A protracted iGAS outbreak in a long-term care facility 2014-2015: control measures and the use of whole-genome sequencing

BACKGROUND

In 2014, two residents of a long-term care facility (LTCF) developed invasive group A streptococcal (iGAS) infections with identical typing (emm 11), resulting in one death. The second resident recovered but had a subsequent episode of emm 11 iGAS infection 10 months later. This second episode was linked to a third case, within 12 days, leading to a further outbreak investigation.

AIM

To combine different techniques to establish whether this was a protracted outbreak, understand transmission pathways and inform appropriate control measures.

METHODS

Following a routine response to the first cluster, the second investigation included a care record review. This informed network analysis of case interactions with staff and visitors during 10 days prior to infection. These data were combined with post-outbreak whole-genome sequencing (WGS) using isolates from cases, and staff and resident screening (44 GAS isolates: 11 outbreak-related and 33 sporadic isolates).

FINDINGS

Two of the three confirmed iGAS cases died (one suffered two episodes). All iGAS cases, and six non-invasive isolates from 2015, were emm 11 (monophylogenetic WGS clade). Network analysis highlighted only indirect contact through staff-visitor interactions between iGAS cases in 2015. This suggested a common source and transmission propagation through carriage and/or environmental contamination over an 11-month period.

CONCLUSIONS

This outbreak highlighted benefits of staff/resident screening and typing as part of routine response. Network analysis and highly discriminatory WGS clarified the protracted nature of the outbreak, supporting findings of hygiene and infection control issues and adding to our understanding of the epidemiology.

Using behavioural activation in the treatment of depression: a control theory perspective

Behavioural activation is an intervention that can be used to counteract the typical patterns of withdrawal, avoidance and inactivity that characterize depression. This paper examines the processes of change that may occur during behavioural activation from the perspective of control theory. Some of the key concepts that are associated with control theory are introduced and the process of change that may occur during behavioural activation is illustrated using two case studies. The case studies provide anecdotal evidence which supports the hypothesis that the effective implementation of behavioural activation may depend upon clients being able to retain or regain the sense of control that they value. The differences between a control-theory-based approach and more orthodox behavioural and cognitive approaches are highlighted and the implications of these differences are discussed. Flexible approaches that are informed by control theory, may offer a useful alternative to the more established behavioural and cognitive approaches towards behavioural activation.

Changes in vagal tone with posture in asthma are related to changes in ventilatory pattern

BACKGROUND

Posturally induced changes in minute ventilation in patients may be autonomically driven. This study aimed to test whether changes in autonomic tone with posture differed between normal and asthmatic subjects and whether this related to changes in indices of ventilation.

METHODS

Ten patients with type 1 brittle asthma (BA), 10 with non-brittle, severe asthma (SA), 10 with mild asthma (MA) and 10 normal individuals were studied lying flat, at 60 degrees head up tilt and flat again each for 30min, assessing end-tidal CO(2) (ETCO(2)), respiratory rate and autonomic tone by heart rate variability.

RESULTS

Parasympathetic tone (as high-frequency [HF] power) fell on tilt in all four groups, all showing increases in LF (low frequency)/HF ratio (sympatho-vagal balance) on tilt (BA, 2.03-4.9; SA, 3.3-8.2; MA, 1.5-4.9; normals, 2.3-6.6). ETCO(2) on tilt fell significantly in all 3 asthma groups (BA, DeltaETCO(2) -0.4, 95% CIs -0.18 to -0.75, P=0.005; SA, -0.7, 95% CIs -0.27 to -1.16, P=0.004; MA, -0.5, 95% CIs -0.14 to -0.78, P=0.01) but not in normals (-0.1, 95% CIs +0.23 to -0.49). The fall in ETCO(2) on tilt correlated with the fall in HF power in all three asthma groups but not in normal subjects.

CONCLUSION

Changes in vagal tone posture are seen on tilt in both normal and asthmatic subjects which relate to changes in ETCO(2) only in asthmatic subjects. This provides support for the hypothesis that hyper-ventilatory response to postural change in asthma is autonomically influenced.

