Lymphatic Drainage of the Peritoneal Space: A Pattern Dependent on Bowel Lymphatics

Background Understanding lymph drainage patterns of the peritoneum could assist in staging and treatment of gastrointestinal and ovarian malignancies. Sentinel lymph nodes (SLNs) have been identified for solid organs and the pleural space. Our purpose was to determine whether the peritoneal space has a predictable lymph node drainage pattern. Methods Rats received intraperitoneal injections of near-infrared (NIR) fluorescent tracers: namely, quantum dots (designed for retention in SLNs) or human serum albumin conjugated with IRDye800 (HSA800; designed for lymphatic flow beyond the SLN). A custom imaging system detected NIR fluorescence at 10 and 20 minutes and 1, 4, and 24 hours after injection. To determine the contribution of viscera to peritoneal lymphatic flow, additional cohorts received bowel resection before NIR tracer injection. Associations with appropriate controls were assessed with the χ² test. Results Quantum dots drained to the celiac, superior mesenteric, and periportal lymph node groups. HSA800 drained to these same groups at early time points but continued flowing to the mediastinal lymph nodes via the thoracic duct. After bowel resection, both tracers were found in the thoracic, not abdominal, lymph node groups. Additionally, HSA800 was no longer found in the thoracic duct but in the anterior chest wall and diaphragmatic lymphatics. Conclusions The peritoneal space drains to the celiac, superior mesenteric, and periportal lymph node groups first. Lymph continues via the thoracic duct to the mediastinal lymph nodes. Bowel lymphatics are a key determinant of peritoneal lymph flow, because bowel resection shifts lymph flow directly to the intrathoracic lymph nodes via chest wall lymphatics. Dr. Parungo was the recipient of an award at the SSO meeting.     

Differentiation of human adult CD34+ stem cells into cells with a neural phenotype: role of astrocytes

It has recently been reported that adult hematopoietic stem cells can differentiate into neural cells, opening new frontiers in therapy for neurodegenerative diseases. In this study, adult human hematopoietic stem cells (HSCs) were isolated via magnetic bead sorting, using a specific CD34 antibody and cultured with human astrocyte culture conditioned medium (ACM). In order to evaluate their differentiation into neurons and/or astrocytes, ACM-treated cultures were probed for the expression of several neural markers. We observed morphological modifications and, after 20 days of treatment, cell morphology displayed extending processes. Immunocytochemistry, Western blotting and RT-PCR showed the expression of neuronal markers such as neurofilaments, neuron specific enolase (NSE) and NeuN in ACM-treated HSCs cultured in poly-L-lysine-coated dishes. On the contrary, when the same ACM-treated cells were grown on a plastic substrate, they expressed high levels of glial fibrillary acidic protein (GFAP), with only weak expression of neuronal markers. Nestin, a neural progenitor cell marker, was present in treated cells, regardless of the substrate. These results demonstrate that astrocytes can generate a suitable microenvironment for inducing HSCs to differentiate into neural cells. Therefore, adult bone marrow may represent a readily accessible source of cells for treating neurodegenerative diseases.     

Neuroendocrine effects of citalopram infusion in anorexia nervosa

Because of the role of serotonin (5HT) in regulating food intake and mood, several studies have focused their attention on the assessment of serotonergic activity in eating disorders, and in particular in anorexia nervosa, but the results have been inconsistent. Citalopram, a highly selective 5HT reuptake inhibitor, has been recently reported as a neuroendocrine probe to assess the serotonergic function in physiological and pathological conditions. We evaluated the adrenocorticotropic hormone (ACTH), cortisol, prolactin (PRL) and growth hormone (GH) secretion during placebo or citalopram IV infusion (20 mg over 120 min), in six women with anorexia nervosa restricter type, and in six healthy women, in order to test the hypothesis that this neurotransmitter system is abnormal in this group of patients. ACTH and PRL secretion was higher during citalopram infusion compared to placebo (p<0.05) in both groups, while cortisol secretion was higher during citalopram infusion only in healthy controls (p<0.05), but not in anorexic patients. GH levels were unaffected by citalopram in both groups. These results demonstrate that serotonergic activation by citalopram affects corticotroph and lactotroph but not somatotroph secretion in anorexic as well as in normal subjects. Our preliminary findings do not support the existence of remarkable alterations in the serotonergic control of anterior pituitary function in anorexia nervosa, while there seems to be an impairment of the adrenal function in this group of patients.     

