Adipocyte-derived inflammatory molecules induce senescent B cells through metabolic pathways

OBJECTIVE

The aim of this study was to demonstrate that an adipocyte tissue-derived conditioned medium (ACM) contains inflammatory molecules that induce senescence in B cells.

METHODS

We incubated blood-derived B cells from lean donors with ACM obtained from the adipose tissue of adult female donors with obesity undergoing weight reduction surgery or with medium as control. After 24 h, cells were harvested, and the expression of transcripts for proinflammatory cytokines (TNF/IL-6), chemokines (IL-8), and for markers of the senescence-associated secretory phenotype (SASP) was measured by quantitative polymerase chain reaction. B cells were also stained with the marker of immunosenescence β-galactosidase, and their metabolic status was evaluated in Seahorse using a Mito Stress Test.

RESULTS

We show that the incubation of B cells from lean donors with ACM induces the expression of transcripts for inflammatory and SASP transcripts, increases the amount of β-galactosidase staining, and induces a metabolic phenotype characterized by higher basal and maximal oxygen consumption, spare respiratory capacity (difference between maximal and basal respiration), nonmitochondrial oxygen consumption, ATP production, and proton leak.

CONCLUSIONS

These results demonstrate that B cells from lean individuals, after incubation with ACM, become inflammatory and senescent, and this occurs through metabolic pathways needed to support their secretory phenotype.

Craniofacial Injuries in Swimming and Water Sports: Implications for Prevention

INTRODUCTION

Water-related recreational activities, including swimming and diving, are widespread. However, they carry a significant risk of craniofacial injuries. Despite the popularity of these activities, comprehensive data on injuries beyond drowning remain scant. This study addresses this gap by providing valuable epidemiological insight into the nature, prevalence, and demographic patterns of craniofacial injuries related to water sports activities.

METHODS

The authors queried the NEISS database for craniofacial injuries related to swimming, diving, and water sports from 2013 to 2022. Data were analyzed for demographics, anatomic locations of injuries, and the activities leading to these injuries.

RESULTS

Between 2013 and 2022, a total of 952,111 craniofacial injuries were associated with swimming and water sports. Of these, 510,706 (53.6%) were male patients, and 441,405 (46.4%) were female. This indicates that males were 1.16 times more likely to sustain such injuries. The age groups most affected were 0 to 9 and 10 to 19 years. Anatomic locations impacted were as follows: ears (58.1%), head (16.8%), face (13.9%), neck (4.8%), eyeballs (4.4%), and mouth (2%). Leading causes were identified as swimming and water sports activities (66.5%), swimming pools and equipment (28.2%), diving or diving boards (4.7%), and scuba diving (0.5%). Notably, 89.2% of patients with diving-related injuries and 99.1% with swimming-related injuries were not admitted to the hospital.

CONCLUSIONS

This study offers critical epidemiological data to supplement targeted prevention strategies and resource allocation in managing craniofacial injuries associated with water activities. The findings highlight the urgent need for specialized care and serve as a foundation for future preventive initiatives.

A Cost Analysis of Mohs and Total Surgical Excision: A Retrospective Review of Skin Cancer Treatments

PURPOSE

Skin cancer risk is elevated in veterans, Whites, and males older than 50 years, who comprise the majority of patients at the Miami VA healthcare system.Treatments include total surgical excision (TSE) with frozen section or permanent pathology, and Mohs surgery. Our protocol consists of Mohs procedures performed offsite followed by reconstruction at the VA. This retrospective study examines the cost difference between TSE and Mohs surgery.

METHODS

A retrospective chart review was performed of VA patients who underwent TSE or Mohs surgery between 2017 and 2019. Patients younger than 18 or those without malignancy on final pathology were excluded. Patients were subdivided into TSE versus Mohs. Cost per operating room minute was determined using published data for similar institutions. Pathology costs were estimated using institution specific Medicare data. T test was performed using SPSS.

