Packaging and containerization of computational methods

Methods for analyzing the full complement of a biomolecule type, e.g., proteomics or metabolomics, generate large amounts of complex data. The software tools used to analyze omics data have reshaped the landscape of modern biology and become an essential component of biomedical research. These tools are themselves quite complex and often require the installation of other supporting software, libraries and/or databases. A researcher may also be using multiple different tools that require different versions of the same supporting materials. The increasing dependence of biomedical scientists on these powerful tools creates a need for easier installation and greater usability. Packaging and containerization are different approaches to satisfy this need by delivering omics tools already wrapped in additional software that makes the tools easier to install and use. In this systematic review, we describe and compare the features of prominent packaging and containerization platforms. We outline the challenges, advantages and limitations of each approach and some of the most widely used platforms from the perspectives of users, software developers and system administrators. We also propose principles to make the distribution of omics software more sustainable and robust to increase the reproducibility of biomedical and life science research.

Hippocampal atrophy and altered brain responses to pleasant tastes among obese compared with healthy weight children

OBJECTIVE

The hippocampus is a key structure implicated in food motivation and intake. Research has shown that the hippocampus is vulnerable to the consumption of a western diet (i.e., high saturated fat and simple carbohydrates). Studies of patients with obesity (OB), compared with healthy weight (HW), show changes in hippocampal volume and response to food cues. Moreover, evidence suggests that OB children, relative to HW, have greater hippocampal response to taste. However, no study has examined the association of hippocampal volume with taste functioning in children. We hypothesized that OB children, relative to HW, would show a significant reduction in hippocampal volume and that decreased volume would be significantly associated with greater activation to taste. Finally, we explored whether hippocampal activation would be associated with measures on eating and eating habits.

SUBJECTS

Twenty-five 8-12-year-old children (i.e., 13 HW, 12 OB) completed a magnetic resonance imaging scan while participating in a taste paradigm (i.e., 1 ml of 10% sucrose or ionic water delivered pseudorandomly every 20 s).

RESULTS

Children with OB, relative to HW, showed reduced left hippocampal volume (t=1.994, P=0.03, 95% confidence interval (CI)=-40.23,  755.42), and greater response to taste in three clusters within the left hippocampus (z=3.3, P=0.001, 95% CI=-0.241, -0.041; z=3.3, P=0.001, 95% CI=-0.2711, -0.0469; z=2.7, P=0.007, 95% CI=-0.6032, -0.0268). Activation within the hippocampus was associated with eating in the absence of hunger (EAH%; t=2.408, P=0.025, 95% CI= 1.751708, 23.94109) and two subscales on a measure of eating behaviors (Food responsiveness, t=2.572, P=0.017, 95% CI= 0.9565195, 9.043440; Food enjoyment, t=2.298, P=0.032, 95% CI=0.2256749, 4.531298).

CONCLUSION

As hypothesized, OB children, relative to HW, had significantly reduced hippocampal volume, and greater hippocampal activation to taste. Moreover, hippocampal activation was associated with measures of eating. These results contribute to research on the relationship between OB, overeating and cognitive impairment.

Extinction retention and fear renewal in a lifetime obsessive-compulsive disorder sample

Obsessive-compulsive disorder (OCD), like other illnesses with prominent anxiety, may involve abnormal fear regulation and consolidation of safety memories. Impaired fear extinction memory (extinction recall, ER) has been shown in individuals with current symptoms of OCD [1]. However, contrary to expectations, the only previous study investigating this phenomenon showed a positive correlation between extinction recall abilities and OCD symptomology (i.e., as OCD symptoms worsened, extinction memory improved). The purpose of the current study was to determine if patients with a lifetime diagnosis of OCD (not necessarily currently symptomatic) also demonstrate impairments in extinction memory, and the relationship between OCD symptomology and extinction memory in this type of sample. In addition, we also examined fear renewal, which has never been investigated in an OCD sample. We enrolled 37 patients with OCD, the majority of whom were on serotonin reuptake inhibitors, and 18 healthy control participants in a 2-day paradigm assessing fear conditioning and extinction (Day 1) and extinction retention and renewal (Day 2). Skin conductance responses (SCRs) were the dependent measure. Results, as in the prior study, indicated that the only between-group difference was impaired ER in OCD patients relative to controls. Contrary to our prediction, OCD symptom severity was not correlated with the magnitude of extinction recall. There were no differences in fear renewal between OCD patients and controls.

