Limited behavioural thermoregulation by adult upriver-migrating sockeye salmon (Oncorhynchus nerka) in the Lower Fraser River, British Columbia

The objective of this study was to combine radio telemetry with individual thermal loggers to assess the extent to which adult migrating sockeye salmon ( Oncorhynchus nerka (Walbaum in Artedi, 1792)) behaviourally thermoregulate during their migration through the Fraser River mainstem, British Columbia. The Fraser mainstem represents a region of the migration route that contains some of the highest mean temperatures encountered by sockeye salmon during their life history. We found that throughout the study area, individual sockeye salmon body temperatures occasionally deviated from ambient temperatures (ΔT), yet individuals maintained a ΔT of –1 °C or cooler for only 5% of their migration through the study region. There were moderate mean deviations of ΔT in two segments that are known to contain thermally stratified waters. In one of the study segments with the greatest ΔT, mean body temperatures decreased as river temperatures increased and ΔT became increasingly positive with higher river discharge rates, but these relationships were not observed in any of the other study segments. No relationship existed between ΔT and migration rate. While periodic associations with cool water were evident, mean body temperatures were not significantly different than mean river temperatures throughout the lower Fraser mainstem. This finding raises further conservation concerns for vulnerable Fraser River sockeye stocks that are predicted to encounter increasing peak summer river temperatures in the coming decades.

Speech, language, and cognition in preschool children with epilepsy

We studied expressive and receptive language, oral motor ability, attention, memory, and intelligence in 20 6-year-old children with epilepsy (14 females, six males; mean age 6y 5mo, range 6y-6y 11mo) without learning disability, cerebral palsy (CP), and/or autism, and in 30 reference children without epilepsy (18 females, 12 males; mean age 6y 5mo, range 6y-6y 11mo). Ten children had partial, six primarily generalized, and four unclassified epilepsy. Fourteen were having monotherapy and six were taking two or more antiepileptic drugs; 13 children were free from seizures 3 months before the assessment. Results show no statistically significant difference between the groups concerning Verbal IQ, expressive and receptive grammar, and receptive vocabulary. The children with epilepsy had a significantly lower Performance IQ and lower scores in tests of oral motor ability, articulation, emerging literacy, auditory attention, short-term memory, and rapid word retrieval. Parent ratings revealed no significant difference in communicative ability. Polytherapy and early onset of epilepsy influenced some results. Preschool children with epilepsy without learning disability, CP, and/or autism may have receptive verbal ability within the normal range but visuoperceptual, auditory attentional, and speech-language difficulties that could affect school achievement. Careful testing of children with epilepsy who appear to be functioning within the normal range is needed because this may reveal specific impairments that require appropriate professional input.

Estimation of renal function in children and adolescents with spinal dysraphism

PURPOSE

In children with spinal dysraphism such as myelomeningocele the relation between muscle mass and body composition varies considerably. Therefore, it is difficult to evaluate the relevance of renal function assessments done with serum creatinine. Since serum cystatin C has been suggested to be independent of body size and composition, this evaluation was compared to chromium(51) edetic acid clearance.

MATERIALS AND METHODS

Simultaneous measurements of cystatin C and chromium(51) edetic acid clearance were performed prospectively in 65 patients 2 to 19 years old with spinal dysraphism.

RESULTS

Cystatin C values were within the normal range in all patients, while chromium(51) edetic acid clearance was reduced in 10. A significant relation was seen.

CONCLUSIONS

Using chromium(51) edetic acid clearance as a gold standard, children with spinal dysraphism and slightly to moderately reduced renal function may remain undiagnosed if cystatin C is used for evaluation.

Complications of Clean Intermittent Catheterization in Young Females With Myelomeningocele: 10 to 19 Years of Followup

PURPOSE

We evaluated the rate of complications associated with catheterization and the risk of urethral lesions in girls with myelomeningocele treated with clean intermittent catheterization for a minimum of 10 years.

MATERIALS AND METHODS

We examined the medical records of 31 females with myelomeningocele followed from the start of clean intermittent catheterization until age 11 to 20 years. Catheterization had been performed for a median of 15 years (range 10 to 19). Altogether, catheterization was used for a total of 459 patient-years. Noncoated polyvinyl chloride catheters were used in all cases. Anticholinergic treatment was given during 176 of the patient-years.

RESULTS

Complications of catheterization were recorded in 13 patients on 20 occasions. Macroscopic hematuria was seen in 4 individuals. In 2 patients the hematuria was caused by urethral polyps that were cured by resection. Difficulties with catheterization occurred in 12 patients. The problems were solved by temporary use of lubrication or by other minor changes in management. There were no difficulties recorded after puberty. The risk of difficulties at catheterization doubled with the use of a Ch8 to Ch10 catheter compared to a Ch12 or larger catheter, and doubled during assisted clean intermittent catheterization compared to clean intermittent self-catheterization.

