Plasmodium gallinaceum: ookinete formation and proteolytic enzyme dynamics in highly refractory Aedes aegypti populations.

Despite significant progress in the identification of the genetic basis of the refractory phenotype, little is known about the physiological mechanism of refractoriness. This study therefore examined the physiological basis of mosquito refractoriness in the Aedes aegypti/P. gallinaceum system, in which a selected refractory strain does not permit Plasmodium oocyst formation. We examined the kinetics of two major proteolytic enzymes involved in blood meal digestion and the dynamics of ookinete formation for two refractory populations (strains Moyo-R and Formosus) and one susceptible population (strain Red). Healthy ookinetes were observed in both the susceptible and the refractory populations, although the susceptible population generally exhibited higher enzymatic activity for trypsin and aminopeptidase than the refractory populations. Parasite numbers in the susceptible Red population showed a 4- to 7-fold decrease in abundance during the transition from the ookinete stage to the oocyst stage, far less than the refractory populations (30- to 92-fold reduction). Due to its smaller body size, Moyo-R individuals generally ingest a smaller blood meal and thus intake fewer gametocytes than Red individuals. Thus, the possibility that refractoriness in the Moyo-R population results from fewer gametocytes being ingested is examined. We found that the Red population remained highly susceptible and the Moyo-R population stayed refractory when those individuals with similar blood meal size were compared. We conclude that failure of oocyst development in the refractory mosquitoes is not due to ookinete damage by proteolytic enzymes or to fewer gametocytes being ingested, but rather is due to a midgut barrier or to some other mechanism.

Reduction of cannula-related laparoscopic complications using a radially expanding access device.

STUDY OBJECTIVE: To determine the safety of a new radially expanding access device compared with complication rates associated with sharp laparoscopic cannulas. DESIGN: Prospective, multicenter study (Canadian Task Force classification II-1). SETTING: Free-standing and hospital-based ambulatory surgery centers. PATIENTS: Two hundred twelve women undergoing various laparoscopic procedures and followed over 44 months. INTERVENTION: Five hundred forty-one radially dilating access devices were used exclusively for laparoscopic abdominal wall access. MEASUREMENTS AND MAIN RESULTS: No major vascular injury, abdominal wall bleeding, intestinal injury, bladder or ureteral injury, liver trauma, or postoperative incisional hernia occurred. One patient developed a postoperative mesenteric hematoma probably caused by a venous injury from the Veress needle. Of the 541 radially expanding access cannulas placed, only 6 (1%) slipped, despite absence of fascial anchoring devices. CONCLUSION: Radially dilating abdominal access devices may reduce laparoscopic complications, lessen a surgeon's exposure to liability, and improve patient outcomes while reducing facility costs. (J Am Assoc Gynecol Laparosc 6(1):79-84, 1999)

Role of orlistat in the treatment of obese patients with type 2 diabetes. A 1-year randomized double-blind study.

OBJECTIVE: Obesity is an important risk factor for type 2 diabetes. Weight loss in patients with type 2 diabetes is associated with improved glycemic control and reduced cardiovascular disease risk factors, but weight loss is notably difficult to achieve and sustain with caloric restriction and exercise. The purpose of this study was to assess the impact of treatment with orlistat, a pancreatic lipase inhibitor, on weight loss, glycemic control, and serum lipid levels in obese patients with type 2 diabetes on sulfonylurea medications. RESEARCH DESIGN AND METHODS: In a multicenter 57-week randomized double-blind placebo-controlled study, 120 mg orlistat or placebo was administered orally three times a day with a mildly hypocaloric diet to 391 obese men and women with type 2 diabetes who were aged > 18 years, had a BMI of 28-40 kg/m2, and were clinically stable on oral sulfonylureas. Changes in body weight, glycemic control, lipid levels, and drug tolerability were measured. RESULTS: After 1 year of treatment, the orlistat group lost 6.2 +/- 0.45% (mean +/- SEM) of initial body weight vs. 4.3 +/- 0.49% in the placebo group (P < 0.001). Twice as many patients receiving orlistat (49 vs. 23%) lost > or = 5% of initial body weight (P < 0.001). Orlistat treatment plus diet compared with placebo plus diet was associated with significant improvement in glycemic control, as reflected in decreases in HbA1c (P < 0.001) and fasting plasma glucose (P < 0.001) and in dosage reductions of oral sulfonylurea medication (P < 0.01). Orlistat therapy also resulted in significantly greater improvements than placebo in several lipid parameters, namely, greater reductions in total cholesterol, (P < 0.001), LDL cholesterol (P < 0.001), triglycerides (P < 0.05), apolipoprotein B (P < 0.001), and the LDL-to-HDL cholesterol ratio (P < 0.001). Mild to moderate and transient gastrointestinal events were reported with orlistat therapy, although their association with study withdrawal was low. Fat-soluble vitamin levels generally remained within the reference range, and vitamin supplementation was required in only a few patients. CONCLUSIONS: Orlistat is an effective treatment modality in obese patients with type 2 diabetes with respect to clinically meaningful weight loss and maintenance of weight loss, improved glycemic control, and improved lipid profile.

