A Comparison of Treatment of OCD Lesions of the Capitellum With Osteochondral Autograft and Allograft Transplantation

Osteochondritis dissecans (OCD) of the capitellum occurs relatively infrequently but can be found in young overhead-throwing athletes, most commonly in baseball players and gymnasts. Although non-operative management can effectively treat stable lesions, unstable lesions can lead to debilitating symptoms of the elbow and diminished quality of life without surgical intervention. This article reviews methods of treating OCD of the capitellum categorized by stability, size, and patient characteristics, and seeks to familiarize the reader with the appropriate selection of osteochondral allograft versus autograft in treating large, unstable lesions. We complement this review with 3 case examples, each using either an osteochondral autograft or allograft, and discuss the decision-making methodology used in each case.

Systematic Review of Capsular Contracture Management following Breast Augmentation: An Update

BACKGROUND

Capsular contracture is one of the most frequent indications for revision following breast augmentation. Management goals focus on restoring breast aesthetics and minimizing subsequent recurrence of capsular contracture. As new data emerge, close review of the data are merited to build evidence-based clinical guidelines to inform surgical practice and management of capsular contracture.

METHODS

A systematic review of the MEDLINE, Embase, and Cochrane Database of Systematic Reviews databases was conducted to characterize the surgical management of capsular contracture in revision breast augmentations. The primary endpoint was capsular contracture recurrence rate.

RESULTS

The review was conducted in November of 2021. Primary search revealed 14,163 results. Initial screening by title left 1223 articles. Abstract review left 90 articles for full-text review, of which 34 were ultimately included and were all observational in nature.

CONCLUSIONS

Capsular contracture management remains an important topic, with limited high-level evidence for establishing clear evidence-based treatment guidelines. Although more evidence is required to assess the effects of capsulectomy, implant exchange, and plane change, these appear to be useful mechanisms for reducing recurrent capsular contracture. There is more evidence regarding the use of acellular dermal matrix, although this still requires long-term follow-up studies. New developments regarding textured implants limit the revision breast augmentation surgeon to smooth devices.

Regional Anesthesia for Wrist Fractures and Dislocations: Are We Really Blocking Opioid Prescribing?

BACKGROUND

The aim of this study was to evaluate the impact of regional anesthesia for the treatment of wrist fractures or dislocation on opioid prescription-filling patterns.

METHODS

Patients undergoing surgery for hand and wrist fractures or dislocations from 2010 to 2018 were identified by using a national insurance claims database. Patients were stratified by procedures conducted with and without regional anesthesia. Preoperative opioids were defined by a filled opioid prescription within 1 month prior to surgery, postoperative within 1 month following the surgery, and prolonged postoperative 3 to 6 months following surgery. Patients' demographic data, comorbidities, additional medications, 30-day emergency department (ED) visits, and hospital readmissions were analyzed.

RESULTS

A total of 24 598 patients treated with and 115 199 patients treated without a regional nerve block for wrist fractures and dislocations were identified. Regional anesthesia was associated with greater postoperative opioid prescription but fewer prolonged postoperative prescriptions. There was an increased odds of all-cause 30-day ED visits but a decreased odds of 30-day hospital readmissions when patients received a regional nerve block prior to surgery.

CONCLUSIONS

In this study, receiving regional anesthesia prior to surgical intervention for wrist fractures or dislocations was associated with increased filling of postoperative opioid prescriptions, but not prolonged postoperative opioid prescriptions. Additional investigation is needed to identify and implement nonnarcotic multimodal analgesia regimens that may help decrease usage of narcotic medications surrounding these procedures.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Is This Going to Hurt, Doc? Predicting Pain with Corticosteroid Injections for Upper Extremity Conditions

Corticosteroid injections (CSIs) are used in a wide variety of upper extremity pathologies for both diagnostic and treatment purposes. Many patients ask about pain associated with the procedure before agreeing to proceed. The purpose of this study was to correlate perceived pain tolerance and resilience with patient-reported injection pain during and immediately after injection.

Methods

One-hundred patients indicated for a CSI for an upper extremity condition were recruited for the study. Patients completed a Brief Resilience Scale, Patient-Reported Outcomes Measurement Information System pain interference form, and assessment of pain tolerance before injection. Physicians predicted pain tolerance and resilience for each patient. Immediately after the procedure, patients completed a second survey, assessing pain during and 1 minute after injection.

Results

Physician-predicted patient resilience and pain tolerance was lower than that self-reported by patients. Pain with injection was inversely correlated with physician-predicted pain tolerance and resilience but not with patient-reported pain tolerance. Injection pain ratings did not correspond with patients' willingness to undergo subsequent injections.

Conclusions

Procedural pain is an important consideration for many patients, especially in awake procedures. Appropriate counseling is crucial to support informed consent and enhance patient outcomes. This study demonstrated that a physician's clinical experience can be used to predict a patient's pain with CSI and should be considered when counseling patients.

The Relationship between Plastic Surgery Residency Instagram Characteristics and Doximity Rank

Social media provides unique insight into the facilities, personnel, and culture of plastic surgery residency programs. Applicants can gain a more holistic view of programs based on their social media accounts. This study aims to evaluate the relationship between the popularity of a program's Instagram account and the program's Doximity ranking and to investigate the factors which contribute to greater viewership, with a special focus on diversity.

Methods

Using Doximity's 2021-2022 Residency Navigator, a list of all integrated plastic surgery residency programs was obtained, and their social media accounts were documented. Instagram accounts were analyzed for metrics, post content, and website links. A 15-month period of posts was analyzed, then grouped into eight categories. Diversity was assessed using average Fitzpatrick skin type for each post containing photographs of people.

Results

Of the 88 programs, 85 (96.6%) had an Instagram account at the time of analysis. Analysis of Instagram post content found that personnel and social function posts had significantly more likes than other categories. Posts with average Fitzpatrick type greater than or equal to III also had significantly more likes. Linear regression demonstrated a positive relationship between higher Doximity rank and number of followers; however, there was no clear relationship between rank and posts per week or engagement score.

Conclusions

Plastic surgery social media accounts may make a positive impact on followers. It is important to understand the factors that can increase engagement and broaden viewership. Tailoring posts based on content popularity and highlighting diversity may help to accomplish these goals.

Longevity of ptosis correction in mastopexy and reduction mammaplasty: A systematic review of techniques

Background

Mastopexy and reduction mammaplasty are commonly performed procedures in plastic surgery with many variations in incision pattern, pedicle design, and additional support maneuvers. Aesthetically pleasing on table results are widely accomplished; however, the longevity of the outcome and sustained correction of ptosis or pseudoptosis is not universal. A systematic review of mastopexy and reduction mammaplasty procedures was performed to investigate which techniques provided the greatest long-term correction of ptosis.

Methods

A broad search of the literature was performed using the PubMed database from inception to December of 2021. Study characteristics, number of patients, number of breasts, technique, outcome, and average follow-up time were extracted for analysis. Study quality was assessed using the Newcastle–Ottawa Scale when applicable.

Results

The primary search yielded 1123 articles. After two levels of screening, 24 articles were identified for analysis. This included 16 case series, seven cohort studies, and one randomized controlled study. From these studies, 1235 patients and 2235 breasts were analyzed. The majority of articles reported on a change in the nipple to inframammary fold and sternal notch to nipple distances.

Conclusions

In the analytical studies, superior and superomedial pedicles tended to provide greater long-term stability than inferior pedicles. Mesh, dermal suspension flaps, and muscular slings showed promise in providing additional support over standard techniques. No single procedure is ideal for all patients; however, this systematic review provides a valuable description of techniques and long-term outcomes to guide surgical planning.

