The difficult journey to treatment for women suffering from heavy menstrual bleeding: a multi-national survey.

PURPOSE: Up to 30% of women of reproductive age experience HMB, which has a substantial impact on their quality of life. A clinical care pathway for women with HMB is an unmet need, but its development requires better understanding of the factors that characterise current diagnosis and management of the condition. MATERIALS AND METHODS: This observational, survey-based study assessed the burden, personal experiences, and path through clinical management of women with HMB in Canada, the USA, Brazil, France and Russia using a detailed, semi-structured online questionnaire. After excluding those reporting relevant organic pathology, responses to the questionnaire from 200 women per country were analysed. RESULTS: Around 75% of women with HMB had actively sought information about heavy periods, mostly through internet research. The mean time from first symptoms until seeking help was 2.9 (Standard deviation, 3.1) years. However, 40% of women had not seen a health care professional about the condition. Furthermore, 54% had never been diagnosed or treated. Only 20% had been diagnosed and received appropriate treatment. Treatment was successful in 69% of those patients currently receiving treatment. Oral contraceptives were the treatment most commonly prescribed for HMB, although the highly effective levonorgestrel-intrauterine system was used by only a small proportion of women. CONCLUSIONS: This study provides insight into the typical journey of a woman with HMB which may help patients and health care professionals improve the path to diagnosis and treatment, although further research with long-term outcomes is needed.

Contraception during Coronavirus-Covid 19 pandemia. Recommendations of the Board of the Italian Society of Contraception.

Purpose: The Italian Society of Contraception identified as one of its priorities the need to give recommendations on management of contraception during Coronavirus-Covid 19 pandemiaMaterials and methods: A concise communication was produced which summarises in an easy-to-read format suitable for clinicians the management of the different contraceptives mostly used. Information how to manage contraception in different conditions is presented.Results: Women may, in general, continue to use either intrauterine and or hormonal contraceptives. The use of condom should be added to any hormonal contraceptive, when the contraceptive efficacy is reduced or when women stop the contraceptive method.Conclusion: At the present time, during the Coronavirus-Covid 19 pandemia, no data contraindicate the use of intrauterine or hormonal contraceptives. Conversely the use of an appropriate contraception is advocate to prevent unintended pregnancies.

The Complexity of Dreams: a Multiscale Entropy Study on Cardiovascular Variability Series.

Uncovering the physiological correlates of dreams is one of the most ambitious aim of multidisciplinary neuroscientific research. Here we investigated Autonomic Nervous System (ANS) dynamics associated with a dream recall, with a particular focus on the complexity assessment on cardiovascular control. We recorded electrocardiogram and arterial blood pressure signals from eight healthy subjects during rapid-eye-movement sleep before awakenings. Recordings were then split into two groups: the ones with a dream experience, and the ones without recall of dream experiences. The randomness of cardiovascular variability series was assessed through Sample Entropy metrics, which did not show any statistical difference between groups. On the other hand, a multiscale complexity analysis based on Distribution Entropy and Fuzzy Entropy revealed that a higher cardiovascular complexity is associated with a dreaming experience.

Sofosbuvir in combination with daclatasvir or simeprevir for 12 weeks in noncirrhotic subjects chronically infected with hepatitis C virus genotype 1: a randomized clinical trial.

