An evaluation of the effects of nonselective and cardioselective β-blockers on wound healing in Sprague Dawley rats

OBJECTIVES

To investigate the effect of a nonselective β-blocker (propranolol) and cardioselective β-blocker (metoprolol) on wound healing in rats using incision and excision wound models and to compare the effect of these drugs on wound healing.

MATERIALS AND METHODS

Propranolol and metoprolol were given orally. Sprague Dawley rats of either sex were used. Incision and excision wound models were used to evaluate the wound-healing activity. Effects of metoprolol and propranolol on tensile strength, period of epithelialization, and hydroxyproline content were observed. Histological analysis was done to see collagen deposition and inflammatory infiltrate.

STATISTICAL ANALYSIS USED

The data was subjected to analysis of variance (ANOVA) followed by Scheffe's test. P < 0.05 was considered to be statistically significant. Statistical analysis was done using SPSS software version 15.0.

RESULTS

Administration of propranolol or metoprolol was shown to decrease tensile strength, delay wound contraction and re-epithelialization, increase inflammatory infiltrate, and reduce collagen density and hydroxyproline levels.

CONCLUSIONS

The results suggest that nonselective and cardioselective β-blockers delay wound healing and these effects are mediated by β1-receptors.

Infraclavicular brachial plexus block: Comparison of posterior cord stimulation with lateral or medial cord stimulation, a prospective double blinded study

BACKGROUND

Infraclavicular approach to the brachial plexus sheath provides anesthesia for surgery on the distal arm, elbow, forearm, wrist, and hand. It has been found that evoked distal motor response or radial nerve-type motor response has influenced the success rate of single-injection infraclavicular brachial plexus block.

AIM

We conducted this study to compare the extent and effectiveness of infraclavicular brachial plexus block achieved by injecting a local anesthetic drug after finding specific muscle action due to neural stimulator guided posterior cord stimulation and lateral cord/medial cord stimulation.

METHODS

After ethical committee approval, patients were randomly assigned to one of the two study groups of 30 patients each. In group 1, posterior cord stimulation was used and in group 2 lateral/medial cord stimulation was used for infraclavicular brachial plexus block. The extent of motor block and effectiveness of sensory block were assessed.

RESULTS

All four motor nerves that were selected for the extent of block were blocked in 23 cases (76.7%) in group 1 and in 15 cases (50.0%) in group 2 (P:0.032). The two groups did not differ significantly in the number of cases in which 0, 1, 2, and 3 nerves were blocked (P>0.05). In group 1, significantly lesser number of patients had pain on surgical manipulation compared with patients of group 2 (P:0.037).

CONCLUSION

Stimulating the posterior cord guided by a nerve stimulator before local anesthetic injection is associated with greater extent of block (in the number of motor nerves blocked) and effectiveness of block (in reporting no pain during the surgery) than stimulation of either the lateral or medial cord.

Evaluation of anti-ulcer effect of amlodipine in gastric ulcer models in rats

Aims:

To study anti-ulcer effect of Amlodipine and compared it with ranitidine in indomethacin, alcohol and pyloric ligation-induced gastric ulcers in wistar rats.

Materials and Methods:

Gastric ulcers were induced in Wistar albino rats by oral administration of indomethacin (200 mg/kg), alcohol (80%, 1 ml/100 gm) and by pyloric ligation. Antiulcer activity of amlodipine (0.5 mg/kg, i.p.) was observed either alone or in combination with ranitidine (15 mg/kg, i.p.), on ulcer index, gastric pH and gastric volume. Statistical analysis was done by ANOVA and unpaired one tailed ‘t‘ test. P<0.05 was considered statistically significant.

Results:

Amlodipine produced significant (P<0.05) decrease in ulcer index and gastric pH as compared to control. It also produced significant (P<0.05) increase in gastric volume as compared to ranitidine. The anti-ulcer effects of ranitidine were significantly higher than that of amlodipine. Combination of amlodipine and ranitidine did not show significant increase in anti-ulcer activity as compared with ranitidine alone.

Conclusions:

Amlodipine produced significant anti-ulcer effects in all 3 experimental models. Amlodipine increased the volume of gastric secretions as compared to ranitidine.

