Hospital Infections Caused by a Group of Recently Recognized Strains of Staphylococcus aureus

A survey was made of the phage-types of staphylococci responsible for cross-infection in a large veterans'' hospital between 1961 and 1964. An earlier survey had shown that in 1959 most of the infections were caused by staphylocci of the “80/81/82” group. In 1961 a new group of staphylococci were first recognized and provisionally designated as “Atypical Group III” strains; these were non-typable by the usual typing phages but showed inhibition patterns with some of the Group III phages. The “Atypical Group III” staphylococci all showed one or other of four patterns of multiple antibiotic resistance. By 1963 these resistant “Atypical Group III” staphylococci had become more frequent than “80/81/82” strains as causative agents of cross-infection, although both groups have continued to cause infections in the hospital. “Atypical Group III” strains mainly infected surgical wounds and skin ulcers, whereas “80/81/82” strains commonly produced primary skin sepsis, such as boils.     

INITIAL CARE OF ACUTE BACK INJURIES

The mechanism of injury to the back should be obtained with the utmost accuracy and set down in the history as a separate paragraph under that heading. This is usually best obtained by questioning and requestioning the patient during the course of the examination. A history of any previous back affections should also be obtained at the first visit.The detailed examination of the back is not complete without a general physical examination.X-ray studies should be done immediately in all cases in which the injury has been caused by direct violence or forceful indirect violence (as in “jackknife” injury).Terms such as “disc disease,” “ruptured intervertebral disc” and various others that convey a similar meaning should not be used as the initial diagnosis and should be withheld until such a diagnosis is definitely established.The plan of treatment may include a period in hospital or of rest at home, or it may be carried out with the patient ambulatory. Corsets and braces should be prescribed only when they are to serve a definite function and the same can be said of physiotherapy.     

MANDIBULAR HERPES ZOSTER—With Report on the Use of Cortisone in a Case with Geniculate Ganglion Symptoms

Herpes zoster, an acute specific viral infection, occurs more commonly than is generally supposed. It should be differentiated from other diseases involving the ear and skin; it must be considered as a possible etiologic agent in some palsies of the facial, glossopharyngeal or vagal nerves.The type of cephalic herpes zoster should be carefully differentiated; cases involving the “geniculate zone” may be other than “Ramsay Hunt''s syndrome.” This syndrome is now defined as a herpes zoster eruption of the external ear at the “geniculate zone” with involvement of the seventh or seventh and eighth nerves.The “topognostic” method is the best for determining the level at which the facial nerve has been affected.It is questioned whether there is a single outstanding therapeutic agent for this disease. Cortisone had no apparent therapeutic effect in a case reported herein.     

Caesarean Section: Could Different Transverse Abdominal Incision Techniques Influence Postpartum Pain and Subsequent Quality of Life? A Systematic Review

The choice of the type of abdominal incision performed in caesarean delivery is made chiefly on the basis of the individual surgeon’s experience and preference. A general consensus on the most appropriate surgical technique has not yet been reached. The aim of this systematic review of the literature is to compare the two most commonly used transverse abdominal incisions for caesarean delivery, the Pfannenstiel incision and the modified Joel-Cohen incision, in terms of acute and chronic post-surgical pain and their subsequent influence in terms of quality of life. Electronic database searches formed the basis of the literature search and the following databases were searched in the time frame between January 1997 and December 2013: MEDLINE, EMBASE Sciencedirect and the Cochrane Library. Key search terms included: “acute pain”, “chronic pain”, “Pfannenstiel incision”, “Misgav-Ladach”, “Joel Cohen incision”, in combination with “Caesarean Section”, “abdominal incision”, “numbness”, “neuropathic pain” and “nerve entrapment”. Data on 4771 patients who underwent caesarean section (CS) was collected with regards to the relation between surgical techniques and postoperative outcomes defined as acute or chronic pain and future pregnancy desire. The Misgav-Ladach incision was associated with a significant advantage in terms of reduction of post-surgical acute and chronic pain. It was indicated as the optimal technique in view of its characteristic of reducing lower pelvic discomfort and pain, thus improving quality of life and future fertility desire. Further studies which are not subject to important bias like pre-existing chronic pain, non-standardized analgesia administration, variable length of skin incision and previous abdominal surgery are required.     