Financial Analysis of Operating a Resident Aesthetic Clinic

BACKGROUND

Recent changes to the plastic surgery residency training requirements along with a general call for expanded education in cosmetic surgery have encouraged many institutions to incorporate resident aesthetic clinics into their curricula. Although the safety and satisfaction rates of resident aesthetic clinics have been well-studied, their financial viability has not. This study reviews the financial viability of the resident aesthetic clinic at the authors' institution through a cost analysis.

METHODS

Billing data were analyzed for all patient visits to the resident aesthetic clinic of the authors' institution during calendar year 2018. Data were extracted, including type and anatomical location of each procedure, charges collected, and supplies used. A financial analysis was performed based on fixed and variable costs and gross revenue.

RESULTS

A total of 100 unique patients were seen in the clinic over a 1-year period, resulting in 53 operations. This included 15 face, four breast, and 34 body contouring procedures. In addition, 160 cosmetic injections were performed. The gross revenue was $69,955 and the net revenue was $36,600.

CONCLUSIONS

The resident aesthetic clinic at the authors' institution proved to be financially viable. The authors encourage other institutions to more closely examine the financial state of their resident aesthetic clinics as well. Furthermore, the authors hope that this analysis demonstrates to other programs that, with certain practice models, cost should not be a barrier to initiating and maintaining this valuable training tool.

Free latissimus dorsi flap for upper extremity reconstruction in a 9-month-old

Successful outcomes for free tissue transfer are well-documented in pediatric patients but less so in infants. Challenges with infants are unique and include implications of prolonged anesthetic exposure. We present a 9-month-old female who underwent a free latissimus dorsi flap to reconstruct a congenital upper extremity lesion threatening limb development.

Vascularized Bone Grafts for Spinal Fusion-Part 1: The Iliac Crest

BACKGROUND

Iliac crest autograft has been the gold standard for harvest of fusion materials in spine surgery. The benefits of a vascularized version of this bone graft-including delivery of stem cells, ability to deliver antibiotics to the fusion bed, and relative ease of harvest-make this technique superior to free bone transfer in the achievement of augmented spinal fusion.

OBJECTIVE

To present a brief summary of similar existing concepts before describing the novel technique of this vascularized posterior iliac crest bone graft.

METHODS

Vascularized posterior iliac crest bone graft can be harvested from the same midline lumbar incision used for thoracolumbar spinal fusion, through lateral dissection around the paraspinals to the iliac crest. Recipient sites in the posterolateral bony spinal gutters may be as rostral as T12 and caudal as the sacrum. The ability to cover multiple lumbar levels can be achieved with desired lengths of the donor iliac crest.

RESULTS

Over 14 vascularized iliac crest bone grafts have been performed to augment lumbar fusion for salvage after pseudoarthrosis. Operative time and bleeding are reduced compared to free flap procedures, and no patients have experienced any complications related to these grafts. Indocyanine green (ICG) angiography has been utilized in a novel way to ensure the vascularity of the bone graft prior to arthrodesis.

CONCLUSION

While long-term follow-up will be required to fully characterize fusion rates and patient morbidity, this innovative surgical option augments spinal fusion in patients with, or at increased risk for, pseudoarthrosis.

Vascularized Bone Grafts in Spinal Reconstruction: An Overview of Nomenclature and Indications

Several vascularized bone grafts (VBGs) have been introduced for reconstruction and augmenting fusion of the spine. The expanding use of VBGs in the field of spinoplastic reconstruction, however, has highlighted the need to clarify the nomenclature for bony reconstruction as well as establish the position of VBGs on the bony reconstructive algorithm. In the current literature, the terms "flap" and "graft" are often applied inconsistently when describing vascularized bone transfer. Such inconsistency creates barriers in communication between physicians, confusion in interpreting the existing studies, and difficulty in comparing surgical techniques. VBGs are defined as bone segments transferred on their corresponding muscular attachments without a named major feeding vessel. The bone is directly vascularized by the muscle attachments and unnamed periosteal feeding vessels. VBGs are best positioned as a separate entity in the bony reconstruction algorithm between nonvascularized bone grafts (N-VBGs) and bone flaps. VBGs offer numerous advantages as they supply fully vascularized bone to the recipient site without the microsurgical techniques or pedicle dissection required for raising bone flaps. Multiple VBGs have been introduced in recent years to optimize these benefits for spinoplastic reconstruction.

Current indications for abdominal-based flaps in hand and forearm reconstruction

Extensive soft tissue loss or injury of the hand and upper extremity is a challenging reconstructive problem traditionally treated with abdominal-based pedicled flaps. Options for coverage included the groin flap based on the superficial circumflex iliac artery, the Scarpa's fascia flap based on the superficial inferior epigastric artery, and the paraumbilical perforator flap from the deep inferior epigastric artery perforators. Despite the ability to provide consistent and pliable soft tissue coverage with ease of elevation, these flaps have several disadvantages including restriction of mobility, requirement for multiple procedures, bulkiness and patient discomfort. With the advent of microsurgery, pedicled regional flaps, and off-the-shelf skin substitutes, the applications for these flaps have narrowed. However several indications still remain. These include: patient and facility factors which deter microsurgery, the absence of recipient vessels after injury, prior surgical use of recipient vessels, the need to preserve major vessels for future reconstruction, and large multi-surface wounds requiring coverage. In this review we detail these indications and provide case examples for each.

How to Maximize Aesthetics in Autologous Breast Reconstruction

With continuous technical and functional advances in the field of breast reconstruction, there is now a greater focus on the artistry and aesthetic aspects of autologous reconstruction. Whereas once surgeons were most concerned with flap survival and vessel patency, they are now dedicated to reconstructing a similarly or even more aesthetically pleasing breast than before tumor resection. We discuss the approach to shaping the breast through the footprint, conus, and skin envelope. We then discuss how donor site aesthetics can be optimized through flap design, scar management, and umbilical positioning. Each patient has a different perception of their ideal breast appearance, and through conversation and counseling, realistic goals can be set to reach optimal aesthetic outcomes in breast reconstruction.

Prepectoral Breast Reconstruction

Prepectoral breast reconstruction was first done in the early 1960s; however, while initial results were promising, high complication rates led surgeons to move toward submuscular implant placement. We soon came to find that submuscular implant placement was not without its own set of drawbacks. Surgeons have since revisited the efficacy of prepectoral breast reconstruction in light of new surgical and technological advances. Following these advancements, complication profiles for prepectoral breast reconstruction have drastically improved. Despite this change, surgeons recognize that prepectoral implant placement is not for everyone and patient selection is critical to success. As increasing numbers of these procedures continue to be done, we must now look to conduct direct comparisons between submuscular and prepectoral breast implant placement so that surgeons can make evidence-based decisions on patient selection and operative planning.

A systematic review of complications in prepectoral breast reconstruction

The use of implants for breast reconstruction began over four decades ago, with implants initially placed in the prepectoral space. Concerns arose regarding the high incidence of capsular contracture and complication rates. With the introduction of acellular dermal matrix (ADM), plastic surgeons are again considering the advantages of prepectoral implant placement. A systematic review was conducted to examine complication profiles in prepectoral breast reconstruction alone versus prepectoral with ADM or mesh. A systematic review of the PubMed database was performed from inception to March 2017 to identify literature on postmastectomy patients undergoing prepectoral breast reconstruction with and without ADM or mesh. Study characteristics, complication rates, and outcomes were extracted for analysis. Study quality was assessed using the Newcastle-Ottawa Scale, and complication profiles were analyzed using the random-effects model. Twenty-seven studies met criteria for inclusion out of 550 identified for review. For 1881 total breasts, the complication rate with ADM was 23.4%, while the rate without an additional implant material was 27.5%. The difference in the capsular contracture rate with and without ADM was 2.3% and 12.4%, respectively. The use of ADM in prepectoral breast reconstruction correlated with lower capsular contracture and overall complications rates; however, rates of implant loss, infection, and mastectomy flap necrosis were higher with the use of ADM. Results were variable across studies, and in general, the quality of evidence reported was low. Because the methodology for outcome assessment was inconsistent, there is a need for further investigation with comparative studies and standardized outcome reporting.

