[Efficacy of 0.05% cyclosporine A combined with vitamin A palmitate in the treatment of meibomian gland dysfunction-related dry eye].

Objective: To evaluate the efficacy of 0.05% cyclosporine A eye drops combined with vitamin A palmitate eye gel in the treatment of dry eye associated with meibomian gland dysfunction (MGD). Methods: A single-center, prospective, randomized, parallel controlled trial design was used to include patients diagnosed with MGD-associated dry eye. The patients were randomly divided into three groups and administered with medications binocularly for 12 weeks. The CsA+VA group was given 0.05% cyclosporine A eye drops twice a day and vitamin A palmitate eye gel three times a day. The CsA+HA group was given 0.05% cyclosporine A eye drops twice a day and 0.1% sodium hyaluronate eye drops three times a day. The HA group was given 0.1% sodium hyaluronate eye drops 3 times a day. The OSDI score, tear meniscus height, fluorescein tear break-up time, Schirmer Ⅰ test (without anesthesia), tear film lipid layer thickness, meibomian gland morphology and function examination, and corneal fluorescein sodium staining score were evaluated at baseline, 4, 8, and 12 weeks after the initiation of the treatment, respectively. Results: A total of 120 patients with MGD-related dry eye met the enrollment criteria, but 10 patients were lost to follow-up; 110 patients were finally included for observation, including 36 patients in the CsA+VA group, 38 in the CsA+HA group and 36 in the HA group. The OSDI score, tear meniscus height, fluorescein tear break-up time and meibomian gland secretion of the 3 groups were significantly improved. At the 12th week of the treatment, the differences of the CsA+VA group [25.45±15.11, (0.30±0.13) mm, (3.72±1.40) s, (5.03±2.52) points] and the CsA+HA group [26.98±16.89, (0.27±0.10) mm, (4.34±1.76) s, (5.11±2.39) points] from the HA group [24.57±11.26, (0.24±0.06) mm, (3.18±1.11) s, (9.11±3.34) points] were statistically significant (P<0.05). Compared with the CsA+HA group [(68.39±26.66) nm], the tear film lipid layer thickness in the CsA+VA group [(72.61±23.65) nm] was significantly increased (P<0.05). In the CsA+VA group, the meibomian gland secretion characters and discharge capacity among patients with severe abnormalities [(6.28±2.59) and (5.89±2.77) points at the 12th week of treatment], moderate abnormalities [(4.27±2.02) and (4.64±2.02) points at the 12th week of treatment] and mild abnormalities [(2.80±0.84) and (2.60±0.55) points at the 12th week of treatment] were significantly different (P<0.05). Conclusion: 0.05% cyclosporine A combined with vitamin A palmitate can significantly improve the symptoms and signs of patients with MGD-related dry eye, especially the tear film lipid layer thickness and the meibomian gland secretion characters and discharge capacity in severe cases.

[Clinical features and predictors of early neurological deterioration in acute isolated pontine infarction].

Objective: To investigate the clinical and imaging characteristics of early neurological deterioration (END) in acute isolated pontine infarction (AIPI) and analyze the predictive factors of END. Methods: Patients with AIPI who were confirmed by magnetic resonance imaging (MRI) in Zhengzhou University People's Hospital from January 2020 to December 2021were collected and divided into END group and non-END group (NEND group). General data and imaging characteristics of the patients were compared between the two groups, the neurological function of patients was evaluated by using the modified Rankin scale (mRS) at 1 and 3 months after stroke. Multivariate binary logistic regression model was used to analyze the risk factors of END after isolated pontine infarction, and the receiver operating characteristic curve(ROC) curve was drawn. Z-test was used to compare the area under the curve to determine the best predictor of END. Results: A total of 113 patients with AIPI were enrolled, including 72 males and 41 females, aged (62±11) years, with 40 cases in the END group and 73 cases in the NEND group. The incidence of END in AIPI was 35.4% (40/113). The National Institutes of Health Stroke Scale (NIHSS) score in the END group (5.15±1.88) was higher than that in the NEND group (4.10±1.63), and the infarcts size in the END group [(2.15±0.39) mm2] was larger than that in the NEND group [(1.61±0.46) mm2] (P=0.002 and P<0.001, respectively). Multivariate binary logistic regression analysis showed that NIHSS score on admission (OR=1.393, 95%CI: 1.017-1.909, P=0.039), infarct size (OR=11.539, 95%CI: 3.574-37.255, P<0.001) were associated with END. Comparing the area of ROC curve, infarct size [area under curve (AUC)=0.787, with a sensitivity of 0.750 and specificity of 0.545] and NIHSS score on admission (AUC=0.688, with a sensitivity of 0.700 and specificity of 0.589) showed no significant difference in the value of predicting END (P=0.056). Conclusion: Patients with AIPI had higher NIHSS score and larger infarct size on admission, and both of them exhibit good predictive performance for END.

