Identification of a Drosophila prolyl endopeptidase and analysis of its expression

Prolyl endopeptidases (PEPs) are believed to be involved in the metabolism of neuropeptide hormones (reviewed in Mentlein [1988]). Genes encoding PEPs have been isolated from various species, but their expression patterns during development have not been determined. In this study, we isolated a gene encoding a predicted PEP from the fruitfly Drosophila melanogaster. The gene encodes a predicted 756-amino acid protein having extensive sequence similarity to human PEP. We demonstrated that the Drosophila gene (DPEP) is expressed in a spatially restricted pattern in imaginal discs and the larval brain. Our results suggest a role for DPEP in the regional specification of larval tissues. They also provide a starting point for a genetic analysis of the function of this enzyme during development.

Cost-effectiveness of family planning and maternal health service delivery strategies in rural Bangladesh

Two alternative service delivery strategies to improve the effectiveness and efficiency of the Bangladesh national Family Planning and Maternal and Child Health programme have been tested: (1) service delivery at cluster spots, a centrally located neighbourhood spot, rather than at the client's home, and (2) increased frequency of outreach clinics merged with immunization spots. The cost-effectiveness of these strategies was compared with baseline estimates of the cost of providing services. The data were collected in two rural sites of Bangladesh, Mirsarai Thana of Chittagong and Abhoynagar Thana of Jessore, in August 1996. The results of this analysis indicate that cluster service delivery of contraceptive services in their present form are not more cost-effective than home delivery services. The cost per birth averted was lower in only one out of three services in each of the field sites. When the cost-effectiveness of increasing the frequency of SCs combined with EPI services was examined, the service delivery was found to be more cost-effective for all services in one thana and for two out of three services in the higher performing thana, Abhoynagar. This implies that the provision of a wider range of services is improving overall cost-effectiveness.

Role of the ATP-binding domain of the human papillomavirus type 11 E1 helicase in E2-dependent binding to the origin

Replication of the genome of human papillomaviruses (HPV) is initiated by the recruitment of the viral E1 helicase to the origin of DNA replication by the viral E2 protein, which binds specifically to the origin. We determined, for HPV type 11 (HPV-11), that the C-terminal 296 amino acids of E1 are sufficient for interaction with the transactivation domain of E2 in the yeast two-hybrid system and in vitro. This region of E1 encompasses the ATP-binding domain. Here we have examined the role of this ATP-binding domain, and of ATP, on E2-dependent binding of E1 to the origin. Several amino acid substitutions in the phosphate-binding loop (P loop), which is implicated in binding the triphosphate moiety of ATP, abolished E2 binding, indicating that the structural integrity of this domain is essential for the interaction. The structural constraints imposed on the E1 P loop may differ between HPV-11 and bovine papillomavirus type 1 (BPV-1), since the P479S substitution that inactivates BPV-1 E1 is tolerated in the HPV-11 enzyme. Other substitutions in the E1 P loop, or in two other conserved motifs of the ATP-binding domain, were tolerated, indicating that ATP binding is not essential for interaction with E2. Nevertheless, ATP-Mg stimulated the E2-dependent binding of E1 to the origin in vitro. This stimulation was maximal at the physiological temperature (37 degrees C) and did not require ATP hydrolysis. In contrast, ATP-Mg did not stimulate the E2-dependent binding to the origin of an E1 protein containing only the C-terminal domain (353 to 649) or that of mutant E1 proteins with alterations in the DNA-binding domain. These results are discussed in light of a model in which the E1 ATP-binding domain is required for formation of the E2-binding surface and can, upon the binding of ATP, facilitate and/or stabilize the interaction of E1 with the origin.

Hedgehog activates the EGF receptor pathway during Drosophila head development

The Hedgehog (Hh) and Epidermal growth factor receptor (EGFR) signaling pathways play critical roles in pattern formation and cell proliferation in invertebrates and vertebrates. In this study, we demonstrate a direct link between these two pathways in Drosophila melanogaster. Hh and EGFR signaling are each required for the formation of a specific region of the head of the adult fruitfly. We show that hh and vein (vn), which encodes a ligand of the Drosophila EGFR (Schnepp, B., Grumbling, G., Donaldson, T. and Simcox, A. (1996) Genes Dev. 10, 2302–13), are expressed in adjacent domains within the imaginal primordium of this region. Using loss- and gain-of-function approaches, we demonstrate that Hh activates vn expression. We also show that Hh activation of vn is mediated through the gene cubitus interruptus (ci) and that this activation requires the C-terminal region of the Ci protein. Finally, we demonstrate that wingless (wg) represses vn expression, thereby limiting the domain of EGFR signaling.

