Medical students' knowledge of HPV, HPV vaccine, and HPV-associated head and neck cancer

On the basis of their training, medical students are considered "the best case scenario" among university students in knowledge of the human papillomavirus (HPV). We evaluated differences in knowledge of HPV, HPV vaccine, and head and neck cancer (HNC) among medical students. A previously validated questionnaire was completed by 247 medical students at a Midwestern university. Outcomes of interest were knowledge score for HPV and HPV vaccine, and HNC, derived from combining questionnaire items to form HPV knowledge and HNC scores, and analyzed using multivariate linear regression. Mean scores for HPV knowledge were 19.4 out of 26, and 7.2 out of 12 for HNC knowledge. In the final multivariate linear regression model, sex, race, and year of study were independently associated with HPV and HPV vaccine knowledge. Males had significantly lower HPV vaccine knowledge than females (β = -1.53; 95% CI: -2.53, -0.52), as did nonwhite students (β = -1.05; 95% CI: -2.07, -0.03). There was a gradient in HPV vaccine knowledge based on the year of study, highest among fourth year students (β = 6.75; 95% CI: 5.17, 8.33). Results were similar for factors associated with HNC knowledge, except for sex. HNC knowledge similarly increased based on year of study, highest for fourth year students (β = 2.50; 95% CI: 1.72, 3.29). Among medical students, gaps remain in knowledge of HPV, HPV vaccine, and HPV-linked HNC. Male medical students have significantly lower knowledge of HPV. This highlights the need to increase medical student knowledge of HPV and HPV-linked HNC.

Differential Outcomes Among Survivors of Head and Neck Cancer Belonging to Racial and Ethnic Minority Groups

Importance

Approximately 1 in 5 new patients with head and neck cancer (HNC) in the US belong to racial and ethnic minority groups, but their survival rates are worse than White individuals. However, because most studies compare Black vs White patients, little is known about survival differences among members of racial and ethnic minority groups.

Objective

To describe differential survival and identify nonclinical factors associated with stage of presentation among patients with HNC belonging to racial and ethnic minority groups.

Design, Setting, and Participants

This population-based retrospective cohort study used data from the 2007 to 2016 Surveillance, Epidemiology, and End Results (SEER) database and included non-Hispanic Black, Asian Pacific Islander, American Indian/Alaska Native, and Hispanic patients with HNC. The data were analyzed from December 2020 to May 2021.

Main Outcomes and Measures

Outcomes were time to event measures: (HNC-specific and all-cause mortality) and stage of presentation. Covariates included nonclinical (age at diagnosis, sex, race and ethnicity, insurance status, marital status, and a composite socioeconomic status [SES]) and clinical factors (stage, cancer site, chemotherapy, radiation, and surgery). A Cox regression model was used to adjust associations of covariates with the hazard of all-cause death, and a Fine and Gray competing risks proportional hazards model was used to estimate associations of covariates with the hazard of HNC-specific death. A proportional log odds ordinal logistic regression identified which nonclinical factors were associated with stage of presentation.

Results

There were 21 966 patients with HNC included in the study (mean [SD] age, 56.02 [11.16] years; 6072 women [27.6%]; 9229 [42.0%] non-Hispanic Black, 6893 [31.4%] Hispanic, 5342 [24.3%] Asian/Pacific Islander, and 502 [2.3%] American Indian/Alaska Native individuals). Black patients had highest proportion with very low SES (3482 [37.7%]) and the lowest crude 5-year overall survival (46%). After adjusting for covariates, Hispanic individuals had an 11% lower subdistribution hazard ratio (sdHR) of HNC-specific mortality (sdHR, 0.89; 95% CI, 0.83-0.95), 15% lower risk for Asian/Pacific Islander individuals (sdHR, 0.85; 95% CI, 0.78-0.93), and a trending lower risk for American Indian/Alaska Native individuals (sdHR, 0.85; 95% CI, 0.71-1.01), compared with non-Hispanic Black individuals. Race, sex, insurance, marital status, and SES were consistently associated with all-cause mortality, HNC-specific mortality, and stage of presentation, with non-Hispanic Black individuals faring worse compared with individuals of other racial and ethnic minority groups.

Conclusions and Relevance

In this cohort study that included only patients with HNC who were members of racial and ethnic minority groups, Black patients had significantly worse outcomes that were not completely explained by stage of presentation. There may be unexplored multilevel factors that are associated with social determinants of health and disparities in HNC outcomes.

Incidence and Risk of Suicide Among Patients With Head and Neck Cancer in Rural, Urban, and Metropolitan Areas

Importance

Patients with head and neck cancer (HNC) are known to be at increased risk of suicide compared with the general population, but there has been insufficient research on whether this risk differs based on patients' rural, urban, or metropolitan residence status.

Objective

To evaluate whether the risk of suicide among patients with HNC differs by rural vs urban or metropolitan residence status.

Design, Setting, and Participants

This cross-sectional study uses data from the Surveillance, Epidemiology, and End Results database on patients aged 18 to 74 years who received a diagnosis of HNC from January 1, 2000, to December 31, 2016. Statistical analysis was conducted from November 27, 2020, to June 3, 2021.

Exposures

Residence status, assessed using 2013 Rural Urban Continuum Codes.

Main Outcomes and Measures

Death due to suicide was assessed by International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes (U03, X60-X84, and Y87.0) and the cause of death recode (50220). Standardized mortality ratios (SMRs) of suicide, assessing the suicide risk among patients with HNC compared with the general population, were calculated. Suicide risk by residence status was compared using Fine-Gray proportional hazards regression models.

