Bacterial adhesion inhibitor prevents infection in a rodent surgical incision model

Surgical site infection risk continues to increase due to lack of efficacy in current standard of care drugs. New methods to treat or prevent antibiotic-resistant bacterial infections are needed. Multivalent Adhesion Molecules (MAM) are bacterial adhesins required for virulence. We developed a bacterial adhesion inhibitor using recombinant MAM fragment bound to polymer scaffold, mimicking MAM7 display on the bacterial surface. Here, we test MAM7 inhibitor efficacy to prevent Gram-positive and Gram-negative infections. Using a rodent model of surgical infection, incision sites were infected with antibiotic-resistant bioluminescent strains of Staphylococcus aureus or Pseudomonas aeruginosa. Infections were treated with MAM7 inhibitor or control suspension. Bacterial abundance was quantified for nine days post infection. Inflammatory responses and histology were characterized using fixed tissue sections. MAM7 inhibitor treatment decreased burden of S. aureus and P. aeruginosa below detection threshold. Bacterial load of groups treated with control were significantly higher than MAM7 inhibitor-treated groups. Treatment with inhibitor reduced colonization of clinically-relevant pathogens in an in vivo model of surgical infection. Use of MAM7 inhibitor to block initial adhesion of bacteria to tissue in surgical incisions may reduce infection rates, presenting a strategy to mitigate overuse of antibiotics to prevent surgical site infections.

Outcomes in patients with poorly differentiated thyroid carcinoma

BACKGROUND

Poorly differentiated thyroid cancer (PDTC) accounts for only 1-15% of all thyroid cancers. Our objective is to report outcomes in a large series of patients with PDTC treated at a single tertiary care cancer center.

METHODS

A total of 91 patients with primary PDTC were treated by initial surgery with or without adjuvant therapy at Memorial Sloan-Kettering Cancer Center from 1986 to 2009. Outcomes were calculated by the Kaplan-Meier method. Clinicopathological characteristics were compared for PDTC patients who died of disease to those who did not by the χ(2) test. Factors predictive of disease-specific survival (DSS) were calculated by univariate and multivariate analysis using the log rank and Cox proportional hazards method, respectively.

RESULTS

With a median follow-up of 50 months, the 5-year overall survival and DSS were 62 and 66%, respectively. The 5-year locoregional and distant control were 81 and 59%, respectively. Of 27 disease-specific deaths, 23 (85%) were due to distant disease. Age ≥ 45 years, pathological tumor size >4 cm, extrathyroidal extension, higher pathological T stage, positive margins, and distant metastases (M1) were predictive of worse DSS on univariate analysis. Multivariate analysis showed that only pT4a stage and M1 were independent predictors of worse DSS.

CONCLUSIONS

With appropriate surgery and adjuvant therapy, excellent locoregional control can be achieved in PDTC. Disease-specific deaths occurred due to distant metastases and rarely due to uncontrolled locoregional recurrence in this series.

Nucleophilic aliphatic substitution reactions of propachlor, alachlor, and metolachlor with bisulfide (HS-) and polysulfides (Sn2-)

Reactions of bisulfide and polysulfides with alachlor, propachlor, and metolachlor were examined in aqueous solution to investigate the role reduced sulfur species could play in effecting abiotic transformations of chloroacetanilide herbicides. Experiments at 25 degrees C demonstrated that reactions were approximately first-order in HS- concentration and revealed that polysulfides are considerably more reactive than HS-. delta H not equal to values for reactions of the three chloroacetanilides with HS- are statistically indistinguishable at the 95% confidence level, as are delta S not equal to values, despite significant differences in second-order rate constants (kHS-). Transformation products were characterized by GC/MS (in some cases following methylation) and were found to be consistent with substitution of chlorine by the sulfur nucleophile. Products containing multiple sulfur atoms were observed for the reactions of chloroacetanilides with polysulfides, while products resulting from reaction with HS- only possessed a single sulfur atom. When second-order rate constants at 25 degrees C are multiplied by HS- and polysulfide concentrations reported in salt marsh porewaters, predicted half-lives range from minutes to hours. HS- and especially polysulfides could thus exert a substantial influence on the fate of chloroacetanilide herbicides in aquatic environments. Oxidation of the resulting sulfur-substituted products could generate ethane sulfonic acid derivatives, previously reported as prevalent chloroacetanilide degradates.

