Wearable positive end-expiratory pressure valve improves exercise performance

We tested a PEEP (4.2 cmH₂O) mouthpiece (PMP) on maximal cycling performance in healthy adults. Experiment-1, PMP vs. non-PMP mouthpiece (CON) [n = 9 (5♂), Age = 30 ± 2 yr]; Experiment-2, PMP vs. no mouthpiece (NMP) [n = 10 (7♂), Age = 27 ± 1 yr]. At timepoint 1 in both experiments (mouthpiece condition randomized) subjects performed graded cycling testing (GXT) (Corival® cycle ergometer) to determine V˙O_{2peak (ml∗kg∗min}⁻¹), O₂pulse _(mlO2∗bt⁻¹), GXT endurance time (GXT-T_(s)), and V˙O_{2(ml∗kg∗min}⁻¹)-at-ventilatory-threshold (V˙O₂ @VT). At timepoint 2 72 h later, subjects completed a ventilatory-threshold-endurance-ride [VTER_(s)] timed to exhaustion at V˙O₂ @VT power _(W). One week later at timepoints 3 and 4 (time-of-day controlled), subjects repeated testing protocols under the alternate mouthpiece condition. Selected results (paired T-test, p<0.05): Experiment 1 PMP vs. CON, respectively: V˙O_2peak ​= ​45.2 ​± ​2.4 vs. 42.4 ​± ​2.3 p<0.05; V˙O₂@VT ​= ​33.7 ​± ​2.0 vs. 32.3 ​± ​1.6; GXT-TTE ​= ​521.7 ​± ​73.4 vs. 495.3 ​± ​72.8 (p<0.05); VTER ​= ​846.2 ​± ​166.0 vs. 743.1 ​± ​124.7; O2pulse ​= ​24.5 ​± ​1.4 vs. 23.1 ​± ​1.3 (p<0.05). Experiment 2 PMP vs. NMP, respectively: V˙O_2peak ​= ​43.3 ​± ​1.6 vs. 41.7 ​± ​1.6 (p<0.05); V˙O₂@VT ​= ​31.1 ​± ​1.2 vs. 29.1 ​± ​1.3 (p<0.05); GXT-TTE ​= ​511.7 ​± ​49.6 vs. 486.4 ​± ​49.6 (p<0.05); VTER 872.4 ​± ​134.0 vs. 792.9 ​± ​122.4; O₂pulse ​= ​24.1 ​± ​0.9 vs. 23.4 ​± ​0.9 (p<0.05). Results demonstrate that the PMP conferred a significant performance benefit to cyclists completing high intensity cycling exercise.

HIV/AIDS surveillance in Egypt: current status and future challenges

By international standards, HIV/AIDS prevalence is low in Egypt (< 0.1%). However, questions about the accuracy of this figure are coupled with fears of an imminent increase in prevalence, with evidence suggesting that, despite Egypt's conservative culture, high-risk behaviour is more widespread than commonly reported and the country's changing socioeconomic context is perpetuating this trend. Through an analysis of the current HIV/AIDS surveillance system in Egypt, this paper explores some of the unique challenges this country faces in dealing with the HIV/AIDS epidemic. It concludes that constraints, such as Egypt's cultural norms and laws, the population's lack of knowledge about HIV/AIDS and the bureaucratic health system, hinder the development and implementation of effective surveillance systems.

The Incidence of Late Cephalohematoma following Craniofacial Surgery

BACKGROUND

Cranial vault remodeling procedures are carried out for both syndromic and nonsyndromic craniosynostosis as well as to correct some acquired deformities of the cranial vault. These procedures improve not only cosmesis but also neurological symptoms. The purpose of this study was to determine the incidence of "late" cephalohematoma, an underreported complication following these complex procedures.

METHODS

A total of 113 patients underwent 127 cranial vault remodeling procedures using autogenous bone over a 6-year period. All patients who developed a late cephalohematoma 75 days or more after surgery were recorded. The time, size, and location of the cephalohematoma, the treatment performed, and the length of follow-up were also recorded. Ages at initial operation and postoperative follow-up were compared between patient groups for statistical differences.