Practical Negotiation for Medical Professionals

Despite incredible advances in medical innovation and education, many students finish medical school, and physicians finish residency, without sound business acumen regarding the financial realities of the modern profession. The curriculum in medical schools and residency programs too often neglects teaching the business of medicine. This overview addresses how physicians can utilize effective negotiation strategies to help develop a medical practice or add value to an existing practice or institution. The authors applied the six foundations of effective negotiating, detailed by Richard Shell in his Bargaining for Advantage , to the medical field to demonstrate the processes involved in effective negotiating. They then outlined a strategy for physicians to adopt when negotiating and showed how this strategy can be used to add value. The six foundations include: developing a personal bargaining style, setting realistic goals, determining authoritative standards, establishing relationships, exploring the other party's interests, and gaining leverage. As physicians complete training, the ability to solely focus on medical knowledge and clinical patient care disappears. It is crucial that physicians invest the time and energy into preparing for the business aspects of this profession in much the same way they prepare for the clinical care of patients. This overview seeks to define the basics of negotiation, characterize the application of negotiation principles toward clinical medicine, and lay the foundation for further discussion and investigation.

Etiology, Prevention, and Management of Infectious Complications of Dermal Fillers

The demand for aesthetic augmentation with soft tissue fillers has greatly increased in recent years and has led to an expansion in the number of products available. Unfortunately, an increase in adverse events has followed. These can be categorized into early, late, and delayed. Early infectious complications generally present as a localized skin infection, cellulitis, or abscess. Fillers can also serve as a focus for chronic infection, which is associated with the development of foreign body granulomas, a late complication. Bacterial colonization and indolent infections of the filler site can lead to biofilms that are extremely difficult to treat. Therefore, it is important to focus on prevention through eliciting a thorough patient history including an injection history, practicing sterile technique, and minimizing tissue trauma. Looking forward, much can be done to curtail complication rates. Early teaching and training, a central recording registry for complications, and a standardized filler passport for patients are suggested.

Milestones of Asian Rhinoplasty

The field of plastic surgery originally developed out of the necessity to reconstruct the human body after the destruction of war. However, injured soldiers were not the only people who desired a change in appearance. After World War II, many people in Asian countries sought to attain a more Western look through surgery. Along with eyes, the nose was the main focus for these cosmetic procedures. In this article, the authors examine the evolution of Asian rhinoplasty from its original description in 1964 to the present. The characteristic anatomical differences between the Western and Asian nose are identified in relation to the technical challenges for rhinoplasty surgeons. Then the benefits and risks of the two major surgical approaches, autograft versus alloplast, are detailed. Finally, the coevolution of techniques and implant usage is traced from a dorsum-only implant, to an L-shaped implant, a cartilaginous cap graft with a one-piece rhinoplasty, an I-shaped implant, and a two-piece augmentation rhinoplasty. Outlining these changes demonstrates the advancement of the field of plastic surgery and the growing expectations of the patient. These advancements have provided the tools necessary to better align a patient's aesthetic goals and their unique anatomical presentation with a specific surgical approach.

Optimal predator risk assessment by the sonar-jamming arctiine moth Bertholdia trigona

Nearly all animals face a tradeoff between seeking food and mates and avoiding predation. Optimal escape theory holds that an animal confronted with a predator should only flee when benefits of flight (increased survival) outweigh the costs (energetic costs, lost foraging time, etc.). We propose a model for prey risk assessment based on the predator's stage of attack. Risk level should increase rapidly from when the predator detects the prey to when it commits to the attack. We tested this hypothesis using a predator – the echolocating bat – whose active biosonar reveals its stage of attack. We used a prey defense – clicking used for sonar jamming by the tiger moth Bertholdia trigona– that can be readily studied in the field and laboratory and is enacted simultaneously with evasive flight. We predicted that prey employ defenses soon after being detected and targeted, and that prey defensive thresholds discriminate between legitimate predatory threats and false threats where a nearby prey is attacked. Laboratory and field experiments using playbacks of ultrasound signals and naturally behaving bats, respectively, confirmed our predictions. Moths clicked soon after bats detected and targeted them. Also, B. trigona clicking thresholds closely matched predicted optimal thresholds for discriminating legitimate and false predator threats for bats using search and approach phase echolocation – the period when bats are searching for and assessing prey. To our knowledge, this is the first quantitative study to correlate the sensory stimuli that trigger defensive behaviors with measurements of signals provided by predators during natural attacks in the field. We propose theoretical models for explaining prey risk assessment depending on the availability of cues that reveal a predator's stage of attack.

Phenotypic and genotypic characterization of competitive exclusion products for use in poultry

AIMS

Phenotypic and genotypic bacteria identification methods were compared for their efficacy in determining the composition of competitive exclusion (CE) products.

METHODS AND RESULTS

Phenotypic methods used for bacterial identification were fatty acid methyl ester profiles, biochemical assays and carbohydrate utilization profiles. Genotypic methods were MicroSeq16S rRNA sequence analysis and BLAST searches of the GenBank sequence database. Agreement between phenotypic and genotypic methods for identification of bacteria isolated from the Preempt CE product was 20%. A defined test mixture of bacteria was identified to the species level 100% by BLAST analysis, 64% by MicroSeq and 36% by phenotypic techniques.

CONCLUSIONS

The wide range of facultative and obligate anaerobic bacteria present in a CE product are more accurately identified with 16S rRNA sequence analyses than with phenotypic identification techniques.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results will provide guidelines for manufacturers of CE products to submit more reliable product information for market approval by regulatory agencies.

Oroesophageal candidiasis is lethal for transgenic mice with combined natural killer and T-cell defects

Germfree transgenic epsilon 26 (Tgepsilon26) mice, which express the full-length human CD3epsilon gene, have combined defects in natural killer (NK) cells and T cells were found to be extremely susceptible to oroesophageal (palate, tongue, esophagus) and gastric (cardia-antrum section) candidiasis. The gnotobiotic Tgepsilon26 mice die, apparently from severe oroesophageal candidiasis, within 2-4 weeks after their alimentary tracts are colonized with Candida albicans. The Tgepsilon26 mice manifest resistance to acute systemic candidiasis (intravenous injection) and to systemic candidiasis of endogenous origin for the first 2 weeks after their alimentary tracts are colonized with C. albicans. Granulocyte depletion data suggest that granulocytes, in the absence of functional NK cells and T cells, can protect Tgepsilon26 mice from acute systemic candidiasis and from systemic candidiasis of endogenous origin, for at least 14 days after alimentary tract colonization. Granulocytes and macrophages, in the absence of NK cells and T cells, are unable to protect Tgepsilon26 mice from lethal oroesophageal candidiasis and systemic candidiasis of endogenous origin which was evident in moribund Tgepsilon26 mice 2-4 weeks after colonization. Thus, non-T cells (i.e., NK cells) and T cells play important roles in resistance to oroesophageal and systemic (acute and of endogenous origin) candidiasis.

