Effect of liposomes and niosomes on skin permeation of enoxacin

The skin permeation and partitioning of a fluorinated quinolone antibacterial agent, enoxacin, in liposomes and niosomes, after topical application, were elucidated in the present study. In vitro percutaneous absorption experiments were performed on nude mouse skin with Franz diffusion cells. The influence of vesicles on the physicochemical property and stability of the formulations were measured. The enhanced delivery across the skin of liposome and niosome encapsulated enoxacin had been observed after selecting the appropriate formulations. The optimized formulations could also reserve a large amount of enoxacin in the skin. A significant relationship between skin permeation and the cumulative amount of enoxacin in the skin was observed. Both permeation enhancer effect and direct vesicle fusion with stratum corneum may contribute to the permeation of enoxacin across skin. Formulation with niosomes demonstrated a higher stability after 48 h incubation compared to liposomes. The inclusion of cholesterol improved the stability of enoxacin liposomes according to the results from encapsulation and turbidity. However, adding negative charges reduced the stability of niosomes. The ability of liposomes and niosomes to modulate drug delivery without significant toxicity makes the two vesicles useful to formulate topical enoxacin.

In vitro and in vivo evaluations of topically applied capsaicin and nonivamide from hydrogels

The purpose of this study was designed to investigate the in vitro and in vivo skin absorption of capsaicin and nonivamide from hydrogels. Various commercialized creams of capsaicin were also compared with hydrogels. Both skin stripping technique and Mexameter were applied to evaluate the level of capsaicin and nonivamide retained in stratum corneum (SC) and skin erythema in vivo. The partition of drug between skin and the hydrogel matrix was considered to play an important role in the permeation process. The in vitro permeation of capsaicin from hydrogels depends on the physicochemical nature and the concentration of the polymer used. The incorporation of nonionic Pluronic F-127 polymer into hydrogels resulted in a retarded release of capsaicin. On the other hand, the in vitro capsaicin permeation showed higher levels in cationic chitosan and anionic carboxymethyl cellulose (CMC) hydrogels than cream bases. The permeation of nonivamide was retarded at the late stage of in vitro application. The inter-subject variation was more significant in the in vivo study than in vitro skin permeation experiments. The cream induced in vivo skin erythema depending on the drug concentration, however, the dose-dependence was not observed in hydrogels. Nonivamide-treated skin showed stronger erythema than capsaicin-treated skin. The present study indicates that there is a moderate correlation between in vitro skin permeation and in vivo erythema responses of topically applied capsaicin and nonivamide. The correlation between drug amount in SC and skin erythema test in vivo was also observed.

Capsaicin and nonivamide as novel skin permeation enhancers for indomethacin

The study was conducted in vitro to investigate the changes of indomethacin transdermal permeation pretreated by capsaicin and nonivamide, two compounds chemically similar to Azone. The combined effect of low frequency ultrasound (20 kHz) and enhancers on the indomethacin permeation was also evaluated. The experimental data demonstrated that capsaicin and nonivamide significantly enhanced the flux of indomethacin across nude mouse skin. Enhancement effects of both analogues were very similar and depended predominantly on the concentration tested. Histological examination coupled with visual scores indicated the safety of capsaicin and nonivamide on skin structure. Simultaneous application of ultrasound and enhancers significantly increased skin permeation of indomethacin compared with either ultrasound or enhancers alone. Better effect was obtained by the combination with capsaicin than nonivamide.

Effect of trilinolein on superoxide dismutase activity and left ventricular pressure in isolated rat hearts subjected to hypoxia and normoxic perfusion

Oxygen-derived free radicals have been implicated in the development of myocardial injury during hypoxia/reperfusion. Antioxidants can effectively inhibit the formation of free radicals and ameliorate the myocardial damage which may occur during hypoxia/reperfusion. Trilinolein is a triacylglycerol recently purified from the traditional Chinese medicinal plant Panax pseudo-ginseng. It has linoleic-acid residues as the only type of fatty acid residue in all three esterified positions of the triacyglycerol. It has been proposed that decreased endogenous superoxide dismutase (SOD) activity may contribute to free radical-mediated reperfusion injury of the ischemic myocardium. In the present study, when isolated rat hearts were subjected to hypoxia for 10, 30, 60 and 90 min without normoxic perfusion, a significant decrease in Mn-SOD activity was shown throughout the period of hypoxia, whereas the Cu.Zn-SOD activity was increased at 10 and 30 min but was not different from the baseline at 60 and 90 min of hypoxia. In rat hearts pretreated with 10(-7) mol/l trilinolein and subjected to 60 min of hypoxia without normoxic perfusion, Cu.Zn-SOD was augmented compared with baseline and compared with hearts subjected to 60 min of hypoxia without trilinolein, whereas Mn-SOD activity was still reduced compared with baseline, although less so than after 60 min of hypoxia without trilinolein. Pretreatment with trilinolein was associated with better preservation of left ventricular function during hypoxia and more rapid return to recovery during normoxic perfusion. This myocardial protective effect may be related to an antioxidant effect through potentiation of SOD, particularly Cu.Zn-SOD during hypoxia.

