, p = 0.000). Logistic regression analysis identified age > 60 years (p = 0.03), DM (p = 0.003), preoperative TP (p < 0.001), and REV (p < 0.001) as significant independent predictors of forefoot amputation healing. Healing probability was calculated and plotted vs. TP for subpopulations based on age, DM, and REV status for both primary forefoot amputation and amputation concomitant with bypass. In this study population, therefore, preoperative TP appeared to be a useful clinical tool for predicting the healing potential of both primary forefoot amputations and amputations plus concomitant bypass for any given patient.

Results of venous thrombectomy in the treatment of deep vein thrombosis

Despite the infrequent use in the United States, venous thrombectomy seems to have a beneficial effect in carefully selected patients with acute iliofemoral thrombosis. The final decision to proceed with venous thrombectomy should be based on a balanced analysis of two factors--the characteristics of the thrombus and the characteristics of the patient. First, the diagnosis of acute deep vein thrombosis must be unequivocally established preoperatively. Accurate anatomic localization is usually achieved with venography, but duplex Doppler examination may be sufficient in selected instances. Second, the distribution of thromboses should be determined. Venous thrombectomy should be considered only in instances of deep vein thrombosis involving the iliofemoral venous segment. Thrombectomy for venous thrombosis below the inguinal ligament has not been consistently beneficial. Third, the age of the thrombus should be estimated. This can usually be accomplished though a careful analysis of the clinical history, but may be corroborated by duplex Doppler or venographic features of the thrombus. Venous thrombectomy should rarely be attempted if the age of the thrombus is thought to be greater than 72 hours. Unfortunately, in many instances the clinical history substantially underestimates the actual age of the underlying thrombus. Fourth, patient characteristics must be assessed preoperatively. While venous thrombectomy can usually be accomplished using local anesthesia, substantial shifts in fluid and acid base balance may be poorly tolerated by elderly, frail patients. In the setting of widespread metastatic disease, rethrombosis rates may be too high to justify thrombectomy in some patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Recurrent intracaval renal cell carcinoma: the role of intravascular ultrasonography

The presence of extension into the vena cava does not preclude curative resection for extensive renal cell carcinomas. However, preoperative assessment of (1) the proximal extent of the tumor and (2) the degree of adherence within the vena cava is necessary to plan operative strategies. The following report describes the successful use of intravascular ultrasonography in the preoperative evaluation of a patient with recurrent renal cell carcinoma with vena caval extension.

Traumatic left renal artery stenosis managed with splenorenal bypass: case report

Splenorenal arterial bypass is a well established technique for the treatment of left renal artery occlusive disease. The following is a case report of the use of splenorenal bypass in the management of concomitant traumatic left renal artery intimal dissection and splenic laceration. Arteriographic and intraoperative findings are presented as well as a review of pertinent literature.

Is routine duplex examination after carotid endarterectomy justified?

Routine follow-up of patients after carotid endarterectomy with duplex scanning is commonly practiced, yet the clinical significance of identifying those with asymptomatic restenosis is unclear. To address this issue we reviewed 120 consecutive patients who underwent 143 carotid endarterectomies from August 1983 to December 1988. One hundred one patients (118 operations) were available for clinical follow-up, and the overall incidence of recurrent symptoms was 6% (6/101). Sixty-three of these patients (78 carotid endarterectomies) had postoperative duplex examination. Two had evidence of residual disease from the time of surgery and were not included in further analysis. Significant recurrent stenosis (greater than 50% diameter reduction) developed in 14 of the remaining 76 arteries (18.2%). Twelve of 14 stenoses remained asymptomatic during follow-up from 18 to 72 months (mean 47.0 months) and did not undergo reoperation. Recurrent ipsilateral hemispheric symptoms developed in two patients with restenosis (14.3%). Four of the 62 arteries without significant recurrent stenosis developed ipsilateral symptoms (6.5%), but none required reoperation during follow-up from 1 to 71 months (mean 31.6 months). Life-table analysis showed no increased risk of transient ischemic attack, stroke, or death in patients with restenosis. This study supports regular clinical follow-up after carotid endarterectomy with emphasis on patient education in the recognition of symptoms. Although duplex scanning may be useful to follow known contralateral asymptomatic disease or evaluate those with recurrent symptoms, its routine use to identify patients with asymptomatic restenosis after carotid endarterectomy may be unnecessary.