OBJECTIVE: To investigate the efficacy and safety of sofosbuvir (SOF) plus daclatasvir (DCV) or simeprevir (SMV) in a randomized, open-label, noninferiority trial of patients infected with hepatitis C virus genotype 1, who were previously unresponsive to pegylated interferon and ribavirin or were treatment naive. METHODS: Patients were randomly assigned to receive SOF (400 mg once daily) plus DCV (60 mg once daily) or SMV (150 mg once daily) for 12 weeks. The analysis included all participants who received at least one dose of the study drugs. The primary endpoint was sustained virologic response 12 weeks after ending treatment (SVR12; hepatitis C virus RNA measured using COBAS TaqMan RT-PCR (lower limit of detection and quantification of 12 UI/mL)). This study was registered at ClinicalTrials.gov (NCT02624063). RESULTS: A total of 125 of 127 enrolled and randomized patients started treatment (n = 65 SOF + DCV; n = 60 SOF + SMV). SVR12 was attained in 121 patients (96.8%): 65 (100%) receiving SOF + DCV (95% confidence interval (CI), 94.5 to 100) and 56 (93.3%) receiving SOF + SMV (95% CI, 83.8 to 98.2; absolute difference, 6.6%; 95% CI, -15.0 to 0). The most common adverse events were fatigue (n = 32, 25.6%), headache (n = 27, 21.6%), and mood swings (n = 24, 19.2%). No patients discontinued therapy. CONCLUSIONS: The overall SVR rate was 96.9%; SOF + DCV (100%) was higher than that of SOF + SMV (93.3%). Despite no statistically significant intergroup difference in SVR12 rates, the noninferiority of SOF + SMV to SOF + DCV could not be established because the difference in efficacy was clinically relevant.

ESC expert statement on the effects on mood of the natural cycle and progestin-only contraceptives.

Hormonal fluctuations during the natural cycle, as well as progestins used for hormonal contraception, can exert effects on mood especially in vulnerable women. Negative effects of levonorgestrel-releasing intrauterine contraception on mood are rare.

Immunocytochemical identification and ontogeny of adenohypophyseal cells in a cave fish, Phreatichthys andruzzii (Cypriniformes: Cyprinidae).

The morphogenesis of the pituitary gland and the chronological appearance of adenohypophyseal cells were investigated for the first time in the Somalian cave fish Phreatichthys andruzzii by immunocytochemistry. The adult adenohypophysis contained: a rostral pars distalis, with prolactin (PRL) cells arranged in follicles and adrenocorticotropic (ACTH) cells, a proximal pars distalis with somatotropic (GH), ß-thyrotropic (TSH), ß-gonadotropic type I (FSH) and type II (LH) cells and a pars intermedia with α-somatolactin (SL), α-melanotropic (MSH) and ß-endorphin (END) cells. All regions were deeply penetrated by neurohypophyseal branches. At hatching (24 h post-fertilization) the pituitary was an oval cell mass, close to the ventral margin of diencephalon. The first immunoreactive cells appeared as follows: PRL at 0·5 days after hatching (dah), GH and SL at 1·5 dah, END at 2 dah, TSH, ACTH and MSH at 2·5 dah, FSH at 28 dah and LH at 90 dah. The neurohypophysis appeared at 5 dah and branched extensively inside the adenohypophysis at 130 dah, but there was no boundary between rostral pars distalis and proximal pars distalis at this stage. The potential indices of prolactin and growth hormone production increased until 28 and 60 dah, respectively. The potential index of growth hormone production correlated positively with total length. Activity of PRL and GH cells, measured as ratio of cell area to nucleus area, was significantly higher in juveniles than in larvae.

Dienogest mediates midkine suppression in endometriosis.