[The prevalence of allergic conjunctivitis based on outpatients in Baotou area].

Objective: To explore the prevalence and influencing factors of allergic conjunctivitis in Baotou area at different times. Methods: A cross-sectional study was conducted in January 2021, 111 patients with allergic conjunctivitis who were admitted to the Department of Ophthalmology, the Second Affiliated Hospital of Baotou Medical College, Inner Mongolia University of Science and Technology in 2020 were selected as the research subjects. The basic information, allergic conditions, living habits and other information of the patients were obtained by self-made questionnaire. The pollen concentration and allergy related indicators(allergic duration and frequency, eye itching score, eye burn score, eye foreign body sensation score, tears score and the total scores) of 2019 and 2020 were analyzed by paired sample t-test. The pollen concentration of 2019 and 2020 were analyzed by Wilcoxon signed rank test. The allergy related indicators of different genders were analyzed by independent sample t-test. The allergy related indicators of different ages were analyzed by one-way analysis of variance. The relationship between the length of wearing masks and the allergy related indicators were analyzed by Spearman correlation analysis. Results: Among the 111 patients with allergic conjunctivitis, 54 were males and 57 were females, ranging in age from 8 to 69 years old, with a median age of 35 years old and an average age of (36.77±13.18) years old. The average pollen concentration in Baotou in 2019 was (125.35±222.64) grains/1 000 square millimeter, and the average pollen concentration in Baotou in 2020 was (107.38±137.29) grains/1 000 square millimeter. There was no significant difference in pollen concentration between the two years(Z=-0.178, P=0.859). The severity of allergic indicators in all patients in 2020 is significantly lower than in 2019(t values were 4.701,3.587,2.582,3.661,4.444,2.784,2.555,3.886,respectively, with P<0.05). The severity of allergic indicators in male patients is lower than that of female patients (t values were -1.558, -1.257, -3.41, -3.085, -2.335, -2.897, -2.652, -4.124, respectively). The prevalence of allergic conjunctivitis dose not vary significant with age (P values were 0.504, 0.095, 0.499, 0.265, 0.284, 0.655, 0.421, 0.976, respectively). In 2020, the average time that patients wear masks is (6.55±3.28) h/d, and there is a correlation with the difference in allergy duration (r=0.191, P=0.045). Conclusion: The severity of allergic conjunctivitis in Baotou in 2020 was significantly improved compared with that in 2019, which may be related to masks wearing.

[Preliminary efficacy of penetrating canaloplasty in primary angle-closure glaucoma].

Objective: To evaluate the preliminary efficacy and safety of penetrating canaloplasty for treating primary angle-closure glaucoma (PACG). Methods: It is a prospective interventional case series study. Twenty-two patients (24 eyes) with PACG were treated with penetrating canaloplasty (video attached) at the Eye Hospital of Wenzhou Medical University from June 2015 to August 2018. This modified canaloplasty was performed by making a window at the corneal-scleral bed. Aqueous was redirected to the opening of Schlemm's canal after the canaloplasty with intension sutures. Postoperative follow-up was made at 1 day, 7 days, 1 month, 3 months, and 6 months. Surgical success was defined as intraocular pressure (IOP) ≤ 21 mmHg (1 mmHg=0.133 kPa) with glaucoma medication (quantified success) and without any glaucoma medication (complete success). Main outcome measures included IOP, number of medication, surgical success rate, complications, and filtering bleb status. One-way repeated measure ANOVA and rank sum test were used in statistical analysis. Results: Due to the failure of circumferential catheterization of the canal, 4 eyes converted to trabeculectomy. A total of 19 PACG patients (20 eyes) achieved the successful 360-degree catheterization of the canal, including 11 males and 8 females. The mean age was (54±7) years old (range: 41-65 years old), and the mean angle-closure range was (326.3±46.6) degrees. The mean preoperative IOP was (38.0±11.9) mmHg with the median medication number of 3 (range: 2-5). The mean postoperative IOP was (14.5±11.1), (16.1±6.0), (17.7±5.5), (15.7±5.0), and (15.4±3.7) mmHg at 1 day, 7 days, 1 month, 3 months, and 6 months, respectively. There was significant difference in IOP between postoperative and preoperative (all P<0.01). The median medication number (range) was 0 (0-3), 0 (0-2), 0(0-3), 0(0-2), and 0 (0-2) at the 5 time points, respectively. There was significant difference in medication number between postoperative and preoperative (all P<0.01). The quantified success rate was 95%(19/20), and the complete success rate was 90%(18/20) at 6 months. Postoperative complications were observed in 7 eyes (35%) of 20 PACG eyes, including 3 eyes (15%) with hyphema, 2 eyes (10%) with shallow anterior chamber, 1 eye (5%) with Descemet membrane detachment, and 1 eye (5%) with filtration obstruction at the trabeculum ostium. According to the results of slit lamp and ultrasound biomicroscopy examinations, 70% of the eyes (14/20) had no filtering bleb. Eight eyes (40%) with IOP spike were observed. Conclusion: Preliminary study shows penetrating canaloplasty is safe and effective in the treatment of PACG, but needs a longer follow-up. (Chin J Ophthalmol, 2019, 55: 448-453).

