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PubMed1996

The circular migration of Puerto Rican women: towards a gendered explanation.

"The purpose of this paper has been to outline a theoretical framework for the explanation of the circulation of Puerto Rican women that brings gender relations to the fore, but frames the island-mainland pattern of mobility in the context of core-periphery capitalist relations. We have argued that gender relations in the home and workplace are vitally important for understanding women's moves to the [United States] and return trips to Puerto Rico. Specifically, we posited that most Puerto Rican women move as tied-migrants or because of their obligation or desire to meet gender responsibilities. In addition, we also viewed migration as an action with the potential to modify gender relations and alter future migration decision-making, as women gain experience in the labour market and exposure to new social and cultural environments." (SUMMARY IN FRE AND SPA)

Americas↗

PubMed1981

Cell proliferation in response to vitreous hemoglobin.

Rabbits were examined at intervals to 90 days after receiving two or three intravitreal injections, on consecutive days, of homologous hemoglobin or saline. Cell proliferation in the vitreous was assessed by scintillation counting and radioautography after intravitreal administration of 3H-thymidine 4 hr prior to sacrifice. Two populations of vitreous cells phagocytize the vitreous hemoglobin and are stimulated to DNA synthesis. Cells that migrate into the vitreous in response to hemoglobin also contribute to total 3H-thymidine uptake. Tritiated thymidine incorporation peaks between 5 to 10 days and again between 22 to 30 days after the first administration of hemoglobin. By 45 to 60 days after two injections and 90 days after three injections the vitreous cell proliferative activity has returned to normal. It is concluded that a bleeding event which leads to the release of hemoglobin in the vitreous stimulates a minor, transient vitreous cell proliferation and a more significant, but also transient, migration of cells into the vitreous. Aside from contributing by phagocytosis to vitreal clearing, no other functions have been ascribed to these cells.

Animals↗

PubMed1990

Migrated tumour fragments in common bile ducts from hepatocellular carcinoma.

Death from hepatocellular carcinoma (HCC) is often heralded by the appearance of jaundice which is usually the result of extensive parenchymal damage from either progressive cirrhosis or diffuse tumour infiltration. In rare cases, patients with HCC may present with obstructive jaundice caused by migrated tumour fragments in the common bile ducts. We report three such patients. One patient underwent repeated palliative surgical and endoscopic procedures to clear the bile ducts of tumour fragments. He returned to a normal life but finally succumbed to the disease 17 months after diagnosis. Two patients underwent major hepatic resection after initial tube decompression of the obstructed bile ducts. One patient was found to have recurrence of the tumour 17 months after surgery and the other patient was well and disease-free 24 months after surgery. It is important to recognize and treat this group of patients with migrated tumour fragments in the common bile ducts, as good palliation and occasional cure are possible.

Adult↗

PubMed2006

The cytoskeleton in the unique cell reproduction by conidiogenesis of the long-neck yeast Fellomyces (Sterigmatomyces) fuzhouensis.

The morphology of conidiogenesis and associated changes in microtubules, actin distribution and ultrastructure were studied in the basidiomycetous yeast Fellomyces fuzhouensis by phase-contrast, fluorescence, and electron microscopy. The interphase cell showed a central nucleus with randomly distributed bundles of microtubules and actin, and actin patches in the cortex. The conidiogenous mother cell developed a slender projection, or stalk, that contained cytoplasmic microtubules and actin cables stretched parallel to the longitudinal axis and actin patches accumulated in the tip. The conidium was produced on this stalk. It contained dispersed cytoplasmic microtubules, actin cables, and patches concentrated in the cortex. Before mitosis, the nucleus migrated through the stalk into the conidium and cytoplasmic microtubules were replaced by a spindle. Mitosis started in the conidium, and one daughter nucleus then returned to the mother via an eccentrically elongated spindle. The cytoplasmic microtubules reappeared after mitosis. A strong fluorescence indicating accumulated actin appeared at the base of the conidium, where the cytoplasm cleaved eccentrically. Actin patches then moved from the stalk together with the retracting cytoplasm to the mother and conidium. No septum was detected in the long neck by electron microscopy, only a small amount of fine "wall material" between the conidium and mother cell. Both cells developed a new wall layer, separating them from the empty neck. The mature conidium disconnected from the empty neck at the end-break, which remained on the mother as a tubular outgrowth. Asexual reproduction by conidiogenesis in the long-neck yeast F. fuzhouensis has unique features distinguishing it from known asexual forms of reproduction in the budding and fission yeasts. Fellomyces fuzhouensis develops a unique long and narrow neck during conidiogenesis, through which the nucleus must migrate into the conidium for eccentric mitosis. This is followed by eccentric cytokinesis. We found neither an actin cytokinetic ring nor a septum in the long neck, from which cytoplasm retracted back to mother cell after cytokinesis. Both the conidium and mother were separated from the empty neck by the development of a new lateral wall (initiated as a wall plug). The cytoskeleton is clearly involved in all these processes.

