One Thousand Liver Transplants: The Hospital Clinic Experience

OBJECTIVES

Our goal was to study a consecutive series of 1000 liver transplants performed in our institution to evaluate the changes over time in donors, recipients, and results.

PATIENTS AND METHODS

With the aim to evaluate differences between transplantation in the first period and the present period, the first consecutive 100 liver transplants performed from June 1988 to June 1990 (first period) were compared with the last consecutive 200 liver transplants performed from January 2001 to June 2003 (second period).

RESULTS

Increased donor age, change in donor cerebral death etiology, and increasing numbers of grafts from alternative methods using cadaveric donors were observed in the second period. Piggy-back technique and the biliary anastomosis without a t-tube was also started in the second period. One-year actuarial patient survival was higher in the second period (84% vs 91.3%). The need for retransplantation in the overall series was 95%. One-, 5-, and 10-year actuarial retransplant survival was 67.7%, 51.3%, and 39.4%, respectively.

CONCLUSIONS

Technical innovations, better understanding of donor and recipient aspects, and global improvements were the reasons for time-related improved results of liver transplantation.

Cost/efficacy clinical trial about the use of T-tube in cadaveric donor liver transplant: preliminary results

Biliary reconstruction is the most common cause of morbidity associated with orthotopic liver transplantation. Our objective was to assess the complications and hospital resources related to the use of a T-tube.

MATERIAL AND METHODS

Among 95 liver transplants performed from October 2002 to November 2003, 84 patients were randomized to receive a T-tube or no T-tube. We analyzed all patients with a follow-up of at least of 3 months.

RESULTS

Fifty-five transplants were analyzed with 8 months mean follow-up, including twenty eight with T-tube and twenty seven without a T-tube. No patient died during the follow-up. The overall rate of biliary complications was 45.4% (25/55) including 21/28 (75%) in the T-tube group and 4/27(14.8%) in the non-T-tube group (P < .0001). Complications related to T-tube extraction occurred in 48.2% (13/27), including 3 cholangitis and 10 leaks. The costs of hospital resources due to radiological studies were 5329 capital JE, Ukrainian for the T-tube group vs 5785 capital JE, Ukrainian for the non-T-tube group. The costs of hospital resources due to treatment were 28,280 capital JE, Ukrainian for the T-tube group vs 10,088 capital JE, Ukrainian for the non-T-tube group.

CONCLUSIONS

Use of a T-tube during orthotopic liver transplantation does not seem justified. Biliary anastomosis stenting is followed by an increased incidence of complications, most of which are related to its use. Hospital stay, radiological studies, and cost of hospital resources are higher among the T-tube patients. Therefore its systematic use is not advisable.

Evolutionary change in the structure of the regulatory region that drives tissue and temporally regulated expression of alcohol dehydrogenase gene in Drosophila funebris

The Adh locus of Drosophilidae is organized as a single gene transcribed from two spatially and temporally regulated promoters except in species of the repleta group, which have two single promoter genes. Here we show that in Drosophila funebris the Adh gene is transcribed from a single promoter, in both larva and adult, with qualitative and quantitative species specific-differences in tissue distribution. The gene is expressed in larval fat body but in other tissues such as gastric caeca, midgut and Malpighian tubules its expression is reduced compared to most Drosophilidae species, and in adults it is almost limited to the fat body. The comparative analysis of gene expression of two strains, which differ by a duplication, indicates that the cis elements necessary for this pattern of expression in larvae are included in the region of 1.55 kb upstream of the transcription initiation site. This new organization reveals the evolution of a different regulatory strategy to express the Adh gene in the subgenus Drosophila.

Binding and activation of human plasminogen by Mycobacterium tuberculosis

The first evidence of the interaction of Mycobacterium tuberculosis with the plasminogen system is herein reported. By FACScan analysis and affinity blotting, lysine-dependent binding of plasminogen to M. tuberculosis was demonstrated. The binding molecules were 30-, 60-, and 66-kDa proteins present in cell wall and soluble protein extracts. The activation of plasminogen, which occurred only in presence of fibrin and was not inhibited by the host serpin, alpha(2)-antiplasmin, was also demonstrated.