STUDY QUESTION: What are the effects of dienogest (DNG) on midkine (MK) production in women with endometriosis? SUMMARY ANSWER: DNG-mediated down-regulation of MK in vivo and in vitro. WHAT IS KNOWN ALREADY: DNG is an oral progestin that alleviates painful symptoms of women with endometriosis with a favourable tolerability and safety profile. Its effects on MK, a growth factor that plays an important role in endometriosis, have not yet been investigated. STUDY DESIGN, SIZE, DURATION: Prospective in vivo study on 283 patients subjected to laparoscopy for benign pathologies in a University hospital and in vitro cultures of primary endometrial stromal cells (ESC) from 6 of these women with histologically confirmed endometriosis. PARTICIPANTS/MATERIALS, SETTING, METHODS: MK concentrations in the peritoneal fluid (PF) of women were measured by ELISA and compared based on endometriosis status and the use of DNG. A subsequent in vitro analysis with ESC was used to confirm the direct influence of DNG and other progestins including, norethisterone acetate (NETA) and medroxyprogesterone acetate (MPA) on MK mRNA production. MAIN RESULTS AND THE ROLE OF CHANCE: The final study population consisted of 253 women. Of these, 165 suffered from endometriosis, with 62 of them taking DNG (DNG group) and 103 taking no hormone treatment (non-DNG group) during at least 3 months before surgery. Another 88 women were endometriosis free (non-endometriosis group). The concentration of MK was highest in the PF of women in the non-DNG group (median 5.26 ng/ml, IQR 2.74-8.46). Significantly lower concentrations were found in the non-endometriosis group (median 3.51 ng/ml, IQR: 1.90-7.53, P = 0.028). The lowest concentrations were found in the DNG group (median 2.44 ng/ml, IQR: 1.12-4.70, P < 0.0001 versus non-DNG group, P = 0.048 versus non-endometriosis group). The treatment of primary cultured ESC with DNG (10(-5) M) suppressed MK mRNA production (P = 0.016), whereas MPA (P = 0.109) and NETA (P = 0.422) at same concentrations did not show a similar effect. LIMITATIONS, REASONS FOR CAUTION: The non-randomized design of the study. WIDER IMPLICATIONS OF THE FINDINGS: These findings could indicate a direct effect of DNG on endometriotic cells that could contribute to its effectiveness in the treatment of this disease. STUDY FUNDING/COMPETING INTERESTS: Funding was received from Swiss National Science Foundation (Grant No. 320030_140774). M.D.M. has received fees for speaking at scientific meetings from Bayer. The other authors have no conflicts of interest to declare.The authors state that the manufacturer of dienogest has in no way influenced the performance or outcomes of this study.

Crystal structures of the components of the Staphylococcus aureus leukotoxin ED.

Staphylococcal leukotoxins are a family of ß-barrel, bicomponent, pore-forming toxins with membrane-damaging functions. These bacterial exotoxins share sequence and structural homology and target several host-cell types. Leukotoxin ED (LukED) is one of these bicomponent pore-forming toxins that Staphylococcus aureus produces in order to suppress the ability of the host to contain the infection. The recent delineation of the important role that LukED plays in S. aureus pathogenesis and the identification of its protein receptors, combined with its presence in S. aureus methicillin-resistant epidemic strains, establish this leukocidin as a possible target for the development of novel therapeutics. Here, the crystal structures of the water-soluble LukE and LukD components of LukED have been determined. The two structures illustrate the tertiary-structural variability with respect to the other leukotoxins while retaining the conservation of the residues involved in the interaction of the protomers in the bipartite leukotoxin in the pore complex.

KDIGO 2012 Clinical Practice Guideline CKD classification rules out creatinine clearance 24 hour urine collection?

OBJECTIVES: The recent guideline for the evaluation and management of Chronic Kidney Disease recommends assessing GFR employing equations based on serum creatinine; despite this, creatinine clearance 24-hour urine collection is used routinely in many settings. In this study we compared the classification assessed from CrCl (creatinine clearance 24h urine collection) and e-GFR calculated with CKD-EPI or MDRD formulas. DESIGN AND METHODS: In this retrospective study we analyze consecutive laboratory data: creatinine clearance 24h urine collection, serum creatinine and demographic data such as sex and age from 15,777 patients >18 years of age collected from 2011 to 2013 in our laboratory at Careggi Hospital. The results were then compared to the estimated GFR calculated with the equations according to the recent treatment guidelines. Consecutive and retrospective laboratory data (creatinine clearance 24h urine collection, serum creatinine and, demographic data such as sex and age) from 15,777 patients >18 years of age seen at Careggi Hospital were collected. RESULTS: Comparison between e-GFR calculated with CKD-EPI or MDRD formulas and GFR according CrCl determinations and bias [95% CI] were 11.34 [-47,4/70.1] and 11.4 [-50.2/73] respectively. The concordance for 18/65 years aged group when compared with e-GFR classification between MDRD vs CKDEPI, MDRD vs CrCl and CKD-EPI vs CrCl were 0.78, 0.34, and 0.41 respectively, while in the 65/110years aged group the concordance Kappas were 0.84, 0.38, and 0.36 respectively. CONCLUSIONS: The use of CrCl provides a different classification than the estimation of GFR using a prediction equation. The CrCl is unreliable when it is necessary to identify CKD subjects with decrease of GFR of 5ml/min/1.73m(2)/year.