Results

Data from 134 510 patients with HNC (101 142 men [75.2%]; mean [SE] age, 57.7 [10.3] years) were analyzed, and 405 suicides were identified. Metropolitan residents composed 86.6% of the sample, urban residents composed 11.7%, and rural residents composed 1.7%. The mortality rate of suicide was 59.2 per 100 000 person-years in metropolitan counties, 64.0 per 100 000 person-years in urban counties, and 126.7 per 100 000 person-years in rural counties. Compared with the general population, the risk of suicide was markedly higher among patients with HNC in metropolitan (SMR, 2.78; 95% CI, 2.49-3.09), urban (SMR, 2.84; 95% CI, 2.13-3.71), and rural (SMR, 5.47; 95% CI, 3.06-9.02) areas. In Fine-Gray competing-risk analyses that adjusted for other covariates, there was no meaningful difference in suicide risk among urban vs metropolitan residents. However, compared with rural residents, residents of urban (subdistribution hazard ratio, 0.52; 95% CI, 0.29-0.94) and metropolitan counties (subdistribution hazard ratio, 0.55; 95% CI, 0.32-0.94) had greatly lower risk of suicide.

Conclusions and Relevance

The findings of this cross-sectional study suggest that suicide risk is elevated in general among patients with HNC but is significantly higher for patients residing in rural areas. Effective suicide prevention strategies in the population of patients with HNC need to account for rural health owing to the high risk of suicide among residents with HNC in rural areas.

Surgical outcomes after radioactive 125I seed versus hookwire localization of non-palpable breast cancer: a multicentre randomized clinical trial

BACKGROUND

Previous studies have suggested improved efficiency and patient outcomes with 125I seed compared with hookwire localization (HWL) in breast-conserving surgery, but high-level evidence of superior surgical outcomes is lacking. The aim of this multicentre pragmatic RCT was to compare re-excision and positive margin rates after localization using 125I seed or hookwire in women with non-palpable breast cancer.

METHODS

Between September 2013 and March 2018, women with non-palpable breast cancer eligible for breast-conserving surgery were assigned randomly to preoperative localization using 125I seeds or hookwires. Randomization was stratified by lesion type (pure ductal carcinoma in situ (DCIS) or other) and study site. Primary endpoints were rates of re-excision and margin positivity. Secondary endpoints were resection volumes and weights.

RESULTS

A total of 690 women were randomized at eight sites; 659 women remained after withdrawal (125I seed, 327; HWL, 332). Mean age was 60.3 years in the 125I seed group and 60.7 years in the HWL group, with no difference between the groups in preoperative lesion size (mean 13.2 mm). Lesions were pure DCIS in 25.9 per cent. The most common radiological lesion types were masses (46.9 per cent) and calcifications (28.2 per cent). The localization modality was ultrasonography in 65.5 per cent and mammography in 33.7 per cent. The re-excision rate after 125I seed localization was significantly lower than for HWL (13.9 versus 18.9 per cent respectively; P = 0.019). There were no significant differences in positive margin rates, or in specimen weights and volumes.

CONCLUSION

Re-excision rates after breast-conserving surgery were significantly lower after 125I seed localization compared with HWL. Registration number: ACTRN12613000655741 (http://www.ANZCTR.org.au/).

Cost-effectiveness of radioguided occult lesion localization using 125I seeds versus hookwire localization before breast-conserving surgery for non-palpable breast cancer

BACKGROUND

The aim was to determine the cost-effectiveness of radioguided occult lesion localization using 125I-labelled seeds (125I seeds) versus hookwire localization in terms of incremental cost per reoperation avoided for women with non-palpable breast cancer undergoing breast-conserving surgery.

METHODS

This study was based on a multicentre RCT with eight study sites comprising seven public hospitals and one private hospital. An Australian public health system perspective was taken. The primary effectiveness outcome for this study was reoperations avoided. Cost-effectiveness was expressed as an incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses were used to explore uncertainty. The willingness to pay (additional cost of localization using 125I seeds justified by reoperation cost avoided) was set at the weighted, top-down cost of reoperation. Costs were in 2019 Australian dollars ($1 was equivalent to €0.62).

RESULTS

The reoperation rate was 13.9 (95 per cent confidence interval 10.7 to 18.0) per cent for the 125I seed group and 18.9 (14.8 to 23.8) per cent for the hookwire localization group. The ICER for 125I seed versus hookwire localization was $4474 per reoperation averted. The results were most sensitive to uncertainty around the probability of reoperation. Accounting for transition probability and cost uncertainty for 125I seed localization, there was a 77 per cent probability that using 125I seeds would be cost-effective, with a willingness to pay of $7693 per reoperation averted.

CONCLUSION

Radioguided occult lesion localization using 125I seeds is likely to be cost-effective, because the marginal (additional) cost compared with hookwire localization is less than the cost of reoperations avoided.

Mechanisms of Parenteral Nutrition-Associated Liver and Gut Injury

Parenteral nutrition (PN) has revolutionized the care of patients with intestinal failure by providing nutrition intravenously. Worldwide, PN remains a standard tool of nutrition delivery in neonatal, pediatric, and adult patients. Though the benefits are evident, patients receiving PN can suffer serious cholestasis due to lack of enteral feeding and sometimes have fatal complications from liver injury and gut atrophy, including PN-associated liver disease or intestinal failure-associated liver disease. Recent studies into gut-systemic cross talk via the bile acid-regulated farnesoid X receptor (FXR)-fibroblast growth factor 19 (FGF19) axis, gut microbial control of the TGR5-glucagon-like peptide (GLP) axis, sepsis, and role of prematurity of hepatobiliary receptors are greatly broadening our understanding of PN-associated injury. It has also been shown that the composition of ω-6/ω-3 polyunsaturated fatty acids given parenterally as lipid emulsions can variably drive damage to hepatocytes and cell integrity. This manuscript reviews the mechanisms for the multifactorial pathogenesis of liver disease and gut injury with PN and discusses novel ameliorative strategies.

Non-mass versus mass-like ultrasound patterns in ductal carcinoma in situ: is there an association with high-risk histology?

AIM

To review the ultrasound (US) patterns of pure ductal carcinoma in situ (DCIS) using a non-mass-like (NML) versus mass-like (ML) classification and to investigate histopathological associations.