CONCLUSIONS

There were remarkably few problems associated with clean intermittent catheterization in these females with myelomeningocele, despite long treatment periods and use of noncoated polyvinyl chloride catheters. Clean intermittent self-catheterization and large size catheters were associated with few complications.

Medical problems in adolescents with myelomeningocele (MMC): an inventory of the Swedish MMC population born during 1986-1989

AIM

To describe the prevalence of myelomeningocele (MMC) and the medical needs of adolescents, 15-18 years, with MMC in Sweden, at a time when they are on the threshold of adulthood, leaving paediatrics.

METHODS

In a retrospective study, we identified all adolescents with MMC, born during 1986-1989 and living in Sweden on July 1, 2004. An inventory was agreed upon with questions concerning their medical problems and need for medical care.

RESULTS

There were 175 persons 15-18 years of age, born with MMC or lipoMMC (prevalence 3.8 per 10,000). Hydrocephalus was seen in 86%, 31% had been operated because of tethered cord syndrome, and 6% for Chiari malformation symptoms. The majority had motor impairments. Clean intermittent catheterisation for bladder emptying was used by 85%, and 59% used enemas on a regular basis because of the neurogenic bowel dysfunction. Renal dysfunction was seen in 1.7% of the adolescents.

CONCLUSION

Lifelong follow-up by many specialists, among others neurologists and neurosurgeons, urotherapists and urologists, orthopaedic surgeons and orthotists, is necessary for individuals with MMC. The complex medical situation, often in combination with cognitive difficulties, makes it necessary to coordinate medical services for this increasing group of adults with multiple impairments.

COMPLICATIONS OF CLEAN INTERMITTENT CATHETERIZATION IN BOYS AND YOUNG MALES WITH NEUROGENIC BLADDER DYSFUNCTION

PURPOSE

We evaluate the risk for urethral lesions and epididymitis in boys with neurogenic bladder dysfunction treated by clean intermittent catheterization (CIC) for a minimum of 10 years.

MATERIALS AND METHODS

The medical records of 28 males with neurogenic bladder dysfunction followed from the start of CIC until the age of 15 to 20 years were reviewed.

RESULTS

CIC had been performed for a median of 16 years (range 10 to 21). Overall CIC was used for 438 years (265 before and 173 after puberty). During 76% of the years a noncoated polyvinyl chloride catheter with lubrication was used and in 24% of years a hydrophilic coated polyvinyl chloride catheter was used. The catheter size was 12C or greater in 43% of the cases. Independence from self-catheterization occurred during 37% of the CIC years. Of the patients 19 experienced at least 1 episode of difficulty inserting the catheter and/or had macroscopic hematuria on a total of 42 occasions. Major urethral lesions were seen on cystoscopy in 7 patients on 9 occasions (5 false passages, 1 superficial recess, 2 meatal stenoses, 1 urethral stricture). Major urethral lesions were not associated with puberty and did not occur during self-catheterization or with use of catheters 12C or greater. Epididymitis was seen in only a 12 year-old boy.

CONCLUSIONS

The overall rate of complications was low. The incidence of major urethral lesions did not increase during puberty. Self-catheterization and 12C catheter or greater seemed to be protective against major lesions.

Sorting for storage in myeloid cells of nonmyeloid proteins and chimeras with the propeptide of myeloperoxidase precursor

During formation of polymorphonuclear neutrophils, proteins are synthesized for storage in granules. Whereas sorting of proteins into distinct subtypes of cytoplasmic granules may reflect the coordinated expression of the proteins contained in them, still the mechanism(s) for the retrieval of proteins from the constitutive secretion is unknown. To investigate the mechanisms of retrieval, nonmyeloid secretory proteins were expressed in myeloid cell lines, and their subcellular fate was assessed. The contribution of the propeptide (MPOpro) of the myeloperoxidase (MPO) precursor was investigated by determining the fate of chimeras containing MPOpro. The nonmyeloid protein alpha(1)-microglobulin (alpha(1)-m) was targeted to storage organelles in 32D cells and colocalized with the lysosomal marker LAMP-1, whereas soluble TNF receptor 1 (sTNFR1) was secreted without granule targeting. Fusion of MPOpro to alpha(1)-m delayed exit from endoplasmic reticulum (ER), but subsequent targeting to dense organelles was indistinguishable from that of alpha(1)-m alone. Fusion proteins between MPOpro and sTNFR1 or green fluorescent protein expressed in myeloid 32D, K562, or PLB-985 cells did not associate stably with calreticulin or calnexin, molecular chaperones that normally interact transiently with the MPO precursor, but were still efficiently retained in the ER followed by degradation. We conclude that normally secreted, nonmyeloid proteins can be targeted efficiently to storage organelles in myeloid cells, that myeloid cells selectively target some proteins for storage but not others, and that MPOpro may contribute to the prolonged ER retention of the MPO precursor independent of the ER-molecular chaperones calreticulin and calnexin.

