Outcomes of transperineal and transrectal ultrasound-guided prostate biopsy.

OBJECTIVE: To compare the clinical outcomes and pathological findings of transperineal ultrasound-guided prostate biopsy (TPUSPB) and transrectal ultrasound-guided prostate biopsy (TRUSPB) in a secondary referral hospital. METHODS: This was a retrospective study of 100 TPUSPBs and 100 TRUSPBs performed in our centre. Pre-biopsy patient parameters (eg, patient age, clinical staging, serum prostate-specific antigen [PSA] level, prostate size, and PSA density), as well as pathological results and 30-day complication and readmission rates, were retrieved from the patients' medical records and compared between the two groups. RESULTS: One hundred TPUSPBs performed from January 2018 to May 2018 and 100 TRUSPBs performed from January 2016 to April 2016 were included for analysis. Mean age did not significantly differ between the groups. The TPUSPB group had a higher mean PSA level, smaller prostate size, and higher PSA density, compared with the TRUSPB group. The overall prostate cancer detection rate was similar between the TPUSPB and TRUSPB groups (35% vs 25%, P=0.123). There were no significant differences between the groups in prostate cancer detection rates after stratification according to PSA density and clinical staging. With respect to complications, no patients developed fever in the TPUSPB group, while 4% of patients in the TRUSPB group had fever and required at least 1-week admission for intravenous antibiotic administration. CONCLUSION: For prostate biopsy, TPUSPB is safer, with no infection complications, and has similar prostate cancer detection rate compared with TRUSPB.

[Investigation on immunization program coverage rate and its safety in children with tuberous sclerosis].

Objective: To investigate the status of immunization of National Immunization Program (NIP) and its adverse reaction rate in children with tuberous sclerosis. Method: Questionnaire survey was adopted to identify the vaccination coverage and its adverse events; 72 cases of children with tuberous sclerosis and 78 normal controls (healthy children completing age-appropriate NIP) admitted to Chinese People's Liberation Army General Hospital from December 2014 to November 2015 were involved into this study. Result: The age-appropriate NIP coverage rate of tuberous sclerosis was 36%(26/72). The coverage rate of bacillus calmette-guerin (BCG), hepatitis B vaccine 1st to 3rd doses (HepB1-3), oral poliovaccine 1st dose (OPV1), diphtheria, pertussis and tetanus 1st dose (DPT1), DPT1-3, meningococcal polysaccharide vaccine group A (MPVA), measles amd rubella vaccine/measles vaccine 1st dose (MRV/MCV1), and Japanese encephalitis vaccine 1st dose (JEV1) were 100%(72 cases), 75%(51 cases), 97%(66 cases), 91%(62 cases), 82%(56 cases), 66%(45 cases), 69%(42 cases), and 61%(37 cases) respectively. The reasons why the children did not complete the vaccination plan were that parents were concerned about vaccination-induced seizures or seizures had not been controlled. Among 72 children with TSC, the rate of adverse events or suspected adverse events after vaccination was 17% (12 cases), which was higher than the normal control children (2 cases, 3%) (χ2=8.799, P<0.05). The main adverse events were seizure events, which accounted for 92%(11 cases). Conclusion: The age-appropriate NIP coverage rate among children with tuberous sclerosis is low. The high incidence of adverse events may be associated with a fact that there are some nervous system abnormalities in cases with tuberous sclerosis. TSC children vaccination is relatively safe, with no serious adverse events.

Phenotypic and genotypic characterization of Chinese children diagnosed with tuberous sclerosis complex.

We investigated the clinical phenotypes and genetic mutations in Chinese children diagnosed with tuberous sclerosis complex (TSC). Sequencing of TSC1 and TSC2 genes was performed in 117 children with TSC and their parents. Association of TSC gene mutations with clinical manifestations was investigated. All gene mutations were heterozygous including in 16 patients (13.7%) with mutations in TSC1 gene and 101 patients (86.3%) with mutations in TSC2 gene. Among the 16 patients with TSC1 gene mutations, 15 different types of mutations were found, which included 5 novel mutations; all patients had skin manifestations and epilepsy. Among the 101 patients with TSC2 mutations, 85 different types of mutations were found, which included 25 novel mutations; 97 patients (96.0%) had skin manifestations; 97 (96.0%) had epilepsy; 74 (73.3%) had intellectual disability and 25 patients (24.8%) were autistic. The clinical phenotype of the 14 children with familial TSC was more severe than that of their parents.