Actins↗

PubMed2002

Small bowel motility and transit after aortic surgery.

OBJECTIVE: The inability to tolerate feedings after aortic surgery prolongs hospitalization. The aim of this study was to define jejunal manometric and small bowel transit characteristics associated with the ileus that follows transperitoneal aortic surgery. METHODS: Five male patients who underwent transperitoneal infrarenal aortobifemoral bypass had intraoperative placement of a jejunal multilumen catheter. The open abdomen allowed precise placement of pressure recording ports at 20, 22, 24, 26, 28, and 38 cm past the ligament of Treitz. Three-hour manometric studies were done after surgery and for 3 postoperative days. The migrating motor complex was identified visually on the manometric tracings, and pressure waves were identified with computer and a motility index calculated. Motility data were compared with healthy control data previously reported in the literature. Small bowel transit was determined with barium and serial abdominal radiographs. RESULTS: All patients had ileus develop with return of bowel sounds at 2 to 7 days (median, 6 days) and flatus at 3 to 9 days (median, 7 days) after surgery. Jejunal motor activity was present within 6 hours of surgery, but the motility index was less in patients then in control subjects. The postoperative migrating motor complexes differed from control subjects in having more phase I, less phase II, and more frequent phase IIIs. Phase III retrograde migration was common in the patients but not in the control subjects. Small bowel transit was 2 days or greater in all patients. CONCLUSION: Motor activity is present in the jejunum shortly after aortic surgery. However, the activity is decreased in intensity and the fasting cycle differs from control subjects. Retrograde migration of phase III is the most likely abnormality, resulting in delayed small bowel transit. The data would predict a high rate of enteral feeding intolerance early after surgery. Future studies should focus on pharmacologic manipulation to rapidly return small bowel motility to a more normal state after aortic surgery.

Aged↗

PubMed1980

Neutrophil chemotaxis and random migration in acute lymphoblastic leukaemia of childhood. Cellular and humoral aspects.

The cellular and humoral components of the neutrophil chemotactic response were studied in 65 children with acute lymphoblastic leukaemia (ALL). An abnormality in both components was found during relapse. In remission the cellular component only was affected. Although less obvious than during relapse the abnormality persisted while all cytotoxic therapy was given, returning to normal several weeks after treatment had been stopped. The absence of significant infection in relapse in this series could be due to the fact that a remisison was achieved within 3 weeks in all patients. However, a positive correlation between the migration index and incidence of bacterial infection during remission stressed the importance of impaired neutrophil chemotaxis in ALL.

Bacterial Infections↗

PubMed2001

Late complications of collapse therapy for pulmonary tuberculosis.

