[La ménopause et le traitement hormonal de la ménopause : une actualisation]

Postmenopausal hormone therapy (MHT) is mainly used for the relief of menopausal symptoms. It can also be prescribed for the treatment of postmenopausal osteoporosis, but nowadays, other medications are given to older patients for this indication. Current, available data, demonstrates that MHT is beneficial as well as safe for postmenopausal, symptomatic women. Modern regimens of MHT comprise lower dosages of estrogens than in the past, either safer progestins or SERMs. These regimens should be the preferred option for women with a uterus. Non-androgenic progestin may present reduced thrombotic and breast cancer risks, and transdermal oestrogen could have a reduced thrombotic risk. Oestrogen-only therapy is the preferred option for women who underwent a hysterectomy. Vaginal oestrogen therapy is indicated for women with atrophic vaginitis and recurrent urinary tract infections.

Route of transmission might influence the clinical expression of periodontal lesions in "human immunodeficiency virus" positive patients

BACKGROUND

Various routes have been reported with respect to the transmission of human immunodeficiency virus (HIV) from one individual to another. But it is not clear whether they alter the clinical expression of the disease. This study was conducted to know whether there exists any difference in the occurrence of periodontal lesions among untreated HIV subjects who acquired the disease either through intravenous drug abuse or sexual contact and to correlate those lesions with immune suppression as indicated by CD 4 T lymphocyte counts.

MATERIALS AND METHODS

In this cross-sectional study 213 HIV-positive subjects who had not started on Highly Active Anti Retroviral Therapy (HAART) were selected and divided into two groups intravenous drug users (IVDU) and non-IVDU (NIVDU). CD 4 T lymphocyte counts were evaluated and clinical examination was done to detect the presence of pathologic periodontal lesions.

RESULTS

Mean probing depth (PD) and clinical attachment level (CAL) are significantly higher in drug users than nondrug users. When periodontal lesions are compared with CD 4 cell counts, it is found that significant inverse relation exists between linear gingival erythema, necrotizing ulcerative periodontitis, and CD 4 counts, but only in nondrug users.

CONCLUSION

An inverse correlation between linear gingival erythema, necrotizing ulcerative periodontitis, and CD 4 counts in NIVDU indicating their reliability as a marker for immune suppression. Periodontitis is more prevalent among drug users indicating some difference in disease expression among the groups.

A humanized monoclonal antibody targeting the β7 integrin selectively blocks intestinal homing of T lymphocytes

BACKGROUND AND PURPOSE

rhuMAb Beta7 is a humanized anti-human β7 monoclonal antibody currently in phase I in inflammatory bowel disease. rhuMAb Beta7 binds the β7 subunit of the integrins α4β7 and αEβ7, blocking interaction with their ligands. These integrins play key roles in immune cell homing to and retention in mucosal sites, and are associated with chronic inflammatory diseases of the gastrointestinal tract. The goal of this study was to evaluate the mucosal specificity of rhuMAb Beta7.

EXPERIMENTAL APPROACH

We assessed the effect of murine anti-Beta7 on lymphocyte homing in mouse models of autoimmune disease. We also compared the effect of rhuMAb Beta7 on circulating mucosal-homing versus peripheral-homing T cells in naïve non-human primates.

KEY RESULTS

In cynomolgus monkeys, occupancy of β7 integrin receptors by rhuMAb Beta7 correlated with an increase in circulating β7(+) mucosal-homing lymphocytes, with no apparent effect on levels of circulating β7(-) peripheral-homing lymphocytes. rhuMAb Beta7 also inhibited lymphocyte homing to the inflamed colons of severe combined immunodeficient mice in CD45RB(high) CD4(+) T-cell transfer models. Consistent with a lack of effect on peripheral homing, in a mouse model of experimental autoimmune encephalomyelitis, anti-β7 treatment resulted in no amelioration of CNS inflammation.

CONCLUSIONS AND IMPLICATIONS

The results presented here suggest that rhuMAb Beta7 selectively blocks lymphocyte homing to the gastrointestinal tract without affecting lymphocyte trafficking to non-mucosal tissues. rhuMAb Beta7 provides a targeted therapeutic approach with the potential for a more attractive benefit:risk ratio than currently available inflammatory bowel disease therapies.

