Cluster of influenza A cases in vaccinated population of adults in Virology Laboratory in Glasgow in December 2012.

BACKGROUND AND AIMS: The majority of influenza infections during the 2012/2013 influenza season in Scotland have been due to influenza A H3N2. We report an outbreak of influenza A H3N2 in a vaccinated population of adults in the Regional Virology Laboratory in Glasgow. This investigation was carried out to confirm the epidemiological link between cases. METHODS AND RESULTS: Staff with clinical symptoms of influenza-like illness were included. Samples were tested by real-time polymerase chain reaction and sequencing. Staff were interviewed to obtain information regarding symptom onset and vaccination status. Eight confirmed cases and six clinically diagnosed cases were reported, which all occurred within 4 days of a lunchtime Christmas quiz. The eight samples subtyped as H3 virus. The haemagglutinin gene in the confirmed cases was sequenced and shown to be identical. Most of the attendees had been immunised against influenza with the same vaccine batch at least 6 weeks earlier. CONCLUSION: This outbreak appears to have been an isolated incident, which arose due to a social event that provided the ideal conditions for transmission of a respiratory disease. It may have been compounded by low-vaccine effectiveness this season. Sequence data supported the epidemiological link.

The influence of space in genetic-environmental relationships when environmental heterogeneity and seed dispersal occur at similar scale.

We tested the importance of microenvironmental topographic parameters as predictors of emmer wheat genetic variation using three classes of single-locus (or at most several-loci) genetic markers (allozymes, glutenins, and qualitative traits) and two classes of markers of polygenic inheritance (phenological and morphological traits). Canonical correspondence analysis (CCA) and redundancy analysis (RDA) detected a significant effect of spatially structured environmental variation on genetic differences between plants for allozymes, glutenins, and quantitative morphological and phenological traits. However, after removing a spatial component of variation in partial CCA and partial RDA, the relationship of the remaining environmental variation with these genetic markers could be explained by chance alone, allowing us to rule out microniche topographic specialization in emmer wheat. Topographic autocorrelation exhibited a certain degree of similarity with genetic marker autocorrelation, indicating similar scales of environmental heterogeneity and seed flow. The detected population genetic structure agrees with one expected under isolation by distance as a result of limited gene flow. A negative relationship of genetic similarity with the logarithm of distance between plants was detected for both molecular markers and quantitative traits, which differed in the strength but not the pattern of association.

Alanine scanning mutagenesis of a type 1 insulin-like growth factor receptor ligand binding site.

The high resolution crystal structure of an N-terminal fragment of the IGF-I receptor, has been reported. While this fragment is itself devoid of ligand binding activity, mutational analysis has indicated that its N terminus (L1, amino acids 1-150) and the C terminus of its cysteine-rich domain (amino acids 190-300) contain ligand binding determinants. Mutational analysis also suggests that amino acids 692-702 from the C terminus of the alpha subunit are critical for ligand binding. A fusion protein, formed from these fragments, binds IGF-I with an affinity similar to that of the whole extracellular domain, suggesting that these are the minimal structural elements of the IGF-I binding site. To further characterize the binding site, we have performed structure directed and alanine-scanning mutagenesis of L1, the cysteine-rich domain and amino acids 692-702. Alanine mutants of residues in these regions were transiently expressed as secreted recombinant receptors and their affinity was determined. In L1 alanine mutants of Asp(8), Asn(11), Tyr(28), His(30), Leu(33), Leu(56), Phe(58), Arg(59), and Trp(79) produced a 2- to 10-fold decrease in affinity and alanine mutation of Phe(90) resulted in a 23-fold decrease in affinity. In the cysteine-rich domain, mutation of Arg(240), Phe(241), Glu(242), and Phe(251) produced a 2- to 10-fold decrease in affinity. In the region between amino acids 692 and 702, alanine mutation of Phe(701) produced a receptor devoid of binding activity and alanine mutations of Phe(693), Glu(693), Asn(694), Leu(696), His(697), Asn(698), and Ile(700) exhibited decreases in affinity ranging from 10- to 30-fold. With the exception of Trp(79), the disruptive mutants in L1 form a discrete epitope on the surface of the receptor. Those in the cysteine-rich domain essential for intact affinity also form a discrete epitope together with Trp(79).

