Experimental endoscopic subcutaneous surgery.

Endoscopic techniques have found increasing applications in general surgery. In this article, an attempt has been made to utilize endoscopy via a subcutaneous approach in an experimental pig model for dissection of fat, muscle, and fascia.     

Temperature dependence of the four ionic processes of spike electrogenesis in eel electroplaques.

Spike electrogenesis of eel electroplaques involves four ionic processes which are controlled by the membrane potential. A threshold depolarization causes normally closed Na permselective channels to open (Na-activation) and normally open K channels to close (K-inactivation). The Na channels then close (Na-inactivation), and as the spike is terminated, the K channels reopen (K-reactivation). The temperature dependence of these four processes has been examined in the present work. Opening of the Na channels and closure and reopening of the K-channels are either effectively instantaneous or are relatively independent of temperature in the range of at least 5 degrees to 22 degrees. Closure of the Na-channels has a Q10 (increase in rate of reaction for each 10 degrees increase in temperature) of about 9, and activation energy (Ea) of this reaction is about 31.5 kcal/mole (132 kJ/mole).     

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.     

The health of women in the US fire service

Background

Despite statements from national fire service organizations, including the International Association of Fire Fighters (IAFF) and the International Association of Fire Chiefs (IAFC), promoting a diverse work force related to gender within the fire service, rates of women firefighters remain very low. Thus, research into why this extensive gender disparity continues is a high priority. Recent years have seen a number of large scale studies on firefighter health and health risk behaviors however, none have focused on the health of women firefighters and nearly all have eliminated women from the sample due to small sample size. Data from the present report is drawn from all females in a large, randomly selected cohort of firefighters in an epidemiological study designed to assess health outcomes and health risk behaviors identified as most important to the fire service.

Methods

Data reported for the present study were collected as baseline data for the Firefighter Injury and Risk Evaluation (FIRE) Study, a longitudinal cohort study examining risk factors for injury in both career and volunteer firefighters in the IAFC Missouri Valley Region. Of the departments assessed, only 8 career and 6 volunteer departments had any women firefighters. All the women solicited for participation chose to enroll in the study. The number of women ranged from 1 to 7 in career departments and 1 to 6 in volunteer departments.

Results

Where possible, comparisons are made between female firefighters and published data on male firefighters as well as comparisons between female firefighters and military members. Compared to male firefighters, females had more favorable body composition among both career and volunteer firefighters. Tobacco use rates were generally higher among females than males and rates among female firefighters were similar to the rates of female military members. While rates of alcohol use were higher than the general population, only one of the participants evidenced responses in the range of concern on the CAGE screening.

Conclusions

In general, the findings offer an interesting glimpse of the health of women in the fire service as a generally healthy occupational workforce with some unique health risk behavior challenges. They also highlight some of the similarities and differences between male and female firefighters and bolster the argument for studying female firefighters as a unique occupational sub-population.     

Full-length but not truncated CD34 inhibits hematopoietic cell differentiation of M1 cells

CD34 is expressed on human and murine hematopoietic stem and progenitor cells and its clinical usefulness for isolation of stem/progenitor cells has been well established. Although expression of CD34 is regulated in a developmental stage-specific manner, the function of CD34 is not known. Recently we have shown that both a full-length and truncated form of CD34 protein is expressed by hematopoietic cells (Blood 84:691, 1994). To test whether failure to suppress either form of CD34 could affect terminal myeloid differentiation, we constitutively expressed these CD34 proteins in murine M1 myeloid leukemia cells, which can be terminally differentiated to macrophages by treatment with interleukin-6 of leukemia inhibitory factor. Surprisingly our results show that forced expression of the full-length but not the truncated form of CD34 impedes terminal differentiation by these agents. Because the difference between the two forms of CD34 protein resides in the length of their respective cytoplasmic tail domains, our findings strongly suggest that the cytoplasmic domain region of full-length CD34 is responsible for the observed maturation arrest phenotype. These findings suggest a potential negative regulatory role for full-length CD34 in hematopoietic cell differentiation and may explain, at least in part, the block in maturation observed in CD34+ acute myeloid leukemia.     

