Evaluation of the efficacy of N-acetylcysteine and bromhexine compared with standard care in preventing hospitalization of outpatients with COVID-19: a double blind randomized clinical trial

INTRODUCTION AND AIM

Since its emergence in December 2019, the coronavirus disease caused by the severe acute respiratory syndrome coronavirus 2 has become a global emergency, spreading rapidly worldwide. In response to the early referral of these patients to outpatient health centers, we decided to seek more effective treatments in the early stages of their referral. This study aims to prevent both the progression and deterioration of the physical conditions of COVID-19 patients, reduce the rate of referrals, and mitigate the risks of hospitalization and death.

MATERIAL AND METHODS

Conducted at Dibaj Therapeutic Center, Hamadan City, Iran, a double-blind randomized controlled trial encompassed 225 COVID-19 patients from April to September 2022. Ethical approval was obtained from Hamadan University of Medical Sciences (Approval No.: IR.UMSHA.REC.1400.957), with the protocol registered in the Iranian Registry of Clinical Trials (Registration No. : IRCT20220302054167N1). In this study, we included patients who tested positive for COVID-19- PCR and were symptomatic, excluding those who were pregnant or had received a COVID-19 vaccine. Patients with oxygen saturation above 92% were allocated to three groups: Group A received N-acetylcysteine, Group B received Bromhexine, and Group C received standard care. Follow-ups on oxygen levels, symptoms, and hospitalization needs were conducted on days 7 and 14, with hospitalized patients monitored for one month post-hospitalization.

RESULTS

The study found that both N-acetylcysteine and Bromhexine can effectively reduce hospitalization rates and mortality and shorten the duration of hospitalization. The third visit of patients who received N-acetylcysteine showed an increase of 1.33% in oxygen saturation compared to their first visit, and in patients who received Bromhexine, this increase was 1.19%. The mortality rate was 9.33% in the control group and zero in both groups of patients who received medication.

CONCLUSION

In conclusion, the results of this study indicate that NAC and bromhexine may be effective in the treatment of patients with positive COVID-19, with a lower hospitalization rate, shorter hospitalization, faster recovery time, and reduced mortality compared to the control group.

Relationship between Lifestyle and Frailty among Iranian Community-Dwelling Older Adults: Pilot Study

Background

Aging affects physical, mental, and social functions, which can lead to an increase in frailty. Old adults with frailty syndrome are prone to disabilities and hospitalization. Lifestyle is a context-based factor that has the potential to prevent frailty.

Objectives

This study aimed to assess the relationship between lifestyle and frailty among Iranian community-dwelling older adults.

Design Setting

This is a descriptive-analytical cross-sectional study. The participants were 513 older adults over 60 years by the convenience sampling method from the retirement center.

Measurements

Data were collected using Tilberg's frailty index, the Iranian elderly lifestyle questionnaire, and the Mini-Cog test. Data were analyzed with SPSS v.26 software by chi-square and logistic regression tests.

Results

The age of the participants was 66.43 ± 4.69 years. The male-to-female sex ratio was 1.5 (39.2% women). The lifestyle of 96 (19.3%) old adults was unfavorable. 18.7 percent of older adults had Frailty syndrome. The logistic regression test showed that moderate and favorable lifestyle (OR= 0.06; 95% CI: 0.02-0.16), age over 75 years (OR= 5.25; 95% CI: 2.35-11.69), retired employment status (OR= 0.13; 95% CI: 0.29-0.05) are factors that have a significant relationship with frailty (P< 0.05).

Conclusion

The findings showed that lifestyle can predict frailty. Therefore, it seems that an optimal lifestyle can prevent the frailty of older adults.

Antibacterial effect of TiO2 modified with poly-amidoamine dendrimer - G3 on S. aureus and E. coli in aqueous solutions

This study investigated bacterial removal using TiO₂ nanoparticles (NPs) modified with poly-amidoamine dendrimer macromolecule (PAMAM, G3). The PAMAM G3/TiO₂ (nanohybrid) was used to specify antibacterial properties via broth microdilution (MBC-Minimum Bactericidal Concentration and MIC-Minimum Inhibitory Concentration-determination), paper disc diffusion, and surface plate count methods. The nanohybrid was characterized via the different techniques. The effects of different factors including initial bacteria count, run time, solution pH, and the nanohybrid concentration were studied. The nanohybrid cytotoxicity was studied on AGS and MKN45 cells line by MTT assay. It was revealed that the nanohybrid was effective in intercepting both bacterial strains growth. The MIC value for S. aureus and E. coli were determined to be 4 and 2 μg/mL, respectively. The MBC value for both strains were calculated to be 32 μg/mL. The results showed removal efficiency of 100% for S. aureus and E. coli bacteria in optimum situation. The decrease in cell viability in the dosage of 32 μg/mL after 72 h treatment for AGS and MKN45 cells line were shown to be 6.2 and 4.6%, respectively. The nanohybrid was able to decrease the S. aureus and E. coli count in solution, which meets the drinking water criterions aligned with WHO guidelines.