RESULTS

Of the 113 patients, 17 developed 18 late cephalohematomas. The incidence for this complication was 15 percent. The median age at operation for all patients was 10 months, and most late cephalohematomas occurred 208 days later (range, 77 to 1416 days), at 12 to 24 months of age. Fronto-orbital advancement was the most commonly performed procedure, and 83.3 percent of late cephalohematomas occurred in the frontal region. No cephalohematomas became infected or required any operative intervention, but they were aspirated.

CONCLUSIONS

Surgeons should inform prospective parents of patients undergoing cranial vault remodeling procedures of this potential complication. This will improve parental awareness and possible avoidance strategies in future patients. Further evaluation and follow-up are required to determine the minimum length of postoperative time after which late cephalohematomas do not occur.

Morphology and Growth of the Mandible in Crouzon, Apert, and Pfeiffer Syndromes

The purpose of this study was to examine mandibular morphology and growth in patients with Crouzon, Pfeiffer, and Apert syndromes using posteroanterior cephalograms. Fifteen patients with Apert (n = 2), Crouzon (n = 11), and Pfeiffer (n = 2) (11 female, 4 male) syndrome were included in this study. All patients had serial posteroanterior cephalograms at 5, 10, and 15 years of age. The bicondylar width, bigonial width, bicondylar/bigonial ratio, and ramus to intercondylar plane angle for each patient were measured on the cephalograms and compared with age-match controls. An analysis of variance analysis was carried out to detect differences between patients and controls and sex differences between patients. In both male and female patients, there was a statistically significant reduction in bicondylar width compared with age-matched controls. Male patients also had a statistically significant increase in bigonial width compared with controls and female patients at 10 and 15 years. The resulting bicondylar/bigonial ratios were significantly reduced, and the ramus to intercondylar plane angles were significantly increased in both male and female patients compared with controls. Unlike previous reports of patients with syndromic synostosis, this study demonstrates that the mandible has significant morphologic and growth abnormalities, including constriction of bicondylar width with near normal bigonial width in female patients. These findings suggest a narrowing at the cranial base with resulting restriction of normal transverse mandibular growth at the condyle. The secondary nature of the mandibular finding is suggested by the near normal or increased transverse growth at the gonion in females and males, respectively. Consequently, the ramus appears torqued inward, forming a greater angle with the cranial base.

Cheek and Eyelid Reconstruction: The Resurrection of the Angle Rotation Flap

BACKGROUND

Reconstruction of larger cheek and eyelid defects may pose a dilemma for surgeons, since flaps used in reconstruction may be difficult to design, be unreliable, require extensive dissection, and result in neck scarring. Consequently, the authors wish to simplify and expand an overlooked flap, the angle rotation flap, which moves tissue in both a medial and upward direction.

METHODS

Twenty patients with cheek and eyelid defects were treated by the angle rotation flap. In this flap design, the angle designed below the ear was closed primarily and the neck tissue previously there was rotated upward and forward to lie in front of the ear. The portion of the flap that was in front of the ear was transposed to the lower lid/cheek area. This flap was modified in several patients by elevation in the deep plane and first-stage tissue expansion.

RESULTS

In all cases, good coverage was provided for medial cheek and lower eyelid defects with minimal scarring on the neck. There were no flap losses of any kind. There were no major complications, and all minor incidences were treated by minimal procedures without long-term sequelae.

CONCLUSION

The modified angle rotation flap is a useful tool for cheek and eyelid defects.