Tissue plasminogen activator followed by percutaneous transluminal coronary angioplasty: one-year TIMI phase II pilot results. TIMI Investigators

The TIMI phase II pilot study enrolled 288 patients with acute myocardial infarction who were treated with recombinant tissue plasminogen activator (rt-PA) within 4 hours of symptom onset and who were assigned to coronary angioplasty of the infarct-related vessel 18 to 48 hours after rt-PA treatment. The patients were followed to ascertain (1) vital status; (2) whether they suffered a recurrent myocardial infarction; (3) whether they received coronary angioplasty or bypass grafting; and (4) whether they were rehospitalized for a cardiac event. Risk factors for these events or combination of these events were identified and reported. The estimated 6-week, 6-month, and 1-year cumulative event rate of death or myocardial infarction was 9.1 +/- 1.7%, 12.9 +/- 2.0%, and 13.6 +/- 2.0%, respectively. With the exception of repeat hospital admissions, most of the above cardiac events occurred early during the patients' follow-up course. Cox proportional hazard analyses revealed that continuing chest pain after rt-PA administration, history of congestive heart failure, low systolic blood pressure at the time of initial evaluation, and history of hypertension increased the risk of death or recurrent myocardial infarction, while a history of chest discomfort at baseline evaluation and older age was predictive of future hospitalization or a revascularization procedure.

Serial noninvasive studies do not herald postoperative failure of femoropopliteal or femorotibial bypass grafts

We performed a 5-year retrospective case-control study of 232 patients undergoing femoropopliteal (n = 188) or femorotibial (n = 44) bypass to determine if serial noninvasive studies herald postoperative graft failure. We correlated serial ankle/arm pressure indices (API) with graft patency. An interval drop in API of greater than or equal to 0.20 was considered hemodynamically significant, but interventional therapy was carried out only for clinically symptomatic graft failure and an API less than 0.20 above the preoperative value. The cumulative 5-year limb salvage rate was 82% and the patient survival was 63%. A significant drop in API did not correlate with cumulative 5-year graft patency. The 5-year cumulative primary graft patency rates were 60% and 62% in patients with stable and interval drops in API, respectively (Z = 0.15, p = N.S.) These results suggest that a significant drop in postoperative API does not predict patients with impending femoropopliteal or femorotibial graft failure. We believe that routine noninvasive surveillance and prophylactic intervention on detected asymptomatic lesions in leg bypass grafts may not be justified.

Plasma catecholamine concentration during and after aorto-femoral bypass grafting

Mean arterial plasma concentration of norepinephrine and epinephrine [NE + E], increased from 2.84 nM (post-induction) to 7.50 nM at the end of an approximately 4-hour operation for aortofemoral bypass grafting (plus unilateral lumbar sympathectomy) in 13 men. It increased to 18.25 nM during the first hour of recovery, and fell to 9.58 nM by the next morning. Thus during recovery, arterial [NE + E], by exceeding the minimum of 10.6 nM [NE] necessary for vasoconstriction, is a probable contributor to postoperative vasospasm as previously hypothesized.

Improvement of flow-cytometric detection of multidrug-resistant cells by cell-volume normalization of intracellular daunorubicin content

To improve the ability of flow cytometry to detect multidrug-resistant cells, we studied the extent to which cell volume heterogeneity accounts for the variance of intracellular daunorubicin (DNR) content. For P388 murine or HL-60 human leukemia cells exposed to DNR (1 micrograms/ml, 60 min), log intracellular DNR content varied in direct proportion to log cell volume measured by flow cytometry, with a correlation coefficient of .9. This relationship was confirmed by cell sorting based on intracellular DNR content with subsequent volume determination of the sorted cells. Normalization of intracellular DNR content for cell volume (thus obtaining intracellular DNR concentration) was accomplished by subtracting log cell volume from log intracellular DNR content for each cell. This resulted in a 34% decrease (range 23-58%) in standard deviation compared to DNR content measurements without volume normalization for all cell types tested. Following exposure to DNR (as above), intracellular DNR content of drug-sensitive P388 or HL-60 cells measured by flow cytometry was 12- and 8-fold greater than that of the multidrug-resistant sublines P388/ADR and HL-60/AR, respectively. However, because of the variance of intracellular DNR content, the predictive value of flow-cytometric determination of intracellular DNR content as a discriminant assay for detecting the frequency of drug-resistant cells in a mixed population was acceptable only when the frequency of resistant cells in the population exceeded 10%. In contrast, volume normalization of intracellular DNR content enhanced the ability of the flow-cytometric assay to discriminate resistant cells by 10-fold for P388 cells and 100-fold for HL-60 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation of highly multidrug-resistant P388 cells from drug-sensitive P388/S cells by flow cytometric cell sorting