Prediction of Hospitalization Length. Quantile Regression Predicts Hospitalization Length and its Related Factors better than Available Methods

BACKGROUND

Length of hospitalization is one of the most important indices in evaluating the efficiency and effectiveness of hospitals and the optimal use of resources. Identifying these indices' associated factors could be useful. This study aimed to investigate effective factors of the length of hospitalization in Zanjan teaching hospitals in 2018 using the Quantile regression model.

METHODS

This cross-sectional study was conducted on 1,031 patients. The study population consisted of patients in orthopaedic, pediatric, internal, surgical and intensive care units. The samples were selected by multistage random sampling. The information was collected by a pre-designed checklist. The Quantile regression model and ordinary regression model were performed on the data.

RESULTS

Of the 1,031 patients admitted to different units, 624 (60.52%) were male. Mean and standard deviation of length of hospitalization for men, women and all patients were 7.25±5.48, 8.09±6.35 and 7.58±5.83 respectively. For 90 percent of patients the length of hospitalization was less than 14 days. Twenty-five percent of patients in pediatric and orthopedic units and ten percent of patients in internal and surgery units were hospitalized less than three days. In all quantiles, patients' length of hospitalization in surgery and orthopedic units, compared to the intensive care unit, and patients hospitalized for injuries and poisonings compared to other causes, had a statistically significant difference. (p<0.05).

CONCLUSION

Due to the heterogeneity (skewness) of the length of hospital stay in different units of the hospital, the quantile regression model predicts the length of hospital stay more precisely than the ordinary regression models.

Poly (amidoamine) generation 6 functionalized Fe3O4@SiO2/GPTMS core-shell magnetic NPs as a new adsorbent for Arsenite adsorption: kinetic, isotherm and thermodynamic studies

In this survey a new route has been developed the preparation of poly (amidoamine) generation 6 (PAMAM-G6) dendrimer functionalized Fe3O4/SiO2 nanoparticle and was used for arsenite (As (III)) adsorption. SiO2 was first grafted onto the surface of Fe3O4 to formation a core-shell structure. Then the introduction of epoxy rings were done by hydrolysis of methylsilane groups of 3-Glycidoxypropyltrimethoxysilane (GPTMS) on OH groups of SiO2 and afterwards, PAMAM-G6 reacted with epoxy rings of GPTMS to obtain a multiamino magnetic adsorbent. The as-prepared nanocomposite was characterized by TEM, Zeta potential, FESEM, VSM, FTIR, Raman and XPS techniques. The effects of reaction time from 5 to 50 min, initial As (III) concentration in the range of 1-10 mgL-1, initial adsorbent concentration in the range of 10-50 mgL-1 and initial pH in the range 3-8 were studied. The resulting of kinetic and isotherm models displays high adsorption affinity (233 mg/g) for As (III) and the adsorbent can reach the adsorbent can reach the adsorption equilibrium at a neutral pH (7). The As (III) loaded nanocomposite could be separated readily from aqueous solution by magnetic and regenerated simply via NaOH. The study of the adsorption procedure showed that the pseudo-second order kinetics and Langmuir isotherm well-fitted with the experimental data of As (III) adsorption onto nanocomposite.

Evaluation of industrial wastes management practices: Case study of the Savojbolagh industrial zone, Iran

The main objective of this research was to investigate the waste characteristics and management activities in the Savojbolagh industrial zone, Iran, in order to rank the active industries from environmental perspectives using an innovative index. First, the industrial categories with over 50 employees were identified and classified according to their production process. Then, 54 industries were selected and all industrial processes, the types and quantities of products, per capita industrial waste generation, physical analysis and management activities in terms of minimisation, storage, processing, recycling and disposal were evaluated. The required data were obtained through questioners, interviews and field observations. A scoring system was prepared for evaluation of environmental status of waste management practices. Results indicated that the total industrial waste generation rate was 67,258 kg d^-1, in which 4528 belonged to hazardous waste. Furthermore, the per capita waste generation rate was 5.51 kg d^-1. Plastic, paper and cardboard and metals constituted the most fractions of wastes, respectively. Food and beverage, metallic and chemical/plastic industries were the biggest waste generators. Metallic industries with total score of 502.5 and non-metalic-mineral industries with the total score of 114 were categorised as the best and worst industries in terms of waste management practices.

