Genetics of canine myxomatous mitral valve disease

Myxomatous mitral valve disease (MMVD) is the most common heart disease and cause of cardiac death in domestic dogs. MMVD is characterised by slow progressive myxomatous degeneration from the tips of the mitral valves onwards with subsequent mitral valve regurgitation, and left atrial and ventricular dilatation. Although the disease usually has a long asymptomatic period, in dogs with severe disease, mortality is typically secondary to left-sided congestive heart failure. Although it is not uncommon for dogs to survive long enough in the asymptomatic period to die from unrelated causes; a proportion of dogs rapidly advance into congestive heart failure. Heightened prevalence in certain breeds, such as the Cavalier King Charles Spaniel, has indicated that MMVD is under a genetic influence. The genetic characterisation of the factors that underlie the difference in progression of disease is of strong interest to those concerned with dog longevity and welfare. Advanced genomic technologies have the potential to provide information that may impact treatment, prevalence, or severity of MMVD through the elucidation of pathogenic mechanisms and the detection of predisposing genetic loci of major effect. Here we describe briefly the clinical nature of the disorder and consider the physiological mechanisms that might impact its occurrence in the domestic dog. Using results from comparative genomics we suggest possible genetic approaches for identifying genetic risk factors within breeds. The Cavalier King Charles Spaniel breed represents a robust resource for uncovering the genetic basis of MMVD.

Association of changes in mental health with weight loss during intensive lifestyle intervention: does the timing matter?

Objective

This study examined changes in mental health symptoms and weight during weight loss treatment. It was hypothesized that worsening mental health would negatively impact weight loss.

Methods

Data were analyzed from a trial of 92 Hispanic women with overweight/obesity and prediabetes, who were randomized to receive intensive lifestyle intervention (ILI), metformin 1,700 mg daily, or standard care. Depression, anxiety and perceived stress were assessed at 0, 6 and 12 months. Six‐ and 12‐month weight change was compared among participants whose symptom scores worsened on any mental health measure (W) vs. improved or remained stable on all three (I/S).

Results

Among ILI participants, the 12‐month difference in weight loss between I/S and W groups was statistically significant: −5.1 kg (P = 0.001). From baseline to 6 months, ILI participants in I/S and W groups experienced comparable weight loss. However, from 6 to 12 months, W participants regained weight, whereas I/S participants experienced continued weight loss. In the metformin and standard care arms, there was no weight difference between I/S and W groups.

Conclusions

In ILI, 12‐month improvement or stability in mental health was significantly associated with weight loss. Weight trajectories between I/S and W groups diverged at 6 months.

Limited low-air insufflation is optimal for colonoscopy

BACKGROUND

Air insufflation is essential in routine colonoscopy, but obtaining optimal insufflation levels has not been discussed in the literature. The aim of this study was to determine optimal air insufflation during colonoscopic examination.

METHODS

Consecutive patients who underwent colonoscopy were randomized to receive high-air insufflation (group A, n = 83), low-air insufflation (group B, n = 84), or low-air insufflation limited to the rectum and sigmoid colon (group C, n = 83). Completion rate, cecal intubation time, propofol dose, need for abdominal compression, and turning of patients, were evaluated. The post-procedure abdominal bloating was assessed with a 0-10 visual analog scale.

RESULTS

The completion rates were similar among the three groups. The cecal intubation time was significantly shorter in group C than in group B (4.1 +/- 1.7 min vs. 5.2 +/- 3.0 min, mean +/- SD, p = 0.005). The dose of propofol was significantly less in group C than in group A (11.7 +/- 3.2 mg vs. 12.7 +/- 3.6 mg, mean +/- SD, p = 0.045). Group C needed the least manual abdominal compression (group A, B, and C: 81.9, 69, and 59%, respectively, p = 0.005) and had the least post-procedure abdominal bloating (group A, B, and C: 2.2 +/- 2.4, 2.2 +/- 2.1, and 1.5 +/- 1.9, respectively, p = 0.04).

CONCLUSIONS

We found that limited use of low-air insufflation in the rectum and sigmoid is the procedure of choice for colonoscopic examination.

Effect of in vitro maturation of mouse oocytes on the health and lifespan of adult offspring

BACKGROUND

In vitro maturation of oocytes can, in some circumstances, provide an alternative approach to gonadotrophin-induced maturation in clinical settings. However, the consequences of these protocols on the long-term health of offspring are unknown. Here, the long-term health status and lifespans of offspring produced by in vitro maturation of mouse oocytes was compared with that of oocytes induced to mature in vivo using gonadotrophin treatment.

METHODS

Mouse oocytes were matured in vitro using both an established optimized system and in the absence of amino acids to produce a suboptimal condition for maturation. Oocytes induced to mature in vivo with gonadotrophins constituted the control group. All metaphase II oocytes were fertilized in vitro and transferred at the 2-cell stage to the oviducts of pseudo-pregnant foster mothers for development to term. Offspring were subjected to a wide variety of physiological and behavioral tests for the first year of life and natural lifespan determined.

RESULTS

There was no difference among the groups in lifespan or in most of the physiological and behavioral analyses. However, the pulse rate and cardiac output were slightly, but significantly, reduced in the optimized in vitro matured group compared with the in vivo matured group (P = 0.0119 and P = 0.0197, respectively). Surprisingly, these decreases were largely abrogated in the in vitro group matured without amino acids.

CONCLUSIONS

Evidence presented here using a mouse model suggests that the in vitro maturation of oocytes has minimal effects on the long-term health of offspring. However, a finding of slight reductions in pulse rate and cardiac output may focus future clinical attention.

The preantral granulosa cell to cumulus cell transition in the mouse ovary: Development of competence to undergo expansion

The transition of preantral to antral follicles is one of the major steps in follicular development, yet little is known about the molecular and functional changes that occur as preantral granulosa cells differentiate into cumulus cells. The cumulus oophorus of large antral follicles undergoes expansion in response to the preovulatory surge of gonadotropins, but preantral granulosa cells do not. The objective of this project was to determine the molecular mechanisms underlying this differential response. Cumulus expansion in vitro requires secretion of cumulus-expansion enabling factors (CEEFs) by the oocyte and stimulation by a ligand, epidermal growth factor (EGF) or follicle-stimulating hormone (FSH). This combined stimulation results in activation of MAPKs (MAPK3/1 (formerly ERK1/2) and MAPK14 (formerly p38)) and increased Has2, Ptgs2, Tnfaip6 and Ptx3 mRNA levels, all of which are required for cumulus expansion. Only fully-grown oocytes from antral follicles were competent to enable expansion and increases in expansion-related transcripts in cumulus cells, whereas growing oocytes of preantral follicles did not. To assess the competence of preantral granulosa cells to generate responses associated with expansion, they were treated with FSH or EGF and co-cultured with fully-grown oocytes secreting CEEFs. MAPKs were activated by EGF in preantral granulosa cells to essentially the same levels as in cumulus cells. Preantral granulosa cells treated with EGF, but not those treated with FSH increased Has2, Ptgs2 and Ptx3 mRNAs to 17-96% of the levels observed in cumulus cells. In contrast, the level of Tnfaip6 mRNA was minimally stimulated in preantral granulosa cells. Therefore, preantral granulosa cells do not undergo expansion for two fundamental reasons. First, the growing oocytes of preantral follicles do not secrete active CEEFs. Second, activation of MAPKs alone in preantral granulosa cells, even in the presence of CEEFs, is not sufficient to increase the expression of essential transcripts, particularly Tnfaip6 mRNA. Thus, preantral granulosa cells differ from cumulus cells in CEEF-dependent processes downstream of the activation of MAPKs.

