Markers for implant placement in CBCT: a technical overview

Cone beam computer tomography (CBCT) is becoming a more accessible modality of imaging within dentistry. It has particular application in the diagnostic treatment planning for dental implant placement. The use of radiographic surgical stents with CBCT can help to provide important information about bone position and therefore placement of implants and final restorations. This article looks at a novel technique, which allows a variety of different marker positions that can be quickly and easily placed and removed. It allows the use of a current prosthesis that can be adapted to act as a surgical stent during CBCT.

The use of ureteral stents and suprapubic catheter in vesicoureteric reflux surgery

The use of ureteric stents in reimplantation surgery is important. The younger the patient, the more important the stenting of ureters post reimplantation becomes, because even minimal oedema following surgery will produce ureteric obstruction unless stents are in place. JJ stents are now the preferred method of choice in ureteric reimplantation surgery, but in the past the patient required another admission to hospital and general anaesthetic to have the stents removed endoscopically. We describe a technique whereby the stents are attached to the suprapubic catheter and are therefore removed prior to the patient's discharge from hospital, thus obviating the need for a second admission and second anaesthetic for the stent removal. We have studied 23 patients with this technique and find that it is a reliable and safe method to use.

Androgen and oestrogen receptor status of the human appendix testis

Since the human appendix testis is a Mullerian duct derivative it has been theorised that rising oestrogen levels in puberty result in enlargement of this organ and consequent predisposition to torsion. This study sought to establish the presence or absence of both androgen and oestrogen receptors in the human appendix testis. Bilateral appendix testis specimens surgically excised from ten patients undergoing scrotal exploration for acute scrotum were stained immunohistochemically for androgen and oestrogen receptors. These were examined by light microscopy. The human appendix testis was found to express both oestrogen and androgen receptors. Marked regional variation of androgen and oestrogen receptor positivity was demonstrated. The surface epithelium and some stromal cells were androgen receptor positive, whereas oestrogen receptors were confined to ductular invaginations, gland-like structures and some stromal cells. Rising levels of androgens and oestrogens in pubertal boys may account for enlargement and the predisposition of the human appendix testis for torsion since this structure contains receptors for both.

Clinical evaluation of a carbon fibre reinforced carbon endodontic post

This study reports a prospective clinical trial comparing a carbon fibre reinforced carbon (CFRC) endodontic post with a conventional prefabricated post. Twenty-seven single rooted maxillary anterior teeth in 18 patients (nine males and nine females; age range 18-60 years) were restored either with a CFRC post or a wrought precious alloy control. Cast type III gold alloy cores were used in conjunction with both post groups. The CRFC posts (n = 16) were cemented with a composite luting agent and the conventional posts (control) were cemented with zinc phosphate. Four failures were recorded in the CFRC post group at 24, 29, 56 and 87 months, compared with one failure in the control group at 84 months. These results suggest that post-retained crowns utilizing a CFRC material and a composite resin luting agent do not perform as well as conventional wrought precious alloy posts.

A prospective comparison of tissue glue versus sutures for circumcision

The safety of wound closure with tissue glue after surgery has been well established. The efficacy of its use in circumcision is poorly documented. The aim of this study was to carry out a comparative study of tissue glue versus suture closure after circumcision. The duration of the operative procedure, pain score, cosmesis and postoperative complications were evaluated. There were no complications in either group. There was no statistically significant difference in the pain score in both groups. However the mean time taken for tissue glue was 16.6 minutes and the mean time taken for sutures was 23.7 minutes. (p < 0.0001) which was statistically significant. The cosmetic appearance was found to be superior in the tissue glue group as there were no suture marks on the join of the shaft skin and foreskin base.

Home resistance training in an elderly woman with coronary heart disease

In the current report, a home-based resistive exercise training program was designed for an older woman with coronary artery disease and chronic heart failure, who was unable to participate in a center-based program. With intermittent on-site instruction, the patient was able to learn and perform the designed exercise program. After 6 months of exercise, muscle strength (handgrip and leg extension) and lean body mass were increased, and indicators of physical functional performance were improved. We conclude that a home resistive-based exercise program, with intermittent on-site exercise counseling, may be an effective method for physical training in older coronary patients unable to travel to a rehabilitation center. Further study of this intervention in a controlled clinical trial appears warranted.