Cognitive deficits in familial Alzheimer's disease associated with M239V mutation of presenilin 2

The neuropsychological assessment of non-demented subjects with gene mutation of familial Alzheimer's disease (AD) provides a model for exploring the early cognitive features of the disease. We evaluated 1 patient and 6 non-demented subjects belonging to a family with AD with M239V mutation of the presenilin 2 gene, aiming to verify the contribution of specific cognitive patterns to the characterization of familial AD. One patient, 3 non-demented subjects with M239V mutation and 3 subjects without mutation from the same family underwent neuropsychological testing. The patient's cognitive profile was characterized by anosognosia, visuospatial agnosia, apraxia and fluent aphasia. Of the 3 non-demented subjects with mutation, 1 showed no deficits, another constructive apraxia and the third spatial perception and memory deficits. The 3 subjects without mutation showed normal abilities. The cognitive deficits of the non-demented subjects with mutations indicate focal dysfunction of the posterior cortical areas, resembling the more extended parieto-occipito-temporal dysfunction of the demented patient. Such grading of visuospatial, praxis, and language impairments highlights a distinctive pattern related to the M239V mutation of the presenilin 2 gene.     

The role of the basolateral amygdala in stimulus-reward memory and extinction memory consolidation and in subsequent conditioned cued reinstatement of cocaine seeking

The consolidation of cue-cocaine associations and extinction learning (i.e. cue-no cocaine associations) into long-term memory probably regulates the long-lasting control of conditioned stimuli (CS) over cocaine-seeking behaviour, and the basolateral amygdala (BLA) may play a role in this phenomenon. To test this hypothesis, rats previously trained to self-administer cocaine underwent a single classical conditioning (CC) session, during which they received passive pairings of cocaine infusions and a novel light + tone stimulus complex. After additional self-administration sessions in the absence of CS presentation and subsequent extinction training sessions, the ability of the CS to reinstate cocaine-seeking on five test days was assessed. Rats received intra-BLA microinfusions of vehicle or the Na+-channel blocker tetrodotoxin (TTX) immediately after CC (consolidation of CS-cocaine associations) or immediately after reinstatement testing (consolidation of extinction learning). TTX administered immediately after CC attenuated subsequent CS-induced reinstatement. In contrast, TTX administered after the first reinstatement test impaired the extinction of cocaine-seeking behaviour during a second reinstatement test by disrupting extinction memory. Overall, these findings suggest that Na+ channel-mediated mechanisms within the BLA mediate the consolidation of both cocaine-stimulus association and extinction learning, two processes that have opposite effects on subsequent cue-induced cocaine-seeking behaviour.     

An update on nonmelanoma skin cancer

Estimates from the American Cancer Society suggest that there are more than two million cases of nonmelanoma skin cancer in the United States per year. The following review highlights the topics of actinic keratoses, basal cell carcinoma, squamous cell carcinoma, Kaposi's sarcoma, and Merkel cell carcinoma. This update on the cutting-edge clinical and dermpathologic research will assist the dermatologist in approaching, diagnosing, and managing nonmelanoma skin carcinoma. Immunologic and genetic research into nonmelanoma skin carcinoma has paved the way for novel therapeutic options for patients who were previously without any viable treatment alternatives. While still in preliminary stages, agents, such as ingenol mebutate, vismodegib, and sirolumus, may become integral drugs in the armamentarium of managing cutaneous carcinoma.     

