Role of endogenous glucagon-like peptide-1 in islet regeneration after partial pancreatectomy

A reduction in beta-cell mass is an important causative factor in type 1 and type 2 diabetes. Glucagon-like peptide-1 (GLP-1) and the long-acting agonist exendin 4 (Ex-4) expand beta-cell mass by stimulating neogenesis and proliferation. In the partial pancreatectomy (Ppx) model, exogenous Ex-4 promotes islet regeneration, leading to sustained improvement in glucose tolerance. In this study, we investigate the potential role of endogenous GLP-1 in islet growth. We examined beta-cell mass regeneration after 70% Ppx in mice receiving the GLP-1 antagonist Ex9-39 and in GLP-1R(-/-) mice. In Ex9-39-treated sham-operated mice, persistent fasting hyperglycemia was observed, but beta-cell mass was not diminished. In pancreatectomized mice, persistent glucose intolerance was noted, but this was not further exacerbated by Ex9-39. Accordingly, beta-cell mass recovery of Ppx mice was not impaired by Ex9-39. In contrast, GLP-1R(-/-) CD1 mice showed worse glucose intolerance after Ppx compared with wild-type CD1 Ppx mice, and this correlated with a significant defect in beta-cell mass regeneration. The recovery of beta-cell mass differed markedly in the BALB/c and CD1 control mice, indicating a significant role of genetic background in the regulation of beta-cell mass. These studies point to a role for endogenous GLP-1 in beta-cell regeneration after Ppx in mice.     

The natural history of hepatitis C virus infection

Chronic hepatitis C virus (HCV) infection is a major health problem worldwide. The natural history of HCV infection is not fully understood. For years, there has been an overestimation of the rate of chronicity in acute HCV. Similar high rates of progression to cirrhosis in chronic HCV were reported. The source of confusion stems from the fact that most acute HCV infections are asymptomatic and never come to medical attention. The consequence of this is that most early studies of natural history reflect the more severe end of the spectrum of the disease. Recent studies reported 43-45% rate of chronicity as opposed to the old rates of 77-85%. Also, the rate of progression to cirrhosis and hepatocellular carcinoma was found to be much lower than previously reported. Multiple factors contribute to the chronicity and progression to cirrhosis, the most important being male gender, age, alcohol intake, and the degree of liver fibrosis on initial biopsy. At least 38% of patients with HCV will manifest symptoms of at least one extrahepatic complication. The most important extrahepatic manifestation is mixed cryoglobulinemia. Other extrahepatic manifestations and their response to antiviral therapy are discussed.     

Chronic renal failure in Iranian children

We investigated chronic renal failure (CRF) in 166 Iranian children (95 boys and 71 girls) from July 1991 to June 1999. The mean age at onset of CRF was 7.9±4.5 years. The most common cause of CRF was congenital urological malformations (78 cases). The second most common cause of CRF was hereditary nephropathy (21%). Glomerular diseases accounted for only 10% of children who later went on to develop renal failure. High rates of cystinosis and primary hyperoxaluria were seen, and these elevated rates could be due to a high prevalence of parental consanguinity. Eighty-six patients required renal replacement therapy, of whom the majority underwent hemodialysis. The prevalence of primary reflux as a cause of CRF was high compared with reports from western countries. Earlier diagnosis and management of urinary tract infections in this group could reduce the prevalence of reflux as a cause of CRF in this population. Received: 15 May 2000 / Revised: 2 October 2000 / Accepted: 5 October 2000     

The relationship between hypertension and anxiety or depression in Hong Kong Chinese

BACKGROUND:

Psychosocial stress can be the cause or the consequence of hypertension.

OBJECTIVE:

To study the association between hypertension and anxiety or depression in adults from Hong Kong, China.

SUBJECTS AND METHODS:

Patients with diagnosed hypertension (n=197) were recruited to complete the Hospital Anxiety and Depression Scale (HADS) questionnaire. The control group comprised 182 normotensive subjects recruited using random telephone numbers.

RESULTS:

The score in the anxiety subscale (HADS-A) of the HADS correlated with age (r= −0.23, P<0.001) and sex (r=0.11, P=0.042), and was found to be higher in women. The score in the depression subscale (HADS-D) correlated with age (r=0.17, P=0.003) and hypertension (r=0.12, P=0.039), but not with sex (r=0.02, P=0.68). When the control subjects were matched for sex and age with the subjects with hypertension, the mean HADS-A score was 5.51±0.41 in 113 hypertensive subjects and 4.38±0.39 in 113 normotensive subjects (P=0.047). The mean HADS-D score was 5.56±0.39 in the hypertensive and 4.76±0.32 in the normotensive subjects (P=0.11). Multiple regression analysis using data from both groups indicated that the HADS-A score was related to the HADS-D score (β=0.49, P<0.001), age (β= −0.25, P<0.001) and sex (β=0.12, P=0.01) (R²=0.28), whereas the HADS-D score was related to the HADS-A score (β=0.48, P<0.001), age (β=0.30, P<0.001), positive smoking status (β=0.13, P=0.004) and lack of exercise habit (β=0.12, P=0.008) (R²=0.31). Hypertension was related to waist circumference, history of parental hypertension and age (R²=0.38, P<0.001). Anxiety and depression scores were rejected as independent variables.

