Heterogeneous Ice Nucleation Studied with Single-Layer Graphene

Control of heterogeneous ice nucleation (HIN) is critical for applications that range from iceophobic surfaces to ice-templated materials. HIN on 2D materials is a particular interesting topic that still lacks extensive experimental investigations. Here, we focus on the HIN on single-layer graphene (SLG) transferred onto different substrates, including silicon, silica, and thermal oxide on silicon. Complemented by other samples without SLG, we obtain a large range of wetting contact angles (WCAs) from 2° to 95°. All pristine SLG samples exhibit a large contact angle of ∼95°, which is close to the theoretical value of 96° for free-standing SLG, irrespective of the substrate and even in the presence of nanoscale wrinkles on SLG, which are due to the transfer process, indicating that the topographical features have little impact on the wetting behavior. Interestingly, SLG displays changes in hydrophobicity upon repeated water droplet freezing-melting-drying cycles due to a shift in Fermi level and/or enhanced water-substrate polar molecular interactions, likely induced by residual adsorption of H₂O molecules. We found that a 0.04 eV decrease in SLG Fermi level reduces the SLG/water interface energy by ∼6 mJ/m², thereby making SLG less hydrophobic. Counterintuitively, the reduction in SLG/water interface energy and the enhanced hydrophilicity after repeated freezing-melting-evaporation cycles actually decreases the freezing temperature by ∼3-4 °C, thereby slightly retarding rather than enhancing HIN. We also found that the water droplet freezing temperature differed by only ∼1 °C on different substrates with WCAs from 2° to 95°, an intriguing and yet reasonable result that confirms that wettability alone is not a good indicator of HIN capability. The HIN rate is rather determined by the difference between substrate/water and substrate/ice interface energies, which was found to stay almost constant for substrates weakly interacting with water/ice via van der Waals or hydrogen bonds, irrespective of hydrophilicity.

COVID-19-Associated Hospitalizations Among Vaccinated and Unvaccinated Adults 18 Years or Older in 13 US States, January 2021 to April 2022

Importance

Understanding risk factors for hospitalization in vaccinated persons and the association of COVID-19 vaccines with hospitalization rates is critical for public health efforts to control COVID-19.

Objective

To determine characteristics of COVID-19-associated hospitalizations among vaccinated persons and comparative hospitalization rates in unvaccinated and vaccinated persons.

Design, Setting, and Participants

From January 1, 2021, to April 30, 2022, patients 18 years or older with laboratory-confirmed SARS-CoV-2 infection were identified from more than 250 hospitals in the population-based COVID-19-Associated Hospitalization Surveillance Network. State immunization information system data were linked to cases, and the vaccination coverage data of the defined catchment population were used to compare hospitalization rates in unvaccinated and vaccinated individuals. Vaccinated and unvaccinated patient characteristics were compared in a representative sample with detailed medical record review; unweighted case counts and weighted percentages were calculated.

Exposures

Laboratory-confirmed COVID-19-associated hospitalization, defined as a positive SARS-CoV-2 test result within 14 days before or during hospitalization.

Main Outcomes and Measures

COVID-19-associated hospitalization rates among vaccinated vs unvaccinated persons and factors associated with COVID-19-associated hospitalization in vaccinated persons were assessed.

Results

Using representative data from 192 509 hospitalizations (see Table 1 for demographic information), monthly COVID-19-associated hospitalization rates ranged from 3.5 times to 17.7 times higher in unvaccinated persons than vaccinated persons regardless of booster dose status. From January to April 2022, when the Omicron variant was predominant, hospitalization rates were 10.5 times higher in unvaccinated persons and 2.5 times higher in vaccinated persons with no booster dose, respectively, compared with those who had received a booster dose. Among sampled cases, vaccinated hospitalized patients with COVID-19 were older than those who were unvaccinated (median [IQR] age, 70 [58-80] years vs 58 [46-70] years, respectively; P < .001) and more likely to have 3 or more underlying medical conditions (1926 [77.8%] vs 4124 [51.6%], respectively; P < .001).

Conclusions and Relevance

In this cross-sectional study of US adults hospitalized with COVID-19, unvaccinated adults were more likely to be hospitalized compared with vaccinated adults; hospitalization rates were lowest in those who had received a booster dose. Hospitalized vaccinated persons were older and more likely to have 3 or more underlying medical conditions and be long-term care facility residents compared with hospitalized unvaccinated persons. The study results suggest that clinicians and public health practitioners should continue to promote vaccination with all recommended doses for eligible persons.