Insert earphone modeling and measurement by IEC-60711 coupler

In this study, an analytical model based on the equivalent circuit method is developed to simulate the frequency response of an insert earphone. This earphone incorporates a miniature loudspeaker commonly used in computer, communication, consumer, and car electronics. Through the laser triangulation method, electroacoustic parameters of a miniature loudspeaker are obtained. Several earphone design configurations are analyzed in accordance with the open and closed states of front leakage hole, vent, and back leakage hole. To validate the analysis, an insert earphone that is attached to IEC-60711 coupler and a specially designed fixture tube is experimentally measured for frequency response using electroacoustic equipment in the air. Simulation and experimental results show good agreement over the complete audible frequency range. Analysis indicates that states of front leakage hole, vent, and back leakage hole of an insert earphone have significant effects on frequency response. The front leakage hole affects the low frequency response, whereas the vent affects the fundamental resonance. Detailed analysis has been provided to further improve the design of insert earphones.

India's Revised National Tuberculosis Control Programme: looking beyond detection and cure

SETTING

Pune District, Maharashtra State, India.

OBJECTIVES

To examine delays experienced by patients in accessing directly observed treatment.

DESIGN

Data were collected from 117 new sputum-positive patients using a semi-structured interview schedule.

RESULTS

Patient delays as well as diagnostic and treatment delays, which reflect the performance of a National TB Programme, were minimal. Provider delays, however, contributed significantly to delayed entry into India's Revised National TB Control Programme (RNTCP). Patients had to resort to multiple contacts with providers due to limitations of these providers in diagnosing or directing patients to the RNTCP. Patients who consulted a private provider participating in the public-private mix (PPM) were more likely to be suspected (OR 2.63, 90% CI 1.04-6.64) and referred (OR 6.8, 95%CI 2.08-22.21) to the RNTCP. Once the patients entered the RNTCP, the response of the system was rapid, with diagnosis offered and treatment initiated within on average 7 days.

CONCLUSION

Interventions aimed at providers to encourage early suspicion and referral to the RNTCP, such as the PPM, are more important in improving patient access to TB care than those focusing on reducing patient delays.

Evaluation of capsaicin ointment at the Korean hand acupressure point K-D2 for prevention of postoperative nausea and vomiting

The K-D2 point is the Korean hand acupressure point in Koryo Hand Therapy for prevention of postoperative nausea and vomiting. We evaluated the efficacy of capsaicin ointment at the K-D2 point in 186 patients undergoing laparoscopic cholecystectomy in a randomised, prospective, double-blind and placebo-controlled study. Patients were randomised to have either placebo ointment or capsaicin ointment applied to the K-D2 point of both hands 1 h before surgery under standardised anaesthesia. The ointment was removed 8 h later. Postoperative nausea and vomiting was evaluated 6 and 24 h following surgery. The incidence of postoperative nausea and vomiting was lower in the capsaicin group, with an absolute risk reduction (ARR) of 21%, a relative risk reduction (RRR) of 50% and a number-needed-to-treat (NNT) of 5 at 0-6 h (p = 0.001), and an ARR of 11%, a RRR of 85% and a NNT of 9 at 6-24 h (p = 0.003). The need for rescue anti-emetic treatment was also lower at 0-6 h (3 (3%) vs 11 (12%); p = 0.04) and at 6-24 h (5 (5%) vs 0; p = 0.02).

Non-human primates: a model for tuberculosis research

A variety of animals have been used for tuberculosis research, and each animal model has its strengths and weaknesses. We sought to develop a non-human primate model of tuberculosis to model aspects of human tuberculosis that are difficult to model in other animals, including the pathology in the lungs, various progression to disease, and immunologic correlates of infection or disease that are likely to be similar in humans. To date, we have infected 17 cynomolgus macaques (Macaca fasicularis) with a low dose (15-25CFU) of Mycobacterium tuberculosis strain Erdman. The monkeys were grouped into three categories on the basis of disease progression: rapid progression (advanced disease by 3 months post-infection), active/chronic infection (signs of disease but a slower progression), and latent infection (no signs of clinical disease). Animals were followed clinically post-infection, including blood work, physical examinations, serial bronchoalveolar lavage (BAL) and gastric aspirates for M. tuberculosis culture, chest radiographs, and tuberculin reactivity. Immunologic assays on cells from blood, BAL fluid, and tissue, have been performed, including proliferation, flow cytometry, ELIspot assays, cytotoxic T lymphocyte (CTL) assays, and ELISAs. The spectrum of disease observed in these monkeys is similar to humans, and this model may be very useful for studying pathogenesis and immunology of tuberculosis, as well as testing vaccines, diagnostic reagents, and drugs prior to use in human populations.

