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PubMed1996

Imported vector- and rodent-borne virus infections--an introduction.

Travel is a potent force in the emergence of virus infections. Migration of humans and animals has been the pathway for disseminating virus diseases throughout history. In recent years, dengue virus has been identified as the most important travel-related, vector-borne virus disease. Other vector-borne virus infections, such as sandfly fever, Rift Valley fever, chikungunya fever and Japanese encephalitis, have been diagnosed in travelers returning from endemic areas. Crimean-Congo haemorrhagic fever may not only be imported by infected live stock, but also by travelers. Of rodent-borne virus infections, Lassa fever has been diagnosed occasionally in travelers returning from endemic areas. The potential impact of imported filoviruses is currently discussed.

Animals↗
PubMed1968

Proteins in nucleocytoplasmic interactions. 3. Redistributions of nuclear proteins during and following mitosis in Amoeba proteus.

The behavior of nuclear proteins in Amoeba proteus was studied by tritiated amino acid labeling, nuclear transplantation, and cytoplasmic amputation. During prophase at least 77% (but probably over 95%) of the nuclear proteins is released to the cytoplasm. These same proteins return to the nucleus within the first 3 hr of interphase. When cytoplasm is amputated from an ameba in mitosis (shen the nuclear proteins are in the cytoplasm), the resultant daughter nuclei are depleted in the labeled nuclear proteins. The degree of depletion is less than proportional to the amount of cytoplasm removed because a portion of rapidly migrating protein (a nuclear protein that is normally shuttling between nucleus and cytoplasm and is thus also present in the cytoplasm) which would normally remain in the cytoplasm is taken up by the reconstituting daughter nuclei. Cytoplasmic fragments cut from mitotic cells are enriched in both major classes of nuclear proteins, i.e. rapidly migrating protein and slow turn-over protein. An interphase nucleus implanted into such an enucleated cell acquires from the cytoplasm essentially all of the excess nuclear proteins of both classes. The data indicate that there is a lack of binding sites in the cytoplasm for the rapidly migrating nuclear protein. The quantitative aspects of the distribution of rapidly migrating protein between the nucleus and the cytoplasm indicate that the distribution is governed primarily by factors within the nucleus.

Amoeba↗
PubMed2003

[Acute encephalitis concurrent with primary infection by Schistosoma mansoni].

A 24-year-old man returning from a trip to Mali was hospitalized for acute encephalitis and fever in association with acute primary infection by Schistosomiasis mansoni. Bilharziasis was suspected from the epidemiological context and presence of eosinophilia. Diagnosis was confirmed by serological testing. Specific treatment using praziquantel and corticotherapy was successful. Central nervous system involvement attributable to embolization of eggs or ectopic migration of adult worms has been reported in association with chronic Schistosomiasis by S. japonicum or S. mansoni. There have been few reports of acute neuroschistosomiais during the acute primary phase of infestation by S. mansoni. Etiology probably involves immunoallergic mechanisms.

Adrenal Cortex Hormones↗
PubMed1985

Change in epithelial keratin expression during healing of rabbit corneal wounds.

Corneal epithelial wound healing following full-thickness trephination and transcorneal freeze injury was studied by electron microscopy and immunofluorescent microscopy using monoclonal antibodies AE1, AE2, and AE3 to human epithelial keratin. Wounds were evaluated at various time intervals between 4 hr and 2 mo after injury. By scanning and transmission electron microscopy, epithelial migration was evident 4 hr after injury and was characterized by thinning of the epithelium and extension of filopodial processes. AE1 monoclonal antibody, which stains specifically the superficial cells of normal corneal epithelium, reacted to cells at the leading edge of the migrating epithelium. By 24 hr, all cells migrating over the wound displayed positive fluorescence with AE1 while the epithelium over the undamaged cornea exhibited normal fluorescence limited to the superficial epithelial cells. In full-thickness corneal wounds, reepithelialization was complete by 1-2 wk; however, all epithelial cells covering the wound remained positive for the AE1 antikeratin antibody. By 2 mo, the AE1 fluorescence returned to normal. In transcorneal freeze injuries, reepithelialization was complete by 4 to 7 days after injury, with all cells overlying the wound reacting with the AE1 antibody. By 2 wk after freeze injury, all epithelial cells appeared to express a normal AE1 staining pattern. No change was noted in the fluorescent distribution of either AE2 antibody, which did not react with the corneal epithelium, or AE3, which reacts with all corneal epithelial cells. These results suggest that healing of corneal epithelial wounds involves changes in keratin expression of the corneal epithelium.