Surgeon's experience influences UKA survivorship: a comparative study between all-poly and metal back designs.

PURPOSE: Concerns exist regarding prosthetic positioning and post-operative limb alignment in unicompartmental knee arthroplasty (UKA). In this study, we hypothesized deviations of the post-op anatomical femoro-tibial angle (aFTA) and the tibial component alignment to be factors influencing UKA survivorship. Moreover, by a comparison between all-poly and metal back UKAs, we hypothesized that prosthetic design plays a role in implant survivorship. METHODS: One hundred ninety-five medial UKAs were performed on 176 patients by two experienced surgeons and one low-UKA user. One hundred and forty-seven UKAs were included in the study: 72 all-poly and 75 metal back. Measurements were performed on radiographs: mechanical femoro-tibial angle, Cartier angle, aFTA and tibial posterior slope (PS) on pre-op radiographs; femoral and tibial component varus/valgus, aFTA and tibial component PS on post-op radiographs. RESULTS: At an average follow-up of 61 months (min. 30, max. 107), 147 UKAs were evaluated: The reported survivorship rate was 93.1 %. Eleven implants underwent revision: ten all-poly and one metal back. No differences were reported between the two groups in the radiographic measurements. Significant radiographic differences were reported between revised and not revised UKAs: Revised UKAs were associated with overcorrection of the pre-op Cartier angle and under correction of pre-op aFTA. Most of revised UKAs were performed by the low-volume UKA surgeon. CONCLUSIONS: Surgeon's experience is essential to achieve good results in UKA: Preserving the tibial epiphyseal axis and avoiding excessive or insufficient corrections of the pre-operative limb alignment are predictor of successful replacement, while prosthetic designs, models and fixation geometry do not affect UKA outcome. LEVEL OF EVIDENCE: IV.

Clinical outcome and bone healing of implants placed with high insertion torque: 12-month results from a multicenter controlled cohort study.

This study evaluated the clinical outcome and the crestal bone resorption of implants placed with high insertion torque (up to 80 N cm). 102 patients were treated with 156 tapered implants. 42 implants (control group) presented insertion torque between 30 and 45 N cm (mean=37.4 SD 8.2). 114 implants (experimental group) were placed with insertion torque between 50 and 80 N cm (mean=74.8 SD 7.9). All implants were early loaded after 2 months. Peri-implant marginal bone levels were assessed immediately after surgery, and at 6- and 12-month follow up examinations. At the 12-month follow up all implants were clinically stable. After 12 months, patients in the experimental group lost an average of 0.41 mm (CI 95% 0.522; 0.263) of crestal bone compared with 0.45 mm (CI 95% 0.561; 0.286) for those in the control group. There were no significant differences between the two groups. No direct or inverse relationship was observed between the insertion torque values and crestal bone resorption. The results show that the use of high insertion torque (up to 80 N cm) did not prevent osseointegration and did not increase bone resorption around tapered implants early loaded up to 1 year after implant placement.

Myocardial damage in dogs affected by heartworm disease (Dirofilaria immitis): immunohistochemical study of cardiac myoglobin and troponin I in naturally infected dogs.