Oocyte maturation and fertilization in marine nemertean worms: using similar sorts of signaling pathways as in mammals, but often with differing results

In marine worms belonging to the phylum Nemertea, oocyte maturation and fertilization are regulated by the same general kinds of signals that control such processes in mammals. However, unlike mammalian oocytes that develop within follicles, nemertean oocytes characteristically lack a surrounding sheath of follicle cells and often respond differently to maturation-related cues than do mammalian oocytes. For example, elevators of cyclic adenosine monophosphate (cAMP) or cyclic guanosine monophosphate (cGMP) levels promote the resumption of meiotic maturation (=germinal vesicle breakdown, GVBD) in nemertean oocytes, whereas increasing intraoocytic cAMP and cGMP typically blocks GVBD in mammals. Similarly, AMP-activated kinase (AMPK) signaling keeps nemertean oocytes from maturing, but in mouse oocytes, AMPK activation triggers GVBD. In addition, protein kinase C (PKC) activity is required for seawater-induced GVBD in nemerteans, whereas some PKCs have been shown to inhibit GVBD in mammals. Furthermore, although fertilization causes both types of oocytes to reorganize their endoplasmic reticulum and generate calcium oscillations that can involve soluble sperm factor activity and inositol 1,4,5-trisphosphate signaling, some discrepancies in the spatiotemporal patterns and underlying mechanisms of fertilization are also evident in nemerteans versus mammals. Thus, to characterize differences and similarities in gamete biology more fully, aspects of oocyte maturation and fertilization in marine nemertean worms are reviewed and briefly compared with related findings that have been published for mammalian oocytes. In addition, possible causes of the alternative responses displayed by oocytes in these two animal groups are addressed.

Plerixafor (AMD3100) in myeloma and lymphoma patients undergoing autologous stem cell transplantation

7100

Background: Poor peripheral blood stem cell (PBSC) mobilization has been reported as an obstacle to autologous stem cell transplant (ASCT). Plerixafor (AMD3100) has been recently approved as a mobilization agent for PBSC in the setting of ASCT. Methods: We retrospectively analyzed the data on patients who received plerixafor in our institution over two-year period. Four lymphoma patients received the drug in their first cycle of mobilization and 17 patients (hard to mobilize, HTM) as a rescue after failing to achieve cell target using G-CSF alone. These patients include 8 multiple myeloma (MM) and 9 lymphoma patients. A control group of 26 randomly picked MM and lymphoma patients who were good mobilizers and received ASCT during the same period were used for comparison. Results: Sixteen of the 17 HTM patients proceeded to ASCT with median CD34+ cell dose of 3.68 X 106/kg (range, 1.88–5.01 X 106), and two of them had tandem transplants. All MM patients achieved minimum cell dose for two ASCTs. One MM patient died of progressive disease prior to ASCT. In comparison to the control group, plerixafor patients tended to have lower median CD34+ cell dose/kg collected and higher number of apheresis days, however the content of CFU-GM/kg on 1st day of apheresis was either equal or higher in the plerixafor group versus the control. The length of hospital stay, number of serious bacterial infection, time to granulocyte engraftment (AGC > 500) and long-term hematopoietic recovery at ≥ 12 mo post ASCT were not different among the two groups. Time to platelet recovery > 20,000/mm3 was similar for the MM patients, while more delayed for the plerixafor mobilized lymphoma patients (24 versus 12 days in the control group). One lymphoma patient in the control died of transplant-related complications before engraftment and none in the plerixafor group. Disease relapse at 12 months post ASCT was 0 and 10 % for plerixafor and control MM patients, respectively, and 46 and 20 % for lymphoma patients. However, the overall survival for both groups was not significantly different. Conclusions: all poor mobilizers were able to obtain adequate transplant CD34+ cell dose by using plerixafor and G-CSF. In general, patients mobilized with plerixafor had similar post transplant course and long-term outcome.

[Table: see text]

Gender aspects on survival among patients admitted to hospital with suspected or diagnosed heart failure

OBJECTIVES AND DESIGN

There are conflicting data on gender differences in survival among heart failure (HF) patients. We prospectively assessed gender differences in survival among 930 consecutive patients (464 [49.9%] women, mean age 76.1+/-10.1 years), admitted to hospital with suspected or diagnosed HF.

