Admission respiratory status predicts mortality in COVID‐19

COVID‐19 has significant case fatality. Glucocorticoids are the only treatment shown to improve survival, but only among patients requiring supplemental oxygen. WHO advises patients to seek medical care for “trouble breathing,” but hypoxemic patients frequently have no respiratory symptoms. Our cohort study of hospitalized COVID‐19 patients shows that respiratory symptoms are uncommon and not associated with mortality. By contrast, objective signs of respiratory compromise—oxygen saturation and respiratory rate—are associated with markedly elevated mortality. Our findings support expanding guidelines to include at‐home assessment of oxygen saturation and respiratory rate in order to expedite life‐saving treatments patients to high‐risk COVID‐19 patients.     

Germ cell damage and Leydig cell insufficiency in recipients of nonmyeloablative transplantation for haematological malignancies

Most bone marrow transplant recipients are infertile due to reversible or irreversible testicular failure. However, little is known about the gonadotoxic potential of the newly introduced nonmyeloablative transplants. We undertook a 24-month longitudinal study in a cohort of 32 recipients of nonmyeloablative transplantation to test whether the combined regimen of fludarabine, melphalan and CAMPATH-1H can induce damage to germ cell (GC) and Leydig cell (LC) compartments. Testicular function was assessed immediately prior to transplantation and at four time points post-transplant to compare hormonal levels before and after the procedure. Two other groups treated with BEAM- and TBI-related regimes were also included in the study group for comparative purposes. GC function was assessed by measuring basal serum follicle stimulating hormone (FSH). LC function was assessed by measuring basal luteinising hormone (LH) and testosterone (T) levels. LC reserve was assessed by measuring the T/LH ratio. As a group, patients who received a non myeloablative transplant sustained severe damage to the GC compartment, as evident from a substantial elevation in the FSH level post-transplant (12 IU/l vs 18.4 IU/l, P<0.001). Similar to the GC injury, patients as a group sustained significant damage to the LC compartment following the transplant (5.4 IU/l vs 9.6 IU/l, P<0.001). In general, patients had reduced LC reserve post-BMT, as evident from a diminished T/LH ratio (2.6 pretransplant vs 1.6 post-transplant P=0.05). Patients who received a nonmyeloablative transplant had a similar effect on the GC and LC compartments compared to those who had a BEAM autograft. On the other hand, patients who received a TBI-based transplant sustained more damage to their GC and LC compartments compared to those who received a nonmyeloblative transplant; however, this was not statistically significant (P=0.09). Our data suggest that this type of regimen is potentially gonadotoxic and consideration should be given to fertility counselling and testosterone replacement therapy post-transplant.     

Effects of peptide YY (PYY) on mouth to caecum intestinal transit time and on the rate of gastric emptying in healthy volunteers.

The effect of an infusion of two doses of peptide YY (PYY), a novel putative gastrointestinal hormone, has been assessed on mouth to caecum intestinal transit time and on the rate of gastric emptying after ingestion of an inert 200 ml liquid meal thought unlikely to interrupt fasting gastrointestinal motility patterns. A low dose of PYY was chosen to give plasma concentrations within the range seen postprandially in healthy subjects, while the high dose mimicked the raised levels seen in several malabsorptive conditions. During infusion of PYY at 0.18 pmol/kg/min plasma concentrations rose from a basal of 8 +/- 2 pmol/l to 38 +/- 5 pmol/l and at 0.51 pmol/kg/min to 87 +/- 10 pmol/l. Mouth to caecum transit time was delayed from 67 +/- 4 mins on the saline infusion day to 94 +/- 7 mins (p less than 0.01) on the low dose and 192 +/- 9 mins (p less than 0.001) on the high dose infusion day. Time to 50% gastric emptying was prolonged from 37 +/- 8 mins during saline infusion to 63 +/- 10 mins (p less than 0.05) during low and 130 +/- 12 mins (p less than 0.001) during high dose infusion. Thus the infusion of PYY shows a dose related inhibition of mouth to caecum intestinal transit time and of the rate of gastric emptying and suggests this novel hormonal peptide to be of importance in gastrointestinal physiology.     

