Nosocomial postoperative endophthalmitis: a 14-year review

Background The objective of this study was to evaluate the incidence, predisposing surgery, management and final visual outcome of postoperative endophthalmitis over a 14-year period at one institute.Methods This retrospective study reviewed all intraocular operations performed between 1 January 1991 and 31 August 2004 at Chang Gung Memorial Hospital, Kaohsiung Medical Center, to determine the incidence of nosocomial postoperative endophthalmitis and the characteristics of patients who developed this condition.Results The overall incidence of postoperative endophthalmitis after intraocular surgery was 0.19% (56 out of 30,219). Postoperative endophthalmitis developed in 56 eyes in 56 patients during the study period. The condition developed after cataract surgery in 46 eyes, after penetrating keratoplasty in 6 eyes, after filtering surgery in 2 eyes, after secondary intraocular lens implant in 1 eye, and after vitrectomy in 1 eye. Postoperative endophthalmitis was culture-positive in 31 cases (55%). The most frequent organism isolated was coagulase-negative Staphylococcus. Factors associated with better visual acuity outcomes included low virulence of isolated pathogen, initial visual acuity of counting fingers or better, and history of cataract surgery compared with other intraocular surgery.Conclusion The overall incidence of endophthalmitis after intraocular surgery was 0.19%. The results of this 14-year review from a local medical center may serve as a source of comparison for other centers and future studies.No proprietary interests     

Multiple opsin mRNA species in bovine retina

Two retina specific cDNAs have been isolated by differential colony hybridization to retina and brain, and one of them, pCR-394, was identified as an opsin cDNA. By Northern hybridization experiment, the opsin cDNA hybridized to two species of bovine mRNA, one approximately 18 S (1800 bp) and the other 22 S (2600 bp). Using pCR-394 as a probe two opsin clones, R-5 (about 1200 bp) and LR-8 (about 2500 bp), were isolated from a cDNA library which was prepared by the method of Okayama-Berg. Each had a different length of 3'-untranslated DNA. The nucleotide sequences of R-5 and LR-8, as well as Northern and Southern hybridization experiments suggest that at least two species of opsin mRNA are expressed from a single gene. When the effects of illumination were examined by Northern hybridization and translation assays, the ratio of the two opsin mRNA species was changed between light- and dark-adapted eyes.     

Inhibitory effects of cordycepin on cyclic nucleotide-dependent and cyclic nucleotide-independent protein kinases

The in vitro effect of cordydepin was tested using various protein kinase preparations. These included cyclic AMP-dependent protein kinase (A-PK) from bovine heart, cyclic GMP-dependent protein kinase (G-PK) from fetal guinea pig lung, and two cyclic nucleotide-independent nuclear protein kinases (PK-I and PK-II) prepared from rat hepatoma 3924A and rat liver. The 50 per cent inhibitory concentrations (id₅₀) of cordycepin for A-PK and G-PK ranged from 1.5–5.0 × 10^?4M and 2.5–8.0 × 10^?4 M, respectively, depending on the presence or absence of cyclic AMP and cyclic GMP in the assay. The id₅₀ of cordycepin with either hepatoma 3924A or rat liver PK-I and PK-II was 4.5 × 10^?5 M and 1.0 × 10^?3 M. respectively. The inhibitory effect of cordycepin was competitive with respect to ATP in all cases. The K_{m} for ATP was increased 3-fold and 5-fold by 5 × 10^?4 M cordycepin for G-PK and A-PK, respectively, while the K_m for ATP was increased 10-fold and 4-fold by 1 × 10^?3 M cordycepin for PK-I and PK-II, respectively.     

Mechanisms underlying phase lag between systemic arterial blood pressure and cerebral blood flow velocity

To explore the mechanisms underlying the phase lag between oscillations in arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV), ABP and CBFV signals were recorded noninvasively from normal volunteers who lay quietly in a supine position. Mean ABP (MAP) and CBFV (MFV) were calculated beat-to-beat by means of integration. Cerebral vascular resistance (CVR) was calculated by dividing MAP with MFV. Frequency domain analysis of MAP, MFV and CVR signals revealed very-low frequency (VLF, 0.016-0.04 Hz), low-frequency (LF, 0.04-0.15 Hz), and high-frequency (HF, 0.15-0.4 Hz) components. The transfer phase of MAP-CVR coupling in the LF and HF range was frequency-dependent, which is equivalent to a time delay of 2 s. However, the transfer phase differed in the CVR-MFV coupling in that the phase was distributed around 180 degrees across the LF and HF ranges. Cross-correlation analysis revealed a positive relationship between MAP-CVR coupling, with MAP leading by 2 s, and a negative relationship between CVR-MFV coupling, with CVR leading by 0.3 s. We concluded that the phase lag between oscillations in ABP and CBFV was chiefly contributed to by the starting latency of cerebral autoregulation (i.e. cerebral vasomotion, revealed by MAP-CVR coupling). Moreover, the negative correlation of the CVR-MFV coupling could offer a different explanation for the physiologic significance of the phase lead of CBFV-ABP oscillations.     