Iatrogenic eccentric full thickness macular holes following vitrectomy with ILM peeling for idiopathic macular holes

PURPOSE

To document a previously unreported complication after vitrectomy with peeling of the internal limiting membrane (ILM) for idiopathic macular holes.

METHOD

Retrospective review of notes of 232 consecutive patients who underwent vitrectomy with peeling of the ILM for idiopathic macular holes from 1996 to 2001. Four patients were found to have eccentric iatrogenic macular holes postoperatively. Optical coherence tomography was used to evaluate these holes.

RESULTS

The idiopathic macular holes were graded from stages II to IV preoperatively with visual acuities from 6/18 to 6/60. All patients had surgery within 6 months of presentation. They underwent vitrectomy with complete separation of the posterior cortical vitreous, peeling of the ILM, injection of platelets (0.1 ml), and gas tamponade with SF6 20%. Postoperatively the patients postured strictly face down for 10 days. Follow-up ranged from 8 months to 6 years. Iatrogenic eccentric macular holes were noted postoperatively. The holes were located between 3 and 6 o'clock in three patients and at 9 o'clock in the fourth patient, relative to the macula. Optical coherence tomography showed them to be full thickness and completely flat. No further intervention was necessary. No complications have arisen during follow-up.

COMMENT

To our knowledge iatrogenic eccentric full thickness macular holes after macular hole surgery have never been reported. We believe that the location of the holes represents the initial site of ILM elevation. These holes are asymptomatic, have not required any treatment and have not caused any complications in up to 6 years of follow-up.

The alphaVbeta6 integrin regulates its own expression with cell crowding: implications for tumour progression

Expression of the growth-promoting integrin alphavbeta6 in colon cancer cells induces gelatinase B secretion and activation, the inhibition of which abolishes alphavbeta6-mediated tumour cell growth within a collagen matrix. Herein, we show that high cell density selectively enhances alphavbeta6 expression in a protein kinase C (PKC)-dependent manner in preference to other beta integrin subunits, resulting in a marked increase in gelatinase B secretion as cells reach confluence. Moreover, PKC activity increases with cell confluence, and the rise in PKC activity is much greater for alphavbeta6-expressing cells than for colon cancer cells which lack alphavbeta6. We propose a self-perpetuating system of colon cancer progression in which the integrin alphavbeta6 provides a means of sustaining tumour cell proliferation. In this model, alphavbeta6 regulates its own expression via a PKC-mediated signalling pathway as tumour cells become crowded and quiescent. The alphavbeta6-mediated induction of gelatinase B secretion facilitates peri-cellular matrix degradation, which helps overcome crowding and restores cell proliferation.

The alphaVbeta6 integrin regulates its own expression with cell crowding: implications for tumour progression

Expression of the growth-promoting integrin alphavbeta6 in colon cancer cells induces gelatinase B secretion and activation, the inhibition of which abolishes alphavbeta6-mediated tumour cell growth within a collagen matrix. Herein, we show that high cell density selectively enhances alphavbeta6 expression in a protein kinase C (PKC)-dependent manner in preference to other beta integrin subunits, resulting in a marked increase in gelatinase B secretion as cells reach confluence. Moreover, PKC activity increases with cell confluence, and the rise in PKC activity is much greater for alphavbeta6-expressing cells than for colon cancer cells which lack alphavbeta6. We propose a self-perpetuating system of colon cancer progression in which the integrin alphavbeta6 provides a means of sustaining tumour cell proliferation. In this model, alphavbeta6 regulates its own expression via a PKC-mediated signalling pathway as tumour cells become crowded and quiescent. The alphavbeta6-mediated induction of gelatinase B secretion facilitates peri-cellular matrix degradation, which helps overcome crowding and restores cell proliferation.