Multiple atresias in a low-birth-weight twin

This report describes a case of 16 small bowel atresias in a twin who was born at 31 weeks' gestation, weighing 1,690 g. All atresias and intestinal segments of 5 cm or less in length were resected, resulting in nine primary anastomoses, preserving 75% (107 cm) of his initial small bowel length. The baby went home on full oral feedings after 10 weeks. Multiple anastomoses in the low-birth-weight neonate can be tolerated with the functional benefit of maximal bowel length. The time taken to tolerate feedings appears to be independent of the number of anastomoses. Vascular anastomoses associated with monochorionic twinning may place both fetuses at risk of intestinal atresia in the event of an ischemic insult, either concurrently or with the demise of one affecting the other. Prenatal ultrasound scan appears to be useful for monitoring the evolution of intestinal atresia. However, the risks of extreme prematurity preclude the delivery of the affected baby at the time of initial diagnosis, and as yet it is unknown whether early delivery will alter the number, type, or prognosis of multiple atresias.

Adhesive techniques

This paper describes the use of adhesive techniques to restore teeth previously affected by tooth surface loss so avoiding the need to remove sound tooth tissue.

The use of adhesive restorations in the management of localised anterior toothwear

Toothwear appears to be increasingly common, particularly in the younger age groups, and will often require restorative intervention to provide satisfactory appearance and function. Well established conventional restorative techniques can be relatively complex and time-consuming and as a consequence may not be accessible for many patients. This paper, with the help of the literature, discusses the alternative application of a variety of adhesive materials and techniques used in the restoration of moderate to severe anterior toothwear.

Sewing-pin perforation of the appendix into the bladder

We report a 2.5-year-old child who presented with an acute abdomen caused by the perforation of a sewing pin through her appendix that had started to penetrate the wall of the bladder.

Embryo research: the challenge for public policy

Complete moral consensus on the status of the human embryo is neither feasible nor necessary for the formulation of ethically acceptable public policy for human embryo research. Significant consensus on permissible human embryo research can rest upon diverse but overlapping moral traditions. Thus, human embryo research policy should do more than reflect mere abstract assertions about the moral status of human embryos. Rather, the moral underpinnings of human embryo research should be derived from a range of values, including the facilitation of human procreation, the advancement of applied scientific knowledge, the reduction of human suffering, and the protection of vulnerable persons from coercion and exploitation.

Intravesical therapy for the treatment of neurogenic bladder in children

BACKGROUND

Oral pharmacotherapy has been commonly used as an adjunct to clean intermittent catheterization (CIC) in the treatment of neurogenic bladder in order to achieve continence, but may be associated with unacceptable side effects. The authors' experience with sterile intravesical preparations of oxybutynin hydrochloride and ephedrine in children is reported here.

METHODS

Patients requiring CIC for neurogenic bladder but with incontinence that was unresponsive to standard oral therapy or that was associated with severe systemic side effects were studied over a 1-year period. Clinical, radiological and urodynamic assessments were made prior to commencing treatment with intravesical oxybutynin hydrochloride. Patients who remained incontinent with poor internal sphincter muscle tone had intravesical ephedrine added.

RESULTS

Seven patients were involved in the study over a 1-year period. Two patients became continent and one patient had an improvement in upper tract dilatation. One patient had a limited improvement with oxybutynin alone but became continent with the addition of ephedrine. Three patients had no response to treatment. There were few side effects.

CONCLUSION

Intravesical agents have a role in the management of paediatric neurogenic bladder for those children with significant adverse sequelae from oral pharmacotherapy who would otherwise require surgical intervention. Intravesical therapy is a safe technique in children with sterile preparations. Further investigation of this modality should be pursued.

An in vitro evaluation of a carbon fiber-based post and core system

STATEMENT OF PROBLEM

A self-contained post and core system, Composipost, comprising an epoxy-based carbon fiber post, a composite core material, and a low viscosity Bis-GMA bonding resin, has recently been marketed for the restoration of pulpless teeth.

PURPOSE

This study compared the in vitro performance and the failure characteristics of the Composipost system against existing post and core combinations.

MATERIAL AND METHODS

Using extracted human teeth, three post and core test groups and one control group were then tested to failure with an obliquely applied compressive load at 130 degrees in a Hounsfield testing-machine with a crosshead speed of 5 cm/minute.

RESULTS

The mean stress values at failure (MNm.2) with standard deviations for each group were as follows: Composipost system 8.89, SD 2.40; stainless steel post and composite core 14.18, SD 3.49; cast gold alloy post and gold alloy core 15.25, SD 4.07; and endodontically treated tooth only 24.84 SD 4.58.

CONCLUSION

The specimens restored with the Composipost system exhibited inferior strength properties in comparison to the other post and core systems tested (p < 0.01). Teeth without post and core foundations tested significantly stronger than the other comparison groups (p < 0.01).