Erb's and cervical somatosensory evoked potentials: correlations with body size

Median and ulnar Erb's (N9) and cervical (N13) somatosensory evoked potentials were correlated with height, arm span, arm length, and Erb's length. All body measurements had high correlations with the N9 and N13 latencies. The highest correlation was obtained between the N9 latency and Erb's length. The N13 latency was correlated higher with height than with arm length. The data suggest that height can be used to construct normogram correlating with the N13 latency.

Quantitative topographic electrophysiology and functional neurologic status in right middle cerebral artery infarction

Thirteen patients with clinically and radiographically defined right middle cerebral artery infarction were studied using EEG, quantitative electroencephalographic (QEEG) spectra, and multi-channel evoked potentials. The purpose of this effort was to develop QEEG rules that related to the patient's neurologic status. Three QEEG relative delta spectral patterns were identified in the right hemisphere which related to neurologic residua. These include limited perisylvian involvement, mixed involvement of perisylvian and extrasylvian regions, and extrasylvian involvement only. While there were parallels between QEEG spectral patterns and auditory, visual and somatosensory evoked potentials, there were modality specific features consistent with functional differences.

Decreased plasma gelsolin fosters a fibrotic tumor microenvironment and promotes chemoradiotherapy resistance in esophageal squamous cell carcinoma

BACKGROUND

Stromal fibrosis is highly associated with therapeutic resistance and poor survival in esophageal squamous cell carcinoma (ESCC) patients. Low expression of plasma gelsolin (pGSN), a serum abundant protein, has been found to correlate with inflammation and fibrosis. Here, we evaluated pGSN expression in patients with different stages of cancer and therapeutic responses, and delineated the molecular mechanisms involved to gain insight into therapeutic strategies for ESCC.

METHODS

Circulating pGSN level in ESCC patients was determined by enzyme-linked immunosorbent assay analysis, and the tissue microarray of tumors was analyzed by immunohistochemistry staining. Cell-based studies were performed to investigate cancer behaviors and molecular mechanisms, and mouse models were used to examine the pGSN-induced tumor suppressive effects in vivo.

RESULTS

Circulating pGSN expression is distinctively decreased during ESCC progression, and low pGSN expression correlates with poor therapeutic responses and poor survival. Methylation-specific PCR analysis confirmed that decreased pGSN expression is partly attributed to the hypermethylation of the GSN promoter, the gene encoding pGSN. Importantly, cell-based immunoprecipitation and protein stability assays demonstrated that pGSN competes with oncogenic tenascin-C (TNC) for the binding and degradation of integrin αvβ3, revealing that decreased pGSN expression leads to the promotion of oncogenic signaling transduction in cancer cells and fibroblasts. Furthermore, overexpression of pGSN caused the attenuation of TNC expression and inactivation of cancer-associated fibroblast (CAF), thereby leading to tumor growth inhibition in mice.

CONCLUSIONS

Our results demonstrated that GSN methylation causes decreased secretion of pGSN, leading to integrin dysregulation, oncogenic TNC activation, and CAF formation. These findings highlight the role of pGSN in therapeutic resistance and the fibrotic tumor microenvironment of ESCC.

Modulation of cytochrome P450-dependent monooxygenases in streptozotocin-induced diabetic hamster: II. Reverse role of insulin in P450 activity and defluorination

BACKGROUND

Metabolic activities of cytochrome (cyt) P450-dependent monooxygenase could be modulated by diabetic state in experimental diabetic animals. The purpose of this study is to validate the effect of insulin on the modulation of the metabolic activity of cyt P450 and the defluorination ability to inhalational anesthetics in diabetic animals.

METHODS

Diabetic state in golden Syrian hamsters was achieved by intraperitoneal injection of streptozotocin 40 mg/kg once a day for 4 days. After stabilization of diabetic state for 6 weeks, a regimen of insulin treatment given subcutaneously was carried out. Metabolic activities of cyt P450 were assessed by the reaction with benzo(a) pyrene, pentoxyresorufin, aniline and erythromycin (specific substrates). The metabolic activities of cyt 1A1, 2B1, 2E1 and 3A4 respectively in a NADPH-generating system in microsomal preparations of the diabetic hamsters were observed before and after insulin treatment, and were compared with the control group. The ability of defluorination was evaluated by measuring the free fluoride metabolites after incubating the microsomes with enflurane in diabetic and insulin-treated hamsters. Contents of cyt P450 isozymes were measured by electrophoresis and immunoblotting before and after insulin treatment. Pathological features of hepatocytes in diabetic hamsters were evaluated microscopically before and after insulin treatment.

