The moon cycle influences reproductive and productive traits in guinea pigs (Cavia porcellus) from a tropical Andean area.

There is currently innumerable evidence showing that the lunar cycle affects various reproductive aspects in farm animals. However, there is very little information on the effect of the lunar cycle on productive traits in these species. A retrospective study was conducted (2015-2018) to evaluate the influence of the lunar cycle on some reproductive and productive traits in a guinea pig (Cavia porcellus) production system in the southern Andean region of Ecuador. A total of 7352 productive and reproductive records of guinea pig females housed in 3 m2 cages with a breeding male were analyzed. The following variables were considered: offspring sex ratio, litter size per cage, number of weaned guinea pigs, mortality, individual and litter weaning weight of guinea pigs, and calving frequency. The lunar cycle was split into eight periods of ~3.7-d length each. Data were analyzed by logistic regression and general linear model, and means were compared by the least mean squares method of the SAS. The offspring sex ratio was not correlated to the lunar cycle. The lunar cycle at mating and calving influenced the litter size per cage, number of weaned, and mortality of guinea pigs. The individual and litter-weaning weights were influenced by the lunar cycle at calving. The frequency of calving was greater around the new and full moon than in the remaining periods of the lunar cycle. In conclusion, the lunar cycle influenced several productive and reproductive traits in guinea pigs, such as litter size, mortality, number of pups weaned, and individual and litter weaning weights. This valuable information may have practical applications in management of guinea pig production systems.

Lunar Cycle Influences Production of Tilapia (Oreochromis spp) Eggs in an Intensive Outdoor Production System in the Tropics.

A robust body of evidence has demonstrated that the lunar cycle plays an important role in the reproduction of fish living in natural environments. However, little is known about the influence of the moon on tilapia reproductive activity in intensive fish farming systems. This study aims to evaluate the influence of the lunar cycle on the reproductive performance of tilapias in an intensive outdoor tropical production system in Latin America. Records of two tilapia strains (Nile tilapia [Oreochromis niloticus; n = 75] and Red tilapia [Oreochromis spp.; n = 1335]) reared in concrete tanks in a commercial fish farm were analyzed. Over a 3-year period, 60,136 captures were made in intervals of 12 to 14 days and 6,600 females were manually spawned. The number of females spawned and the volume of eggs collected from each tank (n = 9) were recorded. Data was analyzed by the general linear model and means were compared by least squares means method. A very slight or no variation was observed when the lunar cycle was split into two halves (crescent and waning). The proportions of females spawned and the volume of eggs per spawned female and per female in the tank varied considerably across the eight periods of the lunar cycle, with greater values in the waning than in the crescent phase. A significantly greater proportion of tilapia spawned and yielded more eggs around the full moon than around the new moon and remaining days of the lunar cycle. The moon cycle affected the reproductive activity of tilapia, which were more reproductively active around the full moon and most of the waning phase.

Treating epiphora in adults with the Wilhelm plastic nasolacrimal stent: mid-term results of a prospective study.

The objective of the present study was to evaluate, in a prospective, single-center study, the effectiveness of the Wilhelm-type stent used in interventional radiology for the management of epiphora. Patients (n = 104; mean age 64 [range 25­88]; 33 male and 71 female) with severe epiphora had the stents inserted (135 stents in 115 eyes) to treat obstruction of the nasolacrimal system. The etiology of the obstruction was idiopathic in 83 cases, chronic dacryocystitis in 31, cases and postsurgical status in 1 case. The overall technical success rate of stent placement was near 94%. Resolution of epiphora was complete in 105 cases and partial in 3 cases. During a mean 13-month follow-up (range 1 week to 28 months), the median duration of primary patency was 11 months, and the percentage of patency at 6 months was 60.8%, at 1 year was 39.6%, and at 2 years was 25%. Stents malfunctioned in 54 cases, and all were easily withdrawn except in 1 case. Of these 27 cases, patency recovered spontaneously in 9 and by way of a second stent in 18. Secondary patency was 50%. Factors presdisposing to lower primary patency are inflammatory etiology and location of the obstruction. The benefit of stent deployment is clear with respect to the resolution of epiphora in candidate patients for percutaneous treatment. Technical and/or design improvements would be welcomed.

Randomized comparison of nasolacrimal cryoplasty versus plastic lacrimal stenting in the management of epiphora in adults.