Influence of smoking on cutaneous delayed-type hyper sensitivity reaction by tuberculin skin test

Tuberculin test (purified protein derivative) is currently accepted as a standard investigation used in the diagnosis of tuberculosis (TB). Although the sensitivity of the test is reliable, a substantial number of those subjected to screening for TB by such test are cigarette smokers. This study is designed to investigate the effect of smoking on cell-mediated delayed-type cellular hypersensitivity (DTH) reaction by PPD. Prospective, case-control study was conducted at the Chest and TB unit of Chest Hospital Kuwait. The study population consisted of 357 healthy volunteers serving as controls and 200 in-patients under direct medical supervision and treatment for tuberculosis as cases. The mean age was 33.69 +/- 8.6 SD; 286 were current smokers and 271 were lifetime non-smokers. PPD test was done using 2TU RT23 SSI-Denmark on all subjects. Median PPD was significant among the cases (P=0.03) between smokers and non-smokers and was highly significant among the healthy controls (P<0.001). No significant difference was seen between median pack years of smoking and PPD levels among the patient group (P=0.264) but the difference was significant among the control group (P<0.001). Univariate analysis of variance (ANOVA) on PPD, taking into account age, pack years of smoking, ethnic groups and BCG scar showed sufficient response but was not statistically significant to all these factors. Smoking habit does not appear to influence the cutaneous delayed type hypersensitivity reaction by tuberculin skin test.

RinoFlow nasal wash and sinus system as a mechanism to deliver medications to the paranasal sinuses: results of a radiolabeled pilot study

Direct delivery of medication to the sinuses with standard nebulizers is difficult to achieve. The nasal inhalation of aerosolized medications is dependent on the size of the particles and the pressure with which they are delivered; when the particles are too small or the pressure is too low, the drug cannot reach the sinuses. The ability of topical medications to treat sinus disorders can be improved if the medication could be delivered directly to the sinuses. We tested the ability of the RinoFlow nasal aerosol delivery device to deposit aerosol directly to the paranasal sinuses. Five normal, healthy subjects used the device to administer technetium Tc 99m nasally. Nuclear scanning was used to detect deposition in the frontal and maxillary sinuses. Three subjects underwent additional testing after administration of a nasal decongestant. Three of the five subjects showed some evidence of direct delivery to the sinuses, although deposition was not uniform or complete. Pretreatment with a decongestant had no apparent effect on subsequent technetium delivery. We conclude that the results of this study are promising and that further study is warranted.

Differential gene expression in migrating renal epithelial cells after wounding

An in vitro model of wound healing was used to study cell migration that is independent of proliferation during renal regeneration after acute tubular necrosis. Monolayer cultures of high-density, quiescent renal epithelial cells of the BSC-1 line were subjected to scrape wounding and then Northern blot analysis was employed to identify genes that mediate cell migration. After wounding the monolayer, there is maximal induction of the immediate-early genes Egr-1, c-fos, NAK-1, and gro at 1 hour, followed by peak induction of connective tissue growth factor (CTGF) and c-myc at 4 hours. Message levels of urokinase-type plasminogen activator (u-PA) and its inhibitor (PAI-1) and heat shock protein (HSP)-70 are markedly raised 4-8 hours after wounding. Constitutive expression is repressed at 1 hour for transcripts that encode receptors for fibronectin (FN), epidermal growth factor, and hepatocyte growth factor (c-met), and the secreted proteins FN and osteopontin. Expression of genes encoding transforming growth factor (TGF)-beta 1 and -beta 2, retinoic acid receptor alpha, int-1, int-2, and gap junction protein which can play a role in cell movement, appeared unchanged after wounding. Differential expression of genes was a function of cell location relative to the wound; NAK-1, PAI-1, and HSP-70 were induced or stimulated only in cells at the wound edge, u-PA was stimulated in cells away from the wound, and CTGF was induced in each of these populations suggesting that cell-to-cell communication may regulate gene expression after wounding. Adenosine diphosphate, a potent stimulator of cell migration which enhances expression of u-PA and PAI-1 in nonwounded cultures, additively stimulates these genes after wounding and may thereby potentiate wound healing. Thus scrape wounding of renal epithelial cells is followed by induction, stimulation, or repression of specific genes with distinct responses in different populations of cells.