Granulocyte colony-stimulating factor versus placebo in addition to penicillin G in a randomized blinded study of gram-negative pneumonia sepsis: analysis of survival and multisystem organ failure

Sepsis is a common cause of morbidity and mortality. Neutrophils are the major defense against bacterial invasion, and granulocyte colony- stimulating factor (G-CSF) augments both neutrophil number and function. In our study, 160 rabbits were inoculated transtracheally with 0.5 mL of a solution containing 10(4) colony forming units per milliliter of Pasteurella multocida. Twenty-four hours later, chest x- rays and quantitative blood cultures demonstrated pneumonia and bacteremia. Therapy was then begun with penicillin G and either recombinant human G-CSF (rG-CSF; 5 to 8 micrograms/kg subcutaneously) or placebo every day for 5 days. Arterial blood gases and 23 other parameters of organ function were performed before inoculation and serially thereafter. All rabbits underwent histologic examination of organs at the time of septic death or when sacrificed on day 6. A total of 149 rabbits survived long enough to initiate therapy. A significant increase in leukocytes by day 4 was found in the rG-CSF-treated group. There was a trend towards improved survival in the rG-CSF group (77% v 67%; P = .13, n = 149). Analysis of pretreatment variables revealed sepsis-induced leukopenia (< or = 2,800/microL) as the only predictor of significantly improved survival with rG-CSF treatment (57% v 39%; P = .04, n = 73). The majority of the survival benefit occurred within the first 24 hours of treatment. This was before the time that a significant difference in mean white blood cell (WBC) count was observed between the study groups, making intravascular leukocytosis an unlikely explanation for the survival advantage in the rG-CSF group. No significant difference in laboratory variables reflecting organ function was demonstrated between the groups. Histologic grading of inflammation (0, normal, to 6, necrosis) in seven organs revealed that the surviving rabbits had mild but statistically significant increased inflammation in the liver, spleen, and noninoculated lung in the rG-CSF versus placebo groups (liver: 2.6 v 1.5, P < or = .0001; spleen: 3.2 v 2.3, P < or = .0001; and noninoculated lung: 2.9 v 2.5, P = .04). Administration of rG-CSF, in addition to penicillin G, in immune competent rabbits with gram-negative sepsis complicated by leukopenia significantly improved survival over antibiotics alone. The administration of rG-CSF in early sepsis for a short therapeutic duration was not associated with any clinically evident toxicity. Clinical trials using rG-CSF in septic patients with leukopenia are indicated.     

Falloposcopic observations of endotubal isthmic plugs as a cause of reversible obstruction and their histological characterization

Eighty falloposcopies were performed in fallopian tubes of women with suspected tubal disease. In three falloposcopies (4%), isthmic plugs were observed occluding the entire isthmic lumen. In all cases these plugs were mobilized by falloposcopic-directed, selected tubal cannulation and aquadissection techniques. Restoration of tubal patency, verified by concurrent chromopertubation under laparoscopic monitoring was achieved in all cases. On one occasion, the isthmic plug was mobilized and identified on the fimbria, and tubal patency was confirmed. When this plug was retrieved and examined histologically, it was found to consist of a cast of debris containing aggregates of histiocyticlike cells of endometrial stromal or mesothelial origin. The genesis of these plugs is unknown. In another subgroup, white to yellow mucus like fragments were observed within the intramural and isthmic lumen during a further 8 of 80 falloposcopies (10%). Whether these mucus like fragments are of physiological or pathophysiological significance remains to be determined. Objective demonstration that isthmic plugs can cause reversible proximal tubal obstruction (PTO) has been achieved using falloposcopy. Falloposcopy offers the diagnostician the ability to objectively classify the cause of PTO. A useful falloposcopic classification and scoring system of tubal lumen lesions has been utilized and is described.     

Laparoscopic exploration of the common bile duct: experience in 16 selected patients.

The authors' initial experience with transcystic duct and direct laparoscopic approaches to the exploration of the common bile duct is reported. The technique requires standard laparoscopic equipment, specialized endoscopes, and instruments developed for urologic stone manipulations. After cholangiography confirmed the presence of common bile duct stones, common duct stone extraction was performed in 16 selected patients age 20-88 years. Stones ranged in size from 1 mm to 30 mm and they were unsuspected in 60% of the patients. Five patients had normal liver function tests and only 3 had clinical evidence of jaundice. Ductal exploration and stone extraction was successful in all 16 patients. One patient required a direct laparoscopic ductal exploration due to the presence of a common hepatic duct stone and the anatomy of the cystic duct. No major complications or deaths were observed in this series. Appropriately trained surgeons can safely and effectively perform laparoscopic common bile duct exploration and stone extraction in selected patients.