Nonfixed duplication containing the Adh gene and a truncated form of the Adhr gene in the Drosophila funebris species group: different modes of evolution of Adh relative to Adhr in Drosophila

The sequence of the genomic region that contains the Adh and Adhr genes of Drosophila funebris was used to demonstrate that both genes are present in species of the funebris group. The sequence of this genomic region reveals a 2.9-kb tandem duplication which encompasses 1.6 kb of the 5' flanking region, the entire Adh gene, and two thirds of the first exon of the Adhr gene in D. funebris. This duplication is not fixed in this species since some strains do not carry the duplication. The Adh duplication has also been found in another species of the funebris group, Drosophila macrospina macrospina. The sequence analysis of the 5'-flanking region of the Adh gene indicates a single promoter and shows stretches of high similarity with cis-acting elements responsible for the expression of Adh in Drosophila melanogaster. In confirmation of this indication, the larval and adult transcripts have the same length, which corresponds to the transcription from the promoter proximal to the coding region. The codon bias of the Adh gene of D. funebris is among the lowest reported for any Adh gene in the Drosophilidae species and is very similar to that of the Adhr gene. The Adhr gene evolves slightly faster than Adh at synonymous positions. At nonsynonymous positions, the Adh gene evolves 2.5 times faster than Adhr in the species pair D. funebris-Drosophila immigrans, while in other interspecific comparisons the average is about 1.25. However, in comparisons between some species within the melanogaster and obscura groups, Adh evolves at half the rate of Adhr. The phylogenetic trees constructed with the coding region of the Adh gene cluster D. funebris and D. immigrans and clearly separate them from the clade in which virilis, repleta, and Hawaiian species are grouped. Using the evolutionary synonymous rate estimated for Hawaiian species, the divergence time of D. funebris from the virilis-repleta-Hawaiian clade was estimated as 34.3 Myr, and the divergence time of D. funebris and D. immigrans was estimated as 23.5 Myr.

CD26 expression and dipeptidyl peptidase IV activity in an aggressive hepatosplenic T-cell lymphoma

The transmembrane serine aminopeptidase dipeptidyl peptidase IV (DPP IV) (also known as CD26) participates in several immunological functions and has a binding affinity for several molecules, including collagen, which may be an integral mechanism for T cells to traverse endothelial barriers. Since CD26 is phenotypically expressed in certain T-cell malignancies, this study utilized a novel four-color cytofluorographic procedure to measure DPP IV enzymatic activity concurrently with the expression of other surface markers in an aggressive hepatosplenic T-cell lymphoma. Immunophenotypic analysis by flow cytometry revealed the tumor to be CD2+, CD3+, CD5-, CD7+, TcR-gamma/delta+, CD4-, CD8+/-, CD56+, and CD11c+. The CD26 molecule was also expressed, and DPP IV activity was present, with the maximal activity detectable after 10 min of incubation. These results represent the initial description of enzymatically active CD26 in a T-cell malignancy, and raise the possibility that this molecule may be a participant in the pathogenetic mechanisms utilized by the neoplastic cells.

Immunological markers of disease progression in patients infected with the human immunodeficiency virus