Psychometric evaluation of the DSM-IV criterion B mania symptoms in an Australian national sample

BACKGROUND

Although numerous studies have examined the latent structure of major depression, less attention has focused on mania. This paper presents the first investigation outside the USA to evaluate the psychometric properties of the DSM-IV criterion B mania symptoms using item response theory (IRT).

METHOD

Data were drawn from the Australian 2007 National Survey of Mental Health and Well-Being (NSMHWB, n = 8841). The psychometric performance of the mania symptoms was evaluated using a two-parameter logistic model. Because substance use disorders (SUDs) frequently co-occur with mania and can influence manic symptom expression, differential item functioning (DIF) between mania respondents with/without a SUD diagnosis was also assessed.

RESULTS

Factor analysis supported a unidimensional trait underlying mania. The grandiosity symptom displayed the highest discrimination whereas discrimination was lowest for decreased need for sleep. Relatively speaking, grandiosity tapped the severe end and increased goal-oriented activities tapped the mild end of the mania severity continuum. The symptoms generally performed equivalently between those with/without a SUD diagnosis, with one exception; the activities with painful consequences symptom was endorsed at lower levels of severity, and hence more frequently, by those with a SUD diagnosis versus those without a SUD diagnosis.

CONCLUSIONS

Accurate conceptualization of latent structure has crucial theoretical, statistical and clinical implications. The symptoms generally performed well in distinguishing between respondents with differing levels of liability, but others did not, suggesting modification is warranted to ensure optimal use in epidemiological samples. Given the dearth of psychometric evaluation studies of mania, further research replicating these results is necessary.

Dopamine D4 receptor gene variation moderates the efficacy of bupropion for smoking cessation

Smokers (≥10 cig/day; N =331) of European ancestry taking part in a double-blind placebo-controlled randomized trial of 12 weeks of treatment with bupropion plus counseling for smoking cessation were genotyped for a VNTR polymorphism in Exon-III of the Dopamine D4 receptor (DRD4) gene. Generalized estimating equations predicting point-prevalence abstinence at end of treatment and 2, 6, and 12-months post-end of treatment indicated that bupropion (vs. placebo) predicted increased odds of abstinence. The main effect of Genotype was not significant. A Genotype × Treatment interaction (p=.005) showed that bupropion predicted increased odds of abstinence in long-allele carriers (OR=1.31, p<.0001), whereas bupropion was not associated with abstinence among short-allele homozygotes (OR=1.06, p=.23). The Genotype × Treatment interaction remained when controlling for demographic and clinical covariates (p=.01) and in analyses predicting continuous abstinence (ps≤.054). Bupropion may be more efficacious for smokers who carry the long-allele, which is relevant to personalized pharmacogenetic treatment approaches.

Use of item response theory to understand differential functioning of DSM-IV major depression symptoms by race, ethnicity and gender

BACKGROUND

Psychological literature and clinical lore suggest that there may be systematic differences in how various demographic groups experience depressive symptoms, particularly somatic symptoms. The aim of the current study was to use methods based on item response theory (IRT) to examine whether, when equating for levels of depression symptom severity, there are demographic differences in the likelihood of reporting DSM-IV depression symptoms.

METHOD

We conducted a secondary analysis of a subset (n=13 753) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) dataset, which includes a large epidemiological sample of English-speaking Americans. We compared data from women and men, Hispanics and non-Hispanic Whites, African Americans and Whites, Asian Americans and Whites, and American Indians and Whites.

RESULTS

There were few differences overall, although the differences that we did find were primarily limited to somatic symptoms, and particularly appetite and weight disturbance.

CONCLUSIONS

For the most part, individuals responded similarly to the criteria used to diagnose major depression across gender and across English-speaking racial and ethnic groups in the USA.

In vitro and in vivo modulation of the equine immune response by parapoxvirus ovis

REASON FOR PERFORMING STUDY

While immune modulators are used routinely in equine medicine, their mechanism of action is not always known.