Calcium oxalate monohydrate crystals stimulate gene expression in renal epithelial cells

Primary or secondary hyperoxaluria is associated with calcium oxalate nephrolithiasis, interstitial fibrosis and progressive renal insufficiency. Monolayer cultures of nontransformed monkey kidney epithelial cells (BSC-1 line) and calcium oxalate monohydrate (COM) crystals were used as a model system to study cell responses to crystal interactions that might occur in the nephrons of patients during periods of hyperoxaluria. To determine if COM crystals signal a change in gene expression, Northern blots were prepared from total renal cellular RNA after the cells were exposed to crystals. The immediate early genes c-myc, EGR-1, and Nur-77 were induced at one hour. At two to six hours stimulated expression of the genes encoding plasminogen activator inhibitor (PAI-1) and platelet-derived growth factor (PDGF)-A chain was detected, but constitutive expression of urokinase-type plasminogen activator (u-PA) was not altered. Expression of connective tissue growth factor (CTGF) was induced at one hour and persisted up to 24 hours. The stimulation of gene expression by COM crystals was relatively crystal- and renal cell-type specific. Thus the interaction of kidney epithelial cells with COM crystals alters expression of genes that encode three classes of proteins: transcriptional activators, a regulator of extracellular matrix (ECM), and growth factors. Activation of PAI-1 gene expression without a change in u-PA favors accumulation of ECM proteins, as does increased expression of PDGF and CTGF which can also stimulate fibroblast proliferation in a paracrine manner. These results suggest that COM crystal-mediated stimulation of specific genes in renal tubular cells may contribute to the development of interstitial fibrosis in hyperoxaluric states.

Developmental regulation of lck gene expression in T lymphocytes

In the mouse and human, mRNA transcripts encoding the lymphocyte-specific protein tyrosine kinase p56lck are derived from two separate promoters resulting in heterogeneity in the 5' untranslated region sequence. The proximal promoter lies just 5' to the coding region for the gene and is active only in thymocytes. In contrast, the distal promoter lies 34 kilobases (kb) 5' in the human, and is active both in thymocytes and mature peripheral T cells. As previously reported, transgenic mice bearing functional proximal promoter sequence juxtaposed with the SV40 large T antigen gene invariably develop lymphoid tumors confined to the thymus. In the current work, transgenic mice bearing a 2.6-kb fragment of the human distal promoter fused to the SV40 large T antigen gene express large T antigen in thymocytes and in peripheral lymphoid cells, and develop tumors of both the thymus and the peripheral lymphoid organs. The ability of the human distal promoter to function appropriately in transgenic mice is consistent with the strong similarity observed between the mouse and human distal promoter sequences. With the exception of a single short interval that serves as a target for binding of nuclear factors, significant sequence similarity is not seen when the distal and proximal promoter sequences are compared. Hence, developmentally regulated, lineage-specific transcription of the lck gene is mediated by distinct promoter sequences that appear to be capable of functioning independently.

Characterization through cDNA cloning of galactoprotein b3 (Gap b3), a cell surface membrane glycoprotein showing enhanced expression on oncogenic transformation. Identification of Gap b3 as a member of the integrin superfamily

Galactoprotein b (Gap b) is a group of glycoproteins of fibroblast cell membranes showing enhanced expression in association with oncogenic transformation (Carter, W.G., and Hakomori, S. (1977) Biochem. Biophys. Res. Commun. 76, 299-308). We purified Gap b3 (one of the Gap b group) to homogeneity from hamster fibroblast NIL cells transformed with polyoma virus (NILpy). Partial amino acid sequence was determined, and the cDNA clones encoding this protein were isolated by oligodeoxynucleotide hybridization. The 5.0-kilobase pair cDNA encodes a protein of 1051 amino acid residues containing a signal peptide (32 residues), a large extracellular domain (959 residues), a transmembrane domain (28 residues), and a short cytoplasmic domain (32 residues). The overall structure of Gap b3 is similar to that of the alpha subunit of so-called integrin receptors in the following respects: (i) presence of metal-binding sequences; (ii) location of a transmembrane domain near C terminus; (iii) matched positions of most of the cysteine residues. This, together with extensive amino acid sequence homology, strongly suggests that Gap b3 is a member of the integrin family. Gap b3 consists of two polypeptide chains (Mr = 110,000 and 30,000), which seem to be proteolytic cleavage products connected by disulfide bonds from a precursor protein. Southern hybridization shows the presence of a single copy gene in mice and humans as well. Northern hybridization analysis shows that the enhanced expression of Gap b3 in transformed cells is due to increased transcription of its message.