To investigate the spontaneous frequency of occurrence of stable multidrug-resistant cells in a population of drug-sensitive cells, we exposed drug sensitive P388/S cells to daunorubicin (dnr) for 1 h, then used fluorescence-activated cell sorting based on intracellular dnr fluorescence to isolate cells within P388/S having different intracellular content of drug. One of the sort windows chosen (low dnr content sort window) isolated only P388/S cells with intracellular drug content equal to or less than that of the known multidrug-resistant subline P388/adr. This sort window constituted approximately 3% of P388/S cells with lowest dnr content. By such a procedure we were able, on one of seven attempts, to isolate and cultivate stable, highly multidrug-resistant cells (comparable to that of P388/adr) from the P388/S cells obtained from the low dnr-content sort window. Net growth of cells in culture was observed 15-20 days after sorting, indicating that of the P388/S cells collected from the low dnr-content sort window, very few were actually highly drug-resistant. On no occasion could resistant cells be cultivated from cells sorted from P388/S with higher dnr content, as would be expected if mutation to a multidrug-resistant phenotype had occurred as a result of exposure to drug. The resistant cells isolated from P388/S by sorting (called P388/LoSort) displayed low intracellular accumulation of dnr that was enhanced by verapamil, were cross-resistant to vincristine and actinomycin-D, and distinct from P388/S, possessed a 150- to 160-kD membrane species identified by Vinca alkaloid photoaffinity labeling.(ABSTRACT TRUNCATED AT 250 WORDS)

Human percutaneous laser angioplasty. Patient selection criteria and early results

Percutaneous transluminal laser angioplasty is a new method for treating atherosclerotic disease previously not amenable to routine percutaneous transluminal angioplasty techniques. Our results compared favorably with other clinical trials. Patient selection criteria include lesions in the superficial femoral or popliteal system not capable of being treated with routine percutaneous transluminal angioplasty. We think that these lesions include high-grade stenoses or short segmental occlusions. Heavily calcified vessels and long segment occlusions measuring greater than 12 cm in length are probably not amenable to percutaneous transluminal laser angioplasty. The long-term results of this form of therapy for peripheral vascular disease remain unknown.

Repair time for oncogenic transformation in C3H/10T1/2 cells subjected to protracted X-irradiation

With exponential cultures of C3H/10T1/2 cells, we have investigated the effect of X-ray dose protraction on oncogenic cell transformation in the dose range 0.25-2 Gy. Within a particular experiment a constant exposure time was used. In different experiments exposure time varied between 1 and 5h. Cell transformation was analysed using the linear-quadratic relation, gamma (D) = alpha 1D + alpha 2D2, between transformation frequency per surviving cell and X-ray dose. Based on values of the linear coefficients, we developed an empirical formula for relating slopes of dose induction curves obtained at high or reduced dose rate condition. Our estimate of repair half-time for cell transformation with 95 per cent confidence limits is 2.4 (1.8, 3.0) h.

Transsphincteric approach to lesions of the rectum

Transsphincteric posterior resection of villous adenomas and small carcinomas restored gastrointestinal continuity and preserved continence in 25 of 26 patients in this study. No patient had local recurrence. This procedure is suitable for villous tumors that are too high for transanal or too low for transabdominal resection, and for small mobile malignancies of the lower 5 cm of the rectum.

Angioscopically monitored saphenous vein valvulotomy

Angioscopy was used during in situ saphenous vein bypass grafting in seven patients. We were able to visualize valve incision, immediately identify and correct incomplete valvulotomy, identify side branches as potential arteriovenous fistulas, and assess distal anastomotic integrity. We encountered no retained valve cusps after angioscopy, as verified by Doppler ultrasound and completion angiography. Angioscopy verified distal anastomotic integrity in all patients with distal vein grafts large enough to accept the angioscope. Angioscopy requires minimal time, is relatively easy to use, serves as an adjunct to Doppler ultrasound and completion angiography, and has future potential as a therapeutic tool.