Effects of probiotic bacteria on humoral immunity to Candida albicans in immunodeficient bg/bg-nu/nu and bg/bg-nu/+ mice

Germfree beige-nude ( bg/bg-nu/nu) and beige-heterozygous ( bg/bg-nu/+) mice were colonized with a pure culture of Candida albicans or with a probiotic bacterium (Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei, or Bifidobacterium infantis). Probiotic-colonized mice were subsequently challenged orally with C. albicans. The effect of prior colonization with probiotic bacteria on the antibody responses of the immunodeficient mice to alimentary tract colonization with C. albicans was compared to the antibody responses of the gnotobiotic mice colonized only with C. albicans. This study demonstrated that, although the probiotic bacteria did not induce a vigorous antibody response to their own antigens, they altered the antibody responses of mice to C. albicans. In T cell competent bg/bg-nu/+mice, B. infantis enhanced and focused IgG1, IgG2A, and IgA responses to C. albicans antigens. Some of the probiotic bacteria also enhanced the IgG1 and IgG2A antibody responses of bg/bg-nu/nu mice to C. albicans antigens. This study not only shows the value of gnotobiotic animal models in demonstrating that probiotic bacteria can affect the capacity of mice to form antibodies to C. albicans, but it also points out their usefulness in comparing the capacity of different probiotic bacteria to produce beneficial health effects in mice.

Probiotic effects of feeding heat-killed Lactobacillus acidophilus and Lactobacillus casei to Candida albicans-colonized immunodeficient mice

Probiotic bacteria can protect immunodeficient mice from orogastric candidiasis but cause some pathology of their own. Severely immunodeficient patients may be at risk if fed viable probiotics, so this study evaluated the probiotic potential of nonviable probiotic bacteria to protect immunodeficient mice from Candida albicans infections. Heat-killed probiotic bacteria were fed to gnotobiotic bg/bg-nu/nu and bg/bg-nu/+ mice to ascertain if they could protect the mice from mucosal and systemic candidiasis. Both heat-killed Lactobacillus acidophilus (HKLA) and heat-killed Lactobacillus casei (HKLC), in comparison to control mice not fed the probiotic bacteria but challenged (oral) with C. albicans, suppressed the severity of orogastric candidiasis in bg/bg-nu/nu mice at 2 weeks after colonization with C. albicans, inhibited disseminated candidiasis in C. albicans-colonized bg/bg-nu/+ mice at 4 weeks after colonization, and suppressed the number of viable C. albicans in the alimentary tract. HKLA, but not HKLC, treatment inhibited disseminated candidiasis in bg/bg-nu/nu mice at 2 weeks after oral challenge and enhanced the proliferative responses of splenocytes from C. albicans-colonized bg/bg-nu/+ mice to C. albicans antigens. Neither HKLA nor HKLC were able to prolong the survival of gnotobiotic bg/bg-nu/nu mice after oral challenge with C. albicans. These results demonstrate that heat-killed lactobacilli can induce some (limited) protection (probiotic effect) against candidiasis in mice.

Mucosal and systemic candidiasis in IL-8Rh-/- BALB/c mice

Germ-free BALB/c mice, genetically engineered to be deficient for interleukin-8 (IL-8) receptor homolog (IL-8Rh-/-), were more susceptible to gastric candidiasis after oral challenge and to acute systemic candidiasis after intravenous challenge than IL-8Rh+/+ controls. In comparison to IL-8Rh+/+ mice, the IL-8Rh-/- mice had slower influx of polymorphonuclear neutrophils (PMN) into Candida albicans-infected tissues and a lower percentage of PMN in peritoneal exudate cells (PEC) elicited with heat-killed C. albicans. PEC from IL-8Rh-/- mice exhibited less luminol-dependent chemiluminescence in response to C. albicans and did not kill C. albicans hyphae as well as PEC from IL-8Rh+/+ mice. C. albicans-colonized IL-8Rh-/- mice showed no histological evidence of systemic candidiasis. These results suggest a role for the IL-8Rh in murine resistance to gastric and acute systemic candidiasis, but not in resistance to systemic candidiasis of endogenous origin.

Early resistance of interleukin-10 knockout mice to acute systemic candidiasis

In contrast to immunocompetent controls, interleukin-10 (IL-10) knockout (KO) mice eliminated an experimental intravenous inoculation with Candida albicans from their kidneys. Improved clearance of C. albicans from the kidneys of IL-10 KO mice was evident at 24 h after intravenous challenge with the fungus. Conversely, mice with a deletion of the IL-4 cytokine gene were more susceptible to systemic candidiasis than were immunocompetent controls. The hyperresistance of IL-10 KO mice to acute systemic candidiasis did not seem to correlate with nitric oxide-mediated immunity, but rather, it appeared to be associated with more efficient effector function of innate cells, possibly neutrophils. In support of the latter hypothesis, we observed that neutrophils from IL-10 KO mice were more efficient at killing C. albicans blastoconidia and hyphae than were neutrophils from immunocompetent control mice. Neither IL-10 KO nor IL-4 KO mice that were monoassociated with C. albicans for 4 weeks showed any histologic evidence of systemic candidiasis of endogenous origin. In contrast to systemic candidiasis, we observed no significant (P < 0.05) differences in susceptibility among IL-10 KO, IL-4 KO, and wild-type (immunocompetent) mice to orogastric candidiasis. Our results suggest that IL-10 exerts a negative effect on the early, innate response to acute systemic candidiasis; however, in comparison to immunocompetent control (wild-type) mice, neither IL-10 nor IL-4 deficiency enhanced susceptibility to orogastric candidiasis.

Variable biotherapeutic effects of Lactobacillus acidophilus isolates on orogastric and systemic candidiasis in immunodeficient mice

Two commercially available isolates of Lactobacillus acidophilus (NCFM and LA-1) were compared for their capacities to protect immunodeficient bg/bg-nu/un and bg/bg-nu/+ mice from candidiasis. L. acidophilus NCFM prolonged survival of adult and neonatal bg/bg-nu/nu mice, inhibited disseminated candidiasis in both mouse strains, suppressed weight loss associated with Candida albicans infection in bg/bg-nu/nu females, but did not decrease the severity or the incidente of orogastric candidiasis in gnotobiotic mice. L. acidophilus LA-1 suppressed numbers of C. albicans in the alimentary tracts of bg/bg-nu/+ mice and reduced the severity of mucosal candidiasis in bg/bg-nu/nuand bg/bg-nu/+ mice; however, L. acidophilus LA-1 did not improve the survival of bg/bg-nu/nu mice after oral challenge (colonization) with C. albicansand it was associated with lethality in gnotobiotic adult female bg/bg-nu/nu mice. These results demonstrate that the two isolates of L. acidophilus differed in their capacity to protect immunodeficient mice from candidiasis.

Biotherapeutic effects of Bifidobacterium spp. on orogastric and systemic candidiasis in immunodeficient mice

Two commercially available Bifidobacterium spp. (Bifidobacterium infantis and Bifidobacterium lactis) were compared for their capacities to protect immunodeficient bg/bg-nu/nuand bg/bg-nu/+mice from orogastric and lethal candidiasis. Both Bifidobacterium spp. prolonged the survival of Candida albicans-colonized adult and neonatal bg/bg-nu/numice. The bifidobacteria affected the production of antibodies to C. albicans, inhibited disseminated candidiasis, suppressed weight loss associated with C. albicans infection, inhibited the growth of C. albicans in the alimentary tract, inhibited systemic candidiasis of endogenous origin, and decreased the severity of gastric candidiasis in both mouse strains. B. infantis inhibited systemic candidiasis of endogenous origin better than B. lactis; however, B. lactis was significantly more effective at inhibiting C. albicans colonization of the alimentary tract, suppressing gastric candidiasis, and protecting bg/bg-nu/numice from lethal candidiasis than B. infantis. These results show that Bifidobacterium spp. can protect immunodeficient mice from candidiasis but different species manifest quantitative and qualitative differences in their probiotic and biotherapeutic effects.