Fracture dynamics of fusion of two anti-plane cracks

The problem of the fracture dynamics of two two-dimensional coplanar anti-plane shear cracks is considered. Both cracks extend under a critical stress-intensity fracture criterion. The two cracks are initiated at different locations and times. A solution developed by Kostrov [Kostrov, B. V. (1966) J. Appl. Math. Mech. 30, 1241-1248] for isolated cracks is used to determine the tearing loci of the cracks up to the time at which the individual cracks begin to interact. In the interaction interval prior to the fusion of the two cracks, both the stresses and the fracture tip loci are determined sequentially by applying the solution to Abel's equation twice iteratively. This method can be used to solve problems of the fusion of any number of coplanar cracks.     

Comparison of haemodynamic effects of oral hydralazine and prazosin hydrochloride in patients with chronic congestive heart failure

The comparative haemodynamic effects of oral prazosin hydrochloride and hydralazine were evaluated in 11 patients with chronic congestive heart failure. The maximum total dose of prazosin received by an individual varied up to 25 mg. Ten patients received a maximum of 75 mg and one received 50 mg of hydralazine at six-hour intervals. There was no significant change in heart rate with either drug. Decrease in mean arterial and left ventricular filling pressures were modest and similar with both agents. With prazosin, the average cardiac index increased 20 per cent and systemic vascular resistance decreased 20 per cent. By contrast, hydralazine increased cardiac index by 58 per cent and decreased systemic vascular resistance by 40 per cent. The increase in stroke work and stroke volume indices was significantly greater with hydralazine than with prazosin. These findings suggest that in some patients with severe chronic congestive heart failure, improvement in left ventricular performance may be greater with hydralazine than with prazosin.     

Reversible hypogonadotrophic hypogonadism in sexually infantile male thalassaemic patients with transfusional iron overload

OBJECTIVE: To determine the severity and reversibility of the lesion in the hypothalamic-pituitary (H-P) axis of male transfusion-dependent thalassaemic patients with failed puberty (FP). DESIGN AND SUBJECTS: The hypothalamic-pituitary axes of 20 male thalassaemic patients (study group) were compared with two male subjects with idiopathic hypogonadotrophic hypogonadism (IHH) and five prepubertal healthy siblings (control group). GnRH-gonadotrophin insufficiency was characterized by nocturnal 12 h ultradian gonadotrophin profiles followed by a 100 microg GnRH bolus test (GBT) 4-6 times at 6 monthly intervals. Thalassaemic and IHH patients were then subjected to pulsatile subcutaneous GnRH infusions every 120 minutes for 3 months. Ultradian gonadotrophin profiles and GBT were repeated after 6 weeks of GnRH infusion and again at 3 months following infusion. MEASUREMENTS: FSH and LH were measured by radio-immunoassay. Ferritin was assayed by an immunoradiometric method. RESULTS: Patients with IHH who were apulsatile prior to infusion, developed normal gonadotrophin pulses with marked increment in their gonadotrophin responses to the GBT after 3 months of GnRH infusion. In contrast, the thalassaemic patients with apulsatile failed puberty (AFP) remained apulsatile (nonresponders) and had no increment in their gonadotrophin responses to the GBT after GnRH infusion. All patients with pulsatile failed puberty (PFP) had abnormal gonadotrophin pulses prior to GnRH infusion. Their pulse defects were either totally or partially corrected (responders) following infusion. The serum ferritin levels (9500 +/- 500 microg/l vs. 5966.67 +/- 1139 microg/l; P < 0.01) and percentage of organ dysfunction (87% vs. 17%; P < 0.01) were higher in the nonresponders than the responders. CONCLUSIONS: This study shows that thalassaemic patients with severe organ damage and iron overload are likely to be apulsatile with irreversible damage to their hypothalamo-pituitary axis, while those with less severe iron overload are likely to have potentially reversible hypogonadotrophic hypogonadism (HH). Our results also suggest that gonadotrophin pulse parameters, rather than the gonadotrophin response to a GnRH bolus following prolonged pulsatile GnRH infusion, may be more useful in discriminating reversible from irreversible hypogonadotrophic hypogonadism.     