Changes in waste stabilisation pond performance resulting from the retrofit of activated sludge treatment upstream: part I--water quality issues

This paper describes changes in effluent quality occurring before and after an upgrade to the Bolivar Wastewater Treatment Plant in South Australia. Trickling filters (TF) were replaced with an activated sludge (AS) plant, prior to tertiary treatment using waste stabilisation ponds (WSPs). The water quality in the WSPs following the upgrade was significantly improved. Reductions in total and soluble BOD, COD, TKN, suspended solids and organic nitrogen were recorded and the predominant form of inorganic nitrogen changed from NH(4)-N to NO(2)/NO(3)-N. The reduction in ammonium and potentially toxic free ammonia removed a control upon the growth of zooplankton, which may have contributed to decreases in algal biomass in the final ponds and consequently lower dissolved oxygen. Additionally, changes in inorganic nitrogen speciation contributed to a slightly elevated pH which reduced numbers of faecal coliforms in WSPs. The AS pretreated influent recorded significantly lower inorganic molar N:P ratio (10-4:1) compared to those fed with TF effluent (17-13:1). Algae within the WSPs may now be nitrogen limited, a condition which may favour the growth of nitrogen-fixing cyanobacteria. The decrease in algal biomass and in dissolved oxygen levels may enhance sedimentary denitrification, further driving the system towards nitrogen limitation.

Changes in waste stabilisation pond performance resulting from the retrofit of activated sludge treatment upstream: part II--Management and operating issues

Bolivar Wastewater Treatment Plant (WWTP) was originally commissioned with trickling filter secondary treatment, followed by waste stabilisation pond (WSP) treatment and marine discharge. In 1999, a dissolved air flotation/filtration (DAFF) plant was commissioned to treat a portion of the WSP effluent for horticultural reuse. In 2001, the trickling filters were replaced with activated sludge treatment. A shift in WSP ecology became evident soon after this time, characterised by a statistically significant reduction in algal counts in the pond effluent, and increased variability in algal counts and occasional population crashes in the ponds. While the photosynthetic capacity of the WSPs has been reduced, the concomitant reduction in organic loading has meant that the WSPs have not become overloaded. As a result of the improvement in water quality leaving the ponds, significant cost savings and improved product water quality have been realised in the subsequent DAFF treatment stage. A number of operating issues have arisen from the change, however, including the re-emergence of a midge fly nuisance at the site. Control of midge flies using chemical spraying has negated the cost savings realised in the DAFF treatment stage. While biomanipulation of the WSP may provide a less aggressive method of midge control, this case demonstrates the difficulty of predicting in advance all ramifications of a retrospective process change.

A synthetic analogue of meiosis-activating sterol (FF-MAS) is a potent agonist promoting meiotic maturation and preimplantation development of mouse oocytes maturing in vitro

BACKGROUND

Follicular fluid-meiosis-activating sterol (FF-MAS) is a factor present in the pre-ovulatory follicle during the time of oocyte maturation. In mouse oocytes maturing in vitro, FF-MAS promotes the completion of meiotic maturation to metaphase II (MII) and improves competence to complete the 2-cell stage to blastocyst transition. We produced analogues of FF-MAS and selected three on the basis of potency to promote the resumption of meiosis by mouse oocytes maintained in meiotic arrest by hypoxanthine. The objective of this study was to determine whether these FF-MAS analogues also affect the quality of oocytes maturing in vitro with respect to the completion of meiotic maturation and augmenting the frequency of development to the blastocyst stage after fertilization in vitro.

METHODS

Cumulus cell-enclosed oocytes were isolated from the small antral follicles of 18 or 20 day post-natal mice. These oocytes normally have a reduced competence to complete meiotic maturation and preimplantation embryo development. Oocytes were isolated at the germinal vesicle stage and matured in vitro using media supplemented with 0.1% ethanol, 1 micromol/l FF-MAS, or 0.1-10 micromol/l FF-MAS analogues ZK255884 (884), ZK255933 (933) and ZK255991 (991). Oocytes that progressed to MII were fertilized in vitro and the percentage developing to the 2-cell and blastocyst stages was determined.

RESULTS

At 1 micromol/l, 991 and 933 increased the portion of oocytes progressing to MII, whereas the lowest dose of 991 and 884 was ineffective. Treatment of maturing oocytes with either 0.1 or 1 micromol/l 933 dramatically increased oocyte competence to complete preimplantation development.

CONCLUSIONS

The synthetic analogue of FF-MAS, ZK255933, is a potent agonist that improves the quality of mouse oocytes matured in vitro. This compound may therefore have therapeutic value for treatment of oocytes from women undergoing therapy for infertility owing to poor oocyte quality.

Prolapsing mucosal polyps: an underrecognized form of colonic polyp--a clinicopathological study of 15 cases

OBJECTIVE

Prolapsing intestinal mucosa occurs in many forms throughout the GI tract. We describe 15 patients with polypoid masses in the sigmoid colon and histological features of mucosal prolapse.

METHODS

Fifteen patients with colon polyps demonstrating endoscopic and histological features of mucosal prolapse were retrospectively identified from our database.

RESULTS

Twelve patients presented with signs and symptoms that were nonspecific, but consistent with mucosal prolapse, such as occult or gross intestinal bleeding and lower abdominal pain. Three patients were asymptomatic. The polyps occurred in the sigmoid colon, usually in association with diverticular disease, and appeared more often in men. Endoscopically, the polyps appeared to be well-circumscribed, hyperemic masses that contrasted sharply with normal-appearing adjacent mucosa. Histological features include glandular crypt abnormalities, fibromuscular obliteration of the lamina propria, and thickened and splayed muscularis mucosa.

CONCLUSIONS

Prolapsing mucosal polyps of the colon are histologically similar to other mucosal prolapsing conditions in the GI tract, such as the solitary rectal ulcer syndrome, inflammatory cloacogenic polyps, inflammatory "cap" polyps, and gastric antral vascular ectasia, and should therefore be designated as part of the "mucosal prolapse syndrome."

Intercellular communication via connexin43 gap junctions is required for ovarian folliculogenesis in the mouse

The ovarian follicle in mammals is a functional syncytium, with the oocyte being coupled with the surrounding cumulus granulosa cells, and the cumulus cells being coupled with each other and with the mural granulosa cells, via gap junctions. The gap junctions coupling granulosa cells in mature follicles contain several different connexins (gap junction channel proteins), including connexins 32, 43, and 45. Connexin43 immunoreactivity can be detected from the onset of folliculogenesis just after birth and persists through ovulation. In order to assess the importance of connexin43 gap junctions for postnatal folliculogenesis, we grafted ovaries from late gestation mouse fetuses or newborn pups lacking connexin43 (Gja1(-)/Gja1(-)) into the kidney capsules of adult females and allowed them to develop for up to 3 weeks (this was necessitated by the neonatal lethality caused by the mutation). By the end of the graft period, tertiary (antral) follicles had developed in grafted normal (wild-type or heterozygote) ovaries. Most follicles in Gja1(-)/Gja1(-) ovaries, however, failed to become multilaminar, with the severity of the effect depending on strain background. Dye transfer experiments indicated that intercellular coupling between granulosa cells is reduced, but not abolished, in the absence of connexin43, consistent with the presence of additional connexins. These results suggest that coupling between granulosa cells mediated specifically by connexin43 channels is required for continued follicular growth. Measurements of oocyte diameters revealed that oocyte growth in mutant follicles is retarded, but not arrested, despite the arrest of folliculogenesis. The mutant follicles are morphologically abnormal: the zona pellucida is poorly developed, the cytoplasm of both granulosa cells and oocytes is vacuolated, and cortical granules are absent from the oocytes. Correspondingly, the mutant oocytes obtained from 3-week grafts failed to undergo meiotic maturation and could not be fertilized, although half of the wild-type oocytes from 3-week grafted ovaries could be fertilized. We conclude that connexin43-containing gap junction channels are required for expansion of the granulosa cell population during the early stages of follicular development and that failure of the granulosa cell layers to develop properly has severe consequences for the oocyte.

A surface plasmon resonance array biosensor based on spectroscopic imaging

We have developed a multi-element transduction system which combines conventional SPR spectroscopy with one-dimensional SPR microscopy to create an effective platform for monitoring binding events on macro- or micro-patterned receptor arrays created on disposable sensor chips. This creates an effective platform for monitoring simultaneous binding events on each of the regions patterned with the receptors. This system has been specifically designed with commercially available components to allow relatively easy duplication. Furthermore, this system can use a proven, simple method to compensate for changes in the bulk index of refraction of the solution containing the analytes due to changes in temperature or solute concentration with simple modifications to the sensor chips alone. Preliminary results demonstrate how this system can be used to monitor several independent biospecific binding events simultaneously.