It has recently been reported that dogs affected by canine heartworm disease (Dirofilaria immitis) can show an increase in plasma levels of myoglobin and cardiac troponin I, two markers of muscle/myocardial injury. In order to determine if this increase is due to myocardial damage, the right ventricle of 24 naturally infected dogs was examined by routine histology and immunohistochemistry with anti-myoglobin and anti-cardiac troponin I antibodies. Microscopic lesions included necrosis and myocyte vacuolization, and were associated with loss of staining for one or both proteins. Results confirm that increased levels of myoglobin and cardiac troponin I are indicative of myocardial damage in dogs affected by heartworm disease.

Osteochondral impaction of the posterior acetabular surface without cortical fracture of any wall or column: an undescribed pattern of acetabular injury.

Surgical treatment of a unusual acetabular fracture is described. This fracture was characterized by impaction and breaking down of the posterior articular surface and comminution of lamina quadrilatera lower portion, without cortical fracture of both columns. The fracture was treated surgically through the Kocher-Langenbeck approach. A small hole was created in the acetabulum posterior wall, the impacted fragment was reduced, and the bone defect was filled with autologous bone from the greater trochanter. A plate was shaped in order to fix both bone graft and fractured fragment.

Evaluation of lung pathology in Dirofilaria immitis-experimentally infected dogs treated with doxycycline or a combination of doxycycline and ivermectin before administration of melarsomine dihydrochloride.

Adulticide therapy in heartworm (Dirofilaria immitis)-infected dogs can lead to thromboembolism, which can seriously compromise post-treatment health status. Lung pathology following adulticide therapy was evaluated in three groups of experimentally infected dogs. Group 1 was treated with doxycycline at 20 mg/kg per os once daily for 30 days post infection followed by an intramuscular injection of melarsomine dihydrochloride (2.5 mg/kg) at Week 12, followed 1 month later by two injections 24 h apart. Group 2 was treated as described for Group 1, with the addition of ivermectin at 6 mcg/kg given monthly per os for 24 weeks post-infection. Group 3 received melarsomine alone, as described above. All dogs were necropsied at Week 24 and lung pathology was evaluated. Lesion criteria included perivascular inflammation and endothelial proliferation. Lesions were scored by two independent pathologists who were blinded as to treatment. Results indicate that doxycycline treatment alone or combined with ivermectin had lower lesion scores than lungs from dogs who had received melarsomine alone. Dogs that received the combined doxycycline/ivermectin protocol and treated with adulticide showed less severe arterial lesions and the virtual absence of thrombi.

Effects of doxycycline on early infections of Dirofilaria immitis in dogs.

The antifilarial effects of tetracycline drugs were first demonstrated when they were found to be highly effective against L(3) and L(4) of Brugia pahangi and Litomosoides sigmodontis in rodent models. Tetracyclines are also now known to have activity against microfilariae and adult Dirofilaria immitis, but assessment of their activity against larval and juvenile heartworms has not been reported previously. This study assessed the effects of doxycycline administered orally at 10mg/kg twice daily for 30-day periods at selected times during the early part of the life cycle of D. immitis in dogs with dual infections of D. immitis and B. pahangi. Twenty beagles were randomly allocated by weight to four groups of five dogs each. On Day 0, each dog was given 50 D. immitis L(3) and 200 B. pahangi L(3) by SC injection. Dogs received doxycycline on Days 0-29 (Group 1); Days 40-69 (Group 2); or Days 65-94 (Group 3). Group 4 served as untreated controls. Blood samples were collected for microfilariae counting and antigen testing. Necropsy for collection of adult heartworms and selected tissues were performed Days 218-222. Heartworms recovered were examined by immunohistology, conventional microscopy/transmission electron microscopy, and molecular biology techniques. No live heartworms were recovered from dogs in Group 1; dogs in Group 2 had 0 to 2 live worms (98.4% efficacy), and dogs in Group 3 had 0-36 live worms (69.6% efficacy). All control dogs had live adult heartworms (25-41). The live worms recovered from dogs in Groups 2 and 3 were less developed and smaller that worms from control dogs. Microfilariae were not detected in any dogs in Groups 1 and 2; one dog in Group 3 had 1 microfilariae/ml at necropsy. All control dogs had microfilariae at necropsy. One dog in Group 1 was antigen positive at one sampling (Day 166). One dog in Group 2 was antigen positive Days 196 and 218-222 and three dogs in Group 3 were antigen positive at one or more samplings All five control dogs were antigen positive at all three sampling times. These findings suggest that doxycycline at 10mg/kg orally twice daily for 30 days has efficacy against migrating tissue-phase larvae and juvenile worms and will delay or restrict microfilarial production.