Probiotic bacteria for prophylaxis and therapy of candidiasis

A good deal of data support a role for probiotic intestinal bacteria in the prophylaxis and therapy of candidiasis. Candida spp. are highly infectious eukaryotes that can colonize and infect humans and other warm-blooded mammals, worldwide. Although most humans manifest antibody- and cell-mediated immune responses to Candida antigens a large percentage of the human population is colonized with Candida spp. in their alimentary and vaginal tracts. The bacterial flora plays a very important probiotic role in the prophylaxis of candidiasis by suppressing the growth of Candida spp. on mucosal and cutaneous surfaces; however, the specific bacteria and the mechanisms they use to inhibit Candida spp. and candidiasis are still poorly understood. The increased incidence of Candida infections, their increasing resistance to antifungal antibiotics and the fact that vaccines to protect against candidiasis are not yet available (and may not work in immunodeficient, Candida-susceptible, patients) provides a strong impetus for new research efforts to explore the use of probiotic, anti- Candida intestinal bacteria for the prophylaxis and therapy of candidiasis.

Candidiasis in interferon-gamma knockout (IFN-gamma-/-) mice

Germ-free C57BL/6 x 129 interferon-gamma knockout (IFN-gamma(-/-)) mice and their immunocompetent (+/-, +/+) counterparts were colonized with a pure culture of Candida albicans to assess their natural susceptibility to mucosal and systemic candidiasis of endogenous origin. Colonization with a pure culture of C. albicans was not lethal for adult or neonatal IFN-gamma(-/-) gnotobiotic mice over the 15-week study. The IFN-gamma(-/-) mice were more susceptible to gastric (cardia-antrum section), anorectal, and acute systemic (intravenous challenge) candidiasis than immunocompetent controls, and some IFN-gamma(-/-) mice developed intestinal adenomas after colonization with C. albicans. The enhanced susceptibility of IFN-gamma(-/-) mice, compared with immunocompetent controls, may be associated with a poor proliferative response of spleen cells to C. albicans antigens and a T helper 2 (IgG1) serum antibody response to C. albicans antigens. Thus, IFN-gamma is important for murine resistance to gastric, anorectal, and acute systemic candidiasis.

Biotherapeutic effects of probiotic bacteria on candidiasis in immunodeficient mice

Four species of probiotic bacteria were assessed for their capacities to protect athymic bg/bg-nu/nu and euthymic bg/bg-nu/+ mice from mucosal and systemic candidiasis. Each bacterial species and Candida albicans colonized the gastrointestinal tracts of both strains of mice. The presence of probiotic bacteria (Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei GG, or Bifidobacterium animalis) in the gastrointestinal tracts prolonged the survival of adult and neonatal bg/bg-nu/nu mice compared to that of isogenic mice colonized with C. albicans alone. The incidence of systemic candidiasis in bg/bg-nu/nu mice was significantly reduced by each of the four probiotic bacterial species. The numbers of C. albicans present in the alimentary tracts of euthymic bg/bg-nu/+ mice were significantly reduced by L. casei GG and B. animalis. None of the probiotic bacteria species completely prevented mucosal candidiasis, but B. animalis reduced its incidence and severity. Probiotic bacteria also modulated antibody- and cell-mediated immune responses to C. albicans. The prolonged survival of mice, decreased severity of mucosal and systemic candidiasis, modulation of immune responses, decreased number of C. albicans in the alimentary tract, and reduced numbers of orogastric infections demonstrated not only that probiotic bacteria have biotherapeutic potential for prophylaxis against and therapy of this fungal disease but also that probiotic bacteria protect mice from candidiasis by a variety of immunologic (thymic and extrathymic) and nonimmunologic mechanisms in this model.

Colonization of congenitally immunodeficient mice with probiotic bacteria

We assessed the capacity of four probiotic bacteria (Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei GG, and Bifidobacterium animalis) to colonize, infect, stimulate immune responses in, and affect the growth and survival of congenitally immunodeficient gnotobiotic beige-athymic (bg/bg-nu/nu) and beige-euthymic (bg/bg-nu/+) mice. The bacteria colonized and persisted, in pure culture, in the alimentary tracts of both mouse strains for the entire study period (12 weeks). Although all adult and neonatal beige-euthymic mice survived probiotic colonization, some infant mortality occurred in beige-athymic pups born to mothers colonized with pure cultures of L. reuteri or L. casei GG. The probiotic bacteria manifested different capacities to adhere to epithelial surfaces, disseminate to internal organs, affect the body weight of adult mice and the growth of neonatal mice, and stimulate immune responses. Although the probiotic species were innocuous for adults, these results suggest that caution and further studies to assess the safety of probiotic bacteria for immunodeficient hosts, especially neonates, are required.

Importance of beta2-microglobulin in murine resistance to mucosal and systemic candidiasis

beta2-Microglobulin knockout (beta2m-/-) mice, which lack major histocompatibility complex class I expression and are deficient in CD8alpha/beta T-cell receptor alpha/beta (TcRalpha/beta) T cells, were as resistant to systemic (intravenous) challenge with Candida albicans as immunocompetent controls. Conversely, the beta2m-/- mutant mice were susceptible to systemic candidiasis of endogenous origin despite the induction of C. albicans-specific antibody and cell-mediated immune responses after colonization with a pure culture of C. albicans. Despite some superficial and transient infections of tongues and esophagi (detected by histology) at 1 to 2 weeks after oral colonization and gastric infections (cardia-antrum section) which were observed at 10 to 12 weeks after oral challenge, C. albicans-colonized beta2m-/- mice showed an overall resistance to candidiasis in other mucosal and cutaneous tissues. These data suggest that immune defects that accompany the loss of beta2-microglobulin play an important role in murine resistance to gastric and disseminated candidiasis of endogenous (intestinal tract) origin and that innate immunity and CD4 TcRalpha/beta as well as CD8alpha/alpha TcRalpha/beta (or -gamma/delta) T cells play an important role in resistance to systemic, cutaneous, and nongastric mucosal tissues.

Human HLA-B27 gene enhances susceptibility of rats to oral infection by Listeria monocytogenes

Germfree rats transgenic for the human genes HLA-B27 and beta 2-microglobulin were colonized with hemolysin-positive (Hly+) or hemolysin-negative (Hly-) strains of Listeria monocytogenes. HLA-B27 rats were very susceptible to infection with Hly+ L monocytogenes none survived beyond 6 days. Conversely, nontransgenic control rats survived alimentary tract colonization with the Hly+ strain, and both transgenic and nontransgenic rats survived colonization with the Hly- strain of L monocytogenes. After colonization with Hly+ L monocytogenes, both transgenic and nontransgenic rats developed severe bowel inflammation which consisted histologically of microab scesses, granulomatous lesions, and ulcers; however, whereas the transgenic rats died within 6 days, only very mild intestinal lesions were seen in nontransgenic rats 10 to 42 days after colonization. Liver and splenic lesions were small and transient in nontransgenic rats. Transgenic and nontransgenic control rats infected with Hly- Listeria developed mild transient diarrhea but showed no histological changes in the intestine. This study thus documents an association between a particular bacterial product (hemolysin produced by L monocytogenes) and the induction of severe inflammatory disease and death in rats expressing HLA-B27 and beta 2-microglobulin.