[Rapamycin in the treatment of cardiac rhabdomyoma associated with tuberous sclerosis complex].

OBJECTIVE: To assess the efficacy and safety of mammalian target of rapamycin (mTOR) inhibitor rapamycin in treatment of children with cardiac rhabdomyoma, associated with tuberous sclerosis complex (TSC). METHOD: The clinical data of children with cardiac rhabdomyomas, who had received a diagnosis of TSC previously, were collected between September 2011 and November 2015 from Pediatric Department of the People's Liberation Army General Hospital.Patients in line with the inclusion criteria received long-term treatment with sirolimus.The starting doses of sirolimus was 1 mg/ (m(2)·d), and the plasma concentration was maintained at 5-10 µg/L.The size and number of cardiac rhabdomyomas were analyzed after treatment with rapamycin, and the efficacy and safety were assessed. The Wilcoxon test was used to analyze data. RESULT: All the 51 children met the inclusion and exclusion criteria, including 30 males and 21 females.The median age for rapamycin treatment was 15.0 months (7.0-35.0 months). Tumors disappeared in 26 (51%) children, decreased by more than 50%(including 50%) in 15 (29%) children, decreased by less than 50% in 5 (12%) children, and had no change or progressed in 4 (8%) children.The number of tumors decreased by 77(72%). The median maximum diameter of tumor was 8.7 (5.9-11.3) mm before treatment, 0.0 (0.0-4.0) mm after treatment, and the median decrease of tumor size were 6.7 (3.9-10.0) mm (Z=-8.817, P<0.01). The median disappearance time was 3.26 (2.92-5.37) months.Among different age groups, after treatment by rapamycin, the rate of tumor's disappearance was 50% (12/24) in 0-1 years group.Tumors disappeared in 10 of 16 patients in >1-3 years group and in 4 of 11 patients in >3 years group.The rate of tumor's disappearance was the highest after 3 months of treatment as compared with 6 and 12 months of treatment.Ten children had adverse event that was related to rapamycin.Canker sore was reported in one child and dyslipidemia was reported in 9 children. CONCLUSION: Rapamycin is efficacious and well tolerate in treatment of cardiac rhabdomyomas associate with TSC, and lead to a reduction in tumor size and number, in addition, significantly shorten the duration of cardiac rhabdomyoma.

Combining cisplatin with cationized catalase decreases nephrotoxicity while improving antitumor activity.

Cisplatin is frequently used to treat solid tumors; however, nephrotoxicity due to its reactive oxygen species-mediated effect limits its use. We tested the ability of cationized catalase, a catalase derivative, to inhibit nephrotoxicity in cisplatin-treated mice. Immunohistochemical analysis showed that the catalase derivative concentrated in the kidney more efficiently than native catalase. Repeated intravenous doses of cationized catalase significantly decreased cisplatin-induced changes in serum creatinine, blood urea nitrogen, nitrite/nitrate levels, lactic dehydrogenase activity, and renal total glutathione and malondialdehyde contents. In addition, cationized catalase effectively blunted cisplatin-induced proximal tubule necrosis but had no significant effect on the cisplatin-induced inhibition of subcutaneous tumor growth. Repeated doses of catalase, especially cationized catalase, significantly increased the survival of cisplatin-treated tumor-bearing mice preventing cisplatin-induced acute death. Our studies suggest that catalase and its derivatives inhibit cisplatin-induced nephrotoxicity, thus improving the efficiency of cisplatin to treat solid tumors.

Effects of pregnant mare serum gonadotropin (eCG) on follicle development and granulosa-cell apoptosis in the pig.