Subincisional Muscular Coverage of Expander Implants in Immediate Breast Reconstruction With Pectoralis Flaps

Immediate breast reconstruction with expander implants is a safe, simple procedure that allows for a rapid physical and emotional postmastectomy recovery. When complications occur, the patient may be left with a prolonged reconstructive course. Such complications may result from thin mastectomy flaps and resulting marginal skin flap necrosis and implant exposure. Muscle coverage of the implant under the skin incision prevents such marginal necrosis of skin flap from becoming a factor in implant loss. This paper demonstrates a simple method for providing subincisional muscle coverage of expander implants with pectoralis muscle flaps. In this technique, a pocket is developed under the pectoralis muscle. The sternal origin of the pectoralis is released from the midsternal position to its inferior origin. The pectoralis muscle is then rotated inferior-laterally and sutured to the dermis of the underside of the inferior mastectomy skin flap, thereby providing subincisional muscle coverage of the expander implant. During a 5-year period, 42 patients between the ages of 36 and 61 underwent breast reconstruction utilizing this technique. In these patients, there were 4 instances of marginal necrosis. In each of these cases, the implants did not become exposed, and all patients completed the expansion process without significant delay and underwent subsequent implant exchange without incident. Five-year follow-up has shown good esthetic results in all patients.

The temporal sequence of periosteal attachment after elevation

This study investigated the adherence of periosteum to bone after elevation to document the temporal sequence of healing at the periosteal/bone interface. There has been a lack of consensus among surgeons as to the time required for healing at this interface; some believe that the healing achieves significant strength in a few days, whereas others believe that the periosteum does not adhere to the bone for many weeks. The aim of this study was to document the time course for healing, completeness of the reattachment, and structural characteristics of the union of bone and periosteum. To test the hypothesis, scalp flaps were elevated in a subperiosteal plane and were reattached in 40 adult guinea pigs and controls. The individual groups were studied at 3, 6, 12, 30, and 90 days postoperatively. Postmortem study consisted of analysis of the mechanical and histologic findings. Strength of adherence was documented by measuring the force required for reverse avulsion of the flaps with an Instron Mini 44 tensiometer. The specimens were also submitted for electron microscopic examination. The mean tension recorded in the plateau phase of avulsion of the flaps was as follows: controls, 78 g; experimental at 3 and 6 days, not applicable (weak adherence not permitting exposure for reverse avulsion); 12 days, 39 g (p = 0.0001); 30 days, 58 g (p = 0.0012), and 90 days, 63 g (p = 0.0229). There was a significant difference between all groups and the controls. Electron microscopic study showed collagen deposition at the bone periosteal interface, which became progressively more organized in the groups studied at 30 and 90 days, with decreasing amounts of inflammation and inflammatory cells. This study demonstrated that healing at the bone/periosteal interface progresses at a rate consistent with healing of most other wounds, dispelling many widespread beliefs that the adherence at this interface was accelerated. The temporal sequence of healing at the periosteal bone interface should be considered in the various procedures in which periosteal flaps are elevated. For example, there is clinical relevance in subperiosteal brow lift procedures, in which the periosteum should be reattached by a fixation technique that will remain stable for a minimum of 30 days to allow adequate adherence between the bone and periosteum at the postoperative elevated brow position.

Chin surgery III: revelations

This article is a logical extension of previous articles written on the topic of aesthetic chin surgery. In it, the authors expand on previously published surgical techniques and provide specific updates to increase success in some unusual situations. They review the indications for and uses of reduced-height implants, discuss the validity of centralized chin incisions in both reconstruction and revisions, show the diversity of mentalis muscle anatomy and chin pad variations, reveal the importance of the lip-to-labiomental crease inclination in cases of macrogenia, note a key update on reefing the mentalis muscle to a higher position for permanent sulcus position, discuss the issues of lower lip position and lower incisor show, and expound on the horizontal smile/chin ptosis phenomenon.

Clinical and scientific considerations in leech therapy for the management of acute venous congestion: an updated review

Any surgical intervention that involves the manipulation of veins, large or small, carries the risk of acute venous congestion. Venous congestion is the product of an imbalance between arterial inflow and venous outflow, and results in the stasis of blood in the tissues that are normally drained by the affected veins. The resultant lack of tissue perfusion causes hypoxia, acidosis, and arterial thrombi formation, which can potentially progress to tissue necrosis and wet gangrene. In the past several decades, the use of leeches (Hirudo medicinalis) has been rediscovered as an effective method of relieving acute venous congestion. This updated review of leech therapy focuses on the use of medicinal leeches in a variety of clinical conditions characterized by acute venous congestion, and points out the experimental use of leeches in other pathological entities. A discussion of the recent scientific findings that explain the possible mechanisms of action of leech therapy is also provided.