Sonographic discrimination between benign and malignant breast lesions with use of disparity processing

RATIONALE AND OBJECTIVES

The authors performed this study to evaluate whether a digital processing technique called disparity processing (DP) can improve the differentiation between benign and malignant breast masses at ultrasound (US) and, thus, reduce the number of benign lesions being sampled for biopsy.

MATERIALS AND METHODS

During an US examination, a sonographer slightly varies the pressure of the probe on the breast surface. DP can be used to evaluate pairs of B scans that represent the different parts of this compression cycle. The apparent displacement of the tissue is measured with DP, and a new image, called a correlation map, is constructed. This new image illustrates the similarity between the speckle patterns around each point. The authors evaluated 25 solid lesions with DP. Results were compared with those from (a) histologic examination of specimens obtained with core or surgical biopsy or (b) cytologic examination of specimens obtained with fine-needle aspiration.

RESULTS

All 25 lesions were correctly diagnosed with DP. There were no false-positive or false-negative findings. All malignancies demonstrated a relatively low-brightness halo around the lesion perimeter with evidence of discontinuity. All benign lesions were associated with relatively high-brightness, continuous halos.

CONCLUSION

The results suggest that DP can help differentiate benign from malignant masses.

Cloning and developmental expression of Xenopus Stat1

Proteins of the STAT family (Signal Transducers and Activators of Transcription) are latent cytoplasmic factors which, upon phosphorylation, are translocated to the nucleus where they participate in gene activation. In this report, we describe the cloning and developmental expression of a Xenopus homolog of Stat1. XStat1 is highly conserved, exhibiting greater than 90% identity in the critical DNA binding, SH2, SH3 and trans-activation domains with both human and murine Stat1. Using RT-PCR, we show that XStat1 is present as a maternal message during early development of Xenopus. The maternal message is translated during cleavage and its product is phosphorylated on tyrosine, a prerequisite for functional activation. During cleavage and gastrula stages, XStat1 is widely expressed throughout the developing embryo. During neurulation and early tailbud stages, XStat1 is expressed in both dorsal axial and ventral tissues. By late tailbud, dorsal XStat1 expression domains are associated with the developing pharyngeal arches and pronephros. These regions of the embryo correspond to the future location of the thymus, sites of dorsal hematopoietic activity, and one location where melanocytes differentiate.

A comparison of cell cycle markers in well-differentiated lobular and ductal carcinomas

Infiltrating lobular carcinoma (ILC) and infiltrating ductal carcinoma (IDC) are similar in many respects and their histologic features occasionally overlap. Despite the many similarities, some clinical follow-up data and the patterns of metastasis suggest that ILC and IDC are biologically distinct. Unfortunately, most breast cancer research has focused almost exclusively on the ductal subtype or has not stressed the biologic or molecular genetic distinctions between breast carcinoma subtypes. Several reports have suggested the possibility that ILCs and IDCs differ with respect to expression of antigens involved in proliferation and cell cycle regulation. Therefore, we undertook an immunohistochemical evaluation of cell cycle related antigens in ILCs, including histologic variants thought to represent aggressive neoplasms, and IDCs matched for histologic grade (Modified Bloom-Richardson Grade I). We believe that different antigen expression profiles could elucidate the biological distinctiveness of breast carcinoma subtypes and possibly provide diagnostically relevant information. We studied the expression of the following antigens in 28 archived, formalin-fixed ILCs and 34 well-differentiated IDCs: estrogen receptor (ER), progesterone receptor (PR), Her 2-neu, mib-1, cyclin D1, p27, p53, mdm-2 and bcl-2. 94% of ILCs and 100% of IDCs expressed ER; 75% of ILCs and 76% of IDCs expressed PR; 4% of ILCs and 13% of IDCs expressed c cerb B-2; ILCs and IDCs both expressed mib-1 in approximately 10% of lesional cells; 82% of ILCs and 54% of IDCs expressed cyclin D1; 90% of ILCs and 83% IDCs expressed p27 strongly; 4% of ILCs and 4% of IDCs expressed p53, 25% of ILCs and 33% of IDCs expressed mdm-2; 96% of ILCs and 100% of IDCs expressed bcl-2. None of the apparent differences were statistically significant. The ILC variants demonstrated immunophenotypes that were essentially similar to ILCs of the usual type. We conclude that ILCs and well-differentiated IDCs show similar proliferation and cell cycle control antigen profiles. Despite their unusual histologic features, most ILC variants appear to maintain a characteristic ILC immunophenotype.