Identification of inexpensive and technically simple immunological tests useful in predicting the progression to AIDS in human immunodeficiency virus (HIV)-infected patients would be especially welcome in developing countries, in which 80% of HIV-infected patients reside and health budgets are low. In the current study, we evaluated CD4+ and total lymphocyte counts and the concentrations in serum of beta 2-microglobulin, p24 antigen, and immunoglobulin A (IgA) as predictors of disease progression in 74 Panamanian HIV-positive patients and 50 HIV-negative healthy individuals. Total lymphocyte and CD4(+)-cell counts for AIDS patients (1,451 +/- 811 cells/microliters, P < 0.001, and 238 +/- 392 cells/microliters, P < 0.0001, respectively and asymptomatic patients (2,393 +/- 664 cells/microliters, P > 0.05, and 784 +/- 475 cells/microliters, P < 0.001, respectively) were lower than those observed for healthy subjects (2,596 +/- 631 cells/microliters and 1,120 +/- 296 cells/microliters, respectively). The levels of beta 2-microglobulin and IgA in serum were significantly elevated in patients with AIDS (5.7 +/- 3.6mg/liter, P < 0.001, and 541 +/- 265 mg/dl, P < 0.0002, respectively) and asymptomatic infected subjects (3.4 +/- 2.1 mg/liter, P = 0.001, and 436 +/- 216 mg/dl, P < 0.0001, respectively) compared with the levels in healthy subjects (2.2 +/- 0.7 mg/liter and 204 +/- 113 mg/dl, respectively). Nonstatistically significant differences (P > 0.05) for concentrations of p24 antigen between asymptomatic infected patients (29 +/- 13 pg/ml) and AIDS patients (40 +/- 23 pg/ml) were observed. Total lymphocyte counts of 1,750 cells/microliters or less, CD4 counts of 200 cells/microliters or less, beta 2-microglobulin concentrations in serum of 4 mg/liter or higher, concentrations of IgA in serum of 450 mg/dl or higher, and the presence in serum of p24 antigen were correlated with elevated risks for developing AIDS. Monitoring both total lymphocytes and beta 2-microglobulin identified 91% of the AIDS patients; these assays may allow reductions in the annual number of CD4(+)-cell evaluations and the costs associated with monitoring both total lymphocytes and beta 2-microglobulin identified 91% of the AIDS patients; these assays may allow reductions in the annual number of CD4(+)-cell evaluations and the costs associated with monitoring the immune status of HIV-positive patients.

Postthaw viability of frozen human ovarian cancer tumor specimens

Thirty-five human ovarian cancer tumor specimens were frozen by both rapid freeze and slow freeze with dimethyl sulfoxide (DMSO) to determine which method results in optimal postthaw viability. Median viability following a rapid freeze was 8% as compared to 90% with slow freeze with DMSO (P = .0001). Eighty-seven percent of tumors had a viability of > 80% following slow freeze with DMSO. When experimentation on human ovarian cancer tumor cells requires postthaw viability, we recommend slow freeze with DMSO.

Structural changes in rat Leydig cells posthypophysectomy: a morphometric and endocrine study

Short and long term responses of the rat Leydig cell were studied posthypophysectomy, at times when germ cell degeneration was first prominent (6 days) and after long term regression of the testis (28 days). In the short term, virtually all structural parameters relating to the volume and surface area of the Leydig cell and its subcellular organelles were significantly lowered compared with those in control animals. Exceptions were the volumes of the nucleolus, heterochromatin, and lysosomes and the surface areas of the nucleus. Structural decreases were generally on the order of 2- to 5-fold in the 6-day period. A statistical analysis of the percent decreases in the short term was performed to determine whether any particular structural features were more sensitive to hypophysectomy than any others. In most instances, no particular organelles were decreased compared to others. However, lipid, although not commonly seen in rat Leydig cells, showed significantly greater percent decreases compared with several other organelles, indicating that the small amount of lipid present is rapidly lost (used) in the short term. After long term hypophysectomy, all structural parameters of the Leydig cell were significantly lowered compared with those in pituitary-intact animals. Only a few parameters (mitochondrial volume, cell surface area, and the surface areas of inner and outer mitochondrial membranes and smooth endoplasmic reticulum) showed more significant decreases in the long term compared with the short term hypophysectomized animals. Most organelle volumes and surface areas correlated positively and significantly with serum and tissue testosterone levels; the exceptions were the volumes of the nucleolus, heterochromatin, lipid, and lysosomes. Compared with the pituitary-intact animal, the content of LH receptors expressed per testis and per Leydig cell was significantly lower in both hypophysectomized groups; however, the number of receptors per given area of individual Leydig cell plasma membrane remained unchanged. Overall, data show that the Leydig cell manifests marked structural changes during early spermatogenic dysfunction.