Forced expression of the cyclin-dependent kinase inhibitor p16(INK4A) in leukemic U-937 cells reveals dissociation between cell cycle and differentiation

OBJECTIVE

The aim of this study was to investigate how the tumor suppressor protein p16(INK4A) interferes with growth and differentiation of leukemic U-937 cells.

MATERIALS AND METHODS

U-937 clones constantly overexpressing the cyclin-dependent kinase inhibitor p16(INK4A) were established. Clones transfected with empty vector were used as controls. The effects of high-level expression of p16(INK4A) on proliferation and cell cycle progression were investigated (cell cycle distribution, proliferation rate, analyses of different cell cycle regulatory proteins). The effect of introduction of p16(INK4A) on capacity for induced differentiation, assayed by capacity to reduce nitroblue tetrazolium, was determined.

RESULTS

Overexpressed p16(INK4A) protein was active as judged by its ability to bind to CDK-4 in a coimmunoprecipitation assay. Clones overexpressing p16(INK4A) grew slower than controls, without any apparent effects on the phosphorylation status of the retinoblastoma protein (pRb). Instead, p16(INK4A) overexpression affected the phosphorylation status of pRb-related pocket protein p130, which was detected in its growth-restraining hypophosphorylated form. Despite an enhanced tendency to accumulate in G(0)/G(1), p16(INK4A)-overexpressing cells were less sensitive to induction of differentiation with vitamin D(3) or ATRA than control cells.

CONCLUSIONS

Constitutive expression of p16(INK4A) in U-937 cells resulted in decreased proliferation as a result of activated p130 rather than pRb. Also, we showed that introduction of p16(INK4A) into U-937 cells impaired their capacity to differentiate. Moreover, the results support the notion that cell differentiation and cell cycle progression are dissociated and independently regulated processes.

Detection by flow cytometry of antibodies against surface and intracellular granulocyte antigens

A flow cytometric technique was used to detect granulocyte antibodies, with attention to the distinction between antibodies directed against surface and intracellularly expressed antigens. Ten serum samples with positive results and 10 with negative results detected by the granulocyte immunofluorescence test (GIFT), together with 10 positive serum samples detected by an indirect immunofluorescence test (IIF) were analyzed against leukocytes from healthy blood donors tested by flow cytometry (FC). Unpermeabilized and permeabilized cells were used to allow identification of surface and intracellular binding, respectively. The results of testing by GIFT corresponded with those by FC, with the exception of the results for four sera: one serum sample was FC negative, GIFT positive, and three samples were FC positive, GIFT negative. The IIF-positive sera were all FC positive, analyzed against permeabilized granulocytes, and one serum was also positive against non-permeabilized granulocytes. Analysis by FC is a readily performed technique, which can be used for the routine detection of antibodies against leukocyte antigens. Screening for granulocyte-specific antibodies can be carried out with pools of granulocytes from three donors. Analysis by FC allows detection of both HLA antibodies and granulocyte-specific antibodies and by using both unpermeabilized and permeabilized cells, antibodies against surface and intracellular antigens, respectively, can be identified.

An immobiline DryStrip application method enabling high-capacity two-dimensional gel electrophoresis

In the field of proteomics the need to detect low-abundance cellular components, such as regulatory proteins, is of critical importance. Two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) is one of the most commonly used separation tools for these biological investigations. In this paper we report an alternative micropreparative 2-D PAGE sample application method, called the "paper bridge loading" method. This method makes it possible to apply a larger sample volume to commercially available immobilized pH gradient (IPG) strips. The Vh products required for focusing are only marginally longer than those used in analytical experiments. The method was compared to traditional cup loading and in-gel rehydration. With 18 cm long narrow-range Immobiline DryStrip pH 4.5-5.5, the "paper bridge" method allowed the application of 10 mg human plasma proteins compared to 3 mg with traditional loading methods. The corresponding figures using Escherichia coli sample was found to be 6 mg and less than 2 mg, respectively. The paper bridge method also showed the best results in terms of spot resolution and separation of high molecular weight proteins.

Structural requirements for intracellular processing and sorting of bactericidal/permeability-increasing protein (BPI): comparison with lipopolysaccharide-binding protein

The bactericidal/permeability-increasing protein (BPI), which is stored in the azurophil granules of neutrophils, and the circulating lipopolysaccharide-binding protein (LBP) share the same structure. Both bind lipopolysaccharide of gram-negative bacteria through their amino-terminal domains. The carboxy-terminal domain of BPI promotes bacterial attachment to phagocytes, whereas the corresponding domain of LBP delivers lipopolysaccharide to monocytes/macrophages. Our aim was to investigate the role of the amino-and carboxy-terminal domains of BPI and LBP for sorting and storage in myeloid cells after transfection of cDNA to two rodent hematopoietic cell lines. Full-length BPI and LBP were both targeted for storage in these cells. Deletion of the carboxy-terminal half of BPI resulted in storage followed by degradation while the reciprocal deletion of the amino-terminal half led to retention in the endoplasmic reticulum for proteasomal degradation. Chimeras between halves of BPI and LBP were also targeted for storage, but those containing carboxy-terminal BPI had the highest stability, again indicating a role for the carboxy-terminal domain of BPI in protection against degradation. Therefore, we propose a critical stability function for the hydrophobic carboxy-terminal domain of BPI during intracellular sorting for storage while the amino-terminal domain may confer targeting for storage.

