Characterisation of salmon calcitonin in spray-dried powder for inhalationEffect of chitosan

Salmon calcitonin (sCT) powders suitable for inhalation, containing chitosan and mannitol as absorption enhancer and protection agent, respectively, were prepared using a spray-drying process. The effect of chitosan on physicochemical stability of sCT in the dry powder was investigated by different analytical techniques. High-performance liquid chromatography (HPLC) analysis indicated that sCT was chemically stable upon spray-drying. With the proportion of chitosan in spray-drying formulation being increased, dissolution of sCT from the dry powders was decreased both in phosphate buffer and acetate buffer. The thioflavine T fluorescence assay showed that no fibrils were present in the spray-dried powder. However, sCT partly fibrillated in the phosphate buffer, but not in acetate buffer. Fourier transform infrared (FTIR) spectra showed that the secondary structure of sCT was slightly changed in the dry powder, yet no aggregate signal was observed. Circular dichroism analysis indicated that the structure of sCT in an aqueous formulation was slightly altered by addition of chitosan. Nevertheless, recovery of sCT was not influenced by chitosan in the aqueous formulation as indicated by HPLC analysis. This study suggested that sCT, in absence of any additives, was stable during the spray-drying process under certain conditions. Addition of chitosan affects recovery of sCT from spray-dried powders, which may be due to formation of a partially irreversible complex between the protein and chitosan during the spray-drying process.

Prospective comparison of the effects of maxacalcitol and calcitriol in chronic hemodialysis patients with secondary hyperparathyroidism: a multicenter, randomized crossover study

BACKGROUND

Maxacalcitol is a vitamin D analogue, which is administered intravenously for secondary hyperparathyroidism in dialysis patients as well as calcitriol. However, few dose-comparison clinical studies have been reported for these drugs. The present multicenter, randomized crossover study was conducted to determine the equivalence of maxacalcitol and calcitriol doses.

METHODS

Subjects comprised 31 patients on chronic hemodialysis with secondary hyperparathyroidism who had not received maxacalcitol or calcitriol in the previous 3 months. Patients were randomly divided into two groups, and maxacalcitol or calcitriol was administered in a crossover design for 12 weeks each. Maxacalcitol and calcitriol doses were adjusted based on serum levels of calcium and intact parathyroid hormone.

RESULTS

After the 12-week maxacalcitol/calcitriol administration, there were no significant differences in levels of calcium (maxacalcitol 2.40+/-0.22 mmol/1 (9.6+/-0.9 mg/dl), calcitriol 2.42 + 0.25 mmol/l (9.7+/-1.0 mg/dl), p = 0.71), phosphate (maxacalcitol 1.97 + 0.42 mmol/l (6.1+/-1.3 mg/dl), calcitriol 2.00+/-0.48 mmol/l (6.2+/-1.5 mg/dl), p = 0.64), intact parathyroid hormone (maxacalcitol 267+/-169 pg/ml, calcitriol 343+/-195 pg/ml, p = 0.11) in serum or other bone-metabolic parameters such as serum alkaline phosphatase. The doses ofmaxacalcitol and calcitriol were 49.3+/-23.7 microg/month and 9.0+/-3.8 microg/month, respectively, and maxacalcitol : calcitriol dose ratio was 5.5: 1. No severe adverse reactions were seen for either maxacalcitol or calcitriol during the study period.

CONCLUSIONS

Comparable therapeutic efficacy can be obtained in the treatment of secondary hyperparathyroidism using either maxacalcitol or calcitriol at a dose ratio of 5.5 : 1.

Gene structure and regulation of alkane monooxygenases in propane-utilizing Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7

Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7 were isolated from soil samples as propane-utilizing bacteria and were found to be able to utilize various gaseous and liquid n-alkanes as carbon and energy sources. One gene cluster, M-prmABCD, and two gene clusters, P-prm1ABCD and P-prm2ABCD, were cloned from the genomes of Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7, respectively. These gene clusters are homologous to the gene cluster encoding the multicomponent propane monooxygenase (prmABCD) of Gordonia sp. TY-5. The expression of prm gene clusters in Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7 was shown to be induced by gaseous n-alkanes (C2-C4) except methane, suggesting that the products of these genes are involved in gaseous n-alkane oxidation. Homologous genes for an alkane hydroxylase system (alk system) involved in liquid n-alkane oxidation were also cloned from the genomic DNA of Mycobacterium sp. TY-6. The alk gene cluster was transcribed in response to liquid n-alkanes (C11-C15). These results indicate that Mycobacterium sp. TY-6 has two distinct gene clusters for multicomponent monooxygenases involved in alkane oxidation. Whole-cell reactions revealed that propane is oxidized to 1-propanol through terminal oxidation in Mycobacterium sp. TY-6 and that propane is oxidized to 1-propanol and 2-propanol through both terminal and subterminal oxidations in Pseudonocardia sp. TY-7. This study reveals the diversity of propane metabolism present in microorganisms.