Natural selection influences AFLP intraspecific genetic variability and introgression patterns in Atlantic eels

Investigating patterns of genetic variation in hybridizing species provides an opportunity to understand the impact of natural selection on intraspecific genetic variability and interspecific gene exchange. The Atlantic eels Anguilla rostrata and A. anguilla each occupy a large heterogeneous habitat upon which natural selection could differentially shape genetic variation. They also produce viable hybrids only found in Iceland. However, the possible footprint of natural selection on patterns of genetic variation within species and introgressive hybridization in Icelandic eels has never been assessed. We revisited amplified fragment length polymorphism data collected previously using population genomics and admixture analyses to test if (i) genetic variation could be influenced by non-neutral mechanisms at both the intra- and interspecific levels, and if (ii) selection could shape the spatio-temporal distribution of Icelandic hybrids. We first found candidate loci for directional selection within both species. Spatial distributions of allelic frequencies displayed by some of these loci were possibly related with the geographical patterns of life-history traits in A. rostrata, and could have been shaped by natural selection associated with an environmental gradient along European coasts in A. anguilla. Second, we identified outlier loci at the interspecific level. Non-neutral introgression was strongly suggested for some of these loci. We detected a locus at which typical A. rostrata allele hardly crossed the species genetic barrier, whereas three other loci showed accelerated patterns of introgression into A. anguilla in Iceland. Moreover, the level of introgression at these three loci increased from the glass eel to the yellow eel stage, supporting the hypothesis that differential survival of admixed genotypes partly explains the spatio-temporal pattern of hybrid abundance previously documented in Iceland.

[Development and validation of laboratory methods for antiretroviral quantitation using HPLC]

OBJECTIVE

Development, validation and error characterization of three analytical methods, by high performance liquid chromatography (HPLC), for the quantitative analysis of ritonavir, saquinavir and abacavir in human plasma.

METHOD

Reagents and instrumentation used, preparation of different standards, sample extraction procedure from biologic matrix, and analytical conditions assayed were detailed to set up three analytical methods. In addition, the validation and the determination of analytical error were also described.

RESULTS

The analytical methods developed for ritonavir, saquinavir and abacavir in human plasma were selective, linear (r2>0.99), precise (coefficients of variation<15%) and accurate (relative errors<15%) over the concentration range selected. The recovery was more than 95% in all methods. Antiretroviral drugs were stable in the storage conditions assayed according to the routine laboratory. The error function discriminated for each analytical method validated was linear in saquinavir (SD=4.84+7.14.10(-2)C) and abacavir (SD=-1.072+3.70.10(-2)C), and non-linear in ritonavir (SD=39.98+2.40.10(-5)C2).

CONCLUSIONS

Three analytical methods were developed and subsequently validated, with validation parameters being within the specifications and attributes of quality established. The error function characterized for each validated method can be used as a heteroscedastic weighting method in the parameter estimation by non-linear regression analysis in clinical pharmacokinetic studies of antiretroviral drugs assayed.

Monoclonal antibody to tumor necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL-R2) induces apoptosis in primary renal cell carcinoma cells in vitro and inhibits tumor growth in vivo

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) triggers apoptosis in a variety of tumor cells through two of its receptors: TRAIL-R1 and TRAIL-R2. We investigate the susceptibility of human renal cell carcinoma (RCC) cells to TRM-1 and HGS-ETR2, 2 human monoclonal agonistic antibodies specific for TRAIL-R1 and TRAIL-R2, respectively. HGS-ETR2 effectively induced apoptotic cell death in 10 of 11 cell cultures, including 2 human RCC cell lines and 9 human primary RCC cell cultures, with a more pronounced effect after preincubation with anti-human IgG Fc. In contrast, TRM-1 was effective in only 1 primary RCC cell culture. The increased effectiveness of HGS-ETR2 for inducing cell death might have been affected by differences in the cell-surface expression of the 2 TRAIL receptors, namely that TRAIL-R2 but not TRAIL-R1 was frequently expressed in most of the RCC cells tested. The activities of caspase-9, -8, -6, and -3 were increased with HGS-ETR2-induced apoptosis, and cell death could be blocked by specific caspase inhibitors for caspase-9, -8, and -3, and the general caspase inhibitor. In vivo administration of HGS-ETR2 with or without cross-linker significantly suppressed tumor growth of subcutaneously inoculated human RCC xenografts in immunodeficient mice. These results suggest the potential utility of TRAIL-R2 antibody as a novel therapeutic agent in RCC.

