Nicotine stimulates angiogenesis and promotes tumor growth and atherosclerosis

We provide anatomic and functional evidence that nicotine induces angiogenesis. We also show that nicotine accelerates the growth of tumor and atheroma in association with increased neovascularization. Nicotine increased endothelial-cell growth and tube formation in vitro, and accelerated fibrovascular growth in vivo. In a mouse model of hind-limb ischemia, nicotine increased capillary and collateral growth, and enhanced tissue perfusion. In mouse models of lung cancer and atherosclerosis, we found that nicotine enhanced lesion growth in association with an increase in lesion vascularity. These effects of nicotine were mediated through nicotinic acetylcholine receptors at nicotine concentrations that are pathophysiologically relevant. The endothelial production of nitric oxide, prostacyclin and vascular endothelial growth factor might have a role in these effects.

Depressed low frequency power of heart rate variability as an independent predictor of sudden death in chronic heart failure

AIMS

Identification of patients with chronic heart failure at risk for sudden death remains difficult. We sought to assess the prognostic value for all-cause and sudden death of time and frequency domain measures of heart rate variability in chronic heart failure.

METHODS AND RESULTS

We prospectively enrolled 190 patients with chronic heart failure in sinus rhythm, mean age 61+/-12 years, 109 (57.4%) in NYHA class II and 81 (42.6%) in classes III or IV, mean cardiothoracic ratio 57.6+/-6.4% and mean left ventricular ejection fraction 28.2+/-8.8%, 85 (45%) with ischaemic and 105 (55%) with idiopathic dilated cardiomyopathy. Time and frequency domain measures of heart rate variability were obtained from 24 h Holter ECG recordings, spectral measures were averaged for calculation of daytime (1000h-1900h) and night-time (2300h-0600h) values. During follow-up (22+/-18 months), 55 patients died, 21 of them suddenly and two presented with a syncopal spontaneous sustained ventricular tachycardia. In multivariate analysis, independent predictors for all-cause mortality were: ischaemic heart disease, cardiothoracic ratio > or =60% and standard deviation of all normal RR intervals <67 ms (RR = 2.5, 95% CI 1.5-4.2). Independent predictors of sudden death were: ischaemic heart disease and daytime low frequency power <3.3 ln (ms(2)) (RR = 2.8, 95% CI 1.2-8.6).

CONCLUSION

Depressed heart rate variability has independent prognostic value in patients with chronic heart failure; spectral analysis identifies an increased risk for sudden death in these patients.

Development of semisynthetic triterpenoid saponin derivatives with immune stimulating activity

Aldehyde-containing triterpene saponins have adjuvant properties, but only those from Quillaja saponaria Molina stimulate the production of cytotoxic T lymphocytes (CTL) against exogenous antigens. Quillaja saponins have two normonoterpene ester moieties, linked linearly to their fucosyl residue, that play a critical role in the stimulation of CTL. These ester moieties are also responsible for these saponins' instability and toxicity. Based on the structure-activity relationships for the different groups of Q. saponaria saponins, new semi-synthetic analogs were developed that have the adjuvanticity of quillaja saponins, yet with less toxicity and greater stability in aqueous solutions. The quillaja saponin analogs were prepared by replacing their hydrolytically unstable ester groups with another lipophilic chain linked by a stable amide bond on these saponins' glucuronic acid residue. One of these analogs, GPI-0100, is a dodecylamide saponin derivative that stimulates an antibody isotype profile that corresponds to a Th1 type immune response, as well as CTL production against exogenous antigens.