Metabolism of ara-C by blast cells from patients with ANLL

The dose-response relationship between extracellular concentration of cytosine arabinoside (ara-C) and intracellular formation of the putative active metabolites of ara-C [ara-C incorporation into DNA and intracellular pools of ara-C in triphosphate form (ara-CTP)] was investigated in blast cells obtained from patients with acute nonlymphocytic leukemia (ANLL) by exposing these cells in vitro to 10, 100, or 1,000 nmol/L of ara-C. We studied 23 untreated patients who subsequently achieved complete remission (CR) with a regimen using daunorubicin and conventional doses of ara-C (ara-C-sensitive group), and 30 patients judged to be ara-C-resistant either by failing initial induction therapy (16 patients) or by having relapsed on an ara-C-containing maintenance regimen (14 patients). In both patient groups, ara-C incorporation into DNA and intracellular ara-CTP both displayed statistically significant increases in response to increasing extracellular concentrations of ara-C (P = .0001 in both cases), with the rate of increase of ara-CTP greater than that of ara-C incorporation. Moreover, blast cells from all patients, even those who were most clinically resistant to ara-C, were able to form ara-CTP and to incorporate ara-C into DNA. Each tenfold increment in extracellular ara-C concentration caused an 8.5-fold increase in ara-CTP, but only a 3.6-fold increase in ara-C incorporation into DNA. Thus, the efficiency of incorporation of ara-C into DNA (defined as the ratio of ara-C incorporation to ara-CTP pools) decreased by 58% with each tenfold increment in the extracellular concentration of ara-C (P less than .0001), presumably as a result of the inhibitory effect of ara-CTP on DNA polymerase. Using an analysis of covariance, modest differences were found in the levels of the ara-C metabolite variables in the ara-C-sensitive group as compared with the resistant group. However, because there was considerable overlap in ara-C metabolite formation among the patient groups, it was not possible to predict clinical outcome by these in vitro assessments of ara-C metabolism.

111 In-labeled leukocytes in the detection of prosthetic vascular graft infections

Making a clinical diagnosis of infection in prosthetic vascular grafts is difficult but when undiagnosed, this condition has a high mortality rate. Using Indium-111-labeled white-blood cells, 30 scans were performed in 21 patients suspected of having a prosthetic graft infection. The diagnosis of infected graft was confirmed by surgery in all cases, and lack of infection was established by resolution of symptoms with conservative therapy. Twenty-four hour scans of autologous Indium-111 leukocytes were obtained, and correlative CT studies were done in 11 cases. There were 13 infected grafts at surgery (purulent material present), and scans were positive in all (100% sensitivity); of 17 scans, there were 15 true negatives and two false positives (88% specificity). Using the criteria of gas or fluid around the graft, the sensitivity of CT was only 37% in a small subset of these patients. One-half of the cases in which infection was suspected clinically had no infection and had negative scans. Various types of grafts and graft materials were used, and there was no correlation with presence or absence of infection on the basis of the type of graft. Extragraft infection sites were found in five patients. In conclusion, use of Indium-111 leukocytes has been found to be an accurate and valuable diagnostic method for evaluation of suspected prosthetic vascular graft infection, and to have higher diagnostic accuracy than CT.

A double beta-lactam combination versus an aminoglycoside-containing regimen as empiric antibiotic therapy for febrile granulocytopenic cancer patients

The double beta-lactam combination of moxalactam plus piperacillin was compared with the aminoglycoside-containing regimen of moxalactam plus amikacin in a prospective, randomized trial of empiric therapy for 302 febrile episodes in granulocytopenic cancer patients. The moxalactam/piperacillin regimen was found to be as effective as the moxalactam/amikacin regimen (70 percent overall responses); responses with moxalactam/piperacillin and moxalactam/amikacin were similar for microbiologically documented infections (24 of 37, 65 percent, versus 20 of 35, 57 percent), for the subgroup with bacteremias (19 of 32 versus 14 of 28), and for clinically documented infections (41 of 58, 71 percent, versus 40 of 48, 83 percent). Responses were similar also for bacteremia in patients with persistent, profound (less than 100/microliter) granulocytopenia. Among profoundly (less than 100/microliter) granulocytopenic patients with gram-negative bacteremia, an increase in the granulocyte count to more than 100/microliter during therapy and a peak bactericidal activity of 1:16 or more (the latter noted in seven of nine moxalactam/piperacillin trials and six of nine moxalactam/amikacin trials) correlated with a favorable clinical response in 85 percent (p less than or equal to 0.00003) and 92 percent (p less than or equal to 0.044), respectively. Although serious side effects were minimal with either regimen, the double beta-lactam combination was associated with significantly less frequent nephrotoxicity (two of 145 versus 12 of 130; p less than or equal to 0.003) and ototoxicity (none of 34 versus seven of 34; p less than or equal to 0.006). The double beta-lactam combination of moxalactam plus piperacillin was found to be as effective as moxalactam plus amikacin but to have significantly less nephro- and ototoxicity.