p53-mediated differentiation of the erythroleukemia cell line K562

The tumor suppressor gene p53 can mediate both apoptosis and cell cycle arrest. In addition, p53 also influences differentiation. To further characterize the differentiation inducing properties of p53, we overexpressed a temperature-inducible p53 mutant (ptsp53Val135) in the erythroleukemia cell line K562. The results show that wild-type p53 and hemin synergistically induce erythroid differentiation of K562 cells, indicating that p53 plays a role in the molecular regulation of differentiation. However, wild-type p53 did not affect phorbol 12-myristate 13-acetate-dependent appearance of the megakaryocyte-related cell surface antigens CD9 and CD61, suggesting that p53 does not generally affect phenotypic modulation. The cyclin-dependent kinase inhibitor p21, a transcriptional target of p53, halts the cell cycle in G1 and has also been implicated in the regulation of differentiation and apoptosis. However, transiently overexpressed p21 did neither induce differentiation nor affect the cell cycle distribution or viability of K562 cells, suggesting that targets downstream of p53 other than p21 are critical for the p53-mediated differentiation response.

Processing and targeting of granule proteins in human neutrophils

Neutrophils contain an assembly of granules destined for regulated secretion, each granule type with distinct constituents formed before terminal differentiation. The earliest granules are designated azurophil (primary), followed in time by specific (secondary), and gelatinase granules as well as secretory vesicles. Transcription factors regulate the genes for the granule proteins to ensure that expression of the gene products to be stored in different organelles is separated in time. Similar to lysosomal enzymes, many granule proteins, in particular those of the heterogeneous azurophil granules, are trimmed by proteolytic processing into mature proteins. Rodent myeloid cell lines have been utilized for research on the processing and targeting of human granule proteins after transfection of cDNA. Results from extensive work on the hematopoietic serine proteases of azurophil granules, employing in vitro mutagenesis, indicate that both an immature and a mature conformation are compatible with targeting for storage in granules. On the other hand, the amino-terminal propeptide of myeloperoxidase facilitates both the export from the endoplasmic reticulum and targeting for storage in granules. Similarly, targeting of defensins rely on an intact propeptide. The proteolytic processing into mature granule protein is most commonly a post-sorting event. Mis-sorting of specific granule proteins into azurophil or lysosome-like granules can result in premature activation and degradation, but represents a potential for manipulating the composition and function of neutrophil granules.

A three-year postoperative evaluation of tension-free vaginal tape

The aim of this study was to evaluate the outcome of tension-free vaginal tape (TVT) 3 years after surgery. Fifty-one women (mean age 52.9) with a genuine stress incontinence underwent the TVT operation. In 10 patients, a prolapse repair was also done simultaneously. The majority of the patients were operated under local anesthesia. All patients were evaluated 3 years after the procedure using a protocol for objective and subjective assessment of the outcome including an evaluation of quality of life related to urinary incontinence. According to the protocol, 46 women (90%) were successfully cured, another 3 patients (6%) were improved, whereas 2 patients (4%) were classified as failures. Few complications occurred. We conclude that TVT is a simple and well-accepted minimal invasive surgery for treatment of female urinary stress incontinence. The outcome 3 years after the operation showed no signs of deterioration compared to the results shortly after surgery. The cure rate of 90% is comparable with the best results of other surgical treatments for female urinary incontinence.

Involvement of the retinoblastoma protein in monocytic and neutrophilic lineage commitment of human bone marrow progenitor cells

The retinoblastoma gene product (pRb) is involved in both cell cycle regulation and cell differentiation. pRb may have dual functions during cell differentiation: partly by promoting a cell cycle brake at G(1) and also by interacting with tissue-specific transcription factors. We recently showed that pRb mediates differentiation of leukemic cell lines involving mechanisms other than the induction of G(1) arrest. In the present study, we investigated the role of pRb in differentiation of human bone marrow progenitor cells. Human bone marrow cells were cultured in a colony-forming unit-granulocyte-macrophage (CFU-GM) assay. The addition of antisense RB oligonucleotides (alpha-RB), but not the addition of sense orientated oligonucleotides (SO) or scrambled oligonucleotides (SCR), reduced the number of colonies staining for nonspecific esterase without affecting the clonogenic growth. Monocytic differentiation of CD34(+) cells supported by FLT3-ligand and interleukin-3 (IL-3) was correlated to high levels of hypophosphorylated pRb, whereas neutrophilic differentiation, supported by granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF), was correlated to low levels. The addition of alpha-RB to liquid cultures of CD34(+) cells, supported with FLT3-ligand and IL-3, inhibited monocytic differentiation. This was judged by morphology, the expression of CD14, and staining for esterase. Moreover, the inhibition of monocytic differentiation of CD34(+) cells mediated by alpha-RB, which is capable of reducing pRb expression, was counterbalanced by an enhanced neutrophilic differentiation response, as judged by morphology and the expression of lactoferrin. CD34(+) cells incubated with oligo buffer, alpha-RB, SO, or SCR showed similar growth rates. Taken together, these data suggest that pRb plays a critical role in the monocytic and neutrophilic lineage commitment of human bone marrow progenitors, probably by mechanisms that are not strictly related to control of cell cycle progression.

