An experimental model for chronic lymphedema

Although a multitude of operations exist for the treatment of lymphedema, none is highly successful. An experimental model that reliably and easily produces chronic lymphedema in an extremity would be useful to study treatments in a controlled and comparative manner and would enhance our understanding of the physiology and treatment of lymphedema. Many models that simulate clinical lymphedema have been described, but they suffer from cumbersome protocols, high laboratory costs, and an inconsistent yield of permanent lymphedema. We describe an experimental model for chronic lymphedema in the lower extremity of the rat that creates a lymphatic block in the groin induced by radiation treatment and one operation--surgical division of the superficial and deep lymphatics. All animals develop stable chronic lymphedema of the lower extremity within days of operation, with swelling that persists for at least 9 months. A mortality rate of 8 percent was associated with this technique. Methods for quantification of limb swelling are described, as is analysis of the lymphatic block by lymphoscintigraphic imaging of lymph channels and nodes. This model has the advantages of simplicity of technique, cost-effective use of rodent subjects, reproducibility of lymphedema, and quantification of results.     

Treatment of lymphedemas by microsurgical lymphatic grafting: what is proved?

Lymphedemas due to a local blockade of the lymphatic system can be treated by bridging the defect with autologous lymphatic grafts. Under the microscope, grafts are anastomosed to peripheral lymphatics distal to and central lymphatics proximal to the regional blockade. In this way, the diminished transport capacity can be restored. In the case of unilateral blockade at the groin or pelvis, the grafts connect the lymphatics of the thigh of the affected leg with lymphatics in the contralateral healthy groin. Between June of 1980 and December of 1986, 55 patients with lymphedemas have been treated by lymphatic grafting. The effect of lymph vessel transplantation has been evaluated by volume measurements and lymphatic scintiscans, showing a persistent patency of grafts, improvement of the transport index, and a persistent reduction in volume of the affected limbs. The reduction reached a level of 80 percent in patients with a follow-up of at least 3 years. The transport index showed an improvement of 30 percent. Autologous lymph vessel transplantation has been shown to be a fundamental step toward the microsurgical treatment of lymphedema.     

The use of free groin flaps in children

The free groin flap is a well-established method of skin coverage. Although its use in children has been reported, there have been no published series specifically in such cases. The authors report 33 consecutive cases of free groin flaps in children in their unit over a period of 9 years (1992 to 2001). Tissue transfer was performed to provide soft-tissue coverage during reconstruction of congenital defects and tumor resection and following trauma. Twenty-six cases (79 percent) involved the upper limb, six cases (18 percent) involved the lower limb, and one case involved the head. The complication rate compares favorably with similar series published for adults, with only two complete failures (6 percent), three (9 percent) minor donor-site complications (superficial wound infection, hypertrophic scarring, and dog-ears), and nine flaps requiring debulking. The reexploration rate was 24 percent, with seven of the eight flaps undergoing reexploration surviving. The groin flap is a reliable flap that can be used safely in children, with minimal morbidity.     

Lymphatic mapping and sentinel lymph node biopsy in patients with melanoma of the lower extremity

Lymphatic mapping and sentinel lymph node biopsy is a new technique used in the surgical treatment of patients with malignant melanoma. The purpose of this study was to evaluate the results of this approach for patients with melanoma of the lower extremity. Between May of 1994 and June of 1997 at the H. Lee Moffitt Cancer Center and Research Institute, 85 consecutive patients with clinical stage I and II melanoma of the lower extremity underwent lymphatic mapping and sentinel lymph node biopsy. These nodes were identified in all 85 patients by intraoperative lymphatic mapping with both radiolymphoscintigraphy and a vital blue dye injection. Eleven patients (12.9 percent) had histologically positive sentinel lymph nodes, and 10 patients underwent inguinal complete lymph node dissections. All 10 patients had no further histologically positive lymph nodes confirmed by subsequent complete dissection. Among 74 patients with histologically negative sentinel lymph nodes, only 2 patients (2.7 percent) developed inguinal nodal metastases during a mean follow-up period of 21.8 months (range, 13.5 to 58.3 months). The sensitivity of lymphatic mapping and sentinel lymph node biopsy in this series was 100 percent and the specificity was 97.3 percent. Therefore, we conclude that the use of lymphatic mapping and sentinel lymph node biopsy can accurately stage patients with melanoma of the lower extremity and provide a rational surgical approach for these patients.     

