Intracytoplasmic lumina–a useful diagnostic feature of adenocarcinomas

The monoclonal antibody NCRC-11, which has epithelial membrane antigen (EMA)-like immunoreactivity, was used to identify intracytoplasmic lumina in a series of 105 adenocarcinomas from various sites and in 283 breast carcinomas; 55% of the non-breast carcinomas and all breast carcinomas except one of spindle cell type contained intracytoplasmic lumina. The highest frequency (16.4% of tumour cells) was found in invasive lobular carcinoma of the breast. The use of antibodies with EMA reactivity is advocated in the routine investigation of metastatic and undifferentiated tumours.     

Effect of low fresh gas flow rates on inspired gas composition in a circle absorber system

Study Objective: To determine the effects of fresh gas f ow on inspired gas composition during low flow anesthesia.

Design: Randomized trial with 2-hour observation periods in patients assigned to one of three groups.

Setting: Inpatient surgery clinic at a medical center.

Patients: Thirty-six patients undergoing abdominal surgery with low flow anesthesia. Interventions: Fresh gas flow was given at a starting rate of 5 L/min for 6 minutes. Thereafter, the fresh gas flow setting was nitrous oxide (N₂O) 1 L/min and oxygen (O₂) 0.6 L/min (Group 1), N₂O 0.5 L/min and O₂ 0.5 L/min (Group 2), and with a moderate surplus of N₂O and O₂ with respect to the patient's O₂ consumption (Group 3).

Measurements and Main Results: The inspired O₂ concentration (FIO₂) was measured using a paramagnetic technique, and N₂O levels were measured with infrared sensors; the inspired nitrogen concentration (FIN₂) was calculated by the following formula: (FIN₂) = 1 - FIO₂ - FIN₂O, where FIN₂O is the inspired N₂O concentration. After 1 hour of anesthesia, FIO₂ was significantly lower in Group 1 than in Groups 2 and 3 (p < 0.01), and FIN₂ was significantly higher in Groups 2 and 3 than in Group 1 (p < 0.01). After 2 hours of anesthesia, (FIN₂) returned to normal in Group 2 but continued to increase in Group 3. FIN₂O was close to 0.7% only in Group 1.

Conclusions: The same initial period of denitrogenation is not adequate to denitrogenate the circle system in all cases. The lower the fresh gas flow, the longer the initial period of denitrogenation should be. Various levels of fresh gas flow for low-flow anesthesia have been suggested, but none guarantees adequate control of inspired gas composition unless f owmeters are continuously adjusted.     

Moderate hyperthyroidism reduces liver amino nitrogen conversion,muscle nitrogen contents and overall nitrogen balance in rats

There are conflicting data on the effect of thyroid hormones on nitrogen metabolism. We determined the basal blood amino nitrogen (amino-N) concentrations, the urea nitrogen (urea-N) synthesis rate and the maximum hepatic capacity of urea nitrogen synthesis during saturating infusion of alanine, in moderately acutely (24 h) and chronically (7 days) hyperthyroid rats and compared this with changes in organ nitrogen contents in muscles and kidney, nitrogen excretion and nitrogen balance. Forty-three rats were made acutely hyperthyroid through administration of 5 μg 100 g^?1 triiodothyronine twice daily (T₃: 2.2 ± 0.7 vs. 0.87 ± 0.04 nmol L^?1, P < 0.01). Fifty-one rats were made chronically hyperthyroid through administration of 12.5 μg 100 g^?1 thyroxine twice daily (T₃: 2.63 ± 0.18 vs. 0.87 ± 0.04 nmol L^?1, P < 0.01). Weight gain was halved in this group. Both acute and chronic hyperthyroidism increased basal blood amino-N concentration in both groups by 16% (4.5 ± 0.15 vs. 3.9 ± 0.13 mmol L^?1 and 4.7 ± 0.12 vs. 3.9 ± 0.13 mmol L^?1, respectively, P < 0.01), and decreased basal urea-N synthesis rate in both groups by 30% [2.7 ± 03 vs. 4.1 ± 0.3 μmol (min ×100 g)^?1 and 3.1 ± 0.3 vs. 4.1 ± 0.3μmol (min ×100 g g)^?1, respectively, P < 0.01]. The capacity of urea-N synthesis during saturation fell in both groups by 35% compared with controls [6.5 ± 0.4 vs. 9.3 ± 0.5 μmol (min ×100 g)^?1 and 5.7 ± 0 .5 vs. 9.3 ± 0.6 μmol (min ×100 g)^?1, respectively, P < 0.01]. Nitrogen contents in the muscles, soleus and extensor digitorum longus, of chronically hyperthyroid rats decreased by 22% and 11%, respectively, whereas kidney N-content increased by 12% (P < 0.05). N-balance and urinary urea-N excretion fell by 30%, whereas faeces-N excretion increased by 80% in hyperthyroid rats. Overall liver function assessed by galactose elimination capacity did not differ among groups. Both acute and chronic moderate hyperthyroidism increase blood amino-N and decrease basal and maximum rate of urea formation. Furthermore, chronic hyperthyroidism reduces N-contents of muscles, urinary urea-N excretion and N-balance. Thyroid hormones thus mobilize muscle-N, whereas amino-N in the liver is spared from irretrievable conversion into urea.     