B cell knockout mice are resistant to mucosal and systemic candidiasis of endogenous origin but susceptible to experimental systemic candidiasis

Germfree J(H)D mice, which lack functional B cells and antibodies, were as resistant to orogastric and disseminated candidiasis of endogenous origin as were immunocompetent controls. Newborn J(H)D mice, in contrast to adult mice, were resistant to alimentary tract colonization by Candida albicans for 5-7 days after birth. C. albicans-colonized J(H)D mice were more resistant to intravenous challenge with C. albicans and had greater splenocyte proliferative responses to C. albicans antigens than did germfree mice or conventional controls. Thus, innate and acquired T cell-mediated immune responses induced after oral immunization are sufficient to protect J(H)D mice from mucosal and systemic candidiasis of endogenous origin; however, functional B cells may be required to protect mice from a primary intravenous challenge with C. albicans.

Gamma delta T cell-induced nitric oxide production enhances resistance to mucosal candidiasis

Despite the prevalence of gamma delta T cells in mucosae that are typically colonized by Candida albicans, little is known of the possible role of these cells in resistance to candidiasis. A sharp increase in the number of gamma delta T cells and macrophages following intraperitoneal inoculation of mice with C. albicans led us to examine the role of these cells in the immune response to C. albicans. We show that the gamma delta T cells enhance macrophage nitric oxide (NO) production and anti-candida activity, in vitro. We also propose that the gamma delta T cells regulate macrophage function during candidiasis in vivo as well, because depletion of these cells abrogated inducible NO synthase expression in mucosae and enhanced murine susceptibility to candidiasis.

Administration of antigranulocyte monoclonal antibody RB6-8C5 prevents expression of acquired resistance to Listeria monocytogenes infection in previously immunized mice

Recent studies have established the importance of neutrophils in innate resistance to Listeria monocytogenes infection in mice. The purpose of this study was to determine the importance of neutrophils in acquired resistance to L. monocytogenes infection. Previously immunized mice that were depleted of neutrophils by administration of the antigranulocyte monoclonal antibody RB6-8C5 demonstrated less resistance to L. monocytogenes challenge than did nonimmunized control mice. In contrast, immunized control mice exhibited a heightened resistance to rechallenge, as expected. These results suggest that neutrophils make previously unrecognized contributions to acquired immunity to a facultative intracellular pathogen.

Recombinant interleukin-12 enhances resistance of mice to Listeria monocytogenes infection

The effect of recombinant murine IL-12 (rIL-12) or anti-IL-12 antibody administration on resistance to murine listeriosis was investigated. Mice given a single 0.5 micrograms dose of rIL-12 had 1.5 log10 fewer listeriae in their spleens and livers as compared with control infected mice 3 days after L. monocytogenes challenge. Conversely, administration of anti-IL-12 IgG caused an equivalent increase in the cfu of L. monocytogenes recovered from the spleens and livers as compared to control mice. This is the first report of such a protective effect from a single dose of rIL-12. Treatment of uninfected mice with rIL-12 induced IFN-gamma mRNA production in their livers. Infection of mice with L. monocytogenes caused a similar increase in IFN-gamma mRNA levels that was not increased further by concurrent treatment with rIL-12. Treatment of mice with an anti-IFN-gamma MAb eliminated the protective effect of IL-12 on Listeria infection. Expression of TNF-alpha, IL-10 and IL-12p40 mRNA in L. monocytogenes-infected mice were not significantly altered by administration of either anti-IL-12 IgG or rIL-12. rIL-12 administration was associated with increased serum AST levels, a measure of liver damage, 1 day after treatment in L. monocytogenes-infected mice. In addition, rIL-12 administration was associated with the increased presence of small inflammatory foci and necrotic hepatocytes in both infected and uninfected mice, suggesting a proinflammatory role for IL-12 in the liver.

Treatment with anti-interleukin-10 monoclonal antibody enhances early resistance to but impairs complete clearance of Listeria monocytogenes infection in mice

Mice that received an anti-interleukin-10 (anti-IL-10) neutralizing monoclonal antibody (MAb) (SXC-1) prior to infection with Listeria monocytogenes initially demonstrated resistance to the infection, as indicated by reduced recovery of L. monocytogenes from their spleens and livers during the first 5 days after challenge. Anti-IL-10 MAb-treated mice then demonstrated reduced resistance during the later stage of infection, as indicated by persistent infection with L. monocytogenes in their livers 11 days after challenge. Aspartate aminotransferase (AST) levels (a measure of liver damage) in the sera of control mice increased between 1 and 5 days after challenge, while anti-IL-10 MAb-treated mice maintained lower AST levels. At 7 days after challenge, AST levels in the sera of control mice decreased as the numbers of organisms declined. In contrast, AST levels increased as the infections persisted in anti-IL-10 MAb-treated mice. The AST levels in serum reflected liver histopathology as anti-IL-10 MAb-treated mice exhibited fewer granulomatous lesions and less necrosis of liver tissue than the control mice during the first 5 days after challenge. Anti-IL-10 MAb treatment altered the expression of inflammatory cytokine mRNAs during L. monocytogenes infection. Control MAb-treated mice exhibited increased expression of tumor necrosis factor alpha and granulocyte-macrophage colony-stimulating factor mRNA in their lives during L. monocytogenes infection, but this increase did not occur in anti-IL-10 MAb-treated mice. Gamma interferon mRNA expression in the livers of the control MAb-treated mice was increased between 1 and 5 days after L. monocytogenes challenge and then decreased at 7 days after challenge. In contrast, gamma interferon mRNA expression in the livers of anti-IL-10 MAb-treated mice was not decreased until 7 days after challenge. These results indicate that endogenous IL-10 has both beneficial and detrimental effects on the host response to L. monocytogenes infection in mice.

Administration of anti-granulocyte mAb RB6-8C5 impairs the resistance of mice to Listeria monocytogenes infection

Mice injected i.p. with RB6-8C5 mAb experienced a profound depletion of neutrophils in the bloodstream and spleen and significant impairment of their resistance to experimental infection with Listeria monocytogenes. Control mice survived i.v. inoculation with 5 x 10(4) L. monocytogenes; whereas, most RB6-8C5 mAb-treated mice inoculated i.v. with as few as 10 L. monocytogenes died within 6 days. RB6-8C5 mAb treatment was particularly deleterious when given within the first 24 h after i.v. inoculation with L. monocytogenes; however, some adverse effect was observed even when administration was delayed until 3 or 5 days after bacterial inoculation. Histopathologic examination of the livers of RB6-8C5 mAb-treated mice revealed necrotic foci that were characterized by few inflammatory cells and massive numbers of Gram-positive bacteria within hepatocytes. Additional evidence that the effects of RB6-8C5 mAb administration were chiefly due to neutrophil depletion include: 1) the effects of RB6-8C5 mAb treatment occurred more rapidly than what is generally seen in mice treated with anti-T cell mAbs, 2) similar results were observed with normal and scid mice, 3) RB6-8C5 mAb administration did not diminish delayed-type hypersensitivity nor the ability of spleen cells from immunized mice to transfer resistance, and 4) natural killer cell activity was unaffected by RB6-8C5 mAb administration. The results of this study provide additional evidence in support of the importance of neutrophils in the early stage of innate resistance to murine listeriosis.