CONTROL OF DIARRHEAL DISEASES IN CALIFORNIA STATE HOSPITALS FOR RETARDED CHILDREN

The three California state hospitals for mentally retarded persons have been having a severe problem with amebic and bacillary dysentery and with other infectious diseases of the gastrointestinal tract. At Sonoma, the oldest of these hospitals, this problem is known to have existed for many years. Improved medical and nursing staffing and the use of antibiotics and other effective drugs developed in recent years have greatly lowered morbidity and mortality rates in these institutions. However, in themselves these measures have not been effective in lowering the incidence of infection.Studies have demonstrated that mass treatment of cottage groups known to have a high incidence of amebic infection has resulted in control of this disease where such mass treatment was followed by adequate laboratory follow-up, with isolation and retreatment of treatment failures. Where mass treatment of such groups has been carried out without such laboratory followup, there was a rapid return to the previous high incidence of infection.Statistics show that these diseases are a serious threat to employees working in these institutions. Increasing attention is being paid to the potential threat to the surrounding communities and the state as a whole from the focus of infection present in these hospitals.     

Helicobacter pylori and Clinical Aspects of Gastric Cancer

In spite of important new insights into the basic mechanisms of gastric carcinogenesis, progress in the management of gastric cancer has been modest. Some modifications in the chemotherapies used for palliation and strategies for downstaging of the disease prior to surgical intervention are noteworthy. The positive experience with endoscopic mucosal resection (EMR) and submucosal dissection (ESD) for treatment of early gastric cancer has been confirmed and extended. The procedure-related morbidity and post-interventional quality of life is clearly favorable compared to open surgical resection in well-selected patients. New data on Helicobacter pylori revealed that eradication after endoscopic resection of early gastric cancer significantly reduces the incidence of recurrent and metachronous gastric neoplasias. It can further improve healing rates of treatment induced gastric ulcers. Eradication therapy therefore remains the best target for prevention of the disease. Critical is the "point of no return" when mucosal alterations (i.e. intestinal metaplasia, glandular atrophy) are no longer reversible. A population-based screen-and-eradicate strategy for H. pylori infection can at present only be recommended in high incidence regions.     

益生菌治疗艾滋病相关腹泻的研究现状和进展

摘要：艾滋病（AIDS）是一种具有极大危害性的传染性疾病。AIDS发病和死亡都呈现明显上升趋势,传播模式发生变化,疫情由高危人群向一般人群扩散。因此,AIDS/HIV已成为中国的一个严重的公共卫生问题,政府对此极为重视。目前AIDS的治疗药物主要包括NNRTIs、NRTIs、PIs、FIs、CRIs和INIs这6大类,因长期使用这些药物的副作用以及此病合并的并发症特性,探讨其发病机制及寻找新的治疗思路,一直是此病研究领域中的热点。随着肠道微生态学研究领域的发展,应用人体无害的益生菌治疗HIV感染相关腹泻逐渐受到全球关注,就此作一综述。     

Lymphoscintigraphy: defining a clinical role

Radionuclide lymphoscintigraphy is a useful technique for differentiating lymphedema from other causes of swelling, and may sometimes be useful for delineating collateral lymphatics, the level of obstruction, and the presence of lymphoceles or abnormal collections of lymphatic vessels, if they communicate sufficiently with normal lymphatic vessels. Standardization of technique is important to provide better intrapatient and even interpatient comparison. Symmetry, numbers, and locations of lymphatic vessels, lymph nodes, abnormal collections, and dermal collaterals are helpful in the qualitative assessment of lymphoscintigraphy. In addition, region-of-interest analysis may be used to quantitate the clearance of the radiopharmaceutical from the injection site and its accumulation in draining lymph nodes. The constellation of findings may be used to assess the severity of the lymphatic obstruction, the involvement of clinically normal limbs, and to plan therapy.     

Use of a whole-slide imaging system to assess the presence and alteration of lymphatic vessels in joint sections of arthritic mice