2-Azetidinone--a new profile of various pharmacological activities

2-azetidinone, a β-lactam four member heterocyclic compound involved in research aimed to evaluate new products that possess interesting biological activities. These compounds reported for their antimicrobial and antifungal activities. Successful introduction of aztreonam as a potent inhibitor of cephalosporinase and ezetimibe as a cholesterol absorption inhibitor proved potential of 2-azetidinone moiety. Subsequently 2-azetidinones were highlighted as a potent mechanism based inhibitor of several enzymes like human tryptase, chymase, thrombin, leukocyte elastase, human cytomegalovirus protease and serine protease enzyme. These derivatives also known to possess antitubercular, anti-inflammatory, antitumor, anti-HIV, antiparkinsonian, antidiabetic and vasopressin V1a antagonist activity. The present review article focuses on the pharmacological profile of 2-azetidinones with their potential activities.

Endogenous production of carbon monoxide in normal and erythroblastotic newborn infants

The endogenous production of carbon monoxide ( V(CO)) in newborn infants was measured by serial determinations of blood carboxyhemoglobin during rebreathing in a closed system. Mean V(CO) in nine full-term infants was 13.7 +/-3.6 mul CO/kg per hr (SD), and in four erythroblastotic infants V(CO) ranged from 37 to 154 mul CO/kg per hr preceding exchange transfusion. Mean red cell life-span (MLS) and total bilirubin production were calculated from V(CO). MLS in normal newborns was 88 +/-15 days (SD), and bilirubin production was 8.5 +/-2.3 mg/kg per 24 hr. This is more than twice the amount of bilirubin normally produced in the adult per kilogram of body weight. Normal infants achieved a net excretion of bilirubin of at least 5.6 +/-2.3 mg/kg per 24 hr (SD) as calculated from the bilirubin production and the measured rise in serum bilirubin concentration.The measurement of V(CO) should prove valuable in the study of red blood cell survival and bilirubin metabolism in the newborn infant.

Pharmacology of levosimendan: inotropic, vasodilatory and cardioprotective effects

WHAT IS KNOWN AND OBJECTIVE

Positive inotropic agents are frequently used in acute decompensated heart failure (ADHF) due to left ventricular systolic dysfunction. These agents are known to improve cardiac performance and peripheral perfusion in the short-term treatment. However, several preclinical and clinical studies emphasized detrimental effects of these drugs on myocardial oxygen demand and on sympathetic tone entailing arrhythmogenesis. Levosimendan is an inotropic agent with an original mechanism of action. This review focuses on major data available for levosimendan.

METHODS

A literature search was conducted in the PubMed database by including studies published in English using combinations of the following key words, levosimendan, inotropic drugs and acute heart failure. Furthermore, bibliographies of selected references were also evaluated for relevant articles. The collection for this review was limited to the most recently available human and animal data.

RESULTS AND DISCUSSION

Levosimendan's vasodilatory and cardioprotective effects are mediated by calcium sensitization of contractile proteins and opening of adenosine triphosphate (ATP)-dependent K+ channels in vascular smooth muscle cells and on mitochondrial ATP-sensitive potassium [mito.K(ATP)] channels. This inotropic agent has mild PDE inhibitory action. Unlike other inotropic agents, levosimendan improves cardiac performance without activating the sympathetic nervous system. Moreover, there are evidences that levosimendan has additional anti-inflammatory and anti-apoptotic properties that prevent cardiac toxicity and contributes to positive hemodynamic response of the drug. Four randomized trials evaluated the effects of levosimendan on mortality in patients with acute decompensated chronic heart failure; nevertheless, a clear benefit has not been demonstrated so far. Although levosimendan is indicated for the treatment of ADHF (class of recommendation IIa, level of evidence B), it is has not been approved in all countries.

WHAT IS NEW AND CONCLUSION

This review summarizes the characteristics and the current knowledge of the literature on levosimendan and its active metabolite OR-1896.