Cocaine-associated dissection of the thoracic aorta

Patients present to emergency departments with a variety of complications related to cocaine abuse. Emergency physicians must be aware of the life- and limb-threatening complications to avoid undue mortality and morbidity. We present the case of a patient with aortic dissection who developed the acute onset of abdominal pain 5 minutes after subcutaneous cocaine use. Four previous reports of cocaine-associated aortic dissection are reported in the literature. These cases and other reports of intra-abdominal vascular injuries related to cocaine use are reviewed. Cocaine's mechanism of action as it relates to aortic dissection and some of the pharmacologic agents available for treatment are discussed.     

Study of anticoagulant mechanism of low molecular weight heparin

The binding ability of low molecular weight heparin (FR-860), and conventional unfractionated heparin (UF-heparin) to factor Xa (F.Xa), thrombin and ATIII was investigated using FR-860- and UF-heparin-Sepharoses. FR-860 could not bind directly to F.Xa. FR-860 bound to thrombin and ATIII with stronger affinity to ATIII than to thrombin. On the other hand, UF-heparin bound to F.Xa, thrombin and ATIII with the strongest affinity to AT III followed by thrombin and F.Xa. AT III mediated the binding between F.Xa and FR-860 and accelerated the reaction between F.Xa and UF-heparin. On the other hand, ATIII did not affect the binding between thrombin and FR-860 or UF-heparin. Diisopropyl fluorophosphate-treated thrombin inhibited the binding between ATIII and FR-860, but not that between ATIII and UF-heparin. These results suggest that the anti-F.Xa activity of FR-860 is mediated by AT III. Furthermore, the difference of antithrombin activity between FR-860 and UF-heparin depends on the capability to form ternary complex of FR-860 or UF-heparin, ATIII and thrombin.     

At high heparin concentrations, protamine concentrations which reverse heparin anticoagulant effects are insufficient to reverse heparin anti-platelet effects

Combined effects of heparin and protamine on plasma clot structure and platelet function were studied. Anticoagulant effects were monitored as changes in aPTT. Clot structure was defined in terms of fibrin fiber mass/length ratio (μ) and clot elastic modulus (EM). Platelet function was studied utilizing platelet aggregation and platelet force development (PFD) measurements. Heparin (1 U/ml) prolonged the aPTT from 30 to >300 seconds, reduced PFD from 5,100 to 0 dynes, decreased μ (in batroxobin-induced gels) from 1.36 to 1.08 × 10¹³ daltons/cm and decreased clot EM from 9,600 to 2000 dynes/cm². Varying amounts of protamine reversed these effects: 16 μg/ml normalized the aPTT, 20 μg/ml normalized PFD, 32 μg/ml corrected μ, and 20 μg/ml returned EM to baseline. At high heparin concentrations (4 U/ml), protamine concentrations which corrected anticoagulant effects were inadequate to reverse antiplatelet effects. A protamine concentration of 40 μg/ml normalized the aPTT and μ, but 140 μg/ml of protamine was required to reverse heparin suppression of force development and clot elastic modulus. Excess protamine inhibited clotting and platelet function. In plasma containing 1 u heparin/ml, 140 μg protamine/ml reduced PFD by 83%, prolonged the aPTT by 63%, and reduced clot EM by 75%. In heparin free plasma, >75 μg protamine/ml prolonged the aPTT. Thus, platelet function and clot structure are sensitive to protamine during heparin neutralization, and anti-platelet effects of heparin may persist when the aPTT is completely corrected. Excess protamine inhibits platelet function and compromises clot structure.     