Economics of using pharmacists as advisers to physicians in risk-sharing contracts

An educational program designed to help physicians control the overall cost of drugs and total health care is described, along with its effectiveness at one managed health care plan. Prime Therapeutics, Inc., developed and manages an ongoing physician education program designed to help primary care physicians control drug and total health care costs. Physician education initiatives in the program are developed by using peer-reviewed literature; selections of preferred drugs are based on evidence of their safety, efficacy, uniqueness, and cost-effectiveness. For a typical educational initiative, a pharmacist meets with the physicians identified as being among the top 20% of prescribers of high-cost drugs addressed by the initiative and delivers a 20-minute presentation. One-on-one meetings with the physicians are then held quarterly to review their prescribing. Each physician is shown comparisons with the prescribing patterns of other physicians in the organization. The clinic chooses to present the clinicwide data as either blinded or nonblinded data. The program was evaluated by comparing per member per month (PMPM) total health care and drug costs for 1996 and 1997 at 12 general medicine clinics in a managed health care plan. Five clinics received no interventions, three clinics allowed the initial presentation and the quarterly face-to-face meetings, and four clinics allowed only the presentation and barred ongoing meetings. In general, the clinics with more interaction between pharmacists and physicians had lower PMPM costs for total health care and drugs than the clinics with less interaction. Pharmacists acting as advisers to primary care physicians in general medicine clinics helped lower PMPM costs for drugs and total health care.

Ureteroscopic biopsy of upper tract urothelial carcinoma: improved diagnostic accuracy and histopathological considerations using a multi-biopsy approach

PURPOSE

We assessed the diagnostic accuracy of a ureteroscopic multi-biopsy approach to upper tract urothelial carcinoma compared with subsequently resected surgical specimens.

MATERIALS AND METHODS

From 1990 to 1998, 45 upper tract lesions were ureteroscopically evaluated and biopsied with 3Fr cup forceps and/or an 11.5Fr resectoscope before nephroureterectomy or ureterectomy. A definitive diagnosis of urothelial carcinoma was made by biopsy in 40 lesions (89%). Each tumor was histopathologically graded but only staged if the lamina propria were uninvolved (Ta), and if the lamina propria were invaded by tumor (T1+).

RESULTS

Of the 40 urothelial tumors 16 (40%) were in the renal pelvis, and 8 (20%) in the proximal and 16 (40%) in the distal ureter. Of the lesions 95% were papillary and 65% were grade 2. Ureteroscopic biopsy grade matched surgical pathological grade in 31 of the 40 cases (78%), and was less than surgical pathological grade in the remainder. Lamina propria was detected in 27 of the 40 biopsies, including 21 of the 34 cup (62%) and all 6 resection loop (100%) biopsies. Ureteroscopic biopsy staging in 27 cases revealed Ta and T1+ disease in 22 and 5, respectively. In the 5 cases in which ureteroscopic biopsy stage was T1+ surgical pathological stage was also pT1+ (range pT1 to pT3). Tumors were pathologically up staged to pT1+ (range pT1 to pT3) in 10 of the 22 cases (45%) in which ureteroscopic biopsy stage was Ta. Tumor location did not affect diagnostic accuracy.