RESULTS

Overall, women had lower unadjusted mortality hazard ratio (HR) than men: HR 0.827; 95% confidence interval (CI) 0.690-0.992; p=0.040. Adjusted HR was 0.786; 95% CI 0.601-1.028; p=0.079. Unadjusted mortality was significantly higher among patients with a discharge HF diagnosis, compared to those without: HR 1.330; 95% CI 1.107-1.597; p=0.002; adjusted p=0.289. Women and men with a discharge HF diagnosis had similar survival: unadjusted HR 1.052; 95% CI 0.829-1.336; p=0.674; adjusted HR 0.875; 95% CI 0.625-1.225; p=0.437. Women had lower mortality risk among patients without a discharge HF diagnosis: HR 0.630, 95% CI 0.476-0.833, p=0.001; adjusted HR 0.611, p=0.036.

CONCLUSION

Prognosis was poor among patients hospitalised with suspected or diagnosed HF. Among all patients, women had better survival, whereas both sexes had similar survival when the HF diagnosis was certified.

Effects on quality of life, symptoms and daily activity 6 months after termination of an exercise training programme in heart failure patients

BACKGROUND

Exercise training in heart failure patients improves exercise capacity, physical function, and quality-of-life. Prior studies indicate a rapid loss of these effects following termination of the training. We wanted to assess any sustained post-training effects on patients global assessment of change in quality-of-life (PGACQoL) and physical function.

METHODS

Fifty-four stable heart failure patients were randomised to exercise or control. The 4-month exercise programme consisted of bicycle training at 80% of maximal intensity three times/week, and 49 patients completed the active study period. At 10 months (6 months post training) 37 patients were assessed regarding PGACQoL, habitual physical activity, and dyspnea-fatigue-index.

RESULTS

Both post-training patients (n=17) and controls (n=20) deteriorated PGACQoL during the 6-month extended follow-up, although insignificantly. However, post-training patients improved PGACQoL slightly but significantly from baseline to 10 months (P=0.006), differing significantly (P=0.023) from controls who were unchanged. Regarding dyspnea-fatigue-index, post-training patients were largely unchanged and controls deteriorated insignificantly, during the extended follow-up as well as from baseline to 10 months. Both groups decreased physical activity insignificantly during the extended follow-up, and from baseline to 10 months post-training patients tended to decrease whereas controls significantly (P=0.007) decreased physical activity.

CONCLUSION

There was no important sustained benefit 6 months after termination of an exercise training programme in heart failure patients. A small, probably clinically insignificant sustained improvement in PGACQoL was seen in post-training patients. Controls significantly decreased the habitual physical activity over 10 months and post-training patients showed a similar trend. Exercise training obviously has to be continuing to result in sustained benefit.

Angiotensin converting enzyme (ACE) inhibitors and heart failure. The consequences of underprescribing

Heart failure (HF) is a common and expensive cardiovascular disease, in economic terms as well as in lives lost. Angiotensin converting enzyme (ACE) inhibitors have been shown to significantly reduce mortality and hospitalisation in HF. However, recent surveys show that the prescription rate of ACE inhibitors for HF is far below what is considered to be optimal. Furthermore, prescribed dosages are usually lower than those recommended based on evidence from clinical trials. This article estimates the consequences, both economic and human, of underprescribing ACE inhibitors in patients with HF. The indication for prescribing an ACE inhibitor varies, and clinical trials have included different categories of patients; it is inappropriate to assess costs in all eligible patients without taking these factors into account. Therefore, we analysed the data with respect to 4 different groups: (i) asymptomatic left ventricular systolic dysfunction (LVSD)--an early stage leading to chronic HF; (ii) chronic HF; and post-myocardial infarction (MI) LVSD differentiated into (iii) post-MI asymptomatic LVSD and (iv) post-MI chronic HF. We also estimated the cost effectiveness of adding an ACE inhibitor to the treatment of patients with HF for whom an ACE inhibitor is not currently prescribed. If only patient populations in which large trials have shown a significant effect of ACE inhibition on mortality are included in the analysis (i.e. excluding asymptomatic patients with LVSD), increasing the number of Swedish patients receiving an ACE inhibitor could save in excess of 3700 lives each year, in addition to reducing the annual number of hospitalisations by 8400. The additional cost would be 101.5 million Swedish kronor (SEK), a cost per life saved of SEK27 200. Chronic HF is the most cost-effective patient population to treat, generating cost savings under certain assumptions. A further 6700 hospitalisations can be avoided should the use of ACE inhibitors be extended to asymptomatic patients with LVSD. Increasing dosages to those used in the large clinical trials may generate additional savings in lives and hospitalisations. In conclusion, the use of ACE inhibitors in HF and LVSD has clearly been proven to be cost effective, and compares favourably with the cost effectiveness of treating hypertension or hypercholesterolaemia. At present, however, ACE inhibitors are not optimally utilised. Given the increasingly constrained resources for healthcare, every effort should be made to increase the use of cost-effective treatments, such as ACE inhibitors in chronic HF and post-MI LVSD.