Retrospective survey of resin-retained cast-metal palatal veneers for the treatment of anterior palatal tooth wear

Anterior palatal tooth wear is easily recognized, but its precise pathogenesis remains unknown. Treatment of this condition with cast-alloy palatal veneers used in combination with an adhesive cement is described. Forty-eight patients, aged 11 to 71, were treated with a total of 210 cast metal veneers over a period of 56 months. Twenty-three of the restorations failed, resulting in an overall success rate of 89%. All failures were confined to 13 patients. A glass polyalkenoate cement was less effective than a chemically active resin composite luting agent. Nickel-chromium veneers cemented with activated resin composite recorded a survival probability of 0.74 at 56 months. Adhesive cast-alloy veneers provided a useful method of restoring maxillary anterior teeth affected by acid erosion.

Harms of excluding pregnant women from clinical research: the case of HIV-infected pregnant women

Since the beginning of the AIDS epidemic, the proportion of AIDS cases among women has continued to rise. Women constituted 23 percent of the AIDS cases reported to the Centers for Disease Control and Prevention (CDC) in 1995, and 81 percent of these women were of childbearing age (13 to 44 years). It was not until 1991, however, that epidemiological studies of women were initiated. By comparison, the representation of HIV-infected women in clinical trials gradually has grown. Undoubtedly, a consequence of the increased numbers of women in clinical and epidemiological research is the earlier identification of and more appropriate treatments for HIV-related syndromes when women present in the clinical setting. Despite this expanded focus on women, however, clear information to guide the treatment of HIV-infected women who are pregnant is still lagging behind.

An immediate resin-bonded bridge using the natural tooth

Missing anterior teeth are commonly replaced immediately with partial dentures, but this may cause embarrassing problems and a poor aesthetic appearance. This paper describes a technique for replacing anterior teeth using the natural tooth as a pontic with a resin-bonded cast metal framework. The main advantage of this technique is that a fixed restoration is provided on the same day as the tooth is removed, providing a major psychological benefit to the patient and maintaining the aesthetics. The short-term results are promising- and recent advances in adhesive dentistry mean that the long-term result should be equally as good.

Pioglitazone treatment for 7 days failed to correct the defect in glucose transport and glucose transporter translocation in obese Zucker rat (fa/fa) skeletal muscle plasma membranes

Insulin resistance in the obese (fa/fa) Zucker rat is associated with decreased insulin stimulated glucose transport in skeletal muscle, due primarily to a failure of insulin to stimulate GLUT4 translocation to the plasma membrane from an intracellular pool (1). The thiazolidinedione analog Pioglitazone (PIO) has been shown to improve glucose tolerance in this and other animal models of insulin resistance. The current study was designed to determine whether 7 days of Pioglitazone treatment (20 mg/kg/day by gavage) would improve glucose transport and/or glucose transporter translocation and intrinsic activity in plasma membranes prepared from hindlimb skeletal muscle of obese Zucker (fa/fa) rats. Basal plasma glucose and insulin concentrations in these animals were unchanged by Pioglitazone, while basal plasma triglyceride and nonesterified fatty acid concentrations (NEFA) were reduced by Pioglitazone treatment (501 +/- 88 vs 161 +/- 13 mg/dl, P < 0.0001) and (678 +/- 95 vs 467 +/- 75 microM, P < 0.05) respectively. Pioglitazone had no effect on basal or insulin stimulated glucose influx (Vmax or Km) into plasma membrane vesicles determined under equilibrium exchange conditions compared to controls. Plasma membrane glucose transporter number (R0) (measured by cytochalasin B binding) under basal or insulin stimulated conditions was unchange by Pioglitazone and R0 failed to increase following insulin stimulation in either group. Glucose transporter turnover number (Vmax/R0) increased 2-fold with insulin stimulation compared to basal in both control and Pioglitazone groups, similar to turnover numbers observed in normal rats. These data confirm that impaired glucose transporter translocation in muscle of the Zucker rat is a major factor contributing to its insulin resistance. We conclude that the improved glucose tolerance observed in fa/fa rats following Pioglitazone treatment is not due to an improvement in basal or insulin stimulated skeletal muscle plasma membrane glucose transport or glucose transporter translocation and that Pioglitazone treatment does not affect transporter intrinsic activity.