Do patients with critical limb ischaemia undergo multiple amputations after infrainguinal bypass surgery?

BACKGROUND: it has been suggested that an aggressive policy of bypass for limb salvage in critical ischaemia may result in patients subsequently undergoing multiple amputations. The aim of this study was to test this suggestion in the context of a dedicated Vascular Surgical Unit in a U.K. teaching hospital. METHODS: three hundred and sixty-eight patients undergoing lower limb bypass operations for critical limb ischaemia between April 1991 and March 1999 were studied retrospectively. Their median age was 69 years (IQR 64--75) and 243 (66%) were men. RESULTS: seventy-five operations were followed by one or more amputation (20%). Only 2% were multiple amputations. Age and sex had no effect on amputation rates, but emergency bypass operations led to a higher rate of amputation in those with critical limb ischaemia. CONCLUSION: patients with critical limb ischaemia who undergo lower limb bypass surgery rarely have subsequent multiple amputation.

The measurement of pupil cycling time.

PURPOSE: To assess the influence of pupil size on pupil cycling time (PCT), a measure which may be elongated in cases of neurological disease. METHOD: Clinically, pupil "cycling" is produced by focusing a slit-lamp beam on the pupil margin. A rhythmic contraction and dilation of the pupil is produced, as changes in pupil size alternately prevent and allow the light beam to reach the retina. In this study, however, the light beam was controlled electronically so that cycling could be produced around different pupil sizes. Measurements of the variation of PCT with pupil size were taken from 22 young normal subjects. RESULTS: PCT was seen to depend upon pupil size, increasing monotonically but non-linearly as size increased. The wave-form of pupil cycling is typically sawtooth, contraction being much faster than dilation. There was considerable variation amongst subjects in the range of pupil sizes where pupil cycling could be elicited. CONCLUSIONS: The results point to the need for a standardised procedure for the measurement of cycling time, because differences in clinical conditions will themselves influence pupil size, as will other external variables such as ambient light level. The results also bring into question neurological explanations for increased PCT in those diseases where pupil size is affected, because normal subjects have PCTs well beyond the accepted limits of normality when their pupils are enlarged.

Employee exposure to diesel exhaust in the electric utility industry.

The purpose of this study was to assess diesel exhaust exposures in the electric utility industry and to compare these findings with worker exposures reported in other industries and to proposed and established occupational exposure limits. Two sampling approaches were used: particulates were analyzed for elemental (EC) and organic (OC) carbon via the thermal-optical method; and gaseous components (NO2, SO2, NO, and CO) were determined using a direct reading instrument, the Metrosonics pm-7400. Concentrations of the gases were all well within established occupational exposure levels. The EC percentage of the total carbon was generally lower than results reported from other studies resulting in OC levels representing a higher percentage of the total carbon concentrations. Smokers had higher average OC exposure (79 micrograms/m3) than nonsmokers (57 micrograms/m3), but cigarette smoke did not contribute to EC levels in this study (smokers and nonsmokers = 3 micrograms/m3). Two of 120 individual personal exposure levels were found to exceed the proposed threshold limit value of 150 micrograms/m3 for total particulate, but geometric mean levels were found to be significantly less than the proposed value. Questions are raised concerning the use of EC as the sole surrogate for estimating diesel content for comparison with an exposure standard.

A randomized clinical trial of cryotherapy, laser vaporization, and loop electrosurgical excision for treatment of squamous intraepithelial lesions of the cervix.