CONCLUSIONS

This multi-biopsy ureteroscopic approach provided the tissue diagnosis of urothelial carcinoma in 89% of cases and predicted exact histopathological grade in 78%. Although it is not accurate as a staging modality, multi-biopsy ureteroscopy may assess lamina propria invasion in two-thirds of cases.

Disparity mapping applied to sonography of the breast: technical note

A two-dimensional sonoelastographic technique called "disparity mapping" was applied to breast sonographic examinations in eight patients to test discrimination between benign and malignant lesions. With probe compression, pairs of gray-scale sonographic scans were obtained about 1 second apart. The disparity mapping procedure calculated the apparent displacement of the speckle pattern about each point in the image and presented that information in the form of a disparity map. Findings were consistent with a firm lesion in two of the three cancers, were indistinguishable from normal tissue in all three fibroadenomas, were indistinguishable from normal findings in one cyst, and showed no disparity in one cyst because it had few internal echoes.

DNA-Binding properties of the replication telomere protein

The replication Telomere Protein, rTP, is a nuclear protein from the ciliate Euplotes crassus that appears to be a novel telomere replication factor. rTP shares extensive amino acid sequence identity with the two proteins that bind and protect the macronuclear telomeres from the ciliates Oxytricha and Euplotes. Since the most extended regions of conservation fall within the DNA-binding domains of the telomere-binding proteins, when rTP was first identified it was predicted to be another structural telomere-binding protein. However, subsequent research demonstrated that rTP transcripts accumulate only during DNA replication and the rTP protein localizes to the sites of DNA replication within Euplotes macronuclei. We have now expressed rTP in a heterologous expression system and have examined the DNA-binding properties of the recombinant protein. We show that rTP binds specifically to the G-strand of Euplotes telomeric DNA and hence has some of the same DNA-binding characteristics as the Euplotes and Oxytricha telomere-binding proteins. However, other aspects of rTP binding are unique. In particular, the protein exhibits a very high off-rate and can bind double-stranded DNA as well as internal tracts of telomeric sequence. We conclude that rTP and the telomere-binding proteins are members of a class of proteins that have a conserved DNA-binding motif tailored to bind the G-strand of telomeric DNA. However, the unique DNA-binding characteristics of rTP indicate that the protein has evolved to fulfil a specialized role during telomere replication.

Management of dementia-related behavioral disturbances: a nonpharmacologic approach

OBJECTIVE

To describe practical nonpharmacologic approaches to dementia-related behavioral problems for enhancement of the function and care of elderly patients with dementia.

DESIGN

We reviewed the pertinent medical literature and summarized strategies and available resources for management of geriatric patients with dementia and behavior problems.

RESULTS

For optimal care of older patients with dementia, key concepts of related behavior problems must be understood. Agitation and aggression, resisting help with care, wandering, incontinence, sleep disturbance, and emotional lability can become difficult management issues with such patients. In some patients, these disruptions can lead to overmedication and nursing home placement. Herein, practical nonpharmacologic measures for management of behavior problems that arise among community-dwelling and institutionalized elderly patients with dementia are discussed. Attention is directed to the medical, psychologic, environmental, and social factors that may contribute to unwanted behaviors.

CONCLUSION

Nonpharmacologic approaches can help ameliorate behavioral problems and assist in the overall care of elderly patients with dementia.

Pronephric carcinoma: chromosomes of cells rescued from apoptosis by an oncogenic herpesvirus detected with a polymerase chain reaction

