Investigating the Impact of Flap Overdesign on Viability

Background  Partial or complete flap necrosis is a detrimental outcome complicating reconstructive surgery. The purpose of this study was to evaluate the impact of flap overdesign on viability in the rat model.

Methods  Forty Sprague-Dawley rats were equally divided into four groups receiving flaps of varying length-to-width ratios: 2:1, 3:1, 4:1, and 5:1. All animals had caudally based, modified McFarlane-style flap created. Areas of survival were assessed 14 days postoperatively and compared among groups using one-way analysis of variance.

Results  The mean areas of flap survival were 8.0 ± 0.0 cm ² , 7.8 ± 1.1 cm ² , 8.3 ± 1.1 cm ² , and 8.1 ± 1.5 cm ² for the 2:1, 3:1, 4:1, and 5:1 length-to-width ratio groups, respectively. There were no statistically significant differences in mean areas of flap survival among groups ( p  > 0.05).

Conclusion  Flap overdesign does not increase the risk of flap necrosis in a random-pattern flap.

Osteomyelitis of the craniofacial skeleton

Skull-based osteomyelitis, which is a true bony infection, originates from a chronic, inadequately treated infection. Because of the complex craniofacial skeletal anatomy and associated aesthetic concerns, osteomyelitis of the craniofacial skeleton must be uniquely managed and is more difficult to treat than osteomyelitis of other bones of the body. It is thought that osteomyelitis is decreasing in prevalence due to broad-spectrum antibiotic treatment; however, it still remains a challenging clinical entity in developing countries and lower socioeconomic areas.

17β-estradiol modifies diabetic wound healing by decreasing matrix metalloproteinase activity 

Postmenopausal women are more susceptible to poor wound healing. This phenomenon can be reversed by estrogen replacement therapy in non-diabetic individuals. Postmenopausal women with type 2 diabetes are more susceptible to wound healing complications, potentially secondary to an estrogen deficiency. Few studies have examined the mechanism of action and effects of estrogens on diabetic wound healing in females. It appears that multiple factors influence delayed wound healing among individuals with diabetes including: an imbalance in cytokines, growth factors, extracellular matrix (ECM) turnover, and oxidant stress (OS). Estrogens have been shown to regulate the expression of genes important for extracellular matrix turnover, including collagen and matrix metalloproteinases (MMP).

METHODS

For this reason, the effects of 17β-estradiol (E2) on MMP-2, MMP-13, and MMP-14 and estrogen receptor alpha and beta (ER-α and -β) expression in the wound tissue of estrogen-deficient female mice with established type 2 diabetes mellitus (C57BL/6J-m Leprdb/2+) were studied.

RESULTS

Topical E2 upregulates ERα in wound tissue thereby improving and accelerating diabetic wound healing in estrogen deficient mice.

CONCLUSION

The mechanism appears to decrease MMP-2, MMP-13, and MMP-14 mediated tissue matrix destruction and increasing collagen content. .

A comprehensive analysis of parotid and salivary gland cancer: worse outcomes for male gender

BACKGROUND

To determine the effects of patient demographics, socioeconomic status (SES) and clinical variables on outcomes for patients with salivary and parotid gland tumors.

METHODS

Florida cancer registry and inpatient hospital data were queried for cancer of the salivary glands diagnosed between 1998-2002.

RESULTS

A total of 1573 patients were identified. Women were diagnosed at a younger age (median age (years): women 60.8 versus men 64.3, P=0.003). Men were more often diagnosed with high grade tumors (65.1% versus 41.9% for women, P<0.001) and advanced disease stage (>stage III: 60.2 versus 49.4%, P<0.001), but underwent surgical extirpation and received radiation at equal rates compared with women. Overall 5-year survival rates was superior in women (67.4% versus 55.6%, P=0.001). By multivariate analysis, adjusted for patient comorbidities, age over 65 (HR 3.43 P=0.008), advanced disease stage (HR 8.05 P<0.001), and high tumor grade (HR 2.33, P<0.001) were independent predictors of worse prognosis. Improved outcomes were observed for female gender (HR 0.68, P=0.011). Tumors located in the parotid gland (HR 0.631 P=0.003) and receiving both surgical extirpation and radiation were predictors of improved survival.

CONCLUSION

Salivary gland tumors carry a worse prognosis than tumors of the parotid. Male patients have worse outcomes.

Further studies on the chronotherapy of asthma with inhaled steroids: the effect of dosage timing on drug efficacy

BACKGROUND

Chronotherapy studies with inhaled corticosteroids have shown optimal therapeutic benefit when steroids are administered four times per day (QID) or once daily at 3 PM.