RESULTS

The defluorination of enflurane and activity of aniline hydroxylase (cyt 2E1) were successfully induced by diabetic state (P < 0.01). The pentoxyresorufin O-dealkylase (cyt 2B1) was inhibited nearly 50% in the diabetic hamster liver when compared with that of control (P < 0.01). While the activities of benzo(a)pyrene hydroxylase (cyt 1A1) and the erythromycin N-demethylase (cyt 3A4) were basically unaffected by diabetes, alterations in content of cyt P450 were parallel to the alterations in enzyme activities. Microscopically, diabetes induced vacuolization with fatty droplets in the hepatocytes. After treatment with insulin injection, the enzyme activities, protein content and pathologic features returned to the baseline similar to the control.

CONCLUSIONS

Our data demonstrated that under diabetic state, metabolic activities of cyt P450 and its extent of defluorination would be polymorphically modulated. After administration of insulin, the activities of cyt P450 and defluorination of enflurane returned to baseline as the blood sugar level had been normalized. This could remind the clinicians of the importance of insulin treatment in the potential drug-to-drug interactions in the diabetic patients.

Estimation of costs due to hospitalization for first-ever stroke patients in northern Taiwan

BACKGROUND

The need for healthcare services and the related costs for stroke patients may rise steadily in the future. Even with the predictable and substantial burden of stroke, little effort has been devoted to measuring the population-based direct medical and nonmedical costs in Taiwan.

METHODS

Data from the study "Epidemiological Study of Stroke, Diabetes, and Cardiovascular Disease," which included 8,705 people older than 35 years of age, and the study "Costs of Stroke," which included 660 first-ever stroke patients, were used for the cost calculations. The cost of hospital care for stroke patients was obtained in two steps. First, the incidence of stroke and readmissions within one year were tallied; the sum was then multiplied by the average length of stay. Second, the total medical and nonmedical costs were divided by the sum obtained from step 1. The resulting quotient obtained was the cost of hospital care for stroke patients per day.

RESULTS

There were 6,691 incidents of stroke and stroke-related readmissions in 1995 (4,041 men and 2,650 women). The total person-days of hospital stay were 233,569 days (144,264 for men and 89,305 days for women). The average medical and nonmedical costs of hospital care per person-day was US $251.4 (NT $6,788 at an exchange rate of US $1 = NT $27). Cost for men (US $287, NT $7,749) was more than for women (US $208, NT $5,616). The total direct costs of hospital care were US $58,710,000 (NT $1,585,000,000) in 1995.

CONCLUSIONS

An average of US $1,682,000 (NT $45,410,000) in hospital care costs for stroke could have been saved in 1995 if the person-day stay had been decreased by only one day.

GDP-bound Rab37 modulates M2-like tumor-associated macrophage polarization by attenuating STAT1 translocation to downregulate the type I IFN pathway

BACKGROUND

Tumor-associated macrophages (TAMs) in the tumor microenvironment (TME) primarily polarize into the M2-phenotype. Our previous study showed that the small GTPase Rab37 mediates IL-6 trafficking in macrophages for M2 polarization. Here, we uncover an unconventional role of Rab37, independent of vesicle trafficking, in promoting M2 polarization of TAMs.

METHODS

The gene profiles in wild-type and Rab37 knockout (KO) bone marrow-derived macrophages (BMDMs) were analyzed using cDNA microarray. The mechanism of Rab37 in regulating the interferon (IFN) pathway was confirmed through in vitro/vivo assays and clinical studies.

RESULTS

Type I IFN signaling was highly enriched in BMDMs from Rab37 KO mice. Moreover, Rab37 induction and decreased type I IFN genes were observed in macrophages treated with lung cancer-conditioned medium and epigenetic drugs, indicating an epigenetic regulation of Rab37 in TAMs. Mechanistically, GDP-bound Rab37 interacted with the nuclear localization sequence of STAT1 to sequest it in the cytosol from its transcription activities, thus leading to the downregulation of IFN genes. Clinically, CD163+/Rab37+/STAT1cytosol in TAMs expression signature correlated with advanced tumor stages and poor survival of lung cancer patients.

CONCLUSIONS

Our findings highlight the cytosolic interaction of Rab37-STAT1 in M2 TAM polarization, with CD163+/Rab37+/STAT1cytosol TAMs as a lung cancer prognosis biomarker.

