Simultaneous total arch replacement and abdominal aortic surgery

It is common to encounter patients with coexisting aortic arch aneurysm and abdominal aortic lesions. We conducted simultaneous total arch replacement and abdominal aortic surgery in 3 patients having such lesions. Mean operative time was 511 minutes and no in-hospital mortality occurred. Postoperative respiratory failure was observed in an 80-year-old patient who recovered and all three patients were discharged in good condition. No other postoperative complication was seen. Simultaneous total arch replacement and abdominal aortic surgery may thus offer advantages to patients with such double aortic lesions if it can be conducted safely.     

The effect of temporal dispersion on compound action potential area in human peripheral nerve

In 32 ulnar nerves of healthy volunteers, the mean area of the compound muscle action potential recorded over abductor digiti minimi was reduced by 7.4% when comparing above-elbow with wrist stimulation and by 1.9% when comparing above-elbow with below-elbow stimulation. In 20 of these nerves, the mean area of the compound nerve action potential (CNAP) recorded over the fifth digit was reduced by 36% when comparing above-elbow with wrist stimulation. Area reduction of the compound action potential, especially of the CNAP, appears to be a characteristic effect of temporal dispersion in peripheral nerve when utilizing the bipolar recording technique routinely employed in clinical neurophysiology. A thorough understanding of the effects caused by temporal dispersion and of their quantitative limits in normal peripheral nerve is important for the proper interpretation of nerve conduction studies.     

The effects of high-nutrient urea on in vitro bullfrog fundic mucosa

The effects of nutrient urea (240 mM) on H+ secretion, potential difference, and resistance were studied in isolated sheets of bullfrog fundic mucosa. H+ secretion was significantly reduced while transmucosal resistance was significantly increased and potential difference was significantly decreased. Measurement of CO2 utilization by, and distribution across, the mucosal sheets demonstrated that oxidative metabolism is increased (tCO2, 4.93 +/- 0.2 to 5.83 +/- 0.3 mumole/cm2 hr-1, P less than 0.05) and that generation of protons (H+) within the oxyntic cell is stimulated (delta CO2, 1.48 +/- 0.1 to 2.22 +/- 0.2 mumole/cm2 hr-1, P less than 0.05, and nutrient HCO-3 1.35 +/- 0.2 to 2.21 +/- 0.2 mueq/cm2 hr-1, P less than 0.05) in spite of paradoxically diminished H+ appearance on the secretory surface. Studies using 120 and 60 mM urea suggest that the effects may be dose dependent. Results with 240 mM sucrose on the nutrient surface would indicate that those seen with urea cannot be attributed entirely to the hyperosmolality. Pretreatment of the mucosal sheets with metiamide (10(-3) M) resulted in the expected decrease in titratable H+ (to 0) but had no effect on urea-stimulated oxidative metabolism (tCO2, 2.09 +/- 0.2 to 2.91 +/- 0.4 mumole/cm2 hr-1, P less than 0.02) or the generation of protons by the oxyntic cell (delta CO2, 0.68 +/- 0.1 to 1.35 +/- 0.3 mumole/cm2 hr-1, P less than 0.02, and nutrient HCO3- 0.83 +/- 0.1 to 1.65 +/- 0.3 mueq/cm2 hr-1, P less than 0.05). Both simultaneous or subsequent treatment with theophylline (5 X 10(-3) M) reversed the inhibitory effect of urea on H+ secretion. Transmission electron microscopy revealed involution of the secretory membrane following treatment with urea but maintenance of the microvillous secreting configuration of the membrane when theophylline was added to the nutrient solution. These results suggest that although nutrient urea stimulates the generation of H+ within the cell it simultaneously inhibits release of H+ by the secretory membrane. Failure to inhibit urea-stimulated generation of H+ within the cell by metiamide indicates that the increased oxidative metabolism and generation of protons stimulated by nutrient urea is probably not histamine-mediated. It is suggested that urea inhibits adenylyl cyclase and thus cAMP-mediated evolution of the secretory membrane with reduced H+ transport, an effect that can be reversed by inhibiting phosphodiesterase with theophylline.     