CONCLUSIONS:

Hypertension was associated with anxiety but not depression; however, age, history of parental hypertension and central obesity appeared to have a stronger association with hypertension in adults from Hong Kong.     

CD4 mimetics sensitize HIV-1-infected cells to ADCC

HIV-1-infected cells presenting envelope glycoproteins (Env) in the CD4-bound conformation on their surface are preferentially targeted by antibody-dependent cell-mediated cytotoxicity (ADCC). HIV-1 has evolved a sophisticated mechanism to avoid exposure of ADCC-mediating Env epitopes by down-regulating CD4 and by limiting the overall amount of Env at the cell surface. Here we report that small-molecule CD4-mimetic compounds induce the CD4-bound conformation of Env, and thereby sensitize cells infected with primary HIV-1 isolates to ADCC mediated by antibodies present in sera, cervicovaginal lavages, and breast milk from HIV-1-infected individuals. Importantly, we identified one CD4 mimetic with the capacity to sensitize endogenously infected ex vivo-amplified primary CD4 T cells to ADCC killing mediated by autologous sera and effector cells. Thus, CD4 mimetics hold the promise of therapeutic utility in preventing and controlling HIV-1 infection.Worldwide, it is estimated that more than 35 million people are living with HIV. In 2013 alone, around 2.1 million people became newly infected with HIV, and 1.5 million people died from AIDS (1). Measures to prevent HIV-1 transmission are desperately needed. Prevention of HIV-1 transmission and progression likely requires approaches that can specifically target and eliminate HIV-1-infected cells. Interestingly, there is increasing evidence supporting a role of antibody (Ab)-dependent cell-mediated cytotoxicity (ADCC) in controlling HIV-1 transmission and disease progression (2–8). Analysis of the correlates of protection in the RV144 vaccine trial suggested that increased ADCC activity was linked with decreased HIV-1 acquisition (9), and Abs with potent ADCC activity were isolated from some RV144 vaccinees (10). Recent studies reported that the viral accessory proteins Nef and Vpu protect HIV-1-infected cells from anti-HIV-1 envelope (Env)-mediated ADCC responses (11–14). Importantly, we and others reported that Env in the CD4-bound conformation was preferentially targeted by ADCC-mediating Abs and sera from HIV-1-infected individuals (11, 12, 15, 16), which represent a significant proportion of anti-Env Abs elicited during natural HIV infection (11, 17). However, the vast majority of circulating HIV-1 strains worldwide express functional Nef and Vpu proteins, which limit the exposure of CD4-induced (CD4i) Env epitopes at the surface of infected cells, likely preventing ADCC responses.Theoretically, agents promoting the CD4-bound Env conformation should expose CD4i epitopes that are readily recognized by ADCC-mediating Abs and sera from infected individuals (11, 12, 15, 16, 18), resulting in the sensitization of HIV-1-infected cells to ADCC. Importantly, modulating Env conformation at the surface of HIV-1-infected cells has become feasible as a result of the availability of small CD4-mimetic compounds (CD4mc). The prototypes of such compounds, NBD-556 and NBD-557, were discovered in a screen for inhibitors of gp120-CD4 interaction (19). These small-molecule ∼337-Da compounds and recent derivatives (DMJ-I-228, JP-III-48) bind in the Phe-43 cavity (20–22), a highly conserved ∼150-ų pocket in the gp120 glycoprotein located at the interface of the inner domain, outer domain, bridging sheet, and CD4 receptor (23). CD4mc block gp120-CD4 interaction and induce thermodynamic changes in gp120 similar to those observed during CD4 or soluble CD4 (sCD4) binding (24). Accordingly, these small molecules, as well as sCD4, can promote the transition of Env to the CD4-bound conformation, thus sensitizing HIV-1 particles to neutralization by otherwise nonneutralizing CD4i Abs (17, 25). Additional strategies using scaffolded miniproteins targeting critical gp120 elements required for CD4 interaction allowed the identification of CD4 mimetics with nanomolar affinity for gp120 (26). One of these variants, M48U1, displayed remarkably potent neutralization of three HIV-1 isolates (27). Its crystal structure in complex with HIV-1 gp120 was recently solved, showing that M48U1 engages the Phe-43 cavity in a manner similar to that of CD4 (28); thus, M48U1 might induce gp120 to adopt the CD4-bound conformation and expose CD4i epitopes. Previous studies exploring the antiviral properties of CD4mc were performed on viral particles (17, 25, 27). However, whether these compounds are able to engage the large amounts of Env present at the surface of infected cells and modulate Env conformation in a way that allows exposure of ADCC-mediating epitopes is currently not known. In this study, we show that CD4mc strongly sensitize HIV-1-infected primary CD4 T cells to ADCC mediated by sera, cervicovaginal fluids, and breast milk from HIV-1-infected individuals, as well as help eliminate infected, ex vivo-expanded primary CD4 T cells from HIV-1-infected individuals. Therefore, CD4mc possess three valuable complementary antiviral properties: direct inactivation of viral particles, sensitization of viral particles to neutralization by otherwise nonneutralizing Abs, and sensitization of HIV-1-infected cells to ADCC-mediated killing.     

