Biomolecular condensates form spatially inhomogeneous network fluids

The functions of biomolecular condensates are thought to be influenced by their material properties, and these will be determined by the internal organization of molecules within condensates. However, structural characterizations of condensates are challenging, and rarely reported. Here, we deploy a combination of small angle neutron scattering, fluorescence recovery after photobleaching, and coarse-grained molecular dynamics simulations to provide structural descriptions of model condensates that are formed by macromolecules from nucleolar granular components (GCs). We show that these minimal facsimiles of GCs form condensates that are network fluids featuring spatial inhomogeneities across different length scales that reflect the contributions of distinct protein and peptide domains. The network-like inhomogeneous organization is characterized by a coexistence of liquid- and gas-like macromolecular densities that engenders bimodality of internal molecular dynamics. These insights suggest that condensates formed by multivalent proteins share features with network fluids formed by systems such as patchy or hairy colloids.

Biomolecular condensates form spatially inhomogeneous network fluids

The functions of biomolecular condensates are thought to be influenced by their material properties, and these will be determined by the internal organization of molecules within condensates. However, structural characterizations of condensates are challenging, and rarely reported. Here, we deploy a combination of small angle neutron scattering, fluorescence recovery after photobleaching, and coarse-grained molecular dynamics simulations to provide structural descriptions of model condensates that are formed by macromolecules from nucleolar granular components (GCs). We show that these minimal facsimiles of GCs form condensates that are network fluids featuring spatial inhomogeneities across different length scales that reflect the contributions of distinct protein and peptide domains. The network-like inhomogeneous organization is characterized by a coexistence of liquid- and gas-like macromolecular densities that engenders bimodality of internal molecular dynamics. These insights suggest that condensates formed by multivalent proteins share features with network fluids formed by systems such as patchy or hairy colloids.

Sequence-specific interactions determine viscoelasticity and aging dynamics of protein condensates

Biomolecular condensates are viscoelastic materials. Here, we report results from investigations into molecular-scale determinants of sequence-encoded and age-dependent viscoelasticity of condensates formed by prion-like low-complexity domains (PLCDs). The terminally viscous forms of PLCD condensates are Maxwell fluids. Measured viscoelastic moduli of these condensates are reproducible using a Rouse-Zimm model that accounts for the network-like organization engendered by reversible physical crosslinks among PLCDs in the dense phase. Measurements and computations show that the strengths of aromatic inter-sticker interactions determine the sequence-specific amplitudes of elastic and viscous moduli as well as the timescales over which elastic properties dominate. PLCD condensates also undergo physical aging on sequence-specific timescales. This is driven by mutations to spacer residues that weaken the metastability of terminally viscous phases. The aging of PLCD condensates is accompanied by disorder-to-order transitions, leading to the formation of non-fibrillar, beta-sheet-containing, semi-crystalline, terminally elastic, Kelvin-Voigt solids. Our results suggest that sequence grammars, which refer to the identities of stickers versus spacers in PLCDs, have evolved to afford control over the metastabilities of terminally viscous fluid phases of condensates. This selection can, in some cases, render barriers for conversion from metastable fluids to globally stable solids to be insurmountable on functionally relevant timescales.

Hablando at home: Examining the interactional resources of a bilingual autistic child

Daily language interactions predict child outcomes. For multilingual families who rear neurodiverse children and who may be minoritized for their language use, a dearth of research examines families' daily language interactions. Utilizing a language socialization framework and a case study methodology, 4,991 English and Spanish utterances from a 5-year old autistic child and his family were collected during naturally occurring interactions over 10 days. Utterances were analyzed for patterns of code-switching by speaker, activity setting, English or Spanish initial language, and code-switch function. Spanish was spoken in most activities. For reading, both languages were equally employed by the father. While participants used both languages across all activity settings, significant variations in code-switching type and function were observed by activity setting and speaker. We discuss implications for how home language resources can be integrated into autism interventions.

Biomolecular condensates form spatially inhomogeneous network fluids

The functions of biomolecular condensates are thought to be influenced by their material properties, and these are in turn determined by the multiscale structural features within condensates. However, structural characterizations of condensates are challenging, and hence rarely reported. Here, we deploy a combination of small angle neutron scattering, fluorescence recovery after photobleaching, and bespoke coarse-grained molecular dynamics simulations to provide structural descriptions of model condensates that mimic nucleolar granular components (GCs). We show that facsimiles of GCs are network fluids featuring spatial inhomogeneities across hierarchies of length scales that reflect the contributions of distinct protein and peptide domains. The network-like inhomogeneous organization is characterized by a coexistence of liquid- and gas-like macromolecular densities that engenders bimodality of internal molecular dynamics. These insights, extracted from a combination of approaches, suggest that condensates formed by multivalent proteins share features with network fluids formed by associative systems such as patchy or hairy colloids.

Phase Transitions of Associative Biomacromolecules

Multivalent proteins and nucleic acids, collectively referred to as multivalent associative biomacromolecules, provide the driving forces for the formation and compositional regulation of biomolecular condensates. Here, we review the key concepts of phase transitions of aqueous solutions of associative biomacromolecules, specifically proteins that include folded domains and intrinsically disordered regions. The phase transitions of these systems come under the rubric of coupled associative and segregative transitions. The concepts underlying these processes are presented, and their relevance to biomolecular condensates is discussed.