Assessment of microbial quality of household water output from desalination systems by the heterotrophic plate count method

Point-of-use household water desalination systems (HWDSs) are becoming popular in Iran because of the deterioration of drinking water. This study aimed to determine the microbial quality of output water from HWDSs in Qom, Iran by using the heterotrophic plate count (HPC) method. Samples of input and output water from 30 HWDSs were collected over a six-month period. Heterotrophic bacteria were tested using the pour plate technique. At the first sampling stage, the HPC level in 23% of samples exceeded the 500 CFU/ml threshold level. On average, for 50% of samples, the HPC level of input samples was 0-10 CFU/ml, for 42% it was 10-100 CFU/ml and for 8% it was 100-500 CFU/ml. For output samples, for 25%, the level of HPC was 0-10 CFU/ml, for 43% it was 10-100 CFU/ml, for 24% it was 100-500 CFU/ml and for 8% it exceeded 500 CFU/ml. For total coliforms the most probable number test was positive for the first and third stages of sampling (3% input samples). The comparison of the averages with national standard values shows that in some cases, the contamination of output water from HWDSs in the city of Qom has been above the standard values.

Antibacterial activity of amino- and amido- terminated poly (amidoamine)-G6 dendrimer on isolated bacteria from clinical specimens and standard strains

Background: Nanoscale poly (amidoamine) dendrimers have been investigated for their biological demands, but their antibacterial activity has not been widely discovered. Thus, the sixth generation of poly (amidoamine) dendrimer (PAMAM-G6) was synthesized and its antibacterial activities were evaluated on Gram-negative bacteria; P. aeruginosa, E. coli, A. baumannii, S. typhimurium, S. dysenteriae, K. pneumoniae, P. mirabilis, and Gram-positive bacteria, and S.aureus and B. subtilis, which were isolated from different clinical specimens and standard strains of these bacteria. Methods: In this study, 980 specimens including urine (47%), blood (27%), sputum (13%), wounds (8%), and burns (5%) were collected from clinical specimens of 16 hospitals and clinics in city of Sabzevar, Iran. Then, the target bacteria were isolated and identified using standard methods. Minimum inhibitory concentration and minimum bactericidal concentrations against Gram-positive and Gram-negative bacteria were determined according to guidelines described by clinical and laboratory standards institute (CLSI). Standard discs were prepared using 0.025, 0.25, 2.5, and 25 μg/mL concentrations of PAMAM-G6 on Mueller-Hinton agar plates to determinate the zone of inhibition. The cytotoxicity of PAMAM-G6 dendrimer was evaluated in HCT116 cells by MTT assay. Results: The most important isolated bacteria were E. coli (23.65%), S. aureus (24.7%), P. aeruginosa (10.49%), B. subtilis (7.7%), S. typhimurium (8.87%), A. baumannii (7.02%), K. pneumoniae (7.1%), P. mirabilis (6.46%), and S. dysenteriae (3.6%). Moreover, it was found that poly (amidoamine)-G6 exhibited more antibacterial efficacy on standard strains than isolated bacteria from clinical samples (p<0.05). The cytotoxicity of PAMAM-G6 to the cells showed that cytotoxicity depended on the concentration level and exposure time. Conclusion: The PAMAM-G6 dendrimer showed a positive impact on the removal of dominant bacterial isolated from clinical specimens and standard strains.

In vitro antibacterial activity of poly (amidoamine)-G7 dendrimer

BACKGROUND

Nano-scale dendrimers are synthetic macromolecules that frequently used in medical and health field. Traditional anibiotics are induce bacterial resistence so there is an urgent need for novel antibacterial drug invention. In the present study seventh generation poly (amidoamine) (PAMAM-G7) dendrimer was synthesized and its antibacterial activities were evaluated against representative Gram- negative and Gram-positive bacteria.