OBJECTIVE: To compare cryotherapy, laser vaporization, and loop electrical excision for treatment of squamous intraepithelial lesions (SILs). METHODS: Women at least 18 years old with biopsy-proven SIL, negative pregnancy tests, negative findings on endocervical curettage, satisfactory colposcopy examinations, and congruent Papanicolaou smear and biopsy results were assigned randomly to treatment after stratification by SIL grade, endocervical gland involvement, and lesion size; they were evaluated 1, 4, 8, 12, 16, 20, and 24 months after treatment. Data were analyzed using chi2 statistics, logistic regression analysis, and the Cox proportional hazards model. RESULTS: Of 498 patients assigned, 108 were excluded (most because of inadequate follow-up), leaving 390 (139 cryotherapy, 121 laser vaporization, 130 loop excision) for analysis. All were followed 6-37 months (mean 16). There were no statistically significant differences in complications, persistence (disease present less than 6 months after treatment), or recurrence (disease present more than 6 months after treatment). Risk of persistent disease was higher among women with large lesions (risk ratio [RR], 18.9; 95% confidence interval [CI], 3.2, 110.6). Recurrence risk was higher among women aged 30 years and older (RR, 2.1; 95% CI, 1.2, 4.3), those with human papillomavirus type 16 or 18 (RR, 2.1; 95% CI, 1.1, 4.0), and those who had had prior treatment (RR, 2.1; 95% CI, 1.1, 3.9). CONCLUSION: The data support a high success rate with all three modalities. No significant difference in success rates was observed between the three treatments in our population. Additional attention and research should be directed toward the higher risk patients identified above.

HIV protease genotype and viral sensitivity to HIV protease inhibitors following saquinavir therapy.

OBJECTIVE: To examine the relationship between HIV protease genotype and altered protease inhibitor sensitivity of isolates from patients after therapy with saquinavir (SQV) in its hard gelatin formulation. DESIGN: Forty-one post-therapy isolates and corresponding baseline samples were obtained from 37 patients in four different clinical trials after therapy with SQV for 16-147 weeks. Post-therapy isolates were selected on the basis of preliminary sequence or drug sensitivity data. RESULTS: Fifteen out of 17 isolates without detectable Val-48 or Met-90 mutations retained sensitivity to SQV. (The remaining isolates showed only a marginal increase in median inhibitory concentration.) In addition, three out of 15 isolates with Met-90 retained sensitivity to all other protease inhibitors tested (indinavir, ritonavir, amprenavir, nelfinavir). Of the isolates showing reduced sensitivity to SQV, six out of 22 retained sensitivity to all other protease inhibitors, whereas only four out of 22 showed broad cross-resistance to all protease inhibitors tested. The reduction in sensitivity correlated closely with the presence of Val-48 or Met-90. Subsequent accessory substitutions were also linked to reduced sensitivity. However, significant linkage was observed only between mutations at residues 48 and 82 and between those at residues 82 and 74. CONCLUSIONS: Recruitment of Val-48/Met-90 mutations was not found to be synonymous with cross-resistance. Indeed, the majority of isolates with these mutations retained sensitivity to at least one protease inhibitor (Val-48, 86%; Met-90, 77%). The recruitment of accessory mutations may occur only after the selection of key resistance mutations. Furthermore, Met-90 was found to be a poor marker of cross-resistance in SQV-treated patients.

Endometrial hyperplasia and endometrial cancer.

Endometrial cancer is the most frequently seen gynecologic neoplasm, but it fortunately has low mortality, which is due largely to its presentation with abnormal bleeding and its subsequent early diagnosis. The morbidity associated with therapy for early lesions is moderate. Hyperplasia with atypia should be treated as early cancers. Many molecular markers are currently under study. Markers may soon help us identify invasive lesions at higher risk of recurring and thus more suitable for adjunct therapy. Screening in the general population is not recommended, but a high-risk group that is more suitable for screening could be identified, including obese and nulliparous women, those treated with unopposed estrogen or tamoxifen, or those with family or past histories of breast or colon cancer. Development of chemoprevention with an oral contraceptive during the reproductive years is under way, and there may be a role for chemoprevention in the reversal of hyperplasias.

Uterine sarcoma.