Pro-convulsant actions of theophylline and caffeine in the hippocampus: implications for the management of temporal lobe epilepsy

The pro-convulsant actions of theophylline and caffeine have been investigated using the hippocampal slice preparation and rats administered kainic acid or Metrazol. Both theophylline and caffeine induced the generation of epileptiform activity in the CA3 region of the hippocampal slice with convulsive dose50 (CD50) values of 3 microM respectively. Kainic acid-induced bursting in hippocampal slices was enhanced by theophylline (0.3-30 microM) and caffeine (1-100 microM). Theophylline induced burst firing in response to electrical stimulation in hippocampal area CA3 but not area CA1. Theophylline (50 mg/kg) strongly potentiated the effect of the limbic convulsant kainic acid in vivo whilst a dose of 200 mg/kg was necessary to significantly lower the threshold dose of Metrazol required to induce generalized convulsions. We conclude that alkylxanthines, probably by antagonizing the effect of endogenous adenosine, exert a pro-convulsant action in the hippocampus which preferentially promotes limbic seizures.     

Alopecia areata in Turkey: demographic and clinical features

Background  Alopecia areata is a complex genetic disease with still many unknown aspects, and many studies have been tried to find some clues about it.
Objective  We aimed to investigate the demographic and clinical characteristics of alopecia areata in Turkish patients.
Methods  Demographic data, localization, attack number in addition to some parameters such as disease duration, severity, age of onset, family history and ophiasis pattern were evaluated in 539 alopecia areata patients.
Results  The male to female ratio was 1.6 : 1. Occipital and beard-moustache areas were mostly affected. Positive family history was noticed in 24.1% of the patients. The age of onset was earlier in women than in men ( P =  0.04). Severe forms showed more persistent (≥ 1 year) disease duration ( P =  0.00). Ophiasis was more common in severe, long duration (≥ 1 year) and early onset (≤ 18 years) disease ( P =  0.00 for all parameters). Childhood alopecia areata (≤ 18 years) was also associated with long duration of the disease ( P =  0.016) and positive family history ( P =  0.008) when compared with adult onset (> 18 years) alopecia areata.     

Flexible tantalum stents implanted in aortas and iliac arteries: effects in normal canines

Vascular endoprostheses made of knitted tantalum wire and expanded over angioplasty balloons were placed into aortas or iliac arteries of 14 normal dogs. Twelve stents were placed into the infrarenal abdominal aorta and two stents in the left common iliac arteries by the left carotid artery approach. To firmly expand the stent against the vascular wall, nominal stent sizes 0.5-1.0 mm larger than the measured arterial diameter were required. Arteriography performed at specified follow-up intervals showed no evidence of thrombi or emboli; all side branches (lumbar arteries) covered by the stents remained patent. Vascular diameter decreased minimally at 8 and 26 weeks, associated with histopathologic evidence of neointimal buildup. This buildup was highest at 8 weeks (mean, 313 microns) and was slightly less at 26 weeks (mean, 223 microns). Almost complete coverage by endothelium was seen as early as 3 weeks. It is concluded that the flexible tantalum wire stents are well tolerated by the arterial wall and become quickly endothelialized. No excessive neointimal buildup was observed during the 6-month study.     

A comparison of thermography and electromyography in the diagnosis of cervical radiculopathy

We studied 20 asymptomatic control subjects and 14 patients with clinically unequivocal cervical radiculopathy to compare the diagnostic value of thermography with that of electromyography. We measured the average skin temperature of designated regions over the neck, shoulder, and upper extremities. We then compared the temperature between corresponding regions of the two limbs, and between fingers innervated by different roots in the same hand. Thermography was abnormal in 6 patients (43%), whereas electromyography was abnormal in 10 (71%). Thermographic abnormalities were seen only in the hands and fingers, and the pattern did not follow the dermatome of the clinically involved cervical root. When compared to electromyography, thermography provided no additional diagnostic information. Thus, thermography does not have an established role in the evaluation of patients with cervical radiculopathy.