Animals↗
PubMed1990

[The serial changes of antibody production, macrophage migration inhibition test (MIT) and histopathologic examination in an experimental hypersensitivity pneumonitis in rabbits].

We developed a hypersensitivity pneumonitis model by sensitizing rabbits intratracheally (IT) twice after two subcutaneous sensitizations (SS), and investigated the serial changes in the production of antibody against micropolyspora faeni (Mf), macrophage migration inhibition test (MIT), and histopathologic features. On the third day after the last IT, the proportions of neutrophils in bronchoalveolar lavage fluid (BALF) increased. The antibody levels of Mf specific-antigen in BALF decreased transiently, but those in serum began to increase. The number of AFC in spleen increased rapidly. Histopathologic examination revealed alveolitis and prominent acute pneumonia. On the seventh day after the last IT, the proportion of lymphocytes in BALF, the antibody levels of Mf specific-antigen in BALF, the number of AFC in BALF, and the percent inhibition of MIT were highest. Histopathologic features were characterized by the formation of prominent epithelioid granulomas. On the fourteenth day after the last IT, these features returned to the state of untreated group. These results indicate that the lesions in this HP model are formed by both type III and type IV immune reactions (Coombs-Gall). It was concluded that the seventh day after the last IT was most appropriate for the study of pathophysiology of human HP.

Actinomycetales↗
PubMed1989

Relaxation effects in the gel electrophoresis of DNA in intermittent fields.

The electrophoretic mobility of restriction fragments of lambda DNA in agarose gels declines if the field is intermittent rather than continuous, with a greater effect on the longer fragments. The changes are compatible with the assumption of two exponential relaxation processes for field-dependent configurational changes, one when the field is turned on and another when it terminates. The length dependence at the extrapolated limit of mobility for short pulses with long intervals corresponds closely to the simple inverse proportionality to length expected from theoretical considerations when the molecular configuration is not affected by the electric field. Simple intermittent fields would allow separation of longer molecules than can ordinarily be resolved. The relaxation times for both the change in conformation imposed by the field and the return to field-free conformation vary as approximately the second power of the length of the molecule, independent of the salt concentration or field strength and varying only slightly with gel density. These relations are not in good agreement with properties expected from reputation theory, and they suggest that a different mechanism must be invoked for the electrophoretic migration of long DNA molecules at ordinary values of field strength.

Bacteriophage lambda↗
PubMed1982

Serum ferritin levels in celiac disease.

Of the various common assayed parameters of iron metabolism, serum ferritin levels are the most discriminatory in distinguishing between non-treated celiac disease and other gastrointestinal disorders in the pediatric age group. Patients on normal diets usually have very low ferritin levels that increase at an average rate of 1 microgram/1/month when placed on a gluten-free diet. When the patient returns to a normal diet, however, ferritin levels decrease rapidly at an average rate of about 4 microgram/1/month. There is a relationship between abnormal intestinal changes and low ferritin levels in celiac disease with improvement in both when the patient is on a gluten-free diet. It is suggested that serial blood ferritin evaluations together with the leukocyte migration inhibition factor production assay should eliminate the need for invasive intestinal biopsies for the confirmation and possible follow-up to response to treatment.

Adolescent↗
PubMedDate not supplied

Female genital tuberculosis: a global review.

Female genital tuberculosis is a symptomless disease inadvertently uncovered during investigation for infertility. The condition is relatively rare and often arises secondary to a primary focus elsewhere. The fallopian tube is the organ most commonly affected. Symptomatic disease usually presents with infertility, pelvic pain or menstrual irregularities. Diagnosis is daunting, even where grounds for suspicion exist. Molecular-based diagnostic methods are likely to play a prominent role in the future. Drug treatment is similar to that of pulmonary tuberculosis, although criteria for assessing the effectiveness of therapy are lacking. Return to fertility after treatment is not encouraging. In-vitro fertilization with embryo transfer remains the most effective method of treating associated infertility. Clinicians need to be aware of the existence of this important cause of infertility in women, in view of the continuing HIV epidemic and the current upsurge in tuberculosis worldwide, as well as the continuing migration of large numbers of women and their families out of areas where tuberculosis is endemic.