HGS-ETR1, a fully human TRAIL-receptor 1 monoclonal antibody, induces cell death in multiple tumour types in vitro and in vivo

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in a variety of tumour cells through activation of TRAIL-R1 and TRAIL-R2 death signalling receptors. Here, we describe the characterisation and activity of HGS-ETR1, the first fully human, agonistic TRAIL-R1 mAb that is being developed as an antitumour therapeutic agent. HGS-ETR1 showed specific binding to TRAIL-R1 receptor. HGS-ETR1 reduced the viability of multiple types of tumour cells in vitro, and induced activation of caspase 8, Bid, caspase 9, caspase 3, and cleavage of PARP, indicating activation of TRAIL-R1 alone was sufficient to induce both extrinsic and intrinsic apoptotic pathways. Treatment of cell lines in vitro with HGS-ETR1 enhanced the cytotoxicity of chemotherapeutic agents (camptothecin, cisplatin, carboplatin, or 5-fluorouracil) even in tumour cell lines that were not sensitive to HGS-ETR1 alone. In vivo administration of HGS-ETR1 resulted in rapid tumour regression or repression of tumour growth in pre-established colon, non-small-cell lung, and renal tumours in xenograft models. Combination of HGS-ETR1 with chemotherapeutic agents (topotecan, 5-fluorouracil, and irinotecan) in three independent colon cancer xenograft models resulted in an enhanced antitumour efficacy compared to either agent alone. Pharmacokinetic studies in the mouse following intravenous injection showed that HGS-ETR1 serum concentrations were biphasic with a terminal half-life of 6.9–8.7 days and a steady-state volume of distribution of approximately 60 ml kg⁻¹. Clearance was 3.6–5.7 ml⁻¹ day⁻¹ kg⁻¹. These data suggest that HGS-ETR1 is a specific and potent antitumour agent with favourable pharmacokinetic characteristics and the potential to provide therapeutic benefit for a broad range of human malignancies.

[Role of plasminogen activator inhibitor type 1 in tumor angiogenesis]

The plasminogen/plasmin system plays a key role in cancer progression, presumably via mediating extracellular matrix degradation and tumour cell migration. High levels of components of the plasminogen activation system, and paradoxically also its inhibitor, plasminogen activator inhibitor 1 (PAI-1), have been correlated with a poor prognosis for patients with cancers of different types. Recent findings clearly suggest that PAI-1 is essential for capillary sprouting during tumour angiogenesis. Moreover, there is accumulating evidence that both the urokinase receptor and PAI-1 are multifunctional proteins involved not only in extracellular matrix proteolysis but also in cellular adhesion and migration through their binding site for vitronectin. The understanding of whether PAI-1 plays a regulatory role in angiogenesis by tightly controlling proteolytic activity or by influencing cell migration could allow a new anti-angiogenic approach for tumour therapy.

New functions of stromal proteases and their inhibitors in tumor progression

Acquisition of invasive metastatic potential through protease expression is a key event in tumor progression. In carcinomas, the production of metalloproteinases and serine proteinases is regulated by a cross talk between stromal cells and cancer cells. Paradoxically, high rather than low levels of their inhibitors predict poor survival of patients suffering from a variety of cancers. Recent observations suggest a much more complex role of these inhibitors in tumor progression than expected initially.

Reducing welfare benefits: consequences for adequacy of and eligibility for benefits

During the past two decades, most states have allowed welfare benefit levels to erode with inflation. Very little attention has been paid by academics and policy makers to the potential effects of the Personal Responsibility and Work Opportunity Reconciliation Act of 1996 on welfare benefit levels. This article provides a number of explanations for likely reductions in states' welfare benefit levels. Consequences of reducing welfare benefit levels are examined. The article shows how small changes in benefit levels can alter profoundly eligibility for welfare. Social workers need to advocate for increases in welfare benefit levels which, at the very least, keep up with inflation.