METHODS

PAMAM-G7 was synthesized with divergent growth method. The structural and surface of PAMAM-G7 were investigated by transmission electron microscopy, scanning electron microscope and fourier transform infrared. Pseudomonas. aeruginosa (n = 15), E. coli (n = 15), Acinetobacter baumanni (n = 15), Shigella dysenteriae (n = 15), Klebsiella pneumoniae (n = 10), Proteus mirabilis (n = 15), Staphylococcus aureus (n = 15) and Bacillus subtilis (n = 10) have been used for antibacterial activity assay. Additionally, representative standard strains for each bacterium were included. Minimum Inhibitory Concentration (MIC) was determined using microdilution method. Subsequently, Minimum Bactericidal Concentration (MBC) was determined by sub-culturing each of the no growth wells onto Mueller Hinton agar medium. The cytotoxicity of PAMAM-G7 dendrimer were evaluated in HCT116 and NIH 3 T3 cells by MTT assay.

RESULTS

The average size of each particle was approximately 20 nm. PAMAM-G7 was potentially to inhibit both Gram positive and gram negative growth. The MIC50 and MIC90 values were determined to be 2-4 μg/ml and 4-8 μg/ml, respectively. The MBC50 and MBC90 values were found to be 64-256 μg/ml and 128-256 μg/ml, respectively. The cytotoxity effect of dendrimer on HCT116 and NIH 3 T3 cells is dependent upon exposure time to and concentration of dendrimers. The most reduction (44.63 and 43%) in cell viability for HCT116 and NIH 3 T3 cells was observed at the highest concentration, 0.85 μM after 72 h treatmentm, respectively.

CONCLUSIONS

This study we conclude that PAMAM-G7 dendrimer could be a potential candidate as a novel antibacterial agent.

The additive effect of excimer laser on non-cultured melanocyte-keratinocyte transplantation for the treatment of vitiligo: a clinical trial in an Iranian population

BACKGROUND

Non-cultured cellular grafting is specified for stable vitiligo treatment as a novel surgical technique, however, the additive effect of excimer laser on melanocytes-keratinocytes transplantation (MKT) have not experienced yet.

OBJECTIVE

To assay the additive effect of excimer laser on MKT for the treatment of vitiligo in an Iranian population.

METHODS AND MATERIALS

In this non-randomized clinical trial, 39 patches were evaluated. Nine patches treated by MKT alone, 10 patches treated by MKT and excimer laser, 10 patches treated with excimer alone and 10 patches left without any treatments as control patches.

RESULTS

In the patches treated with excimer, the percentage reduction of depigmented area from baseline varied, ranging from 0 to 43.9%. In the nine patches treated with non-cultured MKT, the median percentage reduction of depigmented area from baseline was 15.9%. The median percentage reduction of depigmented area in excimer + MKT was 41.9% .In the untreated patches, the median percentage reduction of depigmented area was 0.1%. After controlling for the effect of 'depigmented area at baseline', significant reductions were observed in depigmented area of the patches treated with combination therapy of excimer and non-cultured MKT in comparison with the other therapies and untreated patches.

CONCLUSION

Although pigmentation in our patients was lower than previous reports from Iran and other countries, however, we signified adding excimer to MKT increased the pigmentation rate in treated patches. Further investigations are recommended with longer follow-up and larger series to validate the findings reported here.

Melioidosis: It is not Far from here

In the modern world, with developed traveling facilities, tourism is an important factor in emerging new infectious diseases in non-endemic areas. Therefore, the epidemiology of infections is a considerable issue for physicians and should be taken into account. We report a case of melioidosis in a 69-year-old Iranian man during his trip to Southeast Asia. On admission, he was febrile with tachycardia and tachypnea and had diabetes mellitus and hypertension since eleven years ago. Bronchoscopy and bronchoalveolar lavage (BAL) were performed. Blood and BAL cultures revealed heavy growth of Burkholderia pseudomallei. According to the aforementioned culture results, the patient was treated with meropenem and TMP-SMX, while other antibiotics were discontinued. After 3 weeks, the patient was discharged with stable status and normal pulmonary function; and eradication therapy with TMP-SMX continued for about 3 months. The control lung CT scan after one month demonstrated significant improvement.

Repair of iatrogenic large colon perforation using laparoscopic methods. Case report and review of the literature

Iatrogenic perforation of the colon during elective colonoscopy is a serious complication. Surgical treatment remains the standard of care. We report a patient with a large colonic perforation that occurred during a screening colonoscopy, successfully repaired with laparoscopic methods. Although the safety and efficacy of this approach is not entirely established, laparoscopy can be used to treat iatrogenic colonic perforation when the defect is readily recognized, easily accessible for closure and the bowel preparation is excellent. A laparoscopic approach to treat iatrogenic colon perforation results in decreased morbidity and hospital stay, in addition to a shorter incision length compared to an open method. In those cases where it is feasible and the surgical skill exists, a laparoscopic attempt at colon repair should probably be the initial clinical approach..

