Single Oral Z-Plasty: A Clinical Validation of a Technique for Palatal Lengthening in Primary and Secondary Cleft Palate Repair

BACKGROUND

In cleft palate repair, palate length is associated with improved speech outcomes. Although direct closure offers poor palatal lengthening, use of two opposing Z-plasties may reorient palatal musculature and lengthen the velum. The authors previously described a novel overlapping intravelar veloplasty to achieve longitudinal closure of the nasal mucosa with a single oral Z-plasty (1ZP), lengthening the palate in cadaver studies. This study aims to corroborate this finding in clinical cases.

METHODS

A retrospective comparative study of patients with a cleft palate was conducted. Patients underwent cleft palate closure with 1ZP or intravelar veloplasty with straight-line closure. Preoperative and postoperative measurements of the palate along four dimensions were recorded. Analysis was conducted on preoperative and postoperative measurements within and between groups using the Mann-Whitney-Wilcoxon or chi-square test.

RESULTS

Eighty-five patients were included (1ZP, n = 65; straight-line closure, n = 20). 1ZP increased soft palate length (SPL) by 33% ( P < 0.001) and total palate length (TPL) by 10% ( P < 0.001). Primary 1ZP increased SPL by 33% ( P < 0.001) and TPL by 10% ( P < 0.001). Secondary 1ZP increased SPL by 28% ( P < 0.001) and TPL by 8% ( P < 0.001). When comparing between primary and secondary 1ZP, 1ZP was equal with regard to percentage lengthening in SPL ( P > 0.9) and TPL ( P > 0.3). When compared with straight-line closure, 1ZP showed superior percentage lengthening in SPL ( P < 0.001) and TPL ( P = 0.038).

CONCLUSIONS

1ZP results in a statistically significant increase in palate length in both primary and secondary cleft palate repair. This technique provides an effective alternative in patients for whom 2ZP is not feasible.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

A Cost-effective, 3D Printed Simulation Model Facilitates Learning of Bilobed and Banner Flaps for Mohs Nasal Reconstruction: A Pilot Study

SUMMARY

Flap design for Mohs reconstruction is a complex 3-dimensional decision-making process. Simulation offers trainees the chance to practice techniques safely, prior to opportunities in the operating room. To aide in teaching, we developed a high-fidelity, cost-effective model of the face using three-dimensional (3D) printing to simulate flap reconstruction following Mohs surgery. We describe the design of this model and its impact on the comfort and proficiency of trainees.

Lateral Canthotomy Revisited: A Refined Surgical Approach for Orbital Access

The transconjunctival incision is a common and effective approach for establishing surgical exposure to the orbital floor. When access to the lateral orbit is also required, this incision may be extended by an accompanying lateral canthotomy, which releases the tarsal plates from the conjunctiva. Although this approach broadens surgical access through a simple extension, it is often remarked for unpredictable healing patterns and negative aesthetic sequelae, such as rounding of the lateral canthal angle. Traditionally, lateral canthotomy is performed by a transverse incision through a natural skin crease of the lateral palpebral fissure. Herein, we discuss our experience with a less common approach to lateral canthotomy, in which only the inferior crus of the lateral canthal tendon is divided. This approach limits manipulation of delicate orbital anatomy and aims to minimize unsightly scarring while still affording excellent visualization of the lateral orbit and orbital floor.

Operative technique for a combined transcaruncular-transconjunctival approach to double-walled orbital fractures

Double-walled orbital fractures involving the floor and medial wall are commonly encountered in instances of significant midface trauma. Operative intervention is indicated in the presence of persistent diplopia, significant enophthalmos, or muscle entrapment. Surgical repair of these injuries may be challenging due to large fracture sizes or loss of bony supports. The transconjunctival and transcaruncular approaches have been popularized to reconstruct isolated floor and medial wall fractures, respectively. However, surgical approaches for fractures involving both these walls have not been well described in the literature. In this technical note, we detail a combined transcaruncular-transconjunctival approach that is safe, effective, and aesthetically sensitive.

Comparing diagnosis of midfacial fractures by radiologists and plastic surgeons

BACKGROUND

Clinicians who manage facial fractures often rely on radiologist interpretations to help with assessment and management. Among treating physicians, facial fractures are categorized into clinically relevant patterns of injury. On the other hand, while radiologists are unsurpassed at identifying individual breaks in the bone, larger fracture patterns are not always conveyed in radiology reports.