Streptozotocin-induced deficits in sex behavior and neuroendocrine function in male rats

The effects of streptozotocin-induced (STZ) diabetes on neuroendocrine and sexual function were evaluated in adult male rats. Adult male rats were injected with STZ (50 mg/kg) or vehicle and tested for copulatory behavior 7, 14, and 21 days later. The rats were killed 1 month after STZ or vehicle treatment for measurement of plasma hormone levels, hypothalamic catecholamine turnover, LHRH content, and in vitro pituitary function. The STZ rats showed significant deficits in mount, intromission, and ejaculatory behaviors. Plasma levels of testosterone, LH, FSH, and PRL were all significantly reduced in the STZ compared to the control rats, but in vitro LH secretion was enhanced after STZ treatment. In vitro PRL secretion and the inhibitory response to dopamine did not differ between the two groups. The levels of LHRH were reduced in the medial basal hypothalamus (MBH), but LHRH levels in the median eminence (ME) and anterior hypothalamus (AH) were unchanged after STZ treatment. Norepinephrine turnover was reduced in the ME, MBH, and AH of the STZ rats, while dopamine turnover was unchanged in the ME, increased in the MBH, and reduced in the AH of the STZ rats compared to those in the vehicle-treated controls. These results suggest that changes in pituitary and testicular function in rats made diabetic by STZ treatment are secondary to changes in hypothalamic catecholamine metabolism. Changes in copulatory behavior could be due to both reductions in plasma testosterone levels as well as changes in central neurotransmitter metabolism.

Insulin-like growth factor I levels in proportionate dogs, chondrodystrophic dogs and in giant dogs

Plasma insulin-like growth factor I concentrations from proportionate, chondrodystrophic and giant breeds were evaluated and compared with body size. IGF-I plasma concentrations were 91.2 +/- 10.9 micrograms/l in Keeshounds (proportionate dog), 122.6 +/- 25.4 micrograms/l in Bassethounds (chondrodystrophic dog) and 280 +/- 22.8 micrograms/l in German Shepherds (proportionate dog). The highest IGF-I level (389.6 +/- 24.2 micrograms/l) was found in the New Foundland, a giant breed (mean +/- SEM). The mean body weight was 11.8 +/- 0.4 kg in Keeshounds, 15.4 +/- 1.4 kg in Bassethounds, 32 +/- 1.5 kg in German Shepherds, and 45.6 +/- 1.7 kg in New Foundlands (mean +/- SEM). Body weight and plasma IGF-I concentration were significantly correlated (y (IGF-I) = -7.43 + 8.7 X (body weight); P less than 0.0001.

Malignant angioendotheliomatosis--a true lymphoma: a case of intravascular malignant lymphomatosis studied by southern blot hybridization analysis

Malignant angioendotheliomatosis is a rare, systemic, usually fatal disease characterized by a massive proliferation of large, bizarre-looking mononuclear cells within small and medium-sized blood vessels. The histogenesis of the neoplastic cells has been the subject of long-standing controversy since the disease's initial description. Early investigators concluded that the entity represented a neoplasm of endothelial cells, but recently others have suggested that it is of lymphoid origin. We studied a case of malignant angioendotheliomatosis by Southern blot hybridization analysis which showed clonal rearrangements of the immunoglobulin heavy-chain gene strongly suggesting a B-lymphocyte origin. Our results provide additional evidence that malignant angioendotheliomatosis is an intravascular malignant lymphomatosis.

Effects of photoperiod, hypophysectomy, and follicle-stimulating hormone on testicular follicle-stimulating hormone binding sites in golden hamsters