MATERIALS AND METHODS

The present study was a retrospective analysis of sonographically evident pure DCIS lesions detected in a mammographic (MG) screening programme over a 7-year period from 2008. All lesions had undergone US-guided 14 G core biopsies with no upgrades to invasive disease on surgical histopathology. Lesions that were three-dimensional with convex margins were classified as ML and all others as NML. ML lesions were subdivided into solid, cystic, or mixed, and NML lesions into ductal and non-ductal. Imaging and pathological characteristics of NML versus ML lesions were investigated using logistic regression.

RESULTS

There were 78 lesions in 75 participants. NML lesions accounted for 45 (58%) lesions, comprising 27 (60%) ductal and 18 (40%) non-ductal subtypes. There were 33 (42%) ML lesions; the largest subgroup being solid (n=21, 64%). Significant associations between lesion type and lesion size on US (<15 versus ≥15 mm), presence of US and mammographic calcification and posterior shadowing on sonography were identified. NML lesions had fivefold higher odds (OR=5.41 95% confidence interval [CI]: 2.03, 14.39, p=0.001) to be high grade and sevenfold higher odds (OR=7 95% CI: 1.75, 27.99, p=0.006) to have comedo necrosis on histopathology.

CONCLUSION

DCIS lesions can be successfully classified using ML and NML lesion descriptors and NML morphology on US is associated with histological features of "high-risk" DCIS.

Behavioural responses of stable flies to cattle manure slurry associated odourants

Stable flies (Stomoxys calcitrans [Diptera: Muscidae] L.) are blood-feeding synanthropic pests, which cause significant economic losses in livestock. Stable fly antennae contain olfactory sensilla responsive to host and host environment-associated odours. Field observation indicated that the abundance of stable flies increased significantly in grasslands or crop fields when cattle manure slurry was applied. Major volatile compounds emanating from manure slurry were collected and identified. Behavioural responses of stable flies to those compounds were investigated in laboratory bioassays and field-trapping studies. Results from olfactometer assays revealed that phenol, p-cresol and m-cresol were attractive to adult stable flies. When tested individually, attraction was higher with lower dosages. Stable flies were most attracted to blends of phenol and m-cresol or p-cresol. Traps with binary blend lures caught more stable flies in field trials as well.

Fibromatosis of the breast: a pictorial review of the imaging and histopathology findings

Fibromatosis of the breast is a rare condition that predominantly affects middle-aged women. It is locally aggressive, and exhibits a high incidence of local recurrence. The clinical presentation and radiological appearance are highly suspicious for carcinoma. Definitive diagnosis is made by diagnostic open biopsy. The aim of this review is to illustrate the main radiological and histopathological characteristics of this rare disease to increase awareness of this entity and discuss the role of magnetic resonance imaging (MRI) in its management.

Efficacy of cyromazine to control immature stable flies (Diptera: Muscidae) developing in winter hay feeding sites

Hay mixed with manure and urine residues at sites where hay has been provided as supplemental winter feed for cattle provide an excellent substrate for the development of immature stable flies, Stomoxys calcitrans (L.). Such sites are primary sources of early summer stable flies in the central United States and no effective measures are currently available to control fly development in them. A single application of granular cyromazine in May provided 97% reduction in the number of adult stable flies emerging from hay feeding sites. Stable fly control did not decline during the 12 wk season. A small decline in control was observed relative to anthomyiid, sarcophagid, and syrphid flies developing in the hay feeding sites. However, none of those flies are considered to be pests and > or = 50% control of those flies was maintained for 65 d after application. Cyromazine offers a safe and affordable option for the control of immature stable flies developing in winter hay feeding sites. Controlling those flies should reduce the estimated $2 billion per year of lost production in U.S. cattle industries attributable to stable flies.

Substrate properties of stable fly (Diptera: Muscidae) developmental sites associated with round bale hay feeding sites in eastern Nebraska

Residues at sites where stationary feeders were used to provide hay as supplemental forage for cattle during the winter are developmental substrates for immature stable flies, Stomoxys calcitrans (L.), in the central United States. Spatial patterns in physical (substrate depth, temperature, water content), chemical (pH, electrical conductivity [EC(lab)], total nitrogen [N] and carbon [C], ammoniacal nitrogen [NH(4)-N], extractable phosphorus [P]), and biological (microbial respiration rate) substrate properties for two feeding sites were estimated and the correlations between these properties and adult emergence were characterized. Hay feeding sites had a circular footprint with residues extending ≈7 m from the feeder. With the exception of extractable P and total N, all substrate properties exhibited spatial patterns centered on the feeder location. Adult stable fly emergence densities were significantly correlated with substrate microbial respiration rate, NH(4)-N concentration, EC(lab), total C concentration, pH, and moisture content. Logistic regression indicated that EC best predicted the probability of stable flies emerging from a substrate and that the other properties did not provide additional information. A better understanding of the physical, chemical, and biological conditions needed for stable fly larval development may help in identifying previously unrecognized developmental habitats and management of this pest. Targeted implementation of management practices such as sanitation and chemical treatments can be applied to smaller areas reducing labor and improving cost effectiveness.

Dewatered sewage biosolids provide a productive larval habitat for stable flies and house flies (Diptera: Muscidae)

Species diversity and seasonal abundance of muscoid flies (Diptera: Muscidae) developing in biosolid cake (dewatered biosolids) stored at a wastewater treatment facility in northeastern Kansas were evaluated. Emergence traps were deployed 19 May through 20 October 2009 (22 wk) and 27 May through 18 November 2010 (25 wk). In total, 11,349 muscoid flies were collected emerging from the biosolid cake. Stable flies (Stomoxys calcitrans (L.)) and house flies (Musca domestica (L.)), represented 80 and 18% of the muscoid flies, respectively. An estimated 550 stable flies and 220 house flies per square-meter of surface area developed in the biosolid cake annually producing 450,000 stable flies and 175,000 house flies. Stable fly emergence was seasonally bimodal with a primary peak in mid-July and a secondary peak in late August. House fly emergence peaked with the first stable fly emergence peak and then declined gradually for the remainder of the year. House flies tended to emerge from the biosolid cake sooner after its deposition than did stable flies. In addition, house fly emergence was concentrated around midsummer whereas stable fly emergence began earlier in the spring and continued later into the fall. Biosolid age and temperature were the most important parameters affecting emergence for house flies and stable flies, whereas precipitation was not important for either species. This study highlights the importance of biosolid cake as a larval developmental habitat for stable flies and house flies.