RESULTS

Of 130 patients identified, 82 underwent TSE and 48 underwent Mohs with reconstruction. Cost per operating room minute for inpatient government-owned facilities was $37.94. A flat fee of $1400 for the Mohs surgery was the contracted rate with the offsite institution. Average cost of Mohs surgery with reconstruction was $3534.12. Average cost of TSE with pathology was $2643.85. Total surgical excision was significantly more cost efficient than Mohs with reconstruction (P < 0.01).

CONCLUSIONS

At our institution, TSE seems more cost effective than Mohs with subsequent reconstruction. While these are generalized costs, and data specific to our institution, cost efficiency is an important consideration in improving the value of care for VA patients.

Periorbital Pyoderma Gangrenosum Associated With a Cocaine-Induced Midline Destructive Lesion: Case Report and Review of the Literature

A 72-year-old woman with a history of chronic cocaine use presented 9 months after a dog bite with a large facial ulceration and absent sinonasal structures. Biopsies were negative for infectious, vasculitic, or neoplastic pathologies. The patient was lost to follow up for 15 months and returned with a significantly larger lesion despite abstinence from cocaine. Additional inflammatory and infectious workup was negative. Intravenous steroids were administered with clinical improvement. Therefore, she was diagnosed with pyoderma gangrenosum and cocaine-induced midline destructive lesion due to cocaine/levamisole. Pyoderma gangrenosum is a rare dermatologic condition that uncommonly involves the eye and ocular adnexa. Diagnosis involves clinical examination, response to steroids, exclusion of infectious or autoimmune conditions, and identifying potential triggers including cocaine/levamisole. This report highlights a rare presentation of periorbital pyoderma gangrenosum causing cicatricial ectropion associated with concomitant cocaine-induced midline destructive lesion and reviews important aspects of clinical manifestations, diagnosis, and management of pyoderma gangrenosum and cocaine/levamisole autoimmune phenomenon.

Phenotypic and functional features of B cells from two different human subcutaneous adipose depots

In this study, we have compared frequencies, phenotype, function and metabolic requirements of B cells isolated from the breast and abdominal subcutaneous adipose tissue (AT) of women with obesity who underwent weight reduction surgeries. Results show that B cells from the abdominal AT are more inflammatory than those from the breast, characterized by higher frequencies of inflammatory B cell subsets and higher expression of RNA for inflammatory markers associated with senescence. Secretion of autoimmune antibodies is also higher in the abdominal AT as compared to the breast, and is associated with higher frequencies of autoimmune B cells with the membrane phenotype CD21lowCD95+ B cells expressing the transcription factor T-bet. Moreover, glucose uptake is higher in B cells from the abdominal AT as compared to the breast, thereby suggesting a better capacity to perform glycolysis, needed to support intrinsic B cell inflammation and autoimmune antibody secretion.

Catalase, a therapeutic target in the reversal of estrogen-mediated aging

Despite increasing interest in the reversal of age-related processes, there is a paucity of data regarding the effects of post-menopausal-associated estrogen loss on cellular function. We studied human adipose-derived mesenchymal stem cells (hASCs) isolated from women younger than 45 years old (pre-menopause, pre-hASC) or older than 55 years old (post-menopause, post-hASC). In this study, we provide proof of concept that the age-related ineffective functionality of ASCs can be reversed to improve their ability in promoting tissue repair. We found reduced estrogen receptor expression, decreased estrogen receptor activation, and reduced sensitivity to 17β-estradiol in post-hASCs. This correlated with decreased antioxidants (catalase and superoxide dismutase [SOD] expression) and increased oxidative stress compared with pre-hASCs. Increasing catalase expression in post-hASCs restored estrogen receptor (ER) expression and their functional capacity to promote tissue repair as shown in human skin ex vivo wound healing and in vivo mouse model of lung injury. Our results suggest that the consequences of 17β-estradiol decline on the function of hASCs may be reversible by changing the oxidative stress/antioxidant composition.