Metformin and Resveratrol Inhibited High Glucose-Induced Metabolic Memory of Endothelial Senescence through SIRT1/p300/p53/p21 Pathway

Endothelial senescence plays crucial roles in diabetic vascular complication. Recent evidence indicated that transient hyperglycaemia could potentiate persistent diabetic vascular complications, a phenomenon known as “metabolic memory.” Although SIRT1 has been demonstrated to mediate high glucose-induced endothelial senescence, whether and how “metabolic memory” would affect endothelial senescence through SIRT1 signaling remains largely unknown. In this study, we investigated the involvement of SIRT1 axis as well as the protective effects of resveratrol (RSV) and metformin (MET), two potent SIRT1 activators, during the occurrence of “metabolic memory” of cellular senescence (senescent “memory”). Human umbilical vascular endothelial cells (HUVECs) were cultured in either normal glucose (NG)/high glucose (HG) media for 6 days, or 3 days of HG followed by 3 days of NG (HN), with or without RSV or MET treatment. It was shown that HN incubation triggered persistent downregulation of deacetylase SIRT1 and upregulation of acetyltransferase p300, leading to sustained hyperacetylation (at K382) and activation of p53, and subsequent p53/p21-mediated senescent “memory.” In contrast, senescent “memory” was abrogated by overexpression of SIRT1 or knockdown of p300. Interestingly, we found that SIRT1 and p300 could regulate each other in response to HN stimulation, suggesting that a delicate balance between acetyltransferases and deacetylases may be particularly important for sustained acetylation and activation of non-histone proteins (such as p53), and eventually the occurrence of “metabolic memory.” Furthermore, we found that RSV or MET treatment prevented senescent “memory” by modulating SIRT1/p300/p53/p21 pathway. Notably, early and continuous treatment of MET, but not RSV, was particularly important for preventing senescent “memory.” In conclusion, short-term high glucose stimulation could induce sustained endothelial senescence via SIRT1/p300/p53/p21 pathway. RVS or MET treatment could enhance SIRT1-mediated signaling and thus protect against senescent “memory” independent of their glucose lowering mechanisms. Therefore, they may serve as promising therapeutic drugs against the development of “metabolic memory.”     

Activation of Na+-permeant Cation Channel by Stretch and Cyclic AMP-dependent Phosphorylation in Renal Epithelial A6 Cells

It is currently believed that a nonselective cation (NSC) channel, which responds to arginine vasotocin (an antidiuretic hormone) and stretch, regulates Na⁺ absorption in the distal nephron. However, the mechanisms of regulation of this channel remain incompletely characterized. To study the mechanisms of regulation of this channel, we used renal epithelial cells (A6) cultured on permeable supports. The apical membrane of confluent monolayers of A6 cells expressed a 29-pS channel, which was activated by stretch or by 3-isobutyl-1-methylxanthine (IBMX), an inhibitor of phosphodiesterase. This channel had an identical selectivity for Na⁺, K⁺, Li⁺, and Cs⁺, but little selectivity for Ca²⁺ (P_Ca/P_Na < 0.005) or Cl⁻ (P_Cl/P_Na < 0.01), identifying it as an NSC channel. Stretch had no additional effects on the open probability (P _o) of the IBMX-activated channel. This channel had one open (“O”) and two closed (short “C _S” and long “C _L”) states under basal, stretch-, or IBMX-stimulated conditions. Both stretch and IBMX increased the P _o of the channel without any detectable changes in the mean open or closed times. These observations led us to the conclusion that a kinetic model “C _L ↔ C _S ↔ O” was the most suitable among three possible linear models. According to this model, IBMX or stretch would decrease the leaving rate of the channel for C _L from C _S, resulting in an increase in P _o. Cytochalasin D pretreatment abolished the response to stretch or IBMX without altering the basal activity. H89 (an inhibitor of cAMP-dependent protein kinase) completely abolished the response to both stretch and IBMX, but, unlike cytochalasin D, also diminished the basal activity. We conclude that: (a) the functional properties of the cAMP-activated NSC channel are similar to those of the stretch-activated one, (b) the actin cytoskeleton plays a crucial role in the activation of the NSC channel induced by stretch and cAMP, and (c) the basal activity of the NSC channel is maintained by PKA-dependent phosphorylation but is not dependent on actin microfilaments.     