Dispersal of stable flies (Diptera: Muscidae) from larval development sites in a Nebraska landscape

Seven mark-recapture studies were conducted over 3 yr to assess dispersal of newly emerging adult stable flies, Stomoxys calcitrans L., from larval development sites in a mixed agricultural environment in northeastern Nebraska. Infested hay debris piles were marked by dusting their surfaces with fluorescent pigments, adults were captured with surrounding grids of Alsynite sticky traps, and specimens were dissected to determine feeding histories and reproductive age. Distances and directions of 3,889 marked specimens indicated males and females dispersed equally and in all directions. Midguts of males and females were equally likely to contain blood-meal remnants. Percentage with blood remnants and percentage of females with yolk increased with distance from mark origin, indicating survival and spread were positively associated with host finding success. A time-integrated diffusion model fit to results from the seven studies indicated 50% of stable fly adults had dispersed beyond 1.6 km of their natal site, but only 5% had dispersed beyond 5.1 km. These results indicate that stable fly adults on cattle in a given area are most likely to have originated from larval development sites within an ≈ 5 km radius of the subject cattle.

Assessing nuclear and mitochondrial DNA sequence variation within steinernema (rhabditida: steinernematidae)

DNA sequence analysis was used to characterize the nuclear ribosomal DNA ITS1 region and a portion of the COII and 16S rDNA genes of the mitochondrial genome from Steinernema entomopathogenic nematodes. Nuclear ITS1 nucleotide divergence among seven Steinernema spp. ranged from 6 to 22%, and mtDNA divergence among five species ranged from 12 to 20%. No intraspecific variation was observed among three S. feltiae strains. Phylogenetic analysis of both nuclear and mitochondrial DNA sequences confirms the existing morphological relationships of several Steinernema species. Both the rDNA ITS1 and mtDNA sequences were useful for resolving relationships among Steinernema taxa.

Genetic variation in geographical populations of western and Mexican corn rootworm

Genetic variation in the nuclear rDNA ITS1 region of western corn rootworm, Diabrotica virgifera virgifera (WCR), and Mexican corn rootworm, D. v. zeae (MCR) was studied. Two sites were detected which differentiated WCR and MCR in the 642-base sequence. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the first internal transcribed spacer region (ITS1) sequence revealed no variation within or among the twelve WCR and two MCR populations. PCR-RFLP of 75% of the mitochondrial DNA genome detected one significant polymorphic site out of the approximately 190 restriction sizes observed in WCR. The polymorphism did not differentiate geographical populations of WCR and is not diagnostic for the subspecies. The low levels of variation observed in WCR suggests either high levels of gene flow or a recent geographical expansion from a relatively small base. Gene flow would facilitate the rapid spread of traits that could compromise control programmes, such as insecticide resistance or behavioural modifications. The minimal genetic differentiation between WCR and MCR raises questions about the evolutionary history of these subspecies and how the distinct phenotypes are maintained.

Genetic similarity among pheromone and voltinism races of Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae)

The genetic variability of seven European corn borer populations, Ostrinia nubilalis, from North America and Europe was assessed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis and DNA sequencing. The nuclear ribosomal internal transcribed spacer 1 (ITS-1) region (approximately 500 base pair [bp]) and four mitochondrial (mtDNA) regions (1550 bp total) were examined. The smartweed borer, Ostrinia obumbratalis, and south-Western corn borer, Diatraea grandiosella, were used for comparisons. Of 106 restriction sites identified (80 in mtDNA and 26 in ITS-1), none differentiated geographical populations, pheromone races, or voltine ecotypes of the European corn borer. The lack of variation in the ITS-1 of European corn borer was confirmed by DNA sequence analysis. The genetic similarity of European corn borer populations, despite their wide geographical range and physiological differences, may be explained by a relatively recent origin for the voltinism and pheromone races, gene flow among races, and/or expansion from genetic bottlenecks.

The peptide LSARLAF causes platelet secretion and aggregation by directly activating the integrin alphaIIbbeta3

A novel peptide (designed to bind to alphaIIbbeta3) caused platelet aggregation and aggregation-independent secretion of the contents of alpha-granules in an alphaIIbbeta3-dependent fashion. The agonist peptide induced secretion in the presence of prostaglandin E1. In cell-free assays, alphaIIbbeta3 bound specifically to immobilized agonist peptide and the peptide enhanced the binding of fibrinogen to immobilized alphaIIbbeta3. The agonist peptide apparently activates alphaIIbbeta3 by directly inducing a conformational change in the receptor. This change activates the platelets and causes secretion in a manner independent of fibrinogen binding.

Variabilin, a novel RGD-containing antagonist of glycoprotein IIb-IIIa and platelet aggregation inhibitor from the hard tick Dermacentor variabilis

A novel inhibitor of human platelet aggregation, named variabilin, was isolated from salivary glands of the hard tick Dermacentor variabilis using a combination of gel filtration and high pressure liquid chromatography. Variabilin was a potent antagonist of the fibrinogen receptor glycoprotein IIb-IIIa (GPIIb-IIIa; alphaIIbbeta3) and the vitronectin receptor alphavbeta3. Amino acid sequence analysis by Edman degradation revealed that it has 47 residues, with a molecular weight of 4968.5. Like many other naturally occurring antagonists of GPIIb-IIIa, variabilin contains the RGD (Arg-Gly-Asp) motif. However, unlike the RGD-containing antagonists of GPIIb-IIIa, the RGD sequence of variabilin is not positioned in a loop bracketed by cysteine residues. It has little sequence homology to the other known naturally occurring antagonists of GPIIb-IIIa, including the disintegrins from snakes, decorsin and ornatin from leeches, and disagregin from soft ticks. Variabilin is the first RGD-containing antagonist isolated from ticks.