Experiments were conducted to partially characterize and to examine the regulation of unoccupied testicular follicle-stimulating hormone (FSH) binding sites in adult golden hamsters. Testicular FSH binding sites were measured in the 1800 X gav fraction of whole testicular homogenates using iodinated bovine FSH. Binding of FSH was highly specific for FSH, located primarily in the testes, was time- and temperature-dependent, initially reversible, saturable, and consistent with a model consisting of a single class of high-affinity binding sites (range of equilibrium association constants (Ka) 2-12 X 10(10) M-1). Exposure of hamsters to a short photoperiod consisting of 5L:19D was associated with an increase in concentration (fmol/mg protein), but a reduction in total content (fmol/testes) of testicular FSH binding sites. There was no appreciable 5L:19D-associated alteration in receptor affinity (average Ka = 7.83 X 10(10) M-1). Injections of ovine prolactin (oPRL), ovine luteinizing hormone (oLH), or ovine FSH (oFSH) for 3 days into hamsters housed in 5L:19D for 12 wk had no effect on photoperiod-induced changes in testicular FSH binding sites. On Days 5 and 6 post hypophysectomy, a dramatic increase in FSH binding site concentration occurred, with but marginal effects on binding site affinity. Injections of 5 micrograms oFSH on Days 2, 3, and 4 after hypophysectomy prevented the increase in binding site concentrations measured on Day 5. Injection of a combination of 5 micrograms oFSH, 50 micrograms oPRL, and 25 micrograms oLH also reduced testicular FSH binding site concentrations in hypophysectomized hamsters, but oPRL or oLH by themselves were ineffective. The data indicate a homologous down-regulation of testicular FSH binding sites, but do not exclude the involvement of other hormones.

Prevalence and age at development of enamel hypoplasias in Mexican children

Enamel hypoplasias, deficiencies in enamel thickness resulting from disturbances during the secretory phase of enamel development, are generally believed to result from nonspecific metabolic and nutritional disruptions. However, data are scare on the prevalence and chronological distributions. of hypoplasias in populations experiencing mild to moderate malnutrition. The purpose of this article is to present baseline data on the prevalences and chronological distributions of enamel hypoplasias, by sex and for all deciduous and permanent anterior teeth, in 300 5 to 15-year-old rural Mexican children. Identification of hypoplasias was aided by comparison to a published standard (Federation Dentaire Internationale: Int. Dent. J. 32(2):159-167, 1982). The location of defects, by transverse sixths of tooth crowns, was used to construct distributions of defects by age at development. One or more hypoplasias were detected in 46.7% (95% CI = 40.9-52.5%) of children. Among the unworn and completely erupted teeth, the highest prevalence of defects was found on the permanent maxillary central incisors (44.4% with one or more hypoplasias), followed by the permanent maxillary canine (28.0%) and the remaining permanent teeth (26.2 to 22.2%) Only 6.1% of the completely erupted and unworn deciduous teeth were hypoplastic. The prevalence of enamel defects on the permanent teeth was up to tenfold greater than that found in studies of less marginal populations that used the FDI method. The prevalence of defects in transverse zones suggests a peak frequency of hypoplasias during the second and third years for the permanent teeth, corresponding to the age at weaning in this group. In the deciduous teeth, a smaller peak occurs between 30 and 40 weeks post gestation. The frequency of defects after three years of age is slightly higher in females than males, suggesting a sex difference in access to critical resources.

Regulation of testicular LH/hCG receptors in golden hamsters (Mesocricetus auratus) during development

During prepubertal development in the golden hamster, there are major age-related changes in the number of testicular LH/hCG receptors. Between 22 and 35 days of age, there was greater than 10-fold increase in testicular LH/hCG receptors, followed by a decrease at Day 37. Concomitant with, but preceding slightly, the changes in receptors, were increases in plasma LH and FSH and most noticeably prolactin concentrations, between Days 10 and 20 of age. Inhibition of the increases in plasma levels of prolactin by daily injections of bromocriptine, between 14 and 31 days of age, resulted in suppressed testicular and seminal vesicle weights, and decreased content and concentration of testicular LH/hCG receptors. Similarly, the premature increase in plasma prolactin concentrations in prepubertal hamsters between 6 and 20 days of age, by means of ectopic pituitary transplants, resulted in increased testicular and seminal vesicle weights, as well as an increase in the concentration of testicular LH/hCG receptors. These results strongly suggest that increases in plasma prolactin values during development are important in enhancement of the development of testicular LH/hCG receptors.