Dysphagia-gastroesophageal reflux complex: complications due to dysfunction of solitary tract nucleus-mediated vago-vagal reflex

We report on the complication of gastroesophageal reflux (GER) in four patients with lower brainstem dysfunction. These patients suffered from perinatal asphyxia, cerebellar hemorrhage, or congenital dysphagia of unknown origin and showed facial nerve palsy, inspiratory stridor due to vocal cord paralysis, central sleep apnea, and dysphagia, in various combinations. Naso-intestinal tube feeding was introduced in all of the patients due to recurrent vomiting and aspiration pneumonia resulting from GER. T2-weighted magnetic resonance (MR) imaging revealed symmetrical high intensity lesions in the tegmentum of the lower pons and the medulla oblongata in two of the patients, and pontomedullary atrophy in another patient. In normal subjects, lower esophageal sphincter contraction is provoked by distension of the gastric wall, through a vago-vagal reflex. Since this reflex arc involves the solitary tract nucleus, where the swallowing center is located, the association of dysphagia and GER in the present patients is thought to result from the lesions in the tegmentum of medulla oblongata. We propose the term "dysphagia-GER complex" to describe the disturbed motility of the upper digestive tract due to lower brainstem involvement. In children with brainstem lesions, neurological assessment of GER is warranted, in addition to the examination of other signs of brainstem dysfunction, including dysphagia and respiratory disturbance.

Properties of liposomes coated with hydrophobically modified chitosan in oral liposomal drug delivery

Chitosan (CS) has been widely used as an adhesive coating polymer for oral liposomal drug delivery systems because of its adhesive properties on mucous layers. The coating mechanism or interaction of chitosan and liposomes or mucin mainly depends on electrostatic forces. Thus, to enhance the adhesive properties of chitosan, a hydrophobically modified chitosan, i.e., dodecylated chitosan (DC), was synthesized. BIACORE results showed that both CS and DC could interact with mucin. Differences in sensorgram patterns between chitosan-mucin and dodecylated chitosan-mucin were observed and tentatively attributed to differences in binding kinetics. The zeta potential of dodecylated chitosan-coated liposomes (DC-Lip) showed positive values in both liposomal formulations, i.e., negatively charged and neutral-charge liposomes. These results indicated that DC could be considered a more suitable polymer for coating neutral-charge liposomes than CS because the hydrophobic side chain of DC inserts itself into the lipid bilayer of liposomes. Moreover, CS seemed to be less effective in the coating of a neutral-charge liposome because of the low positive values of its zeta potential. CS provided solely electrostatic forces when used for coating liposomes while DC provided electrostatic and hydrophobic forces due to the long alkyl chain in its backbone. Confocal Laser Scanning Microscopy (CLSM) images indicated that both chitosan-coated liposomes (CS-Lip) and DC-Lip could adhere to and penetrate through the small intestine of rats after oral administration. The pharmacological results showed that DC-Lip had a greater effect in decreasing blood calcium concentration during the first 12 h compared with CS-Lip. Therefore, it can be concluded that dodecylated chitosan can be useful in designing oral liposomal drug delivery systems.

Cholesterol-bile salt vesicles as potential delivery vehicles for drug and vaccine delivery

The aim of this study was to further investigate the interactions between cholesterol (CH) and mixed bile salts (BS) (sodium cholate and sodium deoxycholate) and their suitability for drug and vaccine delivery. Insulin was used as a model protein to assess the ability of CH:BS vesicles to entrap a therapeutically relevant macromolecule. The association of protein (FITC-insulin) with the CH:BS structure was confirmed with fluorescence microscopy, and the overall morphology of the vesicles was examined with atomic force microscopy (AFM). Results demonstrate that the nature of the vesicles formed between CH and BS is dependent not only on the concentration of BS but also on the increasing CH concentration leading to CH crystal formation.