PAROTID TUMOR OPERATIONS—The Case Against Enucleation

So-called mixed “encapsulated” parotid tumors are best managed by surgical procedures which avoid contact with the “capsule.” Enucleation is often a hazardous and incomplete procedure. Subtotal or total parotidectomy with exposure of the facial nerve to avert accidental damage to it is the treatment of choice.Microscopic study of the periphery of such tumors reveals that the “capsule” does not fully encapsulate; hence, enucleation and lesser procedures may leave neoplastic tissue behind.Surgical procedures to achieve complete excision without endangering the facial nerve were carried out in 123 cases. There was local recurrence in one case.     

“Capillary Permeability” in Patients with Collagen Vascular Diseases

“Capillary permeability” to serum albumin has been measured in patients with collagen vascular diseases by a method which compares the dilution of intravenously injected ¹³¹I-human serum albumin and ⁵¹Cr-R.B.C.s. The results indicate an increased capillary permeability comparable to that which occurs in patients with extensive inflammatory skin disease. We suggest that this increased capillary permeability may be the cause of the episodes of oedema which occur in patients with collagen vascular diseases such as disseminated lupus erythematosus, systemic sclerosis, dermatomyositis, polyarteritis nodosa, and rheumatoid arthritis. “Spontaneous periodic oedema” may be the presenting feature of collagen vascular disease and is due to increased capillary permeability.     

Chest Radiographic Patterns and the Transmission of Tuberculosis: Implications for Automated Systems

BackgroundComputer-aided detection to identify and diagnose pulmonary tuberculosis is being explored. While both cavitation on chest radiograph and smear-positivity on microscopy are independent risk factors for the infectiousness of pulmonary tuberculosis it is unknown which radiographic pattern, were it detectable, would provide the greatest public health benefit; i.e. reduced transmission. Herein we provide that evidence.Objectives1) to determine whether pulmonary tuberculosis in a high income, low incidence country is more likely to present with “typical” adult-type pulmonary tuberculosis radiographic features and 2) to determine whether those with “typical” radiographic features are more likely than those without such features to transmit the organism and/or cause secondary cases.MethodsOver a three-year period beginning January 1, 2006 consecutive adults with smear-positive pulmonary tuberculosis in the Province of Alberta, Canada, were identified and their pre-treatment radiographs scored by three independent readers as “typical” (having an upper lung zone predominant infiltrate, with or without cavitation but no discernable adenopathy) or “atypical” (all others). Each patient’s pre-treatment bacillary burden was carefully documented and, during a 30-month transmission window, each patient’s transmission events were recorded. Mycobacteriology, radiology and transmission were compared in those with “typical” versus “atypical” radiographs.FindingsA total of 97 smear-positive pulmonary tuberculosis cases were identified, 69 (71.1%) with and 28 (28.9%) without “typical” chest radiographs. “Typical” cases were more likely to have high bacillary burdens and cavitation (Odds Ratios and 95% Confidence Intervals: 2.75 [1.04–7.31] and 9.10 [2.51–32.94], respectively). Typical cases were also responsible for most transmission events—78% of tuberculin skin test conversions (p<0.002) and 95% of secondary cases in reported close contacts (p<0.01); 94% of secondary cases in “unreported” contacts (p<0.02).ConclusionAs a group, smear-positive pulmonary tuberculosis patients with typical radiographic features constitute the greatest public health risk. This may have implications for automated detection systems.     

