General gynaecology: Intrauterine lignocaine as an anaesthetic during endometrial sampling: a randomised double-blind controlled trial

OBJECTIVE

To evaluate the effectiveness of intrauterine lignocaine as an anaesthetic during endometrial sampling.

DESIGN

Prospective, randomised, double-blind, placebo-controlled trial.

SETTING

Outpatient gynaecological minor operation unit in a public hospital.

POPULATION

Two hundred premenopausal women scheduled for endometrial sampling because of abnormal uterine bleeding.

METHODS

Transcervical intrauterine instillation of 5 mL of 2% lignocaine or 5 mL of normal saline before performing endometrial sampling with vacuum aspirator.

MAIN OUTCOME MEASURES

Evaluation of pain associated with the procedure using a visual analogue scale.

RESULTS

The use of intrauterine lignocaine reduced pain during suction curettage in endometrial sampling.

CONCLUSIONS

Transcervical instillation of lignocaine reduced pain during endometrial sampling.

Germ cell development in the descended and cryptorchid testis and the effects of hormonal manipulation

Germ cell development is an active process in normal testes during the first 4 years after birth, with transformation of the neonatal gonocytes into adult dark spermatogonia and then primary spermatocytes. The hormonal regulation of these changes is not fully understood, with evidence both for and against a role for gonadotrophins and androgens. Early surgical intervention in infancy aims to prevent or reverse germ cell maldevelopment. Although hormonal treatment for maldescent has been shown to be ineffective, there is still controversy over whether it may be useful as an adjunct to surgery to stimulate germ cells. Current evidence suggests that hormonal therapy may not stimulate transformation of neonatal gonocytes but may trigger prepubertal mitosis of primary spermatocytes. Further studies are required to determine the role of hormone treatment on germ cell development.

Outbreak of cyclosporiasis in British Columbia associated with imported Thai basil

Sporadic outbreaks of cyclosporiasis, a common cause of protracted diarrhoea in underdeveloped countries, are often undetected and undiagnosed in industrial countries. In May 2001, an outbreak of Cyclospora cayetanensis gastroenteritis was identified in British Columbia, Canada, with 17 reported cases. We conducted a case-control study involving 12 out of the 17 reported and confirmed case patients. Eleven (92%) of the patients had consumed Thai basil, an essential ingredient in Vietnamese cuisine, compared to 3 out of 16 (19%) of the control patients (P = 0.003). Trace-back investigations implicated Thai basil imported via the United States as the vehicle for this outbreak. This is the first documented sporadic outbreak of cyclosporiasis linked to Thai basil in Canada, and the first outbreak of cyclosporiasis identified in an ethnic immigrant population. This outbreak provides the opportunity to increase our understanding of this emerging pathogen and improve on our prevention and control for future outbreaks.

LEKTI demonstrable by immunohistochemistry of the skin: a potential diagnostic skin test for Netherton syndrome

BACKGROUND

Netherton syndrome (NS) is a rare autosomal recessive condition characterized by ichthyosiform erythroderma, trichorrhexis invaginata and atopic manifestations. Confirming the diagnosis may be difficult in the early stages. Mutations in the SPINK5 gene which encodes for the serine protease inhibitor LEKTI are associated with NS. These mutations create premature termination codons which result in absent or abnormal expression of LEKTI in patients with NS.

OBJECTIVES

To investigate the expression of LEKTI in the skin of patients with NS in comparison with normal controls and patients with other skin conditions, namely atopic dermatitis, psoriasis and nonbullous ichthyosiform erythroderma.

METHODS

Immunohistochemistry was performed on skin sections from four patients with NS, four normal controls, four with atopic dermatitis, two with psoriasis and two with nonbullous ichthyosiform erythroderma, using a primary rabbit polyclonal antibody against LEKTI.

RESULTS

LEKTI was localized to the stratum granulosum in normal skin. All four skin sections from patients with NS showed absent or very reduced staining for LEKTI. Staining in the other disorders showed positive LEKTI expression in varying patterns.

CONCLUSIONS

NS can be difficult to diagnose especially in the early stage, which can lead to inappropriate treatments particularly if it is misdiagnosed as atopic dermatitis. Immunohistochemistry of skin with an antibody against LEKTI is a potentially useful diagnostic test for NS.