A multicenter study of tension-free vaginal tape (TVT) for surgical treatment of stress urinary incontinence

The aim of the study was to evaluate the safety and efficacy of TVT (tension-free vaginal tape) for the surgical treatment of stress urinary incontinence. The design was a prospective open multicenter study including six centers, each operating an approximately 20 patients. In total 131 patients suffering from genuine stress incontinence were included. They were followed for at least 1 year using a specific protocol for objective and subjective evaluation of the outcome. All patients underwent the operation under local anesthesia. Mean operation time was 28 minutes (range 19-41 minutes); 119 (91%) of the patients were cured according to the protocol and another 9 (7%) were significantly improved. There were 3 (2%) failures. The majority of the patients (about 90%) were operated upon on a day-care basis, which implied that they were released from the hospital within 24 hours, with no postoperative catheterization. No defect healing and no tape rejection occurred. Three patients needed an indwelling catheter for 3 days. In 1 patient catheterization was necessary for more than 10 days. Two uncomplicated hematomas and one uncomplicated bladder perforation occurred. Based on the results, we conclude that TVT is a safe and effective ambulatory procedure for surgical treatment of genuine stress urinary incontinence.

p53-dependent and -independent differentiation of leukemic U-937 cells: relationship to cell cycle control

Observations based on overexpression of the suppressor gene p53 or interference with endogenous p53 support a role for p53 in mediating not only growth inhibition and apoptosis but also differentiation. The aim of this study was to characterize the mechanisms of p53-dependent differentiation in the monoblastic leukemia cell line U-937. These cells were transfected with a mutant of the p53 gene expressing wild-type p53 at a permissive temperature. The results showed that wild-type p53 and interferon (IFN)-gamma were able to work synergistically to promote differentiation. This cooperative response was not associated with early G1 arrest of the cell cycle, indicating that p53 can mediate differentiation by mechanisms other than those used for mediating G1 arrest. The differentiation response to transfected p53 with or without INF-gamma was inhibited by cyclic adenosine monophosphate (cAMP)-inducing agents (dibutyryl cyclic adenosine 3':5'-monophosphate, forskolin, and 3-isobutyl-1-methylxanthine) in a dose-dependent manner. In contrast, the differentiation response of p53-negative U-937 cells to 1,25-dihydroxychole-calciferol or all-trans retinoic acid was enhanced by cAMP-inducing agents at optimal concentrations and inhibited at higher concentrations. In addition, 1,25-dihydroxycholecalciferol-mediated differentiation could be achieved in cells arrested in G1 by concomitant incubation with cAMP-inducing agents, indicating that differentiation can occur in the absence of proliferation. In conclusion, the results of this study indicate that p53-dependent and -independent differentiation can occur independently of cell cycle regulation.

The role of the propeptide for processing and sorting of human myeloperoxidase

Myeloperoxidase (MPO), stored in azurophil granules of neutrophils, is critical for an optimal oxygen-dependent microbicidal activity of these cells. Pro-MPO goes through a stepwise proteolytic trimming with elimination of an amino-terminal propeptide to yield one heavy and one light polypeptide chain. The propeptide of MPO may have a role in retention and folding of the nascent protein into its tertiary structure or in targeting of pro-MPO for processing and storage in granules. A propeptide-deleted pro-MPO mutant (MPODeltapro) was constructed to determine if deletion of the propeptide interferes with processing and targeting after transfection to the myeloid 32D cell line. Transfection of full-length cDNA for human MPO results in normal processing and targeting of MPO to cytoplasmic dense organelles. Although the efficiency of incorporation was lower for MPODeltapro, both pro-MPO and MPODeltapro showed heme incorporation indicating that the propeptide is not critical for this process. Deletion of the propeptide results in synthesis of a protein that lacks processing into mature two-chain forms but rather is degraded intracellularly or secreted. The finding of continued degradation of MPODeltapro in the presence of lysosomotrophic agents or brefeldin A rules out that the observed degradation takes place after transfer to granules. Intracellular pro-MPO has high mannose oligosaccharide side chains, whereas stored mature MPO was found to have both high mannose and complex oligosaccharide side chains as judged by only partial sensitivity to endoglycosidase H. The propeptide may normally interfere with the generation of certain complex oligosaccharide chain(s) supported by the finding of high mannose side chains in secreted pro-MPO and lack of them in MPODeltapro that contained complex oligosaccharide side chains only. In conclusion, elimination of the propeptide of pro-MPO blocks the maturation process and abolishes accumulation of the final product in granules suggesting a critical role of the propeptide for late processing of pro-MPO and targeting for storage in granules.