An assessment of digital image analysis to measure fibrosis in liver biopsy specimens of patients with chronic hepatitis C

The aim was to assess the validity of a digitally computed fibrosis ratio as a measure of fibrosis stage in liver biopsy specimens. We scored 230 liver biopsy specimens from patients with chronic hepatitis C for fibrosis using modified Knodell criteria; fibrosis ratios were computed from digital images that encompassed the complete trichrome-stained section of each case. Although an overall correlation between fibrosis ratio and ordinal score was present, subset analysis showed that this correlation existed only among biopsy specimens with high scores (3-6, early bridging fibrosis to established cirrhosis). There was no correlation or difference between category means found among biopsy specimens with low scores (0-3, normal to early bridging fibrosis). Furthermore, concordance by both estimates in direction of fibrosis change among serial liver biopsy specimens was found in only 11 (30%) of 37 pairs compared. The findings suggest that a qualitative assessment of the computerized fibrosis pattern is necessary for the interpretation of computerized fibrosis ratio measurements, particularly in patients with early stage fibrosis.

Role of gut-enriched Krüppel-like factor in colonic cell growth and differentiation

Cancer cells differ from normal cells in many aspects, including hyperproliferation and loss of differentiation. Recent research has focused on the role of transcription factors in regulating abnormal cell growth. Gut-enriched Krüppel-like factor (GKLF) is a newly identified eukaryotic zinc finger protein expressed extensively in the gastrointestinal tract. In the current study, we demonstrated that GKLF mRNA levels were significantly decreased in the dysplastic epithelium of the colon, including adenomatous polyp and cancer. GKLF immunostains in the normal colon were higher at the surface epithelium and gradually decreased toward the crypt, but this gradient was not present in the adenomatous and cancerous mucosa. Constitutive overexpression of GKLF DNA in a human colonic adenocarcinoma cell line (HT-29) decreased [(3)H]thymidine incorporation, whereas suppression of GKLF gene increased DNA synthesis, indicating that downregulation of the GKLF gene might contribute to cellular hyperproliferation. Cyclin D1 (CD1) protein level and CD1-associated kinase activity were decreased in HT-29 cell overexpressed GKLF cDNA, and CD1 promoter activity was profoundly suppressed by GKLF. When HT-29 cells were cultured in the presence of sodium butyrate, GKLF mRNA levels increased as cells acquired more differentiated phenotypes. These results suggest that GKLF plays an important role in regulating cell growth and differentiation in the colonic epithelium and that downregulation of GKLF expression may cause colonic cells to become hyperproliferative. Furthermore, GKLF appears to be a transcriptional repressor of the CD1 gene.

A comparison of colonoscopy and double-contrast barium enema for surveillance after polypectomy. National Polyp Study Work Group

BACKGROUND

After patients have undergone colonoscopic polypectomy, it is uncertain whether colonoscopic examination or a barium enema is the better method of surveillance.

METHODS

As part of the National Polyp Study, we offered colonoscopic examination and double-contrast barium enema for surveillance to patients with newly diagnosed adenomatous polyps. Although barium enema was performed first, the endoscopist did not know the results.

RESULTS

A total of 973 patients underwent one or more colonoscopic examinations for surveillance. In the case of 580 of these patients, we performed 862 paired colonoscopic examinations and barium-enema examinations that met the requirements of the protocol. The findings on barium enema were positive in 222 (26 percent) of the paired examinations, including 139 of the 392 colonoscopic examinations in which one or more polyps were detected (rate of detection, 35 percent; 95 percent confidence interval, 31 to 40 percent). The proportion of examinations in which adenomatous polyps were detected by barium enema colonoscopy was significantly related to the size of the adenomas (P=0.009); the rate was 32 percent for colonoscopic examinations in which the largest adenomas detected were 0.5 cm or less, 53 percent for those in which the largest adenomas detected were 0.6 to 1.0 cm, and 48 percent for those in which the largest adenomas detected exceeded 1.0 cm. Among the 139 paired examinations with positive results on barium enema and negative results on colonoscopic examination in the same location, 19 additional polyps, 12 of which were adenomas, were detected on colonoscopic reexamination.

CONCLUSIONS

In patients who have undergone colonoscopic polypectomy, colonoscopic examination is a more effective method of surveillance than double-contrast barium enema.

Conditions that affect acquisition of developmental competence by mouse oocytes in vitro: FSH, insulin, glucose and ascorbic acid

The simplest unit required for the support of oocyte growth and development is the oocyte-granulosa cell complex. Therefore, a culture system was established that utilizes these complexes to assess mechanisms promoting nuclear, cytoplasmic and genomic maturation in mammalian oocytes. Deletion of serum from the culture, results in increased apoptosis in oocyte-associated granulosa cells (OAGCs), however, addition of ascorbic acid (0.5 mM) significantly reduced the level of apoptosis in the OAGCs, although no improvement of oocyte developmental competence was detected. The effects of reducing glucose during oocyte growth were studied since, under some culture conditions, glucose has deleterious effects on early preimplantation development. Reducing the glucose concentration to 1 mM resulted in the production of oocytes with greatly reduced developmental competence. Deleterious effects of FSH plus insulin during oocyte growth in vitro on preimplantation development are reviewed and discussed in terms of the communication of oocytes with inappropriately developing granulosa cells. Evidence that oocytes promote the appropriate differentiation of OAGCs in intact follicles in vivo is also discussed. It is hypothesized that oocytes control the differentiation of these cells, in order to promote intercellular signaling essential for the acquisition of competence to undergo normal embryogenesis.

Rescue of oocytes from antral follicles of cryopreserved mouse ovaries: competence to undergo maturation, embryogenesis, and development to term

Only primordial and primary follicles of frozen-thawed mouse ovaries survive after grafting to the ovarian bursa; large secondary follicles and antral follicles together with the oocytes contained in them degenerate. This study was undertaken to determine whether fully grown oocytes isolated from the antral follicles of frozen-thawed mouse ovaries are viable and can be rescued to undergo maturation, fertilization, and embryo development in vitro. Ovaries were cryopreserved after removal from 22-day-old (C57BL/6J x SJL/J)F(1) mice, with or without prior priming with equine chorionic gonadotrophin, and fresh non-frozen ovaries were used as controls. Only cumulus cell-denuded oocytes were recovered from frozen unprimed ovaries while both cumulus cell-enclosed and denuded oocytes were retrieved from frozen primed ovaries. Oocytes from both groups of frozen-thawed ovaries were able to undergo maturation, fertilization, and development to the blastocyst stage in vitro, though at lower percentages than oocytes from control unfrozen ovaries. Moreover, 19% of 2-cell stage embryos derived from frozen-thawed primed ovaries, compared with 42% of embryos derived from control primed ovaries, developed to term after transfer to pseudopregnant foster mothers (not significantly different). Therefore, fully grown oocytes in antral follicles survive the cryopreservation protocol, as demonstrated by maturation, fertilization and embryo development in vitro, and development to term after embryo transfer.