PURPOSE

This study aims to assess the frequency with which the terminology describing midfacial fracture patterns is concordant among radiologists and treating clinicians.

METHODS

The authors identified patients with different patterns of midfacial injury including Le Fort I, Le Fort II, Le Fort III, naso-orbito-ethmoid (NOE), and zygomaticomaxillary complex (ZMC) fractures. Plastic surgery consult notes and radiological imaging reports were reviewed for concordance in documentation of injury patterns. Identification of individual fractures consistent with the diagnosed fracture pattern was also recorded.

RESULTS

Radiologists were noted to be highly successful in describing individual fractures of the facial bones, identifying at least two defining components of a fracture pattern in 96% of Le Fort, 88% of NOE, and 94% of ZMC injuries. However, when injury patterns were considered, only 32% of Le Fort, 28% of ZMC, and 6% of NOE fractures were explicitly identified in radiology reports.

CONCLUSIONS

Radiologists are highly skilled in discerning individual fractures in facial trauma cases. However, less reliability was seen in the identification of fracture patterns in midfacial injury, with particular weaknesses in descriptions of NOE and ZMC fractures. This data suggests that greater focus on patterns of midfacial injury would improve the clinical applicability of radiological reports.

Role of pHyde novel gene product as an intrinsic factor for apoptotic pathway in prostate cancer

Induction of apoptotic cell death mechanism can be regulated by internal factor(s), such as by gene product(s) that directly upregulate the apoptosis pathway or indirectly by down-regulating the anti-apoptosis gene. This homeostasis is a normal phenomenon in a biological system disturbed by cancer. It is thus important to find any gene functioning as an upregulator for the apoptosis pathway that may have a potential application in the context of cancer gene therapy. We have cloned a novel rat gene, denoted as pHyde, that fulfilled this objective. Internally, this pHyde gene product renders the stable transfectant of rat prostatic cancer cell lines more susceptible to apoptosis even without any external inducer. By using an external agent, such as 5-fluoro-2'-deoxyuridine (FdUr), apoptotic responses of the stable transfectants are even higher, suggesting that both intrinsic and extrinsic factors work synergistically. The pHyde gene product was termed an intrinsic factor, whereas FdUr was considered an extrinsic factor for the apoptosis in rat prostate cancer model.

Effect of prostate biopsy on the results of the PSA RT-PCR test

OBJECTIVES

To evaluate the effect of prostate biopsy on the prostate-specific antigen (PSA) reverse transcriptase-polymerase chain reaction (RT-PCR) test.

METHODS

Ninety men who were scheduled to undergo prostate biopsy because of an elevated PSA or abnormal digital rectal examination, or both, were recruited to have PSA RT-PCR performed on peripheral blood samples drawn before and at 30 minutes, 1 week, and 1 month after undergoing prostate biopsy. PSA RT-PCR was performed and all PCR products were blotted and hybridized with phosphorus-32 (32-P)-PSA cDNA probe (exon 3 to 5).

RESULTS

Of 90 patients, 77 had a negative prebiopsy PSA RT-PCR result. Of these 77, 2 (2.6%) had a positive PSA RT-PCR result at some point after the biopsy procedure. Both of these patients had no evidence of malignancy on biopsy. The PSA RT-PCR test was positive at 30 minutes for 1 patient, but was negative at 1 week; the other was positive at 1 week but the patient did not return for the 1-month sample.

CONCLUSIONS

Our study indicates that 2.6% of patients with an initially negative PSA RT-PCR will have a positive PSA RT-PCR test after biopsy has been performed. Although this is uncommon, it may have profound implications for those patients in whom it occurs. On the basis of our results, it appears that one should wait longer than 1 week after prostate biopsy before obtaining blood for PSA RT-PCR testing to decrease the likelihood of a spurious PSA RT-PCR result.