Elevated serum IgG titer and avidity to Actinobacillus actinomycetemcomitans serotype c in Japanese periodontitis patients

AIM

The purpose of this study was to characterize serum antibody responses to different serotypes of Actinobacillus actinomycetemcomitans strains in various forms of periodontitis and to determine whether any specific type of A. actinomycetemcomitans was associated with any specific form of periodontitis in a Japanese population.

METHODS

Sonicated whole cell and autoclaved serotype antigens of A. actinomycetemcomitans were used. Serum IgG titer and avidity to A. actinomycetemcomitans were measured by enzyme-linked immunoabsorbant assay (ELISA) and ammonium thiocyanate-dissociation ELISA, respectively, in 46 aggressive periodontitis patients (8 localized, 38 generalized), 28 chronic periodontitis patients, and 18 periodontally healthy subjects. The presence of A. actinomycetemcomitans in plaque and saliva samples was determined using polymerase chain reaction.

RESULTS

Generalized aggressive and chronic periodontitis patients exhibited significantly higher IgG titers than healthy subjects to both sonicated and autoclaved antigens of serotype c strains, while IgG titer to serotype b (Y4) was significantly higher in localized aggressive periodontitis patients compared to healthy subjects. No A. actinomycetemcomitans was detected in localized aggressive periodontitis patients. A. actinomycetemcomitans-positive patients exhibited significantly higher IgG titer and avidity to serotype c than A. actinomycetemcomitans-negative patients. In A. actinomycetemcomitans-positive patients, a significantly positive correlation was observed between antibody titer and avidity to serotype c. A. actinomycetemcomitans-positive patients with generalized aggressive periodontitis showed lower IgG avidities to serotype c than those with chronic periodontitis, though no statistically significant difference was found.

CONCLUSION

A. actinomycetemcomitans serotype c may play a significant role in chronic and generalized aggressive periodontitis, while A. actinomycetemcomitans serotype b may be associated with localized aggressive periodontitis in a Japanese population.

Colloid degeneration of the skin--a case report

A patient with multiple nodules on the chin and scalp is presented. Histologically, the nodules were composed of amorphous materials which also completely filled up the whole dermis. Histochemical observation indicated that the amorphous material in the nodule was a kind of glycoprotein. Electron microscopic examination revealed that the material consists of short wavy fibrils, 60 to 100 A in diameter, and of a low electron-dense amorphous substance. Biochemical examination supported the view that the amorphous material is so-called sialomucoid. The nodules were finally diagnosed as colloid degeneration of the skin (nodular type).

Anesthesia-related mortality and morbidity over a 5-year period in 2,363,038 patients in Japan

BACKGROUND

Statistical data of mortality and morbidity related to anesthesia have not been reported in Japan since World War II. The need to comprehensively examine the events of cardiac arrest as well as mortality prompted the first national study in Japan.

METHODS

Confidential questionnaires were sent to all Japan Society of Anesthesiologists Certified Training Hospitals every year from 1994 through 1998. Collected data were analyzed for incidence of cardiac arrest and other critical events during anesthesia and surgery, and their outcomes within 7 postoperative days. The principal causes of the critical incidents were also analyzed.

RESULTS

With an average response rate of 39.9%, a total of 2,363,038 cases were documented over 5 years. The average incidence per year of cardiac arrest during surgery due to all etiologies and that totally attributable to anesthesia was 7.12 [95%CI: 6.30,7.94] and 1.00 [0.88, 1.12]) per 10,000 cases, respectively. The average mortality per year in the operating room or within 7 postoperative days due to all etiologies and that totally attributable to anesthesia was 7.18 [6.22, 8.13] and 0.21 [0.15, 0.27] per 10,000 cases, respectively. The two principal causes of cardiac arrest during anesthesia and surgery due to all etiologies were massive hemorrhage (31.9%) and surgery (30.2%), and those totally attributable to anesthesia were drug overdose or selection error (15.3%) and serious arrhythmia (13.9%). Preventable human errors caused 53.2% of cardiac arrest and 22.2% of deaths in the operating room totally attributable to anesthesia.

