Intermittent chemotherapy of experimental leprosy in mice

In this study we assess the degree of prolonged bacteriostasis of Mycobacterium leprae after temporary exposure to ehtionamide or thiacetazone, and relate this to their efficacy when administered intermittently to mice with experimental leprosy infections. The results show that temporary exposure of M. leprae to either of these drugs results in a prolonged bacteriostatic effect, but that efficacy is rapidly lost as the interval between doses is increased. Using the mouse foot pad system, growth of M. leprae is not inhibited by thiacetazone when the frequency of administration is less than three times weekly. When ethionamide is administered once weekly, growth of M. leprae is inhibited but bactericidal activity is lost. When ethionamide is administered in combination with continuous dapsone therapy, either continuously or three times weekly, the bactericidal activity of the drug combination is greater than when either drug is administered alone. However, when ethionamide is administered once weekly in combination with continuous dapsone treatment, the bactericidal effect is identical to that when dapsone is given alone: that is, ethionamide makes no contribution to the combination.     

Human pharmacokinetics of molsidomine

Molsidomine is well absorbed by the gastro-intestinal tract and is taken up by the liver during the first passage. Its bioavailability is 60 per cent. Digestive or sublingual absorption is rapid: maximal plasma concentrations are obtained 0.5 to 1.0 hours after administration. Molsidomine is minimally bound by plasma proteins and is distributed in a volume of 1 litre/kg. The excretion is essentially extrarenal: less than 2 per cent of the administered dose is excreted in the form of unchanged molsidomine. Molsidomine is metabolized in the liver to two pharmacologically active metabolites which spontaneously and rapidly breakdown into inactive metabolites which are excreted by the kidneys. The plasma half-life of molsidomine is 1 to 2 hours: it is not modified in patients with renal failure, but it is prolonged in patients with hepatic failure. The kinetics are linear and independent of the route of administration and the dose. There is a correlation between the plasma concentration and the pharmacological effect: the minimal effective concentration is about 5 ng/ml. At the usual dose of 2 mg three times a day, there is no accumulation of the drug.     

THE NEGATIVE CONTROL MECHANISM FOR E. coli DNA REPLICATION

Evidence is presented to show that the initiation of DNA replication in E. coli 555-7 requires synthesis of a protein whose production is correlated with total protein synthesis. Once replication is initiated, however, reinitiation will occur if all further protein synthesis is prevented; a small amount of protein synthesis is sufficient to prevent this unregulated reinitiation. This shows that the initiation of DNA replication is under negative control. A mechanism for the control of DNA replication is proposed; in this mechanism a replication repressor is synthesized periodically, while an antirepressor protein is synthesized continuously. Derepression of initiation results after sufficient accumulation of the antirepressor protein, and repression is re-established by repressor synthesis after the initiation of replication.     

Hemoglobin Volga, β27 (B9) Ala→Asp: Functional and Clinical Correlations of an Unstable Hemoglobin

Hb Volga (β27 Ala→Asp) on the basis of physical tests is only a mildly unstable hemoglobin yet it is associated with a gross re-ticulocytosis. This is partly explicable by an increased oxygen affinity with a compensating erythrocytosis but there is also brisk hemolysis. It is not certain that this hemolysis is due to precipitation of the hemoglobin as in vitro inclusion body formation is not remarkable and there is no evidence of preferential proteolysis of the abnormal subunits, at least in the reticulocytes. There is increased autoxidation and it may be the consequence of this that is the prime cause of hemolysis.     

Benign ulceration of the gecum presenting with massive hemorrhage

Massive gastrointestinal hemorrhage secondary to benign cecal ulceration is a rare occurrence. The diagnosis of bleeding from this benign condition is rerely entertained and is often a finding on a pathologic examination. A case of massive hemorrhage from a cecal ulcer is presented, and the literature is reviewed. The role of angiographic demonstration of the lesion, if angiography is readily available, is emphasized, but surgery is the definitive therapy.     