Correlation between sonography and pathology in thyroid diseases

Ultrasonography was performed on the thyroid glands of 47 patients with various thyroid diseases, in a fresh state, immediately following operation. The thyroid glands were then sectioned along the plane of the most significant sonographic changes. The pathologic changes of the sectioned plane were observed and compared with the sonographic changes. In nodular goiter, the sonographic changes were usually heterogeneous. The margin was either well-defined or ill-defined, and cystic changes might play a minor or major part in the thyroid nodules. In follicular adenoma, the changes were isoechoic in adenoma with embryonal type follicles and hyperechoic in adenoma with colloid type follicles. In adenoma of the oxyphilic cells, the echogenicity was somewhat greater in the hemorrhagic part compared to the area with oncocytic change only. In papillary carcinoma, the lesions usually manifested as well-limited, heterogeneous, hypoechoic nodules. Cystic degenerations were frequently noted. There were discrete particles corresponding to microcalcification in 4 out of 6 cases. In follicular carcinoma, the sonographic changes also showed well-limited nodules. However, the echogenicity was not decreased as much as in papillary carcinoma, and it could be either homogeneous and isoechoic, or hypoechoic. Relatively large particles with an acoustic sign, which corresponded to calcification, were noted in 2 out of 4 cases. In medullary carcinoma, the lesion was well-limited and hypoechoic. The particles present in sonography corresponded to calcification in the amyloid. In Graves' disease, the main sonographic change was a diffusely homogeneous, isoechoic or hypoechoic lesion. Cystic change was rarely present. Dispersed particles were rarely present and corresponded to fibrosis in the thyroid tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Infarction of the superior temporal gyrus: a description of auditory evoked potential latency and amplitude topology

P1 and N1 of the cortical auditory evoked potential (AEP) were studied with multiple electrodes in 10 normal subjects and 6 patients with left middle cerebral artery infarction. Patients were selected based on neurological examination and on CT scans showing both (1) infarction limited to the vascular territory and (2) involvement of posterior portion of superior temporal gyrus. Waveforms recorded from C3, Cz, and C4 were examined for peak latency and amplitude of P1 and N1 on all subjects. Topographic displays of amplitude over P1 and N1 latency ranges were also examined. In normals, P1 was identified in 9 of the 10 subjects at all three electrode sites. In patients, P1 was identified at C3 in only 1 of the 6. N1 was present at all three electrodes in the 10 normal subjects and in 5 of the 6 patients. The remaining patient had N1 at C4 and Cz only. Examination of amplitude topology showed as asymmetric evolution of P1 and N1 in the patients. This asymmetry was not present in normals. The results of this study are consistent with theory that P1 arises from primary auditory cortex. Results further suggest multiple generators for N1. Additional study correlating topographic display from multichannel recordings with CT or MRI in brain-injured patients may bring more insight into N1 generators.

The suppressive role of phytochemical-induced glutathione S-transferase Mu 2 in human urothelial carcinoma cells

Glutathione S-transferases (GSTs) belong to one class of phase 2 detoxification enzymes which are important in metabolism and/or detoxification of various electrophilic endogenous metabolites and xenobiotics. From the available database, we found that GSTM2 gene expression is lower in high stages of bladder urothelial carcinoma than in stage 1 and normal bladder tissue. GSTM2 overexpression retards invasion, migration and tumor sphere formation of bladder cancer cells. Analysis of GSTM2 promoter activity shows that one SP1 site located at - 48 to - 40 bp is important for GSTM2 gene expression in BFTC 905 cells. An SP1 inhibitor, mithramycin A, inhibits GSTM2 promoter activity and protein expression. SP1 overexpression also increases GSTM2 expression in BFTC 905 and 5637 cells. Eight potential phytochemicals were analyzed for GSTM2 promoter activation, and results indicated that baicalein, berberrubine, chalcone, curcumin, resveratrol, and wogonin can increase promoter activity. In endogenous GSTM2 expression, berberrubine and resveratrol activated GSTM2 mRNA and protein expression the most. A DNA methylation inhibitor, 5-aza-deoxycytidine, can decrease GSTM2 gene methylation level and then increase its gene expression; 50 μM berberrubine decreased the GSTM2 gene methylation level, providing a mechanism for activating GSTM2 gene expression. Berberrubine and resveratrol also increased SP1 protein expression as one of the mechanisms for GSTM2 gene expression. In summary, berberrubine and resveratrol activates GSTM2 expression which inhibits cell proliferation, migration, and invasion of bladder cancer cells. The GSTM2 expression mechanism is partially via SP1 activation, and the effect of berberrubine is also partly via DNA CpG demethylation.