Practitioner and student latex exposure and allergy

Greater application of universal precautions has increased practitioner exposure to chemicals present in personal protective equipment. Of prime concern is the latex present in examination and surgical gloves. A survey concerning latex exposure, allergies, and handwashing was administered to three advanced classes of dental students and was sent to 300 private practitioners in Central Indiana. Results indicate that adverse skin reactions to latex start while in dental school. Problems due to latex gloves were reported by 18.6 percent of the students. Student handwashing materials and methods were adequate, except for inadequate washing time. Adverse skin reactions were reported by 24.1 percent of practitioners wearing latex gloves. Two handwashing problems were noted--inadequate washing time and the common use of water instead of an antimicrobial soap after glove removal. Both students and practitioners reported relatively high levels of personal and family histories of allergy to a variety of sources.

Murine HIP/L29 is a heparin-binding protein with a restricted pattern of expression in adult tissues

Heparin/heparan sulfate (Hp/HS)-binding proteins are implicated in a variety of cell biological processes including cell adhesion, modulation of blood coagulation, and cytokine/growth factor action. Hp/HS-interacting protein (HIP) has been identified in various adult tissues in humans. HIP supports high affinity, selective binding to Hp/HS, promotes cell adhesion, and modulates blood coagulation activities via Hp/HS-dependent mechanisms. Herein, a murine ortholog of human HIP is described that is 78.8% identical to human HIP and 99.8% identical at the cDNA level and identical at the amino acid level to a previously described murine ribosomal protein, L29. Western blot analyses and immunohistological staining with affinity-purified antibodies generated against two distinct peptide sequences of murine HIP/L29 indicate that HIP/L29 is differentially expressed in adult murine tissues and cell types. In the normal murine mammary epithelial cell line, NMuMG, HIP/L29 is enriched in the 100,000 x g particulate fraction. HIP/L29 can be solubilized from the 100,000 x g particulate fraction with 0.8 M NaCl, suggesting that it is a peripheral membrane protein. HIP/L29 directly binds 125I-Hp in gel overlay assays and requires 0.75 M NaCl for elution from Hp-agarose. In addition, recombinant murine HIP expressed in Escherichia coli binds Hp in a saturable and highly selective manner, compared with other glycosaminoglycans including dermatan sulfate, chondroitin sulfate, keratan sulfate, and hyaluronic acid. Collectively, these data indicate that murine HIP/L29, like its human ortholog, is a Hp-binding protein expressed in a restricted manner in adult tissues.

Molecular genetic analysis of multi-drug resistance in Indian isolates of Mycobacterium tuberculosis

A total of 116 isolates from patients attending the out-patient department at the All India Institute of Medical Sciences, New Delhi and the New Delhi Tuberculosis Centre, New Delhi, India were collected. They were analyzed for resistance to drugs prescribed in the treatment for tuberculosis. The drug resistance was initially determined by microbiological techniques. The Bactec 460TB system was employed to determine the type and level of resistance in each isolate. The isolates were further characterized at molecular level. The multi-drug loci corresponding to rpo beta, gyr A, kat G were studied for mutation(s) by the polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) technique. The SSCP positive samples were sequenced to characterize the mutations in rpo beta, and gyr A loci. While previously reported mutations in the gyr A and rpo beta loci were found to be present, several novel mutations were also scored in the rpo beta locus. Interestingly, analysis of the gyr A locus showed the presence of point mutation(s) that could not be detected by PCR-SSCP. Furthermore, rifampicin resistance was found to be an important marker for checking multi-drug resistance (MDR) in clinical isolates of Mycobacterium tuberculosis. This is the first report on molecular genetic analysis of MDR tuberculosis from India, and highlights the increasing incidence of MDR in the Indian isolates of M. tuberculosis.