Limited venous access and pacemaker insertion in a haemodialysis patient: case report

The population of haemodialysis patients is increasing as is their age. There is a higher risk of cardiac comorbidities in these patients. Pacing is increasingly common in this group. We present a case highlighting the difficult issues and exemplifies the need for careful planning preprocedure. Haemodialysis patients often have difficult and limited vascular access. Insertion of pacing leads is associated with subclavian vein stenosis. If this is on the side of an AV fistula there is significant risk of losing the fistula with obvious consequences to the patient. Careful consideration of site and route of access needs to be made prior to pacing. The need for involvement of renal and vascular teams before starting the procedure is essential as it is paramount that the best route of access for pacing wires is selected.     

Improvement of the method of collection of blood flowing from the adrenal glands in the experiment on dogs

Blood from the adrenal gland can flow in two directions--into the caudal vena cava and by anastomoses into the portal vein. A method of multiple blood procuring from these vessels in dogs for the purpose of studying the adrenal gland function is suggested. Polyethylene catheters, 0.9 mm in diameter and 35--40 mm in length glued to capron plates, mandrins, Gordeev's needles and blood-drawing needles are necessary. Transperitoneal surgical approach to the caudal and mesenteric veins is to be provided. Purse-string suture is applied on the wall of the mesenteric vein. The catheter is washed with heparin, the mandrin is introduced into it and it is inserted into the Gordeev's needle. A puncture is made in the centre of the purse-string suture with this needle, which is introduced into the vein together with the catheter. Gordeev's needle is withdrawn and the catheter is pushed through to the portal vein. The purse-string suture is tightened, and the capron plate is fixed in the wall of the vein. The mandrin is recovered from the catheter, heparin is administered into its canal, polyethylene plug is inserted and withdrawn through the abdominal wall outside with the aid of the blood-drawing needle. The catheter is introduced into the caudal vena cava in the same way. Blood samples can be obtained on the 14th postoperative day.     

Inflammatory pseudotumor of the liver]

Inflammatory pseudotumor is a pathological process whose cause is unknown, and whose macroscopic appearance is that of a malignant tumor, but it is in fact of inflammatory nature. Inflammatory pseudotumor of the liver is infrequent, but must be taken into account in the differential diagnosis of liver masses. A case report is presented, with review of the literature. Because of its benign nature, an aggressive approach is not recommended.     

MRI diagnosis of cavernous sinus invasion by pituitary adenomas

Several MRI signs are helpful for the preoperative MRI diagnosis of cavernous sinus invasion by an adenoma. The first step is to analyse the percentage of encasement of the intracavernous ICA by the adenoma. If this percentage is greater than or equal to 66%, the cavernous sinus is invaded. If the percentage of encasement of intracavernous CA is less than 25%, the cavernous sinus is not invaded. If the percentage of encasement is between 25 and 66%, the analysis of the cavernous venous compartment, the drawing of intercarotid lines and the analysis of the shape and venous compartments of the cavernous sinus are necessary. The cavernous sinus invasion remains very likely if the carotid sulcus venous compartment is obliterated, or if the lateral intercarotid line is crossed. Conversely, if the median intercarotid line is uncrossed, the superior venous compartment is visible, the cavernous sinus is of normal size, or there is no bulging of its lateral dural wall, invasion of the cavernous sinus space can reliably be excluded.     

Demonstration of a new analytical grading system for the determination of pheochromocytoma within the scope of hypertension control

The problems of the phaeochromocytoma are in its rareness, its appearance--every patient with hypertension can be a carrier of a phaeochromocytoma--, its localisation--10% are situated outside the adrenal glands--, its operability with following permanent normalisation of the pressure. As hypertension is very frequent and the diagnostics is very expensive the finding of carriers of phaeochromocytomas is possible only by means of screening methods. Thus cases with an urgent suspicion are found. Such a method is described, the basis of which is a semiquantitative determination of the vanillic amygdalic acid. Instead of the usually used diazocolour-reagent in connection with a non-optimal buffer a complete nitrophenylantiazotate with a buffer of high ionic strength is taken. The pH-value 10 of the urine which is to be demanded for the colour reaction is thus reached in every case. In order to avoid falsely normal results with every urinary test a preparation with added vanillic amygdalic acid is performed and thus the presence of colour inhibitors is recognized. If the result is pathological a quantitative determination is necessary.     