The influence of timing and route of administration of intravenous ketorolac on analgesia after hand surgery

A double-blind clinical trial was conducted on 47 patients scheduled for hand surgery under general anaesthesia to determine whether ketorolac given as part of an intravenous regional anaesthesia technique could provide better postoperative analgesia than ketorolac given intravenously either before or after surgery. Patients were randomly allocated to one of three groups to receive ketorolac 20 mg: intravenously in the non-operative arm before surgery (systemic presurgery group); intravenously to the operative arm after tourniquet inflation (regional presurgery group); intravenously in the non-operative arm after surgery (systemic postsurgery group). Postoperative pain scores were similar in the systemic presurgery and regional presurgery groups. The mean visual analogue summary pain score during the 24 h after surgery was 12.2 mm higher in the systemic postsurgery group than in the systemic presurgery group (95% CI: 0.8-23.7 mm, p = 0.037). There were no clinically important differences in mean postoperative visual analogue pain scores between the three study groups. There were no statistical differences in the mean postoperative morphine requirements between the three study groups. There is no benefit, in terms of improved postoperative analgesia, in giving ketorolac as an intravenous regional anaesthetic compared with systemic administration before surgery. The administration of ketorolac after surgery, rather then before, is not supported.

A rare case of a pedunculated lipoma in the pharynx

While lipomas on the trunk and limbs are common, they are rare in the upper aerodigestive tract. A case is reported of an 18 cm long pedunculated lipoma arising from the hypopharynx in a 73 year old man. The tumour was asymptomatic until it appeared in the mouth of the patient after a coughing episode.

[The associations between concentration of selenium in semen and sperm parameters as well as oxidative DNA damage in human sperm]

OBJECTIVE

To explore the associations between concentrations of selenium (Se) in serum and semen and sperm parameters as well as oxidative DNA damage in human sperm.

METHODS

Concentrations of selenium in serum and semen were determined using atomic absorption spectrophotometer (AAS). The sperm parameters were detected according to WHO laboratory manual for the examination of human sperm. The levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and deoxyguanosine (dG) in human sperm DNA were measured using HPLC-ECD and HPLC-UV.

RESULTS

Mean semen concentration of selenium was significantly higher in fertile subjects (0.74 mumol/L) than that in infertile subjects (0.56 mumol/L), while there was no significant difference in serum concentrations of selenium between the two groups. Semen volume (3.91 ml vs. 2.79 ml), sperm density (46.4 x 10(9)/L vs. 36.5 x 10(9)/L) and sperm count (168.0 x 10(6) vs. 102.0 x 10(6)) were significantly higher in fertile subjects than those in infertile subjects. There was no significant difference in motility and viability of sperm, and proportion of deformity sperm between the two groups, Significantly positive correlation was observed between semen concentration of Se and sperm density (r = 0.48, P < 0.01 for fertile subjects and r = 0.32, P < 0.05 for infertile subjects) as well as sperm count (r = 0.32, P < 0.05 for fertile subjects and r = 0.26, P < 0.05 for infertile subjects), sperm motility (r = 0.46, P < 0.01 for fertile subjects and r = 0.65, P < 0.01 for infertile subjects) and viability (r = 0.33, P < 0.05 for fertile subjects and r = 0.64, P < 0.01 for infertile subjects). There was no correlation between serum Se concentrations and sperm parameters. Moreover, 8-OHdG levels in sperm DNA inversely correlated with semen Se concentrations in fertile (r = -0.21, P < 0.05) and infertile (r = -0.28, P < 0.05) subjects. However, no significant correlation was found between 8-OHdG levels in sperm DNA and serum Se concentrations in all subjects.

CONCLUSIONS

Semen concentrations of Se were associated with sperm quality and 8-OHdG levels in human sperm. Serum concentrations of Se did not affect sperm quality and oxidative DNA damage in human sperm.

Extraluminal migration of a coin in the oesophagus of a child misdiagnosed as asthma

Ingestion of a foreign body, the commonest being a coin, is a common problem in children. In most cases the coin will pass uneventfully through the gastrointestinal tract. However, on rare occasions it may become lodged in the oesophagus with subsequent extraluminal migration with the potential for serious complications such as vascular fistula or chronic suppurative infection. A case is presented of extraluminal migration of a coin in the oesophageal associated with abscess formation in a 15 month old boy. This case is particularly important because the presenting symptom of wheezing led to the erroneous diagnosis of asthma, which resulted in a three month delay in investigation and treatment. In addition, it raises the issue of whether to perform chest radiography on newly diagnosed asthmatic patients to rule out the presence of a foreign body and thereby prevent serious complications.