Direct regulation of the Xenopus engrailed-2 promoter by the Wnt signaling pathway, and a molecular screen for Wnt-responsive genes, confirm a role for Wnt signaling during neural patterning in Xenopus

The co-activation of Wnt signaling and concomitant inhibition of BMP signaling has previously been implicated in vertebrate neural patterning, as evidenced by the combinatorial induction of engrailed-2 and krox-20 in Xenopus. However, screens have not previously been conducted to identify additional potential target genes. Using a PCR-based screening method we determined that XA-1, xCRISP, UVS.2, two UVS.2-related genes, and xONR1 are induced in response to Xwnt-3a and a BMP-antagonist, noggin. Two additional genes, connexin 30 and retinoic acid receptor gamma were induced by Xwnt-3a alone. To determine whether any of the induced genes are direct targets of Wnt signaling, we focussed on engrailed-2. In the present study we show that the Xenopus engrailed-2 promoter contains three consensus binding sites for LEF/TCF, which are HMG box transcription factors which bind to beta-catenin in response to activation of the Wnt- 1 signaling pathway. An engrailed-2 promoter luciferase reporter construct containing these LEF/TCF sites is induced in embryo explant assays by the combination of Xwnt-3a or beta-catenin and noggin. These LEF/TCF sites are required for expression of engrailed-2, as a dominant negative Xtcf-3 blocks expression of endogenous engrailed-2 as well as expression of the reporter construct. Moreover, mutation of these three LEF/TCF sites abrogates expression of the reporter construct in response to noggin and Xwnt-3a or beta-catenin. We conclude that the engrailed-2 gene is a direct target of the Wnt signaling pathway, and that Wnt signaling works with BMP antagonists to regulate gene expression during patterning of the developing nervous system of Xenopus.

XCtBP is a XTcf-3 co-repressor with roles throughout Xenopus development

XTcf-3 is an HMG box transcription factor that mediates Xenopus dorsal-ventral axis formation. As a Wnt pathway effector, XTcf-3 interacts with beta-catenin and activates the expression of the dorsal organizing gene siamois, while in the absence of beta-catenin, XTcf-3 functions as a transcriptional repressor. We show that XTcf-3 contains amino- and carboxy-terminal repressor domains and have identified a Xenopus member of the C-terminal Binding Protein family of transcriptional co-repressors (XCtBP) as the C-terminal co-repressor. We show that two XCtBP binding sites near the XTcf-3 carboxy-terminus are required for the interaction of XTcf-3 and XCtBP and for the transcriptional repression mediated by the XTcf-3 carboxy-terminal domain. By fusing the GAL4 activation domain to XCtBP we have generated an antimorphic protein, XCtBP/G4A, that activates siamois transcription through an interaction with endogenous XTcf-3. Ectopic expression of XCtBP/G4A demonstrates that XCtBP functions in the regulation of head and notochord development. Our data support a role for XCtBP as a co-repressor throughout Xenopus development and indicate that XCtBP/G4A will be a useful tool in determining how XCtBP functions in various developmental processes.

16-Epiestriol, a novel anti-inflammatory nonglycogenic steroid, does not inhibit IFN-gamma production by murine splenocytes

All the steroidal anti-inflammatory drugs currently available are glucocorticoids. The desired anti-inflammatory activities of glucocorticoids frequently are accompanied by adverse side effects, notably glycogenic activities and profound immunosuppression, that can limit clinical use. We recently identified 16-epiestriol, a naturally occurring steroid, as exhibiting significant anti-inflammatory activity without glycogenic activity. In the present study, we compared the effects of 16-epiestriol and hydrocortisone on the capacity of murine splenocytes to produce interferon-y (IFN-y). We injected young adult male BDF1 mice once with 20 mg/kg hydrocortisone or 20, 5, or 1 mg/kg 16-epiestriol and 4 h later harvested the splenocytes. Flow cytometric analysis confirmed that 16-epiestriol did not alter the number of CD3+ T cells in the spleen. In contrast to the suppressive effects of hydrocortisone, none of the 16-epiestriol concentrations inhibited concanavalin A-stimulated IFN-gamma production by spleen cells, as determined by ELISA. Incubating spleen cells from untreated mice in concentrations of 16-epiestriol ranging from 1 mg/ml to 100 pg/ml did not alter profiles of IFN-gamma production, in contrast to the suppressive dose-response effects of hydrocortisone. Collectively, these results support the contention that 16-epiestriol may be a clinically useful safe anti-inflammatory steroid without profound immunosuppressive activities.