Peste des Petits Ruminants Viruses Re-emerging in China, 2013-2014.

Re-emergence of peste des petits ruminants (PPR) was officially reported in Xinjiang Uygur Autonomous Region in north-western China in November 2013, and then along with the movements of goats and sheep, this disease rapidly spread to other provinces, autonomous regions and municipalities (P/A/M) of China. A total of 256 PPR-affected counties in 22 P/A/M were identified up to September 2014. Phylogenetic analysis revealed that the current circulating strains and Tibet strains isolated previously in 2007, both belonged to lineage IV but in different sub-branches. Nevertheless, compared with the Tibet strains, the current circulating strains shared high degree of genetic homology with those from Pakistan and Tajikistan.

[Correlation between RNA Expression Level and Early PMI in Human Brain Tissue].

OBJECTIVES: To explore the correlation between the expression levels of several RNA markers in human brain tissue and early postmortem interval （PMI）. METHODS: Twelve individuals with known PMI （range from 4.3 to 22.5 h） were selected and total RNA was extracted from brain tissue. Eight commonly used RNA markers were chosen including ß-actin, GAPDH, RPS29, 18S rRNA, 5S rRNA, U6 snRNA, miRNA-9 and miRNA-125b, and the expression levels were detected in brain tissue by real-time fluorescent quantitative PCR. The internal reference markers with stable expression in early PMI were screened using geNorm software and the relationship between its expression level and some relevant factors such as age, gender and cause of death were analyzed. RNA markers normalized by internal reference were inserted into the mathematic model established by previous research for PMI estimation using R software. Model quality was judged by the error rate calculated with estimated PMI. RESULTS: 5S rRNA, miRNA-9 and miRNA-125b showed quite stable expression and their expression levels had no relation with age, gender and cause of death. The error rate of estimated PMI using ß-actin was 24.6%, while GAPDH was 41.0%. CONCLUSIONS: 5S rRNA, miRNA-9 and miRNA-125b are suitable as internal reference markers of human brain tissue owing to their stable expression in early PMI. The expression level of ß-actin correlates well with PMI, which can be used as an additional index for early PMI estimation.

Ingrowth of bone into absorbable bone cement: an in vivo microscopic evaluation.

The purpose of the study reported here was to use an in vivo rabbit model to evaluate the rate of bone ingrowth into remodelable calcium phosphate bone cement. We evaluated an in vivo bone chamber placed in a rabbit tibia with its ingrowth compartment filled with absorbable calcium phosphate bone cement (Norian Skeletal Repair System; Norian Corp, Cupertino, Calif). Five New England white rabbits had a single bone chamber implanted into the proximal right tibia. Observations were made and photomicrographs taken on a weekly basis. Results of morphological analysis showed sequential loss of cement and subsequent bone ingrowth over a testing period of up to 30 weeks. Resorption of bone cement was complete in 1 rabbit. The other rabbits had significant bone ingrowth, which reaffirms the biocompatibility of this material. Results of this study showed that using in vivo microscopy with the rabbit bone chamber model was useful in evaluating bone ingrowth and replacement of absorbable bone cement. This model may make it possible to evaluate various combinations of bone cement and bone growth factors, which could serve as an alternative to autogenous bone grafting.

Effect of polymethylmethacrylate particles on mature bone in the optical bone chamber.