CONCLUSIONS

The rates in Japan of cardiac arrest and death during anesthesia and surgery due to all etiologies as well as those totally attributable to anesthesia are comparable to those of other developed countries.

Mucoadhesive properties of carbopol or chitosan-coated liposomes and their effectiveness in the oral administration of calcitonin to rats

Mucoadhesive liposomes were prepared by coating multilamellar liposomes with Carbopol (CP) in a similar manner to that used in the preparation of chitosan-coated liposomes (CS-Lip) previously reported [Takeuchi et al., Chem. Pharm. Bull. 42 (1994) 1954-1956; Pharm. Res. 13 (1996) 896-901]. The positively charged liposomes containing dipalmitoylphosphatidylcholine (DPPC) and stearylamine at an optimum formulation ratio (40:1) could be coated with CP without aggregation of the liposomal particles during the coating process. The mucoadhesive properties of both the resultant polymer-coated liposomes (CP-Lip and CS-Lip) and the positively or negatively charged noncoated liposomes (Non-Lip) were evaluated using the rat intestine. The order was CS-Lip> or = CP-Lip>positively charged Non-Lip>negatively charged Non-Lip. The adhesive property of CP-Lip decreased on increasing pH of the dispersing medium from pH 5.0 to 7.4, probably owing to the electric repulsion between CP-Lip and the mucus layer. The effectiveness of the liposomal formulations in oral administration of calcitonin was evaluated by measuring the change in the blood calcium concentration of rats. Administration of CP-Lip and CS-Lip containing calcitonin showed an enhanced and prolonged reduction in blood calcium concentration. The overall pharmacological effect of CP- and CS-Lips evaluated by means of the area under the plasma calcium concentration curve was 2.4 and 2.8 times higher than that of negatively and positively charged Non-Lips, respectively.

Papillon-Lefèvre syndrome: serum immunoglobulin G (IgG) subclass antibody response to periodontopathic bacteria. A case report

BACKGROUND

Papillon-Lefevre syndrome (PLS) is a rare autosomal recessive disorder which is characterized by palmar-plantar hyperkeratosis and rapid periodontal destruction of both primary and permanent dentitions. In this case report, we present clinical features, and microbiological and immunological findings of 40 month-old Thai male PLS patient.

METHODS

Microbiological examinations consisted of bacterial culture methods utilizing selective media, morphological identification, and biochemical tests. In addition, the specific serum IgG subclass antibody titers reactive with etiologic periodontal bacteria were determined by the dot-blot immunological analysis and enzyme linked immunosorbent assay (ELISA).

RESULTS

The examinations revealed that the patient harbored 3 major suspected periodontopathic microorganisms, A. actinomycetemcomitans, P. gingivalis, and P. intermedia. The patient's serum IgG1, IgG2, and IgG3, but not IgG4, titers against A. actinomycetemcomitans were dramatically increased. The predominant IgG subclass was IgG1. In contrast, the IgG titers against other tested bacteria, P. gingivalis, P. intermedia, and F. nucleatum, appeared to be similar to those of a healthy control.

CONCLUSIONS

A. actinomycetemcomitans seems to play a pivotal role in the bacteria-host interaction in PLS periodontal pathogenesis. Response of the specific serum IgG subclass antibody titers against the A. actinomycetemcomitans antigen has been demonstrated. This association warrants further investigation.

[Annual study of perioperative mortality and morbidity for the year of 1999 in Japan: the outlines--report of the Japan Society of Anesthesiologists Committee on Operating Room Safety]