Diagnosis, Differential↗
PubMed1993

Melanin repigmentation after gingivectomy: a 5-year clinical and transmission electron microscopic study in humans.

The epithelium-melanin unit is formed by the melanocytes and keratinocytes. There is little information available about the behavior of melanocytes after surgical injury. Five white patients with comparable gingival pigmentation underwent gingivectomy to remove bandlike melanin pigmentations for cosmetic reasons. Biopsy specimens were taken from gingivectomy sites and healing areas 2, 3, 6, 7, 15, 50, and 180 days and 1.5, 3, and 5 years after the procedure. Transmission electron microscopic study revealed melanocytes in the process of migration and undergoing mitosis 6 and 7 days postoperatively. These cells exhibited, in the 15-day specimens, renewal of their dendritic processes and the four different stages of melanosome development. Keratinocytes were devoid of pigmented material until 50 days postoperatively. Clinically, the intensity of the pigmentation varied among the patients. Two reached baseline coloration 1.5 years postsurgery, while three returned to baseline coloration by 3 years postsurgery. Thus, gingival resective procedures, if performed solely for cosmetic reasons, offer no permanent results. (Int J Periodont Rest Dent 1993; 13:85-92.)

Adult↗
PubMed1976

Cell division and tissue repair following localized damage to the mammalian lung.

Small local wounds on the surface of the mouse lung, produced by cauterization, healed by a typical reparative process involving cell migration and increased cell division in alveolar and bronchial tissues. The local cell division response closely resembled the compensatory cell division response in the same organ which follows unilateral pneumonectomy or unilateral collapse of the lung: initially there was an increase in the rate of DNA synthesis followed by an increased rate of entry into mitosis, both of these functions returning to normal levels within a few days. It is therefore suggested that both types of response are governed by a single regulatory mechanism. The results do not support the view that the rate of cell division is regulated by systemically-circulating mitotic control factors and it is proposed that changes in the cell division rate, both in the reparative and in the compensatory types of response, are determined by local alterations in the concentration of regulatory metabolites. The magnitude of the cell division response was much greater in bronchial than in alveolar tissue, a result which is consistent with the view that new alveolar tissue may be produced by the proliferation and diffentiation of bronchial cells.

Animals↗
PubMed1987

Orientation behaviour of toads (Bufo bufo) displaced from the breeding site.

The sensory basis and spatial range of orientation to the breeding site were studied in the toad Bufo bufo, during two breeding seasons. Toads were displaced passively from their breeding pond and fitted with a tracking device to record the path of migration in individuals. The directional choice and the straightness of trails after release were used to quantify the effect of experimental treatments. In both years, control (untreated) toads headed to the breeding site with the same precision at all release sites. The initial orientation of toads blinded by opaque tape over their eyes did not differ from controls, but the return paths were not as direct. The directional choice of anosmic toads was apparently random, however, individuals followed a straight path in a chosen direction. Anosmic toads also blinded were completely disoriented, moving in cycloid trails. Bar magnets glued to the head caused an increase in dispersion of toads. However, in some individual releases a directional bias without increased dispersion was observed. Sky conditions (clear or overcast) did not influence the initial orientation or the dispersion of toads. Nevertheless, the breeding site component was significantly correlated with wind direction in relation to the breeding site. Wind blowing from the breeding site improved the initial orientation, whereas wind from the opposite direction reduced the breeding site component. The spatial range for the ability to relocate the breeding pond after displacement exceeded 3 km, but the time taken to select the correct direction increased with the displacement distance. The results indicate that after displacement the initial orientation of B. bufo is based mainly on olfactory and magnetic cues, with visual control of straightness.

Animals↗
PubMedDate not supplied

The role and interactions of nitric oxide (NO), carbon monoxide (CO), and prostanoids in the pathogenesis of postoperative ileus in rats.