The effect of eCG on follicular development and granulosa-cell apoptosis in sexually mature and immature gilts and on granulosa-cell apoptosis in vitro were studied. The sexually mature gilts were treated with eCG on Day 11 of the estrous cycle, and effects were analyzed at different times after treatment with untreated animals at corresponding stages of the cycle as controls. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), hematoxylin and eosin staining, and DNA ladder. The proportion of apoptotic cells in atretic follicles (39%) was significantly higher (P<0.01) than that in healthy follicles (9%). At 24h after eCG treatment in mature gilts, the total number of follicles visible on the ovarian surface (57 per ovary), the number of small (<3mm) follicles (31.5 per ovary) and the number of medium-sized (3-5mm) follicles (23 per ovary) were significantly higher (P<0.05) than those of control animals (28, 20 and 6.5 per ovary, respectively), and declined gradually thereafter to below the level of control animals. The number of large (>or=5mm) follicles began to show a marked increase at 72h after eCG (8.5 versus 2.5, P<0.05). At 24h after eCG treatment, the proportions of apoptotic cells in small (7.2%) and medium-sized follicles (7.4%) were markedly lower (P<0.01) than those in controls (21.5 and 21%, respectively) and increased gradually thereafter to approach the level in controls. The percentage of apoptotic cells in large follicles (10% at 24h post-eCG) did not change significantly. Before eCG treatment, there were markedly fewer follicles of all types on ovaries of immature gilts than of mature gilts (9 versus 25 per ovary) and the proportion of apoptotic cells in small and medium follicles was high (25 and 34%, respectively). After eCG treatment, the changes in follicle number and proportion of apoptotic cells in the immature gilts followed a similar pattern to that of the mature gilts. Equine chorion gonadotropin inhibited apoptosis of granulosa cells cultured either in vitro or in intact follicles in a dose-dependent manner. Thus, follicular atresia in the pig, as in other animals, was characterized by apoptosis of large numbers of granulosa cells, and eCG promoted follicular development by inhibition of granulosa-cell apoptosis.

Specificity of reinnervation and motor recovery after interposition of an artificial barrier between transected and repaired nerves in adjacency--an experimental study in the rat.

Non-specific re-innervation of target organs caused by misdirected axonal growth at the repair site is regarded as one reason for a poor functional outcome after peripheral nerve transsection and repair. This study investigates the rate of aberrant re-innervation and its influence on motor recovery in the rat sciatic nerve using artificial sheets as barrier between tibial and peroneal nerves. The sciatic nerve was transsected and repaired as follows: epineural sutures (A x 6), fascicular repair of tibial and peroneal nerves respectively (B x 8), and the same as in group B, but separating both nerves using an Integra-sheet with silicone (C x 8), or Integra without silicone (D x 8). As control, solely the tibial nerve was transsected and repaired (E x 5). Final investigations after 4 months revealed that in group C, 50% of the Integra-silicone sheets were dislocated. No dislocation was found in group D. Muscle contraction force of the gastrocnemius muscle was significantly higher in group E as compared to all other groups. However although not significant, group D showed a consistently higher muscle contraction force than groups A, B, and C. Histology in groups A, B, and C with dislocated sheets demonstrated multiple axons growing from the tibial to the peroneal nerve and vice versa. In groups D and E, no such axonal growth was visible. These findings were confirmed by a significantly higher rate of specific reinnervation of the soleus muscle using sequential retrograde double labelling technique. Results of this study suggest that an artificial sheet such as Integra bears the potential of preventing aberrant re-innervation between repaired adjacent nerves resulting in improved motor recovery. Clinically, this technique may be of importance for brachial plexus, sciatic nerve, and facial nerve repair.

Interposition of a pedicle fat flap significantly improves specificity of reinnervation and motor recovery after repair of transected nerves in adjacency in rats.

Despite highest standards in nerve repair, functional recovery following nerve transection still remains unsatisfactory. Nonspecific reinnervation of target organs caused by misdirected axonal growth at the repair site is regarded as one reason for a poor functional outcome. This study was conducted to establish a method for preventing aberrant reinnervation between transected and repaired nerves in adjacency. Rat sciatic nerve was transected and repaired as follows: epineural sutures of the sciatic nerve (group A, n = 6), fascicular repair of tibial and peroneal nerves respectively (group B, n = 8), and, as in group B, separating both nerves using a pedicle fat flap as barrier (group C, n = 8). As control only, the tibial nerve was transected and repaired (group D, n = 5). Muscle contraction force of the gastrocnemius muscle was significantly higher in group C as compared with groups A and B after 4 months. Muscle weight showed significantly lower values in group A as compared with groups B, C, and D. Histologic examination in group C revealed little growth of axons from the tibial to the peroneal nerve and vice versa. This axon crossing was observed only when gaps between the fat cells were available. These findings were confirmed by a significantly lower rate of misdirected axonal growth as compared with groups A and B using sequential retrograde double labeling technique of the soleus motoneuron pool. We conclude that a pedicle fat flap significantly prevents aberrant reinnervation between repaired adjacent nerves resulting in significantly improved motor recovery in rats. Clinically, this is of importance for brachial plexus, sciatic nerve, and facial nerve repair.