Combination angiostatin and endostatin gene transfer induces synergistic antiangiogenic activity in vitro and antitumor efficacy in leukemia and solid tumors in mice

Angiostatin and endostatin are potent endothelial cell growth inhibitors that have been shown to inhibit angiogenesis in vivo and tumor growth in mice. However, tumor shrinkage requires chronic delivery of large doses of these proteins. Here we report synergistic antitumor activity and survival of animals when these factors are delivered in combination to tumors by retroviral gene transfer. We have demonstrated this efficacy in both murine leukemia and melanoma models. Complete loss of tumorigenicity was seen in 40% of the animals receiving tumors transduced by the combination of angiostatin and endostatin in the leukemia model. The synergy was also demonstrated in vitro on human umbilical vein endothelial cell differentiation and this antiangiogenic activity may suggest a mechanism for the antitumor activity in vivo. These findings imply separate pathways by which angiostatin and endostatin mediate their antiangiogenic effects. Together, these data suggest that a combination of antiangiogenic factors delivered by retroviral gene transfer may produce synergistic antitumor effects in both leukemia and solid tumors, thus avoiding long-term administration of recombinant proteins. The data also suggest that novel combinations of antiangiogenic factors delivered into tumors require further investigation as therapeutic modalities.

Spinal cord injury without radiographic abnormality in adults

Spinal cord injury without fractures or bony malalignment on either plain radiographs or computed tomography (SCIWORA) is most commonly found in the paediatric age group. In recent years, magnetic resonance imaging (MRI) has been used to evaluate these patients. The present communication describes SCIWORA in 15 adult patients investigated by MRI. Of the 151 patients with spinal cord injury in 1 year, 15 adult patients had cervical SCIWORA. All patients were evaluated by MRI. The age ranged from 20 - 60 years. Eleven patients had partial cord injury, two had a complete cord syndrome while two had a central cord syndrome. MRI demonstrated an intervertebral disc prolapse in six patients, intramedullary haematoma/contusion in four and cord oedema in four patients. One patient had multiple disc prolapses and associated intramedullary haematoma. Patients with disc prolapse were operated upon and all showed neurological improvement. The rest of the patients were managed conservatively. There was mild improvement in patients with intramedullary haematomas while those with cord oedema alone showed moderate recovery. The pathogenesis of adult SCIWORA is possibly different from that in paediatric age group. Most of the patients with SCIWORA show some abnormality on MR imaging. MRI should therefore be done in all patients with spinal cord injury for diagnostic and prognostic purposes.

Oxygen saturation as a screening test for critical congenital heart disease: a preliminary study

The aim of this study was to assess the utility of arm and leg oxygen saturation as a candidate screening test for the early detection of ductal-dependent left heart obstructive disease. We measured arm and leg oxygen saturation in 2876 newborns admitted to well baby nurseries and 32 newborns with congenital heart disease. Fifty-seven newborns in the well baby nurseries (0.02%) had an abnormal test (leg saturation less than 92% in room air or 7% lower saturation in the leg than in the arm). Four of the 57 had critical congenital heart disease, including 1 with coarctation of the aorta. Of the 32 newborns with congenital heart disease, 11/13 (85%) with left heart obstructive disease had abnormal oxygen saturation tests, as did 15/19 (79%) with other forms of congenital heart disease. Pulse oximetry deserves further study as a screening test for critical congenital heart disease.

Non-hysteretic first-order phase transition with large latent heat and giant low-field magnetocaloric effect

First-order magnetic transitions (FOMTs) with a large discontinuity in magnetization are highly sought in the development of advanced functional magnetic materials. Isosymmetric magnetoelastic FOMTs that do not perturb crystal symmetry are especially rare, and only a handful of material families, almost exclusively transition metal-based, are known to exhibit them. Yet, here we report a surprising isosymmetric FOMT in a rare-earth intermetallic, Eu₂In. What makes this transition in Eu₂In even more remarkable is that it is associated with a large latent heat and an exceptionally high magnetocaloric effect in low magnetic fields, but with tiny lattice discontinuities and negligible hysteresis. An active role of the Eu-5d and In-4p states and a rather unique electronic structure borne by In to Eu charge transfer, altogether result in an unusual exchange mechanism that both sets the transition in motion and unveils an approach toward developing specific magnetic functionalities ad libitum.

