Ethanol stimulates prostacyclin biosynthesis by human neutrophils and potentiates anti-platelet aggregatory effects of prostacyclin

Previous reports on the direct effects of ethanol on human platelet aggregation function have been inconsistent. Ethanol ingestion produces vasodilation and raises intracellular cyclic AMP concentrations, effects similar to those of prostacyclin. We, therefore, hypothesized that ethanol may influence biosynthesis and/or bioactivity of prostacyclin. In our experiments, ethanol in concentrations up to 400 mg% had no consistent inhibitory effect on platelet aggregation in response to epinephrine, ADP, or combination of subthreshold concentrations of epinephrine plus ADP. However, ethanol in concentrations as low as 10 mg% potentiated the platelet aggregation inhibitory effects of prostacyclin. In addition, ethanol (20 mg%) decreased formation of thromboxane A₂ in whole blood by 41% and stimulated formation of prostacyclin by 160% (both P c 0.01). Additional studies using isolated human cells demonstrated synthesis of prostacyclin by neutrophils in the presence of platelets, and this neutrophil prostacyclin formation was enhanced in the presence of ethanol. These effects of alcohol in concentrations achieved after moderate intake may relate to the hemodynamic, biochemical, and cardioprotective effects of ethanol.     

A randomized comparison of labetalol and nitroprusside for induced hypotension

In a randomized study, labetalol-induced hypotension and nitroprusside-induced hypotension were compared in 20 patients (10 in each group) scheduled for major orthopedic procedures. Each patient was subjected to an identical anesthetic protocol and similar drug-induced reductions in mean arterial blood pressure (BP) (50 to 55 mmHg). Nitroprusside infusion was associated with a significant (p < 0.05) increase in heart rate and cardiac output; rebound hypertension was observed in three patients after discontinuation of nitroprusside. Labetalol administration was not associated with any of these findings. Arterial PO₂ decreased in both groups. It was concluded that labetalol offers advantages over nitroprusside.     

Surgical treatment of cholesteatoma: a comparison of closed and open techniques in a follow-up of 164 ears

Reimer A., Andreasson L. & Harris S. (1987) Clin. Otolaryngol. 12 , 447–454 Surgical treatment of cholesteatoma: a comparison of closed and open techniques in a follow-up of 164 ears In the Malmö community (230 000 inhabitants) 188 ears with cholesteatoma were operated on during 1975–1981. This number corresponds to an incidence of 12 cholesteatomas per 100000 inhabitants a year. A detailed follow-up was possible in 164 ears. The primary operation was performed with an intact canal wall technique (CAT) in 148 ears and a radical operation in 40 ears. A planned second look was performed in 138 of the CAT ears and residual cholesteatoma was found in 41 or 30%, mainly in the epitympanic space. An initially good healing and hearing result was obtained in 71 % but in the course of time several ears developed new retractions and a new mastoid cholesteatoma. The number of ears with perfect hearing tended to decrease with time, but about one-third of CAT ears remained intact with good hearing. The CAT technique is preferable in ears with a large mastoid air cell system and when the cholesteatoma is easily accessible by the approach. A planned second look should be performed including ossiculoplasty and obliteration of the antrum. In the remaining cases a radical operation including middle ear reconstruction and obliteration of the mastoid cavity is preferred.     

Characteristics of reproductive life and risk of breast cancer in a case-control study of young nulliparous women

Between 1982 and 1985, a case-control study of nulliparous women, aged 25–45, was conducted to analyse the relationships between the risk of breast cancer and causes of nulliparity, including contraceptive methods. Fifty-one cases of breast cancer diagnosed less than 3 months before interview were matched with 95 controls on age at diagnosis, year of interview, and medical center. The causes of nulliparity related to fernale sterility or subfertility (mechanical or hormonal disorders) were not found to be associated with a significantly higher risk of breast cancer. The causes related to fertilization failure, i.e. no sexual partner, rare sexual intercourse (less than once per month), or partner with abnormal semen, were found to lead to an increased risk. Detailed analysis of contraceptive methods showed that the risk of breast cancer increased (p = 0.02) with a longer duration of use of barrier methods (withdrawal or condom). Conversely, the risk significantly decreased (p = 0.004) with a longer duration of use of non-barrier methods (oral contraceptives, IUD, cap, local spermicides, vaginal douche, safe period, or no method), i.e. methods allowing a direct exposure to human semen.     

Anesthetic management of obstructive sleep apnea patients

Presented is an illustrative case report ana a review of the anesthetic management of obstructive sleep apnea patients. Preoperative evaluation should include a thorough airway evaluation and a comprehensive cardiovascular and pulmonary evaluation. With polysomnography, identification of the severity of sleep apnea can be identified. Although sleep centers vary in their definitions, severe obstructive sleep apnea is diagnosed if the patient demonstrates an apnea index greater than 70 and an oxygen (O₂) desaturation less than 80% with cardiovascular sequelae. Severe sleep apnea patients are at extreme risk for general anesthesia. These risks should be discussed preoperatively with the patient. Unsupervised preoperative sedation should be avoided because of the extreme sensitivity of these patients to sedatives and airway obstruction.

Intraoperative management of the obstructive sleep apnea patient varies depending on the severity of the sleep apnea. Invasive monitoring may be necessary if the patient demonstrates evidence of cardiopulmonary dysfunction. With the assistance of the otolaryngologist, the anesthesiologist can formulate an approach to establishing an airway. Intraoperative opoids and sedatives should be limited.