The effects of heme oxygenase (HO) inhibitors, zinc-protoporphyrin-IX (ZnPP-IX), and tin protoporphyrin-IX (SnPP-IX) and their interactions with L-arginine/nitric oxide synthase (NOS) and cyclooxygenase (COX) pathways were investigated in postoperative ileus in rats. Intestinal transit was measured as Evans blue migration after skin incision, laparotomy or laparotomy plus gut evisceration and handling. Laparotomy and small intestinal manipulations increased blood plasma nitrites/nitrates level 1.88-fold. N(omega)-nitro-L-arginine methyl ester, indomethacin, a selective COX-1 blocker (resveratrol) and COX-2 antagonists (nimesulide, DuP-697, NS-398) reversed the additional inhibitory effects of gut manipulation subsequent to laparotomy. In contrast, N-(3-(aminomethyl)benzyl)acetamidine or S-methylisothiourea, highly selective inducible NOS blockers, remained ineffective. ZnPP-IX and SnPP-IX overturned the effects of laparotomy on dye propulsion, but were only partially effective after laparotomy and gut handling attenuating the additional inhibitory influences of gut manipulation, the intestinal transit reaching 89.21%, 92.87%, 53.46%, and 48.56% of respective controls transit. Salutary effects of L-NAME, ZnPP-IX, and SnPP-IX were dose-dependent, L-arginine or hemin (HO substrate) sensitive. Administration of indomethacin and resveratrol subsequent to SnPP-IX reversed the inhibitory effects of laparotomy and manipulation, amounting to 93.91% and 87.43% of controls. On the other hand, L-NAME injected after SnPP-IX abolished the salutary effects of the latter, study dye migration reached 25.18% of control rat. Therefore we demonstrated that nitric oxide, carbon monoxide, and prostanoids play a role in the pathogenesis of postoperative ileus albeit in different mechanisms. Laparotomy stimulated HO activity, whereas gut manipulation led to an excessive constitutive NOS stimulation accompanied by augmented prostanoid synthesis by COX-1. Unaffected synthesis of either NO or CO enables a return of gastrointestinal transit during postoperative period, whereas a pharmacological blockade of two complementary metabolic pathways provides a most effective measure against postoperative ileus development.

Animals↗
PubMed1989

Effects of bovine TSH on the tissue thyroxine level and metamorphosis in prometamorphic flounder larvae.

Bovine thyroid-stimulating hormone (TSH) was microinjected (0.2 microliter/fish) into prometamorphic flounder larvae and the effects on metamorphosis as well as the tissue thyroxine (T4) and triiodothyronine (T3) levels were studied. After a single injection of TSH (5 mIU/g), the tissue T4 concentration increased markedly after 5 hr, reached a peak after 10 hr, and decreased subsequently. T4 concentration after 24 hr was still higher than in saline-injected fish but returned to the control level 48 hr after the injection. On the other hand, tissue T3 concentration was kept lower than the detectable level (0.2 ng/g) throughout the experimental period of 72 hr after a single injection of TSH (5 mIU/g). TSH treatment also accelerated the process of metamorphic climax, such as shortening of the second fin ray and eye migration. These results suggest that an increased secretion of TSH from the pituitary stimulates the thyroid, resulting in a surge of the tissue T4 concentration which induces the climax of the flounder larvae.

Aging↗
PubMed1987

The vasculature of the guinea-pig thymus: topographic studies by light and electron microscopy.

The three-dimensional vascular distribution and the vascular-parenchymal relationship in normal guinea pig thymus were studied by light, scanning and transmission electron microscopy. Interlobular arteries arising from one thymic artery entered the thymic parenchyma where they branched into arterioles and then formed capillary networks in the cortex and in the medulla. Most cortical capillaries drained to the surface via perpendicular venules which merged into the subcapsular veins. Some vessels of the inner cortex, however, returned blood to the postcapillary venules (PCVs) at the cortico-medullary junction and in the medulla. The vascular supply of the guinea pig thymus is thus characterized by a dual circulation in which venous blood drains either via a subcapsular or via a cortico-medullary route. The endothelium of the postcapillary venule (PCV) was flat and often contained migrating lymphocytes. These venules were surrounded by a perivascular space (PVS) which separated the vessel from the parenchyma and which contained many lymphocytes. This PVS was not lined by cells but was delimited on one side by the abluminal surface of the venular endothelium and on the other side by a thin, sheet-like layer formed by cytoplasmic processes of epithelial reticular cells. This epithelial sheet was not continuous, as there were frequent interruptions or gaps where the PVS communicated directly with the intercellular mesh of the thymic parenchyma. The PVS did not form a continuous longitudinal channel but was interrupted by epithelial trabeculae. Some macrophages and a few plasma cells were seen in the parenchyma near the PVS. These findings suggest that the PCV and the PVS in the thymus may function as pathways for the migration of lymphocytes into or out of the blood circulation.

