The diversity and evolution of odorant receptors in beetles (Coleoptera)

The insect odorant receptors (ORs) are amongst the largest gene families in insect genomes and the primary means by which insects recognize volatile compounds. The evolution of ORs is thus instrumental in explaining the chemical ecology of insects and as a model of evolutionary biology. However, although ORs have been described from numerous insect species, their analysis within and amongst the insect orders has been hindered by a combination of limited genomic information and a tendency of the OR family toward rapid divergence, gain, and loss. We addressed these issues in the insect order Coleoptera through a targeted genomic annotation effort that included 1181 ORs from one species of the sister order Strepsiptera and 10 species representing the four coleopteran suborders. The numbers of ORs in each species varied from hundreds to fewer than 10, but coleopteran ORs could nevertheless be represented within a scheme of nine monophyletic subfamilies. We observed many radiations and losses of genes amongst OR subfamilies, and the diversity of ORs appeared to parallel the host breadth of the study species. However, some small lineages of ORs persisted amongst many coleopteran families, suggesting receptors of key function that underlie the olfactory ecology of beetles.

"Awake" ECCO2R superseded intubation in a near-fatal asthma attack

BACKGROUND

Near-fatal asthma attacks are life threatening events that often require mechanical ventilation. Extracorporeal carbon dioxide removal (ECCO₂R) is, beside extracorporeal membrane oxygenation (ECMO), a well-established rescue option whenever ventilation gets to its limits. But there seems to be very rare experience with those techniques in avoiding mechanical ventilation in severe asthma attacks.

CASE PRESENTATION

A 67-year-old man with a near-fatal asthma attack deteriorated under non-invasive ventilation conditions. Beside pharmacological treatment, the intensivists decided to use an extracorporeal carbon dioxide removal system (ECCO₂R) to avoid sedation and intubation. Within only a few hours, there was a breakthrough and the patient's status improved continuously. One and a half days later, weaning from ECCO₂R was already completed.

CONCLUSIONS

The discussion deals with several advantages of extracorporeal lung support in acute asthma, the potential of avoiding intubation and sedation, as well as the benefits of a conscious and spontaneously breathing patient. Extracorporeal membrane oxygenation (ECMO) in general and ECCO₂R in particular is a highly effective method for the treatment of an acute near-fatal asthma attack. Pathophysiological aspects favor the "awake" approach, without sedation, intubation, and mechanical ventilation. Therefore, experienced clinicians might consider "awake" ECCO₂R in similar cases.

Case Report. Extracorporeal Membrane Oxygenation in Nivolumab Associated Pneumonitis

Background

Newly approved immunotherapeutic agents, like CTLA-4 inhibitors and antibodies against PD-1, are a promising therapeutic option in cancer therapy.

Case presentation

A 74-year-old man, with a history of advanced stage melanoma and treatment with ipilimumab, pembrolizumab and nivolumab, was admitted to the hospital due to respiratory failure with hypoxemia and dyspnoea. He rapidly developed severe acute respiratory distress syndrome (ARDS), which required treatment in the intensive care unit which included mechanical ventilation and extracorporeal membrane oxygenation (ECMO). Computed tomographic imaging (CT) showed signs of a pneumonitis, with an ARDS pattern related to the use of PD-1 antibodies. Treating the patient with high-dose immunosuppressive steroids led to an overall improvement. He was transferred to a rehabilitation hospital and subsequently to his home.

Discussion and conclusion

This is a unique case report of a patient suffering a grade 4 adverse event under nivolumab who survived having been treated with ECMO. It highlights the possibility of associated adverse reactions as well as the use of ECMO in palliative care patients. ECMO can be of great success even in patients with malignancies, but careful decision making should be done on a case by case basis.

Medical and logistical challenges of trauma care in a 12-day cave rescue: A case report

AIM

To describe the case of a patient with a severe head injury at a depth of about 1000 m from the cave entrance in Bavaria, Germany, who received pre-hospital trauma care for 12 days until evacuation.

RESULTS

Search and rescue (SAR) operation involved 728 rescuers, 202 working directly in the cave (for a total of 9239 h) and 7 physicians from five countries. At 6-month follow-up, the patient had recovered completely and resumed his job.

CONCLUSION

This case highlights several pitfalls of trauma care in complex SAR operations, which often rely on expert knowledge and are not yet evidence-based practice.