PURPOSE: To evaluate the efficacy of plastic polyurethane stents compared with nasolacrimal cryoplasty in the management of epiphora in adults. MATERIALS AND METHODS: Patients (N = 37; mean age, 64 years; range, 34-86 y; six men, 31 women) with severe epiphora with partial/complete obstruction of the nasolacrimal system were randomized to have a plastic stent inserted (n = 19) or to undergo balloon dilation cryoplasty (n = 18). Both procedures were conducted on an outpatient basis. Patency was assessed with Kaplan-Meier curves. RESULTS: Initial technical success rate and immediate resolution of epiphora was complete in all cases. At 6 months of follow-up, outcomes were already significantly different between the treatment groups and hence the study was discontinued. Plastic stent placement achieved a primary patency rate of 59.6% at 6 months, compared with 12.4% in the cryoplasty group (P < .0004). Multivariate analysis indicated that other measured variables (sex, age, etiology, previous treatment, and the interventional radiologist's expertise) had no significant effect on the outcomes (P > .05). CONCLUSIONS: Initial success was good in both treatment groups, with nasolacrimal plastic stent placement achieving a level of primary patency superior to the cryoplasty procedure for the relief of epiphora on short-term follow-up. However, long-term outcome evaluation is needed before stent placement can be recommended as an alternative to more established surgical procedures.

Nasolacrimal stenting: toward improving outcomes with a simple modification of the song stent.

The purpose of this study was to evaluate, in a prospective, single-center study, the effectiveness of Song's polyurethane stents, modified "in-house," in the percutaneous management of epiphora. Patients (n = 170; age range 18-83, mean = 64; 50 male, 120 female) with severe epiphora had the modified stents inserted (183 eyes/195 stents) to treat unilateral/bilateral and complete/partial obstruction of the nasolacrimal system. The etiology of the obstruction was idiopathic in 119 cases (61%) and chronic dacryocystitis in 76 (39%). The set designed by Song was used in all patients but modified by us such that the extreme end is cone-shaped. The original technique was slightly modified by us and the procedure was conducted on an outpatient basis. The initial technical success rate of stent placement was 97%. Resolution of epiphora was complete in 180 eyes and partial in 3. On follow-up (mean = 18 months; range: 2 days to 24 months), 165 of 195 stents (85%) remained patent. Primary patency rates at follow-up were 86%, 84%, 84%, and 79% in the first 6 months, second and third 6 months, and the present (24 months), respectively. Stents became obstructed in 30 patients, but all but 2 were easily withdrawn and 20 of these patients remained asymptomatic for a mean of 14 months (secondary patency of 67%). Following stent removal, the withdrawn stent was replaced with a new stent in the same intervention on 14 occasions. In another six cases, patency was re-established without the need of a second stent. The procedure is simple and safe, both in stent insertion as well as in mechanical de-blocking and withdrawal when occluded. Success was >80 % in the short term (1-year follow-up). Stenting failure does not preclude other treatment because with the modification that we had introduced, the extreme end of the stent becomes more accessible to mechanical de-blocking, withdrawal, and relocation. The levels of primary and secondary patencies are promising and warrant more extensive investigation.

Resolution of epiphora with nasolacrimal stents: results of long-term follow-up in a multicenter prospective study.

PURPOSE: To evaluate in a prospective, multicenter setting the long-term effectiveness of polyurethane stents in the percutaneous management of epiphora. MATERIALS AND METHODS: Patients (n = 426; age range, 19-88 years, mean, 48; 91 men, 335 women) with severe epiphora had stents (470 eyes/496 stents) inserted to treat unilateral or bilateral and complete or partial obstruction of the nasolacrimal system. The etiology of the obstruction was idiopathic in 280 cases (59.5%) and chronic dacryocystitis in 190 (40.4%). The stent set designed by Song was used in all patients, and the original technique was slightly modified by us and conducted on an outpatient basis. RESULTS: The initial technical success rate of stent placement was 95%. The average time of the procedure was 6 minutes (range, 3-70). Resolution of epiphora was complete in 452 eyes and partial in 18. On follow-up (mean, 24 months; range, 1 week to 67 months), 340 of 496 stents remained patent (68.5%). Segregating primary patency by year of follow-up, the rates were 75.6%, 68.4%, 64.8%, 60.1%, and 59.2% in the first, second, third, fourth, and the current (67 months) years, respectively. Minor complications such as moderate pain (21 cases), epistaxis (75 cases), palpebral edema and hematoma (31 cases), and headache (four cases) and two acute dacryocystitis events were recorded. Of the 156 obstructed stents, 114 were withdrawn, and 49 of these patients remained asymptomatic for a mean of 27 months (secondary patency, 31.4%). After stent removal, the sac configuration was unchanged in 93 (81.5%), contracted in 11 (9.6%), and widened in 10 (8.8%) cases. CONCLUSIONS: The procedure is simple and safe, both in stent insertion and in withdrawal when occluded. The success rate was >75% in the short term and >55% in the long term. Although not totally without concerns, the technique is attractive for most patients who prefer not to undergo surgery or are unsuitable surgical candidates. Stent failure does not preclude subsequent treatment options and is an excellent first-line treatment of epiphora.