Spaceflight and development of immune responses

The NIH.R1 Space Shuttle experiment was designed to study the effects of spaceflight on rodent development. Pregnant rats were flown on the Space Shuttle for 11 days, and pregnant control rats were maintained in animal enclosure modules in a ground-based chamber under conditions approximating those in flight. Additional controls were in standard housing. The effects of the flight on immunological parameters of dams, fetuses, and pups were determined. Blastogenesis of spleen cells in response to mitogen was inhibited in flown dams but was not inhibited in cells from their pups. Interferon-gamma production by spleen cells showed a trend toward inhibition in flown dams but not in their pups. The response of bone marrow cells to colony-stimulating factor showed a trend toward inhibition after spaceflight in dams, but the response of fetus and pup liver cells was not inhibited. Total serum IgG was not affected by spaceflight. None of the examined immune parameters that were altered in rat dams after spaceflight was found to be altered in their offspring.

Can prosody aid the automatic classification of dialog acts in conversational speech?

Identifying whether an utterance is a statement, question, greeting, and so forth is integral to effective automatic understanding of natural dialog. Little is known, however, about how such dialog acts (DAs) can be automatically classified in truly natural conversation. This study asks whether current approaches, which use mainly word information, could be improved by adding prosodic information. The study is based on more than 1000 conversations from the Switchboard corpus. DAs were hand-annotated, and prosodic features (duration, pause, F0, energy, and speaking rate) were automatically extracted for each DA. In training, decision trees based on these features were inferred; trees were then applied to unseen test data to evaluate performance. Performance was evaluated for prosody models alone, and after combining the prosody models with word information--either from true words or from the output of an automatic speech recognizer. For an overall classification task, as well as three subtasks, prosody made significant contributions to classification. Feature-specific analyses further revealed that although canonical features (such as F0 for questions) were important, less obvious features could compensate if canonical features were removed. Finally, in each task, integrating the prosodic model with a DA-specific statistical language model improved performance over that of the language model alone, especially for the case of recognized words. Results suggest that DAs are redundantly marked in natural conversation, and that a variety of automatically extractable prosodic features could aid dialog processing in speech applications.

Oxidation of the phytoalexin maackiain to 6,6-dihydroxy-maackiain by Colletotrichum gloeosporioides

Phytoalexins are low molecular weight antibiotic compounds produced by plants in response to infection by microbes. These antimicrobial compounds are thought to provide resistance to microbial invasion and colonization. (-)Maackiain and its pterocarpan relatives can be oxidized at a number of sites, including at the 6 carbon. A previously unknown metabolite was produced for (-)maackiain by the broad host-range pathogen Colletotrichum gloeosporioides (Glomerella cingulata). This unknown was identified by LC-MS-MS and NMR spectroscopy to be 6,6a-di-OH-maackiain (3,6,6a-trihydroxy-8,9,methylenedioxy-pterocarpan). It is produced by isolates that represent all four races and pathotypes of C. gloeosporioides isolated from the tropical forage legume Stylosanthes spp. We present evidence that the primary metabolite (-)6a-OH-maackiain is subsequently hydroxylated at carbon 6, a step resulting in a compound that is increased in polarity and decreased in toxicity relative to the parent compound and (-)6a-OH-maackiain. This further oxidation may be required for efficient excretion or carbon source scavenging.

Low flow oxygen delivery via nasal cannula to neonates

Neonates with chronic lung disease often require oxygen in the neonatal intensive care unit. The purpose of this study was to determine (1) the actual inspired oxygen concentration (FiO2) delivered to neonates when using a low-flow flowmeter and a nasal cannula, and (2) the accuracy with which FiO2 could be estimated using a formula that we developed. We studied two groups of infants: 18 infants less than 1,500 g and 13 infants greater than 1,500 g. We measured pharyngeal oxygen levels by sampling pharyngeal gas in infants receiving 100% humidified oxygen by nasal cannula from a low range flow flowmeter. The oxygen flow was increased by 25 mL/min increments from 25 to 200 mL/min. The measured FiO2 was compared with the calculated FiO2 using the formula: [formula: see text] where minute ventilation (VE) equals the minute ventilation in mL/min (VE = VT X respiratory rate). For both groups of infants, increments of 25 mL/min of flow produced distinctive changes in FiO2 at all levels (P < 0.001). The calculated FiO2 did not significantly differ from the actual FiO2 at any flow. The calculated FiO2 was most predictive when using an assumed tidal volume of 5.5 mL/kg. We conclude that an accurate flowmeter connected to 100% humidified oxygen can produce a wide range of predictable FiO2s for neonates, especially those with birthweights of less than 1,500 g. The proposed formula allows useful estimation of the infant's FiO2 when we assume a tidal volume of 5.5 mL/kg.