Epidermal growth factor enhances preimplantation developmental competence of maturing mouse oocytes

The objective of this study was to determine whether epidermal growth factor (EGF) promotes nuclear and cytoplasmic maturation of mouse oocytes grown in vivo or in vitro. In-vivo-grown oocytes were isolated at the germinal vesicle (GV) stage from gonadotrophin-primed (PR) or -unprimed (UPR) 22-day-old mice before in-vitro maturation (IVM). In-vitro-grown (IVG) oocytes were isolated from preantral follicles of 12-day-old mice and grown in vitro without gonadotrophins for 10 days before maturation (IVG/IVM oocytes). IVM and IVG/IVM oocytes were matured in medium supplemented with either EGF (10 ng/ml), follicle stimulating hormone (FSH) (100 ng/ml), EGF plus FSH, or with neither ligand (control). When oocyte-cumulus cell complexes were isolated from PR and UPR mice, IVM with EGF (10 ng/ml), alone or in combination with FSH (100 ng/ml), increased (P < 0.05) the incidence of nuclear maturation to metaphase II. Cytoplasmic maturation of oocytes from PR females, manifested as increased frequency of cleavage to the 2-cell stage and development to the blastocyst stage, was also enhanced with EGF (P < 0.05). Moreover, EGF increased the number of cells per blastocyst, but only in the absence of FSH (P < 0.01). In contrast, EGF, FSH, or EGF plus FSH did not affect the percentage of oocytes from UPR mice completing preimplantation development, but did increase the number of cells per blastocyst. These ligands also increased the proportion of IVG oocytes reaching metaphase II (53-57%) compared with controls (25%; P < 0.05). EGF alone or in combination with FSH increased (P < 0.05) the frequency of blastocyst formation (23% and 28%, respectively) compared with controls (13%). EGF treatment of maturing IVG oocytes produced blastocysts with more cells than other IVG groups (P < 0.05). It is concluded that gonadotrophins in vivo increase the sensitivity or responsiveness of cumulus cell-enclosed oocytes to EGF, thereby promoting both nuclear and cytoplasmic maturation. However, oocyte-granulosa cell complexes grown in vitro become responsive to EGF without gonadotrophin treatment. Thus, nuclear and cytoplasmic maturation of IVG oocytes is promoted by EGF treatment during meiotic maturation.

Comparison of protein synthesis patterns in mouse cumulus cells and mural granulosa cells: effects of follicle-stimulating hormone and insulin on granulosa cell differentiation in vitro

Successful development of mammalian oocytes requires correct interactions between developing oocytes and associated granulosa cells. Development of oocyte-granulosa cell complexes from preantral follicles in vitro does not produce oocytes competent to develop to blastocysts at the same frequency as for oocytes that develop in vivo. Addition of either FSH or insulin to cultures of oocyte-granulosa cell complexes does not improve the frequency of blastocyst development, and the combination of both insulin and FSH is deleterious. Here, high-resolution 2-dimensional PAGE (2D-PAGE) and computerized gel image analysis were used to compare patterns of protein synthesis in cumulus cells and mural granulosa cells of small antral follicles, and then to assess effects of FSH and insulin on the differentiation of oocyte-associated granulosa cells (OAGCs) in vitro. Culture of OAGCs without FSH or insulin resulted in failure to synthesize many proteins at rates characteristic of cumulus cells. Either hormone used alone caused many cumulus cell proteins that were decreased in control cultures to be synthesized at nearly normal cumulus cell rates, and also caused the synthesis of other proteins to be increased or decreased. The two hormones added together produced the greatest change in protein synthetic pattern, including overexpression or underexpression of many proteins not affected by either hormone alone. Addition of these hormones to culture media thus appeared insufficient to elicit a normal cumulus cell phenotype in OAGCs and could lead to complex changes in protein synthesis that may be deleterious to oocyte development. The high-resolution 2D-PAGE approach described here should be a valuable tool in studies on oocyte and granulosa cell development in vitro, since phenotype can be evaluated globally through the display of over 1000 newly synthesized proteins rather than relying upon the expression of just a few genes.

The role of p21ras in pancreatic neoplasia and chronic pancreatitis

K-ras mutations have been detected in both ductal cell carcinoma and intraductal papillary mucinous tumor (IPMT) of pancreas. The frequency of this mutation in ductal cell carcinoma is high, whereas in IPMT, it is variable. It has been suggested that the relatively high frequency of this mutation in ductal cell carcinomas compared with IPMT may account for the differences in biological behavior between these tumor types. More recently, the significance of K-ras mutations in pancreatic tissue has been questioned with the demonstration of this mutation in nonneoplastic pancreata. The current study aims to estimate the relative frequency and evaluate the biological significance of K-ras gene mutations in these neoplasms by performing polymerase chain reaction (PCR) assays of microdissected areas of IPMT, ductal cell carcinomas, and resected chronic pancreatitis. The study also investigates whether alterations of p21ras occur in K-ras mutation-negative cases by using immunohistochemical staining for K-, N- and H-ras. K-ras codon 12 mutations were found almost as frequently in IPMT (71%) as in ductal cell carcinomas (78%). They were also associated with the earliest morphological lesion, flat mucinous change. This mutation also was detected in 42% of cases of chronic pancreatitis. Expression of p21ras was found to correlate closely with K-ras mutation status in IPMT and ductal cell carcinoma. Negative staining for pan-ras, H-ras, and N-ras in cases with wild-type K-ras genes suggests that alternative routes of ras gene alteration are not operative in IPMT or ductal carcinoma. The findings suggest that K-ras activation is frequently associated with both IPMT and ductal cell carcinoma. Its high prevalence in nonneoplastic pancreata suggests that it is also associated with self-limited morphological lesions of the pancreas that do not progress to malignancy.

Factors affecting the developmental competence of mouse oocytes grown in vitro: follicle-stimulating hormone and insulin

This study was undertaken to test the hypothesis that FSH treatment of cultured oocyte-granulosa cell complexes promotes acquisition of competence to complete preimplantation embryo development. Oocyte-granulosa cell complexes were isolated from the preantral follicles of 12-day-old mice and cultured for 10 days in serum-free medium, supplemented with insulin (5 microgram/ml), transferrin (5 microgram/ml), and selenium (5 ng/ml) and containing a highly potent preparation of FSH (0-5 ng/ml). Oocytes were matured and fertilized in vitro and embryos cultured to determine the frequency of development to the blastocyst stage. There was no effect of FSH on oocyte size, general morphology, or competence to resume meiosis. However, addition of FSH to medium containing insulin had a deleterious effect on the percentage of mature oocytes competent to develop to the blastocyst stage. Deletion of insulin from the medium for culture of oocyte-granulosa cell complexes prevented the deleterious effect of FSH, but FSH still did not promote acquisition of competence to complete preimplantation development. Culture of oocyte-granulosa cell complexes with FSH resulted in elevated expression of LH receptor (LHR) mRNA by granulosa cells and stimulated the production of functional LHRs, whether or not insulin was present. However, FSH-induced expression of LHR mRNA reached a maximum steady-state level by 4 days of culture in the presence of insulin, but this level was not reached until 10 days of culture without insulin. Granulosa cells encompassing growing mouse oocytes in vivo do not express LHR mRNA. Thus, expression of LHR mRNA by granulosa cells closely associated with growing oocytes in vitro indicates inappropriate or ambiguous development. In conclusion, conditions occurring during oocyte growth can have profound detrimental effects on oocyte developmental competence to complete preimplantation development, even when oocyte growth, general morphology, and competence to resume meiosis appear unaffected.

7500 years of prehistoric footwear from arnold research cave, missouri

Accelerator mass spectrometer dating of an assemblage of fibrous and leather footwear from Arnold Research Cave in central Missouri documents a long sequence of shoe construction by prehistoric Midwestern peoples, beginning perhaps as early as 8300 calendar years before the present (cal years B.P.). An earlier fibrous sandal form dates from 8325 to 7675 cal years B.P., and later fibrous or leather slip-ons span the period from 5575 to 1070 cal years B.P. The assemblage adds to a growing picture of the highly varied nature of prehistoric footwear production in the United States throughout the Holocene.

Percentages of cervical cytologic diagnoses as a quality assurance method

OBJECTIVE

To demonstrate empirically that the efficiency of rescreening to discover false negative cytologic diagnoses is greatly enhanced by prospectively stratifying accessions according to risk level.

STUDY DESIGN

We stratified accessions from 11 clinical sources and established the rate of diagnoses according to three categories: (1) "within normal limits"/"benign cellular changes" (WNL/BCC), (2) "atypical squamous/glandular cells of undetermined significance" (ASCUS/AGCUS) and (3) "squamous intraepithelial lesion/invasive carcinoma" (SIL/CA). We then prospectively rescreened all negative smears from sources with rates of positive diagnoses (ASCUS/AGCUS and SIL/CA) in excess of 20% and 5% of negative smears from sources with rates of positive diagnoses < 20%. We compared the detection rates of false negatives on rescreening target groups with random rescreening of 10% of all negative smears.

