The Evolutionary Origin of C Photosynthesis in the Grass Subtribe Neurachninae.

The Australian grass subtribe Neurachninae contains closely related species that use C, C, and C photosynthesis. To gain insight into the evolution of C photosynthesis in grasses, we examined leaf gas exchange, anatomy and ultrastructure, and tissue localization of Gly decarboxylase subunit P (GLDP) in nine Neurachninae species. We identified previously unrecognized variation in leaf structure and physiology within that represents varying degrees of C-C intermediacy in the Neurachninae.

Evolutionary implications of C3 -C4 intermediates in the grass Alloteropsis semialata.

C4 photosynthesis is a complex trait resulting from a series of anatomical and biochemical modifications to the ancestral C3 pathway. It is thought to evolve in a stepwise manner, creating intermediates with different combinations of C4 -like components. Determining the adaptive value of these components is key to understanding how C4 photosynthesis can gradually assemble through natural selection.

Multiple photosynthetic transitions, polyploidy, and lateral gene transfer in the grass subtribe Neurachninae.

The Neurachninae is the only grass lineage known to contain C(3), C(4), and C(3)-C(4) intermediate species, and as such has been suggested as a model system for studies of photosynthetic pathway evolution in the Poaceae; however, a lack of a robust phylogenetic framework has hindered this possibility. In this study, plastid and nuclear markers were used to reconstruct evolutionary relationships among Neurachninae species. In addition, photosynthetic types were determined with carbon isotope ratios, and genome sizes with flow cytometry.

Leaf anatomy of c(3)-c(4) species as related to evolution of c(4) photosynthesis.

This study was undertaken to examine the degree of Kranz anatomy development in the species intermediate to C(3) and C(4) types (C(3)-C(4)) in Panicum, Neurachne, Flaveria, and Moricandia. In each genus, C(3) and/or C(4) species were used for comparison. Leaf transections from each species were examined by light and transmission electron microscopy.

Heparin therapy for thromboembolic disorders. A prospective evaluation of 134 cases monitored by the activated coagulation time.

One hundred thirty-four patients with venous thrombosis or pulmonary embolism, confirmed by radiological techniques, received continuous-pump heparin therapy while their responses were monitored by the activated coagulation time (ACT). The suggested protocol was as follows: (1) give an intravenous bolus of about 50 units/kg; (2) follow with 15 to 25 units/kg/hr; (3) modify infusion rate to maintain ACT of 150 to 190 s; (4) after two or three days with ACT in target range, start oral warfarin sodium therapy; (5) after three to five days of warfarin therapy, if prothrombin time is two to 2 1/2 times the control value, discontinue heparin administration. One hundred thirty-two patients responded, with no heparin failures.

Adjusting heparin infusion rates from the initial response to activated coagulation time.

A mathematical description of the dose-response curve of heparin to the activated coagulation time is applied retrospectively to 20 patients treated with continuous heparin infusion. The adjusted heparin dose was compared with a calculated prediction using the theoretical mathematical model. The main actual dose was 28 U/kg/h, and the mean predicted dose was 25.

The distribution of C and C grasses in Australia in relation to climate.

All but four of 833 native and 292 naturalised Australian grasses (Poaceae) have been assigned as having the C or C photosynthetic pathway. In conjunction with comprehensive species composition data for 75 geographic subdivisions Australiawide, this has permitted the construction of distribution maps for C and C grasses. C and C grass distributions have been considered (i) independently, using subdivisional native species numbers; and (ii) relatively, using 'subdivisional % C'.

Sources of error in heparin therapy of thromboembolic disease.

We observed a series of patients with thromboembolic disease treated intravenously with heparin sodium and monitored by the activated coagulation time (ACT) of whole blood. When patients responded slowly, had dangerous hemorrhage, or had ACTs well outside our target range, we analyzed infusion records to determine actual infusion rates. We found the following sources of error: (1) lack of pump precision, (2) interruption of infusion, (3) errors in making up solutions, and (4) failure of infusion or charting techniques.

Unrecognized causes of platelet transfusion failure in the presence of anti-HL-A antibodies.

When in a patient who is receiving random donor platelet infusions there is an inadequate rise in platelet count and anti-human HL-A antibodies are noted in the serum, it is natural to assume that platelet destruction results from an immunologic cause. Nonimmunologic causes of such failure do occur, however. Two of the most common are disseminated intravascular coagulation and splenomegaly.

Cryoprecipitates as a source of fibrinogen in treatment of disseminated introvascular coagulation (DIC).

Cryoprecipitates, in addition to containing factor VIII, contain about one third of the fibrinogen in the plasma from which they were derived. This fibrinogen is functional, as established by successfully preparing two congenital hypofibrinogenemics for major surgery by infusing cryoprecipitates. Cryoprecipitates and platelet concentrates are also used for patients with low levels caused by disseminated intravascular coagulation (DIC).

Progress report: the activated coagulation time of whole blood (ACT).

The activated coagulation time of whole blood (ACT) has, in the nearly ten years since its first description in the literature, proven itself one of the best laboratory tests for the control of heparin therapy, both for patients undergoing treatment for thromboembolic disease and for those on extracorporeal circulation. It is simple, largely free from subjective variation, precise, and quick. Prolongation of the ACT in the heparinized individual is directly proportional to the concentration of heparin in the blood, and the test accurately reflects the semilogarithmic disappearance of the anticoagulant effect in most patients.

The effect of increased contact activation time on the activated partial thromboplastin time.

With the kaolin-cephalin activated partial thromboplastin time technic, the plasmas of persons who have Fletcher factor deficiency have shown considerable shortening of clotting times when contact activation has been lengthened from 3 (PTT-3) to 10 minutes (PTT-10). The authors demonstrate that in plasma of most normal individuals, and in coagulopathies of other sorts, only slight shortening usually occurs. Abnormal shortening occurs in plasmas of a few otherwise normal people, the "slow activators," and patients receiving coumarin drugs, who have greatly prolonged prothrombin times.

A walking donor program for an intensive care nursery.

Repeated transfusions of small increments of blood are frequently required for the sick newborn infant to correct endogenous hypovolemia and/or to replace blood obtained repeatedly for monitoring purposes. Current practices of blood banks are rarely geared to supply the small amounts of blood used for these individual transfusions. To provide a more efficient system, a walking donor program was established in which an appropriate hospital-based individual is cross matched as a donor for an infant for the duration of the infant's hospital stay.

Neutrophilic hypersegmentation without macrocytic anemia.

In five months of examining some 25,000 blood smears of hospital and clinic patients, 200 patients were found whose blood had hypersegmented neutrophiles without macrocytosis of the erythrocytes. Sixty-five of these patients subsequently received adequate laboratory work-up. Seven proved to have a bacterial inhibitor in their serum which interfered with the microbiological assay of folic acid.

The activated coagulation time of whole blood as a routine pre-operative sceening test.

Patients with disorders of hemostasis who undergo surgical procedures are in danger of hemorrhage. While the careful medical history remains the most sensitive test of a bleeding tendency, some such patients can give no suggestive history. In three patients with coagulopathy-one with mild classical hemophilia, one with Christmas disease, and one with warfarin toxicity-the abnormality was missed by routine preoperative history but promptly detected by the routine preoperative use of the activated coagulation time (act).