Left atrioventricular plane displacement is related to both systolic and diastolic left ventricular performance in patients with chronic heart failure

AIMS

Left atrioventricular plane displacement is proposed to reflect left ventricular systolic function and is strongly related to prognosis in patients with heart failure. Left atrioventricular plane displacement is a different measure of left ventricular function compared to ejection fraction, and the factors influencing left atrioventricular plane displacement are insufficiently characterized. We wanted to assess any relationship between left atrioventricular plane displacement and left ventricular diastolic performance.

METHODS AND RESULTS

Left ventricular diastolic filling, left atrioventricular plane displacement, and fractional shortening were assessed by echocardiography/Doppler in 54 patients with chronic heart failure (age 64 +/- 7 years). Left atrioventricular plane displacement correlated significantly with Doppler variables of left ventricular filling, in particular the inverse logarithm of early transmitral flow deceleration time; log-1 Edt (r = -0.61, P < 0.0001, n = 54). Left atrioventricular plane displacement also correlated with fractional shortening (r = 0.49, P < 0.001, n = 50). However, fractional shortening did not correlate with any Doppler variable. Log-1 Edt, fractional shortening, age, heart rate, left ventricular and atrial size, and degree of mitral regurgitation were included in a multiple regression analysis. Only log-1 Edt (P = 0.001) and fractional shortening (P = 0.03) correlated independently with left atrioventricular plane displacement. Among patients with similar fractional shortening, those with more compromised diastolic performance had lower left atrioventricular plane displacement.

CONCLUSION

Left atrioventricular plane displacement was related to both systolic and diastolic left ventricular performance, which may explain some of the discrepancies between left atrioventricular plane displacement and ejection fraction.

Maternal cradling and infant nipple preferences in rhesus monkeys (Macaca mulatta)

This study investigated lateral biases in nipple preferences, maternal cradling, carrying, and retrieval in 41 rhesus macaque (Macaca mulatta) mother-infant dyads living in two captive social groups. Observations were made during the first 6 weeks of infant life using a combination of scan sampling and ad-libitum sampling techniques. Infants exhibited a significant left-nipple preference in the first weeks of life but the bias decreased with infant age. Mothers showed a left-arm bias in carrying their infants but no significant lateral bias in cradling or retrieval. Our results suggest that the left-side cradling bias reported in studies of humans and some other primates reflects a bias in the infant's nipple preference rather than in maternal behavior. The infants' preference for the left nipple is consistent with both Salk's (1960) heartbeat hypothesis and with more recent hypotheses linking this lateral bias with brain asymmetry and hemispheric specialization for mother-infant communication.

Exercise training in heart failure improves quality of life and exercise capacity

AIMS

Benefit from exercise training in heart failure has mainly been shown in men with ischaemic disease. We aimed to examine the effects of exercise training in heart failure patients < or = 75 years old of both sexes and with various aetiology.

METHODS AND RESULTS

Fifty-four patients with stable mild-to-moderate heart failure were randomized to exercise or control, and 49 completed the study (49% > or = 65 years; 29% women; 24% non-ischaemic aetiology; training, n = 22; controls, n = 27). The exercise programme consisted of bicycle training at 80% of maximal intensity over a period of 4 months. Improvements vs controls were found regarding maximal exercise capacity (6 +/- 12 vs -4 +/- 12% [mean +/- SD], P < 0.01) and global quality-of-life (2 [1] vs 0 [1] units [median ¿inter-quartile range¿], P < 0.01), but not regarding maximal oxygen consumption or the dyspnoea-fatigue index. All of these four variables significantly improved in men with ischaemic aetiology compared with controls (n = 11). However, none of these variables improved in women with ischaemic aetiology (n = 5), or in patients with non-ischaemic aetiology (n = 6). The training response was independent of age, left ventricular systolic function, and maximal oxygen consumption. No training-related adverse effects were reported.