Squamous cell carcinoma of the lip. Patterns of relapse and outcome: Reporting the Westmead Hospital experience, 1980-1997

Australia has one of the highest rates of squamous cell carcinoma of the lip in the world. Despite a high cure rate, many studies report relapse rates of between 5% and 20% with an associated mortality of 5-10%. The aim of this study was to review the patterns of relapse and outcome for patients treated at Westmead Hospital, Sydney. Ninety-three eligible patients were identified in a retrospective review of all lip cancer patients referred to Westmead Hospital between 1980 and 1997. Relevant data were extracted from the treatment files and included contact with referring doctors and utilizing the Cancer Council Registry. Equal numbers of patients were treated with radiotherapy alone or surgery (+/- adjuvant radiotherapy). The majority of patients were male (78.5%) with T1N0 cancers (64.5%) of the lower lip. A minority (5.4%) had nodal disease at diagnosis. Following treatment, 31 (33.3%) patients relapsed, 11 at the primary site, 18 at the regional nodes and two at both sites simultaneously. Patients treated with a combined approach (RTx/Sx) experienced a better outcome. Overall cancer-specific survival at 5 years was 85%. These findings highlight a disturbing relapse rate and mortality for a subgroup of patients diagnosed with a more aggressive form of lip cancer. Treatment and follow up of these patients should accordingly be more aggressive.

Prolongation of heterotopic heart allograft survival by portal venous injection of alloantigen: the role of hepatic nonparenchymal cells

The induction of immune hyporesponsiveness in transplantation is a complex interaction between the immune system and the alloantigen. The route by which an antigen is introduced to the immune system plays an important role in the immune response. Antigen delivered via the portal circulation has the ability to induce T-cell hyporesponsiveness. In this study we examined the mechanism responsible for the induction of hyporesponsiveness by assessing immune response following portal vein (pv) injection of donor alloantigen. C57B1/6 mice were immunized via pv with splenic mononuclear cells (SMNC) from BALB/c mice. The recipient immune response was assessed in vivo by murine heterotopic heart transplant survival. SMNC and hepatic nonparenchymal cells (NPC) were isolated from pv immunized animals and used as regulatory cells in a one-way mixed lymphocyte culture (MLC) as a measure of in vitro recipient responder SMNC proliferation. Survival of murine heterotopic heart transplants was prolonged following pv injection of alloantigen (p < .04 compared to nonimmunized or systemically immunized mice). Stimulation of responder SMNCs isolated from pv immunized mice resulted in an antigen-specific hyporesponsiveness (p < .05 compared with nonimmunized or systemically immunized mice). Cocultures of responder SMNCs from nonimmunized (naive) mice with hepatic NPC from previously pv immunized mice resulted in attenuation of T-cell proliferation in MLR following stimulation with donor alloantigen (p < .05 compared to coculture with NPC from nonimmunized mice or SMNC from pv immunized mice). These data would suggest that the hepatic NPC plays an important role in the regulation of the immune response. With further identification of cell subtypes responsible for induction of hyporesponsiveness, future therapies may be directed at these specific targets, thereby minimizing the harmful side effects of current immunosuppressive therapies.

First trimester maternal serum AFP and total hCG in aneuploidies other than trisomy 21

Total human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP) were measured in maternal serum at 10-14 weeks of gestation from 53 pregnancies affected by trisomy 18, 42 cases with trisomy 13, 46 with Turner's syndrome and 13 with other sex aneuploides. The only significant association was the finding of reduced levels of total hCG in cases of trisomy 18 and 13. The association of increased levels of AFP in cases of trisomy 18 with ventral wall defects and the slight increase in AFP in cases of sex chromosomal anomalies other than Turner's syndrome was found. AFP and total hCG are not likely to replace the markers free beta-hCG and PAPP-A in first trimester screening for chromosomal anomalies.