Reaction of mature bone and its vasculature to 3.33 +/- 0.19 microm polymethylmethacrylate (PMMA) particles at a concentration of 2.5 x 10(8)/cc was measured using optical bone chamber implant intravital microscopy. Twelve adult female New Zealand White rabbits were divided into six receiving Healon alone (controls) and six receiving Healon plus PMMA. The particles were introduced to the bone chamber compartment after removing its overlying optical element, which was immediately reinstalled. Reaction was monitored weekly over a 6-week period using video and photographic imaging. Bone was labeled before treatment with oxytetracycline and after treatment with alizarin complexone. Perfusing blood was labeled with fluorescein isothiocyanate dextran-70 kDa (FITC-D70). Parameters measured were net bone resorption, from black and white images, bone turnover, from color images, vascularity, and average vessel caliber. Neither bone turnover nor vessel caliber were significantly affected at the p < or = 0.050 level over time. In contrast, bone resorption was significantly greater and vascularity significantly less in the presence of PMMA. It was inferred that any differences in bone turnover were masked by resorption of new bone. It was concluded that the lack of a PMMA effect on average vessel caliber meant that the vascularity effects were not due to angiogenesis, but to vessel recruitment (or its opposite), an effect more consistent with inflammation than repair. The lack of vascularity increase in PMMA-treated compartments also suggested that increased resorption was a local phenomenon, because blood supply had not increased to provide the extra osteoclasts required for observed net bone loss.

Evidence for reperfusion injury in cortical bone as a function of crush injury ischemia duration: a rabbit bone chamber study.

A model for critical limb ischemia was produced by occluding femoral vessels in 24 rabbits with a pneumatic cuff for 0, 2, 4, or 6 hours. Immediate sequelae and subsequent creeping substitution of cortical bone were observed in vivo using an implanted tibial window, the optical bone chamber implant (with intravital microscopy), and then by light and fluorescence microscopy of fluorochrome-labeled and surface-stained ground sections of retrieved implants. Six rabbits were used as controls (0 h) for each ischemia treatment, and the animals were monitored for 5 weeks postocclusion. A subpopulation of 13 implants was retrieved after euthanization and then histologically assessed for bone necrosis and remodeling. The hypothesis tested was that reperfusion injury during the 24 h after occluder release (reperfusion phase), and vessel perfusion/caliber, angiogenesis, and net bone resorption during the 5 subsequent weeks (creeping substitution phase), would exhibit ischemia duration-dependent effects. All animals could bear weight on the affected limb to ambulate by 1 week posttreatment. Two-way analysis of variance (ANOVA) comparison of the resulting data confirmed a significant difference between control and ischemia-treated rabbits for: (1) vessel perfusion/reperfusion; (2) vessel caliber; and (3) net bone resorption. Vascular responses to 4 vs. 6 h of ischemia were not significantly different, but net bone resorption was strictly ischemia duration-dependent. The conclusion that reperfusion injury was the mechanism spreading ischemia to more vessels was supported by a decrease in reperfusion and caliber of vessels, and an increase in vascular permeability and leukocyte adherence during the reperfusion phase. It is postulated that reperfusion injury produces a secondary ischemia that amplifies the occlusion-created primary ischemia and, in the present work, may have been succeeded by progressive episodes of ischemia, similar to the infarction pattern of ischemic hearts.

Model for intravital microscopic evaluation of the effects of arterial occlusion-caused ischemia in bone.

An in vivo model has been developed for chronic observation of the effects of ischemia on cortical bone remodeling and perfused vascularity. Diaphragm occluders were implanted around the right common iliac artery of four rabbits and inflated to produce 10 h of ischemia to the limb. Microcirculation was monitored with intravital microscopy of injected fluorescent microspheres and FITC-Dextran 70 through a bone window, the tibial bone chamber implant (BCI). Bone resorption and apposition in the BCI were indicated with mineralization dyes. Between 2 and 12 h following release of the occluder, secondary ischemia/no-reflow and other evidence of reperfusion injury were observed. Vessel damage was suggested by abnormally high leakage of FITC-D70 from the few vessels perfused during secondary ischemia. In the weeks following occluder release perfused vasculature increased beyond pre-occlusion levels. Net bone resorption reached a maximum when vascularity passed normal levels. In order to further validate the arterial occlusion model for osteonecrosis, techniques for (1) confirming bone death and (2) detecting increased leukocyte adherence to endothelial cells were added. The dead cell stain Ethidium homodimer-1 was used to tag dead osteocytes immediately after occlusion and produced a measure designated "osteonecrosis index." To detect leukocytes adhering to vessel walls, carboxyfluorescein diacetate, succinimidyl ester was injected at occluder release. An increase in the number of adherent leukocytes was detected.

