The use of cerebral ventriculography for verification of intracerebroventricular cannula placement in the live rat

A technique using cerebral ventriculography for verification of intracerebroventricular cannula placement in the live rat is described. A radiopaque contrast medium, diatrizoate meglumine, was injected into the right lateral ventricle through a cannula stereotaxically implanted into the brain. Radiographic visualization of the radiopaque contrast material in the lateral ventricle and the subarachnoid space verified cannula placement. Transient muscular spasms were observed in about 38% of the injected rats but no lasting changes were observed in the behavior or appearance of these rats.     

A technique for chronic intragastric drug administration in the rat

An improved method for chronic intragastric delivery of drug solutions in the rat is described. The cannula can be easily constructed while the implantation is a simple and a problem-free procedure. Animals suffered no ill effects and resumed normal weight gain profiles after the operation. Since this is a direct stomach cannulation technique, the problems associated with the nasopharyngeal method are avoided. The cannula was tested by administering methadone and observing the characteristic depression of operant responding for food reinforcement. Using the cumulative records, it was possible to detect the onset of drug effect which was found to be about 10 minutes. The cannula is relatively durable and has remained patent in some animals for as long as 10 months without maintenance.     

A simple non-surgical method of intrabronchial instillation for the establishment of respiratory infections in the rat.

A technique involving intubation of weanling rats for intrabronchial instillation of infectious material has been developed to produce a respiratory infection model suitable for experimental infection studies. The technique is performed simply with the use of a metal cannula and an intravenous plastic cannula, and dispenses with the need for illumination, laryngoscopy and extensive manipulation of the animal.     

Improved method for bile collection in unrestrained conscious rats.

We describe an improved method for continuous collection of bile from unrestrained rats. Use of an externally accessible, continuous-loop cannula when cannulating the common bile duct allows for full recovery from anesthetic effects and maintenance of a normal bile salt pool until the cannula loop is cut. Bile resulting from the cut cannula is diverted into a surgically implanted glass collection vessel and removed periodically via an externalized sampling port. Bile flow over a 24-hour collection period averaged 0.98 +/- 0.04 ml/hr (Mean +/- SEM, n = 9) with no gross pathological changes noted upon necropsy. This technique offers the capability of reestablishing conditions as close to physiologic as possible postsurgery to minimize potential artifacts during bile collection.     

Comparison of two techniques for obtaining endometrial bacteriologic cultures in the mare

The endometria of 39 mares were cultured simultaneously using a swab guarded with a double cannula and distal, teflon plug and an unguarded swab with a single, open cannula. Sheep blood (5%) agar, Mac-Conkey's agar, and Sabourad's agar media were innoculated with each swab. The presence of bacterial or fungal growth was determined after 24 and 48 hours of aerobic incubation at 37 C. There were significantly more plates that failed to yield bacterial or fungal growth when streaked with swab specimens obtained with the guarded cannula than when streaked with those obtained with the unguarded cannula. It was concluded that while culturing the endometrium of mares for bacteria or fungi, the use of a guarded instrument consisting of a double cannula with a closed end will result in the recovery of fewer contaminants; therefore, it will be more likely to result in a more accurate representation of uterine bacterial and fungal flora.     

Gynecomastia: suction lipectomy as a contemporary solution

Suction lipectomy is adapted for the correction of gynecomastia. Previous attempts using suction lipectomy for gynecomastia still required the use of sharp dissection for removal of the glandular breast tissue as well as excision of redundant skin. With this new technique, gynecomastia is corrected solely with the use of suction lipectomy. The technique is successful if the gynecomastia is due to excess fat or parenchymal hypertrophy. A 7-mm cannula is inserted first, to remove the adipose tissue. Then a 2.4-mm cannula is used to remove the glandular and ductal tissue. The 7-mm cannula is then reinserted to remove subareolar parenchyma and to make final contour adjustments. The surrounding subcutaneous tissue is easily undermined to avoid a saucer deformity and to allow for skin contraction. Patients return to full activities in 48 hours. A compressive garment is worn for 4 to 6 weeks. The results of 10 patients are discussed.     

Special cannulas for the puncture of implanted catheter port systems

The Huber-Point cannula is generally recommended for portal puncture. Two comparative studies are published that show no advantage in using Huber-point cannulas. This has been verified by technical investigations. A new type of non-coring cannula is described.     

Ultrasound-guided cannulation of the caudal vena cava in the bovine for selective sampling of ovarian effluent

The accuracy of real-time, B-mode ultrasonography was assessed in the visualization and placement of the cannula tip, cranial to the entrance of the ovarian veins as they enter the caudal vena cava of the bovine. A cannula containing a wire guide was introduced into the coccygeal vein via a 14-gauge needle, and was then directed cranially into the caudal vena cava. Once the caudal vena cava was successfully cannulated (7 of 14 cows), ultrasonography allowed for the visualization of the cannula in 7 out of 7 cows. The tip of the cannula was successfully placed cranial to the entrance of the ovarian effuent into the vena cava in 6 of these 7 animals using ultrasound guidance. This was confirmed using progesterone or prostaglandin F(2alpha) radioimmunoassay (RIA). The primary limitation to this technique was the initial catherization of the coccygeal vein which was not achieved in 7 of 14 cows attempted in this study. Successful cannulation was limited to large framed Holstein cows that had at least one calf. Results from this study indicate that real-time, B-mode, ultrasonography is an effective tool for the visualization and accurate placement of the cannula tip within the caudal vena cava. This finding could have implications for research in ovarian hormonal physiology in the cyclic, postpartum or anestrous cow.     