Population genetics and gene variation of stable fly populations (Diptera:Muscidae) in Nebraska

Genetic variation in stable fly, Stomoxys calcitrans (L.), populations from Nebraska, Canada, and Texas was sampled. Four of 12 allozyme loci were polymorphic, with an average of 1.7 alleles per locus. Observed and expected heterozygosities were 0.086 and 0.070, respectively. Nei's genetic distance between populations averaged 0.001 and ranged from 0.000 to 0.005. Wright's F statistics revealed greater variation within than among populations. Allele frequencies were homogeneous among temporal samples from a single population. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of 6.4 kb of the mitochondrial DNA genome with 16 restriction enzymes revealed no variation in stable fly populations from Canada, Nebraska, and Texas. PCR-RFLP analysis of a 2.0-kb fragment of the nuclear ribosomal DNA internally transcribed spacer region also revealed no variation. The lack of genetic differentiation among stable fly populations indicates high levels of gene flow among populations. The low levels of variation observed with biochemical and molecular techniques are consistent with a genetic bottleneck during stable fly colonization of North America.

Mitochondrial DNA variation in screwworm

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used to characterize mitochondrial DNA (mtDNA) variation in screwworms, Cochliomyia hominivorax, and secondary screwworm, C.macellaria, from the Caribbean, North America and South America. Four amplicons, totaling 7.1 kb, were analysed with sixteen restriction enzymes. A total of 133 restriction sites was observed in the two species, 104 in C.hominivorax, of which nineteen were variable, and ninety-five in C.macellaria, none of which was variable. Fourteen mtDNA haplotypes were observed among eighteen C.hominivorax examined. Mean divergence between C.hominivorax haplotypes (d) was 0.0064 substitutions per base-pair and genotypic diversity (G) was 0.97. Mean divergence between C.hominivorax and C.macellaria was 0.0824. Cochliomyia hominivorax haplotypes could be divided into three assemblages representing North America, South America and Jamaica, based on UPGMA clustering with d values. The assemblages did not exhibit complete geographic fidelity. These data were discordant with previously published allozyme data indicating little differentiation between screwworm populations. A scenario invoking historically isolated populations coming into contact with the introduction and movement of European livestock is proposed to explain the observed population structure of screwworm.

Population genetics and gene variation in screwworms (Diptera: Calliphoridae) from Brazil

Allozyme variation in New World screwworm, Cochliomyia hominivorax (Coquerel), populations from Brazil was examined. Variability was observed in 8 of 13 enzyme loci and the frequency of the most common allele was < 0.95 for seven loci. Observed and expected heterozygosities were 0.159 and 0.165, respectively. Comparisons of the Brazilian populations with previously studied populations from Costa Rica resulted in Nei's genetic distances of between 0.000 and 0.006, with the greatest distance being between populations within Brazil. Comparisons with Mexican populations using only three loci resulted in genetic distances < or = 0.031. Goodness-of-fit statistics for Hardy-Weinberg equilibrium and Wright's F statistics indicated small deviations from expected equilibrium genotype frequencies and low levels of differentiation between populations within Brazil. Differentiation among screwworm populations from Brazil, Costa Rica, and Mexico was minimal.

Identification of screwworm species by polymerase chain reaction-restriction fragment length polymorphism

Restriction fragment length polymorphisms in polymerase chain reaction amplified fragments (PCR-RFLP) of mitochondrial DNA were used to differentiate species of New World screwworms (Diptera: Calliphoridae). Twenty-seven restriction enzymes were screened on five regions of mtDNA. Eleven restriction fragment length patterns differentiated New World screwworm, Cochliomyia hominivorax (Coquerel), from secondary screwworm, Cochliomyia macellaria (F.). Five restriction fragment length patterns were polymorphic in C.hominivorax while all fragment patterns were fixed in C.macellaria. Diagnostic restriction fragment length patterns were used for species diagnosis, whereas intraspecific variable patterns were used to characterize field samples and laboratory strains. The PCR-RFLP technique is flexible with regard to developmental stage of the sample and method of preservation. We were able to characterize specimens of all life stages from egg to adult including larvae preserved in alcohol and pinned adults. PCR-RFLP is rapid and inexpensive, enabling specimens to be characterized within 24 h for less than $2.50.

Fibronectin peptide DRVPHSRNSIT and fibronectin receptor peptide DLYYLMDL arrest gastrulation of Rana pipiens

Gastrulation is characterized by dramatic cell migration which is thought to require the interaction of cell adhesion molecules with extracellular molecules. We have tested two novel peptides, a fibronectin peptide and a fibronectin receptor peptide, for their effects on gastrulation of the leopard frog Rana pipiens. The fibronectin peptide DRVPHSRNSIT corresponds to residues 1373-1383 of the cell-binding domain of fibronectin; the receptor peptide DLYYLMDL corresponds to residues 124-131 of beta 1 subunit of a variety of integrins including alpha 5 beta 1. Either of these peptides significantly inhibited gastrulation after being microinjected into mid-blastulae. These results indicate that these sequences may correspond to the ligand/receptor interaction sites of fibronectin and its receptor(s).

Carcinoma of the breast with sarcomatous metaplasia

Carcinoma of the breast with sarcomatous metaplasia (CSM) is a rare and interesting tumour with a poorer prognosis than the usual breast malignancies. The mammographic appearances of this lesion have only previously been described once in the literature. A case of CSM is presented with mammographic-pathological correlation and review of the literature.