Platelet storage for 7 days in second-generation blood bags

Plastic storage bags designed to optimize O2 and CO2 transfer to preserve platelets for 7 days prior to transfusion were studied in vivo and in vitro. Platelets stored 7 days in second-generation CLX bags were compared to platelets stored 3 days in standard (CL-3861) 3-day storage bags and platelets transfused within 24 hours of collection. The CLX bags maintained concentrate pH at a mean of 6.85 +/- 0.03 (SEM) after 7 days, while in standard bags after 3 days of storage, the mean pH was 6.46 +/- 0.03. A smaller proportion of platelets stored 7 days in CLX bags were discarded because of a pH less than 6.0 compared to those stored 3 days in CL-3861 bags (10 vs 21%). Poststorage pH showed strong correlation with concentrate platelet count and weak correlation with concentrate white cell count in both bag types. There was no significant difference in the mean corrected platelet count increments between platelets stored 7 days in second generation CLX bags and those stored 3 days in CL-3861 bags (10,000 and 12,200 at 1 hour, and 7000 and 7500 at 24 hours, respectively) following transfusion to 16 thrombocytopenic recipients. However, transfusion of fresh platelets achieved mean corrected increments at both 1 and 24 hours posttransfusion that were higher than seen with either group of stored platelets (20,100 at 1 hour and 10,800 at 24 hours). Platelets can be stored 7 days in second-generation CLX blood bags with results comparable to those of platelets stored 3 days in standard bags.

Bronchial adenoma: a review of 51 patients

The cases of 51 patients with bronchial adenomas were reviewed. There were 43 bronchial carcinoids, 5 adenoid cystic carcinomas, 2 mixed tumors, and 1 mucoepidermoid carcinoma. The carcinoid group was divided into typical (31, 72%) and atypical (12, 28%) subgroups. Nine carcinoids (20%) were categorized as metastasizing adenomas; in this group, 7 lesions were atypical and 2 were typical. Thirty-two lobectomies, 7 bilobectomies, 8 pneumonectomies, 2 sleeve resections, and 2 tracheal resections were performed. Ten-year survival was 88% for patients with typical carcinoids and 59% for those with atypical carcinoids. In the group with adenoid cystic carcinoma, 1 patient died postoperatively, 1 had recurrence of the tumor, 2 were alive and free from disease 16 and 23 years later, and 1 died of heart disease at 11 years. The patient with mucoepidermoid carcinoma was alive without recurrence 15 years after operation. In conclusion, bronchial adenomas of the carcinoid type are potentially malignant. Their prognosis depends on the histology of the tumor, and on the presence of metastasis to the regional lymph nodes and distant organs.

Thymectomy for myasthenia gravis: 14-year experience

Forty-eight consecutive patients with myasthenia gravis (MG) attended by generalized weakness were treated by complete thymectomy, performed transsternally in 46 patients and through a left thoracotomy in two with thymomas. There were no operative deaths. A 12-year-old child with fulminating MG died of acute pneumonia shortly after hospital discharge. Of the remaining 47 evaluable patients, thymectomy resulted in complete remission in six, marked improvement with a reduced need for medication in 20, and mild improvement on the same dosage of medication in 18. Neither the age of the patient, nor the histopathology of the excised thymus, nor the postoperative change in acetylcholine receptor antibody titer were found to have a significant influence on the response to thymectomy. If the ten patients who were 20 years of age or younger were excluded, the patients with a shorter duration of MG achieved a better response to operation. The authors conclude that thymectomy is effective treatment for MG, regardless of the age of the patient or the type of thymic pathology.

Pharmacokinetics and dosage reduction of cis-diammine(1,1-cyclobutanedicarboxylato)platinum in patients with impaired renal function

cis-Diammine(1,1-cyclobutanedicarboxylato)platinum (CBDCA) is a nonnephrotoxic but myelosuppressive analogue of cisplatin (DDP) with greatly reduced protein binding and greatly increased renal excretion. Thus, CBDCA might produce undue toxicity in patients with decreased renal function. Twenty-two patients [14 females and 8 males; median age, 66 (range, 35 to 83); median Karnofsky performance status, 70 (range, 40 to 90)] with refractory tumors and renal dysfunction [creatinine clearance (CCr) 6 to 83 ml/min] were treated with 31 courses of i.v. bolus CBDCA every 4 to 5 weeks. Dosages were determined by pretreatment CCr. Patients with CCr greater than or equal to 40 ml/min received 400 mg/sq m; patients with CCr 20 to 39 ml/min received 250 mg/sq m; and patients with CCr 0 to 19 ml/min received 150 mg/sq m. Toxicities were assessed by weekly clinical and laboratory assessment. Responses were assessed in patients with measurable disease. Plasma pharmacokinetics and urinary excretion of total and ultrafilterable platinum were measured with flameless atomic absorption spectrometry. Observed toxicities were similar to those in patients with normal renal function. Myelosuppression, especially thrombocytopenia, was the major toxicity. Nausea and vomiting were mild to moderate. There was no ototoxicity, neurotoxicity, or nephrotoxicity or reduction in CCr due to CBDCA. Total body clearance of ultrafilterable platinum correlated highly with CCr. The percentage of reduction in platelet count correlated highly and linearly with the area under the curve (AUC) of plasma-ultrafilterable platinum. However, for any AUC, there was 17% greater platelet reduction in patients who had previously received extensive myelosuppressive chemotherapy than in nonpretreated patients. Since total body clearance is proportional to CCr, platelet reduction is proportional to AUC, and total body clearance = dosage/AUC, we have derived an equation to calculate a dosage that will produce a desired reduction in platelet count. Calculations for theoretical patients (both pretreated and nonpretreated) with CCr of 100 ml/min produce dosages very close to maximum tolerated dosages derived in actual Phase I trials. The actual clinical utility of these predictive equations must await validation in prospective studies with larger numbers of patients.

