[C2 pedicle screw insertion assisted by mobilization of the vertebral artery in cases with high-riding vertebral artery].

Objective: To examine the feasibility, safety, and efficacy of mobilization of the vertebral artery for C2 pedicle screws in cases with high-riding vertebral artery (HRVA). Methods: The clinical data of 12 patients with basilar invagination and atlantoaxial dislocation underwent atlantoaxial reduction and fixation in the Department of Neurosurgery, the First Affiliated Hospital of University of Science and Technology of China between January 2020 and November 2021 were retrospectively analyzed. All patients had high-riding vertebral artery on at least one side that prohibited the insertion of C2 pedicle screws. There were 2 males and 10 females aged (48.0±12.8) years (range: 17 to 67 years). After correction of vertical dislocation during the operation, the C2 pedicle screw insertion and occipitocervical fixation and fusion were performed using the vertebral artery mobilization technique. Neurological function was assessed using the Japanese Orthopedic Association (JOA) scale. The preoperative and postoperative JOA score and the main radiological measurements, including the anterior atlantodental interval (ADI), the distance of the odontoid tip above the Chamberlain line, the clivus-canal angle, were collected and compared by paired t-test. Results: Mobilization of the high-riding vertebral artery was successfully completed, and C2 pedicle screws were then fulfilled after the vertebral artery was protected. There was no injury to the vertebral artery during the operation. Meanwhile, no severe surgical complications such as cerebral infarction or aggravated neurological dysfunction occurred during the perioperative period. Satisfactory C2 pedicle screw placement and reduction were achieved in all 12 patients. All patients achieved bone fusion 6 months after surgery. No looseness and shift in internal fixation or reduction loss was observed during the follow-up period. Compared to the preoperative, the postoperative ADI decreased from (6.1±1.9) mm to (2.0±1.2) mm (t=6.73, P<0.01), the distance of the odontoid tip above the Chamberlain line decreased from (10.4±2.5) mm to (5.5±2.3) mm (t=7.12, P<0.01), the clivus-canal angle increased from (123.4±11.1) ° to (134.7±9.6) ° (t=2.50, P=0.032), the JOA score increased from 13.3±2.1 to 15.6±1.2 (t=6.99, P<0.01). Conclusion: The C2 pedicle screw insertion assisted by mobilization of the vertebral artery is safe and considerably effective, providing a choice for internal fixation in cases with high-riding vertebral arteries.

Micro and Nano Material Carriers for Immunomodulation.

Modulation of the immune system through the use of micro and nano carriers offers opportunities in transplant tolerance, autoimmunity, infectious disease, and cancer. In particular, polymeric, lipid, and inorganic materials have been used as carriers of proteins, nucleic acids, and small drug molecules to direct the immune system toward either suppressive or stimulatory states. Current technologies have focused on the use of particulates or scaffolds, the modulation of materials properties, and the delivery of biologics or small drug molecules to achieve a desired response. Discussed are relevant immunology concepts, the types of biomaterial carriers used for immunomodulation highlighting their benefits and drawbacks, the material properties influencing immune responses, and recent examples in the field of transplant tolerance.

[Clinical effects of scalp flaps pedicled with superficial temporal artery parietal branch in repairing facial destructive burn wounds].

Objective: To explore the clinical effects of scalp flaps pedicled with superficial temporal artery parietal branch in repairing facial destructive burn wounds. Methods: A retrospective observational study was conducted. From January 2016 to December 2021, 15 patients with facial destructive burns who met the inclusion criteria were admitted to Zhengzhou First People's Hospital, including 11 males and 4 females, aged 22 to 79 years. Two patients were complicated with unilateral eyeball destructive burns, two patients were complicated with unilateral auricle defects, eight patients were complicated with lip and cheek defects, and three patients were complicated with lip, cheek, and unilateral nasal alar defects. The burn wound areas ranged from 9 cm×6 cm to 13 cm×10 cm. The scalp flaps pedicled with superficial temporal artery parietal branch, with the area of 10 cm×7 cm to 15 cm×11 cm, were designed, excised, and transferred for repairing burn wounds. The secondary wounds at the donor sites were repaired with medium-thickness scalp grafts. According to patient's needs, the hairs grew at the facial transplanted flap were removed by laser at 2 weeks after the flap was completely viable, or the expanded scalp flap was used to treat the secondary alopecia in the flap donor area of the head at 3 months after the primary wound repair. The survival of the flap/skin graft and the wound healing of the donor and recipient areas after the primary wound repair were recorded. During the follow-up, the appearance of the flap, the scar hyperplasia at the suture site, the repair effect of facial functional parts, the treatment effects of laser hair removal and secondary alopecia treatment at the flap donor site were observed; the patient's satisfaction with the overall repair effect was inquired. Results: After the primary wound repair, all the flaps transplanted to the burn wounds and the skin grafts transplanted to the secondary wounds of the flap donor sites survived well, and the wounds at the donor and recipient sites of flap healed well. The color, texture, and thickness of flap were basically the same as those of normal facial skin, and the scar at the suture site was slight during 3 to 18 months of follow-up period after the primary wound repair. In 11 patients complicated with lip defects, the oral integrity, and the opening and closing functions of mouth were restored with the mouth opening being 2.0-2.5 cm and no microstomia; all the patients could carry out basic language communication, 8 of them could take regular food, and 3 of them could take soft food. The wounds in two patients with unilateral eyeball destructive burns were repaired. In 2 patients complicated with auricle defects, the wounds were repaired, and the external auditory canals were normal. In 3 patients complicated with unilateral nasal alar defects, their noses had poor appearance with reduced nostrils. No hair growth was observed in the facial flap sites after treatment of laser hair removal in 8 patients. Five patients were successfully treated with expanded scalp flaps for secondary alopecia in the flap donor area of the head. The patients were all satisfied with the overall repair effect. Conclusions: The scalp flap pedicled with superficial temporal artery parietal branch has abundant blood supply and is suitable for repairing the wounds in facial destructive burns. It is easy to transfer and can better restore the appearance and function of the recipient area with minimal damage to the flap donor area, which is worthy of clinical promotion.