Effect of TGF-beta on differentiated organoids of the colon carcinoma cell line LIM 1863

The LIM 1863 colon carcinoma cell line grows in suspension as morphologically and functionally organized organoids in serum-containing medium. Addition of TGF-beta caused the organoids to adhere and inhibited DNA synthesis. A 20 min incubation with TGF-beta was sufficient to induce adherence and this could be inhibited by cycloheximide. The adhesion and DNA synthesis inhibition were demonstrated to be separate events. We were not able to detect any changes in matrix or cell membrane antigens. Similarly there were no changes in synthesized proteins (by two-dimensional gel electrophoresis), and no upregulation of proteoglycan. When adhered organoids were lysed from the tissue culture plastic surface, untreated organoids adhered to this surface. This 'conditioned' surface was destroyed by trypsin but not collagenase or medium from normal LIM 1863 cultures. However, the adherent phenotype was prevented when organoids were treated with transforming growth factor-beta (TGF-beta) in the presence of medium conditioned by normal LIM 1863 cultures rather than in fresh medium. The adhesion process was inhibited by an antibody (QE2E5) against beta 1 integrin although no quantitative changes in integrins were observed (by immunoprecipitation or RNA analysis). A second anti-beta 1 integrin antibody (61.2C4) inhibited LIM 1863 adhesion to collagen but not TGF-beta induced adhesion, implying that TGF-beta induced a specific conformational change or interaction of a beta 1 integrin. In this morphologically structured system TGF-beta induced a number of subtle effects including formation of new extracellular matrix and conformational change of a beta 1 integrin, rather than the major quantitative changes in cell/matrix molecules reported previously.

The adherence of silicone oil to standard and heparin-coated PMMA intraocular lenses

During combined cataract extraction and intraocular lens insertion in eyes undergoing removal of silicone oil, we noted that oil became adherent to the implant. This adhesion persisted post-operatively. Although patients seemed not to be symptomatic as a result of this effect, the oil interferes with the fundal examination. Since heparin-coated intraocular lenses are more hydrophilic than unmodified lenses, oil should spread less well on these lenses and therefore be less adherent. This study was conducted to test this hypothesis. Heparin-surface-modified and unmodified polymethylmethacrylate (PMMA) lenses were immersed in 1000 centistoke neat silicone oil and in an emulsion of silicone oil taken from a patient. The lenses were washed with saline solution in an attempt to remove adherent oil. The lenses were photographed for examination and qualitative comparison. It was found that both neat and emulsified silicone oil was strongly adherent to both surface-modified and unmodified lenses, and could not easily be washed off. The heparin-coated lenses showed a tendency for adherence of emulsified oil. It is concluded that heparin coating of intraocular lenses does not prevent, though may reduce, oil adherence. We recommend that care be taken to avoid contact between oil and implant during combined oil removal and cataract extraction.

The silicone gel breast implant controversy: current status and clinical implications

The silicone breast implant controversy has amassed a great deal of media coverage in the past year. Unfortunately, separating fact from fiction has been extremely frustrating and difficult, not only for physicians but for women who have either had or are considering cosmetic or reconstructive surgery of the breast. At a recent meeting attended by most of the board eligible and certified Plastic and Reconstructive Surgeons in the State of Arkansas, it was felt that a consensus statement was needed to clarify the issues and inform other Arkansas physicians of the most up to date information. The result is a fairly comprehensive review which will require your indulgence. Breast implants are placed not only by Plastic and Reconstructive Surgeons, but by Otolaryngologists, "Facial Plastic Surgeons", Obstetricians/Gynecologists, General Surgeons, Dermatologists and Family Practitioners. We believe it is the ethical and legal responsibility of the physicians who elect to perform these procedures to provide adequate care and follow-up for these patients when either real or perceived problems arise. Accurate information, reassurance and occasionally re-operations are required for many of these patients.