B Cells with a Senescent-Associated Secretory Phenotype Accumulate in the Adipose Tissue of Individuals with Obesity

Senescent cells accumulate in the adipose tissue (AT) of individuals with obesity and secrete multiple factors that constitute the senescence-associated secretory phenotype (SASP). This paper aimed at the identification of B cells with a SASP phenotype in the AT, as compared to the peripheral blood, of individuals with obesity. Our results show increased expression of SASP markers in AT versus blood B cells, a phenotype associated with a hyper-metabolic profile necessary to support the increased immune activation of AT-derived B cells as compared to blood-derived B cells. This hyper-metabolic profile is needed for the secretion of the pro-inflammatory mediators (cytokines, chemokines, micro-RNAs) that fuel local and systemic inflammation.

Identification and characterization of adipose tissue-derived human antibodies with “anti-self” specificity

We have previously shown that the human obese adipose tissue (AT) contributes to increased secretion of adipocyte-specific IgG antibodies in individuals with obesity. We have also shown that this occurs without any exogenous stimulation, because the ongoing process of cell death in the obese AT leads to the release of “self” antigens able to induce chronic stimulation of B cells. Here, we confirm and extend our initial observation on a different cohort of individuals, and we show that also the plasma of obese individuals is enriched in IgG antibodies with specificities for adipocyte-derived antigens. Adipocyte-specific IgG secreted in the obese AT are significantly correlated with those present in plasma. Using immunoprecipitation and mass spectrometry, we have identified these antigenic specificities. The antigens are almost exclusively intracellular or cell-associated, usually not “self” antigens, but they are released by cells dying in the AT. These antigens will be used in protein arrays to screen plasma from individuals with obesity and also with autoimmune diseases. We have indeed preliminary evidence that the plasma of Rheumatoid Arthritis patients is enriched in adipocyte-specific IgG antibodies, suggesting that obesity may contribute to pathogenicity in autoimmune patients. Finally, we show for the first time that not only macrophages but also adipocytes in the obese AT are efficient antigen-presenting cells and stimulate the secretion of IgG autoimmune antibodies. They do so because they express the antigen-presenting molecules CD1d and, to a lesser extent, MHC class II, as well as the co-stimulatory molecule CD86. These results may lead to the development of novel therapeutic strategies to controlautoimmunity.

Identification and Characterization of Adipose Tissue-Derived Human Antibodies With "Anti-self" Specificity

We have previously shown that the human obese adipose tissue (AT) contributes to increased secretion of adipocyte-specific IgG antibodies in individuals with obesity. This occurs without any exogenous stimulation, because the ongoing process of cell death in the obese AT leads to the release of "self" antigens able to induce chronic stimulation of B cells. We have identified several mechanisms responsible for the release of "self" antigens, such as hypoxia, cell cytotoxicity, and DNA damage. In this paper, we confirm and extend our initial observation on a different cohort of individuals, and we show that also the plasma of these individuals is enriched in IgG antibodies with specificities for adipocyte-derived antigens. Adipocyte-specific IgG secreted in the obese AT are significantly correlated with those present in plasma. Using immunoprecipitation and mass spectrometry, we have identified these antigenic specificities. The antigens are almost exclusively intracellular or cell-associated, usually not recognized as "self" antigens, but they are released by cells dying in the AT. We also show for the first time that the adipocytes in the obese AT contribute to the secretion of IgG autoimmune antibodies and this seems to be due to their expression of the antigen-presenting molecules CD1d and, to a much lesser extent, MHC class II, as our mechanistic experiments performed in mice have shown. These results may lead to the development of novel therapeutic strategies to control autoimmunity.

Metabolic requirements of human pro-inflammatory B cells in aging and obesity

The subset of pro-inflammatory B cells, called late memory, tissue-like or double negative (DN), accumulates in the blood of elderly individuals. Here we show that DN B cells do not proliferate and do not make antibodies to influenza antigens, but they secrete antibodies with autoimmune reactivity, in agreement with their membrane phenotype (CD95+CD21-CD11c+) and their spontaneous expression of the transcription factor T-bet. These cells also increase in the blood of individuals with obesity and autoimmune diseases, but causative mechanisms and signaling pathways involved are known only in part. In the present paper we compare frequencies and metabolic requirements of these cells in the blood of healthy individuals of different ages and in the blood and the subcutaneous adipose tissue (SAT) of individuals with obesity. Results show that DN B cells from young individuals have minimal metabolic requirements, DN B cells from elderly and obese individuals utilize higher amounts of glucose to perform autoimmune antibody production and enroll in aerobic glycolysis to support their function. DN B cells from the SAT have the highest metabolic requirements as they activate oxidative phosphorylation, aerobic glycolysis and fatty acid oxidation. DN B cells from the SAT also show the highest levels of ROS and the highest levels of phosphorylated AMPK (5'-AMP activated kinase) and Sestrin 1, both able to mitigate stress and cell death. This metabolic advantage drives DN B cell survival and function (secretion of autoimmune antibodies).