Administration of anti-granulocyte mAb RB6-8C5 impairs the resistance of mice to Listeria monocytogenes infection

Mice injected i.p. with RB6-8C5 mAb experienced a profound depletion of neutrophils in the bloodstream and spleen and significant impairment of their resistance to experimental infection with Listeria monocytogenes. Control mice survived i.v. inoculation with 5 x 10(4) L. monocytogenes; whereas, most RB6-8C5 mAb-treated mice inoculated i.v. with as few as 10 L. monocytogenes died within 6 days. RB6-8C5 mAb treatment was particularly deleterious when given within the first 24 h after i.v. inoculation with L. monocytogenes; however, some adverse effect was observed even when administration was delayed until 3 or 5 days after bacterial inoculation. Histopathologic examination of the livers of RB6-8C5 mAb-treated mice revealed necrotic foci that were characterized by few inflammatory cells and massive numbers of Gram-positive bacteria within hepatocytes. Additional evidence that the effects of RB6-8C5 mAb administration were chiefly due to neutrophil depletion include: 1) the effects of RB6-8C5 mAb treatment occurred more rapidly than what is generally seen in mice treated with anti-T cell mAbs, 2) similar results were observed with normal and scid mice, 3) RB6-8C5 mAb administration did not diminish delayed-type hypersensitivity nor the ability of spleen cells from immunized mice to transfer resistance, and 4) natural killer cell activity was unaffected by RB6-8C5 mAb administration. The results of this study provide additional evidence in support of the importance of neutrophils in the early stage of innate resistance to murine listeriosis.

Analysis of cytokine mRNA expression in Listeria-resistant C57BL/6 and Listeria-susceptible A/J mice during Listeria monocytogenes infection

This laboratory previously reported that mRNA expression for many cytokines, as determined by reverse transcription-polymerase chain reaction analysis, is induced rapidly in the spleen during murine listeriosis. In the present study, the patterns of cytokine mRNA expression in spleens and livers of Listeria-resistant C57BL/6 and Listeria-susceptible A/J mice were compared. In addition, in situ hybridization was performed to evaluate the distributions of cytokine mRNA-expressing cells in these tissues. Listeria-resistant C57BL/6 mice demonstrated greater expression of gamma interferon (IFN-gamma) and granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNAs in the spleen than Listeria-susceptible A/J mice. Greater numbers of cells expressing IFN-gamma and GM-CSF mRNAs were observed by in situ hybridization in the spleens of C57BL/6 mice than in those of A/J mice. C57BL/6 and A/J mice did not differ in their expression of IFN-gamma mRNA in the liver. Nor did C57BL/6 and A/J mice differ in their expression of tumor necrosis factor alpha, interleukin-1 alpha (IL-1 alpha), IL-2, IL-4, or IL-6 mRNA in the liver or spleen, as determined by reverse transcription-polymerase chain reaction and in situ hybridization. These results indicate that the greater resistance of C57BL/6 mice to Listeria monocytogenes infection is associated with greater expression of IFN-gamma and GM-CSF mRNAs in the spleen and GM-CSF mRNA in the liver.

Cytokine mRNA expression in livers of mice infected with Listeria monocytogenes

Temporally distinct groups of cytokine expression was observed by reverse transcription-polymerase chain reaction assay, in situ hybridization, and immunohistochemistry in the livers of Listeria monocytogenes-infected mice. One group consisted of interferon-gamma (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), and interleukin-10 (IL-10), for which mRNAs were induced within 1 day after challenge. A second group consisted of IL-2 and IL-4, for which mRNA was strongly expressed at 1 day but then suppressed at 3 days into the infection. Granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-1 alpha, and IL-6 mRNA constituted a third group, which was increased at 3 days after challenge. Distributions of cytokine mRNA-expressing cells in the liver was observed by in situ hybridization. Cells expressing TNF-alpha and IL-1 alpha mRNA were present throughout liver granulomas, whereas cells that expressed IFN-gamma mRNA were observed mostly along the periphery of granulomas. Cells expressing IL-2, IL-4, IL-6, IL-10, and GM-CSF mRNA were distributed principally in the hepatic sinuses. Cells expressing IL-10 mRNA increased in number early in the infection when L. monocytogenes was multiplying in the liver. We conclude that cytokine mRNA expression during the early phases of L. monocytogenes infection in mice is temporally regulated and that IFN-gamma, TNF-alpha, and IL-1 alpha are expressed by cells associated with hepatic granulomas.

Apolipoprotein expression and cellular differentiation in Caco-2 intestinal cells

Caco-2 cells, cultured for 18 days on porous filter supports and conventional plastic culture dishes, were used to study the effects of cellular differentiation on the expression of apolipoprotein (apo) genes. Media of filter-grown cells accumulated more apo B as apo B-48 and contained three times the amount of edited apo B mRNA compared with plastic-grown cells. The accumulation of apo A-I by media of plastic-grown cells was higher than accumulation by filter-grown cells, despite similar concentrations of apo A-I mRNA. The apo A-IV was detectable in the culture media earlier with filter-grown cells compared with plastic-grown cells, despite similar apo A-IV mRNA concentrations. Plastic-grown cells contained more apo E mRNA, and their media accumulated more apo E than filter-grown cells. With the exception of apo A-I, apo gene expression changed with Caco-2 cell differentiation to resemble more closely the patterns seen in adult enterocytes. There were no effects or minimal effects of added retinoic acid, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], or thyroid hormone on apo accumulation in media of filter-grown cultures of Caco-2 cells. However, 1,25(OH)2D3 and thyroid hormone increased apo B, apo A-IV, and apo A-I mRNA concentrations, retinoic acid increased apo B mRNA concentrations alone, and all three reduced apo E mRNA concentrations. Ratios of edited to unedited apo B mRNA were unaffected. In conclusion, culture substratum importantly influences Caco-2 cell differentiation. Soluble factors that influence cellular differentiation may affect apo gene expression over and above effects mediated by the culture substratum.(ABSTRACT TRUNCATED AT 250 WORDS)

ApoB-75, a truncation of apolipoprotein B associated with familial hypobetalipoproteinemia: genetic and kinetic studies

We have identified a mutation of apolipoprotein B (apoB) in a kindred with hypobetalipoproteinemia. Four affected members had plasma concentrations of total cholesterol of 115 +/- 14, low density lipoprotein (LDL)-C of 48 +/- 11, and apoB of 28 +/- 9 (mg/dl mean +/- SD). The values correspond to approximately 30% the values for unaffected relatives. Triglyceride and high density lipoprotein (HDL)-C concentrations were 92 +/- 50 and 49 +/- 4, respectively, neither significantly different from unaffected relatives. Western blots of plasma apoB of affected subjects showed two major bands: apoB-100 and an apoB-75 (mol wt of approximately 418,000). DNA sequencing of the appropriate polymerase chain reaction (PCR)-amplified genomic DNA segment revealed a deletion of the cytidine at nucleotide position 10366, resulting in a premature stop codon at amino acid residue 3387. In apoB-75/apoB-100 heterozygotes, two LDL populations containing either apoB-75 or apoB-100 could be distinguished from each other by gel permeation chromatography and by immunoblotting of nondenaturing gels using monoclonal antibodies B1B3 (epitope between apoB amino acid residues 3506-3635) and C1.4 (epitope between residues 97-526). ApoB-75 LDL were smaller and more dense than apoB-100 LDL. To determine whether the low concentration of apoB-75 was due to its enhanced LDL-receptor-mediated removal, apoB-75 LDL were isolated from the proband's d 1.063-1.090 g/ml fraction (which contained most of the apoB-75 in his plasma) by chromatography on anti-apoB and anti-apoA-I immunoaffinity columns. The resulting pure apoB-75 LDL fraction interacted with the cells 1.5-fold more effectively than apoB-100 LDL (d 1.019-1.063 g/ml). To determine the physiologic mechanism responsible for the hypobetalipoproteinemia, in vivo kinetic studies were performed in two affected subjects, using endogenous labeling of apoB-75 and apoB-100 with [13C]leucine followed by multicompartmental kinetic analyses. Fractional catabolic rates of apoB-75 VLDL and LDL were 2- and 1.3-fold those of apoB-100 very low density lipoprotein (VLDL) and LDL, respectively. Production rates of apoB-75 were approximately 30% of those for apoB-100. This differs from the behavior of apoB-89, a previously described variant, whose FCRs were also increased approximately 1.5-fold relative to apoB-100, but whose production rates were nearly identical to those of apoB-100. Thus, in contrast to the apoB-89 mutation, the apoB-75 mutation imparts two physiologic defects to apoB-75 lipoproteins that account for the hypobetalipoproteinemia, diminished production and increased catabolism.