Latex exposure and allergy: a survey of general dental practitioners and dental students

Gloves are now worn routinely by most general dental practitioners and dental students while treating patients, with latex being the most commonly used glove material. By means of a questionnaire, this study surveyed 160 students in one dental school and 300 randomly selected general dental practitioners in respect of their exposure to latex. Response rates were 74.4 per cent and 57.3 per cent for dental students and practitioners respectively. Adverse skin reactions to the wearing of latex gloves was reported by 18.5 per cent of dental students and 22.8 per cent of practitioners. Analysis of the data indicated that there was an association between student year and adverse skin reaction to latex, an association between years in dental practice and adverse skin reaction to latex and a strong relationship between dentist's gender and adverse skin reaction to latex. Respondents who suffered from eczema or food allergies were more likely to have experienced an adverse skin reaction to latex glove wearing. It is concluded that adverse reactions to latex occur in significant numbers of dental students and dental practitioners, with those who reported personal and familial atopy being more likely to be affected.

Increased nitric oxide production accompanied by the up-regulation of inducible nitric oxide synthase in vascular endothelium from patients with systemic lupus erythematosus

OBJECTIVE

To investigate whether systemic lupus erythematosus (SLE) is accompanied by increased serum nitrite levels, whether active compared with inactive disease is associated with greater nitric oxide (NO) production, and whether endothelial cells or keratinocytes serve as cellular sources of NO by virtue of their increased expression of either constitutive nitric oxide synthase (cNOS) or inducible NOS (iNOS).

METHODS

Fifty-one serum samples (46 from patients with SLE) were analyzed for NO production by measuring nitrite levels in a calorimetric assay. Skin biopsy samples from 21 SLE patients and 11 healthy volunteers were evaluated immunohistochemically, using monoclonal antibodies, for endothelial cell and keratinocyte cNOS and iNOS expression.

RESULTS

Serum nitrite levels were significantly elevated in the 46 patients with SLE (mean +/- SEM 37 +/- 6 microM/liter) compared with controls (15 +/- 7 microM/liter; P < 0.01), and were elevated in patients with active SLE compared with those with inactive disease (46 +/- 7 microM/liter versus 30 +/- 7 microM/liter; P < 0.01). Serum nitrite levels correlated with disease activity (r = 0.47, P = 0.04) and with levels of antibodies to double-stranded DNA (r = 0.35, P = 0.02). Endothelial cell expression of iNOS in SLE patients (mean +/- SEM score 1.5 +/- 0.2) was significantly greater compared with controls (0.6 +/- 0.2; P < 0.01), and higher in patients with active disease compared with those with inactive SLE (1.7 +/- 0.2 versus 1.2 +/- 0.2; P < 0.01). Keratinocyte expression of iNOS was also significantly elevated in SLE patients (0.9 +/- 0.1) compared with controls (0.4 +/- 0.1; P < 0.001). With regard to expression of cNOS, there were no differences between patients with active SLE, those with inactive SLE, and normal controls in either the vascular endothelium or the keratinocytes.

CONCLUSION

NO production is increased in patients with SLE, and 2 potential sources of excessive NO are activated endothelial cells and keratinocytes via up-regulated iNOS.

Central pontine myelinolysis

A 9 year old boy presented with fever, drowsiness, quadriparesis and facial myokymia. MRI showed demyelination in the pontine region. A diagnosis of central pontine myelinolysis was made. Literature review revealed the rarity of uneventful recovery as has been seen in our case.

Transplantation of adenovirally transduced allogeneic chondrocytes into articular cartilage defects in vivo

Gene transfer to chondrocytes followed by intra-articular transplantation may allow for functional modulation of chondrocyte biology and enhanced repair of damaged articular cartilage. We chose to examine the loss of chondrocytes transduced with a recombinant adenovirus containing the gene for Escherichia coli beta-galactosidase (Ad.RSVntlacZ), followed by transplantation into deep and shallow articular cartilage defects using New Zealand White rabbits as an animal model. A type I collagen matrix was used as a carrier for the growth of the transduced chondrocytes and to retain the cells within the surgically created articular defects. Histochemical analysis of matrices recovered from the animals 1, 3 and 10 days after implantation showed the continued loss of lacZ positive chondrocytes. The number of cells recovered from the matrices was also compared with the initial innoculum of transduced cells present within the matrices at the time of implantation. The greatest loss of transduced cells was observed in the first 24 h after implantation. The numbers of transduced cells present within the matrices were relatively constant between 1 and 3 days postimplantation, but had progressively declined by 10 days postimplantation. These results suggest that transduction of chondrocytes followed by intra-articular transplantation in this rabbit model may enable us to examine the biological effects of focal transgenic overexpression of proteins involved in cartilage homeostasis and repair.