Approaches to study of ischemia in bone.

Ischemic osteonecrosis is a complication of certain traumatic and a number of idiopathic conditions. The course of the disease may result in collapse of the convex member of a joint and osteoarthritis, often requiring arthroplasty. Increasing incidence in young adults poses a challenge for development of long-term joint prostheses. Current status of research into the disease is discussed and three new models using intravital microscopy described. The first, an arterial occlusion (AO) model, creates ischemia by occluding the common iliac artery exclusively, avoiding direct trauma on other tissues in the limb. The second, a total occlusion (TO) model utilizes classical tourniquet occlusion of the thigh vessels. The third, a venous occlusion (VO) model, is also a tourniquet procedure but it blocks occlusion of the femoral artery with a protective sheath. Preliminary results from AO and TO studies are reported which show that reperfusion injury is detectible after ischemia doses as short as 4 h. This complication was confirmed by observation of leukocyte adherence, secondary ischemia, and abnormal vessel leakage. Also, a new quantitation of osteonecrosis is introduced whereby fluorescently-tagged dead osteocytes and computer-based image processing provide values for an "osteonecrosis index." Viewing of all vascular events is made possible by intravital microscopy through a bone chamber window implanted in rabbit tibias. It is proposed that such chronic visual techniques allow quantitation of events leading to osteonecrosis as well as the revascularization, resorption and bone apposition of creeping substitution which characterizes postischemia recovery.

Milking dilatation: a pilot study.

Under certain circumstances during microsurgical anastomosis, vasospasm may persist, despite the use of multiple topical vasodilators. Mechanical dilatation may be needed but is difficult to perform in vessels smaller than 1 mm in diameter. Milking dilatation, a simple maneuver similar to a milking patency test, is introduced and tested for vessels of such a size. The femoral arteries of 10 Sprague-Dawley rats were used. Milking dilation was performed on both sides, and a forceful milking dilation method was also used 10 times on one side subsequently. The dilated segments demonstrated a 67.3 percent (29 to 100 percent) increase in their original sizes. The vessels were all patent, with no gross signs of thrombosis or aneurysm formation, when exposed immediately, 1 week, and 4 weeks post procedure. Half of the dilated segments, even those forcefully dilated, returned to their normal size at 4 weeks; the remainder were still dilated. The results of this study demonstrated that milking dilatation is effective and safe for dilating arteries about I mm in diameter or less. However, further study is required before any long-term conclusions can be drawn.

Fibroblast growth factor-2 alters the effect of eroding polylactide-polyglycolide on osteogenesis in the bone chamber.

The effects of recombinant human fibroblast growth factor-2 (rhFGF-2) in the presence of eroding 50:50 poly(DL-lactide-co-glycolide) (PDLLG) on acute bone healing were studied in the optical bone chamber (BCI). BCIs were loaded with disks of PDLLG surrounded by one of four rhFGF-2 doses. Fifty-two female rabbit right tibias were implanted. Commencing the third week post implantation (W3) healing in the BCI compartment was observed weekly, using intravital microscopy, until W8. The doses were: unloaded, loaded with polymer only, and polymer plus 0.5, 1.0, and 10 microg rhFGF-2. Videotaped and photographed bone images were measured and analyzed using a frame-grabber digitizing system. Comparison with controls revealed that ossification rates were significantly above normal in rabbits loaded with polymer plus any of the rhFGF-2 doses. Comparison with polymer-only BCIs showed that PDLLG plus any of the three rhFGF-2 doses was linked with ossification rates significantly higher than baseline. The results indicated that FGF-2 in the dose range studied effectively can overcome the retarding effects of eroding polymer on ossification that has been reported by this laboratory. Interpretation of the retarding effects of the polymer disks, although consistent with previously studied washer-shaped devices of the same material, was complicated by a difference in erosion rate. This result supports the notion that erodible device geometry is a major factor in determining biocompatibility and must be considered in the design of carriers. Accordingly, programming of dose specificity for delivering a given polypeptide cytokine to a given host site must allow for the inhibitory effects of an eroding carrier and the influence of device geometry on these effects and erosion.

Comparative bone healing near eroding polylactide-polyglycolide implants of differing crystallinity in rabbit tibial bone chambers.