Studies on (beta,1-->5) and (beta,1-->6) linked octyl Gal(f) disaccharides as substrates for mycobacterial galactosyltransferase activity

The emergence of multi-drug resistant (MDR) strains of Mycobacterium tuberculosis (MTB) and the continuing pandemic of tuberculosis emphasizes the urgent need for the development of new anti-tubercular agents with novel drug targets. The recent structural elucidation of the mycobacterial cell wall highlights a large variety of structurally unique components that may be a basis for new drug development. This publication describes the synthesis, characterization, and screening of several octyl Galf(beta,1-->5)Galf and octyl Galf(beta,1-->6)Galf derivatives. A cell-free assay system has been utilized for galactosyltransferase activity using UDP[14C]Galf as the glycosyl donor, and in vitro inhibitory activity has been determined in a colorimetric broth microdilution assay system against MTB H37Ra and three clinical isolates of Mycobacterium avium complex (MAC). Certain derivatives showed moderate activities against MTB and MAC. The biological evaluation of these disaccharides suggests that more hydrophobic analogues with a blocked reducing end showed better activity as compared to totally deprotected disaccharides that more closely resemble the natural substrates in cell wall biosynthesis.

Altered immunomodulating and toxicological properties of degraded Quillaja saponaria Molina saponins

Quillaja saponins are readily hydrolyzed under physiological conditions, yielding deacylated forms that are significantly less toxic than their precursors. Yet, deacylated saponins are unable to stimulate a strong primary immune response. Although deacylated saponins elicit a strong total IgG response, their capacity to stimulate a Thl type IgG isotype profile (i.e. high levels of IgG2a and IgG2b) has been significantly diminished. Instead, an IgG profile closer to that of a Th2 immune response is stimulated (i.e. high IgG1 levels). Deacylated saponins have also lost their capacity to elicit an effective T cell immunity, as shown by their stimulation of a marginal lymphoproliferative response and their inability to elicit the production of cytotoxic lymphocytes (CTL). Modification of the immune-modulating properties brought by the degradation of quillaja saponins during vaccine storage may change the intended immune response from a Th1 to a Th2 type. This alteration would have negligible effects on vaccines depending on Th2 immunity mediated by neutralizing antibodies. However, the performance of vaccines directed against intracellular pathogens as well as therapeutic cancer vaccines may be seriously affected by the loss of their capacity to stimulate both a Th1 immune response and the production of CTL.

Tethered cord syndrome in adults

BACKGROUND

The tethered cord syndrome (TCS) is usually diagnosed in childhood and its symptomatic onset in adult life is not common. In the present study, we analyzed the data of patients who presented with TCS in adulthood with the aim of studying the clinical spectrum and management strategies.

CLINICAL MATERIAL

Over a 5-year period, 18 adult patients (more than 18 years of age) with TCS were investigated with MRI and were operated on. Patients with adult TCS could be divided into two groups. Group 1 included patients who were asymptomatic in childhood and presented for the first time in adult life (10 patients). The second group was comprised of patients with preexisting static skeletal/neurological deformities who presented in adult life with new or progressive symptoms (eight patients). Eleven patients had cutaneous stigmata, 15 had motor or sensory deficit, nine had back/leg pain, eight had leg atrophy, and six had sphincter disturbances. The most frequent MRI finding was a low lying cord with an intradural and/or extradural lipoma. The cord was detethered surgically and the tethering lesion excised. Pain was usually relieved after surgery (8 out of 9), but only a few patients (2 out of 6) had improvement of sphincter dysfunction.

CONCLUSIONS

The late presentation of TCS is possibly related to the degree of tethering and the cumulative effect of repeated microtrauma during flexion and extension. Adult patients with persistent back/leg pain and/or neurological or skeletal deformities should be investigated with MRI to establish an early diagnosis. Surgery should be performed in all adult patients with TCS, once the diagnosis is established.