Nitric oxide stimulates ADP ribosylation of actin in association with the inhibition of actin polymerization in human neutrophils

In these studies we provide conclusive evidence that (beta/gamma) actin present in human neutrophils is a substrate for nitric oxide (NO)-dependent ADP ribosylation and that this modification is associated with the inhibition of actin polymerization. A 43-kDa substrate for NO-dependent ADP ribosylation was identified as actin by four methods: (1) comigration with the botulinum C2 toxin substrate by two-dimensional gel electrophoresis (pI 5.2), (2) identity between the peptide map generated by V8 protease digestion of the NO and botulinum C2 substrates, (3) immunoprecipitation with antiactin antibodies, and (4) the ability of NO to ADP ribosylate purified neutrophil G-actin in the presence of plasma membrane cofactors. Because the ADP ribosylation of actin by the botulinum C2 toxin is known to inhibit F-actin polymerization, we examined the effect of NO on actin assembly. Flow cytometry revealed that NO inhibited formyl-methionine-leucine-phenylalanine (fMLP)-dependent (30 s at 37 degrees C) F-actin formation (108 +/- 8 vs. 89 +/- 6 relative fluorescence units, P < .02). These results were confirmed by quantification of F-actin formation by gel scanning (10% sodium dodecyl sulfate gel, Coomassie, and densitometry): pretreatment of polymorphonuclear leukocytes with NO resulted in a reduction of fMLP-induced, cytoskeletal-associated F-actin, which was accompanied by an increase of Triton-soluble G-actin. NO also inhibited F-actin formation, as observed by means of rhodamine phalloidin staining of neutrophils adherent to a fibronectin-coated surface. This effect was accompanied by a dose-dependent inhibition of neutrophil adherence in NO-treated cells. The data indicate that NO inhibits cytoskeletal assembly and adherence in human neutrophils in association with the ADP ribosylation of actin.

Carcinoma of the prostate--state at initial presentation

In this retrospective study an attempt is made to document the stage at initial presentation of prostatic cancer. Of the 142 patients seen, 84% presented in an advanced stage and this explains why radical prostatectomies are rarely done in India. Hence efforts are required to screen the population for early diagnosis of the disease.

Nephrocalcinosis, cholelithiasis, and umbilical vein calcification in a premature infant

A case of calcification of the umbilical vein in a premature infant with nephrocalcinosis and cholelithiasis is described. Such an association might have resulted from prematurity, bronchopulmonary dysplasia, umbilical vein catheterization, total parenteral nutrition, and furosemide therapy. Follow-up ultrasound examination at 9 months of age revealed spontaneous resolution of calcification of both the gallbladder and the umbilical vein but not of the kidneys.

Immunohistochemical localization of blood-retinal barrier breakdown sites associated with post-surgical macular oedema

Post-surgical macular oedema results from blood-retinal barrier breakdown, but it is not accompanied by structural abnormalities in the retinal vessels or retinal pigmented epithelium. Previous studies, using horseradish peroxidase in a primate model, suggested that leakage occurs primarily through this epithelium. This study was conducted to localize sites of the barrier breakdown in humans following different types of intra-ocular surgery and to compare them with eyes affected with ocular inflammatory disease, ocular infection, and choroidal melanoma. Paraffin sections of eyes were immunohistochemically stained for albumin to localize extravascular albumin, which was graded in a masked study. With aphakia/pseudophakia, penetrating keratoplasty, ocular inflammatory disease, ocular infection, and choroidal melanoma, barrier breakdown occurred primarily at the inner blood-retinal barrier (retinal vasculature), but leakage also occurred at the outer barrier (retinal pigmented epithelium). After retinal re-attachment surgery, the inner and outer blood-retinal barriers were equally compromised. Vascular leakage in the optic nerve head coincided with barrier failure in these disorders. The widespread pattern of blood-retinal barrier compromise with leakage at multiple sites suggests that soluble mediators are likely to play a role in postsurgical macular oedema, ocular inflammatory disease, and choroidal melanoma.