Localization of granule proteins in human eosinophil bone marrow progenitors

Eosinophils have a characteristic content of cationic proteins, stored in core-containing specific granules and released at sites of inflammation; coreless granules (sometimes called primary) are present in eosinophil promyelocytes. In order to determine a possible relationship between the two granule subsets, immunoelectron-microscopic techniques were used to determine the presence and precise intragranular distribution of major basic protein (MBP), eosinophil cationic protein (ECP), eosinophil peroxidase (EPO), and arylsulfatase B of eosinophil granules, as well as the Charcot-Leyden crystal (CLC) protein, in eosinophil progenitors of the bone marrow. MBP, ECP, EPO, and arylsulfatase B were observed in both coreless and core-containing (specific) granules. The difference in the distribution of MBP, having a uniform distribution in coreless granules and a crystalloid distribution in core-containing (specific) granules, could indicate a maturational process of a common organelle. CLC protein was distributed in the cytosol, in the euchromatin of the nuclei, but was also present in a rare granular compartment of both immature and mature eosinophils. The present findings suggest that coreless granules develop into core-containing specific granules.

The tumor suppressor gene p53 can mediate transforming growth [corrected] factor beta1-induced differentiation of leukemic cells independently of activation of the retinoblastoma protein

Although the involvement of the tumor suppressor gene p53 in normal hematopoiesis is uncertain, it can give rise to differentiation signals in leukemic cells. It is not clear, however, whether differentiation merely is a consequence of the ability of p53 to arrest cell proliferation or whether hitherto unknown molecular mechanisms are responsible for the p53-mediated differentiation. To further explore the role of p53 in leukemic cell differentiation, we investigated whether transforming growth factor beta1 (TGF-beta1), a cytokine involved in cell cycle control at several levels, can cooperate with wild-type p53 to induce differentiation of monoblastic U-937 and erythroleukemic K562 cells. Indeed, wild-type p53-expressing cells were found to be more sensitive to TGF-beta1-induced differentiation than control cells, lending support to the idea that p53 is of importance for differentiation induction of leukemic cells. In addition, it is shown that TGF-beta1 can suppress p53-mediated cell death, thus reinforcing the differentiation response. The cyclin-dependent kinase inhibitor p21 and the retinoblastoma protein (pRb) are downstream effectors of p53-mediated growth arrest. Therefore, the roles for these molecules in p53-mediated differentiation were examined. The p53-dependent signals of differentiation were associated with induction of p21 in both cell lines investigated. However, activation of pRb by induced hypophosphorylation and concomitant decreased growth rate on p53-mediated differentiation was observed only in U-937 cells expressing an inducible, temperature-sensitive form of p53 but not in K562 cells constitutively expressing p53. Thus, our data suggest a role for p53 in the regulation of differentiation in leukemic cells that can be independent of its ability to activate pRb and arrest cell proliferation.

[Extensive rehabilitation needed in epilepsy. Different models for varying needs]

Many people with epilepsy experience the need for more information concerning their condition and some people require, at times, greater access to rehabilitation services than has previously been available. Information and support may also be required by the family, friends and work colleagues of the patient. Research indicates that rehabilitation needs, for the patient, can arise in relation to poor self-esteem, overprotection as a child, low expectations, reduced cognitive abilities and stigma perceived or experienced in the family, in society, and at work. Successful rehabilitation is individualistic and should therefore be based on an assessment of the individual's needs. Only on the basis of this can realistic goals be identified. In the cases where intensive multidisciplinary rehabilitation is required a thorough medical assessment will also be needed in order to formulate realistic goals. Achievement of these goals may involve input from psychological, neuropsychological, pedagogical, social, employment and family orientated perspectives. Specialists in these areas must be included within, or co-ordinated by, the epilepsy team or rehabilitation service. In Sweden hospital based epilepsy-teams have added psycho-social rehabilitation aspects in their responsibilities and other rehabilitation services have recently begun to focus on the needs of people with epilepsy. This has led to a range of different rehabilitation models being available. The need to develop improved epilepsy rehabilitation services was identified in the 1970s and has recently received short-term funding support to develop new services and build up expertise. It is hoped that in the future these services will continue to find support at both the county and national levels.