Condensates formed by prion-like low-complexity domains have small-world network structures and interfaces defined by expanded conformations

Biomolecular condensates form via coupled associative and segregative phase transitions of multivalent associative macromolecules. Phase separation coupled to percolation is one example of such transitions. Here, we characterize molecular and mesoscale structural descriptions of condensates formed by intrinsically disordered prion-like low complexity domains (PLCDs). These systems conform to sticker-and-spacers architectures. Stickers are cohesive motifs that drive associative interactions through reversible crosslinking and spacers affect the cooperativity of crosslinking and overall macromolecular solubility. Our computations reproduce experimentally measured sequence-specific phase behaviors of PLCDs. Within simulated condensates, networks of reversible inter-sticker crosslinks organize PLCDs into small-world topologies. The overall dimensions of PLCDs vary with spatial location, being most expanded at and preferring to be oriented perpendicular to the interface. Our results demonstrate that even simple condensates with one type of macromolecule feature inhomogeneous spatial organizations of molecules and interfacial features that likely prime them for biochemical activity.

Antiandrogen therapy in hidradenitis suppurativa: finasteride for females

BACKGROUND

Given its widely accepted efficacy, androgen blockade therapy for hidradenitis suppurativa (HS) has become a standard of care. Although much less frequently used than spironolactone, a small number of HS studies have reported finasteride as an alternative treatment for women. In this study, we describe the response to and perception of finasteride therapy in a diverse cohort of women with HS.

AIM

To describe finasteride therapy in a diverse cohort of female patients with HS.

METHODS

We conducted an institutional review board-approved retrospective chart review and telephone survey of 20 female patients aged ≥ 18 years with a diagnosis of HS. Finasteride was prescribed by a single provider at a specialized HS centre.

RESULTS

The mean age of the patients was 34.3 ± 13.5 years. Finasteride was initiated predominantly because of one or more contraindications or poor responsiveness to spironolactone. Most patients interviewed (90%; n = 18) were willing to take finasteride again or continue with therapy if indicated. Of the 20 patients, 10 (50%) reported overall satisfaction with finasteride, while 7 (35%) were neutral and 3 (15%) were dissatisfied. No patient reported worsening disease activity while on finasteride and only one (5%) reported decreased quality of life. When asked about adverse effects of finasteride, 80% (n = 16) reported none, while 20% (n = 4) experienced ≥ 1 of the following: headache, nausea, menstrual irregularities, breast tenderness or reduced libido/sexual function.

CONCLUSIONS

Our study suggests that androgen blockade therapy with finasteride is a safe and effective alternative for female patients with HS who have contraindication(s) or intolerance to spironolactone.

Extracting Information on Linear and Nonlinear Absorption from Two-Beam Action Spectroscopy Data

Two-beam action (2-BA) spectroscopies are a recently developed class of techniques for determining the order(s) of absorption (one-photon, two-photon, etc.) that contribute to an observable signal. When only a single order of absorption is present, 2-BA spectroscopies allow for the determination of that order from data obtained at a single value of the observable. It has been shown previously that when two orders of absorption are present, they can be determined unambiguously from measurements made at several values of the observable. However, this latter approach cannot be used for single-valued observables, such as a polymerization threshold. Here we develop a theoretical comparison between conventional methods that determine the order(s) of absorption using logarithmic plots and 2-BA-based techniques. We also explore how 2-BA plots arising from two orders of absorption deviate from a plot with a single, noninteger exponent. We demonstrate that these deviations can usually be used to identify the two orders of absorption and their relative contributions to the signal on the basis of measurements made at a single value of the observable.

Determination of the contributions of two simultaneous absorption orders using 2-beam action spectroscopy

The concept of a 2-beam action (2-BA) spectroscopy was recently introduced as a method for determining the order of effective nonlinear absorption in multiphoton photoresists. Here we demonstrate that the 2-BA approach can be extended to any measureable observable generated by linear and/or nonlinear absorption. As an example, 2-beam constant-amplitude photocurrent spectroscopy is used to study absorption of a tightly focused, mode-locked or continuous-wave, 800 nm laser by a GaAsP photodiode. The effective order of the absorption process can be measured at any desired value of the photocurrent or photovoltage. A self-consistent framework is presented for using non-integral 2-BA exponents to determine the relative contributions of two absorption mechanisms of different order. The dependence of the ratio of the quadratic and linear contributions on the average excitation power is used to verify that these are the dominant orders of absorption in the photodiode with 800 nm excitation.

Case Report: Industrial X-Ray Injury Treated With Non-Cultured Autologous Adipose-Derived Stromal Vascular Fraction (SVF)