Sarcomas are rare tumors with unpredictable prognosis. They are treated similarly to endometrial cancers. Little is known of epidemiologic risk factors for sarcoma; similarly, little work has been performed assessing molecular alterations in sarcomas. Because of their rarity, uterine sarcomas are not suitable for screening. Chemoprevention studies might target those at risk for recurrence or a second neoplasm.

Ovarian intraepithelial neoplasia and ovarian cancer.

Ovarian cancer accounts for only 4% of cancers in women, but it is the leading cause of death from gynecologic malignancies in the United States. In the general population, a woman's lifetime risk of ovarian cancer is 1.4% but this risk can increase substantially in women with a strong family history of the disease. The high mortality rate from ovarian cancer is due primarily to the difficulty in detecting the disease in early stages; the disease tends to be asymptomatic until it is well advanced. The primary care physician needs to be alert to the possibility of an ovarian malignancy in all women with an intact ovary or ovaries who present with abdominal or pelvic complaints. There are no current recommendations for routine screening for ovarian cancer in the general population. Even in high-risk women, there are currently no convincing data to support extensive screening, although a number of studies looking at this issue are under way. Despite this lack of conclusive evidence, a consensus panel on ovarian cancer convened by the NIH recently issued guidelines for screening high-risk women. They recommend annual rectovaginal pelvic examination, testing of CA 125 level, and transvaginal ultrasonography. Color flow Doppler analysis of the ovarian vessels is also being studied as a possible screening modality. BRCA1 gene testing may soon play a role in women with a strong family history of the disease. Given its high mortality rate, primary prevention strategies for ovarian cancer should be used whenever possible. Oral contraceptive use appears to reduce the risk of ovarian cancer. Prophylactic oophorectomy may be suggested for women at particularly high risk of the disease. Here, too, the primary care physician can play an important role in helping a patient understand the risks and benefits of these options.

Gestational trophoblastic disease.

GTD occurs in fewer than 1 in 1200 pregnancies in the United States, but it is much more common in Asia and Latin America, where its incidence may be as high as 1 in 200 pregnancies. Risk factors for GTD include advanced or young maternal age, low socioeconomic status, and prior hydatidiform mole. Early diagnosis and prompt treatment are key to a favorable outcome, and thus recognition of the signs and symptoms of the disease is important for all physicians. Because these diseases have low incidences and occur after reproductive events, screening for them in the general population is not worthwhile. No chemopreventive agents have yet been studied in women at risk for GTD, but the oral contraceptive is a good candidate.

Clinical applications of genetic testing: implications for the family physician.

Genetic testing may be applied in a variety of clinical situations, including preconception counseling, prenatal diagnosis and postnatal determination of genetic predisposition to disease. The family physician needs to become familiar with the full range of genetic testing possibilities in all phases of the human life cycle. Cystic fibrosis, Huntington's disease and cancer are three diseases for which genetic testing has become a reality, and they serve to illustrate the clinical and ethical dilemmas that arise with this type of testing.

Weak transcriptional activation is sufficient for transformation by v-Myb.

The v-myb oncogene causes monoblastic leukemia in chickens and transforms avian myelomonocytic cells in vitro, v-Myb is a short-lived nuclear protein which binds to DNA in a sequence-specific manner and can activate gene expression in transient DNA transfections. Analysis of a series of v-Myb mutants has shown that the ability to activate transcription appears to be required for leukemic transformation. We have systematically investigated transcriptional activation by v-Myb and have made several new observations: (i) v-Myb is a very weak activator when compared to GAL4; (ii) very weak transcriptional activation by v-Myb is sufficient for transformation, whereas very strong transcriptional activation by a v-Myb-VP16 fusion protein is not; and (iii) v-Myb can activate transcription by two genetically distinct mechanisms, only one of which requires the presence of Myb-binding sites.