Minoxidil therapy in chronic congestive heart failure: Acute plus long-term hemodynamic and clinical study

The hemodynamic response to minoxidil, an orally active, potent vasodilator, was evaluated in 11 patients with severe chronic congestive heart fallure (CHF). The hemodynamic response was determined following single doses of 10, 15, 20, 25, and 30 mg of minoxidil. The hemodynamic response was characterized by marked increases in cardiac index (+63%) and stroke volume index (+52%) and by decrease in systemic vascular resistance (?38%). There was also a slight decrease in pulmonary capillary wedge pressure from an average of 24 ± 8 to 21 ± 7 mm hg. Although the average mean arterial pressure remained unchanged, one patient developed significant hypotension. Chronic minoxidil therapy (eight patients) was associated with fluid retention and weight gain. In four patients in whom fluid retention could be minimized with larger doses of diuretics, a sustained clinical and hemodynamic improvement was observed. These findings suggest that minoxidil has the potential to improve cardiac function and may be useful in chronic vasodilator therapy of CHF, provided fluid retention can be controlled.     

Prevalence of Alloimmunization to Human Platelet Antigen Glycoproteins and Human Leucocyte Antigen Class I in β Thalassemia Major Patients in Western India

Present management of β thalassemia major by regular packed red blood cell (PRBC) transfusions poses risk of alloimmunization not only to red blood cell antigens, but also to human platelet antigens (HPA) and Human leucocyte antigens class I (HLA I). However data in this context is very limited in Indian population. The aim of the study was to determine the prevalence of alloimmunization to HPA and HLA I in β thalassemia major patients who have received multiple PRBC transfusions over the years. A cross sectional study was performed at our tertiary care blood bank. β thalassemia major patients of more than 6 years of age were included who were receiving fresh, leucoreduced and irradiated PRBC units regularly with annual requirement of more than ten PRBC transfusions. A total of 9 out of 80 (11.25 %) patients were found to be alloimmunized for HPA antigens of various specificity and 24 out of 80 (30 %) developed antibodies to HLA I. The awareness of development of alloimmunization to HPA and HLA antigens in multi PRBC transfused thalassemics, despite use of leucofilters will prompt us, to look for improvement in our current PRBC preparations to minimise platelet alloimmunisation. Further studies are required to validate the findings and build the base line data in this regard. This is of importance, especially in view of providing suitable cross-matched platelets when required in future especially when considering future haematopoietic stem cell transplantation (HSCT).     

Cangrelor for patients undergoing percutaneous coronary intervention: evidence from a meta-analysis of randomized trials

Cangrelor is a new parenteral adenosine diphosphate P2Y12 receptor inhibitor with rapid, profound and reversible inhibition of platelet activity. The aim of this meta-analysis was to evaluate efficacy and safety of this new agent in patients undergoing percutaneous coronary intervention (PCI). We searched PubMed, Cochrane Library, EMBASE, Web of Science and CINAHL databases from the inception through April 2013. Randomized controlled trials (RCTs) comparing cangrelor with control (clopidogrel/placebo) were selected. We used the random-effects models to calculate the risk ratio. The primary efficacy outcome was risk of myocardial infarction, and the primary safety outcome was TIMI major bleeding at 48 h. Three RCTs included a total of 25,107 participants. Effects of Cangrelor were not different against comparators for myocardial infarction (MI) (Risk ratio [RR] 0.94, 95 % confidence interval [CI] 0.78–1.13) and all-cause mortality (RR 0.72, 95 % CI 0.36–1.43). However, cangrelor significantly reduced the risk of ischemia-driven revascularization (RR 0.72, 95 % CI 0.52–0.98), stent thrombosis (RR 0.60, 95 % CI 0.44–0.82) and Q wave MI (RR 0.53, 95 % CI 0.30–0.92) without causing extra major bleeding (Thrombolysis in Myocardial infarction criteria) and severe or life-threatening bleeding (Global utilization of streptokinase and tissue plasminogen activator for occluded coronary arteries criteria). Separate analysis against only clopidogrel also showed similar findings except Q wave MI outcome. Use of cangrelor during PCI might reduce the risk of ischemia-driven revascularization and stent thrombosis, without causing extra major bleeding.