Local cutaneous injuries induced by ionizing radiation (IR) are difficult to treat. Many have reported local injection of adipose-derived stromal vascular fraction (SVF), often with additional therapies, as an effective treatment of IR-induced injury even after other local therapies have failed. The authors report a case of a locally recurrent, IR-induced wound that was treated with autologous, non-cultured SVF without other concurrent therapy. A nondestructive testing technician was exposed to 130 kVp x rays to his non-dominant right thumb on 5 October 2011. The wound healed 4 mo after initial conservative therapy with oral/topical α-tocopherol, oral pentoxifylline, naproxen sodium, low-dose oral steroids, topical steroids, hyperbaric oxygen therapy (HBOT), oral antihistamines, and topical aloe vera. Remission lasted approximately 17 mo with one minor relapse in July 2012 after minimal trauma and subsequent healing. Aggressive wound breakdown during June 2013 required additional therapy with HBOT. An erythematous, annular papule developed over the following 12 mo (during which time the patient was not undergoing prescribed treatment). Electron paramagnetic resonance (EPR) done more than 2 mo after exposure to IR revealed dose estimates of 14 ± 3 Gy and 19 ± 6 Gy from two centers using different EPR techniques. The patient underwent debridement of the 0.5 cm papular area, followed by SVF injection into and around the wound bed and throughout the thumb without complication. Eleven months post SVF injection, the patient has been essentially asymptomatic with an intact integument. These results raise the possibility of prolonged benefit from SVF therapy without the use of cytokines. Since there is currently no consensus on the use of isolated SVF therapy in chronic, local IR-induced injury, assessment of this approach in an appropriately powered, controlled trial in experimental animals with local radiation injury appears to be indicated.

Receiving or believing in family support? Contributors to the life quality of Latino and non-Latino families of children with intellectual disability

BACKGROUND

Previous studies have identified the role of family support in mitigating the stress of parents caring for a child with intellectual disability. Less is known about families whose members are willing but unable to support each other because of geographical, structural and economic barriers. Our study examined the contribution to family quality of life (FQL) of family support beliefs, actual assistance from family members, as well as the moderating effects of ethnicity and household income.

METHOD

We conducted telephone interviews with 84 Latino and 61 non-Latino mothers.

RESULTS

Mothers who received more emotional support from partners and other family members reported a higher FQL, controlling for family characteristics. Familism beliefs were also associated with FQL, particularly for Latino mothers. Income was not a significant moderator.

CONCLUSIONS

These findings suggest that some predictors of FQL are partially moderated by ethnicity, while others may be powerful across diverse communities.

Chronic oxidative stress after irradiation: An unproven hypothesis

Injury and organ failure after irradiation of late-responding tissues is a substantial problem in radiation oncology and a major threat after accidental or belligerent exposures. The mechanisms of injury may include death of clonogens, vascular injury, activation of cytokine networks, and/or chronic oxidative stress. Knowledge of mechanisms may guide optimal use of mitigators. The hypothesis of chronic oxidative stress as a mechanism for late radiation injury has received much attention. We review herein the published evidence for chronic oxidative stress in vivo, and for use of antioxidants as mitigators of normal tissue radiation injury. We conclude that there is only indirect evidence for chronic oxidative stress after irradiation, and there are only limited published reports of mitigation by antioxidants. We did not find a differentiation of persistent markers of oxidative stress from an ongoing production of oxygen radicals. It is thus unproven that chronic oxidative stress plays a major role in causing radiation injury and organ failure in late-responding tissues. Further investigation is justified, to identify chronic oxidative stress and to identify optimal mitigators of radiation injury.

Nanocompression of individual multilayered polyhedral nanoparticles

Inorganic layered materials can form hollow multilayered polyhedral nanoparticles. The size of these multi-wall quasi-spherical structures varies from 4 to 300 nm. These materials exhibit excellent tribological and wear-resisting properties. Measuring and evaluating the stiffness of individual nanoparticle is a non-trivial problem. The current paper presents an in situ technique for stiffness measurements of individual WS(2) nanoparticles which are 80 nm or larger using a high resolution scanning electron microscope (HRSEM). Conducting the experiments in the HRSEM allows elucidation of the compression failure strength and the elastic behavior of such nanoparticles under uniaxial compression.

Continued study of the psychometric properties of the McGill quality of life questionnaire

The McGill Quality of Life Questionnaire (MQOL) is a widely used tool that has been specifically developed to measure the quality of life of patients facing a life-threatening illness. Preferably, a self-report instrument has an equal number of items worded positively and negatively. However, all the psychological scales of the MQOL are worded so that a high score is negative, whereas the existential scales are worded so that a high score is positive. The goal of this study was to investigate the influence of MQOL item formatting on patient responses. In order to do so, a modified version of the questionnaire was distributed to and completed by 205 patients in two oncology clinics. The modified version had an equal amount of items worded in a positive direction and negative direction in each of the domains. Results of this study were found to be different from those of other studies: the loading of the items was partly based on scale direction. These changes support the idea that the MQOL formatting has some impact on patient responses. However, factors were also determined by content. Given that MQOL has been widely used and the original formatting provides conceptually clearer subscales, we suggest maintaining the original format, keeping in mind the effect of formatting when interpreting scores.

Sequence Dependence of Charge Transport Properties of DNA

The electrical conduction through three short oligomers (26 base pairs, 8 nm long) with differing numbers of GC base pairs was measured. One strand is poly(A)-poly(T), which is entirely devoid of GC base pairs. Of the two additional strands, one contains 8 and the other 14 GC base pairs. The oligomers were adsorbed on a gold substrate on one side and to a gold nanoparticle on the other side. Conducting atomic force microscope was used for obtaining the current versus voltage curves. We found that in all cases the DNA behaves as a wide band-gap semiconductor, with width depending on the number of GC base pairs. As this number increases, the band-gap narrows. For applied voltages exceeding the band-gap, the current density rises dramatically. The rise becomes sharper with increasing number of GC base pairs, reaching more than 1 nA/nm2 for the oligomer containing 14 GC pairs.