Increased free fat-graft survival with the long-term, local delivery of insulin, insulin-like growth factor-I, and basic fibroblast growth factor by PLGA/PEG microspheres

The present investigation evaluates the effects of long-term, local delivery of insulin, insulin-like growth factor-1 (IGF-1), and basic fibroblast growth factor (bFGF) on fat-graft survival using a poly (lactic-co-glycolic-acid)-polyethylene glycol (PLGA/PEG) microsphere delivery system. Twelve-micrometer PLGA/PEG microspheres incorporated separately with insulin, IGF-1, and bFGF were manufactured using a double-emulsion solvent-extraction technique. Inguinal fat from Sprague Dawley rats was harvested, diced, washed, and mixed with (1) insulin microspheres, (2) insulin-like growth factor-1 microspheres, (3) basic fibroblast growth factor microspheres, (4) a combination of the insulin and IGF-1 microspheres, and (5) a combination of insulin, IGF-1, and bFGF microspheres. The treated fat grafts were implanted autologously into subdermal pockets in six animals for each group. Animals receiving untreated fat grafts and fat grafts treated with blank microspheres constituted two external control groups (six animals per external control group). At 12 weeks, all fat-graft groups were compared on the basis of weight maintenance and a histomorphometric analysis of adipocyte area percentage, indices of volume retention and cell composition, respectively. Weight maintenance was defined as the final graft weight as a percent of the implanted graft weight. All growth factor treatments significantly increased fat-graft weight maintenance objectively, and volume maintenance grossly, in comparison with the untreated and blank microsphere-treated controls. Treatment with insulin and IGF-1, alone or in combination, was found to increase the adipocyte area percentage in comparison with fat grafts treated with bFGF alone or in combination with other growth factors. In conclusion, the findings of this study indicate that long-term, local delivery of growth factors with PLGA/PEG microspheres has the potential to increase fat-graft survival rates. Further, the type of growth factor delivered may influence the cellular/stromal composition of the grafted tissue.

Neural anatomy of the radial forearm flap

Typically the lateral antebrachial cutaneous nerve alone is used to innervate the radial forearm free flap when a sensate flap is required. The authors desired, by means of fresh cadaveric microdissections and by means of local anesthetic injections in living subjects, to map the sensory nerve territories of this flap. Eight radial forearm flaps were elevated and the medial antebrachial cutaneous nerve (MABC), lateral antebrachial cutaneous nerve (LABC), and superficial radial sensory nerve (SRSN) were dissected with the aid of an operating microscope (2.5-10x) and traced to their dermal insertions. In the injection study, the MABC, LABC, and SRSN in eight forearms of 4 subjects were blocked sequentially with 2% lidocaine injections. The resulting sensory deficit from each injection was mapped on the skin and superimposed on the marked radial forearm flap territory. Distribution of the three dissected nerve regions and the sensory deficit after injection were determined by digital images and computer analysis. During flap dissections, mean nerve distributions of total flap area were as follows: LABC, 61.8% (range, 48.3-71.6%); MABC, 33.8% (range, 30.5-38.9%); and SRSN, 34.6% (range, 26.8-44.1%). After nerve block the mapped sensory areas were as follows: LABC, 62.3% (range, 44.5-88.5%); MABC, 19.6% (range, 8.0-35.8%); and SRSN, 19.5% (range, 9.9-26.3%). At least 40% of the total flap area was not innervated by the LABC as identified both by nerve dissection and sensory local anesthetic blockade. By including the LABC, MABC, and SRSN in the radial forearm flap, both the theoretical and the clinically determined useful sensory innervation of the radial forearm flap potentially would be increased.