Crohn's disease with unusual enterouterine fistula in pregnancy

Pregnancy complicated by development of Crohn's disease is rare. The presentation of symptomatic Crohn's disease during pregnancy was initially described in 1946. Crohn's disease has been described in a number of atypical locations and with development of unusual fistulas. The cases associated with pregnancy have in common a clinical picture of (1) delay in diagnosis, (2) frequent premature delivery, (3) surgical intervention during pregnancy, and (4) high fetal and maternal morbidity and mortality. To our knowledge, this case is the first to describe the radiologic findings of an enterouterine fistula in a case of Crohn's disease beginning during pregnancy.

Pancreatic cystogastrostomy by combined upper endoscopy and percutaneous transgastric instrumentation

Minimally invasive endoscopic and radiologic techniques have been reported for internal gastric drainage of pancreatic pseudocysts but these have significant technical limitations. A purely endoscopic approach to cystogastrostomy provides limited access for instrumentation and hemostasis. Radiologically-guided percutaneous techniques cannot regularly provide an adequately wide cystogastrostomy opening. Reported is a patient who had a pancreatic cystogastrostomy performed using a minimally invasive surgical approach combining upper endoscopy and percutaneous transgastric surgical instrumentation. The upper endoscope essentially served as a camera. A percutaneous endoscopic gastrostomy tube served as a port for inserting laparoscopic instruments into the stomach. The laparoscopic instruments were used to create a 1.5 cm cystogastrostomy opening similar in size to what could be created by an open abdominal approach. The laparoscopy instruments provided good tactile feedback and excellent hemostatic control. Avoiding an open abdominal procedure shortened postoperative recovery and reduced patient discomfort. Although the pseudocyst recurred once, the same procedure was performed again and there has not been a recurrence for 10 months. The authors conclude that this minimally invasive surgical procedure provides an excellent alternative approach for internal drainage of selected pancreatic pseudocysts.

Characterization of the in vitro reconstituted cyclin A or B1-dependent cdk2 and cdc2 kinase activities

Human cyclins A and B1 were assembled with the cdk2 or cdc2 protein to reconstitute their respective kinase activities in vitro. Both cyclins complemented either cdk2 or cdc2, yielding kinase activities that supported the phosphorylation of histone H1. Activation of cdk2-catalyzed H1 kinase activity by cyclin A required a 10-min preincubation of the two components, whereas cdc2 kinase supported phosphate incorporation without a detectable time lag upon the addition of cyclin B1, suggesting a slower association rate of cdk2 with cyclin A compared with cdc2 and cyclin B1. Both cdk2 and cyclin A, as well as cdc2 and cyclin B1, formed stable complexes in the absence of ATP and substrate that could be isolated after glycerol gradient centrifugation. Incubation of the isolated complexes with ATP and histone H1 supported the phosphorylation of the substrate. Cyclin A-activated cdk2 or cdc2 phosphorylated p107, a pRB-related cellular protein, 10 times more effectively than the cyclin B1-complexed kinases. This was most likely due to a direct association of cyclin A with p107 (Ewen, M. E., Faha, B., Harlow, E., and Livingston, D. (1992) Science 255, 85-87; Faha, B., Ewen, M. E., Tsai, L.-H., Livingston, D., and Harlow, E. (1992) Science 255, 87-90). The reconstituted cdc2-cyclin B1 complex incorporated 4-5-fold more phosphate into the p34 subunit of the three-subunit (p70, p34, and p14) human single-stranded DNA-binding protein (also called RP-A), a DNA replication and DNA repair factor, than cdc2-cyclin A. No detectable phosphorylation of the p34 protein was observed with cdk2 complexed with either cyclin B1 or A. These data indicate that both cyclins as well as the catalytic subunits are important factors in controlling the rate of phosphorylation of a given substrate. The cyclin-activated cdc2 family kinases may target their cellular substrates through cyclin-mediated protein-protein interactions.

Blunt abdominal aortic trauma in children: case report

Injuries to the abdominal aorta as a result of blunt trauma in children are extremely rare. We encountered one such injury and a review of the literature revealed seven additional cases. Lower extremity ischemia, abdominal bruit, or paraplegia may suggest that diagnosis at the time of injury. Delayed presentations are characterized by abdominal pain or a pulsatile mass, with or without bruit. A high index of suspicion with early aortography is indicated to diagnose blunt aortic trauma.