The recovery o f the sleep apnea patient is extremely important and is the time when most airway emergencies occur. Extubation of the patient should occur when, appropriate surgical personnel and equipment are available in case of an airway emergency. Steroids may be used to decrease the amount of airway swelling. Supplemental O₂ should be used in patients who demonstrate desaturation. Opioids and sedatives should be avoided, as should other drugs that have central and sedating effects. Postoperative pain is effectively controlled with acetaminophen and topical anesthetic sprays. Postoperative monitoring for apnea, desaturation, and dysrhythmias is a necessity in sleep apnea patients.     

Acute anuric renal failure: a complication of combined thrombolytic and antithrombotic therapy

Thrombolytic agents are routinely given to patients with acute myocardial infarction, often in combination with heparin. Genitourinary hemorrhage is an uncommon adverse effect of systemic thrombolysis, and acute azotemic complications are distinctly rare. We describe a case of genitourinary hemorrhage after combined thrombolytic and antithrombotic therapy leading to acute bilateral ureteral obstruction and then briefly review renal complications of systemic thrombolysis.     

Spinal adhesive arachnoiditis

Forty-one cases of spinal adhesive arachnoiditis are presented. The key points are, first, that lumbar disc lesions, their investigations and surgical treatment and the use of nonabsorbable contrast materials are the most common etiological factors and, secondly, that operation is the best treatment. It is our contention that the majority of patients so treated do experience some improvement in what otherwise can be an unbearable amount of pain and disability. The use of adsorbable, nonirritative contrast materials such as Iohexol Parenteral will result in a marked reduction in the frequency of occurrence of arachnoiditis.     

Nasal T-cell lymphoma: a clinicopathological and immunophenotypic analysis of 13 cases

Thirteen cases of nasal lymphomas with T-cell or natural killer (NK)-cell phenotype were studied, with attention to clinical presentation and follow-up, the presence of Epstein-Barr virus (EBV) using in situ hybridization (EBER), the immunophenotype, and the presence of cytotoxic granules. All but two patients presented with stage I disease. In three cases local progression resulted in involvement of the central nervous system. When dissemination occurred, this was predominantly to extranodal localizations, in two cases to the skin. Response to therapy was highly variable, but patients treated with radiotherapy with or without additional chemotherapy had a better prognosis than patients treated with initial chemotherapy alone. All lymphomas were associated with EBV, and most cases howed cytotoxic features, ten of which were CD56 positive. In eight cases a T-cell origin was proven, but in five ases a possible NK-cell origin could not be excluded, No clinical differences were seen between true T-cell lymphomas and possible NK-cell neoplasms. Nasal T-cell lymphomas should be considered as a distinct clinicopathological entity, strongly associated with EBV, and with cytotoxic features in most cases. No prognostic parameters were detected to predict dissemination and response to therapy.     

Quantifying the kinematics of natural and prosthetic knee flexion

A new method has been developed for quantifying knee kinematics during flexion. This method was used to measure knee kinematics from lateral radiographs taken at different angles of flexion with the two femoral condyles superimposed in each image, thus standardizing the plane of flexion-extension. When applied to the radiographs of five healthy male volunteers (age range 21–26 years), it showed that flexion was accompanied by translation between the articular surfaces. Knee kinematics were also measured in five patients after total knee replacement (TKR) surgery with a Kinemax^TM Modular Total Knee prosthesis (Howmedica, Warsaw, Indiana). In the TKR patients, a translation was detected in three out of the five patients. This indicates that the prosthesis is capable of restoring normal kinematics, but does not always do so.     

Planning and delivering high doses to targets surrounding the spinal cord at the lower neck and upper mediastinal levels: static beam-segmentation technique executed with a multileaf collimator

Background and purpose. It remains a technical challenge to limit the dose to the spinal cord below tolerance if, in head and neck or thyroid cancer, the planning target volume reaches to a level below the shoulders. In order to avoid these dose limitations, we developed a standard plan involving Beam Intensity Modulation (BIM) executed by a static technique of beam segmentation. In this standard plan, many machine parameters (gantry angles, couch position, relative beam and segment weights) as well as the beam segmentation rules were identical for all patients. Materials and methods. The standard plan involved: the use of static beams with a single isocenter; BIM by field segmentation executable with a standard Philips multileaf collimator; virtual simulation and dose computation on a general 3D-planning system (Sherouse's GRATIS®); heuristic computation of segment intensities and optimization (improving the dose distribution and reducing the execution time) by human intelligence. The standard plan used 20 segments spread over 8 gantry angles plus 2 non-segmented wedged beams (2 gantry angles). Results. The dose that could be achieved at the lowest target voxel, without exceeding tolerance of the spinal cord (50 Gy at highest voxel) was 70–80 Gy. The in-target 3D dose-inhomogeneity was ≈25%. The shortest time of execution of a treatment (22 segments) on a patient (unpublished) was 25 min. Conclusions. A heuristic model has been developed and investigated to obtain a 3D concave dose distribution applicable to irradiate targets in the lower neck and upper mediastinal regions. The technique spares efficiently the spinal cord and allows the delivery of higher target doses than with conventional techniques. It can be planned as a standard plan using conventional 3D-planning technology. The routine clinical implementation is performed with commercially available equipment, however, at the expense of extended execution times.