Abstract

We investigated the presence and alteration of lymphatic vessels in joints of arthritic mice using a whole-slide imaging system. Joints and long bone sections were cut from paraffin blocks of two mouse models of arthritis: meniscal-ligamentous injury (MLI)-induced osteoarthritis (OA) and TNF transgene (TNF-Tg)-induced rheumatoid arthritis (RA). MLI-OA mice were fed a high fat diet to accelerate OA development. TNF-Tg mice were treated with lymphatic growth factor VEGF-C virus to stimulate lymphangiogenesis. Sections were double immunofluorescence stained with anti-podoplanin and alpha-smooth muscle actin antibodies. The area and number of lymphatic capillaries and mature lymphatic vessels were determined using a whole-slide imaging system and its associated software. Lymphatic vessels in joints were distributed in soft tissues mainly around the joint capsule, ligaments, fat pads and muscles. In long bones, enriched lymphatic vessels were present in the periosteal areas adjacent to the blood vessels. Occasionally, lymphatic vessels were observed in the cortical bone. Increased lymphatic capillaries, but decreased mature lymphatic vessels, were detected in both OA and RA joints. VEGF-C treatment increased lymphatic capillary and mature vessel formation in RA joints. Our findings suggest that the lymphatic system may play an important role in arthritis pathogenesis and treatment.     

A fully coupled fluid-structure interaction model of the secondary lymphatic valve

Abstract

The secondary lymphatic valve is a bi-leaflet structure frequent throughout collecting vessels that serves to prevent retrograde flow of lymph. Despite its vital function in lymph flow and apparent importance in disease development, the lymphatic valve and its associated fluid dynamics have been largely understudied. The goal of this work was to construct a physiologically relevant computational model of an idealized rat mesenteric lymphatic valve using fully coupled fluid-structure interactions to investigate the relationship between three-dimensional flow patterns and stress/deformation within the valve leaflets. The minimum valve resistance to flow, which has been shown to be an important parameter in effective lymphatic pumping, was computed as 268?g/mm⁴?s. Hysteretic behavior of the lymphatic valve was confirmed by comparing resistance values for a given transvalvular pressure drop during opening and closing. Furthermore, eddy structures were present within the sinus adjacent to the valve leaflets in what appear to be areas of vortical flow; the eddy structures were characterized by non-zero velocity values (up to ～4?mm/s) in response to an applied unsteady transvalvular pressure. These modeling capabilities present a useful platform for investigating the complex interplay between soft tissue motion and fluid dynamics of lymphatic valves and contribute to the breadth of knowledge regarding the importance of biomechanics in lymphatic system function.     

The utility of sentinel lymph node biopsy in head and neck melanoma in the pediatric population

Intraoperative lymph node mapping and sentinel lymph node biopsy have proven beneficial techniques in staging adult patients with melanoma of the head and neck, where there is great variability in lymphatic drainage. This technique has also been applied to pediatric patients with truncal cutaneous melanomas in an effort to determine nodal status without the morbidity associated with complete lymph node dissection. Nevertheless, the utility of sentinel lymph node biopsy in head and neck melanoma in the pediatric population has not been established. The objective of the authors' study was to determine the clinical utility of intraoperative lymph node mapping and sentinel lymph node biopsy of head and neck melanoma in the pediatric population. The authors reviewed the records of seven pediatric patients with head and neck melanoma or borderline melanocytic proliferations of unknown biologic potential who underwent intraoperative lymph node mapping and sentinel lymph node biopsy between 1998 and 2001. All sentinel lymph node specimens were examined by a melanoma dermatopathologist for the presence of metastatic melanoma. The mean operative time for each case was 3 hours, 8 minutes (range, 2 hours, 15 minutes to 3 hours, 50 minutes). All seven pediatric patients who underwent extirpation of a primary head and neck melanoma and preoperative lymphoscintigraphy had unique and identifiable basins of drainage to regional nodal groups. Four of seven patients had at least one positive sentinel lymph node. Overall, five of 19 sentinel nodes (26 percent) resected had evidence of metastatic melanoma. Of the patients with positive sentinel lymph nodes, two of the primary lesions were diagnosed as melanoma while two were initially considered atypical melanocytic proliferations of uncertain biologic potential with melanoma in the differential diagnosis. Sentinel lymph nodes in pediatric patients with melanoma of the head and neck can be successfully mapped and biopsied, as in adult patients. In addition, this procedure can provide critical diagnostic information for those pediatric patients with diagnostically challenging, controversial, or borderline melanocytic lesions.     

Clinical relevance of novel imaging technologies for sentinel lymph node identification and staging

The sentinel lymph node (SLN) concept has become a standard of care for patients with breast cancer and melanoma, yet its clinical application to other cancer types has been somewhat limited. This is mainly due to the reduced accuracy of conventional SLN mapping techniques (using blue dye and/or radiocolloids as lymphatic tracers) in cancer types where lymphatic drainage is more complex, and SLNs are within close proximity to other nodes or the tumour site. In recent years, many novel techniques for SLN mapping have been developed including fluorescence, x-ray, and magnetic resonant detection. Whilst each technique has its own advantages/disadvantages, the role of targeted contrast agents (for enhanced retention in the SLN, or for immunostaging) is increasing, and may represent the new standard for mapping the SLN in many solid organ tumours. This review article discusses current limitations of conventional techniques, limiting factors of nanoparticulate based contrast agents, and efforts to circumvent these limitations with modern tracer architecture.     