Diagnosis, management, and outcome of cervicofacial teratomas in neonates: a Childrens Cancer Group study

The management of cervicofacial teratomas in neonates is often complicated and may result in significant morbidity and death. A Childrens Cancer Group (CCG) retrospective study was conducted to evaluate a multiinstitutional experience with the treatment of these extremely rare neoplasms. Twenty neonates with cervicofacial teratomas, presenting from 1971 to 1994, were identified from nine CCG institutions. Fourteen neonates had cervical teratomas, and six had orofacial teratomas. There were 12 males and eight females. A diagnostic prenatal ultrasound examination was performed in six cases. Life-threatening airway obstruction occurred in seven infants (35%) in the early postnatal period. Two neonates died in the delivery room without ever having their airway secured. Two other infants with a prenatal diagnosis survived only because tracheostomies were performed by pediatric surgeons who were in the delivery room. Three other patients were orally intubated, one after sustaining hypoxic cardiac arrest. Eighteen infants had their primary tumor excised. Three patients required tracheostomy. After resection, two patients had evidence of unilateral recurrent laryngeal nerve injury, and two required prolonged thyroid hormone replacement. Histological examination showed eight mature and seven immature teratomas. Four infants (20%) clearly had malignant lesions. Pulmonary metastases occurred in two patients and contributed to one late death at 6 months of age. The overall survival rate was 85%, and the mean follow-up period was 5 years (range, 2 months to 16 years). Twelve of 17 surviving patients (70%) have had an excellent functional and cosmetic outcome. Four children have varying degrees of developmental delay and mental retardation. Hypoxia at birth was believed to have contributed to these problems in two cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypodontia: 2. The management of severe hypodontia

The management of severe lack of teeth in the dental arch presents the clinician with a number of difficulties. In this paper, the second in a series on hypodontia, the problems are outlined and suggestions made as how best to overcome them.

Insulin and Na-dependent alanine transport in skeletal muscle of obese Zucker (fa/fa) rats

Obese Zucker (fa/fa) rat skeletal muscle is characterized by a reduced rate of muscle protein deposition possibly due to alterations in amino acid transport. The purpose of the present study was to investigate alanine transport in plasma membrane vesicles from skeletal muscle of lean and obese Zucker rats, facilitating the study of alanine transport independent of cellular metabolism. Initial rates of alanine transport were measured in the presence and absence of Na using a rapid filtration technique, and the properties of membranes from control and maximally insulin-treated lean and obese Zucker rats were studied. For lean rats, the maximal stimulation (Vmax) for Na-dependent alanine transport was 207 pmol.mg-1.s-1, and the half-maximal affinity constant (K1/2) was 2.3 mM. Insulin treatment increased the Vmax to 387 pmol.mg-1.s-1 with no changes in K1/2. For the obese rats, the Vmax for Na-dependent alanine transport was 248 pmol.mg-1.s-1, and the K1/2 was 2.8 mM. These values were not changed by insulin treatment. Thus Na-dependent alanine transport in obese rat skeletal muscle is resistant to stimulation by insulin; this alteration may contribute to the abnormal muscle protein metabolism observed in these animals.

A review of pediatric cases of urinary tract calculi

A retrospective review was performed of the records of 93 children with urinary tract calculi treated during a 10-year period (1983 to 1992). Two distinct groups of patients were identified. One group comprised 63 Aboriginal children, mainly from the northern region of Western Australia, who presented at a young age (average, 2.8 years) with urinary tract infections and failure to thrive. The other group comprised of 30 non-Aboriginal children, mainly from the metropolitan region, who presented at an older age (average, 6.7 years) with abdominal and flank pain. Calculi were located in the upper urinary tract in 85 children (91.4%) and in the bladder in eight (8.6%). Most patients underwent open surgical procedures for removal of their calculi, and the overall success rate was 86%. In recent years, percutaneous nephrolithotomy has been used successfully in selected patients with renal pelvic calculi. This method seems to be the trend for the future.

Effects of insulin and exercise on amino acid transport in rat skeletal muscle

In the present study, the initial rates of amino acid transport by isolated rat skeletal muscle plasma membrane vesicles were investigated. This approach facilitates the study of the transport of naturally occurring amino acids independent of the effects of cellular metabolism. Alanine and glutamine influxes were measured using a rapid filtration technique. Transport was examined in the presence and absence of Na and the properties of membranes from control, insulin-treated, or acutely exercised rats were studied. Both alanine and glutamine were transported by Na-dependent processes. The values for maximum rate of transport (Vmax) for Na-dependent alanine and glutamine transport were 203 and 224 pmol.mg-1.s-1, respectively. The K1/2 values were 2.9 mM alanine and 1.9 mM glutamine. The Vmax for Na-dependent alanine transport was increased by insulin treatment of the animal and by acute exercise. 2-(Methylamino)-isobutyric acid (MeAIB) partially inhibited the control Na-dependent alanine influx and completely inhibited the increase due to insulin or exercise treatment, indicating the importance of both system A and a non-system A, Na-dependent carrier for alanine transport. The Vmax for Na-dependent MeAIB uptake was also increased by insulin or exercise treatments of the rats. Unlike alanine, Na-dependent glutamine transport was not affected by insulin.