STUDY OBJECTIVES: Collapse therapy for pulmonary tuberculosis involved placement of various materials to occupy space and keep the lung collapsed. Complications are encountered decades later. PATIENTS AND METHODS: Between 1980 and 1997, we treated 31 patients with a history of pulmonary tuberculosis in whom collapse therapy had been used and who later developed complications related to their treatment. Pyogenic empyema was present in 24 patients, pleural calcifications with bronchopleural fistula was present in 3 patients, pleural calcification with nonresolvable pneumothorax was present in 1 patient, and migration of a foreign body with formation of subcutaneous mass occurred in 3 patients. All patients with empyema were treated with antibiotics and tube drainage of pus. In addition, Lucite balls were extracted in 4 patients, lung decortication was performed in 6 patients, thoracoplasty was performed in 2 patients, and fenestration was performed in 16 patients. Bronchopleural fistulas were closed with sutures and reinforced with intercostal muscle flap in three patients; in one patient with pleural calcification and nonresolvable pneumothorax, tube drainage was attempted. In three patients with subcutaneous mass due to paraffin migration, paraffin was extracted. RESULTS: Pulmonary decortication (six patients) and thoracoplasty (two patients) resulted in elimination of empyema. Extraction of Lucite balls resulted in lung expansion and elimination of empyema in three of four patients; draining sinus remains in one patient. Fenestration resulted in elimination of empyema in 12 of 16 patients, with 3 patients with residual draining sinuses and 1 patient with remaining empyema. All bronchopleural fistulas closed with intercostal muscle flap remained closed. Following extraction of paraffin blocks, infection developed in one patient. During the follow-up period, three patients died, all of unrelated causes. CONCLUSIONS: Delayed complications of collapse therapy for tuberculosis should be treated without delay. Pressure on adjacent structures or their erosion presents danger and mandates immediate extraction; however, there is no need for routine removal of every residual plombe. Further increase in the number of multiple-drug resistant strains may force the return of collapse therapy.

Adult↗

PubMed1998

Expression and distribution of adhesion molecule CD44 in healing corneal epithelia.

PURPOSE: To study isoform expression and cellular distribution of CD44, a cell surface glycoprotein thought to be an adhesion molecule in cell-cell and cell-substratum interactions, during corneal epithelial wound healing. METHODS: Reverse transcription-polymerase chain reaction was performed to determine alternatively spliced rat CD44 isoforms. In situ hybridization was carried out on frozen sections of the rat corneas obtained at different time points after epithelial debridement. 35S-Labeled sense and antisense cRNA that recognizes rat CD44 standard form was used as a probe. Immunofluorescence was used to assess expression and localization of CD44 in the rat corneas during reepithelialization. RESULTS: Corneal epithelia contained several alternatively spliced CD44 variants. Four large CD44 variants with inserts V1 through V10, V2 through V10, V3 through V10, and V4 through V10 were differentially expressed in migratory epithelia. The silver grains, indicating CD44 transcripts, started to increase in the epithelial cells surrounding the wound margin 3 hours after wounding and peaked at 18 hours in the basal epithelial cell layers, at which time the epithelia were actively migrating. As the cells began proliferation after wounding, the density of CD44 mRNA label declined but was still significantly higher than that in control specimens. The label returned to basal level as epithelial cells reverted to their normal phenotype. The location of CD44 on cell surfaces during corneal reepithelialization was consistent with the pattern of mRNA production. In the corneas at 18 hours after wounding, CD44 immunoreactivity was elevated in the entire epithelium, from the leading edge to the limbal-corneal border. As happened for the mRNA, the cell surface CD44 declined as cells differentiated to reestablish the multilayered epithelium. CONCLUSIONS: The expression of CD44 correlates with corneal reepithelialization, suggesting that CD44 may be involved in cell-cell interactions that provide adhesive strength for the much-stressed epithelial sheet and in the cell-substratum interactions that mediate cell migration during reepithelialization.

Alternative Splicing↗

PubMed1987

Loss of microtubules and alteration of glycoprotein migration in organ cultures of mouse intestine exposed to nocodazole or colchicine.

Explants from mouse jejunum were cultured for 3-7 h in the absence (control) or presence of colchicine (100 micrograms/ml) or nocodazole (10 micrograms/ml). In recovery experiments, explants were cultured in fresh medium for an additional period. To label glycoproteins, 3H-fucose was added during the last 3 or 6 h of the initial culture or recovery period. Subcellular fractionation studies revealed that colchicine and nocodazole inhibited migration of labelled glycoproteins to the brush border (P2) by 40-45%. Radioautographic studies of absorptive cells showed that colchicine and nocodazole inhibited labelling of the microvillous border by 67% and 87%, while labelling of the basolateral plasma membrane increased by 114% and 275%. Immunocytochemical studies revealed that both colchicine and nocodazole caused the virtual disappearance of the microtubular network in the absorptive cells. It is possible that some glycoproteins normally destined for the microvillous border are rerouted to the basolateral membrane. The observed loss of microtubules after drug treatment suggests that microtubules may play a role in the intracellular migration of membrane glycoproteins. Additional support for this concept is provided by the fact that in recovery experiments the distribution of label returned to control values after the microtubular network became re-established.