A classification of facial wrinkles

An increasing number of injectable filler materials for facial wrinkles and folds points to the need for objective measurements of their effectiveness. Patient satisfaction is the goal, but proof of the value of a particular product requires objective measurement. A wrinkle assessment scale was developed as a simple tool for use by plastic surgeons, dermatologists, and aesthetic surgeons who want to assess the changes resulting from injecting filler materials in their patients. By correlating the grade of the wrinkle in the reference photographs with the wrinkle in a patient's face, a classification of 0 to 5 is assigned. Reliability of the scale was assessed by "live" judgment of 76 wrinkles by nine observers. The same rating was given to 92.7 percent of all wrinkles. In a second trial, photographs from 130 wrinkles were presented to eight observers who rated 89.4 percent of all wrinkles equally. A significant correlation of 87 percent was found between subjective ratings and objective wrinkle depth measured by profilometry on 40 silicone impressions. Manufacturers, monitors of clinical trials, health authorities, and most important, patients will benefit from objective data on current and new injectable materials.

Tacks: a new technique for craniofacial fixation

Biodegradable fixation in craniofacial surgery provides secure fixation while eliminating much of the concern over intracranial migration of metallic plates and screws. One limitation of present biodegradable systems, however, is the need for tapping the drill hole before screw insertion. Herein, a new method of rigid, biodegradable fixation with tacks (Macrapore, Inc., San Diego, CA) is described. The tacks are made of a 70:30 ratio of the L and DL form of polylactic acid (L,DL-PLA). Degradation times range from 18 to 36 months. Newer prototypes are nearly developed for more rapid dissolution times. From April 1999 to February 2000, tack fixation has been applied in 100 patients (51 males, 49 females aged 3 months to 61 years). Indications for operation were craniosynostosis (n = 33); craniofacial trauma or post-traumatic deformities (n = 11); cleft lip and palate (n = 13); craniofacial syndromes (n = 18); other diagnoses (n = 11). Patients underwent fronto-orbital advancement with cranial reshaping; monobloc osteotomy, open reduction-internal fixation of fractures; hypertelorbitism repair; cranioplasty; stabilization of grafts; major cranial reconstruction; zygomatic advancement; alveolar cleft repair; and iliac bone graft donor site protection. Tacks were also used for temporalis muscle and lateral canthal suspension. Follow-up ranged from 16 to 28 months. Complications occurred in 7 patients, 4 of whom had infections and during debridement had biodegradable implants removed. None of the complications appeared to be related to the use of tacks. The tacks are carried in a specially designed holder and may be placed by hand or with the light tap of a mallet on the tack driver. An automatic driver has been developed. Overall, the performance of the tacks has been excellent. They are easily handled by the nursing personnel and rapidly inserted by the surgeon. Stability appears to be excellent. At this time, it is probably preferable to employ tap and screws for orthognathic surgery or other osteotomies with substantial load bearing.

Outcome analysis for correction of single suture craniosynostosis using resorbable fixation

A retrospective review was performed on 63 patients at Childrens Healthcare of Atlanta at Scottish Rite who underwent correction of single-suture craniosynostosis using a resorbable fixation system. Included in the series were 24 patients with metopic synostosis, 15 with sagittal synostosis, and 24 with unicoronal synostosis. The average age at operation was 22.7 months (range: 2.8 months-18 years), and mean follow-up time was 30.7 months (range: 7.1-10 years). Reoperation equal to or exceeding the magnitude of the original procedure occurred in 4.76% of the patients. This was comparable to the reoperation rate observed at our institution using traditional fixation systems. Minor complications related to the use of resorbable plates were also identified, and the final outcome for single-suture synostosis was favorable. Results suggest that resorbable plates and screws are as effective as titanium-based systems in the treatment of single-suture synostosis.

Changes in quality of life following admission to palliative care units

The primary goal of palliative care is to improve the quality of life (QOL) of people with a terminal illness. Previous studies of the impact of hospice/palliative care have documented improvement in physical and psychological symptoms, but not in overall QOL, due in part to the difficulties of measuring QOL. The McGill Quality of Life Questionnaire (MQOL) was developed to assess QOL in persons with advanced illness. MQOL scores were determined on admission and 7-8 days later for sequential eligible and willing patients admitted to five palliative care units. These 88 patients represented 8% of those admitted to the units during the study period. Following the final MQOL completion, patients were interviewed and asked to describe the nature of the changes in QOL they had experienced since admission. Significant improvements were found in the MQOL total score and subscale scores reflecting physical, psychological and existential well-being. In the interviews patients indicated that they had experienced changes in physical, emotional and interpersonal status, in spiritual outlook, and in their preparation for death. They also described the impact of the palliative care unit environment. This is the first study to demonstrate that hospice/palliative care can improve existential well-being in addition to psychological and physical symptoms. It provides evidence in the patients' own words that improvements in QOL go beyond symptom control following admission to a palliative care unit. However, the study results are generalizable only to those few patients admitted who are well enough to complete a questionnaire 1 week after admission.