A simple and practical method in treatment of ingrown nails: splinting by flexible tube

BACKGROUND

The ingrown nail (or onychocryptosis) is a common problem that occurs mostly in the big toe and causes high amounts of morbidity in affected patients. Many therapeutic methods have been described, most of them leading to severe damage to the nail or to frequent relapses. The nail splinting technique is a successful, simple and non-invasive therapeutic method for treating ingrown nails.

OBJECTIVE

To determine efficacy of the plastic tube insertion technique in patients with ingrown toenail and its use as a standard treatment.

MATERIALS AND METHODS

We encountered 32 cases (age range 9-67 years) of ingrown toenails in this clinical trial. All of the patients were treated using the plastic nail tube insertion technique for 7 to 15 days. Patients were examined daily for the first 3 days of treatment and were evaluated 3 and 6 months after treatment. All patients were followed up by a single observer.

RESULTS

Recurrence was seen in only two patients after 6 months of treatment (6.25%).

CONCLUSION

The low recurrence rate using the nail splinting technique in the treatment of ingrown toenail, as well as its simple application, shows that this treatment constitutes an effective, non-invasive method. It appears that this technique can substitute other more invasive surgical methods, particularly in the early stages of this disease.

Bilateral open treatment of spontaneous pneumothorax: a new access

A new technique for bilateral apical bullectomy and pleurectomy via axillary minithoracotomy and transmediastinal access to the contralateral side, was used in 13 patients with bilateral apical blebs and/or pneumothorax. The contralateral space is reached at the posterior superior mediastinum, passing between the first thoracic vertebral bodies (T1-T4) and the oesophagus. The contralateral lung apex is then pulled into the thoracotomy side and apical bullectomy carried out by linear stapler. The obvious advantages of avoiding a second thoracotomy while providing complete solution to the clinical problem are particularly important in young patients with spontaneous pneumothorax caused by bilateral apical blebs.

Patterns of systolic stress distribution on mitral valve anterior leaflet chordal apparatus. A structural mechanical theoretical analysis

Increasing diffusion and complexity of mitral valve repair procedures may prompt an interest in the evaluation of the patterns of stress distribution on the chords, which are, from the structural mechanical point of view, the weakest element of valve apparatus. This theoretical analysis concentrates in particular on the mitral valve anterior leaflet. As is known, the vast majority of the chordae are attached to the anterior leaflet within the coaptation area; during systole they are then necessarily parallel, aligned along the same plane as that of the leaflets' coaptation surface, to which they are attached; moreover the thickness of the chordae increases significantly from the marginal chordae to the more central ones. In normal conditions during systole the progressively wider coaptation surface causes the increasing stress to be supported by an increasing number of progressively thicker chords, which are substantially parallel and aligned on the coaptation surface plane in such a way that they can share the stress between them, according to their thickness; in other words chords form a multifilament functional unit which enrolls elements of increasing thickness in response to the mounting stress. The geometrical modifications of the valve apparatus architecture (annulus dilatation, leaflet retraction, chordal elongation or retraction) often associated with valve insufficiency due to chordal rupture, have the common result of causing, during systole, a radial disarrangement of the direction of most of the secondary chordae which are no longer parallel, aligned on the coaptation surface plane. Due to the negligible elastic module of the valve leaflet, in this new arrangement the various chordae cannot share the stress between themselves as they do in a normal physiological situation; on the contrary the thinner chordae nearer to the free margin are also loaded with the peak systolic stress, thus generating conditions favoring their rupture. It can, therefore, be hypothesized that the anatomopathological picture of valve insufficiency due to chordal rupture may be the final event of a series of geometrical modifications of valve apparatus architecture, the common consequence of which is to load thinner marginal chords with peak systolic stress from which they are normally spared, thus favoring their rupture.

[Partial resection of the tracheal wall and introverting tracheoplasty]

A tracheal tumor involving roughly the half circumference of the tracheal wall and 3.5 cm length, was resected preserving the part of the tracheal cylinder not invaded by the tumor; reconstruction was carried out by an introverting tracheoplasty. This reconstruction technique, already successfully carried out in main bronchus resections, allowed iuxtapositioning of the tracheal rims very firmly without tension, the maneuvers for laryngeal or carenal release being not necessary.