Anesthetic mortality and morbidity in Japan Society of Anesthesiologists (JSA) Certified Training Hospitals (CTH) for the year 1999 were reported as continuation of annual studies started in 1993. The JSA Committee on Operating Room Safety (CORS) sent confidential questionnaires to 774 CTH and received valid responses from 60.3% of hospitals. A total number of 793,840 anesthetics were documented. The respondents were asked to report all cases of cardiac arrests and other critical incidents (serious hypotension, serious hypoxemia and others), and their outcomes (death in operating room, death within 7 days, transfer to vegetative state and rescue without sequelae) as well as one principal cause for each incident from list of 52 items. They were also requested to submit the tabulation of patients by ASA physical status, age distribution, surgery sites and anesthetic methods. Analysis was made by total incidents under anesthesia/surgery, and also by incidents totally attributable to anesthetic management (AM), due to preoperative complications (PC), due to intraoperative pathological events (IP) and due to surgery (SG), with special reference to each of four tabulation groups and the whole group of patients. This paper focused analysis on all patients, as analyses with special reference to ASA physical status, age distribution, surgery sites and anesthetic methods were previously reported. Total incidence of cardiac arrest under anesthesia/surgery was 6.53 per 10,000 anesthetics. PC, IP and SG represented principal causes in 42.9%, 22.0% and 21.4% causes of total cardiac arrest cases, respectively. AM was noted as the principal cause in 12.0% of cases, with an incidence rate of 0.78 per 10,000. In 52 more detailed classification of principal causes, the most frequent cause of cardiac arrest was preoperative hemorrhagic shock, 20.3% of all cardiac arrests. The second cause was massive hemorrhage and/or hypovolemia due to surgical procedures (13.1%), and the third was intraoperative myocardial infarction/coronary ischemia/coronary spasm (9.5%). Prognoses of cardiac arrest cases declined due to PC: 71.1% of cardiac arrests died in the operating room or within 7 days after surgery and only 19.8% survived without sequelae. The best prognoses were found in cardiac arrest cases due to AM: 69.4% survived without sequelae and 12.9% died. The mortality rate post-cardiac arrest was 3.44 per 10,000 anesthetics, of those 0.10 due to AM, 0.57 due to IP, 1.99 due to PC and 0.76 due to SG. The mortality rate after critical incidents other than cardiac arrest such as severe hypotension and severe hypoxemia was 3.75, of those 0.03 due to AM, 0.28 due to IP, 2.31 due to PC and 1.13 due to SG. The final mortality rate attributable to anesthesia/surgery including deaths post-cardiac arrest and after other critical incidents was 7.19 per 10,000 anesthetics and very close to 7.18 [6.22, 8.13], that of mean [95% C.I.] in 1994-1998. The final mortality rate totally attributable to anesthesia was 0.13 per 10,000 anesthetics, which was significantly improved from 0.21 [0.15, 0.27], that of mean [95% C.I.] in 1994-1998. IP, PC and SG showed the final mortality rate of 0.84, 4.30 and 1.89, respectively. Five major causes of all critical incidents were massive hemorrhage due to surgical procedures (20.8%), preoperative hemorrhagic shock (10.7%), surgical technique (8.0%), inappropriate airway management (5.2%) and intraoperative myocardial infarction and coronary ischemia (4.5%). Drug overdose or selection error (3.9%) and overdose of main anesthetic (2.9%) as a result of human error occupied the 7th and 10th places. As far as anesthetic management to reduce mortality and morbidity related to anesthesia is concerned, we should increase vigilance to avoid human errors in addition to improving preanesthetic preparations and assessment of cardiovascular status as well as intraoperative management of cardiovascular events.

Biodegradable nanoparticles for targeted drug delivery in treatment of inflammatory bowel disease

The use of nanoparticles for targeted oral drug delivery to the inflamed gut tissue in inflammatory bowel disease was examined. Such a strategy of local drug delivery would be a distinct improvement compared with existing colon delivery devices for this disease. An experimental colitis was induced by trinitrobenzenesulfonic acid to male Wistar rats. Rolipram, an anti-inflammatory model drug, was incorporated within poly(lactic-coglycolic acid) nanoparticles, which were administered once a day orally for five consecutive days. A clinical activity score and myeloperoxidase activity were determined to assess the inflammation, whereas an adverse effect index reflected the remaining neurotropic effect of rolipram resulting from its systemic absorption. All nanoparticle formulations proved to be as efficient as the drug in solution in mitigating the experimental colitis. The clinical activity score and myeloperoxidase activity decreased significantly after the oral administration of rolipram nanoparticles or solution. During the next 5 days when animals were kept without drug treatment the drug solution group displayed a strong relapse, whereas the nanoparticle groups continued to show reduced inflammation levels. The rolipram solution group had a high adverse effect index, whereas the rolipram nanoparticle groups proved their potential to retain the drug from systemic absorption as evidenced by a significantly reduced index. This new delivery system enabled the drug to accumulate in the inflamed tissue with higher efficiency than when given as solution. The nanoparticle deposition in the inflamed tissue should be given particular consideration in the design of new carrier systems for the treatment of inflammatory bowel disease.