The amphibian pronephros is fated to die during early development. Pronephric cells undergo apoptosis and their function is replaced by the mesonephros, which becomes the functional kidney of the adult frog. Tadpoles of the northern leopard frog, Rana pipiens, were inoculated with a Lucké tumour herpesvirus (LTV) preparation. Most of the animals developed typical Lucké renal carcinomas at metamorphosis. Fewer developed carcinomas of the pronephric cell type. A pronephric carcinoma, rescued from apoptosis by the herpesvirus, was harvested from a post-metamorphic frog. The tumour was judged to be pronephric by its anatomical location (in the anterior part of the body) and because both mesonephric kidneys were intact and tumour-free upon removal of the tumour mass. A tumour fragment was fixed for histological examination, which confirmed that the tissue was a renal carcinoma. A further fragment was subjected to short-term culture in order to produce metaphase cells for cytogenetical analysis. Based upon silverstained nucleolar organizing region numbers, 14 of 15 metaphase cells were estimated to have the diploid number (2N = 26) of chromosomes and a karyotype was constructed which did not appear to differ from that of normal cells. A single cell was estimated to be tetraploid (4N = 52). This is the first report of chromosomes of a pronephric Lucké carcinoma. LTV replicates only in tumour tissue maintained in the cold. Because the frog in this study had been maintained in the laboratory at 22 degrees C for about 10 months, no viruses would have been detectable with electron microscopy. However, the presence of Lucké herpesvirus DNA was detected in tumour homogenates by polymerase chain reaction amplification of a 1.2 kbp Hind III restriction fragment of the LTV DNA. The presence of LTV DNA provided assurance that the rescued pronephric tumour was indeed a Lucké carcinoma.

Physiological mechanisms regulating the conversion of selenite to elemental selenium by Bacillus subtilis

We have demonstrated that the common soil bacterium, Bacillus subtilis, reduces selenite to an insoluble and much less toxic product--the red form of elemental selenium. Reduction was effected by an inducible system that appears to deposit elemental selenium between the cell wall and the plasma membrane. Glucose and sucrose supported selenite reduction. Although malate and citrate supported growth, no significant reduction of selenite occurred, indicating the importance of the redox state of the culture substrate. Selenite reduction in the millimolar concentration range (i.e., cultures supplemented with 1 mM selenite) was not affected by a ten-fold excess of nitrate or sulfate--compounds that serve as alternate electron acceptors and antagonize selenite reduction by anaerobic bacteria. Similarly, nitrite and sulfite did not significantly affect the rate or extent of selenite reduction. B.subtilis was able to grow and produce selenium (Se degree) at selenite concentrations ranging from 0.6 microM to 5 mM (50 ppb to 395 ppm selenium). At the lowest selenite concentration tested, 50 ppb selenium, B.subtilis removed 95% of the selenite from the liquid phase. The results suggest that selenite is reduced via an inducible detoxification system rather than dissimilatory electron transport. The findings establish the potential utility of B.subtilis for the bioremediation of selenite-polluted sites.

Comparison of the two major ARS elements of the ura4 replication origin region with other ARS elements in the fission yeast, Schizosaccharomyces pombe

We have previously reported that the replication origin region located near the ura4 gene on chromosome III of the fission yeast, Schizosaccharomyces pombe, contains three closely spaced origins, each associated with an autonomously replicating sequence (ARS) element. Here we report the nucleotide sequences of two of these ARS elements, ars3002 and ars3003. The two ARS elements are located on either side of a transcribed 1.5 kb open reading frame. Like 11 other S. pombe ARS elements whose sequences have previously been determined in other laboratories, the 2 new ARS elements are unusually A+T-rich. All 13 ARS elements contain easily unwound stretches of DNA. Each of the ARS elements contains numerous copies, at a higher than expected frequency, of short stretches of A+T-rich DNA in which most of the Ts are on one strand and most of the As are on the complementary strand. We discuss the potential significance for ARS function of these multiple asymmetric A+T-rich sequences.