Descending aorta substitution with expandable ends prosthesis. Case report

A case of esophageal cancer infiltrating the left bronchus pars membranacea and the aneurysmal aortic wall was resected en bloc with the bronchial and aortic wall. Descending aorta was substituted by means of a Dacron prosthesis fitted with expandable devices at both ends, allowing a very significant reduction of the clamping time and simplification of this part of the procedure.

[Longitudinal bronchotomy on the pars membranacea for endoscopic foreign body extraction]

Purpose of this paper is to report a case of foreign body obstructing the middle lobe bronchial origin, surgically removed through a longitudinal bronchotomy on the pars membranacea, reached by passing posteriorly to the lung. Anatomical considerations suggest that longitudinal bronchotomy on the pars membranacea of the main bronchial axis (stem bronchi, intermedius br (right), and lower lobar bronchus) gives direct visualization from inside also of foreign bodies sited into the lobar bronchi (sup, middle and lingula), allowing an easy bronchotomy repair, without lumen distortion or stenosis. Since the pulmonary artery is not in contact with this pars membranacea, broncho-arterial fistula in case of suture line dehiscence is quite improbable.

[The surgical physiopathology of essential pulmonary emphysema and volume-reduction intervention]

The breaking of the interalveolar septa represents, in the pathogenetic mechanism of emphysema, a final event, common to the different etiologic agents. This elementary injury causes a series of consequences, essentially of mechanic-structural type (intrapulmonary aerial spaces-confining parenchyma collapse, bronchial obstruction, dead space augmentation) on the thin and articulate bronchoalveolar architecture, whose final rearrangement determines, at least in part, the clinical picture. In short, the break of alveolar septa involves the formation of intraparenchymal aerial spaces with collapse of the confining lung; the compensatory mechanism to this situation, involves the hyperexpansion of the thoracic cage and flattening of the diaphragm, with the aim of allowing ventilation of the healthy residual parenchyma. Because of the finite capability of expansion of the thoracic cage and of the diaphragm in respect to the theoretical capability of the lung of large intraparenchymal aerial spaces formation, it is easy to imagine that emphysema can cause a serious functional respiratory deficit even before a significant quantity of pulmonary parenchyma is destroyed by the pathogenic process. It may then be hypothesized that a simple reduction of the volume of the lung, even sacrificing a part of "working" parenchyma, might allow the residual lung to come back to a normal ventilation, wholly ameliorating the respiratory exchanges. The clinically more remarkable consequence of lung volume reduction is the amelioration of ventilation mechanics with a decreased respiratory work due to the shift of the tidal volume toward values less proximal to the maximal expandability of the thoracic wall and of the diaphragm. On the other end, it is possible to anticipate an equally significant effect on bronchial obstruction, due to the more favorable matching of the compliance of the thoracic wall and that of the lung. LVRS has significant effect on the TV sharing ratio between emphysematous spaces and residual healthy parenchyma; the hyperexpansion of the residual lung in fact causes the distension of the emphysematous spaces, continuing in the natural compensatory mechanism of the emphysema. The decreased ventilation and thus re-breathing of the residual emphysematous spaces, together with the improved ventilation may ameliorate hypercapnia. Obviously no direct effects can be expected from LVRS on the conditions of the alveolar membrane and thus on gas diffusion capacity through it. The time duration of the amelioration achieved with the lung volume reduction is still to be demonstrated.

[Physiopathology of pulmonary emphysema. Analysis of structural changes in the pulmonary architecture and therapeutic implications]

In the pulmonary emphysema a serious respiratory inadequacy can result from the impossibility of the thoracic cage and of the diaphragm to expand beyond a maximum limit, before that a significnat part of pulmonary parenchyma has been destroyed by the pathogenic process. The resection of part of the lung, selectively in the areas where the emphysematous injuries are more pronounced, brings again the ventilation of the residual pulmonary parenchyma toward more physiological expansion values of the thoracic cage and diaphragm, thus decreasing the respiratory work, improving the ventilation mechanics and the bronchial obstruction. The time duration of the improvement achieved with the lung volume reduction is still to be demonstrated. A clinical and therapeutic analysis of this pathology is carried out.