Lymphedema: strategies for management

An important sequela of cancer treatment is lymphedema. Management of this condition must be based on the physiologic functioning of the lymphatic system and tailored to the individual patient's presentation of the disease. Early diagnosis and treatment are essential to prevent worsening of the condition and to help assuage the psychologic impact of the disease. A review of the normal and impaired lymphatic system is presented in this article. Current assessment and treatment options are described, including education of patients in precautions, positioning, exercise, compression garments and bandages, pneumatic pumps, and lymphatic massage. Also included is a discussion of the psychologic impact of the disease as well as management of psychologic symptoms. Various strategies for management of the physical aspects of lymphedema are available. Studies have shown that use of physical treatments such as exercise, compression, and lymphatic massage are effective in reducing the amount of swelling in affected limbs. The specific type, amount, and combination of these treatments continues to be debated. The development of lymphedema is commonly associated with significant psychologic distress that can impact on compliance with physical treatments. Because there is no consensus as to the optimal treatment approach for management of lymphedema, additional research must ensue to determine the efficacy of existing treatments and to develop new management techniques. Clinicians must be attuned to the signs and symptoms of lymphedema in order to make prompt referrals for treatment.

Internal Le Fort III Distraction with Biodegradable Devices

Shortly after the initial application of distraction osteogenesis to the human mandible by McCarthy, distraction osteogenesis was used for gradual lengthening of the midface in children with syndromic craniosynostosis, cleft lip and palate, hemifacial microsomia, and midface hypoplasia from other causes. Both external and internal devices are available for midface distraction. In spite of the many advantages of internal metallic distraction devices, they can be more difficult to remove. By substituting the metallic fixation plates of the Stryker-Leibinger Modular Internal Distraction system, with resorbable MacroPore fixation mesh, only the distractor screw and cable drive need to be removed. Moreover, by using a resorbable stabilizer, the screw and cable components are not needed for the consolidation phase, and can be removed at the completion of active distraction. In this case report of a 4-year-old girl with Crouzon's syndrome, contouring of the resorbable distraction devices was performed using a sterilizable model, 20 mm of distraction was achieved, and 4 days later the distractor screw was replaced with a resorbable stabilizer, resulting in an excellent correction of her midface hypoplasia.

Living with cancer: "good" days and "bad" days--what produces them? Can the McGill quality of life questionnaire distinguish between them?

BACKGROUND

To determine the impact of care on quality of life (QOL), or to detect a change in QOL over time, measures of QOL must remain stable when QOL is stable (test-retest reliability) and change when QOL changes (responsiveness). This study addresses these issues for the McGill Quality of Life Questionnaire (MQOL). Unlike other studies that use disease status to indicate whether QOL has remained stable or changed, in this study the patient determines QOL stability or change. The authors also sought to clarify the determinants of "good" and "bad" days for oncology patients.

METHODS

Patients attending an oncology outpatient clinic or who were being treated by a palliative care service were asked to complete MQOL 4 times: on days they judged to be "good," "average," and "bad" and 2 days after the first completion. They also were asked to directly rate the change in their QOL during the intervals between MQOL completion and to report the most important determinants of their good and bad days.

RESULTS

The test-retest reliability of MQOL as measured by an intraclass correlation coefficient ranged from 0.69 to 0.78. All MQOL scores were significantly different on good, average, and bad days, except for the support subscale, in both clinical settings. Five domains were determinants of QOL: physical symptoms, physical functioning, psychologic well-being, existential well-being, and relationships.

CONCLUSIONS

MQOL's reliability and responsiveness suggest it can be used to determine changes in the QOL of groups. The results allow interpretation of changes in MQOL scores with respect to meaning of the change to oncology patients. This in turn is helpful to determine the sample size required in future studies. Some of the domains important to the QOL of oncology patients are not included in widely used measures of QOL.

Chiari malformation, cervical spine anomalies, and neurologic deficits in velocardiofacial syndrome

The purpose of this investigation was to evaluate the prevalence of Chiari malformation, cervical spine anomalies, and neurologic deficits in patients with velocardio-facial syndrome. This study was a prospective evaluation of 41 consecutive patients with velocardiofacial syndrome, documented by fluorescence in situ hybridization, between March of 1994 and September of 1998. The 23 girls and 18 boys ranged in age from 0.5 to 15.2 years, with a mean age of 6.7 years. Nineteen patients were assessed with magnetic resonance imaging, 39 underwent lateral cephalometric radiography, and all patients were examined for neurologic deficits. Eight of 19 patients (42 percent) had anomalies of the craniovertebral junction, including Chiari type I malformations (n = 4), occipitalization of the atlas (n = 3), and narrowing of the foramen magnum (n = 1). One patient with Chiari malformation required suboccipital craniectomy with laminectomy and decompression. Fourteen of 41 patients (34 percent) had demonstrated neurologic deficits; 10 patients (24 percent) had velar paresis (6 unilateral and 4 bilateral). Chiari malformations, cervical spine anomalies, and neurologic deficits are common in velocardiofacial syndrome. Because these findings may influence the outcome of surgical intervention, routine assessment of patients with velocardiofacial syndrome should include careful orofacial examination, lateral cephalometric radiography, and magnetic resonance imaging of the craniovertebral junction.

