Cone beam computed tomography volumetric airway changes after orthognathic surgery: a systematic review.

The aim of this systematic review was to provide a structured overview of three-dimensional airway volume changes in relation to various orthognathic surgeries. Clinical human studies performing pre- and postoperative three-dimensional airway volume assessments to investigate volumetric changes of the airway after orthognathic surgery were included. Pre-determined inclusion and exclusion criteria were applied in an extensive search of the PubMed, Embase, and Web of Science electronic databases. The cut-off date was set to January 1, 2022. Forty-one articles reporting retrospective and prospective case-control and case series studies were included. All studies were determined to be of medium quality (moderate risk of bias). The included studies were categorized by type of intervention. Pre- and postoperative volumes were extracted from the available data, and volume changes as a percentage of the preoperative levels were calculated. Isolated mandibular setback surgery generally decreased the airway volume. Isolated maxillary or mandibular advancement, bimaxillary advancement, and surgically assisted maxillary expansion generally increased the airway volume in the total airway and oropharynx, among which the effect of bimaxillary advancement surgery appeared most significant. High heterogeneity exists in the terminology and definitions of the airway and its segments. A more uniform methodology for airway volume measurement is needed to provide an insight into the impact on the airway of specific types of surgical intervention. In conclusion, airway volumes are affected after orthognathic surgery, which may be of clinical significance, especially in patients who are predisposed to obstructive sleep apnoea.

Evaluating three commonly used growth media for assessing fumonisin analogues FB1, FB2 and FB3 production by nine Fusarium verticillioides isolates.

Maize is most often infected by the fumonisin-producing Fusarium verticillioides. Total fumonisins of natural infected grain is made up of FB1, FB2 and FB3 with FB1 occurring naturally at higher levels. A maize plant can be infected with more than one F. verticillioides isolate, and finding a reliable method to elucidate the toxigenic potential of these isolates is important to extrapolate the possible fumonisin risk to consumers of grain. It is not clear whether F. verticillioides produces similar fumonisin levels, as well as fumonisin analogue ratios, across media. In this study, nine F. verticillioides isolates were subjected to three methods of fumonisin testing using liquid media, maize patties and a field trial (silk inoculation of grain) in Potchefstroom, South Africa. Spore concentrations of 1 × 106 conidia ml-1 of each isolate were used to inoculate the different media and levels fumonisin analogues were measured using HPLC. Fumonisin production per isolate was highly variable and was influenced by the two-way interaction of F. verticillioides isolate × growth media. Total fumonisins produced in the liquid medium ranged from 0 to 21.3 ppm, on maize patties fumonisins they ranged from 0 to 21.5 ppm, and in the silk inoculation technique they ranged from 0 to 15.5 ppm. The fumonisin analogue FB1 occurred at higher levels followed by FB3 in both in vitro studies. In the silk inoculation technique, fumonisin analogue FB2 was the second highest occurring analogue after FB1. Isolate GCI 282 produced higher FB2 and FB3 levels than FB1 in the patties and grain, respectively. In order not to miscalculate the fumonisin and analogue ratio levels per F. verticillioides isolate, the growth medium will have to be optimised for each isolate and more than one growth medium used.

Effect of Bt-cotton on chrysopids, ladybird beetles and their prey: aphids and whiteflies.

The effect of Bt-cotton, i.e. genetically modified cotton that contain genes expressing delta-endotoxin, on aphid, whitefly, chrysopid and coccinellid populations was determined with a two-year field study at a cotton farm near Marble Hall, South Africa. Although Bt-cotton is lepidopteran specific, non-lepidopteran arthropod populations may be indirectly influenced by the endotoxin. Abundance of aphid, whitefly, chrysopid and coccinellid populations and predator-prey interactions were used as measures to determine possible effects on the populations under investigation. The cultivation of Bt-cotton had no effect on aphid, whitefly, chrysopid or coccinellid abundance. Positive density dependent interactions occurred between aphids and coccinellids which were not influenced by Bt-cotton. A significant relationship between whitefly and coccinellid abundance, i.e. predator-prey reaction, occurred in the control and sprayed non-Bt cotton fields but was absent from the Bt-cotton fields.

Laboratory evaluation of lufenuron on immature stages of potato tuber moth (Lepidoptera: Gelechiidae).

The effects of the chitin synthesis inhibitor lufenuron against potato tuber moth, Phthorimaea operculella (Zeller), eggs were determined by topically exposing different age groups of eggs (1-4 d old) to treated potato tubers (Solanum tuberosum L.) under laboratory conditions. Larval hatch from both treated (4 and 12 g [AI]/100 liter) and untreated tubers was >95%, but mortality of first instars was high in treated tubers (>90%) compared with untreated tubers. Examination of the treated tubers showed that most of the larvae were unable to penetrate or cause any noticeable damage to the potato tubers. However, the few first instars that survived were able to penetrate the tubers and continue their development to the pupal or adult stages. At 12 g (AI)/100 liter, adult emergence was <2% and most of the emerged adults had morphological deformities such as reduced wing size and they were unable to free themselves from the pupal sacs. These data suggest that topical application of lufenuron to eggs before larval hatch would reduce the amount of damage caused by potato tuber moth as part of integrated pest management program.

IgG subclasses in previously healthy adult patients with acute community-acquired pneumonia.

OBJECTIVE: To measure IgG antibody subclasses in previously healthy adult patients with acute community-acquired pneumonia, and to assess any association between differences of subtype levels and severity of illness or prognosis. DESIGN: Prospective study. SETTING: The intensive care unit (ICU) and general medical wards of Hillbrow Hospital, Johannesburg, an urban general hospital. PATIENTS: Sixty-six previously healthy adult patients with acute community-acquired pneumonia, of whom 47 were considered less severely ill, while 19 were admitted to an ICU. OUTCOME MEASURES: Measurement of IgG subclass levels and determination of any association between differences in subtype levels and various poor prognostic factors in pneumonia, need for ICU admission, complications of illness, and APACHE II score of ICU cases or outcome of patients. RESULTS: A number of statistically significant differences (P < 0.05) were noted between the two groups of patients (critically ill v. others) representing well-known negative prognostic factors in pneumonia. A greater degree of tachycardia and tachypnoea and extremes of white cell count, a higher serum urea concentration and multilobar pulmonary consolidation characterised the patients in the ICU. In addition, the mortality rate in the ICU patients was significantly greater (P < 0.0001). Similar findings were noted when survivors and non-survivors were compared. Few abnormalities of IgG subclass levels were noted in the various patient groups, which did not allow adequate analysis of their clinical significance. CONCLUSION: This study demonstrated a small number of abnormalities in IgG subclass levels in previously healthy adult patients with acute community-acquired pneumonia.