Fate of herpesvirus DNA in embryos and tadpoles cloned from Lucké renal carcinoma nuclei

The Lucké renal carcinoma of the northern leopard frog, Rana pipiens, has a herpesvirus aetiology. Lucké tumour nuclei inserted into enucleated frogs' eggs produce development to the swimming tadpole stage. Tissue from these tumour nuclear transplant animals can be induced to survive and differentiate further by allografting to normal tadpoles. We wished to ascertain whether the aetiological agent, the Lucké tumour herpesvirus (LTV), persists in the animals produced by tumour nuclear transplantation. The polymerase chain reaction was used to amplify a 1.2 kbp Hind III restriction fragment of LTV DNA in whole animal homogenates prepared from tumour nuclear transplant tadpoles and normal tadpoles fertilized in vitro. The LTV fragment was not present in the majority (31 of 34) of the cloned animals derived from tumour nuclei, nor was it present in any of five normal tadpoles. Either the 1.2 kbp fragment of LTV DNA was eliminated from most of the cloned animals during the massive reprogramming of the neoplastic genome initiated by insertion of the tumour nuclei into egg cytoplasm, or the nuclei selected for transplantation were primarily those lacking this fragment of LTV DNA. The limited development of the tumour nuclear tadpoles was probably not due to the presence of these viral sequences, but rather reflected the limited plasticity of the tumour cell genome as assayed by nuclear transplantation. Failure to detect the 1.2 kbp fragment of LTV DNA in the majority of mitotic progeny of the Lucké tumour genome does not imply that other parts of the viral genome do not persist.(ABSTRACT TRUNCATED AT 250 WORDS)

Three ARS elements contribute to the ura4 replication origin region in the fission yeast, Schizosaccharomyces pombe

The ura4 replication origin region, which is located near the ura4 gene on chromosome III of the fission yeast, Schizosaccharomyces pombe, contains multiple initiation sites. We have used 2D gel electrophoretic replicon mapping methods to study the distribution of these initiation sites, and have found that they are concentrated near three ARS elements (stretches of DNA which permit autonomous plasmid replication). To determine the roles of these ARS elements in the function of the ura4 origin region, we deleted either one or two of them from the chromosome and then assessed the consequences of the deletions by 2D gel electrophoresis. The results suggest that each of the three ARS elements is responsible for the initiation events in its vicinity and that the ARS elements interfere with each other in a hierarchical fashion. It is possible that the large initiation zones of animal cells are similarly composed of multiple mutually interfering origins.

The presence of DNA sequences of the Lucké herpesvirus in normal and neoplastic kidney tissue of Rana pipiens

The Lucké tumour herpesvirus (LTV) is the aetiological agent of the Lucké renal adenocarcinoma of the northern leopard frog, Rana pipiens. LTV virions can be detected by electron microscopy in renal adenocarcinomata after prolonged exposure to low temperature. Tumours maintained at warm temperatures do not contain viral particles. To gain insight into the processes of viral infection, replication and oncogenesis, evidence was sought for the presence of LTV DNA in warm renal tumours and normal renal tissue. The polymerase chain reaction was used to amplify a Hind III restriction fragment of LTV DNA in tissue homogenates. LTV DNA was detected in a significant percentage of normal kidneys as well as in "virus-free" warm tumours and virus-containing cold tumours.

X-linked mixed hearing loss with stapes fixation: case reports

X-linked mixed hearing loss with stapes fixation is a congenital, recessive anomaly. The condition is characterized by progressive mixed hearing loss, reduced vestibular responses, and congenital fixation of the stapes with perilymph gusher encountered during surgical intervention. This paper describes the audiologic history of a family with two affected male children and one carrier female child. The need for early intervention and the challenges encountered in evaluation and management are discussed.