Blood Pressure: A Consideration of Terminology

Concepts of hypertension have changed and changes in terminology to reflect this state of affairs are suggested. Statistically, the best mortality experience is associated with blood pressure commonly regarded as subnormal, and increments of blood pressure above this level are associated with progressive increases in mortality. The terms “normal”, “benign” and “essential” in relation to blood pressure should be abandoned. “Optimal”, “acceptable” and “hypertensive” ranges of blood pressure are suggested. Hypertension is regarded as a symptom of disease, rather than as a disease in itself, and “hypertension”, when used as a diagnostic label, should be qualified always by the primary disease, if known, or by the modifying phrase, “of unknown cause”, if not known.     

Is Early Tuberculosis Death Associated with Increased Tuberculosis Transmission?

Introduction

Tuberculosis (TB) is now a relatively uncommon disease in high income countries. As such, its diagnosis may be missed or delayed resulting in death before or shortly after the introduction of treatment. Whether early TB death is associated with increased TB transmission is unknown. To determine the transmission risk attributable to early TB death we undertook a case-control study.

Methods

All adults who were: (1) diagnosed with culture-positive pulmonary TB in the Province of Alberta, Canada between 1996 and 2012, and (2) died a TB-related death before or within the first 60 days of treatment, were identified. For each of these “cases” two sets of “controls” were randomly selected from among culture-positive pulmonary TB cases that survived beyond 60 days of treatment. “Controls” were matched by age, sex, population group, +/- smear status. Secondary cases of “cases” and “controls” were identified using conventional and molecular epidemiologic tools and compared. In addition, new infections were identified and compared in contacts of “cases” that died before treatment and contacts of their smear-matched “controls”. Conditional logistic regression was used to find associations in both univariate and multivariate analysis.

Results

“Cases” were as, but not more, likely than “controls” to transmit. This was so whether transmission was measured in terms of the number of “cases” and smear-unmatched or -matched “controls” that had a secondary case, the number of secondary cases that they had or the number of new infections found in contacts of “cases” that died before treatment and their smear-matched “controls”.

Conclusion

In a low TB incidence/low HIV prevalence country, pulmonary TB patients that die a TB-related death before or in the initial phase of treatment and pulmonary TB patients that survive beyond the initial phase of treatment are equally likely to transmit.     

Assessment of Survival and Body Size Variation of Culicoides imicola (Diptera: Ceratopogonidae) as Functions of “Candidatus Cardinium” (Bacteroidetes) Infection Status

“Candidatus Cardinium hertigii” (Bacteroidetes) is a maternally inherited endosymbiont known from several arthropods. Its mechanisms for persistence in host populations are mostly reproductive manipulation, though it has been occasionally reported to improve fitness parameters in several hosts. In Culicoides (Diptera: Ceratopogonidae) biting midges, the prevalence of “Candidatus Cardinium” infection was documented as moderate, with no detectable sex bias. We therefore investigated whether “Candidatus Cardinium” affects important fitness parameters, such as survival and body size, in Culicoides imicola, a dominant vector species. Field-collected midges were trapped and analyzed for survival under different environmental conditions and antibiotic treatment, taking into account “Candidatus Cardinium” infection status and parity status (i.e., parous or nulliparous). Additionally, wing lengths were measured as a proxy parameter for body size and analyzed together with “Candidatus Cardinium” infection data. The findings revealed no difference in survival of Culicoides infected with “Candidatus Cardinium” and that of uninfected midges in both parity states and under all tested conditions: optimal, starvation, heat, and antibiotic treatment. Beyond survival, no wing length difference was found for “Candidatus Cardinium”-infected versus uninfected midges. In aggregate, these findings support our conclusion that “Candidatus Cardinium” does not have an overt effect on the survival and size of adult C. imicola midges. “Candidatus Cardinium” may affect immature stages or may alter adult reproductive performance.     