OBJECTIVE

This study evaluated whether more convenient once-daily dosage times (8 AM and 5:30 PM) produce improvement in asthma equivalent to QID.

METHODS

Efficacy outcome measures included FEV1, peak expiratory flow rates, bronchial responsiveness, use of beta2-agonists, nocturnal awakenings, and responses to a quality of life questionnaire. Systemic effects were blood eosinophil count, cortisol level, 24-hour urinary cortisol, and evaluation for oral candidiasis and dysphonia.

RESULTS

Baseline measurements for all three treatment groups were similar. For morning peak expiratory flow rate, significant improvement was seen for the QID group (p = 0.001) and the 5:30 PM group (p = 0.003), but not the 8 AM group (p = 0.75). For evening peak expiratory flow rate, significant improvement was seen for the QID group (p = 0.005) and the 5:30 PM group (p = 0.01), but not for the 8 AM group (p = 0.47). There were significant improvements in all other outcome variables for each group except PC20. There was a significant improvement in PC20 only in the QID group. The systemic effects of the three regimens were comparable.

CONCLUSION

Dosing of inhaled steroid at 5:30 PM had no increased systemic effects and produced efficacy similar to QID dosing. Dosing at 8 AM did not produce results consistently comparable to QID dosing. Optimal once-daily dosing of inhaled steroid is between 3 PM and 5:30 PM.

Chronobiology and chronotherapy of asthma

There is no doubt that many pathophysiologic conditions change over a 24-hour period and thus therapy needs to be directed at these changes. In particular, asthma has been one of the better-studied disease processes in regard to circadian changes in pathophysiology. As we continue to learn more about circadian changes, better approaches to treating the disease with the same medications will emerge. It should be remembered that many asthmatics do not perceive their degree of bronchoconstriction. This was brought forth in Turner-Warwick's epidemiologic study in that less than one half of the asthmatic individuals who had problems with their asthma every night describe their asthma as being severe. The majority stated they either had mild or moderate asthma. Therefore, it is important that we use objective criteria such as peak flow meters in determining an individual patient's day-to-night changes in lung function. Then, any therapeutic intervention can be objectively determined at home with both the patient and physician gaining knowledge about the ongoing asthmatic process.

Chronotherapy of asthma with inhaled steroids: the effect of dosage timing on drug efficacy

BACKGROUND

Studies in asthma with systemic corticosteroids given at 3:00 PM have shown a superior therapeutic benefit compared with dosing at other time points.

OBJECTIVE

The study was designed to compare beneficial and systemic effects of 800 micrograms of inhaled triamcinolone once daily at 3:00 PM (QD group) versus 200 micrograms conventional four times a day dosing (QID group).

METHODS

Efficacy outcome measures included forced expiratory volume in 1 second (FEV1), peak expiratory flow rates, bronchial responsiveness, and use of beta-agonist. Systemic effects were blood eosinophil and cortisol levels, 24-hour urinary cortisol, and evaluation for oral candidiasis and dysphonia.

RESULTS

The baseline FEV1 was comparable in the two groups: QD = 67% +/- 2% and QID = 66% +/- 2% of predicted value. After 4 weeks of treatment, FEV1 increased similarly in the QD group to 77% +/- 4% and in the QID group to 74% +/- 4% of predicted value. Likewise, the improvement in morning and evening peak expiratory flow rates was not significantly different between the groups. Both QD and QID groups experienced comparable daily decrements in beta-agonist use. The systemic responses to the two regimens as assessed by eosinophil count, morning serum cortisol, and 24-hour urinary cortisol were also comparable.

CONCLUSIONS

The single daily administration of inhaled triamcinolone at 3:00 PM has no increased systemic effects and produces similar improvement in efficacy variables. A dosing strategy based on once daily dosing should increase compliance of inhaled steroid use in the clinical setting.

Age-related response to two Haemophilus influenzae type b vaccines

Two types of Hib vaccines were compared for efficacy and safety in 71 normal children in three age groups: 36 to 72 months, 15 to 18 months, and 6 to 8 months. One vaccine contained the Hib-specific capsular polysaccharide, PRP; the second vaccine contained PRP combined with pertussis vaccine, PRP-P. A third vaccine, DTP, was administered to a control group for each age. Anti-PRP antibody levels were greater after vaccination with PRP-P than after PRP in all three age groups. Immunoresponsiveness to both vaccines increased with age. A lower incidence of side effects was seen with both PRP (15%) and PRP-P (20%) than with DTP (56%). The results suggest that PRP-P is both well tolerated clinically and has greater immunogenicity than PRP.