Altered expression of the retinoblastoma tumor-suppressor gene in leukemic cell lines inhibits induction of differentiation but not G1-accumulation

The retinoblastoma tumor-suppressor gene, RB, has been implicated in tumor suppression, in regulation of the cell cycle, and in mediating cell differentiation. RB is necessary for hematopoiesis in mice, and aberrant RB-expression is associated with the progress and prognosis of leukemia. We have used antisense oligonucleotides, established clones stably expressing an antisense RB construct, and also established clones over expressing the retinoblastoma protein (pRb) to study the role of RB expression in monocytic differentiation induced by all-trans retinoic acid (ATRA) or 1-alpha-25-dihyroxycholecalciferol (Vit D3) in the monoblastic cell line U-937 and erythroid differentiation induced by transforming growth factor beta1 (TGFbeta1) and hemin in the erythroleukemic cell line K562. A reduction in pRb production in antisense RB-transfected U-937 clones was shown. Antisense oligonucleotides as well as expression of the antisense RB construct suppressed differentiation responses to ATRA or Vit D3, as judged by the capability to reduce nitro blue tetrazolium, by the appearance of monocyte-related cell surface antigens and by morphologic criteria. K562 cells showed decreased differentiation response to TGFbeta1, but not to hemin, when incubated with antisense oligonucleotides. U-937 antisense RB-transfected cells were also suppressed in their ability to upregulate levels of hypophosphorylated pRb when induced to differentiate. Although U-937 cells incubated with antisense oligonucleotides and clones expressing the antisense RB construct were hampered in their ability to differentiate on incubation with ATRA or Vit D3, the induced G0/G1-accumulation was similar to differentiating control cells treated with ATRA or Vit D3. Intriguingly, U-937 clones overexpressing RB were also inhibited in their differentiation response to ATRA or Vit D3 but not inhibited in their ability to respond with G0/G1 accumulation when induced with these substances. The results indicate that pRb plays a role in induced differentiation of U-937 cells as well as K562 cells involving mechanisms that, at least partially, are distinct from those inducing G1 accumulation.

Biosynthesis, processing and sorting of neutrophil proteins: insight into neutrophil granule development

Neutrophil granulocytes are specialized phagocytic cells that carry a collection of granules for regulated secretion, each with distinct constituents. The granules can be classified as azurophil (primary), developed first, followed in time by specific (secondary) granules gelatinase granules, and secretory vesicles. Stage- and tissue-specific transcription factors govern the successive expression of genes for granule proteins to allow storage of the gene products in these organelle categories whose packaging is separated in time. Many of the granule proteins, in particular those of the heterogeneous lysosome-like azurophil granules, are subject to extensive post-translational proteolytic processing into mature proteins, most commonly as a post-sorting event. A selective aggregation of proteins destined for storage in granules, as discussed in this review, would facilitate their retention and eliminate a need for distinct sorting motifs on each granule protein. Aggregation of granule proteins, that are often cationic, would be assisted by the anionic serglycin proteoglycans present in neutrophils. The antibacterial granule proteins can serve as models for antibiotics and some of them possess a potentially useful therapeutic ability to bind and neutralize endotoxin. Because aberrant expression of transcription factors regulating the synthesis of granule proteins is often found in leukemia, the clarification of mechanisms regulating the timed expression of granule proteins will shed light on the maturation block in myeloid leukemias.

Levels of certain trace elements in beef and pork imported to Sweden

The levels of Pb, Cd, Ni, Cr, Co, Zn, Cu, Mn, As and Se were determined in beef and pork imported to Sweden from six different countries. Samples of Swedish beef and pork were included for comparison. The results of this survey showed in most cases little difference in levels of these elements between the countries and agreed well with the results from our previous studies. All results for Pb, Cd, Ni and As were below the detection limits of 0.007, 0.001, 0.016 and 0.030 mg/kg fresh weight, respectively. Chromium and cobalt were, in both beef and pork, close to, or below, the detection limits of 0.004 and 0.003 mg/kg fresh wt, respectively. The level of selenium in beef varied considerably between countries, from < 0.030 to 0.18 mg/kg fresh wt. The levels of lead and cadmium from this study differed strongly in some cases from what have been reported in surveys from several countries, among them some countries exporting to Sweden. The importance of a rigorous quality control programme is emphasized.

Cell differentiation in acute myeloid leukemia

Acute myeloid leukemia (AML) is characterized by a differentiation block leading to accumulation of immature cells. Chromosomal translocations in AML affect transcription factors that are involved in regulation of myeloid differentiation. Aberrant expression of these factors interferes with differentiation events and has a role in the pathogenesis of AML through superactivation or (dominant negative) repression of genes regulating proliferation and differentiation or by interference with assembly of the transcription complex for these genes. The maturation arrest can be reversed by certain agents as judged by results from investigations of myeloid leukemic cell lines and from treatment of acute promyelocytic leukemia (APL) patients with all-trans retinoic acid. Inactivation of the p53 and retinoblastoma (Rb) tumor suppressor genes is also associated with the pathogenesis of leukemia through effects on the cell cycle, and manipulation of these genes can affect differentiation of AML cells. With differentiation therapy, when successful as in APL, the leukemic cell mass is reduced to allow restoration of normal hematopoiesis and clinical remission, but the disease is not cured. However, initial reduction of the cell mass by maturation can increase the probability for cure with chemotherapy. Overexpression of suppressor genes may increase the probability for differentiation. Most probably, particular molecular defects of subgroups of AML have to be explored to find optimal strategies for treatment including both blocking the cell cycle, promoting terminal differentiation, and inducing apoptosis as well as strengthening the immune response.