[Clinical effects of single pedicle transfer of expanded axial flap across the midline of the frontal-parietal region in reconstruction of large scar deformities in the face and neck].

Objective: To explore the clinical effects of single pedicle transfer of expanded axial flap across the midline of the frontal-parietal region in reconstruction of large scar deformities in the face and neck. Methods: From January 2016 to August 2019, 10 male patients, aged from 20 to 52 years with post-burn facial and cervical scar deformities, were admitted to the First People's Hospital of Zhengzhou, with the size of scar ranging from 15 cm×7 cm to 23 cm×11 cm. In the first stage, a cylindrical skin and soft tissue expander with rated capacity ranging from 400 to 600 mL was placed in the frontal-parietal region. Another cylindrical expander with rated capacity ranging from 50 to 100 mL was placed in the temporal region of the patient with scars in front of the ear and in cheek. The injection time was 3 to 5 months with the total injection volume being 1.5 to 2.5 times of the rated capacity of expander. In the second stage, the superficial temporal artery frontal branch and its branches were explored, the expander was removed, the scars in the face and neck were conducted resection and contracture relaxation, and the single pedicle transfer of expanded axial flap across the midline of the frontal-parietal region for reconstruction was performed. When the branches of the superficial temporal vessels were difficult to be detected by Doppler ultrasonic blood stream detector, the patient underwent computed tomography (CT) angiography and three-dimensional reconstruction. The donor site in frontal-parietal region was directly sutured, and the wound of the exposed donor site at the pedicle and temporal region was temporarily covered with scar skin. After the suture wound was healed and the hair in expanded flap grew out, hair removal and laser hair removal were performed. Three to four weeks after transplantation of expanded flap, the flap pedicle was cut off, restored, and trimmed in the third stage. The status about the completion of operation, the implantation of expander in the temporal region, CT angiography and three-dimensional reconstruction were recorded. The effective resection area of expanded flap, the length across the midline and the length of the pedicle, and the survival status of the expanded flap and complications after operation were observed. The appearance of donor and recipient sites, the scar recurrence, the appearance and function improvement of patients, and the satisfaction degree of patients were followed up. Results: All the 10 patients successfully completed three stages of operation, of which 6 patients had an auxiliary expander placement in the temporal region, and 5 patients underwent CT angiography and three-dimensional reconstruction. The effective resection area of expanded flap ranged from 18 cm×8 cm to 25 cm×13 cm. The distal end of the flap across the midline extended 4-6 cm to the opposite side, and the length of pedicle was 2-6 cm. All the expanded flaps of patients survived well after formation and transfer. The venous reflux disorder and obvious swelling occurred in 6 patients at the distal end of the flap after operation, and the blood supply recovered after acupuncture bloodletting, etc. Follow-up of 6 to 24 months showed that the color, texture, and thickness of the expanded flaps were similar to those of the facial skin, and no recurrence of scar was observed; the incision in the donor site of the frontal-parietal region was concealed, the hair growth of the temples and head was normal, and the reconstructed hairline was natural; compared with those before operation, the appearance, head-up, mouth-opening, and other functions of patients were significantly improved; the patients were satisfied with the effect of reconstruction. Conclusions: Clinical application of single pedicle transfer of expanded axial flap across the midline of the frontal-parietal region in reconstruction of large scar deformities in the face and neck can achieve a good appearance and function, and the donor site shows good shape, which enriches the application range of the trans-regional blood supply flap. It is a reliable method for reconstruction of large scar deformities in the face and neck.