Differential regulation of alternatively spliced endothelial cell myosin light chain kinase isoforms by p60(Src).

The Ca(2+)/calmodulin-dependent endothelial cell myosin light chain kinase (MLCK) triggers actomyosin contraction essential for vascular barrier regulation and leukocyte diapedesis. Two high molecular weight MLCK splice variants, EC MLCK-1 and EC MLCK-2 (210-214 kDa), in human endothelium are identical except for a deleted single exon in MLCK-2 encoding a 69-amino acid stretch (amino acids 436-505) that contains potentially important consensus sites for phosphorylation by p60(Src) kinase (Lazar, V., and Garcia, J. G. (1999) Genomics 57, 256-267). We have now found that both recombinant EC MLCK splice variants exhibit comparable enzymatic activities but a 2-fold reduction of V(max), and a 2-fold increase in K(0.5 CaM) when compared with the SM MLCK isoform, whereas K(m) was similar in the three isoforms. However, only EC MLCK-1 is readily phosphorylated by purified p60(Src) in vitro, resulting in a 2- to 3-fold increase in EC MLCK-1 enzymatic activity (compared with EC MLCK-2 and SM MLCK). This increased activity of phospho-MLCK-1 was observed over a broad range of submaximal [Ca(2+)] levels with comparable EC(50) [Ca(2+)] for both phosphorylated and unphosphorylated EC MLCK-1. The sites of tyrosine phosphorylation catalyzed by p60(Src) are Tyr(464) and Tyr(471) within the 69-residue stretch deleted in the MLCK-2 splice variant. These results demonstrate for the first time that p60(Src)-mediated tyrosine phosphorylation represents an important mechanism for splice variant-specific regulation of nonmuscle MLCK and vascular cell function.

Nerve transfer to the median nerve using parts of the ulnar and radial nerves in the rabbit--effects on motor recovery of the median nerve and donor nerve morbidity.

In this study, motor re-innervation of the median nerve by transfer of one-third, one-half, and two-thirds of either the agonistic ulnar nerve or the antagonistic radial nerve was investigated in both extremities of 20 rabbits. Recipient median nerve: Muscle contraction force of the flexor digitorum sublimus muscle after a one-third and a one-half of the ulnar nerve transfer achieved an average of 75 and 97% muscle power respectively as compared to conventional end-to-end neurorrhaphy. Muscle contraction force after one-third or one-half of the radial nerve transfer was significantly lower (36%). Donor nerves: Extensor carpi radialis muscle or flexor carpi ulnaris muscle contraction force 6 months postoperatively demonstrated a significant decrease after a one-half ulnar nerve and a two-thirds ulnar or radial nerve transfer, but not after a one-third transfer of either radial or ulnar nerves. Histologically, the number of axons in the re-innervated median nerve and both donor nerves distal to the coaptation site seemed to follow variable patterns. It was concluded that in the rabbit use of one-third of the agonistic ulnar nerve for re-innervation of the median nerve results in useful motor recovery with negligible donor site morbidity. Clinically, this technique may offer an alternative option for proximal nerve injuries or for free functioning muscle transplantations.

Role of the target in end-to-side neurorrhaphy: reinnervation of a single muscle vs. multiple muscles.

The authors examined the effects of end-to-side neurorrhaphy for reinnervation of the musculocutaneous nerve (Group A) which innervates the biceps muscle, compared to reinnervation of the median nerve which innervates multiple muscles in a rat model. Additionally, end-to-end neurorrhaphy to the musculocutaneous nerve using one-third of the median nerve (Group B) was investigated. End-to-end coaptation of the musculocutaneous nerve served as a control (Group C). In a grooming test, the biceps muscle function in Group A animals demonstrated a slower but nearly similar good recovery to Groups B and C. Biceps muscle contraction force investigated after 24 weeks demonstrated no statistically significant differences among all groups. In Groups A and B, no significant impairment of the donor median nerve function was found in a grasping test and the muscle contraction force of the flexor carpi radialis muscle, and histologic evaluation of the musculocutaneous nerve showed multiple regenerated axons distal to the coaptation site. Retrograde double-labeling in Group A animals showed reinnervation of the musculocutaneous nerve by median nerve axons located at the coaptation site. These results validate that end-to-side neurorrhaphy to a nerve innervating a single muscle is more efficient than to a nerve innervating multiple muscles, as demonstrated in an earlier study. The reason for this phenomenon is most likely that all sprouting axons are directed toward one target rather than toward multiple targets, with the latter situation resulting in a smaller number of axons and a variable distribution of axons per target. Since donor nerve sprouting axons were observed at the coaptation site, a relevance of the selected site for end-to-side neurorrhaphy is suggested. Both end-to-side neurorrhaphy and end-to-end neurorrhaphy, using one-third of the median nerve, led to useful functional recovery in this rat model, if an agonistic donor nerve is employed.