Animals↗

PubMed2002

Changes in gastrointestinal motility after subtotal colectomy in dogs.

PURPOSE: This study was conducted to examine recovery from diarrhea after subtotal colectomy by observing changes in gastrointestinal motility, neuropeptides, and autonomic nerves in the enteric nervous system in dogs. METHODS: The moisture volume of intestinal matter recovered from the ileal side of the anastomosis was defined as the diarrhea index. Gastrointestinal motility was measured using strain gauge force transducers (SG) for 24 weeks after subtotal colectomy. Immunohistochemical changes in neuropeptides in the residual intestine, acetylcholinesterase activation of cholinergic fibers, and fluorohistochemical changes of adrenergic fibers in the myenteric plexuses were evaluated. RESULTS: The digestive tract transit time returned to normal in the early postoperative period, but decreased moisture volume was seen in the intestinal matter after 8 postoperative weeks. Migrating contraction waves propagating beyond the site of anastomosis, signaling recovery of intestinal motility, were noted after 8 postoperative weeks, corresponding to reconstruction of cholinergic fibers in the anastomotic section. Transient activation of vasoactive intestinal polypeptide was seen in the residual intestine, but this had normalized by the eighth postoperative week. Lengthened villi in the residual intestine were also seen after 8 postoperative weeks. CONCLUSION: The decreased moisture volume in the intestinal matter is due to the improvements we observed in the eighth postoperative week.

Acetylcholinesterase↗

PubMed1986

Contralateral amaurosis after retrobulbar injection.

Contralateral amaurosis after retrobulbar injection of local anesthetic agents occurred in two patients, a 64-year-old woman and a 57-year-old man. The amaurosis resulted from migration of the anesthetic agents to the optic chiasm and contralateral optic nerve via the subarachnoid space. In both cases visual acuity returned to preoperative levels within 90 minutes. A modified technique in which patients look straight ahead or slightly downward and outward during retrobulbar injection, as opposed to the traditional upward and inward positioning of the globe, avoids inadvertent piercing of the sheaths of the optic nerve and injection of substances into the subarachnoid space.

Akathisia, Drug-Induced↗

PubMed1997

Amyloid precursor protein heat shock response in lymphoblastoid cell lines bearing presenilin-1 mutations.

The amyloid precursor protein (APP) gene promoter contains a heat shock element. An abnormal APP heat shock response could increase accumulation of A beta, the APP metabolite found in Alzheimer's disease amyloid plaques. Since A beta production is affected by presenilin-1 (PS-1) mutations, we investigated whether basal APP levels or response to heat shock were altered in lymphoblastoid cell lines from 8 PS-1 mutation-bearers and 9 control members of Alzheimer's disease families. Lymphoblastoid cell lines were incubated at 42 degrees C for 35 min and allowed to recover at 37 degrees C for 1, 3, 8, 24 and 48 h. APP mRNA levels, quantified using RNA-RNA solution hybridisation, increased significantly at 1 and 3 h post-heat shock to between 123% and 163% of pre-heat shock (0 h) levels and returned to normal by 8 h. Semi-quantitative Western immunoblotting of cell lysates using the 22C11 antibody detected two major bands, migrating at approximately 145 and approximately 120 kDa. Band optical densities increased significantly at 3 h to approximately 155% of 0 h levels, following the increase in APP mRNA levels and showing a similar reversibility. APP mRNA and protein responses were comparable in the PS-1 mutation-bearing and control cell lines. This study shows that both APP mRNA and protein are induced in lymphoblastoid cell lines following heat shock and that this response is not affected by PS-1 mutations which are pathogenic for Alzheimer's disease.

Alzheimer Disease↗

PubMed1998

Aberrant integrin (CR4; alpha(x)beta2; CD11c/CD18) oscillations on neutrophils in a mild form of pyoderma gangrenosum.