Elastocapillary coalescence of plates and pillars

When a fluid-immersed array of supported plates or pillars is dried, evaporation leads to the formation of menisci on the tips of the plates or pillars that bring them together to form complex patterns. Building on prior experimental observations, we use a combination of theory and computation to understand the nature of this instability and its evolution in both the two- and three-dimensional setting of the problem. For the case of plates, we explicitly derive the interaction torques based on the relevant physical parameters associated with pillar deformation, contact-line pinning/depinning and fluid volume changes. A Bloch-wave analysis for our periodic mechanical system captures the window of volumes where the two-plate eigenvalue characterizes the onset of the coalescence instability. We then study the evolution of these binary clusters and their eventual elastic arrest using numerical simulations that account for evaporative dynamics coupled to capillary coalescence. This explains both the formation of hierarchical clusters and the sensitive dependence of the final structures on initial perturbations, as seen in our experiments. We then generalize our analysis to treat the problem of pillar collapse in three dimensions, where the fluid domain is completely connected and the interface is a minimal surface with the uniform mean curvature. Our theory and simulations capture the salient features of experimental observations in a range of different situations and may thus be useful in controlling the ensuing patterns.

Folded edge of turbulence in a pipe

The results of an experimental investigation into the threshold boundary between laminar and disordered pipe flow are presented. Complex features have been uncovered using a highly refined experimental approach where an intermediate periodic state forms an integral part of the transition sequence. In accord with the suggestions produced by a numerical investigation, the boundary is found to be folded with a complicated structure. This raises important questions about accepted definitions of threshold amplitudes in this long-standing problem.

Apical transverse motion as surrogate parameter to determine regional left ventricular function inhomogeneities: a new, integrative approach to left ventricular asynchrony assessment

AIMS

Left ventricular (LV) asynchrony assessment is mostly based on delays between regional myocardial velocity peaks. Regional function is barely considered. We propose apical transverse motion (ATM) as a new parameter integrating both temporal and functional information, which was tested in different conduction delays.

METHODS AND RESULTS

We examined 67 patients, 11 patients with post-infarct ischaemic left bundle branch blocks (iLBBB) and 25 patients with non-ischaemic left bundle branch block (nLBBB), 12 patients with right bundle branch block (RBBB), and 19 normal healthy volunteers (NORM). Longitudinal colour tissue Doppler data were used to calculate the total transverse apex motion (ATM), the transverse motion in the four-chamber view plane alone (ATM(4CV)) as well as regional myocardial deformation and conventional LV asynchrony parameters. Median ATM was 1.8 mm in NORM, 1.5 mm in RBBB (P = 0.999), 2.4 mm in iLBBB (P = 0.183), and 4.3 mm in nLBBB (P < 0.001 vs. NORM and RSB). ATM(4CV) behaved similarly, showed a good correlation with regional deformation data, and distinguished well between NORM and LBBB (AUC = 0.87).

CONCLUSION

Apical transverse motion is a new and simple parameter integrating information on both regional and temporal function inhomogeneities of the LV. It has a potential role in assessing LV asynchrony in the clinical context.

Development of suppressor lymphocytes during acute rejection of rat cardiac allografts and preservation of suppression by anti-IL-2-receptor monoclonal antibody

Suppressor activity was investigated in rats undergoing acute rejection of heterotopic cardiac allografts. Spleen cells were harvested at 7 days from LEW rats rejecting (LEW x BN)F1 heart grafts and fractionated into their T, T suppressor/cytotoxic, and T helper subpopulations. Transfer of alloimmune unseparated spleen cells to syngeneic recipients of (Lew x BN)F1 test grafts accelerated rejection from 8 to 6.5 days (P less than 0.01). Graft survival was prolonged to about 15 days (P less than 0.005) after transfer of the splenic T suppressor/cytotoxic fraction. Treatment of test graft recipients with ART-18, a mouse antirat monoclonal antibody directed against the rat interleukin 2 receptor on the surface of activated lymphocytes, increased graft survival to about 3 weeks (P less than 0.005), and to about 23 days (P less than 0.005) when test graft recipients were treated with ART 18 following transfer of alloimmune unseparated spleen cells. In contrast, ART-18 treatment of test graft recipients already injected with T suppressor/cytotoxic cells had no additive effect. Increased production of endogenous interleukin 2 occurred concomitantly with the onset of rejection in these animals; interleukin 2 release declined during the late stages of rejection when suppressor activity had increased. Similarly, in T-cell-depleted (B) rats, allograft rejection could be produced by immune reconstitution with sensitized lymphocytes, but could be significantly delayed by prior transfer of suppressor cells. These data document the presence of potent suppressor activity in the acutely rejecting host and suggest that the suppressor mechanisms are inhibited less than effector mechanisms by interleukin-2-receptor-targeted therapy.