The time course of muscle-tendon properties and function responses of a five-minute static stretching exercise

The purpose of this study was to investigate the time course of the changes of muscle-tendon mechanical properties and the function responses of the plantar flexor muscles following 5 × 60 s of static stretching.

Fourteen healthy volunteers were tested on four separate days in a random order with three different rest times (0, 5, 10 min) after 5 × 60 s of stretching or following a control period without stretching. During each test, the dorsiflexion range of motion (RoM), passive resistive torque (PRT), and maximum voluntary contraction (MVC) were measured with a dynamometer. Ultrasonography of the gastrocnemius medialis (GM) muscle-tendon junction displacement and motion capture allowed us to determine the length changes in the tendon and muscle, respectively, and hence to calculate their stiffness.

We observed an increase in RoM and decrease in MVC at 0, 5, and 10 min post-stretching. This could be attributed to an increase in muscle elongation which lasted at least 10 min. A decrease in muscle-tendon stiffness was observed immediately, but not 5 or 10 min after the stretching. A decrease in PRT and muscle stiffness was observed up to 5 min after the stretching. No changes were detected in tendon stiffness or in any variable in the control group.

The effects of a 5 × 60 s static stretching exercise changes the muscle-tendon functions (RoM, MVC), which are related to mechanical changes of the muscle but not the tendon structure, respectively. Although the functional changes last for at least 10 min, changes in muscle stiffness were only observed up to 5 min after the stretching exercise.

Secretion of autoimmune antibodies in the human subcutaneous adipose tissue

The adipose tissue (AT) contributes to systemic and B cell intrinsic inflammation, reduced B cell responses and secretion of autoimmune antibodies. In this study we show that adipocytes in the human obese subcutaneous AT (SAT) secrete several pro-inflammatory cytokines and chemokines, which contribute to the establishment and maintenance of local and systemic inflammation, and consequent suboptimal immune responses in obese individuals, as we have previously shown. We also show that pro-inflammatory chemokines recruit immune cells expressing the corresponding receptors to the SAT, where they also contribute to local and systemic inflammation, secreting additional pro-inflammatory mediators. Moreover, we show that the SAT generates autoimmune antibodies. During the development of obesity, reduced oxygen and consequent hypoxia and cell death lead to further release of pro-inflammatory cytokines, “self” protein antigens, cell-free DNA and lipids. All these stimulate class switch and the production of autoimmune IgG antibodies which have been described to be pathogenic. In addition to hypoxia, we have measured cell cytotoxicity and DNA damage mechanisms, which may also contribute to the release of “self” antigens in the SAT. All these processes are significantly elevated in the SAT as compared to the blood. We definitively found that fat-specific IgG antibodies are secreted by B cells in the SAT and that B cells express mRNA for the transcription factor T-bet and the membrane marker CD11c, both involved in the production of autoimmune IgG antibodies. Finally, the SAT also expresses RNA for cytokines known to promote Germinal Center formation, isotype class switch, and plasma cell differentiation. Our results show novel mechanisms for the generation of autoimmune antibody responses in the human SAT and allow the identification of new pathways to possibly manipulate in order to reduce systemic inflammation and autoantibody production in obese individuals.