Dihydropyridine-insensitive calcium currents contribute to function of small cerebral arteries

Although dihydropyridines are widely used for the treatment of vasospasm, their effectiveness is questionable, suggesting that other voltage-dependent calcium channels (VDCCs) contribute to control of cerebrovascular tone. This study therefore investigated the role of dihydropyridine-insensitive VDCCs in cerebrovascular function. Using quantitative PCR and immunohistochemistry, we found mRNA and protein for L-type (Ca_V1.2) and T-type (Ca_V3.1 and Ca_V3.2) channels in adult rat basilar and middle cerebral arteries and their branches. Immunoelectron microscopy revealed both L- and T-type channels in smooth muscle cell (SMC) membranes. Using patch clamp electrophysiology, we found that a high-voltage-activated calcium current, showing T-type channel kinetics and insensitivity to nifedipine and nimodipine, comprised ∼20% of current in SMCs of the main arteries and ∼45% of current in SMCs from branches. Both components were abolished by the T-type antagonists mibefradil, NNC 55-0396, and efonidipine. Although nifedipine completely blocked vasoconstriction in pressurized basilar arteries, a nifedipine-insensitive constriction was found in branches and this increased in magnitude as vessel size decreased. We conclude that a heterogeneous population of VDCCs contributes to cerebrovascular function, with dihydropyridine-insensitive channels having a larger role in smaller vessels. Sensitivity of these currents to nonselective T-type channel antagonists suggests that these drugs may provide a more effective treatment for therapy-refractory cerebrovascular constriction.     

Generalized Anxiety Disorder,Comorbid Major Depression and Heart Rate Variability: A Case-Control Study in Taiwan

Objective

Decreased heart rate variability (HRV) has been reported in generalized anxiety disorder (GAD), but the results are mixed. Little is known about the impact of comorbid major depression (MD) on HRV in GAD patients. Both issues necessitate further investigation.

Methods

Twenty unmedicated, physically healthy GAD patients, 20 GAD patients with a secondary diagnosis of MD, 40 MD patients and 60 matched controls were recruited. We used the Hamilton Anxiety Rating Scale and the Hamilton Depression Rating Scale to assess anxiety and depression severity, respectively. Cardiac autonomic function was evaluated by measuring HRV parameters. Frequency-domain indices of HRV were obtained.

Results

Three patient groups had more anxiety and depression symptoms than control subjects, but heart rates (HRs) were significantly elevated only in GAD patients with comorbid depression. Relative to controls, GAD patients had reduced HRV while GAD patients with comorbid depression displayed the greatest reductions in HRV among three patients groups. Correlation analyses revealed anxiety/depression severity significantly associated with HRs, variance, LF-HRV and HF-HRV. However, separately analyzing among individual groups and adjusting for HRV-associated covariables rendered the correlations non-significant.

Conclusion

Our results suggest that reduction in HRV is a psychophysiological marker of GAD and individuals with comorbid GAD and MD may be distinguished based on psychophysiological correlates (for example, HF-HRV) from non-comorbid GAD patients. Taken into account that comorbid depression may confer increased risks for cardiovascular events in GAD patients, this subgroup of GAD patients may benefit better from cardiovascular risk reduction strategies.     

Isolation of a Natural Antioxidant, Dehydrozingerone from Zingiber officinale and Synthesis of Its Analogues for Recognition of Effective Antioxidant and Antityrosinase Agents

In the present study, the antioxidative and inhibitory activity of Zingiber officinale Rosc. rhizomes-derived materials (on mushroom tyrosinase) were evaluated. The bioactive components of Z. officinale rhizomes were characterized by spectroscopic analysis as zingerone and dehydrozingerone, which exhibited potent antioxidant and tyrosinase inhibition activities. A series of substituted dehydrozingerones [(E)-4-phenyl-3-buten-2-ones] were prepared in admirable yields by the reaction of appropriate benzaldehydes with acetone and the products were evaluated in terms of variation in the dehydrozingerone structure. The synthetic analogues were examined for their antioxidant and antityrosinase activities to probe the most potent analogue. Compound 26 inhibited Fe2+-induced lipid peroxidation in rat brain homogenate with an IC50 = 6.3+/-0.4 microM. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical quencher assay, compounds 2, 7, 17, 26, 28, and 29 showed radical scavenging activity equal to or higher than those of the standard antioxidants, like alpha-tocopherol and ascorbic acid. Compound 27 displayed superior inhibition of tyrosinase activity relative to other examined analogues. Compounds 2, 17, and 26 exhibited non-competitive inhibition against oxidation of 3,4-dihydroxyphenylalanine (L-DOPA). From the present study, it was observed that both number and position of hydroxyl groups on aromatic ring and a double bond between C-3 and C-4 played a critical role in exerting the antioxidant and antityrosinase activity.     

Effects of 5-HT(3) antagonism on postprandial gastric volume and symptoms in humans

BACKGROUND: Alosetron reduces symptoms of dyspepsia, but the physiological basis for the symptomatic benefit is unclear. AIM: To assess 5-HT3 antagonism on postprandial gastric volume and symptoms after ingestion of maximum tolerable volume of a liquid meal. METHODS: In 36 healthy volunteers, we assessed effects of placebo, 0.5 and 1 mg b.d. alosetron on fasting and postprandial gastric volumes (using single photon emission computed tomography) and symptoms based on 100 mm VAS, 30 min after maximum volume ingested. RESULTS: The 5-HT3 antagonist reduced postprandial symptoms (aggregate score: P < 0.05), nausea (P < 0.001), and tended to reduce bloating (P=0.08). Both 0.5 and 1 mg alosetron reduced nausea (P < 0.025); 1 mg alosetron reduced aggregate symptoms (P < 0.05) and bloating (P < 0.05). Effects on pain (P=0.19) and fullness (P=0.14) were not statistically significant. There were no significant effects of the 5-HT3 antagonist on volume of meal tolerated or on SPECT-measured fasting or postprandial gastric volumes. CONCLUSION: 5-HT3 antagonism reduces aggregate symptoms, nausea and bloating after a liquid meal without increase in gastric volumes, suggesting a role for 5-HT3 in afferent functions in healthy humans during the postprandial period.