We have previously shown that the beta2 integrins CR3 and CR4 physically and functionally interact with urokinase receptors (uPAR) on neutrophil plasma membranes in an oscillatory fashion. In this study we have analyzed neutrophils from patient SC, a 34 y old African American female, with aberrant skin window results and recurrent perianal abscesses and pretibial lesions diagnosed as pyoderma gangrenosum. Although untreated migrating normal neutrophils exhibited 20 s sinusoidal oscillations in CR4-uPAR proximity, neutrophils from SC demonstrated a faster oscillation (10 s) in the form of a flyback sawtooth wave. This waveform mimicked that observed for normal neutrophils treated with subsaturating doses of the kinase inhibitors staurosporine, genistein, and erbstatin. As beta2 integrins are regulated by phosphorylation, we tested the hypothesis that the aberrant CR4-uPAR proximity oscillations seen in SC's neutrophils are due to defective kinase activity that might be balanced by a decrease in phosphatase activity. When SC's cells are exposed to subsaturating concentrations of the phosphatase inhibitor pervanadate, this caused the CR4-uPAR oscillations to become sinusoidal in shape with a 20 s period, as seen in normal migrating neutrophils. Although SC's neutrophils were deficient in spontaneous and N-formyl-methionyl-leucyl-phenylalanine-induced polarization, 0.5 microM pervanadate returned cell polarization to nearly normal levels, thus paralleling the acquisition of normal receptor interactions. Inasmuch as SC's cellular phenotype is mimicked by kinase inhibitors and corrected by phosphatase inhibitors, we suggest that a mutation(s) affecting the kinetics of intracellular signaling enzymes, but not blocking the pathway per se, may be responsible for this clinical state.

Adult↗

PubMed2001

Identification of the nucleocytoplasmic shuttling sequence of heterogeneous nuclear ribonucleoprotein D-like protein JKTBP and its interaction with mRNA.

JKTBP proteins are related to a family of heterogeneous nuclear ribonucleoproteins (hnRNPs) that function in mRNA biogenesis and mRNA metabolism. JKTBP proteins constituted of isoforms 1, 2, and 1Delta6 are localized in the nucleus. We show that the dominant form JKTBP1 shuttles between the nucleus and the cytoplasm and interacts with mRNA. Immunofluorescence microscopy and immunoblotting of the subcellular fractions and overexpression of JKTBP tagged with green fluorescent protein indicated that JKTBP1 and JKTBP1Delta6, but not JKTBP2, accumulate in the cytoplasm upon polymerase II transcription inhibition. After release from inhibition, the return of accumulated cytoplasmic JKTBP to the nucleus was temperature-dependent. In heterokaryons, green fluorescent protein-tagged JKTBP1 and JKTBP1Delta6 migrated from the HeLa nucleus to the mouse nucleus, but JKTBP2 did not. Using various JKTBP deletion mutants, the 25-residue C-terminal tail was identified as a shuttling sequence like M9. It is conserved in the C-terminal tails of hnRNP D/AUF1 and type A/B hnRNP/ABBP-1. Analysis of its sequence-specific interacting protein indicated that JKTBP nuclear import is mediated by the receptor transportin 1/karyopherin beta2. UV cross-linking revealed the increased occurrence of JKTBP1 directly interacting with poly(A)(+) RNA in the cytoplasm following actinomycin D treatment. We discuss a role of JKTBP in mRNA nuclear export.

3T3 Cells↗

PubMed1987

Pigment change and melanocyte distribution in guinea pig skin after cutaneous freeze injury.

Cryosurgery has been recommended for the treatment of cutaneous neoplasms, including benign and malignant melanocytic tumors. The main side effect of this treatment is pigment disruption which may be prolonged. There are no quantitative studies on melanocyte distribution after freeze injury. In this study the effect of standardized freeze times on melanocytes in guinea pig skin (tricolored) is described at the anatomic level and at the light and electron microscopic level. Melanocytes are quantified in epidermal sheets following dopa staining at 1-, 2-, and 3-month intervals after freezing. All the lesions were initially hypopigmented with a peripheral rim of hyperpigmentation. This was a transient phenomenon associated with an absence of melanocytes. Pigment migrated into the lesions so that after 3 months all the lesions on black skin were diffusely hyperpigmented. Pigment was slower to return to the red skin. Hair follicles were destroyed in the center of the lesion. The epidermal sheets demonstrated that the hyperpigmentation was an epidermal phenomenon and was associated with increased numbers of melanocytes (p less than 0.001). These melanocytes were distributed evenly throughout the lesion in contrast to the irregular distribution in normal skin.