The inferior non recurrent laryngeal nerve: a major surgical risk during thyroidectomy

It is now widely established that systematic intraoperative location and diligent dissection of the recurrent inferior laryngeal nerve during thyroidectomy are the keystones to assure its anatomic and functional preservation. The possibility of abnormal routes, like a non-recurrent cervical course of the inferior laryngeal nerve is an additional major argument for its systematic identification to avoid surgical damage. In 2517 cervicotomies performed between 1992 and 1997 for at least right thyroid lobe excision or parathyroid glands exploration, 20 cases of non recurrent laryngeal nerve were identified (0.79%). The embryological nature of such a nervous anatomical variation results originally from a vascular disorder, named arteria lusoria in which the fourth right aortic arch is abnormally absorbed, being therefore unable to drag the right recurrent laryngeal nerve down when the heart descends and the neck elongates during embryonic development. The surgeon must be aware of the possibility of a non recurrent laryngeal nerve, which arises directly from the cervical vagus and therefore represents a severe potential pitfall during thyroidectomy. Given the absence of reliable clinical symptoms and signs or investigations indicating preoperatively the possibility of a non recurrent nerve, guidelines are given to prevent intraoperatively this major surgical risk.

Identifying substance abusing delivering women: consequences for child maltreatment reports

OBJECTIVE

The major objective was to determine how and the extent to which SB2669, which requires the identification of substance abusing delivering women, affected the number of children reported for abuse or neglect in several California counties.

METHOD

A monthly time-series model from April 1988 to December 1995 was constructed. The idea underlying the model was that month-to-month changes in the number of child maltreatment reports was a response to the presence of SB2669 in addition to various demographic, social, and economic factors. By separately estimating each county's number of reports, it was assumed that SB2669 did not necessarily affect each county's reports by the same amount, perhaps partially because of different counties' implementation strategies or general policies. Our sampling size consisted of seven high prevalence counties.

RESULTS

The results suggest that the effects of SB2669 on the number of child maltreatment reports are mixed. On an aggregate level, all else constant, and at least for a few years after the passage of SB2669, SB2669 is associated with a decrease in child maltreatment reports in two of the participating counties. This decrease may be due to conscientious implementation of the legislation in these counties. This mixed finding is expected mainly because SB2669, although mandated, was never enforced. Moreover, from the process component of the study we learned that the implementation practices of this legislation vary substantially between and even within counties' hospitals.

CONCLUSIONS/FUTURE DIRECTIONS

A decrease in maltreatment reports in the presence of SB2669 is not necessarily the most desirable outcome in the light of what we know about the relationship between substance abuse and child maltreatment. Law makers need to rethink the purpose of the law and provide the necessary language, tools and training to ensure that the goals of identifying substance abusing mothers and their families are met. Provisions also need to be made that somehow enforce this legislation. These provisions could lessen county-level and hospital-level variability in implementing the law.

Urokinase and the intestinal mucosa: evidence for a role in epithelial cell turnover

BACKGROUND

The functions of urokinase in intestinal epithelia are unknown.

AIMS

To determine the relation of urokinase expressed by intestinal epithelial cells to their position in the crypt-villus/surface axis and of mucosal urokinase activity to epithelial proliferative kinetics in the distal colon.

METHODS

Urokinase expression was examined immunohistochemically in human intestinal mucosa. Urokinase activity was measured colorimetrically in epithelial cells isolated sequentially from the crypt-villus axis of the rat small intestine. In separate experiments, urokinase activity and epithelial kinetics (measured stathmokinetically) were measured in homogenates of distal colonic mucosa of 14 groups of eight rats fed diets known to alter epithelial turnover.

RESULTS

From the crypt base, an ascending gradient of expression and activity of urokinase was associated with the epithelial cells. Median mucosal urokinase activities in each of the dietary groups of rats correlated positively with autologous median number of metaphase arrests per crypt (r=0.68; p<0.005) and per 100 crypt cells (r=0.75; p<0.001), but not with crypt column height.

CONCLUSIONS

Localisation of an enzyme capable of leading to digestion of cell substratum in the region where cells are loosely attached to their basement membrane, and the association of its activity with indexes of cell turnover, suggest a role for urokinase in facilitating epithelial cell loss in the intestine.