Histological long-term outcome of furosemide-induced nephrocalcinosis in the young rat.

The long-term prognosis of furosemide-associated nephrocalcinosis in the infant is still unclear. Although discontinuation of the diuretic often results in radiological resolution of the calcifications, functional abnormalities may persist. The natural history of the renal histopathology of these patients is yet unknown. In the present study we investigated the histological long-term outcome of furosemide-induced nephrocalcinosis in the young rat. Thirty-six weanling male Sprague-Dawley rats were divided into three groups: A controls, B furosemide given for 8 weeks, and C furosemide given for 2 weeks followed by 6 weeks of observation. Metabolic studies at the end of the experiment demonstrated a significant diuretic and natriuretic effect in group B. Kidney histology showed nephrocalcinosis scores (mean +/- SD) of 0.0 +/- 0.0 in A, 2.6 +/- 1.5 in B, and 0.8 +/- 0.6 in C, with B significantly higher than A and C, and C greater than A. Kidney calcium content in B (3,421.9 +/- 2,558.7 micrograms/g dry tissue) was significantly greater than in A (310.4 +/- 21.3) and C (1470.1 +/- 932.2). Another group of 6 rats receiving 2 weeks treatment of furosemide showed a nephrocalcinosis score of 2.2 +/- 1.5, not different from group B, and an additional group of 6 rats treated with furosemide for 2 weeks and observed for another 12 weeks showed a score of 1.3 +/- 0.4, not different from group C. We conclude that most of the renal calcifications induced by furosemide occur during the early days of treatment and that up to 12 weeks after discontinuation of the diuretic, the resolution of the calcifications is only partial.

Six highly active mu-selective opioid peptides identified from two synthetic combinatorial libraries.

Two synthetic combinatorial libraries (SCLs) were prepared, each composed of 52,128,400 L-amino acid hexapeptides, one with and the other without an N-terminal acetyl moiety. The two libraries were used in conjunction with an iterative selection process to identify individual peptides capable of inhibiting the binding of the mu-selective opioid peptide [3H]-[D-Ala2,MePhe4,Gly-ol5]enkephalin to rat brain homogenates. As reported previously, when using the nonacetylated SCL the first five residues identified corresponded exactly to methionine- and leucine-enkephalin, both of which are endogenous opioid peptides. The iterative identification process has now been completed for two additional mixtures found to have activity in the initial screening of this SCL. Two new series unrelated to the enkephalins have been identified: YPFGFO-NH2 and WWPKHO-NH2 (where O = one of the 20 L-amino acids). Individual peptides from each of these were found to be agonists at the mu receptor and have high affinity (IC50 values of the most active peptides were 10-15 nM) and selectivity for the mu receptor. In addition to the acetalins (described previously), two new series have now been identified from the acetylated library: Ac-FRWWYO-NH2 and Ac-RWIG-WO-NH2 (IC50 values of the most active peptides were 5-30 nM). Ac-FRWWYM-NH2 was determined to be an agonist at the mu receptor, whereas Ac-RWIGWR-NH2 was found to be an antagonist at this receptor.

A virilized patient with congenital hemihypertrophy.