Disseminated histoplasmosis in a cat in Europe.

A cat was presented with a history of vomiting, decreased appetite and weight loss. Abnormal findings were poor body condition, pale mucous membranes, dehydration and a palpable abdominal mass. Abdominal ultrasound showed lymph node enlargement, a mass of uncertain origin, thickening of the muscularis layer of the small bowel, focal thickening of the ileum with loss of layering and free peritoneal fluid. Cytology revealed a piogranulomatous infiltrate and numerous macrophages containing oval or round yeast-like cells 2 to 5 microm diameter with a central, spherical, lightly basophilic body surrounded by a clear halo, compatible with Histoplasma capsulatum, within the cytoplasm. Post-mortem examination revealed cavity effusions, granulomatous nodules in lungs, intestine and omentum, thickened intestinal walls and intestinal perforation. Staining with Grocott and immunohistochemistry (IHC) revealed numerous organisms within the granulomatous reaction. H. capsulatum has a worldwide distribution in temperate and subtropical climates. To the author's knowledge, this is the first report of feline histoplasmosis in Europe.

A combination of doxycycline and ivermectin is adulticidal in dogs with naturally acquired heartworm disease (Dirofilaria immitis).

Canine heartworm disease is caused by infection with Dirofilaria immitis, a filarial nematode that resides in the pulmonary arteries and occasionally in the right heart chambers of infected dogs. Here the authors evaluated the effect of a combination of doxycycline (10 mg/kg/sid for 30 days) and ivermectin­pyrantel(6µg/kg [DOSAGE ERROR CORRECTED] of ivermectin+5mg/kg of pyrantel every 15 days for 180 days) on microfilariemia, antigenemia and parasite load at echocardiography in naturally infected dogs from an endemic region of Italy. Dogs were examined monthly for 6 months and followed-up 4 months later. One hundred percent of dogs became negative for circulating microfilariae by day 90, while 8/11 (72.7%) of dogs became antigen-negative by day 300. Of the 7 dogs that were positive for visualization of parasites at echocardiography, 6 (85.7%) became negative by day 300. Treatment was well-tolerated by all dogs. These results suggest that a combination of doxycycline and ivermectin is adulticide in dogs with D. immitis.

Canine bladderworm (Capillaria plica) infection associated with glomerular amyloidosis.

Capillaria plica (Trichuroidea: Capillariidae), commonly known as bladderworm, is a nematode rarely associated with clinical disease that resides in the lower urinary tract of wild and domestic canids. In the present paper a case of canine urinary capillariosis associated with glomerular amyloidosis is described. The dog, an 8-year-old, male, hunting Jagd terrier had a history of weight loss and diarrhoea and was referred to the University of Parma Teaching Veterinary Hospital (UPTVH). Clinical and laboratory tests shown here suggest that C. plica may be a contributing factor to glomerular amyloidosis.

Heartworm and Wolbachia: therapeutic implications.