High-fat diet reduces glucose transporter responses to both insulin and exercise

High-fat diet (HFD) induces skeletal muscle insulin resistance. To investigate associated changes in the plasma membrane glucose transporter, male Sprague-Dawley rats were fed either chow [high-carbohydrate diet (HCD)] or HFD for 3 wk. Plasma membrane vesicles were prepared from hindlimb muscle of control, insulin-stimulated (Ins), and acutely exercised (Ex) rats. Maximal vesicle glucose transport activity (Vmax) increased threefold with Ins and Ex treatment compared with controls in HCD rats; in HFD rats, increases were less than twofold. Transporter numbers (measured by cytochalasin B binding, CB) approximately doubled with Ins and Ex in both diet groups. Intrinsic activity (carrier turnover, Vmax/CB) increased significantly with stimulation in HCD but not HFD rats. Therefore, vesicles from HFD rats showed resistance to both exercise and insulin stimulation of muscle glucose transport. Transporter number increased normally, but intrinsic activity in HFD rats did not respond. Two conclusions are discussed: 1) translocation and activation are distinct, separable steps in transporter stimulation and 2) HFD produces effects that resemble the insulin resistance of starvation.

Adaptations of plasma membrane glucose transport facilitate cryoprotectant distribution in freeze-tolerant frogs

Natural freeze tolerance in several anuran species involves the accumulation of high concentrations of glucose as a cryoprotectant in body fluids and tissues. The present study identifies an important new molecular mechanism supporting freeze tolerance, an adaptive increase in the capacity for facilitated transport of cryoprotectant across plasma membranes by increasing the numbers and/or activity of plasma membrane glucose transporters. Glucose transport by membranes isolated from liver and skeletal muscle was analyzed in two species, the freeze-tolerant wood frog Rana sylvatica and the freeze-intolerant leopard frog Rana pipiens. Membranes from both liver and muscle of R. sylvatica displayed much higher rates of carrier-mediated glucose transport, measured by a rapid filtration technique, compared with corresponding rates for R. pipiens membranes. For the liver Vmax values for glucose transport by membrane vesicles were 69 +/- 18 and 8.4 +/- 2.3 nmol.mg protein-1.s-1 at 10 degrees C for R. sylvatica and R. pipiens, respectively. This difference was due primarily to a greater number of glucose transporters in R. sylvatica liver membranes; the total number of transporter sites, determined by cytochalasin B binding, was 4.7-fold higher in the freeze-tolerant species. For muscle membranes, the Vmax for glucose transport was 4.9 +/- 1 and 0.6 +/- 0.16 nmol.mg-1 x s-1 at 22 degrees C for R. sylvatica and R. pipiens, respectively. However, in muscle there were no differences in the number of membrane transporters between species.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise, unlike insulin, promotes glucose transporter translocation in obese Zucker rat muscle

Insulin or exercise stimulates skeletal muscle glucose transport, most likely by increasing both the number and activity of glucose transporters in the plasma membrane. Skeletal muscle glucose transport of genetically obese Zucker rats (fa/fa) displays a severe insulin resistance that results, at least in part, from a failure of net transporter translocation to the cell membrane (King, P., E. D. Horton, M. Hirshman, and E. S. Horton. J. Clin, Invest. 90: 1568-1575, 1992). The purpose of the present study was to determine if the obese rat muscle was also resistant to the action of acute exercise to increase glucose transport and, if so, to determine if the defect involved transporter translocation as seen in the resistance to insulin. The muscle glucose transport system was investigated in plasma membranes isolated from postprandial, sedentary or acutely exercised, lean and obese Zucker rats. Measurements of D- and L-glucose uptake by membrane vesicles under equilibrium exchange conditions indicated that an acute bout of exercise resulted in a threefold increase in the maximum velocity (Vmax) for lean animals (5.7 vs. 17.6 nmol.mg protein-1.min-1) and a 4.5-fold increase in the Vmax for obese rats (4.1 vs. 18.6 nmol.mg protein-1.min-1). For both lean and obese animals, this increase in transport was associated with an increase in transporter number measured by cytochalasin B binding (1.6- and 2.2-fold, respectively) and with an increase in the average carrier turnover number (1.9- and 2.0-fold, respectively). The results indicate that, unlike a maximal insulin stimulus, acute exercise of the obese Zucker rat promotes both transporter translocation and transporter activation in skeletal muscle.

A teaching strategy for identifying values: a clinical experience with the homeless

Beginning baccalaureate students recorded their thoughts, feelings, and observations after participating in a clinical experience with the homeless. A content analysis protocol was used to uncover the meaning of the encounter. The findings suggest that assigning students to a homeless clinic is one way to help students identify professional values, such as altruism, equality, and human dignity.