Preparation and characterization of specific and high-affinity monoclonal antibodies against morphine

A C6-hemisuccinate derivative of morphine was prepared and conjugated to bovine serum albumin. High titer antibody producing spleen cells were removed and fused with myeloma cells of Sp2/0 origin. A C3-hemisuccinate derivative of morphine was prepared and conjugated to enzyme penicillinase used as a tracer molecule. A novel enzyme-linked immunoadsorbent assay was developed using this conjugate to screen and characterize the monoclonal antibody produced in these experiments. After two successive limiting dilutions, antibodies produced by 5 clones with good affinities ranging from 10(8) to 10(12) M(-1) and less cross-reaction (least for codeine and other structurally related molecules) were selected. These clones were found to be of IgG class with kappa light chain. Subclass determination showed that two of the clones produced IgG2b and three of them produced IgG1 type of antibody. Affinity purifications were performed for the selected clone (MOR-I). Purified antibody was coated onto the wells of microtiter plate. The standard curve was constructed with a sensitivity of 100 pg/mL covering up to 10 ng/mL in buffer and urine. The slope of the standard curve for selected clone in buffer and urine was calculated to be -0.7 and -0.64, respectively.     

The Efficacy of Gabapentin versus Stabilization Splint in Management of Sleep Bruxism

Purpose : This study aimed to determine if the use of gabapentin is more efficacious than a stabilization splint with regard to the intensity of masseter muscle contractions and/or sleep quality for patients experiencing sleep bruxism (SB). Materials and Methods : Twenty patients with SB participated in this clinical study. They were randomly divided into two treatment groups: stabilization splint group (n = 10) and gabapentin group (n = 10). The first polysomnographic examination was performed before the beginning of the experiment for all the participants. At the end of a 2‐month period of stabilization splint therapy or gabapentin usage, a second polysomnographic recording was made. Results : Statistically significant reductions in the number of SB episodes per hour and per night, bruxism time index, total duration of SB episodes per night and number of SB episodes in stages NR I and NR II (p < 0.05) were observed in both groups after treatment. Both treatments significantly reduced the mean intensity of masseter muscle contractions during SB episodes. Moreover, the participants treated with gabapentin showed a significant improvement in total sleep time, slow wave sleep (stage III), and sleep efficiency (p < 0.05). Conclusions : Gabapentin could be an effective treatment modality in SBs, especially in those with poor sleep quality.     

Three-dimensional presentation of the Fourier amplitude and phase: a fast display method for gated cardiac blood-pool SPECT.

The routine clinical use of gated SPECT is inhibited by sophisticated, time-consuming processing techniques. The present paper describes a new technique for the simultaneous three-dimensional presentation of the amplitude and phase of the first Fourier harmonics, with the aim of obtaining detailed information about the ventricular motion in a relatively short time, from each angle of view of three-dimensional space. The method is simple and robust, and processing is automatic. It does not need carefully elaborated techniques for surface determination, because the cardiac surface is merely used as a reference skeleton onto which the functional information of amplitude and phase is mapped. The Fourier analysis before reconstruction results in running times shorter than 15 min and may further open the way for the routine use of gated SPECT.     

Lessons learned from the institution of the Surgical Care Improvement Project at a teaching medical center

Background

The Surgical Care Improvement Project (SCIP) was designed to reduce perioperative complications. We describe our institutional experience in 6 major areas: surgical site infection, venous thromboembolism prevention, use of perioperative β-blockade, serum glucose level greater than 200 mg/dL, normothermia, and the use of electric razors for hair removal.

Methods

This was a retrospective review of surgical cases. Evidence-based training and standardization of system and process were undertaken. Compliance with SCIP guidelines was determined.

Results

Overall SCIP compliance improved from 80% to 94% over a 2-year period. Standardized antibiotic dosing times improved compliance to more than 90%. Appropriate preoperative antibiotic choice improved to 100%. Cessation of antibiotics postoperatively within 24 hours remains a difficult task. Venous thromboembolism prophylaxis has been difficult to achieve because of postoperative bleeding concerns. Administration of β-blockers has remained one of the most difficult problems to correct because of the multiplicity of avenues by which a patient may arrive to the operating suite.

Conclusions

Achievement of the SCIP goals is a formidable, but achievable, process requiring individual, cultural, systems, and institutional changes to achieve success.