Transcapillary fluid balance consequences of missing initial lymphatics studied in a mouse model of primary lymphoedema

To investigate the phenotypic consequences of a deranged lymphangiogenesis in relation to tissue fluid accumulation and the possible role of inflammation in the pathogenesis of lymphoedema, we measured determinants of transcapillary fluid filtration and inflammatory mediators in the interstitial fluid in genetically engineered Chy mice, a model for primary congenital lymphoedema (Milroy's disease). Although initial lymphatics were not present in dermis in any of the areas studied (fore paw, hind paw, thigh and back skin) interstitial fluid pressure ( P _if), measured with micropipettes, and tissue fluid volumes were significantly increased only in the areas with visible swelling – the fore and hind paw, whereas interstitial colloid osmotic pressure (COP_if) was increased in all the skin areas examined. A volume load of 15% of body weight resulted in a more pronounced increase in P _if as well as a four-fold increase in interstitial fluid volume in Chy relative to wild-type (wt) mice, showing the quantitative importance of lymphatics for fluid homeostasis during acute perturbations. A similar level of proinflammatory markers in interstitial fluid in early established lymphoedema (3–4 months) in Chy and wt suggests that inflammation does not have a major pathogenetic role for the development of lymphoedema, whereas a reduced level of the immunomodulatory cytokine interleukin (IL)-4 may result in a reduced immunological defence ability and thus lead to the increase in inflammatory cytokines IL-2 and IL-6 observed at a later stage (11–13 months). Our data suggest that primary lymphoedema results in a high interstitial fluid protein concentration that does not induce an interstitial inflammatory reaction per se , and furthermore shows the paramount importance of the initial lymphatics in tissue fluid homeostasis, especially during perturbations of transcapillary fluid balance.     

Small cell lung cancer in Norway. Should more patients have been offered surgical therapy?

OBJECTIVE: The final outcome of patients with small cell lung cancer (SCLC) is poor with an overall 5-year survival rate of less than 10%. Therefore, the question of surgery in patients with a technically-operable solitary tumor has been raised. The purpose of this study was to identify the proportion of patients with operable SCLC and to assess the prognosis of different treatment strategies. For patients who were operated, we compared the resection specimens from patients with more than 5-year survival with those with shorter survival to see whether the specimens belonged to different subclasses of SCLC. METHODS: In Norway all clinical and pathologic departments submit reports on cancer patients to the Cancer Registry. The Registry also has a law-regulated authority to collect supplemental information regarding diagnosis, treatment and outcome for all cancer patients from the hospitals in charge. All reports on patients diagnosed as having SCLC in limited disease or unknown stage during the time interval 1993-1999 were reviewed. Patients with a T2-tumor, in whom a pneumonectomy would have to be performed, were classified as potentially operable. Five-year relative survival was calculated for patients diagnosed in 1993-1997. RESULTS: During the actual period 2442 individuals with SCLC were identified. The majority was treated with conventional chemotherapy or concurrent chemoradiotherapy while 38 underwent surgical therapy. Following reclassification of 697 patients reported to have limited disease or unknown stage 180 were judged to be in stage I. In addition to the 38 resected patients 14 were considered fit for surgery technically and medically while 97 were found to be potentially operable treatment modalities apart from surgery yielded a 5-year survival rate <7%. For stage I (N=96) the rate was 11.3% in conventionally treated patients compared to 44.9% for those who underwent surgical resection. By pathological review of surgical specimens a diagnosis of SCLC was confirmed in all patients treated by surgery in the groups with long and short survival. CONCLUSION: This investigation demonstrates that patients with SCLC having a peripherally located tumor should be referred to surgery, as long time survival is far better than for conventionally treated patients.     