Cyclosporine and experimental skin allografts: long-term survival in rats treated with low maintenance doses

Although cyclosporine (CsA) is a powerful immunosuppressive agent in organ transplantation, its efficacy in skin transplantation has not been examined completely. We have tested it as primary immunosuppression in a rat skin allograft model. Histoincompatible Brown-Norway skin grafts are rejected in untreated Lewis hosts within 9 +/- 1 days but survive for 22 +/- 3, 34 +/- 2, or 41 +/- 8 days after 7, 14, or 21 days of CsA treatment (15 mg/kg per day subcutaneously), respectively (p less than 0.001). Animals treated daily for 4 weeks died from drug toxicity; however, an initial 2-week course followed by a low maintenance dose (15 mg/kg every fourth day) produced indefinite (greater than 150 days) graft acceptance without side effects. The long-surviving grafts were supple, grew long hair, and showed normal histology. When the drug was stopped at any time during this maintenance period, early signs of rejection (hair loss, epidermal breakdown, and localized ulceration) occurred, which could be reversed completely by a short CsA "pulse" (15 mg/kg per day for 7 days). These experimental data support the potential application of CsA immunosuppression in human skin allotransplantation.

Cyclosporine and experimental skin allografts. II. Indefinite survival and development of specific immunologic unresponsiveness

Immunological unresponsiveness toward skin allografts was studied in cyclosporine (CsA)-treated rats. BN skin grafts survive about 22 days and about 34 days in LEW hosts following 7 or 14 days of daily CsA treatment (15 mg/kg/day), respectively; in unmodified hosts grafts are rejected by 9 days. Indefinite (greater than 100 days) survival can, however, be produced by administering maintenance 15 mg/kg CsA every fourth day, following an initial course of the agent for 14 days. Early signs of graft rejection (hair loss, localized epidermal breakdown, and ulcerations) occurring in some animals were reversed by a CsA "pulse" (15 mg/kg/day) for 7 days, reduced gradually to the maintenance dose. CsA was equally effective when started as late as 4 days after grafting, but ineffectual when started after day 4. Once BN grafts were rejected, the agent could not prevent second-set rejection of donor-specific grafts, but significantly prolonged the survival of third-party (WF) skins. Survival of original BN grafts was unchanged by the placement of second BN grafts during both the inductive and maintenance phases; these second grafts survived as long as the original grafts. In contrast, secondary third-party (WF) grafts were promptly rejected; their destruction did not influence survival of the original grafts. Thus, indefinite survival of rat skin allografts is feasible with low maintenance doses of CsA. Graft rejection at later stages can be reversed by resuming daily therapy. Host unresponsiveness is stable and specific both during the early inductive and later maintenance phases.

T suppressor lymphocytes reverse ongoing acute allograft rejection

(LEW X BN)F1 cardiac allografts are rejected within 8 days in untreated LEW recipients. At the critical time point of 5 days after transplantation, the obviously rejecting grafts are enlarged and maximally infiltrated by host cells as shown by 111In-labeled lymphocyte tracer studies. However, when such hearts were retransplanted back to naive (LEW X BN)F1 secondary hosts, they survive indefinitely, showing that even late rejection is reversible in the absence of sustained host immunological drive. Attempts were then made to abrogate this advanced immune responsiveness using Cyclosporine (CsA). CsA therapy (15 mg/kg/day for 7 days) starting from day 5 produced indefinite graft survival, similar as if initiated at the time of operation. Addition of exogenous IL-2, which drives the proliferation of Tc, could not reverse this effect. Serial changes in phenotype of lymphocyte subpopulations infiltrating both acutely rejecting and indefinitely functioning cardiac allografts in unmodified and CsA treated hosts, respectively, were then studied. Ratio of Th:Tc/s cells in acutely rejecting grafts was 1.6 by day 3; it inverted abruptly to 0.7 by day 5-6, suggesting predominance of Tc/s during the later stages of allograft rejection. Similarly, treatment with CsA produced a transient depression of Th, with recovery of original Th:Tc/s ratio during the next 2-3 weeks. Adoptive transfer experiments were then performed to investigate the functional significance of these findings.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of intrauterine infusions of prostaglandin E2 on luteal function in nonpregnant gilts