Nuclear cardiac ejection fraction and cardiac index in abdominal aortic surgery

Since atherosclerotic heart disease results in more than half of the perioperative deaths that follow abdominal aortic surgery, a prospective protocol was designed for preoperative evaluation and intraoperative hemodynamic monitoring. Twenty men who were prepared to undergo elective operation for aortoiliac occlusive disease (12 patients) and abdominal aortic aneurysm (eight patients) were evaluated with a cardiac scan and right heart catheterization. The night prior to operation, each patient received volume loading with crystalloid based upon ventricular performance curves. At the time of the operation, all patients were anesthetized with narcotics and nitrous oxide, and hemodynamic parameters were recorded throughout the operation. Aortic crossclamping resulted in a marked depression in CI in all patients. CI remained depressed P less than 0.05 after unclamping in the majority of patients. There were two perioperative deaths, both from myocardial infarction or failure. Both patients had ejection fractions less than 30% and initial CIs less than 2 L/M2, while the survivors' mean ejection fraction was 63% +/- 1 and their mean CI was 3.2 L/M2 +/- 0.6. We conclude that preoperative evaluation of ejection fraction can select those patients at a high risk of cardiac death from abdominal aortic operation. These patients should receive intensive preoperative monitoring with enhancement of ventricular performance.

Age and morbidity of vagotomy with antrectomy or pyloroplasty

Seven hundred ninety-three vagotomies with either pyloroplasty (645 patients) or antrectomy (148 patients) were reviewed between 1970 and 1981. Mortality was lowest with elective pyloroplasty (0.4 percent) followed by elective antrectomy (0.7 percent), and emergency pyloroplasty (5.1 percent). The risk of death was significantly higher (p less than 0.05) for the older half of the population (older than 55 years of age). Major morbidity was lowest after elective pyloroplasty (6.3 percent) when compared with elective antrectomy (10.6 percent), and greatest after emergency pyloroplasty (18.1 percent). Proved ulcer recurrence was most frequently seen after pyloroplasty (4.5 percent) and least frequently seen after antrectomy of age) had a significantly decreased risk of ulcer recurrence (p less than 0.001). Disabling sequelae occurred in 3.6 percent of those who underwent pyloroplasty, in 5.6 percent of those who underwent antrectomy with Billroth I reconstruction, and in 8.5 percent of those who underwent antrectomy with Billroth II reconstruction. Significantly more patients who underwent antrectomy with Billroth II reconstruction required reoperation (p less than 0.01) than did those who underwent either pyloroplasty or antrectomy with Billroth I reconstruction. Although antrectomy has become a popular operation, vagotomy combined with pyloroplasty is still the procedure of choice in patients over the age of 55 years. In those requiring emergency operations for duodenal ulcer, and in those in whom antrectomy is technically difficult because of a badly scarred duodenum. Billroth II reconstruction should be avoided after vagotomy and antrectomy.

Posterior surgical approaches to the rectum

This report summarizes experience with 19 posterior approaches to the rectum including nine trans-sacral (Kraske) and ten trans-sphincteric (Mason) procedures. This study included 12 men and 7 women, ranging in age from 18 to 89 years. Surgical indications included villous tumors in nine patients, various benign problems in four patients, primary carcinomas in three patients, and recurrent cancer in three patients. Eight complications developed in the 19 patients including: four fecal fistulae, two wound dehiscences, one rectal stricture, and one sacrococcygeal hernia. Spontaneous closure of the fecal fistulae occurred in two patients, and two patients required proximal colostomies. Fecal continence was achieved in 18 of the 19 patients. No patient died as a complication of the procedure. No recurrent tumors have developed. The conclusion is that a posterior approach to the rectum is a safe and effective procedure for various benign and for selected malignant conditions. It is particularly suitable for villous tumors that are too high for transanal resection and too low for transabdominal resection. It is an effective procedure for small, exophytic, mobile carcinomas of the lower 10 cm of the rectum in selected patients.

