Diving-related fatalities caused by underwater explosions: a report of two cases.

The authors report two cases of diving-related water blast with fatal outcome resulting from nearby underwater explosions. Water blast with fatal outcome almost exclusively occurs in wars at sea. Underwater explosions are extremely rare in diving because of the limited exposure. Forensic findings in both cases reported included expected injuries to gas-filled organs such as the middle ear, lungs, and intestine; some rarely described injuries such as rupture of the liver, spleen, and kidneys; and also some lesions that were not found in a search of the literature: rupture of the heart and contusion of the hypophysis. Injuries caused by fatal underwater explosions should be carefully evaluated in forensic medicine to provide data that may support a criminal investigation.

Linear and nonlinear analysis of pressure and flow during mechanical ventilation.

OBJECTIVE: Linear modeling as a method of exploring respiratory mechanics during mechanical ventilation, was compared to nonlinear modeling for flow dependence of resistance in three distinct groups of patients, those with: (a) normal respiratory function (NRF), (b) chronic obstructive pulmonary disease (COPD), or (c) adult respiratory distress syndrome (ARDS). DESIGN AND PATIENTS: Airways opening pressure (Pao), flow (V'), and volume (V) signals were recorded in 32 ICU mechanically ventilated patients, under sedation and muscle relaxation (10 NRF, 11 COPD, 11 ARDS). All patients were ventilated with controlled mandatory ventilation mode at three levels of end-expiratory pressure (PEEPe): 0, 5, and 10 hPa. Data were analyzed according to: (a) Pao = PE + Ers V + Rrs V' and (b) Pao = PE + Ers V + k1V' + k2¿V'¿V'; where Ers and Rrs represent the intubated respiratory system (RS) elastance and resistance, k1 and k2 the linear and the nonlinear RS resistive coefficients, and PE the end-expiratory pressure. The model's goodness of fit to the data was evaluated by the root mean square difference of predicted minus measured Pao values. RESULTS: NRF data fit both models well at all PEEPe levels. ARDS and particularly COPD data fit the nonlinear model better. Values of k2 were often negative in COPD and ARDS groups, and they increased in parallel with PEEPe. A gradual increase in PEEPe resulted in better fit of ARDS and COPD data to both models. CONCLUSIONS: The model of V' dependence of resistance is more suitable for the ARDS and particularly the COPD groups. PEEP tends to diminish the V' dependence of respiratory resistance during the respiratory cycle, particularly in the COPD group, probably through an indirect effect of the increased lung volume.

Tracing as part of tuberculosis control in a rural Cambodian district during 1992.

SETTING: The rural Cambodian district of Banteay Meas, population 74,464. OBJECTIVE: To evaluate the effectiveness of a district based tracing program developed to improve tuberculosis control program treatment results. Specifically, to assess factors affecting patient non-adherence to therapy and return of patients to treatment. DESIGN: All patients started on treatment during 1992 were included. Standardized cohort analysis methods were applied to assess treatment outcome for all tuberculosis cases registered during Trimesters I-III. Absconders for the year were traced and followed as a separate cohort. Those returning to therapy were followed until the end of the study period in October 1993. RESULTS: Activity in 1992 included 171 admissions and 46 absconders. Of the 46, 57% were met at home. Among those met, 81% returned to treatment. Males absconded more than females even though females accounted for a majority of admissions. Socioeconomic factors (68%) were cited most often as the reason for non-adherence. Distance was not a factor. Cohort analysis showed improvement in the treatment completion rate (54.8% vs 69.2% vs 64%) coupled with a drop in the absconding rate (35.5% vs 25% vs 20%). Of the 21 patients returning, 76% have either completed or nearly completed treatment. CONCLUSION: These results support tracing as an effective means to improve patient adherence in rural Cambodia, thereby strengthening tuberculosis control programs at district level.

[Classification of R-factors. Possible errors and their elimination]. / Klassifizierung von R-Faktoren. Fehlermöglichkeiten und deren Beseitigung.

The necessity for classifying plasmids is emphasized. From our results the uniformity of a nosocomial infectious outbreak is only given by the R-factor and not by the infectious agent. Determination of the appropriate pilus groups by sexphages using the HFRT-system and identification of incompatibility as a further means of subdividing the pilus groups into incompatibility groups is described. A distinction is made between incoming- and resident incompatibility. To eliminate possible errors in plasmid classification the following points are considered: 1. Testing in recombination deficient rec A- -strains of E. coli K12 to avoid any recombination of the plasmids. 2. Trypsin addition to remove the possibility of plasmid coded colicin production. 3. A proper choice of the indicator plasmids. 4. Consideration of the spontaneous loss of the indicator plasmid and also an occurrence of transposons coding for an additional pilus type.

Combined effect of intercalating agents and antibiotics on R-factor carrying bacteria in broth culture.

Growth of Salmonella typhimurium LT2 and Escherichia coli K12 bearing any of four R-factors of the fi+ and fi- group in repressed and derepressed form was not inhibited by a combination of ethidium bromide with ampicillin and kanamycin.