RESULTS

The rates of SIL/CA, ASCUS/AGCUS and WNL/BCC varied from 0 to 43%, 4% to 14% and 46% to 94%, respectively. Rescreening 10% of all negative smears revealed a false negative fraction of 3%; rescreening target groups revealed a false negative fraction of 5.9%.

CONCLUSION

The yield of prospectively detected false negative diagnoses was significantly increased by targeting high-risk accession groups. When cytology laboratories serve diverse populations, stratifying accessions by risk to permit increased sampling from the proportionately higher risk categories is a simple and effective device to maximize the yield and benefit from rescreening.

Computer-controlled laser ablation: a convenient and versatile tool for micropatterning biofunctional synthetic surfaces for applications in biosensing and tissue engineering

This paper describes laser-based methods for preparing micropatterns of bioactive molecular species in self-assembled monolayers (SAMs) and micropatterns of proteins and other biological molecules immobilized on solid substrates. Applications of these micropatterned surfaces in multianalyte biosensing and tissue engineering are emphasized. The focus of the paper is on the use of a computer-controlled laser ablation system comprising a research-grade inverted optical microscope, a pulsed nitrogen-pumped dye laser emitting at 390 nm, a programmable sample stage, and the computerized control system. The laser system can be implemented in a typical biosensor or tissue culture laboratory to enable the facile and reproducible fabrication of micropatterned surfaces by several methods. Various methods for patterning are discussed with examples given and emphasis placed on (1) laser ablation in the fabrication of photolithography masks, (2) electrochemical patterning of SAMs, and (3) laser desorption of SAMs. The relative merits of each technique are discussed with respect to application in fabrication of active surfaces for biosensing and tissue culture applications.

Fine-needle aspiration cytology diagnosis of colloid nodule versus follicular variant of papillary carcinoma of the thyroid

The cytologic differential diagnosis of colloid nodule (CN) and the follicular variant of papillary carcinoma (FVPC) is difficult with common morphologic features. To assess the utility of 18 cytologic morphometric parameters in the diagnosis of these thyroid lesions we evaluated 31 FNA samples that had histologic confirmation of the diagnoses. These 31 cases included 15 cases of CN, 8 cases of FVPC, and 8 cases of the usual variant of papillary carcinoma (UVPC) for reference values. For the morphometric analysis we used an Optimas 4.0 image analysis system. Comparing the CN group with the UVPC group revealed that eight of the parameters had statistically significant differences. The UVPC specimens were more cellular, less cohesive, had presence of papillary cellular groups more frequently, larger nuclei (UVPC: 109.33 +/- 30.19 microns2; CN: 66.81 +/- 15.02 microns2), higher nuclear to cytoplasmic (N/C) ratio, larger nucleoli, and present nuclear grooves and nuclear pseudoinclusions more frequently. The FVPC group differed from the CN group only in three parameters which included larger nuclei (98.49 +/- 18.24 microns2), higher N/C ratio, and a more frequent presence of nuclear pseudoinclusions. When we compared these two variants of papillary carcinoma, we found that the UVPC specimens had less cellular cohesion, less preservation of the architectural polarity and a more frequent presence of papillary cellular groups than the FVPC. The FVPC can be differentiated from CN based on nuclear changes, which included a larger size, higher N/C ratio, and presence of pseudoinclusions. The absence of cellular cohesion and polarity combined with the presence of papillary groups are useful in separating the UVPC from the FVPC. A cutoff of 75 microns2 should be used in separating benign from malignant nuclei.

Comparison of preimplantation developmental competence after mouse oocyte growth and development in vitro and in vivo

Culture systems for oocytes are essential for the experimental analysis of the basic mechanisms of oocyte development and, moreover, they will eventually find wide application in agriculture, the clinic, and wildlife preservation. Here, progress in mouse oocyte growth and development in vitro using oocyte-granulosa cell complexes from preantral follicles is reviewed. Oocyte-granulosa cell complexes were isolated from preantral (secondary) follicles of 12 day old mice, grown in vitro for 10 days, then matured and fertilized in vitro. The developmental competence of these oocytes was compared with oocytes grown in vivo and isolated from 22 day old mice, then matured and fertilized in vitro. In vitro-grown oocytes did not achieve the same size as their in vivo-grown counterparts. However, when oocytes were grown in medium containing fetal bovine serum, their preimplantation developmental competence was equivalent to that of in vivo-grown oocytes. Surprisingly, more blastocysts per animal were produced when oocytes were grown in vitro than in vivo. There was no correlation between oocyte size and either preimplantation developmental competence or number of cells per blastocyst. Oocytes grown in serum-free medium did not achieve the same developmental competence as oocytes grown in medium supplemented with serum. Lastly, the health status as an adult of the only animal born after complete oocyte development in vitro is described and discussed.

Digital imagery/telecytology. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial

ISSUES

Optical digital imaging and its related technologies have applications in cytopathology that encompass training and education, image analysis, diagnosis, report documentation and archiving, and telecommunications. Telecytology involves the use of telecommunications to transmit cytology images for the purposes of diagnosis, consultation or education. This working paper provides a mainly informational overview of optical digital imaging and summarizes current technologic resources and applications and some of the ethical and legal implications of the use of these new technologies in cytopathology.

CONSENSUS POSITION

Computer hardware standards for optical digital imagery will continue to be driven mainly by commercial interests and nonmedical imperatives, but professional organizations can play a valuable role in developing recommendations or standards for digital image sampling, documentation, archiving, authenticity safeguards and teleconsultation protocols; in addressing patient confidentiality and ethical, legal and informed consent issues; and in providing support for quality assurance and standardization of digital image-based testing. There is some evidence that high levels of accuracy for telepathology diagnosis can be achieved using existing dynamic systems, which may also be applicable to telecytology consultation. Static systems for both telepathology and telecytology, which have the advantage of considerably lower cost, appear to have lower levels of accuracy. Laboratories that maintain digital image databases should adopt practices and protocols that ensure patient confidentiality. Individuals participating in telecommunication of digital images for diagnosis should be properly qualified, meet licensing requirements and use procedures that protect patient confidentiality. Such individuals should be cognizant of the limitations of the technology and employ quality assurance practices that ensure the validity and accuracy of each consultation. Even in an informal teleconsultation setting one should define the extent of participation and be mindful of potential malpractice liability.

ONGOING ISSUES

Digital imagery applications will continue to present new opportunities and challenges. Position papers such as this are directed toward assisting the profession to stay informed and in control of these applications in the laboratory. Telecytology is an area in particular need of studies of good quality to provide data on factors affecting accuracy. New technologic approaches to addressing the issue of selective sampling in static image consultation are needed. The use of artificial intelligence software as an adjunct to enhance the accuracy and reproducibility of cytologic diagnosis of digital images in routine and consultation settings deserves to be pursued. Other telecytology-related issues that require clarification and the adoption of workable guidelines include interstate licensure and protocols to define malpractice liability.

Oocyte control of granulosa cell development: how and why

Interaction between oocytes and granulosa cells is complex and involves both gap junctions and paracrine signalling factors. Oocyte development in antral follicles is highly dependent on communication with cumulus cells, a subset of granulosa cells that is intimately associated with oocytes. Cumulus cells express characteristics distinct from the mural granulosa cells of preovulatory follicles. The thesis of this paper is that, without the influence of oocytes, the pathway of granulosa cell differentiation in antral follicles leads to the establishment of the mural granulosa cell phenotype. Oocytes in antral follicles abrogate that pathway of granulosa cell differentiation and promote the development of the cumulus cell phenotype. Oocytes may do this in order to control their own microenvironment by regulating differentiation of the supporting cells that are in direct communication with them. Possibly, some aspects of the mural granulosa cell phenotype are antagonistic to, or insufficient for, supporting the final stages of oocyte development. We present evidence that oocytes control their environment by suppressing differentiation of the mural granulosa cell phenotype and promoting differentiation of the cumulus cell phenotype. They achieve this suppression via the secretion of labile paracrine signalling factors. Errors in this regulatory mechanism, whether instigated by defects in the production of oocyte-derived ligands or granulosa cell responses to them, may result in the production of oocytes unable to undergo embryo development or that undergo abnormal follicular development.

