The relevance of pulse repetition rate and radiant exposure to the neurophysiological effects of low-intensity laser (820 nm/pulsed wave) irradiation upon skin temperature and antidromic conduction latencies in the human median nerve

The effects of low-intensity near-infra-red laser irradiation (820 nm; 1.5 and 9.0 J cm^–2; pulsed at 12 Hz, 73 Hz and 5 kHz) upon peripheral neurophysiology and skin temperature were investigated using antidromic conduction studies in the human median nerve in vivo. Healthy human volunteers (n = 90) were recruited and allocated randomly to either a control group (n=10) or one of eight experimental groups (two radiant exposures, 1.5 J cm^–2 and 9.0 J cm^–2 at one of three pulse repetition rates, 12 Hz, 73 Hz or 5 kHz, in addition to a placebo group for each radiant exposure;n = 10 all groups). Analysis of variance (ANOVA) demonstrated a significant (p0.05) decrease in skin temperature following irradiation at the lowest radiant exposure (1.5 J cm^–2) combined with pulse repetition rates of 73 Hz and 5 kHz, with the greatest effect at 73 Hz. These changes in skin temperature were coupled with increases in negative peak latency (NPL); ie changes in NPL were inversely related to changes in skin temperature. However, in contrast to the authors' previous findings using continuous wave (CW) laser irradiation, differences in NPL were not found to be significant. These findings, therefore, provide little evidence of the neuro-physiological effects of low-intensity infra-red irradiation at the dosage levels and pulse repetition rates used here.     

Analgesia after inguinal herniorrhaphy with laparoscopic inspection of the peritoneum in children. Caudal block versus ilioinguinal/iliohypogastric block

The authors prospectively evaluated the efficacy of caudal epidural block versus local infiltration combined with ilioinguinal/iliohypogastric block for analgesia after inguinal herniorrhaphy with laparoscopic inspection of the peritoneum. During standardized anesthetic care, 24 children were randomized to Group I (caudal epidural block with 1.2 mL/kg of 0.25% bupivacaine) or to Group II (local infiltration with an ilioinguinal/iliohypogastric block). Postoperative pain scores were significantly lower at all four evaluation points in Group I than in Group II. Patients in Group I had a significantly decreased requirement for supplemental intravenous fentanyl. Intra-operative requirements for isoflurane were decreased in Group I. The expired concentration of isoflurane was 0.4 +/- 0.1 (mean +/- SEM) in Group I and 1.5 +/- 0.3 in Group II. Time to extubation was 3.8 +/- 0.5 minutes in Group I and 8.2 +/- 1.1 minutes in Group II. The time from arrival in the postanesthesia care unit until discharge home was 113 +/- 3 minutes in Group I and 152 +/- 11 minutes in Group II. Caudal epidural block was more effective than local infiltration in controlling pain after herniorrhaphy with laparoscopy in children and resulted in earlier discharge home.     

Predictors of sun protective behaviors among school students

A random sample of students (N = 3,655) in Grades 7, 9, and 11 from 55 schools in Queensland (Australia) were surveyed about their sun protection knowledge, attitudes, and behaviors. An aggregate sun protection behavior index (SPBI) was developed from self-reported behaviors on a school day and a weekend day. Repeated measures regression analyses revealed that negative views of sun protection measures were associated with low scores on the SPBI, an association that was strongest among older students and in larger schools. Low perceived parental sun protective behaviors were associated with low SPBI ratings, and this association was greatest in small schools and on Saturdays. Older students had lower SPBI ratings, but their scores increased on Saturdays. Gender did not appear to be independently related to the SPBI after adjustment for the other variables. These findings reinforce the need for adolescent sun protection programs to address the complex interactions among psychological, social, and environmental factors that influence different subgroups of the student population.     

Measurement tools used in the study of eccentric contraction-induced injury

The objective of this review is to evaluate the measurement tools currently used in the study of eccentric contraction-induced muscle injury, with emphasis on their usefulness for quantifying the magnitude and duration of the injury and as indicators of muscle functional deficits. In studies in humans, it was concluded that measurements of maximal voluntary contraction torque and range of motion provide the best methods for quantifying muscle injury. Similarly, in animal studies, the in vitro measurement of electrically elicited force under isometric conditions was considered to be the best of the measurement tools currently in use. For future studies, more effort should be put into measuring other contractile parameters (e.g. force/torque-velocity and force/torque-length relationships maximal shortening velocity and fatigue susceptibility) that may reflect injury-induced functional impairments. The use of histology, ratings of soreness and the measurement of blood or bath levels of myofibre proteins should be discouraged for purposes of quantifying muscle injury and/or functional impairment.     