OBJECTIVES

To determine the effect of a commercial preparation of inactivated parapoxvirus ovis (Orf virus; PPVO) on cytokine gene expression by equine peripheral blood mononuclear cells (PBMC) both in vitro and in vivo.

METHODS

PBMC were prepared from 6 mixed-breed yearlings and cultured in vitro with PPVO with or without Concanavalin A (Con A) for 24 h. Effects on the expression of IFNalpha, IFNbeta IFNgamma, TNFalpha and IL-18 were analysed by real time quantitative PCR (RT-PCR). In addition, 12 yearling horses were treated with PPVO and whole blood RNA samples were prepared at regular intervals to assess effects on in vivo cytokine gene expression. Six of those yearlings were later treated with saline and served as treatment controls. Nine additional yearlings were injected intradermally with a single dose and their injection sites biopsied at 24 and 48 h for cytokine expression.

RESULTS

In vitro culture of PBMC with PPVO led to a significant increase in IFNalpha and IFNbeta gene expression compared to mock-stimulated cultures. In addition, expression of IFNgamma and TNFalpha was significantly higher in PBMC stimulated with PPVO and Con A, than those stimulated with Con A alone. No changes were observed in IL-18 gene expression in vitro. Treatment of horses with a 3-dose regimen of PPVO resulted in elevation of IFNgamma gene expression, which was detected 24 h after the first dose and declined thereafter. Intradermal inoculation led to increased expression of IFNgamma along with IFNbeta, IL-15 and IL-18.

CONCLUSIONS

Together these results indicate that PPVO stimulated IFNgamma production both in vitro and in vivo. Increased cytokine expression could account for its immunomodulatory activity.

POTENTIAL RELEVANCE

The absence of adverse reactions and clear indications of increased expression of cytokine gene expression supports previous clinical uses for this immune modulator in those situations when increased expression of IFNgamma is warranted.

Clinical, EEG, and quantitative MRI differences in pediatric frontal and temporal lobe epilepsy

OBJECTIVE

To examine the clinical, electrographic, and quantitative MRI differences between frontal lobe (FLE) and mesial temporal lobe epilepsy (MTLE) in children.

METHODS

The population included children who underwent video-EEG monitoring between 1995 and 2000 who were classified as either FLE (n = 39) or MTLE (n = 17) according to the criteria of the International League Against Epilepsy. Clinical, EEG, and quantitative MRI data (including frontal cortical volumes) were compared between the two syndromes and a control group (n = 42).

RESULTS

In FLE, seizures were significantly briefer, more frequent, and predominantly from sleep, and had differing motor characteristics. The rates of bilateral epileptiform interictal and ictal EEG abnormalities were significantly higher in FLE. A nonlesional MRI was significantly more common in FLE. Mean frontal cortical volume in FLE was significantly lower than MTLE and controls. Seizure freedom after surgery was lower in FLE.

CONCLUSIONS

The clinical syndrome of FLE is clearly distinct from MTLE. The etiology of this disorder is unknown in the majority of cases despite extensive investigation. Because of a lack of a clearly defined etiology and frequent nonlateralizing EEG changes, few of these children are considered optimal surgical candidates. The demonstration of bilateral frontal cortical volume loss and bilateral EEG abnormalities suggests that FLE is a bilateral disease in a high proportion of patients. The outcome in those patients who were deemed surgical candidates was significantly worse than the MTLE cases.

Flight paramedic scope of practice: current level and breadth

This study's objective was to determine the current level and breadth of flight paramedic scope of practice. A six-item survey of lead flight paramedics in 158 air medical programs addressed five issues: 1) Certifications required above state certification; 2) Procedures included in scope of practice; 3) Medications flight paramedics are allowed to administer; 4) Requirements needed to expand scope of practice; and 5) Views on establishing a National Flight Paramedic Certification to alter their scope of practice. Eighty programs out of the 90 respondents (89%) stated that they utilize flight paramedics. Of these 80 programs that use flight paramedics, 76 programs (95%) require certification in ACLS, 65 (81%) in PALS, and 50 (63%) in BCLS. Paramedics are allowed to perform cricothyroidotomy in 68 programs (85%), pericardiocentesis in 24 (30%), and tube thoracostomy in 23 (29%). Medications approved for administration include streptokinase in 37 programs (46 %), r-TPA in 48 (60%), and succinylcholine in 50 (63%). In 61 programs (76%), the scope of practice is determined solely by the air medical director. Eighteen respondents (23%) believe that the development of a National Flight Paramedic Certification Program would alter their scope of practice. In conclusion, flight paramedic scope of practice varies enormously. Since most medical directors have the authority to alter flight paramedic scope of practice and few programs believe that a National Flight Paramedic Certification would alter their practice, medical directors should work directly with flight paramedics to expand their scope of practice.