Genomic plasticity of the Lucké renal carcinoma: a review

The differentiation potential of the Lucké renal carcinoma of the northern leopard frog, Rana pipiens, can be characterized by the nuclear transplantation procedure. Transplantation of tumor nuclei into activated and enucleated ova results, in the best of cases, in swimming larvae which fail to feed. The larvae die in about 10 to 14 days. Rescue of tumor nuclear transplantation tadpole tissue, destined to die, has been accomplished by allografting fragments of that tissue to normal hosts. The allografts persist and differentiate a diversity of tissues which cannot be distinguished by histological analysis from allografted normal control tissue. Allografts are an imperfect mode of assay for histological competence because of the immune response of the host. Lymphocytes and eosinophils invade the grafts in about 40 days. The host immune response occurs in both experimental and control allografts. Consequently, we believe that added histogenetic potential exists in the genome of the Lucké renal carcinoma. We propose that unexpressed differentiative potential of the grafted tissue can be extracted by abrogation of the immune response of the host. A herpesvirus is the etiological agent of the Lucké renal carcinoma. We currently seek to detect viral DNA in tissue derived from tumor nuclear transplant embryos. The presence of the viral genetic material in normal mitotic progeny of Lucké tumor cells, if demonstrated, raises the question of the long-term stability of differentiated cells derived from a virus tumor. Alternatively, absence of viral DNA in the tumor nuclear transplant tissue would suggest that normal differentiation ensues after elimination of the oncogenic DNA from that tissue. Loss of viral DNA may prognosticate stable differentiation.

Characterization of platelet activation induced by HLA antibodies associated with alloimmune thrombocytopenia

The platelet-activating properties of plasma containing multispecific HLA antibodies were studied in plasma from several persons stimulated by platelet or red blood cell transfusion or by pregnancy. Antibodies were characterized by their lymphocytotoxic effects and by a monoclonal antibody antigen--capture enzyme-linked immunoassay. Plasma from each patient induced dose-dependent aggregation and release of adenosine triphosphate with antigen-positive platelet-rich plasma. Plasma from three patients induced normal aggregation and adenosine triphosphate release with platelet-rich plasma from donors who had taken platelet inhibiting medications (e.g. aspirin, piroxicam). In contrast, these platelets failed to release adenosine triphosphate when stimulated with 5 mumol/L adenosine diphosphate. Platelets were fully activated when saturated with HLA antibodies from one patient, although little or no stimulation was observed at 50% saturation suggesting that additional plasma cofactors and/or a threshold of bound antibody were required for activation. With a murine monoclonal antibody specific for P-selectin and antimurine immunoglobulin G labeled with iodine 125, plasma from each patient was found to induce P-selectin expression that was approximately 50% of that induced by 0.2 U/ml thrombin. Expression on platelets of P-selectin induced by plasma from one patient was independent of whether the donor had taken aspirin. Purified immunoglobulin G from this same patient stimulated platelet activation, as did the patient's serum, but no activation was observed with F(ab')2 fragments prepared from the immunoglobulin G. These studies demonstrate that HLA antibodies (1) mediate expression of P-selectin on the platelet surface, (2) are as potent as thrombin in activating platelets previously exposed to antiinflammatory agents, and (3) require an intact Fc domain to activate platelets.

Cytogenetic analysis of triploid renal carcinoma in Rana pipiens

To provide a cytogenetic marker for nuclear transplantation experiments, triploid Rana pipiens embryos were produced. These embryos were injected with Lucké tumor herpesvirus. The chromosome profile of a renal carcinoma that developed in one of these triploid embryos was compared to the chromosomal profiles of a naturally occurring diploid renal carcinoma and a diploid renal tumor maintained as serial anterior eye chamber allografts for over 7 yr. Examination of Ag-NOR-stained chromosome spreads from the putative triploid and naturally occurring putative diploid tumor revealed the expected results. The vast majority of the chromosome spreads, 54/57 (95%) and 6/7 (86%), respectively, displayed euploid chromosome and Ag-NOR profiles: 3N = 39 with three Ag-NORs at the secondary constrictions in the long arm of chromosome 10 (10q) and 2N = 26 with two Ag-NORs in 10q. Chromosome profiles from the long-term allografted tumor were highly aneuploid (82%) and, based on their Ag-NOR content, displayed variations in their 2N, 3N, and 4N numbers. These data indicate that the majority of recently transformed triploid Lucké tumor cells can provide donor nuclei suitable for the characterization of developmental potential.