The origin and loss of the ubiquitin activating enzyme gene on the mammalian Y chromosome

Mammalian sex chromosomes are thought to be descended from a homologous pair of autosomes: a testis-determining allele which defined the Y chromosome arose, recombination between the nascent X and Y chromosomes became restricted and the Y chromosome gradually lost its non-essential genetic functions. This model was originally inferred from the occurrence of few Y-linked genetic traits, pairing of the X and Y chromosomes during male meiosis and, more recently, the existence of X-Y homologous genes. The comparative analysis of such genes is a means by which the validity of this model can be evaluated. One well-studied example of an X-Y homologous gene is the ubiquitin activating enzyme gene ( UBE1 ), which is X-linked with a distinct Y-linked gene in many eutherian ('placental') and metatherian (marsupial) mammals. Nonetheless, no UBE1 homologue has yet been detected on the human Y chromosome. Here we describe a more extensive study of UBE1 homologues in primates and a prototherian mammal, the platypus. Our findings indicate that UBE1 lies within the X-Y pairing segment of the platypus but is absent from the human Y chromosome, having been lost from the Y chromosome during evolution of the primate lineage. Thus UBE1 illustrates the key steps of 'autosomal to X-specific' evolution of genes on the sex chromosomes.

Analysis of mutation rates in the SMCY/SMCX genes shows that mammalian evolution is male driven

Mammalian evolution is believed to be male driven because the greater number of germ cell divisions per generation in males increases the opportunity for errors in DNA replication. Since the Y Chromosome (Chr) replicates exclusively in males, its genes should also evolve faster than X or autosomal genes. In addition, estimating the overall male-to-female mutation ratio (alpha m) is of great importance as a large alpha m implies that replication-independent mutagenic events play a relatively small role in evolution. A small alpha m suggests that the impact of these factors may, in fact, be significant. In order to address this problem, we have analyzed the rates of evolution in the homologous X-Y common SMCX/SMCY genes from three different species--mouse, human, and horse. The SMC genes were chosen because the X and Y copies are highly homologous, well conserved in evolution, and in all probability functionally interchangeable. Sequence comparisons and analysis of synonymous substitutions in approximately 1kb of the 5' coding region of the SMC genes reveal that the Y-linked copies are evolving approximately 1.8 times faster than their X homologs. The male-to-female mutation ratio alpha m was estimated to be 3. These data support the hypothesis that mammalian evolution is male driven. However, the ratio value is far smaller than suggested in earlier works, implying significance of replication-independent mutagenic events in evolution.

Can prostate-specific antigen reverse transcriptase-polymerase chain reaction be used as a prospective test to diagnose prostate cancer?

The present study addressed the question as to whether prostate-specific antigen reverse transcriptase-polymerase chain reaction (PSA RT-PCR) could be used to identify prospectively men who have prostate cancer and to help determine which patients with an initially negative biopsy would benefit from rebiopsy. PSA RT-PCR was performed prospectively on 90 patients who were to have a prostate biopsy because of an elevated PSA level, an abnormal digital rectal examination, or both. PSA RT-PCR was performed, and the sensitivity of the test was enhanced by hybridization of the PCR with a 32P-labeled PSA cDNA probe (exons 3-5). Of the 90 men, 36 (40%) had prostate cancer on biopsy. Of these 36 men, 5 (13.9%) had a positive PSA RT-PCR finding, whereas 31 (84.1%) tested negative. Of 54 men with negative biopsies, 8 (14.8%) had a positive PSA RT-PCR result. The sensitivity of PSA RT-PCR for the detection of biopsy-proven prostate cancer was 13.9% and the specificity was 85.2%. Only 3 of 12 (25%) patients with advanced disease had a positive test result. The sensitivity of PSA RT-PCR for the detection of biopsy-proven prostate adenocarcinoma in men suspected of having prostate cancer is poor. Indeed, men without biopsy-proven prostate cancer are just as likely to have a positive result in the PSA RT-PCR as are men with cancer. Whether these men with negative prostate biopsies and positive PSA RT-PCR findings may eventually develop prostate cancer remains to be determined. At this time, PSA RT-PCR for the prospective detection of prostate cancer should be considered investigational.