Selection of donor nerves--an important factor in end-to-side neurorrhaphy.

We have examined the effects of end-to-side neurorrhaphy on peripheral nerve regeneration using the median nerve as recipient nerve and either the antagonistic radial nerve or the agonistic ulnar nerve as donor nerves in rat upper limbs. A perineural window was created in all cases. Motor recovery up to 16 weeks postoperation was tested with the grasping test. No recovery of motor function was evident after end-to-side neurorrhaphy of the median nerve to the antagonistic radial nerve, whereas six of eight rats with end-to-side neurorrhaphy to the agonistic ulnar nerve achieved 367 g +/- 47 g grasping power as compared to 526 g +/- 6 g in end-to-end coapted control animals. No significant difference in flexor digitorum sublimus-motor nerve conduction velocity was found among all three groups. Radial nerve stimulation produced simultaneous contraction of both extensor and flexor muscles of the lower arm that disabled any coordinated movement of the paw. Histology (toluidine blue, acetylcholinesterase-stain) showed multiple regenerated (motor)-axons distal to the coaptation site in the median nerve. Reinnervation of the median nerve solely by the respective donor nerve was demonstrated by a retrograde double labelling technique. These results show that averaged 70% muscle power as compared to end-to-end neurorrhaphy with well coordinated muscle function can be achieved by axonal sprouting through end-to-side neurorrhaphy if an agonistic nerve is used as donor nerve. However, satisfying results are unpredictable. Antagonistic nerves show the ability to induce axonal regeneration, but no useful function can be expected.

Effects of insulin-like growth factor-1 in motor nerve regeneration after nerve transection and repair vs. nerve crushing injury in the rat.

Despite highest standards in nerve repair, functional recovery following nerve transection still remains unsatisfactory. Non-specific re-innervation of target organs are regarded as one reason for a poor functional outcome. Insulin-like growth factor-1 (IGF-1) has demonstrated promoting effects on sciatic nerve regeneration after crushing injury. Similarly, IGF-1 has shown a direct inductive effect on motoneuron growth associated protein-43 (GAP-43) which is believed to play a role in axon guidance during development. Based on this fact we have examined the trophic effects of recombinant human IGF-1 on peripheral motor nerve regeneration following transection and epineural repair in rats median nerve. RhIGF-1 (0.5 mg/kg/rat) was administered subcutaneously to the neck of the repaired side for 14 days postoperation. Accuracy of re-innervation of the flexor carpi radialis muscle motoneuron pool was studied by sequential retrograde double labelling technique. Motor recovery was tested with the grasping test. No significant differences between experimental and control animals in accuracy of re-innervation and in recovery of muscle power could be demonstrated. Non-specific re-innervation of the flexor carpi radialis muscle was found in 23.2% in the experimental group and in 24.2% in the control group. These results demonstrate that systemically applied rhIGF-1 failed to improve functional motor recovery after nerve transection and repair in the rat as it was demonstrated after nerve crushing injury in several studies. Furthermore, systemically applied IGF-1 did not improve accuracy of re-innervation after axotomy and repair in adult rats.

In vitro and in vivo photosensitizing capabilities of 5-ALA in vascular endothelial cells.

BACKGROUND: The object of our study is to evaluate the feasibility of photodynamic therapy for complicated hemangiomas. We studied the effect of the photosensitizing agent 5-aminolevulinic acid (5-ALA) in both in vitro and in vivo models. METHODS: The in vitro photosensitizing activity of 5-ALA was examined in a microvascular endothelial cell (MEC) culture system. 5-ALA was added in various concentrations and the cells were illuminated at 630 nm. The percentage of MEC killed was measured by either a Live/Dead assay or an lactate dehydrogenase (LDH) assay. The effect of varying the light energy dose delivered at 630 nm after the administration of 5-ALA was studied by determining the amount of necrosis produced in chicken combs. RESULTS: The combination of 5-ALA at a concentration of 35 micrograms/ml, and illumination by 100 mW/cm2 of laser light at 630 nm wavelength, caused 50% cell kill in the MEC culture system. Chicken combs of animals that received 200 mg/kg of 5-ALA and illumination at a power density of 80 mW/cm2 had a depth of injury of 362.5 +/- 27.6 microns upon histological examination. Those combs that received 100 or 120 mW/cm2 showed a depth of injury of 732.5 +/- 29.1 and 792.5 +/- 36.0 microns respectively. CONCLUSION: 5-ALA is effective in sensitizing human MEC to laser illumination. However, the degree of absorption and tissue destruction in different anatomical structures should be considered in future clinical studies.