Screening for trisomy 13 by fetal nuchal translucency and maternal serum free beta-hCG and PAPP-A at 10-14 weeks of gestation

In 42 cases of trisomy 13 at 10-14 weeks of gestation, compared with 947 controls, the median multiple of the median (MoM) of maternal serum free beta-human chorionic gonadotrophin (beta-hCG) and pregnancy associated plasma protein A (PAPP-A) was significantly decreased (0.506 MoM and 0.248 MoM respectively), whilst fetal nuchal translucency was increased (2.872 MoM). In 38% and 71% of cases of trisomy 13 maternal serum free beta-hCG and PAPP-A was below the 5th centile of the appropriate normal range for gestation and in 62% of cases the nuchal translucency was above the 95th centile. When combined together in a multivariate algorithm with maternal age, 90% of cases of trisomy 13 could be detected at a 0.5% false positive rate or 84% at a 0.1% false positive rate. We conclude that specific trisomy 13 risks should be part of developing risk algorithms combining maternal serum biochemistry and nuchal translucency for use in first trimester screening alongside those for trisomy 21 and trisomy 18.

Serum CA125 at 11-14 weeks of gestation in women with morphologically normal ovaries

In a number of pregnant women ovarian cysts are found incidentally during the routine first trimester scan. These cysts may pose diagnostic difficulties, and the measurement of serum CA125 levels can be used to aid management. In this study we measured maternal serum CA125 levels in 188 women with uncomplicated pregnancies between 11-14 weeks of gestation. All women had morphologically normal ovaries observed on ultrasound examination. The median serum CA125 levels were 23.4 U/mL (range 2.2-166.3 U/mL, 95% reference interval 5.28-70.15) and did not change significantly with gestation. We conclude that CA125 levels are increased at 11-14 weeks of gestation and cut off values which are used to assess the nature of ovarian cysts in nonpregnant women cannot be applied to pregnant women at this gestation.

Dual role of glutathione in selenite-induced oxidative stress and apoptosis in human hepatoma cells

It is well known that glutathione, the major intracellular antioxidant, is closely involved in the metabolism and bioactivity of selenium. In the present study, glutathione was demonstrated to play a dual role on selenite (Se)-induced oxidative stress and apoptosis in human hepatoma HepG(2) cells. The experiment was carried out in two different modes to modulate intracellular reduced glutathione (GSH) content. In Mode A (pretreatment), cells were pretreated with N-acetylcysteine (NAC), buthionine sulfoximine (BSO), or GSH prior to Se exposure. In Mode B (simultaneous treatment), cells were treated with Se and NAC, BSO, or GSH simultaneously. It was found that Se-induced oxidative stress and apoptosis are closely related to the intracellular level of GSH. Both the increase and depletion of GSH content significantly enhanced Se-induced oxidative stress and apoptosis in HepG(2) cells. Results from this study clearly demonstrated that GSH has a dual role in the effects of Se on cancer cells: (i) GSH acts as a pro-oxidant, facilitating Se-induced oxidative stress, and (ii) GSH acts as an antioxidant, protecting against Se-induced oxidative stress and apoptosis. Understanding such a unique association between GSH and Se may help to explain the controversy in the literature over the complex relationship between selenium and glutathione, and ultimately the capability of selenium to prevent cancer.

Detection of oxidative DNA damage in human sperm and its association with sperm function and male infertility

The expanding research interest in the last two decades on reactive oxygen species (ROS), oxidative stress, and male infertility has led to the development of various techniques for evaluating oxidative DNA damage in human spermatozoa. Measurement of 8-hydroxydeoxyguanosine (8-OHdG) offers a specific and quantitative biomarker on the extent of oxidative DNA damage caused by ROS in human sperm. The close correlations of 8-OHdG level with male fertility, sperm function and routine seminal parameters indicate the potential diagnostic value of this technique in clinical applications. On the other hand, single cell gel electrophoresis (SCGE or comet assay) and terminal deoxynucleotidyl transferase (TdT) mediated dUTP nick end labeling (TUNEL) assay have also been demonstrated to be sensitive, and reliable methods for measuring DNA strand breaks in human spermatozoa. As certain technical limitations were inherent in each of these tests, it is believed that a combination of these assays will offer more comprehensive information for a better understanding of oxidative DNA damage and its biological significance in sperm function and male infertility.