Two trials were conducted to study the effects of intrauterine infusions of prostaglandin E2 (PGE2) on luteal function in nonpregnant gilts. Cannulae were surgically implanted on day 9 postestrus into the lumen of each horn with a cephalic vein cannula inserted for collection of peripheral blood. Intrauterine infusions of 0, 25, 75 or 200 microg of PGE2 were initiated at 0900 h on day 12 and administered thereafter every 12 hr until estrus or day 22 in the first trial. The second trial protocol included an increase in the dose of PGE2 administered as well as the frequency of infusion. Infusion of 0, 200, 300 or 400 microg PGE2 was begun at 0300 h on day 12 and continued every 6 hr until estrus or day 22. Cephalic plasma samples for progesterone analysis were collected every six hours from 0300 h on day 11 to 2100 h on day 26 in both trials. In Trial 1 mean plasma progesterone concentrations for all treatments were not different (P>0.05) from the controls on any given day of the estrous cycle. Interestrous interval was unaffected by intrauterine infusion of PGE2. The mean plasma progesterone concentrations for all treatments were not different (P>0.05) from the controls on days 11-18 of the estrous cycle in Trial 2. However, plasma progesterone concentrations for the 200-microg and 300-microg PGE2 groups appeared to be greater than the controls on days 14 and 15, indicating a possible delay in the decline of progesterone for these groups. The mean plasma progesterone concentrations for the treatment groups were lower (P<0.05) than the controls on days 20-26 of the cycle. treatment cycle length did not differ (P>0.05) from previous cycle length; thus treatment with PGE2 had no effect on interestrous interval. PGE2 may have retarded the decline of progesterone secretion by the corpus luteum in some cases, but at these dosages and frequencies of administration PGE2 was ineffective in prolonging luteal maintenance.

Pressure, temperature, and repetitive impulse generation in crustacean axons

Increases in nerve axon excitability, including repetitive activity, have from time to time been reported in nerves subjected to high hydrostatic pressure. With the description of the high-pressure nervous syndrome (HPNS) in human divers and experimental animals, this phenomenon is of interest as a possible basis for the hyperexcitability associated with HPNS. The present study was designed to define the relationships between temperature, pressure, and repetitive activity in isolated crayfish axons. Crayfish claw nerves were exposed to helium pressures between 1 and 200 atmospheres absolute (ATA) in a temperature-controlled recording chamber. Repetitive and spontaneous impulses were reliably evoked on compression. The probability of repetitive response was increased by low temperature and high pressure; the frequency of the repetitive activity was increased by high temperature and pressure. Repetitive activity appeared spontaneously in the unstimulated preparation but could be entrained by the stimulus. The results are consistent with a mechanism involving changes in nerve membrane lipid fluidity and in the time course of membrane ionic channel state changes, including those involved in repolarization and accommodation.

Anesthetics inhibit pressure-induced repetitive impulse generation

Repetitive and spontaneous impulse generation appears in nerve axons exposed to high pressure. This phenomenon is a possible basis for high-pressure nervous syndrome (HPNS) or pressure reversal of anesthesia, two examples of an antagonistic interaction between anesthetic drugs and high pressure. In the present study, the interactions between three classes of anesthetic drug (ethyl alcohol, the volatile inhalation agent halothane, and phenobarbital) and repetitive activity were explored. Ethyl alcohol (5% in solution) and halothane (1.3 and 3.4% in oxygen) inhibited pressure-induced repetitive activity. Phenobarbital at 0.25 mM in solution, the maximum concentration obtainable at low temperature, was partially effective. The three drugs produce an unconscious state that is "reversed" at hyperbaric pressure. Halothane and phenobarbital inhibit HPNS, but ethyl alcohol has not been tested for this property. The results thus support a relevance of repetitive activity to HPNS, to pressure reversal of anesthesia, or to both.