Ectopic expression of bone sialoprotein in human thyroid cancer

Bone sialoprotein (BSP) is a small, highly posttranslationally modified integrin binding protein found in the mineral compartment of developing bone. The recent discovery that BSP can be detected in a variety of human cancers, particularly those that metastasize preferentially to the skeleton, shed light on potential new biological functions for this protein. The demonstration of a positive association between BSP expression in primary breast tumors and the development of bone metastases suggests that this glycoprotein could play a role in the selective implantation of breast cancer cells in bone. BSP is also expressed in most lung and prostate cancers as well as in multiple myeloma, three other osteotropic malignancies. Because thyroid carcinoma also metastasizes preferentially to the skeleton, we decided to look at the expression of BSP in a collection of 145 thyroid malignant lesions including 24 follicular thyroid carcinomas (FTCs), 55 papillary thyroid carcinomas (PTCs), 19 medullary thyroid carcinomas (MTCs), 23 anaplastic carcinomas (ACs), and 24 poorly differentiated carcinomas (PDCs). BSP expression was evaluated by immunoperoxidase technique using two specific polyclonal antibodies. Most of the thyroid carcinomas (72%) examined expressed high levels of BSP. Expression of BSP was significantly lower in FTCs and MTCs compared with PDCs, which are more aggressive (p = 0.0009 and 0.0003, respectively). Our study demonstrates for the first time that ectopic BSP expression is a common feature of thyroid cancer. The prognostic value of BSP detection in thyroid adenocarcinoma and the potential role of BSP in the propension of this type of cancer to metastasize to bone are currently under investigation.

Wheat bran suppresses potato starch--potentiated colorectal tumorigenesis at the aberrant crypt stage in a rat model

BACKGROUND & AIMS

Starch that escapes digestion in the small intestine (resistant starch [RS]) may act similarly to nonstarch polysaccharides in the colon. The aim of this study was to examine the effect of raw potato starch alone and in combination with wheat bran on tumor development and precancer events in a rat model of colorectal cancer.

METHODS

Three groups of rats received either a low-RS/low-fiber ("basic") diet, the basic diet containing raw potato starch as 20% of carbohydrate content, or the potato starch diet plus 10% of "wheat bran" fiber. Epithelial proliferation, aberrant crypt foci (ACF), and tumors were measured 6 and 20 weeks after a 10-week course of dimethylhydrazine.

RESULTS

Rats on the potato starch diet had tumors more frequently and had larger tumors than rats consuming the wheat bran or basic diets. Parallel effects on the density of ACF were found 6 weeks after the carcinogen. Although epithelial proliferation was significantly enhanced by potato starch compared with the basic diet, the addition of wheat bran did not suppress this enhancement.

CONCLUSIONS

This type-2 RS enhances epithelial proliferation, ACF density, and tumor formation. The addition of wheat bran to an RS-containing diet suppresses tumorigenesis, acting on events responsible for the formation of ACF but not the events controlling the hyperproliferative phase.

Serum-free organ culture of suckling rat jejunum: effect of regulatory hormones

To facilitate the study of regulators of differentiation and proliferation of small intestinal epithelium in the suckling rat we have developed a serum-free organ culture system and used it to examine epithelial responsiveness to various regulatory hormones. These hormones included the insulin-like growth factors (IGFs) whose action can be blocked by binding proteins in serum. Jejunal explants from 5-day-old suckling rats maintained better brush border enzyme activity and better histology when cultured under hyperbaric conditions for 24 h in serum-free Dulbecco's modified Eagle's medium/F12 medium than in RPMI 1640 plus 10% fetal bovine serum. Tissue responsiveness to various regulatory hormones was then tested in the serum-free medium. Insulin had no significant effect on morphology, proliferation rate, or enzyme activity in 5-day explants after 24 h in culture. However, insulin did increase lactase activity and induce the early appearance of sucrase in 10- and 12-day explants after 48 h in culture. Dexamethasone increased specific activities of alkaline phosphatase (30%, P < 0.001) and lactase (15%, P < 0.001), and reduced shedding of alkaline phosphatase into the medium (P < 0.001), in explants of 5-day-old rats cultured over 24 h. Dexamethasone combined with insulin had no obvious effect on the rate of protein or DNA synthesis but did increase villus height (P = 0.04) and crypt depth (P = 0.001) and acted synergistically to further increase lactase activity above levels obtained by either alone. IGF-I and IGF-II, des-(1-3)IGF-I, fibroblast growth factor (FGF), and growth hormone (GH) had no effect on morphology or biochemical activity of explants after 24 or 48 h culture.(ABSTRACT TRUNCATED AT 250 WORDS)