Development of arterial and lymphatic collaterals under the action of a UHF magnetic field]

The work performed in 48 experimental and 24 control rats dealt with the development of arterial and lymphatic collaterals of pelvic extremities under effects of magnetic field of ultra high frequency (15 and 30 vt) in terms from 2 up to 6 weeks after surgery and exposure to magnetic field. The methods of investigation were arterio- and lymphoroentgenography and dissection. It has been established that formation of arterial collaterals in experimental rats takes place in all zones during the second week after cutting femoral arteries. The rate of the development of arterial collaterals was accelerated as compared with control animals. The lymph outflow after exposure to the influence of magnetic field of UHF goes mainly along superficial collaterals to groin nodes. The influence of the magnetic field of UHF appears to be accompanied by stable dilatation of super ficial lymph vessels, and due to this the lymph outflows along these vessels.     

Hemoblastosis and leukemia morbidity in the townsfolk of Seversk and of Siberian group of chemical enterprises personnel

Hemoblastosis and leukemia morbidity has been analyzed in the townsfolk of Seversk (in particular, Seversk residents and Siberian Group of Chemical Enterprises (SGCE) personnel). The standardized relative risk ratios for hemoblastosis morbidity in menes and womens of Seversk were found to be significantly higher in comparison with the regional standard ratios (in 1.8 and 1.5 times correspondingly). Hemoblastosis and leukemia morbidity rate in SGCE males is significantly higher in comparison with the similar regional standard ratios. Leukemia morbidity dependence due to cumulative external gamma-radiation in a dose range up to 1 Sv has not been found in SGCE personnel, without regard to chronic lymphatic leukemia.     

Evidence for SH2 Domain-Containing 5′-Inositol Phosphatase-2 (SHIP2) Contributing to a Lymphatic Dysfunction

The lymphatic vasculature plays a critical role in a number of disease conditions of increasing prevalence, such as autoimmune disorders, obesity, blood vascular diseases, and cancer metastases. Yet, unlike the blood vasculature, the tools available to interrogate the molecular basis of lymphatic dysfunction/disease have been lacking. More recently, investigators have reported that dysregulation of the PI3K pathway is involved in syndromic human diseases that involve abnormal lymphatic vasculatures, but there have been few compelling results that show the direct association of this molecular pathway with lymphatic dysfunction in humans. Using near-infrared fluorescence lymphatic imaging (NIRFLI) to phenotype and next generation sequencing (NGS) for unbiased genetic discovery in a family with non-syndromic lymphatic disease, we discovered a rare, novel mutation in INPPL1 that encodes the protein SHIP2, which is a negative regulator of the PI3K pathway, to be associated with lymphatic dysfunction in the family. In vitro interrogation shows that SHIP2 is directly associated with impairment of normal lymphatic endothelial cell (LEC) behavior and that SHIP2 associates with receptors that are associated in lymphedema, implicating its direct involvement in the lymphatic vasculature.     

Biomarkers of lymphatic function and disease: state of the art and future directions

Substantial advances have accrued over the last decade in the identification of the processes that contribute to lymphatic vascular development in health and disease. Identification of distinct regulatory milestones, from a variety of genetic models, has led to a stepwise chronology of lymphatic development. Several molecular species have been identified as important tissue biomarkers of lymphatic development and function. At present, vascular endothelial growth-factor receptor (VEGFR)-3/VEGF-C/VEGF-D signaling has proven useful in the identification of clinical lymphatic metastatic potential and the assessment of cancer prognosis. Similar biomarkers, to be utilized as surrogates for the assessment of inherited and acquired diseases of the lymphatic circulation, are actively sought, and will represent a signal advance in biomedical investigation.     

Global mapping of lymphatic filariasis

Disease maps are becoming increasingly important in infectious disease epidemiology and control. For lymphatic filariasis, the development of such maps has been hampered in the past by the lack of data on the geographical distribution of levels of infection or disease. Here, Edwin Michael and Don Bundy present an atlas for this parasitic disease derived from a recently compiled geographical database. Focusing on mapping and analysis of case prevalence data at the global and regional levels, the authors show how mapping the geographical distribution is integral not only to assessing spatial patterns in the infection and disease distribution but also to stratifying endemic areas by infection and/or disease rate.     