Administration of anti-IL-4 monoclonal antibody 11B11 increases the resistance of mice to Listeria monocytogenes infection

The role of endogenous IL-4 in resistance to Listeria monocytogenes infection was investigated by in vivo administration of an anti-IL-4 mAb (11B11). Mice treated with 0.01 to 0.4 mg of anti-IL-4 mAb before L. monocytogenes challenge demonstrated a significantly reduced peak bacterial burden in their livers and spleens and accelerated bacterial clearance from these organs. In addition, histopathologic damage to the liver was reduced. Maximal protection was achieved by i.p. injection of 0.1 mg of anti-IL-4 mAb 2 or 24 h before L. monocytogenes challenge; treatment with anti-IL-4 mAb after injection of L. monocytogenes had no effect on antilisterial resistance. Anti-IL-4 mAb-treated and control Listeria-infected mice exhibited similar patterns of IFN-gamma, IL-2, and IL-4 mRNA, as determined by polymerase chain reaction amplification of RNA extracted from spleen cells. In both anti-IL-4 mAb-treated and control mice, IFN-gamma, IL-2, and IL-4 mRNA were produced within 4 h after challenge. Cytokine mRNA levels were similar for anti-IL-4 mAb-treated and control mice, except for the greater amount of IFN-gamma mRNA in the anti-IL-4 mAb-treated mice at 4 h after L. monocytogenes challenge. IFN-gamma and IL-2 mRNA levels were sustained for at least 5 days, whereas IL-4 mRNA was undetectable by 3 days after challenge. There were no significant differences in the amounts of IL-4 and IFN-gamma detected in culture supernatants of spleen cells from anti-IL-4 mAb-treated and control Listeria-infected mice. These results suggest that endogenous IL-4, a cytokine thought to be produced principally by Th2 cells, has a deleterious effect on host defense against the facultative intracellular pathogen L. monocytogenes. Administration of an anti-IL-4 mAb increases antilisterial resistance without causing a detectable shift to a Th1 type of cytokine response.

Administration of anti-IL-4 monoclonal antibody 11B11 increases the resistance of mice to Listeria monocytogenes infection

The role of endogenous IL-4 in resistance to Listeria monocytogenes infection was investigated by in vivo administration of an anti-IL-4 mAb (11B11). Mice treated with 0.01 to 0.4 mg of anti-IL-4 mAb before L. monocytogenes challenge demonstrated a significantly reduced peak bacterial burden in their livers and spleens and accelerated bacterial clearance from these organs. In addition, histopathologic damage to the liver was reduced. Maximal protection was achieved by i.p. injection of 0.1 mg of anti-IL-4 mAb 2 or 24 h before L. monocytogenes challenge; treatment with anti-IL-4 mAb after injection of L. monocytogenes had no effect on antilisterial resistance. Anti-IL-4 mAb-treated and control Listeria-infected mice exhibited similar patterns of IFN-gamma, IL-2, and IL-4 mRNA, as determined by polymerase chain reaction amplification of RNA extracted from spleen cells. In both anti-IL-4 mAb-treated and control mice, IFN-gamma, IL-2, and IL-4 mRNA were produced within 4 h after challenge. Cytokine mRNA levels were similar for anti-IL-4 mAb-treated and control mice, except for the greater amount of IFN-gamma mRNA in the anti-IL-4 mAb-treated mice at 4 h after L. monocytogenes challenge. IFN-gamma and IL-2 mRNA levels were sustained for at least 5 days, whereas IL-4 mRNA was undetectable by 3 days after challenge. There were no significant differences in the amounts of IL-4 and IFN-gamma detected in culture supernatants of spleen cells from anti-IL-4 mAb-treated and control Listeria-infected mice. These results suggest that endogenous IL-4, a cytokine thought to be produced principally by Th2 cells, has a deleterious effect on host defense against the facultative intracellular pathogen L. monocytogenes. Administration of an anti-IL-4 mAb increases antilisterial resistance without causing a detectable shift to a Th1 type of cytokine response.

ApoB-54.8, a truncated apolipoprotein found primarily in VLDL, is associated with a nonsense mutation in the apoB gene and hypobetalipoproteinemia

A new, large kindred with hypobetalipoproteinemia and a previously undescribed truncated form of apolipoprotein B (apoB) has been identified. The asymptomatic, Caucasian male proband (CK, aged 37 years) has total plasma cholesterol, triglyceride, low density lipoprotein-(LDL) cholesterol, high density lipoprotein- (HDL) cholesterol, and apoB concentrations of 108, 131, 32, 50, and 16 mg/dl, respectively. Plasma samples of 11 family members spanning three generations, which had less than 5th percentile concentrations of LDL-cholesterol, contained three apoB bands detected on immunoblots: the normal apoB-100 and apoB-48 and an unusual band of apparent molecular mass of 299,356 +/- 9580 daltons (approximately 54% the molecular weight of apoB-100). Additional immunoblotting experiments using several different anti-apoB monoclonal antibodies showed that the carboxyl terminal of apoB-100 had been deleted somewhere between amino acid residues 2148-2488. A segment of genomic DNA from the proband was amplified by polymerase chain reaction (PCR) between nucleotides 7491-7791 of Exon 26 of the apoB gene. The DNA segment was cloned into pGEM3Zf(-) and sequenced. A C----T transition was found at nucleotide 7665, resulting in a premature stop codon at amino acid residue 2486 corresponding to apoB-54.8. These results were confirmed by direct sequencing of PCR products from three apoB-54.8 positive and three apoB-54.8 negative kindred members. Allele-specific oligonucleotides were used to identify other affected family members. Cosegregation of apoB-54.8 with the C----T transition occurred in all cases. Based on haplotypes constructed from restriction fragment length polymorphism, variable number of tandem repeats, and 5' insertion/deletion analyses and from the presence or absence of apoB-54.8, it was possible to assign a single allele of apoB to the mutation throughout the family. In contrast with other shorter truncations such as apoB-31, apoB-40, and apoB-46, which are found with particles in the HDL density range, and apoB-89 that is found primarily with LDL, apoB-54.8 was found primarily in very low density lipoproteins, much less in LDL, and was virtually absent in HDL. This suggests that the length of the truncation may significantly affect the metabolism of the associated lipoprotein particles.

Hydroxy sulfoxides derived from norbornene: determination of stereochemistry, and synthesis by stereoselective oxidation

The structure (5) of one of the hydroxy sulfoxides formed by thiol-oxygen cooxidation of norbornene has been determined by X-ray diffraction. Other products have been related to it by appropriate chemical transformations. The stereospecific, or highly stereoselective, conversion of suitable hydroxy sulfides into one of the two possible diastereoisomeric hydroxy sulfoxides demonstrates the directive influence of the hydroxyl group on oxidation of vicinal sulfur.