Peritoneal dialysis in infants.

A commercially available closed dialysis system and a new peritoneal cannula with potential advantages for infants have been developed. The dialysis set includes three dialysate bags that may be connected to the filling burette; the warming coil of the set is placed in a thermostatically controlled water bath. The peritoneal catheter comprises a flexible tube with side holes and a sharp short bevelled needle with obturator. Advantages of the new equipment over previously available equipment are that the cannula is easier to insert; there is less risk of contaminating the dialysate since the tubing set is unbroken from supply to cannula; the mix of the dialysate may be changed easily without interrupting dialysis; and the equipment may be assembled easily by unskilled staff.     

Simplified surgical placement and stabilization methods for intracerebroventricular cannulas in rat lateral ventricles

Intracerebroventricular cannulation in rat models is an efficient tool for exploring the effects of substances directly injected into the CNS, bypassing the blood-brain barrier. Techniques for surgically securing the ICV cannula require a balance between ease of application and adequate stability. The authors tested several methods of lateral ventricle cannula stabilization, especially focusing on a comparison of cyanoacrylate gel to cranioplastic cement with an anchoring bone screw.     

Maintenance of silastic–teflon shunts for intermittent haemodialysis

The occurrence of infection in the tissues surrounding external arteriovenous shunts was studied and die important relationship of pyogenic infection to clotting was confirmed. The local application of fusidic add tulle and lanolin greatly reduced the occurrence of both infection and clotting and the need for cannula replacement.Urokinase used for declotting shunts when standard procedures had failed, restored blood flow whether dotting was related to infection or to local vascular factors. This treatment is not advised when clotting is associated with a local abscess, as it may make cannula replacement necessary. Severe local vascular factors, such as metastatic calcification, Raynaud''s phenomenon, and venous stenosis, may lead to poor blood flow, so that despite clot lysis elective cannula replacement or the creation of a subcutaneous arteriovenous fistula is required.     

一种简易小鼠尾部皮肤移植教学实验改良方法的建立

目的 为本校生物工程系实验动物学课程小鼠尾部皮肤移植实验课提供一种合适的操作方法.方法 分别用0.7%、1%、1.5%戊巴比妥钠和10%水合氯醛对小鼠进行麻醉试验,选出合适的麻醉方法;再进行小鼠尾部皮肤移植,对比玻璃套管法和创可贴法2种包扎方法的效果,以选出合适的手术方法.结果 0.7%和1%戊巴比妥钠麻醉持续时间过短,1.5%戊巴比妥钠和10%水合氯醛能维持足够手术操作所需的时间,但1.5%戊巴比妥钠易导致动物死亡,故采用10%水合氯醛麻醉小鼠较合适;玻璃套管法包扎的效果较创可贴法为好且更简便.结论 10%水合氯醛麻醉结合玻璃套管法包扎进行小鼠尾部皮肤移植是一种有效、简便、经济的小鼠尾部皮肤移植手术实验方法;此方法技术失败率低,适合学生实验课采用.     

Perfusion fixation of the newborn opossum: equipment and techniques.

A 30-gauge cannula was used to perfuse fixative through the fragile heart of a newborn opossum. The cannula was gently maneuvered into the heart and held in place with a specially designed manipulator. The flow rate of the fixative was regulated with an infusion set connected to the cannula.     

A simple method for intragastric administration of powdered materials to rats

A simple technique was used for administration of powdered material directly into the stomach of rats. A commerically available positive displacement pipetting device was filled by tamping the cannula tip into the powder. The contents of the cannula could then be discharged into the stomach by insertion of the cannula via the esophagus. The device required only minor modifications prior to its use in this manner. The technique provided a means of accurate dosing of insoluble materials and eliminated the difficulties encountered in the oral administration of suspensions.     

The effect of sampling technique on acid-base balance and other blood parameters in the sheep.

The effect of 4 sampling routines--venipuncture, intravenous cannula, intravenous cannula following the administration of a tranquiliser (xylidino dihydrothiazine hydrochloride), intravenous cannula following exercise--were compared. Blood pH and base excess values were similar after venipuncture and cannula sampling, but higher (P less than 0 with 05) after the administration of the tranquiliser and lower (P less than 3 with 05) following exercise. Blood haemoglobin, haematocrit and lactate levels followed this pattern, while plasma protein levels were similar for all treatments except after exercise, where they were higher (P less than 0 with 05). The recovery of various blood parameters to normal values after a period of exercise was also studied: acid-base balance had returned to near normal within 60 min, while haemoglobin and haematocrit levels had returned to normal within 10 min.     