Topoisomerase II alpha expression in normal, inflammatory, and neoplastic conditions of the gastric and colonic mucosa

Topoisomerase II alpha (TP) excises and reconnects double-stranded super-coiled DNA during the replicative cell cycle. We studied the localization of TP and Ki-67 in inflammatory and neoplastic mucosal lesions of the stomach and of TP in similar conditions of the colon. TP expression was correlated with tumor stage, grade, and survival time in the colonic tumors to evaluate its potential utility as a predictive marker for clinical outcome. Forty-three sections of chronic gastritis, lesions indefinite for dysplasia, low- and high-grade dysplasia, and gastric adenocarcinomas were immunostained with antibody against TP and Ki-67. For the colon, 71 sections of normal mucosa, chronic colitis, hyperplastic polyps, adenomas, and carcinomas were examined; fresh tissue was analyzed by flow cytometry. Expression of TP in non-neoplastic gastric mucosa was maximal in neck/foveolar cells and focal in surface and deep gland cells. Increased surface and deep gland positivity was found in low-grade dysplasia and a diffuse distribution of positive cells in high-grade dysplasia and carcinoma. The Ki-67 staining pattern was similar. TP in non-neoplastic colon was restricted to the lower crypt zone; it was greatly expanded in the surface/upper crypt region in adenomas and was diffuse in carcinomas. Flow cytometric analysis revealed TP expression mainly in the S and G2/M phase, with higher labeling index in tumors. There was no correlation of TP with stage, grade, or survival times in the colonic tumors. Staining for TP and Ki-67 might help in the distinction of inflammatory and neoplastic lesions of the stomach and colon.

Uptake and salvage of hypoxanthine mediates developmental arrest in preimplantation mouse embryos

Preimplantation mouse embryos become arrested after first or second cleavage when cultured in hypoxanthine-supplemented Whitten's medium. We present evidence that the hypoxanthine-induced arrest is dependent on uptake and salvage of hypoxanthine and depletion of phosphoribosylpyrophosphate (PRPP) levels. Hypoxanthine uptake increased during the 2-cell stage and was augmented by glucose. HPLC analysis of [14C]hypoxanthine metabolism revealed that hypoxanthine was salvaged and converted to ATP and guanosine triphosphate (GTP), with a shift to more guanyl nucleotide production at the 3- to 4-cell stage. In embryos from mice with a null mutation for the salvage enzyme hypoxanthine-guanine phosphoribosyltransferase, hypoxanthine did not block development nor was it taken up by the embryos. Glucose, which is required for the hypoxanthine-induced arrest, produced a 5.3-fold increase in PRPP levels at the 2-cell stage, which was eliminated by hypoxanthine. We conclude that metabolism of hypoxanthine to nucleotides mediates its inhibitory action on preimplantation mouse embryos via negative feedback on PRPP synthetase, ultimately resulting in decreased PRPP availability and arrest of other PRPP-dependent pathways. Finally, reversal of the block by EDTA and cAMP-elevating agents may be mediated by alterations in hypoxanthine or glucose uptake, or by changes in the relative metabolism of hypoxanthine.

Digital imaging in anatomic pathology

Advances in computer technology continue to bring new innovations to departments of anatomic pathology. This article briefly reviews the present status of digital optical imaging, and explores the directions that this technology may lead over the next several years. Technical requirements for digital microscopic and gross imaging, and the available options for image archival and retrieval are summarized. The advantages of digital images over conventional photography in the conference room, and the usefulness of digital imaging in the frozen section suite and gross room, as an adjunct to surgical signout and as a resource for training and education, are discussed. An approach to the future construction of digital histologic sections and the computer as microscope is described. The digital technologic applications that are now available as components of the surgical pathologist's workstation are enumerated. These include laboratory information systems, computerized voice recognition, and on-line or CD-based literature searching, texts and atlases and, in some departments, on-line image databases. The authors suggest that, in addition to these resources that are already available, tomorrow's surgical pathology workstation will include network-linked digital histologic databases, on-line software for image analysis and 3-D image enhancement, expert systems, and ultimately, advanced pattern recognition capabilities. In conclusion, the authors submit that digital optical imaging is likely to have a significant and positive impact on the future development of anatomic pathology.

Postmortem evaluation of homotypic variation in shoe characteristics of 201 thoroughbred racehorses

OBJECTIVES

To develop a standard technique for evaluation of racehorse shoes, to assess homotypic variation (interlimb variation) in shoe characteristics, and to determine whether shoe characteristics varied with age and sex.

DESIGN

Cross-sectional study.

ANIMALS

Thoroughbred racehorses (n = 201) that died or were euthanatized at California racetracks between August 1992 and July 1994.

PROCEDURE

Shoe characteristics were measured on horses examined after death. Percentage of agreement was used to compare shoe characteristics between limbs (homotypic variation). Using chi 2 analysis, shoe characteristics were compared between horses grouped by age and sex.

RESULTS

Toe grabs were present on 90.5% of horses, and rim shoes were present on 15.9% of horses. Heel traction devices were less frequent on front (2.5%) than rear (6%) hooves. Pads were present on 24.9% of horses, with bonded rim pads most common. Special types of shoes were present cn 5% of horses. Percentage of agreement between left and right front hooves and between left and right rear hooves was high (20/25 variables; % agreement > or = 99). In contrast, percentage of agreement between left front and left rear hooves and between right front and right rear hooves was low (2/25 variables; % agreement > or = 99). Presence of a pad was significantly (P < 0.05) associated with age, and several shoe variable (size, presence of a special shoe, overall wear matched) were significantly (P < 0.05) associated with sex.

CLINICAL RELEVANCE

Except for variables related to special shoes, wear, and weight, 1 shoe for the respective fore- or hind limbs could be used as an indicator for the contralateral shoe worn by Thoroughbred racehorses without substantial loss of information. However, 1 shoe could not be used as an indicator for shoe characteristics of all 4 limbs. Some shoe characteristics are associated with age and sex, and these variables should be considered possible confounders in studies of shoe characteristics.

The adenoma-carcinoma sequence in colorectal neoplasia

In this article the epidemiologic, pathologic, molecular, and clinical evidence for the adenoma-carcinoma sequence is reviewed. The authors describe the morphologic evolution of the precursor adenomas, from the earliest discernible abnormality of the colon to adenomas with advanced pathologic features, the factors that determine the risk of progression of adenomas to adenocarcinoma, the molecular events that parallel or underlie the morphologic changes, the outcome of clinical interventions that have tested this hypothesis, and the time frame within which this progression is likely to occur.

Factors influencing outcome of surgery for primary aldosteronism

OBJECTIVE

To identify factors that influence the outcome of surgery for primary aldosteronism.

DESIGN

A retrospective clinical series, with a mean follow-up of 106 months (range, 12-280 months), of 42 patients who underwent adrenalectomy for primary aldosteronism between the years 1970 and 1993.

SETTING

All patients were operated on at the Boston University Medical Center Hospital.

PATIENTS AND INTERVENTION

We reviewed the records of 22 women and 20 men, ranging in age from 25 to 68 years, who underwent adrenalectomy for primary aldosteronism. Tests performed for preoperative classification of the adrenal pathological abnormalities included adrenal venous sampling, postural stimulation test, iodocholesterol I 131 scintigraphy, and computed tomography.

MAIN OUTCOME MEASURES

The surgical outcome was classified as follows: response, normal blood pressure measurement (< 160/95 mm Hg) without medication; incomplete response, normal blood pressure measurement with medication or blood pressure measurement greater than 160/95 mm Hg despite antihypertensive treatment.