Two great cardiac veins: demonstration by computed tomography, conventional coronary angiography, and during surgery

A 62-year-old man with typical angina pectoris was referredfor imaging of the coronary arteries to detect stenoses. Multislicecomputed tomography (CT) demonstrated significant     

Structure and Function of Plasmid pColD157 of Enterohemorrhagic Escherichia coli O157 and Its Distribution among Strains from Patients with Diarrhea and Hemolytic-Uremic Syndrome

In this study, pColD157, a 6.7-kb colicinogenic plasmid of enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain CL40cu, was characterized by restriction mapping and determination of its complete nucleotide sequence. The sequence consists of 6,675 bp and shows a high degree of similarity to the nucleotide sequence of colicinogenic plasmids pColD-CA23 and pColK. Seven potential genes were located on pColD157, three of which were closely related (>97.9%) to the colicin D structural gene and the corresponding immunity and lysis genes of plasmid pColD-CA23, and these were therefore designated cda, cdi, and cdl, respectively, using the reference extension -CL40 for differentiation. The adjacent 3′ region is related to the origin of replication of pColD-CA23. In contrast, the remaining part of the plasmid harbors a cluster of genes, closely related to the mobilization genes of pColK, which is followed by a 0.3-kb stretch homologous to the pColK resolution function. These determinants were designated mbdA, mbdB, mbdC, and mbdD and cdr, respectively. Southern blot analysis was performed with a probe specific for the cda gene of pColD157 and two groups of EHEC O157:H7 isolates from patients with diarrhea or hemolytic-uremic syndrome resident in Germany. Whereas 16 of 46 E. coli O157 strains isolated between 1987 and 1991 harbored plasmid pColD157, only 1 of 50 strains isolated during 1996 carried this plasmid. In addition, all strains harboring plasmid pColD157 were shown to have colicinogenic activity.     

Elektronenmikroskopische Untersuchungen am embryonalen Mycetom der Kleinzikade Euscelis plebejus Fall. (Homoptera,Cicadina)

Zusammenfassung Die a-Symbionten von Euscelis plebejus treten während der Embryonalentwicklung ihres Wirts in zwei morphologischen Typen auf, die als Infektionsstadium und als vegetative Form beschrieben werden. Die Infektionsstadien teilen sich durch septenartiges Einwachsen der Symbiontenmembranen. Infektionsstadien von Zikadensymbionten waren bisher nur während der Ovarialinfektion aus den Mycetomen weiblicher Imagines bekannt. Die a-Infektionsformen sind gekennzeichnet durch ihr elektronendichtes Cytoplasma, eine ungleichmäßige Verteilung der Ribosomen mit einer ribosomenfreien Randzone und durch Membrankörper. Das Cytoplasma der vegetativen Symbionten erscheint elektronendurch lässiger. Die Ribosomen liegen homogen in der Cytoplasmagrundsubstanz verteilt.Die a-Symbionten liegen vom Zeitpunkt der Eiablage bis zum Eindringen in die a₁-Mycetocyten als Infektionsstadien vor. Nach der Aufnahme in die a₁-Mycetocyten nehmen sie das Aussehen vegetativer Formen an. Im transitorischen Mycetom erscheinen erneut Infektionsstadien während der Übersiedelung in die zweikernigen a₂-Mycetocyten.Jeder Symbiont wird von zwei eigenen Membranen umgeben. Beim Eindringen von Ooplasma in den Symbiontenball wird jeder Symbiont von einer Wirtsmembran umhüllt, die er bis zur Infektion der Wirtszelle behält. In den Mycetocyten umgibt eine offensichtlich vom Wirtscytoplasma erneut gebildete Hüllmembran die vegetativen Symbionten. In den vegetativen a-Symbionten tritt häufig ein mikrofibrillärer kristallartiger Einschlußkörper auf. — Kernäquivalentstrukturen waren in keinem Symbiontenstadium cytologisch mit Sicherheit nachzuweisen.