Molecular cloning of the human gene, PNKP, encoding a polynucleotide kinase 3'-phosphatase and evidence for its role in repair of DNA strand breaks caused by oxidative damage

Mammalian polynucleotide kinases catalyze the 5'-phosphorylation of nucleic acids and can have associated 3'-phosphatase activity, predictive of an important function in DNA repair following ionizing radiation or oxidative damage. The sequences of three tryptic peptides from a bovine 60-kDa polypeptide that correlated with 5'-DNA kinase and 3'-phosphatase activities identified human and murine dbEST clones. The 57.1-kDa conceptual translation product of this gene, polynucleotide kinase 3'-phosphatase (PNKP), contained a putative ATP binding site and a potential 3'-phosphatase domain with similarity to L-2-haloacid dehalogenases. BLAST searches identified possible homologs in Caenorhabditis elegans, Schizosaccharomyces pombe, and Drosophila melanogaster. The gene was localized to chromosome 19q13.3-13.4. Northern analysis indicated a 2-kilobase mRNA in eight human tissues. A glutathione S-transferase-PNKP fusion protein displayed 5'-DNA kinase and 3'-phosphatase activities. PNKP is the first gene for a DNA-specific kinase from any organism. PNKP expression partially rescued the sensitivity to oxidative damaging agents of the Escherichia coli DNA repair-deficient xth nfo double mutant. PNKP gene function restored termini suitable for DNA polymerase, consistent with in vivo removal of 3'-phosphate groups, facilitating DNA repair.

Pharyngeal pouch endoscopic stapling--are post-operative barium swallow radiographs of any value?

Posterior pharyngeal pouch endoscopic stapling has gained increasing popularity among otolaryngologists especially in elderly patients. Post-operative barium swallow appearances can create confusion with the appearance of persistent pouches. We describe our experience in 10 patients, three of whom had external excision with cricopharyngeal myotomy and the remaining seven had endoscopic stapling approach. All three patients who had external excision showed no residual pouch whereas all seven patients who had endoscopic techniques performed showed some residual pouch. We were unsuccessful in our attempt to correlate post-operative symptoms with radiological appearance. Attempts by other radiologists at identifying pre- and post-operative barium swallow radiographs in patients who had endoscopic stapling of pharyngeal pouch were unsuccessful. We conclude that post-operative barium swallow radiography plays no role in determining the success of endoscopic stapling of pharyngeal pouch.

Anti-IL-4 treatment prevents dermal collagen deposition in the tight-skin mouse model of scleroderma

The tight-skin (Tsk/+) mutant mouse, a putative murine model of scleroderma, is characterized primarily by the excessive deposition of collagen and other extracellular matrix molecules in the dermis, and also by a developmentally acquired defect in pulmonary architecture. Passive transfer experiments have suggested an etiologic role for the immune system in Tsk/+ dermal pathology. In addition, CD4+ T lymphocytes have been shown to be required for the excessive accumulation of dermal collagen in these mice. As IL-4, a product of differentiated CD4+ T cells, is capable of regulating the synthesis of various matrix molecules (including type I collagen) by fibroblasts in vitro, we investigated the potential role of IL-4 in mediating Tsk/+ dermal fibrosis. Confirming that Tsk/+ cells are capable of responding to IL-4, we found receptors for this cytokine on Tsk/+ embryonic fibroblasts and a dermal fibroblast cell line derived from these mice. Furthermore, IL-4 receptors on Tsk/+ fibroblasts were functional since IL-4 stimulation in vitro increased type I collagen secretion from these cells. These results demonstrated the potential for IL-4 to be directly involved in the excessive deposition of dermal collagen in Tsk/+ mice. Critical insight into the role played by IL-4 in mediating the dermal phenotype, however, was obtained following the administration of neutralizing anti-lL-4 antibodies to Tsk/+ mice. This treatment prevented the development of dermal fibrosis, leading to normalization of dermal collagen content. Given the requirement for CD4+ T cells in Tsk/+ dermal fibrosis, our results suggest that Th2 cells and/or factors elaborated by this T cell subset may play a key role in regulating dermal collagen content in this strain.

The difficulties encountered in completing an audit cycle in a district general hospital

Clinical audit has brought about tremendous improvements in the quality of clinical practice in all aspects of health care. However, completing an audit cycle presents many obstacles. We present our experience in the difficulties encountered in implementing changes to current practice. The factors involved are discussed.