Resuscitation of the terminally ill

The CMA believes that there are conditions of ill health and inevitable death for which a “no resuscitation” order, signed by the attending physician, is appropriate and ethically acceptable. The association encourages physicians who are faced with the decision of writing a “no resuscitation” or “do not resuscitate” order to consider the clinical criteria and procedural guidelines in the Joint Statement on Terminal Illness. This protocol is intended as a basic, national guideline for those involved in the care of the terminally ill. Individual institutions may wish to develop their own directives as an adjunct to the national statement.     

Cooperating elephants mitigate competition until the stakes get too high

Cooperation is ubiquitous in the animal kingdom as it aims to maximize benefits through joint action. Selection, however, may also favor competitive behaviors that could violate cooperation. How animals mitigate competition is hotly debated, with particular interest in primates and little attention paid thus far to nonprimates. Using a loose-string pulling apparatus, we explored cooperative and competitive behavior, as well as mitigation of the latter, in semi-wild Asian elephants (Elephas maximus). Our results showed that elephants first maintained a very high cooperation rate (average = 80.8% across 45 sessions). Elephants applied “block,” “fight back,” “leave,” “move side,” and “submission” as mitigation strategies and adjusted these strategies according to their affiliation and rank difference with competition initiators. They usually applied a “fight back” mitigation strategy as a sanction when competition initiators were low ranking or when they had a close affiliation, but were submissive if the initiators were high ranking or when they were not closely affiliated. However, when the food reward was limited, the costly competitive behaviors (“monopoly” and “fight”) increased significantly, leading to a rapid breakdown in cooperation. The instability of elephant cooperation as a result of benefit reduction mirrors that of human society, suggesting that similar fundamental principles may underlie the evolution of cooperation across species.

This study shows that in a task requiring coordinated pulling, elephants compete for access to food but work to mitigate competition in order to maintain cooperation. If the cost of competition becomes too high, however, cooperation breaks down entirely. This behavior mirrors that seen in humans and other great apes, suggesting that certain cooperative mechanisms are not unique to primates.     

Memory for Expectation-Violating Concepts: The Effects of Agents and Cultural Familiarity

Previous research has shown that ideas which violate our expectations, such as schema-inconsistent concepts, enjoy privileged status in terms of memorability. In our study, memory for concepts that violate cultural (cultural schema-level) expectations (e.g., “illiterate teacher”, “wooden bottle”, or “thorny grass”) versus domain-level (ontological) expectations (e.g., “speaking cat”, “jumping maple”, or “melting teacher”) was examined. Concepts that violate cultural expectations, or counter-schematic, were remembered to a greater extent compared with concepts that violate ontological expectations and with intuitive concepts (e.g., “galloping pony”, “drying orchid”, or “convertible car”), in both immediate recall, and delayed recognition tests. Importantly, concepts related to agents showed a memory advantage over concepts not pertaining to agents, but this was true only for expectation-violating concepts. Our results imply that intuitive, everyday concepts are equally attractive and memorable regardless of the presence or absence of agents. However, concepts that violate our expectations (cultural-schema or domain-level) are more memorable when pertaining to agents (humans and animals) than to non-agents (plants or objects/artifacts). We conclude that due to their evolutionary salience, cultural ideas which combine expectancy violations and the involvement of an agent are especially memorable and thus have an enhanced probability of being successfully propagated.     