Controversies in the management of subdural empyema. A study of 41 cases with review of literature

Forty one cases of subdural empyema treated between 1977 and 1988 at the Postgraduate Institute of Medical Education and Research. Chandigarh, have been analysed. The patients ranged from 9 days to 80 years of age. There were 22 children, including 11 infants. Fever, altered sensorium and seizures were the most common symptoms present for 1 day to 6 months. Otogenic infection was the commonest aetiological factor followed by postoperative and posttraumatic causes. Thirty seven patients had supratentorial empyemas, including 4 with parafalcine collections, three had infratentorial empyemas, and in one there was extension of the empyema from the supratentorial to the infratentorial compartment. Therapeutic modalities used included percutaneous needle aspirations in infants and burr hole evacuation and craniotomies in adults. A wide spectrum of organisms was detected. Mortality in this series was 24%, which was mainly attributable to the deteriorated neurological status prior to treatment. A detailed review of the literature has been given, highlighting various controversies in the management of SDE. Important prognostic factors and a treatment plan are suggested.

Amphotericin B use in a community hospital, with special emphasis on side effects

The purpose of this study was to analyze the usage of amphotericin B desoxycholate in a small community hospital, with special emphasis on its side effects and need for premedication. We performed a retrospective chart review for patients who received intravenous amphotericin B from January 1993 to May 1996. Temperature elevation, clinical symptoms during infusion, need for premedication, and fluctuations in serum potassium and creatinine values were especially noted. Statistical analysis showed that toxicity indicated by laboratory values (laboratory toxicity) increased with increasing amphotericin B dose, but clinical side-effects decreased with advancing age. Clinical side effects were not associated with total amphotericin B dosage; laboratory toxicity in our study was not more prevalent in elderly patients. The main finding of this study was that most patients tolerate amphotericin B well and only 23% of patients needed premedication. Our fungal cure rate was 83%. New, expensive preparations of amphotericin B should be reserved for the small subset of patients who either are intolerant of amphotericin B desoxycholate or need high doses for systemic fungal infections.

Excision of pituitary adenomas: randomized comparison of surgical modalities

The aim of this randomized prospective study was to compare the efficacy of endoscopic versus standard microsurgical excision of pituitary adenomas, and to evaluate the merits and demerits of each approach. Twenty patients with a pituitary adenoma were randomly divided into two groups comprising of 10 cases each. Ten cases were operated by endoscopic endonasal trans-sphenoidal approach by endoscopic rhinologist (EETSS group) and other 10 cases were excised by microsurgical endonasal trans-sphenoidal approach by a neurosurgeon (SMETSS group). In both the groups complete excision was achieved in 50% of patients (unpaired t-test, p = 1.00). In EETSS group mean operative time was 64.5 +/- 19.16 min (range 50 - 100 min). In the SMETSS group, mean operative time was 75.5 +/- 18.48 min (range 55 - 120 min; unpaired t-test, p = 0.64, statistically not significant). In the EETSS group blood loss ranged between 100 and 190 ml (mean 100 +/- 42.16 ml). In the SMETSS group blood loss ranged between 50 and 250 ml (mean loss of 120 +/- 58.69 ml; unpaired t-test, p < 0.05, statistically significant). Postoperative nasoseptal complications were more common in SMETSS group (Chi-square test, p < 0.05, statistically significant). Endoscopic approach provides a wide surgical field and broad lateral vision making easier distinction of tumour tissue: gland and gland diaphragm interface. Thus, there is less blood loss and nasoseptal complications, whereas there was no statistically significant difference in operative time and complete tumour removal.