Internal craniofacial distraction with biodegradable devices: early stabilization and protected bone regeneration

Internal craniofacial distraction has several advantages over distraction with external devices. The scars may be less conspicuous; the devices are buried and therefore easier for patients to tolerate; and the devices are more rigidly secured to bone, preventing uncontrolled rotation of the advancing segments. There are several types of internal devices. The Modular Internal Distraction System developed by one of the authors (S.R.C.) and Stryker-Leibinger, Inc. has had widespread use for midface distraction, but requires a substantial surgical procedure for device removal. This is justified in selected children with syndromic craniosynostosis, who frequently need secondary orbitocranial reconstruction at the conclusion of distraction with any type of device. It would be preferable to develop a device that would retain the positive characteristics of the Modular Internal Distraction system, while allowing easy removability. Moreover, the entire distraction procedure would benefit from a technique that would assist in bone regeneration within the distraction gap. Such a biodegradable, stabilizing device may enable early explanation, accelerating the recovery period, while providing fixation of the distraction gap and protected bone regeneration. Accordingly, we have developed a new, biodegradable distraction device with Macropore, Inc. that may be used with the Modular Internal Distraction system to permit easy removability of the device without the need for a large operation for exposure. Second, we have developed a biodegradable stabilizer that permits earlier removal of the distraction device while providing simultaneous fixation and protected bone regeneration. Last, we have demonstrated the feasibility of midcourse correction of the distraction procedure, should this be necessary for whatever reason.

Intralesional laser therapy of extensive hemangiomas in 100 consecutive pediatric patients

The authors have treated 100 consecutive pediatric patients with capillary/cavernous hemangiomas (age range, 1.3 months to 16 years; mean age, 26.6 months; 30 male and 70 female patients) with intralesional laser therapy during a 3-year period. All patients have been followed for a minimum of 6 months after treatment (range, 6-36 months; mean, 18 months). Indications for intralesional laser treatment included interference with vision, blockage of the nose or mouth, ulceration, bleeding, and rapid, uncontrollable growth. The Nd:YAG laser was used in 70 patients, and the Potassium, Titanyl, Phosphate (KTP) laser was used in 30 patients. Fifty-five hemangiomas were in the head and neck region, excluding the orbit; 25 were in the trunk or extremities; 10 were periorbital; and 10 involved multiple sites. Seventy patients (70%) received one treatment, 20 patients (20%) received two treatments, 7 patients (7%) received three treatments, and 3 patients (3%) received four or more treatments. No appreciable differences were noted between treatment with the Nd:YAG and KTP lasers. Forty-six patients had more than a 90% reduction in the overall size of the hemangiomas whereas 54 patients had a 50% to 90% reduction in the size of the hemangioma. After maximal reduction in size of the cavernous component was achieved, the external capillary component, found in 68 patients, was treated with a tunable dye laser. Seventy-six patients underwent surgical resection after maximal lesion involution. Residual induration due to lesion fibrosis was treated with local steroid injections in 13 patients. There were four operative complications attributable to intralesional laser therapy. Two patients had residual midfacial weakness, and two patients had punctuated skin burns after intralesional treatment. The authors have found intralesional laser therapy to be a valuable tool in the treatment of large capillary/cavernous hemangiomas, often rendering an inoperable lesion safely resectable, or markedly decreasing the size and functional impact of the lesion.

Iliac crest bone graft harvesting techniques: a comparison

This study was undertaken to compare the morbidity of traditional iliac bone graft harvesting techniques for grafting alveolar clefts to minimally invasive techniques. Fifty-five age-matched patients, ages 6.5 to 16 years (mean, 11.2 years), 22 girls and 33 boys, were divided into three groups. The traditional bone window open harvesting technique served as the control group. Two different minimally invasive techniques, one that used a bone grinder and another that used a trephine, for bone harvesting were compared with the control. Both invasive techniques were statistically superior, p < 0.05, in terms of total time pain medication was necessary (mean of 12.0 hours for bone grinder, 17.6 hours for trephine, 26.0 hours for control), operative time for bone harvest (mean of 11 minutes for bone grinder and trephine, 20 minute for control), and mean incision length (2 cm for bone grinder and trephine, 5 cm for control). Patients exposed to the minimally invasive techniques had fewer complications, a trend toward earlier ambulation, and shorter hospital stays when compared with the bone grinder technique. The patients exposed to the bone grinder demonstrated earlier ambulation and fewer requirements for analgesia when compared with the trephine technique, although these results did not reach statistical significance. The trephine technique was useful when maxillary osteotomies were combined with alveolar bone grafting, because it provided structural bone grafts and cancellous bone. On the basis of these findings, the bone grinder is the preferred technique for harvesting alveolar bone grafts when no structural support is required. These authors no longer use the traditional bone window open harvesting technique.

The use of hydroxyapatite cement in secondary craniofacial reconstruction

Sixty-one patients underwent secondary craniofacial reconstruction for contour defects using hydroxyapatite cement over a 3-year period (20-month mean follow-up). There were 56 children, aged 2.2 to 18 years (mean, 10.7 years), 21 boys and 35 girls. This is the first series of pediatric patients in whom the use of hydroxyapatite cement has been reported. There were five adults aged 21 to 46 years (mean, 32 years), 3 men and 2 women. Thirty-one patients underwent reconstruction for secondary orbitocranial defects after surgery for synostosis, 7 after surgery for hypertelorism, 10 for posttraumatic skull defects, and 13 for a variety of other facial skeletal defects. There were seven complications (11 percent), ranging from a retained drain to postoperative seromas, all of which required reoperation without loss of the contour correction. All of the complications occurred in the first 18 months of our study. There has been excellent retention of implant volume with no recurrence of contour defects to date. We have not found any visible evidence of interference with craniofacial growth over the study period. We conclude that hydroxyapatite cement is a versatile and safe biomaterial when used for the correction of secondary craniofacial contour defects in children and adults. The coupling of antibiotics with this biomaterial may have applications in the treatment of osteomyelitis.