De novo adipose tissue generation through long-term, local delivery of insulin and insulin-like growth factor-1 by PLGA/PEG microspheres in an in vivo rat model: a novel concept and capability

This study was undertaken to characterize the duration of long-term growth factor delivery by poly(lactic-co-glycolic-acid)-polyethylene glycol (PLGA/PEG) microspheres and to evaluate the potential of long-term delivery of insulin and insulin-like growth factor-1 (IGF-1) for the de novo generation of adipose tissue in vivo. PLGA/PEG microspheres containing insulin and IGF-1, separately, were produced by a double-emulsion solvent-extraction technique. In the first phase of the experiment, the in vitro release kinetics of the microspheres were evaluated for the optical density and polyacrylamide gel electrophoresis of solutions incubated with insulin-containing microspheres for four different periods of time (n = 1). The finding of increased concentrations of soluble insulin with increased incubation time confirmed continual protein release. In the second stage of the experiment, 16 rats were divided equally into four study groups (insulin, IGF-1, insulin + IGF-1, and blank microspheres) (n = 4). Insulin and IGF-1 containing microspheres were administered directly to the deep muscular fascia of the rat abdominal wall to evaluate the potential for de novo adipose tissue generation via adipogenic differentiation from native nonadipocyte cell pools in vivo. Animals treated with blank microspheres served as an external control group. At the 4-week harvest period, multiple ectopic islands of adipose tissue were observed on the abdominal wall of the animals treated with insulin, IGF-1, and insulin + IGF-1 microspheres. Such islands were not seen in the blank microsphere group. Hematoxylin and eosin-stained sections of the growth factor groups demonstrated mature adipocytes interspersed with fibrous tissue superficial to the abdominal wall musculature and continuous with the fascia. Oil-Red-O stained sections demonstrated that these cells contained lipid. Computer-aided image analysis of histologic sections confirmed that there were statistically significant increases in the amount of "ectopic" adipose neotissue developed on the abdominal wall of animals treated with growth factor microspheres. In conclusion, this study confirms the long-term release of proteins from PLGA/PEG microspheres up to 4 weeks and demonstrates the potential of long-term local insulin and IGF-1 to induce adipogenic differentiation to mature lipid-containing adipocytes from nonadipocyte cell pools in vivo at 4 weeks.

Continuous versus interrupted suturing of traumatic lacerations: a time, cost, and complication rate comparison

BACKGROUND

The most frequently used techniques in the repair of traumatic lacerations are interrupted and continuous suturing.

METHODS

We performed a prospective study of interrupted and continuous suturing techniques evaluating suturing rates, suture economy, and complication rates in the repair of 101 traumatic lacerations.

RESULTS

Continuous closure was accomplished at a statistically faster rate (mean, 0.276 cm/min) than interrupted closure (mean, 0.175 cm/min; p = 0.004). Less suture material was used in the continuous closures (0.321 suture packets/cm) than in interrupted closures (0.508 suture packets/cm; p = 0.03). No statistically significant difference existed in the complication rate between the two closure methods (continuous, 1 of 44; interrupted, 1 of 57; p = 0.59).

CONCLUSION

Although suturing technique should be selected primarily on the basis of wound characteristics and surgeon preference, continuous suturing warrants consideration for the closure of traumatic lacerations because of its time/material economy and the lack increased complication rates.

Transfer of flexor carpi ulnaris branch of the ulnar nerve to the pronator teres nerve: histomorphometric analysis

Partial median-nerve injury high in the upper extremity, resulting from brachial plexus neuritis or trauma, can affect the pronator teres muscle and result in the inability to pronate the forearm. A nerve transfer from an ulnar nerve-innervated branch to the flexor carpi ulnaris (FCU) muscle to the branch to the pronator teres (PT) is an attractive option in this clinical scenario. This study, a histomorphometric analysis of nine cadaver specimens harvested at the proposed FCU branch to PT branch transfer site, demonstrates sufficient similarities between the two branches in total number of nerve fibers (371.6 with SEM 35.1, and 361.9 with SEM 47.1; p = 0.87) and nerve cross-sectional area (122,181 microm2 with SEM 14,546 microm2, and 142,492 microm2 with SEM 19,633 microm2; p = 0.42), to predict a functional transfer result. In addition, clinical application of this transfer resulted in functional pronation strength of M4+.