Haemodialysis for renal failure in diabetes mellitus - abstract

The prognosis for diabetic patients with end-stage renal disease (ERSD) treated by all modalities of renal replacement therapy is not as good as for non-diabetics. The literature, prior to 1976, reported a very poor prognosis for diabetic patients treated by haemodialysis. With the widespread introduction of continous ambulatory peritoneal dialysis (CAPD) in the 1970s, this was advocated as the dialysis treatment of choice for diabetic patients with ERSD. Several large studies reported after the mid-1980s do not confirm any significant advantage of CAPD over haemodialysis for diabetic patients. The results for long-term haemodialysis in patients with diabetes mellitus have improved tremendously over the last two decades. In most renal failure programmes in the world (England, New Zealand and Southern Europe excepted), diabetes mellitus is the leading cause of ERSD, and over 80 per cent of these patients are treated by haemodialysis. Although transplantation continues to show superior results to dialysis, the fact remains that older and sicker patients are treated by haemodialysis while the younger patients with less co-morbid conditions are accepted for transplantation. Also, haemodialysis for ERSD has results approaching those for cadaveric renal transplantation when adjustments for age and co-morbid conditions are made (AU)

Carboxy-terminal elements of c-Myb negatively regulate transcriptional activation in cis and in trans.

The c-Myb protein plays a key role in normal hematopoiesis, and truncation results in its activation to a transforming protein. Truncation of the c-Myb carboxyl terminus also greatly increases its transcriptional activating activity. The role of specific carboxy-terminal domains in negative regulation was investigated using Myb and Myb fusions with GAL4, LexA, or VP16. Negative regulatory activity of the carboxyl terminus in cis resides in at least two regions. A sequence in one of these regions can also inhibit transcriptional activation by Myb, Myb-VP16, or LexA-Myb proteins in trans. Regulation in trans, or suppression, is independent of c-Myb DNA binding and, therefore, likely involves protein-protein interaction. Suppression does not require the presence of a predicted heptad leucine repeat structure on either molecule. The target of suppression is a sequence that contains part of the minimal Myb transcriptional activation domain. This sequence can confer suppressibility on fusion proteins containing heterologous DNA-binding or transcriptional activation domains.

The implications of the Human Genome Project for family practice.

The Human Genome Project is an international effort to map and sequence the human genome. The information it will generate has been referred to by some as the "new anatomy," and may play an important role in the future of medicine. However, as with any new technological advancement, the outcome of the Human Genome Project and the subsequent availability of new technology will raise a myriad of ethical, legal, and social concerns. The fear is that this technology will be applied in the clinical setting before the appropriate infrastructure is in place to deal with the issues it will raise. The family physician, far from being merely an interested observer in this process, will be responsible for the delivery of much of this technology as it becomes available. As an intermediary between the technology and the individual patient, the physician has a unique obligation to join in the thoughtful consideration and debate of these issues.

A highly conserved cysteine in the v-Myb DNA-binding domain is essential for transformation and transcriptional trans-activation.

The v-Myb protein is nuclear, binds to DNA in a sequence-specific fashion, regulates the transcription of various reporter gene and transforms myelomonocytic cells. Cysteine is one of the most conserved residues during protein evolution and has been implicated in DNA binding, protein-protein interaction and redox regulation of various proteins. Therefore, we have now individually substituted each of the seven cysteines of v-Myb with a serine. All seven mutant proteins bound to DNA when they were expressed in E. coli. However, mutant C65S neither trans-activated transcription in vivo nor transformed myeloid cells, although it was transported into the nucleus. This cysteine is conserved in the Myb-related proteins of animals, plants, yeast and the cellular slime mold Dictyostelium discoideum. The C65S mutation and a nearby codon insertion mutation also abolished trans-activation by fusion proteins containing the v-Myb DNA-binding domain and the strong constitutive activation domain of herpes simplex virus (HSV) VP16. Because this domain of VP16 appears to activate transcription whenever it is bound upstream of an appropriate promoter, these results imply that C65 may be required for high-affinity DNA binding in vivo. In support of this hypothesis, we have also shown that, in contrast to wild-type v-Myb, mutant C65S is unable to block transcription from a reporter gene in which Myb binding sites overlap the initiation site.