CONCLUSION

Supervised exercise training was safe and beneficial in heart failure patients < or = 75 years, especially in men with ischaemic aetiology. The effects of exercise training in women and patients with non-ischaemic aetiology should be further examined.

Quality of life in patients with ischaemic heart disease: a prospective controlled study

OBJECTIVES

To assess quality of life in patients after acute myocardial infarction (AMI), coronary artery by-pass grafting surgery (CABG) and percutaneous transluminal coronary angioplasty (PTCA) as compared with healthy controls.

DESIGN

Self-administered questionnaires were completed 1 month and 1 year after the event.

SETTING

Department of Cardiology, University Hospital, Malmö, Sweden; 1989-1992.

SUBJECTS

296 AMI, 99 CABG, 18 PTCA patients and 88 randomly selected healthy controls were included; 349 patients completed the entire programme.

MAIN OUTCOME MEASURES

Quality of life in the dimensions of perceived general health, thoracic pain, breathlessness, feeling of arrhythmia, anxiety, depression, self-esteem, experience of social life and sex life.

RESULTS

Patients differed from controls in both psychological and somatic aspects of QL after 1 month. Furthermore, 1 month after the event AMI patients experienced more anxiety (P = 0.001) than CABG patients, whilst CABG patients experienced a poorer sex life (P < 0.001) than AMI patients. One year after the event patients differed from controls primarily in somatic symptoms: no significant differences were found across patient groups. Patients who sought emergency out-patient care during the follow-up year for clinically diagnosed angina pectoris or cardiac incompensation had reported higher levels of thoracic pain (P < 0.001) and breathlessness (P < 0.001) at 1 month follow-up than patients who did not seek such care.

CONCLUSIONS

Quality of life is considerably affected in patients following a cardiac event, especially during the initial recovery phase. Although substantial improvement in quality of life occurs over time, the persistence of residual distress at 1-year follow-up is a challenge for clinicians concerned with the full rehabilitation of the cardiac patient.

Left ventricular atrioventricular plane displacement: an echocardiographic technique for rapid assessment of prognosis in heart failure

OBJECTIVE

To assess the prognostic value of atrioventricular plane displacement in heart failure patients.

DESIGN

Patients were followed prospectively for one year after atrioventricular plane displacement determination.

SETTING

Malmö University Hospital, with a primary catchment area of 250,000 inhabitants.

PATIENTS

181 patients with a clinical diagnosis of heart failure; age 75.7 (SD 5.2) years, duration of heart failure 2.7 (5.7) years; 100 men, 81 women.

MAIN OUTCOME MEASURES

Mortality in relation to atrioventricular plane displacement.

RESULTS

Total mortality was 22.7% (41/181), and was highly significantly (P = 0.001) related to atrioventricular plane displacement. Mortality within prospectively defined categories of displacement was: > or = 10.0 mm, 0% (0/19); 8.2 to 9.9 mm, 10.3% (3/29); 6.4 to 8.1 mm, 19.4% (12/62); and < 6.4 mm, 36.6% (26/71). The groups were similar in age, sex, angiotensin converting enzyme inhibitor and beta blocker treatment, and cause and duration of heart failure.

CONCLUSIONS

Mortality in heart failure is strongly related to atrioventricular plane displacement.

Distribution and morphology of dopaminergic amacrine cells in the retina of the turtle (Pseudemys scripta elegans)

A light microscopical study of the cell types that stain by immunohistochemistry for the synthesizing enzyme for dopamine, tyrosine hydroxylase, has been performed on the retina of the turtle Pseudemys scripta elegans. The immunostain can be localized to a single morphological type of amacrine cell. The cells are like A28 cells of a Golgi classification. They have medium sized dendritic fields that range in diameter from 200 to 700 micron with eccentricity from the visual streak. The amacrines have a tri-stratified dendritic tree with tiers of fine, curved dendrites ramifying in strata S1, lower S2 and the S4/5 border of the inner plexiform layer. We, like others, can find no good evidence that these cells are interplexiform cells. The dopaminergic amacrine cells have a low frequency (approximately 1300-1500 total cells in 130 mm2 retina), with their highest density occurring in the visual streak (60 cells per mm2). The density profiles fall in elliptical isodensity rings from the visual streak towards the peripheral retina. At all points on the retina the dendritic fields maintain a constant coverage factor independent of eccentricity. A comparison of the dopaminergic amacrine cells in the turtle and other vertebrate retinae is made.