Effects of photoperiod and hCG on the regulation of testicular LH/hCG receptors in Syrian hamsters (Mesocricetus auratus)

The regulation of testicular LH/hCG receptors was studied in Syrian (golden) hamsters with testicular atrophy induced by exposure to short photoperiod (5L:19D) and in gonadally active hamsters kept in a long photoperiod (14L:10D). By 24 h after injection of hCG, long-photoperiod hamsters showed a dose-related decrease in the number of testicular LH/hCG receptors. At 48 and 72 h, there was a recovery from this 'down-regulation'. The recovery was much faster than has been reported for the rat and mouse, and it resulted in elevation of testicular LH/hCG receptor concentrations above basal values. Hamsters with short photoperiod-induced testicular atrophy showed an increase in testicular LH/hCG receptors after injection of hCG, except for animals injected with a very high dose. The hCG-induced increase in testicular LH/hCG binding in these animals was associated with reappearance of testosterone responses to subsequent hCG stimulation. Response of testicular LH/hCG receptors to hCG in prepubertal hamsters resembled that measured in animals with short photoperiod-induced gonadal atrophy.

Effects of different numbers of ectopic pituitary transplants on regulation of testicular LH/hCG and prolactin receptors in the hamster (Mesocricetus auratus)

Adult male hamsters were given transplants of 1/2, 1, 2, 3 or 4 pituitaries under the kidney capsule and were killed 4 weeks later. Pituitary transplants produced a significant, dose-related increase in plasma prolactin levels, no changes in plasma LH and an increase in plasma FSH. Concentration of LH/hCG receptors in the testes was significantly increased in animals with 2 or 3 transplants and concentration of testicular prolactin receptors was significantly increased in those given 2 transplants. The apparent stimulatory effects of 1/2, 1 or 4 transplants on testicular LH/hCG and prolactin binding were not statistically significant. Some of the animals were injected with 0.3 i.u. hCG/g body weight 24 h before being killed. This produced a significant reduction in the levels of prolactin receptors and an apparent reduction in the levels of LH/hCG receptors in the testes. Elevation of plasma testosterone concentrations in response to hCG was significantly greater in animals given 3 or 4 pituitary transplants than in the remaining groups. These results provide further evidence that prolactin increases the number of LH/hCG and prolactin receptors in the hamster testis and suggest that changing the number of ectopic pituitary transplants may result in biphasic effects on the testis, with 2 or 3 transplants being maximally stimulatory.

Testicular LH receptors during aging in Fisher 344 rats

Levels of serum LH, prolactin, testosterone, progesterone and 17-OH progesterone and the testicular concentration and total content of LH receptors were measured in 4-, 11-, 18-, and 27-month-old Fisher 344 rats. All 27-month-old rats had Leydig cell tumors. At first, testicular LH receptor levels decreased with age, but with the appearance of the testicular tumors, these levels increased dramatically. Serum prolactin levels fluctuated with age, but were significantly decreased in 27-month-old rats, as were serum LH levels. Serum testosterone levels decreased steadily with age, while the testosterone-LH receptor ratio remained constant until the appearance of the testicular tumors, after which the ratio decreased precipitously. Serum progesterone levels remained constant throughout the life of Fisher 344 rats until the appearance of testicular tumors, when they increased dramatically. Serum 17-OH progesterone levels were increased significantly at 11 and 27 months as compared to four months of age, but levels at 18 months were similar to those seen in the 4-month-old animals. Therefore, in aged Fisher 344 rats with spontaneous Leydig cell tumors, there is an alteration in the testicular testosterone synthesizing pathway at a step after progesterone.

Autoregulation of testicular luteinizing hormone receptors in hypogonadal (hpg/hpg) mice

The autoregulation of testicular luteinizing hormone (LH) receptors was studied in hypogonadal (hpg/hpg) and normal mice. The basal concentration of LH receptors was more than three-fold higher in hpg/hpg than in normal mice. After injection of hCG, hpg/hpg mice showed a decrease in LH receptor levels which was not observed in normal mice. Plasma testosterone was undetectable in hpg/hpg mice, even after treatment with a single dose of hCG. Plasma prolactin levels were higher in hpg/hpg than in normal mice. The increase in basal LH receptor levels is thought to be due to a compensatory mechanism in which elevated prolactin could play a role. The differences between hpg/hpg and normal mice in the autoregulation of LH receptors observed could be due to the "hypersensitivity" of the physiologically immature testis in hpg/hpg mice to the action of hCG, to gonadotropin deficiency, particularly during the earlier stages of development, or to a direct effect of the hpg locus on the metabolism of LH receptors.