The role of distraction osteogenesis in the management of craniofacial disorders

Since its introduction in the medical literature in 1992 by McCarthy, distraction osteogenesis of the craniofacial skeleton has become a standard surgical therapy. The present report attempts to trace the development of craniofacial distraction from the perspective of one of the early proponents of the technique. Although the earliest application of distraction was in children with severe unilateral or bilateral mandibular deficiency, its use for functional abnormalities such as apnoea were especially appealing. Distraction osteogenesis for the midface began with external appliances that were attached to the teeth. Newer, buried devices have eliminated the need for external devices in all LeFort III and monobloc cases. For LeFort I and mandibular cases, the ideal internal device has not been manufactured.

An anatomic evaluation of the furlow double opposing Z-plasty technique of cleft palate repair

The aim of this investigation was to examine velar anatomy following the Furlow double opposing Z-plasty in order to analyse the theoretical effects of this technique. Thirty patients with cleft lip and/or cleft palate who underwent primary Furlow palatoplasties between 1989 and 1994 were reviewed. The mean age at the time of surgery was 6.4 months. Evaluation was performed at a mean time of 2.9 years postoperatively, and consisted of oral examination of the position of the velar dimple and measurements of velar dimensions from standard lateral cephalograms. A comparative statistical analysis of velar length (n = 17) and thickness (n = 14) was performed using 2 historical control groups (non-cleft norms and non-Furlow cleft palate repairs). The Furlow procedure produced posterior dimples in 19 of 26 patients adequately rated on oral examination, suggesting successful repositioning of the velar musculature in transverse orientation. The mean velar length was not significantly different from that of norms (being 0.72 mm less), suggesting that the Furlow Z-plasty results in the attainment of near normal velar length. In contrast, the mean velar length was 0.46 mm greater compared to non-Furlow repairs. Although this difference was not statistically significant, it suggests that the Furlow Z-plasty may be more effective in increasing velar length compared to non-Furlow palatoplasty techniques. Velar thickness was significantly greater compared to both norms (P = 0.002) and non-Furlow repairs (P = 0.001). These data suggest that the Furlow double opposing Z-plasty repositions the velar muscles in transverse orientation, and increases both velar length and thickness, lending weight to the theoretical effects of this procedure. The anatomic basis of these changes and their functional implications are discussed.

Monobloc and facial bipartition distraction with internal devices

Distraction osteogenesis (DO) permits gradual lengthening of the craniofacial skeleton. With the advent of new internal devices, monobloc (M) and facial bipartition (FB) DO are feasible. The rationale behind M and FB distraction is (1) gradual advancement of the M segment is not associated with a substantial retrofrontal dead space; (2) because 5 to 7 days elapse prior to distraction, the nasofrontal opening, in theory, is allowed to remucosalize; (3) gradual expansion of the soft tissues takes advantage of skin creep, potentially limiting relapse; (4) the procedure appears to be less invasive with decreased blood loss and operative time, enabling its use in infants; (5) overdistraction may eliminate or reduce the frequency of subsequent procedures; and (6) the procedure may be combined with FB and skull vault remodeling to provide excellent results in more complex craniofacial dysostosis problems. Five children underwent M advancement (N = 3) and M with FB (N = 2) at 9 months to 5 years of age to correct functional abnormalities such as corneal exposure, increased intracranial pressure, and apnea, as well as severe craniofacial disfigurement. Each patient underwent from 22 to 30 mm of distraction with the Modular Internal Distraction (MID) system, developed by the first author (SRC). There was one infection late in the series along the DO cable track. There were no cases of epidural abscess. In conclusion, MDO, with and without FB, appears to be a safe and effective technique for transcranial frontofacial advancement. The morbidity of the procedure appears to be less than that of conventional M advancement.

Craniofacial distraction with a modular internal distraction system: evolution of design and surgical techniques

The present report summarizes the evolution of design for a modular internal distraction system that is applicable throughout the craniofacial region. Eleven patients (5 boys, 6 girls), whose ages ranged from 4 months to 10 years at the time of distraction, constitute the basis for this study. The clinical indications for distraction were exorbitism with corneal exposure (n = 1), obstructive sleep apnea (n = 4), tracheostomy decannulation (n = 1), severe maxillary hypoplasia with class III malocclusion (n = 3), severe vertical and sagittal maxillary deficiency with anophthalmia (n = 1), and relapse following frontoorbital advancement in a case of rare craniofacial clefting (n = 1). Twenty-two distraction devices were used in these 11 patients. Two initial prototypes were tested (prototype 1 = 8 devices; prototype 2 = 2 devices) until the modular internal distraction system (MIDS, Howmedica-Leibinger, Inc.) was developed (n = 12 devices). The craniofacial osteotomies used were Le Fort III (n = 4), monobloc (n = 3), mandibular (n = 3), Le Fort I (n = 2), and cranial (n = 1). The distraction distances ranged from 11 to 28 mm. One patient undergoing mandibular distraction developed transient swelling in the left mandibular region, which responded to antibiotics. There were no other complications. Depending on the age of the patient and the length of distraction, the distraction gap was allowed to consolidate from 6 weeks to 3 months. The devices were then removed on either an outpatient or a 23-hour-stay basis. The modular internal distraction system permits widespread application of easily customizable, buried distraction devices throughout the craniofacial region.