Nosocomial pulmonary tuberculosis

The impact of nosocomial tuberculosis remains poorly known. There is a real risk that is relatively higher when the probability of community acquisition declines. Diagnosis is difficult due to the natural history of tuberculosis infection so that most cases of nosocomial contamination result in infection without disease expression. The nosocomial origin is rarely recognized. Though diagnosis is difficult, prevention is well described: early diagnosis of tuberculosis disease and treatment as well as respiratory isolation in case of suspected tuberculous bacilli. Particular care is required in units managing immunodepressed patients where the risk of contamination and development of overt tuberculosis is greater.     

The influence of the flow of the reacting gas on the conditions for a thermal explosion

The classical problem of thermal explosion is modified so that the chemically active gas is not at rest but is flowing in a long cylindrical pipe. Up to a certain section the heat-conducting walls of the pipe are held at low temperature so that the reaction rate is small and there is no heat release; at that section the ambient temperature is increased and an exothermic reaction begins. The question is whether a slow reaction regime will be established or a thermal explosion will occur. The mathematical formulation of the problem is presented. It is shown that when the pipe radius is larger than a critical value, the solution of the new problem exists only up to a certain distance along the axis. The critical radius is determined by conditions in a problem with a uniform axial temperature. The loss of existence is interpreted as a thermal explosion; the critical distance is the safe reactor's length. Both laminar and developed turbulent flow regimes are considered. In a computational experiment the loss of the existence appears as a divergence of a numerical procedure; numerical calculations reveal asymptotic scaling laws with simple powers for the critical distance.     

Endoscopic resection of small inflammatory fibroid polyp of the colon

Inflammatory fibroid polyp (IFP) is a solitary intestinal lesion of unknown etiology. Although IFP is benign, laparotomy for the resection of colonic IFP is performed in most cases because the polyp is usually large. We report a successful endoscopic resection of cecal IFP. It is considered that colonic IFP should be resected endoscopically if the polyp is small and is located submucosally.     

Intestinal regulation of pancreatic enzyme secretion: stimulatory and inhibitory mechanisms]

How exocrine pancreatic secretion is regulated is only partly known. It is assumed that interaction of several neural and hormonal mechanisms is involved. In man, the intestinal component of these control mechanisms is very important while extra-intestinal mechanisms (such as the cephalic and the gastric phase) play lesser roles. Regulation of pancreatic secretion by the intestine is composed of three main mechanisms. 1. The proximal intestinal (duodenal) phase of the secretory response to a meal is elicited by nutrients within the proximal intestinal lumen. It is mediated mainly by interactions between cholinergic reflexes and release of the peptide hormone cholecystokinin (CCK). Recent data suggest that part of the action of CCK is not exerted directly on the acinar cellular level, but rather by modulation of cholinergic inputs. 2. The distal intestinal (ileal) phase is elicited by contact of the distal intestinal mucosa with nutrients that pass through the ileal lumen due to physiological malabsorption. The ileum (in contrast to the duodenum) induces net-inhibition of pancreatic secretion. The mediation is unknown, candidate mediators are PYY and GLP-1. 3. Intestinal feedback-regulation of pancreatic secretion in humans is controlled by intraluminal protease activity; this mechanism is not covered in the present paper.     

Post-infarct left ventricular free wall rupture-not always a lethal complication of acute myocardial infarction

Post-myocardial infarction cardiac rupture is an important complication and cause of death in the period following myocardial infarction. It is rarely diagnosed before death. However, early diagnosis is crucial as successful treatment is possible with surgery. A successful outcome is sometimes compromised by difficult anatomy or an extensive infarct. Presentation, diagnosis and treatment of cardiac rupture is reviewed in this article, and is illustrated by five cases of cardiac rupture.     