Eroding poly(DL-lactide-co-glycolide) (PDLLG) washers and poly(L-lactide-co-glycolide) (PLLG) threads were observed chronically in vivo following loading in a bone chamber tibial implant (BCI). Images were recorded using intravital microscopy of the implanted rabbit. Erosion and bone healing, as represented by angiogenesis and osteogenesis, was determined from changes in projected area of observed polymer, vessels and bone, respectively. Erosion rates of the two polymers were significantly different. Healing adjacent to both polymers differed significantly from controls. Healing response to each polymer was also different, with the faster eroding PDLLG causing more deviation from normal osteogenesis and angiogenesis than did PLLG. It was speculated that the faster eroding polymer released macrophage-stimulating fragments earlier in the healing process, thus altering the normal macrophage-endothelial cell interaction which in turn affected angiogenesis-linked components of osteogenesis.

Fibroblast growth factor-2 alters the effect of eroding polylactide-polyglycolide on angiogenesis in the bone chamber.

The effects of recombinant human fibroblast growth factor-2 in the presence of eroding 50:50 poly(DL-lactide-co-glycolide) on angiogenesis during acute bone defect healing were studied in the optical bone chamber. Bone chambers were loaded with disks of poly(DL-lactide-co-glycolide) surrounded by one of four doses of recombinant human fibroblast growth factor-2. Fifty-two female rabbit right tibias were implanted. Commencing with the third postimplantation week, healing into the bone chamber compartment was observed weekly, with use of intravital microscopy, until week 8. The treatment groups were as follows: unloaded, loaded with polymer only, and loaded with polymer plus-0.5, -1.0, and -10 microg recombinant human fibroblast growth factor-2. Videotaped and photographed bone images were measured and analyzed with a frame-grabber digitizing system. Comparison with controls or polymer alone revealed that angiogenesis rates were significantly above normal in rabbits loaded with polymer plus either of the two highest recombinant human fibroblast growth factor-2 doses. The effects of these doses were not, however, significantly different from each other, indicating a plateauing rather than monotonically increasing response. It was concluded that recombinant human fibroblast growth factor-2 in the dose- range studied can effectively overcome the retarding effects of eroding polymer on angiogenesis in bone, which has been reported previously by this laboratory. In contrast to these results, no statistically significant differences in angiogenesis rate as a function of time could be detected. It is suggested that this apparent lack of variation is linked to observed alterations in vessel patterns from week-to-week. The clinical relevance of these results is that inhibitory carrier effects can be compensated for by increasing the dose of loaded agent where the effect being inhibited is the one being treated, or by adding an agent specific for the inhibited effect. In either case, geometry of the carrier must be considered when programming for delivery rate.

Acidity near eroding polylactide-polyglycolide in vitro and in vivo in rabbit tibial bone chambers.

Eroding poly(DL-lactide-co-glycolide)(PDLLG) washers were observed chronically in vitro and in vivo following loading in a bone chamber tibial implant (BCI). Images were recorded using intravital microscopy of the implanted rabbit and direct pH measurements were obtained of the tissue in the bone chamber using a combination probe-reference microelectrode. While statistically significant pH differences were found between the control (unloaded) and experimental (PDLLG-bearing) BCIs, they were only of the order of 0.2 pH units. This value proved to be physiologically insignificant as no statistically significant difference in bone defect healing, as indicated by angiogenesis, was detected. It was shown that the measured small pH changes during PDLLG washers erosion would result whether the buffer was phosphate-buffered saline replaced weekly or interstitial fluid subject to vascular exchanges.

Rat tail: a useful model for microvascular training.

The rat femoral vessel model is widely used as the basic model for microvascular training; however, it offers only a limited number of anastomoses and vessel sizes. Rat tail vessels provide long length, almost as long as the tail; adequate diameters, from about 1 mm to 0.2 mm; as well as the economy and a convenient location for practicing microvascular anastomoses. It is also the best choice for anastomosing vessels smaller than 0.5 mm diameter. Using stored, frozen tails harvested from sacrificed rats of other projects makes it even more frugal and convenient. Hence, it is an ideal model for microvascular training. The related anatomy and dissecting method are described and discussed.

Toe-to-thumb transplantation in the rat.

A toe harvested from the hind foot of a rat was successfully transplanted to the rat thumb position, with vessel and nerve anastomoses. With this technique practiced, there will be more ease, confidence, and success when doing toe-to-hand or small tissue transplantations or replantations in humans, even in infants. The procedure is described and discussed.