Growing skull fractures: a clinical study of 41 patients

Growing skull fractures are rare complications of head injury, occurring almost exclusively in infants and children under the age of three. A retrospective review at our Institute yielded 41 patients with this entity over a period of 20 years (1975-1995). The age at presentation ranged from less than 1 year to 62 years, with 33 (80.5%) patients being less than 5 years of age. The cause of injury was either a fall from a height (93%) or a road traffic accident. The most common location of a growing skull fracture was either parietal or frontoparietal (56%). One patient had a posterior fossa growing skull fracture. CT scan was performed in 19 patients which demonstrated an underlying porencephalic cyst, hydrocephalus or a cyst communicating with the ventricle. In 5 children, a ventriculo-peritoneal shunt alone was performed. Twenty four patients underwent a duro- and cranioplasty while a duroplasty alone was performed in 8 patients. The material used for cranioplasty included acrylic, wire mesh, steel plates or autologous bone. Three patients died, one due to an anaesthetic complication and two as a result of postoperative meningitis. Post-operative CSF leaks occurred in 3 patients, which were managed by a lumbar drain. Six patients had local wound infection.

Acupressure wristbands do not prevent postoperative nausea and vomiting after urological endoscopic surgery

PURPOSE

To evaluate the efficacy of acupressure wristbands in the prevention of postoperative nausea and vomiting (PONV).

METHODS

Two hundred ASA I-II patients undergoing elective endoscopic urological procedures were included in a randomized, prospective, double blind, placebo-controlled study. Spherical beads of acupressure wristbands were placed at the P6 points in the anterior surface of both forearms in Group I patients (acupressure group, n = 100) whereas, in Group 2 (control group, n = 100) they were placed inappropriately on the posterior surface. The acupressure wristbands were applied 30 min before induction of anesthesia and were removed six hours postoperatively. Anesthesia was induced with thiopental and maintained with nitrous oxide and oxygen, fentanyl, isoflurane and vecuronium. The tracheas were extubated on the operation table after patients received neostigmine and atropine. Post operative nausea and vomiting were evaluated separately as none, mild, moderate or severe at the time of patient's arrival in PACU, then at six hours and twenty-four hours after surgery by a blinded observer.

RESULTS

In the acupressure group, 25 patients had PONV compared with 29 patients in the control group (P = NS).

CONCLUSION

Application of acupressure wristbands at the P6 of both forearms 30 min before induction of anesthesia did not decrease the incidence of PONV in patients undergoing endoscopic urological procedures.

Radiosurgery: a minimally interventional alternative to microsurgery in the management of acoustic neuroma

We report the results of treatment with radiosurgery of 29 tumours in 27 patients with acoustic neuromas between 1986 and 1989. The median follow-up was 6.6 years. The treatment appears to be an effective alternative to surgery for patients with tumours of 3 cm diameter or less. The mortality and morbidity of the treatment and the presentation of cranial nerve function is comparable to the very best surgical results. Every patient with an acoustic neuroma should be informed about this alternative to direct surgery.

Intracranial fungal granuloma

BACKGROUND

Intracranial fungal granulomas are uncommon and their pathogenesis, clinical picture, and effectiveness of therapy remains unclear.

METHODS

Thirty-two cases were studied retrospectively in two groups: (1) Rhinocerebral group (22 cases) had a chronic paranasal sinus (PNS) disease with secondary involvement of skull base, cranial nerves, and/or brain. The granulomas were adherent to dura, firm, avascular, and tough, requiring a knife to cut. (2) Primary intracranial group (10 cases) had no detectable PNS lesion at initial presentation. The granulomas were soft, suckable, and contained pus or necrotic material.

RESULTS

Postoperative and overall mortality were 37.5% and 50%, respectively. Meningoencephalitis was the most common cause of death. Altered sensorium, pus in the granuloma, and/or severe brain edema were poor prognostic factors. All survivors except four have symptomatic residual or recurrent lesions.

CONCLUSION

Early diagnosis with MRI or stereotactic biopsy, radical surgery, and high dose and chronic suppressive chemotherapy may improve overall results in these cases.