Differentiation status of rat enterocytes after intestinal adaptation to jejunoileal bypass

The differentiation status of epithelial cells in intestinal adaptation remains unclear. To determine whether enterocytes reach optimum maturity following adaptation after 85% shortening of the rat gut by jejunoileal bypass surgery, activities of two brush border enzymatic markers of differentiation, alkaline phosphatase and sucrase, were examined in subpopulations of epithelial cells isolated sequentially from the villus/crypt axis of normal (sham operated) and hyperplastic mucosa. In jejunal villi, adaptational hyperplasia was associated with an increase in total epithelial alkaline phosphatase, but not total sucrase, activity; alkaline phosphatase activity increased most obviously in cells at the 11-50% position (from the tip) on villi. In hyperplastic ileal villi, total alkaline phosphatase activity fell, although sucrase activity did not change significantly. Specific activity (per mg protein) of sucrase on jejunal villus epithelium was reduced by the adaptational changes to bypass; alkaline phosphatase specific activity remained unchanged. In the ileum, despite adaptational changes to bypass, there was no increase in the normally low specific activities of sucrase and alkaline phosphatase. Bypass surgery did not change the major site of expression of either enzyme on jejunal or ileal villi. In conclusion, enzymatic markers of functional differentiation are not all equally affected by adaptational hyperplasia. Hypertrophy of villi and increased cell proliferation seen in jejunum remaining exposed to luminal contents resulted in an increase in the alkaline phosphatase but not the sucrase content. This is not, therefore, the result of a simple immaturity of villus cells. Morphological adaptation in the ileum, however, is not accompanied by adaptation of brush border enzyme markers of differentiation, confirming a functional immaturity of these cells. Strategies for increasing the expression of these markers may have clinical value.

Relationship between the sympathetic nervous system and vascular smooth muscle: a morphometric study of adult and juvenile spontaneously hypertensive rat/Wistar-Kyoto rat caudal artery

The relationship between the sympathetic nervous system and vascular smooth muscle has been assessed in adult and juvenile spontaneously hypertensive rats (SHR) and compared with age-matched Wistar-Kyoto rats (WKY) using ultrastructural and light microscopic morphometric analysis of the caudal artery. The absolute volume of smooth muscle in the caudal artery of adult SHR (14-19) months was 169% greater than that in WKY vessels. As well, the axonal volume was 89% greater than that in the WKY. There was also a 51% increase in the number of vesicles per volume of varicosity in SHR compared to WKY. At 3 weeks of age the volume of both smooth muscle and axons within the caudal artery of SHR and WKY was not significantly different. However, there was a significantly greater number of vesicles (25%) per unit volume of varicosity in the SHR compared to the WKY. Thus, in the caudal artery there appears to be a relationship between smooth muscle cell volume and axonal volume. An increase in arterial smooth muscle volume (whether it be due to growth or hypertrophy) is accompanied by an increase in axonal volume, or vice versa. The significant increase in the number of vesicles per unit volume of varicosity in the SHR, compared to the WKY reported here, is consistent with other published data indicating an increased availability or turnover of transmitter in these animals. Since the blood pressures of the SHR and WKY are similar at 3 weeks, the apparent increase in sympathetic nerve activity observed suggests that this may be an initiating factor in the development of high blood pressure in SHR.