Midface distraction

Since the initial application of distraction osteogenesis to the human mandible by McCarthy, distraction osteogenesis has been used for gradual lengthening of the midface in children with syndromic craniosynostosis, cleft lip and palate, hemifacial microsomia, and midface hypoplasia from other causes. Both external and internal devices are available that permit midface distraction. The background of midface distraction and the development of a Modular Internal Distraction (MID) system that permits widespread use of easily customized, buried distraction devices throughout the craniofacial region are presented. The relative and potential clinical indications for distraction, treatment planning, patient preparation, and possible surgical orthodontic interactions during distraction, as well as a variety of case examples showing the MID system, are discussed.

Airway disorders in hemifacial microsomia

The anatomic components of hemifacial microsomia have been classified previously, but their relevance to functional abnormalities has not been stressed. In a recent review of the literature, we found that the frequency and severity of airway disorders, especially those leading to upper airway obstruction and/or obstructive sleep apnea, had not been reported. Accordingly, a retrospective study of 38 patients (21 male, 17 female), aged 6 months to 22 years (mean, 8 years 3 months) with hemifacial microsomia was undertaken to ascertain the frequency and severity of airway disorders in hemifacial microsomia. Upper airway disorders fell broadly within three categories: group I (n = 22, 58 percent) was asymptomatic for airway disturbances; group II (n = 7, 18 percent) had a medical history suspect for intermittent obstructive sleep apnea or had a perioperative apneic event; and group III (n = 9, 24 percent) had a definite history of obstructive sleep apnea or upper airway obstruction requiring tracheotomy or apnea surgery. Group III versus groups II and I had a higher incidence of bilateral involvement (33 percent versus 14 percent and none), a greater percentage of M2, M2a, M2b, and M3 mandibular deformities (88.9 percent versus 28.6 percent and 18.2 percent), more severe orbital involvement (33 percent O2 and O3 versus none in group II and 9 percent in group I), and more severe soft-tissue involvement (89 percent S2 and S3 versus 29 percent and 23 percent). Patients with more severe mandibular and orbital deformities, but not ear or vertebral abnormalities, appear at a greater risk for obstructive sleep apnea. The relationship of OMENS-Plus (extracraniofacial anomalies) to apnea was variable but was found more commonly in group II (86 percent) and group III (56 percent) than in group I (32 percent) patients. Group III patients had a higher frequency of cardiac anomalies (44 percent versus 29 percent in group II and 23 percent in group I). The incidence of obstructive sleep apnea in our population of patients with hemifacial microsomia approaches 24 percent. Patients with hemifacial microsomia should undergo routine screening for obstructive sleep apnea: a positive history warrants polysomnographic and anatomic workup.

Alternatives to tracheostomy in infants and children with obstructive sleep apnea

PURPOSE

Since 1989, 70 children have been treated surgically with varying degrees of obstructive sleep apnea (OSA). Of these, 29 patients had completely failed conventional medical and surgical treatment and were considered tracheostomy (T) candidates, whereas five had previously undergone T for severe OSA as infants and did not respond to standard decannulation protocols. The preoperative diagnoses were cerebral palsy (n = 5), Down's syndrome (n = 5), hemifacial microsomia (n = 4), Pierre Robin sequence (n = 6), and a mixed group of craniofacial disorders (n = 14). The patients ranged in age from 2.5 weeks to > or =18 months (mean, 7.32 years). Preoperatively, four patients were on ventilators and one suffered a cardiac arrest, attesting to the severity of OSA.

METHODS

To enlarge the caliber of the airway, each patient underwent an aggressive surgical treatment protocol. All sites of upper airway obstruction were treated simultaneously by a combination of craniofacial skeletal expansion and soft-tissue reduction.

RESULTS

Tracheostomy was avoided in 90.4% of patients. Temporary or "permanent T" were required in three patients (9.6%). One patient with cerebral palsy had recurrent OSA and died. A second patient with severe laryngotracheomalacia and retrognathia who did not respond to apnea surgery underwent a tracheostomy and ultimately died of pulmonary causes. Four patients (7.8%) required supplemental home oxygen or continuous positive airway pressure. The average preoperative respiratory disturbance index, defined as the average number of apneic and hypopneic events per hour of sleep, dropped from 25.9 to 4.4 after surgery. The average lowest recorded oxygen saturation during overnight polysomnography rose from 61% to 92% after surgery. Of the five patients with permanent T, four had thus far been decannulated. Complications occurred in 10 patients, 50% of which were related to minor problems with mandibular distraction devices.

CONCLUSION

Our results confirm the efficacy of an aggressive surgical approach to the treatment of OSA in children, avoiding the necessity for tracheostomy or permitting decannulation of permanent T in the majority of cases.

Pemphigus vegetans-Neumann variant associated with intranasal heroin abuse

Pemphigus vegetans is variant of pemphigus vulgaris accounting for 5% of all patients with pemphigus disorders. We describe a case of pemphigus vegetans-Neumann type associated with intranasal heroin abuse, restricted to the modified mucous membranes. The results of routine histology and direct and indirect immunofluorescence studies confirmed the diagnosis. The patient responded to oral prednisone of 40 mg daily for 1 month, followed by reduction to a maintenance dose of 15 mg daily. A complete remission was sustained for 6 months. The relationship between intranasal heroin use and the development of pemphigus vegetans remains uncertain but appears to be an intriguing possibility in this patient.