RESULTS

Twenty-five patients (60%) became normotensive following surgery. The following factors were associated with a complete response to adrenalectomy by univariate analysis: adenoma classification (odds ratio [OR] = 9.6, P = .002); preoperative response to spironolactone (OR = 8.3, P = .007); age younger than 44 years (OR = 6.2, P = .009); and duration of hypertension less than 5 years (OR = 5.1, P = .03). Response to spironolactone was predictive only in cases classified as adenoma (P = .004). Duration of hypertension showed a strong correlation with age (r = 0.62). Using stepwise logistic regression, adenoma pathological classification, response to spironolactone, and duration of hypertension less than 5 years contributed independently to a predictive model. Micronodular hyperplasia alone was associated with incomplete response. The presence of coexisting micronodular hyperplasia in patients with adenoma did not affect the odds for a complete response. Computed tomography for preoperative diagnosis of adenoma showed the same level of accuracy (75%) as that for postural stimulation test and iodocholesterol scintigraphy, but less than that for adrenal venous sampling (91%).

CONCLUSIONS

The study showed that the main determinants of a surgical cure of hypertension in primary aldosteronism were presence of adenoma and preoperative response to spironolactone. We favor computed tomography as the initial test to establish preoperative diagnosis of adenoma because of its reproducibility and high specifity.

Building a new health system: implications for public health management and practice

Changes in the health care system should encourage private-sector health care providers and the public health system to work in partnership to improve the public health of all citizens. Minnesota, with its recent comprehensive health reform efforts, has made a strong commitment to strengthen the public health system in performing those functions that are critical to protecting the health of the public and meeting public health goals that are identified by the state and local communities.

Risk of colorectal cancer in the families of patients with adenomatous polyps. National Polyp Study Workgroup

BACKGROUND

The adenoma-adenocarcinoma sequence in colorectal cancer suggests an increased risk of colorectal cancer in the families of patients with adenomatous polyps.

METHODS

A random sample of participants in the National Polyp Study who had newly diagnosed adenomatous polyps were interviewed for information on the history of colorectal cancer in their parents and siblings. The risk of colorectal cancer in family members was analyzed according to the characteristics of the patients with adenomas and in comparison with a sample of patients' spouses, who served as controls.

RESULTS

Among the patients with adenomas, 1199 provided information on whether they had a family history of colorectal cancer. After the exclusion of families for which information was incomplete and of 48 patients who had been referred for colonoscopy solely because they had a family history of colorectal cancer, there were 1031 patients with adenomas, 1865 parents, 2381 siblings, and 1411 spouse controls. The relative risk of colorectal cancer, adjusted for the year of birth and sex, was 1.78 for the parents and siblings of the patients with adenomas as compared with the spouse controls (95 percent confidence interval, 1.18 to 2.67). The relative risk for siblings of patients in whom adenomas were diagnosed before 60 years of age was 2.59 (95 percent confidence interval, 1.46 to 4.58) as compared with the siblings of patients who were 60 or older at the time of diagnosis and after adjustment for the sibling's year of birth and sex and a parental history of colorectal cancer. The risk increased with decreasing age at the time of the diagnosis of adenoma (P for trend < 0.001). The relative risk for the siblings of patients who had a parent with colorectal cancer, as compared with those who had no parent with cancer, was 3.25 (95 percent confidence interval, 1.92 to 5.52), after adjustment for the sibling's year of birth and sex and the patient's age at diagnosis.

CONCLUSIONS

Siblings and parents of patients with adenomatous polyps are at increased risk for colorectal cancer, particularly when the adenoma is diagnosed before the age of 60 or--in the case of siblings--when a parent has had colorectal cancer.

Development in vitro of mouse oocytes from primordial follicles

The objective of these studies was to achieve complete oocyte development in vitro beginning with the oocytes in the primordial follicles of newborn mouse ovaries. A two-step strategy was developed: first the ovaries of newborn mice were grown in organ culture for 8 days, and then the developing oocyte-granulosa cell complexes were isolated from the organ-cultured ovaries and cultured for an additional 14 days. The oocytes of primordial follicles are approximately 4190 microns3 in volume (20 microns in diameter), and this volume increased by approximately 53,810 microns3 to a final size of 58,000 microns3--a 13.8-fold increase--during the 8 days of organ culture. In the first experiment the oocyte-granulosa cell complexes were grown in control medium or in medium supplemented with FSH (0.5 ng/ml), epidermal growth factor (EGF; 1.0 ng/ml), or EGF plus FSH. Only 50-60% of the complexes cultured in control medium or in medium supplemented with FSH were recovered at the end of the 14-day culture period. In contrast, more than 90% of the complexes cultured in medium supplemented with EGF were recovered. The median size of the oocytes grown in control medium was 176,800 microns3 (69-microns diameter), while the median size of those grown in medium supplemented with EGF was slightly smaller (136,400-microns3 volume; 63-microns diameter), due to the survival of more smaller-size oocytes in EGF-containing medium. Thirty percent of the oocytes recovered after development in FSH-containing medium were competent to undergo germinal vesicle breakdown (GVB). In the second set of experiments, oocyte-granulosa cell complexes isolated from organ-cultured ovaries were cultured in medium supplemented with either 0.5 or 5.0 ng/ml FSH or with these same concentrations of FSH plus 1.0 ng/ml EGF. Again, increased oocyte recovery was observed in the groups cultured with EGF. There was no difference among the groups in the percentage of the oocytes that acquired competence to undergo GVB (32%) or in the percentage of GVB oocytes that produced a polar body, thus indicating progression of meiosis to metaphase II (22%). When the mature oocytes were inseminated, 21% underwent fertilization and cleavage to the 2-cell stage in the groups without EGF during oocyte development, while 42% underwent fertilization and cleavage to the 2-cell stage in the groups cultured with EGF. Less than 2% of the 2-cell-stage embryos developed to the blastocyst stage in any of the groups. One hundred and ninety 2-cell-stage embryos were transferred to the oviducts of pseudopregnant females; two females produced one pup each; one was living and the other had apparently died recently. The results reported here clearly show that complete development of oocytes in vitro from the primordial follicle stage is possible and establish the framework for further studies using oocytes from laboratory animals as model systems for the development of oocytes from humans as well as from animals of agricultural and zoological importance.

Detection of p21ras mutations in colorectal adenomas and carcinomas by enzyme-linked immunosorbent assay

BACKGROUND

Point mutations of the ras protooncogene, primarily within codons 12 and 13, are commonly identified in colorectal carcinomas and large adenomas. Despite data suggesting that ras genotyping may have clinical significance with respect to colorectal cancer screening and prognosis, more widespread use has been limited because of the lack of a suitable assay system. The principal objective of this study was to assess the feasibility and validity of a qualitative enzyme-linked immunosorbent assay (ELISA) for detecting the four most common ras mutations in human colorectal tumors at the protein (p21ras) level.

METHODS

Tissue homogenates (11-121 micrograms) from endoscopically or surgically resected colorectal adenomas, carcinomas, and normal mucosae were evaluated by a commercially available ELISA (Oncogene Science, Inc. Cambridge, MA) for mutant p21ras containing arginine position 12 (arg12), valine position 12 (val12), aspartate position 12 (asp12), and aspartate position 13 (asp13) amino acid substitutions. Portions of the same tissue from an initial series of 27 specimens also were subjected to mutant-enriched polymerase chain reaction (PCR) and/or PCR amplification with subsequent DNA sequence analysis to validate the ELISA data.

RESULTS

Forty-seven adenomas, 9 carcinomas, and 14 normal mucosae were assayed. Mutations were identified in 16 (34%) of the adenomas (7-asp12, 7-val12, 2-asp13), 3 (33%) of the carcinomas (1-asp12, 1-arg12, 1-asp13), and none of the normal mucosae by ELISA: Polymerase Chain Reaction and DNA sequencing analyses demonstrated identical results for 21 of the 23 (91%) and 14 of 16 (88%) homogenates tested, respectively. The ELISA demonstrated an overall sensitivity of 80-86%, specificity of 90-92%, positive predictive value of 86-100%, and negative predictive value of 86-91%.