Paclitaxel, cisplatin and etoposide combination chemotherapy: a comparison of dose intensity in two multifractionated dose schemas

66 patients with a variety of tumour types received the multifractionated TPE three drug regimen in a non-random allocation as a 5 day schedule (schedule A) or as a twice weekly schedule (schedule B). The dose per fraction for each component drug was 35, 40 or 50 mg/m2 for both paclitaxel and etoposide and for cisplatin, the dose per fraction was 15 mg/m2. The total paclitaxel and etoposide dose was 175, 200, 250 mg/m2 3 week cycle. For schedule A, grade 3 or 4 neutropenia was observed in 70/114 cycles (61%) with two treatment related deaths from 50 treated patients. For schedule B, grade 3 neutropenia was observed in 1 of 30 courses (3%) with one drug related death from 19 treated patients. Dose intensity was increased by 20% for both paclitaxel and etoposide with the twice weekly schedule and at all dose levels, with haematological toxicity substantially reduced relative to schedule A. Using multifractionated schedules, a twice weekly open ended schedule results in an approximately 20% greater dose intensity and less toxicity compared with a 5 day schedule repeated every 3 weeks. The recommended dose schedule for TPE is paclitaxel 40 mg/m2; cisplatin 15 mg/m2 and etoposide 40 mg/m2 twice weekly for 3 weeks repeated every 4 weeks.

Hybridization between introduced smooth cordgrass (Spartina alterniflora; Poaceae) and native California cordgrass (S. foliosa) in San Francisco Bay, California, USA

Introduced Spartina alterniflora (smooth cordgrass) is rapidly invading intertidal mudflats in San Francisco Bay, California. At several sites, S. alterniflora co-occurs with native S. foliosa (California cordgrass), a species endemic to California salt marshes. In this study, random amplified polymorphic DNA markers (RAPDs) specific to each Spartina species were identified and used to test for hybridization between the native and introduced Spartina species in the greenhouse and in the field. Greenhouse crosses were made using S. alterniflora as the pollen donor and S. foliosa as the maternal plant, and these crosses produced viable seeds. The hybrid status of the crossed offspring was confirmed with the RAPD markers. Hybrids had low self-fertility but high fertility when back-crossed with S. foliosa pollen. Hybrids were also found established at two field sites in San Francisco Bay; these hybrids appeared vigorous and morphologically intermediate between the parental species. Field observations suggested that hybrids were recruiting more rapidly than the native S. foliosa. Previous work identified competition from introduced S. alterniflora as a threat to native S. foliosa. In this study, we identify introgression and the spread of hybrids as an additional, perhaps even more serious threat to conservation of S. foliosa in San Francisco Bay.

Molecular detection of an importation of type 3 wild poliovirus into Canada from The Netherlands in 1993

During the fall and winter of 1992-1993 an outbreak of wild poliovirus type 3-associated poliomyelitis involving 71 patients occurred in The Netherlands. Almost all of the individuals involved in the outbreak belonged to an orthodox religious denomination that prohibits vaccination. A surveillance was initiated to determine if there had been an importation of this same strain of wild poliovirus into a southern Alberta community with a similar religious affiliation. Viral culture of stool samples from consenting individuals in the community resulted in viral isolates which typed as poliovirus type 3. Sequencing of amplicons generated from both the 5' nontranslated region and the VP1/2A portion of the genomes from representative poliovirus isolates indicated a greater than 99% genetic similarity to the strain from The Netherlands. The results of this study show that the utilization of PCR-based diagnostics offers an important molecular tool for the concise and rapid surveillance of possible cases of wild poliovirus importation into communities with individuals at risk for infection.