Treatment of recurrent dislocation of the temporomandibular joint with type A botulinum toxin

A case is reported of a 56-year-old woman who suffered from recurrent dislocations of the temporomandibular joint (TMJ) secondary to an exacerbated tetraspastic syndrome of multiple sclerosis. Following chemical denervation of the masseter and pterygoid muscles with injections of type A botulinum toxin, no further dislocations occurred for periods of up to four months. The treatment has been repeated five times. Some of the indications and possible adverse reactions to this therapy are discussed and comparisons made with other, conventional methods for managing recurrent dislocation of the TMJ.     

Benzodiazepines for acute pain in children

When pediatric pain is refractory and unresponsive to appropriate use of analgesic agents, there might be additional physical or psychologic dimensions of the pain that are not addressed by the analgesics. In addition to appropriate analgesic therapy, the psychologic needs of the child should be directly addressed and appropriate adjunctive physical modalities employed. Although benzodiazepines lack direct analgesic effects, they can reduce the distress associated with acute pain states by decreasing anxiety, insomnia, and muscle spasms that can be associated with acute pain. Intermediate or long-acting benzodiazepines in modest doses can be useful adjunctive agents when used short term for the treatment of selected acute pain complaints. In the highly distressed school-age child or adolescent with pain complaints relatively unresponsive to appropriate care, judicious use of benzodiazepines is worthy of consideration.     

Characterization of cytosolic phospholipases C from porcine aortic endothelial cells

Phospholipases C (PLCs) are ubiquitous enzymes which play key roles in the response of cells to extracellular agonists. Endothelial cells are involved in myriad normal and pathophysiologic functions. Although it is known that agonists activate PLCs in endothelial cells, second messengers form, and cellular responses ensue, more knowledge is needed about the specific types of PLCs in these cells. To this end, cytosolic PLCs from porcine aortic endothelial cells were partially purified by ammonium sulfate fractionation and column chromatography on DEAE-Sepharose CL-6B and heparin-agarose. Three PLC isozymes immunologically similar to bovine brain PLC-β, PLC-γ, and PLC-δ were identified. The relative levels of PLC activities in the cytosol were: PLC-β, 50%; PLC-γ, 44%; PLC-δ, 6%. The level of PLC-β activity in porcine endothelial cells appeared higher than the levels reported for several established cell lines, suggesting that this enzyme may play a specific role in endothelial cell function. Elution profiles of PLC activity with phosphatidylinositol 4,5-bisphosphate (Ptdlns(4,5)P₂) as substrate were similar to those with phosphatidylinositol (Ptdlns) as substrate, indicating that cytosolic PLCs hydrolyze both Ptdlns and Ptdlns(4,5)P₂ and no Ptdlns(4,5)P₂-specific PLC was present in the cytosol. The catalytic properties of the partially purified PLC isozymes from porcine endothelial cells were similar to their counterparts from bovine brain. These include the dependence of hydrolysis of Ptdlns on Ca²⁺, the optimal Ca²⁺ concentrations for the hydrolysis of Ptdlns and Ptdlns(4,5)P₂, the pH optima, and the stimulatory effects of deoxycholate.     

Use of general purpose mechanical computer assisted engineering software in orthopaedic surgical planning: advantages and limitations

Two surgical plans were developed for an appropriately complex reconstructive orthopaedic surgery case. One plan was developed with customary methods using two-dimensional (2D) radiographs. The second plan was developed with general purpose mechanical computer assisted engineering (MCAE) software using x-ray computed tomography (CT) data. The limitations of each method are identified. To create a surgical plan using three-dimensional (3D) medical datasets and MCAE software, five necessary steps were identified: (a) data reduction; (b) contour extraction; (c) 3D model creation; (d) extraction of mass properties; (e) model idealization. The principal limitation of general purpose MCAE software is the lack of pre-processing modules with which to address the unique requirements of medical image datasets.