'Footprinting' proteins on DNA with peroxonitrous acid

The peroxonitrite anion (ONOO-) is a stable species in alkaline solution that quickly generates a strong oxidant at neutral pH. A convenient procedure for the preparation of ONOOK has been developed based on the procedure of Keith & Powell [(1969) J. Chem. Soc. A, 90], which when added to a sample of duplex DNA buffered at neutral pH rapidly generates a strong oxidant capable of nonspecifically cleaving the DNA present. We show that this solution containing ONOOK can be used to hydroxyl radical footprint the binding the cl-repressor (cl) of phage lambda with the right operator, OR. In addition, we show that the individual-site binding isotherms determined by quantitative DNase I, Fe-EDTA and ONOOK footprinting are identical within experimental error. The identical isotherms obtained with the three different reagents with greatly differing sampling times indicates that the sampling time of the footprinting probe need not be short relative to the kinetic dissociation constants that govern protein-DNA interactions.

Insulin resistance in obese Zucker rat (fa/fa) skeletal muscle is associated with a failure of glucose transporter translocation

The genetically obese Zucker rat (fa/fa) is characterized by a severe resistance to the action of insulin to stimulate skeletal muscle glucose transport. The goal of the present study was to identify whether the defect associated with this insulin resistance involves an alteration of transporter translocation and/or transporter activity. Various components of the muscle glucose transport system were investigated in plasma membranes isolated from basal or maximally insulin-treated skeletal muscle of lean and obese Zucker rats. Measurements of D- and L-glucose uptake by membrane vesicles under equilibrium exchange conditions indicated that insulin treatment resulted in a four-fold increase in the Vmax for carrier-mediated transport for lean animals [from 4.5 to 17.5 nmol/(mg.s)] but only a 2.5-fold increase for obese rats [from 3.6 to 9.1 nmol/(mg.s)]. In the lean animals, this increase in glucose transport function was associated with a 1.8-fold increase in the transporter number as indicated by cytochalasin B binding, a 1.4-fold increase in plasma membrane GLUT4 protein, and a doubling of the average carrier turnover number (intrinsic activity). In the obese animals, there was no change in plasma membrane transporter number measured by cytochalasin B binding, or in GLUT4 or GLUT1 protein. However, there was an increase in carrier turnover number similar to that seen in the lean litter mates. Measurements of GLUT4 mRNA in red gastrocnemius muscle showed no difference between lean and obese rats. We conclude that the insulin resistance of the obese rats involves the failure of translocation of transporters, while the action of insulin to increase the average carrier turnover number is normal.

The replacement of missing maxillary central incisor teeth incorporating a midline diastema with a fixed-fixed resin-retained bridge

The replacement of maxillary central incisor teeth with the maintenance of a midline diastema can create considerable problems for the restorative dental surgeon. This case report illustrates the treatment of such a case using a fixed-fixed resin-retained bridge with a modified palatal connector. Alternative treatment options are discussed.

Born before arrival--uncovering the hazards

In a retrospective case controlled study the demographic background and outcome of 193 mothers whose babies were born before arrival at hospital was compared to that of a control group who delivered within the maternity units of 2 teaching hospitals in Hong Kong. Mothers who delivered before arrival at hospital were significantly more likely to be single, to have received no antenatal care, to have an unplanned pregnancy, low family income and to come from a socially disadvantaged group such as Vietnamese refugees and illegal immigrants from China. Lacerations to the genital tract, postnatal anaemia and blood transfusions were more common in the study group. Results of cervical cytology and rubella status were available in significantly fewer of these mothers. They were more likely to be ambivalent about contraception and less likely to attend the postnatal clinic. The perinatal mortality and morbidity was significantly increased.

Glycine transport by human red blood cells and ghosts: evidence for glycine anion and proton cotransport by band 3

Stilbene-sensitive glycine transport was investigated in human red blood cells and ghosts. We have found that this component of glycine transport was inhibited by the stilbene derivatives 4,4'-dinitrostilbene-2,2'-disulfonic acid (DNDS) and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS); the apparent constant for inhibition by DNDS was 4 microM in the presence of 150 mM chloride. DNDS-sensitive glycine influx was modulated by pH such that as pH was increased from 5.9 to 9.2, transport increased from 2.5 to 140 mumol.kg Hb-1.h-1 at 37 degrees C and 100 microM glycine. The increased transport was correlated with an increase in the amount of glycine present as the anion over this pH range (0.03-40 microM glycine anion), but, in addition, pH had a direct effect on transport. Glycine influx was studied as a function of glycine anion concentration with anion varied by changing pH at a constant total glycine concentration and by changing total glycine at a constant pH. A comparison of these data demonstrated that the stilbene-sensitive glycine anion flux is stimulated by protons with half-maximal stimulation below pH 6.5 and suggests that the glycine anion and a proton are cotransported. Inorganic anions transported by band 3, including Cl, NO3, and SO4, inhibited glycine transport. Glycine flux into resealed ghosts was inhibited by Cl with an inhibition constant of 25 mM. The similarities between the kinetic constants for transport inhibition by Cl and DNDS and the kinetic constants for Cl and DNDS binding to band 3 suggest that the DNDS-sensitive glycine anion and proton cotransport is via band 3.