Groin flap design and versatility

The groin flap is a reliable and well-established reconstructive option for pedicled or free-tissue transfer. Concern regarding its variable vascular origin and caliber has limited its use. To overcome this, a simplified guideline based on the transverse diameter of the patient's index and long fingers at the distal interphalangeal level has been developed. Thus "rule of two finger widths" positions the origin of the vascular pedicle from the femoral vessels two finger widths below the inguinal ligament, the upper flap border two finger widths above the inguinal ligament, the lower flap border two finger widths below the vascular origin, and both parallel to the flap axis, which lies along a line from the vascular origin to the anterosuperior iliac spine. This new groin flap design provides the necessary guidelines for vascular identification, accommodates pediatric and adult stature, and ensures primary donor-site closure if flap dimensions are within the prescribed boundaries. In addition, a new sartorius-cutaneous groin flap is presented. This combines the cutaneous groin flap with the proximal sartorius muscle (up to 15 cm), which is supplied by the deep vessels of the superficial circumflex iliac system. The sartorius-cutaneous groin flap further emphasizes the concept of single-pedicle compound or combined flaps and additionally enhances the extensive reconstructive versatility of previously described groin flaps. Over 200 pedicled and free groin flaps have been performed according to the "rule of two finger widths" over the past 5 years. There have been no complications related to flap design, such as difficulty with flap elevation, marginal necrosis, or donor-site closure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Periorbital lymphatic malformation: clinical course and management in 42 patients

Lymphatic malformation in the orbital cavity and surrounding region often causes disfigurement and visual problems. To better clarify the evolution and treatment of this condition, the authors studied a retrospective cohort of 42 consecutive patients seen between 1971 and 2003 and analyzed anatomic features, complications, and management. The ratio of female to male patients was 1:1. Most periorbital lymphatic malformations were noted at birth (59 percent), presenting as either unilateral swelling (60 percent) or a periorbital mass (24 percent). Sixty-two percent of lesions were on the left side. The ipsilateral cheek, temple, and forehead also were involved in 57 percent of patients. Twenty-two percent of lesions were intraconal, 30 percent were extraconal, and 48 percent were in both spaces. Forty-five percent of children had an associated cerebral developmental venous anomaly. Periorbital lymphatic malformation caused major morbidity; 52 percent of patients had intralesional bleeding and 26 percent of patients had a history of infection. Other common complications included intermittent swelling (76 percent), blepharoptosis (52 percent), proptosis (45 percent), pain (21 percent), amblyopia (33 percent), chemosis (19 percent), astigmatism (17 percent), and strabismus (7 percent). Ultimately, 40 percent of children had diminished vision and 7 percent became blind in the affected eye. Management of periorbital lymphatic malformation involved an interdisciplinary team that included an interventional radiologist, a craniofacial surgeon, and an ophthalmologist. The two therapeutic strategies were sclerotherapy (40 percent) and resection (57 percent); most patients required several interventions. A coronal approach was used for subtotal excision of fronto-temporal-orbital lymphatic malformation in 13 patients, whereas a tarsal incision was used for lesions isolated to the eyelid (n = 14). Ocular proptosis was temporarily managed by tarsorrhaphy (n = 9), but expansion of the bony orbit was needed to correct persistent proptosis (n = 8). Orbital exenteration was necessary in two patients.     

Applications of single nucleotide polymorphisms in crop genetics

The discovery of single nucleotide polymorphisms (SNPs) and insertions/deletions, which are the basis of most differences between alleles, has been simplified by recent developments in sequencing technology. SNP discovery in many crop species, such as corn and soybean, is relatively straightforward because of their high level of intraspecific nucleotide diversity, and the availability of many gene and expressed sequence tag (EST) sequences. For these species, direct readout of SNP haplotypes is possible. Haplotype-based analysis is more informative than analysis based on individual SNPs, and has more power in analyzing association with phenotypes. The elite germplasm of some crops may have been subjected to bottlenecks relatively recently, increasing the amount of linkage disequilibrium (LD) present and facilitating the association of SNP haplotypes at candidate gene loci with phenotypes. Whole-genome scans may help identify genome regions that are associated with interesting phenotypes if sufficient LD is present. Technological improvements make the use of SNP and indel markers attractive for high-throughput use in marker-assisted breeding, EST mapping and the integration of genetic and physical maps.