A safer, more effective adulticidal treatment and a safe method for reducing microfilaremia and breaking transmission of heartworm disease early in the treatment are needed. The present study evaluated efficacy of ivermectin (IVM) and doxycycline (DOXY) alone or together (with or without melarsomine [MEL]) in dogs with induced adult heartworm infection and assessed the ability of microfilariae from DOXY-treated dogs to develop to L3 in Aedes aegypti mosquitoes and subsequently to become reproductive adults in dogs. Thirty beagles were each infected with 16 adult heartworms by intravenous transplantation. Six weeks later, dogs were ranked by microfilarial count and randomly allocated to 6 groups of 5 dogs each. Beginning on Day 0, Group 1 received IVM (6 mcg/kg) weekly for 36 weeks. Group 2 received DOXY (10 mcg/(kgday)) orally Weeks 1-6, 10-11, 16-17, 22-25, and 28-33. Groups 3 and 5 received IVM and DOXY according to doses and schedules used for Groups 1 and 2. At Week 24, Groups 3 and 4 received an intramuscular injection of MEL (2.5 mg/kg), followed 1 month later by two injections 24h apart. Group 6 was not treated. Blood samples were collected for periodic microfilaria counts and antigen (Ag) testing (and later immunologic evaluation and molecular biology procedures). Radiographic and physical examinations, hematology/clinical chemistry testing, and urinalysis were done before infection, before Day 0, and periodically during the treatment period. At 36 weeks, the dogs were euthanized and necropsied for worm recovery, collection of lung, liver, kidney, and spleen samples for examination by immunohistochemistry and conventional histological methods. All dogs treated with IVM + DOXY (with or without MEL) were amicrofilaremic after Week 9. Microfilarial counts gradually decreased in dogs treated with IVM or DOXY, but most had a few microfilariae at necropsy. Microfilarial counts for dogs treated only with MEL were similar to those for controls. Antigen test scores gradually decreased with IVM + DOXY (with or without MEL) and after MEL. Antigen scores for IVM or DOXY alone were similar to controls throughout the study. Reduction of adult worms was 20.3% for IVM, 8.7% for DOXY, 92.8% for IVM + DOXY + MEL, 100% for MEL, and 78.3% for IVM + DOXY. Mosquitoes that fed on blood from DOXY-treated dogs had L3 normal in appearance but were not infective for dogs. Preliminary observations suggest that administration of DOXY+IVM for several months prior to (or without) MEL will eliminate adult HW with less potential for severe thromboembolism than MEL alone.

Wolbachia and its influence on the pathology and immunology of Dirofilaria immitis infection.

Since the definitive identification in 1995 of the bacterial endosymbiont Wolbachia that resides in different tissues of the filarial worm Dirofilaria immitis, there has been increasing interest to understand whether and what role it plays in the pathogenesis of and immune response to heartworm infection. The present study evaluated the effects of treatments on lung pathology in 20 beagle dogs experimentally infected with D. immitis. Dogs in Group 1 were treated with doxycycline (10 mg/kg/day) orally from weeks 0-6, 10-12, 16-18, 22-26, and 28-34. Dogs in Group 2 served as infected, non-treated controls. Dogs in Group 3 were given doxycycline as described for Group 1 combined with weekly oral doses of ivermectin (6 mcg/kg) for 34 weeks and intramuscular (IM) melarsomine (2.5 mg/kg) at week 24, followed by two additional melarsomine injections 24h apart 1 month later. Group 4 received only melarsomine as described for Group 3. Lung lesion criteria, scored by two independent blinded pathologists, included perivascular inflammation and endothelial proliferation. Doxycycline treatment alone had no effect on lesion scores, whereas the combination of doxycycline and ivermectin resulted in less severe perivascular inflammation. All lungs were evaluated for positive immunostaining for the Wolbachia surface protein (WSP). Control dogs showed numerous thrombi, intense perivascular and interstitial inflammation and, occasionally, positive staining for WSP. Interestingly, dogs receiving doxycycline/ivermectin/melarsomine showed significantly less severe arterial lesions and the virtual absence of thrombi.