Complementary peptides that interfere with platelet aggregation and adherence

This article describes the application of the molecular recognition hypothesis to the critically important process of fibrinogen binding to platelets, a process that is the subject of extensive and intensive basic and clinical research. The objectives of the studies summarized below were to design, synthesize, and characterize peptides that can inhibit the binding of fibrinogen and related ligands to human platelets and thereby prevent platelet aggregation, adhesion, and clot retraction. The purpose of doing this work was twofold: first, to determine whether the molecular recognition hypothesis could serve as a useful rationale for the design of peptides that can specifically inhibit the binding of fibrinogen and related ligands to platelets; and second, to use these peptides to try to learn where fibrinogen binds to the platelet fibrinogen receptor. It was hoped that the results obtained not only would provide insight into platelet function but also might provide a rationale for the design of a clinically useful anti-thrombotic agent. Although our studies are not complete, they have resulted in the design of a variety of peptides that can inhibit platelet aggregation, adhesion, and clot retraction as a consequence of specifically inhibiting the binding of fibrinogen and related ligands to the platelet fibrinogen receptor. Although none of these peptides appears to be ligand specific, one or two of them may be specific for platelets.

Antibodies to GPIIb alpha (300-312) inhibit Fg binding, clot retraction, and platelet adhesion to multiple ligands

We previously reported that a peptide with the sequence Gly-Ala-Pro-Leu (GAPL) found as residues 309-312 in glycoprotein IIb alpha (GPIIb) comprises at least part of a Fg binding site on GPIIb (1). Subsequent studies demonstrated that a peptide corresponding to residues 300-312 of GPIIb alpha can bind to Fg and Vn, and is a potent inhibitor of platelet aggregation and the adhesion of activated platelets to at least four adhesive ligands: Fg, Fn, Vn, and vWf (2). Here, the production and initial characterization of polyclonal antibodies against this peptide are described. ELISAs and dot-blot assays reveal the specificity of the antibodies for the peptide immunogen. In immunoblots, the antibodies recognize GPIIb under reducing conditions. The binding of Fg to immobilized GPIIb/IIIa, the rate of clot retraction and the adhesion of stimulated platelets to Fg, fibronectin (Fn), vitronectin (Vn), and von Willebrand factor (vWf) were inhibited by these antibodies, but not by a control IgG. These results together with our earlier published data indicate that GPIIb alpha (300-312) comprises at least part of a common ligand binding site within the integrin alpha IIb subunit.

Characterization of adhesion of "resting" and stimulated platelets to fibrinogen and its fragments

Adhesion of resting and stimulated platelets to immobilized fibrinogen (Fg) was characterized using various forms of Fg, receptor peptide mimics, and antibodies to glycoprotein (GP) IIb/IIIa and Fg. Resting platelets adhered to Fg, but to less than half the extent of the same platelets stimulated with epinephrine/ADP. The adhesion of resting and stimulated platelets to Fg was inhibited by a receptor peptide mimic (G13, a peptide corresponding to residues 300-312 of GPIIb), anti-GPIIb/IIIa antibodies, and a monoclonal antibody (4A5) against the carboxyl terminus of the gamma chain of Fg. The results presented here demonstrate that the alpha chain RGD platelet recognition sites are not required to mediate the adhesion of either stimulated or resting platelets to immobilized Fg. Although stimulated platelets can adhere extensively to monomeric Fg containing one functional gamma chain, resting platelets require bivalent Fg containing two functional gamma chains to mediate irreversible adhesion to Fg.

MR evaluation of the temporomandibular joint in juvenile rheumatoid arthritis

Temporomandibular joint (TMJ) disease is uncommon in children but frequently occurs in juvenile rheumatoid arthritis (JRA). Involvement is often asymptomatic; however, it can lead to growth disturbances and facial deformity. Thirty TMJs in 15 children (11 girls and 4 boys aged 3.5-18 years) with JRA were evaluated clinically and by MRI. Plain films were reviewed when available. Magnetic resonance imaging parameters included T1-weighted and in some cases T2-weighted or gradient recall echo sequences. We assessed condylar configuration, glenoid fossa changes, presence of erosions, disk abnormality, range of motion, and presence of joint effusions or pannus. Abnormalities included cortical erosions (n = 19), disk thinning (n = 18), and perforation (n = 2). Reduction of joint movement (n = 20), joint locking (n = 3), and pannus/effusions (n = 5) were also found. Magnetic resonance imaging is a useful technique for the detection of TMJ involvement in JRA. Early detection and therapeutic intervention may lessen or prevent subsequent deformities.

A peptide corresponding to GPIIb alpha 300-312, a presumptive fibrinogen gamma-chain binding site on the platelet integrin GPIIb/IIIa, inhibits the adhesion of platelets to at least four adhesive ligands

The platelet fibrinogen (Fg) receptor (GPIIb/IIIa) is an integrin which plays a critical role in hemostasis by recognizing at least the four adhesive ligands: Fg, fibronectin (Fn), vitronectin (Vn), and von Willebrand factor (vWf). We reported that residues 309-312 of GPIIb alpha appear to comprise at least part of a Fg binding site on the Fg receptor (Gartner, T. K., and Taylor, D. B. (1990) Thromb. Res. 60, 291-309). Here we report that the peptide GPIIb alpha 300-312 (G13) inhibits platelet aggregation and binds Fg and Vn. Significantly, this peptide inhibits the adhesion of stimulated platelets to Fg, Fn, Vn, and vWf, but not the adhesion of resting platelets to Fn. Thus, GPIIb 300-312 may constitute a specific but common recognition site on GPIIb/IIIa for both LGGAKQAGDV- and RGD-containing ligands.