Prosthesis for aortic arch substitution

BACKGROUND

The risk of neurologic complications in aortic arch prosthetic substitution is directly related to the duration of the circulatory arrest. The purpose of this article is to report the experiments on animals of a device for simplifying and quickening the vascular anastomosis in aortic arch substitution.

METHODS

The device consists of expandable loops of stainless steel wire, sewn to the proximal end of a Dacron prosthesis. An actuating removable guide allows the stainless steel wire loops to be expanded and tightened, in such a way that the prosthesis diameter is varied, while maintaining a regular cylindric shape. The prosthesis end is then transformed into a rigid cylindrical ring, approximately half the maximal diameter in length, with a variable and controllable diameter. A composite graft was prepared, fitted with the expandable device at the distal end of the main prosthesis as well as at each end of the branches for the supraaortic trunks. Cardiopulmonary bypass was established by cannulation of the right atrium and left iliac artery. The prosthesis was positioned very easily and quickly during a brief hypothermic circulatory arrest; ascending aorta anastomosis was carried out by the standard technique after central nervous system reperfusion was resumed. Acute experiments were carried out in 5 swine.

RESULTS

Four of 5 animals survived the procedure without detectable neurologic sequelae. At sacrifice the prosthesis was found to be properly sited without lumen distortion or thrombosis.

CONCLUSIONS

The main advantages of this device and modality of arch substitution in a clinical setting would include drastic reduction of the circulatory arrest time, easy and reliable hemostasis of the anastomosis line, and accurate and firm approximation of the dissection layers in case of dissecting aneurysms.

[A device for synthesis of the costal plane after posterolateral thoracotomy using transosseous incisions to prevent compression of intercostal nerves]

The purpose of this paper is to illustrate the use of a device to quickly perform little holes in the costal lateral arch for synthesis of the standard posterolateral thoracotomy. The working principle of the instrument is similar to that of a hollow punch device. Preliminary laboratory experience allowed to identify the best diameter of the costal holes (2 mm), without fracture. Absorbable suture were passed through the holes and tied to approximate the facing ribs. The modality of costal plane synthesis, very easy and quick with this device, makes possible to prevent intercostal nerve compression and accidental intercostal vessel lacerations. The so frequent, severe and often long lasting painful sequelae of thoracotomy, on the other hand so rare in other surgical wound (i.e. laparotomy, sternotomy, etc.) justify in our opinion the routine use of this costal plane synthesis technique.

[Invaginated bronchoplasty: wedge resection and sleeve reconstruction]

The purpose of this report is to illustrate a bronchoplastic technique in upper right lobectomy which is equivalent to sleeve resection but allows to preserve the unaffected portion of the bronchial wall. The technique consists in the resection of the infiltrated bronchial wall, sparing the unaffected part The distal bronchial stump is then invaginated into the stem bronchus in such a way that the anastomosis line is located at the highest possible level, ideally where it would be carried out if standard sleeve resection would be performed. The anastomosis is accomplished by U-Shaped, 3-0 vicryl sutures. The major advantage of this procedure is probably due to the preservation of the systemic artery bronchial supply to the distal stump passing through the unaffected bronchial wall; the resulting more vital distal stump may reduce incidence of suture line healing problems.

Potentials of liposomes in diagnosis and treatment of pulmonary metastases: an experimental study in the rat

OBJECTIVE

The ultimate goal of the therapy of lung metastases is to destroy all malignant cells while sparing normal ones. Liposomes represent a novel approach for the selective transport of tracers and therapeutic agents to cancer cells because of their flexibility, low toxicity, wide range of possible variants, simplicity to make, and because agents can be entrapped in them in their native states in large amounts. We have studied the biodistribution of "Stealth" liposomes in the experimental model of lung metastases in the rat.

METHODS

The secondaries were induced by i.v. injection 20. 10(6) cancer cells (DHD/K12/TRb line) in BD-IX rats. The study of the liposome biodistribution in the rat was carried out by the use of unilamellar liposomes with homogeneous size distribution (0.1 microns), the liposomes were labeled with Cholesteryl-Bodipy. The rats were sacrificed at scheduled times after the injection; blood, urine, metastatic and healthy lung, colon, liver and spleen were analysed by a microcytofluorimetric examination.

RESULTS

Liposomes prolonged the circulation time of Cholesteryl-Bodipy. Only spleen and lung metastases exhibited an accretion of fluorescent liposomes.

CONCLUSIONS

The biodistribution of such formulation of liposomes in rats with lung metastases, may be of considerable importance in diagnosis and therapy of the secondaries, for increasing the concentration of tracers and therapeutic agents in tumor tissue while minimizing the likelihood of aspecific distribution and toxicity to non target tissue.