Educating nursing home staff in lower extremity assessment and care

A neglected area of care for the elderly in long-term care facilities is that of appropriate assessment and care of the lower extremities, particularly the feet. Two assessment guides--one for the registered nurse and one for the nursing assistant--are presented.

Recurrent congenital chylothorax

Congenital chylothorax is an uncommon but well-described condition. Recurrent congenital chylothorax is extremely rare. Yancy and Spock (1967) reviewed 31 reported cases of spontaneous chylothorax which occurred in the first 2 months of life and noted that male infants were affected twice as commonly as females. Two other cases of recurrent congenital chylothorax in male offspring (Defoort and Thiery, 1978; Reece et al., 1987) led to the suggestion of possible X-linked recessive inheritance. We describe a case of recurrent congenital chylothorax in which two consecutive female infants in a sibship were affected. The underlying cause of this disorder remains unknown. Inheritance as an X-linked recessive is not possible and this case is suggestive of autosomal recessive inheritance. The case also serves to emphasize the need for caution in counselling for recurrence risks when the underlying aetiology of the disorder is unknown.

Mosaic partial trisomy 17q2

Examination of an infant born after prenatal diagnosis of mosaic partial trisomy 17q2 showed the unique phenotypic features of this chromosomal abnormality, that is, frontal bossing, large mouth, brachyrhizomelia, and hexadactyly. Amniocentesis was performed because of polyhydramnios and ultrasound diagnosis of fetal craniofacial dysmorphology and rhizomelic shortening of the limbs. Chromosomal mosaicism was restricted to fetal tissue and amniotic fluid cells. The placental chromosomal complement was normal, suggesting that the abnormality developed after differentiation of embryonic and trophoblastic cells. This emphasises the usefulness of cytogenetic evaluation of placental, fetal, and amniotic fluid cells in delineating the pathogenesis of congenital abnormalities.

Grand multiparity: a reappraisal of the risks

An excellent maternal and perinatal outcome is reported in a group of grand multipara of low socioeconomic status. These observations on a group of patients who are traditionally considered to be high risk show that in a healthy population with access to modern medical care and hospital delivery, a favorable outcome can be achieved despite a low socioeconomic or refugee status.

Resistance to torsional forces of various post and core designs

This in vitro study investigated the resistance of various post and core designs to torsional forces. Cast gold, parallel-sided, serrated post and cores were cemented in extracted teeth. The test groups were made up of the following designs: controls without an antirotational feature, keyway form, coronal flare form, auxiliary pin form, a cervical collar form, and included a tapered post group. The specimens were mounted on an Instron Universal testing machine and a torsional force was applied to the core using a lever arm until failure. All the antirotational features tested elevated resistance to torque. Failure occurred through fracture of the tooth, the cement, or an optional auxiliary pin. The cervical collar was the most favorable design, embracing resistance and reducing tooth fractures.

Mid-ileal stricture and spinal injury sustained by a 7 year old child restrained by a lap seat belt involved in a motor vehicle accident

Lap belts are a feature of the middle seat occupant in the rear seat of most Australian family cars. Without the provision of a child harness, they are inadequate to restrain children under eight years of age. We report a motor vehicle accident involving a seven year old child wearing an adult lap belt which resulted in an ileal stricture and a potentially unstable distraction injury of the lumbar spine.

Primary obstructive megaureter

Twenty-three children with primary obstructive megaureters presented between 1978 and 1988 to the Princess Margaret Hospital for Children in Perth. Twenty-eight ureters were treated. Urinary infections were the presenting feature in 14 children. The obstructive segment was transvesically excised. Histopathologic examination of the distal, intramural ureter showed fibromuscular disarray with a relative increase in fibrous tissue and reduction of musculature in all specimens. Twenty-two ureters were tapered by excision and all 28 were reimplanted using an antireflux technique. Seventeen children were followed for an average of 3 years. Seven children showed renal growth, reduction in ureteric size by greater than 2 cm, improvement in glomerular filtration rate by more than 10%, no obstruction on reflux, and no infections in postoperative period. Four children showed all the above but suffered one or more infections after the operation. Of the remaining 6 children, 3 had postoperative obstruction and 3 had vesicoureteric reflux.