The peptides APLHK, EHIPA and GAPL are hydropathically equivalent peptide mimics of a fibrinogen binding domain of glycoprotein IIb/IIIa

The anticomplementarity hypothesis predicted that the peptides APLHK, EHIPA, GAPL and LGVPPR would be functional mimics of a fibrinogen binding domain(s) in the fibrinogen receptor. The peptides APLHK and EHIPA were derived by translation of the cRNA of vitronectin m-RNA. The peptides GAPL and LGVPPR result from translations of the cRNA of von Willebrand factor m-RNA. The peptides APLHK, EHIPA, and GAPL, but not LGVPPRT, are hydropathically equivalent and inhibit fibrinogen binding to platelets. APLHK and EHIPA are hydropathic retromers. Thus for one pair of these peptides, the direction of their backbones did not affect function.

The peptide Glu-His-Ile-Pro-Ala binds fibrinogen and inhibits platelet aggregation and adhesion to fibrinogen and vitronectin

Antiplatelet agents are clinically useful as antithrombotic entities. The importance of antiplatelet agents led us to design, synthesize, and characterize a new antiplatelet peptide. This peptide is a presumptive mimic of a ligand binding site on the platelet fibrinogen receptor. Unlike peptides related to Arg-Gly-Asp-Ser and His-His-Leu-Gly-Gly-Ala-Lys-Gln-Ala-Gly-Asp-Val that bind to the fibrinogen receptor, this peptide binds to fibrinogen. The anticomplementarity hypothesis was used to design this presumptive peptide mimic of the vitronectin binding site on the fibrinogen receptor, glycoprotein IIb/IIIa complexes. The resulting peptide (Glu-His-Ile-Pro-Ala) has the characteristics of a fibrinogen binding site mimic: It binds fibrinogen and inhibits both the adhesion of platelets to fibrinogen and platelet aggregation. The peptide also inhibits the adhesion of platelets to vitronectin. The antiplatelet activity of this mimic peptide was dependent on its amino acid sequence, since closely related analogues were either inactive or less active inhibitors of platelet function than the original peptide. These results demonstrate that the peptide Glu-His-Ile-Pro-Ala has the characteristics expected of a mimic of a glycoprotein IIb/IIIa ligand binding site.

Arteriopathy and coarctation of the abdominal aorta in children with mucopolysaccharidosis: imaging findings

Eight children with mucopolysaccharidosis I (MPS I), representing 33% of all children with MPS I seen at our institution during an 18-year period, developed hypertension. Five of these hypertensive children also exhibited symptoms of aortic coarctation. The radiographic evaluation of four of these children with MPS I (three with Hurler syndrome, MPS I H, and one with Scheie disease, MPS I S) and arteriopathy affecting the thoracic aorta, abdominal aorta, and visceral and renal arteries is presented. Hypertension developed in all four children before they were 4 years old; three had differences between upper- and lower-extremity blood pressures. Irregular narrowing of the abdominal aorta with either multiple minor asymmetric wall lesions (n = 2) or abrupt concentric narrowing (n = 2) was present in all children as shown by aortography (n = 3), sonography (n = 3), MR imaging (n = 2), and/or autopsy (n = 1). A variety of other vessels also were involved, including the ascending aorta (n = 1) and vertebral (n = 1), axillary (n = 1), intercostal (n = 2), lumbar (n = 2), mesenteric (n = 3), renal (n = 2), and iliac arteries (n = 3). Autopsy in one child demonstrated thickened heart valves, narrowing of the coronary arteries, and irregularity of the aorta due to deposition of mucopolysaccharide material within the intima. Our series demonstrates various facets of the arteriopathy of MPS I as shown by sonography, MR imaging, and angiography.

In vitro activity of ceftriaxone and amikacin against Pseudomonas aeruginosa

Ceftriaxone and amikacin were combined at ratios of 1:1, 5:1, and 10:1 and tested in vitro against Pseudomonas aeruginosa. The activity was determined using the Steers-Foltz replicator and the agar dilution technique with Mueller-Hinton agar. Under all conditions tested, including those simulating severe infection (10(5) to 10(6) colony-forming units per spot), the organisms were more susceptible to the combination than to the single agents. With a conventional inoculum of 10(4) colony-forming units per spot, the combinations gave 97-100% coverage against P. aeruginosa. The increased activity of the combinations resulted in MIC90 values which were below the expected serum/plasma levels for significantly longer time periods than the MIC90 values observed with the individual agents.

The amino acid sequence Gly-Ala-Pro-Leu appears to be a fibrinogen binding site in the platelet integrin, glycoprotein IIb

The amino acid sequence Gly-Ala-Pro-Leu-Arg-Val is predicted by the anticomplementarity hypothesis to be a fibrinogen binding site on human platelet fibrinogen receptors. The peptide Ala-Pro-Leu-Arg-Val binds fibrinogen and inhibits platelet aggregation and clot retraction. The peptide Gly-Ala-Pro-Leu is the shortest sequence within the predicted sequence which potently inhibits the adhesion of platelets to fibrinogen and platelet aggregation. The sequence Gly-Ala-Pro-Leu is present as residues 309-312 in glycoprotein IIb, the alpha-subunit of the glycoprotein IIb/IIIa complex, the fibrinogen receptor. The sequence Gly-Ala-Pro-Leu is present in 4 of 8 integrin alpha-subunits and Gly-Ala-Pro is present in 8 of 8 integrin alpha-subunits.

Cavitating pulmonary nodules in histiocytosis-X high resolution CT demonstration

In a case of pulmonary histiocytosis, high resolution C.T. scanning (H.R.C.T) showed multiple small ring shaped peripheral pulmonary lesions. This has not, to our knowledge been previously reported in the radiological literature. The possible pathogenesis of these lesions is described. With the advent of H.R.C.T this appearance should become more widely recognised in the future. H.R.C.T was of considerable assistance in diagnosis of this patient with non-specific findings on the plain chest film.