Axillary Lymph Node Echo-Guided Fine-Needle Aspiration Cytology Enables Breast Cancer Patients to Avoid a Sentinel Lymph Node Biopsy. Preliminary Experience and a Review of the Literature

Purpose For many years, the status of the axillary lymph nodes has been determined by an axillary lymphadenectomy. However, a sentinel lymph node biopsy has been shown to effectively replace the need for an axillary lymphadenectomy in order to determine the axillary staging. This study presents the preliminary results regarding the efficacy of fine-needle aspiration cytology (FNAC) to identify metastatic axillary lymph nodes in the pre-operative phase. Methods One hundred lymph nodes from 100 patients with histologically and cytologically confirmed breast cancer (cT1–2 cN0) underwent echo-guided FNAC. The diagnostic accuracy (sensitivity, specificity, positive predictive value [PPV], negative predictive value [NPV]) for the axillary metastases was evaluated based on the histological findings of either a sentinel lymph node biopsy or an axillary lymphadenectomy as a reference standard. Results It was possible to avoid a sentinel lymph node biopsy in 30% of the cases; the sensitivity was 68%, specificity 100%, PPV 100%, and NPV 65%. Echo-guided FNAC of the axillary lymph nodes should thus be included among the regular diagnostic procedures of presurgical staging. Conclusion This simple, inexpensive, and minimally invasive technique makes it possible to avoid the additional cost of a sentinel lymph node biopsy while also sparing the patient the stress of undergoing a second surgery.     

Intraoperative Evaluation of Sentinel Lymph Nodes for Metastatic Melanoma by Imprint Cytology

Background Sentinel lymph node biopsy (SLN) has revolutionized nodal staging. Accurate intraoperative evaluation of SLN permits a single procedure, with lymphadenectomy being performed during the initial operative procedure when the SLN is positive. There is a paucity of literature on intraoperative imprint cytology (IIC) evaluation of the SLN in melanoma. The purpose of this article is to present an update to our experience with IIC for SLN in melanoma. Methods Melanoma patients had SLNs examined by IIC. SLNs were bisected, and imprints were made from each half. Imprints were stained with hematoxylin and eosin and with Diff-Quik. Paraffin-embedded sections were examined with multiple hematoxylin and eosin–stained sections from the SLNs in conjunction with immunohistochemical staining for S-100, Melan-A, and HMB-45 proteins. Results Metastases were identified in 40 (17%) of 229 patients. Of these, 13 patients were detected by IIC (sensitivity, 33%). The negative predictive value was 88%. No false-positive results were identified (specificity, 100%). The positive predictive value was 100%. The accuracy of IIC was 78%. The sensitivity for detecting macrometastases (>2 mm) was better than that for detecting micrometastases (≤2 mm): 62% vs. 16% (P < .01). Patients with positive SLNs by IIC had lymphadenectomy under the same anesthetic. A total of 533 nonsentinel lymph nodes were identified in 42 patients. Only two patients (8%) had positive nonsentinel lymph nodes after a negative IIC. Conclusions IIC is a viable alternative to frozen sectioning when intraoperative evaluation is desired. IIC is significantly more sensitive for macrometastases. IIC evaluation of SLNs in melanoma makes a single operative procedure possible for a significant proportion of patients with regional nodal metastases. Presented at the Society of Surgical Oncology, San Diego, California, March 24, 2006.     

Sustained Inflammasome Activity in Macrophages Impairs Wound Healing in Type 2 Diabetic Humans and Mice

The hypothesis of this study was that sustained activity of the Nod-like receptor protein (NLRP)-3 inflammasome in wounds of diabetic humans and mice contributes to the persistent inflammatory response and impaired healing characteristic of these wounds. Macrophages (Mp) isolated from wounds on diabetic humans and db/db mice exhibited sustained inflammasome activity associated with low level of expression of endogenous inflammasome inhibitors. Soluble factors in the biochemical milieu of these wounds are sufficient to activate the inflammasome, as wound-conditioned medium activates caspase-1 and induces release of interleukin (IL)-1β and IL-18 in cultured Mp via a reactive oxygen species–mediated pathway. Importantly, inhibiting inflammasome activity in wounds of db/db mice using topical application of pharmacological inhibitors improved healing of these wounds, induced a switch from proinflammatory to healing-associated Mp phenotypes, and increased levels of prohealing growth factors. Furthermore, data generated from bone marrow–transfer experiments from NLRP-3 or caspase-1 knockout to db/db mice indicated that blocking inflammasome activity in bone marrow cells is sufficient to improve healing. Our findings indicate that sustained inflammasome activity in wound Mp contributes to impaired early healing responses of diabetic wounds and that the inflammasome may represent a new therapeutic target for improving healing in diabetic individuals.     