[Effects of free anterolateral femoral or medial calf flaps in the repair of severe facial burns].

Objective: To explore the effects of free anterolateral femoral or medial calf flaps in the repair of severe facial burns. Methods: From January 2014 to October 2017, 18 patients with severe facial burns were admitted to Zhengzhou First People's Hospital, including 12 males and 6 females, aged 15-78 years. Autologous intermediate split-thickness skin grafts were transplanted to replace oral mucosa in 4 patients with perforating cheek defects, and 8 patients underwent early vacuum sealing drainage and autologous intermediate split-thickness skin grafting to reduce the wound area to 14 cm×6 cm-22 cm×14 cm before flap transplantation. The wounds of 15 patients were repaired with free anterolateral femoral flaps, and the wounds of the other 3 patients were repaired with free medial calf flaps. The area of flaps ranged from 16 cm×7 cm to 24 cm×17 cm. The facial artery or superficial temporal artery was anastomosed end-to-end with lateral femoral circumflex artery or posterior tibial artery under microscope routinely and manually, and the two accompanying veins were anastomosed end-to-end by Coupler microvascular anastomat. The donor site was sutured or transplanted with autologous intermediate split-thickness skin graft. The anastomosis time of veins was recorded. The patency rate of vascular was calculated. The survival status of flaps were observed. The recovery of recipient area was observed during follow-up. Results: The anastomosis time of two veins in this group was 6-10 minutes, with an average of 8.5 minutes. The patency rates of veins and arteries were 100%. There was no vascular crisis due to the anastomosis problem. The free flaps survived well in 16 patients; one patient had hemorrhage under the flap 6 hours after operation, and the blood circulation of flaps turned well after hemostasis by surgical exploration; the other patient had 3 cm necrosis at the distal end of flap after operation, and the wound was closed after dressing change and autologous intermediate split-thickness skin grafting. The patients were followed up for 2 to 24 months after discharge. Most of the five senses function recovered. The color and texture of the flaps were not consistent with those of the normal facial skin. Some flaps were slightly swollen. Oral integrity was restored in 4 patients with perforating cheek defect with mouth opening of 2.2-3.5 cm. Conclusions: Free anterolateral thigh flaps or medial calf flaps can repair severe facial burn wounds. It takes less time to anastomose venous vessels by microvascular anastomat during operation and can ensure the quality of venous anastomosis.

[Application effects of CT angiography and three-dimensional reconstruction technique in repairing scar around the mouth and chin with expanded forehead axial flap].

Objective: To explore application effects of CT angiography (CTA) and three-dimensional reconstruction technique in repairing scar around the mouth and chin with expanded forehead axial flap. Methods: From June 2013 to October 2017, 9 patients with hyperplastic scar around the mouth and chin after deep burns on face were admitted to our unit. The sizes of scars of patients ranged from 8 cm×7 cm to 13 cm×8 cm. One cylindrical skin soft-tissue dilator with nominal volume of 400 to 500 mL was implanted in forehead area of each patient. Five to six months after the dilator was implanted, scar around the mouth and chin was resected, and the dilator was removed. The secondary wound after scar resection was repaired by expanded forehead axial flap with bilateral superficial temporal vessel pedicles. Three of the nine patients received microstomia diorthosis at the same time. Before the operation, CTA and three-dimensional reconstruction were applied to obtain three-dimensional images of superficial temporal arteries and the branches in the donor site, which could identify the travel, adjacent location, and vascular anastomosis of the above-mentioned vessels to guide flap design. The sizes of flaps of patients ranged from 25 cm×9 cm to 30 cm×8 cm. Two to three weeks after the operation, flap pedicles were cut off, restored, and trimmed. The donor site was sutured directly. Ten to twelve days after the flap repair operation, the flap site received depilation treatment with semiconductor freezing point laser once a month for 4 to 6 times. Results: Flaps of all patients survived well, with no blood circulation disorder. The flaps of three patients were slightly bulky, while they were with natural appearance after flap thinning operation in 3 months post flap repair operation. During follow-up of 6 months to 2 years after the operation, color, texture, and thickness of the flaps were close to normal skin around scars. The appearance of perioral and mental region, and opening function of mouth improved significantly, with no recurrence of scar. Frontotemporal incision was hidden, hair on head grew normally, and reconstructed hairline was natural. Conclusions: Scar around the mouth and chin repaired with expanded forehead axial flap were with good appearance and function in operation area and good shape in donor site. CTA and three-dimensional reconstruction technique can provide clear three-dimensional images of superficial temporal arteries and the branches in expanded forehead axial flaps, which can provide reliable basis for preoperative designing of flap, reduce operative risk, and improve survival rate of flap, thus having clinical application value.