Altered hypothalamic monoamine metabolism and pituitary prolactin regulation in female spontaneously hypertensive rats

Prolactin (PRL) secretion after aromatic amino acid decarboxylase inhibition with NSD-1015 was significantly elevated in female spontaneously hypertensive rats (SHR) as compared to normotensive (WKY) controls. Although basal PRL levels tended to be elevated in SHR rats, the differences were not significant. In vitro PRL secretion was also significantly elevated in the SHR rats as compared to the WKY rats, but the SHR rats were more responsive to the inhibitory effects of dopamine (DA). Despite changes in pituitary PRL secretion and DA response, there was no apparent difference in tubero-infundibular DA activity between the two rat strains. Hypothalamic serotonin levels were elevated in SHR rats, but metabolism did not appear to be significantly changed based on measurements of 5-hydroxytryptophan accumulation after NSD-1015 treatment.

Effects of alleles at the W locus on testicular luteinizing hormone receptors in adult mice

The autoregulation of testicular LH receptors was studied in Wx/Wv mice with germ cell aplasia and in normal (+/+) mice. To assess the effects of each individual allele, Wx/+ and Wv/+ mice were also examined. Basal testicular LH receptor concentration was higher in Wx/Wv mice than in all other genotypes, and higher in Wx/+ than in +/+ mice. Twenty-four h after injection of 0.3 IU hCG/g bw, LH receptor concentration was decreased in +/+ and Wv/+ mice, but not in Wx/Wv or Wx/+ animals. Administration of hCG caused a significant increase in plasma testosterone levels in all genotypes. However, injection of the highest dose of hCG used (0.9 IU/g bw) caused a significantly greater elevation in plasma testosterone in Wx/Wv than in +/+ mice. Plasma gonadotropin levels were significantly higher in Wx/Wv mice than in all other genotypes. The present results indicate that the Wx allele is responsible for the changes in testicular function observed in Wx/Wv mice, and suggest that this allele may be involved in the genetic regulation of testicular LH receptors in the mouse.

Relationship of the length of exposure to short photoperiod to the effect of prolactin on pituitary and testicular function in the golden hamster

Adult male golden hamsters were given ectopic pituitary transplants at the time of transfer from a long (stimulatory) photoperiod (14 h L:10 h D) to a short photoperiod (5L:19D) or at various intervals thereafter. Grafts given at the time of transfer to 5L:19D failed to maintain plasma FSH levels significantly above those observed in sham-operated controls or to prevent regression of the testes. Grafts given after 4 weeks in 5L:19D increased plasma FSH levels and significantly diminished the decrease in testicular volume. Grafts given 14 weeks after transfer to 5L:19D caused a modest increase in plasma FSH levels and did not significantly alter the time course of testicular redevelopment. Similarly, grafts given 18 weeks after transfer to 5L:19D had no effect on testicular weight measured 2.5 weeks later. These results indicate that the ability of prolactin (secreted by the grafted pituitary) to increase testicular size and the responsiveness of the hypothalamic-pituitary system to prolactin gradually increase during short photoperiod-induced testicular regression, are maximal when the testes are fully regressed and decrease again during spontaneous redevelopment of the testes. We suggest that the effects of prolactin on the testes in golden hamsters are partly mediated by prolactin-induced stimulation of FSH release from the in-situ pituitary.

Teaching andrology in U.S. and Canadian medical schools: a questionnaire

Based on the questionnaires answered by 60 of the 140 schools surveyed, it is apparent that the teaching of andrology receives little emphasis in the schools' curricula. The lack of support given to the teaching of andrology is more evident at the postgraduate than at the undergraduate level. Although andrology is relatively new as an independent biochemical specialty, it is suggested that increased availability of information on andrology to students and physicians would have a positive impact on the quality of health care.