Preparation of Poly Aluminum-Ferric Chloride (PAFC) Coagulant by Extracting Aluminum and Iron Ions from High Iron Content Coal Gangue

Poly aluminum-ferric Chloride (PAFC) is a new type of high efficiency coagulant. In this study, high iron type gangue is used as a main raw material. It is calcined at 675 °C for 1 h and 3% CaF₂ is added to the calcined powder and reacted with 20% hydrochloric acid at 93 °C for 4 h. The leaching ratio of aluminum ions is 90% and that of iron ions is 91%. After Fe²⁺ ions are oxidized in the filtrate, CaCO₃ is used to adjust the pH of the filtrate to 0.7. The microwave power is adjusted to 80 W and the filtrate is radiated for 5 min. After being aged for 24 h, PAFC product is obtained. The prepared PAFC is used to treat mine water and compared with the results of PAC and PAF, the turbidity removal ratio of PAFC is 99.6%, which is greater than 96.4% of PAC and 93.7% of PAF. PAFC is a mixture with different degrees of polymerization. It demonstrates that extracting aluminum and iron ions from high iron content gangue to prepare PAFC by microwave is efficient and feasible.     

肺小血管炎的研究进展

肺小血管炎(SVVL)是原发性小血管炎累及肺脏血管的一组疾患.因本病与抗中性粒细胞胞浆抗体(ANCA)密切相关,故称为抗中性粒细胞胞浆抗体相关性小血管炎(AAVS).主要包括:韦格纳肉芽肿病(WG)、显微镜下多血管炎(MPA)、变应性肉芽肿性血管炎(CSS)[1],常可累及多个系统.肺是原发性小血管炎累及频率最高的脏器之一,据报道肺脏受累占75%,仅次于肾脏,且是造成死亡的主要原因.其临床表现复杂多变,缺乏特异性,常常被误诊为其它疾病,延误治疗.而经积极治疗,其生存率明显上升.因此有必要提高对SVVL的认识.     

Antithrombotics in pre-hospital phase of acute coronary syndromes

Antithrombotic therapies are the corner stone of acute coronary syndrome management. We have the proof that many of them should be initiated during the prehospital care because their clinical benefit is time-dependent. The hypothesis that anticoagulation therapy is an effective treatment of STEMI, which benefit is time-dependent, is now validated. It is also fair to affirm that GP lIb/IIIa receptor inhibitors are the adjuvant therapy of choice for primary PCI. Indeed, these medications reduce short-term and long-term mortality. This clinical benefit is time dependent. Clopidogrel therapy is probably also a medication of the prehospital phase. It is well established now that the biological efficacy of this pro drug is loading dose dependent. It is also demonstrated that its clinical efficacy depends on the time delay between symptom onset and initiation of the therapy. However, the clinical benefit of prehospital administration remains to be established.     

Mother-to-infant transmission of hepatitis C virus

The rate of mother-to-infant transmission of hepatitis C virus (HCV) is approximately 5%, but is higher when the mother is co-infected with HIV Vertical transmission is restricted to infants whose mothers are viraemic. The risk of transmission increases with increasing maternal viral load but a specific cut-off value predicting infection cannot be defined. There is no specific HCV genotype which is preferentially transmitted. The mode of delivery (caesarean versus vaginal) does not appear to influence the rate of transmission, but firm evidence is lacking. There is no evidence to suggest an increased risk of HCV transmission through breast feeding. Pregnancy is not contra-indicated in HCV-infected women. Without drugs to treat established infections in mothers and infants and interventions to prevent vertical transmission, routine HCV screening is not recommended in pregnant women.     

Treatment of intracoronary thrombus in the catheterisation laboratory in acute coronary syndrome patients

Treatment of intracoronary thrombus is well documented. Three situations should be differentiated Primary percutaneous coronary intervention for early STEMI presenters is the most frequent one. Glycoprotein IIb/IIIa inhibitors are the gold standard antithrombotic treatment with a clear mortality benefit with abciximab. Thrombectomy with simple to use devices is another attractive option for interventionalists, although there is no clear established clinical benefit. Rescue PCI following failed thrombolysis is a more complicated situation given the underlying bleeding risk that is difficult to evaluate. The second situation is when a thrombus appears during an elective PCI. Although much less frequent than primary PCI, it is more often related to a lack of identification of the risk, to an inappropriate choice of the materials or to a non-optimal upstream antithrombotic treatment. A careful identification of all potential relevant causes is the key point of the management strategy. Post-PCI rethrombosis is the third situation and probably the less frequent. However, it is the most difficult to deal with.