Cytotoxicity of (2,2':6',2'-terpyridine)platinum(II) complexes to Leishmania donovani, Trypanosoma cruzi, and Trypanosoma brucei

A range of (2,2':6',2'-terpyridine)platinum(II) complexes are shown to possess antiprotozoal activity in vitro against Leishmania donovani, Trypanosoma cruzi, and Trypanosoma brucei,the causative organisms of tropical diseases leishmaniasis and trypanosomiasis. The best compounds caused 100% and 78% inhibition of growth of the intracellular amastigote forms of L. donovani and T. cruzi, respectively, at a concentration of 1 microM and 100% inhibition of growth of the bloodstream trypomastigote forms of T. brucei at a concentration of 0.03 microM. The results obtained with complexes in which the fourth ligand to platinum(II) is capable of being substituted with a substitution inert hydroxyethanethiolate complex are compared. The ammine complexes show high antiprotozoal activity suggesting that the trans influence of the 2,2':6',2'-terpyridine ligand has a profound effect on the ease of displacement of the fourth ligand in (2,2':6',2' -terpyridine)platinum(II) complexes, although nonbonded interaction between the ammine ligand and the 6 and 6' ' hydrogens probably also weakens the ligation to Pt(II).     

Prognostic significance of DNA ploidy in Ta/Tl bladder cancer: A southwest oncology group study

While 80% of transitional cell carcinomas (TCC) present as Ta Tl lesions, they account for only 15% of deaths caused by TCC. We have evaluated the ability of DNA ploidy analysis to predict outcome in 228 patients with Ta Tl TCC. All patients were judged to be at increased risk for tumor recurrence due to having two occurrences of Stage TI tumor within 56 weeks, or three or more tumors presenting simultaneously within 16 weeks of registration. Concurrent carcinoma in situ was acceptable. All patients were treated with either bacillus Calmette Guerin (BCG) immunotherapy or mitomycin-C (MMC) intravesical chemotherapy. Patients with nondiploid tumors had higher hazard rates for both tumor progression and death (p = 0.007 and p = 0.016, respectively); however, the prognostic information of DNA ploidy was not additive to tumor grade.     

The vasa vasorum and angioplasty

Interruption of flow in the vasa vasorum may lead to medial necrosis and aneurysm formation. The purpose of this study was to determine whether angioplasty produces significant alterations in the morphology or blood flow of the vasa vasorum of the dilated artery. The morphology of the canine vasa vasorum was studied before and after angioplasty; in a separate experiment vessel wall blood flow (VWBF) in canine carotid arteries was measured after angioplasty to determine whether physiologic regulation of the blood flow was disrupted by arterial dilation. No morphologic changes could be demonstrated in the vasa vasorum of the dilated artery; however, VWBF was increased by 1194 +/- 215% (mean +/- standard error, p less than 0.01) between 90 and 120 minutes after angioplasty. VWBF in the adjacent nondilated arterial segment was also increased (720 +/- 177% between 10-30 minutes, p less than 0.01) but returned toward normal after 60 minutes. Adenosine caused a "paradoxical" decrease in VWBF (p less than 0.05) of the dilated arterial segment while causing increased VWBF (p less than 0.05) in the thoracic aorta. Angioplasty appears to produce persistent hyperemia in the dilated arterial wall. A paradoxical response to adenosine suggests that vasa vasorum in the dilated arterial segment are maximally vasodilated. This may be due to mechanical disruption of vasomotor tone or to release of vasoactive substances.     

Anomalous kinetic visual fields found in family members of patients with a confirmed diagnosis of Gilles de la Tourette syndrome.

Three visual manifestations of Gilles de la Tourette syndrome (TS), a neuropsychiatric disorder, have been previously reported. In this paper we report anomalies in the measured kinetic paracentral visual field of TS patients and their family members. We found that 96% of TS patients exhibited paracentral kinetic visual field defects (nasal and temporal steps, enlargement, "ringing," and/or baring of the blind spot). Ninety-three percent of fathers of TS children and, surprisingly, about 80% of mothers exhibit these characteristic visual field anomalies. Sample data and examples of family studies are reported.     

Structural studies on tazobactam.

Tazobactam (3, C10H12N4O5S) is an effective inhibitor of bacterial beta-lactamases. It crystallizes with unit cell dimensions a = 10.230 (2) A, b = 14.396 (2) A, and c = 17.291 (2) A in space group P2(1)2(1)2(1). Compared to the related inhibitor sulbactam (2), which lacks the triazole ring, crystalline tazobactam exhibits very similar beta-lactam geometry and the same S(1) envelope conformation of the thiazolidine ring. However, in both independent molecules of 3 a triazole ring nitrogen atom accepts an intermolecular hydrogen bond; similar interaction by this moiety of 3 with a hydrogen-bond donor on the enzyme, which is impossible for 2, could account for its enhanced inhibitory power. Semiempirical molecular orbital calculations show pronounced negative potential there. Molecular mechanics supports the hypothesis that the carboxyl group can rotate freely and the triazole ring can "flip".