Localization of fodrin during fertilization and early development of sea urchins and mice

Fodrin, a spectrin-like protein, is localized in gametes, zygotes, and embryos from sea urchins and mice. Mammalian fodrin comprises two polypeptides with molecular weights of approximately 240 kDa (alpha) and 235 kDa (beta). An antibody specific for mammalian alpha-fodrin cross-reacted with a 240-kDa polypeptide from sea urchin egg extracts. This indicates that sea urchins contain a protein of similar electrophoretic mobility and immunological properties to mammalian alpha-fodrin. When this antibody was used to stain the sea urchin gametes with indirect immunofluorescence, fodrin-specific fluorescence was localized to the acrosome of the sperm and was distributed over the entire egg near the surface in a punctate pattern similar to the distribution of polymeric actin. During sperm incorporation, the fodrin-specific fluorescence is found at the site of sperm incorporation, in the fertilization cone. After fertilization, the intensity of fodrin fluorescence increases. During mitosis and cytokinesis in sea urchins, the entire surface of the egg remains stained; the cleavage furrow also was stained but no more intensely than was the rest of the egg surface. Antibody labeling with colloidal gold followed by electron microscopy showed that fodrin was loated in the cytoplasm immediately beneath the plasma membrane. In unfertilized mouse oocytes, both actin and fodrin were stained most intensely beneath the membrane adjacent to the meiotic spindle. After insemination, the cell surfaces of the pronucleate egg and the second polar body were stained; however, the actin matrix surrounding the apposed pronuclei did not bind the fodrin antibody. During cytokinesis in the mouse, the cleavage furrow stained more intensely than did the rest of the egg cortex, and in embryos the cell borders were delineated. These results indicate that organisms as unrelated to mammals as sea urchins have fodrin-like proteins; the rearrangements of such proteins suggest that they participate in the actin-mediated events at the cell surface during fertilization and early development in both mice and sea urchins.

Latrunculin inhibits the microfilament-mediated processes during fertilization, cleavage and early development in sea urchins and mice

Latrunculin A, a marine toxin from a Red Sea sponge, is a potent inhibitor of the microfilament-mediated processes of fertilization and early development in sea urchins and in mice. Sperm from sea urchins, but not those from Limulus or mice, were affected by latrunculin, and fertilization in both sea urchins and in mice was arrested but at different stages. Sea urchin sperm treated with 2.6 microM latrunculin are unable to assemble acrosomal processes and their ability to fertilize eggs is impaired. The unwinding of the Limulus sperm acrosomal process occurs in the presence of latrunculin. Treated mouse sperm are able to fertilize mouse oocytes in vitro, suggesting that microfilaments may not be required in this mammalian sperm. In sea urchin eggs, sperm incorporation, microvillar elongation and cytokinesis are inhibited. Microtubule-mediated motility occurs normally. 20 nM latrunculin prevents the morphogenetic movements during gastrulation. It reduces the viscosity of actin gels from sea urchin egg homogenates. In unfertilized mouse oocytes, it prevents the colcemid-induced dispersion of the meiotic chromosomes; accumulations of cortical actin are noted adjacent to the scattered chromosomes. Sperm incorporation during mouse fertilization in vitro is unaffected suggesting that sperm entry may occur independent of microfilament activity in mammals. However, the apposition of the pronuclei at the center of the egg cytoplasm does not occur, providing evidence that cytoplasmic microfilaments may be required for the motions leading to pronuclear union during mouse fertilization. It inhibits the second polar body formation and cytokinesis. These results indicate that latrunculin is a potent inhibitor of microfilament-mediated processes in sperm, eggs and embryos, and that it may prove to be a powerful new drug for exploring the cellular behavior of microfilaments in the maintenance of cell shape and during motility.

The effects of artificial postoperative hematoma on patency of microvascular anastomoses in rat femoral blood vessels

The effect of hematoma formation on thrombus formation at microvascular anastomotic sites in the femoral arteries and veins of rats was investigated. No difference in anastomotic patency or thrombus formation was observed in the presence of perivascular hematoma, although compression secondary to hematoma formation was not an experimental variable. This study suggests the possibility that the velocity of blood flow (which increases with vasoconstriction) counteracts the thrombogenicity of changes in the flow volume (which decreases with vasoconstriction) by preventing the accumulation of thrombogenic materials. The authors suggest that the role of vasoconstriction in relation to thrombus formation and anastomotic patency should be explored further using topical vasoconstrictors and appropriate platelet fractions.