Combination chemotherapy for advanced adenocarcinoma of the cervix

A patient with advanced adenocarcinoma of the cervix was treated only with cisplatin and mitomycin C (MMC). The regimen achieved a complete response, confirmed by chest radiograph and computed axial tomography scan, lasting 50 months. The patient is alive with recurrent disease 59 months after diagnosis. No severe drug-related toxicity occurred.

First 3 years of the National AIDS Clearinghouse

The National AIDS Clearinghouse is an information service provided by the Centers for Disease Control. The Clearinghouse was established in 1987 to respond to increasing numbers of public and professional inquiries, to disseminate accurate information, and to make referrals to local sources of information and assistance. Four data bases--Resources and Services Database containing information about more than 16,000 organizations that provide counseling and testing for human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) and other education and prevention services; Educational Materials Database containing more than 8,000 individual, hard-to-find educational materials; Funding Database; and the AIDS Clinical Trial Information Service (ACTIS) Database--are searched by information specialists to respond to more than 45,000 requests annually for information from a variety of health professionals, organizations, and the general public. Between 1987 and 1991, the Clearinghouse disseminated more than 60 million copies of publications related to HIV and AIDS. Information and education remain the most critical tools for the prevention of HIV infection, and the National AIDS Clearinghouse provides an essential element for the dissemination of education and prevention information.

Effects of nebulized lignocaine on the intraocular pressure responses to tracheal intubation

We have examined the effect of preoperative administration of nebulized lignocaine or saline on the intraocular pressure (IOP) response to tracheal intubation in 20 adults. In the saline group, tracheal intubation was associated with a significant increase in IOP above control and preintubation values (P less than 0.01); in the lignocaine group there was no change in IOP following intubation. After intubation, IOP was significantly less in the lignocaine group than in the saline group (P less than 0.05).

Human oocyte-cumulus complexes stimulate the human acrosome reaction

Oocyte-cumulus complexes were obtained, after induced ovulation, from infertile patients participating in an in-vitro fertilization programme. About 6 h after retrieval and depending on the expansion of the cumulus, 100,000 motile spermatozoa, prepared by a migration-centrifugation method, were added. After 14-18 h incubation at 37 degrees C, oocytes were examined for signs of fertilization (pronuclei and polar body formation) and then removed; spermatozoa remaining in the incubation medium were fixed for transmission electron microscopy. To provide an adequate number of cells for observation, spermatozoa from a minimum of 3-5 oocytes from the same patient were pooled. When sufficient spermatozoa were available after insemination, the remainder of the suspension was incubated at 37 degrees C and fixed along with the corresponding oocyte-incubated sample. In all, 32 sperm samples were assessed and fertilized oocytes were obtained with 29 of these. In the 24 samples in which greater than 100 spermatozoa (mean of 192) could be assessed, 32% of spermatozoa had initiated or completed the acrosome reaction. In the 15 of these 24 samples for which oocyte-free controls were available, 31% of cells were reacting or reacted, compared with 15% of cells (P less than 0.001) in the controls. In the remaining 8 samples, incubated with oocyte-cumulus complexes, less than 100 but greater than or equal to 20 spermatozoa (mean of 42) were assessed and again 32% of spermatozoa were reacted.(ABSTRACT TRUNCATED AT 250 WORDS)

Extended exposure to follicular fluid is required for significant stimulation of the acrosome reaction in human spermatozoa