Dayside response of the magnetosphere to a small shock compression: Van Allen Probes, Magnetospheric MultiScale, and GOES-13

Observations from Magnetospheric MultiScale (~8 Re) and Van Allen Probes (~5 and 4 Re) show that the initial dayside response to a small interplanetary shock is a double-peaked dawnward electric field, which is distinctly different from the usual bipolar (dawnward and then duskward) signature reported for large shocks. The associated E × B flow is radially inward. The shock compressed the magnetopause to inside 8 Re, as observed by Magnetospheric MultiScale (MMS), with a speed that is comparable to the E × B flow. The magnetopause speed and the E × B speeds were significantly less than the propagation speed of the pulse from MMS to the Van Allen Probes and GOES-13, which is consistent with the MHD fast mode. There were increased fluxes of energetic electrons up to several MeV. Signatures of drift echoes and response to ULF waves also were seen. These observations demonstrate that even very weak shocks can have significant impact on the radiation belts.

The Relationship of Bacterial Biofilms and Capsular Contracture in Breast Implants

Capsular contracture is a common sequelae of implant-based breast augmentation. Despite its prevalence, the etiology of capsular contracture remains controversial. Numerous studies have identified microbial biofilms on various implantable materials, including breast implants. Furthermore, biofilms have been implicated in subclinical infections associated with other surgical implants. In this review, we discuss microbial biofilms as a potential etiology of capsular contracture. The review also outlines the key diagnostic modalities available to identify the possible infectious agents found in biofilm, as well as available preventative and treatment measures.

Electron densities inferred from plasma wave spectra obtained by the Waves instrument on Van Allen Probes

The twin Van Allen Probe spacecraft, launched in August 2012, carry identical scientific payloads. The Electric and Magnetic Field Instrument Suite and Integrated Science suite includes a plasma wave instrument (Waves) that measures three magnetic and three electric components of plasma waves in the frequency range of 10 Hz to 12 kHz using triaxial search coils and the Electric Fields and Waves triaxial electric field sensors. The Waves instrument also measures a single electric field component of waves in the frequency range of 10 to 500 kHz. A primary objective of the higher-frequency measurements is the determination of the electron density ne at the spacecraft, primarily inferred from the upper hybrid resonance frequency fuh. Considerable work has gone into developing a process and tools for identifying and digitizing the upper hybrid resonance frequency in order to infer the electron density as an essential parameter for interpreting not only the plasma wave data from the mission but also as input to various magnetospheric models. Good progress has been made in developing algorithms to identify fuh and create a data set of electron densities. However, it is often difficult to interpret the plasma wave spectra during active times to identify fuh and accurately determine ne . In some cases, there is no clear signature of the upper hybrid band, and the low-frequency cutoff of the continuum radiation is used. We describe the expected accuracy of ne and issues in the interpretation of the electrostatic wave spectrum.

Baby sleeping bag and conventional bedding conditions--comparative investigations by infrared thermography

BACKGROUND

Thermal stress is a risk factor for sudden infant death syndrome (SIDS). Recently, baby sleeping bags have been recommended as a preventive measure against SIDS. The aim of this study was to describe in which way the use of baby sleeping bags might influence thermoregulation of sleeping infants and maybe the incidence of SIDS.

METHODS

Body surface temperature was recorded by use of infrared thermography in 15 infants (median age 49 days). Recordings were done twice: after sleeping for 60 min under a blanket and after sleeping for 60 min in a baby sleeping bag. Temperature was recorded and compared for defined sites of body surface.

RESULTS

Infants' mean body surface temperature as well as core temperature after sleeping in a baby sleeping bag did not show significant differences when compared to infants sleeping under a conventional blanket.

CONCLUSION

Under controlled conditions, core temperature and mean body surface temperature are comparable, equally if using a baby sleeping bag or conventional bedding. However, under the more uncontrolled conditions of baby care at home, sleeping bags might provide a more constant temperature profile, while other bedding conditions may lead to significant variations of temperature pattern.

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. .