The influence of surgery and anaesthesia on the pharmacokinetics of pethidine in the horse

The plasma concentration of pethidine was measured in 16 horses, after its administration intravenously (i.v.) at a dose rate of 1 mg/kg bodyweight (bwt). In eight animals studied before surgery, the plasma levels of the drug decreased in a bi-exponential manner with a distributive half life of 3 mins and an elimination half life of 57.7 mins. Total body clearance was 17.7 ml/kg bwt/min. The remaining horses were investigated immediately after a period of anaesthesia and surgery and in these animals the drug exhibited smaller volumes of distribution (V1 cand Vdarea) and a significantly lower clearance rate of 12.8 ml/kg bwt/min in these animals. Correlation between the plasma concentration of pethidine and information published previously on the duration of action of the agent in the horses suggests that plasma levels of approximately 0.4 microgram/ml are required to produce analgesia in this species.

Impairment of helper T-cell function and lymphokine-activated killer cytotoxicity following severe head injury

Infection is a major complication of severe head injury, occurring in 50% to 75% of patients who survive to hospitalization. Previous investigations of immune activity following head injury have demonstrated suppression of helper T-cell activation. In this study, the in vitro production of interferon-gamma (INF-gamma), interleukin-1 (IL-1), and interleukin-2 (IL-2) was determined in 25 head-injured patients following incubation of peripheral blood lymphocytes (PBL's) with the lymphocyte mitogen phytohemagglutin (PHA). In order to elucidate the functional status of cellular cytotoxicity, lymphokine-activated killer (LAK) cell cytotoxicity assays were performed both prior to and following incubation of PBL's with IL-2 in five patients with severe head injury. The production of INF-gamma and IL-2 by PHA-stimulated PBL's was maximally depressed within 24 hours of injury (p less than 0.001 for INF-gamma, p = 0.035 for IL-2) and partially normalized within 21 days of injury. There was no change in the production of IL-1. When comparing the in vitro LAK cell cytotoxicity of PBL's from head-injured patients and normal subjects, there was a significant depression in LAK cell cytotoxicity both prior to (p = 0.010) and following (p less than 0.001) incubation of PBL's with IL-2. The results of this study indicate that IL-2 and INF-gamma production, normally required for inducing cell-mediated immunity, is suppressed following severe head injury. The failure of IL-2 to enhance LAK cell cytotoxicity suggest that factors other than decreased IL-2 production, such as inhibitory soluble mediators or suppressor lymphocytes, may be responsible for the reduction in cellular immune activity following severe head injury. These findings may have significant implications in designing clinical studies aimed at reducing the incidence of infection following severe head injury.

Synapsis, strand scission, and strand exchange induced by the FLP recombinase: analysis with half-FRT sites

We have used a previously described cross-linking assay and half-FRT site substrates to examine the requirements for synapsis, strand exchange, and strand scission. The cross-linking assay showed that the minimum functional FRT site needed for synapsis contains two inverted FLP-binding elements surrounding an 8-bp core. This indicates that four FLP molecules interact with four binding elements in a synaptic complex. The analysis using half-sites showed that the enzyme can catalyze efficient strand exchange between a half-site and the intact FRT site. The reaction occurred only if the half-site had at least 2 bp but no more than 4 bp of the adjoining core sequence. The exchange occurred exclusively at the regions of limited core homology between the respective half-site and the FRT site. The absence of strand exchange between an intact site and a half-site bearing regions of core nonhomology indicates that 1 bp of homology is not sufficient for the formation of stable recombinant structures. Qian et al. (X.-H. Qian, R. B. Inman, and M. M. Cox, J. Biol. Chem. 265:21779-21788, 1990) have recently shown that the FLP protein can catalyze the formation of dimeric, trimeric, and tetrameric complexes with half-FRT sites. We show that only half-sites that contained at least 2 bp of adjacent core could form stable dimer products and be cleaved by the enzyme. Stable dimers were formed between a noncleavable half-site and a cleavable half-site, suggesting that only a single cleavage event is needed for the formation of the dimer.

Further studies on the antinociceptive activity and respiratory effects of buprenorphine in sheep

The thermal and mechanical analgesic profile of buprenorphine at a dose rate of 1.5 micrograms/kg i.v. was investigated in five sheep. This dose produced significant analgesia for 40 min against the thermal stimulus, but no mechanical antinociception. A higher dose rate of 12 micrograms/kg also failed to produce antinociception to a mechanical stimulus. In addition, the effect of the drug (6 micrograms/kg) on respiratory gas tensions was determined and no significant changes were observed.