A case controlled study of pregnancy complicated by severe maternal anaemia

The perinatal outcome of 96 patients who had an antenatal haemoglobin value of less than 8.0 g/dl was compared with that of a similar number of controls who were matched for age and parity. Sixty-one patients (63%) had iron deficiency anaemia, 25 (26%) had alpha or beta thalassaemia minor, 7 (7.3%) had iron deficiency and thalassaemia trait, 2 had idiopathic pancytopenia and 1 had haemolytic anaemia due to systemic lupus erythematosus. Patients in the study group attended the antenatal booking clinic later, had less weight gain during pregnancy and their babies had lower birth-weights (2,984 g versus 3,177 g p less than 0.01) although there was no significant difference in the period of gestation at delivery. Six patients in the study group had placental abruption and another 2 patients had stillbirths but neither of these complications occurred in the control group. Although 37 patients (39%) in the study group received an antenatal blood transfusion, 53 (55%) of this group also had postnatal anaemia.

The impact of multiple induced abortions on the outcome of subsequent pregnancy

The obstetric outcome of 285 women with a history of previous multiple induced abortions is compared to that of 285 age matched primigravidas. In the study group, 219 women had 2 previous induced abortions and 66 had 3 or more, the maximum number being 8. There was a higher incidence of unmarried women and smokers in this group but a lower incidence of uneducated women. There was no difference in the incidence of antenatal complications between the 2 groups. The mean gestation at delivery, duration of labour and mode of delivery were comparable. There was an increased incidence (p less than 0.01) of retained placenta in the subgroup of women with 3 or more previous induced abortions. There were no maternal or perinatal deaths. The mean birth-weight was comparable and there were no infants weighing less than 1,500 g in either group. We conclude that multiple previous induced abortions appear to have minimal impact on the obstetric outcome of subsequent pregnancy in this population, and in the absence of other risk factors there is no need to alter standard obstetric management in this group of women.

The authority of families to make medical decisions for incompetent patients after the Cruzan decision

I want to approach this difficult topic not from the professional perspective of a lawyer, but rather as the person I am in multiple relationships: wife, mother, step-mother, daughter, and step-daughter. I would suggest to you that none of us can avoid thinking about the role of families in making decisions for incompetent patients without viewing the questions that arise through lenses created by the roles we play in multiple relationships. I would also suggest to you that none of us can avoid thinking about the possibility of becoming incompetent ourselves without thinking about the relationships we have with our families.

My remarks here will be addressed primarily to the Cruzan decision, so they will be most obviously applicable to patients in a persistent vegetative state. However, I intend for my reflections to apply to decision-making about all incompetent adult patients.

Obstetric outcome among Vietnamese refugees in Hong Kong: an age-matched case-controlled study

The obstetric performance of 308 Vietnamese refugees is compared with that of 308 age-matched Hong Kong Chinese patients. Vietnamese women were of higher parity and had an increased incidence of late booking and unreliable dates. Significant differences were found in the incidence of previous termination of pregnancy, iron-deficiency anemia, parasitic infestation, tuberculosis (TB) and syphilis. There was no significant difference in the mean birthweight between the two groups. However, there were twice as many low birthweight (less than 2500 g) infants amongst the Vietnamese whereas the Chinese patients had a higher incidence of macrosomic (greater than 4 kg) infants. There were no perinatal deaths and no significant perinatal morbidity.

An in vitro evaluation of a prototype CFRC prefabricated post developed for the restoration of pulpless teeth

Carbon fibre reinforced carbon (CFRC) in the form of a prefabricated post has recently been developed and is theoretically acceptable for consideration in an endodontic post-retained crown system. This study compared four different types of postcore system cemented into 40 extracted anterior human teeth. The test groups consisted of CFRC posts cemented with a composite resin luting agent, and used with either a cast gold alloy core (Group B) or a composite resin core (Group C). Two existing post-core techniques were used as controls for comparison with the CFRC groups. One control was a prefabricated wrought precious alloy post having a cast gold alloy core, and cemented with zinc phosphate cement (Group A). The other was a prefabricated stainless steel post with a composite resin core, and cemented with a composite resin luting agent (Group D). All specimens were restored with a gold alloy crown and tested to failure with an obliquely applied compressive load at 130 degrees in an Instron using a cross-head speed of 5 cm min-1. The results showed that post-retained crowns using a prefabricated CFRC post exhibited properties comparable with, and in some cases better than, those of existing prefabricated posts. The mode of failure of specimens restored with a CFRC post was more favourable to the remaining tooth tissue than was that of specimens restored with a metallic post.