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Electron microscopic studies on the embryonic mycetome of the leafhopper Euscelis plebejus fall. (Homoptera, cicadina)

Summary During the embryonic development of their host the a-symbiotes of the leafhopper Euscelis plebejus appear in two different morphological types: infective form and vegetative form. The infective forms are able to multiply by ingrowth of their membranes. Until now infective forms of leafhopper symbiotes were only known from the ovarial infection by adult female mycetomes. The infective form of the a-symbiote is characterized by its electron dense cytoplasm, an asymmetric distribution of the ribosomes, a ribosome-free border, and by membraneous bodies. The cytoplasm of the vegetative form is less electron dense and the ribosomes are scattered throughout the cytoplasm.From the time of oviposition until they enter the a₁-mycetocytes, the a-symbiotes are found as the infective form. After entering the a₁-mycetocytes they take on the appearance of the vegetative form. In the transitory mycetome the infective forms appear again during the transition into the binucleate a₂-mycetocytes.Each symbiote is surrounded by two unit membranes of its own. As the ooplasm penetrates the symbiote mass, each symbiote is also surrounded by a host membrane, which remains until the infection of the host cells. In the mycetocytes the vegetative symbiotes have a new membrane around them, which is obviously developed from the cytoplasm of the host cell. In the vegetative a-symbiotes there is frequently a paracrystalline inclusion. — It was impossible to demonstrate nucleoid structure with certainty in any symbiote form.

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Abkürzungen a a-Symbionten - a_i a-Infektionsstadien - a_v vegetative a-Symbionten - a-Mc a-Mycetocyt - a-Z a-Zelle - eK elektronendichter Körper - ER endoplasmat. Retikulum - M₁ innere Symbiontenmembran - M₂ äußere Symbiontenmembran - M₃ Hüllmembran - Mf Mikrofibrillen - Mi Mitochondrien - Mk Membrankörper - Mt Mikrotubuli - Nu Zellkern - Py Kernpyknosen - Ri Ribosomen - Sb Symbiontenball - Sm Symbiontenmembranen - t t-Symbionten - t_v vegetative t-Symbionten - t-Mc t-Mycetocyt - t-Z t-Zelle - Zm Zellmembran Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.Herrn Prof. Dr. K. Sander danke ich für stete Förderung meiner Arbeit und Frau A. Kaufmann für die Einführung in die elektronenmikroskopische Technik.     

The development of goal-directed reaching in infants: hand trajectory formation and joint torque control

Nine young infants were followed longitudinally from 4 to 15 months of age. We recorded early spontaneous movements and reaching movements to a stationary target. Time-position data of the hand (endpoint), shoulder, and elbow were collected using an optoelectronic measurement system (ELITE). We analyzed the endpoint kinematics and the intersegmental dynamics of the shoulder and elbow joint to investigate how changes in proximal torque control determined the development of hand trajectory formation. Two developmental phases of hand trajectory formation were identified: a first phase of rapid improvements between 16 and 24 weeks of age, the time of reaching onset for all infants. During that time period the number of movement units per reach and movement time decreased dramatically. In a second phase (28–64 weeks), a period of fine-tuning of the sensorimotor system, we saw slower, more gradual changes in the endpoint kinematics. The analysis of the underlying intersegmental joint torques revealed the following results: first, the range of muscular and motiondependent torques (relative to body weight) did not change significantly with age. That is, early reaching was not confined by limitations in producing task-adequate levels of muscular torque. Second, improvements in the endpoint kinematics were not accomplished by minimizing amplitude of muscle and reactive torques. Third, the relative timing of muscular and motion-dependent torque peaks showed a systematic development toward an adult timing profile with increasing age. In conclusion, the development toward invariant characteristics of the hand trajectory is mirrored by concurrent changes in the control of joint forces. The acquisition of stable patterns of intersegmental coordination is not achieved by simply regulating force amplitude, but more so by modulating the correct timing of joint force production and by the system's use of reactive forces. Our findings support the view that development of reaching is a process of unsupervised learning with no external or innate teacher prescribing the desired kinematics or kinetics of the movement.