Hemodynamic effects of aerobic vs resistance exercise

Previous studies suggest that aerobic exercise lowers blood pressure (BP), while isometric exercise increases BP, at least transiently. The purpose of this study was to examine the hemodynamic effect of a 6-week training period of aerobic exercise or weight training. Twenty deconditioned healthy males ages 18-36, self-selected a training regimen. The aerobic group exercised 30 min/day, 4 times each week to achieve 60-80% maximal heart rate. The resistance group lifted weights at 65-80% maximal voluntary contraction; 3-4 sets of 8-12 repetitions; 3 day/week using large muscle groups. Hemodynamic measurements of heart rate, BP, venous capacitance, forearm blood flow, and vascular resistance were made at baseline and week 6 by plethysmography and analyzed by 2-way ANOVA. The groups showed no differences in baseline characteristics. A training effect was confirmed by a decrease in resting heart rate in the aerobic group (71.5 +/- 4.4 to 64.5 +/- 3.7, beats per minute, P = 0.004), and an increase in total work capacity in the weight lifting group (6231 vs 7508, P = 0.01). Forearm blood flow increased similarly in both groups, averaging 17% (3.5 +/- 0.2 vs 4.2 +/- 0.2 ml 100 g/min, P = 0.03), while forearm vascular resistance fell 19% (28.8 +/- 1.7 vs 24.3 +/- 1.7 mm Hg/ml/min 100 g, P = 0.08). The main differences between the groups after training was found in their response to isometric stress (1/3 maximal handgrip). The weight-lifting group had a greater increase of forearm blood flow and venous capacitance, less increase in systolic BP (SBP) and a greater fall of forearm vascular resistance, (P < 0.05) while the aerobic group had less increase in SBP and heart rate (P < 0.04) but no significant change of forearm hemodynamics. We conclude that both aerobic and repetitive weight programs have short term favorable effects on resting forearm BP and resistance. The exercise programs differ in altering the individual's physiologic response to subsequent isometric stress. However, exercise training of longer duration or greater intensity or frequency could alter these results.

Risk of fetal mosaicism when placental mosaicism is diagnosed by chorionic villus sampling

OBJECTIVE

Our purpose was to determine the risk of fetal mosaicism when placental mosaicism is found on chorionic villus sampling.

STUDY DESIGN

We present a case of mosaic trisomy 22 detected on chorionic villus sampling and subsequently found in the fetus. A review of comprehensive chorionic villus sampling studies with emphasis on follow-up for fetal mosaicism was conducted.

RESULTS

Among 13 studies reviewed, 469 cases of placental mosaicism are presented; fetal mosaicism was found in 50 (10.7%). Factors associated with fetal mosaicism are (1) mosaicism on mesenchymal core culture and (2) type of chromosome abnormality involved--specifically, marker chromosomes (26.7%) and common autosomal trisomies (19.0%). Amniocentesis predicted fetal genotype in 93% to 100% of cases of placental mosaicism, depending on the cell type in which mosaicism was diagnosed.

CONCLUSIONS

Although mosaicism is usually confined to the placenta, the fetus is involved in about 10% cases. Patients should be counseled about this risk and the accuracy of follow-up amniocentesis.

A novel X gene with a widely transcribed Y-linked homologue escapes X-inactivation in mouse and human

A new gene, designated Smcx, was cloned from the mouse X chromosome by its homology to the Y located gene Smcy. Using direct in situ hybridisation Smcx was mapped to the distal end of the mouse X chromosome (XF2-XF4) and its human homologue, SMCX, was mapped to proximal Xp (Xp11.1-Xp11.2). Further meiotic mapping in the mouse placed Smcx in the Plp-Pdha1 interval. As Smcx/SMCX have widely expressed homologues on the Y chromosome, they appeared good candidates for genes that escape X-inactivation. In the human we show this to be the case as SMCX is expressed in hamster-human hybrids containing either an active or inactive human X chromosome. Two alleles of Smcx were found to be expressed in T(16;X)16H female mice despite the intact X chromosome being inactive in all cells. This indicates that Smcx is also not subject to X-inactivation and provides the first example of a gene that is expressed from inactive and active X chromosomes in the mouse.

A mouse Y chromosome gene encoded by a region essential for spermatogenesis and expression of male-specific minor histocompatibility antigens

A new mouse Y chromosome gene, Smcy, has been isolated from the region encoding Spy, a spermatogenesis gene and Hya and Sdma, the genes that, respectively, control the expression of the male specific minor histocompatibility antigen H-Y, as measured by specific T-cell assays and the serologically detected male antigen SDMA. Smcy is well conserved on the Y in mouse, man and even marsupials. It is expressed in all adult male tissues tested and can also be detected during mouse development from as early as two cells. In addition, its human Y homologue, SMCY, is expressed in multiple tissues and maps to the same Yq deletion interval as the human H-Y antigen controlling locus, HY.

Solar Neutrinos: Proposal for a New Test

The predicted flux on the earth of solar neutrinos has eluded detection, confounding current ideas of solar energy production by nuclear fusion. The dominant low-energy component of that flux can be detected by mass-spectrometric assay of the induced tiny concentration of 1.6 x 10(7) year lead-205 in old thallium minerals. Comments are solicited from those in all relevant disciplines.