Evaluating the Efficacy of Photodynamic Therapy with 20% Aminolevulinic Acid and Microdermabrasion as a Combination Treatment Regimen for Acne Scarring: A Split-face,Randomized, Double-blind Pilot Study

Acne scarring is a consequence of abnormal resolution of wound healing after damage that occurs in the sebaceous follicle during acne inflammation. No trial to date has evaluated the efficacy of the combination of microdermabrasion and photodynamic therapy for acne scarring. This single-center, double-blinded pilot study enrolled subjects with moderate-to-severe acne scarring who were randomly assigned in a blinded fashion to use aminolevulinic acid and vehicle in a split-face fashion after full-face treatment with microdermabrasion. On average, 80 percent of the patients displayed more improvement in scarring on the aminolevulinic acid split face versus the vehicle split face after five treatments. Using two different noninvasive mechanisms of targeting acne scarring provided for a safe treatment regimen characterized by more efficacious results with respect to higher rates of scarring improvement.Acne affects nearly 80 percent of adolescents and young adults. A recent community-based study of close to 800 subjects reported the overall acne scarring prevalence to be 14 percent in women and 11 percent in men.1 Severe scarring caused by acne is associated with substantial physical and psychological distress and has been associated with poor self-esteem, emotional debilitation, and lowered academic performance.2Acne scarring is a consequence of abnormal resolution of wound healing after damage that occurs in the sebaceous follicle during acne inflammation.3 The cause is due to either increased formation of tissue (hypertrophic scars or keloids) or damage to tissue (ice pick, rolling, and boxcar scars), leaving atrophic scars. All types of acne, from papulopustular to nodulocystic disease, can cause scarring; therefore, adequate treatment must be started early.4 Of the therapeutic approaches available for acne scarring, microdermabrasion represents a noninvasive efficacious treatment for contour irregularities. A molecular trial showed that after a single microdermabrasion treatment, matrix metalloproteinases involved in dermal remodeling and wound healing were upregulated in the biopsies taken from subjects with severe acne scarring.5Photodynamic therapy (PDT) involves the topical administration of aminolevulinic acid (ALA) and has been successfully utilized as a noninvasive treatment modality for acne. While not photosensitive by itself, ALA is converted by keratinocytes to protoporphyrin IX, which is a photosensitive compound that is activated by a blue light source. The reactive oxygen species formed in this reaction produce beneficial immunological changes. In the murine contact hypersensitivity model, PDT-ALA was found to cause local immunosuppression by decreasing the number of epidermal Langerhans cells, a finding which suggests that PDT has a potential immunological contribution to clinical efficacy for inflammatory diseases.Additionally, PDT has been shown to stimulate various matrix metalloproteinases, which may explain the collagen remodeling produced by this method. The side effect profile of topical ALA-PDT is extremely favorable, with mild pain and temporary cutaneous photosensitivity reported as the most frequent documented adverse effects. Many studies concerning the anti-inflammatory effects of PDT on acne have been published; however, a study specifically focusing on the use of PDT for acne scarring has yet to be conducted.No trial to date has evaluated the efficacy of the combination of microdermabrasion and ALA-PDT for acne scarring. However, targeting acne scarring with microdermabrasion followed by ALA-PDT appears to be logical. The authors hypothesize that the ability to increase the permeability barrier via the use of microdermabrasion will enhance the absorption of 5-ALA and thereby increase the efficacy of the combination treatment for acne scarring. They also hypothesize that utilizing microdermabrasion prior to application of ALA will speed the acid’s absorption, shortening the incubation time needed to 60 minutes, which could greatly enhance both patient convenience and physician productivity.The efficacy of the combination procedure may provide for a faster, yet longer-sustained clearance effect. In summary, by using two different mechanisms of targeting acne scarring, the authors expect to have more efficacious results with respect to higher rates of scarring improvement. They also hope to bring to the forefront a new therapeutic regimen for acne scarring, which combines two provider-applied modalities.