Administrative and technical support of ambulatory infusional cancer chemotherapy (ICC)

The term "infusion" is generally equated with the parental administration of drugs in a continuous mode of delivery over some unspecified length of time. However, in terms of applicability to this paper, ICC will imply a minimum of a 24-hour delivery schedule and may include four to 7-day schedules up to protracted infusions covering many weeks. Infusional Cancer Chemotherapy programs may employ a single drug used with or without concomitant radiation therapy or admixtures of two and three drugs. Sequential alternating infusions of drug admixtures are a common mode of treatment which allow maximization of dose with minimal side effects and toxicities. The ICC model is based on the tenet that the quality of the program is directly related to the safety, efficiency, and continuity of the care provided. The supporting structures of an ICC program are rooted in four administrative and technical requisites. Strategies for program support include: 1) a team to carry out the treatment approach and to provide instructional and physical care support; 2) pre-established guidelines, protocols, policies, and procedures by which to administer the program; 3) achievement of a safe and reliable means of venous access which promotes the outpatient status; 4) a source for an accurate and reliable ambulatory infusion device and delivery system. A referral base may encompass a wide geographical area, and the patient population may be varied as to ethnicity, intellectual capacity, age, level of activity, family support and life style, thus it is important to develop a program to support the majority of patients as opposed to the carefully selected few.

Ambulatory infusional cancer chemotherapy: nursing role in patient management. The Cancer Center of Boston

The role of nursing in infusional cancer chemotherapy (ICC) may vary depending on the practice setting. Nurses in free-standing centers and office practices perform many duties that nurses in other facilities may not, because of the lack of many of the supports that benefit hospitals with their multidepartmental and hierarchical structures. Nurses function collaboratively with physicians in the planning and the implementation of patient treatment. Patient-related nursing responsibilities include patient/family education, drug preparation and administration, patient assessment for treatment toxicity, recognition and management of complications related to the catheter or infusion device, and telephone triage. Other duties more removed from patient care might include inventory management, research data collection and management, quality assurance and improvement, compliance with regulatory issues, and a myriad of other responsibilities. The transition of patient care to the outpatient setting has broadened the scope of nursing to include nonpatient care responsibilities due to financial constraints brought about by health care reform, changes in reimbursement patterns, and overhead required to maintain and deliver quality patient care. As a result of nursing responsibilities, it becomes paramount that the aforementioned constructs for program support are in place and that all nurses are consistently trained and have a template to follow for patient treatment and management. Nursing ability to perform patient-related tasks should be proven by formal written and practical competencies repeated annually and as procedural changes are implemented. The paragraphs to follow suggest nursing management of patients receiving ICC using a model developed at The Cancer Center of Boston (TCC).

Surveillance of the patient receiving infusional cancer chemotherapy: nursing role in recognition and management of catheter-related complications. The Cancer Center of Boston

Surveillance of the patient on infusional cancer chemotherapy (ICC) is paramount to patient safety. Key to this issue is diligence in monitoring for complications of infusion catheters. Nursing knowledge and awareness are essential for the early detection of such complications. The following is a composite of the manifestations of commonly experienced catheter-related complications. The incidence, detection and management issues are presented from the perspective of 15 years experience with ICC at The Cancer Center of Boston (TCC).

Human bone cell phenotypes differ depending on their skeletal site of origin

This report describes skeletal site-related differences in human osteoblastic cell metabolism in studies of four patients. Northern analyses of the constitutive growth factor messenger ribonucleic acid (mRNA) expression pattern in mandibular and iliac crest-derived human osteoblastic cells (based on within-patient comparisons) revealed higher mRNA levels for strong mitogenic growth factors such as basic fibroblast growth factor (bFGF) and insulin-like growth factor II (IGF-II) in the rapidly proliferating and less alkaline phosphatase (ALP)-expressing mandibular osteoblastic cells compared to those in the lower bFGF and IGF-II mRNA levels in slowly proliferating iliac human osteoblastic cells exhibiting a higher ALP expression level. In contrast, transforming growth factor-beta (TGF beta) mRNA was more abundant in iliac human osteoblastic cells than in mandibular osteoblastic cells. Furthermore, we found that there was a proportionality, based on data from both sites, between the level of constitutive TGF beta mRNA and the response to exogenously administered bFGF or IGF-II. A comparable pattern of growth characteristics and mRNA expression was also observed in transformed human osteoblastic cells that had been subcloned in sublines expressing high and low levels of the human osteoblastic differentiation marker ALP. These findings are consistent with 1) skeletal site-related differences in human bone cell phenotypes, and 2) decreased IGF-II and bFGF expression and increased TGF beta expression and responsiveness to bFGF and IGF-II in human bone cells exhibiting a high ALP expression.