Systemic factors are trophic in bypassed rat small intestine in the absence of luminal contents

Mucosal histology, crypt cell proliferation and brush border enzymes were measured in rats with varying degrees of jejunoileal bypass, in order to compare the effect of systemic and luminal factors on adaptive growth and differentiation (brush border enzymes) in small intestinal epithelium. Eighty five percent jejunoileal bypass caused a functional short gut; in intestine remaining in continuity there were significant increases in segmental weight, villus area and crypt depth, compared with sham operated controls and 25% jejunoileal bypass rats. Despite villus cell hyperplasia in 85% bypass rats, mucosal sucrase and alkaline phosphatase fell in jejunum and remained low in ileum, while leucine amino peptidase rose in ileum. There was a significant fall in villus area (p less than 0.01) and crypt cell production (p less than 0.001) in self emptying loops of 25% bypass rats not exposed to luminal contents compared with control segments of sham operated rats. In contrast, self emptying loops of 85% bypass rats were not atrophied despite the much greater distance from luminal nutrients; the villus area (p less than 0.01) and crypt cell production (p less than 0.005) were higher than in 25% bypass rats, and at least as great as in sham operated rats. These results indicate that adaptive hyperplasia has a variable effect on expression of brush border enzymes which might reflect villus cell immaturity. The atrophic effect of diversion of luminal contents can be counteracted by systemic growth factors released as part of the adaptive response; thus systemic growth factors are not dependent on a permissive effect of luminal contents.

Dietitians' development of an enteral nutrition management package

Several dietitians at the Royal Victoria Hospital, Montreal, examined current hospital practices in enteral feeding and defined three major areas of concern that are known to influence the management of enterally-fed patients. These concerns deal with physicians' perceptions, nursing management and cost. In order to address these concerns and consequently improve the management of enterally-fed patients, an Enteral Nutrition Management Package consisting of an order form, flow sheet and monitoring record was developed. The package provides standardized guidelines for enterally-fed patients and emphasizes the need for monitoring patients' clinical progress. The usefulness of the package is dependent upon the participation of every member of the health care team including the physician, nurse and dietitian. The development of the package is the result of initiative taken by clinical dietitians in addressing patient care concerns in enteral nutrition within a multidisciplinary system.

Olfactory bulb dopamine neurons survive deafferentation-induced loss of tyrosine hydroxylase

Peripheral deafferentation of the rodent olfactory bulb results in loss of dopamine content, tyrosine hydroxylase activity and immunocytochemical staining for tyrosine hydroxylase in juxtaglomerular dopamine neurons. Reinnervation of the bulb by afferent neurons results in the return of all parameters to control levels suggesting that the dopamine neurons did not degenerate but that the expression of tyrosine hydroxylase enzyme was transneuronally regulated in a static population of juxtaglomerular cells. To evaluate this possibility, we determined the activity and immunocytochemical localization of the second enzyme in the dopamine biosynthetic pathway, DOPA decarboxylase. At a time when tyrosine hydroxylase activity was reduced to 25% of control values, DOPA decarboxylase activity in the lesioned bulb was maintained at about 65% of that in the unlesioned bulb. Immunocytochemical staining with antibodies to both enzymes, performed sequentially in the same sections, demonstrated that in the unlesioned bulb tyrosine hydroxylase and DOPA decarboxylase are co-localized in the same population of juxtaglomerular neurons. Similar results were obtained in adjacent sections each stained with one of the two antibodies. In contrast, in the deafferented bulb, about three times as many neurons were stained with DOPA decarboxylase as with tyrosine hydroxylase antibodies. The DOPA decarboxylase activity measurements and immunocytochemistry argue for the continued presence, in the lesioned olfactory bulb, of a population of tyrosine hydroxylase deficient dopamine neurons. The data suggest that olfactory receptor cell innervation transneuronally regulates the expression of tyrosine hydroxylase by mechanisms separate from those controlling the levels of DOPA decarboxylase.

Catecholamine-serotonin interaction effects on activity in rats neonatally treated with 6-hydroxydopamine

The effect of increased central serotonergic levels on motor activity was investigated in rats neonatally treated with 6-hydroxydopamine (6-OHDA) in the lateral ventricles. Regional brain assays of monoamine levels in 90-day-old rats showed depletion of catecholamines, but not of serotonin, in the forebrain accompanied by a large elevation of norepinephrine, and minor elevation of serotonin, in the hindbrain. Measures of behavioral activity in adulthood were taken after treatment with saline, pargyline, L-tryptophan, or pargyline given 30 min before L-tryptophan. The combined treatment of pargyline plus L-tryptophan produced hyperactivity in controls and this effect was blocked in the 6-OHDA-treated animals. These findings indicate that the serotonergic system is capable of influencing motor activity, but that this influence is blocked in animals permanently depleted of catecholamines in their terminal field regions.