Animals↗

PubMed1987

Isosteric conversion of protein carboxyl groups into carboxamide groups. II. Application to lysozyme.

For isosteric conversion of carboxyl groups of proteins into amide groups, ammonolysis of protein esters under mild conditions was attempted. Ammonolysis of methyl esters of lysozyme and bovine serum albumin proved to be incomplete. Highly reactive N-ethylsalicylamide esters of guanylated lysozyme were therefore prepared by subjecting the protein to reaction with N-ethylbenzisoxazolium ion at pH 4.2, 0 degree. Per molecule, 5-7 ester groups were introduced, with concomitant decrease of activity of 80-90%. Only 0.3 tyrosine was modified. On hydrolysis at pH 9.2 the activity was completely restored. At pH 7.9 three classes of ester groups could be distinguished: one group of high rate of hydrolysis (k1 = 1.5 min-1), three groups of intermediate rate (k2 = 0.13 min-1) and two groups of low rate (k3 = 0.018 min-1). The intermediate rate approximated the rate of hydrolysis of the model compound benzoylglycine N-ethylsalicylamide ester (k = 0.15 min-1). Ammonolysis at pH 9.2 in 2.0 M ammonia/ammonium acetate provided complete conversion of the ester groups into amide groups without restoration of activity, confirming the essentiality of certain carboxyl groups. In particular, rearrangement of the ester groups into relatively stable imide groups by O-N acyl migration was found to be completely absent. When native lysozyme was esterified with N-ethylbenzisoxazolium ion the activity did not completely return on hydrolysis.

Acetates↗

PubMed2002

Structural dynamics of myoglobin: ligand migration among protein cavities studied by Fourier transform infrared/temperature derivative spectroscopy.

Fourier transform infrared (FTIR) spectroscopy in the CO stretch bands combined with temperature derivative spectroscopy (TDS) was used to characterize intermediate states obtained by photolysis of two sperm whale mutant myoglobins, YQR (L29(B10)Y, H64(E7)Q, T67(E10)R) and YQRF (with an additional I107(G8)F replacement). Both mutants assume two different bound-state conformations, A(0) and A(3), which can be distinguished by their different CO bands near 1965 and 1933 cm(-1). They most likely originate from different conformations of the Gln-64 side chain. Within each A substate, a number of photoproduct states have been characterized on the basis of the temperature dependence of recombination in TDS experiments. Different locations and orientations of the ligand within the protein can be distinguished by the infrared spectra of the photolyzed CO. Recombination from the primary docking site, B, near the heme dominates below 50 K. Above 60 K, ligand rebinding occurs predominantly from a secondary docking site, C', in which the CO is trapped in the Xe4 cavity on the distal side, as shown by crystallography of photolyzed YQR and L29W myoglobin CO. Another kinetic state (C") has been identified from which rebinding occurs around 130 K. Moreover, a population appearing above the solvent glass transition at approximately 180 K (D state) is assigned to rebinding from the Xe1 cavity, as suggested by the photoproduct structure of the L29W sperm whale myoglobin mutant. For both the YQR and YQRF mutants, rebinding from the B sites near the heme differs for the two A substates, supporting the view that the return of the ligand from the C', C", and D states is not governed by the recombination barrier at the heme iron but rather by migration to the active site. Comparison of YQR and YQRF shows that access to the Xe4 site (C') is severely restricted by introduction of the bulky Phe side chain at position 107.

Animals↗

PubMed1994

Changing western German internal migration systems during the second half of the 1980s.

"This study has two purposes. First, we will analyze in detail the extent to which regional demographic changes during the second half of the 1980s represent a return to concentration in western Germany.... The second purpose of this paper will be to measure regional demographic impacts in western Germany as the result of the large East to West movement of population that occurred before formal unification...." The results indicate that "the slow downward trend toward greater spatial deconcentration in West Germany during the time period 1970 to 1984 shifted back toward concentration from 1985 and through 1988." This involved both labor market changes affecting primarily the population aged 25-49, and greater concentrations of population in densely populated regions such as the Ruhr-Rhine and Saarland.

Demography↗