Analgesic activity and respiratory effects of butorphanol in sheep

The analgesic drug butorphanol tartrate has proved useful clinically in horses and dogs but its analgesic profile had not yet been investigated in sheep. This study was initiated to determine the thermal and mechanical antinociceptive activity of butorphanol (at the dose rates 0.05, 0.1 and 0.2 mg kg-1) in sheep. The drug produced significant analgesia in the thermal test system, the duration of which was dose related but no significant elevation in mechanical pressure thresholds could be detected. In a further set of experiments the dose rate was increased to 0.4 mg kg-1 and mechanical testing was repeated. There was still no clinically significant elevation in pressure thresholds. At a dose rate of 0.2 mg kg-1 the drug had no detectable effect on respiratory blood gas tensions. Behavioural changes were severe if a dose rate of 0.2 mg kg-1 was exceeded.

Plasma amino acid patterns in very low birth weight infants during parenteral nutrition

Plasma amino acids were measured in eight very low birth weight infants (less than or equal to 1000 gm) before and after infusion of parenteral alimentations with Freamine III. Significant elevation in serum threonine, valine, isoleucine, methionine, serine, proline, glycine and ornithine was noted after twenty four hours of infusion. On the other hand, significant decreases in taurine and tyrosine levels were noted. Our study suggests that current solution is not optimal for premature neonates and the amount of protein administered during the first week in infants weighing less than or equal to 1000 gm should be decreased from the recommended 2.5-3.0 gm/kg/day.

Cotinine validation of self-reported smoking in commercially run community surveys

A validation study was carried out on self-reported smoking for 1177 people in Sydney and Melbourne in 1983. Because of its long half life and the fact that smoking is its only source in body fluids, saliva cotinine was chosen as the validation measure. Cotinine levels above 250 nmol/l were used to classify people as smokers. The sensitivity of self-reported smoking was 92.6% and the specificity was 93.4%. There was some evidence that people in the process of changing their smoking status might be slow in updating their self-classification. The smoking prevalence estimate based on cotinine levels was found to be 1.7% lower than that for self-reported smoking status. The small proportion of false negatives and false positives suggests that commercially collected data banks can be valid sources of prevalence data. Correlation between cotinine level and reported cigarette consumption was not affected by sample volume, and was similar to that achieved for carbon monoxide and thiocyanate at a low 0.34. Regression analysis using self-reported cigarette consumption filter/non-filter cigarettes, and time since last cigarette as predictors, explained 13.6% of the variance in cotinine level.

Retinal acuity evaluation with the potential acuity meter in glaucoma patients

The potential acuity meter (PAM) is designed to evaluate retinal acuity in the presence of media opacities. We looked at patients with glaucoma but with clear media, and compared best corrected visual acuity with PAM results to see if they produced comparable results. Sixty eyes in 38 glaucoma patients and 20 eyes in 10 normal ocular patients were evaluated. Our results indicate that PAM visual acuity is a reliable indicator of Snellen visual acuity in normal eyes, in eyes with mild to moderate glaucomatous damage, and when PAM visual acuity measurements were better than 20/60. However, when visual field loss is severe and when PAM visual acuity readings were worse than 20/60, the correspondence between these and Snellen visual acuity was erratic. Poor PAM results will not correlate with postoperative visual acuity in patients with advanced glaucoma and cataracts.

Lack of effect of pulsed ultrasound on the mammalian EEG

Anesthetized rhesus monkeys and rabbits were exposed to pulsed ultrasound, from a 1.8 cm diameter transducer placed against the head. Each ultrasonic exposure lasted 4 min; it consisted of a series of 1-2 mu sec pulses, with a frequency spectrum broadly centered about the transducer resonant frequency of 1.5 MHz, repeated at a rate of 950 Hz. The time averaged ultrasonics power was 12.6 mW, with an estimated peak power of ca. 15 watts. No changes were observed in the EEG or its power spectrum during or immediately after the exposure. This contrasts to a previous report of significant changes in the EEG of squirrel monkeys during comparable exposures to pulsed ultrasound. Analysis of the earlier reported results suggests that some of the "effects" were due to aliasing artifacts.