The effect of human follicular fluid (FF) on the incidence of spontaneous acrosome reactions (AR) in human spermatozoa was examined over a 24-25 h period using electron microscopy. Suspensions of motile spermatozoa were prepared by a swim-up method in Earle's medium, known to support in-vitro fertilization. After adjusting the concentration to 10 x 10(6) cells/ml, suspensions were diluted 1:1 with medium (control) or FF, the latter giving a final concentration of 50% FF. In addition, at 5 h and 24 h an aliquant of the control suspension was removed, diluted 1:1 with FF and incubated for 1 h; the three suspensions were examined at 6 h and 25 h. Continuous exposure to 50% FF stimulated the AR, the effect being significant (P less than 0.001) at 25 h. However, the 1-h short exposure of spermatozoa to FF did not produce an increase in AR, even after 24 h preincubation. In a separate series of experiments, the effect of continuous incubation for 24 h in increasing concentrations of FF was investigated. A significant linear dose-dependent effect on the AR was observed with all concentrations assessed (P less than 0.01 for 12.5% FF and P less than 0.001 for 25, 50, 75 and 100% FF, compared with FF-free control). Therefore, human FF can stimulate the AR, but only after a continuous exposure to FF. A short exposure to FF, even after 24 h preincubation, does not trigger an increased AR response.

Non-contact retinal photocoagulation using the Volk +90 dioptre lens

The Volk +90 dioptre lens offers a stereoscopic, wide-field (60 degrees) retinal view without the disadvantage of contact funduscopy. Used in conjunction with the slit-lamp, the lens gives a bright, inverted, magnified image of the posterior segment. Its uses in the diagnosis of posterior pole pathology, detailed examination of the optic disc and fundus photography are well established.

Task-related responses of monkey medullary dorsal horn neurons

Medullary dorsal horn neurons with trigeminal sensory properties have been previously shown to have additional responses associated with cues relevant to the successful execution of a behavioral task. These "task-related" responses were evoked by environmental cues but were independent of the specific stimulus parameters. We have examined further the characteristics of task-related responses in medullary dorsal horn neurons of three monkeys. Single-unit activity was recorded while the monkeys were performing behavioral tasks that required them to discriminate thermal or visual stimuli for a liquid reward. Forty-five percent (34/75) of the medullary dorsal horn neurons studied exhibited task-related activity that was significantly correlated with the stereotypical behavioral events that occurred during the tasks. Similar events occurring outside of the task produced no response. In addition to the task-related activity of these medullary dorsal horn neurons, responses to mechanical and/or thermal stimuli presented within the neuron's receptive field were demonstrated in 28 of 34 cases. These sensory responses also were evoked by the same stimuli presented outside of the behavioral task. Fifteen of the neurons with task-related responses could be activated antidromically from thalamic stimulating electrodes. Task-related responses were categorized according to their relationship to the three phases of the behavioral trial: trial initiation, trial continuation, and trial termination. Although an individual task-related response was associated with a single behavioral event, most medullary dorsal horn neurons (30/34) exhibited a reproducible pattern of task-related responses that occurred during more than one phase of the trial. Trial-initiation task-related responses were subdivided depending on their correlation with specific events that occurred within that phase of the trial. One-third of the 18 excitatory trial-initiation responses were associated with the visual stimulus that cued the monkey to begin the trial; the remaining two-thirds were associated with the monkey's press of the button that actually initiated the trial. Trial-continuation task-related responses (observed while the monkey waited for a thermal stimulus that triggered a rewarded motor response) were shown to be independent of the actual temperature of the thermal stimulus. In addition these trial-continuation task-related responses were also noted during trials without a thermal stimulus, in which the trigger cue was the onset of a light (in a visual task).(ABSTRACT TRUNCATED AT 400 WORDS)

The medullary dorsal horn: a target for the expression of opiate effects on the perceived intensity of noxious heat