Energy usage for food service infrared heat processing of egg sandwich loaf

Simulating volume demand within hospital food service departments, infrared heat processing conditions were used to heat two similar protein menu items to determine both energy consumption required for heat processing and energy/nutrient rations. A larger, conveyorized infrared oven (CTX-70) and a smaller, infrared unit (Krups 2002) were used to heat process varying sizes of oven loads which ranged from one to 36 slices. Although no significant differences were found for product yield after 12, 24 and 36 slices were heat processed in the CTX-70, the energy usage was significantly different: 637, 798 and 1005 watt hours/load were consumed, respectively. In the Krups 2002, a load of one slice had greater heat processing losses than either two or four slices. Energy consumption was 39, 47 and 50 watt hours/load to heat process one, two and four slices in the Krups 2002, respectively. Significantly more energy was used to heat process turkey-ham than egg sandwich loaf in the Krups 2002. The potential use of energy/nutrient rations by dietitians was discussed.

Arterial embolectomy in the leg. Results in a referral hospital

The clinical characteristics and course of 90 patients in whom 121 arterial emboli occurred from 1968 to 1978 were reviewed. The factor that correlated most significantly with a favorable outcome was the interval from onset of symptoms until arterial embolectomy was performed. The results of embolectomy were excellent in the patients operated on within 6 hours of symptoms (amputation rate 4 percent, mortality rate 15 percent), but less favorable in the patients operated on within 6 to 12 hours of onset of symptoms (amputation rate 27 percent, mortality 40 percent). Mortality (48 percent) and amputation (52 percent) rates in the patients operated on 12 to 48 hours after onset of symptoms were excessive. It is recommended that immediate embolectomy be performed in all potentially viable extremities in patients who present within 12 hours of symptoms, but that after 12 hours only those limbs with obvious viability (not paralyzed or anesthetic) should be operated on. Alternatives for the remainder are high dose intravenous heparinization or expedient amputation. In patients who present greater than 60 hours after the onset of symptoms, embolectomy can be performed with low morbidity and mortality.

Activated clotting time monitoring of intraoperative heparinization: our experience and comparison of two techniques

The activated clotting time (ACT) has been used clinically for 41/2 years to monitor the adequacy of intraoperative heparinization in both cardiopulmonary bypass (CPBP) and peripheral vascular surgery (PVS) patients. Since January, 1976, we have operated on 440 PVS patients in our institutions, of whom 255 had intraoperative monitoring of heparinization by means of the ACT test; an additional 185 patients received heparin according to an empiric protocol. An automated machine for determining the ACT (Hemochron) had been used on the last 28 patients in the ACT group. We conclude that: (1) the ACT is an acurate method of monitoring anticoagulation during PVS, (2) the Hemochron is a simple and effective machine to perform the ACT, (3) values obtained by the Hemochron generally exceed those of the ACT done by hand by approximately 20 seconds at lower levels of heparin and are equal at higher levels of heparin, (4) supplemental heparin was required in 22% of our patients to maintain their ACT values at twice control values, (5) the response to heparin is twofold: an initial sensitivity or resistance followed by an independent and variable rate of consumption, and (6) the ACT is a useful method for predicting inadequate heparin reversal or heparin rebound at the conclusion of the operation.

Infected prosthetic grafts

An experience with 20 infected prosthetic grafts in a series of 652 prosthetic arterial reconstructions has been reviewed. There was 13 aortofemoral, one straight aortic, three femoropopliteal, one carotid subclavian, one axilloaxillary, and an axillocarotid graft. The most common site of infection was the groin. All patients had received preoperative and postoperative broad-spectrum antibiotic coverage, perhaps contributing to a high incidence of Gram-negative bacterial cultures. Early procrastination contributed to morbidity and mortality. Attempts at local wound management with drainage and irrigation generally failed, especially if the suture line was involved. Graft excision without revascularization resulted in a number of amputations and a high mortality. Excision of the entire aortofemoral graft combined with extra-anatomical revascularization was uniformly fatal. Our experience suggests that the first objective should be to establish operatively the extent of the infection. If very localized, antibiotic irrigation may cure. Involvement of one side can be treated in one stage by extra-anatomical bypass using the obturator foramen coupled with excision of the infected portion. If the entire graft is involved, we recommend extra-anatomical bypass as the initial procedure. High-dose antibiotic for systemic effect are then administered and two to three days later the infected graft is removed.