Six-year progression of destructive periodontal disease in 2 subgroups of elderly Chinese.

Two groups of elderly chinese were selected from a large epidemiological sample on the basis of a low ("best" group) or a high ("worst" group) number of sites with attachment loss levels > or = 6 mm and/or pocket depth > or = 4 mm and at least 16 teeth present. Six years later the patients were clinically reexamined and the subgingival microflora was assessed. This paper presents the clinical characteristics of destructive periodontal disease progression among the two subgroups. The "best" group lost an average of 1.8 teeth, contrasting the average loss of 5.3 teeth among the "worst" group. Virtually all teeth lost among the "worst" group had a baseline attachment loss level > or = 4 mm, in contrast to 48% among the "best" group. While dental caries could be identified as a cause of tooth loss in both groups, the excess tooth loss among the "worst" group seems attributable to periodontal destruction. The average of 1.21 mm attachment/site lost among the "best" group was not statistically significantly different from the 1.36 mm/site lost among the "worst" group during the 6 years. Individual mean losses of attachment ranged from a gain of 0.03 mm to a loss of 3.19 mm. An attachment loss > or = 2 mm at a site was highly positively associated with a high initial attachment loss level (> or = 4 mm) at that site among the "best" group, whereas a highly negative association was seen among the "worst" group.(ABSTRACT TRUNCATED AT 250 WORDS)

Tooth mortality and periodontal conditions in 60-80-year-old Chinese.

The study comprised 544 persons aged 60 yr or more from two urban Residential Areas and one rural village (including a nursing home) of Beijing area. Overall, the sample accounted for 81% of the total population of elderly aged 60 yr or more in the village/areas so defined. Each person was examined for dental status, plaque, calculus, gingivitis, loss of attachment, pocket depth and tooth mobility. Edentulousness was seen in 0-29% of the persons examined, depending on age and sex. The mean number of teeth present ranged from 6.9 to 23.9, depending on age and sex, and area. The oral hygiene was poor; approximately 50% of all surfaces had immediately visible plaque deposits and calculus. About 50% of the surfaces had a loss of attachment greater than or equal to 4 mm, while less than 15% presented pockets greater than or equal to 4 mm. More than 50% of the individuals had loss of attachment greater than or equal to 4 mm on more than 40% of their surfaces. The proportion of surfaces per person with loss of attachment greater than or equal to 7 mm; and pockets greater than or equal to 4 mm, respectively, showed a pronounced skewed distribution. These findings indicate that a subfraction of individuals is responsible for a substantial proportion of the severe periodontal breakdown leading to loss of teeth. This, in turn, raises important questions as to the most appropriate strategies for the prevention and control of periodontal diseases for the Chinese population.

Rapid-processing procedure for heat polymerization of polymethyl methacrylate in a pressure cooker with automatic controls.

This study introduces a new rapid-processing procedure for curing polymethyl methacrylate denture base resin in an automatically controlled pressure cooker. The cooker filled with water was inflated with 6 kgf/cm2 air pressure and heated to 120 degrees C (248 degrees F) and maintained for 10 minutes. No significant differences were found between the new pressure cooker method and the conventional method for surface hardness and porosity (p > 0.05). The pressure cooker significantly shortened polymerization time, and the polymerization is controlled automatically.

FTIR study of horseradish peroxidase in reverse micelles.

Fourier transform infrared (FTIR) method was used to study the secondary structures of horseradish peroxidase (HRP) in aqueous solution and in reverse micelles for the first time. Results indicated that the structure of HRP in sodium bis(2-ethylhexy)sulfosuccinate (AOT) reverse micelles was close to that in aqueous solution. In cetyltrimethylammonium bromide (CTAB) and sodium dodecylfate (SDS) reverse micelles the position of some bands changed. Results indicated that the secondary structure had a close relationship with the surfactant species of the reverse micelles. Among the three types of reverse micelles, the system of AOT reverse micelles was probably the most beneficial reaction media to HRP.

[The distribution of normal oral flora in 49 healthy children and juvenile].

The frequencies and proportions of predominant cultiv ableoral bacteria associated with 49 healthy children and juvenile (6-25 yr old) were studied. A total of 72 bacterial species belonging to 28 genus were detected in 195 samples of saliva, fissure plaque, supragingival plaque, and subgingival plaque. The predominant bacteria were Oral streptococci, Neisseria, Actinomyces, Capnocytophaga, Bacteroides and Fusobacterium in the normal oral cavity of healthy children and juvenile. There were differences in the distribution of the predominant flora, e.g. Fusobacterium and Bacteroides had higher incidence and proportion in the subgingival plaque than in the fissure plaque.