Characterization of In Vivo Dopamine Release as Determined by Brain Microdialysis After Acute and Subchronic Implantations: Methodological Aspects

Infusion of tetrodotoxin (TTX) through the dialysis membrane and perfusion with calcium-free Ringer solution (calcium depletion) were used to evaluate the dopamine release determined by in vivo brain dialysis. Several hours after implantation, the dopamine release recorded by the U-shaped cannula did not respond to calcium depletion and was only partly (approximately 50%) TTX dependent. The half-life of the TTX-independent dopamine overflow was determined to be 2 h. In contrast, when a transstriatal cannula was used, the dopamine output displayed calcium and TTX dependency. Differences in the dimensions of the two types of probes are a likely explanation for the observed effects. Twenty-four hours after implantation, both types of cannula fulfilled the criteria of calcium and TTX dependency. The results indicate that infusion of TTX-containing or calcium-free Ringer solution can be used to estimate the functional damage caused by the implantation of the cannula.     

A Shoshonean Origin for the Plains Shield Bearing Warrior Motif

Abstract

The shield bearing warrior is a distinctive motif characteristic of the rock art of the Northwestern Plains. It also occurs commonly in the eastern Great Basin as an element of Fremont rock art. Detailed similarities between Plains and Great Basin shield figures suggest cultural relationships between the two areas. This has led some authors to propose that the motif originated in the Northwestern Plains and diffused to the Great Basin. Others argue that the motif spread from the Great Basin to the Plains. Relative dates recently obtained for shield figures at Northwestern Plains sites support the latter hypothesis. A Shoshonean origin for the Northwestern Plains shield figures is suggested by the dates, and the coincidence between the distribution of the motif, the distribution of diagnostic Shoshonean artifacts. and the ethnohistorically known range of the Plains Shoshone. It is suggested that the Shoshone borrowed the motif from the Fremont Culture during a period of interaction between the two groups.

The shield bearing warrior, a distinctive motif that depicts a pedestrian warrior whose body is represented by a large circular shield (Fig. 1), is frequently encountered in the rock art of the western United States. It is especially common at sites on the Northwestern Plains and in the eastern Great Basin (Fig. 2).     

Reformative cannula electrodes for His bundle electrogram recording in isolated rat hearts

His bundle electrogram (HBE) recording is an important method for the study of the atrioventricular conduction system. However, the current HBE recording methods in isolated animal hearts have some disadvantages, such as unstable recording due to the difficulty in fixing electrodes as a result of intense heart beat, the small amplitude of the His signal or the possibility to destroy the integrity of heart structure. To overcome these disadvantages, we designed and manufactured reliable, inexpensive and easy-made bipolar cannula electrodes, which combine the functions of Langendorff-perfusion aortic cannula and recording electrodes. With the cannula electrodes, the operation of HBE recording becomes easier and clearer; hence, more stable recordings can be obtained in isolated rat hearts.     

The metabolism of dopamine in rat caudate nucleus can be increased by in vivo “dialysis” perfusion cannulae

The development of dialysis cannula techniques coupled with high performance liquid chromatography and electrochemical detection (HPLC-EC) has provided a means to continuously sample extracellular fluid from deep brain structures $\text{in vivo}$. The present studies show that with HPLC-EC analysis of the acid metabolites of dopamine (DA) and 5-hydroxytryptamine (5-HT) in samples from dialysis cannulae implanted in the caudate nucleus of anaesthetized rats, it is possible to determine the time course of the response of dopamine- and 5-HT containing neurones to administration of monoamine oxidase inhibitors and haloperidol. The tissue concentrations of the DA and 5-HT metabolites were also determined at the conclusion of each individual experiment in both the caudate nucleus containing a cannula and in that without a cannula. In perfusion experiments where no drug was administered the content of the DA metabolites, but not that of the 5-HT metabolite, were significantly elevated in the caudate nucleus containing the cannula as compared with the contralateral tissue. These increases occurred whether the cannula was perfused or not, suggesting that the presence of the cannula may have been causing a lesion which altered the activity of the DA neurones. These results emphasize the importance of tissue analysis in conjunction with the dialysis experiments, especially where perfusion sample contents of the monoamine metabolites are being measured as a reflection of the effects of behavioural manipulation or drug treatment on endogenous neuronal activity.     

Chronic intratumoral chemotherapy of a rat tumor with cisplatin and fluorouracil

In order to demonstrate the feasibility and efficacy of intratumoral chemotherapy, brain tumors in rats were treated by direct infusion of cisplatin or fluorouracil. Each animal was initially implanted in the midline cerebellum with a chronic stainless-steel cannula, and 2 weeks later 1 X 10(5) 9L cells were injected through the cannula. 8 days after tumor cell transplantation, a small implantable pump containing drug, or saline as a control, was connected up to the same cannula, and the solution was pumped into the tumor region for 7 days. The results showed that both drugs produced statistically significant increases in survival as compared to the controls.