An 18 year old woman with congenital hemihypertrophy of her left side, presented with the rapid onset of virilism, hypertension and a cushingoid appearance. A computed tomographic examination revealed adrenal and hepatic masses. Adrenocortical carcinoma was confirmed by surgical pathology. Hemihypertrophy is linked to a variety of benign and malignant disorders that usually appear during childhood. These disorders include adrenocortical carcinoma and hepatoblastoma. We bring this case to clinical attention to increase awareness that adult patients with congenital hemihypertrophy are still at a significant risk of developing neoplasms.

Effect of lidocaine on the hematopoietic properties of recombinant human erythropoietin in the uremic rat.

Subcutaneous injections of recombinant human erythropoietin (rHuEPO) produce considerable pain which can result in noncompliance. As a prelude to an investigation of the possible use of local anesthetics as additives to subcutaneous rHuEPO, we examined the effect of the addition of lidocaine on the erythropoietic properties of rHuEPO. Two weeks after 5/6 nephrectomy, 22 rats were randomly assigned to the following groups: normal saline, rHuEPO, lidocaine, and rHuEPO plus lidocaine. Injections were given three times a week for 2 weeks. No change in hematocrit was observed in the saline and lidocaine groups. The hematocrit of the rHuEPO rats increased from 44.5 +/- 1.4% (mean +/- SD) to 61.6 +/- 2.1% (P < 0.0005), and that of the rHuEPO plus lidocaine group from 42.8 +/- 4.3% to 63.9 +/- 3.0% (P < 0.005), with no difference between the groups. We conclude that the combination of rHuEPO plus lidocaine is as effective as rHuEPO alone in increasing the hematocrit of rats with chronic renal failure.

Affinity labeling of the mu opioid receptor in bovine striatal membranes with [3H]-14 beta-(bromoacetamido)-7,8-dihydromorphine.

[3H]-14 beta-(Bromoacetamido)-7,8-dihydromorphine ([3H]H2BAM) was synthesized and tested for its ability to selectively label mu opioid receptors in bovine striatal membranes. Incubating membranes with N-tosyl-L-phenylalanine chloromethyl ketone and dithiothreitol before the addition of [3H]H2BAM reduced nonspecific [3H]H2BAM binding so that [3H]H2BAM binding to opioid receptors was up to 70% of the total [3H]H2BAM binding and was dependent on [3H]H2BAM concentration, incubation time, and pH of the reaction. At pH 7.5, [3H]H2BAM bound selectively to the mu opioid receptor, but mainly noncovalently. After the initial binding of [3H]H2BAM to the receptor, membranes were washed and then incubated at 37 degrees C in 50 mM Tris-HCl, pH 8.5, for 3 h, a time that resulted in greater than 80% of the [3H]H2BAM associated with the receptor becoming covalently bound to the opioid receptor. The mu-selective peptide [D-Ala2,(Me)Phe4,Gly(ol)5]enkephalin inhibited [3H]H2BAM labeling of membranes, while delta- or kappa-selective compounds were ineffective. Both NaCl and the nonhydrolyzable guanine nucleotide analog guanylyl 5'-imidodiphosphate reduced the incorporation of [3H]H2BAM into membranes. When [3H]H2BAM-labeled striatal membranes were separated under reducing conditions on a sodium dodecyl sulfate-polyacrylamide gel, two proteins with molecular weights of 54,000 and 44,000 were specifically labeled. The 54-kDa protein was present in a greater amount than the 44-kDa protein. Both proteins bound to wheat germ agglutinin-Sepharose and concanavalin A-Sepharose, suggesting that both proteins contain multiple carbohydrate moieties. Despite the inclusion of protease inhibitors, the 44-kDa protein may be a proteolytic fragment of the 54-kDa protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral vasculitis in acute post-streptococcal glomerulonephritis.

Neurological complications in acute post-streptococcal glomerulonephritis (APSGN) have been traditionally attributed to hypertensive encephalopathy. A 9-year-old girl with biopsy-documented APSGN developed seizures at a time she was normotensive and biochemically well balanced. Computed tomography of her brain was consistent with vasculitis, a finding which was also clinically supported by apparent vasculitic involvement of other organ systems. All clinical, laboratory and radiological abnormalities resolved with recovery from the APSGN. We suggest that on rare occasions neurological complications in APSGN may result from involvement of the central nervous system in multiorgan transient vasculitis.