An unusual case of polydactyly of the thumb

We present an unusual case of polydactyly of the thumb. The patient, despite having a fully developed nail bed, had a duplication at the metacarpophalangeal level consisting of a single bony phalanx. The Wassel classification of polydactyly, which is the most commonly cited classification scheme, does not include this particular anomaly. In addition, there has been no reference to this type of polydactyly in the literature.

The intradermal anatomy of the inframammary fold

The anatomy of the inframammary fold has been a subject of controversy. This report describes the anatomic location and the histologic structure of the inframammary fold on the basis of caderveric dissections and microscopic examination. Ten breast cadaver dissections were performed on female cadavers (ages 35 to 72). Twenty specimens after en bloc resections of the inframammary fold and subcutaneous tissue, including the pectoralis muscle, were harvested. Specimens were examined for gross collagen stricture by using India ink to highlight the collagenous aspects of the subcutaneous soft-tissue networks. The inframammary fold skin and dermis from the contralateral breast and control samples of skin and dermis from the upper chest and the abdomen were collected for microscopic studies. These samples were stained with Sirius red and examined microscopically by polarized light. On histologic examination, regular arrays of collagen were found running parallel with the inframammary fold, and the control sections showed random patterns of collagen deposition. On gross examination, a condensation of the superficial fascial system was observed. This formed a zone of adherence between the skin and the underlying pectoralis fascia. The conclusion of this study is that the inframammary fold is an intrinsic dermal structure consisting of regular arrays of collagen held in place by a zone of adherence that is a specialized area of the superficial fascial system. The clinical significance of this study is that the intradermal structure of the inframammary fold should be preserved in any breast procedure for natural aesthetic results.

Antibody to transforming growth factor beta reduces collagen production in injured peripheral nerve

Epineurial scarring in peripheral nerve after injury inhibits normal axonal regeneration primarily due to fibroblast deposition of type I collagen. The transforming growth factor beta (TGF-beta) family is an important class of signaling molecules that has been shown to stimulate fibroblasts to produce collagen. The aim of this study was to design a prototypic therapeutic system in which the neutralization of TGF-beta in crushed rat sciatic nerve would decrease collagen formation. A total of 45 experimental Lewis rats were used. Group 1 animals (20 rats) sustained a unilateral crush injury to the sciatic nerve with injection of phosphate buffer solution. Group 2 animals (20 rats) sustained a unilateral crush injury to the sciatic nerve with injection of phosphate-buffered saline and goat, anti-rat, panspecific TGF-beta antibody. Group 3 control animals (five rats) underwent only exposure of sciatic nerve with injection of antibody. All animals were killed at 14 days and sciatic nerve specimens were harvested at that time. Slides of experimental tissue were processed using a 35S-labeled oligomer for procollagen alpha-1 mRNA, then dipped in photographic emulsion and examined by darkfield autoradiography. Morphometric analysis of pixel counts was then performed. A significant reduction in total pixel count per high-power field and in total number of fibroblasts per high-power field was found in crushed rat sciatic nerve treated with anti-TGF-beta antibody when compared with those treated only with phosphate-buffered saline. These findings are consistent with successful reduction in procollagen induction after a crush injury by topical administration of blocking antibody against transforming growth factor beta. The concept of growth factor blockade for therapeutic collagen reduction is attractive in the context of nerve injury, and the current article provides a model for future clinical application.

The effect of a single dose of metrifonate on Schistosoma haematobium infection in Egyptian school children

Egyptian school children infected with Schistosoma haematobium and treated with a single dose of metrifonate, 10 mg/kg body weight, had a marked reduction in urine egg counts reaching 90% during a 30-week follow-up. While cure rate was higher among lightly infected persons, percentage reduction in egg counts was greater among the heavily infected. After a summer period of probable high risk exposure reinfection rate in those children who were treated and cured was 4.7% as compared to 6% in previously uninfected children.