Allosteric Communication Occurs via Networks of Tertiary and Quaternary Motions in Proteins

Allosteric proteins bind an effector molecule at one site resulting in a functional change at a second site. We hypothesize that allosteric communication in proteins relies upon networks of quaternary (collective, rigid-body) and tertiary (residue–residue contact) motions. We argue that cyclic topology of these networks is necessary for allosteric communication. An automated algorithm identifies rigid bodies from the displacement between the inactive and the active structures and constructs “quaternary networks” from these rigid bodies and the substrate and effector ligands. We then integrate quaternary networks with a coarse-grained representation of contact rearrangements to form “global communication networks” (GCNs). The GCN reveals allosteric communication among all substrate and effector sites in 15 of 18 multidomain and multimeric proteins, while tertiary and quaternary networks exhibit such communication in only 4 and 3 of these proteins, respectively. Furthermore, in 7 of the 15 proteins connected by the GCN, 50% or more of the substrate-effector paths via the GCN are “interdependent” paths that do not exist via either the tertiary or the quaternary network. Substrate-effector “pathways” typically are not linear but rather consist of polycyclic networks of rigid bodies and clusters of rearranging residue contacts. These results argue for broad applicability of allosteric communication based on structural changes and demonstrate the utility of the GCN. Global communication networks may inform a variety of experiments on allosteric proteins as well as the design of allostery into non-allosteric proteins.     

Plant intelligence: Why,why not or where?

The concept of plant intelligence, as proposed by Anthony Trewavas, has raised considerable discussion. However, plant intelligence remains loosely defined; often it is either perceived as practically synonymous to Darwinian fitness, or reduced to a mere decorative metaphor. A more strict view can be taken, emphasizing necessary prerequisites such as memory and learning, which requires clarifying the definition of memory itself. To qualify as memories, traces of past events have to be not only stored, but also actively accessed. We propose a criterion for eliminating false candidates of possible plant intelligence phenomena in this stricter sense: an “intelligent” behavior must involve a component that can be approximated by a plausible algorithmic model involving recourse to stored information about past states of the individual or its environment. Re-evaluation of previously presented examples of plant intelligence shows that only some of them pass our test.

“You were hurt?” Kumiko said, looking at the scar.Sally looked down. “Yeah.”“Why didn''t you have it removed?”“Sometimes it''s good to remember.”“Being hurt?”“Being stupid.”—(W. Gibson: Mona Lisa Overdrive)

Key words: intelligence, memory, learning, plant development, mathematical models, plant neurobiology, definition of terms     

How Often Are Antibiotic-Resistant Bacteria Said to “Evolve” in the News?

Media plays an important role in informing the general public about scientific ideas. We examine whether the word “evolve,” sometimes considered controversial by the general public, is frequently used in the popular press. Specifically, we ask how often articles discussing antibiotic resistance use the word “evolve” (or its lexemes) as opposed to alternative terms such as “emerge” or “develop.” We chose the topic of antibiotic resistance because it is a medically important issue; bacterial evolution is a central player in human morbidity and mortality. We focused on the most widely-distributed newspapers written in English in the United States, United Kingdom, Canada, India, and Australia. We examined all articles that focused primarily on the evolution of antibiotic resistance, were published in 2014 or earlier, and were accessible in online archives, for a total of 1639 articles. The total years examined per newspaper ranged from 5 to 37 years with a median of 27 years, and the overall range was 1978–2014. We quantified how many articles included the term “evolve” and analyzed how this varied with newspaper, country, and time. We found that an overall rate of 18% of articles used the term “evolve” but with significant variation among countries. Newspapers in the United Kingdom had the highest rate (24%), more than double of those in India (9%), the country with the lowest rate. These frequencies were lower than those found in scientific papers from both evolutionary journals and biomedical journals. There were no statistically significant changes in frequency and no trends when “evolve” usage was compared against variables such as newspaper circulation, liberal/conservative bias, time, and state evolution acceptance in U.S. newspapers. This study highlights the globally low usage of the word “evolve” in the popular press. We suggest this low usage may affect public understanding and acceptance of evolutionary concepts.