Expandable prosthesis for sutureless anastomosis in thoracic aorta prosthetic substitution

OBJECTIVE

Most complications of descending aorta prosthetic substitution seem mainly to be related directly (ischemia to distal organs, i.e. liver, kidney, spinal cord) or indirectly (extracorporeal circulation or shunts and systemic heparinization complications) to the duration of blood flow interruption. the purpose of this study is to report the results of animal experimentation of a new device for sutureless prosthetic substitution of the descending thoracic aorta, with a very short cross-clamping phase.

METHODS

The device consists of expandable loops of stainless steel wires, sewn to the proximal end of a Dacron prosthesis. The stainless steel wire loops can be expanded and tightened by activating a removable guide in such a way that the prosthesis varies its diameter, while maintaining a regular cylindrical shape. The device was prepared in two different configurations, one for long segments (expandable prosthesis end) and the other to be used for very short segments or as an anastomotic ring between prosthetic or vascular stumps (quick anastomotic ring). The expandable prosthesis end was tested in swine experiments by performing the prosthetic substitution of the first 10 cm of descending cross-clamped aorta, the prosthesis being fixed with the device both at the proximal and the distal ends (six experiments). All animals survived the procedure, that was accomplished with a very short cross-clamping time. The quick anastomotic ring was used to anastomose two prosthesis ends, at the middle of the prosthetic segment used for descending aorta substitution (two swine), to perform the distal anastomosis in the same model of descending aorta substitution (one swine) and simply to re-anastomose a subtotally transected descending aorta (one swine).

RESULTS

The present experience proved the reliability of the device to carry out a sutureless, accurate, simple and quick anastomosis. Its advantage over an intraluminal ringed prosthesis is much easier insertion of the retracted wired end into the vascular stumps, thus allowing for a prosthetic diameter appropriate to the substituted vessel.

CONCLUSIONS

The reduced cross-clamping feature of the device would suggest its use mainly in thoracic aorta prosthetic substitution for the prevention of ischemic damage to distal organs; it can also be used to advantage wherever an end-to-end vascular or prosthetic anastomosis is indicated, providing an accurate, stented anastomosis.

Aortic wall structural strengthening by intraluminal net prosthesis to arrest aneurysm progression and to prevent dissection and rupture

The major limitation implicit in the endovascular procedures for aortic prosthetic substitution is that they cannot be used in those tracts of the aorta where important collateral branches originate (aortic arch, thoraco-abdominal tract, upper abdominal), that would be occluded by the prosthesis. In order to overcome this limitation we hypothesized the endovascular positioning of a prosthesis in the form of a wide mesh network that would be gradually and spontaneously covered by new intima and included in the aortic wall. The fabric framework linked to the aortic wall would then condition its significant, regular and uniform mechanical strengthening that fractionates and partially absorbs the centrifuge pulsatile stress of the bloodstream. The purpose of this paper is to report the results of the insertion of a braided Prolene net prosthesis in the first 7 cm of the descending aorta of ten swine. The animals were killed after 6 weeks, the substituted segment removed and aortic wall compliance measured under standardized conditions. The prosthesis was found entirely covered by new intima, well embodied in the aortic wall. The intercostal collateral included in the substituted segment was patent, as proved by bubble formation during underwater insufflation. Compliance of the prosthesis segment was significantly lower than that of the adjacent descending aorta. Histology showed a regular net prosthesis inclusion deep in the neo-intima layer. Present results indicate the technical feasibility of the procedure, achieving significant aortic wall strengthening without affecting the collateral (intercostal) circulation.

The backflow from the pulmonary circulation for identification of the aortic origin of the bronchial arteries in experimental left single lung transplantation

The ideal solution to the bronchial healing problems in lung transplant would be the reconstruction of the bronchial arteries at time of transplantation. The problems with this approach are essentially technical being difficult to identify and preserve the bronchial arteries in humans. The purpose of this paper is to report our experience with an experimental model in dog to easily identify and preserve bronchial circulation in single lung transplantation. The technique is based on the preservation during harvesting of the aortic origin of the first five couples of arterial orifices. Identification of the orifice(s) connected with the bronchial circulation is carried out by the backflow which takes place from the pulmonary circulation after organ reperfusion is resumed. The identified orifice(s) is then anastomosed to the descending recipient aorta, tangentially clamped.