Cellular proteins bind to the 3' and 5' untranslated regions of dengue 2 virus genome

In vitro generated cloned full length dengue 2 virus untranslated regions (UTRs) were used in RNA gel mobility shift assays to examine cellular factors binding to the virus genomes. Cellular factors in lysates of Vero (monkey) and C6/36 (mosquito) cells bound specifically and non-specifically to the dengue 2 virus 3' UTR. Non-specific interaction with the 5' UTR, resulting in formation of at least 4 band shift complexes was noted with lysate of the C6/36 cells only. Pre-treating the cell lysates with proteinase K affected binding of cellular factors to the dengue 2 virus UTRs, suggesting that the cellular factors were proteins. These findings suggest that cellular proteins could interact with specific sites on the dengue virus genomes.

Intra-abdominal and pelvic abscess in Crohn's disease: results of noninvasive and surgical management

BACKGROUND

Intra-abdominal and pelvic abscesses occur in 10-30 per cent of patients with Crohn's disease. The aim of this study was to establish the clinical characteristics and outcome of patients admitted over a 4-year period with an abdominal or pelvic abscess secondary to Crohn's disease.

METHODS

Patients with Crohn's disease-related intra-abdominal or pelvic abscess were identified from a prospectively collected database, comprising all admissions between 1991 and 1994. Medical records were reviewed retrospectively and data gathered regarding management and outcome.

RESULTS

Thirty-six patients were identified with Crohn's disease-related abscess, of whom 15 were considered for initial percutaneous drainage. Drainage was technically possible in eight of these patients: it failed in four, gave good long-term results in two, and was followed by recurrence after 3 years in one and by later surgery unrelated to the abscess in one. Twenty-eight patients underwent surgery, with only four requiring a stoma. Complications occurred in 12 patients. At 3 months, 22 of the 36 patients were in remission.

CONCLUSION

Crohn's intra-abdominal abscesses are associated with a high morbidity rate. Selected cases can be drained percutaneously, without adding to the morbidity, and sometimes resulting in abscess resolution.

Clinical significance of methohexital, meperidine, and diazepam in breast milk

Concentrations in breast milk of medications used during general anesthesia were measured to determine whether interruption of breast-feeding was indicated. Breast milk and maternal blood samples were obtained from nine women undergoing tubal sterilization under general anesthesia. Concentrations of methohexital, meperidine, diazepam, and nordiazepam were determined for each sample by gas chromatography. Methohexital levels declined rapidly after the first hour and were undetectable at 24 hours. Meperidine was present in both milk and blood during the recovery period but not at 24 hours. Infant-exposure indices for methohexital were less than 1% and ranged from 1.2% to 3.5% for meperidine. The maximum doses of methohexital and meperidine to an infant, in a 100 mL feeding 1 hour after induction of anesthesia were estimated to be 0.04 mg and 0.06 mg, respectively. Diazepam and nordiazepam were not detectable in any sample of milk or blood. The maximum possible infant-exposure index for diazepam would be 3%. The amounts of methohexital, meperidine and diazepam excreted into breast milk do not warrant interruption of breast-feeding.

Studies of Giardia spp. and Cryptosporidium spp. in two adjacent watersheds

Two adjacent British Columbia, Canada, watersheds with similar topographical features were studied. Both the Black Mountain Irrigation District (BMID) and the Vernon Irrigation District (VID) serve rural agricultural communities which are active in cattle ranching. The present study was carried out in five phases, during which a total of 249 surface water samples were tested in the study watersheds. The aims of these phases were to determine levels of parasite contamination in raw water samples collected from the intakes as well as from other sites in each watershed and to investigate cattle in the watersheds as potential sources of parasite contamination of surface drinking water supplies. Giardia cysts were not detected in the raw water samples collected from lake sources at the headwaters of both watersheds but were found in 100% (70 or 70) of water samples collected at the BMID intake and 97% (68 of 70) of water samples collected at the VID intake. Significantly higher levels (P < 0.05) of Giardia cysts were found at the BMID intake (phase 1, 7 to 2,215 cysts per 100 liters; phase 3, 4.6 to 1,880 cysts per 100 liters) when compared with that of the VID intake (2 to 114 cysts per 100 liters). The BMID watershed has a more complex system of surface water sources than the VID watershed. Cattle have access to creeks in the BMID watershed, whereas access is restricted in the VID watershed. Collection of raw water samples from a creek upstream and downstream of a cattle ranch in the BMID watershed showed that the downstream location had significantly higher (P < 0.05) levels (0.6 to 42.9 cysts per 100 liters and 1.4 to 300.0 oocysts per 100 liters) of both Giardia cysts and Cryptosporidium oocysts than those of the upstream location (0.5 to 34.4 cysts per 100 liters and 0.5 to 34.4 oocysts per 100 liters). Peak concentrations of both parasites coincided with calving activity. Fecal samples, collected from cattle in both watersheds, showed 10% (3 of 30) in the BMID and 50% (5 of 10) in the VID watersheds to be Giardia positive. No Cryptosporidium-positive fecal samples were found. Giardia cysts isolated from the BMID watershed were repeatedly infective to gerbils in contrast to those from the VID watershed. The 10 BMID drinking water Giardia isolates retrieved into culture and biotyped showed zymodeme and karyotype heterogeneity. The differences in patterns of parasite contamination and cattle management practices contribute to the unique watershed characteristics observed between two areas which are topographically similar and geographically adjacent.