CONCLUSIONS

The ELISA is a feasible and valid approach for identifying p21ras mutations in human colorectal adenomas and carcinomas.

Prevention of colorectal cancer: guidelines based on new data. WHO Collaborating Center for the Prevention of Colorectal Cancer

Recently published good quality data are the basis for this update. The newly reported studies include randomized trials, non-randomized cohort studies, and case-control studies; some of the data had mortality reduction as the endpoint. These guidelines, which were developed by the WHO Collaborating Center for the Prevention of Colorectal Cancer at Memorial Sloan-Kettering Cancer Center in conjunction with an International Advisory Committee, include primary prevention, screening of average-risk individuals, screening of individuals with heritable factors for colorectal cancer, surveillance of patients with colorectal polyps, and surveillance of patients with chronic ulcerative colitis. A list of papers reviewed for this update are cited, including recently published trials evaluating faecal occult-blood testing, case-control studies of sigmoidoscopy, the National Polyp study, and familial colon cancer studies. These guidelines will help inform patients and guide physicians in their approach to the prevention of colorectal cancer.

Prevention of colorectal cancer by colonoscopic polypectomy. The National Polyp Study Workgroup

BACKGROUND

The current practice of removing adenomatous polyps of the colon and rectum is based on the belief that this will prevent colorectal cancer. To address the hypothesis that colonoscopic polypectomy reduces the incidence of colorectal cancer, we analyzed the results of the National Polyp Study with reference to other published results.

METHODS

The study cohort consisted of 1418 patients who had a complete colonoscopy during which one or more adenomas of the colon or rectum were removed. The patients subsequently underwent periodic colonoscopy during an average follow-up of 5.9 years, and the incidence of colorectal cancer was ascertained. The incidence rate of colorectal cancer was compared with that in three reference groups, including two cohorts in which colonic polyps were not removed and one general-population registry, after adjustment for sex, age, and polyp size.

RESULTS

Ninety-seven percent of the patients were followed clinically for a total of 8401 person-years, and 80 percent returned for one or more of their scheduled colonoscopies. Five asymptomatic early-stage colorectal cancers (malignant polyps) were detected by colonoscopy (three at three years, one at six years, and one at seven years). No symptomatic cancers were detected. The numbers of colorectal cancers expected on the basis of the rates in the three reference groups were 48.3, 43.4, and 20.7, for reductions in the incidence of colorectal cancer of 90, 88, and 76 percent, respectively (P < 0.001).

CONCLUSIONS

Colonoscopic polypectomy resulted in a lower-than-expected incidence of colorectal cancer. These results support the view that colorectal adenomas progress to adenocarcinomas, as well as the current practice of searching for and removing adenomatous polyps to prevent colorectal cancer.

Carbohydrate dependence during marathon running

To test the hypothesis that marathon running is dependent on lipid oxidation, 12 post-absorptive males (31.9 +/- 2.1 yr) ran a treadmill marathon and substrate utilization was assessed. Subjects were placed into a fast (F < or = 2 hr, 45 min; 73.3% VO2max), or a slow (S < or = 3 hr, 45 min; 64.5% VO2max) marathon group. The day before testing subjects rested, but ate their normal diet. Subjects were tested in the morning after an overnight fast, and only tap water, at a rate of 1 l.h, was ingested during exercise. Blood glucose concentration rose at exercise onset, peaked at approximately an hour, but then decreased over time remaining at or above resting levels. Free fatty acids and glycerol rose continuously. No significant differences in plasma FFA, glycerol, or blood glucose concentrations were observed between F or S groups during the marathon. Mean blood lactate concentration was significantly higher (P < 0.05) in the F (2.1 +/- 0.3 mM) group than the S (1.2 +/- 0.2 mM) during exercise. Mean plasma epinephrine was significantly higher in the F (0.9 +/- 0.2 ng.ml-1) than the S (0.6 +/- 0.2 ng.ml-1) group; norepinephrine was also higher in F (3.9 +/- 1.4 ng.ml-1) than the S (2.5 +/- 0.9 ng.ml-1, P < or = 0.05). Blood lactate and epinephrine concentrations correlated significantly (4r = 0.76 and 0.78 in F and S groups, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

SIDS--a developmental neurological perspective

Most SIDS deaths occur between 2 and 4 months of age. Neural transformations may be important in SIDS. Evidence of delayed myelination has been found in SIDS victims. However a simple neuro-developmental model is insufficient to explain SIDS. The age of death profile is reportedly similar for pre-term and full-term SIDS victims. Another developmental change is that IgG levels are lowest when SIDS risk peaks, and there is data linking SIDS and infections. Prone position may also increase risk. While a developmental model emphasizing neural transformation is useful, other factors affect risk also.

Metastatic adenocarcinoma of an unknown primary site. A comparison of the relative contributions of morphology, minimal essential clinical data and CEA immunostaining status

Measurement of the relative contributions of morphology alone; minimal essential clinical data; immunohistologic reactivity of a prototypic tumor marker, carcinoembryonic antigen (CEA); and the process by which a pathologist can identify the origin of a metastatic adenocarcinoma of unknown primary site is the subject of this report. To standardize the case material, we used an image digitizing and archival system to present 100 metastatic adenocarcinomas of known primary site as unknowns to two pathologists. The images were selected to show only gland-forming areas of the carcinomas and excluded all normal tissue elements. They were viewed, initially without, and then with, identification of gender and metastatic site. Subsequently, the results of immunoperoxidase staining for CEA, assessed independently by a third pathologist, were provided. Our analysis showed that, overall, the correct primary site was chosen as choice 1, 2, or 3 in 72% and 76%, and as choice 1 in 49% and 47% of cases, respectively. Accuracy was highest for prostatic, ovarian, and breast carcinomas, and lowest for upper-gastrointestinal tract, biliary tract, and pancreatic adenocarcinoma. Statistical analysis showed the largest increments in accuracy in the choice 1 prediction in each tumor category were achieved by provision of minimal essential clinical data. Knowledge of CEA status did not affect overall accuracy; however, it increased the odds of making the correct diagnosis for ovarian, colorectal, and endometrial (both pathologists) carcinomas, and for prostatic, pulmonary and esophago-gastric adenocarcinomas (one pathologist). The study exemplifies a model for the objective measurement of the contribution of ancillary studies, such as immunoperoxidase markers, to the accuracy of pathologic diagnosis.

Randomized comparison of surveillance intervals after colonoscopic removal of newly diagnosed adenomatous polyps. The National Polyp Study Workgroup

BACKGROUND

The identification and removal of adenomatous polyps and post-polypectomy surveillance are considered to be important for the control of colorectal cancer. In current practice, the intervals between colonoscopies after polypectomy are variable, often a year long, and not based on data from randomized clinical trials. We sought to determine whether follow-up colonoscopy at three years would detect important colonic lesions as well as follow-up colonoscopy at both one and three years.

METHODS

Patients were eligible if they had one or more adenomas, no previous polypectomy, and a complete colonoscopy and all their polyps had been removed. They were randomly assigned to have follow-up colonoscopy at one and three years or at three years only. The two study end points were the detection of any adenoma, and the detection of adenomas with advanced pathological features (defined as those > 1 cm in diameter and those with high-grade dysplasia or invasive cancer).

RESULTS

Of 2632 eligible patients, 1418 were randomly assigned to the two follow-up groups, 699 to the two-examination group and 719 to the one-examination group. The percentage of patients with adenomas in the group examined at one and three years was 41.7 percent, as compared with 32.0 percent in the group examined at three years (P = 0.006). The percentage of patients with adenomas with advanced pathological features was the same in both groups (3.3 percent).

CONCLUSIONS

Colonoscopy performed three years after colonoscopic removal of adenomatous polyps detects important colonic lesions as effectively as follow-up colonoscopy after both one and three years. An interval of at least three years is recommended before follow-up colonoscopy after both one and three years. An interval of at least three years is recommended before follow-up examination after colonoscopic removal of newly diagnosed adenomatous polyps. Adoption of this recommendation nationally should reduce the cost of post-polypectomy surveillance and screening.