Operative correction of proximal blocks of the subclavian or innominate arteries

Ninety-four operations were performed on 90 individuals with occlusive disease of the subclavian or innominate arteries during the past 17 years. The left subclavian was occluded in 71, the right in 10, and the innominate in 9. Presenting symptomatology was neurological in 34, arm ischemia in 30 and combined in 26. Blood pressure was reduced by 30 mmHg on the involved side in all. An extrathoracic approach was used in 78 and a transthoracic approach in 16. Early mortality 18.7% and morbidity 18.7% was associated with the transthoracic approach. Long subcutaneous axillo-axillary and axillo-carotid are prone to thrombosis and skin erosion. Carotid-subclavian grafts used in 64 remain patent, occasionally become infected (4.7%), are associated with a low mortality and do not develop "carotid steal". When associated with vascular insufficiency of the lower extremity (44%) the brachiocephalic lesion should be corrected first.

Management of persimmon bezoars (diospyrobezoars)

Since 1946, 20 men and one woman aged 40 to 76 years (average 57) were operated upon for complications of diospyrobezoars. Shortly after eating persimmons, 11 (52.4%) had severe abdominal cramping, anusea, vomiting, and pyrexia. Twelve of 17 (70.9%) with gastric bezoars had hematemesis or melena caused by an associated gastric ulcer, while five (29.1%) had only moderate dyspepsia. In four (19.1%), the bezoar had lodged in the ileum, causing obstruction. Enzymatic therapy is indicated in those with minor symptoms. Gastrotomy or gastrotomy with bezoar removal and wedge resection of the gastric ulcer is recommended when enzymatic therapy fails, or when there is gastric outlet obstruction or marrise hemorrhage. Emergency exploration with removal is necessary when the persimmon bezoar causes ileal obstruction.

Activated clotting time (ACT) monitoring of intraoperative heparinization in peripheral vascular surgery

We conclude that (1) the activated clotting time (ACT) is an accurate method of monitoring anti-coagulation during peripheral vascular surgery and can easily be performed by a technician in the operating room or at the bedside; (2) an initial heparinizing dose of 120 to 130 units/kg is adequate in 95 per cent of the patients; (3) the ACT should be maintained at greater than twice the control values (180 to 200 seconds), which required supplementation within 2 hours in 21 per cent; (4) the response to heparin is twofold: an initial sensitivity or resistance followed by an independent and variable rate of consumption; (5) the patient's heparin dose-response curve should be used to calculate the amount of supplemental heparin needed to maintain the ACT at a safe level; (6) protamine should be given if the ACT at the conclusion of the operation is greater than 150 seconds (50 per cent of our patients); and (7) a final ACT 15 to 30 minutes postoperatively should be obtained to ensure adequate reversal or to detect heparin rebound or depletion of clotting factors.

Vasospasm in the lower extremities during and following arterial reconstruction

Foot temperatures of 36 patients were recorded continuously in the operating room and in the surgical intensive care unit (SICU) for 1-3 days. Operations included aortofemoral endarterectomy, arterioplasty, and bypass grafting. Regardless of severity of the operation, all had cold extremities on entering the SICU. The subsequent warming of the big toes, which started after 4-12 hours in the SICU, if at all, was classified according to a scheme of 6 deviations from a basic trend. This latter was a bilateral, continuous increase in 1-2 hours to 34 degrees C or higher where it remained with minor oscillations. Unilateral deviations were either diminished warming or no warming on one side. Bilateral deviations included stepwise increments to 34 degrees C, diminished increments, and no warming. Neurogenic vasospasm appeared to be the principal factor diminishing blood flow, with circulating vasoconstrictors and organic blocks as additional less important factors. Subsequent amputations of nine limbs were partially correlated with the categories of digital warming.

Identification of heparin resistance during cardiac and vascular surgery

An investigation of the response of the activated clotting time to systemic heparinization during cardiopulmonary bypass and peripheral vascular surgery was prompted by the death from clotting of a patient with endocarditis while undergoing valve replacement. The activated clotting time during cardiopulmonary bypass was thereafter maintained at 300 to 400 seconds. Consumption of heparin sodium, derived from an individual dose-response curve, was 0.01 to 3.86 units/kg/min. There was no correlation between initial heparin resistance and the subsequent rate of consumption. Some patients undergoing peripheral vascular surgery required additional heparin after an initial standard dose of 8,000 units so as to maintain their activated clotting time at twice the control values. These data are discussed in relation to previous articles, and recommendations are made for adequate intraoperative heparinization.