Expression of the p53 tumor suppressor gene induces differentiation and promotes induction of differentiation by 1,25-dihydroxycholecalciferol in leukemic U-937 cells

Leukemic U-937 cells, which lack normal p53, were stably transfected with a temperature-sensitive mutant of p53 to investigate the consequences for growth and differentiation. On induction of wild-type p53 activity at the permissive temperature, some of these cells underwent maturation as judged by the capacity for oxidative burst and the appearance of monocyte related cell surface molecules. Moreover, wild-type p53-expressing cells were more sensitive than p53-negative control cells to induction of differentiation by 1,25-dihydroxycholecalciferol; a twofold to fourfold increase of the fraction of cells showing signs of terminal maturation was observed when wild-type p53-expressing cells were incubated with 1,25-dihydroxycholecalciferol at concentrations that only slightly affected control cells. Whereas wild-type p53 activity per se induced maturation of certain cells, other underwent cell death judging from the reduced capability to exclude trypan blue and the appearance of fragmented DNA in flow cytometric analysis. The p53-induced cell death could be inhibited by incubation with 1,25-dihydroxy-cholecalciferol, but not all-trans retinoic acid. Thus, 1,25-dihydroxycholecalciferol, seemed to increase the survival of wild-type p53-expressing cells and to cooperate with wild-type p53 to induce differentiation. The data imply that p53-mediated maturation in U-937 cells depends on optimal regulation of signals for differentiation, survival and proliferation, and suggest a role for p53 in the differentiation induction of leukemic cells.

Carboxyl-terminal prodomain-deleted human leukocyte elastase and cathepsin G are efficiently targeted to granules and enzymatically activated in the rat basophilic/mast cell line RBL

The hematopoietic neutral serine proteases leukocyte elastase and cathepsin G are synthesized as inactive precursors, but become activated by removal of an amino-terminal dipeptide and are stored in granules. Moreover, the pro forms of elastase and cathepsin G show carboxyl-terminal prodomains of 20 and 11 amino acids, respectively, which are not present in the mature enzymes. To investigate mechanisms of processing, activation, and granular targeting, we have utilized transgenic expression of myeloid serine proteases in the rat basophilic/mast cell line RBL-1 (Gullberg, U., Lindmark, A., Nilsson, E., Persson, A.-M., and Olsson, I. (1994) J. Biol. Chem. 269, 25219-25225). Leukocyte elastase was stably expressed in RBL-1 cells, and the translation products were characterized by biosynthetic labeling followed by immunoprecipitation, SDS-polyacrylamide gel electrophoresis, and fluorography. Processing of a main pro form of 34 kDa into mature 31- and 29-kDa forms was demonstrated. Translocation of mature forms to granule-containing fractions was shown by subcellular fractionation experiments. The processed forms were enzymatically active, judging by the occurrence of amino-terminal processing demonstrated by radiosequence analysis, the acquisition of affinity for the protease inhibitor aprotinin, and the appearance of elastase activity in transfected RBL cells. To investigate the function of the carboxyl-terminal prodomains, deletion mutants of leukocyte elastase and cathepsin G lacking the carboxyl-terminal extension were constructed and transfected into RBL cells. Our results show that as full-length proteins, the deletion mutants were converted to active enzymes and transferred to granules with kinetics similar to that of wild-type enzymes. We conclude that human leukocyte elastase and cathepsin G are converted into enzymatically active forms when expressed in RBL cells and targeted for storage in granules; the carboxyl-terminal prodomains are necessary neither for enzymatic activation nor for targeting to granules in RBL cells.

[Hematopoiesis. Biological mass production closely regulated by cytokines]

Haematopoiesis is regulated by unrelated, pleiotropic, and diverse regulatory molecules, cytokines, whose membrane receptors are related and restricted to a few families manifesting sequence homology. Most members of the cytokine receptor family which lack tyrosine kinase activity are composed of multiple chains. An accessory signal transducer can be shared by members of the receptor family. Cytokine receptor oligomerisation is required for signal transduction, which includes phosphorylation of receptors and cytoplasmic proteins. Upon ligand binding, the receptors for erythropoietin and G-CSF form homodimers, whereas other members of the receptor family form hetero-oligomers in order to generate high-affinity receptor and signal transduction. In their cytoplasmic part, cytokine receptors contain distinct functional domains, proximal and distal to the membrane, that generate separate signals. Cytokines can be used to minimise chemotherapy-induced neutropenia and treat chronic neutropenia, and to shorten the period of aplasia following bone marrow transplantation.