Renal-pancreatic-hepatic dysplasia in siblings

Fewer than 20 children with complete renal-pancreatic-hepatic dysplasia have been reported since first described in 1959. We report two brothers with renal-pancreatic-hepatic dysplasia, one of whom had hypertrophic cardiomyopathy and pancreatic exocrine insufficiency, previously unreported associated findings.

K-ras mutation in colorectal carcinomas from singapore

54 sporadic colorectal cancers were analyzed for aberrations in the K-ras oncogene. DNA was extracted from frozen tissues obtained from surgical resection and analyzed for mutations in codons 12, 13 and 61 of the K-ras oncogene using single strand conformation polymorphism analysis (SSCP) and direct sequencing. Point mutations in the K-ras oncogene were found in 26/54 (48%) cases, all of which resulted in amino acid substitutions. No other types of mutations (e.g. insertions or deletions) were found. 4 of the mutations were at codon 12, 22 in codon 13 and only 1 was a codon 61 mutant. G-->A transitions were found to be predominant. A remarkable finding was the high preponderance of (13)Gly-(13)Ser mutations (54%). No correlation was observed between K-ras mutations and tumor location, Dukes' stage, differentiation levels, age or sex of the patient.

Spectral studies of magnesium porphyrin--apomyoglobin and apohemoglobin complexes

Complexes of magnesium protoporphyrin and magnesium mesoporphyrin with apomyoglobin and apohemoglobin have been prepared and studied by electronic, circular dichroism, and optical rotatory dispersion spectroscopy. The myoglobin complexes show prominent splittings and red shifts of the visible absorption bands, with respect to those for the hemoglobin analogs. Comparisons are made with other heme protein systems that display similar spectral features. Different reasons for the observations are considered, including multiple conformer formation, polarity effects of the protein environment, and the formation of six-coordinate magnesium species through H2O coordination for the Mb complexes (the latter explanation being favored).

Selection for mercurial resistance in hospital settings

The frequency of resistance to Hg2+ in 1980 to 1981 collections from Barnes Hospital, St. Louis, Mo., was only 2% for Staphylococcus aureus and 9% for Escherichia coli. The frequency of Hg2+ resistance in E. coli isolates from Jikei University Hospital, Tokyo, Japan, was 57% during 1972 to 1977 and decreased to 29% in 1979 to 1982; for S. aureus the frequency of Hg2+ resistance dropped from 36% in 1972 to 1977 to 10% in 1979 to 1982. Frequencies of resistances to cadmium (S. aureus) and arsenic (S. aureus and E. coli) remained approximately constant during this time. The decrease in frequency of mercurial resistance is attributed to the termination of the use of organomercurials (largely phenylmercury and thimerosal) in hospital liquid detergents and disinfectants. It is proposed that selection for mercurial resistance occurred within the hospital setting when there was widespread use of mercurials. The resistance patterns and phage types for each of four new mercurial-resistant S. aureus isolates from St. Louis were distinct, indicating that no single type of "hospital staph" predominates. Furthermore, resistance to thimerosal, merbromin, and methylmercury and the ability to volatilize 14C from [14C]methylmercury were found with the new isolates and never with previously known mercurial resistance plasmids in S. aureus.