Complex wound management with an artificial dermal regeneration template

The following case reports on the successful use of Integra® (Integra LifeSciences, Plainsboro, NJ) as an alternative for coverage of exposed tibia in a patient with necrotizing fasciitis and significant comorbidities. Necrotizing fasciitis is a generalized term that is used to describe soft tissue infections in which necrosis of the fascia and subcutaneous tissue occurs. Necrotizing fasciitis will often begin with disproportionate pain, localized erythema, and skin discoloration with vesicle formation. As the disease progresses along fascial planes, an area of deep necrosis develops with eventual signs of systemic toxicity and sepsis. Diagnosis of this condition can be quite challenging, and the diagnostic value of laboratory tests is limited. Aggressive treatment of necrotizing fasciitis is extremely important; the infection develops rapidly and can quickly lead to systemic toxicity and death. Traditionally, management of necrotizing fasciitis consists of resuscitation and stabilization of the patient, aggressive surgical debridement of all nonviable tissue, and the administration of broad-spectrum antibiotics. Reconstructive surgery is indicated for many patients who have recovered from necrotizing fasciitis. Integra, an artificial dermal regeneration template (DRT), has emerged as an adjunct to split-thickness grafts or tissue transfers. This case exemplifies the potential for DRT to provide another, more direct alternative for coverage of a complex, exposed wound. .

An improved method to determine neuromuscular properties using force laws - From single muscle to applications in human movements

We evaluate an improved method for individually determining neuromuscular properties in vivo. The method is based on Hill's equation used as a force law combined with Newton's equation of motion. To ensure the range of validity of Hill's equation, we first perform detailed investigations on in vitro single muscles. The force-velocity relation determined with the model coincides well with results obtained by standard methods (r=.99) above 20% of the isometric force. In addition, the model-predicted force curves during work loop contractions very well agree with measurements (mean difference: 2-3%). Subsequently, we deduce theoretically under which conditions it is possible to combine several muscles of the human body to model muscles. This leads to a model equation for human leg extension movements containing parameters for the muscle properties and for the activation. To numerically determine these invariant neuromuscular properties we devise an experimental method based on concentric and isometric leg extensions. With this method we determine individual muscle parameters from experiments such that the simulated curves agree well with experiments (r=.99). A reliability test with 12 participants revealed correlations r=.72-.91 for the neuromuscular parameters (p<.01). Predictions of similar movements under different conditions show mean errors of about 5%. In addition, we present applications in sports practise and theory.

The use of decellularized dermal grafting (AlloDerm) in persistent oro-nasal fistulas after tertiary cleft palate repair

To assess the efficacy of decellularized dermal grafting as an adjunct to the closure of recurrent oro-nasal fistulas. Five consecutive patients with recurrent oro-nasal fistulas were repaired with decellularized dermal grafting sandwiched between oral and nasal flaps of a von Langenbeck palatal repair. All patients had previously undergone a minimum of three prior palatal repairs with the recurrence of their oro-nasal fistula in the post-alveolar area. Decellularized dermal graft was placed between the nasal mucosa and the levator veli palatine muscle. Patients were followed postoperatively and assessed for infection, dehiscence, signs of rejection, and fistula recurrence. All patients were followed for an average of three months. Clinical examination revealed no recurrence of their oro-nasal fistula nor associated symptoms of nasal reflux. Decellularized dermal grafts were not rejected nor extruded from the site of surgical repair. Decellularized dermal graft should be considered for use in the treatment of recurrent oro-nasal fistula after cleft palate repair. We would also like to encourage further clinical study.

Pediatric Breast Deformity

Congenital breast anomalies represent a relatively common set of disorders encountered by pediatric plastic surgeons with a spectrum of severity that ranges widely from the relatively benign polythelia to the very complex disorders such as Poland's syndrome and tuberous breast deformities. While the former can be treated in a single surgical setting with minimal morbidity, the more complicated disorders often require a staged reconstructive algorithm. Some disorders also require a multidisciplinary management for both workup and management. Although rarely a source of functional morbidity, these physical deformities are often a significant source of psychological stress for the adolescent male or female who feels alienated from their peers. The purpose of this article is to review the most common congenital breast disorders including the diagnosis, workup, and management especially the timing of surgical intervention as guided by normal developmental milestones.