Genetics of screwworm: new genetic markers and preliminary linkage map

Eight new genetic markers for Cochliomyia hominivorax (Diptera: Calliphoridae), the screwworm, are characterized. The markers include three eye mutants, lemon-eye (le), cherry-eye (ch), and red-eye (re); one wing mutant, curly-wing (cw); and four allozyme markers, amylase (Amy-1), glycerol-3-phosphate dehydrogenase (Gpd), phosphoglucomutase (Pgm), and octanol dehydrogenase (Odh). The markers are associated into four linkage groups. Radiation-induced translocations were used to correlate the linkage groups with their respective chromosomes. A preliminary genetic linkage map with these and three previously characterized loci is presented.

Dominant craniometaphyseal dysplasia--a family study over five generations

A two month old male infant being investigated for nasal obstruction was noted to have the typical facies and radiological changes of craniometaphyseal dysplasia. Investigation of the family detected 9 individuals in 4 generations with radiological evidence of craniometaphyseal dysplasia. Their ages ranged from 2 months to 70 years. Three presented with nasal obstruction, one with facial nerve dysfunction and three had developed deafness in or before their third decade. Two were asymptomatic. One family member, now dead, was known to have had early onset of deafness but had not been examined or X-rayed. All of the affected individuals were noted to have had the typical facies in childhood. Characteristic radiological findings in the cranium and long bones were present to a varying degree and were most prominent in those presenting in infancy.

A survey of professional music therapists concerning entry level competencies

The project suggests that intended therapeutic outcomes should determine the professional competencies needed to achieve those results. Competency identification literature reflects use of presage, process and product criteria, expert consensus, job task analysis, and practitioner testimony. The present project was completed in two phases. The Phase I survey contained 150 competency statements to be rated on an 8-point necessity scale by all responding Registered Music Therapists (RMTs). Phase II contained 100 items that were rated by RMTs and Certified Music Therapists (CMTs). Findings showed a preference for an eclectic approach to treatment, the psychiatric hospital as the most used setting, and the developmentally disabled as the largest client group. Over two thirds of all responding therapists had a bachelor's degree with less than 5 years' experience. Most competencies obtained average ratings in the upper half of the scale and were placed in similarly rated groups. Very few items had ratings that reflected differences in respondent characteristics.

Foraminal encroachment syndrome in true lumbosacral spondylolisthesis: a preliminary report

The source of pain in isthmic spondylolisthesis is uncertain. Some authors believe that spondylolysis and/or spondylolisthesis is not a predisposing factor to low back pain and that the mere presence of isthmic spondylolisthesis may, indeed, not be the cause of low back pain in the patient. This study explores a possible source of biomechanical dysfunction as an origin of pain in isthmic spondylolisthesis. One hundred and twenty lumbar intervertebral disc angles were measured, 60 of which had spondylolisthesis and the remaining 60 without spondylolisthesis for comparison of the effect that spondylolisthesis has on intervertebral disc angulation of the lumbar spine. The results reveal that the L4-L5 joint has the greatest biomechanical stress placed upon it by virtue that it had the highest intervertebral disc angulation when the component of spondylolisthesis was a factor at L5-S1. Therefore, due to increased intervertebral disc angles at L4-L5, a biomechanical stressing and resulting hyperextension of the facet articulation at L4-L5 may represent a source of symptomatology in isthmic spondylolisthesis of L5-S1.

The activation of the nicotinic acetylcholine receptor by the transmitter

Experimental evidence has been published from isolated guinea pig muscle in vitro, and from direct ligand binding to receptors from T. californica, indicating that two agonist ions react with the nicotinic receptor by exchanging for one magnesium ion. It is the basis of the ion exchange receptor pair model, in which two acetylcholine ions exchange for one magnesium ion in contact with and between a pair of negatively charged receptor groups about 4 A apart. In the resting state the electrostatic attraction between the negatively charged receptor groups and the Mg2+ ion exerts a binding force. This binding force is opposed by the quantum mechanical repulsions of the electron clouds of the charged groups and ions in contact, together with the mutual repulsion of the pair of receptor oxyanions. When the Mg2+ ion is replaced by two acetylcholine ions the quaternary heads of the latter are positioned so that they form two mutually repelling ACh+ receptor group dipoles. As the Mg2+ ion leaves, its rehydration energy contributes to the sum of the electron cloud repulsions and the ACh+ receptor group dipole repulsions, causing the receptor groups to be forced apart activating the receptor macromolecule. The subsequent decrease in ACh+ concentration results in the reestablishment of the resting state. The coulombic electrostatic energy, the Born repulsion energy, the London attraction energy and the oxyanion ACh+ dipole repulsion energies have been calculated and shown to be consistent with the model. The displacement of the Mg2+ by two ACh+ ions makes several hundred kcals of energy available for receptor group separation and receptor activation.

Music in general hospital treatment from 1900 to 1950

Beginning at the turn of the century, this report examines the effect of the recently invented phonograph on practical and experimental efforts to reconcile the century-old separation of medicine and music. Progressing chronologically, events are examined which affected the use of music in physical medicine during the first half of the 20th century. Topics include the first college course-work in hospital music, important theories regarding the neurological basis of musical effects, early research investigating the influence of music on physiological behavior, the inclusion of permanent musical hardware in hospital construction, social and physical rehabilitation in orthopedic medicine, psychological applications in pediatrics and psychosomatic medicine, and the use of music to combat pain in surgical, dental, obstetrical, and gynecological procedures.

Movement of labelled decamethonium in muscle fibres of the rat

1. Tritium-labelled decamethonium accumulated in diaphragm muscles of the rat in vitro with a peak at the end-plate region and the distributions were fitted by Gaussian curves. 2. Prolonged wash in physiological saline (10 hr) produced some loss in radioactivity but no detectable spread of the labelled compound along the fibres, which indicated that the decamethonium was not in a mobile form. 3. Rats injected with labelled decamethonium showed radioactivity in the diaphragm muscles after 21 days. 4. A slow spread of the labelled compound along the fibres was detected, and from the widening of the Gaussian curves the apparent diffusion coefficient was 1.2 X 10(-8) cm2sec-1, which is less than 1/500 of that in free solution.