We examined the effects of morphine microinjected into the medullary dorsal horn (MDH) on the ability of monkeys to detect temperature increases in the noxious heat range. Behavioral detection latency and the percentage of correct detections were used as measures of the perceived intensity of noxious heat stimuli. Three monkeys were trained to detect a change (T2) of 0.4, 0.6, or 1.0 degrees C from a previous noxious heat level of 46 degrees C (T1). Effects on attentional, motivational, and motoric aspects of the monkeys' behavior were assessed by having them detect innocuous cooling and visual stimuli in tasks of similar difficulty. Morphine (1, 3, and 10 micrograms) microinjected into the MDH produced a dose-dependent and stimulus-intensity-dependent increase in the latency to detection of the T2 stimuli. These effects were opiate receptor-mediated since they were antagonized by systemically administered naloxone (0.5 mg/kg, i.m.) given 40 min after the microinjection of morphine. There were no effects of morphine on the behavioral detection latencies to the innocuous cooling and visual stimuli, indicating that the effects of morphine were modality-specific and independent of changes in motivation, attention, or motoric ability. These data demonstrate a pharmacologically specific effect of opiates on the perceived intensity of noxious heat stimuli at the earliest central relay pathway transmitting noxious information.

Posterior chamber intraocular lens implantation--a new forceps to simplify capsular bag fixation

The case for capsular bag fixation of the Sinsky-Kratz type of posterior chamber intraocular implant lens is presented, and the various methods in use to position implant lenses are outlined. The new forceps are described and the rationale for their adoption and use is given in an illustrated, step-by-step fashion. Their additional use in anterior chamber intraocular lens implantation is mentioned. There is a brief summary of the author's experience with this instrument.

Dorsal horn opiate administration attenuates the perceived intensity of noxious heat stimulation in behaving monkey

In monkeys trained to detect and discriminate noxious heat stimuli, morphine microinjected into the medullary dorsal horn attenuated the perceived intensity of noxious heat in a dose- and stimulus-dependent fashion. These data demonstrate a pharmacologically specific effect of opiates on the sensory intensity component of pain at the earliest central relay pathway transmitting noxious information.

Toronto multiagency child abuse research project: the abused and the abuser

Information from 422 cases of child mistreatment in Toronto was gathered from the files of a child welfare agency and a children's hospital. These data were compared to patterns reported in previous studies and clinical writings on child mistreatment to investigate similarities and differences in families whose children have been abused in Canada, England, and the United States. Findings from the present study were similar to others in many respects. The differences were primarily in the area of lower incidences of such problems as perinatal difficulties in the children and intellectual limitations and social isolation in the parents; however, there was a higher incidence of single-parent families. The results suggest that clinicians should bear in mind that child mistreatment cannot be ruled out on the grounds that no serious problems have been noted for the child or the family.

Effects of disopyramide on left ventricular function: assessment by radionuclide cineangiography

To determine the effects of disopyramide on resting systolic left ventricular (LV) function and LV functional reserve, gated equilibrium radionuclide cineangiography was performed at rest and during maximal symptom-limited supine bicycle exercise in 12 patients after a single 300 mg oral loading dose of disopyramide, and in 22 patients (including the 12 patients just mentioned) after they received disopyramide 150 mg 4 times daily for 5 to 10 days (average 7). The oral loading dose (average serum level 3.6 +/- 1.3 micrograms/ml [standard deviation] produced decreases in ejection fraction in 9 of 12 patients with a decrease in average resting ejection fraction from 40 +/- 15% to 33 +/- 11% (p less than 0.005). However, the lower, sustained dosage of disopyramide was associated with a lower average serum level of 2.5 +/- 0.8 micrograms/ml and with smaller but significant decreases in ejection fraction in 3 of 22 patients during exercise only. At this dosage there was no significant decrease in average ejection fraction for the group at rest or during exercise. Adverse effects of disopyramide on ejection fraction occurred even in patients with previously normal LV function at rest. Hence, disopyramide may be associated with significant decreases in LV systolic function, particularly when given in high, oral "loading" doses. However, sustained therapy with lower dosages as well as lower drug levels is also associated with less depression of LV function.

The use of barium meals by general practitioners and hospital doctors

A random sample of the records of patients having barium meal examinations at a district general hospital was reviewed. In both males and females, there was no significant difference in the proportions of abnormalities between referrals from hospital doctors and general practitioners. Younger males were less likely to show abnormalities than older males, but there was no age difference in the proportions of abnormal barium meals in females. There was a smaller proportion of major abnormalities (19 per cent) in female than male patients (28 per cent). This study does not suggest that any reduction of direct access barium meal examinations for general practitioners is necessary.