Animals↗
PubMed2003

Chronic exposure to low levels of antigen in the periphery causes reversible functional impairment correlating with changes in CD5 levels in monoclonal CD8 T cells.

This study describes a double-transgenic model in which monoclonal CD8 F5 T cells are chronically exposed to self Ag (nucleoprotein) in the periphery, but are not affected during thymic development. Chronic exposure of CD8 T cells to their cognate Ag rendered them unable to proliferate or produce cytokines in response to antigenic stimulation in vitro. However, the cells still retained some killer function in vivo and continuously eliminated APC expressing high levels of Ag. In addition, when crossed with mice expressing Ag in the anterior pituitary gland (triple-transgenic mice), F5 T cells migrated to this site and killed growth hormone producing somatotrophs. The anergic state was reversible upon transfer into Ag-free recipients, resulting in full recovery of in vitro responsiveness to Ag. Anergic CD8 T cells express higher levels of CD5, a negative regulator of T cell signaling, whereas after transfer and residence in Ag-free hosts, CD5 levels returned to normal. This suggests that up-regulation of negative T cell regulators in peripheral T cells exposed to chronic stimulation by Ag may prevent full functionality and thus avoid overt autoreactivity.

Adoptive Transfer↗
PubMed1986

The treatment of the painful hip in cerebral palsy by total hip replacement or hip arthrodesis.

The painful dislocated or subluxated hip in the patient with cerebral palsy presents a difficult problem in management. Twenty-three patients with cerebral palsy who had a painful subluxated or dislocated hip with degenerative changes were operated on at The Hospital for Special Surgery. Eight patients had a unilateral hip arthrodesis. Six had a successful arthrodesis initially, resulting in relief of pain and return to the preoperative functional level. A pseudarthrosis developed in two patients, but both had successful revision surgery, one by a second arthrodesis and the other by a total hip replacement. Thirteen of the fifteen patients with a total hip replacement were pain-free and functioning at a level consistent with their over-all involvement. One patient had migration of the greater trochanter and slight bending of the femoral component, with persistent pain. A second patient had progressive loosening of the femoral component over a period of seven years, but continued to walk with minimum pain. Two patients had a recurrent dislocation, one requiring revision of the femoral component and the other, of the acetabular component. We think that the presence of cerebral palsy, even in the patient with severe involvement, is not a contraindication for either a hip arthrodesis or a total hip replacement for a painful deformed or degenerated hip. These patients should be treated for the pain in the hip, and the presence of the underlying neuromuscular disorder should not deter the appropriate treatment. For unilateral hip disease in patients who are unable to walk and in young, active patients, we recommend hip fusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Arthroplasty for trapeziometacarpal arthrosis.

We evaluated twenty-eight patients (30 thumbs) after ligament reconstruction arthroplasty for trapeziometacarpal arthrosis. The mean age was 60 years, 86% were women, and the average follow up was 38 months. Subjective results showed excellent (40%) or good (57%) pain relief in 97% of patients. Return to previous work or activity level was achieved in 98%. Overall satisfaction was observed in 86% of patients, mostly because of pain relief. Functional improvement was reported for many activities except for jar opening, which continued postoperatively to be the most difficult task to perform. Thumb mobility improved postoperatively. Key pinch strength showed an overall decrease of 27%. Proximal migration of the thumb metacarpal measured 27% and radial subluxation measured 1%. Thumb metacarpophalangeal joint hyperextension was present in > 50% preoperatively and in 7 of 30 thumbs postoperatively. Hyperextension was prevalent among women on hormone replacement therapy including three patients who had recurrence of these deformities in spite of attempts to stabilize this joint during surgery.

Activities of Daily Living↗