Mouse cartilage matrix deficiency (cmd) caused by a 7 bp deletion in the aggrecan gene

Mouse cartilage matrix deficiency (cmd) is an autosomal recessive mutation characterized by cleft palate, short limbs, tail and snout. Heterozygous mice show normal size and phenotype, while homozygous mice die just after birth due to respiratory failure. Biochemical and immunohistochemical characterization of cmd cartilage reveals normal levels of type II collagen and link protein, but an absence of the large cartilage proteoglycan, aggrecan. Here, we have mapped the aggrecan gene to a region of mouse chromosome 7 near the cmd locus. DNA sequencing of the aggrecan gene identified a 7 bp deletion in exon 5 resulting in a severely truncated molecule. The finding of an aggrecan mutation in the cmd mouse confirms the critical role of aggrecan in cartilage formation.

Is there cognitive decline in schizophrenia? A cross-sectional study

The issue of progressive cognitive decline in patients with schizophrenia has been debated. We performed a cross-sectional study of patients with chronic schizophrenia, aged from 18 to 69 years, in order to address this issue. The patients included in this study passed a rigorous screen for any comorbid condition with an adverse impact on central nervous system function. We assessed intellectual deterioration with a battery of neuropsychological tests known to be sensitive to cognitive impairment in progressive dementia. No evidence of accelerated intellectual decline was found. No significant differences were found between the five age-derived cohorts (18-29, 30-39, 40-49, 50-59, and 60-69 years of age) on the Mini-Mental State Examination, Dementia Rating Scale, or other tests sensitive to dementia. While performance on the Boston Naming Test significantly declined with age, this was mainly due to age rather than duration of illness. However, it is important to note that mean performances on the majority of the tests were abnormal across all cohorts studied. These results suggest that intellectual function does not markedly decline during the adulthood of patients with schizophrenia. The course of schizophrenia is more consistent with a static encephalopathy than a dementing disorder.

Campylobacter fetus diarrhea in a Hutterite colony: epidemiological observations and typing of the causative organism

Following a case of Campylobacter fetus sepsis and meningitis in a 4-month-old female member of a Hutterite colony, an epidemiological investigation revealed at least 18 cases of diarrhea in other members of the colony. C. fetus was isolated from 7 of 15 fecal samples submitted from affected persons. A case control study suggested that persons who worked in the abattoir were 2.03 times more likely to have had diarrhea, but none of the risk factors studied were significant. The epicurve of the outbreak was inconclusive as to the likely mode of spread of C. fetus. All of the C. fetus strains isolated from the blood of the infant and from the fecal samples were the same by biochemical and antibiotic susceptibility tests. Pulsed-field gel electrophoresis showed that all isolates produced identical restriction endonuclease patterns and differed from other nonepidemiologically related strains of C. fetus.

The molecular and structural basis of hearing impairment in mice with the cpk mutant gene

We studied hearing impairment and cochlear ultrastructure in C57BL/6J mice containing the cpk mutant gene. Heterozygous cpk/+ mutant mice, 6-8 months old, showed a marked hearing loss as demonstrated by auditory evoked potentials with some showing hearing loss at 90 db sound pressure. Ultrastructural studies of first cochlear turn disclosed the absence of organs of Corti, no tissues on the basilar membrane, scanty spiral ganglia, normal tectorial membrane, and vacuolation of the stria vascularis. Reissner's membrane is normal at the endolymphatic side, but transparent at the perilymphatic side. In the second turn the organ of Corti are normal but Nuel's space is full of debris. The cpk mutant mice have hearing impairment perhaps due to deficiencies of genes expressing vital basement membrane components.