Job involvement and job satisfaction of South African nurses compared with other professions.

The study was designed primarily to compare the work outcomes of job satisfaction and job involvement of South African nurses with those of members of 13 other professional groups in South Africa and with American nurses where data was available. Secondary aims included identifying areas where job satisfaction was particularly low and demonstrating the relative independence of the job involvement and job satisfaction constructs. A questionnaire incorporating the Kanungo Job Involvement Scale and the Short Form of the Minnesota Job Satisfaction Questionnaire was mailed to random samples of people between the ages of 29 and 41 drawn from 14 professional registers. There were 114 nurses in the final sample and 1677 members of other professions. Differences among professions were tested for significance using one-way analyses of variance and Bonferroni ranges tests. South African Nurses were shown to have extremely low job satisfaction relative to American nurses and to other professional groups in South-Africa. By contrast their job involvement was moderately high. The implications of these findings for the medical profession as a whole and for nurses in particular are discussed. The fear is expressed that wide spread dissatisfaction may lead to fewer people entering the profession and highly trained people leaving.

Affinity labeling of mu opioid receptors by sulfhydryl alkylating derivatives of morphine and morphinone.

After reduction of a disulfide bond at or near the mu opioid binding site in rat brain membranes, incubating membranes with 14 beta-bromoacetamido derivatives of either morphine, dihydromorphine, morphinone, or dihydromorphinone resulted in the irreversible inhibition of mu opioid binding to rat brain membranes. Without the addition of the disulfide bond-reducing reagent dithiothreitol, these affinity ligands bound reversibly to opioid binding sites. Binding to either delta or kappa opioid binding sites was not altered by alkylation of the membranes with the affinity ligands. The percentage of irreversible inhibition of mu opioid binding was dependent on the time and temperature of the incubation of membranes with the affinity ligands and on the concentrations of dithiothreitol and the affinity ligands. Incubating membranes with morphine afforded almost complete protection from alkylation of the mu opioid binding site. Naloxone and the l-isomer levorphanol also protected the site from alkylation, whereas the d-isomer dextrorphan and the kappa-selective opioid U50,488H did not protect the site. The mu-selective peptide [D-Ala2, (Me)Phe4,Gly(ol)5]enkephalin was the peptide that afforded the greatest protection. These studies have shown that, after the reduction of a disulfide bond at or near the mu opioid binding site, this sulfhydryl group can be specifically alkylated, resulting in the affinity labeling of the mu opioid binding site.

Infectious peritonitis in patients receiving intraperitoneal chemotherapy.

A total of 32 episodes of infectious peritonitis developed in 90 patients receiving intraperitoneal chemotherapy. Staphylococcus epidermidis was the organism most commonly cultured, accounting for 65 percent of isolates. Result of initial gram stain was positive in 35 percent of cases. The development of fever and abdominal pain as well as rising peripheral and peritoneal fluid white blood cell counts was helpful in the making of a diagnosis of infectious peritonitis. Seventy-five percent of patients were cured with antibiotic therapy alone whereas one quarter also required removal of the semi-permanent catheter. Patients treated with intraperitoneal chemotherapy delivered by dialysis exchange over several days exhibited significantly more episodes of infection than patients treated by a single-drug instillation each month. Although the development of bacterial peritonitis remains a problem during intracavitary chemotherapy, the use of subcutaneous ports and meticulous sterile technique during catheter manipulation will hopefully decrease the risk of occurrence of this potentially avoidable complication.

Measurement of spatial stability of spark position in burst-mode breakdown with the Nd:YAG laser.

Measurements to determine the precise position of the spark produced by optical breakdown in ocular media with a repetitive sequence of pulses from a Nd:YAG laser have been made. The results show that the location of the spark along the beam axis remains fixed within +/- 10 micrometers (the resolution of the experiment) for pulses with a time separation of 20 milliseconds, indicating that the surgical effects of a sequence of pulses can be cumulative.