Hearing loss and hearing aid use in Hispanic adults: results from the Hispanic Health and Nutrition Examination Survey

Data from the Hispanic Health and Nutrition Examination Survey were employed to investigate the prevalence of hearing loss and hearing aid use in Mexican-American, Cuban-American, and Puerto Rican adults. Hearing loss was 6 to 14 times more prevalent in older (ages 54 to 74) vs younger (ages 20 through 34) subjects. Cuban Americans and Mexican Americans tended to have a similar prevalence of hearing loss, whereas Puerto Ricans had markedly lower rates. Mexican-American men had higher rates of hearing loss than Mexican-American women. The prevalence of hearing aid use among hearing-impaired individuals ranged from 2% to 11%. Implications for future research are discussed.

Allografts of tumor nuclear transplantation embryos: differentiation competence

The developmental potential of nuclei can be studied by nuclear transplantation. Although amphibian blastula nuclei and other early embryonic nuclei are totipotent, to our knowledge no nucleus from an adult cell has ever been shown to be totipotent by this procedure. Transfer of Lucké renal carcinoma nuclei into enucleated eggs results in prefeeding swimming tadpoles. Inasmuch as these tadpoles die, rescue of this pluripotential tissue was attempted by grafting fragments of triploid tumor nuclear transplant tadpoles to the tails of normal diploid Rana pipiens hosts. Grafts of tumor nuclear transplant tadpole tissue were histologically indistinguishable from grafts of normally fertilized embryos and developed normal-appearing structures such as complete eyes, well-differentiated neural tissues, kidney tubules, and gut epithelium. Moreover, histological differentiation in tumor nuclear transplant grafts was comparable to that observed in 50-day-old normal larvae. Grafting enhanced the survival of tumor nuclear transplant tissue from no more than 14 days as part of the donor tadpole to 40 days at which time the grafts were harvested as healthy tissue. Thus, both differentiation and survival of tumor nuclear transplant tissue were augmented with the grafting procedure. Cytophotometric analysis of ploidy was used to confirm the tumor origin of the donor tissue.

Culture of PNKT-4B cells at invasion permissive and restrictive temperatures. I. Chromosomal analysis

PNKT-4B is an aneuploid cell line derived from a herpesvirus-induced renal adenocarcinoma of Rana pipiens that displays restricted invasion at 21 degrees C or cooler and invasion at 23 degrees C through 28 degrees C. Metaphase chromosomes obtained from subcultures (passages 297; 345-347) grown at 18 degrees C or 28 degrees C were Giemsa stained or N-banded with acidic silver nitrate. Cells grown at 18 degrees C displayed a modal chromosome number of 41, while 28 degrees C cultures displayed a modal number of 40. The distribution of the chromosomes suggests that the two temperatures may be allowing growth of different subclonal populations. N-banding of chromosomes at both temperatures revealed an increase of active nucleolar organizer regions (NORs) over normal frog tissues, 2/2N. Analysis of 200 N-banded spreads from cells grown at each temperature revealed modal numbers of 9 NORs/cell and modal numbers of 6 NOR-containing chromosomes/cell. Nine specific NOR-containing chromosomes were identified and scored. Similar distributions were observed at 18 degrees C and 28 degrees C. The data imply that the modal number of PNKT-4B has shifted since it was first described, 39, and differs at invasion-permissive and -restrictive temperatures. Increased numbers of active NORs and alterations of NOR-containing chromosomes imply an amplification of rDNA over the amount in normal frog.

Ultrasound transducer models for piezoelectric polymer films

A method is presented for determining the piezoelectric constants and the frequency-dependent dielectric properties of the polymers from a five-step algorithm based on analysis of air-loaded broadband impedance measurements. It is shown how to account for the frequency-dependent lossy properties of these films in an equivalent impedance circuit model and a modified Mason's model. Comparisons between the models and actual film transducers show excellent broadband simulation of both electrical input impedance and ultrasonic pulse-echo performance.

Sports anemia: a review of the literature

Sports anemia has been referred to as an anemic or borderline anemic state in physically active individuals, particularly athletes. This paper is a review of literature on sports anemia, including whom it may affect and its effect on performance, and its diagnosis. In general, sports anemia has been found to be a self-limiting condition and usually does not require treatment.