Studies of the mechanism by which androgens enhance mitogenesis and differentiation in bone cells

Recently, we reported a direct effect of androgens on murine and human bone cells to stimulate bone cell proliferation and differentiation. To test whether this effect of androgenic steroids might be mediated by growth factors, we measured relative concentrations of insulin-like growth factor-I and -II (IGF-I and IGF-II) and transforming growth factor-beta (TGF beta) in the conditioned medium from androgen-treated murine calvarial cell cultures. Only the concentration of TGF beta was increased. Consistent with the increased secretion of TGF beta in the mouse calvarial cell system, we observed an increased expression of TGF beta mRNA in a normal human osteoblastic cell system. We also determined whether androgens alter the response to growth factors. We found that dihydrotestosterone (DHT) treatment enhanced the mitogenic effects of fibroblast growth factor (FGF) and IGF-II but not those of IGF-I. The enhanced effect of FGF and IGF-II after DHT pretreatment was not affected by addition of TGF beta-blocking antibodies or by changing the culture medium. This indicated that in addition to increased release of TGF beta, another mechanism might be involved in the action of DHT on human and murine bone cells. Thus, we investigated the binding of human IGF-II to human osteoblastic cells and observed an increase in IGF-II binding after DHT treatment. Our results are consistent with a mechanism of action of androgens on bone cells that involves the induction of TGF beta and, in addition, may sensitize the cells to show an enhanced response to FGF and IGF-II, possibly by changing the receptor binding of mitogenic growth factors.

Acute changes in renal function associated with deferoxamine therapy

In three patients who received intravenous deferoxamine there was a twofold to eightfold increase in plasma creatinine level and a parallel decrease in creatinine clearance that resolved when treatment with the drug was discontinued. In two thalassemic patients, diuresis was evident by urine output exceeding fluid intake. The mechanism was studied in dogs that exhibited an acute and significant decrease in inulin and para-aminohippuric acid clearances induced by intravenous deferoxamine. Saline diuresis could prevent the decrease in the glomerular filtration rate but not the decrease in renal blood flow caused by deferoxamine. Deferoxamine induced an acute increase in the fractional excretion of sodium, potassium, chloride, phosphate, and urate, which may explain the relative diuresis observed in two of the patients. In a subsequent experiment, ferrioxamine induced an increase in the fractional excretion of sodium and chloride but did not affect the glomerular filtration rate and renal blood flow. Our studies suggest that adequate hydration may be needed to preserve renal hemodynamics during intravenous deferoxamine therapy. Repeated measurements of renal function should accompany treatment with this agent.

Interaction of fibrinogen with staphylococcal clumping factor and with platelets

Fibrinogen, a clottable plasma glycoprotein, participates in cell adhesion phenomena involving prokaryotic cells, e.g. staphylococci, and eukaryotic cell fragments, e.g. platelets. Among the three chains (alpha, beta, gamma) of human fibrinogen, the gamma chain bears the main site recognizing the staphylococcal clumping receptor and human platelet receptor induced by ADP. The platelet receptors are also recognized, albeit less avidly, by a site associated with the alpha chain. The gamma chain site recognizing staphylococcal clumping factor exists on the COOH-terminal segment of this chain encompassing the 15 residues (gamma 397-411) including the COOH-terminal valine. The location of the gamma chain site interacting with the human platelet receptor had been pinpointed to the 27 residue CNBr COOH-terminal segment (gamma 385-411). The results of enzymatic degradation of the 27-residue peptide indicate that the continuity of the last 15 amino acid residues at the COOH-terminal end of the gamma chain of human fibrinogen seems to be essential for its interaction with human platelets. The sequence of the gamma chain interacting with the platelet receptor (gamma 385-411) indicates that this segment is a unique region of fibrinogen endowed with three important functions: cross-linking of fibrin, clumping of staphylococci, and aggregation of platelets. [Note added in proof: Recently we obtained evidence that dodecapeptide gamma 393-411 fully retains platelet receptor recognition site (Kloczewiak et al. 1983. Clin. Res 31:534A.)]

Arteriovenous fistula complicating renal transplantation

A case of arteriovenous fistula of the major transplant vessels contributing to posttransplant hypertension hypertension and severe microangiopathic hemolytic anemia is reported. Improvement in blood pressure and correction of anemia followed ligation of the fistula. This case reinforces the need for diagnostic evaluation of all patients with sustained post-transplant hypertension.