Thrombin induces thrombomodulin mRNA expression via the proteolytically activated thrombin receptor in cultured bovine smooth muscle cells.

Thrombin, an important mitogen governing smooth muscle cell proliferation, binds to cultured bovine aortic smooth muscle cells (BASMCs) via both the proteolytically activated thrombin receptor (PATR) and thrombomodulin (TM). Although TM mRNA expression and functional activity is regulated by thrombin in human endothelial cells and mouse hemangioma cells, it remains unclear in those models whether the increased TM mRNA expression observed upon thrombin stimulation is mediated through the activation of PATR or via TM occupancy. We observed in cultured BASMCs that TM mRNA is increased threefold to sixfold by either thrombin, basic fibroblast growth factor (bFGF), or platelet-derived growth factor (PDGF). The increase in TM mRNA with thrombin is time dependent (maximal at 3 hours), a consequence of increased mRNA stability, and accompanied by increases in cell surface TM functional activity. Thrombin-induced TM mRNA was reproduced by the hexameric thrombin receptor-activating peptide (TRAP6) and augmented by a TM-specific antibody. Together, these data suggest that up-regulation of TM mRNA by thrombin is mediated via the PATR. We speculate that increases in BASMC TM mRNA and activity after thrombin may contribute to the impaired thrombus formation observed after atherosclerotic vascular injury.

Detection of human papillomavirus DNA in biopsy-proven cervical squamous intraepithelial lesions in pregnant women.

This study analyzed cervical squamous intraepithelial lesions (SILs) in pregnant women for human papillomavirus (HPV) using in situ hybridization analysis. HPV DNA was detected in 77% (23/30) of low-grade SILs as compared to 89% of such lesions in nonpregnant women. The detection rate in high-grade SILs was 41% (9/22) compared to 70% in nonpregnant women. Analysis by the polymerase chain reaction showed that the detection rates were similar (96-100%) for low- and high-grade lesions in pregnant and nonpregnant women, which demonstrates that in situ negative tissues indeed contained HPV DNA. Low-grade SILs contained a heterogeneous group of at least 14 different HPV types, whereas most high-grade SILs contained HPV 16. We concluded that cervical SILs in pregnant women are invariably associated with HPV. Further study is needed to determine which of several possible variables, such as the age of the lesion and the viral copy number, may explain the apparent decreased detection rate of HPV by in situ hybridization in SILs during pregnancy.

The distribution of serum albumin in the rat testis, studied by electron microscope immunocytochemistry on ultrathin frozen sections.

The distribution of serum albumin is of interest in the rat testis because this protein is the principal carrier for testosterone in the plasma and interstitial fluid of this species. We have localized extravascular serum albumin in the rat testis at the electron microscope level, using gold particle immunocytochemistry on ultrathin frozen sections of tissue fixed lightly by perfusion. The same localization was obtained with three different antisera. Preabsorption and normal rabbit serum controls were negative, and Western blots of testis extracts showed major activity only at the molecular weight of albumin. Serum albumin occurred in substantial concentration throughout extracellular space in the interstitial tissue, as well as in the space between the boundary layer and the base of the seminiferous epithelium. Immunoreactivity extended between Sertoli cells, as well as around spermatogonia and early primary spermatocytes (to stage 11), but did not traverse the Sertoli-Sertoli junctions that comprise the blood-testis barrier. Macrophages in the interstitial tissue showed some endocytic activity. If perfusion fixation was carried out in a manner that flushed most of the albumin from the interstitial space, then a layer of albumin remained on the surface of Leydig cells and many macrophages but was minimal or absent on the surface of other cell types that are normally in contact with albumin, such as Sertoli cells, spermatogonia, myoid cells, lymphatic endothelium, fibroblasts, or cells of blood vessels.