Congenital Melanosis: An Update

Congenital nevi remain a constant and challenging clinical entity for plastic surgeons due to the unsettled question regarding the true incidence of conversion to melanoma. This paper will review the recent distinction described in the literature. To truly obtain a current authoritative accord, a new interdisciplinary consensus conference should probably be convened to review and initiate new standards regarding available treatment modalities and their indications.

The relation between Hill's equation and individual muscle properties

In this paper we deal with movement-independent individual muscle properties derived from Hill's equation. Relations between these properties are found by theoretical considerations. We define a dimensionless quantity that turns out to play a major role in characterizing individual muscle properties, and we analyse normalization and symmetry behaviour of the parameters in Hill's equation. This leads to a systematic, transparent, and useful overview of mathematical relations involving muscle parameters. We examine the experimentally determined parameters of 62 subjects to find additional empirical relations between the muscle properties described by the parameters of Hill's equation. In the light of the theoretical end empirical results we investigate the connections between maximum efficiency, endurance, and fibre composition.

Should Nevus Sebaceus of Jadassohn in Children be Excised? A Study of 757 Cases, and Literature Review

The incidence of basal cell carcinoma and the need for prophylactic excision in children with nevus sebaceus of Jadassohn have been a topic of controversy. The authors performed a retrospective analysis of 757 cases from 1996 to 2002 in children aged 16 years or younger. No cases of basal cell cancer were found in the nevus sebaceus group. Recent studies in children corroborate these findings and question the need for prophylactic surgical removal of the nevus sebaceus.

Dermoscopy for Congenital Melanocytic Nevi

Small and medium congenital melanocytic nevi are relatively common but present a small but significant risk of malignant transformation. Because prophylactic excision of all nevi is impractical, dermoscopic evaluation has a role in the clinical decision-making process. Dermoscopy of benign congenital nevi reveals a globular or homogenous pattern, black or brown dots and globules, small milia-like cysts within the globules, and terminal hairs. Dermoscopic criteria of melanoma are outlined here, with discussion of common scoring methods, the seven-point checklist, the ABCD rule, pattern analysis, and the Menzies criteria. Serial examination of congenital nevi with dermoscopy and excision of those lesions with malignant criteria are useful in the management of congenital melanocytic nevi.

Reconstruction after extirpation of sacral malignancies

Defects after extirpation of either sacral or rectal tumors often present a reconstructive challenge to plastics surgeons. Because of their relative infrequency, management guidelines, in the authors' opinion, have been overlooked. They think that successful, comprehensive treatment lends itself to an integrated team approach. They review their experience with immediate reconstruction after total sacrectomy for sacral malignancies performed between 1996 and 2001. Medical records were reviewed retrospectively for the surgical procedure, postoperative complications, and eventual outcome. A total of 9 patients underwent sacrectomy with a gluteus maximus flap for reconstruction. Six patients had a simultaneous omental flap for complete obliteration of the surgical defect. The authors' experience suggests that this combination of techniques is a reliable approach for reconstruction of these extensive surgical defects.

Approaches to cleft lip and palate repair

Facial clefts remain one of the most common congenital anomalies encountered by plastic surgeons. Over the last few decades, surgical results have continued to improve due to the interdisciplinary approach to this complex clinical problem.

Holmium YAG laser-assisted osteotomies in plastic and reconstructive surgery: a preliminary report

An Omnipulse holmium-yttrium aluminum garnet (YAG) laser was used to assist in the harvesting of outer table or split calvarial bone grafts in cadaver skulls. Two- or 4-mm depth and 0.55-mm width holes in the outer cortex of cadaveric calvarium were formed without apparent gross periosteal or bony injury. Osteotomes were then used to shave or split calvarial grafts by connecting the 2- and 4-mm depth holes, respectively. The procedure was efficient as well as precise. We believe that this method of bone graft harvesting may have the added benefit of safety by decreasing the incidence of inadvertent dural penetration. This study will lead to further analysis of the potential use for additional bony work with the Omnipulse holmium-YAG laser.

Symptomatic solitary granular cell tumor of the trachea

The granular cell tumor is a neoplasm that has generated considerable controversy. A rare case of solitary granular cell tumor located in the cervical trachea is described with a new mode of therapy using the carbon dioxide laser.